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Linux 2.6.28-rc5
[cris-mirror.git] / net / ipv4 / udp.c
blobcf02701ced48091d9eecb6765fe80934a3dc73c8
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@lxorguk.ukuu.org.uk>
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 struct hlist_head udp_hash[UDP_HTABLE_SIZE];
112 DEFINE_RWLOCK(udp_hash_lock);
113
114 int sysctl_udp_mem[3] __read_mostly;
115 int sysctl_udp_rmem_min __read_mostly;
116 int sysctl_udp_wmem_min __read_mostly;
117
118 EXPORT_SYMBOL(sysctl_udp_mem);
119 EXPORT_SYMBOL(sysctl_udp_rmem_min);
120 EXPORT_SYMBOL(sysctl_udp_wmem_min);
121
122 atomic_t udp_memory_allocated;
123 EXPORT_SYMBOL(udp_memory_allocated);
124
125 static int udp_lib_lport_inuse(struct net *net, __u16 num,
126 const struct hlist_head udptable[],
127 struct sock *sk,
128 int (*saddr_comp)(const struct sock *sk1,
129 const struct sock *sk2))
130 {
131 struct sock *sk2;
132 struct hlist_node *node;
133
134 sk_for_each(sk2, node, &udptable[udp_hashfn(net, num)])
135 if (net_eq(sock_net(sk2), net) &&
136 sk2 != sk &&
137 sk2->sk_hash == num &&
138 (!sk2->sk_reuse || !sk->sk_reuse) &&
139 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if
140 || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
141 (*saddr_comp)(sk, sk2))
142 return 1;
143 return 0;
144 }
145
146 /**
147 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
148 *
149 * @sk: socket struct in question
150 * @snum: port number to look up
151 * @saddr_comp: AF-dependent comparison of bound local IP addresses
152 */
153 int udp_lib_get_port(struct sock *sk, unsigned short snum,
154 int (*saddr_comp)(const struct sock *sk1,
155 const struct sock *sk2 ) )
156 {
157 struct hlist_head *udptable = sk->sk_prot->h.udp_hash;
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 low, high, remaining;
165 unsigned rand;
166 unsigned short first;
167
168 inet_get_local_port_range(&low, &high);
169 remaining = (high - low) + 1;
170
171 rand = net_random();
172 snum = first = rand % remaining + low;
173 rand |= 1;
174 while (udp_lib_lport_inuse(net, snum, udptable, sk,
175 saddr_comp)) {
176 do {
177 snum = snum + rand;
178 } while (snum < low || snum > high);
179 if (snum == first)
180 goto fail;
181 }
182 } else if (udp_lib_lport_inuse(net, snum, udptable, sk, saddr_comp))
183 goto fail;
184
185 inet_sk(sk)->num = snum;
186 sk->sk_hash = snum;
187 if (sk_unhashed(sk)) {
188 sk_add_node(sk, &udptable[udp_hashfn(net, snum)]);
189 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
190 }
191 error = 0;
192 fail:
193 write_unlock_bh(&udp_hash_lock);
194 return error;
195 }
196
197 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
198 {
199 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
200
201 return ( !ipv6_only_sock(sk2) &&
202 (!inet1->rcv_saddr || !inet2->rcv_saddr ||
203 inet1->rcv_saddr == inet2->rcv_saddr ));
204 }
205
206 int udp_v4_get_port(struct sock *sk, unsigned short snum)
207 {
208 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal);
209 }
210
211 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
212 * harder than this. -DaveM
213 */
214 static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
215 __be16 sport, __be32 daddr, __be16 dport,
216 int dif, struct hlist_head udptable[])
217 {
218 struct sock *sk, *result = NULL;
219 struct hlist_node *node;
220 unsigned short hnum = ntohs(dport);
221 int badness = -1;
222
223 read_lock(&udp_hash_lock);
224 sk_for_each(sk, node, &udptable[udp_hashfn(net, hnum)]) {
225 struct inet_sock *inet = inet_sk(sk);
226
227 if (net_eq(sock_net(sk), net) && sk->sk_hash == hnum &&
228 !ipv6_only_sock(sk)) {
229 int score = (sk->sk_family == PF_INET ? 1 : 0);
230 if (inet->rcv_saddr) {
231 if (inet->rcv_saddr != daddr)
232 continue;
233 score+=2;
234 }
235 if (inet->daddr) {
236 if (inet->daddr != saddr)
237 continue;
238 score+=2;
239 }
240 if (inet->dport) {
241 if (inet->dport != sport)
242 continue;
243 score+=2;
244 }
245 if (sk->sk_bound_dev_if) {
246 if (sk->sk_bound_dev_if != dif)
247 continue;
248 score+=2;
249 }
250 if (score == 9) {
251 result = sk;
252 break;
253 } else if (score > badness) {
254 result = sk;
255 badness = score;
256 }
257 }
258 }
259 if (result)
260 sock_hold(result);
261 read_unlock(&udp_hash_lock);
262 return result;
263 }
264
265 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
266 __be16 sport, __be16 dport,
267 struct hlist_head udptable[])
268 {
269 struct sock *sk;
270 const struct iphdr *iph = ip_hdr(skb);
271
272 if (unlikely(sk = skb_steal_sock(skb)))
273 return sk;
274 else
275 return __udp4_lib_lookup(dev_net(skb->dst->dev), iph->saddr, sport,
276 iph->daddr, dport, inet_iif(skb),
277 udptable);
278 }
279
280 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
281 __be32 daddr, __be16 dport, int dif)
282 {
283 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, udp_hash);
284 }
285 EXPORT_SYMBOL_GPL(udp4_lib_lookup);
286
287 static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
288 __be16 loc_port, __be32 loc_addr,
289 __be16 rmt_port, __be32 rmt_addr,
290 int dif)
291 {
292 struct hlist_node *node;
293 struct sock *s = sk;
294 unsigned short hnum = ntohs(loc_port);
295
296 sk_for_each_from(s, node) {
297 struct inet_sock *inet = inet_sk(s);
298
299 if (!net_eq(sock_net(s), net) ||
300 s->sk_hash != hnum ||
301 (inet->daddr && inet->daddr != rmt_addr) ||
302 (inet->dport != rmt_port && inet->dport) ||
303 (inet->rcv_saddr && inet->rcv_saddr != loc_addr) ||
304 ipv6_only_sock(s) ||
305 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
306 continue;
307 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
308 continue;
309 goto found;
310 }
311 s = NULL;
312 found:
313 return s;
314 }
315
316 /*
317 * This routine is called by the ICMP module when it gets some
318 * sort of error condition. If err < 0 then the socket should
319 * be closed and the error returned to the user. If err > 0
320 * it's just the icmp type << 8 | icmp code.
