linux/net/ipv4/ping.c
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   1/*
   2 * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3 *              operating system.  INET is implemented using the  BSD Socket
   4 *              interface as the means of communication with the user level.
   5 *
   6 *              "Ping" sockets
   7 *
   8 *              This program is free software; you can redistribute it and/or
   9 *              modify it under the terms of the GNU General Public License
  10 *              as published by the Free Software Foundation; either version
  11 *              2 of the License, or (at your option) any later version.
  12 *
  13 * Based on ipv4/udp.c code.
  14 *
  15 * Authors:     Vasiliy Kulikov / Openwall (for Linux 2.6),
  16 *              Pavel Kankovsky (for Linux 2.4.32)
  17 *
  18 * Pavel gave all rights to bugs to Vasiliy,
  19 * none of the bugs are Pavel's now.
  20 *
  21 */
  22
  23#include <linux/uaccess.h>
  24#include <linux/types.h>
  25#include <linux/fcntl.h>
  26#include <linux/socket.h>
  27#include <linux/sockios.h>
  28#include <linux/in.h>
  29#include <linux/errno.h>
  30#include <linux/timer.h>
  31#include <linux/mm.h>
  32#include <linux/inet.h>
  33#include <linux/netdevice.h>
  34#include <net/snmp.h>
  35#include <net/ip.h>
  36#include <net/icmp.h>
  37#include <net/protocol.h>
  38#include <linux/skbuff.h>
  39#include <linux/proc_fs.h>
  40#include <linux/export.h>
  41#include <net/sock.h>
  42#include <net/ping.h>
  43#include <net/udp.h>
  44#include <net/route.h>
  45#include <net/inet_common.h>
  46#include <net/checksum.h>
  47
  48#if IS_ENABLED(CONFIG_IPV6)
  49#include <linux/in6.h>
  50#include <linux/icmpv6.h>
  51#include <net/addrconf.h>
  52#include <net/ipv6.h>
  53#include <net/transp_v6.h>
  54#endif
  55
  56struct ping_table {
  57        struct hlist_nulls_head hash[PING_HTABLE_SIZE];
  58        rwlock_t                lock;
  59};
  60
  61static struct ping_table ping_table;
  62struct pingv6_ops pingv6_ops;
  63EXPORT_SYMBOL_GPL(pingv6_ops);
  64
  65static u16 ping_port_rover;
  66
  67static inline int ping_hashfn(struct net *net, unsigned int num, unsigned int mask)
  68{
  69        int res = (num + net_hash_mix(net)) & mask;
  70
  71        pr_debug("hash(%d) = %d\n", num, res);
  72        return res;
  73}
  74EXPORT_SYMBOL_GPL(ping_hash);
  75
  76static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table,
  77                                             struct net *net, unsigned int num)
  78{
  79        return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
  80}
  81
  82int ping_get_port(struct sock *sk, unsigned short ident)
  83{
  84        struct hlist_nulls_node *node;
  85        struct hlist_nulls_head *hlist;
  86        struct inet_sock *isk, *isk2;
  87        struct sock *sk2 = NULL;
  88
  89        isk = inet_sk(sk);
  90        write_lock_bh(&ping_table.lock);
  91        if (ident == 0) {
  92                u32 i;
  93                u16 result = ping_port_rover + 1;
  94
  95                for (i = 0; i < (1L << 16); i++, result++) {
  96                        if (!result)
  97                                result++; /* avoid zero */
  98                        hlist = ping_hashslot(&ping_table, sock_net(sk),
  99                                            result);
 100                        ping_portaddr_for_each_entry(sk2, node, hlist) {
 101                                isk2 = inet_sk(sk2);
 102
 103                                if (isk2->inet_num == result)
 104                                        goto next_port;
 105                        }
 106
 107                        /* found */
 108                        ping_port_rover = ident = result;
 109                        break;
 110next_port:
 111                        ;
 112                }
 113                if (i >= (1L << 16))
 114                        goto fail;
 115        } else {
 116                hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
 117                ping_portaddr_for_each_entry(sk2, node, hlist) {
 118                        isk2 = inet_sk(sk2);
 119
 120                        /* BUG? Why is this reuse and not reuseaddr? ping.c
 121                         * doesn't turn off SO_REUSEADDR, and it doesn't expect
 122                         * that other ping processes can steal its packets.
