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Merge branch 'davem-next' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik...
[deliverable/linux.git] / net / ipv4 / udp.c
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 * The User Datagram Protocol (UDP).
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
11 * Alan Cox, <Alan.Cox@linux.org>
12 * Hirokazu Takahashi, <taka@valinux.co.jp>
13 *
14 * Fixes:
15 * Alan Cox : verify_area() calls
16 * Alan Cox : stopped close while in use off icmp
17 * messages. Not a fix but a botch that
18 * for udp at least is 'valid'.
19 * Alan Cox : Fixed icmp handling properly
20 * Alan Cox : Correct error for oversized datagrams
21 * Alan Cox : Tidied select() semantics.
22 * Alan Cox : udp_err() fixed properly, also now
23 * select and read wake correctly on errors
24 * Alan Cox : udp_send verify_area moved to avoid mem leak
25 * Alan Cox : UDP can count its memory
26 * Alan Cox : send to an unknown connection causes
27 * an ECONNREFUSED off the icmp, but
28 * does NOT close.
29 * Alan Cox : Switched to new sk_buff handlers. No more backlog!
30 * Alan Cox : Using generic datagram code. Even smaller and the PEEK
31 * bug no longer crashes it.
32 * Fred Van Kempen : Net2e support for sk->broadcast.
33 * Alan Cox : Uses skb_free_datagram
34 * Alan Cox : Added get/set sockopt support.
35 * Alan Cox : Broadcasting without option set returns EACCES.
36 * Alan Cox : No wakeup calls. Instead we now use the callbacks.
37 * Alan Cox : Use ip_tos and ip_ttl
38 * Alan Cox : SNMP Mibs
39 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support.
40 * Matt Dillon : UDP length checks.
41 * Alan Cox : Smarter af_inet used properly.
42 * Alan Cox : Use new kernel side addressing.
43 * Alan Cox : Incorrect return on truncated datagram receive.
44 * Arnt Gulbrandsen : New udp_send and stuff
45 * Alan Cox : Cache last socket
46 * Alan Cox : Route cache
47 * Jon Peatfield : Minor efficiency fix to sendto().
48 * Mike Shaver : RFC1122 checks.
49 * Alan Cox : Nonblocking error fix.
50 * Willy Konynenberg : Transparent proxying support.
51 * Mike McLagan : Routing by source
52 * David S. Miller : New socket lookup architecture.
53 * Last socket cache retained as it
54 * does have a high hit rate.
55 * Olaf Kirch : Don't linearise iovec on sendmsg.
56 * Andi Kleen : Some cleanups, cache destination entry
57 * for connect.
58 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
59 * Melvin Smith : Check msg_name not msg_namelen in sendto(),
60 * return ENOTCONN for unconnected sockets (POSIX)
61 * Janos Farkas : don't deliver multi/broadcasts to a different
62 * bound-to-device socket
63 * Hirokazu Takahashi : HW checksumming for outgoing UDP
64 * datagrams.
65 * Hirokazu Takahashi : sendfile() on UDP works now.
66 * Arnaldo C. Melo : convert /proc/net/udp to seq_file
67 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
68 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind
69 * a single port at the same time.
70 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
71 * James Chapman : Add L2TP encapsulation type.
72 *
73 *
74 * This program is free software; you can redistribute it and/or
75 * modify it under the terms of the GNU General Public License
76 * as published by the Free Software Foundation; either version
77 * 2 of the License, or (at your option) any later version.
78 */
79
80 #include <asm/system.h>
81 #include <asm/uaccess.h>
82 #include <asm/ioctls.h>
83 #include <linux/bootmem.h>
84 #include <linux/types.h>
85 #include <linux/fcntl.h>
86 #include <linux/module.h>
87 #include <linux/socket.h>
88 #include <linux/sockios.h>
89 #include <linux/igmp.h>
90 #include <linux/in.h>
91 #include <linux/errno.h>
92 #include <linux/timer.h>
93 #include <linux/mm.h>
94 #include <linux/inet.h>
95 #include <linux/netdevice.h>
96 #include <net/tcp_states.h>
97 #include <linux/skbuff.h>
98 #include <linux/proc_fs.h>
99 #include <linux/seq_file.h>
100 #include <net/net_namespace.h>
101 #include <net/icmp.h>
102 #include <net/route.h>
103 #include <net/checksum.h>
104 #include <net/xfrm.h>
105 #include "udp_impl.h"
106
107 /*
108 * Snmp MIB for the UDP layer
109 */
110
111 DEFINE_SNMP_STAT(struct udp_mib, udp_statistics) __read_mostly;
112 EXPORT_SYMBOL(udp_statistics);
113
114 DEFINE_SNMP_STAT(struct udp_mib, udp_stats_in6) __read_mostly;
115 EXPORT_SYMBOL(udp_stats_in6);
116
117 struct hlist_head udp_hash[UDP_HTABLE_SIZE];
118 DEFINE_RWLOCK(udp_hash_lock);
119
120 int sysctl_udp_mem[3] __read_mostly;
121 int sysctl_udp_rmem_min __read_mostly;
122 int sysctl_udp_wmem_min __read_mostly;
123
124 EXPORT_SYMBOL(sysctl_udp_mem);
125 EXPORT_SYMBOL(sysctl_udp_rmem_min);
126 EXPORT_SYMBOL(sysctl_udp_wmem_min);
127
128 atomic_t udp_memory_allocated;
129 EXPORT_SYMBOL(udp_memory_allocated);
130
131 static inline int __udp_lib_lport_inuse(struct net *net, __u16 num,
132 const struct hlist_head udptable[])
133 {
134 struct sock *sk;
135 struct hlist_node *node;
136
137 sk_for_each(sk, node, &udptable[num & (UDP_HTABLE_SIZE - 1)])
138 if (net_eq(sock_net(sk), net) && sk->sk_hash == num)
139 return 1;
140 return 0;
141 }
142
143 /**
144 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
145 *
146 * @sk: socket struct in question
147 * @snum: port number to look up
148 * @saddr_comp: AF-dependent comparison of bound local IP addresses
149 */
150 int udp_lib_get_port(struct sock *sk, unsigned short snum,
151 int (*saddr_comp)(const struct sock *sk1,
152 const struct sock *sk2 ) )
153 {
154 struct hlist_head *udptable = sk->sk_prot->h.udp_hash;
155 struct hlist_node *node;
156 struct hlist_head *head;
157 struct sock *sk2;
158 int error = 1;
159 struct net *net = sock_net(sk);
160
161 write_lock_bh(&udp_hash_lock);
162
163 if (!snum) {
164 int i, low, high, remaining;
165 unsigned rover, best, best_size_so_far;
166
167 inet_get_local_port_range(&low, &high);
168 remaining = (high - low) + 1;
169
170 best_size_so_far = UINT_MAX;
171 best = rover = net_random() % remaining + low;
