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).
8 * Version: $Id: udp.c,v 1.102 2002/02/01 22:01:04 davem Exp $
10 * Authors: Ross Biro, <bir7@leland.Stanford.Edu>
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
13 * Alan Cox, <Alan.Cox@linux.org>
14 * Hirokazu Takahashi, <taka@valinux.co.jp>
17 * Alan Cox : verify_area() calls
18 * Alan Cox : stopped close while in use off icmp
19 * messages. Not a fix but a botch that
20 * for udp at least is 'valid'.
21 * Alan Cox : Fixed icmp handling properly
22 * Alan Cox : Correct error for oversized datagrams
23 * Alan Cox : Tidied select() semantics.
24 * Alan Cox : udp_err() fixed properly, also now
25 * select and read wake correctly on errors
26 * Alan Cox : udp_send verify_area moved to avoid mem leak
27 * Alan Cox : UDP can count its memory
28 * Alan Cox : send to an unknown connection causes
29 * an ECONNREFUSED off the icmp, but
31 * Alan Cox : Switched to new sk_buff handlers. No more backlog!
32 * Alan Cox : Using generic datagram code. Even smaller and the PEEK
33 * bug no longer crashes it.
34 * Fred Van Kempen : Net2e support for sk->broadcast.
35 * Alan Cox : Uses skb_free_datagram
36 * Alan Cox : Added get/set sockopt support.
37 * Alan Cox : Broadcasting without option set returns EACCES.
38 * Alan Cox : No wakeup calls. Instead we now use the callbacks.
39 * Alan Cox : Use ip_tos and ip_ttl
40 * Alan Cox : SNMP Mibs
41 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support.
42 * Matt Dillon : UDP length checks.
43 * Alan Cox : Smarter af_inet used properly.
44 * Alan Cox : Use new kernel side addressing.
45 * Alan Cox : Incorrect return on truncated datagram receive.
46 * Arnt Gulbrandsen : New udp_send and stuff
47 * Alan Cox : Cache last socket
48 * Alan Cox : Route cache
49 * Jon Peatfield : Minor efficiency fix to sendto().
50 * Mike Shaver : RFC1122 checks.
51 * Alan Cox : Nonblocking error fix.
52 * Willy Konynenberg : Transparent proxying support.
53 * Mike McLagan : Routing by source
54 * David S. Miller : New socket lookup architecture.
55 * Last socket cache retained as it
56 * does have a high hit rate.
57 * Olaf Kirch : Don't linearise iovec on sendmsg.
58 * Andi Kleen : Some cleanups, cache destination entry
60 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
61 * Melvin Smith : Check msg_name not msg_namelen in sendto(),
62 * return ENOTCONN for unconnected sockets (POSIX)
63 * Janos Farkas : don't deliver multi/broadcasts to a different
64 * bound-to-device socket
65 * Hirokazu Takahashi : HW checksumming for outgoing UDP
67 * Hirokazu Takahashi : sendfile() on UDP works now.
68 * Arnaldo C. Melo : convert /proc/net/udp to seq_file
69 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
70 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind
71 * a single port at the same time.
72 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
75 * This program is free software; you can redistribute it and/or
76 * modify it under the terms of the GNU General Public License
77 * as published by the Free Software Foundation; either version
78 * 2 of the License, or (at your option) any later version.
