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.
6 * The User Datagram Protocol (UDP).
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>
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
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
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
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.
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.
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>
93 #include <linux/errno.h>
94 #include <linux/timer.h>
96 #include <linux/inet.h>
97 #include <linux/netdevice.h>
98 #include <linux/slab.h>
99 #include <net/tcp_states.h>
100 #include <linux/skbuff.h>
101 #include <linux/proc_fs.h>
102 #include <linux/seq_file.h>
103 #include <net/net_namespace.h>
104 #include <net/icmp.h>
105 #include <net/route.h>
106 #include <net/checksum.h>
107 #include <net/xfrm.h>
108 #include "udp_impl.h"
110 struct udp_table udp_table __read_mostly;
111 EXPORT_SYMBOL(udp_table);
113 long sysctl_udp_mem[3] __read_mostly;
114 EXPORT_SYMBOL(sysctl_udp_mem);
116 int sysctl_udp_rmem_min __read_mostly;
117 EXPORT_SYMBOL(sysctl_udp_rmem_min);
119 int sysctl_udp_wmem_min __read_mostly;
120 EXPORT_SYMBOL(sysctl_udp_wmem_min);
122 atomic_long_t udp_memory_allocated;
123 EXPORT_SYMBOL(udp_memory_allocated);
125 #define MAX_UDP_PORTS 65536
126 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
128 static int udp_lib_lport_inuse(struct net *net, __u16 num,
129 const struct udp_hslot *hslot,
130 unsigned long *bitmap,
132 int (*saddr_comp)(const struct sock *sk1,
133 const struct sock *sk2),
137 struct hlist_nulls_node *node;
139 sk_nulls_for_each(sk2, node, &hslot->head)
140 if (net_eq(sock_net(sk2), net) &&
142 (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
143 (!sk2->sk_reuse || !sk->sk_reuse) &&
144 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
145 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
146 (*saddr_comp)(sk, sk2)) {
148 __set_bit(udp_sk(sk2)->udp_port_hash >> log,
157 * Note: we still hold spinlock of primary hash chain, so no other writer
158 * can insert/delete a socket with local_port == num
160 static int udp_lib_lport_inuse2(struct net *net, __u16 num,
161 struct udp_hslot *hslot2,
163 int (*saddr_comp)(const struct sock *sk1,
164 const struct sock *sk2))
167 struct hlist_nulls_node *node;
170 spin_lock(&hslot2->lock);
171 udp_portaddr_for_each_entry(sk2, node, &hslot2->head)
172 if (net_eq(sock_net(sk2), net) &&
174 (udp_sk(sk2)->udp_port_hash == num) &&
175 (!sk2->sk_reuse || !sk->sk_reuse) &&
176 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
177 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
178 (*saddr_comp)(sk, sk2)) {
182 spin_unlock(&hslot2->lock);
187 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
189 * @sk: socket struct in question
190 * @snum: port number to look up
191 * @saddr_comp: AF-dependent comparison of bound local IP addresses
192 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains,
195 int udp_lib_get_port(struct sock *sk, unsigned short snum,
196 int (*saddr_comp)(const struct sock *sk1,
197 const struct sock *sk2),
198 unsigned int hash2_nulladdr)
200 struct udp_hslot *hslot, *hslot2;
201 struct udp_table *udptable = sk->sk_prot->h.udp_table;
203 struct net *net = sock_net(sk);
206 int low, high, remaining;
208 unsigned short first, last;
209 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
211 inet_get_local_port_range(&low, &high);
212 remaining = (high - low) + 1;
215 first = (((u64)rand * remaining) >> 32) + low;
217 * force rand to be an odd multiple of UDP_HTABLE_SIZE
219 rand = (rand | 1) * (udptable->mask + 1);
220 last = first + udptable->mask + 1;
222 hslot = udp_hashslot(udptable, net, first);
223 bitmap_zero(bitmap, PORTS_PER_CHAIN);
224 spin_lock_bh(&hslot->lock);
225 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
226 saddr_comp, udptable->log);
230 * Iterate on all possible values of snum for this hash.
231 * Using steps of an odd multiple of UDP_HTABLE_SIZE
232 * give us randomization and full range coverage.
235 if (low <= snum && snum <= high &&
236 !test_bit(snum >> udptable->log, bitmap) &&
237 !inet_is_reserved_local_port(snum))
240 } while (snum != first);
241 spin_unlock_bh(&hslot->lock);
242 } while (++first != last);
245 hslot = udp_hashslot(udptable, net, snum);
246 spin_lock_bh(&hslot->lock);
247 if (hslot->count > 10) {
249 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum;
251 slot2 &= udptable->mask;
252 hash2_nulladdr &= udptable->mask;
254 hslot2 = udp_hashslot2(udptable, slot2);
255 if (hslot->count < hslot2->count)
256 goto scan_primary_hash;
258 exist = udp_lib_lport_inuse2(net, snum, hslot2,
260 if (!exist && (hash2_nulladdr != slot2)) {
261 hslot2 = udp_hashslot2(udptable, hash2_nulladdr);
262 exist = udp_lib_lport_inuse2(net, snum, hslot2,
271 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk,
276 inet_sk(sk)->inet_num = snum;
277 udp_sk(sk)->udp_port_hash = snum;
278 udp_sk(sk)->udp_portaddr_hash ^= snum;
279 if (sk_unhashed(sk)) {
280 sk_nulls_add_node_rcu(sk, &hslot->head);
282 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
284 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
285 spin_lock(&hslot2->lock);
286 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
289 spin_unlock(&hslot2->lock);
293 spin_unlock_bh(&hslot->lock);
297 EXPORT_SYMBOL(udp_lib_get_port);
299 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
301 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
303 return (!ipv6_only_sock(sk2) &&
304 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr ||
305 inet1->inet_rcv_saddr == inet2->inet_rcv_saddr));
308 static unsigned int udp4_portaddr_hash(struct net *net, __be32 saddr,
311 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
314 int udp_v4_get_port(struct sock *sk, unsigned short snum)
316 unsigned int hash2_nulladdr =
317 udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum);
318 unsigned int hash2_partial =
319 udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0);
321 /* precompute partial secondary hash */
322 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
323 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal, hash2_nulladdr);
326 static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr,
328 __be16 sport, __be32 daddr, __be16 dport, int dif)
