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udp: secondary hash on (local port, local address)
[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@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/highmem.h>
85 #include <linux/swap.h>
86 #include <linux/types.h>
87 #include <linux/fcntl.h>
88 #include <linux/module.h>
89 #include <linux/socket.h>
90 #include <linux/sockios.h>
91 #include <linux/igmp.h>
92 #include <linux/in.h>
93 #include <linux/errno.h>
94 #include <linux/timer.h>
95 #include <linux/mm.h>
96 #include <linux/inet.h>
97 #include <linux/netdevice.h>
98 #include <net/tcp_states.h>
99 #include <linux/skbuff.h>
100 #include <linux/proc_fs.h>
101 #include <linux/seq_file.h>
102 #include <net/net_namespace.h>
103 #include <net/icmp.h>
104 #include <net/route.h>
105 #include <net/checksum.h>
106 #include <net/xfrm.h>
107 #include "udp_impl.h"
108
109 struct udp_table udp_table __read_mostly;
110 EXPORT_SYMBOL(udp_table);
111
112 int sysctl_udp_mem[3] __read_mostly;
113 EXPORT_SYMBOL(sysctl_udp_mem);
114
115 int sysctl_udp_rmem_min __read_mostly;
116 EXPORT_SYMBOL(sysctl_udp_rmem_min);
117
118 int sysctl_udp_wmem_min __read_mostly;
119 EXPORT_SYMBOL(sysctl_udp_wmem_min);
120
121 atomic_t udp_memory_allocated;
122 EXPORT_SYMBOL(udp_memory_allocated);
123
124 #define MAX_UDP_PORTS 65536
125 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
126
127 static int udp_lib_lport_inuse(struct net *net, __u16 num,
128 const struct udp_hslot *hslot,
129 unsigned long *bitmap,
130 struct sock *sk,
131 int (*saddr_comp)(const struct sock *sk1,
132 const struct sock *sk2),
133 unsigned int log)
134 {
135 struct sock *sk2;
136 struct hlist_nulls_node *node;
137
138 sk_nulls_for_each(sk2, node, &hslot->head)
139 if (net_eq(sock_net(sk2), net) &&
140 sk2 != sk &&
141 (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
142 (!sk2->sk_reuse || !sk->sk_reuse) &&
143 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if
144 || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
145 (*saddr_comp)(sk, sk2)) {
146 if (bitmap)
147 __set_bit(udp_sk(sk2)->udp_port_hash >> log,
148 bitmap);
149 else
150 return 1;
151 }
152 return 0;
153 }
154
155 /**
156 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
157 *
158 * @sk: socket struct in question
159 * @snum: port number to look up
160 * @saddr_comp: AF-dependent comparison of bound local IP addresses
161 */
162 int udp_lib_get_port(struct sock *sk, unsigned short snum,
163 int (*saddr_comp)(const struct sock *sk1,
164 const struct sock *sk2))
165 {
166 struct udp_hslot *hslot, *hslot2;
167 struct udp_table *udptable = sk->sk_prot->h.udp_table;
168 int error = 1;
169 struct net *net = sock_net(sk);
170
171 if (!snum) {
172 int low, high, remaining;
173 unsigned rand;
174 unsigned short first, last;
175 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
176
177 inet_get_local_port_range(&low, &high);
178 remaining = (high - low) + 1;
179
180 rand = net_random();
181 first = (((u64)rand * remaining) >> 32) + low;
182 /*
183 * force rand to be an odd multiple of UDP_HTABLE_SIZE
184 */
185 rand = (rand | 1) * (udptable->mask + 1);
186 for (last = first + udptable->mask + 1;
187 first != last;
188 first++) {
189 hslot = udp_hashslot(udptable, net, first);
190 bitmap_zero(bitmap, PORTS_PER_CHAIN);
191 spin_lock_bh(&hslot->lock);
192 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
193 saddr_comp, udptable->log);
194
195 snum = first;
196 /*
197 * Iterate on all possible values of snum for this hash.
198 * Using steps of an odd multiple of UDP_HTABLE_SIZE
199 * give us randomization and full range coverage.
200 */
201 do {
202 if (low <= snum && snum <= high &&
203 !test_bit(snum >> udptable->log, bitmap))
204 goto found;
205 snum += rand;
206 } while (snum != first);
207 spin_unlock_bh(&hslot->lock);
208 }
209 goto fail;
210 } else {
211 hslot = udp_hashslot(udptable, net, snum);
212 spin_lock_bh(&hslot->lock);
213 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk,
214 saddr_comp, 0))
215 goto fail_unlock;
216 }
217 found:
218 inet_sk(sk)->inet_num = snum;
219 udp_sk(sk)->udp_port_hash = snum;
220 udp_sk(sk)->udp_portaddr_hash ^= snum;
221 if (sk_unhashed(sk)) {
222 sk_nulls_add_node_rcu(sk, &hslot->head);
223 hslot->count++;
224 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
225
226 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
227 spin_lock(&hslot2->lock);
228 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
229 &hslot2->head);
230 hslot2->count++;
231 spin_unlock(&hslot2->lock);
232 }
233 error = 0;
234 fail_unlock:
235 spin_unlock_bh(&hslot->lock);
236 fail:
237 return error;
238 }
239 EXPORT_SYMBOL(udp_lib_get_port);
240
241 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
242 {
243 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
244
245 return (!ipv6_only_sock(sk2) &&
246 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr ||
247 inet1->inet_rcv_saddr == inet2->inet_rcv_saddr));
248 }
249
250 static unsigned int udp4_portaddr_hash(struct net *net, __be32 saddr,
251 unsigned int port)
252 {
253 return jhash_1word(saddr, net_hash_mix(net)) ^ port;
254 }
255
256 int udp_v4_get_port(struct sock *sk, unsigned short snum)
257 {
258 /* precompute partial secondary hash */
259 udp_sk(sk)->udp_portaddr_hash =
260 udp4_portaddr_hash(sock_net(sk),
261 inet_sk(sk)->inet_rcv_saddr,
262 0);
263 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal);
264 }
265
266 static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr,
267 unsigned short hnum,
268 __be16 sport, __be32 daddr, __be16 dport, int dif)
269 {
270 int score = -1;
271
272 if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
273 !ipv6_only_sock(sk)) {
274 struct inet_sock *inet = inet_sk(sk);
275
276 score = (sk->sk_family == PF_INET ? 1 : 0);
277 if (inet->inet_rcv_saddr) {
278 if (inet->inet_rcv_saddr != daddr)
279 return -1;
280 score += 2;
281 }
282 if (inet->inet_daddr) {
283 if (inet->inet_daddr != saddr)
284 return -1;
285 score += 2;
286 }
287 if (inet->inet_dport) {
288 if (inet->inet_dport != sport)
289 return -1;
290 score += 2;
291 }
292 if (sk->sk_bound_dev_if) {
293 if (sk->sk_bound_dev_if != dif)
294 return -1;
295 score += 2;
296 }
297 }
298 return score;
299 }
300
301 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
302 * harder than this. -DaveM
303 */
304 static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
305 __be16 sport, __be32 daddr, __be16 dport,
306 int dif, struct udp_table *udptable)
307 {
308 struct sock *sk, *result;
309 struct hlist_nulls_node *node;
310 unsigned short hnum = ntohs(dport);
311 unsigned int hash = udp_hashfn(net, hnum, udptable->mask);
312 struct udp_hslot *hslot = &udptable->hash[hash];
313 int score, badness;
314
315 rcu_read_lock();
316 begin:
317 result = NULL;
318 badness = -1;
319 sk_nulls_for_each_rcu(sk, node, &hslot->head) {
320 score = compute_score(sk, net, saddr, hnum, sport,
321 daddr, dport, dif);
322 if (score > badness) {
323 result = sk;
324 badness = score;
325 }
326 }
327 /*
328 * if the nulls value we got at the end of this lookup is
329 * not the expected one, we must restart lookup.
