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         }
  80 }
  81
  82 static int inet_diag_msg_sctpladdrs_fill(struct sk_buff *skb,
  83                                          struct list_head *address_list)
  84 {
  85         struct sctp_sockaddr_entry *laddr;
  86         int addrlen = sizeof(struct sockaddr_storage);
  87         int addrcnt = 0;
  88         struct nlattr *attr;
  89         void *info = NULL;
  90
  91         list_for_each_entry_rcu(laddr, address_list, list)
  92                 addrcnt++;
  93
  94         attr = nla_reserve(skb, INET_DIAG_LOCALS, addrlen * addrcnt);
  95         if (!attr)
  96                 return -EMSGSIZE;
  97
  98         info = nla_data(attr);
  99         list_for_each_entry_rcu(laddr, address_list, list) {
 100                 memcpy(info, &laddr->a, sizeof(laddr->a));
 101                 memset(info + sizeof(laddr->a), 0, addrlen - sizeof(laddr->a));
 102                 info += addrlen;
 103         }
 104
 105         return 0;
 106 }
 107
 108 static int inet_diag_msg_sctpaddrs_fill(struct sk_buff *skb,
 109                                         struct sctp_association *asoc)
 110 {
 111         int addrlen = sizeof(struct sockaddr_storage);
 112         struct sctp_transport *from;
 113         struct nlattr *attr;
 114         void *info = NULL;
 115
 116         attr = nla_reserve(skb, INET_DIAG_PEERS,
 117                            addrlen * asoc->peer.transport_count);
 118         if (!attr)
 119                 return -EMSGSIZE;
 120
 121         info = nla_data(attr);
 122         list_for_each_entry(from, &asoc->peer.transport_addr_list,
 123                             transports) {
 124                 memcpy(info, &from->ipaddr, sizeof(from->ipaddr));
 125                 memset(info + sizeof(from->ipaddr), 0,
 126                        addrlen - sizeof(from->ipaddr));
 127                 info += addrlen;
 128         }
 129
 130         return 0;
 131 }
 132
 133 /* sctp asoc/ep fill*/
 134 static int inet_sctp_diag_fill(struct sock *sk, struct sctp_association *asoc,
 135                                struct sk_buff *skb,
 136                                const struct inet_diag_req_v2 *req,
 137                                struct user_namespace *user_ns,
 138                                int portid, u32 seq, u16 nlmsg_flags,
 139                                const struct nlmsghdr *unlh,
 140                                bool net_admin)
 141 {
 142         struct sctp_endpoint *ep = sctp_sk(sk)->ep;
 143         struct list_head *addr_list;
 144         struct inet_diag_msg *r;
 145         struct nlmsghdr  *nlh;
 146         int ext = req->idiag_ext;
 147         struct sctp_infox infox;
 148         void *info = NULL;
 149
 150         nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
 151                         nlmsg_flags);
 152         if (!nlh)
 153                 return -EMSGSIZE;
 154
 155         r = nlmsg_data(nlh);
 156         BUG_ON(!sk_fullsock(sk));
 157
 158         r->idiag_timer = 0;
 159         r->idiag_retrans = 0;
 160         r->idiag_expires = 0;
 161         if (asoc) {
 162                 inet_diag_msg_sctpasoc_fill(r, sk, asoc);
 163         } else {
 164                 inet_diag_msg_common_fill(r, sk);
 165                 r->idiag_state = sk->sk_state;
 166         }
 167
 168         if (inet_diag_msg_attrs_fill(sk, skb, r, ext, user_ns, net_admin))
 169                 goto errout;
 170
 171         if (ext & (1 << (INET_DIAG_SKMEMINFO - 1))) {
 172                 u32 mem[SK_MEMINFO_VARS];
 173                 int amt;
 174
 175                 if (asoc && asoc->ep->sndbuf_policy)
 176                         amt = asoc->sndbuf_used;
 177                 else
 178                         amt = sk_wmem_alloc_get(sk);
 179                 mem[SK_MEMINFO_WMEM_ALLOC] = amt;
 180                 if (asoc && asoc->ep->rcvbuf_policy)
 181                         amt = atomic_read(&asoc->rmem_alloc);
 182                 else
 183                         amt = sk_rmem_alloc_get(sk);
 184                 mem[SK_MEMINFO_RMEM_ALLOC] = amt;
 185                 mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
 186                 mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
 187                 mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
 188                 mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
 189                 mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
 190                 mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len;
 191                 mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