172
173 /* 1st pass: look for empty (or shortest) hash chain */
174 for (i = 0; i < UDP_HTABLE_SIZE; i++) {
175 int size = 0;
176
177 head = &udptable[rover & (UDP_HTABLE_SIZE - 1)];
178 if (hlist_empty(head))
179 goto gotit;
180
181 sk_for_each(sk2, node, head) {
182 if (++size >= best_size_so_far)
183 goto next;
184 }
185 best_size_so_far = size;
186 best = rover;
187 next:
188 /* fold back if end of range */
189 if (++rover > high)
190 rover = low + ((rover - low)
191 & (UDP_HTABLE_SIZE - 1));
192
193
194 }
195
196 /* 2nd pass: find hole in shortest hash chain */
197 rover = best;
198 for (i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++) {
199 if (! __udp_lib_lport_inuse(net, rover, udptable))
200 goto gotit;
201 rover += UDP_HTABLE_SIZE;
202 if (rover > high)
203 rover = low + ((rover - low)
204 & (UDP_HTABLE_SIZE - 1));
205 }
206
207
208 /* All ports in use! */
209 goto fail;
210
211 gotit:
212 snum = rover;
213 } else {
214 head = &udptable[snum & (UDP_HTABLE_SIZE - 1)];
215
216 sk_for_each(sk2, node, head)
217 if (sk2->sk_hash == snum &&
218 sk2 != sk &&
219 net_eq(sock_net(sk2), net) &&
220 (!sk2->sk_reuse || !sk->sk_reuse) &&
221 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if
222 || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
223 (*saddr_comp)(sk, sk2) )
224 goto fail;
225 }
226
227 inet_sk(sk)->num = snum;
228 sk->sk_hash = snum;
229 if (sk_unhashed(sk)) {
230 head = &udptable[snum & (UDP_HTABLE_SIZE - 1)];
231 sk_add_node(sk, head);
232 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
233 }
234 error = 0;
235 fail:
236 write_unlock_bh(&udp_hash_lock);
237 return error;
238 }
239
240 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
241 {
242 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
243
244 return ( !ipv6_only_sock(sk2) &&
245 (!inet1->rcv_saddr || !inet2->rcv_saddr ||
246 inet1->rcv_saddr == inet2->rcv_saddr ));
247 }
248
249 int udp_v4_get_port(struct sock *sk, unsigned short snum)
250 {
251 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal);
252 }
253
254 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
255 * harder than this. -DaveM
256 */
257 static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
258 __be16 sport, __be32 daddr, __be16 dport,
259 int dif, struct hlist_head udptable[])
260 {
261 struct sock *sk, *result = NULL;
262 struct hlist_node *node;
263 unsigned short hnum = ntohs(dport);
264 int badness = -1;
265
266 read_lock(&udp_hash_lock);
267 sk_for_each(sk, node, &udptable[hnum & (UDP_HTABLE_SIZE - 1)]) {
268 struct inet_sock *inet = inet_sk(sk);
269
270 if (net_eq(sock_net(sk), net) && sk->sk_hash == hnum &&
271 !ipv6_only_sock(sk)) {
272 int score = (sk->sk_family == PF_INET ? 1 : 0);
273 if (inet->rcv_saddr) {
274 if (inet->rcv_saddr != daddr)
275 continue;
276 score+=2;
277 }
278 if (inet->daddr) {
279 if (inet->daddr != saddr)
280 continue;
281 score+=2;
282 }
283 if (inet->dport) {
284 if (inet->dport != sport)
285 continue;
286 score+=2;
287 }
288 if (sk->sk_bound_dev_if) {
289 if (sk->sk_bound_dev_if != dif)
290 continue;
291 score+=2;
292 }
293 if (score == 9) {
294 result = sk;
295 break;
296 } else if (score > badness) {
297 result = sk;
298 badness = score;
299 }
300 }
301 }
302 if (result)
303 sock_hold(result);
304 read_unlock(&udp_hash_lock);
305 return result;
306 }
307
308 static inline struct sock *udp_v4_mcast_next(struct sock *sk,
309 __be16 loc_port, __be32 loc_addr,
310 __be16 rmt_port, __be32 rmt_addr,
311 int dif)
312 {
313 struct hlist_node *node;
314 struct sock *s = sk;
315 unsigned short hnum = ntohs(loc_port);
316
317 sk_for_each_from(s, node) {
318 struct inet_sock *inet = inet_sk(s);
319
320 if (s->sk_hash != hnum ||
321 (inet->daddr && inet->daddr != rmt_addr) ||
322 (inet->dport != rmt_port && inet->dport) ||
323 (inet->rcv_saddr && inet->rcv_saddr != loc_addr) ||
324 ipv6_only_sock(s) ||
325 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
326 continue;
327 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
328 continue;
329 goto found;
330 }
331 s = NULL;
332 found:
333 return s;
334 }
335
336 /*
337 * This routine is called by the ICMP module when it gets some
338 * sort of error condition. If err < 0 then the socket should
339 * be closed and the error returned to the user. If err > 0
340 * it's just the icmp type << 8 | icmp code.
341 * Header points to the ip header of the error packet. We move
342 * on past this. Then (as it used to claim before adjustment)
343 * header points to the first 8 bytes of the udp header. We need
344 * to find the appropriate port.
345 */
346
347 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct hlist_head udptable[])
348 {
349 struct inet_sock *inet;
350 struct iphdr *iph = (struct iphdr*)skb->data;
351 struct udphdr *uh = (struct udphdr*)(skb->data+(iph->ihl<<2));
352 const int type = icmp_hdr(skb)->type;
353 const int code = icmp_hdr(skb)->code;
354 struct sock *sk;
355 int harderr;
356 int err;
357
358 sk = __udp4_lib_lookup(dev_net(skb->dev), iph->daddr, uh->dest,
359 iph->saddr, uh->source, skb->dev->ifindex, udptable);
360 if (sk == NULL) {
361 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
362 return; /* No socket for error */
363 }
364
365 err = 0;
366 harderr = 0;
367 inet = inet_sk(sk);
368
369 switch (type) {
370 default:
371 case ICMP_TIME_EXCEEDED:
372 err = EHOSTUNREACH;
373 break;
374 case ICMP_SOURCE_QUENCH:
375 goto out;
376 case ICMP_PARAMETERPROB:
377 err = EPROTO;
378 harderr = 1;
379 break;
380 case ICMP_DEST_UNREACH:
381 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
382 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
383 err = EMSGSIZE;
384 harderr = 1;
385 break;
386 }
387 goto out;
388 }
389 err = EHOSTUNREACH;
390 if (code <= NR_ICMP_UNREACH) {
391 harderr = icmp_err_convert[code].fatal;
392 err = icmp_err_convert[code].errno;
393 }
394 break;
395 }
396
397 /*
398 * RFC1122: OK. Passes ICMP errors back to application, as per
399 * 4.1.3.3.
