John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1 | /* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io |
| 2 | * |
| 3 | * This program is free software; you can redistribute it and/or |
| 4 | * modify it under the terms of version 2 of the GNU General Public |
| 5 | * License as published by the Free Software Foundation. |
| 6 | * |
| 7 | * This program is distributed in the hope that it will be useful, but |
| 8 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 10 | * General Public License for more details. |
| 11 | */ |
| 12 | |
| 13 | /* A BPF sock_map is used to store sock objects. This is primarly used |
| 14 | * for doing socket redirect with BPF helper routines. |
| 15 | * |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 16 | * A sock map may have BPF programs attached to it, currently a program |
| 17 | * used to parse packets and a program to provide a verdict and redirect |
| 18 | * decision on the packet are supported. Any programs attached to a sock |
| 19 | * map are inherited by sock objects when they are added to the map. If |
| 20 | * no BPF programs are attached the sock object may only be used for sock |
| 21 | * redirect. |
| 22 | * |
| 23 | * A sock object may be in multiple maps, but can only inherit a single |
| 24 | * parse or verdict program. If adding a sock object to a map would result |
| 25 | * in having multiple parsing programs the update will return an EBUSY error. |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 26 | * |
| 27 | * For reference this program is similar to devmap used in XDP context |
| 28 | * reviewing these together may be useful. For an example please review |
| 29 | * ./samples/bpf/sockmap/. |
| 30 | */ |
| 31 | #include <linux/bpf.h> |
| 32 | #include <net/sock.h> |
| 33 | #include <linux/filter.h> |
| 34 | #include <linux/errno.h> |
| 35 | #include <linux/file.h> |
| 36 | #include <linux/kernel.h> |
| 37 | #include <linux/net.h> |
| 38 | #include <linux/skbuff.h> |
| 39 | #include <linux/workqueue.h> |
| 40 | #include <linux/list.h> |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 41 | #include <linux/mm.h> |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 42 | #include <net/strparser.h> |
John Fastabend | 34f79502 | 2017-10-18 07:10:36 -0700 | [diff] [blame] | 43 | #include <net/tcp.h> |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 44 | #include <linux/ptr_ring.h> |
| 45 | #include <net/inet_common.h> |
John Fastabend | e20f733 | 2018-04-23 15:39:28 -0700 | [diff] [blame] | 46 | #include <linux/sched/signal.h> |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 47 | |
Chenbo Feng | 6e71b04 | 2017-10-18 13:00:22 -0700 | [diff] [blame] | 48 | #define SOCK_CREATE_FLAG_MASK \ |
| 49 | (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY) |
| 50 | |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 51 | struct bpf_sock_progs { |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 52 | struct bpf_prog *bpf_tx_msg; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 53 | struct bpf_prog *bpf_parse; |
| 54 | struct bpf_prog *bpf_verdict; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 55 | }; |
| 56 | |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 57 | struct bpf_stab { |
| 58 | struct bpf_map map; |
| 59 | struct sock **sock_map; |
| 60 | struct bpf_sock_progs progs; |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 61 | raw_spinlock_t lock; |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 62 | }; |
| 63 | |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 64 | struct bucket { |
| 65 | struct hlist_head head; |
| 66 | raw_spinlock_t lock; |
| 67 | }; |
| 68 | |
| 69 | struct bpf_htab { |
| 70 | struct bpf_map map; |
| 71 | struct bucket *buckets; |
| 72 | atomic_t count; |
| 73 | u32 n_buckets; |
| 74 | u32 elem_size; |
| 75 | struct bpf_sock_progs progs; |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 76 | struct rcu_head rcu; |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 77 | }; |
| 78 | |
| 79 | struct htab_elem { |
| 80 | struct rcu_head rcu; |
| 81 | struct hlist_node hash_node; |
| 82 | u32 hash; |
| 83 | struct sock *sk; |
| 84 | char key[0]; |
| 85 | }; |
| 86 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 87 | enum smap_psock_state { |
| 88 | SMAP_TX_RUNNING, |
| 89 | }; |
| 90 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 91 | struct smap_psock_map_entry { |
| 92 | struct list_head list; |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 93 | struct bpf_map *map; |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 94 | struct sock **entry; |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 95 | struct htab_elem __rcu *hash_link; |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 96 | }; |
| 97 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 98 | struct smap_psock { |
| 99 | struct rcu_head rcu; |
John Fastabend | ffa3566 | 2018-03-18 12:56:54 -0700 | [diff] [blame] | 100 | refcount_t refcnt; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 101 | |
| 102 | /* datapath variables */ |
| 103 | struct sk_buff_head rxqueue; |
| 104 | bool strp_enabled; |
| 105 | |
| 106 | /* datapath error path cache across tx work invocations */ |
| 107 | int save_rem; |
| 108 | int save_off; |
| 109 | struct sk_buff *save_skb; |
| 110 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 111 | /* datapath variables for tx_msg ULP */ |
| 112 | struct sock *sk_redir; |
| 113 | int apply_bytes; |
| 114 | int cork_bytes; |
| 115 | int sg_size; |
| 116 | int eval; |
| 117 | struct sk_msg_buff *cork; |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 118 | struct list_head ingress; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 119 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 120 | struct strparser strp; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 121 | struct bpf_prog *bpf_tx_msg; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 122 | struct bpf_prog *bpf_parse; |
| 123 | struct bpf_prog *bpf_verdict; |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 124 | struct list_head maps; |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 125 | spinlock_t maps_lock; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 126 | |
| 127 | /* Back reference used when sock callback trigger sockmap operations */ |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 128 | struct sock *sock; |
| 129 | unsigned long state; |
| 130 | |
| 131 | struct work_struct tx_work; |
| 132 | struct work_struct gc_work; |
| 133 | |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 134 | struct proto *sk_proto; |
| 135 | void (*save_close)(struct sock *sk, long timeout); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 136 | void (*save_data_ready)(struct sock *sk); |
| 137 | void (*save_write_space)(struct sock *sk); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 138 | }; |
| 139 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 140 | static void smap_release_sock(struct smap_psock *psock, struct sock *sock); |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 141 | static int bpf_tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
| 142 | int nonblock, int flags, int *addr_len); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 143 | static int bpf_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); |
| 144 | static int bpf_tcp_sendpage(struct sock *sk, struct page *page, |
| 145 | int offset, size_t size, int flags); |
John Fastabend | 9901c5d | 2018-06-30 06:17:36 -0700 | [diff] [blame] | 146 | static void bpf_tcp_close(struct sock *sk, long timeout); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 147 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 148 | static inline struct smap_psock *smap_psock_sk(const struct sock *sk) |
| 149 | { |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 150 | return rcu_dereference_sk_user_data(sk); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 151 | } |
| 152 | |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 153 | static bool bpf_tcp_stream_read(const struct sock *sk) |
| 154 | { |
| 155 | struct smap_psock *psock; |
| 156 | bool empty = true; |
| 157 | |
| 158 | rcu_read_lock(); |
| 159 | psock = smap_psock_sk(sk); |
| 160 | if (unlikely(!psock)) |
| 161 | goto out; |
| 162 | empty = list_empty(&psock->ingress); |
| 163 | out: |
| 164 | rcu_read_unlock(); |
| 165 | return !empty; |
| 166 | } |
| 167 | |
John Fastabend | 9901c5d | 2018-06-30 06:17:36 -0700 | [diff] [blame] | 168 | enum { |
| 169 | SOCKMAP_IPV4, |
| 170 | SOCKMAP_IPV6, |
| 171 | SOCKMAP_NUM_PROTS, |
| 172 | }; |
| 173 | |
| 174 | enum { |
| 175 | SOCKMAP_BASE, |
| 176 | SOCKMAP_TX, |
| 177 | SOCKMAP_NUM_CONFIGS, |
| 178 | }; |
| 179 | |
| 180 | static struct proto *saved_tcpv6_prot __read_mostly; |
| 181 | static DEFINE_SPINLOCK(tcpv6_prot_lock); |
| 182 | static struct proto bpf_tcp_prots[SOCKMAP_NUM_PROTS][SOCKMAP_NUM_CONFIGS]; |
| 183 | static void build_protos(struct proto prot[SOCKMAP_NUM_CONFIGS], |
| 184 | struct proto *base) |
| 185 | { |
| 186 | prot[SOCKMAP_BASE] = *base; |
| 187 | prot[SOCKMAP_BASE].close = bpf_tcp_close; |
| 188 | prot[SOCKMAP_BASE].recvmsg = bpf_tcp_recvmsg; |
| 189 | prot[SOCKMAP_BASE].stream_memory_read = bpf_tcp_stream_read; |
| 190 | |
| 191 | prot[SOCKMAP_TX] = prot[SOCKMAP_BASE]; |
| 192 | prot[SOCKMAP_TX].sendmsg = bpf_tcp_sendmsg; |
| 193 | prot[SOCKMAP_TX].sendpage = bpf_tcp_sendpage; |
| 194 | } |
| 195 | |
| 196 | static void update_sk_prot(struct sock *sk, struct smap_psock *psock) |
| 197 | { |
| 198 | int family = sk->sk_family == AF_INET6 ? SOCKMAP_IPV6 : SOCKMAP_IPV4; |
| 199 | int conf = psock->bpf_tx_msg ? SOCKMAP_TX : SOCKMAP_BASE; |
| 200 | |
| 201 | sk->sk_prot = &bpf_tcp_prots[family][conf]; |
| 202 | } |
| 203 | |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 204 | static int bpf_tcp_init(struct sock *sk) |
| 205 | { |
| 206 | struct smap_psock *psock; |
| 207 | |
| 208 | rcu_read_lock(); |
| 209 | psock = smap_psock_sk(sk); |
| 210 | if (unlikely(!psock)) { |
| 211 | rcu_read_unlock(); |
| 212 | return -EINVAL; |
| 213 | } |
| 214 | |
| 215 | if (unlikely(psock->sk_proto)) { |
| 216 | rcu_read_unlock(); |
| 217 | return -EBUSY; |
| 218 | } |
| 219 | |
| 220 | psock->save_close = sk->sk_prot->close; |
| 221 | psock->sk_proto = sk->sk_prot; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 222 | |
John Fastabend | 9901c5d | 2018-06-30 06:17:36 -0700 | [diff] [blame] | 223 | /* Build IPv6 sockmap whenever the address of tcpv6_prot changes */ |
| 224 | if (sk->sk_family == AF_INET6 && |
| 225 | unlikely(sk->sk_prot != smp_load_acquire(&saved_tcpv6_prot))) { |
| 226 | spin_lock_bh(&tcpv6_prot_lock); |
| 227 | if (likely(sk->sk_prot != saved_tcpv6_prot)) { |
| 228 | build_protos(bpf_tcp_prots[SOCKMAP_IPV6], sk->sk_prot); |
| 229 | smp_store_release(&saved_tcpv6_prot, sk->sk_prot); |
| 230 | } |
| 231 | spin_unlock_bh(&tcpv6_prot_lock); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 232 | } |
John Fastabend | 9901c5d | 2018-06-30 06:17:36 -0700 | [diff] [blame] | 233 | update_sk_prot(sk, psock); |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 234 | rcu_read_unlock(); |
| 235 | return 0; |
| 236 | } |
| 237 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 238 | static void smap_release_sock(struct smap_psock *psock, struct sock *sock); |
| 239 | static int free_start_sg(struct sock *sk, struct sk_msg_buff *md); |
| 240 | |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 241 | static void bpf_tcp_release(struct sock *sk) |
| 242 | { |
| 243 | struct smap_psock *psock; |
| 244 | |
| 245 | rcu_read_lock(); |
| 246 | psock = smap_psock_sk(sk); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 247 | if (unlikely(!psock)) |
| 248 | goto out; |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 249 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 250 | if (psock->cork) { |
| 251 | free_start_sg(psock->sock, psock->cork); |
| 252 | kfree(psock->cork); |
| 253 | psock->cork = NULL; |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 254 | } |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 255 | |
John Fastabend | 0e94d87 | 2018-04-02 12:50:52 -0700 | [diff] [blame] | 256 | if (psock->sk_proto) { |
| 257 | sk->sk_prot = psock->sk_proto; |
| 258 | psock->sk_proto = NULL; |
| 259 | } |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 260 | out: |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 261 | rcu_read_unlock(); |
| 262 | } |
| 263 | |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 264 | static struct htab_elem *lookup_elem_raw(struct hlist_head *head, |
| 265 | u32 hash, void *key, u32 key_size) |
| 266 | { |
| 267 | struct htab_elem *l; |
| 268 | |
| 269 | hlist_for_each_entry_rcu(l, head, hash_node) { |
| 270 | if (l->hash == hash && !memcmp(&l->key, key, key_size)) |
| 271 | return l; |
| 272 | } |
| 273 | |
| 274 | return NULL; |
| 275 | } |
| 276 | |
| 277 | static inline struct bucket *__select_bucket(struct bpf_htab *htab, u32 hash) |
| 278 | { |
| 279 | return &htab->buckets[hash & (htab->n_buckets - 1)]; |
| 280 | } |
| 281 | |
| 282 | static inline struct hlist_head *select_bucket(struct bpf_htab *htab, u32 hash) |
| 283 | { |
| 284 | return &__select_bucket(htab, hash)->head; |
| 285 | } |
| 286 | |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 287 | static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l) |
| 288 | { |
| 289 | atomic_dec(&htab->count); |
| 290 | kfree_rcu(l, rcu); |
| 291 | } |
| 292 | |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 293 | static struct smap_psock_map_entry *psock_map_pop(struct sock *sk, |
| 294 | struct smap_psock *psock) |
| 295 | { |
| 296 | struct smap_psock_map_entry *e; |
| 297 | |
| 298 | spin_lock_bh(&psock->maps_lock); |
| 299 | e = list_first_entry_or_null(&psock->maps, |
| 300 | struct smap_psock_map_entry, |
| 301 | list); |
| 302 | if (e) |
| 303 | list_del(&e->list); |
| 304 | spin_unlock_bh(&psock->maps_lock); |
| 305 | return e; |
| 306 | } |
| 307 | |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 308 | static void bpf_tcp_close(struct sock *sk, long timeout) |
