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; |
| 61 | }; |
| 62 | |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 63 | struct bucket { |
| 64 | struct hlist_head head; |
| 65 | raw_spinlock_t lock; |
| 66 | }; |
| 67 | |
| 68 | struct bpf_htab { |
| 69 | struct bpf_map map; |
| 70 | struct bucket *buckets; |
| 71 | atomic_t count; |
| 72 | u32 n_buckets; |
| 73 | u32 elem_size; |
| 74 | struct bpf_sock_progs progs; |
| 75 | }; |
| 76 | |
| 77 | struct htab_elem { |
| 78 | struct rcu_head rcu; |
| 79 | struct hlist_node hash_node; |
| 80 | u32 hash; |
| 81 | struct sock *sk; |
| 82 | char key[0]; |
| 83 | }; |
| 84 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 85 | enum smap_psock_state { |
| 86 | SMAP_TX_RUNNING, |
| 87 | }; |
| 88 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 89 | struct smap_psock_map_entry { |
| 90 | struct list_head list; |
| 91 | struct sock **entry; |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 92 | struct htab_elem *hash_link; |
| 93 | struct bpf_htab *htab; |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 94 | }; |
| 95 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 96 | struct smap_psock { |
| 97 | struct rcu_head rcu; |
John Fastabend | ffa3566 | 2018-03-18 12:56:54 -0700 | [diff] [blame] | 98 | refcount_t refcnt; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 99 | |
| 100 | /* datapath variables */ |
| 101 | struct sk_buff_head rxqueue; |
| 102 | bool strp_enabled; |
| 103 | |
| 104 | /* datapath error path cache across tx work invocations */ |
| 105 | int save_rem; |
| 106 | int save_off; |
| 107 | struct sk_buff *save_skb; |
| 108 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 109 | /* datapath variables for tx_msg ULP */ |
| 110 | struct sock *sk_redir; |
| 111 | int apply_bytes; |
| 112 | int cork_bytes; |
| 113 | int sg_size; |
| 114 | int eval; |
| 115 | struct sk_msg_buff *cork; |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 116 | struct list_head ingress; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 117 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 118 | struct strparser strp; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 119 | struct bpf_prog *bpf_tx_msg; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 120 | struct bpf_prog *bpf_parse; |
| 121 | struct bpf_prog *bpf_verdict; |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 122 | struct list_head maps; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 123 | |
| 124 | /* Back reference used when sock callback trigger sockmap operations */ |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 125 | struct sock *sock; |
| 126 | unsigned long state; |
| 127 | |
| 128 | struct work_struct tx_work; |
| 129 | struct work_struct gc_work; |
| 130 | |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 131 | struct proto *sk_proto; |
| 132 | void (*save_close)(struct sock *sk, long timeout); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 133 | void (*save_data_ready)(struct sock *sk); |
| 134 | void (*save_write_space)(struct sock *sk); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 135 | }; |
| 136 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 137 | static void smap_release_sock(struct smap_psock *psock, struct sock *sock); |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 138 | static int bpf_tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
| 139 | int nonblock, int flags, int *addr_len); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 140 | static int bpf_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); |
| 141 | static int bpf_tcp_sendpage(struct sock *sk, struct page *page, |
| 142 | int offset, size_t size, int flags); |
| 143 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 144 | static inline struct smap_psock *smap_psock_sk(const struct sock *sk) |
| 145 | { |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 146 | return rcu_dereference_sk_user_data(sk); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 147 | } |
| 148 | |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 149 | static bool bpf_tcp_stream_read(const struct sock *sk) |
| 150 | { |
| 151 | struct smap_psock *psock; |
| 152 | bool empty = true; |
| 153 | |
| 154 | rcu_read_lock(); |
| 155 | psock = smap_psock_sk(sk); |
| 156 | if (unlikely(!psock)) |
| 157 | goto out; |
| 158 | empty = list_empty(&psock->ingress); |
| 159 | out: |
| 160 | rcu_read_unlock(); |
| 161 | return !empty; |
| 162 | } |
| 163 | |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 164 | static struct proto tcp_bpf_proto; |
| 165 | static int bpf_tcp_init(struct sock *sk) |
| 166 | { |
| 167 | struct smap_psock *psock; |
| 168 | |
| 169 | rcu_read_lock(); |
| 170 | psock = smap_psock_sk(sk); |
| 171 | if (unlikely(!psock)) { |
| 172 | rcu_read_unlock(); |
| 173 | return -EINVAL; |
| 174 | } |
| 175 | |
| 176 | if (unlikely(psock->sk_proto)) { |
| 177 | rcu_read_unlock(); |
| 178 | return -EBUSY; |
| 179 | } |
| 180 | |
| 181 | psock->save_close = sk->sk_prot->close; |
| 182 | psock->sk_proto = sk->sk_prot; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 183 | |
| 184 | if (psock->bpf_tx_msg) { |
| 185 | tcp_bpf_proto.sendmsg = bpf_tcp_sendmsg; |
| 186 | tcp_bpf_proto.sendpage = bpf_tcp_sendpage; |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 187 | tcp_bpf_proto.recvmsg = bpf_tcp_recvmsg; |
| 188 | tcp_bpf_proto.stream_memory_read = bpf_tcp_stream_read; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 189 | } |
| 190 | |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 191 | sk->sk_prot = &tcp_bpf_proto; |
| 192 | rcu_read_unlock(); |
| 193 | return 0; |
| 194 | } |
| 195 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 196 | static void smap_release_sock(struct smap_psock *psock, struct sock *sock); |
| 197 | static int free_start_sg(struct sock *sk, struct sk_msg_buff *md); |
| 198 | |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 199 | static void bpf_tcp_release(struct sock *sk) |
| 200 | { |
| 201 | struct smap_psock *psock; |
| 202 | |
| 203 | rcu_read_lock(); |
| 204 | psock = smap_psock_sk(sk); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 205 | if (unlikely(!psock)) |
| 206 | goto out; |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 207 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 208 | if (psock->cork) { |
| 209 | free_start_sg(psock->sock, psock->cork); |
| 210 | kfree(psock->cork); |
| 211 | psock->cork = NULL; |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 212 | } |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 213 | |
John Fastabend | 0e94d87 | 2018-04-02 12:50:52 -0700 | [diff] [blame] | 214 | if (psock->sk_proto) { |
| 215 | sk->sk_prot = psock->sk_proto; |
| 216 | psock->sk_proto = NULL; |
| 217 | } |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 218 | out: |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 219 | rcu_read_unlock(); |
| 220 | } |
| 221 | |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 222 | static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l) |
| 223 | { |
| 224 | atomic_dec(&htab->count); |
| 225 | kfree_rcu(l, rcu); |
| 226 | } |
| 227 | |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 228 | static void bpf_tcp_close(struct sock *sk, long timeout) |
| 229 | { |
| 230 | void (*close_fun)(struct sock *sk, long timeout); |
| 231 | struct smap_psock_map_entry *e, *tmp; |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 232 | struct sk_msg_buff *md, *mtmp; |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 233 | struct smap_psock *psock; |
| 234 | struct sock *osk; |
| 235 | |
| 236 | rcu_read_lock(); |
| 237 | psock = smap_psock_sk(sk); |
| 238 | if (unlikely(!psock)) { |
| 239 | rcu_read_unlock(); |
| 240 | return sk->sk_prot->close(sk, timeout); |
| 241 | } |
| 242 | |
| 243 | /* The psock may be destroyed anytime after exiting the RCU critial |
| 244 | * section so by the time we use close_fun the psock may no longer |
| 245 | * be valid. However, bpf_tcp_close is called with the sock lock |
| 246 | * held so the close hook and sk are still valid. |
| 247 | */ |
| 248 | close_fun = psock->save_close; |
| 249 | |
| 250 | write_lock_bh(&sk->sk_callback_lock); |
John Fastabend | 820ed3f | 2018-04-02 12:50:46 -0700 | [diff] [blame] | 251 | if (psock->cork) { |
| 252 | free_start_sg(psock->sock, psock->cork); |
| 253 | kfree(psock->cork); |
| 254 | psock->cork = NULL; |
| 255 | } |
| 256 | |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 257 | list_for_each_entry_safe(md, mtmp, &psock->ingress, list) { |
| 258 | list_del(&md->list); |
| 259 | free_start_sg(psock->sock, md); |
| 260 | kfree(md); |
| 261 | } |
| 262 | |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 263 | list_for_each_entry_safe(e, tmp, &psock->maps, list) { |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 264 | if (e->entry) { |
| 265 | osk = cmpxchg(e->entry, sk, NULL); |
| 266 | if (osk == sk) { |
| 267 | list_del(&e->list); |
| 268 | smap_release_sock(psock, sk); |
| 269 | } |
| 270 | } else { |
| 271 | hlist_del_rcu(&e->hash_link->hash_node); |
| 272 | smap_release_sock(psock, e->hash_link->sk); |
| 273 | free_htab_elem(e->htab, e->hash_link); |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 274 | } |
| 275 | } |
| 276 | write_unlock_bh(&sk->sk_callback_lock); |
| 277 | rcu_read_unlock(); |
| 278 | close_fun(sk, timeout); |
| 279 | } |
| 280 | |
John Fastabend | 04686ef | 2017-10-31 19:17:31 -0700 | [diff] [blame] | 281 | enum __sk_action { |
| 282 | __SK_DROP = 0, |
| 283 | __SK_PASS, |
| 284 | __SK_REDIRECT, |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 285 | __SK_NONE, |
John Fastabend | 04686ef | 2017-10-31 19:17:31 -0700 | [diff] [blame] | 286 | }; |
| 287 | |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 288 | static struct tcp_ulp_ops bpf_tcp_ulp_ops __read_mostly = { |
| 289 | .name = "bpf_tcp", |
| 290 | .uid = TCP_ULP_BPF, |
| 291 | .user_visible = false, |
| 292 | .owner = NULL, |
| 293 | .init = bpf_tcp_init, |
| 294 | .release = bpf_tcp_release, |
| 295 | }; |
| 296 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 297 | static int memcopy_from_iter(struct sock *sk, |
| 298 | struct sk_msg_buff *md, |
| 299 | struct iov_iter *from, int bytes) |
| 300 | { |
| 301 | struct scatterlist *sg = md->sg_data; |
| 302 | int i = md->sg_curr, rc = -ENOSPC; |
| 303 | |
| 304 | do { |
| 305 | int copy; |
| 306 | char *to; |
| 307 | |
| 308 | if (md->sg_copybreak >= sg[i].length) { |
| 309 | md->sg_copybreak = 0; |
| 310 | |
| 311 | if (++i == MAX_SKB_FRAGS) |
| 312 | i = 0; |
| 313 | |
| 314 | if (i == md->sg_end) |
| 315 | break; |
| 316 | } |
| 317 | |
| 318 | copy = sg[i].length - md->sg_copybreak; |
| 319 | to = sg_virt(&sg[i]) + md->sg_copybreak; |
| 320 | md->sg_copybreak += copy; |
| 321 | |
| 322 | if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) |
| 323 | rc = copy_from_iter_nocache(to, copy, from); |
| 324 | else |
| 325 | rc = copy_from_iter(to, copy, from); |
| 326 | |
| 327 | if (rc != copy) { |
| 328 | rc = -EFAULT; |
| 329 | goto out; |
| 330 | } |
| 331 | |
| 332 | bytes -= copy; |
| 333 | if (!bytes) |
| 334 | break; |
| 335 | |
| 336 | md->sg_copybreak = 0; |
| 337 | if (++i == MAX_SKB_FRAGS) |
| 338 | i = 0; |
| 339 | } while (i != md->sg_end); |
| 340 | out: |
| 341 | md->sg_curr = i; |
| 342 | return rc; |
| 343 | } |
| 344 | |
| 345 | static int bpf_tcp_push(struct sock *sk, int apply_bytes, |
| 346 | struct sk_msg_buff *md, |
| 347 | int flags, bool uncharge) |
| 348 | { |
| 349 | bool apply = apply_bytes; |
| 350 | struct scatterlist *sg; |
| 351 | int offset, ret = 0; |
| 352 | struct page *p; |
| 353 | size_t size; |
| 354 | |
| 355 | while (1) { |
| 356 | sg = md->sg_data + md->sg_start; |
| 357 | size = (apply && apply_bytes < sg->length) ? |
| 358 | apply_bytes : sg->length; |
| 359 | offset = sg->offset; |
| 360 | |
| 361 | tcp_rate_check_app_limited(sk); |
| 362 | p = sg_page(sg); |
| 363 | retry: |