332 if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
333 !ipv6_only_sock(sk)) {
334 struct inet_sock *inet = inet_sk(sk);
336 score = (sk->sk_family == PF_INET ? 1 : 0);
337 if (inet->inet_rcv_saddr) {
338 if (inet->inet_rcv_saddr != daddr)
342 if (inet->inet_daddr) {
343 if (inet->inet_daddr != saddr)
347 if (inet->inet_dport) {
348 if (inet->inet_dport != sport)
352 if (sk->sk_bound_dev_if) {
353 if (sk->sk_bound_dev_if != dif)
362 * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num)
364 #define SCORE2_MAX (1 + 2 + 2 + 2)
365 static inline int compute_score2(struct sock *sk, struct net *net,
366 __be32 saddr, __be16 sport,
367 __be32 daddr, unsigned int hnum, int dif)
371 if (net_eq(sock_net(sk), net) && !ipv6_only_sock(sk)) {
372 struct inet_sock *inet = inet_sk(sk);
374 if (inet->inet_rcv_saddr != daddr)
376 if (inet->inet_num != hnum)
379 score = (sk->sk_family == PF_INET ? 1 : 0);
380 if (inet->inet_daddr) {
381 if (inet->inet_daddr != saddr)
385 if (inet->inet_dport) {
386 if (inet->inet_dport != sport)
390 if (sk->sk_bound_dev_if) {
391 if (sk->sk_bound_dev_if != dif)
400 /* called with read_rcu_lock() */
401 static struct sock *udp4_lib_lookup2(struct net *net,
402 __be32 saddr, __be16 sport,
403 __be32 daddr, unsigned int hnum, int dif,
404 struct udp_hslot *hslot2, unsigned int slot2)
406 struct sock *sk, *result;
407 struct hlist_nulls_node *node;
413 udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
414 score = compute_score2(sk, net, saddr, sport,
416 if (score > badness) {
419 if (score == SCORE2_MAX)
424 * if the nulls value we got at the end of this lookup is
425 * not the expected one, we must restart lookup.
426 * We probably met an item that was moved to another chain.
428 if (get_nulls_value(node) != slot2)
433 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
435 else if (unlikely(compute_score2(result, net, saddr, sport,
436 daddr, hnum, dif) < badness)) {
444 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
445 * harder than this. -DaveM
447 static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
448 __be16 sport, __be32 daddr, __be16 dport,
449 int dif, struct udp_table *udptable)
451 struct sock *sk, *result;
452 struct hlist_nulls_node *node;
453 unsigned short hnum = ntohs(dport);
454 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
455 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
459 if (hslot->count > 10) {
460 hash2 = udp4_portaddr_hash(net, daddr, hnum);
461 slot2 = hash2 & udptable->mask;
462 hslot2 = &udptable->hash2[slot2];
463 if (hslot->count < hslot2->count)
466 result = udp4_lib_lookup2(net, saddr, sport,
470 hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
471 slot2 = hash2 & udptable->mask;
472 hslot2 = &udptable->hash2[slot2];
473 if (hslot->count < hslot2->count)
476 result = udp4_lib_lookup2(net, saddr, sport,
477 htonl(INADDR_ANY), hnum, dif,
486 sk_nulls_for_each_rcu(sk, node, &hslot->head) {
487 score = compute_score(sk, net, saddr, hnum, sport,
489 if (score > badness) {
495 * if the nulls value we got at the end of this lookup is
496 * not the expected one, we must restart lookup.
497 * We probably met an item that was moved to another chain.
499 if (get_nulls_value(node) != slot)
503 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
505 else if (unlikely(compute_score(result, net, saddr, hnum, sport,
506 daddr, dport, dif) < badness)) {
515 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
516 __be16 sport, __be16 dport,
517 struct udp_table *udptable)
520 const struct iphdr *iph = ip_hdr(skb);
522 if (unlikely(sk = skb_steal_sock(skb)))
525 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport,
526 iph->daddr, dport, inet_iif(skb),
530 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
531 __be32 daddr, __be16 dport, int dif)
533 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
535 EXPORT_SYMBOL_GPL(udp4_lib_lookup);
537 static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
538 __be16 loc_port, __be32 loc_addr,
539 __be16 rmt_port, __be32 rmt_addr,
542 struct hlist_nulls_node *node;
544 unsigned short hnum = ntohs(loc_port);
546 sk_nulls_for_each_from(s, node) {
547 struct inet_sock *inet = inet_sk(s);
549 if (!net_eq(sock_net(s), net) ||
550 udp_sk(s)->udp_port_hash != hnum ||
551 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
552 (inet->inet_dport != rmt_port && inet->inet_dport) ||
553 (inet->inet_rcv_saddr &&
554 inet->inet_rcv_saddr != loc_addr) ||
556 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
558 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
568 * This routine is called by the ICMP module when it gets some
569 * sort of error condition. If err < 0 then the socket should
570 * be closed and the error returned to the user. If err > 0
571 * it's just the icmp type << 8 | icmp code.
572 * Header points to the ip header of the error packet. We move
573 * on past this. Then (as it used to claim before adjustment)
574 * header points to the first 8 bytes of the udp header. We need
575 * to find the appropriate port.
578 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
580 struct inet_sock *inet;
581 const struct iphdr *iph = (const struct iphdr *)skb->data;
582 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
583 const int type = icmp_hdr(skb)->type;
584 const int code = icmp_hdr(skb)->code;
588 struct net *net = dev_net(skb->dev);
590 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
591 iph->saddr, uh->source, skb->dev->ifindex, udptable);
593 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
594 return; /* No socket for error */
603 case ICMP_TIME_EXCEEDED:
606 case ICMP_SOURCE_QUENCH:
608 case ICMP_PARAMETERPROB:
612 case ICMP_DEST_UNREACH:
613 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
614 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
622 if (code <= NR_ICMP_UNREACH) {
623 harderr = icmp_err_convert[code].fatal;
624 err = icmp_err_convert[code].errno;
630 * RFC1122: OK. Passes ICMP errors back to application, as per
633 if (!inet->recverr) {
634 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
637 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
640 sk->sk_error_report(sk);
645 void udp_err(struct sk_buff *skb, u32 info)
647 __udp4_lib_err(skb, info, &udp_table);
651 * Throw away all pending data and cancel the corking. Socket is locked.