 123                         */
 124                        if ((isk2->inet_num == ident) &&
 125                            (sk2 != sk) &&
 126                            (!sk2->sk_reuse || !sk->sk_reuse))
 127                                goto fail;
 128                }
 129        }
 130
 131        pr_debug("found port/ident = %d\n", ident);
 132        isk->inet_num = ident;
 133        if (sk_unhashed(sk)) {
 134                pr_debug("was not hashed\n");
 135                sock_hold(sk);
 136                hlist_nulls_add_head(&sk->sk_nulls_node, hlist);
 137                sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 138        }
 139        write_unlock_bh(&ping_table.lock);
 140        return 0;
 141
 142fail:
 143        write_unlock_bh(&ping_table.lock);
 144        return 1;
 145}
 146EXPORT_SYMBOL_GPL(ping_get_port);
 147
 148void ping_hash(struct sock *sk)
 149{
 150        pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
 151        BUG(); /* "Please do not press this button again." */
 152}
 153
 154void ping_unhash(struct sock *sk)
 155{
 156        struct inet_sock *isk = inet_sk(sk);
 157        pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
 158        if (sk_hashed(sk)) {
 159                write_lock_bh(&ping_table.lock);
 160                hlist_nulls_del(&sk->sk_nulls_node);
 161                sock_put(sk);
 162                isk->inet_num = 0;
 163                isk->inet_sport = 0;
 164                sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
 165                write_unlock_bh(&ping_table.lock);
 166        }
 167}
 168EXPORT_SYMBOL_GPL(ping_unhash);
 169
 170static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
 171{
 172        struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
 173        struct sock *sk = NULL;
 174        struct inet_sock *isk;
 175        struct hlist_nulls_node *hnode;
 176        int dif = skb->dev->ifindex;
 177
 178        if (skb->protocol == htons(ETH_P_IP)) {
 179                pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
 180                         (int)ident, &ip_hdr(skb)->daddr, dif);
 181#if IS_ENABLED(CONFIG_IPV6)
 182        } else if (skb->protocol == htons(ETH_P_IPV6)) {
 183                pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
 184                         (int)ident, &ipv6_hdr(skb)->daddr, dif);
 185#endif
 186        }
 187
 188        read_lock_bh(&ping_table.lock);
 189
 190        ping_portaddr_for_each_entry(sk, hnode, hslot) {
 191                isk = inet_sk(sk);
 192
 193                pr_debug("iterate\n");
 194                if (isk->inet_num != ident)
 195                        continue;
 196
 197                if (skb->protocol == htons(ETH_P_IP) &&
 198                    sk->sk_family == AF_INET) {
 199                        pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
 200                                 (int) isk->inet_num, &isk->inet_rcv_saddr,
 201                                 sk->sk_bound_dev_if);
 202
 203                        if (isk->inet_rcv_saddr &&
 204                            isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
 205                                continue;
 206#if IS_ENABLED(CONFIG_IPV6)
 207                } else if (skb->protocol == htons(ETH_P_IPV6) &&
 208                           sk->sk_family == AF_INET6) {
 209
 210                        pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
 211                                 (int) isk->inet_num,
 212                                 &sk->sk_v6_rcv_saddr,
 213                                 sk->sk_bound_dev_if);
 214
 215                        if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
 216                            !ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
 217                                             &ipv6_hdr(skb)->daddr))
 218                                continue;
 219#endif
 220                }
 221
 222                if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
 223                        continue;
 224
 225                sock_hold(sk);
 226                goto exit;
 227        }
 228
 229        sk = NULL;
 230exit:
 231        read_unlock_bh(&ping_table.lock);
 232
 233        return sk;
 234}
 235
 236static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
 237                                          kgid_t *high)
 238{
 239        kgid_t *data = net->ipv4.ping_group_range.range;
 240        unsigned int seq;
 241
 242        do {
 243                seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
 244
 245                *low = data[0];
 246                *high = data[1];
 247        } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
 248}
 249
 250
 251int ping_init_sock(struct sock *sk)
 252{
 253        struct net *net = sock_net(sk);
 254        kgid_t group = current_egid();
 255        struct group_info *group_info;
 256        int i, j, count;
 257        kgid_t low, high;
 258        int ret = 0;
 259
 260        inet_get_ping_group_range_net(net, &low, &high);
 261        if (gid_lte(low, group) && gid_lte(group, high))
 262                return 0;
 263
 264        group_info = get_current_groups();
 265        count = group_info->ngroups;
 266        for (i = 0; i < group_info->nblocks; i++) {
 267                int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
 268                for (j = 0; j < cp_count; j++) {
 269                        kgid_t gid = group_info->blocks[i][j];
 270                        if (gid_lte(low, gid) && gid_lte(gid, high))
 271                                goto out_release_group;
 272                }
 273
 274                count -= cp_count;
 275        }
 276
 277        ret = -EACCES;
 278
 279out_release_group:
 280        put_group_info(group_info);
 281        return ret;
 282}
 283EXPORT_SYMBOL_GPL(ping_init_sock);
 284
 285void ping_close(struct sock *sk, long timeout)
 286{
 287        pr_debug("ping_close(sk=%p,sk->num=%u)\n",
 288                 inet_sk(sk), inet_sk(sk)->inet_num);
 289        pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter);
 290
 291        sk_common_release(sk);
 292}
 293EXPORT_SYMBOL_GPL(ping_close);
 294
 295/* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
 296static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
