1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* SCTP kernel implementation 3 * (C) Copyright Red Hat Inc. 2017 4 * 5 * This file is part of the SCTP kernel implementation 6 * 7 * These functions implement sctp diag support. 8 * 9 * Please send any bug reports or fixes you make to the 10 * email addresched(es): 11 * lksctp developers <linux-sctp@vger.kernel.org> 12 * 13 * Written or modified by: 14 * Xin Long <lucien.xin@gmail.com> 15 */ 16 17 #include <linux/module.h> 18 #include <linux/inet_diag.h> 19 #include <linux/sock_diag.h> 20 #include <net/sctp/sctp.h> 21 22 static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r, 23 void *info); 24 25 /* define some functions to make asoc/ep fill look clean */ 26 static void inet_diag_msg_sctpasoc_fill(struct inet_diag_msg *r, 27 struct sock *sk, 28 struct sctp_association *asoc) 29 { 30 union sctp_addr laddr, paddr; 31 struct dst_entry *dst; 32 struct timer_list *t3_rtx = &asoc->peer.primary_path->T3_rtx_timer; 33 34 laddr = list_entry(asoc->base.bind_addr.address_list.next, 35 struct sctp_sockaddr_entry, list)->a; 36 paddr = asoc->peer.primary_path->ipaddr; 37 dst = asoc->peer.primary_path->dst; 38 39 r->idiag_family = sk->sk_family; 40 r->id.idiag_sport = htons(asoc->base.bind_addr.port); 41 r->id.idiag_dport = htons(asoc->peer.port); 42 r->id.idiag_if = dst ? dst->dev->ifindex : 0; 43 sock_diag_save_cookie(sk, r->id.idiag_cookie); 44 45 #if IS_ENABLED(CONFIG_IPV6) 46 if (sk->sk_family == AF_INET6) { 47 *(struct in6_addr *)r->id.idiag_src = laddr.v6.sin6_addr; 48 *(struct in6_addr *)r->id.idiag_dst = paddr.v6.sin6_addr; 49 } else 50 #endif 51 { 52 memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src)); 53 memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst)); 54 55 r->id.idiag_src[0] = laddr.v4.sin_addr.s_addr; 56 r->id.idiag_dst[0] = paddr.v4.sin_addr.s_addr; 57 } 58 59 r->idiag_state = asoc->state; 60 if (timer_pending(t3_rtx)) { 61 r->idiag_timer = SCTP_EVENT_TIMEOUT_T3_RTX; 62 r->idiag_retrans = asoc->rtx_data_chunks; 63 r->idiag_expires = jiffies_to_msecs(t3_rtx->expires - jiffies); 64 } 65 } 66 67 static int inet_diag_msg_sctpladdrs_fill(struct sk_buff *skb, 68 struct list_head *address_list) 69 { 70 struct sctp_sockaddr_entry *laddr; 71 int addrlen = sizeof(struct sockaddr_storage); 72 int addrcnt = 0; 73 struct nlattr *attr; 74 void *info = NULL; 75 76 rcu_read_lock(); 77 list_for_each_entry_rcu(laddr, address_list, list) 78 addrcnt++; 79 rcu_read_unlock(); 80 81 attr = nla_reserve(skb, INET_DIAG_LOCALS, addrlen * addrcnt); 82 if (!attr) 83 return -EMSGSIZE; 84 85 info = nla_data(attr); 86 rcu_read_lock(); 87 list_for_each_entry_rcu(laddr, address_list, list) { 88 memcpy(info, &laddr->a, sizeof(laddr->a)); 89 memset(info + sizeof(laddr->a), 0, addrlen - sizeof(laddr->a)); 90 info += addrlen; 91 92 if (!