653 void udp_flush_pending_frames(struct sock *sk)
655 struct udp_sock *up = udp_sk(sk);
660 ip_flush_pending_frames(sk);
663 EXPORT_SYMBOL(udp_flush_pending_frames);
666 * udp4_hwcsum - handle outgoing HW checksumming
667 * @skb: sk_buff containing the filled-in UDP header
668 * (checksum field must be zeroed out)
669 * @src: source IP address
670 * @dst: destination IP address
672 static void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
674 struct udphdr *uh = udp_hdr(skb);
675 struct sk_buff *frags = skb_shinfo(skb)->frag_list;
676 int offset = skb_transport_offset(skb);
677 int len = skb->len - offset;
683 * Only one fragment on the socket.
685 skb->csum_start = skb_transport_header(skb) - skb->head;
686 skb->csum_offset = offsetof(struct udphdr, check);
687 uh->check = ~csum_tcpudp_magic(src, dst, len,
691 * HW-checksum won't work as there are two or more
692 * fragments on the socket so that all csums of sk_buffs
696 csum = csum_add(csum, frags->csum);
698 } while ((frags = frags->next));
700 csum = skb_checksum(skb, offset, hlen, csum);
701 skb->ip_summed = CHECKSUM_NONE;
703 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
705 uh->check = CSUM_MANGLED_0;
709 static int udp_send_skb(struct sk_buff *skb, __be32 daddr, __be32 dport)
711 struct sock *sk = skb->sk;
712 struct inet_sock *inet = inet_sk(sk);
714 struct rtable *rt = (struct rtable *)skb_dst(skb);
716 int is_udplite = IS_UDPLITE(sk);
717 int offset = skb_transport_offset(skb);
718 int len = skb->len - offset;
722 * Create a UDP header
725 uh->source = inet->inet_sport;
727 uh->len = htons(len);
730 if (is_udplite) /* UDP-Lite */
731 csum = udplite_csum(skb);
733 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */
735 skb->ip_summed = CHECKSUM_NONE;
738 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
740 udp4_hwcsum(skb, rt->rt_src, daddr);
744 csum = udp_csum(skb);
746 /* add protocol-dependent pseudo-header */
747 uh->check = csum_tcpudp_magic(rt->rt_src, daddr, len,
748 sk->sk_protocol, csum);
750 uh->check = CSUM_MANGLED_0;
753 err = ip_send_skb(skb);
755 if (err == -ENOBUFS && !inet->recverr) {
756 UDP_INC_STATS_USER(sock_net(sk),
757 UDP_MIB_SNDBUFERRORS, is_udplite);
761 UDP_INC_STATS_USER(sock_net(sk),
762 UDP_MIB_OUTDATAGRAMS, is_udplite);
767 * Push out all pending data as one UDP datagram. Socket is locked.
769 static int udp_push_pending_frames(struct sock *sk)
771 struct udp_sock *up = udp_sk(sk);
772 struct inet_sock *inet = inet_sk(sk);
773 struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
777 skb = ip_finish_skb(sk, fl4);
781 err = udp_send_skb(skb, fl4->daddr, fl4->fl4_dport);
789 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
792 struct inet_sock *inet = inet_sk(sk);
793 struct udp_sock *up = udp_sk(sk);
794 struct flowi4 fl4_stack;
797 struct ipcm_cookie ipc;
798 struct rtable *rt = NULL;
801 __be32 daddr, faddr, saddr;
804 int err, is_udplite = IS_UDPLITE(sk);
805 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
806 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
808 struct ip_options_data opt_copy;
817 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
823 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
825 fl4 = &inet->cork.fl.u.ip4;
828 * There are pending frames.
829 * The socket lock must be held while it's corked.
832 if (likely(up->pending)) {
833 if (unlikely(up->pending != AF_INET)) {
841 ulen += sizeof(struct udphdr);
844 * Get and verify the address.
847 struct sockaddr_in * usin = (struct sockaddr_in *)msg->msg_name;
848 if (msg->msg_namelen < sizeof(*usin))
850 if (usin->sin_family != AF_INET) {
851 if (usin->sin_family != AF_UNSPEC)
852 return -EAFNOSUPPORT;
855 daddr = usin->sin_addr.s_addr;
856 dport = usin->sin_port;
860 if (sk->sk_state != TCP_ESTABLISHED)
861 return -EDESTADDRREQ;
862 daddr = inet->inet_daddr;
863 dport = inet->inet_dport;
864 /* Open fast path for connected socket.
865 Route will not be used, if at least one option is set.
869 ipc.addr = inet->inet_saddr;
871 ipc.oif = sk->sk_bound_dev_if;
872 err = sock_tx_timestamp(sk, &ipc.tx_flags);
875 if (msg->msg_controllen) {
876 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
884 struct ip_options_rcu *inet_opt;
887 inet_opt = rcu_dereference(inet->inet_opt);
889 memcpy(&opt_copy, inet_opt,
890 sizeof(*inet_opt) + inet_opt->opt.optlen);
891 ipc.opt = &opt_copy.opt;
897 ipc.addr = faddr = daddr;
899 if (ipc.opt && ipc.opt->opt.srr) {
902 faddr = ipc.opt->opt.faddr;
905 tos = RT_TOS(inet->tos);
906 if (sock_flag(sk, SOCK_LOCALROUTE) ||
907 (msg->msg_flags & MSG_DONTROUTE) ||
908 (ipc.opt && ipc.opt->opt.is_strictroute)) {
913 if (ipv4_is_multicast(daddr)) {
915 ipc.oif = inet->mc_index;
917 saddr = inet->mc_addr;
922 rt = (struct rtable *)sk_dst_check(sk, 0);
925 struct net *net = sock_net(sk);
928 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos,
929 RT_SCOPE_UNIVERSE, sk->sk_protocol,
930 inet_sk_flowi_flags(sk)|FLOWI_FLAG_CAN_SLEEP,
931 faddr, saddr, dport, inet->inet_sport);
933 security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
934 rt = ip_route_output_flow(net, fl4, sk);
938 if (err == -ENETUNREACH)
939 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
944 if ((rt->rt_flags & RTCF_BROADCAST) &&
945 !sock_flag(sk, SOCK_BROADCAST))
948 sk_dst_set(sk, dst_clone(&rt->dst));
951 if (msg->msg_flags&MSG_CONFIRM)
957 daddr = ipc.addr = fl4->daddr;
959 /* Lockless fast path for the non-corking case. */
961 skb = ip_make_skb(sk, fl4, getfrag, msg->msg_iov, ulen,
962 sizeof(struct udphdr), &ipc, &rt,
965 if (skb && !IS_ERR(skb))
966 err = udp_send_skb(skb, daddr, dport);
971 if (unlikely(up->pending)) {
972 /* The socket is already corked while preparing it. */
973 /* ... which is an evident application bug. --ANK */
976 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
981 * Now cork the socket to pend data.
