1 /* 2 * linux/fs/lockd/mon.c 3 * 4 * The kernel statd client. 5 * 6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> 7 */ 8 9 #include <linux/types.h> 10 #include <linux/utsname.h> 11 #include <linux/kernel.h> 12 #include <linux/sunrpc/clnt.h> 13 #include <linux/sunrpc/xprtsock.h> 14 #include <linux/sunrpc/svc.h> 15 #include <linux/lockd/lockd.h> 16 #include <linux/lockd/sm_inter.h> 17 18 19 #define NLMDBG_FACILITY NLMDBG_MONITOR 20 #define NSM_PROGRAM 100024 21 #define NSM_VERSION 1 22 23 enum { 24 NSMPROC_NULL, 25 NSMPROC_STAT, 26 NSMPROC_MON, 27 NSMPROC_UNMON, 28 NSMPROC_UNMON_ALL, 29 NSMPROC_SIMU_CRASH, 30 NSMPROC_NOTIFY, 31 }; 32 33 struct nsm_args { 34 __be32 addr; /* remote address */ 35 u32 prog; /* RPC callback info */ 36 u32 vers; 37 u32 proc; 38 39 char *mon_name; 40 }; 41 42 struct nsm_res { 43 u32 status; 44 u32 state; 45 }; 46 47 static struct rpc_clnt * nsm_create(void); 48 49 static struct rpc_program nsm_program; 50 static LIST_HEAD(nsm_handles); 51 static DEFINE_SPINLOCK(nsm_lock); 52 53 /* 54 * Local NSM state 55 */ 56 int nsm_local_state; 57 58 static void nsm_display_ipv4_address(const struct sockaddr *sap, char *buf, 59 const size_t len) 60 { 61 const struct sockaddr_in *sin = (struct sockaddr_in *)sap; 62 snprintf(buf, len, "%pI4", &sin->sin_addr.s_addr); 63 } 64 65 static void nsm_display_ipv6_address(const struct sockaddr *sap, char *buf, 66 const size_t len) 67 { 68 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap; 69 70 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) 71 snprintf(buf, len, "%pI4", &sin6->sin6_addr.s6_addr32[3]); 72 else if (sin6->sin6_scope_id != 0) 73 snprintf(buf, len, "%pI6%%%u", &sin6->sin6_addr, 74 sin6->sin6_scope_id); 75 else 76 snprintf(buf, len, "%pI6", &sin6->sin6_addr); 77 } 78 79 static void nsm_display_address(const struct sockaddr *sap, 80 char *buf, const size_t len) 81 { 82 switch (sap->sa_family) { 83 case AF_INET: 84 nsm_display_ipv4_address(sap, buf, len); 85 break; 86 case AF_INET6: 87 nsm_display_ipv6_address(sap, buf, len); 88 break; 89 default: 90 snprintf(buf, len, "unsupported address family"); 91 break; 92 } 93 } 94 95 /* 96 * Common procedure for NSMPROC_MON/NSMPROC_UNMON calls 97 */ 98 static int 99 nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res) 100 { 101 struct rpc_clnt *clnt; 102 int status; 103 struct nsm_args args = { 104 .addr = nsm_addr_in(nsm)->sin_addr.s_addr, 105 .prog = NLM_PROGRAM, 106 .vers = 3, 107 .proc = NLMPROC_NSM_NOTIFY, 108 .mon_name = nsm->sm_mon_name, 109 }; 110 struct rpc_message msg = { 111 .rpc_argp = &args, 112 .rpc_resp = res, 113 }; 114 115 clnt = nsm_create(); 116 if (IS_ERR(clnt)) { 117 status = PTR_ERR(clnt); 118 dprintk("lockd: failed to create NSM upcall transport, " 119 "status=%d\n", status); 120 goto out; 121 } 122 123 memset(res, 0, sizeof(*res)); 124 125 msg.rpc_proc = &clnt->cl_procinfo[proc]; 126 status = rpc_call_sync(clnt, &msg, 0); 127 if (status < 0) 128 dprintk("lockd: NSM upcall RPC failed, status=%d\n", 129 status); 130 else 131 status = 0; 132 rpc_shutdown_client(clnt); 133 out: 134 return status; 135 } 136 137 /** 138 * nsm_monitor - Notify a peer in case we reboot 139 * @host: pointer to nlm_host of peer to notify 140 * 141 * If this peer is not already monitored, this function sends an 142 * upcall to the local rpc.statd to record the name/address of 143 * the peer to notify in case we reboot. 