| 309 | { |
| 310 | void (*close_fun)(struct sock *sk, long timeout); |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 311 | struct smap_psock_map_entry *e; |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 312 | struct sk_msg_buff *md, *mtmp; |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 313 | struct smap_psock *psock; |
| 314 | struct sock *osk; |
| 315 | |
John Fastabend | 99ba2b5 | 2018-07-05 08:50:04 -0700 | [diff] [blame] | 316 | lock_sock(sk); |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 317 | rcu_read_lock(); |
| 318 | psock = smap_psock_sk(sk); |
| 319 | if (unlikely(!psock)) { |
| 320 | rcu_read_unlock(); |
John Fastabend | 99ba2b5 | 2018-07-05 08:50:04 -0700 | [diff] [blame] | 321 | release_sock(sk); |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 322 | return sk->sk_prot->close(sk, timeout); |
| 323 | } |
| 324 | |
| 325 | /* The psock may be destroyed anytime after exiting the RCU critial |
| 326 | * section so by the time we use close_fun the psock may no longer |
| 327 | * be valid. However, bpf_tcp_close is called with the sock lock |
| 328 | * held so the close hook and sk are still valid. |
| 329 | */ |
| 330 | close_fun = psock->save_close; |
| 331 | |
John Fastabend | 820ed3f | 2018-04-02 12:50:46 -0700 | [diff] [blame] | 332 | if (psock->cork) { |
| 333 | free_start_sg(psock->sock, psock->cork); |
| 334 | kfree(psock->cork); |
| 335 | psock->cork = NULL; |
| 336 | } |
| 337 | |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 338 | list_for_each_entry_safe(md, mtmp, &psock->ingress, list) { |
| 339 | list_del(&md->list); |
| 340 | free_start_sg(psock->sock, md); |
| 341 | kfree(md); |
| 342 | } |
| 343 | |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 344 | e = psock_map_pop(sk, psock); |
| 345 | while (e) { |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 346 | if (e->entry) { |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 347 | struct bpf_stab *stab = container_of(e->map, struct bpf_stab, map); |
| 348 | |
| 349 | raw_spin_lock_bh(&stab->lock); |
| 350 | osk = *e->entry; |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 351 | if (osk == sk) { |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 352 | *e->entry = NULL; |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 353 | smap_release_sock(psock, sk); |
| 354 | } |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 355 | raw_spin_unlock_bh(&stab->lock); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 356 | } else { |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 357 | struct htab_elem *link = rcu_dereference(e->hash_link); |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 358 | struct bpf_htab *htab = container_of(e->map, struct bpf_htab, map); |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 359 | struct hlist_head *head; |
| 360 | struct htab_elem *l; |
| 361 | struct bucket *b; |
| 362 | |
| 363 | b = __select_bucket(htab, link->hash); |
| 364 | head = &b->head; |
| 365 | raw_spin_lock_bh(&b->lock); |
| 366 | l = lookup_elem_raw(head, |
| 367 | link->hash, link->key, |
| 368 | htab->map.key_size); |
| 369 | /* If another thread deleted this object skip deletion. |
| 370 | * The refcnt on psock may or may not be zero. |
| 371 | */ |
| 372 | if (l) { |
| 373 | hlist_del_rcu(&link->hash_node); |
| 374 | smap_release_sock(psock, link->sk); |
| 375 | free_htab_elem(htab, link); |
| 376 | } |
| 377 | raw_spin_unlock_bh(&b->lock); |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 378 | } |
Daniel Borkmann | d40b011 | 2018-08-16 21:49:08 +0200 | [diff] [blame] | 379 | kfree(e); |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 380 | e = psock_map_pop(sk, psock); |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 381 | } |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 382 | rcu_read_unlock(); |
John Fastabend | 99ba2b5 | 2018-07-05 08:50:04 -0700 | [diff] [blame] | 383 | release_sock(sk); |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 384 | close_fun(sk, timeout); |
| 385 | } |
| 386 | |
John Fastabend | 04686ef | 2017-10-31 19:17:31 -0700 | [diff] [blame] | 387 | enum __sk_action { |
| 388 | __SK_DROP = 0, |
| 389 | __SK_PASS, |
| 390 | __SK_REDIRECT, |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 391 | __SK_NONE, |
John Fastabend | 04686ef | 2017-10-31 19:17:31 -0700 | [diff] [blame] | 392 | }; |
| 393 | |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 394 | static struct tcp_ulp_ops bpf_tcp_ulp_ops __read_mostly = { |
| 395 | .name = "bpf_tcp", |
| 396 | .uid = TCP_ULP_BPF, |
| 397 | .user_visible = false, |
| 398 | .owner = NULL, |
| 399 | .init = bpf_tcp_init, |
| 400 | .release = bpf_tcp_release, |
| 401 | }; |
| 402 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 403 | static int memcopy_from_iter(struct sock *sk, |
| 404 | struct sk_msg_buff *md, |
| 405 | struct iov_iter *from, int bytes) |
| 406 | { |
| 407 | struct scatterlist *sg = md->sg_data; |
| 408 | int i = md->sg_curr, rc = -ENOSPC; |
| 409 | |
| 410 | do { |
| 411 | int copy; |
| 412 | char *to; |
| 413 | |
| 414 | if (md->sg_copybreak >= sg[i].length) { |
| 415 | md->sg_copybreak = 0; |
| 416 | |
| 417 | if (++i == MAX_SKB_FRAGS) |
| 418 | i = 0; |
| 419 | |
| 420 | if (i == md->sg_end) |
| 421 | break; |
| 422 | } |
| 423 | |
| 424 | copy = sg[i].length - md->sg_copybreak; |
| 425 | to = sg_virt(&sg[i]) + md->sg_copybreak; |
| 426 | md->sg_copybreak += copy; |
| 427 | |
| 428 | if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) |
| 429 | rc = copy_from_iter_nocache(to, copy, from); |
| 430 | else |
| 431 | rc = copy_from_iter(to, copy, from); |
| 432 | |
| 433 | if (rc != copy) { |
| 434 | rc = -EFAULT; |
| 435 | goto out; |
| 436 | } |
| 437 | |
| 438 | bytes -= copy; |
| 439 | if (!bytes) |
| 440 | break; |
| 441 | |
| 442 | md->sg_copybreak = 0; |
| 443 | if (++i == MAX_SKB_FRAGS) |
| 444 | i = 0; |
| 445 | } while (i != md->sg_end); |
| 446 | out: |
| 447 | md->sg_curr = i; |
| 448 | return rc; |
| 449 | } |
| 450 | |
| 451 | static int bpf_tcp_push(struct sock *sk, int apply_bytes, |
| 452 | struct sk_msg_buff *md, |
| 453 | int flags, bool uncharge) |
| 454 | { |
| 455 | bool apply = apply_bytes; |
| 456 | struct scatterlist *sg; |
| 457 | int offset, ret = 0; |
| 458 | struct page *p; |
| 459 | size_t size; |
| 460 | |
| 461 | while (1) { |
| 462 | sg = md->sg_data + md->sg_start; |
| 463 | size = (apply && apply_bytes < sg->length) ? |
| 464 | apply_bytes : sg->length; |
| 465 | offset = sg->offset; |
| 466 | |
| 467 | tcp_rate_check_app_limited(sk); |
| 468 | p = sg_page(sg); |
| 469 | retry: |
| 470 | ret = do_tcp_sendpages(sk, p, offset, size, flags); |
| 471 | if (ret != size) { |
| 472 | if (ret > 0) { |
| 473 | if (apply) |
| 474 | apply_bytes -= ret; |
John Fastabend | 3cc9a47 | 2018-05-02 13:50:19 -0700 | [diff] [blame] | 475 | |
| 476 | sg->offset += ret; |
| 477 | sg->length -= ret; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 478 | size -= ret; |
| 479 | offset += ret; |
| 480 | if (uncharge) |
| 481 | sk_mem_uncharge(sk, ret); |
| 482 | goto retry; |
| 483 | } |
| 484 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 485 | return ret; |
| 486 | } |
| 487 | |
| 488 | if (apply) |
| 489 | apply_bytes -= ret; |
| 490 | sg->offset += ret; |
| 491 | sg->length -= ret; |
| 492 | if (uncharge) |
| 493 | sk_mem_uncharge(sk, ret); |
| 494 | |
| 495 | if (!sg->length) { |
| 496 | put_page(p); |
| 497 | md->sg_start++; |
| 498 | if (md->sg_start == MAX_SKB_FRAGS) |
| 499 | md->sg_start = 0; |
Prashant Bhole | 6ef6d84 | 2018-03-30 09:21:00 +0900 | [diff] [blame] | 500 | sg_init_table(sg, 1); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 501 | |
| 502 | if (md->sg_start == md->sg_end) |
| 503 | break; |
| 504 | } |
| 505 | |
| 506 | if (apply && !apply_bytes) |
| 507 | break; |
| 508 | } |
| 509 | return 0; |
| 510 | } |
| 511 | |
| 512 | static inline void bpf_compute_data_pointers_sg(struct sk_msg_buff *md) |
| 513 | { |
| 514 | struct scatterlist *sg = md->sg_data + md->sg_start; |
| 515 | |
| 516 | if (md->sg_copy[md->sg_start]) { |
| 517 | md->data = md->data_end = 0; |
| 518 | } else { |
| 519 | md->data = sg_virt(sg); |
| 520 | md->data_end = md->data + sg->length; |
| 521 | } |
| 522 | } |
| 523 | |
| 524 | static void return_mem_sg(struct sock *sk, int bytes, struct sk_msg_buff *md) |
| 525 | { |
| 526 | struct scatterlist *sg = md->sg_data; |
| 527 | int i = md->sg_start; |
| 528 | |
| 529 | do { |
| 530 | int uncharge = (bytes < sg[i].length) ? bytes : sg[i].length; |
| 531 | |
| 532 | sk_mem_uncharge(sk, uncharge); |
| 533 | bytes -= uncharge; |
| 534 | if (!bytes) |
| 535 | break; |
| 536 | i++; |
| 537 | if (i == MAX_SKB_FRAGS) |
| 538 | i = 0; |
| 539 | } while (i != md->sg_end); |
| 540 | } |
| 541 | |
John Fastabend | abaeb09 | 2018-05-02 13:50:29 -0700 | [diff] [blame] | 542 | static void free_bytes_sg(struct sock *sk, int bytes, |
| 543 | struct sk_msg_buff *md, bool charge) |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 544 | { |
| 545 | struct scatterlist *sg = md->sg_data; |
| 546 | int i = md->sg_start, free; |
| 547 | |
| 548 | while (bytes && sg[i].length) { |
| 549 | free = sg[i].length; |
| 550 | if (bytes < free) { |
| 551 | sg[i].length -= bytes; |
| 552 | sg[i].offset += bytes; |
John Fastabend | abaeb09 | 2018-05-02 13:50:29 -0700 | [diff] [blame] | 553 | if (charge) |
| 554 | sk_mem_uncharge(sk, bytes); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 555 | break; |
| 556 | } |
| 557 | |
John Fastabend | abaeb09 | 2018-05-02 13:50:29 -0700 | [diff] [blame] | 558 | if (charge) |
| 559 | sk_mem_uncharge(sk, sg[i].length); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 560 | put_page(sg_page(&sg[i])); |
| 561 | bytes -= sg[i].length; |
| 562 | sg[i].length = 0; |
| 563 | sg[i].page_link = 0; |
| 564 | sg[i].offset = 0; |
| 565 | i++; |
| 566 | |
| 567 | if (i == MAX_SKB_FRAGS) |
| 568 | i = 0; |
| 569 | } |
John Fastabend | abaeb09 | 2018-05-02 13:50:29 -0700 | [diff] [blame] | 570 | md->sg_start = i; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 571 | } |
| 572 | |
| 573 | static int free_sg(struct sock *sk, int start, struct sk_msg_buff *md) |
| 574 | { |
| 575 | struct scatterlist *sg = md->sg_data; |
| 576 | int i = start, free = 0; |
| 577 | |
| 578 | while (sg[i].length) { |
| 579 | free += sg[i].length; |
| 580 | sk_mem_uncharge(sk, sg[i].length); |
John Fastabend | 7ebc14d | 2018-07-05 08:50:10 -0700 | [diff] [blame] | 581 | if (!md->skb) |
| 582 | put_page(sg_page(&sg[i])); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 583 | sg[i].length = 0; |
| 584 | sg[i].page_link = 0; |
| 585 | sg[i].offset = 0; |
| 586 | i++; |
| 587 | |
| 588 | if (i == MAX_SKB_FRAGS) |
| 589 | i = 0; |
| 590 | } |
John Fastabend | 7ebc14d | 2018-07-05 08:50:10 -0700 | [diff] [blame] | 591 | if (md->skb) |
| 592 | consume_skb(md->skb); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 593 | |
| 594 | return free; |
| 595 | } |
| 596 | |
| 597 | static int free_start_sg(struct sock *sk, struct sk_msg_buff *md) |
| 598 | { |
| 599 | int free = free_sg(sk, md->sg_start, md); |
| 600 | |
| 601 | md->sg_start = md->sg_end; |
| 602 | return free; |
| 603 | } |
| 604 | |
| 605 | static int free_curr_sg(struct sock *sk, struct sk_msg_buff *md) |
| 606 | { |
| 607 | return free_sg(sk, md->sg_curr, md); |
| 608 | } |
| 609 | |
| 610 | static int bpf_map_msg_verdict(int _rc, struct sk_msg_buff *md) |
| 611 | { |
| 612 | return ((_rc == SK_PASS) ? |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 613 | (md->sk_redir ? __SK_REDIRECT : __SK_PASS) : |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 614 | __SK_DROP); |
| 615 | } |
| 616 | |
| 617 | static unsigned int smap_do_tx_msg(struct sock *sk, |
| 618 | struct smap_psock *psock, |
| 619 | struct sk_msg_buff *md) |
| 620 | { |
| 621 | struct bpf_prog *prog; |
| 622 | unsigned int rc, _rc; |
| 623 | |
| 624 | preempt_disable(); |
| 625 | rcu_read_lock(); |
| 626 | |
| 627 | /* If the policy was removed mid-send then default to 'accept' */ |
| 628 | prog = READ_ONCE(psock->bpf_tx_msg); |
| 629 | if (unlikely(!prog)) { |
| 630 | _rc = SK_PASS; |
| 631 | goto verdict; |
| 632 | } |
| 633 | |
| 634 | bpf_compute_data_pointers_sg(md); |
John Fastabend | 303def3 | 2018-05-17 14:16:58 -0700 | [diff] [blame] | 635 | md->sk = sk; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 636 | rc = (*prog->bpf_func)(md, prog->insnsi); |
| 637 | psock->apply_bytes = md->apply_bytes; |
| 638 | |
| 639 | /* Moving return codes from UAPI namespace into internal namespace */ |
| 640 | _rc = bpf_map_msg_verdict(rc, md); |
| 641 | |
| 642 | /* The psock has a refcount on the sock but not on the map and because |
| 643 | * we need to drop rcu read lock here its possible the map could be |
| 644 | * removed between here and when we need it to execute the sock |
| 645 | * redirect. So do the map lookup now for future use. |
| 646 | */ |
| 647 | if (_rc == __SK_REDIRECT) { |
| 648 | if (psock->sk_redir) |
| 649 | sock_put(psock->sk_redir); |
| 650 | psock->sk_redir = do_msg_redirect_map(md); |
| 651 | if (!psock->sk_redir) { |
| 652 | _rc = __SK_DROP; |
| 653 | goto verdict; |
| 654 | } |
| 655 | sock_hold(psock->sk_redir); |
| 656 | } |
| 657 | verdict: |
| 658 | rcu_read_unlock(); |
| 659 | preempt_enable(); |
| 660 | |
| 661 | return _rc; |
| 662 | } |
| 663 | |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 664 | static int bpf_tcp_ingress(struct sock *sk, int apply_bytes, |
| 665 | struct smap_psock *psock, |
| 666 | struct sk_msg_buff *md, int flags) |
| 667 | { |
| 668 | bool apply = apply_bytes; |
| 669 | size_t size, copied = 0; |
| 670 | struct sk_msg_buff *r; |
| 671 | int err = 0, i; |
| 672 | |
| 673 | r = kzalloc(sizeof(struct sk_msg_buff), __GFP_NOWARN | GFP_KERNEL); |
| 674 | if (unlikely(!r)) |
| 675 | return -ENOMEM; |
| 676 | |
| 677 | lock_sock(sk); |
| 678 | r->sg_start = md->sg_start; |
| 679 | i = md->sg_start; |
| 680 | |
| 681 | do { |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 682 | size = (apply && apply_bytes < md->sg_data[i].length) ? |
