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_tsp_dump_one(struct sctp_transport *tsp, void *p)
 249 {
 250         struct sctp_association *assoc = tsp->asoc;
 251         struct sock *sk = tsp->asoc->base.sk;
 252         struct sctp_comm_param *commp = p;
 253         struct sk_buff *in_skb = commp->skb;
 254         const struct inet_diag_req_v2 *req = commp->r;
 255         const struct nlmsghdr *nlh = commp->nlh;
 256         struct net *net = sock_net(in_skb->sk);
 257         struct sk_buff *rep;
 258         int err;
 259
 260         err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
 261         if (err)
 262                 goto out;
 263
 264         err = -ENOMEM;
 265         rep = nlmsg_new(inet_assoc_attr_size(assoc), GFP_KERNEL);
 266         if (!rep)
 267                 goto out;
 268
 269         lock_sock(sk);
 270         if (sk != assoc->base.sk) {
 271                 release_sock(sk);
 272                 sk = assoc->base.sk;
 273                 lock_sock(sk);
 274         }
 275         err = inet_sctp_diag_fill(sk, assoc, rep, req,
 276                                   sk_user_ns(NETLINK_CB(in_skb).sk),
 277                                   NETLINK_CB(in_skb).portid,
 278                                   nlh->nlmsg_seq, 0, nlh,
 279                                   commp->net_admin);
 280         release_sock(sk);
 281         if (err < 0) {
 282                 WARN_ON(err == -EMSGSIZE);
 283                 kfree_skb(rep);
 284                 goto out;
 285         }
 286
 287         err = nlmsg_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid);
 288
 289 out:
 290         return err;
 291 }
 292
 293 static int sctp_sock_dump(struct sctp_transport *tsp, void *p)
 294 {
 295         struct sctp_endpoint *ep = tsp->asoc->ep;
 296         struct sctp_comm_param *commp = p;
 297         struct sock *sk = ep->base.sk;
 298         struct sk_buff *skb = commp->skb;
 299         struct netlink_callback *cb = commp->cb;
 300         const struct inet_diag_req_v2 *r = commp->r;
 301         struct sctp_association *assoc;
 302         int err = 0;
 303
 304         lock_sock(sk);
 305         list_for_each_entry(assoc, &ep->asocs, asocs) {
 306                 if (cb->args[4] < cb->args[1])
 307                         goto next;
 308
 309                 if (r->id.idiag_sport != htons(assoc->base.bind_addr.port) &&
 310                     r->id.idiag_sport)
 311                         goto next;
 312                 if (r->id.idiag_dport != htons(assoc->peer.port) &&
 313                     r->id.idiag_dport)
 314                         goto next;
 315
 316                 if (!cb->args[3] &&
 317                     inet_sctp_diag_fill(sk, NULL, skb, r,
 318                                         sk_user_ns(NETLINK_CB(cb->skb).sk),
 319                                         NETLINK_CB(cb->skb).portid,
 320                                         cb->nlh->nlmsg_seq,
 321                                         NLM_F_MULTI, cb->nlh,
 322                                         commp->net_admin) < 0) {
 323                         err = 1;
 324                         goto release;
 325                 }
 326                 cb->args[3] = 1;
 327
 328                 if (inet_sctp_diag_fill(sk, assoc, skb, r,
 329                                         sk_user_ns(NETLINK_CB(cb->skb).sk),
 330                                         NETLINK_CB(cb->skb).portid,
 331                                         cb->nlh->nlmsg_seq, 0, cb->nlh,
 332                                         commp->net_admin) < 0) {
 333                         err = 1;
 334                         goto release;
 335                 }
 336 next:
 337                 cb->args[4]++;
 338         }
 339         cb->args[1] = 0;