81 #include <asm/system.h>
82 #include <asm/uaccess.h>
83 #include <asm/ioctls.h>
84 #include <linux/types.h>
85 #include <linux/fcntl.h>
86 #include <linux/module.h>
87 #include <linux/socket.h>
88 #include <linux/sockios.h>
90 #include <linux/errno.h>
91 #include <linux/timer.h>
93 #include <linux/config.h>
94 #include <linux/inet.h>
95 #include <linux/ipv6.h>
96 #include <linux/netdevice.h>
99 #include <net/protocol.h>
100 #include <linux/skbuff.h>
101 #include <linux/proc_fs.h>
102 #include <linux/seq_file.h>
103 #include <net/sock.h>
105 #include <net/icmp.h>
106 #include <net/route.h>
107 #include <net/inet_common.h>
108 #include <net/checksum.h>
109 #include <net/xfrm.h>
112 * Snmp MIB for the UDP layer
115 DEFINE_SNMP_STAT(struct udp_mib, udp_statistics);
117 struct hlist_head udp_hash[UDP_HTABLE_SIZE];
118 DEFINE_RWLOCK(udp_hash_lock);
120 /* Shared by v4/v6 udp. */
123 static int udp_v4_get_port(struct sock *sk, unsigned short snum)
125 struct hlist_node *node;
127 struct inet_sock *inet = inet_sk(sk);
129 write_lock_bh(&udp_hash_lock);
131 int best_size_so_far, best, result, i;
133 if (udp_port_rover > sysctl_local_port_range[1] ||
134 udp_port_rover < sysctl_local_port_range[0])
135 udp_port_rover = sysctl_local_port_range[0];
136 best_size_so_far = 32767;
137 best = result = udp_port_rover;
138 for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) {
139 struct hlist_head *list;
142 list = &udp_hash[result & (UDP_HTABLE_SIZE - 1)];
143 if (hlist_empty(list)) {
144 if (result > sysctl_local_port_range[1])
145 result = sysctl_local_port_range[0] +
146 ((result - sysctl_local_port_range[0]) &
147 (UDP_HTABLE_SIZE - 1));
151 sk_for_each(sk2, node, list)
152 if (++size >= best_size_so_far)
154 best_size_so_far = size;
159 for(i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++, result += UDP_HTABLE_SIZE) {
160 if (result > sysctl_local_port_range[1])
161 result = sysctl_local_port_range[0]
162 + ((result - sysctl_local_port_range[0]) &
163 (UDP_HTABLE_SIZE - 1));
164 if (!udp_lport_inuse(result))
167 if (i >= (1 << 16) / UDP_HTABLE_SIZE)
170 udp_port_rover = snum = result;
172 sk_for_each(sk2, node,
173 &udp_hash[snum & (UDP_HTABLE_SIZE - 1)]) {
174 struct inet_sock *inet2 = inet_sk(sk2);
176 if (inet2->num == snum &&
178 !ipv6_only_sock(sk2) &&
179 (!sk2->sk_bound_dev_if ||
180 !sk->sk_bound_dev_if ||
181 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
182 (!inet2->rcv_saddr ||
184 inet2->rcv_saddr == inet->rcv_saddr) &&
185 (!sk2->sk_reuse || !sk->sk_reuse))
190 if (sk_unhashed(sk)) {
191 struct hlist_head *h = &udp_hash[snum & (UDP_HTABLE_SIZE - 1)];
194 sock_prot_inc_use(sk->sk_prot);
196 write_unlock_bh(&udp_hash_lock);
200 write_unlock_bh(&udp_hash_lock);
204 static void udp_v4_hash(struct sock *sk)
209 static void udp_v4_unhash(struct sock *sk)
211 write_lock_bh(&udp_hash_lock);
212 if (sk_del_node_init(sk)) {
213 inet_sk(sk)->num = 0;
214 sock_prot_dec_use(sk->sk_prot);
216 write_unlock_bh(&udp_hash_lock);
219 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
220 * harder than this. -DaveM
222 static struct sock *udp_v4_lookup_longway(u32 saddr, u16 sport,
223 u32 daddr, u16 dport, int dif)
225 struct sock *sk, *result = NULL;
226 struct hlist_node *node;
227 unsigned short hnum = ntohs(dport);
230 sk_for_each(sk, node, &udp_hash[hnum & (UDP_HTABLE_SIZE - 1)]) {
231 struct inet_sock *inet = inet_sk(sk);
233 if (inet->num == hnum && !ipv6_only_sock(sk)) {
234 int score = (sk->sk_family == PF_INET ? 1 : 0);
235 if (inet->rcv_saddr) {
236 if (inet->rcv_saddr != daddr)
241 if (inet->daddr != saddr)
246 if (inet->dport != sport)
250 if (sk->sk_bound_dev_if) {
251 if (sk->sk_bound_dev_if != dif)
258 } else if(score > badness) {
267 static __inline__ struct sock *udp_v4_lookup(u32 saddr, u16 sport,
268 u32 daddr, u16 dport, int dif)
272 read_lock(&udp_hash_lock);
273 sk = udp_v4_lookup_longway(saddr, sport, daddr, dport, dif);
276 read_unlock(&udp_hash_lock);
280 static inline struct sock *udp_v4_mcast_next(struct sock *sk,
281 u16 loc_port, u32 loc_addr,
282 u16 rmt_port, u32 rmt_addr,
285 struct hlist_node *node;
287 unsigned short hnum = ntohs(loc_port);
289 sk_for_each_from(s, node) {
290 struct inet_sock *inet = inet_sk(s);
292 if (inet->num != hnum ||
293 (inet->daddr && inet->daddr != rmt_addr) ||
294 (inet->dport != rmt_port && inet->dport) ||
295 (inet->rcv_saddr && inet->rcv_saddr != loc_addr) ||
297 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
299 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
309 * This routine is called by the ICMP module when it gets some
310 * sort of error condition. If err < 0 then the socket should
311 * be closed and the error returned to the user. If err > 0
312 * it's just the icmp type << 8 | icmp code.
