net/sctp/diag.c

   1 /* SCTP kernel implementation
   2  * (C) Copyright Red Hat Inc. 2017
   3  *
   4  * This file is part of the SCTP kernel implementation
   5  *
   6  * These functions implement sctp diag support.
   7  *
   8  * This SCTP implementation is free software;
   9  * you can redistribute it and/or modify it under the terms of
  10  * the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2, or (at your option)
  12  * any later version.
  13  *
  14  * This SCTP implementation is distributed in the hope that it
  15  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  16  *                 ************************
  17  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  18  * See the GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with GNU CC; see the file COPYING.  If not, see
  22  * <http://www.gnu.org/licenses/>.
  23  *
  24  * Please send any bug reports or fixes you make to the
  25  * email addresched(es):
  26  *    lksctp developers <linux-sctp@vger.kernel.org>
  27  *
  28  * Written or modified by:
  29  *    Xin Long <lucien.xin@gmail.com>
  30  */
  31
  32 #include <linux/module.h>
  33 #include <linux/inet_diag.h>
  34 #include <linux/sock_diag.h>
  35 #include <net/sctp/sctp.h>
  36
  37 static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
  38                                void *info);
  39
  40 /* define some functions to make asoc/ep fill look clean */
  41 static void inet_diag_msg_sctpasoc_fill(struct inet_diag_msg *r,
  42                                         struct sock *sk,
  43                                         struct sctp_association *asoc)
  44 {
  45         union sctp_addr laddr, paddr;
  46         struct dst_entry *dst;
  47         struct timer_list *t3_rtx = &asoc->peer.primary_path->T3_rtx_timer;
  48
  49         laddr = list_entry(asoc->base.bind_addr.address_list.next,
  50                            struct sctp_sockaddr_entry, list)->a;
  51         paddr = asoc->peer.primary_path->ipaddr;
  52         dst = asoc->peer.primary_path->dst;
  53
  54         r->idiag_family = sk->sk_family;
  55         r->id.idiag_sport = htons(asoc->base.bind_addr.port);
  56         r->id.idiag_dport = htons(asoc->peer.port);
  57         r->id.idiag_if = dst ? dst->dev->ifindex : 0;
  58         sock_diag_save_cookie(sk, r->id.idiag_cookie);
  59
  60 #if IS_ENABLED(CONFIG_IPV6)
  61         if (sk->sk_family == AF_INET6) {
  62                 *(struct in6_addr *)r->id.idiag_src = laddr.v6.sin6_addr;
  63                 *(struct in6_addr *)r->id.idiag_dst = paddr.v6.sin6_addr;
  64         } else
  65 #endif
  66         {
  67                 memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src));
  68                 memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst));
  69
  70                 r->id.idiag_src[0] = laddr.v4.sin_addr.s_addr;
  71                 r->id.idiag_dst[0] = paddr.v4.sin_addr.s_addr;
  72         }
  73
  74         r->idiag_state = asoc->state;
  75         if (timer_pending(t3_rtx)) {
  76                 r->idiag_timer = SCTP_EVENT_TIMEOUT_T3_RTX;
  77                 r->idiag_retrans = asoc->rtx_data_chunks;
  78                 r->idiag_expires = jiffies_to_msecs(t3_rtx->expires - jiffies);
  79         } else {
  80                 r->idiag_timer = 0;
  81                 r->idiag_retrans = 0;
  82                 r->idiag_expires = 0;
  83         }
  84 }
  85
  86 static int inet_diag_msg_sctpladdrs_fill(struct sk_buff *skb,
  87                                          struct list_head *address_list)
  88 {
  89         struct sctp_sockaddr_entry *laddr;
  90         int addrlen = sizeof(struct sockaddr_storage);
  91         int addrcnt = 0;
  92         struct nlattr *attr;
  93         void *info = NULL;
  94
  95         list_for_each_entry_rcu(laddr, address_list, list)
  96                 addrcnt++;
  97
  98         attr = nla_reserve(skb, INET_DIAG_LOCALS, addrlen * addrcnt);
  99         if (!attr)
 100                 return -EMSGSIZE;
 101
 102         info = nla_data(attr);
 103         list_for_each_entry_rcu(laddr, address_list, list) {
 104                 memcpy(info, &laddr->a, sizeof(laddr->a));
 105                 memset(info + sizeof(laddr->a), 0, addrlen - sizeof(laddr->a));
 106                 info += addrlen;
 107         }
 108
 109         return 0;
 110 }
 111