321 * Header points to the ip header of the error packet. We move
322 * on past this. Then (as it used to claim before adjustment)
323 * header points to the first 8 bytes of the udp header. We need
324 * to find the appropriate port.
325 */
326
327 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct hlist_head udptable[])
328 {
329 struct inet_sock *inet;
330 struct iphdr *iph = (struct iphdr*)skb->data;
331 struct udphdr *uh = (struct udphdr*)(skb->data+(iph->ihl<<2));
332 const int type = icmp_hdr(skb)->type;
333 const int code = icmp_hdr(skb)->code;
334 struct sock *sk;
335 int harderr;
336 int err;
337 struct net *net = dev_net(skb->dev);
338
339 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
340 iph->saddr, uh->source, skb->dev->ifindex, udptable);
341 if (sk == NULL) {
342 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
343 return; /* No socket for error */
344 }
345
346 err = 0;
347 harderr = 0;
348 inet = inet_sk(sk);
349
350 switch (type) {
351 default:
352 case ICMP_TIME_EXCEEDED:
353 err = EHOSTUNREACH;
354 break;
355 case ICMP_SOURCE_QUENCH:
356 goto out;
357 case ICMP_PARAMETERPROB:
358 err = EPROTO;
359 harderr = 1;
360 break;
361 case ICMP_DEST_UNREACH:
362 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
363 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
364 err = EMSGSIZE;
365 harderr = 1;
366 break;
367 }
368 goto out;
369 }
370 err = EHOSTUNREACH;
371 if (code <= NR_ICMP_UNREACH) {
372 harderr = icmp_err_convert[code].fatal;
373 err = icmp_err_convert[code].errno;
374 }
375 break;
376 }
377
378 /*
379 * RFC1122: OK. Passes ICMP errors back to application, as per
380 * 4.1.3.3.
381 */
382 if (!inet->recverr) {
383 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
384 goto out;
385 } else {
386 ip_icmp_error(sk, skb, err, uh->dest, info, (u8*)(uh+1));
387 }
388 sk->sk_err = err;
389 sk->sk_error_report(sk);
390 out:
391 sock_put(sk);
392 }
393
394 void udp_err(struct sk_buff *skb, u32 info)
395 {
396 __udp4_lib_err(skb, info, udp_hash);
397 }
398
399 /*
400 * Throw away all pending data and cancel the corking. Socket is locked.
401 */
402 void udp_flush_pending_frames(struct sock *sk)
403 {
404 struct udp_sock *up = udp_sk(sk);
405
406 if (up->pending) {
407 up->len = 0;
408 up->pending = 0;
409 ip_flush_pending_frames(sk);
410 }
411 }
412 EXPORT_SYMBOL(udp_flush_pending_frames);
413
414 /**
415 * udp4_hwcsum_outgoing - handle outgoing HW checksumming
416 * @sk: socket we are sending on
417 * @skb: sk_buff containing the filled-in UDP header
418 * (checksum field must be zeroed out)
419 */
420 static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
421 __be32 src, __be32 dst, int len )
422 {
423 unsigned int offset;
424 struct udphdr *uh = udp_hdr(skb);
425 __wsum csum = 0;
426
427 if (skb_queue_len(&sk->sk_write_queue) == 1) {
428 /*
429 * Only one fragment on the socket.
430 */
431 skb->csum_start = skb_transport_header(skb) - skb->head;
432 skb->csum_offset = offsetof(struct udphdr, check);
433 uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0);
434 } else {
435 /*
436 * HW-checksum won't work as there are two or more
437 * fragments on the socket so that all csums of sk_buffs
438 * should be together
439 */
440 offset = skb_transport_offset(skb);
441 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
442
443 skb->ip_summed = CHECKSUM_NONE;
444
445 skb_queue_walk(&sk->sk_write_queue, skb) {
446 csum = csum_add(csum, skb->csum);
447 }
448
449 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
450 if (uh->check == 0)
451 uh->check = CSUM_MANGLED_0;
452 }
453 }
454
455 /*
456 * Push out all pending data as one UDP datagram. Socket is locked.
457 */
458 static int udp_push_pending_frames(struct sock *sk)
459 {
460 struct udp_sock *up = udp_sk(sk);
461 struct inet_sock *inet = inet_sk(sk);
462 struct flowi *fl = &inet->cork.fl;
463 struct sk_buff *skb;
464 struct udphdr *uh;
465 int err = 0;
466 int is_udplite = IS_UDPLITE(sk);
467 __wsum csum = 0;
468
469 /* Grab the skbuff where UDP header space exists. */
470 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
471 goto out;
472
473 /*
474 * Create a UDP header
475 */
476 uh = udp_hdr(skb);
477 uh->source = fl->fl_ip_sport;
478 uh->dest = fl->fl_ip_dport;
479 uh->len = htons(up->len);
480 uh->check = 0;
481
482 if (is_udplite) /* UDP-Lite */
483 csum = udplite_csum_outgoing(sk, skb);
484
485 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */
486
487 skb->ip_summed = CHECKSUM_NONE;
488 goto send;
489
490 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
491
492 udp4_hwcsum_outgoing(sk, skb, fl->fl4_src,fl->fl4_dst, up->len);
493 goto send;
494
495 } else /* `normal' UDP */
496 csum = udp_csum_outgoing(sk, skb);
497
498 /* add protocol-dependent pseudo-header */
499 uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len,
500 sk->sk_protocol, csum );
501 if (uh->check == 0)
502 uh->check = CSUM_MANGLED_0;
503
504 send:
505 err = ip_push_pending_frames(sk);
506 out:
507 up->len = 0;
508 up->pending = 0;
509 if (!err)
510 UDP_INC_STATS_USER(sock_net(sk),
511 UDP_MIB_OUTDATAGRAMS, is_udplite);
512 return err;
513 }
514
515 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
516 size_t len)
517 {
518 struct inet_sock *inet = inet_sk(sk);
519 struct udp_sock *up = udp_sk(sk);
520 int ulen = len;
521 struct ipcm_cookie ipc;
522 struct rtable *rt = NULL;
523 int free = 0;
524 int connected = 0;
525 __be32 daddr, faddr, saddr;
526 __be16 dport;
527 u8 tos;
528 int err, is_udplite = IS_UDPLITE(sk);
529 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
530 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
531
532 if (len > 0xFFFF)
533 return -EMSGSIZE;
534
535 /*
536 * Check the flags.