 297                                struct sockaddr *uaddr, int addr_len) {
 298        struct net *net = sock_net(sk);
 299        if (sk->sk_family == AF_INET) {
 300                struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
 301                int chk_addr_ret;
 302
 303                if (addr_len < sizeof(*addr))
 304                        return -EINVAL;
 305
 306                pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
 307                         sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
 308
 309                chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
 310
 311                if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
 312                        chk_addr_ret = RTN_LOCAL;
 313
 314                if ((sysctl_ip_nonlocal_bind == 0 &&
 315                    isk->freebind == 0 && isk->transparent == 0 &&
 316                     chk_addr_ret != RTN_LOCAL) ||
 317                    chk_addr_ret == RTN_MULTICAST ||
 318                    chk_addr_ret == RTN_BROADCAST)
 319                        return -EADDRNOTAVAIL;
 320
 321#if IS_ENABLED(CONFIG_IPV6)
 322        } else if (sk->sk_family == AF_INET6) {
 323                struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
 324                int addr_type, scoped, has_addr;
 325                struct net_device *dev = NULL;
 326
 327                if (addr_len < sizeof(*addr))
 328                        return -EINVAL;
 329
 330                if (addr->sin6_family != AF_INET6)
 331                        return -EINVAL;
 332
 333                pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
 334                         sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
 335
 336                addr_type = ipv6_addr_type(&addr->sin6_addr);
 337                scoped = __ipv6_addr_needs_scope_id(addr_type);
 338                if ((addr_type != IPV6_ADDR_ANY &&
 339                     !(addr_type & IPV6_ADDR_UNICAST)) ||
 340                    (scoped && !addr->sin6_scope_id))
 341                        return -EINVAL;
 342
 343                rcu_read_lock();
 344                if (addr->sin6_scope_id) {
 345                        dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
 346                        if (!dev) {
 347                                rcu_read_unlock();
 348                                return -ENODEV;
 349                        }
 350                }
 351                has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
 352                                                    scoped);
 353                rcu_read_unlock();
 354
 355                if (!(isk->freebind || isk->transparent || has_addr ||
 356                      addr_type == IPV6_ADDR_ANY))
 357                        return -EADDRNOTAVAIL;
 358
 359                if (scoped)
 360                        sk->sk_bound_dev_if = addr->sin6_scope_id;
 361#endif
 362        } else {
 363                return -EAFNOSUPPORT;
 364        }
 365        return 0;
 366}
 367
 368static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
 369{
 370        if (saddr->sa_family == AF_INET) {
 371                struct inet_sock *isk = inet_sk(sk);
 372                struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
 373                isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
 374#if IS_ENABLED(CONFIG_IPV6)
 375        } else if (saddr->sa_family == AF_INET6) {
 376                struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
 377                struct ipv6_pinfo *np = inet6_sk(sk);
 378                sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
 379#endif
 380        }
 381}
 382
 383static void ping_clear_saddr(struct sock *sk, int dif)
 384{
 385        sk->sk_bound_dev_if = dif;
 386        if (sk->sk_family == AF_INET) {
 387                struct inet_sock *isk = inet_sk(sk);
 388                isk->inet_rcv_saddr = isk->inet_saddr = 0;
 389#if IS_ENABLED(CONFIG_IPV6)
 390        } else if (sk->sk_family == AF_INET6) {
 391                struct ipv6_pinfo *np = inet6_sk(sk);
 392                memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
 393                memset(&np->saddr, 0, sizeof(np->saddr));
 394#endif
 395        }
 396}
 397/*
 398 * We need our own bind because there are no privileged id's == local ports.
 399 * Moreover, we don't allow binding to multi- and broadcast addresses.
 400 */
 401
 402int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 403{
 404        struct inet_sock *isk = inet_sk(sk);
 405        unsigned short snum;
 406        int err;
 407        int dif = sk->sk_bound_dev_if;
 408
 409        err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
 410        if (err)
 411                return err;
 412
 413        lock_sock(sk);
 414
 415        err = -EINVAL;
 416        if (isk->inet_num != 0)
 417                goto out;
 418
 419        err = -EADDRINUSE;
 420        ping_set_saddr(sk, uaddr);
 421        snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
 422        if (ping_get_port(sk, snum) != 0) {
 423                ping_clear_saddr(sk, dif);
 424                goto out;
 425        }
 426
 427        pr_debug("after bind(): num = %d, dif = %d\n",
 428                 (int)isk->inet_num,
 429                 (int)sk->sk_bound_dev_if);
 430
 431        err = 0;
 432        if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
 433                sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
 434#if IS_ENABLED(CONFIG_IPV6)
 435        if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
 436                sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
 437#endif
 438
 439        if (snum)
 440                sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
 441        isk->inet_sport = htons(isk->inet_num);
 442        isk->inet_daddr = 0;
 443        isk->inet_dport = 0;
 444
 445#if IS_ENABLED(CONFIG_IPV6)
 446        if (sk->sk_family == AF_INET6)
 447                memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
 448#endif
 449
 450        sk_dst_reset(sk);
 451out:
 452        release_sock(sk);
 453        pr_debug("ping_v4_bind -> %d\n", err);
 454        return err;
 455}
 456EXPORT_SYMBOL_GPL(ping_bind);
 457
 458/*
 459 * Is this a supported type of ICMP message?
