Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 2 | /* |
| 3 | * linux/fs/nfs/dns_resolve.c |
| 4 | * |
| 5 | * Copyright (c) 2009 Trond Myklebust <Trond.Myklebust@netapp.com> |
| 6 | * |
| 7 | * Resolves DNS hostnames into valid ip addresses |
| 8 | */ |
| 9 | |
Bryan Schumaker | c2e8139 | 2010-08-11 09:37:53 +0100 | [diff] [blame] | 10 | #ifdef CONFIG_NFS_USE_KERNEL_DNS |
| 11 | |
Bryan Schumaker | 89d77c8 | 2012-07-30 16:05:25 -0400 | [diff] [blame] | 12 | #include <linux/module.h> |
Bryan Schumaker | c2e8139 | 2010-08-11 09:37:53 +0100 | [diff] [blame] | 13 | #include <linux/sunrpc/clnt.h> |
Jeff Layton | 5976687 | 2013-02-04 12:50:00 -0500 | [diff] [blame] | 14 | #include <linux/sunrpc/addr.h> |
Bryan Schumaker | c2e8139 | 2010-08-11 09:37:53 +0100 | [diff] [blame] | 15 | #include <linux/dns_resolver.h> |
Trond Myklebust | 1728017 | 2012-03-11 13:11:00 -0400 | [diff] [blame] | 16 | #include "dns_resolve.h" |
Bryan Schumaker | c2e8139 | 2010-08-11 09:37:53 +0100 | [diff] [blame] | 17 | |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 18 | ssize_t nfs_dns_resolve_name(struct net *net, char *name, size_t namelen, |
Bryan Schumaker | c2e8139 | 2010-08-11 09:37:53 +0100 | [diff] [blame] | 19 | struct sockaddr *sa, size_t salen) |
| 20 | { |
| 21 | ssize_t ret; |
| 22 | char *ip_addr = NULL; |
| 23 | int ip_len; |
| 24 | |
David Howells | a58946c | 2019-06-26 21:02:33 +0100 | [diff] [blame] | 25 | ip_len = dns_query(net, NULL, name, namelen, NULL, &ip_addr, NULL, |
| 26 | false); |
Bryan Schumaker | c2e8139 | 2010-08-11 09:37:53 +0100 | [diff] [blame] | 27 | if (ip_len > 0) |
Stanislav Kinsbursky | bc224f5 | 2012-01-26 15:11:33 +0400 | [diff] [blame] | 28 | ret = rpc_pton(net, ip_addr, ip_len, sa, salen); |
Bryan Schumaker | c2e8139 | 2010-08-11 09:37:53 +0100 | [diff] [blame] | 29 | else |
| 30 | ret = -ESRCH; |
| 31 | kfree(ip_addr); |
| 32 | return ret; |
| 33 | } |
| 34 | |
| 35 | #else |
| 36 | |
Bryan Schumaker | 89d77c8 | 2012-07-30 16:05:25 -0400 | [diff] [blame] | 37 | #include <linux/module.h> |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 38 | #include <linux/hash.h> |
| 39 | #include <linux/string.h> |
| 40 | #include <linux/kmod.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 41 | #include <linux/slab.h> |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 42 | #include <linux/socket.h> |
| 43 | #include <linux/seq_file.h> |
| 44 | #include <linux/inet.h> |
| 45 | #include <linux/sunrpc/clnt.h> |
Jeff Layton | 5976687 | 2013-02-04 12:50:00 -0500 | [diff] [blame] | 46 | #include <linux/sunrpc/addr.h> |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 47 | #include <linux/sunrpc/cache.h> |
| 48 | #include <linux/sunrpc/svcauth.h> |
Stanislav Kinsbursky | 9df69c8 | 2011-11-25 17:13:12 +0300 | [diff] [blame] | 49 | #include <linux/sunrpc/rpc_pipe_fs.h> |
Anna Schumaker | 694e096 | 2013-11-13 12:29:08 -0500 | [diff] [blame] | 50 | #include <linux/nfs_fs.h> |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 51 | |
Anna Schumaker | 694e096 | 2013-11-13 12:29:08 -0500 | [diff] [blame] | 52 | #include "nfs4_fs.h" |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 53 | #include "dns_resolve.h" |
| 54 | #include "cache_lib.h" |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 55 | #include "netns.h" |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 56 | |
| 57 | #define NFS_DNS_HASHBITS 4 |
| 58 | #define NFS_DNS_HASHTBL_SIZE (1 << NFS_DNS_HASHBITS) |