537 */
538
539 if (msg->msg_flags&MSG_OOB) /* Mirror BSD error message compatibility */
540 return -EOPNOTSUPP;
541
542 ipc.opt = NULL;
543
544 if (up->pending) {
545 /*
546 * There are pending frames.
547 * The socket lock must be held while it's corked.
548 */
549 lock_sock(sk);
550 if (likely(up->pending)) {
551 if (unlikely(up->pending != AF_INET)) {
552 release_sock(sk);
553 return -EINVAL;
554 }
555 goto do_append_data;
556 }
557 release_sock(sk);
558 }
559 ulen += sizeof(struct udphdr);
560
561 /*
562 * Get and verify the address.
563 */
564 if (msg->msg_name) {
565 struct sockaddr_in * usin = (struct sockaddr_in*)msg->msg_name;
566 if (msg->msg_namelen < sizeof(*usin))
567 return -EINVAL;
568 if (usin->sin_family != AF_INET) {
569 if (usin->sin_family != AF_UNSPEC)
570 return -EAFNOSUPPORT;
571 }
572
573 daddr = usin->sin_addr.s_addr;
574 dport = usin->sin_port;
575 if (dport == 0)
576 return -EINVAL;
577 } else {
578 if (sk->sk_state != TCP_ESTABLISHED)
579 return -EDESTADDRREQ;
580 daddr = inet->daddr;
581 dport = inet->dport;
582 /* Open fast path for connected socket.
583 Route will not be used, if at least one option is set.
584 */
585 connected = 1;
586 }
587 ipc.addr = inet->saddr;
588
589 ipc.oif = sk->sk_bound_dev_if;
590 if (msg->msg_controllen) {
591 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
592 if (err)
593 return err;
594 if (ipc.opt)
595 free = 1;
596 connected = 0;
597 }
598 if (!ipc.opt)
599 ipc.opt = inet->opt;
600
601 saddr = ipc.addr;
602 ipc.addr = faddr = daddr;
603
604 if (ipc.opt && ipc.opt->srr) {
605 if (!daddr)
606 return -EINVAL;
607 faddr = ipc.opt->faddr;
608 connected = 0;
609 }
610 tos = RT_TOS(inet->tos);
611 if (sock_flag(sk, SOCK_LOCALROUTE) ||
612 (msg->msg_flags & MSG_DONTROUTE) ||
613 (ipc.opt && ipc.opt->is_strictroute)) {
614 tos |= RTO_ONLINK;
615 connected = 0;
616 }
617
618 if (ipv4_is_multicast(daddr)) {
619 if (!ipc.oif)
620 ipc.oif = inet->mc_index;
621 if (!saddr)
622 saddr = inet->mc_addr;
623 connected = 0;
624 }
625
626 if (connected)
627 rt = (struct rtable*)sk_dst_check(sk, 0);
628
629 if (rt == NULL) {
630 struct flowi fl = { .oif = ipc.oif,
631 .nl_u = { .ip4_u =
632 { .daddr = faddr,
633 .saddr = saddr,
634 .tos = tos } },
635 .proto = sk->sk_protocol,
636 .uli_u = { .ports =
637 { .sport = inet->sport,
638 .dport = dport } } };
639 struct net *net = sock_net(sk);
640
641 security_sk_classify_flow(sk, &fl);
642 err = ip_route_output_flow(net, &rt, &fl, sk, 1);
643 if (err) {
644 if (err == -ENETUNREACH)
645 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
646 goto out;
647 }
648
649 err = -EACCES;
650 if ((rt->rt_flags & RTCF_BROADCAST) &&
651 !sock_flag(sk, SOCK_BROADCAST))
652 goto out;
653 if (connected)
654 sk_dst_set(sk, dst_clone(&rt->u.dst));
655 }
656
657 if (msg->msg_flags&MSG_CONFIRM)
658 goto do_confirm;
659 back_from_confirm:
660
661 saddr = rt->rt_src;
662 if (!ipc.addr)
663 daddr = ipc.addr = rt->rt_dst;
664
665 lock_sock(sk);
666 if (unlikely(up->pending)) {
667 /* The socket is already corked while preparing it. */
668 /* ... which is an evident application bug. --ANK */
669 release_sock(sk);
670
671 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
672 err = -EINVAL;
673 goto out;
674 }
675 /*
676 * Now cork the socket to pend data.
677 */
678 inet->cork.fl.fl4_dst = daddr;
679 inet->cork.fl.fl_ip_dport = dport;
680 inet->cork.fl.fl4_src = saddr;
681 inet->cork.fl.fl_ip_sport = inet->sport;
682 up->pending = AF_INET;
683
684 do_append_data:
685 up->len += ulen;
686 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
687 err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
688 sizeof(struct udphdr), &ipc, rt,
689 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
690 if (err)
691 udp_flush_pending_frames(sk);
692 else if (!corkreq)
693 err = udp_push_pending_frames(sk);
694 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
695 up->pending = 0;
696 release_sock(sk);
697
698 out:
699 ip_rt_put(rt);
700 if (free)
701 kfree(ipc.opt);
702 if (!err)
703 return len;
704 /*
705 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
706 * ENOBUFS might not be good (it's not tunable per se), but otherwise
707 * we don't have a good statistic (IpOutDiscards but it can be too many
708 * things). We could add another new stat but at least for now that
709 * seems like overkill.
710 */
711 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
712 UDP_INC_STATS_USER(sock_net(sk),
713 UDP_MIB_SNDBUFERRORS, is_udplite);
714 }
715 return err;
716
717 do_confirm:
718 dst_confirm(&rt->u.dst);
719 if (!(msg->msg_flags&MSG_PROBE) || len)
720 goto back_from_confirm;
721 err = 0;
722 goto out;
723 }
724
725 int udp_sendpage(struct sock *sk, struct page *page, int offset,
726 size_t size, int flags)
727 {
728 struct udp_sock *up = udp_sk(sk);
729 int ret;
730
731 if (!up->pending) {
732 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
733
734 /* Call udp_sendmsg to specify destination address which
735 * sendpage interface can't pass.