| 683 | apply_bytes : md->sg_data[i].length; |
| 684 | |
| 685 | if (!sk_wmem_schedule(sk, size)) { |
| 686 | if (!copied) |
| 687 | err = -ENOMEM; |
| 688 | break; |
| 689 | } |
| 690 | |
| 691 | sk_mem_charge(sk, size); |
John Fastabend | 4fcfdfb | 2018-04-23 15:39:33 -0700 | [diff] [blame] | 692 | r->sg_data[i] = md->sg_data[i]; |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 693 | r->sg_data[i].length = size; |
| 694 | md->sg_data[i].length -= size; |
| 695 | md->sg_data[i].offset += size; |
| 696 | copied += size; |
| 697 | |
| 698 | if (md->sg_data[i].length) { |
| 699 | get_page(sg_page(&r->sg_data[i])); |
| 700 | r->sg_end = (i + 1) == MAX_SKB_FRAGS ? 0 : i + 1; |
| 701 | } else { |
| 702 | i++; |
| 703 | if (i == MAX_SKB_FRAGS) |
| 704 | i = 0; |
| 705 | r->sg_end = i; |
| 706 | } |
| 707 | |
| 708 | if (apply) { |
| 709 | apply_bytes -= size; |
| 710 | if (!apply_bytes) |
| 711 | break; |
| 712 | } |
| 713 | } while (i != md->sg_end); |
| 714 | |
| 715 | md->sg_start = i; |
| 716 | |
| 717 | if (!err) { |
| 718 | list_add_tail(&r->list, &psock->ingress); |
| 719 | sk->sk_data_ready(sk); |
| 720 | } else { |
| 721 | free_start_sg(sk, r); |
| 722 | kfree(r); |
| 723 | } |
| 724 | |
| 725 | release_sock(sk); |
| 726 | return err; |
| 727 | } |
| 728 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 729 | static int bpf_tcp_sendmsg_do_redirect(struct sock *sk, int send, |
| 730 | struct sk_msg_buff *md, |
| 731 | int flags) |
| 732 | { |
John Fastabend | abaeb09 | 2018-05-02 13:50:29 -0700 | [diff] [blame] | 733 | bool ingress = !!(md->flags & BPF_F_INGRESS); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 734 | struct smap_psock *psock; |
John Fastabend | abaeb09 | 2018-05-02 13:50:29 -0700 | [diff] [blame] | 735 | int err = 0; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 736 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 737 | rcu_read_lock(); |
| 738 | psock = smap_psock_sk(sk); |
| 739 | if (unlikely(!psock)) |
| 740 | goto out_rcu; |
| 741 | |
| 742 | if (!refcount_inc_not_zero(&psock->refcnt)) |
| 743 | goto out_rcu; |
| 744 | |
| 745 | rcu_read_unlock(); |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 746 | |
| 747 | if (ingress) { |
| 748 | err = bpf_tcp_ingress(sk, send, psock, md, flags); |
| 749 | } else { |
| 750 | lock_sock(sk); |
| 751 | err = bpf_tcp_push(sk, send, md, flags, false); |
| 752 | release_sock(sk); |
| 753 | } |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 754 | smap_release_sock(psock, sk); |
| 755 | if (unlikely(err)) |
| 756 | goto out; |
| 757 | return 0; |
| 758 | out_rcu: |
| 759 | rcu_read_unlock(); |
| 760 | out: |
John Fastabend | abaeb09 | 2018-05-02 13:50:29 -0700 | [diff] [blame] | 761 | free_bytes_sg(NULL, send, md, false); |
| 762 | return err; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 763 | } |
| 764 | |
| 765 | static inline void bpf_md_init(struct smap_psock *psock) |
| 766 | { |
| 767 | if (!psock->apply_bytes) { |
| 768 | psock->eval = __SK_NONE; |
| 769 | if (psock->sk_redir) { |
| 770 | sock_put(psock->sk_redir); |
| 771 | psock->sk_redir = NULL; |
| 772 | } |
| 773 | } |
| 774 | } |
| 775 | |
| 776 | static void apply_bytes_dec(struct smap_psock *psock, int i) |
| 777 | { |
| 778 | if (psock->apply_bytes) { |
| 779 | if (psock->apply_bytes < i) |
| 780 | psock->apply_bytes = 0; |
| 781 | else |
| 782 | psock->apply_bytes -= i; |
| 783 | } |
| 784 | } |
| 785 | |
| 786 | static int bpf_exec_tx_verdict(struct smap_psock *psock, |
| 787 | struct sk_msg_buff *m, |
| 788 | struct sock *sk, |
| 789 | int *copied, int flags) |
| 790 | { |
| 791 | bool cork = false, enospc = (m->sg_start == m->sg_end); |
| 792 | struct sock *redir; |
| 793 | int err = 0; |
| 794 | int send; |
| 795 | |
| 796 | more_data: |
| 797 | if (psock->eval == __SK_NONE) |
| 798 | psock->eval = smap_do_tx_msg(sk, psock, m); |
| 799 | |
| 800 | if (m->cork_bytes && |
| 801 | m->cork_bytes > psock->sg_size && !enospc) { |
| 802 | psock->cork_bytes = m->cork_bytes - psock->sg_size; |
| 803 | if (!psock->cork) { |
| 804 | psock->cork = kcalloc(1, |
| 805 | sizeof(struct sk_msg_buff), |
| 806 | GFP_ATOMIC | __GFP_NOWARN); |
| 807 | |
| 808 | if (!psock->cork) { |
| 809 | err = -ENOMEM; |
| 810 | goto out_err; |
| 811 | } |
| 812 | } |
| 813 | memcpy(psock->cork, m, sizeof(*m)); |
| 814 | goto out_err; |
| 815 | } |
| 816 | |
| 817 | send = psock->sg_size; |
| 818 | if (psock->apply_bytes && psock->apply_bytes < send) |
| 819 | send = psock->apply_bytes; |
| 820 | |
| 821 | switch (psock->eval) { |
| 822 | case __SK_PASS: |
| 823 | err = bpf_tcp_push(sk, send, m, flags, true); |
| 824 | if (unlikely(err)) { |
| 825 | *copied -= free_start_sg(sk, m); |
| 826 | break; |
| 827 | } |
| 828 | |
| 829 | apply_bytes_dec(psock, send); |
| 830 | psock->sg_size -= send; |
| 831 | break; |
| 832 | case __SK_REDIRECT: |
| 833 | redir = psock->sk_redir; |
| 834 | apply_bytes_dec(psock, send); |
| 835 | |
| 836 | if (psock->cork) { |
| 837 | cork = true; |
| 838 | psock->cork = NULL; |
| 839 | } |
| 840 | |
| 841 | return_mem_sg(sk, send, m); |
| 842 | release_sock(sk); |
| 843 | |
| 844 | err = bpf_tcp_sendmsg_do_redirect(redir, send, m, flags); |
| 845 | lock_sock(sk); |
| 846 | |
John Fastabend | fec51d4 | 2018-05-02 13:50:24 -0700 | [diff] [blame] | 847 | if (unlikely(err < 0)) { |
| 848 | free_start_sg(sk, m); |
| 849 | psock->sg_size = 0; |
| 850 | if (!cork) |
| 851 | *copied -= send; |
| 852 | } else { |
| 853 | psock->sg_size -= send; |
| 854 | } |
| 855 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 856 | if (cork) { |
| 857 | free_start_sg(sk, m); |
John Fastabend | fec51d4 | 2018-05-02 13:50:24 -0700 | [diff] [blame] | 858 | psock->sg_size = 0; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 859 | kfree(m); |
| 860 | m = NULL; |
John Fastabend | fec51d4 | 2018-05-02 13:50:24 -0700 | [diff] [blame] | 861 | err = 0; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 862 | } |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 863 | break; |
| 864 | case __SK_DROP: |
| 865 | default: |
John Fastabend | abaeb09 | 2018-05-02 13:50:29 -0700 | [diff] [blame] | 866 | free_bytes_sg(sk, send, m, true); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 867 | apply_bytes_dec(psock, send); |
| 868 | *copied -= send; |
| 869 | psock->sg_size -= send; |
| 870 | err = -EACCES; |
| 871 | break; |
| 872 | } |
| 873 | |
| 874 | if (likely(!err)) { |
| 875 | bpf_md_init(psock); |
| 876 | if (m && |
| 877 | m->sg_data[m->sg_start].page_link && |
| 878 | m->sg_data[m->sg_start].length) |
| 879 | goto more_data; |
| 880 | } |
| 881 | |
| 882 | out_err: |
| 883 | return err; |
| 884 | } |
| 885 | |
John Fastabend | e20f733 | 2018-04-23 15:39:28 -0700 | [diff] [blame] | 886 | static int bpf_wait_data(struct sock *sk, |
| 887 | struct smap_psock *psk, int flags, |
| 888 | long timeo, int *err) |
| 889 | { |
| 890 | int rc; |
| 891 | |
| 892 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
| 893 | |
| 894 | add_wait_queue(sk_sleep(sk), &wait); |
| 895 | sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); |
| 896 | rc = sk_wait_event(sk, &timeo, |
| 897 | !list_empty(&psk->ingress) || |
| 898 | !skb_queue_empty(&sk->sk_receive_queue), |
| 899 | &wait); |
| 900 | sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); |
| 901 | remove_wait_queue(sk_sleep(sk), &wait); |
| 902 | |
| 903 | return rc; |
| 904 | } |
| 905 | |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 906 | static int bpf_tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
| 907 | int nonblock, int flags, int *addr_len) |
| 908 | { |
| 909 | struct iov_iter *iter = &msg->msg_iter; |
| 910 | struct smap_psock *psock; |
| 911 | int copied = 0; |
| 912 | |
| 913 | if (unlikely(flags & MSG_ERRQUEUE)) |
| 914 | return inet_recv_error(sk, msg, len, addr_len); |
| 915 | |
| 916 | rcu_read_lock(); |
| 917 | psock = smap_psock_sk(sk); |
| 918 | if (unlikely(!psock)) |
| 919 | goto out; |
| 920 | |
| 921 | if (unlikely(!refcount_inc_not_zero(&psock->refcnt))) |
| 922 | goto out; |
| 923 | rcu_read_unlock(); |
| 924 | |
| 925 | if (!skb_queue_empty(&sk->sk_receive_queue)) |
| 926 | return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len); |
| 927 | |
| 928 | lock_sock(sk); |
John Fastabend | e20f733 | 2018-04-23 15:39:28 -0700 | [diff] [blame] | 929 | bytes_ready: |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 930 | while (copied != len) { |
| 931 | struct scatterlist *sg; |
| 932 | struct sk_msg_buff *md; |
| 933 | int i; |
| 934 | |
| 935 | md = list_first_entry_or_null(&psock->ingress, |
| 936 | struct sk_msg_buff, list); |
| 937 | if (unlikely(!md)) |
| 938 | break; |
| 939 | i = md->sg_start; |
| 940 | do { |
| 941 | struct page *page; |
| 942 | int n, copy; |
| 943 | |
| 944 | sg = &md->sg_data[i]; |
| 945 | copy = sg->length; |
| 946 | page = sg_page(sg); |
| 947 | |
| 948 | if (copied + copy > len) |
| 949 | copy = len - copied; |
| 950 | |
| 951 | n = copy_page_to_iter(page, sg->offset, copy, iter); |
| 952 | if (n != copy) { |
| 953 | md->sg_start = i; |
| 954 | release_sock(sk); |
| 955 | smap_release_sock(psock, sk); |
| 956 | return -EFAULT; |
| 957 | } |
| 958 | |
| 959 | copied += copy; |
| 960 | sg->offset += copy; |
| 961 | sg->length -= copy; |
| 962 | sk_mem_uncharge(sk, copy); |
| 963 | |
| 964 | if (!sg->length) { |
| 965 | i++; |
| 966 | if (i == MAX_SKB_FRAGS) |
| 967 | i = 0; |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 968 | if (!md->skb) |
| 969 | put_page(page); |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 970 | } |
| 971 | if (copied == len) |
| 972 | break; |
| 973 | } while (i != md->sg_end); |
| 974 | md->sg_start = i; |
| 975 | |
| 976 | if (!sg->length && md->sg_start == md->sg_end) { |
| 977 | list_del(&md->list); |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 978 | if (md->skb) |
| 979 | consume_skb(md->skb); |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 980 | kfree(md); |
| 981 | } |
| 982 | } |
| 983 | |
John Fastabend | e20f733 | 2018-04-23 15:39:28 -0700 | [diff] [blame] | 984 | if (!copied) { |
| 985 | long timeo; |
| 986 | int data; |
| 987 | int err = 0; |
| 988 | |
| 989 | timeo = sock_rcvtimeo(sk, nonblock); |
| 990 | data = bpf_wait_data(sk, psock, flags, timeo, &err); |
| 991 | |
| 992 | if (data) { |
| 993 | if (!skb_queue_empty(&sk->sk_receive_queue)) { |
| 994 | release_sock(sk); |
| 995 | smap_release_sock(psock, sk); |
| 996 | copied = tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len); |
| 997 | return copied; |
| 998 | } |
| 999 | goto bytes_ready; |
| 1000 | } |
| 1001 | |
| 1002 | if (err) |
| 1003 | copied = err; |
| 1004 | } |
| 1005 | |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 1006 | release_sock(sk); |
| 1007 | smap_release_sock(psock, sk); |
| 1008 | return copied; |
| 1009 | out: |
| 1010 | rcu_read_unlock(); |
| 1011 | return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len); |
| 1012 | } |
| 1013 | |
| 1014 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1015 | static int bpf_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) |
| 1016 | { |
| 1017 | int flags = msg->msg_flags | MSG_NO_SHARED_FRAGS; |
| 1018 | struct sk_msg_buff md = {0}; |
| 1019 | unsigned int sg_copy = 0; |
| 1020 | struct smap_psock *psock; |
| 1021 | int copied = 0, err = 0; |
| 1022 | struct scatterlist *sg; |
| 1023 | long timeo; |
| 1024 | |
| 1025 | /* Its possible a sock event or user removed the psock _but_ the ops |
| 1026 | * have not been reprogrammed yet so we get here. In this case fallback |
| 1027 | * to tcp_sendmsg. Note this only works because we _only_ ever allow |
| 1028 | * a single ULP there is no hierarchy here. |
| 1029 | */ |
| 1030 | rcu_read_lock(); |
| 1031 | psock = smap_psock_sk(sk); |
| 1032 | if (unlikely(!psock)) { |
| 1033 | rcu_read_unlock(); |
| 1034 | return tcp_sendmsg(sk, msg, size); |
| 1035 | } |
| 1036 | |
| 1037 | /* Increment the psock refcnt to ensure its not released while sending a |
| 1038 | * message. Required because sk lookup and bpf programs are used in |
| 1039 | * separate rcu critical sections. Its OK if we lose the map entry |
| 1040 | * but we can't lose the sock reference. |
| 1041 | */ |
| 1042 | if (!refcount_inc_not_zero(&psock->refcnt)) { |
| 1043 | rcu_read_unlock(); |
| 1044 | return tcp_sendmsg(sk, msg, size); |
| 1045 | } |
| 1046 | |
| 1047 | sg = md.sg_data; |
Prashant Bhole | 6ef6d84 | 2018-03-30 09:21:00 +0900 | [diff] [blame] | 1048 | sg_init_marker(sg, MAX_SKB_FRAGS); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1049 | rcu_read_unlock(); |
| 1050 | |
| 1051 | lock_sock(sk); |
| 1052 | timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); |
| 1053 | |
| 1054 | while (msg_data_left(msg)) { |
Daniel Borkmann | 7c81c71 | 2018-08-08 19:23:14 +0200 | [diff] [blame] | 1055 | struct sk_msg_buff *m = NULL; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1056 | bool enospc = false; |
| 1057 | int copy; |
| 1058 | |
| 1059 | if (sk->sk_err) { |
Daniel Borkmann | 5121700 | 2018-08-08 19:23:13 +0200 | [diff] [blame] | 1060 | err = -sk->sk_err; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1061 | goto out_err; |
| 1062 | } |
| 1063 | |
| 1064 | copy = msg_data_left(msg); |
| 1065 | if (!sk_stream_memory_free(sk)) |
| 1066 | goto wait_for_sndbuf; |
| 1067 | |
| 1068 | m = psock->cork_bytes ? psock->cork : &md; |
| 1069 | m->sg_curr = m->sg_copybreak ? m->sg_curr : m->sg_end; |
| 1070 | err = sk_alloc_sg(sk, copy, m->sg_data, |
| 1071 | m->sg_start, &m->sg_end, &sg_copy, |
| 1072 | m->sg_end - 1); |
| 1073 | if (err) { |
| 1074 | if (err != -ENOSPC) |
| 1075 | goto wait_for_memory; |
| 1076 | enospc = true; |
| 1077 | copy = sg_copy; |
| 1078 | } |
| 1079 | |
| 1080 | err = memcopy_from_iter(sk, m, &msg->msg_iter, copy); |
| 1081 | if (err < 0) { |
| 1082 | free_curr_sg(sk, m); |
| 1083 | goto out_err; |
| 1084 | } |
| 1085 | |
| 1086 | psock->sg_size += copy; |
| 1087 | copied += copy; |
| 1088 | sg_copy = 0; |
| 1089 | |
| 1090 | /* When bytes are being corked skip running BPF program and |
| 1091 | * applying verdict unless there is no more buffer space. In |