| 59 | |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 60 | struct nfs_dns_ent { |
| 61 | struct cache_head h; |
| 62 | |
| 63 | char *hostname; |
| 64 | size_t namelen; |
| 65 | |
| 66 | struct sockaddr_storage addr; |
| 67 | size_t addrlen; |
Trond Myklebust | 437f914 | 2018-10-01 10:41:50 -0400 | [diff] [blame] | 68 | struct rcu_head rcu_head; |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 69 | }; |
| 70 | |
| 71 | |
Trond Myklebust | ebed920 | 2010-03-02 13:06:22 -0500 | [diff] [blame] | 72 | static void nfs_dns_ent_update(struct cache_head *cnew, |
| 73 | struct cache_head *ckey) |
| 74 | { |
| 75 | struct nfs_dns_ent *new; |
| 76 | struct nfs_dns_ent *key; |
| 77 | |
| 78 | new = container_of(cnew, struct nfs_dns_ent, h); |
| 79 | key = container_of(ckey, struct nfs_dns_ent, h); |
| 80 | |
| 81 | memcpy(&new->addr, &key->addr, key->addrlen); |
| 82 | new->addrlen = key->addrlen; |
| 83 | } |
| 84 | |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 85 | static void nfs_dns_ent_init(struct cache_head *cnew, |
| 86 | struct cache_head *ckey) |
| 87 | { |
| 88 | struct nfs_dns_ent *new; |
| 89 | struct nfs_dns_ent *key; |
| 90 | |
| 91 | new = container_of(cnew, struct nfs_dns_ent, h); |
| 92 | key = container_of(ckey, struct nfs_dns_ent, h); |
| 93 | |
| 94 | kfree(new->hostname); |
Trond Myklebust | a8bd9dd | 2020-02-02 17:57:07 -0500 | [diff] [blame] | 95 | new->hostname = kmemdup_nul(key->hostname, key->namelen, GFP_KERNEL); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 96 | if (new->hostname) { |
| 97 | new->namelen = key->namelen; |
Trond Myklebust | ebed920 | 2010-03-02 13:06:22 -0500 | [diff] [blame] | 98 | nfs_dns_ent_update(cnew, ckey); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 99 | } else { |
| 100 | new->namelen = 0; |
| 101 | new->addrlen = 0; |
| 102 | } |
| 103 | } |
| 104 | |
Trond Myklebust | 437f914 | 2018-10-01 10:41:50 -0400 | [diff] [blame] | 105 | static void nfs_dns_ent_free_rcu(struct rcu_head *head) |
| 106 | { |
| 107 | struct nfs_dns_ent *item; |
| 108 | |
| 109 | item = container_of(head, struct nfs_dns_ent, rcu_head); |
| 110 | kfree(item->hostname); |
| 111 | kfree(item); |
| 112 | } |
| 113 | |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 114 | static void nfs_dns_ent_put(struct kref *ref) |
| 115 | { |
| 116 | struct nfs_dns_ent *item; |
| 117 | |
| 118 | item = container_of(ref, struct nfs_dns_ent, h.ref); |
Trond Myklebust | a648273 | 2018-10-05 10:27:20 -0400 | [diff] [blame] | 119 | call_rcu(&item->rcu_head, nfs_dns_ent_free_rcu); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 120 | } |
| 121 | |
| 122 | static struct cache_head *nfs_dns_ent_alloc(void) |
| 123 | { |
| 124 | struct nfs_dns_ent *item = kmalloc(sizeof(*item), GFP_KERNEL); |
| 125 | |
| 126 | if (item != NULL) { |
| 127 | item->hostname = NULL; |
| 128 | item->namelen = 0; |
| 129 | item->addrlen = 0; |
| 130 | return &item->h; |
| 131 | } |
| 132 | return NULL; |
| 133 | }; |
| 134 | |
| 135 | static unsigned int nfs_dns_hash(const struct nfs_dns_ent *key) |
| 136 | { |
| 137 | return hash_str(key->hostname, NFS_DNS_HASHBITS); |
| 138 | } |
| 139 | |
| 140 | static void nfs_dns_request(struct cache_detail *cd, |
| 141 | struct cache_head *ch, |
| 142 | char **bpp, int *blen) |
| 143 | { |
| 144 | struct nfs_dns_ent *key = container_of(ch, struct nfs_dns_ent, h); |
| 145 | |
| 146 | qword_add(bpp, blen, key->hostname); |
