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TOMOYO Linux Cross Reference
Linux/net/ipv4/ping.c

Version: ~ [ linux-5.3 ] ~ [ linux-5.2.15 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.73 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.144 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.193 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.193 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.73 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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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/ipv6.h>
 37 #include <net/icmp.h>
 38 #include <net/protocol.h>
 39 #include <linux/skbuff.h>
 40 #include <linux/proc_fs.h>
 41 #include <linux/export.h>
 42 #include <net/sock.h>
 43 #include <net/ping.h>
 44 #include <net/udp.h>
 45 #include <net/route.h>
 46 #include <net/inet_common.h>
 47 #include <net/checksum.h>
 48 
 49 
 50 static struct ping_table ping_table;
 51 
 52 static u16 ping_port_rover;
 53 
 54 static inline int ping_hashfn(struct net *net, unsigned int num, unsigned int mask)
 55 {
 56         int res = (num + net_hash_mix(net)) & mask;
 57 
 58         pr_debug("hash(%d) = %d\n", num, res);
 59         return res;
 60 }
 61 
 62 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table,
 63                                              struct net *net, unsigned int num)
 64 {
 65         return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
 66 }
 67 
 68 static int ping_v4_get_port(struct sock *sk, unsigned short ident)
 69 {
 70         struct hlist_nulls_node *node;
 71         struct hlist_nulls_head *hlist;
 72         struct inet_sock *isk, *isk2;
 73         struct sock *sk2 = NULL;
 74 
 75         isk = inet_sk(sk);
 76         write_lock_bh(&ping_table.lock);
 77         if (ident == 0) {
 78                 u32 i;
 79                 u16 result = ping_port_rover + 1;
 80 
 81                 for (i = 0; i < (1L << 16); i++, result++) {
 82                         if (!result)
 83                                 result++; /* avoid zero */
 84                         hlist = ping_hashslot(&ping_table, sock_net(sk),
 85                                             result);
 86                         ping_portaddr_for_each_entry(sk2, node, hlist) {
 87                                 isk2 = inet_sk(sk2);
 88 
 89                                 if (isk2->inet_num == result)
 90                                         goto next_port;
 91                         }
 92 
 93                         /* found */
 94                         ping_port_rover = ident = result;
 95                         break;
 96 next_port:
 97                         ;
 98                 }
 99                 if (i >= (1L << 16))
100                         goto fail;
101         } else {
102                 hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
103                 ping_portaddr_for_each_entry(sk2, node, hlist) {
104                         isk2 = inet_sk(sk2);
105 
106                         if ((isk2->inet_num == ident) &&
107                             (sk2 != sk) &&
108                             (!sk2->sk_reuse || !sk->sk_reuse))
109                                 goto fail;
110                 }
111         }
112 
113         pr_debug("found port/ident = %d\n", ident);
114         isk->inet_num = ident;
115         if (sk_unhashed(sk)) {
116                 pr_debug("was not hashed\n");
117                 sock_hold(sk);
118                 hlist_nulls_add_head(&sk->sk_nulls_node, hlist);
119                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
120         }
121         write_unlock_bh(&ping_table.lock);
122         return 0;
123 
124 fail:
125         write_unlock_bh(&ping_table.lock);
126         return 1;
127 }
128 
129 static void ping_v4_hash(struct sock *sk)
130 {
131         pr_debug("ping_v4_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
132         BUG(); /* "Please do not press this button again." */
133 }
134 
135 static void ping_v4_unhash(struct sock *sk)
136 {
137         struct inet_sock *isk = inet_sk(sk);
138         pr_debug("ping_v4_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
139         if (sk_hashed(sk)) {
140                 write_lock_bh(&ping_table.lock);
141                 hlist_nulls_del(&sk->sk_nulls_node);
142                 sock_put(sk);
143                 isk->inet_num = 0;
144                 isk->inet_sport = 0;
145                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
146                 write_unlock_bh(&ping_table.lock);
147         }
148 }
149 
150 static struct sock *ping_v4_lookup(struct net *net, __be32 saddr, __be32 daddr,
151                                    u16 ident, int dif)
152 {
153         struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
154         struct sock *sk = NULL;
155         struct inet_sock *isk;
156         struct hlist_nulls_node *hnode;
157 
158         pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
159                  (int)ident, &daddr, dif);
160         read_lock_bh(&ping_table.lock);
161 
162         ping_portaddr_for_each_entry(sk, hnode, hslot) {