736 * This will succeed only when the socket is connected.
737 */
738 ret = udp_sendmsg(NULL, sk, &msg, 0);
739 if (ret < 0)
740 return ret;
741 }
742
743 lock_sock(sk);
744
745 if (unlikely(!up->pending)) {
746 release_sock(sk);
747
748 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n");
749 return -EINVAL;
750 }
751
752 ret = ip_append_page(sk, page, offset, size, flags);
753 if (ret == -EOPNOTSUPP) {
754 release_sock(sk);
755 return sock_no_sendpage(sk->sk_socket, page, offset,
756 size, flags);
757 }
758 if (ret < 0) {
759 udp_flush_pending_frames(sk);
760 goto out;
761 }
762
763 up->len += size;
764 if (!(up->corkflag || (flags&MSG_MORE)))
765 ret = udp_push_pending_frames(sk);
766 if (!ret)
767 ret = size;
768 out:
769 release_sock(sk);
770 return ret;
771 }
772
773 /*
774 * IOCTL requests applicable to the UDP protocol
775 */
776
777 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
778 {
779 switch (cmd) {
780 case SIOCOUTQ:
781 {
782 int amount = atomic_read(&sk->sk_wmem_alloc);
783 return put_user(amount, (int __user *)arg);
784 }
785
786 case SIOCINQ:
787 {
788 struct sk_buff *skb;
789 unsigned long amount;
790
791 amount = 0;
792 spin_lock_bh(&sk->sk_receive_queue.lock);
793 skb = skb_peek(&sk->sk_receive_queue);
794 if (skb != NULL) {
795 /*
796 * We will only return the amount
797 * of this packet since that is all
798 * that will be read.
799 */
800 amount = skb->len - sizeof(struct udphdr);
801 }
802 spin_unlock_bh(&sk->sk_receive_queue.lock);
803 return put_user(amount, (int __user *)arg);
804 }
805
806 default:
807 return -ENOIOCTLCMD;
808 }
809
810 return 0;
811 }
812
813 /*
814 * This should be easy, if there is something there we
815 * return it, otherwise we block.
816 */
817
818 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
819 size_t len, int noblock, int flags, int *addr_len)
820 {
821 struct inet_sock *inet = inet_sk(sk);
822 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
823 struct sk_buff *skb;
824 unsigned int ulen, copied;
825 int peeked;
826 int err;
827 int is_udplite = IS_UDPLITE(sk);
828
829 /*
830 * Check any passed addresses
831 */
832 if (addr_len)
833 *addr_len=sizeof(*sin);
834
835 if (flags & MSG_ERRQUEUE)
836 return ip_recv_error(sk, msg, len);
837
838 try_again:
839 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
840 &peeked, &err);
841 if (!skb)
842 goto out;
843
844 ulen = skb->len - sizeof(struct udphdr);
845 copied = len;
846 if (copied > ulen)
847 copied = ulen;
848 else if (copied < ulen)
849 msg->msg_flags |= MSG_TRUNC;
850
851 /*
852 * If checksum is needed at all, try to do it while copying the
853 * data. If the data is truncated, or if we only want a partial
854 * coverage checksum (UDP-Lite), do it before the copy.
855 */
856
857 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
858 if (udp_lib_checksum_complete(skb))
859 goto csum_copy_err;
860 }
861
862 if (skb_csum_unnecessary(skb))
863 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
864 msg->msg_iov, copied );
865 else {
866 err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
867
868 if (err == -EINVAL)
869 goto csum_copy_err;
870 }
871
872 if (err)
873 goto out_free;
874
875 if (!peeked)
876 UDP_INC_STATS_USER(sock_net(sk),
877 UDP_MIB_INDATAGRAMS, is_udplite);
878
879 sock_recv_timestamp(msg, sk, skb);
880
881 /* Copy the address. */
882 if (sin)
883 {
884 sin->sin_family = AF_INET;
885 sin->sin_port = udp_hdr(skb)->source;
886 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
887 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
888 }
889 if (inet->cmsg_flags)
890 ip_cmsg_recv(msg, skb);
891
892 err = copied;
893 if (flags & MSG_TRUNC)
894 err = ulen;
895
896 out_free:
897 lock_sock(sk);
898 skb_free_datagram(sk, skb);
899 release_sock(sk);
900 out:
901 return err;
902
903 csum_copy_err:
904 lock_sock(sk);
905 if (!skb_kill_datagram(sk, skb, flags))
906 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
907 release_sock(sk);
908
909 if (noblock)
910 return -EAGAIN;
911 goto try_again;
912 }
913
914
915 int udp_disconnect(struct sock *sk, int flags)
916 {
917 struct inet_sock *inet = inet_sk(sk);
918 /*
919 * 1003.1g - break association.
920 */
921
922 sk->sk_state = TCP_CLOSE;
923 inet->daddr = 0;
924 inet->dport = 0;
925 sk->sk_bound_dev_if = 0;
926 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
927 inet_reset_saddr(sk);
928
929 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
930 sk->sk_prot->unhash(sk);
931 inet->sport = 0;
932 }
933 sk_dst_reset(sk);
934 return 0;
935 }
936
937 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
938 {
939 int is_udplite = IS_UDPLITE(sk);
940 int rc;
941
942 if ((rc = sock_queue_rcv_skb(sk, skb)) < 0) {
943 /* Note that an ENOMEM error is charged twice */
944 if (rc == -ENOMEM)
945 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
946 is_udplite);
947 goto drop;
948 }
949
950 return 0;
951
952 drop:
953 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
954 kfree_skb(skb);
955 return -1;
956 }
957
958 /* returns:
959 * -1: error
960 * 0: success
961 * >0: "udp encap" protocol resubmission
962 *
963 * Note that in the success and error cases, the skb is assumed to
964 * have either been requeued or freed.
965 */
966 int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
967 {
968 struct udp_sock *up = udp_sk(sk);
969 int rc;
970 int is_udplite = IS_UDPLITE(sk);
971
972 /*
973 * Charge it to the socket, dropping if the queue is full.