| 364 | ret = do_tcp_sendpages(sk, p, offset, size, flags); |
| 365 | if (ret != size) { |
| 366 | if (ret > 0) { |
| 367 | if (apply) |
| 368 | apply_bytes -= ret; |
John Fastabend | 3cc9a47 | 2018-05-02 13:50:19 -0700 | [diff] [blame] | 369 | |
| 370 | sg->offset += ret; |
| 371 | sg->length -= ret; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 372 | size -= ret; |
| 373 | offset += ret; |
| 374 | if (uncharge) |
| 375 | sk_mem_uncharge(sk, ret); |
| 376 | goto retry; |
| 377 | } |
| 378 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 379 | return ret; |
| 380 | } |
| 381 | |
| 382 | if (apply) |
| 383 | apply_bytes -= ret; |
| 384 | sg->offset += ret; |
| 385 | sg->length -= ret; |
| 386 | if (uncharge) |
| 387 | sk_mem_uncharge(sk, ret); |
| 388 | |
| 389 | if (!sg->length) { |
| 390 | put_page(p); |
| 391 | md->sg_start++; |
| 392 | if (md->sg_start == MAX_SKB_FRAGS) |
| 393 | md->sg_start = 0; |
Prashant Bhole | 6ef6d84 | 2018-03-30 09:21:00 +0900 | [diff] [blame] | 394 | sg_init_table(sg, 1); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 395 | |
| 396 | if (md->sg_start == md->sg_end) |
| 397 | break; |
| 398 | } |
| 399 | |
| 400 | if (apply && !apply_bytes) |
| 401 | break; |
| 402 | } |
| 403 | return 0; |
| 404 | } |
| 405 | |
| 406 | static inline void bpf_compute_data_pointers_sg(struct sk_msg_buff *md) |
| 407 | { |
| 408 | struct scatterlist *sg = md->sg_data + md->sg_start; |
| 409 | |
| 410 | if (md->sg_copy[md->sg_start]) { |
| 411 | md->data = md->data_end = 0; |
| 412 | } else { |
| 413 | md->data = sg_virt(sg); |
| 414 | md->data_end = md->data + sg->length; |
| 415 | } |
| 416 | } |
| 417 | |
| 418 | static void return_mem_sg(struct sock *sk, int bytes, struct sk_msg_buff *md) |
| 419 | { |
| 420 | struct scatterlist *sg = md->sg_data; |
| 421 | int i = md->sg_start; |
| 422 | |
| 423 | do { |
| 424 | int uncharge = (bytes < sg[i].length) ? bytes : sg[i].length; |
| 425 | |
| 426 | sk_mem_uncharge(sk, uncharge); |
| 427 | bytes -= uncharge; |
| 428 | if (!bytes) |
| 429 | break; |
| 430 | i++; |
| 431 | if (i == MAX_SKB_FRAGS) |
| 432 | i = 0; |
| 433 | } while (i != md->sg_end); |
| 434 | } |
| 435 | |
John Fastabend | abaeb09 | 2018-05-02 13:50:29 -0700 | [diff] [blame] | 436 | static void free_bytes_sg(struct sock *sk, int bytes, |
| 437 | struct sk_msg_buff *md, bool charge) |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 438 | { |
| 439 | struct scatterlist *sg = md->sg_data; |
| 440 | int i = md->sg_start, free; |
| 441 | |
| 442 | while (bytes && sg[i].length) { |
| 443 | free = sg[i].length; |
| 444 | if (bytes < free) { |
| 445 | sg[i].length -= bytes; |
| 446 | sg[i].offset += bytes; |
John Fastabend | abaeb09 | 2018-05-02 13:50:29 -0700 | [diff] [blame] | 447 | if (charge) |
| 448 | sk_mem_uncharge(sk, bytes); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 449 | break; |
| 450 | } |
| 451 | |
John Fastabend | abaeb09 | 2018-05-02 13:50:29 -0700 | [diff] [blame] | 452 | if (charge) |
| 453 | sk_mem_uncharge(sk, sg[i].length); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 454 | put_page(sg_page(&sg[i])); |
| 455 | bytes -= sg[i].length; |
| 456 | sg[i].length = 0; |
| 457 | sg[i].page_link = 0; |
| 458 | sg[i].offset = 0; |
| 459 | i++; |
| 460 | |
| 461 | if (i == MAX_SKB_FRAGS) |
| 462 | i = 0; |
| 463 | } |
John Fastabend | abaeb09 | 2018-05-02 13:50:29 -0700 | [diff] [blame] | 464 | md->sg_start = i; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 465 | } |
| 466 | |
| 467 | static int free_sg(struct sock *sk, int start, struct sk_msg_buff *md) |
| 468 | { |
| 469 | struct scatterlist *sg = md->sg_data; |
| 470 | int i = start, free = 0; |
| 471 | |
| 472 | while (sg[i].length) { |
| 473 | free += sg[i].length; |
| 474 | sk_mem_uncharge(sk, sg[i].length); |
| 475 | put_page(sg_page(&sg[i])); |
| 476 | sg[i].length = 0; |
| 477 | sg[i].page_link = 0; |
| 478 | sg[i].offset = 0; |
| 479 | i++; |
| 480 | |
| 481 | if (i == MAX_SKB_FRAGS) |
| 482 | i = 0; |
| 483 | } |
| 484 | |
| 485 | return free; |
| 486 | } |
| 487 | |
| 488 | static int free_start_sg(struct sock *sk, struct sk_msg_buff *md) |
| 489 | { |
| 490 | int free = free_sg(sk, md->sg_start, md); |
| 491 | |
| 492 | md->sg_start = md->sg_end; |
| 493 | return free; |
| 494 | } |
| 495 | |
| 496 | static int free_curr_sg(struct sock *sk, struct sk_msg_buff *md) |
| 497 | { |
| 498 | return free_sg(sk, md->sg_curr, md); |
| 499 | } |
| 500 | |
| 501 | static int bpf_map_msg_verdict(int _rc, struct sk_msg_buff *md) |
| 502 | { |
| 503 | return ((_rc == SK_PASS) ? |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 504 | (md->sk_redir ? __SK_REDIRECT : __SK_PASS) : |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 505 | __SK_DROP); |
| 506 | } |
| 507 | |
| 508 | static unsigned int smap_do_tx_msg(struct sock *sk, |
| 509 | struct smap_psock *psock, |
| 510 | struct sk_msg_buff *md) |
| 511 | { |
| 512 | struct bpf_prog *prog; |
| 513 | unsigned int rc, _rc; |
| 514 | |
| 515 | preempt_disable(); |
| 516 | rcu_read_lock(); |
| 517 | |
| 518 | /* If the policy was removed mid-send then default to 'accept' */ |
| 519 | prog = READ_ONCE(psock->bpf_tx_msg); |
| 520 | if (unlikely(!prog)) { |
| 521 | _rc = SK_PASS; |
| 522 | goto verdict; |
| 523 | } |
| 524 | |
| 525 | bpf_compute_data_pointers_sg(md); |
John Fastabend | 303def3 | 2018-05-17 14:16:58 -0700 | [diff] [blame] | 526 | md->sk = sk; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 527 | rc = (*prog->bpf_func)(md, prog->insnsi); |
| 528 | psock->apply_bytes = md->apply_bytes; |
| 529 | |
| 530 | /* Moving return codes from UAPI namespace into internal namespace */ |
| 531 | _rc = bpf_map_msg_verdict(rc, md); |
| 532 | |
| 533 | /* The psock has a refcount on the sock but not on the map and because |
| 534 | * we need to drop rcu read lock here its possible the map could be |
| 535 | * removed between here and when we need it to execute the sock |
| 536 | * redirect. So do the map lookup now for future use. |
| 537 | */ |
| 538 | if (_rc == __SK_REDIRECT) { |
| 539 | if (psock->sk_redir) |
| 540 | sock_put(psock->sk_redir); |
| 541 | psock->sk_redir = do_msg_redirect_map(md); |
| 542 | if (!psock->sk_redir) { |
| 543 | _rc = __SK_DROP; |
| 544 | goto verdict; |
| 545 | } |
| 546 | sock_hold(psock->sk_redir); |
| 547 | } |
| 548 | verdict: |
| 549 | rcu_read_unlock(); |
| 550 | preempt_enable(); |
| 551 | |
| 552 | return _rc; |
| 553 | } |
| 554 | |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 555 | static int bpf_tcp_ingress(struct sock *sk, int apply_bytes, |
| 556 | struct smap_psock *psock, |
| 557 | struct sk_msg_buff *md, int flags) |
| 558 | { |
| 559 | bool apply = apply_bytes; |
| 560 | size_t size, copied = 0; |
| 561 | struct sk_msg_buff *r; |
| 562 | int err = 0, i; |
| 563 | |
| 564 | r = kzalloc(sizeof(struct sk_msg_buff), __GFP_NOWARN | GFP_KERNEL); |
| 565 | if (unlikely(!r)) |
| 566 | return -ENOMEM; |
| 567 | |
| 568 | lock_sock(sk); |
| 569 | r->sg_start = md->sg_start; |
| 570 | i = md->sg_start; |
| 571 | |
| 572 | do { |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 573 | size = (apply && apply_bytes < md->sg_data[i].length) ? |
| 574 | apply_bytes : md->sg_data[i].length; |
| 575 | |
| 576 | if (!sk_wmem_schedule(sk, size)) { |
| 577 | if (!copied) |
| 578 | err = -ENOMEM; |
| 579 | break; |
| 580 | } |
| 581 | |
| 582 | sk_mem_charge(sk, size); |
John Fastabend | 4fcfdfb | 2018-04-23 15:39:33 -0700 | [diff] [blame] | 583 | r->sg_data[i] = md->sg_data[i]; |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 584 | r->sg_data[i].length = size; |
| 585 | md->sg_data[i].length -= size; |
| 586 | md->sg_data[i].offset += size; |
| 587 | copied += size; |
| 588 | |
| 589 | if (md->sg_data[i].length) { |
| 590 | get_page(sg_page(&r->sg_data[i])); |
| 591 | r->sg_end = (i + 1) == MAX_SKB_FRAGS ? 0 : i + 1; |
| 592 | } else { |
| 593 | i++; |
| 594 | if (i == MAX_SKB_FRAGS) |
| 595 | i = 0; |
| 596 | r->sg_end = i; |
| 597 | } |
| 598 | |
| 599 | if (apply) { |
| 600 | apply_bytes -= size; |
| 601 | if (!apply_bytes) |
| 602 | break; |
| 603 | } |
| 604 | } while (i != md->sg_end); |
| 605 | |
| 606 | md->sg_start = i; |
| 607 | |
| 608 | if (!err) { |
| 609 | list_add_tail(&r->list, &psock->ingress); |
| 610 | sk->sk_data_ready(sk); |
| 611 | } else { |
| 612 | free_start_sg(sk, r); |
| 613 | kfree(r); |
| 614 | } |
| 615 | |
| 616 | release_sock(sk); |
| 617 | return err; |
| 618 | } |
| 619 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 620 | static int bpf_tcp_sendmsg_do_redirect(struct sock *sk, int send, |
| 621 | struct sk_msg_buff *md, |
| 622 | int flags) |
| 623 | { |
John Fastabend | abaeb09 | 2018-05-02 13:50:29 -0700 | [diff] [blame] | 624 | bool ingress = !!(md->flags & BPF_F_INGRESS); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 625 | struct smap_psock *psock; |
| 626 | struct scatterlist *sg; |
John Fastabend | abaeb09 | 2018-05-02 13:50:29 -0700 | [diff] [blame] | 627 | int err = 0; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 628 | |
| 629 | sg = md->sg_data; |
| 630 | |
| 631 | rcu_read_lock(); |
| 632 | psock = smap_psock_sk(sk); |
| 633 | if (unlikely(!psock)) |
| 634 | goto out_rcu; |
| 635 | |
| 636 | if (!refcount_inc_not_zero(&psock->refcnt)) |
| 637 | goto out_rcu; |
| 638 | |
| 639 | rcu_read_unlock(); |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 640 | |
| 641 | if (ingress) { |
| 642 | err = bpf_tcp_ingress(sk, send, psock, md, flags); |
| 643 | } else { |
| 644 | lock_sock(sk); |
| 645 | err = bpf_tcp_push(sk, send, md, flags, false); |
| 646 | release_sock(sk); |
| 647 | } |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 648 | smap_release_sock(psock, sk); |
| 649 | if (unlikely(err)) |
| 650 | goto out; |
| 651 | return 0; |
| 652 | out_rcu: |
| 653 | rcu_read_unlock(); |
| 654 | out: |
John Fastabend | abaeb09 | 2018-05-02 13:50:29 -0700 | [diff] [blame] | 655 | free_bytes_sg(NULL, send, md, false); |
| 656 | return err; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 657 | } |
| 658 | |
| 659 | static inline void bpf_md_init(struct smap_psock *psock) |
| 660 | { |
| 661 | if (!psock->apply_bytes) { |
| 662 | psock->eval = __SK_NONE; |
| 663 | if (psock->sk_redir) { |
| 664 | sock_put(psock->sk_redir); |
| 665 | psock->sk_redir = NULL; |
| 666 | } |
| 667 | } |
| 668 | } |
| 669 | |
| 670 | static void apply_bytes_dec(struct smap_psock *psock, int i) |
| 671 | { |
| 672 | if (psock->apply_bytes) { |
| 673 | if (psock->apply_bytes < i) |
| 674 | psock->apply_bytes = 0; |
| 675 | else |
| 676 | psock->apply_bytes -= i; |
| 677 | } |
| 678 | } |
| 679 | |
| 680 | static int bpf_exec_tx_verdict(struct smap_psock *psock, |
| 681 | struct sk_msg_buff *m, |
| 682 | struct sock *sk, |
| 683 | int *copied, int flags) |
| 684 | { |
| 685 | bool cork = false, enospc = (m->sg_start == m->sg_end); |
| 686 | struct sock *redir; |
| 687 | int err = 0; |
| 688 | int send; |
| 689 | |
| 690 | more_data: |
| 691 | if (psock->eval == __SK_NONE) |
| 692 | psock->eval = smap_do_tx_msg(sk, psock, m); |
| 693 | |
| 694 | if (m->cork_bytes && |
| 695 | m->cork_bytes > psock->sg_size && !enospc) { |
| 696 | psock->cork_bytes = m->cork_bytes - psock->sg_size; |
| 697 | if (!psock->cork) { |
| 698 | psock->cork = kcalloc(1, |
| 699 | sizeof(struct sk_msg_buff), |
| 700 | GFP_ATOMIC | __GFP_NOWARN); |
| 701 | |
| 702 | if (!psock->cork) { |
| 703 | err = -ENOMEM; |
| 704 | goto out_err; |
| 705 | } |
| 706 | } |
| 707 | memcpy(psock->cork, m, sizeof(*m)); |
| 708 | goto out_err; |
| 709 | } |
| 710 | |
| 711 | send = psock->sg_size; |
| 712 | if (psock->apply_bytes && psock->apply_bytes < send) |
| 713 | send = psock->apply_bytes; |
| 714 | |
| 715 | switch (psock->eval) { |
| 716 | case __SK_PASS: |
| 717 | err = bpf_tcp_push(sk, send, m, flags, true); |
| 718 | if (unlikely(err)) { |
| 719 | *copied -= free_start_sg(sk, m); |
| 720 | break; |
| 721 | } |
| 722 | |
| 723 | apply_bytes_dec(psock, send); |
| 724 | psock->sg_size -= send; |
| 725 | break; |