163                 isk = inet_sk(sk);
164 
165                 pr_debug("found: %p: num = %d, daddr = %pI4, dif = %d\n", sk,
166                          (int)isk->inet_num, &isk->inet_rcv_saddr,
167                          sk->sk_bound_dev_if);
168 
169                 pr_debug("iterate\n");
170                 if (isk->inet_num != ident)
171                         continue;
172                 if (isk->inet_rcv_saddr && isk->inet_rcv_saddr != daddr)
173                         continue;
174                 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
175                         continue;
176 
177                 sock_hold(sk);
178                 goto exit;
179         }
180 
181         sk = NULL;
182 exit:
183         read_unlock_bh(&ping_table.lock);
184 
185         return sk;
186 }
187 
188 static void inet_get_ping_group_range_net(struct net *net, gid_t *low,
189                                           gid_t *high)
190 {
191         gid_t *data = net->ipv4.sysctl_ping_group_range;
192         unsigned int seq;
193 
194         do {
195                 seq = read_seqbegin(&sysctl_local_ports.lock);
196 
197                 *low = data[0];
198                 *high = data[1];
199         } while (read_seqretry(&sysctl_local_ports.lock, seq));
200 }
201 
202 
203 static int ping_init_sock(struct sock *sk)
204 {
205         struct net *net = sock_net(sk);
206         gid_t group = current_egid();
207         gid_t range[2];
208         struct group_info *group_info = get_current_groups();
209         int i, j, count = group_info->ngroups;
210         kgid_t low, high;
211 
212         inet_get_ping_group_range_net(net, range, range+1);
213         low = make_kgid(&init_user_ns, range[0]);
214         high = make_kgid(&init_user_ns, range[1]);
215         if (!gid_valid(low) || !gid_valid(high) || gid_lt(high, low))
216                 return -EACCES;
217 
218         if (range[0] <= group && group <= range[1])
219                 return 0;
220 
221         for (i = 0; i < group_info->nblocks; i++) {
222                 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
223                 for (j = 0; j < cp_count; j++) {
224                         kgid_t gid = group_info->blocks[i][j];
225                         if (gid_lte(low, gid) && gid_lte(gid, high))
226                                 return 0;
227                 }
228 
229                 count -= cp_count;
230         }
231 
232         return -EACCES;
233 }
234 
235 static void ping_close(struct sock *sk, long timeout)
236 {
237         pr_debug("ping_close(sk=%p,sk->num=%u)\n",
238                  inet_sk(sk), inet_sk(sk)->inet_num);
239         pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter);
240 
241         sk_common_release(sk);
242 }
243 
244 /*
245  * We need our own bind because there are no privileged id's == local ports.
246  * Moreover, we don't allow binding to multi- and broadcast addresses.
247  */
248 
249 static int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
250 {
251         struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
252         struct inet_sock *isk = inet_sk(sk);
253         unsigned short snum;
254         int chk_addr_ret;
255         int err;
256 
257         if (addr_len < sizeof(struct sockaddr_in))
258                 return -EINVAL;
259 
260         pr_debug("ping_v4_bind(sk=%p,sa_addr=%08x,sa_port=%d)\n",
261                  sk, addr->sin_addr.s_addr, ntohs(addr->sin_port));
262 
263         chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
264         if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
265                 chk_addr_ret = RTN_LOCAL;
266 
267         if ((sysctl_ip_nonlocal_bind == 0 &&
268             isk->freebind == 0 && isk->transparent == 0 &&
269              chk_addr_ret != RTN_LOCAL) ||
270             chk_addr_ret == RTN_MULTICAST ||
271             chk_addr_ret == RTN_BROADCAST)
272                 return -EADDRNOTAVAIL;
273 
274         lock_sock(sk);
275 
276         err = -EINVAL;
277         if (isk->inet_num != 0)
278                 goto out;
279 
280         err = -EADDRINUSE;
281         isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
282         snum = ntohs(addr->sin_port);
283         if (ping_v4_get_port(sk, snum) != 0) {
284                 isk->inet_saddr = isk->inet_rcv_saddr = 0;
285                 goto out;
286         }
287 
288         pr_debug("after bind(): num = %d, daddr = %pI4, dif = %d\n",
289                  (int)isk->inet_num,
290                  &isk->inet_rcv_saddr,
291                  (int)sk->sk_bound_dev_if);
292 
293         err = 0;
294         if (isk->inet_rcv_saddr)
295                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
296         if (snum)
297                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
298         isk->inet_sport = htons(isk->inet_num);
299         isk->inet_daddr = 0;
300         isk->inet_dport = 0;
301         sk_dst_reset(sk);
302 out:
303         release_sock(sk);
304         pr_debug("ping_v4_bind -> %d\n", err);
305         return err;
306 }
307 
308 /*
309  * Is this a supported type of ICMP message?