| 1092 | * the ENOSPC case simply run BPF prorgram with currently |
| 1093 | * accumulated data. We don't have much choice at this point |
| 1094 | * we could try extending the page frags or chaining complex |
| 1095 | * frags but even in these cases _eventually_ we will hit an |
| 1096 | * OOM scenario. More complex recovery schemes may be |
| 1097 | * implemented in the future, but BPF programs must handle |
| 1098 | * the case where apply_cork requests are not honored. The |
| 1099 | * canonical method to verify this is to check data length. |
| 1100 | */ |
| 1101 | if (psock->cork_bytes) { |
| 1102 | if (copy > psock->cork_bytes) |
| 1103 | psock->cork_bytes = 0; |
| 1104 | else |
| 1105 | psock->cork_bytes -= copy; |
| 1106 | |
| 1107 | if (psock->cork_bytes && !enospc) |
| 1108 | goto out_cork; |
| 1109 | |
| 1110 | /* All cork bytes accounted for re-run filter */ |
| 1111 | psock->eval = __SK_NONE; |
| 1112 | psock->cork_bytes = 0; |
| 1113 | } |
| 1114 | |
| 1115 | err = bpf_exec_tx_verdict(psock, m, sk, &copied, flags); |
| 1116 | if (unlikely(err < 0)) |
| 1117 | goto out_err; |
| 1118 | continue; |
| 1119 | wait_for_sndbuf: |
| 1120 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); |
| 1121 | wait_for_memory: |
| 1122 | err = sk_stream_wait_memory(sk, &timeo); |
Daniel Borkmann | 7c81c71 | 2018-08-08 19:23:14 +0200 | [diff] [blame] | 1123 | if (err) { |
| 1124 | if (m && m != psock->cork) |
| 1125 | free_start_sg(sk, m); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1126 | goto out_err; |
Daniel Borkmann | 7c81c71 | 2018-08-08 19:23:14 +0200 | [diff] [blame] | 1127 | } |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1128 | } |
| 1129 | out_err: |
| 1130 | if (err < 0) |
| 1131 | err = sk_stream_error(sk, msg->msg_flags, err); |
| 1132 | out_cork: |
| 1133 | release_sock(sk); |
| 1134 | smap_release_sock(psock, sk); |
| 1135 | return copied ? copied : err; |
| 1136 | } |
| 1137 | |
| 1138 | static int bpf_tcp_sendpage(struct sock *sk, struct page *page, |
| 1139 | int offset, size_t size, int flags) |
| 1140 | { |
| 1141 | struct sk_msg_buff md = {0}, *m = NULL; |
| 1142 | int err = 0, copied = 0; |
| 1143 | struct smap_psock *psock; |
| 1144 | struct scatterlist *sg; |
| 1145 | bool enospc = false; |
| 1146 | |
| 1147 | rcu_read_lock(); |
| 1148 | psock = smap_psock_sk(sk); |
| 1149 | if (unlikely(!psock)) |
| 1150 | goto accept; |
| 1151 | |
| 1152 | if (!refcount_inc_not_zero(&psock->refcnt)) |
| 1153 | goto accept; |
| 1154 | rcu_read_unlock(); |
| 1155 | |
| 1156 | lock_sock(sk); |
| 1157 | |
Prashant Bhole | 6ef6d84 | 2018-03-30 09:21:00 +0900 | [diff] [blame] | 1158 | if (psock->cork_bytes) { |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1159 | m = psock->cork; |
Prashant Bhole | 6ef6d84 | 2018-03-30 09:21:00 +0900 | [diff] [blame] | 1160 | sg = &m->sg_data[m->sg_end]; |
| 1161 | } else { |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1162 | m = &md; |
Prashant Bhole | 6ef6d84 | 2018-03-30 09:21:00 +0900 | [diff] [blame] | 1163 | sg = m->sg_data; |
| 1164 | sg_init_marker(sg, MAX_SKB_FRAGS); |
| 1165 | } |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1166 | |
| 1167 | /* Catch case where ring is full and sendpage is stalled. */ |
| 1168 | if (unlikely(m->sg_end == m->sg_start && |
| 1169 | m->sg_data[m->sg_end].length)) |
| 1170 | goto out_err; |
| 1171 | |
| 1172 | psock->sg_size += size; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1173 | sg_set_page(sg, page, size, offset); |
| 1174 | get_page(page); |
| 1175 | m->sg_copy[m->sg_end] = true; |
| 1176 | sk_mem_charge(sk, size); |
| 1177 | m->sg_end++; |
| 1178 | copied = size; |
| 1179 | |
| 1180 | if (m->sg_end == MAX_SKB_FRAGS) |
| 1181 | m->sg_end = 0; |
| 1182 | |
| 1183 | if (m->sg_end == m->sg_start) |
| 1184 | enospc = true; |
| 1185 | |
| 1186 | if (psock->cork_bytes) { |
| 1187 | if (size > psock->cork_bytes) |
| 1188 | psock->cork_bytes = 0; |
| 1189 | else |
| 1190 | psock->cork_bytes -= size; |
| 1191 | |
| 1192 | if (psock->cork_bytes && !enospc) |
| 1193 | goto out_err; |
| 1194 | |
| 1195 | /* All cork bytes accounted for re-run filter */ |
| 1196 | psock->eval = __SK_NONE; |
| 1197 | psock->cork_bytes = 0; |
| 1198 | } |
| 1199 | |
| 1200 | err = bpf_exec_tx_verdict(psock, m, sk, &copied, flags); |
| 1201 | out_err: |
| 1202 | release_sock(sk); |
| 1203 | smap_release_sock(psock, sk); |
| 1204 | return copied ? copied : err; |
| 1205 | accept: |
| 1206 | rcu_read_unlock(); |
| 1207 | return tcp_sendpage(sk, page, offset, size, flags); |
| 1208 | } |
| 1209 | |
| 1210 | static void bpf_tcp_msg_add(struct smap_psock *psock, |
| 1211 | struct sock *sk, |
| 1212 | struct bpf_prog *tx_msg) |
| 1213 | { |
| 1214 | struct bpf_prog *orig_tx_msg; |
| 1215 | |
| 1216 | orig_tx_msg = xchg(&psock->bpf_tx_msg, tx_msg); |
| 1217 | if (orig_tx_msg) |
| 1218 | bpf_prog_put(orig_tx_msg); |
| 1219 | } |
| 1220 | |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 1221 | static int bpf_tcp_ulp_register(void) |
| 1222 | { |
John Fastabend | 9901c5d | 2018-06-30 06:17:36 -0700 | [diff] [blame] | 1223 | build_protos(bpf_tcp_prots[SOCKMAP_IPV4], &tcp_prot); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1224 | /* Once BPF TX ULP is registered it is never unregistered. It |
| 1225 | * will be in the ULP list for the lifetime of the system. Doing |
| 1226 | * duplicate registers is not a problem. |
| 1227 | */ |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 1228 | return tcp_register_ulp(&bpf_tcp_ulp_ops); |
| 1229 | } |
| 1230 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1231 | static int smap_verdict_func(struct smap_psock *psock, struct sk_buff *skb) |
| 1232 | { |
| 1233 | struct bpf_prog *prog = READ_ONCE(psock->bpf_verdict); |
| 1234 | int rc; |
| 1235 | |
| 1236 | if (unlikely(!prog)) |
John Fastabend | 04686ef | 2017-10-31 19:17:31 -0700 | [diff] [blame] | 1237 | return __SK_DROP; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1238 | |
| 1239 | skb_orphan(skb); |
John Fastabend | 34f79502 | 2017-10-18 07:10:36 -0700 | [diff] [blame] | 1240 | /* We need to ensure that BPF metadata for maps is also cleared |
| 1241 | * when we orphan the skb so that we don't have the possibility |
| 1242 | * to reference a stale map. |
| 1243 | */ |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1244 | TCP_SKB_CB(skb)->bpf.sk_redir = NULL; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1245 | skb->sk = psock->sock; |
John Fastabend | 0ea488f | 2018-07-05 08:50:15 -0700 | [diff] [blame] | 1246 | bpf_compute_data_end_sk_skb(skb); |
John Fastabend | 34f79502 | 2017-10-18 07:10:36 -0700 | [diff] [blame] | 1247 | preempt_disable(); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1248 | rc = (*prog->bpf_func)(skb, prog->insnsi); |
John Fastabend | 34f79502 | 2017-10-18 07:10:36 -0700 | [diff] [blame] | 1249 | preempt_enable(); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1250 | skb->sk = NULL; |
| 1251 | |
John Fastabend | 04686ef | 2017-10-31 19:17:31 -0700 | [diff] [blame] | 1252 | /* Moving return codes from UAPI namespace into internal namespace */ |
John Fastabend | bfa64075 | 2017-10-27 09:45:53 -0700 | [diff] [blame] | 1253 | return rc == SK_PASS ? |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1254 | (TCP_SKB_CB(skb)->bpf.sk_redir ? __SK_REDIRECT : __SK_PASS) : |
John Fastabend | 04686ef | 2017-10-31 19:17:31 -0700 | [diff] [blame] | 1255 | __SK_DROP; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1256 | } |
| 1257 | |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1258 | static int smap_do_ingress(struct smap_psock *psock, struct sk_buff *skb) |
| 1259 | { |
| 1260 | struct sock *sk = psock->sock; |
| 1261 | int copied = 0, num_sg; |
| 1262 | struct sk_msg_buff *r; |
| 1263 | |
| 1264 | r = kzalloc(sizeof(struct sk_msg_buff), __GFP_NOWARN | GFP_ATOMIC); |
| 1265 | if (unlikely(!r)) |
| 1266 | return -EAGAIN; |
| 1267 | |
| 1268 | if (!sk_rmem_schedule(sk, skb, skb->len)) { |
| 1269 | kfree(r); |
| 1270 | return -EAGAIN; |
| 1271 | } |
| 1272 | |
| 1273 | sg_init_table(r->sg_data, MAX_SKB_FRAGS); |
| 1274 | num_sg = skb_to_sgvec(skb, r->sg_data, 0, skb->len); |
| 1275 | if (unlikely(num_sg < 0)) { |
| 1276 | kfree(r); |
| 1277 | return num_sg; |
| 1278 | } |
| 1279 | sk_mem_charge(sk, skb->len); |
| 1280 | copied = skb->len; |
| 1281 | r->sg_start = 0; |
| 1282 | r->sg_end = num_sg == MAX_SKB_FRAGS ? 0 : num_sg; |
| 1283 | r->skb = skb; |
| 1284 | list_add_tail(&r->list, &psock->ingress); |
| 1285 | sk->sk_data_ready(sk); |
| 1286 | return copied; |
| 1287 | } |
| 1288 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1289 | static void smap_do_verdict(struct smap_psock *psock, struct sk_buff *skb) |
| 1290 | { |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1291 | struct smap_psock *peer; |
John Fastabend | 90a9631 | 2017-09-01 11:29:26 -0700 | [diff] [blame] | 1292 | struct sock *sk; |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1293 | __u32 in; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1294 | int rc; |
| 1295 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1296 | rc = smap_verdict_func(psock, skb); |
| 1297 | switch (rc) { |
John Fastabend | 04686ef | 2017-10-31 19:17:31 -0700 | [diff] [blame] | 1298 | case __SK_REDIRECT: |
John Fastabend | 34f79502 | 2017-10-18 07:10:36 -0700 | [diff] [blame] | 1299 | sk = do_sk_redirect_map(skb); |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1300 | if (!sk) { |
| 1301 | kfree_skb(skb); |
| 1302 | break; |
| 1303 | } |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1304 | |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1305 | peer = smap_psock_sk(sk); |
| 1306 | in = (TCP_SKB_CB(skb)->bpf.flags) & BPF_F_INGRESS; |
| 1307 | |
| 1308 | if (unlikely(!peer || sock_flag(sk, SOCK_DEAD) || |
| 1309 | !test_bit(SMAP_TX_RUNNING, &peer->state))) { |
| 1310 | kfree_skb(skb); |
| 1311 | break; |
| 1312 | } |
| 1313 | |
| 1314 | if (!in && sock_writeable(sk)) { |
| 1315 | skb_set_owner_w(skb, sk); |
| 1316 | skb_queue_tail(&peer->rxqueue, skb); |
| 1317 | schedule_work(&peer->tx_work); |
| 1318 | break; |
| 1319 | } else if (in && |
| 1320 | atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) { |
| 1321 | skb_queue_tail(&peer->rxqueue, skb); |
| 1322 | schedule_work(&peer->tx_work); |
| 1323 | break; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1324 | } |
| 1325 | /* Fall through and free skb otherwise */ |
John Fastabend | 04686ef | 2017-10-31 19:17:31 -0700 | [diff] [blame] | 1326 | case __SK_DROP: |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1327 | default: |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1328 | kfree_skb(skb); |
| 1329 | } |
| 1330 | } |
| 1331 | |
| 1332 | static void smap_report_sk_error(struct smap_psock *psock, int err) |
| 1333 | { |
| 1334 | struct sock *sk = psock->sock; |
| 1335 | |
| 1336 | sk->sk_err = err; |
| 1337 | sk->sk_error_report(sk); |
| 1338 | } |
| 1339 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1340 | static void smap_read_sock_strparser(struct strparser *strp, |
| 1341 | struct sk_buff *skb) |
| 1342 | { |
| 1343 | struct smap_psock *psock; |
| 1344 | |
| 1345 | rcu_read_lock(); |
| 1346 | psock = container_of(strp, struct smap_psock, strp); |
| 1347 | smap_do_verdict(psock, skb); |
| 1348 | rcu_read_unlock(); |
| 1349 | } |
| 1350 | |
| 1351 | /* Called with lock held on socket */ |
| 1352 | static void smap_data_ready(struct sock *sk) |
| 1353 | { |
| 1354 | struct smap_psock *psock; |
| 1355 | |
John Fastabend | d26e597d | 2017-08-28 07:10:45 -0700 | [diff] [blame] | 1356 | rcu_read_lock(); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1357 | psock = smap_psock_sk(sk); |
John Fastabend | d26e597d | 2017-08-28 07:10:45 -0700 | [diff] [blame] | 1358 | if (likely(psock)) { |
| 1359 | write_lock_bh(&sk->sk_callback_lock); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1360 | strp_data_ready(&psock->strp); |
John Fastabend | d26e597d | 2017-08-28 07:10:45 -0700 | [diff] [blame] | 1361 | write_unlock_bh(&sk->sk_callback_lock); |
| 1362 | } |
| 1363 | rcu_read_unlock(); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1364 | } |
| 1365 | |
| 1366 | static void smap_tx_work(struct work_struct *w) |
| 1367 | { |
| 1368 | struct smap_psock *psock; |
| 1369 | struct sk_buff *skb; |
| 1370 | int rem, off, n; |
| 1371 | |
| 1372 | psock = container_of(w, struct smap_psock, tx_work); |
| 1373 | |
| 1374 | /* lock sock to avoid losing sk_socket at some point during loop */ |
| 1375 | lock_sock(psock->sock); |
| 1376 | if (psock->save_skb) { |
| 1377 | skb = psock->save_skb; |
| 1378 | rem = psock->save_rem; |
| 1379 | off = psock->save_off; |
| 1380 | psock->save_skb = NULL; |
| 1381 | goto start; |
| 1382 | } |
| 1383 | |
| 1384 | while ((skb = skb_dequeue(&psock->rxqueue))) { |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1385 | __u32 flags; |
| 1386 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1387 | rem = skb->len; |
| 1388 | off = 0; |
| 1389 | start: |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1390 | flags = (TCP_SKB_CB(skb)->bpf.flags) & BPF_F_INGRESS; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1391 | do { |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1392 | if (likely(psock->sock->sk_socket)) { |
| 1393 | if (flags) |
| 1394 | n = smap_do_ingress(psock, skb); |
| 1395 | else |
| 1396 | n = skb_send_sock_locked(psock->sock, |
| 1397 | skb, off, rem); |
| 1398 | } else { |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1399 | n = -EINVAL; |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1400 | } |
| 1401 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1402 | if (n <= 0) { |
| 1403 | if (n == -EAGAIN) { |
| 1404 | /* Retry when space is available */ |
| 1405 | psock->save_skb = skb; |
| 1406 | psock->save_rem = rem; |
| 1407 | psock->save_off = off; |
| 1408 | goto out; |
| 1409 | } |
| 1410 | /* Hard errors break pipe and stop xmit */ |
| 1411 | smap_report_sk_error(psock, n ? -n : EPIPE); |
| 1412 | clear_bit(SMAP_TX_RUNNING, &psock->state); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1413 | kfree_skb(skb); |