| 726 | case __SK_REDIRECT: |
| 727 | redir = psock->sk_redir; |
| 728 | apply_bytes_dec(psock, send); |
| 729 | |
| 730 | if (psock->cork) { |
| 731 | cork = true; |
| 732 | psock->cork = NULL; |
| 733 | } |
| 734 | |
| 735 | return_mem_sg(sk, send, m); |
| 736 | release_sock(sk); |
| 737 | |
| 738 | err = bpf_tcp_sendmsg_do_redirect(redir, send, m, flags); |
| 739 | lock_sock(sk); |
| 740 | |
John Fastabend | fec51d4 | 2018-05-02 13:50:24 -0700 | [diff] [blame] | 741 | if (unlikely(err < 0)) { |
| 742 | free_start_sg(sk, m); |
| 743 | psock->sg_size = 0; |
| 744 | if (!cork) |
| 745 | *copied -= send; |
| 746 | } else { |
| 747 | psock->sg_size -= send; |
| 748 | } |
| 749 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 750 | if (cork) { |
| 751 | free_start_sg(sk, m); |
John Fastabend | fec51d4 | 2018-05-02 13:50:24 -0700 | [diff] [blame] | 752 | psock->sg_size = 0; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 753 | kfree(m); |
| 754 | m = NULL; |
John Fastabend | fec51d4 | 2018-05-02 13:50:24 -0700 | [diff] [blame] | 755 | err = 0; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 756 | } |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 757 | break; |
| 758 | case __SK_DROP: |
| 759 | default: |
John Fastabend | abaeb09 | 2018-05-02 13:50:29 -0700 | [diff] [blame] | 760 | free_bytes_sg(sk, send, m, true); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 761 | apply_bytes_dec(psock, send); |
| 762 | *copied -= send; |
| 763 | psock->sg_size -= send; |
| 764 | err = -EACCES; |
| 765 | break; |
| 766 | } |
| 767 | |
| 768 | if (likely(!err)) { |
| 769 | bpf_md_init(psock); |
| 770 | if (m && |
| 771 | m->sg_data[m->sg_start].page_link && |
| 772 | m->sg_data[m->sg_start].length) |
| 773 | goto more_data; |
| 774 | } |
| 775 | |
| 776 | out_err: |
| 777 | return err; |
| 778 | } |
| 779 | |
John Fastabend | e20f733 | 2018-04-23 15:39:28 -0700 | [diff] [blame] | 780 | static int bpf_wait_data(struct sock *sk, |
| 781 | struct smap_psock *psk, int flags, |
| 782 | long timeo, int *err) |
| 783 | { |
| 784 | int rc; |
| 785 | |
| 786 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
| 787 | |
| 788 | add_wait_queue(sk_sleep(sk), &wait); |
| 789 | sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); |
| 790 | rc = sk_wait_event(sk, &timeo, |
| 791 | !list_empty(&psk->ingress) || |
| 792 | !skb_queue_empty(&sk->sk_receive_queue), |
| 793 | &wait); |
| 794 | sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); |
| 795 | remove_wait_queue(sk_sleep(sk), &wait); |
| 796 | |
| 797 | return rc; |
| 798 | } |
| 799 | |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 800 | static int bpf_tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
| 801 | int nonblock, int flags, int *addr_len) |
| 802 | { |
| 803 | struct iov_iter *iter = &msg->msg_iter; |
| 804 | struct smap_psock *psock; |
| 805 | int copied = 0; |
| 806 | |
| 807 | if (unlikely(flags & MSG_ERRQUEUE)) |
| 808 | return inet_recv_error(sk, msg, len, addr_len); |
| 809 | |
| 810 | rcu_read_lock(); |
| 811 | psock = smap_psock_sk(sk); |
| 812 | if (unlikely(!psock)) |
| 813 | goto out; |
| 814 | |
| 815 | if (unlikely(!refcount_inc_not_zero(&psock->refcnt))) |
| 816 | goto out; |
| 817 | rcu_read_unlock(); |
| 818 | |
| 819 | if (!skb_queue_empty(&sk->sk_receive_queue)) |
| 820 | return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len); |
| 821 | |
| 822 | lock_sock(sk); |
John Fastabend | e20f733 | 2018-04-23 15:39:28 -0700 | [diff] [blame] | 823 | bytes_ready: |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 824 | while (copied != len) { |
| 825 | struct scatterlist *sg; |
| 826 | struct sk_msg_buff *md; |
| 827 | int i; |
| 828 | |
| 829 | md = list_first_entry_or_null(&psock->ingress, |
| 830 | struct sk_msg_buff, list); |
| 831 | if (unlikely(!md)) |
| 832 | break; |
| 833 | i = md->sg_start; |
| 834 | do { |
| 835 | struct page *page; |
| 836 | int n, copy; |
| 837 | |
| 838 | sg = &md->sg_data[i]; |
| 839 | copy = sg->length; |
| 840 | page = sg_page(sg); |
| 841 | |
| 842 | if (copied + copy > len) |
| 843 | copy = len - copied; |
| 844 | |
| 845 | n = copy_page_to_iter(page, sg->offset, copy, iter); |
| 846 | if (n != copy) { |
| 847 | md->sg_start = i; |
| 848 | release_sock(sk); |
| 849 | smap_release_sock(psock, sk); |
| 850 | return -EFAULT; |
| 851 | } |
| 852 | |
| 853 | copied += copy; |
| 854 | sg->offset += copy; |
| 855 | sg->length -= copy; |
| 856 | sk_mem_uncharge(sk, copy); |
| 857 | |
| 858 | if (!sg->length) { |
| 859 | i++; |
| 860 | if (i == MAX_SKB_FRAGS) |
| 861 | i = 0; |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 862 | if (!md->skb) |
| 863 | put_page(page); |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 864 | } |
| 865 | if (copied == len) |
| 866 | break; |
| 867 | } while (i != md->sg_end); |
| 868 | md->sg_start = i; |
| 869 | |
| 870 | if (!sg->length && md->sg_start == md->sg_end) { |
| 871 | list_del(&md->list); |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 872 | if (md->skb) |
| 873 | consume_skb(md->skb); |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 874 | kfree(md); |
| 875 | } |
| 876 | } |
| 877 | |
John Fastabend | e20f733 | 2018-04-23 15:39:28 -0700 | [diff] [blame] | 878 | if (!copied) { |
| 879 | long timeo; |
| 880 | int data; |
| 881 | int err = 0; |
| 882 | |
| 883 | timeo = sock_rcvtimeo(sk, nonblock); |
| 884 | data = bpf_wait_data(sk, psock, flags, timeo, &err); |
| 885 | |
| 886 | if (data) { |
| 887 | if (!skb_queue_empty(&sk->sk_receive_queue)) { |
| 888 | release_sock(sk); |
| 889 | smap_release_sock(psock, sk); |
| 890 | copied = tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len); |
| 891 | return copied; |
| 892 | } |
| 893 | goto bytes_ready; |
| 894 | } |
| 895 | |
| 896 | if (err) |
| 897 | copied = err; |
| 898 | } |
| 899 | |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 900 | release_sock(sk); |
| 901 | smap_release_sock(psock, sk); |
| 902 | return copied; |
| 903 | out: |
| 904 | rcu_read_unlock(); |
| 905 | return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len); |
| 906 | } |
| 907 | |
| 908 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 909 | static int bpf_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) |
| 910 | { |
| 911 | int flags = msg->msg_flags | MSG_NO_SHARED_FRAGS; |
| 912 | struct sk_msg_buff md = {0}; |
| 913 | unsigned int sg_copy = 0; |
| 914 | struct smap_psock *psock; |
| 915 | int copied = 0, err = 0; |
| 916 | struct scatterlist *sg; |
| 917 | long timeo; |
| 918 | |
| 919 | /* Its possible a sock event or user removed the psock _but_ the ops |
| 920 | * have not been reprogrammed yet so we get here. In this case fallback |
| 921 | * to tcp_sendmsg. Note this only works because we _only_ ever allow |
| 922 | * a single ULP there is no hierarchy here. |
| 923 | */ |
| 924 | rcu_read_lock(); |
| 925 | psock = smap_psock_sk(sk); |
| 926 | if (unlikely(!psock)) { |
| 927 | rcu_read_unlock(); |
| 928 | return tcp_sendmsg(sk, msg, size); |
| 929 | } |
| 930 | |
| 931 | /* Increment the psock refcnt to ensure its not released while sending a |
| 932 | * message. Required because sk lookup and bpf programs are used in |
| 933 | * separate rcu critical sections. Its OK if we lose the map entry |
| 934 | * but we can't lose the sock reference. |
| 935 | */ |
| 936 | if (!refcount_inc_not_zero(&psock->refcnt)) { |
| 937 | rcu_read_unlock(); |
| 938 | return tcp_sendmsg(sk, msg, size); |
| 939 | } |
| 940 | |
| 941 | sg = md.sg_data; |
Prashant Bhole | 6ef6d84 | 2018-03-30 09:21:00 +0900 | [diff] [blame] | 942 | sg_init_marker(sg, MAX_SKB_FRAGS); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 943 | rcu_read_unlock(); |
| 944 | |
| 945 | lock_sock(sk); |
| 946 | timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); |
| 947 | |
| 948 | while (msg_data_left(msg)) { |
| 949 | struct sk_msg_buff *m; |
| 950 | bool enospc = false; |
| 951 | int copy; |
| 952 | |
| 953 | if (sk->sk_err) { |
| 954 | err = sk->sk_err; |
| 955 | goto out_err; |
| 956 | } |
| 957 | |
| 958 | copy = msg_data_left(msg); |
| 959 | if (!sk_stream_memory_free(sk)) |
| 960 | goto wait_for_sndbuf; |
| 961 | |
| 962 | m = psock->cork_bytes ? psock->cork : &md; |
| 963 | m->sg_curr = m->sg_copybreak ? m->sg_curr : m->sg_end; |
| 964 | err = sk_alloc_sg(sk, copy, m->sg_data, |
| 965 | m->sg_start, &m->sg_end, &sg_copy, |
| 966 | m->sg_end - 1); |
| 967 | if (err) { |
| 968 | if (err != -ENOSPC) |
| 969 | goto wait_for_memory; |
| 970 | enospc = true; |
| 971 | copy = sg_copy; |
| 972 | } |
| 973 | |
| 974 | err = memcopy_from_iter(sk, m, &msg->msg_iter, copy); |
| 975 | if (err < 0) { |
| 976 | free_curr_sg(sk, m); |
| 977 | goto out_err; |
| 978 | } |
| 979 | |
| 980 | psock->sg_size += copy; |
| 981 | copied += copy; |
| 982 | sg_copy = 0; |
| 983 | |
| 984 | /* When bytes are being corked skip running BPF program and |
| 985 | * applying verdict unless there is no more buffer space. In |
| 986 | * the ENOSPC case simply run BPF prorgram with currently |
| 987 | * accumulated data. We don't have much choice at this point |
| 988 | * we could try extending the page frags or chaining complex |
| 989 | * frags but even in these cases _eventually_ we will hit an |
| 990 | * OOM scenario. More complex recovery schemes may be |
| 991 | * implemented in the future, but BPF programs must handle |
| 992 | * the case where apply_cork requests are not honored. The |
| 993 | * canonical method to verify this is to check data length. |
| 994 | */ |
| 995 | if (psock->cork_bytes) { |
| 996 | if (copy > psock->cork_bytes) |
| 997 | psock->cork_bytes = 0; |
| 998 | else |
| 999 | psock->cork_bytes -= copy; |
| 1000 | |
| 1001 | if (psock->cork_bytes && !enospc) |
| 1002 | goto out_cork; |
| 1003 | |
| 1004 | /* All cork bytes accounted for re-run filter */ |
| 1005 | psock->eval = __SK_NONE; |
| 1006 | psock->cork_bytes = 0; |
| 1007 | } |
| 1008 | |
| 1009 | err = bpf_exec_tx_verdict(psock, m, sk, &copied, flags); |
| 1010 | if (unlikely(err < 0)) |
| 1011 | goto out_err; |
| 1012 | continue; |
| 1013 | wait_for_sndbuf: |
| 1014 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); |
| 1015 | wait_for_memory: |
| 1016 | err = sk_stream_wait_memory(sk, &timeo); |
| 1017 | if (err) |
| 1018 | goto out_err; |
| 1019 | } |
| 1020 | out_err: |
| 1021 | if (err < 0) |
| 1022 | err = sk_stream_error(sk, msg->msg_flags, err); |
| 1023 | out_cork: |
| 1024 | release_sock(sk); |
| 1025 | smap_release_sock(psock, sk); |
| 1026 | return copied ? copied : err; |
| 1027 | } |
| 1028 | |
| 1029 | static int bpf_tcp_sendpage(struct sock *sk, struct page *page, |
| 1030 | int offset, size_t size, int flags) |
| 1031 | { |
| 1032 | struct sk_msg_buff md = {0}, *m = NULL; |
| 1033 | int err = 0, copied = 0; |
| 1034 | struct smap_psock *psock; |
| 1035 | struct scatterlist *sg; |
| 1036 | bool enospc = false; |
| 1037 | |
| 1038 | rcu_read_lock(); |
| 1039 | psock = smap_psock_sk(sk); |
| 1040 | if (unlikely(!psock)) |
| 1041 | goto accept; |
| 1042 | |
| 1043 | if (!refcount_inc_not_zero(&psock->refcnt)) |
| 1044 | goto accept; |
| 1045 | rcu_read_unlock(); |
| 1046 | |
| 1047 | lock_sock(sk); |
| 1048 | |
Prashant Bhole | 6ef6d84 | 2018-03-30 09:21:00 +0900 | [diff] [blame] | 1049 | if (psock->cork_bytes) { |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1050 | m = psock->cork; |
Prashant Bhole | 6ef6d84 | 2018-03-30 09:21:00 +0900 | [diff] [blame] | 1051 | sg = &m->sg_data[m->sg_end]; |
| 1052 | } else { |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1053 | m = &md; |
Prashant Bhole | 6ef6d84 | 2018-03-30 09:21:00 +0900 | [diff] [blame] | 1054 | sg = m->sg_data; |
| 1055 | sg_init_marker(sg, MAX_SKB_FRAGS); |
| 1056 | } |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1057 | |
| 1058 | /* Catch case where ring is full and sendpage is stalled. */ |
| 1059 | if (unlikely(m->sg_end == m->sg_start && |
| 1060 | m->sg_data[m->sg_end].length)) |
| 1061 | goto out_err; |
| 1062 | |