| 147 | (*bpp)[-1] = '\n'; |
| 148 | } |
| 149 | |
| 150 | static int nfs_dns_upcall(struct cache_detail *cd, |
| 151 | struct cache_head *ch) |
| 152 | { |
| 153 | struct nfs_dns_ent *key = container_of(ch, struct nfs_dns_ent, h); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 154 | |
Trond Myklebust | 65286b8 | 2020-03-01 18:21:42 -0500 | [diff] [blame] | 155 | if (test_and_set_bit(CACHE_PENDING, &ch->flags)) |
| 156 | return 0; |
| 157 | if (!nfs_cache_upcall(cd, key->hostname)) |
| 158 | return 0; |
| 159 | clear_bit(CACHE_PENDING, &ch->flags); |
| 160 | return sunrpc_cache_pipe_upcall_timeout(cd, ch); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 161 | } |
| 162 | |
| 163 | static int nfs_dns_match(struct cache_head *ca, |
| 164 | struct cache_head *cb) |
| 165 | { |
| 166 | struct nfs_dns_ent *a; |
| 167 | struct nfs_dns_ent *b; |
| 168 | |
| 169 | a = container_of(ca, struct nfs_dns_ent, h); |
| 170 | b = container_of(cb, struct nfs_dns_ent, h); |
| 171 | |
| 172 | if (a->namelen == 0 || a->namelen != b->namelen) |
| 173 | return 0; |
| 174 | return memcmp(a->hostname, b->hostname, a->namelen) == 0; |
| 175 | } |
| 176 | |
| 177 | static int nfs_dns_show(struct seq_file *m, struct cache_detail *cd, |
| 178 | struct cache_head *h) |
| 179 | { |
| 180 | struct nfs_dns_ent *item; |
| 181 | long ttl; |
| 182 | |
| 183 | if (h == NULL) { |
| 184 | seq_puts(m, "# ip address hostname ttl\n"); |
| 185 | return 0; |
| 186 | } |
| 187 | item = container_of(h, struct nfs_dns_ent, h); |
NeilBrown | c5b29f8 | 2010-08-12 16:55:22 +1000 | [diff] [blame] | 188 | ttl = item->h.expiry_time - seconds_since_boot(); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 189 | if (ttl < 0) |
| 190 | ttl = 0; |
| 191 | |
| 192 | if (!test_bit(CACHE_NEGATIVE, &h->flags)) { |
| 193 | char buf[INET6_ADDRSTRLEN+IPV6_SCOPE_ID_LEN+1]; |
| 194 | |
| 195 | rpc_ntop((struct sockaddr *)&item->addr, buf, sizeof(buf)); |
| 196 | seq_printf(m, "%15s ", buf); |
| 197 | } else |
| 198 | seq_puts(m, "<none> "); |
| 199 | seq_printf(m, "%15s %ld\n", item->hostname, ttl); |
| 200 | return 0; |
| 201 | } |
| 202 | |
Trond Myklebust | 0a6566e | 2009-12-03 15:54:01 -0500 | [diff] [blame] | 203 | static struct nfs_dns_ent *nfs_dns_lookup(struct cache_detail *cd, |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 204 | struct nfs_dns_ent *key) |
| 205 | { |
| 206 | struct cache_head *ch; |
| 207 | |
Trond Myklebust | 437f914 | 2018-10-01 10:41:50 -0400 | [diff] [blame] | 208 | ch = sunrpc_cache_lookup_rcu(cd, |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 209 | &key->h, |
| 210 | nfs_dns_hash(key)); |
| 211 | if (!ch) |
| 212 | return NULL; |
| 213 | return container_of(ch, struct nfs_dns_ent, h); |
| 214 | } |
| 215 | |
Trond Myklebust | 0a6566e | 2009-12-03 15:54:01 -0500 | [diff] [blame] | 216 | static struct nfs_dns_ent *nfs_dns_update(struct cache_detail *cd, |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 217 | struct nfs_dns_ent *new, |
| 218 | struct nfs_dns_ent *key) |
| 219 | { |
| 220 | struct cache_head *ch; |
| 221 | |
| 222 | ch = sunrpc_cache_update(cd, |
| 223 | &new->h, &key->h, |
| 224 | nfs_dns_hash(key)); |
| 225 | if (!ch) |
| 226 | return NULL; |
| 227 | return container_of(ch, struct nfs_dns_ent, h); |
| 228 | } |
| 229 | |
| 230 | static int nfs_dns_parse(struct cache_detail *cd, char *buf, int buflen) |
| 231 | { |
| 232 | char buf1[NFS_DNS_HOSTNAME_MAXLEN+1]; |