| 1414 | goto out; |
| 1415 | } |
| 1416 | rem -= n; |
| 1417 | off += n; |
| 1418 | } while (rem); |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1419 | |
| 1420 | if (!flags) |
| 1421 | kfree_skb(skb); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1422 | } |
| 1423 | out: |
| 1424 | release_sock(psock->sock); |
| 1425 | } |
| 1426 | |
| 1427 | static void smap_write_space(struct sock *sk) |
| 1428 | { |
| 1429 | struct smap_psock *psock; |
John Fastabend | 9b2e038 | 2018-08-22 08:37:37 -0700 | [diff] [blame] | 1430 | void (*write_space)(struct sock *sk); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1431 | |
| 1432 | rcu_read_lock(); |
| 1433 | psock = smap_psock_sk(sk); |
| 1434 | if (likely(psock && test_bit(SMAP_TX_RUNNING, &psock->state))) |
| 1435 | schedule_work(&psock->tx_work); |
John Fastabend | 9b2e038 | 2018-08-22 08:37:37 -0700 | [diff] [blame] | 1436 | write_space = psock->save_write_space; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1437 | rcu_read_unlock(); |
John Fastabend | 9b2e038 | 2018-08-22 08:37:37 -0700 | [diff] [blame] | 1438 | write_space(sk); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1439 | } |
| 1440 | |
| 1441 | static void smap_stop_sock(struct smap_psock *psock, struct sock *sk) |
| 1442 | { |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1443 | if (!psock->strp_enabled) |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1444 | return; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1445 | sk->sk_data_ready = psock->save_data_ready; |
| 1446 | sk->sk_write_space = psock->save_write_space; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1447 | psock->save_data_ready = NULL; |
| 1448 | psock->save_write_space = NULL; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1449 | strp_stop(&psock->strp); |
| 1450 | psock->strp_enabled = false; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1451 | } |
| 1452 | |
| 1453 | static void smap_destroy_psock(struct rcu_head *rcu) |
| 1454 | { |
| 1455 | struct smap_psock *psock = container_of(rcu, |
| 1456 | struct smap_psock, rcu); |
| 1457 | |
| 1458 | /* Now that a grace period has passed there is no longer |
| 1459 | * any reference to this sock in the sockmap so we can |
| 1460 | * destroy the psock, strparser, and bpf programs. But, |
| 1461 | * because we use workqueue sync operations we can not |
| 1462 | * do it in rcu context |
| 1463 | */ |
| 1464 | schedule_work(&psock->gc_work); |
| 1465 | } |
| 1466 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1467 | static void smap_release_sock(struct smap_psock *psock, struct sock *sock) |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1468 | { |
John Fastabend | ffa3566 | 2018-03-18 12:56:54 -0700 | [diff] [blame] | 1469 | if (refcount_dec_and_test(&psock->refcnt)) { |
| 1470 | tcp_cleanup_ulp(sock); |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 1471 | write_lock_bh(&sock->sk_callback_lock); |
John Fastabend | ffa3566 | 2018-03-18 12:56:54 -0700 | [diff] [blame] | 1472 | smap_stop_sock(psock, sock); |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 1473 | write_unlock_bh(&sock->sk_callback_lock); |
John Fastabend | ffa3566 | 2018-03-18 12:56:54 -0700 | [diff] [blame] | 1474 | clear_bit(SMAP_TX_RUNNING, &psock->state); |
| 1475 | rcu_assign_sk_user_data(sock, NULL); |
| 1476 | call_rcu_sched(&psock->rcu, smap_destroy_psock); |
| 1477 | } |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1478 | } |
| 1479 | |
| 1480 | static int smap_parse_func_strparser(struct strparser *strp, |
| 1481 | struct sk_buff *skb) |
| 1482 | { |
| 1483 | struct smap_psock *psock; |
| 1484 | struct bpf_prog *prog; |
| 1485 | int rc; |
| 1486 | |
| 1487 | rcu_read_lock(); |
| 1488 | psock = container_of(strp, struct smap_psock, strp); |
| 1489 | prog = READ_ONCE(psock->bpf_parse); |
| 1490 | |
| 1491 | if (unlikely(!prog)) { |
| 1492 | rcu_read_unlock(); |
| 1493 | return skb->len; |
| 1494 | } |
| 1495 | |
| 1496 | /* Attach socket for bpf program to use if needed we can do this |
| 1497 | * because strparser clones the skb before handing it to a upper |
| 1498 | * layer, meaning skb_orphan has been called. We NULL sk on the |
| 1499 | * way out to ensure we don't trigger a BUG_ON in skb/sk operations |
| 1500 | * later and because we are not charging the memory of this skb to |
| 1501 | * any socket yet. |
| 1502 | */ |
| 1503 | skb->sk = psock->sock; |
John Fastabend | 0ea488f | 2018-07-05 08:50:15 -0700 | [diff] [blame] | 1504 | bpf_compute_data_end_sk_skb(skb); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1505 | rc = (*prog->bpf_func)(skb, prog->insnsi); |
| 1506 | skb->sk = NULL; |
| 1507 | rcu_read_unlock(); |
| 1508 | return rc; |
| 1509 | } |
| 1510 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1511 | static int smap_read_sock_done(struct strparser *strp, int err) |
| 1512 | { |
| 1513 | return err; |
| 1514 | } |
| 1515 | |
| 1516 | static int smap_init_sock(struct smap_psock *psock, |
| 1517 | struct sock *sk) |
| 1518 | { |
Eric Biggers | 3fd8712 | 2017-08-24 14:38:51 -0700 | [diff] [blame] | 1519 | static const struct strp_callbacks cb = { |
| 1520 | .rcv_msg = smap_read_sock_strparser, |
| 1521 | .parse_msg = smap_parse_func_strparser, |
| 1522 | .read_sock_done = smap_read_sock_done, |
| 1523 | }; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1524 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1525 | return strp_init(&psock->strp, sk, &cb); |
| 1526 | } |
| 1527 | |
| 1528 | static void smap_init_progs(struct smap_psock *psock, |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1529 | struct bpf_prog *verdict, |
| 1530 | struct bpf_prog *parse) |
| 1531 | { |
| 1532 | struct bpf_prog *orig_parse, *orig_verdict; |
| 1533 | |
| 1534 | orig_parse = xchg(&psock->bpf_parse, parse); |
| 1535 | orig_verdict = xchg(&psock->bpf_verdict, verdict); |
| 1536 | |
| 1537 | if (orig_verdict) |
| 1538 | bpf_prog_put(orig_verdict); |
| 1539 | if (orig_parse) |
| 1540 | bpf_prog_put(orig_parse); |
| 1541 | } |
| 1542 | |
| 1543 | static void smap_start_sock(struct smap_psock *psock, struct sock *sk) |
| 1544 | { |
| 1545 | if (sk->sk_data_ready == smap_data_ready) |
| 1546 | return; |
| 1547 | psock->save_data_ready = sk->sk_data_ready; |
| 1548 | psock->save_write_space = sk->sk_write_space; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1549 | sk->sk_data_ready = smap_data_ready; |
| 1550 | sk->sk_write_space = smap_write_space; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1551 | psock->strp_enabled = true; |
| 1552 | } |
| 1553 | |
| 1554 | static void sock_map_remove_complete(struct bpf_stab *stab) |
| 1555 | { |
| 1556 | bpf_map_area_free(stab->sock_map); |
| 1557 | kfree(stab); |
| 1558 | } |
| 1559 | |
| 1560 | static void smap_gc_work(struct work_struct *w) |
| 1561 | { |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1562 | struct smap_psock_map_entry *e, *tmp; |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 1563 | struct sk_msg_buff *md, *mtmp; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1564 | struct smap_psock *psock; |
| 1565 | |
| 1566 | psock = container_of(w, struct smap_psock, gc_work); |
| 1567 | |
| 1568 | /* no callback lock needed because we already detached sockmap ops */ |
| 1569 | if (psock->strp_enabled) |
| 1570 | strp_done(&psock->strp); |
| 1571 | |
| 1572 | cancel_work_sync(&psock->tx_work); |
| 1573 | __skb_queue_purge(&psock->rxqueue); |
| 1574 | |
| 1575 | /* At this point all strparser and xmit work must be complete */ |
| 1576 | if (psock->bpf_parse) |
| 1577 | bpf_prog_put(psock->bpf_parse); |
| 1578 | if (psock->bpf_verdict) |
| 1579 | bpf_prog_put(psock->bpf_verdict); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1580 | if (psock->bpf_tx_msg) |
| 1581 | bpf_prog_put(psock->bpf_tx_msg); |
| 1582 | |
| 1583 | if (psock->cork) { |
| 1584 | free_start_sg(psock->sock, psock->cork); |
| 1585 | kfree(psock->cork); |
| 1586 | } |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1587 | |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 1588 | list_for_each_entry_safe(md, mtmp, &psock->ingress, list) { |
| 1589 | list_del(&md->list); |
| 1590 | free_start_sg(psock->sock, md); |
| 1591 | kfree(md); |
| 1592 | } |
| 1593 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1594 | list_for_each_entry_safe(e, tmp, &psock->maps, list) { |
| 1595 | list_del(&e->list); |
| 1596 | kfree(e); |
| 1597 | } |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1598 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1599 | if (psock->sk_redir) |
| 1600 | sock_put(psock->sk_redir); |
| 1601 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1602 | sock_put(psock->sock); |
| 1603 | kfree(psock); |
| 1604 | } |
| 1605 | |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1606 | static struct smap_psock *smap_init_psock(struct sock *sock, int node) |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1607 | { |
| 1608 | struct smap_psock *psock; |
| 1609 | |
Martin KaFai Lau | 96eabe7 | 2017-08-18 11:28:00 -0700 | [diff] [blame] | 1610 | psock = kzalloc_node(sizeof(struct smap_psock), |
| 1611 | GFP_ATOMIC | __GFP_NOWARN, |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1612 | node); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1613 | if (!psock) |
| 1614 | return ERR_PTR(-ENOMEM); |
| 1615 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1616 | psock->eval = __SK_NONE; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1617 | psock->sock = sock; |
| 1618 | skb_queue_head_init(&psock->rxqueue); |
| 1619 | INIT_WORK(&psock->tx_work, smap_tx_work); |
| 1620 | INIT_WORK(&psock->gc_work, smap_gc_work); |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1621 | INIT_LIST_HEAD(&psock->maps); |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 1622 | INIT_LIST_HEAD(&psock->ingress); |
John Fastabend | ffa3566 | 2018-03-18 12:56:54 -0700 | [diff] [blame] | 1623 | refcount_set(&psock->refcnt, 1); |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 1624 | spin_lock_init(&psock->maps_lock); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1625 | |
| 1626 | rcu_assign_sk_user_data(sock, psock); |
| 1627 | sock_hold(sock); |
| 1628 | return psock; |
| 1629 | } |
| 1630 | |
| 1631 | static struct bpf_map *sock_map_alloc(union bpf_attr *attr) |
| 1632 | { |
| 1633 | struct bpf_stab *stab; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1634 | u64 cost; |
Eric Dumazet | 952fad8 | 2018-02-13 15:33:52 -0800 | [diff] [blame] | 1635 | int err; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1636 | |
John Fastabend | fb50df8 | 2017-10-18 07:11:22 -0700 | [diff] [blame] | 1637 | if (!capable(CAP_NET_ADMIN)) |
| 1638 | return ERR_PTR(-EPERM); |
| 1639 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1640 | /* check sanity of attributes */ |
| 1641 | if (attr->max_entries == 0 || attr->key_size != 4 || |
Chenbo Feng | 6e71b04 | 2017-10-18 13:00:22 -0700 | [diff] [blame] | 1642 | attr->value_size != 4 || attr->map_flags & ~SOCK_CREATE_FLAG_MASK) |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1643 | return ERR_PTR(-EINVAL); |
| 1644 | |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 1645 | err = bpf_tcp_ulp_register(); |
| 1646 | if (err && err != -EEXIST) |
| 1647 | return ERR_PTR(err); |
| 1648 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1649 | stab = kzalloc(sizeof(*stab), GFP_USER); |
| 1650 | if (!stab) |
| 1651 | return ERR_PTR(-ENOMEM); |
| 1652 | |
Jakub Kicinski | bd47564 | 2018-01-11 20:29:06 -0800 | [diff] [blame] | 1653 | bpf_map_init_from_attr(&stab->map, attr); |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 1654 | raw_spin_lock_init(&stab->lock); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1655 | |
| 1656 | /* make sure page count doesn't overflow */ |
| 1657 | cost = (u64) stab->map.max_entries * sizeof(struct sock *); |
Eric Dumazet | 952fad8 | 2018-02-13 15:33:52 -0800 | [diff] [blame] | 1658 | err = -EINVAL; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1659 | if (cost >= U32_MAX - PAGE_SIZE) |
| 1660 | goto free_stab; |
| 1661 | |
| 1662 | stab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT; |
| 1663 | |
| 1664 | /* if map size is larger than memlock limit, reject it early */ |
| 1665 | err = bpf_map_precharge_memlock(stab->map.pages); |
| 1666 | if (err) |
| 1667 | goto free_stab; |
| 1668 | |
Dan Carpenter | f740c34 | 2017-08-25 23:27:14 +0300 | [diff] [blame] | 1669 | err = -ENOMEM; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1670 | stab->sock_map = bpf_map_area_alloc(stab->map.max_entries * |
Martin KaFai Lau | 96eabe7 | 2017-08-18 11:28:00 -0700 | [diff] [blame] | 1671 | sizeof(struct sock *), |
| 1672 | stab->map.numa_node); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1673 | if (!stab->sock_map) |
| 1674 | goto free_stab; |
| 1675 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1676 | return &stab->map; |
| 1677 | free_stab: |
| 1678 | kfree(stab); |
| 1679 | return ERR_PTR(err); |
| 1680 | } |
| 1681 | |
John Fastabend | 54fedb4 | 2018-06-30 06:17:41 -0700 | [diff] [blame] | 1682 | static void smap_list_map_remove(struct smap_psock *psock, |
| 1683 | struct sock **entry) |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1684 | { |
| 1685 | struct smap_psock_map_entry *e, *tmp; |
| 1686 | |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 1687 | spin_lock_bh(&psock->maps_lock); |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1688 | list_for_each_entry_safe(e, tmp, &psock->maps, list) { |
Daniel Borkmann | d40b011 | 2018-08-16 21:49:08 +0200 | [diff] [blame] | 1689 | if (e->entry == entry) { |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1690 | list_del(&e->list); |
Daniel Borkmann | d40b011 | 2018-08-16 21:49:08 +0200 | [diff] [blame] | 1691 | kfree(e); |
| 1692 | } |
John Fastabend | 54fedb4 | 2018-06-30 06:17:41 -0700 | [diff] [blame] | 1693 | } |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 1694 | spin_unlock_bh(&psock->maps_lock); |
John Fastabend | 54fedb4 | 2018-06-30 06:17:41 -0700 | [diff] [blame] | 1695 | } |
| 1696 | |