310  */
311 
312 static inline int ping_supported(int type, int code)
313 {
314         if (type == ICMP_ECHO && code == 0)
315                 return 1;
316         return 0;
317 }
318 
319 /*
320  * This routine is called by the ICMP module when it gets some
321  * sort of error condition.
322  */
323 
324 static int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
325 
326 void ping_err(struct sk_buff *skb, u32 info)
327 {
328         struct iphdr *iph = (struct iphdr *)skb->data;
329         struct icmphdr *icmph = (struct icmphdr *)(skb->data+(iph->ihl<<2));
330         struct inet_sock *inet_sock;
331         int type = icmph->type;
332         int code = icmph->code;
333         struct net *net = dev_net(skb->dev);
334         struct sock *sk;
335         int harderr;
336         int err;
337 
338         /* We assume the packet has already been checked by icmp_unreach */
339 
340         if (!ping_supported(icmph->type, icmph->code))
341                 return;
342 
343         pr_debug("ping_err(type=%04x,code=%04x,id=%04x,seq=%04x)\n", type,
344                  code, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
345 
346         sk = ping_v4_lookup(net, iph->daddr, iph->saddr,
347                             ntohs(icmph->un.echo.id), skb->dev->ifindex);
348         if (sk == NULL) {
349                 pr_debug("no socket, dropping\n");
350                 return; /* No socket for error */
351         }
352         pr_debug("err on socket %p\n", sk);
353 
354         err = 0;
355         harderr = 0;
356         inet_sock = inet_sk(sk);
357 
358         switch (type) {
359         default:
360         case ICMP_TIME_EXCEEDED:
361                 err = EHOSTUNREACH;
362                 break;
363         case ICMP_SOURCE_QUENCH:
364                 /* This is not a real error but ping wants to see it.
365                  * Report it with some fake errno. */
366                 err = EREMOTEIO;
367                 break;
368         case ICMP_PARAMETERPROB:
369                 err = EPROTO;
370                 harderr = 1;
371                 break;
372         case ICMP_DEST_UNREACH:
373                 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
374                         if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
375                                 err = EMSGSIZE;
376                                 harderr = 1;
377                                 break;
378                         }
379                         goto out;
380                 }
381                 err = EHOSTUNREACH;
382                 if (code <= NR_ICMP_UNREACH) {
383                         harderr = icmp_err_convert[code].fatal;
384                         err = icmp_err_convert[code].errno;
385                 }
386                 break;
387         case ICMP_REDIRECT:
388                 /* See ICMP_SOURCE_QUENCH */
389                 err = EREMOTEIO;
390                 break;
391         }
392 
393         /*
394          *      RFC1122: OK.  Passes ICMP errors back to application, as per
395          *      4.1.3.3.
396          */
397         if (!inet_sock->recverr) {
398                 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
399                         goto out;
400         } else {
401                 ip_icmp_error(sk, skb, err, 0 /* no remote port */,
402                          info, (u8 *)icmph);
403         }
404         sk->sk_err = err;
405         sk->sk_error_report(sk);
406 out:
407         sock_put(sk);
408 }
409 
410 /*
411  *      Copy and checksum an ICMP Echo packet from user space into a buffer.