983 fl4 = &inet->cork.fl.u.ip4;
986 fl4->fl4_dport = dport;
987 fl4->fl4_sport = inet->inet_sport;
988 up->pending = AF_INET;
992 err = ip_append_data(sk, fl4, getfrag, msg->msg_iov, ulen,
993 sizeof(struct udphdr), &ipc, &rt,
994 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
996 udp_flush_pending_frames(sk);
998 err = udp_push_pending_frames(sk);
999 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1010 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1011 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1012 * we don't have a good statistic (IpOutDiscards but it can be too many
1013 * things). We could add another new stat but at least for now that
1014 * seems like overkill.
1016 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1017 UDP_INC_STATS_USER(sock_net(sk),
1018 UDP_MIB_SNDBUFERRORS, is_udplite);
1023 dst_confirm(&rt->dst);
1024 if (!(msg->msg_flags&MSG_PROBE) || len)
1025 goto back_from_confirm;
1029 EXPORT_SYMBOL(udp_sendmsg);
1031 int udp_sendpage(struct sock *sk, struct page *page, int offset,
1032 size_t size, int flags)
1034 struct inet_sock *inet = inet_sk(sk);
1035 struct udp_sock *up = udp_sk(sk);
1039 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
1041 /* Call udp_sendmsg to specify destination address which
1042 * sendpage interface can't pass.
1043 * This will succeed only when the socket is connected.
1045 ret = udp_sendmsg(NULL, sk, &msg, 0);
1052 if (unlikely(!up->pending)) {
1055 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n");
1059 ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
1060 page, offset, size, flags);
1061 if (ret == -EOPNOTSUPP) {
1063 return sock_no_sendpage(sk->sk_socket, page, offset,
1067 udp_flush_pending_frames(sk);
1072 if (!(up->corkflag || (flags&MSG_MORE)))
1073 ret = udp_push_pending_frames(sk);
1083 * first_packet_length - return length of first packet in receive queue
1086 * Drops all bad checksum frames, until a valid one is found.
1087 * Returns the length of found skb, or 0 if none is found.
1089 static unsigned int first_packet_length(struct sock *sk)
1091 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue;
1092 struct sk_buff *skb;
1095 __skb_queue_head_init(&list_kill);
1097 spin_lock_bh(&rcvq->lock);
1098 while ((skb = skb_peek(rcvq)) != NULL &&
1099 udp_lib_checksum_complete(skb)) {
1100 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
1102 atomic_inc(&sk->sk_drops);
1103 __skb_unlink(skb, rcvq);
1104 __skb_queue_tail(&list_kill, skb);
1106 res = skb ? skb->len : 0;
1107 spin_unlock_bh(&rcvq->lock);
1109 if (!skb_queue_empty(&list_kill)) {
1110 bool slow = lock_sock_fast(sk);
1112 __skb_queue_purge(&list_kill);
1113 sk_mem_reclaim_partial(sk);
1114 unlock_sock_fast(sk, slow);
1120 * IOCTL requests applicable to the UDP protocol
1123 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
1128 int amount = sk_wmem_alloc_get(sk);
1130 return put_user(amount, (int __user *)arg);
1135 unsigned int amount = first_packet_length(sk);
1139 * We will only return the amount
1140 * of this packet since that is all
1141 * that will be read.
1143 amount -= sizeof(struct udphdr);
1145 return put_user(amount, (int __user *)arg);
1149 return -ENOIOCTLCMD;
1154 EXPORT_SYMBOL(udp_ioctl);
1157 * This should be easy, if there is something there we
1158 * return it, otherwise we block.
1161 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
1162 size_t len, int noblock, int flags, int *addr_len)
1164 struct inet_sock *inet = inet_sk(sk);
1165 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
1166 struct sk_buff *skb;
1170 int is_udplite = IS_UDPLITE(sk);
1174 * Check any passed addresses
1177 *addr_len = sizeof(*sin);
1179 if (flags & MSG_ERRQUEUE)
1180 return ip_recv_error(sk, msg, len);
1183 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
1188 ulen = skb->len - sizeof(struct udphdr);
1191 else if (len < ulen)
1192 msg->msg_flags |= MSG_TRUNC;
1195 * If checksum is needed at all, try to do it while copying the
1196 * data. If the data is truncated, or if we only want a partial
1197 * coverage checksum (UDP-Lite), do it before the copy.
1200 if (len < ulen || UDP_SKB_CB(skb)->partial_cov) {
1201 if (udp_lib_checksum_complete(skb))
1205 if (skb_csum_unnecessary(skb))
1206 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
1209 err = skb_copy_and_csum_datagram_iovec(skb,
1210 sizeof(struct udphdr),
1221 UDP_INC_STATS_USER(sock_net(sk),
1222 UDP_MIB_INDATAGRAMS, is_udplite);
1224 sock_recv_ts_and_drops(msg, sk, skb);
1226 /* Copy the address. */
1228 sin->sin_family = AF_INET;
1229 sin->sin_port = udp_hdr(skb)->source;
1230 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1231 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1233 if (inet->cmsg_flags)
1234 ip_cmsg_recv(msg, skb);
1237 if (flags & MSG_TRUNC)
1241 skb_free_datagram_locked(sk, skb);
1246 slow = lock_sock_fast(sk);
1247 if (!skb_kill_datagram(sk, skb, flags))
1248 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1249 unlock_sock_fast(sk, slow);
1257 int udp_disconnect(struct sock *sk, int flags)
1259 struct inet_sock *inet = inet_sk(sk);
1261 * 1003.1g - break association.