| 1697 | static void smap_list_hash_remove(struct smap_psock *psock, |
| 1698 | struct htab_elem *hash_link) |
| 1699 | { |
| 1700 | struct smap_psock_map_entry *e, *tmp; |
| 1701 | |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 1702 | spin_lock_bh(&psock->maps_lock); |
John Fastabend | 54fedb4 | 2018-06-30 06:17:41 -0700 | [diff] [blame] | 1703 | list_for_each_entry_safe(e, tmp, &psock->maps, list) { |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 1704 | struct htab_elem *c = rcu_dereference(e->hash_link); |
John Fastabend | 54fedb4 | 2018-06-30 06:17:41 -0700 | [diff] [blame] | 1705 | |
Daniel Borkmann | d40b011 | 2018-08-16 21:49:08 +0200 | [diff] [blame] | 1706 | if (c == hash_link) { |
John Fastabend | 54fedb4 | 2018-06-30 06:17:41 -0700 | [diff] [blame] | 1707 | list_del(&e->list); |
Daniel Borkmann | d40b011 | 2018-08-16 21:49:08 +0200 | [diff] [blame] | 1708 | kfree(e); |
| 1709 | } |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1710 | } |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 1711 | spin_unlock_bh(&psock->maps_lock); |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1712 | } |
| 1713 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1714 | static void sock_map_free(struct bpf_map *map) |
| 1715 | { |
| 1716 | struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
| 1717 | int i; |
| 1718 | |
| 1719 | synchronize_rcu(); |
| 1720 | |
| 1721 | /* At this point no update, lookup or delete operations can happen. |
| 1722 | * However, be aware we can still get a socket state event updates, |
| 1723 | * and data ready callabacks that reference the psock from sk_user_data |
| 1724 | * Also psock worker threads are still in-flight. So smap_release_sock |
| 1725 | * will only free the psock after cancel_sync on the worker threads |
| 1726 | * and a grace period expire to ensure psock is really safe to remove. |
| 1727 | */ |
| 1728 | rcu_read_lock(); |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 1729 | raw_spin_lock_bh(&stab->lock); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1730 | for (i = 0; i < stab->map.max_entries; i++) { |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1731 | struct smap_psock *psock; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1732 | struct sock *sock; |
| 1733 | |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 1734 | sock = stab->sock_map[i]; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1735 | if (!sock) |
| 1736 | continue; |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 1737 | stab->sock_map[i] = NULL; |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1738 | psock = smap_psock_sk(sock); |
John Fastabend | 5731a87 | 2018-01-04 20:02:09 -0800 | [diff] [blame] | 1739 | /* This check handles a racing sock event that can get the |
| 1740 | * sk_callback_lock before this case but after xchg happens |
| 1741 | * causing the refcnt to hit zero and sock user data (psock) |
| 1742 | * to be null and queued for garbage collection. |
| 1743 | */ |
| 1744 | if (likely(psock)) { |
John Fastabend | 54fedb4 | 2018-06-30 06:17:41 -0700 | [diff] [blame] | 1745 | smap_list_map_remove(psock, &stab->sock_map[i]); |
John Fastabend | 5731a87 | 2018-01-04 20:02:09 -0800 | [diff] [blame] | 1746 | smap_release_sock(psock, sock); |
| 1747 | } |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1748 | } |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 1749 | raw_spin_unlock_bh(&stab->lock); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1750 | rcu_read_unlock(); |
| 1751 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1752 | sock_map_remove_complete(stab); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1753 | } |
| 1754 | |
| 1755 | static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next_key) |
| 1756 | { |
| 1757 | struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
| 1758 | u32 i = key ? *(u32 *)key : U32_MAX; |
| 1759 | u32 *next = (u32 *)next_key; |
| 1760 | |
| 1761 | if (i >= stab->map.max_entries) { |
| 1762 | *next = 0; |
| 1763 | return 0; |
| 1764 | } |
| 1765 | |
| 1766 | if (i == stab->map.max_entries - 1) |
| 1767 | return -ENOENT; |
| 1768 | |
| 1769 | *next = i + 1; |
| 1770 | return 0; |
| 1771 | } |
| 1772 | |
| 1773 | struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key) |
| 1774 | { |
| 1775 | struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
| 1776 | |
| 1777 | if (key >= map->max_entries) |
| 1778 | return NULL; |
| 1779 | |
| 1780 | return READ_ONCE(stab->sock_map[key]); |
| 1781 | } |
| 1782 | |
| 1783 | static int sock_map_delete_elem(struct bpf_map *map, void *key) |
| 1784 | { |
| 1785 | struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1786 | struct smap_psock *psock; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1787 | int k = *(u32 *)key; |
| 1788 | struct sock *sock; |
| 1789 | |
| 1790 | if (k >= map->max_entries) |
| 1791 | return -EINVAL; |
| 1792 | |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 1793 | raw_spin_lock_bh(&stab->lock); |
| 1794 | sock = stab->sock_map[k]; |
| 1795 | stab->sock_map[k] = NULL; |
| 1796 | raw_spin_unlock_bh(&stab->lock); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1797 | if (!sock) |
| 1798 | return -EINVAL; |
| 1799 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1800 | psock = smap_psock_sk(sock); |
| 1801 | if (!psock) |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 1802 | return 0; |
Daniel Borkmann | 166ab6f | 2018-08-16 21:49:09 +0200 | [diff] [blame] | 1803 | if (psock->bpf_parse) { |
| 1804 | write_lock_bh(&sock->sk_callback_lock); |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1805 | smap_stop_sock(psock, sock); |
Daniel Borkmann | 166ab6f | 2018-08-16 21:49:09 +0200 | [diff] [blame] | 1806 | write_unlock_bh(&sock->sk_callback_lock); |
| 1807 | } |
John Fastabend | 54fedb4 | 2018-06-30 06:17:41 -0700 | [diff] [blame] | 1808 | smap_list_map_remove(psock, &stab->sock_map[k]); |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1809 | smap_release_sock(psock, sock); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1810 | return 0; |
| 1811 | } |
| 1812 | |
| 1813 | /* Locking notes: Concurrent updates, deletes, and lookups are allowed and are |
| 1814 | * done inside rcu critical sections. This ensures on updates that the psock |
| 1815 | * will not be released via smap_release_sock() until concurrent updates/deletes |
| 1816 | * complete. All operations operate on sock_map using cmpxchg and xchg |
| 1817 | * operations to ensure we do not get stale references. Any reads into the |
| 1818 | * map must be done with READ_ONCE() because of this. |
| 1819 | * |
| 1820 | * A psock is destroyed via call_rcu and after any worker threads are cancelled |
| 1821 | * and syncd so we are certain all references from the update/lookup/delete |
| 1822 | * operations as well as references in the data path are no longer in use. |
| 1823 | * |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1824 | * Psocks may exist in multiple maps, but only a single set of parse/verdict |
| 1825 | * programs may be inherited from the maps it belongs to. A reference count |
| 1826 | * is kept with the total number of references to the psock from all maps. The |
| 1827 | * psock will not be released until this reaches zero. The psock and sock |
| 1828 | * user data data use the sk_callback_lock to protect critical data structures |
| 1829 | * from concurrent access. This allows us to avoid two updates from modifying |
| 1830 | * the user data in sock and the lock is required anyways for modifying |
| 1831 | * callbacks, we simply increase its scope slightly. |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1832 | * |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1833 | * Rules to follow, |
| 1834 | * - psock must always be read inside RCU critical section |
| 1835 | * - sk_user_data must only be modified inside sk_callback_lock and read |
| 1836 | * inside RCU critical section. |
| 1837 | * - psock->maps list must only be read & modified inside sk_callback_lock |
| 1838 | * - sock_map must use READ_ONCE and (cmp)xchg operations |
| 1839 | * - BPF verdict/parse programs must use READ_ONCE and xchg operations |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1840 | */ |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1841 | |
| 1842 | static int __sock_map_ctx_update_elem(struct bpf_map *map, |
| 1843 | struct bpf_sock_progs *progs, |
| 1844 | struct sock *sock, |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1845 | void *key) |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1846 | { |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1847 | struct bpf_prog *verdict, *parse, *tx_msg; |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1848 | struct smap_psock *psock; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1849 | bool new = false; |
Gustavo A. R. Silva | 0e43645 | 2018-05-17 09:08:43 -0500 | [diff] [blame] | 1850 | int err = 0; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1851 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1852 | /* 1. If sock map has BPF programs those will be inherited by the |
| 1853 | * sock being added. If the sock is already attached to BPF programs |
| 1854 | * this results in an error. |
| 1855 | */ |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1856 | verdict = READ_ONCE(progs->bpf_verdict); |
| 1857 | parse = READ_ONCE(progs->bpf_parse); |
| 1858 | tx_msg = READ_ONCE(progs->bpf_tx_msg); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1859 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1860 | if (parse && verdict) { |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1861 | /* bpf prog refcnt may be zero if a concurrent attach operation |
| 1862 | * removes the program after the above READ_ONCE() but before |
| 1863 | * we increment the refcnt. If this is the case abort with an |
| 1864 | * error. |
| 1865 | */ |
John Fastabend | 9617456 | 2018-05-17 14:06:40 -0700 | [diff] [blame] | 1866 | verdict = bpf_prog_inc_not_zero(verdict); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1867 | if (IS_ERR(verdict)) |
| 1868 | return PTR_ERR(verdict); |
| 1869 | |
John Fastabend | 9617456 | 2018-05-17 14:06:40 -0700 | [diff] [blame] | 1870 | parse = bpf_prog_inc_not_zero(parse); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1871 | if (IS_ERR(parse)) { |
| 1872 | bpf_prog_put(verdict); |
| 1873 | return PTR_ERR(parse); |
| 1874 | } |
| 1875 | } |
| 1876 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1877 | if (tx_msg) { |
John Fastabend | 9617456 | 2018-05-17 14:06:40 -0700 | [diff] [blame] | 1878 | tx_msg = bpf_prog_inc_not_zero(tx_msg); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1879 | if (IS_ERR(tx_msg)) { |
John Fastabend | a593f70 | 2018-05-17 14:06:35 -0700 | [diff] [blame] | 1880 | if (parse && verdict) { |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1881 | bpf_prog_put(parse); |
John Fastabend | a593f70 | 2018-05-17 14:06:35 -0700 | [diff] [blame] | 1882 | bpf_prog_put(verdict); |
| 1883 | } |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1884 | return PTR_ERR(tx_msg); |
| 1885 | } |
| 1886 | } |
| 1887 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1888 | psock = smap_psock_sk(sock); |
| 1889 | |
| 1890 | /* 2. Do not allow inheriting programs if psock exists and has |
| 1891 | * already inherited programs. This would create confusion on |
| 1892 | * which parser/verdict program is running. If no psock exists |
| 1893 | * create one. Inside sk_callback_lock to ensure concurrent create |
| 1894 | * doesn't update user data. |
| 1895 | */ |
| 1896 | if (psock) { |
| 1897 | if (READ_ONCE(psock->bpf_parse) && parse) { |
| 1898 | err = -EBUSY; |
| 1899 | goto out_progs; |
| 1900 | } |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1901 | if (READ_ONCE(psock->bpf_tx_msg) && tx_msg) { |
| 1902 | err = -EBUSY; |
| 1903 | goto out_progs; |
| 1904 | } |
| 1905 | if (!refcount_inc_not_zero(&psock->refcnt)) { |
| 1906 | err = -EAGAIN; |
| 1907 | goto out_progs; |
| 1908 | } |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1909 | } else { |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1910 | psock = smap_init_psock(sock, map->numa_node); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1911 | if (IS_ERR(psock)) { |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1912 | err = PTR_ERR(psock); |
| 1913 | goto out_progs; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1914 | } |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1915 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1916 | set_bit(SMAP_TX_RUNNING, &psock->state); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1917 | new = true; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1918 | } |
| 1919 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1920 | /* 3. At this point we have a reference to a valid psock that is |
| 1921 | * running. Attach any BPF programs needed. |
| 1922 | */ |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1923 | if (tx_msg) |
| 1924 | bpf_tcp_msg_add(psock, sock, tx_msg); |
| 1925 | if (new) { |
| 1926 | err = tcp_set_ulp_id(sock, TCP_ULP_BPF); |
| 1927 | if (err) |
| 1928 | goto out_free; |
| 1929 | } |
| 1930 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1931 | if (parse && verdict && !psock->strp_enabled) { |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1932 | err = smap_init_sock(psock, sock); |
| 1933 | if (err) |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1934 | goto out_free; |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1935 | smap_init_progs(psock, verdict, parse); |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 1936 | write_lock_bh(&sock->sk_callback_lock); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1937 | smap_start_sock(psock, sock); |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 1938 | write_unlock_bh(&sock->sk_callback_lock); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1939 | } |
| 1940 | |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1941 | return err; |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1942 | out_free: |
