linux/net/sctp/diag.c
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   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
  22static 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 */
  26static 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
  71static 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
  97static 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*/
 123static 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
 215errout:
 216        nlmsg_cancel(skb, nlh);
 217        return -EMSGSIZE;
 218}
 219
 220/* callback and param */
 221struct 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
 229static 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(1) /* INET_DIAG_SHUTDOWN */
 241                + nla_total_size(1) /* INET_DIAG_TOS */
 242                + nla_total_size(1) /* INET_DIAG_TCLASS */
 243                + nla_total_size(4) /* INET_DIAG_MARK */
 244                + nla_total_size(4) /* INET_DIAG_CLASS_ID */
 245                + nla_total_size(addrlen * asoc->peer.transport_count)
 246                + nla_total_size(addrlen * addrcnt)
 247                + nla_total_size(sizeof(struct inet_diag_meminfo))
 248                + nla_total_size(sizeof(struct inet_diag_msg))
 249                + 64;
 250}
 251
 252static int sctp_tsp_dump_one(struct sctp_transport *tsp, void *p)
 253{
 254        struct sctp_association *assoc = tsp->asoc;
 255        struct sock *sk = tsp->asoc->base.sk;
 256        struct sctp_comm_param *commp = p;
 257        struct sk_buff *in_skb = commp->skb;
 258        const struct inet_diag_req_v2 *req = commp->r;
 259        const struct nlmsghdr *nlh = commp->nlh;
 260        struct net *net = sock_net(in_skb->sk);
 261        struct sk_buff *rep;
 262        int err;
 263
 264        err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
 265        if (err)
 266                goto out;
 267
 268        err = -ENOMEM;
 269        rep = nlmsg_new(inet_assoc_attr_size(assoc), GFP_KERNEL);
 270        if (!rep)
 271                goto out;
 272
 273        lock_sock(sk);
 274        if (sk != assoc->base.sk) {
 275                release_sock(sk);
 276                sk = assoc->base.sk;
 277                lock_sock(sk);
 278        }
 279        err = inet_sctp_diag_fill(sk, assoc, rep, req,
 280                                  sk_user_ns(NETLINK_CB(in_skb).sk),
 281                                  NETLINK_CB(in_skb).portid,
 282                                  nlh->nlmsg_seq, 0, nlh,
 283                                  commp->net_admin);
 284        release_sock(sk);
 285        if (err < 0) {
 286                WARN_ON(err == -EMSGSIZE);
 287                kfree_skb(rep);
 288                goto out;
 289        }
 290
 291        err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
 292                              MSG_DONTWAIT);
 293        if (err > 0)
 294                err = 0;
 295out:
 296        return err;
 297}
 298
 299static int sctp_sock_dump(struct sctp_transport *tsp, void *p)
 300{
 301        struct sctp_endpoint *ep = tsp->asoc->ep;
 302        struct sctp_comm_param *commp = p;
 303        struct sock *sk = ep->base.sk;
 304        struct sk_buff *skb = commp->skb;
 305        struct netlink_callback *cb = commp->cb;
 306        const struct inet_diag_req_v2 *r = commp->r;
 307        struct sctp_association *assoc;
 308        int err = 0;
 309
 310        lock_sock(sk);
 311        list_for_each_entry(assoc, &ep->asocs, asocs) {
 312                if (cb->args[4] < cb->args[1])
 313                        goto next;
 314
 315                if (r->id.idiag_sport != htons(assoc->base.bind_addr.port) &&
 316                    r->id.idiag_sport)
 317                        goto next;
 318                if (r->id.idiag_dport != htons(assoc->peer.port) &&
 319                    r->id.idiag_dport)
 320                        goto next;
 321
 322                if (!cb->args[3] &&
 323                    inet_sctp_diag_fill(sk, NULL, skb, r,
 324                                        sk_user_ns(NETLINK_CB(cb->skb).sk),
 325                                        NETLINK_CB(cb->skb).portid,