 460 */
 461
 462static inline int ping_supported(int family, int type, int code)
 463{
 464        return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
 465               (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
 466}
 467
 468/*
 469 * This routine is called by the ICMP module when it gets some
 470 * sort of error condition.
 471 */
 472
 473void ping_err(struct sk_buff *skb, int offset, u32 info)
 474{
 475        int family;
 476        struct icmphdr *icmph;
 477        struct inet_sock *inet_sock;
 478        int type;
 479        int code;
 480        struct net *net = dev_net(skb->dev);
 481        struct sock *sk;
 482        int harderr;
 483        int err;
 484
 485        if (skb->protocol == htons(ETH_P_IP)) {
 486                family = AF_INET;
 487                type = icmp_hdr(skb)->type;
 488                code = icmp_hdr(skb)->code;
 489                icmph = (struct icmphdr *)(skb->data + offset);
 490        } else if (skb->protocol == htons(ETH_P_IPV6)) {
 491                family = AF_INET6;
 492                type = icmp6_hdr(skb)->icmp6_type;
 493                code = icmp6_hdr(skb)->icmp6_code;
 494                icmph = (struct icmphdr *) (skb->data + offset);
 495        } else {
 496                BUG();
 497        }
 498
 499        /* We assume the packet has already been checked by icmp_unreach */
 500
 501        if (!ping_supported(family, icmph->type, icmph->code))
 502                return;
 503
 504        pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
 505                 skb->protocol, type, code, ntohs(icmph->un.echo.id),
 506                 ntohs(icmph->un.echo.sequence));
 507
 508        sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
 509        if (sk == NULL) {
 510                pr_debug("no socket, dropping\n");
 511                return; /* No socket for error */
 512        }
 513        pr_debug("err on socket %p\n", sk);
 514
 515        err = 0;
 516        harderr = 0;
 517        inet_sock = inet_sk(sk);
 518
 519        if (skb->protocol == htons(ETH_P_IP)) {
 520                switch (type) {
 521                default:
 522                case ICMP_TIME_EXCEEDED:
 523                        err = EHOSTUNREACH;
 524                        break;
 525                case ICMP_SOURCE_QUENCH:
 526                        /* This is not a real error but ping wants to see it.
 527                         * Report it with some fake errno.
 528                         */
 529                        err = EREMOTEIO;
 530                        break;
 531                case ICMP_PARAMETERPROB:
 532                        err = EPROTO;
 533                        harderr = 1;
 534                        break;
 535                case ICMP_DEST_UNREACH:
 536                        if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
 537                                ipv4_sk_update_pmtu(skb, sk, info);
 538                                if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
 539                                        err = EMSGSIZE;
 540                                        harderr = 1;
 541                                        break;
 542                                }
 543                                goto out;
 544                        }
 545                        err = EHOSTUNREACH;
 546                        if (code <= NR_ICMP_UNREACH) {
 547                                harderr = icmp_err_convert[code].fatal;
 548                                err = icmp_err_convert[code].errno;
 549                        }
 550                        break;
 551                case ICMP_REDIRECT:
 552                        /* See ICMP_SOURCE_QUENCH */
 553                        ipv4_sk_redirect(skb, sk);
 554                        err = EREMOTEIO;
 555                        break;
 556                }
 557#if IS_ENABLED(CONFIG_IPV6)
 558        } else if (skb->protocol == htons(ETH_P_IPV6)) {
 559                harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
 560#endif
 561        }
 562
 563        /*
 564         *      RFC1122: OK.  Passes ICMP errors back to application, as per
 565         *      4.1.3.3.
 566         */
 567        if ((family == AF_INET && !inet_sock->recverr) ||
 568            (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
 569                if (!harderr || sk->sk_state != TCP_ESTABLISHED)
 570                        goto out;
 571        } else {
 572                if (family == AF_INET) {
 573                        ip_icmp_error(sk, skb, err, 0 /* no remote port */,
 574                                      info, (u8 *)icmph);
 575#if IS_ENABLED(CONFIG_IPV6)
 576                } else if (family == AF_INET6) {
 577                        pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
 578                                                   info, (u8 *)icmph);
 579#endif
 580                }
 581        }
 582        sk->sk_err = err;
 583        sk->sk_error_report(sk);
 584out:
 585        sock_put(sk);
 586}
 587EXPORT_SYMBOL_GPL(ping_err);
 588
 589/*
 590 *      Copy and checksum an ICMP Echo packet from user space into a buffer
 591 *      starting from the payload.
 592 */
 593
 594int ping_getfrag(void *from, char *to,
 595                 int offset, int fraglen, int odd, struct sk_buff *skb)
 596{
 597        struct pingfakehdr *pfh = (struct pingfakehdr *)from;
 598
 599        if (offset == 0) {
 600                if (fraglen < sizeof(struct icmphdr))
 601                        BUG();
 602                if (csum_partial_copy_fromiovecend(to + sizeof(struct icmphdr),
 603                            pfh->iov, 0, fraglen - sizeof(struct icmphdr),
 604                            &pfh->wcheck))
 605                        return -EFAULT;
 606        } else if (offset < sizeof(struct icmphdr)) {
 607                        BUG();
 608        } else {
 609                if (csum_partial_copy_fromiovecend
 610                                (to, pfh->iov, offset - sizeof(struct icmphdr),
 611                                 fraglen, &pfh->wcheck))
 612                        return -EFAULT;
 613        }
 614
 615#if IS_ENABLED(CONFIG_IPV6)
 616        /* For IPv6, checksum each skb as we go along, as expected by
 617         * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
 618         * wcheck, it will be finalized in ping_v4_push_pending_frames.