 192
 193                 if (nla_put(skb, INET_DIAG_SKMEMINFO, sizeof(mem), &mem) < 0)
 194                         goto errout;
 195         }
 196
 197         if (ext & (1 << (INET_DIAG_INFO - 1))) {
 198                 struct nlattr *attr;
 199
 200                 attr = nla_reserve_64bit(skb, INET_DIAG_INFO,
 201                                          sizeof(struct sctp_info),
 202                                          INET_DIAG_PAD);
 203                 if (!attr)
 204                         goto errout;
 205
 206                 info = nla_data(attr);
 207         }
 208         infox.sctpinfo = (struct sctp_info *)info;
 209         infox.asoc = asoc;
 210         sctp_diag_get_info(sk, r, &infox);
 211
 212         addr_list = asoc ? &asoc->base.bind_addr.address_list
 213                          : &ep->base.bind_addr.address_list;
 214         if (inet_diag_msg_sctpladdrs_fill(skb, addr_list))
 215                 goto errout;
 216
 217         if (asoc && (ext & (1 << (INET_DIAG_CONG - 1))))
 218                 if (nla_put_string(skb, INET_DIAG_CONG, "reno") < 0)
 219                         goto errout;
 220
 221         if (asoc && inet_diag_msg_sctpaddrs_fill(skb, asoc))
 222                 goto errout;
 223
 224         nlmsg_end(skb, nlh);
 225         return 0;
 226
 227 errout:
 228         nlmsg_cancel(skb, nlh);
 229         return -EMSGSIZE;
 230 }
 231
 232 /* callback and param */
 233 struct sctp_comm_param {
 234         struct sk_buff *skb;
 235         struct netlink_callback *cb;
 236         const struct inet_diag_req_v2 *r;
 237         const struct nlmsghdr *nlh;
 238         bool net_admin;
 239 };
 240
 241 static size_t inet_assoc_attr_size(struct sctp_association *asoc)
 242 {
 243         int addrlen = sizeof(struct sockaddr_storage);
 244         int addrcnt = 0;
 245         struct sctp_sockaddr_entry *laddr;
 246
 247         list_for_each_entry_rcu(laddr, &asoc->base.bind_addr.address_list,
 248                                 list)
 249                 addrcnt++;
 250
 251         return    nla_total_size(sizeof(struct sctp_info))
 252                 + nla_total_size(addrlen * asoc->peer.transport_count)
 253                 + nla_total_size(addrlen * addrcnt)
 254                 + nla_total_size(sizeof(struct inet_diag_msg))
 255                 + inet_diag_msg_attrs_size()
 256                 + nla_total_size(sizeof(struct inet_diag_meminfo))
 257                 + 64;
 258 }
 259
 260 static int sctp_tsp_dump_one(struct sctp_transport *tsp, void *p)
 261 {
 262         struct sctp_association *assoc = tsp->asoc;
 263         struct sock *sk = tsp->asoc->base.sk;
 264         struct sctp_comm_param *commp = p;
 265         struct sk_buff *in_skb = commp->skb;
 266         const struct inet_diag_req_v2 *req = commp->r;
 267         const struct nlmsghdr *nlh = commp->nlh;
 268         struct net *net = sock_net(in_skb->sk);
 269         struct sk_buff *rep;
 270         int err;
 271
 272         err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
 273         if (err)
 274                 goto out;
 275
 276         err = -ENOMEM;
 277         rep = nlmsg_new(inet_assoc_attr_size(assoc), GFP_KERNEL);
 278         if (!rep)
 279                 goto out;
 280
 281         lock_sock(sk);
 282         if (sk != assoc->base.sk) {
 283                 release_sock(sk);
 284                 sk = assoc->base.sk;
 285                 lock_sock(sk);
 286         }
 287         err = inet_sctp_diag_fill(sk, assoc, rep, req,
 288                                   sk_user_ns(NETLINK_CB(in_skb).sk),
 289                                   NETLINK_CB(in_skb).portid,
 290                                   nlh->nlmsg_seq, 0, nlh,
 291                                   commp->net_admin);
 292         release_sock(sk);
 293         if (err < 0) {
 294                 WARN_ON(err == -EMSGSIZE);
 295                 kfree_skb(rep);
 296                 goto out;
 297         }
 298
 299         err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
 300                               MSG_DONTWAIT);
 301         if (err > 0)
 302                 err = 0;
 303 out:
 304         return err;
 305 }
 306
 307 static int sctp_sock_dump(struct sctp_endpoint *ep, struct sctp_transport *tsp, void *p)
 308 {
 309         struct sctp_comm_param *commp = p;
 310         struct sock *sk = ep->base.sk;
 311         struct sk_buff *skb = commp->skb;
 312         struct netlink_callback *cb = commp->cb;
 313         const struct inet_diag_req_v2 *r = commp->r;
 314         struct sctp_association *assoc;
 315         int err = 0;
 316