974 */
975 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
976 goto drop;
977 nf_reset(skb);
978
979 if (up->encap_type) {
980 /*
981 * This is an encapsulation socket so pass the skb to
982 * the socket's udp_encap_rcv() hook. Otherwise, just
983 * fall through and pass this up the UDP socket.
984 * up->encap_rcv() returns the following value:
985 * =0 if skb was successfully passed to the encap
986 * handler or was discarded by it.
987 * >0 if skb should be passed on to UDP.
988 * <0 if skb should be resubmitted as proto -N
989 */
990
991 /* if we're overly short, let UDP handle it */
992 if (skb->len > sizeof(struct udphdr) &&
993 up->encap_rcv != NULL) {
994 int ret;
995
996 ret = (*up->encap_rcv)(sk, skb);
997 if (ret <= 0) {
998 UDP_INC_STATS_BH(sock_net(sk),
999 UDP_MIB_INDATAGRAMS,
1000 is_udplite);
1001 return -ret;
1002 }
1003 }
1004
1005 /* FALLTHROUGH -- it's a UDP Packet */
1006 }
1007
1008 /*
1009 * UDP-Lite specific tests, ignored on UDP sockets
1010 */
1011 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1012
1013 /*
1014 * MIB statistics other than incrementing the error count are
1015 * disabled for the following two types of errors: these depend
1016 * on the application settings, not on the functioning of the
1017 * protocol stack as such.
1018 *
1019 * RFC 3828 here recommends (sec 3.3): "There should also be a
1020 * way ... to ... at least let the receiving application block
1021 * delivery of packets with coverage values less than a value
1022 * provided by the application."
1023 */
1024 if (up->pcrlen == 0) { /* full coverage was set */
1025 LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage "
1026 "%d while full coverage %d requested\n",
1027 UDP_SKB_CB(skb)->cscov, skb->len);
1028 goto drop;
1029 }
1030 /* The next case involves violating the min. coverage requested
1031 * by the receiver. This is subtle: if receiver wants x and x is
1032 * greater than the buffersize/MTU then receiver will complain
1033 * that it wants x while sender emits packets of smaller size y.
1034 * Therefore the above ...()->partial_cov statement is essential.
1035 */
1036 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1037 LIMIT_NETDEBUG(KERN_WARNING
1038 "UDPLITE: coverage %d too small, need min %d\n",
1039 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1040 goto drop;
1041 }
1042 }
1043
1044 if (sk->sk_filter) {
1045 if (udp_lib_checksum_complete(skb))
1046 goto drop;
1047 }
1048
1049 rc = 0;
1050
1051 bh_lock_sock(sk);
1052 if (!sock_owned_by_user(sk))
1053 rc = __udp_queue_rcv_skb(sk, skb);
1054 else
1055 sk_add_backlog(sk, skb);
1056 bh_unlock_sock(sk);
1057
1058 return rc;
1059
1060 drop:
1061 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1062 kfree_skb(skb);
1063 return -1;
1064 }
1065
1066 /*
1067 * Multicasts and broadcasts go to each listener.
1068 *
1069 * Note: called only from the BH handler context,
1070 * so we don't need to lock the hashes.
1071 */
1072 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1073 struct udphdr *uh,
1074 __be32 saddr, __be32 daddr,
1075 struct hlist_head udptable[])
1076 {
1077 struct sock *sk;
1078 int dif;
1079
1080 read_lock(&udp_hash_lock);
1081 sk = sk_head(&udptable[udp_hashfn(net, ntohs(uh->dest))]);
1082 dif = skb->dev->ifindex;
1083 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
1084 if (sk) {
1085 struct sock *sknext = NULL;
1086
1087 do {
1088 struct sk_buff *skb1 = skb;
1089
1090 sknext = udp_v4_mcast_next(net, sk_next(sk), uh->dest,
1091 daddr, uh->source, saddr,
1092 dif);
1093 if (sknext)
1094 skb1 = skb_clone(skb, GFP_ATOMIC);
1095
1096 if (skb1) {
1097 int ret = udp_queue_rcv_skb(sk, skb1);
1098 if (ret > 0)
1099 /* we should probably re-process instead
1100 * of dropping packets here. */
1101 kfree_skb(skb1);
1102 }
1103 sk = sknext;
1104 } while (sknext);
1105 } else
1106 kfree_skb(skb);
1107 read_unlock(&udp_hash_lock);
1108 return 0;
1109 }
1110
1111 /* Initialize UDP checksum. If exited with zero value (success),
1112 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1113 * Otherwise, csum completion requires chacksumming packet body,
1114 * including udp header and folding it to skb->csum.
1115 */
1116 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
1117 int proto)
1118 {
1119 const struct iphdr *iph;
1120 int err;
1121
1122 UDP_SKB_CB(skb)->partial_cov = 0;
1123 UDP_SKB_CB(skb)->cscov = skb->len;
1124
1125 if (proto == IPPROTO_UDPLITE) {
1126 err = udplite_checksum_init(skb, uh);
1127 if (err)
1128 return err;
1129 }
1130
1131 iph = ip_hdr(skb);
1132 if (uh->check == 0) {
1133 skb->ip_summed = CHECKSUM_UNNECESSARY;
1134 } else if (skb->ip_summed == CHECKSUM_COMPLETE) {
1135 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1136 proto, skb->csum))
1137 skb->ip_summed = CHECKSUM_UNNECESSARY;
1138 }
1139 if (!skb_csum_unnecessary(skb))
1140 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
1141 skb->len, proto, 0);
1142 /* Probably, we should checksum udp header (it should be in cache
1143 * in any case) and data in tiny packets (< rx copybreak).
1144 */
1145
1146 return 0;
1147 }
1148
1149 /*
1150 * All we need to do is get the socket, and then do a checksum.
1151 */
1152
1153 int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
1154 int proto)
1155 {
1156 struct sock *sk;
1157 struct udphdr *uh = udp_hdr(skb);
1158 unsigned short ulen;
1159 struct rtable *rt = (struct rtable*)skb->dst;
1160 __be32 saddr = ip_hdr(skb)->saddr;
1161 __be32 daddr = ip_hdr(skb)->daddr;
1162 struct net *net = dev_net(skb->dev);
1163
1164 /*
1165 * Validate the packet.