330 * We probably met an item that was moved to another chain.
331 */
332 if (get_nulls_value(node) != hash)
333 goto begin;
334
335 if (result) {
336 if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
337 result = NULL;
338 else if (unlikely(compute_score(result, net, saddr, hnum, sport,
339 daddr, dport, dif) < badness)) {
340 sock_put(result);
341 goto begin;
342 }
343 }
344 rcu_read_unlock();
345 return result;
346 }
347
348 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
349 __be16 sport, __be16 dport,
350 struct udp_table *udptable)
351 {
352 struct sock *sk;
353 const struct iphdr *iph = ip_hdr(skb);
354
355 if (unlikely(sk = skb_steal_sock(skb)))
356 return sk;
357 else
358 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport,
359 iph->daddr, dport, inet_iif(skb),
360 udptable);
361 }
362
363 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
364 __be32 daddr, __be16 dport, int dif)
365 {
366 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
367 }
368 EXPORT_SYMBOL_GPL(udp4_lib_lookup);
369
370 static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
371 __be16 loc_port, __be32 loc_addr,
372 __be16 rmt_port, __be32 rmt_addr,
373 int dif)
374 {
375 struct hlist_nulls_node *node;
376 struct sock *s = sk;
377 unsigned short hnum = ntohs(loc_port);
378
379 sk_nulls_for_each_from(s, node) {
380 struct inet_sock *inet = inet_sk(s);
381
382 if (!net_eq(sock_net(s), net) ||
383 udp_sk(s)->udp_port_hash != hnum ||
384 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
385 (inet->inet_dport != rmt_port && inet->inet_dport) ||
386 (inet->inet_rcv_saddr &&
387 inet->inet_rcv_saddr != loc_addr) ||
388 ipv6_only_sock(s) ||
389 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
390 continue;
391 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
392 continue;
393 goto found;
394 }
395 s = NULL;
396 found:
397 return s;
398 }
399
400 /*
401 * This routine is called by the ICMP module when it gets some
402 * sort of error condition. If err < 0 then the socket should
403 * be closed and the error returned to the user. If err > 0
404 * it's just the icmp type << 8 | icmp code.
405 * Header points to the ip header of the error packet. We move
406 * on past this. Then (as it used to claim before adjustment)
407 * header points to the first 8 bytes of the udp header. We need
408 * to find the appropriate port.
409 */
410
411 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
412 {
413 struct inet_sock *inet;
414 struct iphdr *iph = (struct iphdr *)skb->data;
415 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
416 const int type = icmp_hdr(skb)->type;
417 const int code = icmp_hdr(skb)->code;
418 struct sock *sk;
419 int harderr;
420 int err;
421 struct net *net = dev_net(skb->dev);
422
423 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
424 iph->saddr, uh->source, skb->dev->ifindex, udptable);
425 if (sk == NULL) {
426 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
427 return; /* No socket for error */
428 }
429
430 err = 0;
431 harderr = 0;
432 inet = inet_sk(sk);
433
434 switch (type) {
435 default:
436 case ICMP_TIME_EXCEEDED:
437 err = EHOSTUNREACH;
438 break;
439 case ICMP_SOURCE_QUENCH:
440 goto out;
441 case ICMP_PARAMETERPROB:
442 err = EPROTO;
443 harderr = 1;
444 break;
445 case ICMP_DEST_UNREACH:
446 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
447 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
448 err = EMSGSIZE;
449 harderr = 1;
450 break;
451 }
452 goto out;
453 }
454 err = EHOSTUNREACH;
455 if (code <= NR_ICMP_UNREACH) {
456 harderr = icmp_err_convert[code].fatal;
457 err = icmp_err_convert[code].errno;
458 }
459 break;
460 }
461
462 /*
463 * RFC1122: OK. Passes ICMP errors back to application, as per
464 * 4.1.3.3.
465 */
466 if (!inet->recverr) {
467 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
468 goto out;
469 } else {
470 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
471 }
472 sk->sk_err = err;
473 sk->sk_error_report(sk);
474 out:
475 sock_put(sk);
476 }
477
478 void udp_err(struct sk_buff *skb, u32 info)
479 {
480 __udp4_lib_err(skb, info, &udp_table);
481 }
482
483 /*
484 * Throw away all pending data and cancel the corking. Socket is locked.
485 */
486 void udp_flush_pending_frames(struct sock *sk)
487 {
488 struct udp_sock *up = udp_sk(sk);
489
490 if (up->pending) {
491 up->len = 0;
492 up->pending = 0;
493 ip_flush_pending_frames(sk);
494 }
495 }
496 EXPORT_SYMBOL(udp_flush_pending_frames);
497
498 /**
499 * udp4_hwcsum_outgoing - handle outgoing HW checksumming
500 * @sk: socket we are sending on
501 * @skb: sk_buff containing the filled-in UDP header
502 * (checksum field must be zeroed out)
503 */
504 static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
505 __be32 src, __be32 dst, int len)
506 {
507 unsigned int offset;
508 struct udphdr *uh = udp_hdr(skb);
509 __wsum csum = 0;
510
511 if (skb_queue_len(&sk->sk_write_queue) == 1) {
512 /*
513 * Only one fragment on the socket.
514 */
515 skb->csum_start = skb_transport_header(skb) - skb->head;
516 skb->csum_offset = offsetof(struct udphdr, check);
517 uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0);
518 } else {
519 /*
520 * HW-checksum won't work as there are two or more
521 * fragments on the socket so that all csums of sk_buffs
522 * should be together
523 */
524 offset = skb_transport_offset(skb);
525 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
526
527 skb->ip_summed = CHECKSUM_NONE;
528
529 skb_queue_walk(&sk->sk_write_queue, skb) {
530 csum = csum_add(csum, skb->csum);
531 }
532
533 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
534 if (uh->check == 0)
535 uh->check = CSUM_MANGLED_0;
536 }
537 }
538
539 /*
540 * Push out all pending data as one UDP datagram. Socket is locked.