 326                                        cb->nlh->nlmsg_seq,
 327                                        NLM_F_MULTI, cb->nlh,
 328                                        commp->net_admin) < 0) {
 329                        err = 1;
 330                        goto release;
 331                }
 332                cb->args[3] = 1;
 333
 334                if (inet_sctp_diag_fill(sk, assoc, skb, r,
 335                                        sk_user_ns(NETLINK_CB(cb->skb).sk),
 336                                        NETLINK_CB(cb->skb).portid,
 337                                        cb->nlh->nlmsg_seq, 0, cb->nlh,
 338                                        commp->net_admin) < 0) {
 339                        err = 1;
 340                        goto release;
 341                }
 342next:
 343                cb->args[4]++;
 344        }
 345        cb->args[1] = 0;
 346        cb->args[3] = 0;
 347        cb->args[4] = 0;
 348release:
 349        release_sock(sk);
 350        return err;
 351}
 352
 353static int sctp_sock_filter(struct sctp_transport *tsp, void *p)
 354{
 355        struct sctp_endpoint *ep = tsp->asoc->ep;
 356        struct sctp_comm_param *commp = p;
 357        struct sock *sk = ep->base.sk;
 358        const struct inet_diag_req_v2 *r = commp->r;
 359        struct sctp_association *assoc =
 360                list_entry(ep->asocs.next, struct sctp_association, asocs);
 361
 362        /* find the ep only once through the transports by this condition */
 363        if (tsp->asoc != assoc)
 364                return 0;
 365
 366        if (r->sdiag_family != AF_UNSPEC && sk->sk_family != r->sdiag_family)
 367                return 0;
 368
 369        return 1;
 370}
 371
 372static int sctp_ep_dump(struct sctp_endpoint *ep, void *p)
 373{
 374        struct sctp_comm_param *commp = p;
 375        struct sock *sk = ep->base.sk;
 376        struct sk_buff *skb = commp->skb;
 377        struct netlink_callback *cb = commp->cb;
 378        const struct inet_diag_req_v2 *r = commp->r;
 379        struct net *net = sock_net(skb->sk);
 380        struct inet_sock *inet = inet_sk(sk);
 381        int err = 0;
 382
 383        if (!net_eq(sock_net(sk), net))
 384                goto out;
 385
 386        if (cb->args[4] < cb->args[1])
 387                goto next;
 388
 389        if (!(r->idiag_states & TCPF_LISTEN) && !list_empty(&ep->asocs))
 390                goto next;
 391
 392        if (r->sdiag_family != AF_UNSPEC &&
 393            sk->sk_family != r->sdiag_family)
 394                goto next;
 395
 396        if (r->id.idiag_sport != inet->inet_sport &&
 397            r->id.idiag_sport)
 398                goto next;
 399
 400        if (r->id.idiag_dport != inet->inet_dport &&
 401            r->id.idiag_dport)
 402                goto next;
 403
 404        if (inet_sctp_diag_fill(sk, NULL, skb, r,
 405                                sk_user_ns(NETLINK_CB(cb->skb).sk),
 406                                NETLINK_CB(cb->skb).portid,
 407                                cb->nlh->nlmsg_seq, NLM_F_MULTI,
 408                                cb->nlh, commp->net_admin) < 0) {
 409                err = 2;
 410                goto out;
 411        }
 412next:
 413        cb->args[4]++;
 414out:
 415        return err;
 416}
 417
 418/* define the functions for sctp_diag_handler*/
 419static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
 420                               void *info)
 421{
 422        struct sctp_infox *infox = (struct sctp_infox *)info;
 423
 424        if (infox->asoc) {
 425                r->idiag_rqueue = atomic_read(&infox->asoc->rmem_alloc);
 426                r->idiag_wqueue = infox->asoc->sndbuf_used;
 427        } else {
 428                r->idiag_rqueue = sk->sk_ack_backlog;
 429                r->idiag_wqueue = sk->sk_max_ack_backlog;
 430        }
 431        if (infox->sctpinfo)
 432                sctp_get_sctp_info(sk, infox->asoc, infox->sctpinfo);
 433}
 434
 435static int sctp_diag_dump_one(struct sk_buff *in_skb,
 436                              const struct nlmsghdr *nlh,