144 * 145 * Returns zero if the peer is monitored by the local rpc.statd; 146 * otherwise a negative errno value is returned. 147 */ 148 int nsm_monitor(const struct nlm_host *host) 149 { 150 struct nsm_handle *nsm = host->h_nsmhandle; 151 struct nsm_res res; 152 int status; 153 154 dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name); 155 156 if (nsm->sm_monitored) 157 return 0; 158 159 /* 160 * Choose whether to record the caller_name or IP address of 161 * this peer in the local rpc.statd's database. 162 */ 163 nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf; 164 165 status = nsm_mon_unmon(nsm, NSMPROC_MON, &res); 166 if (res.status != 0) 167 status = -EIO; 168 if (status < 0) 169 printk(KERN_NOTICE "lockd: cannot monitor %s\n", nsm->sm_name); 170 else 171 nsm->sm_monitored = 1; 172 return status; 173 } 174 175 /** 176 * nsm_unmonitor - Unregister peer notification 177 * @host: pointer to nlm_host of peer to stop monitoring 178 * 179 * If this peer is monitored, this function sends an upcall to 180 * tell the local rpc.statd not to send this peer a notification 181 * when we reboot. 182 */ 183 void nsm_unmonitor(const struct nlm_host *host) 184 { 185 struct nsm_handle *nsm = host->h_nsmhandle; 186 struct nsm_res res; 187 int status; 188 189 if (atomic_read(&nsm->sm_count) == 1 190 && nsm->sm_monitored && !nsm->sm_sticky) { 191 dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name); 192 193 status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res); 194 if (res.status != 0) 195 status = -EIO; 196 if (status < 0) 197 printk(KERN_NOTICE "lockd: cannot unmonitor %s\n", 198 nsm->sm_name); 199 else 200 nsm->sm_monitored = 0; 201 } 202 } 203 204 /** 205 * nsm_find - Find or create a cached nsm_handle 206 * @sap: pointer to socket address of handle to find 207 * @salen: length of socket address 208 * @hostname: pointer to C string containing hostname to find 209 * @hostname_len: length of C string 210 * @create: one means create new handle if not found in cache 211 * 212 * Behavior is modulated by the global nsm_use_hostnames variable 213 * and by the @create argument. 214 * 215 * Returns a cached nsm_handle after bumping its ref count, or if 216 * @create is set, returns a fresh nsm_handle if a handle that 217 * matches @sap and/or @hostname cannot be found in the handle cache. 218 * Returns NULL if an error occurs. 219 */ 220 struct nsm_handle *nsm_find(const struct sockaddr *sap, const size_t salen, 221 const char *hostname, const size_t hostname_len, 222 const int create) 223 { 224 struct nsm_handle *nsm = NULL; 225 struct nsm_handle *pos; 226 227 if (!sap) 228 return NULL; 229 230 if (hostname && memchr(hostname, '/', hostname_len) != NULL) { 231 if (printk_ratelimit()) { 232 printk(KERN_WARNING "Invalid hostname \"%.*s\" " 233 "in NFS lock request\n", 234 (int)hostname_len, hostname); 235 } 236 return NULL; 237 } 238 239 retry: 240 spin_lock(&nsm_lock); 241 list_for_each_entry(pos, &nsm_handles, sm_link) { 242 243 if (hostname && nsm_use_hostnames) { 244 if (strlen(pos->sm_name) != hostname_len 245 || memcmp(pos->sm_name, hostname, hostname_len)) 246 continue; 247 } else if (!nlm_cmp_addr(nsm_addr(pos), sap)) 248 continue; 249 atomic_inc(&pos->sm_count); 250 kfree(nsm); 251 nsm = pos; 252 goto found; 253 } 254 if (nsm) { 255 