541 */
542 static int udp_push_pending_frames(struct sock *sk)
543 {
544 struct udp_sock *up = udp_sk(sk);
545 struct inet_sock *inet = inet_sk(sk);
546 struct flowi *fl = &inet->cork.fl;
547 struct sk_buff *skb;
548 struct udphdr *uh;
549 int err = 0;
550 int is_udplite = IS_UDPLITE(sk);
551 __wsum csum = 0;
552
553 /* Grab the skbuff where UDP header space exists. */
554 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
555 goto out;
556
557 /*
558 * Create a UDP header
559 */
560 uh = udp_hdr(skb);
561 uh->source = fl->fl_ip_sport;
562 uh->dest = fl->fl_ip_dport;
563 uh->len = htons(up->len);
564 uh->check = 0;
565
566 if (is_udplite) /* UDP-Lite */
567 csum = udplite_csum_outgoing(sk, skb);
568
569 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */
570
571 skb->ip_summed = CHECKSUM_NONE;
572 goto send;
573
574 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
575
576 udp4_hwcsum_outgoing(sk, skb, fl->fl4_src, fl->fl4_dst, up->len);
577 goto send;
578
579 } else /* `normal' UDP */
580 csum = udp_csum_outgoing(sk, skb);
581
582 /* add protocol-dependent pseudo-header */
583 uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len,
584 sk->sk_protocol, csum);
585 if (uh->check == 0)
586 uh->check = CSUM_MANGLED_0;
587
588 send:
589 err = ip_push_pending_frames(sk);
590 if (err) {
591 if (err == -ENOBUFS && !inet->recverr) {
592 UDP_INC_STATS_USER(sock_net(sk),
593 UDP_MIB_SNDBUFERRORS, is_udplite);
594 err = 0;
595 }
596 } else
597 UDP_INC_STATS_USER(sock_net(sk),
598 UDP_MIB_OUTDATAGRAMS, is_udplite);
599 out:
600 up->len = 0;
601 up->pending = 0;
602 return err;
603 }
604
605 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
606 size_t len)
607 {
608 struct inet_sock *inet = inet_sk(sk);
609 struct udp_sock *up = udp_sk(sk);
610 int ulen = len;
611 struct ipcm_cookie ipc;
612 struct rtable *rt = NULL;
613 int free = 0;
614 int connected = 0;
615 __be32 daddr, faddr, saddr;
616 __be16 dport;
617 u8 tos;
618 int err, is_udplite = IS_UDPLITE(sk);
619 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
620 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
621
622 if (len > 0xFFFF)
623 return -EMSGSIZE;
624
625 /*
626 * Check the flags.
627 */
628
629 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
630 return -EOPNOTSUPP;
631
632 ipc.opt = NULL;
633 ipc.shtx.flags = 0;
634
635 if (up->pending) {
636 /*
637 * There are pending frames.
638 * The socket lock must be held while it's corked.
639 */
640 lock_sock(sk);
641 if (likely(up->pending)) {
642 if (unlikely(up->pending != AF_INET)) {
643 release_sock(sk);
644 return -EINVAL;
645 }
646 goto do_append_data;
647 }
648 release_sock(sk);
649 }
650 ulen += sizeof(struct udphdr);
651
652 /*
653 * Get and verify the address.
654 */
655 if (msg->msg_name) {
656 struct sockaddr_in * usin = (struct sockaddr_in *)msg->msg_name;
657 if (msg->msg_namelen < sizeof(*usin))
658 return -EINVAL;
659 if (usin->sin_family != AF_INET) {
660 if (usin->sin_family != AF_UNSPEC)
661 return -EAFNOSUPPORT;
662 }
663
664 daddr = usin->sin_addr.s_addr;
665 dport = usin->sin_port;
666 if (dport == 0)
667 return -EINVAL;
668 } else {
669 if (sk->sk_state != TCP_ESTABLISHED)
670 return -EDESTADDRREQ;
671 daddr = inet->inet_daddr;
672 dport = inet->inet_dport;
673 /* Open fast path for connected socket.
674 Route will not be used, if at least one option is set.
675 */
676 connected = 1;
677 }
678 ipc.addr = inet->inet_saddr;
679
680 ipc.oif = sk->sk_bound_dev_if;
681 err = sock_tx_timestamp(msg, sk, &ipc.shtx);
682 if (err)
683 return err;
684 if (msg->msg_controllen) {
685 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
686 if (err)
687 return err;
688 if (ipc.opt)
689 free = 1;
690 connected = 0;
691 }
692 if (!ipc.opt)
693 ipc.opt = inet->opt;
694
695 saddr = ipc.addr;
696 ipc.addr = faddr = daddr;
697
698 if (ipc.opt && ipc.opt->srr) {
699 if (!daddr)
700 return -EINVAL;
701 faddr = ipc.opt->faddr;
702 connected = 0;
703 }
704 tos = RT_TOS(inet->tos);
705 if (sock_flag(sk, SOCK_LOCALROUTE) ||
706 (msg->msg_flags & MSG_DONTROUTE) ||
707 (ipc.opt && ipc.opt->is_strictroute)) {
708 tos |= RTO_ONLINK;
709 connected = 0;
710 }
711
712 if (ipv4_is_multicast(daddr)) {
713 if (!ipc.oif)
714 ipc.oif = inet->mc_index;
715 if (!saddr)
716 saddr = inet->mc_addr;
717 connected = 0;
718 }
719
720 if (connected)
721 rt = (struct rtable *)sk_dst_check(sk, 0);
722
723 if (rt == NULL) {
724 struct flowi fl = { .oif = ipc.oif,
725 .mark = sk->sk_mark,
726 .nl_u = { .ip4_u =
727 { .daddr = faddr,
728 .saddr = saddr,
729 .tos = tos } },
730 .proto = sk->sk_protocol,
731 .flags = inet_sk_flowi_flags(sk),
732 .uli_u = { .ports =
733 { .sport = inet->inet_sport,
734 .dport = dport } } };
735 struct net *net = sock_net(sk);
736
737 security_sk_classify_flow(sk, &fl);
738 err = ip_route_output_flow(net, &rt, &fl, sk, 1);
739 if (err) {
740 if (err == -ENETUNREACH)
741 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
742 goto out;
743 }
744
745 err = -EACCES;
746 if ((rt->rt_flags & RTCF_BROADCAST) &&
747 !sock_flag(sk, SOCK_BROADCAST))
748 goto out;
749 if (connected)
750 sk_dst_set(sk, dst_clone(&rt->u.dst));
751 }
752
753 if (msg->msg_flags&MSG_CONFIRM)
754 goto do_confirm;
755 back_from_confirm:
756
757 saddr = rt->rt_src;
758 if (!ipc.addr)
759 daddr = ipc.addr = rt->rt_dst;
760
761 lock_sock(sk);
762 if (unlikely(up->pending)) {
763 /* The socket is already corked while preparing it. */
764 /* ... which is an evident application bug. --ANK */
765 release_sock(sk);
766
767 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
768 err = -EINVAL;
769 goto out;
770 }
771 /*
772 * Now cork the socket to pend data.
773 */
774 inet->cork.fl.fl4_dst = daddr;
775 inet->cork.fl.fl_ip_dport = dport;
776 inet->cork.fl.fl4_src = saddr;
777 inet->cork.fl.fl_ip_sport = inet->inet_sport;
778 up->pending = AF_INET;
779
780 do_append_data:
781 up->len += ulen;
782 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
783 err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
784 sizeof(struct udphdr), &ipc, &rt,
785 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
786 if (err)
787 udp_flush_pending_frames(sk);
788 else if (!corkreq)
789 err = udp_push_pending_frames(sk);
790 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
791 up->pending = 0;
792 release_sock(sk);
793
794 out:
795 ip_rt_put(rt);
796 if (free)
797 kfree(ipc.opt);
798 if (!err)
799 return len;
800 /*
801 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
802 * ENOBUFS might not be good (it's not tunable per se), but otherwise
803 * we don't have a good statistic (IpOutDiscards but it can be too many
804 * things). We could add another new stat but at least for now that
805 * seems like overkill.