| 1943 | smap_release_sock(psock, sock); |
| 1944 | out_progs: |
John Fastabend | a593f70 | 2018-05-17 14:06:35 -0700 | [diff] [blame] | 1945 | if (parse && verdict) { |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1946 | bpf_prog_put(parse); |
John Fastabend | a593f70 | 2018-05-17 14:06:35 -0700 | [diff] [blame] | 1947 | bpf_prog_put(verdict); |
| 1948 | } |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1949 | if (tx_msg) |
| 1950 | bpf_prog_put(tx_msg); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1951 | return err; |
| 1952 | } |
| 1953 | |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1954 | static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, |
| 1955 | struct bpf_map *map, |
| 1956 | void *key, u64 flags) |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1957 | { |
| 1958 | struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1959 | struct bpf_sock_progs *progs = &stab->progs; |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 1960 | struct sock *osock, *sock = skops->sk; |
| 1961 | struct smap_psock_map_entry *e; |
| 1962 | struct smap_psock *psock; |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1963 | u32 i = *(u32 *)key; |
| 1964 | int err; |
| 1965 | |
| 1966 | if (unlikely(flags > BPF_EXIST)) |
| 1967 | return -EINVAL; |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1968 | if (unlikely(i >= stab->map.max_entries)) |
| 1969 | return -E2BIG; |
| 1970 | |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 1971 | e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN); |
| 1972 | if (!e) |
| 1973 | return -ENOMEM; |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1974 | |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 1975 | err = __sock_map_ctx_update_elem(map, progs, sock, key); |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1976 | if (err) |
| 1977 | goto out; |
| 1978 | |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 1979 | /* psock guaranteed to be present. */ |
| 1980 | psock = smap_psock_sk(sock); |
| 1981 | raw_spin_lock_bh(&stab->lock); |
| 1982 | osock = stab->sock_map[i]; |
| 1983 | if (osock && flags == BPF_NOEXIST) { |
| 1984 | err = -EEXIST; |
| 1985 | goto out_unlock; |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1986 | } |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 1987 | if (!osock && flags == BPF_EXIST) { |
| 1988 | err = -ENOENT; |
| 1989 | goto out_unlock; |
| 1990 | } |
| 1991 | |
| 1992 | e->entry = &stab->sock_map[i]; |
| 1993 | e->map = map; |
| 1994 | spin_lock_bh(&psock->maps_lock); |
| 1995 | list_add_tail(&e->list, &psock->maps); |
| 1996 | spin_unlock_bh(&psock->maps_lock); |
| 1997 | |
| 1998 | stab->sock_map[i] = sock; |
| 1999 | if (osock) { |
| 2000 | psock = smap_psock_sk(osock); |
| 2001 | smap_list_map_remove(psock, &stab->sock_map[i]); |
| 2002 | smap_release_sock(psock, osock); |
| 2003 | } |
| 2004 | raw_spin_unlock_bh(&stab->lock); |
| 2005 | return 0; |
| 2006 | out_unlock: |
| 2007 | smap_release_sock(psock, sock); |
| 2008 | raw_spin_unlock_bh(&stab->lock); |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 2009 | out: |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 2010 | kfree(e); |
John Fastabend | e23afe5 | 2018-05-16 16:38:14 -0700 | [diff] [blame] | 2011 | return err; |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 2012 | } |
| 2013 | |
| 2014 | int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type) |
| 2015 | { |
| 2016 | struct bpf_sock_progs *progs; |
John Fastabend | 464bc0f | 2017-08-28 07:10:04 -0700 | [diff] [blame] | 2017 | struct bpf_prog *orig; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 2018 | |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 2019 | if (map->map_type == BPF_MAP_TYPE_SOCKMAP) { |
| 2020 | struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
| 2021 | |
| 2022 | progs = &stab->progs; |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2023 | } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH) { |
| 2024 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| 2025 | |
| 2026 | progs = &htab->progs; |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 2027 | } else { |
John Fastabend | 81374aa | 2017-08-28 07:11:43 -0700 | [diff] [blame] | 2028 | return -EINVAL; |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 2029 | } |
John Fastabend | 81374aa | 2017-08-28 07:11:43 -0700 | [diff] [blame] | 2030 | |
John Fastabend | 464bc0f | 2017-08-28 07:10:04 -0700 | [diff] [blame] | 2031 | switch (type) { |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 2032 | case BPF_SK_MSG_VERDICT: |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 2033 | orig = xchg(&progs->bpf_tx_msg, prog); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 2034 | break; |
John Fastabend | 464bc0f | 2017-08-28 07:10:04 -0700 | [diff] [blame] | 2035 | case BPF_SK_SKB_STREAM_PARSER: |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 2036 | orig = xchg(&progs->bpf_parse, prog); |
John Fastabend | 464bc0f | 2017-08-28 07:10:04 -0700 | [diff] [blame] | 2037 | break; |
| 2038 | case BPF_SK_SKB_STREAM_VERDICT: |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 2039 | orig = xchg(&progs->bpf_verdict, prog); |
John Fastabend | 464bc0f | 2017-08-28 07:10:04 -0700 | [diff] [blame] | 2040 | break; |
| 2041 | default: |
| 2042 | return -EOPNOTSUPP; |
| 2043 | } |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 2044 | |
John Fastabend | 464bc0f | 2017-08-28 07:10:04 -0700 | [diff] [blame] | 2045 | if (orig) |
| 2046 | bpf_prog_put(orig); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 2047 | |
| 2048 | return 0; |
| 2049 | } |
| 2050 | |
Sean Young | fdb5c45 | 2018-06-19 00:04:24 +0100 | [diff] [blame] | 2051 | int sockmap_get_from_fd(const union bpf_attr *attr, int type, |
| 2052 | struct bpf_prog *prog) |
| 2053 | { |
| 2054 | int ufd = attr->target_fd; |
| 2055 | struct bpf_map *map; |
| 2056 | struct fd f; |
| 2057 | int err; |
| 2058 | |
| 2059 | f = fdget(ufd); |
| 2060 | map = __bpf_map_get(f); |
| 2061 | if (IS_ERR(map)) |
| 2062 | return PTR_ERR(map); |
| 2063 | |
| 2064 | err = sock_map_prog(map, prog, attr->attach_type); |
| 2065 | fdput(f); |
| 2066 | return err; |
| 2067 | } |
| 2068 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 2069 | static void *sock_map_lookup(struct bpf_map *map, void *key) |
| 2070 | { |
| 2071 | return NULL; |
| 2072 | } |
| 2073 | |
| 2074 | static int sock_map_update_elem(struct bpf_map *map, |
| 2075 | void *key, void *value, u64 flags) |
| 2076 | { |
| 2077 | struct bpf_sock_ops_kern skops; |
| 2078 | u32 fd = *(u32 *)value; |
| 2079 | struct socket *socket; |
| 2080 | int err; |
| 2081 | |
| 2082 | socket = sockfd_lookup(fd, &err); |
| 2083 | if (!socket) |
| 2084 | return err; |
| 2085 | |
| 2086 | skops.sk = socket->sk; |
| 2087 | if (!skops.sk) { |
| 2088 | fput(socket->file); |
| 2089 | return -EINVAL; |
| 2090 | } |
| 2091 | |
John Fastabend | 435bf0d | 2017-10-18 07:10:15 -0700 | [diff] [blame] | 2092 | if (skops.sk->sk_type != SOCK_STREAM || |
| 2093 | skops.sk->sk_protocol != IPPROTO_TCP) { |
| 2094 | fput(socket->file); |
| 2095 | return -EOPNOTSUPP; |
| 2096 | } |
| 2097 | |
John Fastabend | 99ba2b5 | 2018-07-05 08:50:04 -0700 | [diff] [blame] | 2098 | lock_sock(skops.sk); |
| 2099 | preempt_disable(); |
| 2100 | rcu_read_lock(); |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 2101 | err = sock_map_ctx_update_elem(&skops, map, key, flags); |
John Fastabend | 99ba2b5 | 2018-07-05 08:50:04 -0700 | [diff] [blame] | 2102 | rcu_read_unlock(); |
| 2103 | preempt_enable(); |
| 2104 | release_sock(skops.sk); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 2105 | fput(socket->file); |
| 2106 | return err; |
| 2107 | } |
| 2108 | |
John Fastabend | ba6b8de | 2018-04-23 15:39:23 -0700 | [diff] [blame] | 2109 | static void sock_map_release(struct bpf_map *map) |
John Fastabend | 3d9e952 | 2018-02-05 10:17:54 -0800 | [diff] [blame] | 2110 | { |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 2111 | struct bpf_sock_progs *progs; |
John Fastabend | 3d9e952 | 2018-02-05 10:17:54 -0800 | [diff] [blame] | 2112 | struct bpf_prog *orig; |
| 2113 | |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2114 | if (map->map_type == BPF_MAP_TYPE_SOCKMAP) { |
| 2115 | struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
| 2116 | |
| 2117 | progs = &stab->progs; |
| 2118 | } else { |
| 2119 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| 2120 | |
| 2121 | progs = &htab->progs; |
| 2122 | } |
| 2123 | |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 2124 | orig = xchg(&progs->bpf_parse, NULL); |
John Fastabend | 3d9e952 | 2018-02-05 10:17:54 -0800 | [diff] [blame] | 2125 | if (orig) |
| 2126 | bpf_prog_put(orig); |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 2127 | orig = xchg(&progs->bpf_verdict, NULL); |
John Fastabend | 3d9e952 | 2018-02-05 10:17:54 -0800 | [diff] [blame] | 2128 | if (orig) |
| 2129 | bpf_prog_put(orig); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 2130 | |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 2131 | orig = xchg(&progs->bpf_tx_msg, NULL); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 2132 | if (orig) |
| 2133 | bpf_prog_put(orig); |
John Fastabend | 3d9e952 | 2018-02-05 10:17:54 -0800 | [diff] [blame] | 2134 | } |
| 2135 | |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2136 | static struct bpf_map *sock_hash_alloc(union bpf_attr *attr) |
| 2137 | { |
| 2138 | struct bpf_htab *htab; |
| 2139 | int i, err; |
| 2140 | u64 cost; |
| 2141 | |
| 2142 | if (!capable(CAP_NET_ADMIN)) |
| 2143 | return ERR_PTR(-EPERM); |
| 2144 | |
| 2145 | /* check sanity of attributes */ |
Daniel Borkmann | b845c89 | 2018-08-21 15:55:00 +0200 | [diff] [blame] | 2146 | if (attr->max_entries == 0 || |
| 2147 | attr->key_size == 0 || |
| 2148 | attr->value_size != 4 || |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2149 | attr->map_flags & ~SOCK_CREATE_FLAG_MASK) |
| 2150 | return ERR_PTR(-EINVAL); |
| 2151 | |
Yonghong Song | 683d2ac | 2018-05-16 14:06:26 -0700 | [diff] [blame] | 2152 | if (attr->key_size > MAX_BPF_STACK) |
| 2153 | /* eBPF programs initialize keys on stack, so they cannot be |
| 2154 | * larger than max stack size |
| 2155 | */ |
| 2156 | return ERR_PTR(-E2BIG); |
| 2157 | |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2158 | err = bpf_tcp_ulp_register(); |
| 2159 | if (err && err != -EEXIST) |
| 2160 | return ERR_PTR(err); |
| 2161 | |
| 2162 | htab = kzalloc(sizeof(*htab), GFP_USER); |
| 2163 | if (!htab) |
| 2164 | return ERR_PTR(-ENOMEM); |
| 2165 | |
| 2166 | bpf_map_init_from_attr(&htab->map, attr); |
| 2167 | |
| 2168 | htab->n_buckets = roundup_pow_of_two(htab->map.max_entries); |
| 2169 | htab->elem_size = sizeof(struct htab_elem) + |
| 2170 | round_up(htab->map.key_size, 8); |
| 2171 | err = -EINVAL; |
| 2172 | if (htab->n_buckets == 0 || |
| 2173 | htab->n_buckets > U32_MAX / sizeof(struct bucket)) |
| 2174 | goto free_htab; |
| 2175 | |
| 2176 | cost = (u64) htab->n_buckets * sizeof(struct bucket) + |
| 2177 | (u64) htab->elem_size * htab->map.max_entries; |
| 2178 | |
| 2179 | if (cost >= U32_MAX - PAGE_SIZE) |
| 2180 | goto free_htab; |
| 2181 | |
| 2182 | htab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT; |
| 2183 | err = bpf_map_precharge_memlock(htab->map.pages); |
| 2184 | if (err) |
| 2185 | goto free_htab; |
| 2186 | |
| 2187 | err = -ENOMEM; |
| 2188 | htab->buckets = bpf_map_area_alloc( |
| 2189 | htab->n_buckets * sizeof(struct bucket), |
| 2190 | htab->map.numa_node); |
| 2191 | if (!htab->buckets) |
| 2192 | goto free_htab; |
| 2193 | |
| 2194 | for (i = 0; i < htab->n_buckets; i++) { |
| 2195 | INIT_HLIST_HEAD(&htab->buckets[i].head); |
| 2196 | raw_spin_lock_init(&htab->buckets[i].lock); |
| 2197 | } |
| 2198 | |
| 2199 | return &htab->map; |
| 2200 | free_htab: |
| 2201 | kfree(htab); |
| 2202 | return ERR_PTR(err); |
| 2203 | } |
| 2204 | |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 2205 | static void __bpf_htab_free(struct rcu_head *rcu) |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2206 | { |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 2207 | struct bpf_htab *htab; |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2208 | |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 2209 | htab = container_of(rcu, struct bpf_htab, rcu); |
| 2210 | bpf_map_area_free(htab->buckets); |
| 2211 | kfree(htab); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2212 | } |
| 2213 | |
| 2214 | static void sock_hash_free(struct bpf_map *map) |
| 2215 | { |
| 2216 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| 2217 | int i; |
| 2218 | |
| 2219 | synchronize_rcu(); |
| 2220 | |
| 2221 | /* At this point no update, lookup or delete operations can happen. |
| 2222 | * However, be aware we can still get a socket state event updates, |
| 2223 | * and data ready callabacks that reference the psock from sk_user_data |
| 2224 | * Also psock worker threads are still in-flight. So smap_release_sock |
| 2225 | * will only free the psock after cancel_sync on the worker threads |
| 2226 | * and a grace period expire to ensure psock is really safe to remove. |
| 2227 | */ |
| 2228 | rcu_read_lock(); |
| 2229 | for (i = 0; i < htab->n_buckets; i++) { |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 2230 | struct bucket *b = __select_bucket(htab, i); |
| 2231 | struct hlist_head *head; |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2232 | struct hlist_node *n; |
| 2233 | struct htab_elem *l; |
| 2234 | |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 2235 | raw_spin_lock_bh(&b->lock); |
| 2236 | head = &b->head; |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2237 | hlist_for_each_entry_safe(l, n, head, hash_node) { |
| 2238 | struct sock *sock = l->sk; |
| 2239 | struct smap_psock *psock; |
| 2240 | |
| 2241 | hlist_del_rcu(&l->hash_node); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2242 | psock = smap_psock_sk(sock); |
| 2243 | /* This check handles a racing sock event that can get |
| 2244 | * the sk_callback_lock before this case but after xchg |