| 233 | struct nfs_dns_ent key, *item; |
NeilBrown | 8d96b10 | 2012-10-31 12:16:01 +1100 | [diff] [blame] | 234 | unsigned int ttl; |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 235 | ssize_t len; |
| 236 | int ret = -EINVAL; |
| 237 | |
| 238 | if (buf[buflen-1] != '\n') |
| 239 | goto out; |
| 240 | buf[buflen-1] = '\0'; |
| 241 | |
| 242 | len = qword_get(&buf, buf1, sizeof(buf1)); |
| 243 | if (len <= 0) |
| 244 | goto out; |
Stanislav Kinsbursky | 599ec12 | 2012-01-19 18:51:04 +0400 | [diff] [blame] | 245 | key.addrlen = rpc_pton(cd->net, buf1, len, |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 246 | (struct sockaddr *)&key.addr, |
| 247 | sizeof(key.addr)); |
| 248 | |
| 249 | len = qword_get(&buf, buf1, sizeof(buf1)); |
| 250 | if (len <= 0) |
| 251 | goto out; |
| 252 | |
| 253 | key.hostname = buf1; |
| 254 | key.namelen = len; |
| 255 | memset(&key.h, 0, sizeof(key.h)); |
| 256 | |
NeilBrown | 8d96b10 | 2012-10-31 12:16:01 +1100 | [diff] [blame] | 257 | if (get_uint(&buf, &ttl) < 0) |
| 258 | goto out; |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 259 | if (ttl == 0) |
| 260 | goto out; |
NeilBrown | c5b29f8 | 2010-08-12 16:55:22 +1000 | [diff] [blame] | 261 | key.h.expiry_time = ttl + seconds_since_boot(); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 262 | |
| 263 | ret = -ENOMEM; |
| 264 | item = nfs_dns_lookup(cd, &key); |
| 265 | if (item == NULL) |
| 266 | goto out; |
| 267 | |
| 268 | if (key.addrlen == 0) |
| 269 | set_bit(CACHE_NEGATIVE, &key.h.flags); |
| 270 | |
| 271 | item = nfs_dns_update(cd, &key, item); |
| 272 | if (item == NULL) |
| 273 | goto out; |
| 274 | |
| 275 | ret = 0; |
| 276 | cache_put(&item->h, cd); |
| 277 | out: |
| 278 | return ret; |
| 279 | } |
| 280 | |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 281 | static int do_cache_lookup(struct cache_detail *cd, |
| 282 | struct nfs_dns_ent *key, |
| 283 | struct nfs_dns_ent **item, |
| 284 | struct nfs_cache_defer_req *dreq) |
| 285 | { |
| 286 | int ret = -ENOMEM; |
| 287 | |
| 288 | *item = nfs_dns_lookup(cd, key); |
| 289 | if (*item) { |
| 290 | ret = cache_check(cd, &(*item)->h, &dreq->req); |
| 291 | if (ret) |
| 292 | *item = NULL; |
| 293 | } |
| 294 | return ret; |
| 295 | } |
| 296 | |
| 297 | static int do_cache_lookup_nowait(struct cache_detail *cd, |
| 298 | struct nfs_dns_ent *key, |
| 299 | struct nfs_dns_ent **item) |
| 300 | { |
| 301 | int ret = -ENOMEM; |
| 302 | |
| 303 | *item = nfs_dns_lookup(cd, key); |
| 304 | if (!*item) |
| 305 | goto out_err; |
| 306 | ret = -ETIMEDOUT; |
| 307 | if (!test_bit(CACHE_VALID, &(*item)->h.flags) |
NeilBrown | c5b29f8 | 2010-08-12 16:55:22 +1000 | [diff] [blame] | 308 | || (*item)->h.expiry_time < seconds_since_boot() |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 309 | || cd->flush_time > (*item)->h.last_refresh) |
| 310 | goto out_put; |
| 311 | ret = -ENOENT; |
| 312 | if (test_bit(CACHE_NEGATIVE, &(*item)->h.flags)) |
| 313 | goto out_put; |
| 314 | return 0; |
| 315 | out_put: |
| 316 | cache_put(&(*item)->h, cd); |
| 317 | out_err: |
| 318 | *item = NULL; |
| 319 | return ret; |
| 320 | } |
| 321 | |
| 322 | static int do_cache_lookup_wait(struct cache_detail *cd, |
| 323 | struct nfs_dns_ent *key, |
| 324 | struct nfs_dns_ent **item) |
| 325 | { |
| 326 | struct nfs_cache_defer_req *dreq; |
| 327 | int ret = -ENOMEM; |
| 328 | |
| 329 | dreq = nfs_cache_defer_req_alloc(); |