 619         */
 620        if (pfh->family == AF_INET6) {
 621                skb->csum = pfh->wcheck;
 622                skb->ip_summed = CHECKSUM_NONE;
 623                pfh->wcheck = 0;
 624        }
 625#endif
 626
 627        return 0;
 628}
 629EXPORT_SYMBOL_GPL(ping_getfrag);
 630
 631static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
 632                                       struct flowi4 *fl4)
 633{
 634        struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
 635
 636        pfh->wcheck = csum_partial((char *)&pfh->icmph,
 637                sizeof(struct icmphdr), pfh->wcheck);
 638        pfh->icmph.checksum = csum_fold(pfh->wcheck);
 639        memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
 640        skb->ip_summed = CHECKSUM_NONE;
 641        return ip_push_pending_frames(sk, fl4);
 642}
 643
 644int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
 645                        void *user_icmph, size_t icmph_len) {
 646        u8 type, code;
 647
 648        if (len > 0xFFFF)
 649                return -EMSGSIZE;
 650
 651        /*
 652         *      Check the flags.
 653         */
 654
 655        /* Mirror BSD error message compatibility */
 656        if (msg->msg_flags & MSG_OOB)
 657                return -EOPNOTSUPP;
 658
 659        /*
 660         *      Fetch the ICMP header provided by the userland.
 661         *      iovec is modified! The ICMP header is consumed.
 662         */
 663        if (memcpy_fromiovec(user_icmph, msg->msg_iov, icmph_len))
 664                return -EFAULT;
 665
 666        if (family == AF_INET) {
 667                type = ((struct icmphdr *) user_icmph)->type;
 668                code = ((struct icmphdr *) user_icmph)->code;
 669#if IS_ENABLED(CONFIG_IPV6)
 670        } else if (family == AF_INET6) {
 671                type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
 672                code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
 673#endif
 674        } else {
 675                BUG();
 676        }
 677
 678        if (!ping_supported(family, type, code))
 679                return -EINVAL;
 680
 681        return 0;
 682}
 683EXPORT_SYMBOL_GPL(ping_common_sendmsg);
 684
 685static int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 686                           size_t len)
 687{
 688        struct net *net = sock_net(sk);
 689        struct flowi4 fl4;
 690        struct inet_sock *inet = inet_sk(sk);
 691        struct ipcm_cookie ipc;
 692        struct icmphdr user_icmph;
 693        struct pingfakehdr pfh;
 694        struct rtable *rt = NULL;
 695        struct ip_options_data opt_copy;
 696        int free = 0;
 697        __be32 saddr, daddr, faddr;
 698        u8  tos;
 699        int err;
 700
 701        pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
 702
 703        err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
 704                                  sizeof(user_icmph));
 705        if (err)
 706                return err;
 707
 708        /*
 709         *      Get and verify the address.
 710         */
 711
 712        if (msg->msg_name) {
 713                DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
 714                if (msg->msg_namelen < sizeof(*usin))
 715                        return -EINVAL;
 716                if (usin->sin_family != AF_INET)
 717                        return -EINVAL;
 718                daddr = usin->sin_addr.s_addr;
 719                /* no remote port */
 720        } else {
 721                if (sk->sk_state != TCP_ESTABLISHED)
 722                        return -EDESTADDRREQ;
 723                daddr = inet->inet_daddr;
 724                /* no remote port */
 725        }
 726
 727        ipc.addr = inet->inet_saddr;
 728        ipc.opt = NULL;
 729        ipc.oif = sk->sk_bound_dev_if;
 730        ipc.tx_flags = 0;
 731        ipc.ttl = 0;
 732        ipc.tos = -1;
 733
 734        sock_tx_timestamp(sk, &ipc.tx_flags);
 735
 736        if (msg->msg_controllen) {
 737                err = ip_cmsg_send(sock_net(sk), msg, &ipc, false);
 738                if (err)
 739                        return err;
 740                if (ipc.opt)
 741                        free = 1;
 742        }
 743        if (!ipc.opt) {
 744                struct ip_options_rcu *inet_opt;
 745
 746                rcu_read_lock();
 747                inet_opt = rcu_dereference(inet->inet_opt);
 748                if (inet_opt) {
 749                        memcpy(&opt_copy, inet_opt,
 750                               sizeof(*inet_opt) + inet_opt->opt.optlen);
 751                        ipc.opt = &opt_copy.opt;
 752                }
 753                rcu_read_unlock();
 754        }
 755
 756        saddr = ipc.addr;
 757        ipc.addr = faddr = daddr;
 758
 759        if (ipc.opt && ipc.opt->opt.srr) {
 760                if (!daddr)
 761                        return -EINVAL;
 762                faddr = ipc.opt->opt.faddr;
 763        }
 764        tos = get_rttos(&ipc, inet);
 765        if (sock_flag(sk, SOCK_LOCALROUTE) ||
 766            (msg->msg_flags & MSG_DONTROUTE) ||
 767            (ipc.opt && ipc.opt->opt.is_strictroute)) {