1264 sk->sk_state = TCP_CLOSE;
1265 inet->inet_daddr = 0;
1266 inet->inet_dport = 0;
1267 sock_rps_save_rxhash(sk, 0);
1268 sk->sk_bound_dev_if = 0;
1269 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1270 inet_reset_saddr(sk);
1272 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1273 sk->sk_prot->unhash(sk);
1274 inet->inet_sport = 0;
1279 EXPORT_SYMBOL(udp_disconnect);
1281 void udp_lib_unhash(struct sock *sk)
1283 if (sk_hashed(sk)) {
1284 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1285 struct udp_hslot *hslot, *hslot2;
1287 hslot = udp_hashslot(udptable, sock_net(sk),
1288 udp_sk(sk)->udp_port_hash);
1289 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1291 spin_lock_bh(&hslot->lock);
1292 if (sk_nulls_del_node_init_rcu(sk)) {
1294 inet_sk(sk)->inet_num = 0;
1295 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1297 spin_lock(&hslot2->lock);
1298 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1300 spin_unlock(&hslot2->lock);
1302 spin_unlock_bh(&hslot->lock);
1305 EXPORT_SYMBOL(udp_lib_unhash);
1308 * inet_rcv_saddr was changed, we must rehash secondary hash
1310 void udp_lib_rehash(struct sock *sk, u16 newhash)
1312 if (sk_hashed(sk)) {
1313 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1314 struct udp_hslot *hslot, *hslot2, *nhslot2;
1316 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1317 nhslot2 = udp_hashslot2(udptable, newhash);
1318 udp_sk(sk)->udp_portaddr_hash = newhash;
1319 if (hslot2 != nhslot2) {
1320 hslot = udp_hashslot(udptable, sock_net(sk),
1321 udp_sk(sk)->udp_port_hash);
1322 /* we must lock primary chain too */
1323 spin_lock_bh(&hslot->lock);
1325 spin_lock(&hslot2->lock);
1326 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1328 spin_unlock(&hslot2->lock);
1330 spin_lock(&nhslot2->lock);
1331 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
1334 spin_unlock(&nhslot2->lock);
1336 spin_unlock_bh(&hslot->lock);
1340 EXPORT_SYMBOL(udp_lib_rehash);
1342 static void udp_v4_rehash(struct sock *sk)
1344 u16 new_hash = udp4_portaddr_hash(sock_net(sk),
1345 inet_sk(sk)->inet_rcv_saddr,
1346 inet_sk(sk)->inet_num);
1347 udp_lib_rehash(sk, new_hash);
1350 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1354 if (inet_sk(sk)->inet_daddr)
1355 sock_rps_save_rxhash(sk, skb->rxhash);
1357 rc = ip_queue_rcv_skb(sk, skb);
1359 int is_udplite = IS_UDPLITE(sk);
1361 /* Note that an ENOMEM error is charged twice */
1363 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1365 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1377 * >0: "udp encap" protocol resubmission
1379 * Note that in the success and error cases, the skb is assumed to
1380 * have either been requeued or freed.
1382 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1384 struct udp_sock *up = udp_sk(sk);
1386 int is_udplite = IS_UDPLITE(sk);
1389 * Charge it to the socket, dropping if the queue is full.
1391 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1395 if (up->encap_type) {
1397 * This is an encapsulation socket so pass the skb to
1398 * the socket's udp_encap_rcv() hook. Otherwise, just
1399 * fall through and pass this up the UDP socket.
1400 * up->encap_rcv() returns the following value:
1401 * =0 if skb was successfully passed to the encap
1402 * handler or was discarded by it.
1403 * >0 if skb should be passed on to UDP.
1404 * <0 if skb should be resubmitted as proto -N
1407 /* if we're overly short, let UDP handle it */
1408 if (skb->len > sizeof(struct udphdr) &&
1409 up->encap_rcv != NULL) {
1412 ret = (*up->encap_rcv)(sk, skb);
1414 UDP_INC_STATS_BH(sock_net(sk),
1415 UDP_MIB_INDATAGRAMS,
1421 /* FALLTHROUGH -- it's a UDP Packet */
1425 * UDP-Lite specific tests, ignored on UDP sockets
1427 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1430 * MIB statistics other than incrementing the error count are
1431 * disabled for the following two types of errors: these depend
1432 * on the application settings, not on the functioning of the
1433 * protocol stack as such.
1435 * RFC 3828 here recommends (sec 3.3): "There should also be a
1436 * way ... to ... at least let the receiving application block
1437 * delivery of packets with coverage values less than a value
1438 * provided by the application."
1440 if (up->pcrlen == 0) { /* full coverage was set */
1441 LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage "
1442 "%d while full coverage %d requested\n",
1443 UDP_SKB_CB(skb)->cscov, skb->len);
1446 /* The next case involves violating the min. coverage requested
1447 * by the receiver. This is subtle: if receiver wants x and x is
1448 * greater than the buffersize/MTU then receiver will complain
1449 * that it wants x while sender emits packets of smaller size y.
1450 * Therefore the above ...()->partial_cov statement is essential.
1452 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1453 LIMIT_NETDEBUG(KERN_WARNING
1454 "UDPLITE: coverage %d too small, need min %d\n",
1455 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1460 if (rcu_dereference_raw(sk->sk_filter)) {
1461 if (udp_lib_checksum_complete(skb))
1466 if (sk_rcvqueues_full(sk, skb))
1472 if (!sock_owned_by_user(sk))
1473 rc = __udp_queue_rcv_skb(sk, skb);
1474 else if (sk_add_backlog(sk, skb)) {
1483 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1484 atomic_inc(&sk->sk_drops);
1490 static void flush_stack(struct sock **stack, unsigned int count,
1491 struct sk_buff *skb, unsigned int final)
1494 struct sk_buff *skb1 = NULL;
1497 for (i = 0; i < count; i++) {
1499 if (likely(skb1 == NULL))
1500 skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
1503 atomic_inc(&sk->sk_drops);
1504 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1506 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
1510 if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0)
1518 * Multicasts and broadcasts go to each listener.