--addrcnt) 93 break; 94 } 95 rcu_read_unlock(); 96 97 return 0; 98 } 99 100 static int inet_diag_msg_sctpaddrs_fill(struct sk_buff *skb, 101 struct sctp_association *asoc) 102 { 103 int addrlen = sizeof(struct sockaddr_storage); 104 struct sctp_transport *from; 105 struct nlattr *attr; 106 void *info = NULL; 107 108 attr = nla_reserve(skb, INET_DIAG_PEERS, 109 addrlen * asoc->peer.transport_count); 110 if (!attr) 111 return -EMSGSIZE; 112 113 info = nla_data(attr); 114 list_for_each_entry(from, &asoc->peer.transport_addr_list, 115 transports) { 116 memcpy(info, &from->ipaddr, sizeof(from->ipaddr)); 117 memset(info + sizeof(from->ipaddr), 0, 118 addrlen - sizeof(from->ipaddr)); 119 info += addrlen; 120 } 121 122 return 0; 123 } 124 125 /* sctp asoc/ep fill*/ 126 static int inet_sctp_diag_fill(struct sock *sk, struct sctp_association *asoc, 127 struct sk_buff *skb, 128 const struct inet_diag_req_v2 *req, 129 struct user_namespace *user_ns, 130 int portid, u32 seq, u16 nlmsg_flags, 131 const struct nlmsghdr *unlh, 132 bool net_admin) 133 { 134 struct sctp_endpoint *ep = sctp_sk(sk)->ep; 135 struct list_head *addr_list; 136 struct inet_diag_msg *r; 137 struct nlmsghdr *nlh; 138 int ext = req->idiag_ext; 139 struct sctp_infox infox; 140 void *info = NULL; 141 142 nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r), 143 nlmsg_flags); 144 if (!nlh) 145 return -EMSGSIZE; 146 147 r = nlmsg_data(nlh); 148 BUG_ON(!sk_fullsock(sk)); 149 150 r->idiag_timer = 0; 151 r->idiag_retrans = 0; 152 r->idiag_expires = 0; 153 if (asoc) { 154 inet_diag_msg_sctpasoc_fill(r, sk, asoc); 155 } else { 156 inet_diag_msg_common_fill(r, sk); 157 r->idiag_state = sk->sk_state; 158 } 159 160 if (inet_diag_msg_attrs_fill(sk, skb, r, ext, user_ns, net_admin)) 161 goto errout; 162 163 if (ext & (1 << (INET_DIAG_SKMEMINFO - 1))) { 164 u32 mem[SK_MEMINFO_VARS]; 165 int amt; 166 167 if (asoc && asoc->ep->sndbuf_policy) 168 amt = asoc->sndbuf_used; 169 else 170 amt = sk_wmem_alloc_get(sk); 171 mem[SK_MEMINFO_WMEM_ALLOC] = amt; 172 if (asoc && asoc->ep->rcvbuf_policy) 173 amt = atomic_read(&asoc->rmem_alloc); 174 else 175 amt = sk_rmem_alloc_get(sk); 176 mem[SK_MEMINFO_RMEM_ALLOC] = amt; 177 mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf; 178 mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf; 179 mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc; 180 mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued; 181 mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc); 182 mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len); 183 mem[SK_MEMINFO_DROPS] = sk_drops_read(sk); 184 185 if (nla_put(skb, INET_DIAG_SKMEMINFO, sizeof(mem), &mem) < 0) 186 goto errout; 187 } 188 189 if (ext & (1 << (INET_DIAG_INFO - 1))) { 190 struct nlattr *attr; 191 192 attr = nla_reserve_64bit(skb, INET_DIAG_INFO, 193 sizeof(struct sctp_info), 194 INET_DIAG_PAD); 195 if (!attr) 196 goto errout; 197 198 info = nla_data(attr); 199 } 200 infox.sctpinfo = (struct sctp_info *)info; 201 infox.asoc = asoc; 202 sctp_diag_get_info(sk, r, &infox); 203 204 addr_list = asoc ? &asoc->base.bind_addr.address_list 205 : &ep->base.bind_addr.address_list; 206 if (inet_diag_msg_sctpladdrs_fill(skb, addr_list)) 207 goto errout; 208 209 if (asoc && (ext & (1 << (INET_DIAG_CONG - 1)))) 210 if (nla_put_string(skb, INET_DIAG_CONG, "reno") < 0) 211 goto errout; 212 213 if (asoc && inet_diag_msg_sctpaddrs_fill(skb, asoc)) 214 goto errout; 215 216 nlmsg_end(skb, nlh); 217 return 0; 218 219 errout: 220 nlmsg_cancel(skb, nlh); 221 return -EMSGSIZE; 222 } 223 224 /* callback and param */ 225 struct sctp_comm_param { 226 struct sk_buff *skb; 227 struct netlink_callback *cb; 228 const struct inet_diag_req_v2 *r; 229 const struct nlmsghdr *nlh; 230 bool net_admin; 231 }; 232 233 static size_t inet_assoc_attr_size(struct sock *sk, 234 struct sctp_association *asoc) 235 { 236 int addrlen = sizeof(struct sockaddr_storage); 237 int addrcnt = 0; 238 struct sctp_sockaddr_entry *laddr; 239 240 list_for_each_entry_rcu(laddr, &asoc->base.bind_addr.address_list, 241 list, lockdep_sock_is_held(sk)) 242 addrcnt++; 243 244 return nla_total_size(sizeof(struct sctp_info)) 245 + nla_total_size(addrlen * asoc->peer.transport_count) 246 + nla_total_size(addrlen * addrcnt) 247 + nla_total_size(sizeof(struct inet_diag_msg)) 248 + inet_diag_msg_attrs_size() 249 + nla_total_size(sizeof(struct inet_diag_meminfo)) 250 + 64; 251 } 252 253 static int sctp_sock_dump_one(struct sctp_endpoint *ep, struct sctp_transport *tsp, void *p) 254 { 255 struct sctp_association *assoc = tsp->asoc; 256 struct sctp_comm_param *commp = p; 257 struct sock *sk = ep->base.sk; 258 const struct inet_diag_req_v2 *req = commp->r; 259 struct sk_buff *skb = commp->skb; 260 struct sk_buff *rep; 261 int err; 262 263 err = sock_diag_check_cookie(sk, req->id.idiag_cookie); 264 if (err) 265 return err; 266 267 lock_sock(sk); 268 269 rep = nlmsg_new(inet_assoc_attr_size(sk, assoc), GFP_KERNEL); 270 if (!rep) { 271 release_sock(sk); 272 return -ENOMEM; 273 } 274 275 if (ep != assoc->ep) { 276 err = -EAGAIN; 277 goto out; 278 } 279 280 err = inet_sctp_diag_fill(sk, assoc, rep, req, sk_user_ns(NETLINK_CB(skb).sk), 281 NETLINK_CB(skb).portid, commp->nlh->nlmsg_seq, 0, 282 commp->nlh, commp->net_admin); 283 if (err < 0) { 284 WARN_ON(err == -EMSGSIZE); 285 goto out; 286 } 287 release_sock(sk); 288 289 return nlmsg_unicast(sock_net(skb->sk)->diag_nlsk, rep, NETLINK_CB(skb).portid); 290 291 out: 292 release_sock(sk); 293 kfree_skb(rep); 294 return err; 295 } 296 297 static int sctp_sock_dump(struct sctp_endpoint *ep, struct sctp_transport *tsp, void *p) 298 { 299 struct sctp_comm_param *commp = p; 300 struct sock *sk = ep->base.sk; 301 struct sk_buff *skb = commp->skb; 302 struct netlink_callback *cb = commp->cb; 303 const struct inet_diag_req_v2 *r = commp->r; 304 struct sctp_association *assoc; 305 int err = 0; 306 307 lock_sock(sk); 308 if (ep != tsp->asoc->ep) 309 goto release; 310 list_for_each_entry(assoc, &ep->asocs, asocs) { 311 if (cb->args[4] < cb->args[1]) 312 goto next; 313 314 if (r->id.idiag_sport != htons(assoc->base.bind_addr.port) && 315 r->id.idiag_sport) 316 goto next; 317 if (r->id.idiag_dport != htons(assoc->peer.port) && 318 r->id.idiag_dport) 319 goto next; 320 321 if (!cb->args[3] && 322 inet_sctp_diag_fill(sk, NULL, skb, r, 323 sk_user_ns(NETLINK_CB(cb->skb).sk), 324 