400 */
401 if (!inet->recverr) {
402 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
403 goto out;
404 } else {
405 ip_icmp_error(sk, skb, err, uh->dest, info, (u8*)(uh+1));
406 }
407 sk->sk_err = err;
408 sk->sk_error_report(sk);
409 out:
410 sock_put(sk);
411 }
412
413 void udp_err(struct sk_buff *skb, u32 info)
414 {
415 __udp4_lib_err(skb, info, udp_hash);
416 }
417
418 /*
419 * Throw away all pending data and cancel the corking. Socket is locked.
420 */
421 void udp_flush_pending_frames(struct sock *sk)
422 {
423 struct udp_sock *up = udp_sk(sk);
424
425 if (up->pending) {
426 up->len = 0;
427 up->pending = 0;
428 ip_flush_pending_frames(sk);
429 }
430 }
431 EXPORT_SYMBOL(udp_flush_pending_frames);
432
433 /**
434 * udp4_hwcsum_outgoing - handle outgoing HW checksumming
435 * @sk: socket we are sending on
436 * @skb: sk_buff containing the filled-in UDP header
437 * (checksum field must be zeroed out)
438 */
439 static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
440 __be32 src, __be32 dst, int len )
441 {
442 unsigned int offset;
443 struct udphdr *uh = udp_hdr(skb);
444 __wsum csum = 0;
445
446 if (skb_queue_len(&sk->sk_write_queue) == 1) {
447 /*
448 * Only one fragment on the socket.
449 */
450 skb->csum_start = skb_transport_header(skb) - skb->head;
451 skb->csum_offset = offsetof(struct udphdr, check);
452 uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0);
453 } else {
454 /*
455 * HW-checksum won't work as there are two or more
456 * fragments on the socket so that all csums of sk_buffs
457 * should be together
458 */
459 offset = skb_transport_offset(skb);
460 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
461
462 skb->ip_summed = CHECKSUM_NONE;
463
464 skb_queue_walk(&sk->sk_write_queue, skb) {
465 csum = csum_add(csum, skb->csum);
466 }
467
468 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
469 if (uh->check == 0)
470 uh->check = CSUM_MANGLED_0;
471 }
472 }
473
474 /*
475 * Push out all pending data as one UDP datagram. Socket is locked.
476 */
477 static int udp_push_pending_frames(struct sock *sk)
478 {
479 struct udp_sock *up = udp_sk(sk);
480 struct inet_sock *inet = inet_sk(sk);
481 struct flowi *fl = &inet->cork.fl;
482 struct sk_buff *skb;
483 struct udphdr *uh;
484 int err = 0;
485 int is_udplite = IS_UDPLITE(sk);
486 __wsum csum = 0;
487
488 /* Grab the skbuff where UDP header space exists. */
489 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
490 goto out;
491
492 /*
493 * Create a UDP header
494 */
495 uh = udp_hdr(skb);
496 uh->source = fl->fl_ip_sport;
497 uh->dest = fl->fl_ip_dport;
498 uh->len = htons(up->len);
499 uh->check = 0;
500
501 if (is_udplite) /* UDP-Lite */
502 csum = udplite_csum_outgoing(sk, skb);
503
504 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */
505
506 skb->ip_summed = CHECKSUM_NONE;
507 goto send;
508
509 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
510
511 udp4_hwcsum_outgoing(sk, skb, fl->fl4_src,fl->fl4_dst, up->len);
512 goto send;
513
514 } else /* `normal' UDP */
515 csum = udp_csum_outgoing(sk, skb);
516
517 /* add protocol-dependent pseudo-header */
518 uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len,
519 sk->sk_protocol, csum );
520 if (uh->check == 0)
521 uh->check = CSUM_MANGLED_0;
522
523 send:
524 err = ip_push_pending_frames(sk);
525 out:
526 up->len = 0;
527 up->pending = 0;
528 if (!err)
529 UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS, is_udplite);
530 return err;
531 }
532
533 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
534 size_t len)
535 {
536 struct inet_sock *inet = inet_sk(sk);
537 struct udp_sock *up = udp_sk(sk);
538 int ulen = len;
539 struct ipcm_cookie ipc;
540 struct rtable *rt = NULL;
541 int free = 0;
542 int connected = 0;
543 __be32 daddr, faddr, saddr;
544 __be16 dport;
545 u8 tos;
546 int err, is_udplite = IS_UDPLITE(sk);
547 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
548 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
549
550 if (len > 0xFFFF)
551 return -EMSGSIZE;
552
553 /*
554 * Check the flags.
555 */
556
557 if (msg->msg_flags&MSG_OOB) /* Mirror BSD error message compatibility */
558 return -EOPNOTSUPP;
559
560 ipc.opt = NULL;
561
562 if (up->pending) {
563 /*
564 * There are pending frames.
565 * The socket lock must be held while it's corked.
566 */
567 lock_sock(sk);
568 if (likely(up->pending)) {
569 if (unlikely(up->pending != AF_INET)) {
570 release_sock(sk);
571 return -EINVAL;
572 }
573 goto do_append_data;
574 }
575 release_sock(sk);
576 }
577 ulen += sizeof(struct udphdr);
578
579 /*
580 * Get and verify the address.
581 */
582 if (msg->msg_name) {
583 struct sockaddr_in * usin = (struct sockaddr_in*)msg->msg_name;
584 if (msg->msg_namelen < sizeof(*usin))
585 return -EINVAL;
586 if (usin->sin_family != AF_INET) {
587 if (usin->sin_family != AF_UNSPEC)
588 return -EAFNOSUPPORT;
589 }
590
591 daddr = usin->sin_addr.s_addr;
592 dport = usin->sin_port;
593 if (dport == 0)
594 return -EINVAL;
595 } else {
596 if (sk->sk_state != TCP_ESTABLISHED)
597 return -EDESTADDRREQ;
598 daddr = inet->daddr;
599 dport = inet->dport;
600 /* Open fast path for connected socket.