1520 * Note: called only from the BH handler context.
1522 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1524 __be32 saddr, __be32 daddr,
1525 struct udp_table *udptable)
1527 struct sock *sk, *stack[256 / sizeof(struct sock *)];
1528 struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
1530 unsigned int i, count = 0;
1532 spin_lock(&hslot->lock);
1533 sk = sk_nulls_head(&hslot->head);
1534 dif = skb->dev->ifindex;
1535 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
1537 stack[count++] = sk;
1538 sk = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest,
1539 daddr, uh->source, saddr, dif);
1540 if (unlikely(count == ARRAY_SIZE(stack))) {
1543 flush_stack(stack, count, skb, ~0);
1548 * before releasing chain lock, we must take a reference on sockets
1550 for (i = 0; i < count; i++)
1551 sock_hold(stack[i]);
1553 spin_unlock(&hslot->lock);
1556 * do the slow work with no lock held
1559 flush_stack(stack, count, skb, count - 1);
1561 for (i = 0; i < count; i++)
1569 /* Initialize UDP checksum. If exited with zero value (success),
1570 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1571 * Otherwise, csum completion requires chacksumming packet body,
1572 * including udp header and folding it to skb->csum.
1574 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
1577 const struct iphdr *iph;
1580 UDP_SKB_CB(skb)->partial_cov = 0;
1581 UDP_SKB_CB(skb)->cscov = skb->len;
1583 if (proto == IPPROTO_UDPLITE) {
1584 err = udplite_checksum_init(skb, uh);
1590 if (uh->check == 0) {
1591 skb->ip_summed = CHECKSUM_UNNECESSARY;
1592 } else if (skb->ip_summed == CHECKSUM_COMPLETE) {
1593 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1595 skb->ip_summed = CHECKSUM_UNNECESSARY;
1597 if (!skb_csum_unnecessary(skb))
1598 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
1599 skb->len, proto, 0);
1600 /* Probably, we should checksum udp header (it should be in cache
1601 * in any case) and data in tiny packets (< rx copybreak).
1608 * All we need to do is get the socket, and then do a checksum.
1611 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1616 unsigned short ulen;
1617 struct rtable *rt = skb_rtable(skb);
1618 __be32 saddr, daddr;
1619 struct net *net = dev_net(skb->dev);
1622 * Validate the packet.
1624 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1625 goto drop; /* No space for header. */
1628 ulen = ntohs(uh->len);
1629 saddr = ip_hdr(skb)->saddr;
1630 daddr = ip_hdr(skb)->daddr;
1632 if (ulen > skb->len)
1635 if (proto == IPPROTO_UDP) {
1636 /* UDP validates ulen. */
1637 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
1642 if (udp4_csum_init(skb, uh, proto))
1645 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1646 return __udp4_lib_mcast_deliver(net, skb, uh,
1647 saddr, daddr, udptable);
1649 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1652 int ret = udp_queue_rcv_skb(sk, skb);
1655 /* a return value > 0 means to resubmit the input, but
1656 * it wants the return to be -protocol, or 0
1663 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1667 /* No socket. Drop packet silently, if checksum is wrong */
1668 if (udp_lib_checksum_complete(skb))
1671 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1672 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
1675 * Hmm. We got an UDP packet to a port to which we
1676 * don't wanna listen. Ignore it.
1682 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1683 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1694 * RFC1122: OK. Discards the bad packet silently (as far as
1695 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1697 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1698 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1705 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1710 int udp_rcv(struct sk_buff *skb)
1712 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1715 void udp_destroy_sock(struct sock *sk)
1717 bool slow = lock_sock_fast(sk);
1718 udp_flush_pending_frames(sk);
1719 unlock_sock_fast(sk, slow);
1723 * Socket option code for UDP
1725 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1726 char __user *optval, unsigned int optlen,
1727 int (*push_pending_frames)(struct sock *))
1729 struct udp_sock *up = udp_sk(sk);
1732 int is_udplite = IS_UDPLITE(sk);
1734 if (optlen < sizeof(int))
1737 if (get_user(val, (int __user *)optval))
1747 (*push_pending_frames)(sk);
1755 case UDP_ENCAP_ESPINUDP:
1756 case UDP_ENCAP_ESPINUDP_NON_IKE:
1757 up->encap_rcv = xfrm4_udp_encap_rcv;
1759 case UDP_ENCAP_L2TPINUDP:
1760 up->encap_type = val;
1769 * UDP-Lite's partial checksum coverage (RFC 3828).
1771 /* The sender sets actual checksum coverage length via this option.
1772 * The case coverage > packet length is handled by send module. */
1773 case UDPLITE_SEND_CSCOV:
1774 if (!is_udplite) /* Disable the option on UDP sockets */
1775 return -ENOPROTOOPT;
1776 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
1778 else if (val > USHRT_MAX)
1781 up->pcflag |= UDPLITE_SEND_CC;
1784 /* The receiver specifies a minimum checksum coverage value. To make
1785 * sense, this should be set to at least 8 (as done below). If zero is
1786 * used, this again means full checksum coverage. */
1787 case UDPLITE_RECV_CSCOV:
1788 if (!is_udplite) /* Disable the option on UDP sockets */
1789 return -ENOPROTOOPT;
1790 if (val != 0 && val < 8) /* Avoid silly minimal values. */
1792 else if (val > USHRT_MAX)
1795 up->pcflag |= UDPLITE_RECV_CC;
1805 EXPORT_SYMBOL(udp_lib_setsockopt);
1807 int udp_setsockopt(struct sock *sk, int level, int optname,
1808 char __user *optval, unsigned int optlen)
1810 if (level == SOL_UDP || level == SOL_UDPLITE)
1811 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1812 udp_push_pending_frames);
1813 return ip_setsockopt(sk, level, optname, optval, optlen);
1816 #ifdef CONFIG_COMPAT
1817 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
1818 char __user *optval, unsigned int optlen)
1820 if (level == SOL_UDP || level == SOL_UDPLITE)
1821 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1822 udp_push_pending_frames);
1823 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
1827 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
1828 char __user *optval, int __user *optlen)
1830 struct udp_sock *up = udp_sk(sk);
1833 if (get_user(len, optlen))
1836 len = min_t(unsigned int, len, sizeof(int));
1847 val = up->encap_type;
1850 /* The following two cannot be changed on UDP sockets, the return is
1851 * always 0 (which corresponds to the full checksum coverage of UDP). */
1852 case UDPLITE_SEND_CSCOV:
1856 case UDPLITE_RECV_CSCOV:
1861 return -ENOPROTOOPT;
1864 if (put_user(len, optlen))
1866 if (copy_to_user(optval, &val, len))
1870 EXPORT_SYMBOL(udp_lib_getsockopt);
1872 int udp_getsockopt(struct sock *sk, int level, int optname,
1873 char __user *optval, int __user *optlen)
1875 if (level == SOL_UDP || level == SOL_UDPLITE)
1876 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1877 return ip_getsockopt(sk, level, optname, optval, optlen);
1880 #ifdef CONFIG_COMPAT
1881 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
1882 char __user *optval, int __user *optlen)
1884 if (level == SOL_UDP || level == SOL_UDPLITE)
1885 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1886 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
1890 * udp_poll - wait for a UDP event.
