net/sctp/diag.c

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