601 Route will not be used, if at least one option is set.
602 */
603 connected = 1;
604 }
605 ipc.addr = inet->saddr;
606
607 ipc.oif = sk->sk_bound_dev_if;
608 if (msg->msg_controllen) {
609 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
610 if (err)
611 return err;
612 if (ipc.opt)
613 free = 1;
614 connected = 0;
615 }
616 if (!ipc.opt)
617 ipc.opt = inet->opt;
618
619 saddr = ipc.addr;
620 ipc.addr = faddr = daddr;
621
622 if (ipc.opt && ipc.opt->srr) {
623 if (!daddr)
624 return -EINVAL;
625 faddr = ipc.opt->faddr;
626 connected = 0;
627 }
628 tos = RT_TOS(inet->tos);
629 if (sock_flag(sk, SOCK_LOCALROUTE) ||
630 (msg->msg_flags & MSG_DONTROUTE) ||
631 (ipc.opt && ipc.opt->is_strictroute)) {
632 tos |= RTO_ONLINK;
633 connected = 0;
634 }
635
636 if (ipv4_is_multicast(daddr)) {
637 if (!ipc.oif)
638 ipc.oif = inet->mc_index;
639 if (!saddr)
640 saddr = inet->mc_addr;
641 connected = 0;
642 }
643
644 if (connected)
645 rt = (struct rtable*)sk_dst_check(sk, 0);
646
647 if (rt == NULL) {
648 struct flowi fl = { .oif = ipc.oif,
649 .nl_u = { .ip4_u =
650 { .daddr = faddr,
651 .saddr = saddr,
652 .tos = tos } },
653 .proto = sk->sk_protocol,
654 .uli_u = { .ports =
655 { .sport = inet->sport,
656 .dport = dport } } };
657 security_sk_classify_flow(sk, &fl);
658 err = ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 1);
659 if (err) {
660 if (err == -ENETUNREACH)
661 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
662 goto out;
663 }
664
665 err = -EACCES;
666 if ((rt->rt_flags & RTCF_BROADCAST) &&
667 !sock_flag(sk, SOCK_BROADCAST))
668 goto out;
669 if (connected)
670 sk_dst_set(sk, dst_clone(&rt->u.dst));
671 }
672
673 if (msg->msg_flags&MSG_CONFIRM)
674 goto do_confirm;
675 back_from_confirm:
676
677 saddr = rt->rt_src;
678 if (!ipc.addr)
679 daddr = ipc.addr = rt->rt_dst;
680
681 lock_sock(sk);
682 if (unlikely(up->pending)) {
683 /* The socket is already corked while preparing it. */
684 /* ... which is an evident application bug. --ANK */
685 release_sock(sk);
686
687 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
688 err = -EINVAL;
689 goto out;
690 }
691 /*
692 * Now cork the socket to pend data.
693 */
694 inet->cork.fl.fl4_dst = daddr;
695 inet->cork.fl.fl_ip_dport = dport;
696 inet->cork.fl.fl4_src = saddr;
697 inet->cork.fl.fl_ip_sport = inet->sport;
698 up->pending = AF_INET;
699
700 do_append_data:
701 up->len += ulen;
702 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
703 err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
704 sizeof(struct udphdr), &ipc, rt,
705 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
706 if (err)
707 udp_flush_pending_frames(sk);
708 else if (!corkreq)
709 err = udp_push_pending_frames(sk);
710 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
711 up->pending = 0;
712 release_sock(sk);
713
714 out:
715 ip_rt_put(rt);
716 if (free)
717 kfree(ipc.opt);
718 if (!err)
719 return len;
720 /*
721 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
722 * ENOBUFS might not be good (it's not tunable per se), but otherwise
723 * we don't have a good statistic (IpOutDiscards but it can be too many
724 * things). We could add another new stat but at least for now that
725 * seems like overkill.
726 */
727 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
728 UDP_INC_STATS_USER(UDP_MIB_SNDBUFERRORS, is_udplite);
729 }
730 return err;
731
732 do_confirm:
733 dst_confirm(&rt->u.dst);
734 if (!(msg->msg_flags&MSG_PROBE) || len)
735 goto back_from_confirm;
736 err = 0;
737 goto out;
738 }
739
740 int udp_sendpage(struct sock *sk, struct page *page, int offset,
741 size_t size, int flags)
742 {
743 struct udp_sock *up = udp_sk(sk);
744 int ret;
745
746 if (!up->pending) {
747 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
748
749 /* Call udp_sendmsg to specify destination address which
750 * sendpage interface can't pass.
751 * This will succeed only when the socket is connected.
752 */
753 ret = udp_sendmsg(NULL, sk, &msg, 0);
754 if (ret < 0)
755 return ret;
756 }
757
758 lock_sock(sk);
759
760 if (unlikely(!up->pending)) {
761 release_sock(sk);
762
763 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n");
764 return -EINVAL;
765 }
766
767 ret = ip_append_page(sk, page, offset, size, flags);
768 if (ret == -EOPNOTSUPP) {
769 release_sock(sk);
770 return sock_no_sendpage(sk->sk_socket, page, offset,
771 size, flags);
772 }
773 if (ret < 0) {
774 udp_flush_pending_frames(sk);
775 goto out;
776 }
777
778 up->len += size;
779 if (!(up->corkflag || (flags&MSG_MORE)))
780 ret = udp_push_pending_frames(sk);
781 if (!ret)
782 ret = size;
783 out:
784 release_sock(sk);
785 return ret;
786 }
787
788 /*
789 * IOCTL requests applicable to the UDP protocol
790 */
791
792 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
793 {
794 switch (cmd) {
795 case SIOCOUTQ:
796 {
797 int amount = atomic_read(&sk->sk_wmem_alloc);
798 return put_user(amount, (int __user *)arg);
799 }
800
801 case SIOCINQ:
802 {
803 struct sk_buff *skb;
804 unsigned long amount;
805
806 amount = 0;
807 spin_lock_bh(&sk->sk_receive_queue.lock);
808 skb = skb_peek(&sk->sk_receive_queue);
809 if (skb != NULL) {
810 /*
811 * We will only return the amount
812 * of this packet since that is all
813 * that will be read.
814 */
815 amount = skb->len - sizeof(struct udphdr);
816 }
817 spin_unlock_bh(&sk->sk_receive_queue.lock);
818 return put_user(amount, (int __user *)arg);
819 }
820
821 default:
822 return -ENOIOCTLCMD;
823 }
824
825 return 0;
826 }
827
828 /*
829 * This should be easy, if there is something there we
830 * return it, otherwise we block.
831 */
832
833 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
834 size_t len, int noblock, int flags, int *addr_len)
835 {
836 struct inet_sock *inet = inet_sk(sk);
837 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
838 struct sk_buff *skb;
839 unsigned int ulen, copied;
840 int peeked;
841 int err;
842 int is_udplite = IS_UDPLITE(sk);
843
844 /*
845 * Check any passed addresses
846 */
847 if (addr_len)
848 *addr_len=sizeof(*sin);
849
850 if (flags & MSG_ERRQUEUE)
851 return ip_recv_error(sk, msg, len);
852
853 try_again:
854 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
855 &peeked, &err);
856 if (!skb)
857 goto out;
858
859 ulen = skb->len - sizeof(struct udphdr);
860 copied = len;
861 if (copied > ulen)
862 copied = ulen;
863 else if (copied < ulen)
864 msg->msg_flags |= MSG_TRUNC;
865
866 /*
867 * If checksum is needed at all, try to do it while copying the
868 * data. If the data is truncated, or if we only want a partial
869 * coverage checksum (UDP-Lite), do it before the copy.