| 1063 | psock->sg_size += size; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1064 | sg_set_page(sg, page, size, offset); |
| 1065 | get_page(page); |
| 1066 | m->sg_copy[m->sg_end] = true; |
| 1067 | sk_mem_charge(sk, size); |
| 1068 | m->sg_end++; |
| 1069 | copied = size; |
| 1070 | |
| 1071 | if (m->sg_end == MAX_SKB_FRAGS) |
| 1072 | m->sg_end = 0; |
| 1073 | |
| 1074 | if (m->sg_end == m->sg_start) |
| 1075 | enospc = true; |
| 1076 | |
| 1077 | if (psock->cork_bytes) { |
| 1078 | if (size > psock->cork_bytes) |
| 1079 | psock->cork_bytes = 0; |
| 1080 | else |
| 1081 | psock->cork_bytes -= size; |
| 1082 | |
| 1083 | if (psock->cork_bytes && !enospc) |
| 1084 | goto out_err; |
| 1085 | |
| 1086 | /* All cork bytes accounted for re-run filter */ |
| 1087 | psock->eval = __SK_NONE; |
| 1088 | psock->cork_bytes = 0; |
| 1089 | } |
| 1090 | |
| 1091 | err = bpf_exec_tx_verdict(psock, m, sk, &copied, flags); |
| 1092 | out_err: |
| 1093 | release_sock(sk); |
| 1094 | smap_release_sock(psock, sk); |
| 1095 | return copied ? copied : err; |
| 1096 | accept: |
| 1097 | rcu_read_unlock(); |
| 1098 | return tcp_sendpage(sk, page, offset, size, flags); |
| 1099 | } |
| 1100 | |
| 1101 | static void bpf_tcp_msg_add(struct smap_psock *psock, |
| 1102 | struct sock *sk, |
| 1103 | struct bpf_prog *tx_msg) |
| 1104 | { |
| 1105 | struct bpf_prog *orig_tx_msg; |
| 1106 | |
| 1107 | orig_tx_msg = xchg(&psock->bpf_tx_msg, tx_msg); |
| 1108 | if (orig_tx_msg) |
| 1109 | bpf_prog_put(orig_tx_msg); |
| 1110 | } |
| 1111 | |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 1112 | static int bpf_tcp_ulp_register(void) |
| 1113 | { |
| 1114 | tcp_bpf_proto = tcp_prot; |
| 1115 | tcp_bpf_proto.close = bpf_tcp_close; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1116 | /* Once BPF TX ULP is registered it is never unregistered. It |
| 1117 | * will be in the ULP list for the lifetime of the system. Doing |
| 1118 | * duplicate registers is not a problem. |
| 1119 | */ |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 1120 | return tcp_register_ulp(&bpf_tcp_ulp_ops); |
| 1121 | } |
| 1122 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1123 | static int smap_verdict_func(struct smap_psock *psock, struct sk_buff *skb) |
| 1124 | { |
| 1125 | struct bpf_prog *prog = READ_ONCE(psock->bpf_verdict); |
| 1126 | int rc; |
| 1127 | |
| 1128 | if (unlikely(!prog)) |
John Fastabend | 04686ef | 2017-10-31 19:17:31 -0700 | [diff] [blame] | 1129 | return __SK_DROP; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1130 | |
| 1131 | skb_orphan(skb); |
John Fastabend | 34f79502 | 2017-10-18 07:10:36 -0700 | [diff] [blame] | 1132 | /* We need to ensure that BPF metadata for maps is also cleared |
| 1133 | * when we orphan the skb so that we don't have the possibility |
| 1134 | * to reference a stale map. |
| 1135 | */ |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1136 | TCP_SKB_CB(skb)->bpf.sk_redir = NULL; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1137 | skb->sk = psock->sock; |
Daniel Borkmann | 6aaae2b | 2017-09-25 02:25:50 +0200 | [diff] [blame] | 1138 | bpf_compute_data_pointers(skb); |
John Fastabend | 34f79502 | 2017-10-18 07:10:36 -0700 | [diff] [blame] | 1139 | preempt_disable(); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1140 | rc = (*prog->bpf_func)(skb, prog->insnsi); |
John Fastabend | 34f79502 | 2017-10-18 07:10:36 -0700 | [diff] [blame] | 1141 | preempt_enable(); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1142 | skb->sk = NULL; |
| 1143 | |
John Fastabend | 04686ef | 2017-10-31 19:17:31 -0700 | [diff] [blame] | 1144 | /* Moving return codes from UAPI namespace into internal namespace */ |
John Fastabend | bfa64075 | 2017-10-27 09:45:53 -0700 | [diff] [blame] | 1145 | return rc == SK_PASS ? |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1146 | (TCP_SKB_CB(skb)->bpf.sk_redir ? __SK_REDIRECT : __SK_PASS) : |
John Fastabend | 04686ef | 2017-10-31 19:17:31 -0700 | [diff] [blame] | 1147 | __SK_DROP; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1148 | } |
| 1149 | |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1150 | static int smap_do_ingress(struct smap_psock *psock, struct sk_buff *skb) |
| 1151 | { |
| 1152 | struct sock *sk = psock->sock; |
| 1153 | int copied = 0, num_sg; |
| 1154 | struct sk_msg_buff *r; |
| 1155 | |
| 1156 | r = kzalloc(sizeof(struct sk_msg_buff), __GFP_NOWARN | GFP_ATOMIC); |
| 1157 | if (unlikely(!r)) |
| 1158 | return -EAGAIN; |
| 1159 | |
| 1160 | if (!sk_rmem_schedule(sk, skb, skb->len)) { |
| 1161 | kfree(r); |
| 1162 | return -EAGAIN; |
| 1163 | } |
| 1164 | |
| 1165 | sg_init_table(r->sg_data, MAX_SKB_FRAGS); |
| 1166 | num_sg = skb_to_sgvec(skb, r->sg_data, 0, skb->len); |
| 1167 | if (unlikely(num_sg < 0)) { |
| 1168 | kfree(r); |
| 1169 | return num_sg; |
| 1170 | } |
| 1171 | sk_mem_charge(sk, skb->len); |
| 1172 | copied = skb->len; |
| 1173 | r->sg_start = 0; |
| 1174 | r->sg_end = num_sg == MAX_SKB_FRAGS ? 0 : num_sg; |
| 1175 | r->skb = skb; |
| 1176 | list_add_tail(&r->list, &psock->ingress); |
| 1177 | sk->sk_data_ready(sk); |
| 1178 | return copied; |
| 1179 | } |
| 1180 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1181 | static void smap_do_verdict(struct smap_psock *psock, struct sk_buff *skb) |
| 1182 | { |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1183 | struct smap_psock *peer; |
John Fastabend | 90a9631 | 2017-09-01 11:29:26 -0700 | [diff] [blame] | 1184 | struct sock *sk; |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1185 | __u32 in; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1186 | int rc; |
| 1187 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1188 | rc = smap_verdict_func(psock, skb); |
| 1189 | switch (rc) { |
John Fastabend | 04686ef | 2017-10-31 19:17:31 -0700 | [diff] [blame] | 1190 | case __SK_REDIRECT: |
John Fastabend | 34f79502 | 2017-10-18 07:10:36 -0700 | [diff] [blame] | 1191 | sk = do_sk_redirect_map(skb); |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1192 | if (!sk) { |
| 1193 | kfree_skb(skb); |
| 1194 | break; |
| 1195 | } |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1196 | |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1197 | peer = smap_psock_sk(sk); |
| 1198 | in = (TCP_SKB_CB(skb)->bpf.flags) & BPF_F_INGRESS; |
| 1199 | |
| 1200 | if (unlikely(!peer || sock_flag(sk, SOCK_DEAD) || |
| 1201 | !test_bit(SMAP_TX_RUNNING, &peer->state))) { |
| 1202 | kfree_skb(skb); |
| 1203 | break; |
| 1204 | } |
| 1205 | |
| 1206 | if (!in && sock_writeable(sk)) { |
| 1207 | skb_set_owner_w(skb, sk); |
| 1208 | skb_queue_tail(&peer->rxqueue, skb); |
| 1209 | schedule_work(&peer->tx_work); |
| 1210 | break; |
| 1211 | } else if (in && |
| 1212 | atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) { |
| 1213 | skb_queue_tail(&peer->rxqueue, skb); |
| 1214 | schedule_work(&peer->tx_work); |
| 1215 | break; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1216 | } |
| 1217 | /* Fall through and free skb otherwise */ |
John Fastabend | 04686ef | 2017-10-31 19:17:31 -0700 | [diff] [blame] | 1218 | case __SK_DROP: |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1219 | default: |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1220 | kfree_skb(skb); |
| 1221 | } |
| 1222 | } |
| 1223 | |
| 1224 | static void smap_report_sk_error(struct smap_psock *psock, int err) |
| 1225 | { |
| 1226 | struct sock *sk = psock->sock; |
| 1227 | |
| 1228 | sk->sk_err = err; |
| 1229 | sk->sk_error_report(sk); |
| 1230 | } |
| 1231 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1232 | static void smap_read_sock_strparser(struct strparser *strp, |
| 1233 | struct sk_buff *skb) |
| 1234 | { |
| 1235 | struct smap_psock *psock; |
| 1236 | |
| 1237 | rcu_read_lock(); |
| 1238 | psock = container_of(strp, struct smap_psock, strp); |
| 1239 | smap_do_verdict(psock, skb); |
| 1240 | rcu_read_unlock(); |
| 1241 | } |
| 1242 | |
| 1243 | /* Called with lock held on socket */ |
| 1244 | static void smap_data_ready(struct sock *sk) |
| 1245 | { |
| 1246 | struct smap_psock *psock; |
| 1247 | |
John Fastabend | d26e597d | 2017-08-28 07:10:45 -0700 | [diff] [blame] | 1248 | rcu_read_lock(); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1249 | psock = smap_psock_sk(sk); |
John Fastabend | d26e597d | 2017-08-28 07:10:45 -0700 | [diff] [blame] | 1250 | if (likely(psock)) { |
| 1251 | write_lock_bh(&sk->sk_callback_lock); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1252 | strp_data_ready(&psock->strp); |
John Fastabend | d26e597d | 2017-08-28 07:10:45 -0700 | [diff] [blame] | 1253 | write_unlock_bh(&sk->sk_callback_lock); |
| 1254 | } |
| 1255 | rcu_read_unlock(); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1256 | } |
| 1257 | |
| 1258 | static void smap_tx_work(struct work_struct *w) |
| 1259 | { |
| 1260 | struct smap_psock *psock; |
| 1261 | struct sk_buff *skb; |
| 1262 | int rem, off, n; |
| 1263 | |
| 1264 | psock = container_of(w, struct smap_psock, tx_work); |
| 1265 | |
| 1266 | /* lock sock to avoid losing sk_socket at some point during loop */ |
| 1267 | lock_sock(psock->sock); |
| 1268 | if (psock->save_skb) { |
| 1269 | skb = psock->save_skb; |
| 1270 | rem = psock->save_rem; |
| 1271 | off = psock->save_off; |
| 1272 | psock->save_skb = NULL; |
| 1273 | goto start; |
| 1274 | } |
| 1275 | |
| 1276 | while ((skb = skb_dequeue(&psock->rxqueue))) { |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1277 | __u32 flags; |
| 1278 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1279 | rem = skb->len; |
| 1280 | off = 0; |
| 1281 | start: |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1282 | flags = (TCP_SKB_CB(skb)->bpf.flags) & BPF_F_INGRESS; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1283 | do { |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1284 | if (likely(psock->sock->sk_socket)) { |
| 1285 | if (flags) |
| 1286 | n = smap_do_ingress(psock, skb); |
| 1287 | else |
| 1288 | n = skb_send_sock_locked(psock->sock, |
| 1289 | skb, off, rem); |
| 1290 | } else { |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1291 | n = -EINVAL; |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1292 | } |
| 1293 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1294 | if (n <= 0) { |
| 1295 | if (n == -EAGAIN) { |
| 1296 | /* Retry when space is available */ |
| 1297 | psock->save_skb = skb; |
| 1298 | psock->save_rem = rem; |
| 1299 | psock->save_off = off; |
| 1300 | goto out; |
| 1301 | } |
| 1302 | /* Hard errors break pipe and stop xmit */ |
| 1303 | smap_report_sk_error(psock, n ? -n : EPIPE); |
| 1304 | clear_bit(SMAP_TX_RUNNING, &psock->state); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1305 | kfree_skb(skb); |
| 1306 | goto out; |
| 1307 | } |
| 1308 | rem -= n; |
| 1309 | off += n; |
| 1310 | } while (rem); |
John Fastabend | fa24669 | 2018-03-28 12:49:25 -0700 | [diff] [blame] | 1311 | |
| 1312 | if (!flags) |
| 1313 | kfree_skb(skb); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1314 | } |
| 1315 | out: |
| 1316 | release_sock(psock->sock); |
| 1317 | } |
| 1318 | |
| 1319 | static void smap_write_space(struct sock *sk) |
| 1320 | { |
| 1321 | struct smap_psock *psock; |
| 1322 | |
| 1323 | rcu_read_lock(); |
| 1324 | psock = smap_psock_sk(sk); |
| 1325 | if (likely(psock && test_bit(SMAP_TX_RUNNING, &psock->state))) |
| 1326 | schedule_work(&psock->tx_work); |
| 1327 | rcu_read_unlock(); |
| 1328 | } |
| 1329 | |
| 1330 | static void smap_stop_sock(struct smap_psock *psock, struct sock *sk) |
| 1331 | { |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1332 | if (!psock->strp_enabled) |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1333 | return; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1334 | sk->sk_data_ready = psock->save_data_ready; |
| 1335 | sk->sk_write_space = psock->save_write_space; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1336 | psock->save_data_ready = NULL; |
| 1337 | psock->save_write_space = NULL; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1338 | strp_stop(&psock->strp); |