 768                tos |= RTO_ONLINK;
 769        }
 770
 771        if (ipv4_is_multicast(daddr)) {
 772                if (!ipc.oif)
 773                        ipc.oif = inet->mc_index;
 774                if (!saddr)
 775                        saddr = inet->mc_addr;
 776        } else if (!ipc.oif)
 777                ipc.oif = inet->uc_index;
 778
 779        flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
 780                           RT_SCOPE_UNIVERSE, sk->sk_protocol,
 781                           inet_sk_flowi_flags(sk), faddr, saddr, 0, 0);
 782
 783        security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
 784        rt = ip_route_output_flow(net, &fl4, sk);
 785        if (IS_ERR(rt)) {
 786                err = PTR_ERR(rt);
 787                rt = NULL;
 788                if (err == -ENETUNREACH)
 789                        IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
 790                goto out;
 791        }
 792
 793        err = -EACCES;
 794        if ((rt->rt_flags & RTCF_BROADCAST) &&
 795            !sock_flag(sk, SOCK_BROADCAST))
 796                goto out;
 797
 798        if (msg->msg_flags & MSG_CONFIRM)
 799                goto do_confirm;
 800back_from_confirm:
 801
 802        if (!ipc.addr)
 803                ipc.addr = fl4.daddr;
 804
 805        lock_sock(sk);
 806
 807        pfh.icmph.type = user_icmph.type; /* already checked */
 808        pfh.icmph.code = user_icmph.code; /* ditto */
 809        pfh.icmph.checksum = 0;
 810        pfh.icmph.un.echo.id = inet->inet_sport;
 811        pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
 812        pfh.iov = msg->msg_iov;
 813        pfh.wcheck = 0;
 814        pfh.family = AF_INET;
 815
 816        err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
 817                        0, &ipc, &rt, msg->msg_flags);
 818        if (err)
 819                ip_flush_pending_frames(sk);
 820        else
 821                err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
 822        release_sock(sk);
 823
 824out:
 825        ip_rt_put(rt);
 826        if (free)
 827                kfree(ipc.opt);
 828        if (!err) {
 829                icmp_out_count(sock_net(sk), user_icmph.type);
 830                return len;
 831        }
 832        return err;
 833
 834do_confirm:
 835        dst_confirm(&rt->dst);
 836        if (!(msg->msg_flags & MSG_PROBE) || len)
 837                goto back_from_confirm;
 838        err = 0;
 839        goto out;
 840}
 841
 842int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 843                 size_t len, int noblock, int flags, int *addr_len)
 844{
 845        struct inet_sock *isk = inet_sk(sk);
 846        int family = sk->sk_family;
 847        struct sk_buff *skb;
 848        int copied, err;
 849
 850        pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
 851
 852        err = -EOPNOTSUPP;
 853        if (flags & MSG_OOB)
 854                goto out;
 855
 856        if (flags & MSG_ERRQUEUE) {
 857                if (family == AF_INET) {
 858                        return ip_recv_error(sk, msg, len, addr_len);
 859#if IS_ENABLED(CONFIG_IPV6)
 860                } else if (family == AF_INET6) {
 861                        return pingv6_ops.ipv6_recv_error(sk, msg, len,
 862                                                          addr_len);
 863#endif
 864                }
 865        }
 866
 867        skb = skb_recv_datagram(sk, flags, noblock, &err);
 868        if (!skb)
 869                goto out;
 870
 871        copied = skb->len;
 872        if (copied > len) {
 873                msg->msg_flags |= MSG_TRUNC;
 874                copied = len;
 875        }
 876
 877        /* Don't bother checking the checksum */
 878        err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 879        if (err)
 880                goto done;
 881
 882        sock_recv_timestamp(msg, sk, skb);
 883
 884        /* Copy the address and add cmsg data. */
 885        if (family == AF_INET) {
 886                DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
 887
 888                if (sin) {
 889                        sin->sin_family = AF_INET;
 890                        sin->sin_port = 0 /* skb->h.uh->source */;
 891                        sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
 892                        memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
 893                        *addr_len = sizeof(*sin);
 894                }
 895
 896                if (isk->cmsg_flags)
 897                        ip_cmsg_recv(msg, skb);
 898
 899#if IS_ENABLED(CONFIG_IPV6)
 900        } else if (family == AF_INET6) {
 901                struct ipv6_pinfo *np = inet6_sk(sk);
 902                struct ipv6hdr *ip6 = ipv6_hdr(skb);
 903                DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
 904
 905                if (sin6) {
 906                        sin6->sin6_family = AF_INET6;
 907                        sin6->sin6_port = 0;
 908                        sin6->sin6_addr = ip6->saddr;
 909                        sin6->sin6_flowinfo = 0;