313 * Header points to the ip header of the error packet. We move
314 * on past this. Then (as it used to claim before adjustment)
315 * header points to the first 8 bytes of the udp header. We need
316 * to find the appropriate port.
319 void udp_err(struct sk_buff *skb, u32 info)
321 struct inet_sock *inet;
322 struct iphdr *iph = (struct iphdr*)skb->data;
323 struct udphdr *uh = (struct udphdr*)(skb->data+(iph->ihl<<2));
324 int type = skb->h.icmph->type;
325 int code = skb->h.icmph->code;
330 sk = udp_v4_lookup(iph->daddr, uh->dest, iph->saddr, uh->source, skb->dev->ifindex);
332 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
333 return; /* No socket for error */
342 case ICMP_TIME_EXCEEDED:
345 case ICMP_SOURCE_QUENCH:
347 case ICMP_PARAMETERPROB:
351 case ICMP_DEST_UNREACH:
352 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
353 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
361 if (code <= NR_ICMP_UNREACH) {
362 harderr = icmp_err_convert[code].fatal;
363 err = icmp_err_convert[code].errno;
369 * RFC1122: OK. Passes ICMP errors back to application, as per
372 if (!inet->recverr) {
373 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
376 ip_icmp_error(sk, skb, err, uh->dest, info, (u8*)(uh+1));
379 sk->sk_error_report(sk);
385 * Throw away all pending data and cancel the corking. Socket is locked.
387 static void udp_flush_pending_frames(struct sock *sk)
389 struct udp_sock *up = udp_sk(sk);
394 ip_flush_pending_frames(sk);
399 * Push out all pending data as one UDP datagram. Socket is locked.
401 static int udp_push_pending_frames(struct sock *sk, struct udp_sock *up)
403 struct inet_sock *inet = inet_sk(sk);
404 struct flowi *fl = &inet->cork.fl;
409 /* Grab the skbuff where UDP header space exists. */
410 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
414 * Create a UDP header
417 uh->source = fl->fl_ip_sport;
418 uh->dest = fl->fl_ip_dport;
419 uh->len = htons(up->len);
422 if (sk->sk_no_check == UDP_CSUM_NOXMIT) {
423 skb->ip_summed = CHECKSUM_NONE;
427 if (skb_queue_len(&sk->sk_write_queue) == 1) {
429 * Only one fragment on the socket.
431 if (skb->ip_summed == CHECKSUM_HW) {
432 skb->csum = offsetof(struct udphdr, check);
433 uh->check = ~csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst,
434 up->len, IPPROTO_UDP, 0);
436 skb->csum = csum_partial((char *)uh,
437 sizeof(struct udphdr), skb->csum);
438 uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst,
439 up->len, IPPROTO_UDP, skb->csum);
444 unsigned int csum = 0;
446 * HW-checksum won't work as there are two or more
447 * fragments on the socket so that all csums of sk_buffs
448 * should be together.
450 if (skb->ip_summed == CHECKSUM_HW) {
451 int offset = (unsigned char *)uh - skb->data;
452 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
454 skb->ip_summed = CHECKSUM_NONE;
456 skb->csum = csum_partial((char *)uh,
457 sizeof(struct udphdr), skb->csum);
460 skb_queue_walk(&sk->sk_write_queue, skb) {
461 csum = csum_add(csum, skb->csum);
463 uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst,
464 up->len, IPPROTO_UDP, csum);
469 err = ip_push_pending_frames(sk);
477 static unsigned short udp_check(struct udphdr *uh, int len, unsigned long saddr, unsigned long daddr, unsigned long base)
479 return(csum_tcpudp_magic(saddr, daddr, len, IPPROTO_UDP, base));
482 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
485 struct inet_sock *inet = inet_sk(sk);
486 struct udp_sock *up = udp_sk(sk);
488 struct ipcm_cookie ipc;
489 struct rtable *rt = NULL;
492 u32 daddr, faddr, saddr;
496 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
505 if (msg->msg_flags&MSG_OOB) /* Mirror BSD error message compatibility */
512 * There are pending frames.