 340         cb->args[3] = 0;
 341         cb->args[4] = 0;
 342 release:
 343         release_sock(sk);
 344         return err;
 345 }
 346
 347 static int sctp_sock_filter(struct sctp_transport *tsp, void *p)
 348 {
 349         struct sctp_endpoint *ep = tsp->asoc->ep;
 350         struct sctp_comm_param *commp = p;
 351         struct sock *sk = ep->base.sk;
 352         const struct inet_diag_req_v2 *r = commp->r;
 353         struct sctp_association *assoc =
 354                 list_entry(ep->asocs.next, struct sctp_association, asocs);
 355
 356         /* find the ep only once through the transports by this condition */
 357         if (tsp->asoc != assoc)
 358                 return 0;
 359
 360         if (r->sdiag_family != AF_UNSPEC && sk->sk_family != r->sdiag_family)
 361                 return 0;
 362
 363         return 1;
 364 }
 365
 366 static int sctp_ep_dump(struct sctp_endpoint *ep, void *p)
 367 {
 368         struct sctp_comm_param *commp = p;
 369         struct sock *sk = ep->base.sk;
 370         struct sk_buff *skb = commp->skb;
 371         struct netlink_callback *cb = commp->cb;
 372         const struct inet_diag_req_v2 *r = commp->r;
 373         struct net *net = sock_net(skb->sk);
 374         struct inet_sock *inet = inet_sk(sk);
 375         int err = 0;
 376
 377         if (!net_eq(sock_net(sk), net))
 378                 goto out;
 379
 380         if (cb->args[4] < cb->args[1])
 381                 goto next;
 382
 383         if (!(r->idiag_states & TCPF_LISTEN) && !list_empty(&ep->asocs))
 384                 goto next;
 385
 386         if (r->sdiag_family != AF_UNSPEC &&
 387             sk->sk_family != r->sdiag_family)
 388                 goto next;
 389
 390         if (r->id.idiag_sport != inet->inet_sport &&
 391             r->id.idiag_sport)
 392                 goto next;
 393
 394         if (r->id.idiag_dport != inet->inet_dport &&
 395             r->id.idiag_dport)
 396                 goto next;
 397
 398         if (inet_sctp_diag_fill(sk, NULL, skb, r,
 399                                 sk_user_ns(NETLINK_CB(cb->skb).sk),
 400                                 NETLINK_CB(cb->skb).portid,
 401                                 cb->nlh->nlmsg_seq, NLM_F_MULTI,
 402                                 cb->nlh, commp->net_admin) < 0) {
 403                 err = 2;
 404                 goto out;
 405         }
 406 next:
 407         cb->args[4]++;
 408 out:
 409         return err;
 410 }
 411
 412 /* define the functions for sctp_diag_handler*/
 413 static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
 414                                void *info)
 415 {
 416         struct sctp_infox *infox = (struct sctp_infox *)info;
 417
 418         if (infox->asoc) {
 419                 r->idiag_rqueue = atomic_read(&infox->asoc->rmem_alloc);
 420                 r->idiag_wqueue = infox->asoc->sndbuf_used;
 421         } else {
 422                 r->idiag_rqueue = READ_ONCE(sk->sk_ack_backlog);
 423                 r->idiag_wqueue = READ_ONCE(sk->sk_max_ack_backlog);
 424         }
 425         if (infox->sctpinfo)
 426                 sctp_get_sctp_info(sk, infox->asoc, infox->sctpinfo);
 427 }
 428
 429 static int sctp_diag_dump_one(struct netlink_callback *cb,
 430                               const struct inet_diag_req_v2 *req)
 431 {
 432         struct sk_buff *in_skb = cb->skb;
 433         struct net *net = sock_net(in_skb->sk);
 434         const struct nlmsghdr *nlh = cb->nlh;
 435         union sctp_addr laddr, paddr;
 436         struct sctp_comm_param commp = {
 437                 .skb = in_skb,
 438                 .r = req,
 439                 .nlh = nlh,
 440                 .net_admin = netlink_net_capable(in_skb, CAP_NET_ADMIN),
 441         };
 442