 910                        if (np->sndflow)
 911                                sin6->sin6_flowinfo = ip6_flowinfo(ip6);
 912                        sin6->sin6_scope_id =
 913                                ipv6_iface_scope_id(&sin6->sin6_addr,
 914                                                    IP6CB(skb)->iif);
 915                        *addr_len = sizeof(*sin6);
 916                }
 917
 918                if (inet6_sk(sk)->rxopt.all)
 919                        pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
 920                if (skb->protocol == htons(ETH_P_IPV6) &&
 921                    inet6_sk(sk)->rxopt.all)
 922                        pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
 923                else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
 924                        ip_cmsg_recv(msg, skb);
 925#endif
 926        } else {
 927                BUG();
 928        }
 929
 930        err = copied;
 931
 932done:
 933        skb_free_datagram(sk, skb);
 934out:
 935        pr_debug("ping_recvmsg -> %d\n", err);
 936        return err;
 937}
 938EXPORT_SYMBOL_GPL(ping_recvmsg);
 939
 940int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 941{
 942        pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
 943                 inet_sk(sk), inet_sk(sk)->inet_num, skb);
 944        if (sock_queue_rcv_skb(sk, skb) < 0) {
 945                kfree_skb(skb);
 946                pr_debug("ping_queue_rcv_skb -> failed\n");
 947                return -1;
 948        }
 949        return 0;
 950}
 951EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
 952
 953
 954/*
 955 *      All we need to do is get the socket.
 956 */
 957
 958void ping_rcv(struct sk_buff *skb)
 959{
 960        struct sock *sk;
 961        struct net *net = dev_net(skb->dev);
 962        struct icmphdr *icmph = icmp_hdr(skb);
 963
 964        /* We assume the packet has already been checked by icmp_rcv */
 965
 966        pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
 967                 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
 968
 969        /* Push ICMP header back */
 970        skb_push(skb, skb->data - (u8 *)icmph);
 971
 972        sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
 973        if (sk != NULL) {
 974                pr_debug("rcv on socket %p\n", sk);
 975                ping_queue_rcv_skb(sk, skb_get(skb));
 976                sock_put(sk);
 977                return;
 978        }
 979        pr_debug("no socket, dropping\n");
 980
 981        /* We're called from icmp_rcv(). kfree_skb() is done there. */
 982}
 983EXPORT_SYMBOL_GPL(ping_rcv);
 984
 985struct proto ping_prot = {
 986        .name =         "PING",
 987        .owner =        THIS_MODULE,
 988        .init =         ping_init_sock,
 989        .close =        ping_close,
 990        .connect =      ip4_datagram_connect,
 991        .disconnect =   udp_disconnect,
 992        .setsockopt =   ip_setsockopt,
 993        .getsockopt =   ip_getsockopt,
 994        .sendmsg =      ping_v4_sendmsg,
 995        .recvmsg =      ping_recvmsg,
 996        .bind =         ping_bind,
 997        .backlog_rcv =  ping_queue_rcv_skb,
 998        .release_cb =   ip4_datagram_release_cb,
 999        .hash =         ping_hash,
1000        .unhash =       ping_unhash,
1001        .get_port =     ping_get_port,
1002        .obj_size =     sizeof(struct inet_sock),
1003};
1004EXPORT_SYMBOL(ping_prot);
1005
1006#ifdef CONFIG_PROC_FS
1007
1008static struct sock *ping_get_first(struct seq_file *seq, int start)
1009{
1010        struct sock *sk;
1011        struct ping_iter_state *state = seq->private;
1012        struct net *net = seq_file_net(seq);
1013
1014        for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1015             ++state->bucket) {
1016                struct hlist_nulls_node *node;
1017                struct hlist_nulls_head *hslot;
1018
1019                hslot = &ping_table.hash[state->bucket];
1020
1021                if (hlist_nulls_empty(hslot))
1022                        continue;
1023
1024                sk_nulls_for_each(sk, node, hslot) {
1025                        if (net_eq(sock_net(sk), net) &&
1026                            sk->sk_family == state->family)
1027                                goto found;
1028                }
1029        }
1030        sk = NULL;
1031found:
1032        return sk;
1033}
1034
1035static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1036{
1037        struct ping_iter_state *state = seq->private;
1038        struct net *net = seq_file_net(seq);
1039
1040        do {
1041                sk = sk_nulls_next(sk);
1042        } while (sk && (!net_eq(sock_net(sk), net)));
1043
1044        if (!sk)
1045                return ping_get_first(seq, state->bucket + 1);
1046        return sk;
1047}
1048
1049static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1050{
1051        struct sock *sk = ping_get_first(seq, 0);
1052
1053        if (sk)
1054                while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1055                        --pos;
1056        return pos ? NULL : sk;
1057}
1058
1059void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1060{