| 1339 | psock->strp_enabled = false; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1340 | } |
| 1341 | |
| 1342 | static void smap_destroy_psock(struct rcu_head *rcu) |
| 1343 | { |
| 1344 | struct smap_psock *psock = container_of(rcu, |
| 1345 | struct smap_psock, rcu); |
| 1346 | |
| 1347 | /* Now that a grace period has passed there is no longer |
| 1348 | * any reference to this sock in the sockmap so we can |
| 1349 | * destroy the psock, strparser, and bpf programs. But, |
| 1350 | * because we use workqueue sync operations we can not |
| 1351 | * do it in rcu context |
| 1352 | */ |
| 1353 | schedule_work(&psock->gc_work); |
| 1354 | } |
| 1355 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1356 | static void smap_release_sock(struct smap_psock *psock, struct sock *sock) |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1357 | { |
John Fastabend | ffa3566 | 2018-03-18 12:56:54 -0700 | [diff] [blame] | 1358 | if (refcount_dec_and_test(&psock->refcnt)) { |
| 1359 | tcp_cleanup_ulp(sock); |
| 1360 | smap_stop_sock(psock, sock); |
| 1361 | clear_bit(SMAP_TX_RUNNING, &psock->state); |
| 1362 | rcu_assign_sk_user_data(sock, NULL); |
| 1363 | call_rcu_sched(&psock->rcu, smap_destroy_psock); |
| 1364 | } |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1365 | } |
| 1366 | |
| 1367 | static int smap_parse_func_strparser(struct strparser *strp, |
| 1368 | struct sk_buff *skb) |
| 1369 | { |
| 1370 | struct smap_psock *psock; |
| 1371 | struct bpf_prog *prog; |
| 1372 | int rc; |
| 1373 | |
| 1374 | rcu_read_lock(); |
| 1375 | psock = container_of(strp, struct smap_psock, strp); |
| 1376 | prog = READ_ONCE(psock->bpf_parse); |
| 1377 | |
| 1378 | if (unlikely(!prog)) { |
| 1379 | rcu_read_unlock(); |
| 1380 | return skb->len; |
| 1381 | } |
| 1382 | |
| 1383 | /* Attach socket for bpf program to use if needed we can do this |
| 1384 | * because strparser clones the skb before handing it to a upper |
| 1385 | * layer, meaning skb_orphan has been called. We NULL sk on the |
| 1386 | * way out to ensure we don't trigger a BUG_ON in skb/sk operations |
| 1387 | * later and because we are not charging the memory of this skb to |
| 1388 | * any socket yet. |
| 1389 | */ |
| 1390 | skb->sk = psock->sock; |
Daniel Borkmann | 6aaae2b | 2017-09-25 02:25:50 +0200 | [diff] [blame] | 1391 | bpf_compute_data_pointers(skb); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1392 | rc = (*prog->bpf_func)(skb, prog->insnsi); |
| 1393 | skb->sk = NULL; |
| 1394 | rcu_read_unlock(); |
| 1395 | return rc; |
| 1396 | } |
| 1397 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1398 | static int smap_read_sock_done(struct strparser *strp, int err) |
| 1399 | { |
| 1400 | return err; |
| 1401 | } |
| 1402 | |
| 1403 | static int smap_init_sock(struct smap_psock *psock, |
| 1404 | struct sock *sk) |
| 1405 | { |
Eric Biggers | 3fd8712 | 2017-08-24 14:38:51 -0700 | [diff] [blame] | 1406 | static const struct strp_callbacks cb = { |
| 1407 | .rcv_msg = smap_read_sock_strparser, |
| 1408 | .parse_msg = smap_parse_func_strparser, |
| 1409 | .read_sock_done = smap_read_sock_done, |
| 1410 | }; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1411 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1412 | return strp_init(&psock->strp, sk, &cb); |
| 1413 | } |
| 1414 | |
| 1415 | static void smap_init_progs(struct smap_psock *psock, |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1416 | struct bpf_prog *verdict, |
| 1417 | struct bpf_prog *parse) |
| 1418 | { |
| 1419 | struct bpf_prog *orig_parse, *orig_verdict; |
| 1420 | |
| 1421 | orig_parse = xchg(&psock->bpf_parse, parse); |
| 1422 | orig_verdict = xchg(&psock->bpf_verdict, verdict); |
| 1423 | |
| 1424 | if (orig_verdict) |
| 1425 | bpf_prog_put(orig_verdict); |
| 1426 | if (orig_parse) |
| 1427 | bpf_prog_put(orig_parse); |
| 1428 | } |
| 1429 | |
| 1430 | static void smap_start_sock(struct smap_psock *psock, struct sock *sk) |
| 1431 | { |
| 1432 | if (sk->sk_data_ready == smap_data_ready) |
| 1433 | return; |
| 1434 | psock->save_data_ready = sk->sk_data_ready; |
| 1435 | psock->save_write_space = sk->sk_write_space; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1436 | sk->sk_data_ready = smap_data_ready; |
| 1437 | sk->sk_write_space = smap_write_space; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1438 | psock->strp_enabled = true; |
| 1439 | } |
| 1440 | |
| 1441 | static void sock_map_remove_complete(struct bpf_stab *stab) |
| 1442 | { |
| 1443 | bpf_map_area_free(stab->sock_map); |
| 1444 | kfree(stab); |
| 1445 | } |
| 1446 | |
| 1447 | static void smap_gc_work(struct work_struct *w) |
| 1448 | { |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1449 | struct smap_psock_map_entry *e, *tmp; |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 1450 | struct sk_msg_buff *md, *mtmp; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1451 | struct smap_psock *psock; |
| 1452 | |
| 1453 | psock = container_of(w, struct smap_psock, gc_work); |
| 1454 | |
| 1455 | /* no callback lock needed because we already detached sockmap ops */ |
| 1456 | if (psock->strp_enabled) |
| 1457 | strp_done(&psock->strp); |
| 1458 | |
| 1459 | cancel_work_sync(&psock->tx_work); |
| 1460 | __skb_queue_purge(&psock->rxqueue); |
| 1461 | |
| 1462 | /* At this point all strparser and xmit work must be complete */ |
| 1463 | if (psock->bpf_parse) |
| 1464 | bpf_prog_put(psock->bpf_parse); |
| 1465 | if (psock->bpf_verdict) |
| 1466 | bpf_prog_put(psock->bpf_verdict); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1467 | if (psock->bpf_tx_msg) |
| 1468 | bpf_prog_put(psock->bpf_tx_msg); |
| 1469 | |
| 1470 | if (psock->cork) { |
| 1471 | free_start_sg(psock->sock, psock->cork); |
| 1472 | kfree(psock->cork); |
| 1473 | } |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1474 | |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 1475 | list_for_each_entry_safe(md, mtmp, &psock->ingress, list) { |
| 1476 | list_del(&md->list); |
| 1477 | free_start_sg(psock->sock, md); |
| 1478 | kfree(md); |
| 1479 | } |
| 1480 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1481 | list_for_each_entry_safe(e, tmp, &psock->maps, list) { |
| 1482 | list_del(&e->list); |
| 1483 | kfree(e); |
| 1484 | } |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1485 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1486 | if (psock->sk_redir) |
| 1487 | sock_put(psock->sk_redir); |
| 1488 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1489 | sock_put(psock->sock); |
| 1490 | kfree(psock); |
| 1491 | } |
| 1492 | |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1493 | static struct smap_psock *smap_init_psock(struct sock *sock, int node) |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1494 | { |
| 1495 | struct smap_psock *psock; |
| 1496 | |
Martin KaFai Lau | 96eabe7 | 2017-08-18 11:28:00 -0700 | [diff] [blame] | 1497 | psock = kzalloc_node(sizeof(struct smap_psock), |
| 1498 | GFP_ATOMIC | __GFP_NOWARN, |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1499 | node); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1500 | if (!psock) |
| 1501 | return ERR_PTR(-ENOMEM); |
| 1502 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1503 | psock->eval = __SK_NONE; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1504 | psock->sock = sock; |
| 1505 | skb_queue_head_init(&psock->rxqueue); |
| 1506 | INIT_WORK(&psock->tx_work, smap_tx_work); |
| 1507 | INIT_WORK(&psock->gc_work, smap_gc_work); |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1508 | INIT_LIST_HEAD(&psock->maps); |
John Fastabend | 8934ce2 | 2018-03-28 12:49:15 -0700 | [diff] [blame] | 1509 | INIT_LIST_HEAD(&psock->ingress); |
John Fastabend | ffa3566 | 2018-03-18 12:56:54 -0700 | [diff] [blame] | 1510 | refcount_set(&psock->refcnt, 1); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1511 | |
| 1512 | rcu_assign_sk_user_data(sock, psock); |
| 1513 | sock_hold(sock); |
| 1514 | return psock; |
| 1515 | } |
| 1516 | |
| 1517 | static struct bpf_map *sock_map_alloc(union bpf_attr *attr) |
| 1518 | { |
| 1519 | struct bpf_stab *stab; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1520 | u64 cost; |
Eric Dumazet | 952fad8 | 2018-02-13 15:33:52 -0800 | [diff] [blame] | 1521 | int err; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1522 | |
John Fastabend | fb50df8 | 2017-10-18 07:11:22 -0700 | [diff] [blame] | 1523 | if (!capable(CAP_NET_ADMIN)) |
| 1524 | return ERR_PTR(-EPERM); |
| 1525 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1526 | /* check sanity of attributes */ |
| 1527 | if (attr->max_entries == 0 || attr->key_size != 4 || |
Chenbo Feng | 6e71b04 | 2017-10-18 13:00:22 -0700 | [diff] [blame] | 1528 | attr->value_size != 4 || attr->map_flags & ~SOCK_CREATE_FLAG_MASK) |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1529 | return ERR_PTR(-EINVAL); |
| 1530 | |
John Fastabend | 1aa12bd | 2018-02-05 10:17:49 -0800 | [diff] [blame] | 1531 | err = bpf_tcp_ulp_register(); |
| 1532 | if (err && err != -EEXIST) |
| 1533 | return ERR_PTR(err); |
| 1534 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1535 | stab = kzalloc(sizeof(*stab), GFP_USER); |
| 1536 | if (!stab) |
| 1537 | return ERR_PTR(-ENOMEM); |
| 1538 | |
Jakub Kicinski | bd47564 | 2018-01-11 20:29:06 -0800 | [diff] [blame] | 1539 | bpf_map_init_from_attr(&stab->map, attr); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1540 | |
| 1541 | /* make sure page count doesn't overflow */ |
| 1542 | cost = (u64) stab->map.max_entries * sizeof(struct sock *); |
Eric Dumazet | 952fad8 | 2018-02-13 15:33:52 -0800 | [diff] [blame] | 1543 | err = -EINVAL; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1544 | if (cost >= U32_MAX - PAGE_SIZE) |
| 1545 | goto free_stab; |
| 1546 | |
| 1547 | stab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT; |
| 1548 | |
| 1549 | /* if map size is larger than memlock limit, reject it early */ |
| 1550 | err = bpf_map_precharge_memlock(stab->map.pages); |
| 1551 | if (err) |
| 1552 | goto free_stab; |
| 1553 | |
Dan Carpenter | f740c34 | 2017-08-25 23:27:14 +0300 | [diff] [blame] | 1554 | err = -ENOMEM; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1555 | stab->sock_map = bpf_map_area_alloc(stab->map.max_entries * |
Martin KaFai Lau | 96eabe7 | 2017-08-18 11:28:00 -0700 | [diff] [blame] | 1556 | sizeof(struct sock *), |
| 1557 | stab->map.numa_node); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1558 | if (!stab->sock_map) |
| 1559 | goto free_stab; |
| 1560 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1561 | return &stab->map; |
| 1562 | free_stab: |
| 1563 | kfree(stab); |
| 1564 | return ERR_PTR(err); |
| 1565 | } |
| 1566 | |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 1567 | static void smap_list_remove(struct smap_psock *psock, |
| 1568 | struct sock **entry, |
| 1569 | struct htab_elem *hash_link) |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1570 | { |
| 1571 | struct smap_psock_map_entry *e, *tmp; |
| 1572 | |
| 1573 | list_for_each_entry_safe(e, tmp, &psock->maps, list) { |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 1574 | if (e->entry == entry || e->hash_link == hash_link) { |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1575 | list_del(&e->list); |
| 1576 | break; |
| 1577 | } |
| 1578 | } |
| 1579 | } |
| 1580 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1581 | static void sock_map_free(struct bpf_map *map) |
| 1582 | { |
| 1583 | struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
| 1584 | int i; |
| 1585 | |
| 1586 | synchronize_rcu(); |
| 1587 | |
| 1588 | /* At this point no update, lookup or delete operations can happen. |
| 1589 | * However, be aware we can still get a socket state event updates, |
| 1590 | * and data ready callabacks that reference the psock from sk_user_data |
| 1591 | * Also psock worker threads are still in-flight. So smap_release_sock |
| 1592 | * will only free the psock after cancel_sync on the worker threads |