513 * The socket lock must be held while it's corked.
516 if (likely(up->pending)) {
517 if (unlikely(up->pending != AF_INET)) {
525 ulen += sizeof(struct udphdr);
528 * Get and verify the address.
531 struct sockaddr_in * usin = (struct sockaddr_in*)msg->msg_name;
532 if (msg->msg_namelen < sizeof(*usin))
534 if (usin->sin_family != AF_INET) {
535 if (usin->sin_family != AF_UNSPEC)
536 return -EAFNOSUPPORT;
539 daddr = usin->sin_addr.s_addr;
540 dport = usin->sin_port;
544 if (sk->sk_state != TCP_ESTABLISHED)
545 return -EDESTADDRREQ;
548 /* Open fast path for connected socket.
549 Route will not be used, if at least one option is set.
553 ipc.addr = inet->saddr;
555 ipc.oif = sk->sk_bound_dev_if;
556 if (msg->msg_controllen) {
557 err = ip_cmsg_send(msg, &ipc);
568 ipc.addr = faddr = daddr;
570 if (ipc.opt && ipc.opt->srr) {
573 faddr = ipc.opt->faddr;
576 tos = RT_TOS(inet->tos);
577 if (sk->sk_localroute || (msg->msg_flags & MSG_DONTROUTE) ||
578 (ipc.opt && ipc.opt->is_strictroute)) {
583 if (MULTICAST(daddr)) {
585 ipc.oif = inet->mc_index;
587 saddr = inet->mc_addr;
592 rt = (struct rtable*)sk_dst_check(sk, 0);
595 struct flowi fl = { .oif = ipc.oif,
600 .proto = IPPROTO_UDP,
602 { .sport = inet->sport,
603 .dport = dport } } };
604 err = ip_route_output_flow(&rt, &fl, sk, !(msg->msg_flags&MSG_DONTWAIT));
609 if ((rt->rt_flags & RTCF_BROADCAST) &&
610 !sock_flag(sk, SOCK_BROADCAST))
613 sk_dst_set(sk, dst_clone(&rt->u.dst));
616 if (msg->msg_flags&MSG_CONFIRM)
622 daddr = ipc.addr = rt->rt_dst;
625 if (unlikely(up->pending)) {
626 /* The socket is already corked while preparing it. */
627 /* ... which is an evident application bug. --ANK */
630 NETDEBUG(if (net_ratelimit()) printk(KERN_DEBUG "udp cork app bug 2\n"));
635 * Now cork the socket to pend data.
637 inet->cork.fl.fl4_dst = daddr;
638 inet->cork.fl.fl_ip_dport = dport;
639 inet->cork.fl.fl4_src = saddr;
640 inet->cork.fl.fl_ip_sport = inet->sport;
641 up->pending = AF_INET;
645 err = ip_append_data(sk, ip_generic_getfrag, msg->msg_iov, ulen,
646 sizeof(struct udphdr), &ipc, rt,
647 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
649 udp_flush_pending_frames(sk);
651 err = udp_push_pending_frames(sk, up);
659 UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS);
665 dst_confirm(&rt->u.dst);
666 if (!(msg->msg_flags&MSG_PROBE) || len)
667 goto back_from_confirm;
672 static int udp_sendpage(struct sock *sk, struct page *page, int offset,
673 size_t size, int flags)
675 struct udp_sock *up = udp_sk(sk);
679 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
681 /* Call udp_sendmsg to specify destination address which
682 * sendpage interface can't pass.
683 * This will succeed only when the socket is connected.
685 ret = udp_sendmsg(NULL, sk, &msg, 0);
692 if (unlikely(!up->pending)) {
695 NETDEBUG(if (net_ratelimit()) printk(KERN_DEBUG "udp cork app bug 3\n"));
699 ret = ip_append_page(sk, page, offset, size, flags);
700 if (ret == -EOPNOTSUPP) {
702 return sock_no_sendpage(sk->sk_socket, page, offset,
706 udp_flush_pending_frames(sk);
711 if (!(up->corkflag || (flags&MSG_MORE)))
712 ret = udp_push_pending_frames(sk, up);
721 * IOCTL requests applicable to the UDP protocol
724 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
730 int amount = atomic_read(&sk->sk_wmem_alloc);
731 return put_user(amount, (int __user *)arg);
737 unsigned long amount;
740 spin_lock_irq(&sk->sk_receive_queue.lock);
741 skb = skb_peek(&sk->sk_receive_queue);
744 * We will only return the amount
745 * of this packet since that is all
748 amount = skb->len - sizeof(struct udphdr);
750 spin_unlock_irq(&sk->sk_receive_queue.lock);
751 return put_user(amount, (int __user *)arg);
760 static __inline__ int __udp_checksum_complete(struct sk_buff *skb)
762 return (unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum));
765 static __inline__ int udp_checksum_complete(struct sk_buff *skb)
767 return skb->ip_summed != CHECKSUM_UNNECESSARY &&
768 __udp_checksum_complete(skb);
772 * This should be easy, if there is something there we
773 * return it, otherwise we block.