1061        struct ping_iter_state *state = seq->private;
1062        state->bucket = 0;
1063        state->family = family;
1064
1065        read_lock_bh(&ping_table.lock);
1066
1067        return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1068}
1069EXPORT_SYMBOL_GPL(ping_seq_start);
1070
1071static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1072{
1073        return ping_seq_start(seq, pos, AF_INET);
1074}
1075
1076void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1077{
1078        struct sock *sk;
1079
1080        if (v == SEQ_START_TOKEN)
1081                sk = ping_get_idx(seq, 0);
1082        else
1083                sk = ping_get_next(seq, v);
1084
1085        ++*pos;
1086        return sk;
1087}
1088EXPORT_SYMBOL_GPL(ping_seq_next);
1089
1090void ping_seq_stop(struct seq_file *seq, void *v)
1091{
1092        read_unlock_bh(&ping_table.lock);
1093}
1094EXPORT_SYMBOL_GPL(ping_seq_stop);
1095
1096static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1097                int bucket)
1098{
1099        struct inet_sock *inet = inet_sk(sp);
1100        __be32 dest = inet->inet_daddr;
1101        __be32 src = inet->inet_rcv_saddr;
1102        __u16 destp = ntohs(inet->inet_dport);
1103        __u16 srcp = ntohs(inet->inet_sport);
1104
1105        seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1106                " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
1107                bucket, src, srcp, dest, destp, sp->sk_state,
1108                sk_wmem_alloc_get(sp),
1109                sk_rmem_alloc_get(sp),
1110                0, 0L, 0,
1111                from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1112                0, sock_i_ino(sp),
1113                atomic_read(&sp->sk_refcnt), sp,
1114                atomic_read(&sp->sk_drops));
1115}
1116
1117static int ping_v4_seq_show(struct seq_file *seq, void *v)
1118{
1119        seq_setwidth(seq, 127);
1120        if (v == SEQ_START_TOKEN)
1121                seq_puts(seq, "  sl  local_address rem_address   st tx_queue "
1122                           "rx_queue tr tm->when retrnsmt   uid  timeout "
1123                           "inode ref pointer drops");
1124        else {
1125                struct ping_iter_state *state = seq->private;
1126
1127                ping_v4_format_sock(v, seq, state->bucket);
1128        }
1129        seq_pad(seq, '\n');
1130        return 0;
1131}
1132
1133static const struct seq_operations ping_v4_seq_ops = {
1134        .show           = ping_v4_seq_show,
1135        .start          = ping_v4_seq_start,
1136        .next           = ping_seq_next,
1137        .stop           = ping_seq_stop,
1138};
1139
1140static int ping_seq_open(struct inode *inode, struct file *file)
1141{
1142        struct ping_seq_afinfo *afinfo = PDE_DATA(inode);
1143        return seq_open_net(inode, file, &afinfo->seq_ops,
1144                           sizeof(struct ping_iter_state));
1145}
1146
1147const struct file_operations ping_seq_fops = {
1148        .open           = ping_seq_open,
1149        .read           = seq_read,
1150        .llseek         = seq_lseek,
1151        .release        = seq_release_net,
1152};
1153EXPORT_SYMBOL_GPL(ping_seq_fops);
1154
1155static struct ping_seq_afinfo ping_v4_seq_afinfo = {
1156        .name           = "icmp",
1157        .family         = AF_INET,
1158        .seq_fops       = &ping_seq_fops,
1159        .seq_ops        = {
1160                .start          = ping_v4_seq_start,
1161                .show           = ping_v4_seq_show,
1162                .next           = ping_seq_next,
1163                .stop           = ping_seq_stop,
1164        },
1165};
1166
1167int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo)
1168{
1169        struct proc_dir_entry *p;
1170        p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1171                             afinfo->seq_fops, afinfo);
1172        if (!p)
1173                return -ENOMEM;
1174        return 0;
1175}
1176EXPORT_SYMBOL_GPL(ping_proc_register);
1177
1178void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo)
1179{
1180        remove_proc_entry(afinfo->name, net->proc_net);
1181}
1182EXPORT_SYMBOL_GPL(ping_proc_unregister);
1183
1184static int __net_init ping_v4_proc_init_net(struct net *net)
1185{
1186        return ping_proc_register(net, &ping_v4_seq_afinfo);
1187}
1188
1189static void __net_exit ping_v4_proc_exit_net(struct net *net)
1190{
1191        ping_proc_unregister(net, &ping_v4_seq_afinfo);
1192}
1193
1194static struct pernet_operations ping_v4_net_ops = {
1195        .init = ping_v4_proc_init_net,
1196        .exit = ping_v4_proc_exit_net,
1197};
1198
1199int __init ping_proc_init(void)
1200{
1201        return register_pernet_subsys(&ping_v4_net_ops);
1202}
1203
1204void ping_proc_exit(void)
1205{
1206        unregister_pernet_subsys(&ping_v4_net_ops);
1207}
1208
1209#endif
1210
1211void __init ping_init(void)
1212{
1213        int i;
1214
1215        for (i = 0; i < PING_HTABLE_SIZE; i++)
1216                INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1217        rwlock_init(&ping_table.lock);
1218}
1219