 112 static int inet_diag_msg_sctpaddrs_fill(struct sk_buff *skb,
 113                                         struct sctp_association *asoc)
 114 {
 115         int addrlen = sizeof(struct sockaddr_storage);
 116         struct sctp_transport *from;
 117         struct nlattr *attr;
 118         void *info = NULL;
 119
 120         attr = nla_reserve(skb, INET_DIAG_PEERS,
 121                            addrlen * asoc->peer.transport_count);
 122         if (!attr)
 123                 return -EMSGSIZE;
 124
 125         info = nla_data(attr);
 126         list_for_each_entry(from, &asoc->peer.transport_addr_list,
 127                             transports) {
 128                 memcpy(info, &from->ipaddr, sizeof(from->ipaddr));
 129                 memset(info + sizeof(from->ipaddr), 0,
 130                        addrlen - sizeof(from->ipaddr));
 131                 info += addrlen;
 132         }
 133
 134         return 0;
 135 }
 136
 137 /* sctp asoc/ep fill*/
 138 static int inet_sctp_diag_fill(struct sock *sk, struct sctp_association *asoc,
 139                                struct sk_buff *skb,
 140                                const struct inet_diag_req_v2 *req,
 141                                struct user_namespace *user_ns,
 142                                int portid, u32 seq, u16 nlmsg_flags,
 143                                const struct nlmsghdr *unlh,
 144                                bool net_admin)
 145 {
 146         struct sctp_endpoint *ep = sctp_sk(sk)->ep;
 147         struct list_head *addr_list;
 148         struct inet_diag_msg *r;
 149         struct nlmsghdr  *nlh;
 150         int ext = req->idiag_ext;
 151         struct sctp_infox infox;
 152         void *info = NULL;
 153
 154         nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
 155                         nlmsg_flags);
 156         if (!nlh)
 157                 return -EMSGSIZE;
 158
 159         r = nlmsg_data(nlh);
 160         BUG_ON(!sk_fullsock(sk));
 161
 162         if (asoc) {
 163                 inet_diag_msg_sctpasoc_fill(r, sk, asoc);
 164         } else {
 165                 inet_diag_msg_common_fill(r, sk);
 166                 r->idiag_state = sk->sk_state;
 167                 r->idiag_timer = 0;
 168                 r->idiag_retrans = 0;
 169         }
 170
 171         if (inet_diag_msg_attrs_fill(sk, skb, r, ext, user_ns, net_admin))
 172                 goto errout;
 173
 174         if (ext & (1 << (INET_DIAG_SKMEMINFO - 1))) {
 175                 u32 mem[SK_MEMINFO_VARS];
 176                 int amt;
 177
 178                 if (asoc && asoc->ep->sndbuf_policy)
 179                         amt = asoc->sndbuf_used;
 180                 else
 181                         amt = sk_wmem_alloc_get(sk);
 182                 mem[SK_MEMINFO_WMEM_ALLOC] = amt;
 183                 if (asoc && asoc->ep->rcvbuf_policy)
 184                         amt = atomic_read(&asoc->rmem_alloc);
 185                 else
 186                         amt = sk_rmem_alloc_get(sk);
 187                 mem[SK_MEMINFO_RMEM_ALLOC] = amt;
 188                 mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
 189                 mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
 190                 mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
 191                 mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
 192                 mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
 193                 mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len;
 194                 mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
 195
 196                 if (nla_put(skb, INET_DIAG_SKMEMINFO, sizeof(mem), &mem) < 0)
 197                         goto errout;
 198         }
 199
 200         if (ext & (1 << (INET_DIAG_INFO - 1))) {
 201                 struct nlattr *attr;
 202
 203                 attr = nla_reserve_64bit(skb, INET_DIAG_INFO,
 204                                          sizeof(struct sctp_info),
 205                                          INET_DIAG_PAD);
 206                 if (!attr)
 207                         goto errout;
 208
 209                 info = nla_data(attr);
 210         }
 211         infox.sctpinfo = (struct sctp_info *)info;
 212         infox.asoc = asoc;
 213         sctp_diag_get_info(sk, r, &infox);
 214