806 */
807 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
808 UDP_INC_STATS_USER(sock_net(sk),
809 UDP_MIB_SNDBUFERRORS, is_udplite);
810 }
811 return err;
812
813 do_confirm:
814 dst_confirm(&rt->u.dst);
815 if (!(msg->msg_flags&MSG_PROBE) || len)
816 goto back_from_confirm;
817 err = 0;
818 goto out;
819 }
820 EXPORT_SYMBOL(udp_sendmsg);
821
822 int udp_sendpage(struct sock *sk, struct page *page, int offset,
823 size_t size, int flags)
824 {
825 struct udp_sock *up = udp_sk(sk);
826 int ret;
827
828 if (!up->pending) {
829 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
830
831 /* Call udp_sendmsg to specify destination address which
832 * sendpage interface can't pass.
833 * This will succeed only when the socket is connected.
834 */
835 ret = udp_sendmsg(NULL, sk, &msg, 0);
836 if (ret < 0)
837 return ret;
838 }
839
840 lock_sock(sk);
841
842 if (unlikely(!up->pending)) {
843 release_sock(sk);
844
845 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n");
846 return -EINVAL;
847 }
848
849 ret = ip_append_page(sk, page, offset, size, flags);
850 if (ret == -EOPNOTSUPP) {
851 release_sock(sk);
852 return sock_no_sendpage(sk->sk_socket, page, offset,
853 size, flags);
854 }
855 if (ret < 0) {
856 udp_flush_pending_frames(sk);
857 goto out;
858 }
859
860 up->len += size;
861 if (!(up->corkflag || (flags&MSG_MORE)))
862 ret = udp_push_pending_frames(sk);
863 if (!ret)
864 ret = size;
865 out:
866 release_sock(sk);
867 return ret;
868 }
869
870
871 /**
872 * first_packet_length - return length of first packet in receive queue
873 * @sk: socket
874 *
875 * Drops all bad checksum frames, until a valid one is found.
876 * Returns the length of found skb, or 0 if none is found.
877 */
878 static unsigned int first_packet_length(struct sock *sk)
879 {
880 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue;
881 struct sk_buff *skb;
882 unsigned int res;
883
884 __skb_queue_head_init(&list_kill);
885
886 spin_lock_bh(&rcvq->lock);
887 while ((skb = skb_peek(rcvq)) != NULL &&
888 udp_lib_checksum_complete(skb)) {
889 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
890 IS_UDPLITE(sk));
891 atomic_inc(&sk->sk_drops);
892 __skb_unlink(skb, rcvq);
893 __skb_queue_tail(&list_kill, skb);
894 }
895 res = skb ? skb->len : 0;
896 spin_unlock_bh(&rcvq->lock);
897
898 if (!skb_queue_empty(&list_kill)) {
899 lock_sock(sk);
900 __skb_queue_purge(&list_kill);
901 sk_mem_reclaim_partial(sk);
902 release_sock(sk);
903 }
904 return res;
905 }
906
907 /*
908 * IOCTL requests applicable to the UDP protocol
909 */
910
911 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
912 {
913 switch (cmd) {
914 case SIOCOUTQ:
915 {
916 int amount = sk_wmem_alloc_get(sk);
917
918 return put_user(amount, (int __user *)arg);
919 }
920
921 case SIOCINQ:
922 {
923 unsigned int amount = first_packet_length(sk);
924
925 if (amount)
926 /*
927 * We will only return the amount
928 * of this packet since that is all
929 * that will be read.
930 */
931 amount -= sizeof(struct udphdr);
932
933 return put_user(amount, (int __user *)arg);
934 }
935
936 default:
937 return -ENOIOCTLCMD;
938 }
939
940 return 0;
941 }
942 EXPORT_SYMBOL(udp_ioctl);
943
944 /*
945 * This should be easy, if there is something there we
946 * return it, otherwise we block.
947 */
948
949 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
950 size_t len, int noblock, int flags, int *addr_len)
951 {
952 struct inet_sock *inet = inet_sk(sk);
953 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
954 struct sk_buff *skb;
955 unsigned int ulen, copied;
956 int peeked;
957 int err;
958 int is_udplite = IS_UDPLITE(sk);
959
960 /*
961 * Check any passed addresses
962 */
963 if (addr_len)
964 *addr_len = sizeof(*sin);
965
966 if (flags & MSG_ERRQUEUE)
967 return ip_recv_error(sk, msg, len);
968
969 try_again:
970 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
971 &peeked, &err);
972 if (!skb)
973 goto out;
974
975 ulen = skb->len - sizeof(struct udphdr);
976 copied = len;
977 if (copied > ulen)
978 copied = ulen;
979 else if (copied < ulen)
980 msg->msg_flags |= MSG_TRUNC;
981
982 /*
983 * If checksum is needed at all, try to do it while copying the
984 * data. If the data is truncated, or if we only want a partial
985 * coverage checksum (UDP-Lite), do it before the copy.
986 */
987
988 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
989 if (udp_lib_checksum_complete(skb))
990 goto csum_copy_err;
991 }
992
993 if (skb_csum_unnecessary(skb))
994 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
995 msg->msg_iov, copied);
996 else {
997 err = skb_copy_and_csum_datagram_iovec(skb,
998 sizeof(struct udphdr),
999 msg->msg_iov);
1000
1001 if (err == -EINVAL)
1002 goto csum_copy_err;
1003 }
1004
1005 if (err)
1006 goto out_free;
1007
1008 if (!peeked)
1009 UDP_INC_STATS_USER(sock_net(sk),
1010 UDP_MIB_INDATAGRAMS, is_udplite);
1011
1012 sock_recv_ts_and_drops(msg, sk, skb);
1013
1014 /* Copy the address. */
1015 if (sin) {
1016 sin->sin_family = AF_INET;
1017 sin->sin_port = udp_hdr(skb)->source;
1018 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1019 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1020 }
1021 if (inet->cmsg_flags)
1022 ip_cmsg_recv(msg, skb);
1023
1024 err = copied;
1025 if (flags & MSG_TRUNC)
1026 err = ulen;
1027
1028 out_free:
1029 skb_free_datagram_locked(sk, skb);
1030 out:
1031 return err;
1032
1033 csum_copy_err:
1034 lock_sock(sk);
1035 if (!skb_kill_datagram(sk, skb, flags))
1036 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1037 release_sock(sk);
1038
1039 if (noblock)
1040 return -EAGAIN;
1041 goto try_again;
1042 }
1043
1044
1045 int udp_disconnect(struct sock *sk, int flags)
1046 {
1047 struct inet_sock *inet = inet_sk(sk);
1048 /*
1049 * 1003.1g - break association.