1891 * @file - file struct
1893 * @wait - poll table
1895 * This is same as datagram poll, except for the special case of
1896 * blocking sockets. If application is using a blocking fd
1897 * and a packet with checksum error is in the queue;
1898 * then it could get return from select indicating data available
1899 * but then block when reading it. Add special case code
1900 * to work around these arguably broken applications.
1902 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
1904 unsigned int mask = datagram_poll(file, sock, wait);
1905 struct sock *sk = sock->sk;
1907 /* Check for false positives due to checksum errors */
1908 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
1909 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk))
1910 mask &= ~(POLLIN | POLLRDNORM);
1915 EXPORT_SYMBOL(udp_poll);
1917 struct proto udp_prot = {
1919 .owner = THIS_MODULE,
1920 .close = udp_lib_close,
1921 .connect = ip4_datagram_connect,
1922 .disconnect = udp_disconnect,
1924 .destroy = udp_destroy_sock,
1925 .setsockopt = udp_setsockopt,
1926 .getsockopt = udp_getsockopt,
1927 .sendmsg = udp_sendmsg,
1928 .recvmsg = udp_recvmsg,
1929 .sendpage = udp_sendpage,
1930 .backlog_rcv = __udp_queue_rcv_skb,
1931 .hash = udp_lib_hash,
1932 .unhash = udp_lib_unhash,
1933 .rehash = udp_v4_rehash,
1934 .get_port = udp_v4_get_port,
1935 .memory_allocated = &udp_memory_allocated,
1936 .sysctl_mem = sysctl_udp_mem,
1937 .sysctl_wmem = &sysctl_udp_wmem_min,
1938 .sysctl_rmem = &sysctl_udp_rmem_min,
1939 .obj_size = sizeof(struct udp_sock),
1940 .slab_flags = SLAB_DESTROY_BY_RCU,
1941 .h.udp_table = &udp_table,
1942 #ifdef CONFIG_COMPAT
1943 .compat_setsockopt = compat_udp_setsockopt,
1944 .compat_getsockopt = compat_udp_getsockopt,
1946 .clear_sk = sk_prot_clear_portaddr_nulls,
1948 EXPORT_SYMBOL(udp_prot);
1950 /* ------------------------------------------------------------------------ */
1951 #ifdef CONFIG_PROC_FS
1953 static struct sock *udp_get_first(struct seq_file *seq, int start)
1956 struct udp_iter_state *state = seq->private;
1957 struct net *net = seq_file_net(seq);
1959 for (state->bucket = start; state->bucket <= state->udp_table->mask;
1961 struct hlist_nulls_node *node;
1962 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
1964 if (hlist_nulls_empty(&hslot->head))
1967 spin_lock_bh(&hslot->lock);
1968 sk_nulls_for_each(sk, node, &hslot->head) {
1969 if (!net_eq(sock_net(sk), net))
1971 if (sk->sk_family == state->family)
1974 spin_unlock_bh(&hslot->lock);
1981 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
1983 struct udp_iter_state *state = seq->private;
1984 struct net *net = seq_file_net(seq);
1987 sk = sk_nulls_next(sk);
1988 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
1991 if (state->bucket <= state->udp_table->mask)
1992 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
1993 return udp_get_first(seq, state->bucket + 1);
1998 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
2000 struct sock *sk = udp_get_first(seq, 0);
2003 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
2005 return pos ? NULL : sk;
2008 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
2010 struct udp_iter_state *state = seq->private;
2011 state->bucket = MAX_UDP_PORTS;
2013 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
2016 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2020 if (v == SEQ_START_TOKEN)
2021 sk = udp_get_idx(seq, 0);
2023 sk = udp_get_next(seq, v);
2029 static void udp_seq_stop(struct seq_file *seq, void *v)
2031 struct udp_iter_state *state = seq->private;
2033 if (state->bucket <= state->udp_table->mask)
2034 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2037 static int udp_seq_open(struct inode *inode, struct file *file)
2039 struct udp_seq_afinfo *afinfo = PDE(inode)->data;
2040 struct udp_iter_state *s;
2043 err = seq_open_net(inode, file, &afinfo->seq_ops,
2044 sizeof(struct udp_iter_state));
2048 s = ((struct seq_file *)file->private_data)->private;
2049 s->family = afinfo->family;
2050 s->udp_table = afinfo->udp_table;
2054 /* ------------------------------------------------------------------------ */
2055 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
2057 struct proc_dir_entry *p;
2060 afinfo->seq_fops.open = udp_seq_open;
2061 afinfo->seq_fops.read = seq_read;
2062 afinfo->seq_fops.llseek = seq_lseek;
2063 afinfo->seq_fops.release = seq_release_net;
2065 afinfo->seq_ops.start = udp_seq_start;
2066 afinfo->seq_ops.next = udp_seq_next;
2067 afinfo->seq_ops.stop = udp_seq_stop;
2069 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2070 &afinfo->seq_fops, afinfo);
2075 EXPORT_SYMBOL(udp_proc_register);
2077 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
2079 proc_net_remove(net, afinfo->name);
2081 EXPORT_SYMBOL(udp_proc_unregister);
2083 /* ------------------------------------------------------------------------ */
2084 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
2085 int bucket, int *len)
2087 struct inet_sock *inet = inet_sk(sp);