list_add(&nsm->sm_link, &nsm_handles); 256 goto found; 257 } 258 spin_unlock(&nsm_lock); 259 260 if (!create) 261 return NULL; 262 263 nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL); 264 if (nsm == NULL) 265 return NULL; 266 267 memcpy(nsm_addr(nsm), sap, salen); 268 nsm->sm_addrlen = salen; 269 nsm->sm_name = (char *) (nsm + 1); 270 memcpy(nsm->sm_name, hostname, hostname_len); 271 nsm->sm_name[hostname_len] = '\0'; 272 nsm_display_address((struct sockaddr *)&nsm->sm_addr, 273 nsm->sm_addrbuf, sizeof(nsm->sm_addrbuf)); 274 atomic_set(&nsm->sm_count, 1); 275 goto retry; 276 277 found: 278 spin_unlock(&nsm_lock); 279 return nsm; 280 } 281 282 /** 283 * nsm_release - Release an NSM handle 284 * @nsm: pointer to handle to be released 285 * 286 */ 287 void nsm_release(struct nsm_handle *nsm) 288 { 289 if (!nsm) 290 return; 291 if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) { 292 list_del(&nsm->sm_link); 293 spin_unlock(&nsm_lock); 294 kfree(nsm); 295 } 296 } 297 298 /* 299 * Create NSM client for the local host 300 */ 301 static struct rpc_clnt * 302 nsm_create(void) 303 { 304 struct sockaddr_in sin = { 305 .sin_family = AF_INET, 306 .sin_addr.s_addr = htonl(INADDR_LOOPBACK), 307 .sin_port = 0, 308 }; 309 struct rpc_create_args args = { 310 .protocol = XPRT_TRANSPORT_UDP, 311 .address = (struct sockaddr *)&sin, 312 .addrsize = sizeof(sin), 313 .servername = "localhost", 314 .program = &nsm_program, 315 .version = NSM_VERSION, 316 .authflavor = RPC_AUTH_NULL, 317 }; 318 319 return rpc_create(&args); 320 } 321 322 /* 323 * XDR functions for NSM. 324 * 325 * See http://www.opengroup.org/ for details on the Network 326 * Status Monitor wire protocol. 327 */ 328 329 static int encode_nsm_string(struct xdr_stream *xdr, const char *string) 330 { 331 const u32 len = strlen(string); 332 __be32 *p; 333 334 if (unlikely(len > SM_MAXSTRLEN)) 335 return -EIO; 336 p = xdr_reserve_space(xdr, sizeof(u32) + len); 337 if (unlikely(p == NULL)) 338 return -EIO; 339 xdr_encode_opaque(p, string, len); 340 return 0; 341 } 342 343 /* 344 * "mon_name" specifies the host to be monitored. 345 */ 346 static int encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp) 347 { 348 return encode_nsm_string(xdr, argp->mon_name); 349 } 350 351 /* 352 * The "my_id" argument specifies the hostname and RPC procedure 353 * to be called when the status manager receives notification 354 * (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name" 355 * has changed. 356 */ 357 static int encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp) 358 { 359 int status; 360 __be32 *p; 361 362 status = encode_nsm_string(xdr, utsname()->nodename); 363 if (unlikely(status != 0)) 364 return status; 365 p = xdr_reserve_space(xdr, 3 * sizeof(u32)); 366 if (unlikely(p == NULL)) 367 return -EIO; 368 *p++ = htonl(argp->prog); 369 *p++ = htonl(argp->vers); 370 *p++ = htonl(argp->proc); 371 return 0; 372 } 373 374 /* 375 * The "mon_id" argument specifies the non-private arguments 376 * of an NSMPROC_MON or NSMPROC_UNMON call. 377 */ 378 static int encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp) 379 { 380 int status; 381 382 status = encode_mon_name(xdr, argp); 383 if (unlikely(status != 0)) 384 return status; 385 return encode_my_id(xdr, argp); 386 } 387 388 /* 389 * The "priv" argument may contain private information required 390 * by the NSMPROC_MON call. This information will be supplied in the 391 * NLMPROC_SM_NOTIFY call. 392 * 393 * Linux provides the raw IP address of the monitored host, 394 * left in network byte order. 