 317         lock_sock(sk);
 318         if (ep != tsp->asoc->ep)
 319                 goto release;
 320         list_for_each_entry(assoc, &ep->asocs, asocs) {
 321                 if (cb->args[4] < cb->args[1])
 322                         goto next;
 323
 324                 if (r->id.idiag_sport != htons(assoc->base.bind_addr.port) &&
 325                     r->id.idiag_sport)
 326                         goto next;
 327                 if (r->id.idiag_dport != htons(assoc->peer.port) &&
 328                     r->id.idiag_dport)
 329                         goto next;
 330
 331                 if (!cb->args[3] &&
 332                     inet_sctp_diag_fill(sk, NULL, skb, r,
 333                                         sk_user_ns(NETLINK_CB(cb->skb).sk),
 334                                         NETLINK_CB(cb->skb).portid,
 335                                         cb->nlh->nlmsg_seq,
 336                                         NLM_F_MULTI, cb->nlh,
 337                                         commp->net_admin) < 0) {
 338                         err = 1;
 339                         goto release;
 340                 }
 341                 cb->args[3] = 1;
 342
 343                 if (inet_sctp_diag_fill(sk, assoc, skb, r,
 344                                         sk_user_ns(NETLINK_CB(cb->skb).sk),
 345                                         NETLINK_CB(cb->skb).portid,
 346                                         cb->nlh->nlmsg_seq, 0, cb->nlh,
 347                                         commp->net_admin) < 0) {
 348                         err = 1;
 349                         goto release;
 350                 }
 351 next:
 352                 cb->args[4]++;
 353         }
 354         cb->args[1] = 0;
 355         cb->args[3] = 0;
 356         cb->args[4] = 0;
 357 release:
 358         release_sock(sk);
 359         return err;
 360 }
 361
 362 static int sctp_sock_filter(struct sctp_endpoint *ep, struct sctp_transport *tsp, void *p)
 363 {
 364         struct sctp_comm_param *commp = p;
 365         struct sock *sk = ep->base.sk;
 366         const struct inet_diag_req_v2 *r = commp->r;
 367         struct sctp_association *assoc =
 368                 list_entry(ep->asocs.next, struct sctp_association, asocs);
 369
 370         /* find the ep only once through the transports by this condition */
 371         if (tsp->asoc != assoc)
 372                 return 0;
 373
 374         if (r->sdiag_family != AF_UNSPEC && sk->sk_family != r->sdiag_family)
 375                 return 0;
 376
 377         return 1;
 378 }
 379
 380 static int sctp_ep_dump(struct sctp_endpoint *ep, void *p)
 381 {
 382         struct sctp_comm_param *commp = p;
 383         struct sock *sk = ep->base.sk;
 384         struct sk_buff *skb = commp->skb;
 385         struct netlink_callback *cb = commp->cb;
 386         const struct inet_diag_req_v2 *r = commp->r;
 387         struct net *net = sock_net(skb->sk);
 388         struct inet_sock *inet = inet_sk(sk);
 389         int err = 0;
 390
 391         if (!net_eq(sock_net(sk), net))
 392                 goto out;
 393
 394         if (cb->args[4] < cb->args[1])
 395                 goto next;
 396
 397         if (!(r->idiag_states & TCPF_LISTEN) && !list_empty(&ep->asocs))
 398                 goto next;
 399
 400         if (r->sdiag_family != AF_UNSPEC &&
 401             sk->sk_family != r->sdiag_family)
 402                 goto next;
 403
 404         if (r->id.idiag_sport != inet->inet_sport &&
 405             r->id.idiag_sport)
 406                 goto next;
 407
 408         if (r->id.idiag_dport != inet->inet_dport &&
 409             r->id.idiag_dport)
 410                 goto next;
 411
 412         if (inet_sctp_diag_fill(sk, NULL, skb, r,
 413                                 sk_user_ns(NETLINK_CB(cb->skb).sk),
 414                                 NETLINK_CB(cb->skb).portid,
 415                                 cb->nlh->nlmsg_seq, NLM_F_MULTI,
 416                                 cb->nlh, commp->net_admin) < 0) {
 417                 err = 2;
 418                 goto out;
 419         }
 420 next:
 421         cb->args[4]++;
 422 out:
 423         return err;
 424 }
 425
 426 /* define the functions for sctp_diag_handler*/
 427 static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
 428                                void *info)
 429 {
 430         struct sctp_infox *infox = (struct sctp_infox *)info;
 431
 432         if (infox->asoc) {
 433                 r->idiag_rqueue = atomic_read(&infox->asoc->rmem_alloc);
 434                 r->idiag_wqueue = infox->asoc->sndbuf_used;
 435         } else {