1166 */
1167 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1168 goto drop; /* No space for header. */
1169
1170 ulen = ntohs(uh->len);
1171 if (ulen > skb->len)
1172 goto short_packet;
1173
1174 if (proto == IPPROTO_UDP) {
1175 /* UDP validates ulen. */
1176 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
1177 goto short_packet;
1178 uh = udp_hdr(skb);
1179 }
1180
1181 if (udp4_csum_init(skb, uh, proto))
1182 goto csum_error;
1183
1184 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1185 return __udp4_lib_mcast_deliver(net, skb, uh,
1186 saddr, daddr, udptable);
1187
1188 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1189
1190 if (sk != NULL) {
1191 int ret = udp_queue_rcv_skb(sk, skb);
1192 sock_put(sk);
1193
1194 /* a return value > 0 means to resubmit the input, but
1195 * it wants the return to be -protocol, or 0
1196 */
1197 if (ret > 0)
1198 return -ret;
1199 return 0;
1200 }
1201
1202 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1203 goto drop;
1204 nf_reset(skb);
1205
1206 /* No socket. Drop packet silently, if checksum is wrong */
1207 if (udp_lib_checksum_complete(skb))
1208 goto csum_error;
1209
1210 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1211 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
1212
1213 /*
1214 * Hmm. We got an UDP packet to a port to which we
1215 * don't wanna listen. Ignore it.
1216 */
1217 kfree_skb(skb);
1218 return 0;
1219
1220 short_packet:
1221 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From " NIPQUAD_FMT ":%u %d/%d to " NIPQUAD_FMT ":%u\n",
1222 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1223 NIPQUAD(saddr),
1224 ntohs(uh->source),
1225 ulen,
1226 skb->len,
1227 NIPQUAD(daddr),
1228 ntohs(uh->dest));
1229 goto drop;
1230
1231 csum_error:
1232 /*
1233 * RFC1122: OK. Discards the bad packet silently (as far as
1234 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1235 */
1236 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From " NIPQUAD_FMT ":%u to " NIPQUAD_FMT ":%u ulen %d\n",
1237 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1238 NIPQUAD(saddr),
1239 ntohs(uh->source),
1240 NIPQUAD(daddr),
1241 ntohs(uh->dest),
1242 ulen);
1243 drop:
1244 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1245 kfree_skb(skb);
1246 return 0;
1247 }
1248
1249 int udp_rcv(struct sk_buff *skb)
1250 {
1251 return __udp4_lib_rcv(skb, udp_hash, IPPROTO_UDP);
1252 }
1253
1254 void udp_destroy_sock(struct sock *sk)
1255 {
1256 lock_sock(sk);
1257 udp_flush_pending_frames(sk);
1258 release_sock(sk);
1259 }
1260
1261 /*
1262 * Socket option code for UDP
1263 */
1264 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1265 char __user *optval, int optlen,
1266 int (*push_pending_frames)(struct sock *))
1267 {
1268 struct udp_sock *up = udp_sk(sk);
1269 int val;
1270 int err = 0;
1271 int is_udplite = IS_UDPLITE(sk);
1272
1273 if (optlen<sizeof(int))
1274 return -EINVAL;
1275
1276 if (get_user(val, (int __user *)optval))
1277 return -EFAULT;
1278
1279 switch (optname) {
1280 case UDP_CORK:
1281 if (val != 0) {
1282 up->corkflag = 1;
1283 } else {
1284 up->corkflag = 0;
1285 lock_sock(sk);
1286 (*push_pending_frames)(sk);
1287 release_sock(sk);
1288 }
1289 break;
1290
1291 case UDP_ENCAP:
1292 switch (val) {
1293 case 0:
1294 case UDP_ENCAP_ESPINUDP:
1295 case UDP_ENCAP_ESPINUDP_NON_IKE:
1296 up->encap_rcv = xfrm4_udp_encap_rcv;
1297 /* FALLTHROUGH */
1298 case UDP_ENCAP_L2TPINUDP:
1299 up->encap_type = val;
1300 break;
1301 default:
1302 err = -ENOPROTOOPT;
1303 break;
1304 }
1305 break;
1306
1307 /*
1308 * UDP-Lite's partial checksum coverage (RFC 3828).
1309 */
1310 /* The sender sets actual checksum coverage length via this option.
1311 * The case coverage > packet length is handled by send module. */
1312 case UDPLITE_SEND_CSCOV:
1313 if (!is_udplite) /* Disable the option on UDP sockets */
1314 return -ENOPROTOOPT;
1315 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
1316 val = 8;
1317 else if (val > USHORT_MAX)
1318 val = USHORT_MAX;
1319 up->pcslen = val;
1320 up->pcflag |= UDPLITE_SEND_CC;
1321 break;
1322
1323 /* The receiver specifies a minimum checksum coverage value. To make
1324 * sense, this should be set to at least 8 (as done below). If zero is
1325 * used, this again means full checksum coverage. */
1326 case UDPLITE_RECV_CSCOV:
1327 if (!is_udplite) /* Disable the option on UDP sockets */
1328 return -ENOPROTOOPT;
1329 if (val != 0 && val < 8) /* Avoid silly minimal values. */
1330 val = 8;
1331 else if (val > USHORT_MAX)
1332 val = USHORT_MAX;
1333 up->pcrlen = val;
1334 up->pcflag |= UDPLITE_RECV_CC;
1335 break;
1336
1337 default:
1338 err = -ENOPROTOOPT;
1339 break;
1340 }
1341
1342 return err;
1343 }
1344
1345 int udp_setsockopt(struct sock *sk, int level, int optname,
1346 char __user *optval, int optlen)
1347 {
1348 if (level == SOL_UDP || level == SOL_UDPLITE)
1349 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1350 udp_push_pending_frames);
1351 return ip_setsockopt(sk, level, optname, optval, optlen);
1352 }
1353
1354 #ifdef CONFIG_COMPAT
1355 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
1356 char __user *optval, int optlen)
1357 {
1358 if (level == SOL_UDP || level == SOL_UDPLITE)
1359 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1360 udp_push_pending_frames);
1361 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
1362 }
1363 #endif
1364
1365 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
1366 char __user *optval, int __user *optlen)
1367 {
1368 struct udp_sock *up = udp_sk(sk);
1369 int val, len;
1370
1371 if (get_user(len,optlen))
1372 return -EFAULT;
1373
1374 len = min_t(unsigned int, len, sizeof(int));
1375
1376 if (len < 0)
1377 return -EINVAL;
1378
1379 switch (optname) {
1380 case UDP_CORK:
1381 val = up->corkflag;
1382 break;
1383
1384 case UDP_ENCAP:
1385 val = up->encap_type;
1386 break;
1387
1388 /* The following two cannot be changed on UDP sockets, the return is
1389 * always 0 (which corresponds to the full checksum coverage of UDP). */
1390 case UDPLITE_SEND_CSCOV:
1391 val = up->pcslen;
1392 break;
1393
1394 case UDPLITE_RECV_CSCOV:
1395 val = up->pcrlen;
1396 break;
1397
1398 default:
1399 return -ENOPROTOOPT;
1400 }
1401
1402 if (put_user(len, optlen))
1403 return -EFAULT;
1404 if (copy_to_user(optval, &val,len))
1405 return -EFAULT;
1406 return 0;
1407 }
1408
1409 int udp_getsockopt(struct sock *sk, int level, int optname,
1410 char __user *optval, int __user *optlen)
1411 {
1412 if (level == SOL_UDP || level == SOL_UDPLITE)
1413 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1414 return ip_getsockopt(sk, level, optname, optval, optlen);
1415 }
1416
1417 #ifdef CONFIG_COMPAT
1418 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
1419 char __user *optval, int __user *optlen)
1420 {
1421 if (level == SOL_UDP || level == SOL_UDPLITE)
1422 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1423 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
1424 }
1425 #endif
1426 /**
1427 * udp_poll - wait for a UDP event.