395 */ 396 static int encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp) 397 { 398 __be32 *p; 399 400 p = xdr_reserve_space(xdr, SM_PRIV_SIZE); 401 if (unlikely(p == NULL)) 402 return -EIO; 403 *p++ = argp->addr; 404 *p++ = 0; 405 *p++ = 0; 406 *p++ = 0; 407 return 0; 408 } 409 410 static int xdr_enc_mon(struct rpc_rqst *req, __be32 *p, 411 const struct nsm_args *argp) 412 { 413 struct xdr_stream xdr; 414 int status; 415 416 xdr_init_encode(&xdr, &req->rq_snd_buf, p); 417 status = encode_mon_id(&xdr, argp); 418 if (unlikely(status)) 419 return status; 420 return encode_priv(&xdr, argp); 421 } 422 423 static int xdr_enc_unmon(struct rpc_rqst *req, __be32 *p, 424 const struct nsm_args *argp) 425 { 426 struct xdr_stream xdr; 427 428 xdr_init_encode(&xdr, &req->rq_snd_buf, p); 429 return encode_mon_id(&xdr, argp); 430 } 431 432 static int xdr_dec_stat_res(struct rpc_rqst *rqstp, __be32 *p, 433 struct nsm_res *resp) 434 { 435 struct xdr_stream xdr; 436 437 xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p); 438 p = xdr_inline_decode(&xdr, 2 * sizeof(u32)); 439 if (unlikely(p == NULL)) 440 return -EIO; 441 resp->status = ntohl(*p++); 442 resp->state = ntohl(*p); 443 444 dprintk("lockd: xdr_dec_stat_res status %d state %d\n", 445 resp->status, resp->state); 446 return 0; 447 } 448 449 static int xdr_dec_stat(struct rpc_rqst *rqstp, __be32 *p, 450 struct nsm_res *resp) 451 { 452 struct xdr_stream xdr; 453 454 xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p); 455 p = xdr_inline_decode(&xdr, sizeof(u32)); 456 if (unlikely(p == NULL)) 457 return -EIO; 458 resp->state = ntohl(*p); 459 460 dprintk("lockd: xdr_dec_stat state %d\n", resp->state); 461 return 0; 462 } 463 464 #define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN)) 465 #define SM_my_id_sz (SM_my_name_sz+3) 466 #define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN)) 467 #define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz) 468 #define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE)) 469 #define SM_mon_sz (SM_mon_id_sz+SM_priv_sz) 470 #define SM_monres_sz 2 471 #define SM_unmonres_sz 1 472 473 static struct rpc_procinfo nsm_procedures[] = { 474 [NSMPROC_MON] = { 475 .p_proc = NSMPROC_MON, 476 .p_encode = (kxdrproc_t)xdr_enc_mon, 477 .p_decode = (kxdrproc_t)xdr_dec_stat_res, 478 .p_arglen = SM_mon_sz, 479 .p_replen = SM_monres_sz, 480 .p_statidx = NSMPROC_MON, 481 .p_name = "MONITOR", 482 }, 483 [NSMPROC_UNMON] = { 484 .p_proc = NSMPROC_UNMON, 485 .p_encode = (kxdrproc_t)xdr_enc_unmon, 486 .p_decode = (kxdrproc_t)xdr_dec_stat, 487 .p_arglen = SM_mon_id_sz, 488 .p_replen = SM_unmonres_sz, 489 .p_statidx = NSMPROC_UNMON, 490 .p_name = "UNMONITOR", 491 }, 492 }; 493 494 static struct rpc_version nsm_version1 = { 495 .number = 1, 496 .nrprocs = ARRAY_SIZE(nsm_procedures), 497 .procs = nsm_procedures 498 }; 499 500 static struct rpc_version * nsm_version[] = { 501 [1] = &nsm_version1, 502 }; 503 504 static struct rpc_stat nsm_stats; 505 506 static struct rpc_program nsm_program = { 507 .name = "statd", 508 .number = NSM_PROGRAM, 509 .nrvers = ARRAY_SIZE(nsm_version), 510 .version = nsm_version, 511 .stats = &nsm_stats 512 }; 513