| 330 | if (!dreq) |
| 331 | goto out; |
| 332 | ret = do_cache_lookup(cd, key, item, dreq); |
| 333 | if (ret == -EAGAIN) { |
| 334 | ret = nfs_cache_wait_for_upcall(dreq); |
| 335 | if (!ret) |
| 336 | ret = do_cache_lookup_nowait(cd, key, item); |
| 337 | } |
| 338 | nfs_cache_defer_req_put(dreq); |
| 339 | out: |
| 340 | return ret; |
| 341 | } |
| 342 | |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 343 | ssize_t nfs_dns_resolve_name(struct net *net, char *name, |
| 344 | size_t namelen, struct sockaddr *sa, size_t salen) |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 345 | { |
| 346 | struct nfs_dns_ent key = { |
| 347 | .hostname = name, |
| 348 | .namelen = namelen, |
| 349 | }; |
| 350 | struct nfs_dns_ent *item = NULL; |
| 351 | ssize_t ret; |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 352 | struct nfs_net *nn = net_generic(net, nfs_net_id); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 353 | |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 354 | ret = do_cache_lookup_wait(nn->nfs_dns_resolve, &key, &item); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 355 | if (ret == 0) { |
| 356 | if (salen >= item->addrlen) { |
| 357 | memcpy(sa, &item->addr, item->addrlen); |
| 358 | ret = item->addrlen; |
| 359 | } else |
| 360 | ret = -EOVERFLOW; |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 361 | cache_put(&item->h, nn->nfs_dns_resolve); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 362 | } else if (ret == -ENOENT) |
| 363 | ret = -ESRCH; |
| 364 | return ret; |
| 365 | } |
| 366 | |
Stanislav Kinsbursky | 483479c | 2013-02-04 14:02:35 +0300 | [diff] [blame] | 367 | static struct cache_detail nfs_dns_resolve_template = { |
| 368 | .owner = THIS_MODULE, |
| 369 | .hash_size = NFS_DNS_HASHTBL_SIZE, |
| 370 | .name = "dns_resolve", |
| 371 | .cache_put = nfs_dns_ent_put, |
| 372 | .cache_upcall = nfs_dns_upcall, |
Stanislav Kinsbursky | 73fb847 | 2013-02-04 14:02:45 +0300 | [diff] [blame] | 373 | .cache_request = nfs_dns_request, |
Stanislav Kinsbursky | 483479c | 2013-02-04 14:02:35 +0300 | [diff] [blame] | 374 | .cache_parse = nfs_dns_parse, |
| 375 | .cache_show = nfs_dns_show, |
| 376 | .match = nfs_dns_match, |
| 377 | .init = nfs_dns_ent_init, |
| 378 | .update = nfs_dns_ent_update, |
| 379 | .alloc = nfs_dns_ent_alloc, |
| 380 | }; |
| 381 | |
| 382 | |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 383 | int nfs_dns_resolver_cache_init(struct net *net) |
| 384 | { |
Stanislav Kinsbursky | 483479c | 2013-02-04 14:02:35 +0300 | [diff] [blame] | 385 | int err; |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 386 | struct nfs_net *nn = net_generic(net, nfs_net_id); |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 387 | |
Stanislav Kinsbursky | 483479c | 2013-02-04 14:02:35 +0300 | [diff] [blame] | 388 | nn->nfs_dns_resolve = cache_create_net(&nfs_dns_resolve_template, net); |
| 389 | if (IS_ERR(nn->nfs_dns_resolve)) |
| 390 | return PTR_ERR(nn->nfs_dns_resolve); |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 391 | |
Stanislav Kinsbursky | 483479c | 2013-02-04 14:02:35 +0300 | [diff] [blame] | 392 | err = nfs_cache_register_net(net, nn->nfs_dns_resolve); |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 393 | if (err) |
| 394 | goto err_reg; |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 395 | return 0; |
| 396 | |
| 397 | err_reg: |