 436                 r->idiag_rqueue = sk->sk_ack_backlog;
 437                 r->idiag_wqueue = sk->sk_max_ack_backlog;
 438         }
 439         if (infox->sctpinfo)
 440                 sctp_get_sctp_info(sk, infox->asoc, infox->sctpinfo);
 441 }
 442
 443 static int sctp_diag_dump_one(struct sk_buff *in_skb,
 444                               const struct nlmsghdr *nlh,
 445                               const struct inet_diag_req_v2 *req)
 446 {
 447         struct net *net = sock_net(in_skb->sk);
 448         union sctp_addr laddr, paddr;
 449         struct sctp_comm_param commp = {
 450                 .skb = in_skb,
 451                 .r = req,
 452                 .nlh = nlh,
 453                 .net_admin = netlink_net_capable(in_skb, CAP_NET_ADMIN),
 454         };
 455
 456         if (req->sdiag_family == AF_INET) {
 457                 laddr.v4.sin_port = req->id.idiag_sport;
 458                 laddr.v4.sin_addr.s_addr = req->id.idiag_src[0];
 459                 laddr.v4.sin_family = AF_INET;
 460
 461                 paddr.v4.sin_port = req->id.idiag_dport;
 462                 paddr.v4.sin_addr.s_addr = req->id.idiag_dst[0];
 463                 paddr.v4.sin_family = AF_INET;
 464         } else {
 465                 laddr.v6.sin6_port = req->id.idiag_sport;
 466                 memcpy(&laddr.v6.sin6_addr, req->id.idiag_src,
 467                        sizeof(laddr.v6.sin6_addr));
 468                 laddr.v6.sin6_family = AF_INET6;
 469
 470                 paddr.v6.sin6_port = req->id.idiag_dport;
 471                 memcpy(&paddr.v6.sin6_addr, req->id.idiag_dst,
 472                        sizeof(paddr.v6.sin6_addr));
 473                 paddr.v6.sin6_family = AF_INET6;
 474         }
 475
 476         return sctp_transport_lookup_process(sctp_tsp_dump_one,
 477                                              net, &laddr, &paddr, &commp);
 478 }
 479
 480 static void sctp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 481                            const struct inet_diag_req_v2 *r, struct nlattr *bc)
 482 {
 483         u32 idiag_states = r->idiag_states;
 484         struct net *net = sock_net(skb->sk);
 485         struct sctp_comm_param commp = {
 486                 .skb = skb,
 487                 .cb = cb,
 488                 .r = r,
 489                 .net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN),
 490         };
 491         int pos = cb->args[2];
 492
 493         /* eps hashtable dumps
 494          * args:
 495          * 0 : if it will traversal listen sock
 496          * 1 : to record the sock pos of this time's traversal
 497          * 4 : to work as a temporary variable to traversal list
 498          */
 499         if (cb->args[0] == 0) {
 500                 if (!(idiag_states & TCPF_LISTEN))
 501                         goto skip;
 502                 if (sctp_for_each_endpoint(sctp_ep_dump, &commp))
 503                         goto done;
 504 skip:
 505                 cb->args[0] = 1;
 506                 cb->args[1] = 0;
 507                 cb->args[4] = 0;
 508         }
 509
 510         /* asocs by transport hashtable dump
 511          * args:
 512          * 1 : to record the assoc pos of this time's traversal
 513          * 2 : to record the transport pos of this time's traversal
 514          * 3 : to mark if we have dumped the ep info of the current asoc
 515          * 4 : to work as a temporary variable to traversal list
 516          * 5 : to save the sk we get from travelsing the tsp list.
 517          */
 518         if (!(idiag_states & ~(TCPF_LISTEN | TCPF_CLOSE)))
 519                 goto done;
 520
 521         sctp_transport_traverse_process(sctp_sock_filter, sctp_sock_dump,
 522                                         net, &pos, &commp);
 523         cb->args[2] = pos;
 524
 525 done:
 526         cb->args[1] = cb->args[4];
 527         cb->args[4] = 0;
 528 }
 529
 530 static const struct inet_diag_handler sctp_diag_handler = {
 531         .dump            = sctp_diag_dump,
 532         .dump_one        = sctp_diag_dump_one,
 533         .idiag_get_info  = sctp_diag_get_info,
 534         .idiag_type      = IPPROTO_SCTP,
 535         .idiag_info_size = sizeof(struct sctp_info),
 536 };
 537
 538 static int __init sctp_diag_init(void)
 539 {
 540         return inet_diag_register(&sctp_diag_handler);
 541 }
 542
 543 static void __exit sctp_diag_exit(void)
 544 {
 545         inet_diag_unregister(&sctp_diag_handler);
 546 }
 547
 548 module_init(sctp_diag_init);
 549 module_exit(sctp_diag_exit);
 550 MODULE_LICENSE("GPL");
 551 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-132);