1050 */
1051
1052 sk->sk_state = TCP_CLOSE;
1053 inet->inet_daddr = 0;
1054 inet->inet_dport = 0;
1055 sk->sk_bound_dev_if = 0;
1056 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1057 inet_reset_saddr(sk);
1058
1059 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1060 sk->sk_prot->unhash(sk);
1061 inet->inet_sport = 0;
1062 }
1063 sk_dst_reset(sk);
1064 return 0;
1065 }
1066 EXPORT_SYMBOL(udp_disconnect);
1067
1068 void udp_lib_unhash(struct sock *sk)
1069 {
1070 if (sk_hashed(sk)) {
1071 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1072 struct udp_hslot *hslot, *hslot2;
1073
1074 hslot = udp_hashslot(udptable, sock_net(sk),
1075 udp_sk(sk)->udp_port_hash);
1076 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1077
1078 spin_lock_bh(&hslot->lock);
1079 if (sk_nulls_del_node_init_rcu(sk)) {
1080 hslot->count--;
1081 inet_sk(sk)->inet_num = 0;
1082 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1083
1084 spin_lock(&hslot2->lock);
1085 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1086 hslot2->count--;
1087 spin_unlock(&hslot2->lock);
1088 }
1089 spin_unlock_bh(&hslot->lock);
1090 }
1091 }
1092 EXPORT_SYMBOL(udp_lib_unhash);
1093
1094 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1095 {
1096 int rc = sock_queue_rcv_skb(sk, skb);
1097
1098 if (rc < 0) {
1099 int is_udplite = IS_UDPLITE(sk);
1100
1101 /* Note that an ENOMEM error is charged twice */
1102 if (rc == -ENOMEM)
1103 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1104 is_udplite);
1105 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1106 kfree_skb(skb);
1107 return -1;
1108 }
1109
1110 return 0;
1111
1112 }
1113
1114 /* returns:
1115 * -1: error
1116 * 0: success
1117 * >0: "udp encap" protocol resubmission
1118 *
1119 * Note that in the success and error cases, the skb is assumed to
1120 * have either been requeued or freed.
1121 */
1122 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1123 {
1124 struct udp_sock *up = udp_sk(sk);
1125 int rc;
1126 int is_udplite = IS_UDPLITE(sk);
1127
1128 /*
1129 * Charge it to the socket, dropping if the queue is full.
1130 */
1131 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1132 goto drop;
1133 nf_reset(skb);
1134
1135 if (up->encap_type) {
1136 /*
1137 * This is an encapsulation socket so pass the skb to
1138 * the socket's udp_encap_rcv() hook. Otherwise, just
1139 * fall through and pass this up the UDP socket.
1140 * up->encap_rcv() returns the following value:
1141 * =0 if skb was successfully passed to the encap
1142 * handler or was discarded by it.
1143 * >0 if skb should be passed on to UDP.
1144 * <0 if skb should be resubmitted as proto -N
1145 */
1146
1147 /* if we're overly short, let UDP handle it */
1148 if (skb->len > sizeof(struct udphdr) &&
1149 up->encap_rcv != NULL) {
1150 int ret;
1151
1152 ret = (*up->encap_rcv)(sk, skb);
1153 if (ret <= 0) {
1154 UDP_INC_STATS_BH(sock_net(sk),
1155 UDP_MIB_INDATAGRAMS,
1156 is_udplite);
1157 return -ret;
1158 }
1159 }
1160
1161 /* FALLTHROUGH -- it's a UDP Packet */
1162 }
1163
1164 /*
1165 * UDP-Lite specific tests, ignored on UDP sockets
1166 */
1167 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1168
1169 /*
1170 * MIB statistics other than incrementing the error count are
1171 * disabled for the following two types of errors: these depend
1172 * on the application settings, not on the functioning of the
1173 * protocol stack as such.
1174 *
1175 * RFC 3828 here recommends (sec 3.3): "There should also be a
1176 * way ... to ... at least let the receiving application block
1177 * delivery of packets with coverage values less than a value
1178 * provided by the application."
1179 */
1180 if (up->pcrlen == 0) { /* full coverage was set */
1181 LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage "
1182 "%d while full coverage %d requested\n",
1183 UDP_SKB_CB(skb)->cscov, skb->len);
1184 goto drop;
1185 }
1186 /* The next case involves violating the min. coverage requested
1187 * by the receiver. This is subtle: if receiver wants x and x is
1188 * greater than the buffersize/MTU then receiver will complain
1189 * that it wants x while sender emits packets of smaller size y.
1190 * Therefore the above ...()->partial_cov statement is essential.
1191 */
1192 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1193 LIMIT_NETDEBUG(KERN_WARNING
1194 "UDPLITE: coverage %d too small, need min %d\n",
1195 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1196 goto drop;
1197 }
1198 }
1199
1200 if (sk->sk_filter) {
1201 if (udp_lib_checksum_complete(skb))
1202 goto drop;
1203 }
1204
1205 rc = 0;
1206
1207 bh_lock_sock(sk);
1208 if (!sock_owned_by_user(sk))
1209 rc = __udp_queue_rcv_skb(sk, skb);
1210 else
1211 sk_add_backlog(sk, skb);
1212 bh_unlock_sock(sk);
1213
1214 return rc;
1215
1216 drop:
1217 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1218 atomic_inc(&sk->sk_drops);
1219 kfree_skb(skb);
1220 return -1;
1221 }
1222
1223 /*
1224 * Multicasts and broadcasts go to each listener.
1225 *
1226 * Note: called only from the BH handler context,
1227 * so we don't need to lock the hashes.
1228 */
1229 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1230 struct udphdr *uh,
1231 __be32 saddr, __be32 daddr,
1232 struct udp_table *udptable)
1233 {
1234 struct sock *sk;
1235 struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
1236 int dif;
1237
1238 spin_lock(&hslot->lock);
1239 sk = sk_nulls_head(&hslot->head);
1240 dif = skb->dev->ifindex;
1241 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
1242 if (sk) {
1243 struct sock *sknext = NULL;
1244
1245 do {
1246 struct sk_buff *skb1 = skb;
1247
1248 sknext = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest,
1249 daddr, uh->source, saddr,
1250 dif);
1251 if (sknext)
1252 skb1 = skb_clone(skb, GFP_ATOMIC);
1253
1254 if (skb1) {
1255 int ret = udp_queue_rcv_skb(sk, skb1);
1256 if (ret > 0)
1257 /* we should probably re-process instead
1258 * of dropping packets here. */
1259 kfree_skb(skb1);
1260 }
1261 sk = sknext;
1262 } while (sknext);
1263 } else
1264 consume_skb(skb);
1265 spin_unlock(&hslot->lock);
1266 return 0;
1267 }
1268
1269 /* Initialize UDP checksum. If exited with zero value (success),
1270 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1271 * Otherwise, csum completion requires chacksumming packet body,
1272 * including udp header and folding it to skb->csum.
1273 */
1274 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
1275 int proto)
1276 {
1277 const struct iphdr *iph;
1278 int err;
1279
1280 UDP_SKB_CB(skb)->partial_cov = 0;
1281 UDP_SKB_CB(skb)->cscov = skb->len;
1282
1283 if (proto == IPPROTO_UDPLITE) {
1284 err = udplite_checksum_init(skb, uh);
1285 if (err)
1286 return err;
1287 }
1288
1289 iph = ip_hdr(skb);
1290 if (uh->check == 0) {
1291 skb->ip_summed = CHECKSUM_UNNECESSARY;
1292 } else if (skb->ip_summed == CHECKSUM_COMPLETE) {
1293 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1294 proto, skb->csum))
1295 skb->ip_summed = CHECKSUM_UNNECESSARY;
1296 }
1297 if (!skb_csum_unnecessary(skb))
1298 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
1299 skb->len, proto, 0);
1300 /* Probably, we should checksum udp header (it should be in cache
1301 * in any case) and data in tiny packets (< rx copybreak).