870 */
871
872 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
873 if (udp_lib_checksum_complete(skb))
874 goto csum_copy_err;
875 }
876
877 if (skb_csum_unnecessary(skb))
878 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
879 msg->msg_iov, copied );
880 else {
881 err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
882
883 if (err == -EINVAL)
884 goto csum_copy_err;
885 }
886
887 if (err)
888 goto out_free;
889
890 if (!peeked)
891 UDP_INC_STATS_USER(UDP_MIB_INDATAGRAMS, is_udplite);
892
893 sock_recv_timestamp(msg, sk, skb);
894
895 /* Copy the address. */
896 if (sin)
897 {
898 sin->sin_family = AF_INET;
899 sin->sin_port = udp_hdr(skb)->source;
900 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
901 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
902 }
903 if (inet->cmsg_flags)
904 ip_cmsg_recv(msg, skb);
905
906 err = copied;
907 if (flags & MSG_TRUNC)
908 err = ulen;
909
910 out_free:
911 lock_sock(sk);
912 skb_free_datagram(sk, skb);
913 release_sock(sk);
914 out:
915 return err;
916
917 csum_copy_err:
918 lock_sock(sk);
919 if (!skb_kill_datagram(sk, skb, flags))
920 UDP_INC_STATS_USER(UDP_MIB_INERRORS, is_udplite);
921 release_sock(sk);
922
923 if (noblock)
924 return -EAGAIN;
925 goto try_again;
926 }
927
928
929 int udp_disconnect(struct sock *sk, int flags)
930 {
931 struct inet_sock *inet = inet_sk(sk);
932 /*
933 * 1003.1g - break association.
934 */
935
936 sk->sk_state = TCP_CLOSE;
937 inet->daddr = 0;
938 inet->dport = 0;
939 sk->sk_bound_dev_if = 0;
940 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
941 inet_reset_saddr(sk);
942
943 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
944 sk->sk_prot->unhash(sk);
945 inet->sport = 0;
946 }
947 sk_dst_reset(sk);
948 return 0;
949 }
950
951 /* returns:
952 * -1: error
953 * 0: success
954 * >0: "udp encap" protocol resubmission
955 *
956 * Note that in the success and error cases, the skb is assumed to
957 * have either been requeued or freed.
958 */
959 int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
960 {
961 struct udp_sock *up = udp_sk(sk);
962 int rc;
963 int is_udplite = IS_UDPLITE(sk);
964
965 /*
966 * Charge it to the socket, dropping if the queue is full.
967 */
968 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
969 goto drop;
970 nf_reset(skb);
971
972 if (up->encap_type) {
973 /*
974 * This is an encapsulation socket so pass the skb to
975 * the socket's udp_encap_rcv() hook. Otherwise, just
976 * fall through and pass this up the UDP socket.
977 * up->encap_rcv() returns the following value:
978 * =0 if skb was successfully passed to the encap
979 * handler or was discarded by it.
980 * >0 if skb should be passed on to UDP.
981 * <0 if skb should be resubmitted as proto -N
982 */
983
984 /* if we're overly short, let UDP handle it */
985 if (skb->len > sizeof(struct udphdr) &&
986 up->encap_rcv != NULL) {
987 int ret;
988
989 ret = (*up->encap_rcv)(sk, skb);
990 if (ret <= 0) {
991 UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS,
992 is_udplite);
993 return -ret;
994 }
995 }
996
997 /* FALLTHROUGH -- it's a UDP Packet */
998 }
999
1000 /*
1001 * UDP-Lite specific tests, ignored on UDP sockets
1002 */
1003 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1004
1005 /*
1006 * MIB statistics other than incrementing the error count are
1007 * disabled for the following two types of errors: these depend
1008 * on the application settings, not on the functioning of the
1009 * protocol stack as such.
1010 *
1011 * RFC 3828 here recommends (sec 3.3): "There should also be a
1012 * way ... to ... at least let the receiving application block
1013 * delivery of packets with coverage values less than a value
1014 * provided by the application."
1015 */
1016 if (up->pcrlen == 0) { /* full coverage was set */
1017 LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage "
1018 "%d while full coverage %d requested\n",
1019 UDP_SKB_CB(skb)->cscov, skb->len);
1020 goto drop;
1021 }
1022 /* The next case involves violating the min. coverage requested
1023 * by the receiver. This is subtle: if receiver wants x and x is
1024 * greater than the buffersize/MTU then receiver will complain
1025 * that it wants x while sender emits packets of smaller size y.
1026 * Therefore the above ...()->partial_cov statement is essential.
1027 */
1028 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1029 LIMIT_NETDEBUG(KERN_WARNING
1030 "UDPLITE: coverage %d too small, need min %d\n",
1031 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1032 goto drop;
1033 }
1034 }
1035
1036 if (sk->sk_filter) {
1037 if (udp_lib_checksum_complete(skb))
1038 goto drop;
1039 }
1040
1041 if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) {
1042 /* Note that an ENOMEM error is charged twice */
1043 if (rc == -ENOMEM)
1044 UDP_INC_STATS_BH(UDP_MIB_RCVBUFERRORS, is_udplite);
1045 goto drop;
1046 }
1047
1048 return 0;
1049
1050 drop:
1051 UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite);
1052 kfree_skb(skb);
1053 return -1;
1054 }
1055
1056 /*
1057 * Multicasts and broadcasts go to each listener.
1058 *
1059 * Note: called only from the BH handler context,
1060 * so we don't need to lock the hashes.
1061 */
1062 static int __udp4_lib_mcast_deliver(struct sk_buff *skb,
1063 struct udphdr *uh,
1064 __be32 saddr, __be32 daddr,
1065 struct hlist_head udptable[])
1066 {
1067 struct sock *sk;
1068 int dif;
1069
1070 read_lock(&udp_hash_lock);
1071 sk = sk_head(&udptable[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]);
1072 dif = skb->dev->ifindex;
1073 sk = udp_v4_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif);
1074 if (sk) {
1075 struct sock *sknext = NULL;
1076
1077 do {
1078 struct sk_buff *skb1 = skb;
1079
1080 sknext = udp_v4_mcast_next(sk_next(sk), uh->dest, daddr,
1081 uh->source, saddr, dif);
1082 if (sknext)
1083 skb1 = skb_clone(skb, GFP_ATOMIC);
1084
1085 if (skb1) {
1086 int ret = 0;
1087
1088 bh_lock_sock_nested(sk);
1089 if (!sock_owned_by_user(sk))
1090 ret = udp_queue_rcv_skb(sk, skb1);
1091 else
1092 sk_add_backlog(sk, skb1);
1093 bh_unlock_sock(sk);
1094
1095 if (ret > 0)
1096 /* we should probably re-process instead
1097 * of dropping packets here. */
1098 kfree_skb(skb1);
1099 }
1100 sk = sknext;
1101 } while (sknext);
1102 } else
1103 kfree_skb(skb);
1104 read_unlock(&udp_hash_lock);
1105 return 0;
1106 }
1107
1108 /* Initialize UDP checksum. If exited with zero value (success),
1109 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1110 * Otherwise, csum completion requires chacksumming packet body,
1111 * including udp header and folding it to skb->csum.