 215         addr_list = asoc ? &asoc->base.bind_addr.address_list
 216                          : &ep->base.bind_addr.address_list;
 217         if (inet_diag_msg_sctpladdrs_fill(skb, addr_list))
 218                 goto errout;
 219
 220         if (asoc && (ext & (1 << (INET_DIAG_CONG - 1))))
 221                 if (nla_put_string(skb, INET_DIAG_CONG, "reno") < 0)
 222                         goto errout;
 223
 224         if (asoc && inet_diag_msg_sctpaddrs_fill(skb, asoc))
 225                 goto errout;
 226
 227         nlmsg_end(skb, nlh);
 228         return 0;
 229
 230 errout:
 231         nlmsg_cancel(skb, nlh);
 232         return -EMSGSIZE;
 233 }
 234
 235 /* callback and param */
 236 struct sctp_comm_param {
 237         struct sk_buff *skb;
 238         struct netlink_callback *cb;
 239         const struct inet_diag_req_v2 *r;
 240         const struct nlmsghdr *nlh;
 241         bool net_admin;
 242 };
 243
 244 static size_t inet_assoc_attr_size(struct sctp_association *asoc)
 245 {
 246         int addrlen = sizeof(struct sockaddr_storage);
 247         int addrcnt = 0;
 248         struct sctp_sockaddr_entry *laddr;
 249
 250         list_for_each_entry_rcu(laddr, &asoc->base.bind_addr.address_list,
 251                                 list)
 252                 addrcnt++;
 253
 254         return    nla_total_size(sizeof(struct sctp_info))
 255                 + nla_total_size(addrlen * asoc->peer.transport_count)
 256                 + nla_total_size(addrlen * addrcnt)
 257                 + nla_total_size(sizeof(struct inet_diag_msg))
 258                 + inet_diag_msg_attrs_size()
 259                 + nla_total_size(sizeof(struct inet_diag_meminfo))
 260                 + 64;
 261 }
 262
 263 static int sctp_tsp_dump_one(struct sctp_transport *tsp, void *p)
 264 {
 265         struct sctp_association *assoc = tsp->asoc;
 266         struct sock *sk = tsp->asoc->base.sk;
 267         struct sctp_comm_param *commp = p;
 268         struct sk_buff *in_skb = commp->skb;
 269         const struct inet_diag_req_v2 *req = commp->r;
 270         const struct nlmsghdr *nlh = commp->nlh;
 271         struct net *net = sock_net(in_skb->sk);
 272         struct sk_buff *rep;
 273         int err;
 274
 275         err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
 276         if (err)
 277                 goto out;
 278
 279         err = -ENOMEM;
 280         rep = nlmsg_new(inet_assoc_attr_size(assoc), GFP_KERNEL);
 281         if (!rep)
 282                 goto out;
 283
 284         lock_sock(sk);
 285         if (sk != assoc->base.sk) {
 286                 release_sock(sk);
 287                 sk = assoc->base.sk;
 288                 lock_sock(sk);
 289         }
 290         err = inet_sctp_diag_fill(sk, assoc, rep, req,
 291                                   sk_user_ns(NETLINK_CB(in_skb).sk),
 292                                   NETLINK_CB(in_skb).portid,
 293                                   nlh->nlmsg_seq, 0, nlh,
 294                                   commp->net_admin);
 295         release_sock(sk);
 296         if (err < 0) {
 297                 WARN_ON(err == -EMSGSIZE);
 298                 kfree_skb(rep);
 299                 goto out;
 300         }
 301
 302         err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
 303                               MSG_DONTWAIT);
 304         if (err > 0)
 305                 err = 0;
 306 out:
 307         return err;
 308 }
 309
 310 static int sctp_sock_dump(struct sctp_transport *tsp, void *p)
 311 {
 312         struct sctp_endpoint *ep = tsp->asoc->ep;
 313         struct sctp_comm_param *commp = p;
 314         struct sock *sk = ep->base.sk;
 315         struct sk_buff *skb = commp->skb;
 316         struct netlink_callback *cb = commp->cb;
 317         const struct inet_diag_req_v2 *r = commp->r;
 318         struct sctp_association *assoc;
 319         int err = 0;
 320
 321         lock_sock(sk);
 322         list_for_each_entry(assoc, &ep->asocs, asocs) {
 323                 if (cb->args[4] < cb->args[1])
 324                         goto next;
 325
 326                 if (r->id.idiag_sport != htons(assoc->base.bind_addr.port) &&
 327                     r->id.idiag_sport)
 328                         goto next;
 329                 if (r->id.idiag_dport != htons(assoc->peer.port) &&
 330                     r->id.idiag_dport)