2088 __be32 dest = inet->inet_daddr;
2089 __be32 src = inet->inet_rcv_saddr;
2090 __u16 destp = ntohs(inet->inet_dport);
2091 __u16 srcp = ntohs(inet->inet_sport);
2093 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
2094 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d%n",
2095 bucket, src, srcp, dest, destp, sp->sk_state,
2096 sk_wmem_alloc_get(sp),
2097 sk_rmem_alloc_get(sp),
2098 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
2099 atomic_read(&sp->sk_refcnt), sp,
2100 atomic_read(&sp->sk_drops), len);
2103 int udp4_seq_show(struct seq_file *seq, void *v)
2105 if (v == SEQ_START_TOKEN)
2106 seq_printf(seq, "%-127s\n",
2107 " sl local_address rem_address st tx_queue "
2108 "rx_queue tr tm->when retrnsmt uid timeout "
2109 "inode ref pointer drops");
2111 struct udp_iter_state *state = seq->private;
2114 udp4_format_sock(v, seq, state->bucket, &len);
2115 seq_printf(seq, "%*s\n", 127 - len, "");
2120 /* ------------------------------------------------------------------------ */
2121 static struct udp_seq_afinfo udp4_seq_afinfo = {
2124 .udp_table = &udp_table,
2126 .owner = THIS_MODULE,
2129 .show = udp4_seq_show,
2133 static int __net_init udp4_proc_init_net(struct net *net)
2135 return udp_proc_register(net, &udp4_seq_afinfo);
2138 static void __net_exit udp4_proc_exit_net(struct net *net)
2140 udp_proc_unregister(net, &udp4_seq_afinfo);
2143 static struct pernet_operations udp4_net_ops = {
2144 .init = udp4_proc_init_net,
2145 .exit = udp4_proc_exit_net,
2148 int __init udp4_proc_init(void)
2150 return register_pernet_subsys(&udp4_net_ops);
2153 void udp4_proc_exit(void)
2155 unregister_pernet_subsys(&udp4_net_ops);
2157 #endif /* CONFIG_PROC_FS */
2159 static __initdata unsigned long uhash_entries;
2160 static int __init set_uhash_entries(char *str)
2164 uhash_entries = simple_strtoul(str, &str, 0);
2165 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
2166 uhash_entries = UDP_HTABLE_SIZE_MIN;
2169 __setup("uhash_entries=", set_uhash_entries);
2171 void __init udp_table_init(struct udp_table *table, const char *name)
2175 if (!CONFIG_BASE_SMALL)
2176 table->hash = alloc_large_system_hash(name,
2177 2 * sizeof(struct udp_hslot),
2179 21, /* one slot per 2 MB */
2185 * Make sure hash table has the minimum size
2187 if (CONFIG_BASE_SMALL || table->mask < UDP_HTABLE_SIZE_MIN - 1) {
2188 table->hash = kmalloc(UDP_HTABLE_SIZE_MIN *
2189 2 * sizeof(struct udp_hslot), GFP_KERNEL);
2192 table->log = ilog2(UDP_HTABLE_SIZE_MIN);
2193 table->mask = UDP_HTABLE_SIZE_MIN - 1;
2195 table->hash2 = table->hash + (table->mask + 1);
2196 for (i = 0; i <= table->mask; i++) {
2197 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
2198 table->hash[i].count = 0;
2199 spin_lock_init(&table->hash[i].lock);
2201 for (i = 0; i <= table->mask; i++) {
2202 INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i);
2203 table->hash2[i].count = 0;
2204 spin_lock_init(&table->hash2[i].lock);
2208 void __init udp_init(void)
2210 unsigned long nr_pages, limit;
2212 udp_table_init(&udp_table, "UDP");
2213 /* Set the pressure threshold up by the same strategy of TCP. It is a
2214 * fraction of global memory that is up to 1/2 at 256 MB, decreasing
2215 * toward zero with the amount of memory, with a floor of 128 pages.
2217 nr_pages = totalram_pages - totalhigh_pages;
2218 limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
2219 limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
2220 limit = max(limit, 128UL);
2221 sysctl_udp_mem[0] = limit / 4 * 3;
2222 sysctl_udp_mem[1] = limit;
2223 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
2225 sysctl_udp_rmem_min = SK_MEM_QUANTUM;
2226 sysctl_udp_wmem_min = SK_MEM_QUANTUM;
2229 int udp4_ufo_send_check(struct sk_buff *skb)
2231 const struct iphdr *iph;
2234 if (!pskb_may_pull(skb, sizeof(*uh)))
2240 uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
2242 skb->csum_start = skb_transport_header(skb) - skb->head;
2243 skb->csum_offset = offsetof(struct udphdr, check);
2244 skb->ip_summed = CHECKSUM_PARTIAL;
2248 struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, u32 features)
2250 struct sk_buff *segs = ERR_PTR(-EINVAL);
2255 mss = skb_shinfo(skb)->gso_size;
2256 if (unlikely(skb->len <= mss))
2259 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
2260 /* Packet is from an untrusted source, reset gso_segs. */
2261 int type = skb_shinfo(skb)->gso_type;
2263 if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) ||
2264 !(type & (SKB_GSO_UDP))))
2267 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
2273 /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
2274 * do checksum of UDP packets sent as multiple IP fragments.
2276 offset = skb_checksum_start_offset(skb);
2277 csum = skb_checksum(skb, offset, skb->len - offset, 0);
2278 offset += skb->csum_offset;
2279 *(__sum16 *)(skb->data + offset) = csum_fold(csum);
2280 skb->ip_summed = CHECKSUM_NONE;
2282 /* Fragment the skb. IP headers of the fragments are updated in
2283 * inet_gso_segment()
2285 segs = skb_segment(skb, features);