 443         if (req->sdiag_family == AF_INET) {
 444                 laddr.v4.sin_port = req->id.idiag_sport;
 445                 laddr.v4.sin_addr.s_addr = req->id.idiag_src[0];
 446                 laddr.v4.sin_family = AF_INET;
 447
 448                 paddr.v4.sin_port = req->id.idiag_dport;
 449                 paddr.v4.sin_addr.s_addr = req->id.idiag_dst[0];
 450                 paddr.v4.sin_family = AF_INET;
 451         } else {
 452                 laddr.v6.sin6_port = req->id.idiag_sport;
 453                 memcpy(&laddr.v6.sin6_addr, req->id.idiag_src,
 454                        sizeof(laddr.v6.sin6_addr));
 455                 laddr.v6.sin6_family = AF_INET6;
 456
 457                 paddr.v6.sin6_port = req->id.idiag_dport;
 458                 memcpy(&paddr.v6.sin6_addr, req->id.idiag_dst,
 459                        sizeof(paddr.v6.sin6_addr));
 460                 paddr.v6.sin6_family = AF_INET6;
 461         }
 462
 463         return sctp_transport_lookup_process(sctp_tsp_dump_one,
 464                                              net, &laddr, &paddr, &commp);
 465 }
 466
 467 static void sctp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 468                            const struct inet_diag_req_v2 *r)
 469 {
 470         u32 idiag_states = r->idiag_states;
 471         struct net *net = sock_net(skb->sk);
 472         struct sctp_comm_param commp = {
 473                 .skb = skb,
 474                 .cb = cb,
 475                 .r = r,
 476                 .net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN),
 477         };
 478         int pos = cb->args[2];
 479
 480         /* eps hashtable dumps
 481          * args:
 482          * 0 : if it will traversal listen sock
 483          * 1 : to record the sock pos of this time's traversal
 484          * 4 : to work as a temporary variable to traversal list
 485          */
 486         if (cb->args[0] == 0) {
 487                 if (!(idiag_states & TCPF_LISTEN))
 488                         goto skip;
 489                 if (sctp_for_each_endpoint(sctp_ep_dump, &commp))
 490                         goto done;
 491 skip:
 492                 cb->args[0] = 1;
 493                 cb->args[1] = 0;
 494                 cb->args[4] = 0;
 495         }
 496
 497         /* asocs by transport hashtable dump
 498          * args:
 499          * 1 : to record the assoc pos of this time's traversal
 500          * 2 : to record the transport pos of this time's traversal
 501          * 3 : to mark if we have dumped the ep info of the current asoc
 502          * 4 : to work as a temporary variable to traversal list
 503          * 5 : to save the sk we get from travelsing the tsp list.
 504          */
 505         if (!(idiag_states & ~(TCPF_LISTEN | TCPF_CLOSE)))
 506                 goto done;
 507
 508         sctp_for_each_transport(sctp_sock_filter, sctp_sock_dump,
 509                                 net, &pos, &commp);
 510         cb->args[2] = pos;
 511
 512 done:
 513         cb->args[1] = cb->args[4];
 514         cb->args[4] = 0;
 515 }
 516
 517 static const struct inet_diag_handler sctp_diag_handler = {
 518         .dump            = sctp_diag_dump,
 519         .dump_one        = sctp_diag_dump_one,
 520         .idiag_get_info  = sctp_diag_get_info,
 521         .idiag_type      = IPPROTO_SCTP,
 522         .idiag_info_size = sizeof(struct sctp_info),
 523 };
 524
 525 static int __init sctp_diag_init(void)
 526 {
 527         return inet_diag_register(&sctp_diag_handler);
 528 }
 529
 530 static void __exit sctp_diag_exit(void)
 531 {
 532         inet_diag_unregister(&sctp_diag_handler);
 533 }
 534
 535 module_init(sctp_diag_init);
 536 module_exit(sctp_diag_exit);
 537 MODULE_LICENSE("GPL");
 538 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-132);