1302 */
1303
1304 return 0;
1305 }
1306
1307 /*
1308 * All we need to do is get the socket, and then do a checksum.
1309 */
1310
1311 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1312 int proto)
1313 {
1314 struct sock *sk;
1315 struct udphdr *uh;
1316 unsigned short ulen;
1317 struct rtable *rt = skb_rtable(skb);
1318 __be32 saddr, daddr;
1319 struct net *net = dev_net(skb->dev);
1320
1321 /*
1322 * Validate the packet.
1323 */
1324 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1325 goto drop; /* No space for header. */
1326
1327 uh = udp_hdr(skb);
1328 ulen = ntohs(uh->len);
1329 if (ulen > skb->len)
1330 goto short_packet;
1331
1332 if (proto == IPPROTO_UDP) {
1333 /* UDP validates ulen. */
1334 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
1335 goto short_packet;
1336 uh = udp_hdr(skb);
1337 }
1338
1339 if (udp4_csum_init(skb, uh, proto))
1340 goto csum_error;
1341
1342 saddr = ip_hdr(skb)->saddr;
1343 daddr = ip_hdr(skb)->daddr;
1344
1345 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1346 return __udp4_lib_mcast_deliver(net, skb, uh,
1347 saddr, daddr, udptable);
1348
1349 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1350
1351 if (sk != NULL) {
1352 int ret = udp_queue_rcv_skb(sk, skb);
1353 sock_put(sk);
1354
1355 /* a return value > 0 means to resubmit the input, but
1356 * it wants the return to be -protocol, or 0
1357 */
1358 if (ret > 0)
1359 return -ret;
1360 return 0;
1361 }
1362
1363 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1364 goto drop;
1365 nf_reset(skb);
1366
1367 /* No socket. Drop packet silently, if checksum is wrong */
1368 if (udp_lib_checksum_complete(skb))
1369 goto csum_error;
1370
1371 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1372 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
1373
1374 /*
1375 * Hmm. We got an UDP packet to a port to which we
1376 * don't wanna listen. Ignore it.
1377 */
1378 kfree_skb(skb);
1379 return 0;
1380
1381 short_packet:
1382 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1383 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1384 &saddr,
1385 ntohs(uh->source),
1386 ulen,
1387 skb->len,
1388 &daddr,
1389 ntohs(uh->dest));
1390 goto drop;
1391
1392 csum_error:
1393 /*
1394 * RFC1122: OK. Discards the bad packet silently (as far as
1395 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1396 */
1397 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1398 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1399 &saddr,
1400 ntohs(uh->source),
1401 &daddr,
1402 ntohs(uh->dest),
1403 ulen);
1404 drop:
1405 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1406 kfree_skb(skb);
1407 return 0;
1408 }
1409
1410 int udp_rcv(struct sk_buff *skb)
1411 {
1412 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1413 }
1414
1415 void udp_destroy_sock(struct sock *sk)
1416 {
1417 lock_sock(sk);
1418 udp_flush_pending_frames(sk);
1419 release_sock(sk);
1420 }
1421
1422 /*
1423 * Socket option code for UDP
1424 */
1425 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1426 char __user *optval, unsigned int optlen,
1427 int (*push_pending_frames)(struct sock *))
1428 {
1429 struct udp_sock *up = udp_sk(sk);
1430 int val;
1431 int err = 0;
1432 int is_udplite = IS_UDPLITE(sk);
1433
1434 if (optlen < sizeof(int))
1435 return -EINVAL;
1436
1437 if (get_user(val, (int __user *)optval))
1438 return -EFAULT;
1439
1440 switch (optname) {
1441 case UDP_CORK:
1442 if (val != 0) {
1443 up->corkflag = 1;
1444 } else {
1445 up->corkflag = 0;
1446 lock_sock(sk);
1447 (*push_pending_frames)(sk);
1448 release_sock(sk);
1449 }
1450 break;
1451
1452 case UDP_ENCAP:
1453 switch (val) {
1454 case 0:
1455 case UDP_ENCAP_ESPINUDP:
1456 case UDP_ENCAP_ESPINUDP_NON_IKE:
1457 up->encap_rcv = xfrm4_udp_encap_rcv;
1458 /* FALLTHROUGH */
1459 case UDP_ENCAP_L2TPINUDP:
1460 up->encap_type = val;
1461 break;
1462 default:
1463 err = -ENOPROTOOPT;
1464 break;
1465 }
1466 break;
1467
1468 /*
1469 * UDP-Lite's partial checksum coverage (RFC 3828).
1470 */
1471 /* The sender sets actual checksum coverage length via this option.
1472 * The case coverage > packet length is handled by send module. */
1473 case UDPLITE_SEND_CSCOV:
1474 if (!is_udplite) /* Disable the option on UDP sockets */
1475 return -ENOPROTOOPT;
1476 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
1477 val = 8;
1478 else if (val > USHORT_MAX)
1479 val = USHORT_MAX;
1480 up->pcslen = val;
1481 up->pcflag |= UDPLITE_SEND_CC;
1482 break;
1483
1484 /* The receiver specifies a minimum checksum coverage value. To make
1485 * sense, this should be set to at least 8 (as done below). If zero is
1486 * used, this again means full checksum coverage. */
1487 case UDPLITE_RECV_CSCOV:
1488 if (!is_udplite) /* Disable the option on UDP sockets */
1489 return -ENOPROTOOPT;
1490 if (val != 0 && val < 8) /* Avoid silly minimal values. */
1491 val = 8;
1492 else if (val > USHORT_MAX)
1493 val = USHORT_MAX;
1494 up->pcrlen = val;
1495 up->pcflag |= UDPLITE_RECV_CC;
1496 break;
1497
1498 default:
1499 err = -ENOPROTOOPT;
1500 break;
1501 }
1502
1503 return err;
1504 }
1505 EXPORT_SYMBOL(udp_lib_setsockopt);
1506
1507 int udp_setsockopt(struct sock *sk, int level, int optname,
1508 char __user *optval, unsigned int optlen)
1509 {
1510 if (level == SOL_UDP || level == SOL_UDPLITE)
1511 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1512 udp_push_pending_frames);
1513 return ip_setsockopt(sk, level, optname, optval, optlen);
1514 }
1515
1516 #ifdef CONFIG_COMPAT
1517 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
1518 char __user *optval, unsigned int optlen)
1519 {
1520 if (level == SOL_UDP || level == SOL_UDPLITE)
1521 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1522 udp_push_pending_frames);
1523 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
1524 }
1525 #endif
1526
1527 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
1528 char __user *optval, int __user *optlen)
1529 {
1530 struct udp_sock *up = udp_sk(sk);
1531 int val, len;
1532
1533 if (get_user(len, optlen))
1534 return -EFAULT;
1535
1536 len = min_t(unsigned int, len, sizeof(int));
1537
1538 if (len < 0)
1539 return -EINVAL;
1540
1541 switch (optname) {
1542 case UDP_CORK:
1543 val = up->corkflag;
1544 break;
1545
1546 case UDP_ENCAP:
1547 val = up->encap_type;
1548 break;
1549
1550 /* The following two cannot be changed on UDP sockets, the return is
1551 * always 0 (which corresponds to the full checksum coverage of UDP). */
1552 case UDPLITE_SEND_CSCOV:
1553 val = up->pcslen;
1554 break;
1555
1556 case UDPLITE_RECV_CSCOV:
1557 val = up->pcrlen;
1558 break;
1559
1560 default:
1561 return -ENOPROTOOPT;
1562 }
1563
1564 if (put_user(len, optlen))
1565 return -EFAULT;
1566 if (copy_to_user(optval, &val, len))
1567 return -EFAULT;
1568 return 0;
1569 }
1570 EXPORT_SYMBOL(udp_lib_getsockopt);
1571
1572 int udp_getsockopt(struct sock *sk, int level, int optname,
1573 char __user *optval, int __user *optlen)
1574 {
1575 if (level == SOL_UDP || level == SOL_UDPLITE)
1576 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1577 return ip_getsockopt(sk, level, optname, optval, optlen);
1578 }
1579
1580 #ifdef CONFIG_COMPAT
1581 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
1582 char __user *optval, int __user *optlen)
1583 {
1584 if (level == SOL_UDP || level == SOL_UDPLITE)
1585 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1586 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
1587 }
1588 #endif
1589 /**
1590 * udp_poll - wait for a UDP event.