412  */
413 
414 struct pingfakehdr {
415         struct icmphdr icmph;
416         struct iovec *iov;
417         __wsum wcheck;
418 };
419 
420 static int ping_getfrag(void *from, char *to,
421                         int offset, int fraglen, int odd, struct sk_buff *skb)
422 {
423         struct pingfakehdr *pfh = (struct pingfakehdr *)from;
424 
425         if (offset == 0) {
426                 if (fraglen < sizeof(struct icmphdr))
427                         BUG();
428                 if (csum_partial_copy_fromiovecend(to + sizeof(struct icmphdr),
429                             pfh->iov, 0, fraglen - sizeof(struct icmphdr),
430                             &pfh->wcheck))
431                         return -EFAULT;
432 
433                 return 0;
434         }
435         if (offset < sizeof(struct icmphdr))
436                 BUG();
437         if (csum_partial_copy_fromiovecend
438                         (to, pfh->iov, offset - sizeof(struct icmphdr),
439                          fraglen, &pfh->wcheck))
440                 return -EFAULT;
441         return 0;
442 }
443 
444 static int ping_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
445                                     struct flowi4 *fl4)
446 {
447         struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
448 
449         pfh->wcheck = csum_partial((char *)&pfh->icmph,
450                 sizeof(struct icmphdr), pfh->wcheck);
451         pfh->icmph.checksum = csum_fold(pfh->wcheck);
452         memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
453         skb->ip_summed = CHECKSUM_NONE;
454         return ip_push_pending_frames(sk, fl4);
455 }
456 
457 static int ping_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
458                         size_t len)
459 {
460         struct net *net = sock_net(sk);
461         struct flowi4 fl4;
462         struct inet_sock *inet = inet_sk(sk);
463         struct ipcm_cookie ipc;
464         struct icmphdr user_icmph;
465         struct pingfakehdr pfh;
466         struct rtable *rt = NULL;
467         struct ip_options_data opt_copy;
468         int free = 0;
469         __be32 saddr, daddr, faddr;
470         u8  tos;
471         int err;
472 
473         pr_debug("ping_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
474 
475 
476         if (len > 0xFFFF)
477                 return -EMSGSIZE;
478 
479         /*
480          *      Check the flags.
481          */
482 
483         /* Mirror BSD error message compatibility */
484         if (msg->msg_flags & MSG_OOB)
485                 return -EOPNOTSUPP;
486 
487         /*
488          *      Fetch the ICMP header provided by the userland.
489          *      iovec is modified!
490          */
491 
492         if (memcpy_fromiovec((u8 *)&user_icmph, msg->msg_iov,
493                              sizeof(struct icmphdr)))
494                 return -EFAULT;
495         if (!ping_supported(user_icmph.type, user_icmph.code))
496                 return -EINVAL;
497 
498         /*
499          *      Get and verify the address.
500          */
501 
502         if (msg->msg_name) {
503                 struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
504                 if (msg->msg_namelen < sizeof(*usin))
505                         return -EINVAL;
506                 if (usin->sin_family != AF_INET)
507                         return -EINVAL;
508                 daddr = usin->sin_addr.s_addr;
509                 /* no remote port */
510         } else {
511                 if (sk->sk_state != TCP_ESTABLISHED)
512                         return -EDESTADDRREQ;
513                 daddr = inet->inet_daddr;
514                 /* no remote port */
515         }
516 
517         ipc.addr = inet->inet_saddr;
518         ipc.opt = NULL;
519         ipc.oif = sk->sk_bound_dev_if;
520         ipc.tx_flags = 0;
521         err = sock_tx_timestamp(sk, &ipc.tx_flags);
522         if (err)
523                 return err;
524 
525         if (msg->msg_controllen) {
526                 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
527                 if (err)
528                         return err;
529                 if (ipc.opt)
530                         free = 1;
531         }
532         if (!ipc.opt) {
533                 struct ip_options_rcu *inet_opt;
534 
535                 rcu_read_lock();
536                 inet_opt = rcu_dereference(inet->inet_opt);
537                 if (inet_opt) {
538                         memcpy(&opt_copy, inet_opt,
539                                sizeof(*inet_opt) + inet_opt->opt.optlen);
540                         ipc.opt = &opt_copy.opt;
541                 }
542                 rcu_read_unlock();
543         }
544 
545         saddr = ipc.addr;
546         ipc.addr = faddr = daddr;
547 
548         if (ipc.opt && ipc.opt->opt.srr) {
549                 if (!daddr)
550                         return -EINVAL;
551                 faddr = ipc.opt->opt.faddr;