1112 */
1113 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
1114 int proto)
1115 {
1116 const struct iphdr *iph;
1117 int err;
1118
1119 UDP_SKB_CB(skb)->partial_cov = 0;
1120 UDP_SKB_CB(skb)->cscov = skb->len;
1121
1122 if (proto == IPPROTO_UDPLITE) {
1123 err = udplite_checksum_init(skb, uh);
1124 if (err)
1125 return err;
1126 }
1127
1128 iph = ip_hdr(skb);
1129 if (uh->check == 0) {
1130 skb->ip_summed = CHECKSUM_UNNECESSARY;
1131 } else if (skb->ip_summed == CHECKSUM_COMPLETE) {
1132 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1133 proto, skb->csum))
1134 skb->ip_summed = CHECKSUM_UNNECESSARY;
1135 }
1136 if (!skb_csum_unnecessary(skb))
1137 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
1138 skb->len, proto, 0);
1139 /* Probably, we should checksum udp header (it should be in cache
1140 * in any case) and data in tiny packets (< rx copybreak).
1141 */
1142
1143 return 0;
1144 }
1145
1146 /*
1147 * All we need to do is get the socket, and then do a checksum.
1148 */
1149
1150 int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
1151 int proto)
1152 {
1153 struct sock *sk;
1154 struct udphdr *uh = udp_hdr(skb);
1155 unsigned short ulen;
1156 struct rtable *rt = (struct rtable*)skb->dst;
1157 __be32 saddr = ip_hdr(skb)->saddr;
1158 __be32 daddr = ip_hdr(skb)->daddr;
1159
1160 /*
1161 * Validate the packet.
1162 */
1163 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1164 goto drop; /* No space for header. */
1165
1166 ulen = ntohs(uh->len);
1167 if (ulen > skb->len)
1168 goto short_packet;
1169
1170 if (proto == IPPROTO_UDP) {
1171 /* UDP validates ulen. */
1172 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
1173 goto short_packet;
1174 uh = udp_hdr(skb);
1175 }
1176
1177 if (udp4_csum_init(skb, uh, proto))
1178 goto csum_error;
1179
1180 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1181 return __udp4_lib_mcast_deliver(skb, uh, saddr, daddr, udptable);
1182
1183 sk = __udp4_lib_lookup(dev_net(skb->dev), saddr, uh->source, daddr,
1184 uh->dest, inet_iif(skb), udptable);
1185
1186 if (sk != NULL) {
1187 int ret = 0;
1188 bh_lock_sock_nested(sk);
1189 if (!sock_owned_by_user(sk))
1190 ret = udp_queue_rcv_skb(sk, skb);
1191 else
1192 sk_add_backlog(sk, skb);
1193 bh_unlock_sock(sk);
1194 sock_put(sk);
1195
1196 /* a return value > 0 means to resubmit the input, but
1197 * it wants the return to be -protocol, or 0
1198 */
1199 if (ret > 0)
1200 return -ret;
1201 return 0;
1202 }
1203
1204 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1205 goto drop;
1206 nf_reset(skb);
1207
1208 /* No socket. Drop packet silently, if checksum is wrong */
1209 if (udp_lib_checksum_complete(skb))
1210 goto csum_error;
1211
1212 UDP_INC_STATS_BH(UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1213 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
1214
1215 /*
1216 * Hmm. We got an UDP packet to a port to which we
1217 * don't wanna listen. Ignore it.
1218 */
1219 kfree_skb(skb);
1220 return 0;
1221
1222 short_packet:
1223 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From " NIPQUAD_FMT ":%u %d/%d to " NIPQUAD_FMT ":%u\n",
1224 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1225 NIPQUAD(saddr),
1226 ntohs(uh->source),
1227 ulen,
1228 skb->len,
1229 NIPQUAD(daddr),
1230 ntohs(uh->dest));
1231 goto drop;
1232
1233 csum_error:
1234 /*
1235 * RFC1122: OK. Discards the bad packet silently (as far as
1236 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1237 */
1238 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From " NIPQUAD_FMT ":%u to " NIPQUAD_FMT ":%u ulen %d\n",
1239 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1240 NIPQUAD(saddr),
1241 ntohs(uh->source),
1242 NIPQUAD(daddr),
1243 ntohs(uh->dest),
1244 ulen);
1245 drop:
1246 UDP_INC_STATS_BH(UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1247 kfree_skb(skb);
1248 return 0;
1249 }
1250
1251 int udp_rcv(struct sk_buff *skb)
1252 {
1253 return __udp4_lib_rcv(skb, udp_hash, IPPROTO_UDP);
1254 }
1255
1256 int udp_destroy_sock(struct sock *sk)
1257 {
1258 lock_sock(sk);
1259 udp_flush_pending_frames(sk);
1260 release_sock(sk);
1261 return 0;
1262 }
1263
1264 /*
1265 * Socket option code for UDP
1266 */
1267 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1268 char __user *optval, int optlen,
1269 int (*push_pending_frames)(struct sock *))
1270 {
1271 struct udp_sock *up = udp_sk(sk);
1272 int val;
1273 int err = 0;
1274 int is_udplite = IS_UDPLITE(sk);
1275
1276 if (optlen<sizeof(int))
1277 return -EINVAL;
1278
1279 if (get_user(val, (int __user *)optval))
1280 return -EFAULT;
1281
1282 switch (optname) {
1283 case UDP_CORK:
1284 if (val != 0) {
1285 up->corkflag = 1;
1286 } else {
1287 up->corkflag = 0;
1288 lock_sock(sk);
1289 (*push_pending_frames)(sk);
1290 release_sock(sk);
1291 }
1292 break;
1293
1294 case UDP_ENCAP:
1295 switch (val) {
1296 case 0:
1297 case UDP_ENCAP_ESPINUDP:
1298 case UDP_ENCAP_ESPINUDP_NON_IKE:
1299 up->encap_rcv = xfrm4_udp_encap_rcv;
1300 /* FALLTHROUGH */
1301 case UDP_ENCAP_L2TPINUDP:
1302 up->encap_type = val;
1303 break;
1304 default:
1305 err = -ENOPROTOOPT;
1306 break;
1307 }
1308 break;
1309
1310 /*
1311 * UDP-Lite's partial checksum coverage (RFC 3828).
1312 */
1313 /* The sender sets actual checksum coverage length via this option.