 331                         goto next;
 332
 333                 if (!cb->args[3] &&
 334                     inet_sctp_diag_fill(sk, NULL, skb, r,
 335                                         sk_user_ns(NETLINK_CB(cb->skb).sk),
 336                                         NETLINK_CB(cb->skb).portid,
 337                                         cb->nlh->nlmsg_seq,
 338                                         NLM_F_MULTI, cb->nlh,
 339                                         commp->net_admin) < 0) {
 340                         err = 1;
 341                         goto release;
 342                 }
 343                 cb->args[3] = 1;
 344
 345                 if (inet_sctp_diag_fill(sk, assoc, skb, r,
 346                                         sk_user_ns(NETLINK_CB(cb->skb).sk),
 347                                         NETLINK_CB(cb->skb).portid,
 348                                         cb->nlh->nlmsg_seq, 0, cb->nlh,
 349                                         commp->net_admin) < 0) {
 350                         err = 1;
 351                         goto release;
 352                 }
 353 next:
 354                 cb->args[4]++;
 355         }
 356         cb->args[1] = 0;
 357         cb->args[3] = 0;
 358         cb->args[4] = 0;
 359 release:
 360         release_sock(sk);
 361         return err;
 362 }
 363
 364 static int sctp_sock_filter(struct sctp_transport *tsp, void *p)
 365 {
 366         struct sctp_endpoint *ep = tsp->asoc->ep;
 367         struct sctp_comm_param *commp = p;
 368         struct sock *sk = ep->base.sk;
 369         const struct inet_diag_req_v2 *r = commp->r;
 370         struct sctp_association *assoc =
 371                 list_entry(ep->asocs.next, struct sctp_association, asocs);
 372
 373         /* find the ep only once through the transports by this condition */
 374         if (tsp->asoc != assoc)
 375                 return 0;
 376
 377         if (r->sdiag_family != AF_UNSPEC && sk->sk_family != r->sdiag_family)
 378                 return 0;
 379
 380         return 1;
 381 }
 382
 383 static int sctp_ep_dump(struct sctp_endpoint *ep, void *p)
 384 {
 385         struct sctp_comm_param *commp = p;
 386         struct sock *sk = ep->base.sk;
 387         struct sk_buff *skb = commp->skb;
 388         struct netlink_callback *cb = commp->cb;
 389         const struct inet_diag_req_v2 *r = commp->r;
 390         struct net *net = sock_net(skb->sk);
 391         struct inet_sock *inet = inet_sk(sk);
 392         int err = 0;
 393
 394         if (!net_eq(sock_net(sk), net))
 395                 goto out;
 396
 397         if (cb->args[4] < cb->args[1])
 398                 goto next;
 399
 400         if (!(r->idiag_states & TCPF_LISTEN) && !list_empty(&ep->asocs))
 401                 goto next;
 402
 403         if (r->sdiag_family != AF_UNSPEC &&
 404             sk->sk_family != r->sdiag_family)
 405                 goto next;
 406
 407         if (r->id.idiag_sport != inet->inet_sport &&
 408             r->id.idiag_sport)
 409                 goto next;
 410
 411         if (r->id.idiag_dport != inet->inet_dport &&
 412             r->id.idiag_dport)
 413                 goto next;
 414
 415         if (inet_sctp_diag_fill(sk, NULL, skb, r,
 416                                 sk_user_ns(NETLINK_CB(cb->skb).sk),
 417                                 NETLINK_CB(cb->skb).portid,
 418                                 cb->nlh->nlmsg_seq, NLM_F_MULTI,
 419                                 cb->nlh, commp->net_admin) < 0) {
 420                 err = 2;
 421                 goto out;
 422         }
 423 next:
 424         cb->args[4]++;
 425 out:
 426         return err;
 427 }
 428
 429 /* define the functions for sctp_diag_handler*/
 430 static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
 431                                void *info)
 432 {
 433         struct sctp_infox *infox = (struct sctp_infox *)info;
 434
 435         if (infox->asoc) {
 436                 r->idiag_rqueue = atomic_read(&infox->asoc->rmem_alloc);
 437                 r->idiag_wqueue = infox->asoc->sndbuf_used;
 438         } else {
 439                 r->idiag_rqueue = sk->sk_ack_backlog;
 440                 r->idiag_wqueue = sk->sk_max_ack_backlog;
 441         }
 442         if (infox->sctpinfo)
 443                 sctp_get_sctp_info(sk, infox->asoc, infox->sctpinfo);
 444 }
 445