552         }
553         tos = RT_TOS(inet->tos);
554         if (sock_flag(sk, SOCK_LOCALROUTE) ||
555             (msg->msg_flags & MSG_DONTROUTE) ||
556             (ipc.opt && ipc.opt->opt.is_strictroute)) {
557                 tos |= RTO_ONLINK;
558         }
559 
560         if (ipv4_is_multicast(daddr)) {
561                 if (!ipc.oif)
562                         ipc.oif = inet->mc_index;
563                 if (!saddr)
564                         saddr = inet->mc_addr;
565         } else if (!ipc.oif)
566                 ipc.oif = inet->uc_index;
567 
568         flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
569                            RT_SCOPE_UNIVERSE, sk->sk_protocol,
570                            inet_sk_flowi_flags(sk), faddr, saddr, 0, 0);
571 
572         security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
573         rt = ip_route_output_flow(net, &fl4, sk);
574         if (IS_ERR(rt)) {
575                 err = PTR_ERR(rt);
576                 rt = NULL;
577                 if (err == -ENETUNREACH)
578                         IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
579                 goto out;
580         }
581 
582         err = -EACCES;
583         if ((rt->rt_flags & RTCF_BROADCAST) &&
584             !sock_flag(sk, SOCK_BROADCAST))
585                 goto out;
586 
587         if (msg->msg_flags & MSG_CONFIRM)
588                 goto do_confirm;
589 back_from_confirm:
590 
591         if (!ipc.addr)
592                 ipc.addr = fl4.daddr;
593 
594         lock_sock(sk);
595 
596         pfh.icmph.type = user_icmph.type; /* already checked */
597         pfh.icmph.code = user_icmph.code; /* ditto */
598         pfh.icmph.checksum = 0;
599         pfh.icmph.un.echo.id = inet->inet_sport;
600         pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
601         pfh.iov = msg->msg_iov;
602         pfh.wcheck = 0;
603 
604         err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
605                         0, &ipc, &rt, msg->msg_flags);
606         if (err)
607                 ip_flush_pending_frames(sk);
608         else
609                 err = ping_push_pending_frames(sk, &pfh, &fl4);
610         release_sock(sk);
611 
612 out:
613         ip_rt_put(rt);
614         if (free)
615                 kfree(ipc.opt);
616         if (!err) {
617                 icmp_out_count(sock_net(sk), user_icmph.type);
618                 return len;
619         }
620         return err;
621 
622 do_confirm:
623         dst_confirm(&rt->dst);
624         if (!(msg->msg_flags & MSG_PROBE) || len)
625                 goto back_from_confirm;
626         err = 0;
627         goto out;
628 }
629 
630 static int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
631                         size_t len, int noblock, int flags, int *addr_len)
632 {
633         struct inet_sock *isk = inet_sk(sk);
634         struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
635         struct sk_buff *skb;
636         int copied, err;
637 
638         pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
639 
640         err = -EOPNOTSUPP;
641         if (flags & MSG_OOB)
642                 goto out;
643 
644         if (addr_len)
645                 *addr_len = sizeof(*sin);
646 
647         if (flags & MSG_ERRQUEUE)
648                 return ip_recv_error(sk, msg, len);
649 
650         skb = skb_recv_datagram(sk, flags, noblock, &err);
651         if (!skb)
652                 goto out;
653 
654         copied = skb->len;
655         if (copied > len) {
656                 msg->msg_flags |= MSG_TRUNC;
657                 copied = len;
658         }
659 
660         /* Don't bother checking the checksum */
661         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
662         if (err)
663                 goto done;
664 
665         sock_recv_timestamp(msg, sk, skb);
666 
667         /* Copy the address. */
668         if (sin) {
669                 sin->sin_family = AF_INET;
670                 sin->sin_port = 0 /* skb->h.uh->source */;
671                 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
672                 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
673         }
674         if (isk->cmsg_flags)
675                 ip_cmsg_recv(msg, skb);
676         err = copied;
677 
678 done:
679         skb_free_datagram(sk, skb);
680 out:
681         pr_debug("ping_recvmsg -> %d\n", err);
682         return err;
683 }
684 
685 static int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
686 {
687         pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
688                  inet_sk(sk), inet_sk(sk)->inet_num, skb);
689         if (sock_queue_rcv_skb(sk, skb) < 0) {
690                 kfree_skb(skb);
691                 pr_debug("ping_queue_rcv_skb -> failed\n");
692                 return -1;
693         }
694         return 0;
695 }
696 
697 
698 /*
699  *      All we need to do is get the socket.