| 2245 | * causing the refcnt to hit zero and sock user data |
| 2246 | * (psock) to be null and queued for garbage collection. |
| 2247 | */ |
| 2248 | if (likely(psock)) { |
John Fastabend | 54fedb4 | 2018-06-30 06:17:41 -0700 | [diff] [blame] | 2249 | smap_list_hash_remove(psock, l); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2250 | smap_release_sock(psock, sock); |
| 2251 | } |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 2252 | free_htab_elem(htab, l); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2253 | } |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 2254 | raw_spin_unlock_bh(&b->lock); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2255 | } |
| 2256 | rcu_read_unlock(); |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 2257 | call_rcu(&htab->rcu, __bpf_htab_free); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2258 | } |
| 2259 | |
| 2260 | static struct htab_elem *alloc_sock_hash_elem(struct bpf_htab *htab, |
| 2261 | void *key, u32 key_size, u32 hash, |
| 2262 | struct sock *sk, |
| 2263 | struct htab_elem *old_elem) |
| 2264 | { |
| 2265 | struct htab_elem *l_new; |
| 2266 | |
| 2267 | if (atomic_inc_return(&htab->count) > htab->map.max_entries) { |
| 2268 | if (!old_elem) { |
| 2269 | atomic_dec(&htab->count); |
| 2270 | return ERR_PTR(-E2BIG); |
| 2271 | } |
| 2272 | } |
| 2273 | l_new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN, |
| 2274 | htab->map.numa_node); |
Daniel Borkmann | eb29429 | 2018-08-22 18:09:17 +0200 | [diff] [blame] | 2275 | if (!l_new) { |
| 2276 | atomic_dec(&htab->count); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2277 | return ERR_PTR(-ENOMEM); |
Daniel Borkmann | eb29429 | 2018-08-22 18:09:17 +0200 | [diff] [blame] | 2278 | } |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2279 | |
| 2280 | memcpy(l_new->key, key, key_size); |
| 2281 | l_new->sk = sk; |
| 2282 | l_new->hash = hash; |
| 2283 | return l_new; |
| 2284 | } |
| 2285 | |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2286 | static inline u32 htab_map_hash(const void *key, u32 key_len) |
| 2287 | { |
| 2288 | return jhash(key, key_len, 0); |
| 2289 | } |
| 2290 | |
| 2291 | static int sock_hash_get_next_key(struct bpf_map *map, |
| 2292 | void *key, void *next_key) |
| 2293 | { |
| 2294 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| 2295 | struct htab_elem *l, *next_l; |
| 2296 | struct hlist_head *h; |
| 2297 | u32 hash, key_size; |
| 2298 | int i = 0; |
| 2299 | |
| 2300 | WARN_ON_ONCE(!rcu_read_lock_held()); |
| 2301 | |
| 2302 | key_size = map->key_size; |
| 2303 | if (!key) |
| 2304 | goto find_first_elem; |
| 2305 | hash = htab_map_hash(key, key_size); |
| 2306 | h = select_bucket(htab, hash); |
| 2307 | |
| 2308 | l = lookup_elem_raw(h, hash, key, key_size); |
| 2309 | if (!l) |
| 2310 | goto find_first_elem; |
| 2311 | next_l = hlist_entry_safe( |
| 2312 | rcu_dereference_raw(hlist_next_rcu(&l->hash_node)), |
| 2313 | struct htab_elem, hash_node); |
| 2314 | if (next_l) { |
| 2315 | memcpy(next_key, next_l->key, key_size); |
| 2316 | return 0; |
| 2317 | } |
| 2318 | |
| 2319 | /* no more elements in this hash list, go to the next bucket */ |
| 2320 | i = hash & (htab->n_buckets - 1); |
| 2321 | i++; |
| 2322 | |
| 2323 | find_first_elem: |
| 2324 | /* iterate over buckets */ |
| 2325 | for (; i < htab->n_buckets; i++) { |
| 2326 | h = select_bucket(htab, i); |
| 2327 | |
| 2328 | /* pick first element in the bucket */ |
| 2329 | next_l = hlist_entry_safe( |
| 2330 | rcu_dereference_raw(hlist_first_rcu(h)), |
| 2331 | struct htab_elem, hash_node); |
| 2332 | if (next_l) { |
| 2333 | /* if it's not empty, just return it */ |
| 2334 | memcpy(next_key, next_l->key, key_size); |
| 2335 | return 0; |
| 2336 | } |
| 2337 | } |
| 2338 | |
| 2339 | /* iterated over all buckets and all elements */ |
| 2340 | return -ENOENT; |
| 2341 | } |
| 2342 | |
| 2343 | static int sock_hash_ctx_update_elem(struct bpf_sock_ops_kern *skops, |
| 2344 | struct bpf_map *map, |
| 2345 | void *key, u64 map_flags) |
| 2346 | { |
| 2347 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| 2348 | struct bpf_sock_progs *progs = &htab->progs; |
| 2349 | struct htab_elem *l_new = NULL, *l_old; |
| 2350 | struct smap_psock_map_entry *e = NULL; |
| 2351 | struct hlist_head *head; |
| 2352 | struct smap_psock *psock; |
| 2353 | u32 key_size, hash; |
| 2354 | struct sock *sock; |
| 2355 | struct bucket *b; |
| 2356 | int err; |
| 2357 | |
| 2358 | sock = skops->sk; |
| 2359 | |
| 2360 | if (sock->sk_type != SOCK_STREAM || |
| 2361 | sock->sk_protocol != IPPROTO_TCP) |
| 2362 | return -EOPNOTSUPP; |
| 2363 | |
| 2364 | if (unlikely(map_flags > BPF_EXIST)) |
| 2365 | return -EINVAL; |
| 2366 | |
| 2367 | e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN); |
| 2368 | if (!e) |
| 2369 | return -ENOMEM; |
| 2370 | |
| 2371 | WARN_ON_ONCE(!rcu_read_lock_held()); |
| 2372 | key_size = map->key_size; |
| 2373 | hash = htab_map_hash(key, key_size); |
| 2374 | b = __select_bucket(htab, hash); |
| 2375 | head = &b->head; |
| 2376 | |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 2377 | err = __sock_map_ctx_update_elem(map, progs, sock, key); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2378 | if (err) |
| 2379 | goto err; |
| 2380 | |
John Fastabend | 547b3aa | 2018-07-05 08:05:56 -0700 | [diff] [blame] | 2381 | /* psock is valid here because otherwise above *ctx_update_elem would |
| 2382 | * have thrown an error. It is safe to skip error check. |
| 2383 | */ |
| 2384 | psock = smap_psock_sk(sock); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2385 | raw_spin_lock_bh(&b->lock); |
| 2386 | l_old = lookup_elem_raw(head, hash, key, key_size); |
| 2387 | if (l_old && map_flags == BPF_NOEXIST) { |
| 2388 | err = -EEXIST; |
| 2389 | goto bucket_err; |
| 2390 | } |
| 2391 | if (!l_old && map_flags == BPF_EXIST) { |
| 2392 | err = -ENOENT; |
| 2393 | goto bucket_err; |
| 2394 | } |
| 2395 | |
| 2396 | l_new = alloc_sock_hash_elem(htab, key, key_size, hash, sock, l_old); |
| 2397 | if (IS_ERR(l_new)) { |
| 2398 | err = PTR_ERR(l_new); |
| 2399 | goto bucket_err; |
| 2400 | } |
| 2401 | |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 2402 | rcu_assign_pointer(e->hash_link, l_new); |
Daniel Borkmann | 585f5a6 | 2018-08-16 21:49:10 +0200 | [diff] [blame] | 2403 | e->map = map; |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 2404 | spin_lock_bh(&psock->maps_lock); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2405 | list_add_tail(&e->list, &psock->maps); |
John Fastabend | e9db4ef | 2018-06-30 06:17:47 -0700 | [diff] [blame] | 2406 | spin_unlock_bh(&psock->maps_lock); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2407 | |
| 2408 | /* add new element to the head of the list, so that |
| 2409 | * concurrent search will find it before old elem |
| 2410 | */ |
| 2411 | hlist_add_head_rcu(&l_new->hash_node, head); |
| 2412 | if (l_old) { |
| 2413 | psock = smap_psock_sk(l_old->sk); |
| 2414 | |
| 2415 | hlist_del_rcu(&l_old->hash_node); |
John Fastabend | 54fedb4 | 2018-06-30 06:17:41 -0700 | [diff] [blame] | 2416 | smap_list_hash_remove(psock, l_old); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2417 | smap_release_sock(psock, l_old->sk); |
| 2418 | free_htab_elem(htab, l_old); |
| 2419 | } |
| 2420 | raw_spin_unlock_bh(&b->lock); |
| 2421 | return 0; |
| 2422 | bucket_err: |
John Fastabend | 547b3aa | 2018-07-05 08:05:56 -0700 | [diff] [blame] | 2423 | smap_release_sock(psock, sock); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2424 | raw_spin_unlock_bh(&b->lock); |
| 2425 | err: |
| 2426 | kfree(e); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2427 | return err; |
| 2428 | } |
| 2429 | |
| 2430 | static int sock_hash_update_elem(struct bpf_map *map, |
| 2431 | void *key, void *value, u64 flags) |
| 2432 | { |
| 2433 | struct bpf_sock_ops_kern skops; |
| 2434 | u32 fd = *(u32 *)value; |
| 2435 | struct socket *socket; |
| 2436 | int err; |
| 2437 | |
| 2438 | socket = sockfd_lookup(fd, &err); |
| 2439 | if (!socket) |
| 2440 | return err; |
| 2441 | |
| 2442 | skops.sk = socket->sk; |
| 2443 | if (!skops.sk) { |
| 2444 | fput(socket->file); |
| 2445 | return -EINVAL; |
| 2446 | } |
| 2447 | |
John Fastabend | 99ba2b5 | 2018-07-05 08:50:04 -0700 | [diff] [blame] | 2448 | lock_sock(skops.sk); |
| 2449 | preempt_disable(); |
| 2450 | rcu_read_lock(); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2451 | err = sock_hash_ctx_update_elem(&skops, map, key, flags); |
John Fastabend | 99ba2b5 | 2018-07-05 08:50:04 -0700 | [diff] [blame] | 2452 | rcu_read_unlock(); |
| 2453 | preempt_enable(); |
| 2454 | release_sock(skops.sk); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2455 | fput(socket->file); |
| 2456 | return err; |
| 2457 | } |
| 2458 | |
| 2459 | static int sock_hash_delete_elem(struct bpf_map *map, void *key) |
| 2460 | { |
| 2461 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| 2462 | struct hlist_head *head; |
| 2463 | struct bucket *b; |
| 2464 | struct htab_elem *l; |
| 2465 | u32 hash, key_size; |
| 2466 | int ret = -ENOENT; |
| 2467 | |
| 2468 | key_size = map->key_size; |
| 2469 | hash = htab_map_hash(key, key_size); |
| 2470 | b = __select_bucket(htab, hash); |
| 2471 | head = &b->head; |
| 2472 | |
| 2473 | raw_spin_lock_bh(&b->lock); |
| 2474 | l = lookup_elem_raw(head, hash, key, key_size); |
| 2475 | if (l) { |
| 2476 | struct sock *sock = l->sk; |
| 2477 | struct smap_psock *psock; |
| 2478 | |
| 2479 | hlist_del_rcu(&l->hash_node); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2480 | psock = smap_psock_sk(sock); |
| 2481 | /* This check handles a racing sock event that can get the |
| 2482 | * sk_callback_lock before this case but after xchg happens |
| 2483 | * causing the refcnt to hit zero and sock user data (psock) |
| 2484 | * to be null and queued for garbage collection. |
| 2485 | */ |
| 2486 | if (likely(psock)) { |
John Fastabend | 54fedb4 | 2018-06-30 06:17:41 -0700 | [diff] [blame] | 2487 | smap_list_hash_remove(psock, l); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2488 | smap_release_sock(psock, sock); |
| 2489 | } |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2490 | free_htab_elem(htab, l); |
| 2491 | ret = 0; |
| 2492 | } |
| 2493 | raw_spin_unlock_bh(&b->lock); |
| 2494 | return ret; |
| 2495 | } |
| 2496 | |
| 2497 | struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key) |
| 2498 | { |
| 2499 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| 2500 | struct hlist_head *head; |
| 2501 | struct htab_elem *l; |
| 2502 | u32 key_size, hash; |
| 2503 | struct bucket *b; |
| 2504 | struct sock *sk; |
| 2505 | |
| 2506 | key_size = map->key_size; |
| 2507 | hash = htab_map_hash(key, key_size); |
| 2508 | b = __select_bucket(htab, hash); |
| 2509 | head = &b->head; |
| 2510 | |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2511 | l = lookup_elem_raw(head, hash, key, key_size); |
| 2512 | sk = l ? l->sk : NULL; |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2513 | return sk; |
| 2514 | } |
| 2515 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 2516 | const struct bpf_map_ops sock_map_ops = { |
| 2517 | .map_alloc = sock_map_alloc, |
| 2518 | .map_free = sock_map_free, |
| 2519 | .map_lookup_elem = sock_map_lookup, |
| 2520 | .map_get_next_key = sock_map_get_next_key, |
| 2521 | .map_update_elem = sock_map_update_elem, |
| 2522 | .map_delete_elem = sock_map_delete_elem, |
John Fastabend | ba6b8de | 2018-04-23 15:39:23 -0700 | [diff] [blame] | 2523 | .map_release_uref = sock_map_release, |
Daniel Borkmann | e8d2bec | 2018-08-12 01:59:17 +0200 | [diff] [blame] | 2524 | .map_check_btf = map_check_no_btf, |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 2525 | }; |
| 2526 | |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2527 | const struct bpf_map_ops sock_hash_ops = { |
| 2528 | .map_alloc = sock_hash_alloc, |
| 2529 | .map_free = sock_hash_free, |
| 2530 | .map_lookup_elem = sock_map_lookup, |
| 2531 | .map_get_next_key = sock_hash_get_next_key, |
| 2532 | .map_update_elem = sock_hash_update_elem, |
| 2533 | .map_delete_elem = sock_hash_delete_elem, |
John Fastabend | caac76a | 2018-06-30 06:17:52 -0700 | [diff] [blame] | 2534 | .map_release_uref = sock_map_release, |
Daniel Borkmann | e8d2bec | 2018-08-12 01:59:17 +0200 | [diff] [blame] | 2535 | .map_check_btf = map_check_no_btf, |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2536 | }; |
| 2537 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 2538 | BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, bpf_sock, |
| 2539 | struct bpf_map *, map, void *, key, u64, flags) |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 2540 | { |
| 2541 | WARN_ON_ONCE(!rcu_read_lock_held()); |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 2542 | return sock_map_ctx_update_elem(bpf_sock, map, key, flags); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 2543 | } |
| 2544 | |
| 2545 | const struct bpf_func_proto bpf_sock_map_update_proto = { |
| 2546 | .func = bpf_sock_map_update, |
| 2547 | .gpl_only = false, |
| 2548 | .pkt_access = true, |
| 2549 | .ret_type = RET_INTEGER, |
| 2550 | .arg1_type = ARG_PTR_TO_CTX, |
| 2551 | .arg2_type = ARG_CONST_MAP_PTR, |
| 2552 | .arg3_type = ARG_PTR_TO_MAP_KEY, |
| 2553 | .arg4_type = ARG_ANYTHING, |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 2554 | }; |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2555 | |
| 2556 | BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, bpf_sock, |
| 2557 | struct bpf_map *, map, void *, key, u64, flags) |
| 2558 | { |
| 2559 | WARN_ON_ONCE(!rcu_read_lock_held()); |
| 2560 | return sock_hash_ctx_update_elem(bpf_sock, map, key, flags); |
| 2561 | } |
| 2562 | |
| 2563 | const struct bpf_func_proto bpf_sock_hash_update_proto = { |
| 2564 | .func = bpf_sock_hash_update, |
| 2565 | .gpl_only = false, |
| 2566 | .pkt_access = true, |
| 2567 | .ret_type = RET_INTEGER, |
| 2568 | .arg1_type = ARG_PTR_TO_CTX, |
| 2569 | .arg2_type = ARG_CONST_MAP_PTR, |
| 2570 | .arg3_type = ARG_PTR_TO_MAP_KEY, |
| 2571 | .arg4_type = ARG_ANYTHING, |
| 2572 | }; |