| 1593 | * and a grace period expire to ensure psock is really safe to remove. |
| 1594 | */ |
| 1595 | rcu_read_lock(); |
| 1596 | for (i = 0; i < stab->map.max_entries; i++) { |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1597 | struct smap_psock *psock; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1598 | struct sock *sock; |
| 1599 | |
| 1600 | sock = xchg(&stab->sock_map[i], NULL); |
| 1601 | if (!sock) |
| 1602 | continue; |
| 1603 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1604 | write_lock_bh(&sock->sk_callback_lock); |
| 1605 | psock = smap_psock_sk(sock); |
John Fastabend | 5731a87 | 2018-01-04 20:02:09 -0800 | [diff] [blame] | 1606 | /* This check handles a racing sock event that can get the |
| 1607 | * sk_callback_lock before this case but after xchg happens |
| 1608 | * causing the refcnt to hit zero and sock user data (psock) |
| 1609 | * to be null and queued for garbage collection. |
| 1610 | */ |
| 1611 | if (likely(psock)) { |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 1612 | smap_list_remove(psock, &stab->sock_map[i], NULL); |
John Fastabend | 5731a87 | 2018-01-04 20:02:09 -0800 | [diff] [blame] | 1613 | smap_release_sock(psock, sock); |
| 1614 | } |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1615 | write_unlock_bh(&sock->sk_callback_lock); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1616 | } |
| 1617 | rcu_read_unlock(); |
| 1618 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1619 | sock_map_remove_complete(stab); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1620 | } |
| 1621 | |
| 1622 | static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next_key) |
| 1623 | { |
| 1624 | struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
| 1625 | u32 i = key ? *(u32 *)key : U32_MAX; |
| 1626 | u32 *next = (u32 *)next_key; |
| 1627 | |
| 1628 | if (i >= stab->map.max_entries) { |
| 1629 | *next = 0; |
| 1630 | return 0; |
| 1631 | } |
| 1632 | |
| 1633 | if (i == stab->map.max_entries - 1) |
| 1634 | return -ENOENT; |
| 1635 | |
| 1636 | *next = i + 1; |
| 1637 | return 0; |
| 1638 | } |
| 1639 | |
| 1640 | struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key) |
| 1641 | { |
| 1642 | struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
| 1643 | |
| 1644 | if (key >= map->max_entries) |
| 1645 | return NULL; |
| 1646 | |
| 1647 | return READ_ONCE(stab->sock_map[key]); |
| 1648 | } |
| 1649 | |
| 1650 | static int sock_map_delete_elem(struct bpf_map *map, void *key) |
| 1651 | { |
| 1652 | struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1653 | struct smap_psock *psock; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1654 | int k = *(u32 *)key; |
| 1655 | struct sock *sock; |
| 1656 | |
| 1657 | if (k >= map->max_entries) |
| 1658 | return -EINVAL; |
| 1659 | |
| 1660 | sock = xchg(&stab->sock_map[k], NULL); |
| 1661 | if (!sock) |
| 1662 | return -EINVAL; |
| 1663 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1664 | write_lock_bh(&sock->sk_callback_lock); |
| 1665 | psock = smap_psock_sk(sock); |
| 1666 | if (!psock) |
| 1667 | goto out; |
| 1668 | |
| 1669 | if (psock->bpf_parse) |
| 1670 | smap_stop_sock(psock, sock); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 1671 | smap_list_remove(psock, &stab->sock_map[k], NULL); |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1672 | smap_release_sock(psock, sock); |
| 1673 | out: |
| 1674 | write_unlock_bh(&sock->sk_callback_lock); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1675 | return 0; |
| 1676 | } |
| 1677 | |
| 1678 | /* Locking notes: Concurrent updates, deletes, and lookups are allowed and are |
| 1679 | * done inside rcu critical sections. This ensures on updates that the psock |
| 1680 | * will not be released via smap_release_sock() until concurrent updates/deletes |
| 1681 | * complete. All operations operate on sock_map using cmpxchg and xchg |
| 1682 | * operations to ensure we do not get stale references. Any reads into the |
| 1683 | * map must be done with READ_ONCE() because of this. |
| 1684 | * |
| 1685 | * A psock is destroyed via call_rcu and after any worker threads are cancelled |
| 1686 | * and syncd so we are certain all references from the update/lookup/delete |
| 1687 | * operations as well as references in the data path are no longer in use. |
| 1688 | * |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1689 | * Psocks may exist in multiple maps, but only a single set of parse/verdict |
| 1690 | * programs may be inherited from the maps it belongs to. A reference count |
| 1691 | * is kept with the total number of references to the psock from all maps. The |
| 1692 | * psock will not be released until this reaches zero. The psock and sock |
| 1693 | * user data data use the sk_callback_lock to protect critical data structures |
| 1694 | * from concurrent access. This allows us to avoid two updates from modifying |
| 1695 | * the user data in sock and the lock is required anyways for modifying |
| 1696 | * callbacks, we simply increase its scope slightly. |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1697 | * |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1698 | * Rules to follow, |
| 1699 | * - psock must always be read inside RCU critical section |
| 1700 | * - sk_user_data must only be modified inside sk_callback_lock and read |
| 1701 | * inside RCU critical section. |
| 1702 | * - psock->maps list must only be read & modified inside sk_callback_lock |
| 1703 | * - sock_map must use READ_ONCE and (cmp)xchg operations |
| 1704 | * - BPF verdict/parse programs must use READ_ONCE and xchg operations |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1705 | */ |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1706 | |
| 1707 | static int __sock_map_ctx_update_elem(struct bpf_map *map, |
| 1708 | struct bpf_sock_progs *progs, |
| 1709 | struct sock *sock, |
| 1710 | struct sock **map_link, |
| 1711 | void *key) |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1712 | { |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1713 | struct bpf_prog *verdict, *parse, *tx_msg; |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1714 | struct smap_psock_map_entry *e = NULL; |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1715 | struct smap_psock *psock; |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1716 | bool new = false; |
Gustavo A. R. Silva | 0e43645 | 2018-05-17 09:08:43 -0500 | [diff] [blame] | 1717 | int err = 0; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1718 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1719 | /* 1. If sock map has BPF programs those will be inherited by the |
| 1720 | * sock being added. If the sock is already attached to BPF programs |
| 1721 | * this results in an error. |
| 1722 | */ |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1723 | verdict = READ_ONCE(progs->bpf_verdict); |
| 1724 | parse = READ_ONCE(progs->bpf_parse); |
| 1725 | tx_msg = READ_ONCE(progs->bpf_tx_msg); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1726 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1727 | if (parse && verdict) { |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1728 | /* bpf prog refcnt may be zero if a concurrent attach operation |
| 1729 | * removes the program after the above READ_ONCE() but before |
| 1730 | * we increment the refcnt. If this is the case abort with an |
| 1731 | * error. |
| 1732 | */ |
John Fastabend | 9617456 | 2018-05-17 14:06:40 -0700 | [diff] [blame] | 1733 | verdict = bpf_prog_inc_not_zero(verdict); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1734 | if (IS_ERR(verdict)) |
| 1735 | return PTR_ERR(verdict); |
| 1736 | |
John Fastabend | 9617456 | 2018-05-17 14:06:40 -0700 | [diff] [blame] | 1737 | parse = bpf_prog_inc_not_zero(parse); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1738 | if (IS_ERR(parse)) { |
| 1739 | bpf_prog_put(verdict); |
| 1740 | return PTR_ERR(parse); |
| 1741 | } |
| 1742 | } |
| 1743 | |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1744 | if (tx_msg) { |
John Fastabend | 9617456 | 2018-05-17 14:06:40 -0700 | [diff] [blame] | 1745 | tx_msg = bpf_prog_inc_not_zero(tx_msg); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1746 | if (IS_ERR(tx_msg)) { |
John Fastabend | a593f70 | 2018-05-17 14:06:35 -0700 | [diff] [blame] | 1747 | if (parse && verdict) { |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1748 | bpf_prog_put(parse); |
John Fastabend | a593f70 | 2018-05-17 14:06:35 -0700 | [diff] [blame] | 1749 | bpf_prog_put(verdict); |
| 1750 | } |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1751 | return PTR_ERR(tx_msg); |
| 1752 | } |
| 1753 | } |
| 1754 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1755 | write_lock_bh(&sock->sk_callback_lock); |
| 1756 | psock = smap_psock_sk(sock); |
| 1757 | |
| 1758 | /* 2. Do not allow inheriting programs if psock exists and has |
| 1759 | * already inherited programs. This would create confusion on |
| 1760 | * which parser/verdict program is running. If no psock exists |
| 1761 | * create one. Inside sk_callback_lock to ensure concurrent create |
| 1762 | * doesn't update user data. |
| 1763 | */ |
| 1764 | if (psock) { |
| 1765 | if (READ_ONCE(psock->bpf_parse) && parse) { |
| 1766 | err = -EBUSY; |
| 1767 | goto out_progs; |
| 1768 | } |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1769 | if (READ_ONCE(psock->bpf_tx_msg) && tx_msg) { |
| 1770 | err = -EBUSY; |
| 1771 | goto out_progs; |
| 1772 | } |
| 1773 | if (!refcount_inc_not_zero(&psock->refcnt)) { |
| 1774 | err = -EAGAIN; |
| 1775 | goto out_progs; |
| 1776 | } |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1777 | } else { |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1778 | psock = smap_init_psock(sock, map->numa_node); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1779 | if (IS_ERR(psock)) { |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1780 | err = PTR_ERR(psock); |
| 1781 | goto out_progs; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1782 | } |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1783 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1784 | set_bit(SMAP_TX_RUNNING, &psock->state); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1785 | new = true; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1786 | } |
| 1787 | |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 1788 | if (map_link) { |
| 1789 | e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN); |
| 1790 | if (!e) { |
| 1791 | err = -ENOMEM; |
| 1792 | goto out_progs; |
| 1793 | } |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1794 | } |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1795 | |
| 1796 | /* 3. At this point we have a reference to a valid psock that is |
| 1797 | * running. Attach any BPF programs needed. |
| 1798 | */ |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1799 | if (tx_msg) |
| 1800 | bpf_tcp_msg_add(psock, sock, tx_msg); |
| 1801 | if (new) { |
| 1802 | err = tcp_set_ulp_id(sock, TCP_ULP_BPF); |
| 1803 | if (err) |
| 1804 | goto out_free; |
| 1805 | } |
| 1806 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1807 | if (parse && verdict && !psock->strp_enabled) { |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1808 | err = smap_init_sock(psock, sock); |
| 1809 | if (err) |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1810 | goto out_free; |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1811 | smap_init_progs(psock, verdict, parse); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1812 | smap_start_sock(psock, sock); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1813 | } |
| 1814 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1815 | /* 4. Place psock in sockmap for use and stop any programs on |
| 1816 | * the old sock assuming its not the same sock we are replacing |
| 1817 | * it with. Because we can only have a single set of programs if |
| 1818 | * old_sock has a strp we can stop it. |