1591 * @file - file struct
1592 * @sock - socket
1593 * @wait - poll table
1594 *
1595 * This is same as datagram poll, except for the special case of
1596 * blocking sockets. If application is using a blocking fd
1597 * and a packet with checksum error is in the queue;
1598 * then it could get return from select indicating data available
1599 * but then block when reading it. Add special case code
1600 * to work around these arguably broken applications.
1601 */
1602 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
1603 {
1604 unsigned int mask = datagram_poll(file, sock, wait);
1605 struct sock *sk = sock->sk;
1606
1607 /* Check for false positives due to checksum errors */
1608 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
1609 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk))
1610 mask &= ~(POLLIN | POLLRDNORM);
1611
1612 return mask;
1613
1614 }
1615 EXPORT_SYMBOL(udp_poll);
1616
1617 struct proto udp_prot = {
1618 .name = "UDP",
1619 .owner = THIS_MODULE,
1620 .close = udp_lib_close,
1621 .connect = ip4_datagram_connect,
1622 .disconnect = udp_disconnect,
1623 .ioctl = udp_ioctl,
1624 .destroy = udp_destroy_sock,
1625 .setsockopt = udp_setsockopt,
1626 .getsockopt = udp_getsockopt,
1627 .sendmsg = udp_sendmsg,
1628 .recvmsg = udp_recvmsg,
1629 .sendpage = udp_sendpage,
1630 .backlog_rcv = __udp_queue_rcv_skb,
1631 .hash = udp_lib_hash,
1632 .unhash = udp_lib_unhash,
1633 .get_port = udp_v4_get_port,
1634 .memory_allocated = &udp_memory_allocated,
1635 .sysctl_mem = sysctl_udp_mem,
1636 .sysctl_wmem = &sysctl_udp_wmem_min,
1637 .sysctl_rmem = &sysctl_udp_rmem_min,
1638 .obj_size = sizeof(struct udp_sock),
1639 .slab_flags = SLAB_DESTROY_BY_RCU,
1640 .h.udp_table = &udp_table,
1641 #ifdef CONFIG_COMPAT
1642 .compat_setsockopt = compat_udp_setsockopt,
1643 .compat_getsockopt = compat_udp_getsockopt,
1644 #endif
1645 };
1646 EXPORT_SYMBOL(udp_prot);
1647
1648 /* ------------------------------------------------------------------------ */
1649 #ifdef CONFIG_PROC_FS
1650
1651 static struct sock *udp_get_first(struct seq_file *seq, int start)
1652 {
1653 struct sock *sk;
1654 struct udp_iter_state *state = seq->private;
1655 struct net *net = seq_file_net(seq);
1656
1657 for (state->bucket = start; state->bucket <= state->udp_table->mask;
1658 ++state->bucket) {
1659 struct hlist_nulls_node *node;
1660 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
1661
1662 if (hlist_nulls_empty(&hslot->head))
1663 continue;
1664
1665 spin_lock_bh(&hslot->lock);
1666 sk_nulls_for_each(sk, node, &hslot->head) {
1667 if (!net_eq(sock_net(sk), net))
1668 continue;
1669 if (sk->sk_family == state->family)
1670 goto found;
1671 }
1672 spin_unlock_bh(&hslot->lock);
1673 }
1674 sk = NULL;
1675 found:
1676 return sk;
1677 }
1678
1679 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
1680 {
1681 struct udp_iter_state *state = seq->private;
1682 struct net *net = seq_file_net(seq);
1683
1684 do {
1685 sk = sk_nulls_next(sk);
1686 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
1687
1688 if (!sk) {
1689 if (state->bucket <= state->udp_table->mask)
1690 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
1691 return udp_get_first(seq, state->bucket + 1);
1692 }
1693 return sk;
1694 }
1695
1696 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
1697 {
1698 struct sock *sk = udp_get_first(seq, 0);
1699
1700 if (sk)
1701 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
1702 --pos;
1703 return pos ? NULL : sk;
1704 }
1705
1706 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
1707 {
1708 struct udp_iter_state *state = seq->private;
1709 state->bucket = MAX_UDP_PORTS;
1710
1711 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1712 }
1713
1714 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1715 {
1716 struct sock *sk;
1717
1718 if (v == SEQ_START_TOKEN)
1719 sk = udp_get_idx(seq, 0);
1720 else
1721 sk = udp_get_next(seq, v);
1722
1723 ++*pos;
1724 return sk;
1725 }
1726
1727 static void udp_seq_stop(struct seq_file *seq, void *v)
1728 {
1729 struct udp_iter_state *state = seq->private;
1730
1731 if (state->bucket <= state->udp_table->mask)
1732 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
1733 }
1734
1735 static int udp_seq_open(struct inode *inode, struct file *file)
1736 {
1737 struct udp_seq_afinfo *afinfo = PDE(inode)->data;
1738 struct udp_iter_state *s;
1739 int err;
1740
1741 err = seq_open_net(inode, file, &afinfo->seq_ops,
1742 sizeof(struct udp_iter_state));
1743 if (err < 0)
1744 return err;
1745
1746 s = ((struct seq_file *)file->private_data)->private;
1747 s->family = afinfo->family;
1748 s->udp_table = afinfo->udp_table;
1749 return err;
1750 }
1751
1752 /* ------------------------------------------------------------------------ */
1753 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
1754 {
1755 struct proc_dir_entry *p;
1756 int rc = 0;
1757
1758 afinfo->seq_fops.open = udp_seq_open;
1759 afinfo->seq_fops.read = seq_read;
1760 afinfo->seq_fops.llseek = seq_lseek;
1761 afinfo->seq_fops.release = seq_release_net;
1762
1763 afinfo->seq_ops.start = udp_seq_start;
1764 afinfo->seq_ops.next = udp_seq_next;
1765 afinfo->seq_ops.stop = udp_seq_stop;
1766
1767 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1768 &afinfo->seq_fops, afinfo);
1769 if (!p)
1770 rc = -ENOMEM;
1771 return rc;
1772 }
1773 EXPORT_SYMBOL(udp_proc_register);
1774
1775 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
1776 {
1777 proc_net_remove(net, afinfo->name);
1778 }
1779 EXPORT_SYMBOL(udp_proc_unregister);
1780
1781 /* ------------------------------------------------------------------------ */
1782 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
1783 int bucket, int *len)
1784 {
1785 struct inet_sock *inet = inet_sk(sp);
1786 __be32 dest = inet->inet_daddr;
1787 __be32 src = inet->inet_rcv_saddr;
1788 __u16 destp = ntohs(inet->inet_dport);
1789 __u16 srcp = ntohs(inet->inet_sport);