1428 * @file - file struct
1429 * @sock - socket
1430 * @wait - poll table
1431 *
1432 * This is same as datagram poll, except for the special case of
1433 * blocking sockets. If application is using a blocking fd
1434 * and a packet with checksum error is in the queue;
1435 * then it could get return from select indicating data available
1436 * but then block when reading it. Add special case code
1437 * to work around these arguably broken applications.
1438 */
1439 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
1440 {
1441 unsigned int mask = datagram_poll(file, sock, wait);
1442 struct sock *sk = sock->sk;
1443 int is_lite = IS_UDPLITE(sk);
1444
1445 /* Check for false positives due to checksum errors */
1446 if ( (mask & POLLRDNORM) &&
1447 !(file->f_flags & O_NONBLOCK) &&
1448 !(sk->sk_shutdown & RCV_SHUTDOWN)){
1449 struct sk_buff_head *rcvq = &sk->sk_receive_queue;
1450 struct sk_buff *skb;
1451
1452 spin_lock_bh(&rcvq->lock);
1453 while ((skb = skb_peek(rcvq)) != NULL &&
1454 udp_lib_checksum_complete(skb)) {
1455 UDP_INC_STATS_BH(sock_net(sk),
1456 UDP_MIB_INERRORS, is_lite);
1457 __skb_unlink(skb, rcvq);
1458 kfree_skb(skb);
1459 }
1460 spin_unlock_bh(&rcvq->lock);
1461
1462 /* nothing to see, move along */
1463 if (skb == NULL)
1464 mask &= ~(POLLIN | POLLRDNORM);
1465 }
1466
1467 return mask;
1468
1469 }
1470
1471 struct proto udp_prot = {
1472 .name = "UDP",
1473 .owner = THIS_MODULE,
1474 .close = udp_lib_close,
1475 .connect = ip4_datagram_connect,
1476 .disconnect = udp_disconnect,
1477 .ioctl = udp_ioctl,
1478 .destroy = udp_destroy_sock,
1479 .setsockopt = udp_setsockopt,
1480 .getsockopt = udp_getsockopt,
1481 .sendmsg = udp_sendmsg,
1482 .recvmsg = udp_recvmsg,
1483 .sendpage = udp_sendpage,
1484 .backlog_rcv = __udp_queue_rcv_skb,
1485 .hash = udp_lib_hash,
1486 .unhash = udp_lib_unhash,
1487 .get_port = udp_v4_get_port,
1488 .memory_allocated = &udp_memory_allocated,
1489 .sysctl_mem = sysctl_udp_mem,
1490 .sysctl_wmem = &sysctl_udp_wmem_min,
1491 .sysctl_rmem = &sysctl_udp_rmem_min,
1492 .obj_size = sizeof(struct udp_sock),
1493 .h.udp_hash = udp_hash,
1494 #ifdef CONFIG_COMPAT
1495 .compat_setsockopt = compat_udp_setsockopt,
1496 .compat_getsockopt = compat_udp_getsockopt,
1497 #endif
1498 };
1499
1500 /* ------------------------------------------------------------------------ */
1501 #ifdef CONFIG_PROC_FS
1502
1503 static struct sock *udp_get_first(struct seq_file *seq)
1504 {
1505 struct sock *sk;
1506 struct udp_iter_state *state = seq->private;
1507 struct net *net = seq_file_net(seq);
1508
1509 for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
1510 struct hlist_node *node;
1511 sk_for_each(sk, node, state->hashtable + state->bucket) {
1512 if (!net_eq(sock_net(sk), net))
1513 continue;
1514 if (sk->sk_family == state->family)
1515 goto found;
1516 }
1517 }
1518 sk = NULL;
1519 found:
1520 return sk;
1521 }
1522
1523 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
1524 {
1525 struct udp_iter_state *state = seq->private;
1526 struct net *net = seq_file_net(seq);
1527
1528 do {
1529 sk = sk_next(sk);
1530 try_again:
1531 ;
1532 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
1533
1534 if (!sk && ++state->bucket < UDP_HTABLE_SIZE) {
1535 sk = sk_head(state->hashtable + state->bucket);
1536 goto try_again;
1537 }
1538 return sk;
1539 }
1540
1541 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
1542 {
1543 struct sock *sk = udp_get_first(seq);
1544
1545 if (sk)
1546 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
1547 --pos;
1548 return pos ? NULL : sk;
1549 }
1550
1551 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
1552 __acquires(udp_hash_lock)
1553 {
1554 read_lock(&udp_hash_lock);
1555 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1556 }
1557
1558 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1559 {
1560 struct sock *sk;
1561
1562 if (v == SEQ_START_TOKEN)
1563 sk = udp_get_idx(seq, 0);
1564 else
1565 sk = udp_get_next(seq, v);
1566
1567 ++*pos;
1568 return sk;
1569 }
1570
1571 static void udp_seq_stop(struct seq_file *seq, void *v)
1572 __releases(udp_hash_lock)
1573 {
1574 read_unlock(&udp_hash_lock);
1575 }
1576
1577 static int udp_seq_open(struct inode *inode, struct file *file)
1578 {
1579 struct udp_seq_afinfo *afinfo = PDE(inode)->data;
1580 struct udp_iter_state *s;
1581 int err;
1582
1583 err = seq_open_net(inode, file, &afinfo->seq_ops,