1314 * The case coverage > packet length is handled by send module. */
1315 case UDPLITE_SEND_CSCOV:
1316 if (!is_udplite) /* Disable the option on UDP sockets */
1317 return -ENOPROTOOPT;
1318 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
1319 val = 8;
1320 up->pcslen = val;
1321 up->pcflag |= UDPLITE_SEND_CC;
1322 break;
1323
1324 /* The receiver specifies a minimum checksum coverage value. To make
1325 * sense, this should be set to at least 8 (as done below). If zero is
1326 * used, this again means full checksum coverage. */
1327 case UDPLITE_RECV_CSCOV:
1328 if (!is_udplite) /* Disable the option on UDP sockets */
1329 return -ENOPROTOOPT;
1330 if (val != 0 && val < 8) /* Avoid silly minimal values. */
1331 val = 8;
1332 up->pcrlen = val;
1333 up->pcflag |= UDPLITE_RECV_CC;
1334 break;
1335
1336 default:
1337 err = -ENOPROTOOPT;
1338 break;
1339 }
1340
1341 return err;
1342 }
1343
1344 int udp_setsockopt(struct sock *sk, int level, int optname,
1345 char __user *optval, int optlen)
1346 {
1347 if (level == SOL_UDP || level == SOL_UDPLITE)
1348 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1349 udp_push_pending_frames);
1350 return ip_setsockopt(sk, level, optname, optval, optlen);
1351 }
1352
1353 #ifdef CONFIG_COMPAT
1354 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
1355 char __user *optval, int optlen)
1356 {
1357 if (level == SOL_UDP || level == SOL_UDPLITE)
1358 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1359 udp_push_pending_frames);
1360 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
1361 }
1362 #endif
1363
1364 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
1365 char __user *optval, int __user *optlen)
1366 {
1367 struct udp_sock *up = udp_sk(sk);
1368 int val, len;
1369
1370 if (get_user(len,optlen))
1371 return -EFAULT;
1372
1373 len = min_t(unsigned int, len, sizeof(int));
1374
1375 if (len < 0)
1376 return -EINVAL;
1377
1378 switch (optname) {
1379 case UDP_CORK:
1380 val = up->corkflag;
1381 break;
1382
1383 case UDP_ENCAP:
1384 val = up->encap_type;
1385 break;
1386
1387 /* The following two cannot be changed on UDP sockets, the return is
1388 * always 0 (which corresponds to the full checksum coverage of UDP). */
1389 case UDPLITE_SEND_CSCOV:
1390 val = up->pcslen;
1391 break;
1392
1393 case UDPLITE_RECV_CSCOV:
1394 val = up->pcrlen;
1395 break;
1396
1397 default:
1398 return -ENOPROTOOPT;
1399 }
1400
1401 if (put_user(len, optlen))
1402 return -EFAULT;
1403 if (copy_to_user(optval, &val,len))
1404 return -EFAULT;
1405 return 0;
1406 }
1407
1408 int udp_getsockopt(struct sock *sk, int level, int optname,
1409 char __user *optval, int __user *optlen)
1410 {
1411 if (level == SOL_UDP || level == SOL_UDPLITE)
1412 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1413 return ip_getsockopt(sk, level, optname, optval, optlen);
1414 }
1415
1416 #ifdef CONFIG_COMPAT
1417 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
1418 char __user *optval, int __user *optlen)
1419 {
1420 if (level == SOL_UDP || level == SOL_UDPLITE)
1421 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1422 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
1423 }
1424 #endif
1425 /**
1426 * udp_poll - wait for a UDP event.
1427 * @file - file struct
1428 * @sock - socket
1429 * @wait - poll table
1430 *
1431 * This is same as datagram poll, except for the special case of
1432 * blocking sockets. If application is using a blocking fd
1433 * and a packet with checksum error is in the queue;
1434 * then it could get return from select indicating data available
1435 * but then block when reading it. Add special case code
1436 * to work around these arguably broken applications.
1437 */
1438 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
1439 {
1440 unsigned int mask = datagram_poll(file, sock, wait);
1441 struct sock *sk = sock->sk;
1442 int is_lite = IS_UDPLITE(sk);
1443
1444 /* Check for false positives due to checksum errors */
1445 if ( (mask & POLLRDNORM) &&
1446 !(file->f_flags & O_NONBLOCK) &&
1447 !(sk->sk_shutdown & RCV_SHUTDOWN)){
1448 struct sk_buff_head *rcvq = &sk->sk_receive_queue;
1449 struct sk_buff *skb;
1450
1451 spin_lock_bh(&rcvq->lock);
1452 while ((skb = skb_peek(rcvq)) != NULL &&
1453 udp_lib_checksum_complete(skb)) {
1454 UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_lite);
1455 __skb_unlink(skb, rcvq);
1456 kfree_skb(skb);
1457 }
1458 spin_unlock_bh(&rcvq->lock);
1459
1460 /* nothing to see, move along */
1461 if (skb == NULL)
1462 mask &= ~(POLLIN | POLLRDNORM);
1463 }
1464
1465 return mask;
1466
1467 }
1468
1469 struct proto udp_prot = {
1470 .name = "UDP",
1471 .owner = THIS_MODULE,
1472 .close = udp_lib_close,
1473 .connect = ip4_datagram_connect,
1474 .disconnect = udp_disconnect,
1475 .ioctl = udp_ioctl,
1476 .destroy = udp_destroy_sock,
1477 .setsockopt = udp_setsockopt,
1478 .getsockopt = udp_getsockopt,
1479 .sendmsg = udp_sendmsg,
1480 .recvmsg = udp_recvmsg,
1481 .sendpage = udp_sendpage,
1482 .backlog_rcv = udp_queue_rcv_skb,
1483 .hash = udp_lib_hash,
1484 .unhash = udp_lib_unhash,
1485 .get_port = udp_v4_get_port,
1486 .memory_allocated = &udp_memory_allocated,
1487 .sysctl_mem = sysctl_udp_mem,
1488 .sysctl_wmem = &sysctl_udp_wmem_min,
1489 .sysctl_rmem = &sysctl_udp_rmem_min,
1490 .obj_size = sizeof(struct udp_sock),
1491 .h.udp_hash = udp_hash,
1492 #ifdef CONFIG_COMPAT
1493 .compat_setsockopt = compat_udp_setsockopt,
1494 .compat_getsockopt = compat_udp_getsockopt,
1495 #endif
1496 };
1497
1498 /* ------------------------------------------------------------------------ */
1499 #ifdef CONFIG_PROC_FS
1500
1501 static struct sock *udp_get_first(struct seq_file *seq)
1502 {
1503 struct sock *sk;
1504 struct udp_iter_state *state = seq->private;
1505 struct net *net = seq_file_net(seq);
1506
1507 for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
1508 struct hlist_node *node;
1509 sk_for_each(sk, node, state->hashtable + state->bucket) {
1510 if (!net_eq(sock_net(sk), net))
1511 continue;
1512 if (sk->sk_family == state->family)