Stanislav Kinsbursky | 483479c | 2013-02-04 14:02:35 +0300 | [diff] [blame] | 398 | cache_destroy_net(nn->nfs_dns_resolve, net); |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 399 | return err; |
| 400 | } |
| 401 | |
| 402 | void nfs_dns_resolver_cache_destroy(struct net *net) |
| 403 | { |
| 404 | struct nfs_net *nn = net_generic(net, nfs_net_id); |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 405 | |
Stanislav Kinsbursky | 462b8f6 | 2013-02-04 14:02:40 +0300 | [diff] [blame] | 406 | nfs_cache_unregister_net(net, nn->nfs_dns_resolve); |
Stanislav Kinsbursky | 483479c | 2013-02-04 14:02:35 +0300 | [diff] [blame] | 407 | cache_destroy_net(nn->nfs_dns_resolve, net); |
Stanislav Kinsbursky | 1b340d0 | 2011-11-25 17:13:04 +0300 | [diff] [blame] | 408 | } |
| 409 | |
Trond Myklebust | c8d74d9 | 2013-06-01 11:50:58 -0400 | [diff] [blame] | 410 | static int nfs4_dns_net_init(struct net *net) |
| 411 | { |
| 412 | return nfs_dns_resolver_cache_init(net); |
| 413 | } |
| 414 | |
| 415 | static void nfs4_dns_net_exit(struct net *net) |
| 416 | { |
| 417 | nfs_dns_resolver_cache_destroy(net); |
| 418 | } |
| 419 | |
| 420 | static struct pernet_operations nfs4_dns_resolver_ops = { |
| 421 | .init = nfs4_dns_net_init, |
| 422 | .exit = nfs4_dns_net_exit, |
| 423 | }; |
| 424 | |
Stanislav Kinsbursky | 9df69c8 | 2011-11-25 17:13:12 +0300 | [diff] [blame] | 425 | static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event, |
| 426 | void *ptr) |
| 427 | { |
| 428 | struct super_block *sb = ptr; |
| 429 | struct net *net = sb->s_fs_info; |
| 430 | struct nfs_net *nn = net_generic(net, nfs_net_id); |
| 431 | struct cache_detail *cd = nn->nfs_dns_resolve; |
| 432 | int ret = 0; |
| 433 | |
| 434 | if (cd == NULL) |
| 435 | return 0; |
| 436 | |
| 437 | if (!try_module_get(THIS_MODULE)) |
| 438 | return 0; |
| 439 | |
| 440 | switch (event) { |
| 441 | case RPC_PIPEFS_MOUNT: |
| 442 | ret = nfs_cache_register_sb(sb, cd); |
| 443 | break; |
| 444 | case RPC_PIPEFS_UMOUNT: |
| 445 | nfs_cache_unregister_sb(sb, cd); |
| 446 | break; |
| 447 | default: |
| 448 | ret = -ENOTSUPP; |
| 449 | break; |
| 450 | } |
| 451 | module_put(THIS_MODULE); |
| 452 | return ret; |
| 453 | } |
| 454 | |
| 455 | static struct notifier_block nfs_dns_resolver_block = { |
| 456 | .notifier_call = rpc_pipefs_event, |
| 457 | }; |
| 458 | |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 459 | int nfs_dns_resolver_init(void) |
| 460 | { |
Trond Myklebust | c8d74d9 | 2013-06-01 11:50:58 -0400 | [diff] [blame] | 461 | int err; |
| 462 | |
| 463 | err = register_pernet_subsys(&nfs4_dns_resolver_ops); |
| 464 | if (err < 0) |
| 465 | goto out; |
| 466 | err = rpc_pipefs_notifier_register(&nfs_dns_resolver_block); |
| 467 | if (err < 0) |
| 468 | goto out1; |
| 469 | return 0; |
| 470 | out1: |
| 471 | unregister_pernet_subsys(&nfs4_dns_resolver_ops); |
| 472 | out: |
| 473 | return err; |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 474 | } |
| 475 | |
| 476 | void nfs_dns_resolver_destroy(void) |
| 477 | { |
Stanislav Kinsbursky | 9df69c8 | 2011-11-25 17:13:12 +0300 | [diff] [blame] | 478 | rpc_pipefs_notifier_unregister(&nfs_dns_resolver_block); |
Trond Myklebust | c8d74d9 | 2013-06-01 11:50:58 -0400 | [diff] [blame] | 479 | unregister_pernet_subsys(&nfs4_dns_resolver_ops); |
Trond Myklebust | e571cbf | 2009-08-19 18:12:27 -0400 | [diff] [blame] | 480 | } |
Bryan Schumaker | c2e8139 | 2010-08-11 09:37:53 +0100 | [diff] [blame] | 481 | #endif |