1584 sizeof(struct udp_iter_state));
1585 if (err < 0)
1586 return err;
1587
1588 s = ((struct seq_file *)file->private_data)->private;
1589 s->family = afinfo->family;
1590 s->hashtable = afinfo->hashtable;
1591 return err;
1592 }
1593
1594 /* ------------------------------------------------------------------------ */
1595 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
1596 {
1597 struct proc_dir_entry *p;
1598 int rc = 0;
1599
1600 afinfo->seq_fops.open = udp_seq_open;
1601 afinfo->seq_fops.read = seq_read;
1602 afinfo->seq_fops.llseek = seq_lseek;
1603 afinfo->seq_fops.release = seq_release_net;
1604
1605 afinfo->seq_ops.start = udp_seq_start;
1606 afinfo->seq_ops.next = udp_seq_next;
1607 afinfo->seq_ops.stop = udp_seq_stop;
1608
1609 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1610 &afinfo->seq_fops, afinfo);
1611 if (!p)
1612 rc = -ENOMEM;
1613 return rc;
1614 }
1615
1616 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
1617 {
1618 proc_net_remove(net, afinfo->name);
1619 }
1620
1621 /* ------------------------------------------------------------------------ */
1622 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
1623 int bucket, int *len)
1624 {
1625 struct inet_sock *inet = inet_sk(sp);
1626 __be32 dest = inet->daddr;
1627 __be32 src = inet->rcv_saddr;
1628 __u16 destp = ntohs(inet->dport);
1629 __u16 srcp = ntohs(inet->sport);
1630
1631 seq_printf(f, "%4d: %08X:%04X %08X:%04X"
1632 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d%n",
1633 bucket, src, srcp, dest, destp, sp->sk_state,
1634 atomic_read(&sp->sk_wmem_alloc),
1635 atomic_read(&sp->sk_rmem_alloc),
1636 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
1637 atomic_read(&sp->sk_refcnt), sp,
1638 atomic_read(&sp->sk_drops), len);
1639 }
1640
1641 int udp4_seq_show(struct seq_file *seq, void *v)
1642 {
1643 if (v == SEQ_START_TOKEN)
1644 seq_printf(seq, "%-127s\n",
1645 " sl local_address rem_address st tx_queue "
1646 "rx_queue tr tm->when retrnsmt uid timeout "
1647 "inode ref pointer drops");
1648 else {
1649 struct udp_iter_state *state = seq->private;
1650 int len;
1651
1652 udp4_format_sock(v, seq, state->bucket, &len);
1653 seq_printf(seq, "%*s\n", 127 - len ,"");
1654 }
1655 return 0;
1656 }
1657
1658 /* ------------------------------------------------------------------------ */
1659 static struct udp_seq_afinfo udp4_seq_afinfo = {
1660 .name = "udp",
1661 .family = AF_INET,
1662 .hashtable = udp_hash,
1663 .seq_fops = {
1664 .owner = THIS_MODULE,
1665 },
1666 .seq_ops = {
1667 .show = udp4_seq_show,
1668 },
1669 };
1670
1671 static int udp4_proc_init_net(struct net *net)
1672 {
1673 return udp_proc_register(net, &udp4_seq_afinfo);
1674 }
1675
1676 static void udp4_proc_exit_net(struct net *net)
1677 {
1678 udp_proc_unregister(net, &udp4_seq_afinfo);
1679 }
1680
1681 static struct pernet_operations udp4_net_ops = {
1682 .init = udp4_proc_init_net,
1683 .exit = udp4_proc_exit_net,
1684 };
1685
1686 int __init udp4_proc_init(void)
1687 {
1688 return register_pernet_subsys(&udp4_net_ops);
1689 }
1690
1691 void udp4_proc_exit(void)
1692 {
1693 unregister_pernet_subsys(&udp4_net_ops);
1694 }
1695 #endif /* CONFIG_PROC_FS */
1696
1697 void __init udp_init(void)
1698 {
1699 unsigned long limit;
1700
1701 /* Set the pressure threshold up by the same strategy of TCP. It is a
1702 * fraction of global memory that is up to 1/2 at 256 MB, decreasing
1703 * toward zero with the amount of memory, with a floor of 128 pages.
1704 */
1705 limit = min(nr_all_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
1706 limit = (limit * (nr_all_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
1707 limit = max(limit, 128UL);
1708 sysctl_udp_mem[0] = limit / 4 * 3;
1709 sysctl_udp_mem[1] = limit;
1710 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
1711
1712 sysctl_udp_rmem_min = SK_MEM_QUANTUM;
1713 sysctl_udp_wmem_min = SK_MEM_QUANTUM;
1714 }
1715
1716 EXPORT_SYMBOL(udp_disconnect);
1717 EXPORT_SYMBOL(udp_hash);
1718 EXPORT_SYMBOL(udp_hash_lock);
1719 EXPORT_SYMBOL(udp_ioctl);
1720 EXPORT_SYMBOL(udp_prot);
1721 EXPORT_SYMBOL(udp_sendmsg);
1722 EXPORT_SYMBOL(udp_lib_getsockopt);
1723 EXPORT_SYMBOL(udp_lib_setsockopt);
1724 EXPORT_SYMBOL(udp_poll);
1725 EXPORT_SYMBOL(udp_lib_get_port);
1726
1727 #ifdef CONFIG_PROC_FS
1728 EXPORT_SYMBOL(udp_proc_register);
1729 EXPORT_SYMBOL(udp_proc_unregister);
1730 #endif
CRIS linux kernel tree