1513 goto found;
1514 }
1515 }
1516 sk = NULL;
1517 found:
1518 return sk;
1519 }
1520
1521 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
1522 {
1523 struct udp_iter_state *state = seq->private;
1524 struct net *net = seq_file_net(seq);
1525
1526 do {
1527 sk = sk_next(sk);
1528 try_again:
1529 ;
1530 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
1531
1532 if (!sk && ++state->bucket < UDP_HTABLE_SIZE) {
1533 sk = sk_head(state->hashtable + state->bucket);
1534 goto try_again;
1535 }
1536 return sk;
1537 }
1538
1539 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
1540 {
1541 struct sock *sk = udp_get_first(seq);
1542
1543 if (sk)
1544 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
1545 --pos;
1546 return pos ? NULL : sk;
1547 }
1548
1549 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
1550 __acquires(udp_hash_lock)
1551 {
1552 read_lock(&udp_hash_lock);
1553 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1554 }
1555
1556 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1557 {
1558 struct sock *sk;
1559
1560 if (v == SEQ_START_TOKEN)
1561 sk = udp_get_idx(seq, 0);
1562 else
1563 sk = udp_get_next(seq, v);
1564
1565 ++*pos;
1566 return sk;
1567 }
1568
1569 static void udp_seq_stop(struct seq_file *seq, void *v)
1570 __releases(udp_hash_lock)
1571 {
1572 read_unlock(&udp_hash_lock);
1573 }
1574
1575 static int udp_seq_open(struct inode *inode, struct file *file)
1576 {
1577 struct udp_seq_afinfo *afinfo = PDE(inode)->data;
1578 struct udp_iter_state *s;
1579 int err;
1580
1581 err = seq_open_net(inode, file, &afinfo->seq_ops,
1582 sizeof(struct udp_iter_state));
1583 if (err < 0)
1584 return err;
1585
1586 s = ((struct seq_file *)file->private_data)->private;
1587 s->family = afinfo->family;
1588 s->hashtable = afinfo->hashtable;
1589 return err;
1590 }
1591
1592 /* ------------------------------------------------------------------------ */
1593 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
1594 {
1595 struct proc_dir_entry *p;
1596 int rc = 0;
1597
1598 afinfo->seq_fops.open = udp_seq_open;
1599 afinfo->seq_fops.read = seq_read;
1600 afinfo->seq_fops.llseek = seq_lseek;
1601 afinfo->seq_fops.release = seq_release_net;
1602
1603 afinfo->seq_ops.start = udp_seq_start;
1604 afinfo->seq_ops.next = udp_seq_next;
1605 afinfo->seq_ops.stop = udp_seq_stop;
1606
1607 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1608 &afinfo->seq_fops, afinfo);
1609 if (!p)
1610 rc = -ENOMEM;
1611 return rc;
1612 }
1613
1614 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
1615 {
1616 proc_net_remove(net, afinfo->name);
1617 }
1618
1619 /* ------------------------------------------------------------------------ */
1620 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
1621 int bucket, int *len)
1622 {
1623 struct inet_sock *inet = inet_sk(sp);
1624 __be32 dest = inet->daddr;
1625 __be32 src = inet->rcv_saddr;
1626 __u16 destp = ntohs(inet->dport);
1627 __u16 srcp = ntohs(inet->sport);
1628
1629 seq_printf(f, "%4d: %08X:%04X %08X:%04X"
1630 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p%n",
1631 bucket, src, srcp, dest, destp, sp->sk_state,
1632 atomic_read(&sp->sk_wmem_alloc),
1633 atomic_read(&sp->sk_rmem_alloc),
1634 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
1635 atomic_read(&sp->sk_refcnt), sp, len);
1636 }
1637
1638 int udp4_seq_show(struct seq_file *seq, void *v)
1639 {
1640 if (v == SEQ_START_TOKEN)
1641 seq_printf(seq, "%-127s\n",
1642 " sl local_address rem_address st tx_queue "
1643 "rx_queue tr tm->when retrnsmt uid timeout "
1644 "inode");
1645 else {
1646 struct udp_iter_state *state = seq->private;
1647 int len;
1648
1649 udp4_format_sock(v, seq, state->bucket, &len);
1650 seq_printf(seq, "%*s\n", 127 - len ,"");
1651 }
1652 return 0;
1653 }
1654
1655 /* ------------------------------------------------------------------------ */
1656 static struct udp_seq_afinfo udp4_seq_afinfo = {
1657 .name = "udp",
1658 .family = AF_INET,
1659 .hashtable = udp_hash,
1660 .seq_fops = {
1661 .owner = THIS_MODULE,
1662 },
1663 .seq_ops = {
1664 .show = udp4_seq_show,
1665 },
1666 };
1667
1668 static int udp4_proc_init_net(struct net *net)
1669 {
1670 return udp_proc_register(net, &udp4_seq_afinfo);
1671 }
1672
1673 static void udp4_proc_exit_net(struct net *net)
1674 {
1675 udp_proc_unregister(net, &udp4_seq_afinfo);
1676 }
1677
1678 static struct pernet_operations udp4_net_ops = {
1679 .init = udp4_proc_init_net,
1680 .exit = udp4_proc_exit_net,
1681 };
1682
1683 int __init udp4_proc_init(void)
1684 {
1685 return register_pernet_subsys(&udp4_net_ops);
1686 }
1687
1688 void udp4_proc_exit(void)
1689 {
1690 unregister_pernet_subsys(&udp4_net_ops);
1691 }
1692 #endif /* CONFIG_PROC_FS */
1693
1694 void __init udp_init(void)
1695 {
1696 unsigned long limit;
1697
1698 /* Set the pressure threshold up by the same strategy of TCP. It is a
1699 * fraction of global memory that is up to 1/2 at 256 MB, decreasing
1700 * toward zero with the amount of memory, with a floor of 128 pages.
1701 */
1702 limit = min(nr_all_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
1703 limit = (limit * (nr_all_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
1704 limit = max(limit, 128UL);
1705 sysctl_udp_mem[0] = limit / 4 * 3;
1706 sysctl_udp_mem[1] = limit;
1707 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
1708
1709 sysctl_udp_rmem_min = SK_MEM_QUANTUM;
1710 sysctl_udp_wmem_min = SK_MEM_QUANTUM;
1711 }
1712
1713 EXPORT_SYMBOL(udp_disconnect);
1714 EXPORT_SYMBOL(udp_hash);
1715 EXPORT_SYMBOL(udp_hash_lock);
1716 EXPORT_SYMBOL(udp_ioctl);
1717 EXPORT_SYMBOL(udp_prot);
1718 EXPORT_SYMBOL(udp_sendmsg);
1719 EXPORT_SYMBOL(udp_lib_getsockopt);
1720 EXPORT_SYMBOL(udp_lib_setsockopt);
1721 EXPORT_SYMBOL(udp_poll);
1722 EXPORT_SYMBOL(udp_lib_get_port);
1723
1724 #ifdef CONFIG_PROC_FS
1725 EXPORT_SYMBOL(udp_proc_register);
1726 EXPORT_SYMBOL(udp_proc_unregister);
1727 #endif
Linux kernel - Deliverables
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