| 1819 | */ |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1820 | if (map_link) { |
| 1821 | e->entry = map_link; |
| 1822 | list_add_tail(&e->list, &psock->maps); |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1823 | } |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1824 | write_unlock_bh(&sock->sk_callback_lock); |
| 1825 | return err; |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1826 | out_free: |
| 1827 | smap_release_sock(psock, sock); |
| 1828 | out_progs: |
John Fastabend | a593f70 | 2018-05-17 14:06:35 -0700 | [diff] [blame] | 1829 | if (parse && verdict) { |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1830 | bpf_prog_put(parse); |
John Fastabend | a593f70 | 2018-05-17 14:06:35 -0700 | [diff] [blame] | 1831 | bpf_prog_put(verdict); |
| 1832 | } |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1833 | if (tx_msg) |
| 1834 | bpf_prog_put(tx_msg); |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1835 | write_unlock_bh(&sock->sk_callback_lock); |
| 1836 | kfree(e); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1837 | return err; |
| 1838 | } |
| 1839 | |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1840 | static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, |
| 1841 | struct bpf_map *map, |
| 1842 | void *key, u64 flags) |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1843 | { |
| 1844 | struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1845 | struct bpf_sock_progs *progs = &stab->progs; |
| 1846 | struct sock *osock, *sock; |
| 1847 | u32 i = *(u32 *)key; |
| 1848 | int err; |
| 1849 | |
| 1850 | if (unlikely(flags > BPF_EXIST)) |
| 1851 | return -EINVAL; |
| 1852 | |
| 1853 | if (unlikely(i >= stab->map.max_entries)) |
| 1854 | return -E2BIG; |
| 1855 | |
| 1856 | sock = READ_ONCE(stab->sock_map[i]); |
| 1857 | if (flags == BPF_EXIST && !sock) |
| 1858 | return -ENOENT; |
| 1859 | else if (flags == BPF_NOEXIST && sock) |
| 1860 | return -EEXIST; |
| 1861 | |
| 1862 | sock = skops->sk; |
| 1863 | err = __sock_map_ctx_update_elem(map, progs, sock, &stab->sock_map[i], |
| 1864 | key); |
| 1865 | if (err) |
| 1866 | goto out; |
| 1867 | |
| 1868 | osock = xchg(&stab->sock_map[i], sock); |
| 1869 | if (osock) { |
| 1870 | struct smap_psock *opsock = smap_psock_sk(osock); |
| 1871 | |
| 1872 | write_lock_bh(&osock->sk_callback_lock); |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 1873 | smap_list_remove(opsock, &stab->sock_map[i], NULL); |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1874 | smap_release_sock(opsock, osock); |
| 1875 | write_unlock_bh(&osock->sk_callback_lock); |
| 1876 | } |
| 1877 | out: |
John Fastabend | e23afe5 | 2018-05-16 16:38:14 -0700 | [diff] [blame] | 1878 | return err; |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1879 | } |
| 1880 | |
| 1881 | int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type) |
| 1882 | { |
| 1883 | struct bpf_sock_progs *progs; |
John Fastabend | 464bc0f | 2017-08-28 07:10:04 -0700 | [diff] [blame] | 1884 | struct bpf_prog *orig; |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1885 | |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1886 | if (map->map_type == BPF_MAP_TYPE_SOCKMAP) { |
| 1887 | struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
| 1888 | |
| 1889 | progs = &stab->progs; |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 1890 | } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH) { |
| 1891 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| 1892 | |
| 1893 | progs = &htab->progs; |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1894 | } else { |
John Fastabend | 81374aa | 2017-08-28 07:11:43 -0700 | [diff] [blame] | 1895 | return -EINVAL; |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1896 | } |
John Fastabend | 81374aa | 2017-08-28 07:11:43 -0700 | [diff] [blame] | 1897 | |
John Fastabend | 464bc0f | 2017-08-28 07:10:04 -0700 | [diff] [blame] | 1898 | switch (type) { |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1899 | case BPF_SK_MSG_VERDICT: |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1900 | orig = xchg(&progs->bpf_tx_msg, prog); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1901 | break; |
John Fastabend | 464bc0f | 2017-08-28 07:10:04 -0700 | [diff] [blame] | 1902 | case BPF_SK_SKB_STREAM_PARSER: |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1903 | orig = xchg(&progs->bpf_parse, prog); |
John Fastabend | 464bc0f | 2017-08-28 07:10:04 -0700 | [diff] [blame] | 1904 | break; |
| 1905 | case BPF_SK_SKB_STREAM_VERDICT: |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1906 | orig = xchg(&progs->bpf_verdict, prog); |
John Fastabend | 464bc0f | 2017-08-28 07:10:04 -0700 | [diff] [blame] | 1907 | break; |
| 1908 | default: |
| 1909 | return -EOPNOTSUPP; |
| 1910 | } |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1911 | |
John Fastabend | 464bc0f | 2017-08-28 07:10:04 -0700 | [diff] [blame] | 1912 | if (orig) |
| 1913 | bpf_prog_put(orig); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1914 | |
| 1915 | return 0; |
| 1916 | } |
| 1917 | |
| 1918 | static void *sock_map_lookup(struct bpf_map *map, void *key) |
| 1919 | { |
| 1920 | return NULL; |
| 1921 | } |
| 1922 | |
| 1923 | static int sock_map_update_elem(struct bpf_map *map, |
| 1924 | void *key, void *value, u64 flags) |
| 1925 | { |
| 1926 | struct bpf_sock_ops_kern skops; |
| 1927 | u32 fd = *(u32 *)value; |
| 1928 | struct socket *socket; |
| 1929 | int err; |
| 1930 | |
| 1931 | socket = sockfd_lookup(fd, &err); |
| 1932 | if (!socket) |
| 1933 | return err; |
| 1934 | |
| 1935 | skops.sk = socket->sk; |
| 1936 | if (!skops.sk) { |
| 1937 | fput(socket->file); |
| 1938 | return -EINVAL; |
| 1939 | } |
| 1940 | |
John Fastabend | 435bf0d | 2017-10-18 07:10:15 -0700 | [diff] [blame] | 1941 | if (skops.sk->sk_type != SOCK_STREAM || |
| 1942 | skops.sk->sk_protocol != IPPROTO_TCP) { |
| 1943 | fput(socket->file); |
| 1944 | return -EOPNOTSUPP; |
| 1945 | } |
| 1946 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 1947 | err = sock_map_ctx_update_elem(&skops, map, key, flags); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 1948 | fput(socket->file); |
| 1949 | return err; |
| 1950 | } |
| 1951 | |
John Fastabend | ba6b8de | 2018-04-23 15:39:23 -0700 | [diff] [blame] | 1952 | static void sock_map_release(struct bpf_map *map) |
John Fastabend | 3d9e952 | 2018-02-05 10:17:54 -0800 | [diff] [blame] | 1953 | { |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1954 | struct bpf_sock_progs *progs; |
John Fastabend | 3d9e952 | 2018-02-05 10:17:54 -0800 | [diff] [blame] | 1955 | struct bpf_prog *orig; |
| 1956 | |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 1957 | if (map->map_type == BPF_MAP_TYPE_SOCKMAP) { |
| 1958 | struct bpf_stab *stab = container_of(map, struct bpf_stab, map); |
| 1959 | |
| 1960 | progs = &stab->progs; |
| 1961 | } else { |
| 1962 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| 1963 | |
| 1964 | progs = &htab->progs; |
| 1965 | } |
| 1966 | |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1967 | orig = xchg(&progs->bpf_parse, NULL); |
John Fastabend | 3d9e952 | 2018-02-05 10:17:54 -0800 | [diff] [blame] | 1968 | if (orig) |
| 1969 | bpf_prog_put(orig); |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1970 | orig = xchg(&progs->bpf_verdict, NULL); |
John Fastabend | 3d9e952 | 2018-02-05 10:17:54 -0800 | [diff] [blame] | 1971 | if (orig) |
| 1972 | bpf_prog_put(orig); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1973 | |
John Fastabend | e5cd3ab | 2018-05-14 10:00:16 -0700 | [diff] [blame] | 1974 | orig = xchg(&progs->bpf_tx_msg, NULL); |
John Fastabend | 4f738ad | 2018-03-18 12:57:10 -0700 | [diff] [blame] | 1975 | if (orig) |
| 1976 | bpf_prog_put(orig); |
John Fastabend | 3d9e952 | 2018-02-05 10:17:54 -0800 | [diff] [blame] | 1977 | } |
| 1978 | |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 1979 | static struct bpf_map *sock_hash_alloc(union bpf_attr *attr) |
| 1980 | { |
| 1981 | struct bpf_htab *htab; |
| 1982 | int i, err; |
| 1983 | u64 cost; |
| 1984 | |
| 1985 | if (!capable(CAP_NET_ADMIN)) |
| 1986 | return ERR_PTR(-EPERM); |
| 1987 | |
| 1988 | /* check sanity of attributes */ |
| 1989 | if (attr->max_entries == 0 || attr->value_size != 4 || |
| 1990 | attr->map_flags & ~SOCK_CREATE_FLAG_MASK) |
| 1991 | return ERR_PTR(-EINVAL); |
| 1992 | |
Yonghong Song | 683d2ac | 2018-05-16 14:06:26 -0700 | [diff] [blame] | 1993 | if (attr->key_size > MAX_BPF_STACK) |
| 1994 | /* eBPF programs initialize keys on stack, so they cannot be |
| 1995 | * larger than max stack size |
| 1996 | */ |
| 1997 | return ERR_PTR(-E2BIG); |
| 1998 | |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 1999 | err = bpf_tcp_ulp_register(); |
| 2000 | if (err && err != -EEXIST) |
| 2001 | return ERR_PTR(err); |
| 2002 | |
| 2003 | htab = kzalloc(sizeof(*htab), GFP_USER); |
| 2004 | if (!htab) |
| 2005 | return ERR_PTR(-ENOMEM); |
| 2006 | |
| 2007 | bpf_map_init_from_attr(&htab->map, attr); |
| 2008 | |
| 2009 | htab->n_buckets = roundup_pow_of_two(htab->map.max_entries); |
| 2010 | htab->elem_size = sizeof(struct htab_elem) + |
| 2011 | round_up(htab->map.key_size, 8); |
| 2012 | err = -EINVAL; |
| 2013 | if (htab->n_buckets == 0 || |
| 2014 | htab->n_buckets > U32_MAX / sizeof(struct bucket)) |
| 2015 | goto free_htab; |
| 2016 | |
| 2017 | cost = (u64) htab->n_buckets * sizeof(struct bucket) + |
| 2018 | (u64) htab->elem_size * htab->map.max_entries; |
| 2019 | |
| 2020 | if (cost >= U32_MAX - PAGE_SIZE) |
| 2021 | goto free_htab; |
| 2022 | |
| 2023 | htab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT; |
| 2024 | err = bpf_map_precharge_memlock(htab->map.pages); |
| 2025 | if (err) |
| 2026 | goto free_htab; |
| 2027 | |
| 2028 | err = -ENOMEM; |
| 2029 | htab->buckets = bpf_map_area_alloc( |
| 2030 | htab->n_buckets * sizeof(struct bucket), |
| 2031 | htab->map.numa_node); |
| 2032 | if (!htab->buckets) |
| 2033 | goto free_htab; |
| 2034 | |
| 2035 | for (i = 0; i < htab->n_buckets; i++) { |
| 2036 | INIT_HLIST_HEAD(&htab->buckets[i].head); |
| 2037 | raw_spin_lock_init(&htab->buckets[i].lock); |
| 2038 | } |
| 2039 | |
| 2040 | return &htab->map; |
| 2041 | free_htab: |
| 2042 | kfree(htab); |
| 2043 | return ERR_PTR(err); |
| 2044 | } |
| 2045 | |
| 2046 | static inline struct bucket *__select_bucket(struct bpf_htab *htab, u32 hash) |
| 2047 | { |
| 2048 | return &htab->buckets[hash & (htab->n_buckets - 1)]; |
| 2049 | } |
| 2050 | |
| 2051 | static inline struct hlist_head *select_bucket(struct bpf_htab *htab, u32 hash) |
| 2052 | { |
| 2053 | return &__select_bucket(htab, hash)->head; |
| 2054 | } |
| 2055 | |
| 2056 | static void sock_hash_free(struct bpf_map *map) |
| 2057 | { |
| 2058 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| 2059 | int i; |
| 2060 | |
| 2061 | synchronize_rcu(); |
| 2062 | |
| 2063 | /* At this point no update, lookup or delete operations can happen. |
| 2064 | * However, be aware we can still get a socket state event updates, |
| 2065 | * and data ready callabacks that reference the psock from sk_user_data |
| 2066 | * Also psock worker threads are still in-flight. So smap_release_sock |
| 2067 | * will only free the psock after cancel_sync on the worker threads |
| 2068 | * and a grace period expire to ensure psock is really safe to remove. |
| 2069 | */ |
| 2070 | rcu_read_lock(); |
| 2071 | for (i = 0; i < htab->n_buckets; i++) { |
| 2072 | struct hlist_head *head = select_bucket(htab, i); |
| 2073 | struct hlist_node *n; |
| 2074 | struct htab_elem *l; |
| 2075 | |
| 2076 | hlist_for_each_entry_safe(l, n, head, hash_node) { |
| 2077 | struct sock *sock = l->sk; |
| 2078 | struct smap_psock *psock; |
| 2079 | |
| 2080 | hlist_del_rcu(&l->hash_node); |
| 2081 | write_lock_bh(&sock->sk_callback_lock); |
| 2082 | psock = smap_psock_sk(sock); |
| 2083 | /* This check handles a racing sock event that can get |
| 2084 | * the sk_callback_lock before this case but after xchg |
| 2085 | * causing the refcnt to hit zero and sock user data |