 437                              const struct inet_diag_req_v2 *req)
 438{
 439        struct net *net = sock_net(in_skb->sk);
 440        union sctp_addr laddr, paddr;
 441        struct sctp_comm_param commp = {
 442                .skb = in_skb,
 443                .r = req,
 444                .nlh = nlh,
 445                .net_admin = netlink_net_capable(in_skb, CAP_NET_ADMIN),
 446        };
 447
 448        if (req->sdiag_family == AF_INET) {
 449                laddr.v4.sin_port = req->id.idiag_sport;
 450                laddr.v4.sin_addr.s_addr = req->id.idiag_src[0];
 451                laddr.v4.sin_family = AF_INET;
 452
 453                paddr.v4.sin_port = req->id.idiag_dport;
 454                paddr.v4.sin_addr.s_addr = req->id.idiag_dst[0];
 455                paddr.v4.sin_family = AF_INET;
 456        } else {
 457                laddr.v6.sin6_port = req->id.idiag_sport;
 458                memcpy(&laddr.v6.sin6_addr, req->id.idiag_src,
 459                       sizeof(laddr.v6.sin6_addr));
 460                laddr.v6.sin6_family = AF_INET6;
 461
 462                paddr.v6.sin6_port = req->id.idiag_dport;
 463                memcpy(&paddr.v6.sin6_addr, req->id.idiag_dst,
 464                       sizeof(paddr.v6.sin6_addr));
 465                paddr.v6.sin6_family = AF_INET6;
 466        }
 467
 468        return sctp_transport_lookup_process(sctp_tsp_dump_one,
 469                                             net, &laddr, &paddr, &commp);
 470}
 471
 472static void sctp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 473                           const struct inet_diag_req_v2 *r, struct nlattr *bc)
 474{
 475        u32 idiag_states = r->idiag_states;
 476        struct net *net = sock_net(skb->sk);
 477        struct sctp_comm_param commp = {
 478                .skb = skb,
 479                .cb = cb,
 480                .r = r,
 481                .net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN),
 482        };
 483        int pos = cb->args[2];
 484
 485        /* eps hashtable dumps
 486         * args:
 487         * 0 : if it will traversal listen sock
 488         * 1 : to record the sock pos of this time's traversal
 489         * 4 : to work as a temporary variable to traversal list
 490         */
 491        if (cb->args[0] == 0) {
 492                if (!(idiag_states & TCPF_LISTEN))
 493                        goto skip;
 494                if (sctp_for_each_endpoint(sctp_ep_dump, &commp))
 495                        goto done;
 496skip:
 497                cb->args[0] = 1;
 498                cb->args[1] = 0;
 499                cb->args[4] = 0;
 500        }
 501
 502        /* asocs by transport hashtable dump
 503         * args:
 504         * 1 : to record the assoc pos of this time's traversal
 505         * 2 : to record the transport pos of this time's traversal
 506         * 3 : to mark if we have dumped the ep info of the current asoc
 507         * 4 : to work as a temporary variable to traversal list
 508         * 5 : to save the sk we get from travelsing the tsp list.
 509         */
 510        if (!(idiag_states & ~(TCPF_LISTEN | TCPF_CLOSE)))
 511                goto done;
 512
 513        sctp_for_each_transport(sctp_sock_filter, sctp_sock_dump,
 514                                net, &pos, &commp);
 515        cb->args[2] = pos;
 516
 517done:
 518        cb->args[1] = cb->args[4];
 519        cb->args[4] = 0;
 520}
 521
 522static const struct inet_diag_handler sctp_diag_handler = {
 523        .dump            = sctp_diag_dump,
 524        .dump_one        = sctp_diag_dump_one,
 525        .idiag_get_info  = sctp_diag_get_info,
 526        .idiag_type      = IPPROTO_SCTP,
 527        .idiag_info_size = sizeof(struct sctp_info),
 528};
 529
 530static int __init sctp_diag_init(void)
 531{
 532        return inet_diag_register(&sctp_diag_handler);
 533}
 534
 535static void __exit sctp_diag_exit(void)
 536{
 537        inet_diag_unregister(&sctp_diag_handler);
 538}
 539
 540module_init(sctp_diag_init);
 541module_exit(sctp_diag_exit);
 542MODULE_LICENSE("GPL");
 543MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-132);
 544