 446 static int sctp_diag_dump_one(struct sk_buff *in_skb,
 447                               const struct nlmsghdr *nlh,
 448                               const struct inet_diag_req_v2 *req)
 449 {
 450         struct net *net = sock_net(in_skb->sk);
 451         union sctp_addr laddr, paddr;
 452         struct sctp_comm_param commp = {
 453                 .skb = in_skb,
 454                 .r = req,
 455                 .nlh = nlh,
 456                 .net_admin = netlink_net_capable(in_skb, CAP_NET_ADMIN),
 457         };
 458
 459         if (req->sdiag_family == AF_INET) {
 460                 laddr.v4.sin_port = req->id.idiag_sport;
 461                 laddr.v4.sin_addr.s_addr = req->id.idiag_src[0];
 462                 laddr.v4.sin_family = AF_INET;
 463
 464                 paddr.v4.sin_port = req->id.idiag_dport;
 465                 paddr.v4.sin_addr.s_addr = req->id.idiag_dst[0];
 466                 paddr.v4.sin_family = AF_INET;
 467         } else {
 468                 laddr.v6.sin6_port = req->id.idiag_sport;
 469                 memcpy(&laddr.v6.sin6_addr, req->id.idiag_src,
 470                        sizeof(laddr.v6.sin6_addr));
 471                 laddr.v6.sin6_family = AF_INET6;
 472
 473                 paddr.v6.sin6_port = req->id.idiag_dport;
 474                 memcpy(&paddr.v6.sin6_addr, req->id.idiag_dst,
 475                        sizeof(paddr.v6.sin6_addr));
 476                 paddr.v6.sin6_family = AF_INET6;
 477         }
 478
 479         return sctp_transport_lookup_process(sctp_tsp_dump_one,
 480                                              net, &laddr, &paddr, &commp);
 481 }
 482
 483 static void sctp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 484                            const struct inet_diag_req_v2 *r, struct nlattr *bc)
 485 {
 486         u32 idiag_states = r->idiag_states;
 487         struct net *net = sock_net(skb->sk);
 488         struct sctp_comm_param commp = {
 489                 .skb = skb,
 490                 .cb = cb,
 491                 .r = r,
 492                 .net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN),
 493         };
 494         int pos = cb->args[2];
 495
 496         /* eps hashtable dumps
 497          * args:
 498          * 0 : if it will traversal listen sock
 499          * 1 : to record the sock pos of this time's traversal
 500          * 4 : to work as a temporary variable to traversal list
 501          */
 502         if (cb->args[0] == 0) {
 503                 if (!(idiag_states & TCPF_LISTEN))
 504                         goto skip;
 505                 if (sctp_for_each_endpoint(sctp_ep_dump, &commp))
 506                         goto done;
 507 skip:
 508                 cb->args[0] = 1;
 509                 cb->args[1] = 0;
 510                 cb->args[4] = 0;
 511         }
 512
 513         /* asocs by transport hashtable dump
 514          * args:
 515          * 1 : to record the assoc pos of this time's traversal
 516          * 2 : to record the transport pos of this time's traversal
 517          * 3 : to mark if we have dumped the ep info of the current asoc
 518          * 4 : to work as a temporary variable to traversal list
 519          * 5 : to save the sk we get from travelsing the tsp list.
 520          */
 521         if (!(idiag_states & ~(TCPF_LISTEN | TCPF_CLOSE)))
 522                 goto done;
 523
 524         sctp_for_each_transport(sctp_sock_filter, sctp_sock_dump,
 525                                 net, &pos, &commp);
 526         cb->args[2] = pos;
 527
 528 done:
 529         cb->args[1] = cb->args[4];
 530         cb->args[4] = 0;
 531 }
 532
 533 static const struct inet_diag_handler sctp_diag_handler = {
 534         .dump            = sctp_diag_dump,
 535         .dump_one        = sctp_diag_dump_one,
 536         .idiag_get_info  = sctp_diag_get_info,
 537         .idiag_type      = IPPROTO_SCTP,
 538         .idiag_info_size = sizeof(struct sctp_info),
 539 };
 540
 541 static int __init sctp_diag_init(void)
 542 {
 543         return inet_diag_register(&sctp_diag_handler);
 544 }
 545
 546 static void __exit sctp_diag_exit(void)
 547 {
 548         inet_diag_unregister(&sctp_diag_handler);
 549 }
 550
 551 module_init(sctp_diag_init);
 552 module_exit(sctp_diag_exit);
 553 MODULE_LICENSE("GPL");
 554 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-132);