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