700  */
701 
702 void ping_rcv(struct sk_buff *skb)
703 {
704         struct sock *sk;
705         struct net *net = dev_net(skb->dev);
706         struct iphdr *iph = ip_hdr(skb);
707         struct icmphdr *icmph = icmp_hdr(skb);
708         __be32 saddr = iph->saddr;
709         __be32 daddr = iph->daddr;
710 
711         /* We assume the packet has already been checked by icmp_rcv */
712 
713         pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
714                  skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
715 
716         /* Push ICMP header back */
717         skb_push(skb, skb->data - (u8 *)icmph);
718 
719         sk = ping_v4_lookup(net, saddr, daddr, ntohs(icmph->un.echo.id),
720                             skb->dev->ifindex);
721         if (sk != NULL) {
722                 pr_debug("rcv on socket %p\n", sk);
723                 ping_queue_rcv_skb(sk, skb_get(skb));
724                 sock_put(sk);
725                 return;
726         }
727         pr_debug("no socket, dropping\n");
728 
729         /* We're called from icmp_rcv(). kfree_skb() is done there. */
730 }
731 
732 struct proto ping_prot = {
733         .name =         "PING",
734         .owner =        THIS_MODULE,
735         .init =         ping_init_sock,
736         .close =        ping_close,
737         .connect =      ip4_datagram_connect,
738         .disconnect =   udp_disconnect,
739         .setsockopt =   ip_setsockopt,
740         .getsockopt =   ip_getsockopt,
741         .sendmsg =      ping_sendmsg,
742         .recvmsg =      ping_recvmsg,
743         .bind =         ping_bind,
744         .backlog_rcv =  ping_queue_rcv_skb,
745         .hash =         ping_v4_hash,
746         .unhash =       ping_v4_unhash,
747         .get_port =     ping_v4_get_port,
748         .obj_size =     sizeof(struct inet_sock),
749 };
750 EXPORT_SYMBOL(ping_prot);
751 
752 #ifdef CONFIG_PROC_FS
753 
754 static struct sock *ping_get_first(struct seq_file *seq, int start)
755 {
756         struct sock *sk;
757         struct ping_iter_state *state = seq->private;
758         struct net *net = seq_file_net(seq);
759 
760         for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
761              ++state->bucket) {
762                 struct hlist_nulls_node *node;
763                 struct hlist_nulls_head *hslot;
764 
765                 hslot = &ping_table.hash[state->bucket];
766 
767                 if (hlist_nulls_empty(hslot))
768                         continue;
769 
770                 sk_nulls_for_each(sk, node, hslot) {
771                         if (net_eq(sock_net(sk), net))
772                                 goto found;
773                 }
774         }
775         sk = NULL;
776 found:
777         return sk;
778 }
779 
780 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
781 {
782         struct ping_iter_state *state = seq->private;
783         struct net *net = seq_file_net(seq);
784 
785         do {
786                 sk = sk_nulls_next(sk);
787         } while (sk && (!net_eq(sock_net(sk), net)));
788 
789         if (!sk)
790                 return ping_get_first(seq, state->bucket + 1);
791         return sk;
792 }
793 
794 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
795 {
796         struct sock *sk = ping_get_first(seq, 0);
797 
798         if (sk)
799                 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
800                         --pos;
801         return pos ? NULL : sk;
802 }
803 
804 static void *ping_seq_start(struct seq_file *seq, loff_t *pos)
805 {
806         struct ping_iter_state *state = seq->private;
807         state->bucket = 0;
808 
809         read_lock_bh(&ping_table.lock);
810 
811         return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
812 }
813 
814 static void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
815 {