1790
1791 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1792 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d%n",
1793 bucket, src, srcp, dest, destp, sp->sk_state,
1794 sk_wmem_alloc_get(sp),
1795 sk_rmem_alloc_get(sp),
1796 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
1797 atomic_read(&sp->sk_refcnt), sp,
1798 atomic_read(&sp->sk_drops), len);
1799 }
1800
1801 int udp4_seq_show(struct seq_file *seq, void *v)
1802 {
1803 if (v == SEQ_START_TOKEN)
1804 seq_printf(seq, "%-127s\n",
1805 " sl local_address rem_address st tx_queue "
1806 "rx_queue tr tm->when retrnsmt uid timeout "
1807 "inode ref pointer drops");
1808 else {
1809 struct udp_iter_state *state = seq->private;
1810 int len;
1811
1812 udp4_format_sock(v, seq, state->bucket, &len);
1813 seq_printf(seq, "%*s\n", 127 - len, "");
1814 }
1815 return 0;
1816 }
1817
1818 /* ------------------------------------------------------------------------ */
1819 static struct udp_seq_afinfo udp4_seq_afinfo = {
1820 .name = "udp",
1821 .family = AF_INET,
1822 .udp_table = &udp_table,
1823 .seq_fops = {
1824 .owner = THIS_MODULE,
1825 },
1826 .seq_ops = {
1827 .show = udp4_seq_show,
1828 },
1829 };
1830
1831 static int udp4_proc_init_net(struct net *net)
1832 {
1833 return udp_proc_register(net, &udp4_seq_afinfo);
1834 }
1835
1836 static void udp4_proc_exit_net(struct net *net)
1837 {
1838 udp_proc_unregister(net, &udp4_seq_afinfo);
1839 }
1840
1841 static struct pernet_operations udp4_net_ops = {
1842 .init = udp4_proc_init_net,
1843 .exit = udp4_proc_exit_net,
1844 };
1845
1846 int __init udp4_proc_init(void)
1847 {
1848 return register_pernet_subsys(&udp4_net_ops);
1849 }
1850
1851 void udp4_proc_exit(void)
1852 {
1853 unregister_pernet_subsys(&udp4_net_ops);
1854 }
1855 #endif /* CONFIG_PROC_FS */
1856
1857 static __initdata unsigned long uhash_entries;
1858 static int __init set_uhash_entries(char *str)
1859 {
1860 if (!str)
1861 return 0;
1862 uhash_entries = simple_strtoul(str, &str, 0);
1863 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
1864 uhash_entries = UDP_HTABLE_SIZE_MIN;
1865 return 1;
1866 }
1867 __setup("uhash_entries=", set_uhash_entries);
1868
1869 void __init udp_table_init(struct udp_table *table, const char *name)
1870 {
1871 unsigned int i;
1872
1873 if (!CONFIG_BASE_SMALL)
1874 table->hash = alloc_large_system_hash(name,
1875 2 * sizeof(struct udp_hslot),
1876 uhash_entries,
1877 21, /* one slot per 2 MB */
1878 0,
1879 &table->log,
1880 &table->mask,
1881 64 * 1024);
1882 /*
1883 * Make sure hash table has the minimum size
1884 */
1885 if (CONFIG_BASE_SMALL || table->mask < UDP_HTABLE_SIZE_MIN - 1) {
1886 table->hash = kmalloc(UDP_HTABLE_SIZE_MIN *
1887 2 * sizeof(struct udp_hslot), GFP_KERNEL);
1888 if (!table->hash)
1889 panic(name);
1890 table->log = ilog2(UDP_HTABLE_SIZE_MIN);
1891 table->mask = UDP_HTABLE_SIZE_MIN - 1;
1892 }
1893 table->hash2 = table->hash + (table->mask + 1);
1894 for (i = 0; i <= table->mask; i++) {
1895 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
1896 table->hash[i].count = 0;
1897 spin_lock_init(&table->hash[i].lock);
1898 }
1899 for (i = 0; i <= table->mask; i++) {
1900 INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i);
1901 table->hash2[i].count = 0;
1902 spin_lock_init(&table->hash2[i].lock);
1903 }
1904 }
1905
1906 void __init udp_init(void)
1907 {
1908 unsigned long nr_pages, limit;
1909
1910 udp_table_init(&udp_table, "UDP");
1911 /* Set the pressure threshold up by the same strategy of TCP. It is a
1912 * fraction of global memory that is up to 1/2 at 256 MB, decreasing
1913 * toward zero with the amount of memory, with a floor of 128 pages.
1914 */
1915 nr_pages = totalram_pages - totalhigh_pages;
1916 limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
1917 limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
1918 limit = max(limit, 128UL);
1919 sysctl_udp_mem[0] = limit / 4 * 3;
1920 sysctl_udp_mem[1] = limit;
1921 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
1922
1923 sysctl_udp_rmem_min = SK_MEM_QUANTUM;
1924 sysctl_udp_wmem_min = SK_MEM_QUANTUM;
1925 }
1926
1927 int udp4_ufo_send_check(struct sk_buff *skb)
1928 {
1929 const struct iphdr *iph;
1930 struct udphdr *uh;
1931
1932 if (!pskb_may_pull(skb, sizeof(*uh)))
1933 return -EINVAL;
1934
1935 iph = ip_hdr(skb);
1936 uh = udp_hdr(skb);
1937
1938 uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1939 IPPROTO_UDP, 0);
1940 skb->csum_start = skb_transport_header(skb) - skb->head;
1941 skb->csum_offset = offsetof(struct udphdr, check);
1942 skb->ip_summed = CHECKSUM_PARTIAL;
1943 return 0;
1944 }
1945
1946 struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, int features)
1947 {
1948 struct sk_buff *segs = ERR_PTR(-EINVAL);
1949 unsigned int mss;
1950 int offset;
1951 __wsum csum;
1952
1953 mss = skb_shinfo(skb)->gso_size;
1954 if (unlikely(skb->len <= mss))
1955 goto out;
1956
1957 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
1958 /* Packet is from an untrusted source, reset gso_segs. */
1959 int type = skb_shinfo(skb)->gso_type;
1960
1961 if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) ||
1962 !(type & (SKB_GSO_UDP))))
1963 goto out;
1964
1965 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
1966
1967 segs = NULL;
1968 goto out;
1969 }
1970
1971 /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
1972 * do checksum of UDP packets sent as multiple IP fragments.
1973 */
1974 offset = skb->csum_start - skb_headroom(skb);
1975 csum = skb_checksum(skb, offset, skb->len - offset, 0);
1976 offset += skb->csum_offset;
1977 *(__sum16 *)(skb->data + offset) = csum_fold(csum);
1978 skb->ip_summed = CHECKSUM_NONE;
1979
1980 /* Fragment the skb. IP headers of the fragments are updated in
1981 * inet_gso_segment()
1982 */
1983 segs = skb_segment(skb, features);
1984 out:
1985 return segs;
1986 }
1987
Linux kernel - Deliverables
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