NETLINK_CB(cb->skb).portid, 325 cb->nlh->nlmsg_seq, 326 NLM_F_MULTI, cb->nlh, 327 commp->net_admin) < 0) { 328 err = 1; 329 goto release; 330 } 331 cb->args[3] = 1; 332 333 if (inet_sctp_diag_fill(sk, assoc, skb, r, 334 sk_user_ns(NETLINK_CB(cb->skb).sk), 335 NETLINK_CB(cb->skb).portid, 336 cb->nlh->nlmsg_seq, 0, cb->nlh, 337 commp->net_admin) < 0) { 338 err = 1; 339 goto release; 340 } 341 next: 342 cb->args[4]++; 343 } 344 cb->args[1] = 0; 345 cb->args[3] = 0; 346 cb->args[4] = 0; 347 release: 348 release_sock(sk); 349 return err; 350 } 351 352 static int sctp_sock_filter(struct sctp_endpoint *ep, struct sctp_transport *tsp, void *p) 353 { 354 struct sctp_comm_param *commp = p; 355 struct sock *sk = ep->base.sk; 356 const struct inet_diag_req_v2 *r = commp->r; 357 358 /* find the ep only once through the transports by this condition */ 359 if (!list_is_first(&tsp->asoc->asocs, &ep->asocs)) 360 return 0; 361 362 if (r->sdiag_family != AF_UNSPEC && sk->sk_family != r->sdiag_family) 363 return 0; 364 365 return 1; 366 } 367 368 static int sctp_ep_dump(struct sctp_endpoint *ep, void *p) 369 { 370 struct sctp_comm_param *commp = p; 371 struct sock *sk = ep->base.sk; 372 struct sk_buff *skb = commp->skb; 373 struct netlink_callback *cb = commp->cb; 374 const struct inet_diag_req_v2 *r = commp->r; 375 struct net *net = sock_net(skb->sk); 376 struct inet_sock *inet = inet_sk(sk); 377 int err = 0; 378 379 if (!net_eq(sock_net(sk), net)) 380 goto out; 381 382 if (cb->args[4] < cb->args[1]) 383 goto next; 384 385 if (!(r->idiag_states & TCPF_LISTEN) && !list_empty(&ep->asocs)) 386 goto next; 387 388 if (r->sdiag_family != AF_UNSPEC && 389 sk->sk_family != r->sdiag_family) 390 goto next; 391 392 if (r->id.idiag_sport != inet->inet_sport && 393 r->id.idiag_sport) 394 goto next; 395 396 if (r->id.idiag_dport != inet->inet_dport && 397 r->id.idiag_dport) 398 goto next; 399 400 if (inet_sctp_diag_fill(sk, NULL, skb, r, 401 sk_user_ns(NETLINK_CB(cb->skb).sk), 402 NETLINK_CB(cb->skb).portid, 403 cb->nlh->nlmsg_seq, NLM_F_MULTI, 404 cb->nlh, commp->net_admin) < 0) { 405 err = 2; 406 goto out; 407 } 408 next: 409 cb->args[4]++; 410 out: 411 return err; 412 } 413 414 /* define the functions for sctp_diag_handler*/ 415 static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r, 416 void *info) 417 { 418 struct sctp_infox *infox = (struct sctp_infox *)info; 419 420 if (infox->asoc) { 421 r->idiag_rqueue = atomic_read(&infox->asoc->rmem_alloc); 422 r->idiag_wqueue = infox->asoc->sndbuf_used; 423 } else { 424 r->idiag_rqueue = READ_ONCE(sk->sk_ack_backlog); 425 r->idiag_wqueue = READ_ONCE(sk->sk_max_ack_backlog); 426 } 427 if (infox->sctpinfo) 428 sctp_get_sctp_info(sk, infox->asoc, infox->sctpinfo); 429 } 430 431 static int sctp_diag_dump_one(struct netlink_callback *cb, 432 const struct inet_diag_req_v2 *req) 433 { 434 struct sk_buff *skb = cb->skb; 435 struct net *net = sock_net(skb->sk); 436 const struct nlmsghdr *nlh = cb->nlh; 437 union sctp_addr laddr, paddr; 438 int dif = req->id.idiag_if; 439 struct sctp_comm_param commp = { 440 .skb = skb, 441 .r = req, 442 .nlh = nlh, 443 .net_admin = netlink_net_capable(skb, CAP_NET_ADMIN), 444 }; 445 446 if (req->sdiag_family == AF_INET) { 447 laddr.v4.sin_port = req->id.idiag_sport; 448 laddr.v4.sin_addr.s_addr = req->id.idiag_src[0]; 449 laddr.v4.sin_family = AF_INET; 450 451 paddr.v4.sin_port = req->id.idiag_dport; 452 paddr.v4.sin_addr.s_addr = req->id.idiag_dst[0]; 453 paddr.v4.sin_family = AF_INET; 454 } else { 455 laddr.v6.sin6_port = req->id.idiag_sport; 456 memcpy(&laddr.v6.sin6_addr, req->id.idiag_src, 457 sizeof(laddr.v6.sin6_addr)); 458 laddr.v6.sin6_family = AF_INET6; 459 460 paddr.v6.sin6_port = req->id.idiag_dport; 461 memcpy(&paddr.v6.sin6_addr, req->id.idiag_dst, 462 sizeof(paddr.v6.sin6_addr)); 463 paddr.v6.sin6_family = AF_INET6; 464 } 465 466 return sctp_transport_lookup_process(sctp_sock_dump_one, 467 net, &laddr, &paddr, &commp, dif); 468 } 469 470 static void sctp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, 471 const struct inet_diag_req_v2 *r) 472 { 473 u32 idiag_states = r->idiag_states; 474 struct net *net = sock_net(skb->sk); 475 struct sctp_comm_param commp = { 476 .skb = skb, 477 .cb = cb, 478 .r = r, 479 .net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN), 480 }; 481 int pos = cb->args[2]; 482 483 /* eps hashtable dumps 484 * args: 485 * 0 : if it will traversal listen sock 486 * 1 : to record the sock pos of this time's traversal 487 * 4 : to work as a temporary variable to traversal list 488 */ 489 if (cb->args[0] == 0) { 490 if (!(idiag_states & TCPF_LISTEN)) 491 goto skip; 492 if (sctp_for_each_endpoint(sctp_ep_dump, &commp)) 493 goto done; 494 skip: 495 cb->args[0] = 1; 496 cb->args[1] = 0; 497 cb->args[4] = 0; 498 } 499 500 /* asocs by transport hashtable dump 501 * args: 502 * 1 : to record the assoc pos of this time's traversal 503 * 2 : to record the transport pos of this time's traversal 504 * 3 : to mark if we have dumped the ep info of the current asoc 505 * 4 : to work as a temporary variable to traversal list 506 * 5 : to save the sk we get from travelsing the tsp list. 507 */ 508 if (!(idiag_states & ~(TCPF_LISTEN | TCPF_CLOSE))) 509 goto done; 510 511 sctp_transport_traverse_process(sctp_sock_filter, sctp_sock_dump, 512 net, &pos, &commp); 513 cb->args[2] = pos; 514 515 done: 516 cb->args[1] = cb->args[4]; 517 cb->args[4] = 0; 518 } 519 520 static const struct inet_diag_handler sctp_diag_handler = { 521 .owner = THIS_MODULE, 522 .dump = sctp_diag_dump, 523 .dump_one = sctp_diag_dump_one, 524 .idiag_get_info = sctp_diag_get_info, 525 .idiag_type = IPPROTO_SCTP, 526 .idiag_info_size = sizeof(struct sctp_info), 527 }; 528 529 static int __init sctp_diag_init(void) 530 { 531 return inet_diag_register(&sctp_diag_handler); 532 } 533 534 static void __exit sctp_diag_exit(void) 535 { 536 inet_diag_unregister(&sctp_diag_handler); 537 } 538 539 module_init(sctp_diag_init); 540 module_exit(sctp_diag_exit); 541 MODULE_LICENSE("GPL"); 542 MODULE_DESCRIPTION("SCTP socket monitoring via SOCK_DIAG"); 543 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-132); 544