| 2086 | * (psock) to be null and queued for garbage collection. |
| 2087 | */ |
| 2088 | if (likely(psock)) { |
| 2089 | smap_list_remove(psock, NULL, l); |
| 2090 | smap_release_sock(psock, sock); |
| 2091 | } |
| 2092 | write_unlock_bh(&sock->sk_callback_lock); |
| 2093 | kfree(l); |
| 2094 | } |
| 2095 | } |
| 2096 | rcu_read_unlock(); |
| 2097 | bpf_map_area_free(htab->buckets); |
| 2098 | kfree(htab); |
| 2099 | } |
| 2100 | |
| 2101 | static struct htab_elem *alloc_sock_hash_elem(struct bpf_htab *htab, |
| 2102 | void *key, u32 key_size, u32 hash, |
| 2103 | struct sock *sk, |
| 2104 | struct htab_elem *old_elem) |
| 2105 | { |
| 2106 | struct htab_elem *l_new; |
| 2107 | |
| 2108 | if (atomic_inc_return(&htab->count) > htab->map.max_entries) { |
| 2109 | if (!old_elem) { |
| 2110 | atomic_dec(&htab->count); |
| 2111 | return ERR_PTR(-E2BIG); |
| 2112 | } |
| 2113 | } |
| 2114 | l_new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN, |
| 2115 | htab->map.numa_node); |
| 2116 | if (!l_new) |
| 2117 | return ERR_PTR(-ENOMEM); |
| 2118 | |
| 2119 | memcpy(l_new->key, key, key_size); |
| 2120 | l_new->sk = sk; |
| 2121 | l_new->hash = hash; |
| 2122 | return l_new; |
| 2123 | } |
| 2124 | |
| 2125 | static struct htab_elem *lookup_elem_raw(struct hlist_head *head, |
| 2126 | u32 hash, void *key, u32 key_size) |
| 2127 | { |
| 2128 | struct htab_elem *l; |
| 2129 | |
| 2130 | hlist_for_each_entry_rcu(l, head, hash_node) { |
| 2131 | if (l->hash == hash && !memcmp(&l->key, key, key_size)) |
| 2132 | return l; |
| 2133 | } |
| 2134 | |
| 2135 | return NULL; |
| 2136 | } |
| 2137 | |
| 2138 | static inline u32 htab_map_hash(const void *key, u32 key_len) |
| 2139 | { |
| 2140 | return jhash(key, key_len, 0); |
| 2141 | } |
| 2142 | |
| 2143 | static int sock_hash_get_next_key(struct bpf_map *map, |
| 2144 | void *key, void *next_key) |
| 2145 | { |
| 2146 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| 2147 | struct htab_elem *l, *next_l; |
| 2148 | struct hlist_head *h; |
| 2149 | u32 hash, key_size; |
| 2150 | int i = 0; |
| 2151 | |
| 2152 | WARN_ON_ONCE(!rcu_read_lock_held()); |
| 2153 | |
| 2154 | key_size = map->key_size; |
| 2155 | if (!key) |
| 2156 | goto find_first_elem; |
| 2157 | hash = htab_map_hash(key, key_size); |
| 2158 | h = select_bucket(htab, hash); |
| 2159 | |
| 2160 | l = lookup_elem_raw(h, hash, key, key_size); |
| 2161 | if (!l) |
| 2162 | goto find_first_elem; |
| 2163 | next_l = hlist_entry_safe( |
| 2164 | rcu_dereference_raw(hlist_next_rcu(&l->hash_node)), |
| 2165 | struct htab_elem, hash_node); |
| 2166 | if (next_l) { |
| 2167 | memcpy(next_key, next_l->key, key_size); |
| 2168 | return 0; |
| 2169 | } |
| 2170 | |
| 2171 | /* no more elements in this hash list, go to the next bucket */ |
| 2172 | i = hash & (htab->n_buckets - 1); |
| 2173 | i++; |
| 2174 | |
| 2175 | find_first_elem: |
| 2176 | /* iterate over buckets */ |
| 2177 | for (; i < htab->n_buckets; i++) { |
| 2178 | h = select_bucket(htab, i); |
| 2179 | |
| 2180 | /* pick first element in the bucket */ |
| 2181 | next_l = hlist_entry_safe( |
| 2182 | rcu_dereference_raw(hlist_first_rcu(h)), |
| 2183 | struct htab_elem, hash_node); |
| 2184 | if (next_l) { |
| 2185 | /* if it's not empty, just return it */ |
| 2186 | memcpy(next_key, next_l->key, key_size); |
| 2187 | return 0; |
| 2188 | } |
| 2189 | } |
| 2190 | |
| 2191 | /* iterated over all buckets and all elements */ |
| 2192 | return -ENOENT; |
| 2193 | } |
| 2194 | |
| 2195 | static int sock_hash_ctx_update_elem(struct bpf_sock_ops_kern *skops, |
| 2196 | struct bpf_map *map, |
| 2197 | void *key, u64 map_flags) |
| 2198 | { |
| 2199 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| 2200 | struct bpf_sock_progs *progs = &htab->progs; |
| 2201 | struct htab_elem *l_new = NULL, *l_old; |
| 2202 | struct smap_psock_map_entry *e = NULL; |
| 2203 | struct hlist_head *head; |
| 2204 | struct smap_psock *psock; |
| 2205 | u32 key_size, hash; |
| 2206 | struct sock *sock; |
| 2207 | struct bucket *b; |
| 2208 | int err; |
| 2209 | |
| 2210 | sock = skops->sk; |
| 2211 | |
| 2212 | if (sock->sk_type != SOCK_STREAM || |
| 2213 | sock->sk_protocol != IPPROTO_TCP) |
| 2214 | return -EOPNOTSUPP; |
| 2215 | |
| 2216 | if (unlikely(map_flags > BPF_EXIST)) |
| 2217 | return -EINVAL; |
| 2218 | |
| 2219 | e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN); |
| 2220 | if (!e) |
| 2221 | return -ENOMEM; |
| 2222 | |
| 2223 | WARN_ON_ONCE(!rcu_read_lock_held()); |
| 2224 | key_size = map->key_size; |
| 2225 | hash = htab_map_hash(key, key_size); |
| 2226 | b = __select_bucket(htab, hash); |
| 2227 | head = &b->head; |
| 2228 | |
| 2229 | err = __sock_map_ctx_update_elem(map, progs, sock, NULL, key); |
| 2230 | if (err) |
| 2231 | goto err; |
| 2232 | |
| 2233 | /* bpf_map_update_elem() can be called in_irq() */ |
| 2234 | raw_spin_lock_bh(&b->lock); |
| 2235 | l_old = lookup_elem_raw(head, hash, key, key_size); |
| 2236 | if (l_old && map_flags == BPF_NOEXIST) { |
| 2237 | err = -EEXIST; |
| 2238 | goto bucket_err; |
| 2239 | } |
| 2240 | if (!l_old && map_flags == BPF_EXIST) { |
| 2241 | err = -ENOENT; |
| 2242 | goto bucket_err; |
| 2243 | } |
| 2244 | |
| 2245 | l_new = alloc_sock_hash_elem(htab, key, key_size, hash, sock, l_old); |
| 2246 | if (IS_ERR(l_new)) { |
| 2247 | err = PTR_ERR(l_new); |
| 2248 | goto bucket_err; |
| 2249 | } |
| 2250 | |
| 2251 | psock = smap_psock_sk(sock); |
| 2252 | if (unlikely(!psock)) { |
| 2253 | err = -EINVAL; |
| 2254 | goto bucket_err; |
| 2255 | } |
| 2256 | |
| 2257 | e->hash_link = l_new; |
| 2258 | e->htab = container_of(map, struct bpf_htab, map); |
| 2259 | list_add_tail(&e->list, &psock->maps); |
| 2260 | |
| 2261 | /* add new element to the head of the list, so that |
| 2262 | * concurrent search will find it before old elem |
| 2263 | */ |
| 2264 | hlist_add_head_rcu(&l_new->hash_node, head); |
| 2265 | if (l_old) { |
| 2266 | psock = smap_psock_sk(l_old->sk); |
| 2267 | |
| 2268 | hlist_del_rcu(&l_old->hash_node); |
| 2269 | smap_list_remove(psock, NULL, l_old); |
| 2270 | smap_release_sock(psock, l_old->sk); |
| 2271 | free_htab_elem(htab, l_old); |
| 2272 | } |
| 2273 | raw_spin_unlock_bh(&b->lock); |
| 2274 | return 0; |
| 2275 | bucket_err: |
| 2276 | raw_spin_unlock_bh(&b->lock); |
| 2277 | err: |
| 2278 | kfree(e); |
| 2279 | psock = smap_psock_sk(sock); |
| 2280 | if (psock) |
| 2281 | smap_release_sock(psock, sock); |
| 2282 | return err; |
| 2283 | } |
| 2284 | |
| 2285 | static int sock_hash_update_elem(struct bpf_map *map, |
| 2286 | void *key, void *value, u64 flags) |
| 2287 | { |
| 2288 | struct bpf_sock_ops_kern skops; |
| 2289 | u32 fd = *(u32 *)value; |
| 2290 | struct socket *socket; |
| 2291 | int err; |
| 2292 | |
| 2293 | socket = sockfd_lookup(fd, &err); |
| 2294 | if (!socket) |
| 2295 | return err; |
| 2296 | |
| 2297 | skops.sk = socket->sk; |
| 2298 | if (!skops.sk) { |
| 2299 | fput(socket->file); |
| 2300 | return -EINVAL; |
| 2301 | } |
| 2302 | |
| 2303 | err = sock_hash_ctx_update_elem(&skops, map, key, flags); |
| 2304 | fput(socket->file); |
| 2305 | return err; |
| 2306 | } |
| 2307 | |
| 2308 | static int sock_hash_delete_elem(struct bpf_map *map, void *key) |
| 2309 | { |
| 2310 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| 2311 | struct hlist_head *head; |
| 2312 | struct bucket *b; |
| 2313 | struct htab_elem *l; |
| 2314 | u32 hash, key_size; |
| 2315 | int ret = -ENOENT; |
| 2316 | |
| 2317 | key_size = map->key_size; |
| 2318 | hash = htab_map_hash(key, key_size); |
| 2319 | b = __select_bucket(htab, hash); |
| 2320 | head = &b->head; |
| 2321 | |
| 2322 | raw_spin_lock_bh(&b->lock); |
| 2323 | l = lookup_elem_raw(head, hash, key, key_size); |
| 2324 | if (l) { |
| 2325 | struct sock *sock = l->sk; |
| 2326 | struct smap_psock *psock; |
| 2327 | |
| 2328 | hlist_del_rcu(&l->hash_node); |
| 2329 | write_lock_bh(&sock->sk_callback_lock); |
| 2330 | psock = smap_psock_sk(sock); |
| 2331 | /* This check handles a racing sock event that can get the |
| 2332 | * sk_callback_lock before this case but after xchg happens |
| 2333 | * causing the refcnt to hit zero and sock user data (psock) |
| 2334 | * to be null and queued for garbage collection. |
| 2335 | */ |
| 2336 | if (likely(psock)) { |
| 2337 | smap_list_remove(psock, NULL, l); |
| 2338 | smap_release_sock(psock, sock); |
| 2339 | } |
| 2340 | write_unlock_bh(&sock->sk_callback_lock); |
| 2341 | free_htab_elem(htab, l); |
| 2342 | ret = 0; |
| 2343 | } |
| 2344 | raw_spin_unlock_bh(&b->lock); |
| 2345 | return ret; |
| 2346 | } |
| 2347 | |
| 2348 | struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key) |
| 2349 | { |
| 2350 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
| 2351 | struct hlist_head *head; |
| 2352 | struct htab_elem *l; |
| 2353 | u32 key_size, hash; |
| 2354 | struct bucket *b; |
| 2355 | struct sock *sk; |
| 2356 | |
| 2357 | key_size = map->key_size; |
| 2358 | hash = htab_map_hash(key, key_size); |
| 2359 | b = __select_bucket(htab, hash); |
| 2360 | head = &b->head; |
| 2361 | |
| 2362 | raw_spin_lock_bh(&b->lock); |
| 2363 | l = lookup_elem_raw(head, hash, key, key_size); |
| 2364 | sk = l ? l->sk : NULL; |
| 2365 | raw_spin_unlock_bh(&b->lock); |
| 2366 | return sk; |
| 2367 | } |
| 2368 | |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 2369 | const struct bpf_map_ops sock_map_ops = { |
| 2370 | .map_alloc = sock_map_alloc, |
| 2371 | .map_free = sock_map_free, |
| 2372 | .map_lookup_elem = sock_map_lookup, |
| 2373 | .map_get_next_key = sock_map_get_next_key, |
| 2374 | .map_update_elem = sock_map_update_elem, |
| 2375 | .map_delete_elem = sock_map_delete_elem, |
John Fastabend | ba6b8de | 2018-04-23 15:39:23 -0700 | [diff] [blame] | 2376 | .map_release_uref = sock_map_release, |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 2377 | }; |
| 2378 | |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2379 | const struct bpf_map_ops sock_hash_ops = { |
| 2380 | .map_alloc = sock_hash_alloc, |
| 2381 | .map_free = sock_hash_free, |
| 2382 | .map_lookup_elem = sock_map_lookup, |
| 2383 | .map_get_next_key = sock_hash_get_next_key, |
| 2384 | .map_update_elem = sock_hash_update_elem, |
| 2385 | .map_delete_elem = sock_hash_delete_elem, |
| 2386 | }; |
| 2387 | |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 2388 | BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, bpf_sock, |
| 2389 | struct bpf_map *, map, void *, key, u64, flags) |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 2390 | { |
| 2391 | WARN_ON_ONCE(!rcu_read_lock_held()); |
John Fastabend | 2f857d0 | 2017-08-28 07:10:25 -0700 | [diff] [blame] | 2392 | return sock_map_ctx_update_elem(bpf_sock, map, key, flags); |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 2393 | } |
| 2394 | |
| 2395 | const struct bpf_func_proto bpf_sock_map_update_proto = { |
| 2396 | .func = bpf_sock_map_update, |
| 2397 | .gpl_only = false, |
| 2398 | .pkt_access = true, |
| 2399 | .ret_type = RET_INTEGER, |
| 2400 | .arg1_type = ARG_PTR_TO_CTX, |
| 2401 | .arg2_type = ARG_CONST_MAP_PTR, |
| 2402 | .arg3_type = ARG_PTR_TO_MAP_KEY, |
| 2403 | .arg4_type = ARG_ANYTHING, |
John Fastabend | 174a79f | 2017-08-15 22:32:47 -0700 | [diff] [blame] | 2404 | }; |
John Fastabend | 8111038 | 2018-05-14 10:00:17 -0700 | [diff] [blame] | 2405 | |
| 2406 | BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, bpf_sock, |
| 2407 | struct bpf_map *, map, void *, key, u64, flags) |
| 2408 | { |
| 2409 | WARN_ON_ONCE(!rcu_read_lock_held()); |
| 2410 | return sock_hash_ctx_update_elem(bpf_sock, map, key, flags); |
| 2411 | } |
| 2412 | |
| 2413 | const struct bpf_func_proto bpf_sock_hash_update_proto = { |
| 2414 | .func = bpf_sock_hash_update, |
| 2415 | .gpl_only = false, |
| 2416 | .pkt_access = true, |
| 2417 | .ret_type = RET_INTEGER, |
| 2418 | .arg1_type = ARG_PTR_TO_CTX, |
| 2419 | .arg2_type = ARG_CONST_MAP_PTR, |
| 2420 | .arg3_type = ARG_PTR_TO_MAP_KEY, |
| 2421 | .arg4_type = ARG_ANYTHING, |
| 2422 | }; |