816         struct sock *sk;
817 
818         if (v == SEQ_START_TOKEN)
819                 sk = ping_get_idx(seq, 0);
820         else
821                 sk = ping_get_next(seq, v);
822 
823         ++*pos;
824         return sk;
825 }
826 
827 static void ping_seq_stop(struct seq_file *seq, void *v)
828 {
829         read_unlock_bh(&ping_table.lock);
830 }
831 
832 static void ping_format_sock(struct sock *sp, struct seq_file *f,
833                 int bucket, int *len)
834 {
835         struct inet_sock *inet = inet_sk(sp);
836         __be32 dest = inet->inet_daddr;
837         __be32 src = inet->inet_rcv_saddr;
838         __u16 destp = ntohs(inet->inet_dport);
839         __u16 srcp = ntohs(inet->inet_sport);
840 
841         seq_printf(f, "%5d: %08X:%04X %08X:%04X"
842                 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d%n",
843                 bucket, src, srcp, dest, destp, sp->sk_state,
844                 sk_wmem_alloc_get(sp),
845                 sk_rmem_alloc_get(sp),
846                 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
847                 atomic_read(&sp->sk_refcnt), sp,
848                 atomic_read(&sp->sk_drops), len);
849 }
850 
851 static int ping_seq_show(struct seq_file *seq, void *v)
852 {
853         if (v == SEQ_START_TOKEN)
854                 seq_printf(seq, "%-127s\n",
855                            "  sl  local_address rem_address   st tx_queue "
856                            "rx_queue tr tm->when retrnsmt   uid  timeout "
857                            "inode ref pointer drops");
858         else {
859                 struct ping_iter_state *state = seq->private;
860                 int len;
861 
862                 ping_format_sock(v, seq, state->bucket, &len);
863                 seq_printf(seq, "%*s\n", 127 - len, "");
864         }
865         return 0;
866 }
867 
868 static const struct seq_operations ping_seq_ops = {
869         .show           = ping_seq_show,
870         .start          = ping_seq_start,
871         .next           = ping_seq_next,
872         .stop           = ping_seq_stop,
873 };
874 
875 static int ping_seq_open(struct inode *inode, struct file *file)
876 {
877         return seq_open_net(inode, file, &ping_seq_ops,
878                            sizeof(struct ping_iter_state));
879 }
880 
881 static const struct file_operations ping_seq_fops = {
882         .open           = ping_seq_open,
883         .read           = seq_read,
884         .llseek         = seq_lseek,
885         .release        = seq_release_net,
886 };
887 
888 static int ping_proc_register(struct net *net)
889 {
890         struct proc_dir_entry *p;
891         int rc = 0;
892 
893         p = proc_net_fops_create(net, "icmp", S_IRUGO, &ping_seq_fops);
894         if (!p)
895                 rc = -ENOMEM;
896         return rc;
897 }
898 
899 static void ping_proc_unregister(struct net *net)
900 {
901         proc_net_remove(net, "icmp");
902 }
903 
904 
905 static int __net_init ping_proc_init_net(struct net *net)
906 {
907         return ping_proc_register(net);
908 }
909 
910 static void __net_exit ping_proc_exit_net(struct net *net)
911 {
912         ping_proc_unregister(net);
913 }
914 
915 static struct pernet_operations ping_net_ops = {
916         .init = ping_proc_init_net,
917         .exit = ping_proc_exit_net,
918 };
919 
920 int __init ping_proc_init(void)
921 {
922         return register_pernet_subsys(&ping_net_ops);
923 }
924 
925 void ping_proc_exit(void)
926 {
927         unregister_pernet_subsys(&ping_net_ops);
928 }
929 
930 #endif
931 
932 void __init ping_init(void)
933 {
934         int i;
935 
936         for (i = 0; i < PING_HTABLE_SIZE; i++)
937                 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
938         rwlock_init(&ping_table.lock);
939 }
940 

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