776 static int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
777 size_t len, int noblock, int flags, int *addr_len)
779 struct inet_sock *inet = inet_sk(sk);
780 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
785 * Check any passed addresses
788 *addr_len=sizeof(*sin);
790 if (flags & MSG_ERRQUEUE)
791 return ip_recv_error(sk, msg, len);
794 skb = skb_recv_datagram(sk, flags, noblock, &err);
798 copied = skb->len - sizeof(struct udphdr);
801 msg->msg_flags |= MSG_TRUNC;
804 if (skb->ip_summed==CHECKSUM_UNNECESSARY) {
805 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
807 } else if (msg->msg_flags&MSG_TRUNC) {
808 if (__udp_checksum_complete(skb))
810 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
813 err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
822 sock_recv_timestamp(msg, sk, skb);
824 /* Copy the address. */
827 sin->sin_family = AF_INET;
828 sin->sin_port = skb->h.uh->source;
829 sin->sin_addr.s_addr = skb->nh.iph->saddr;
830 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
832 if (inet->cmsg_flags)
833 ip_cmsg_recv(msg, skb);
836 if (flags & MSG_TRUNC)
837 err = skb->len - sizeof(struct udphdr);
840 skb_free_datagram(sk, skb);
845 UDP_INC_STATS_BH(UDP_MIB_INERRORS);
848 if (flags&MSG_PEEK) {
850 spin_lock_irq(&sk->sk_receive_queue.lock);
851 if (skb == skb_peek(&sk->sk_receive_queue)) {
852 __skb_unlink(skb, &sk->sk_receive_queue);
855 spin_unlock_irq(&sk->sk_receive_queue.lock);
860 skb_free_datagram(sk, skb);
868 int udp_disconnect(struct sock *sk, int flags)
870 struct inet_sock *inet = inet_sk(sk);
872 * 1003.1g - break association.
875 sk->sk_state = TCP_CLOSE;
878 sk->sk_bound_dev_if = 0;
879 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
880 inet_reset_saddr(sk);
882 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
883 sk->sk_prot->unhash(sk);
890 static void udp_close(struct sock *sk, long timeout)
892 sk_common_release(sk);
896 * 1 if the the UDP system should process it
897 * 0 if we should drop this packet
898 * -1 if it should get processed by xfrm4_rcv_encap
900 static int udp_encap_rcv(struct sock * sk, struct sk_buff *skb)
905 struct udp_sock *up = udp_sk(sk);
906 struct udphdr *uh = skb->h.uh;
910 __u8 *udpdata = (__u8 *)uh + sizeof(struct udphdr);
911 __u32 *udpdata32 = (__u32 *)udpdata;
912 __u16 encap_type = up->encap_type;
914 /* if we're overly short, let UDP handle it */
915 if (udpdata > skb->tail)
918 /* if this is not encapsulated socket, then just return now */
922 len = skb->tail - udpdata;
924 switch (encap_type) {
926 case UDP_ENCAP_ESPINUDP:
927 /* Check if this is a keepalive packet. If so, eat it. */
928 if (len == 1 && udpdata[0] == 0xff) {
930 } else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0 ) {
931 /* ESP Packet without Non-ESP header */
932 len = sizeof(struct udphdr);
934 /* Must be an IKE packet.. pass it through */
937 case UDP_ENCAP_ESPINUDP_NON_IKE:
938 /* Check if this is a keepalive packet. If so, eat it. */
939 if (len == 1 && udpdata[0] == 0xff) {
941 } else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) &&
942 udpdata32[0] == 0 && udpdata32[1] == 0) {
944 /* ESP Packet with Non-IKE marker */
945 len = sizeof(struct udphdr) + 2 * sizeof(u32);
947 /* Must be an IKE packet.. pass it through */
952 /* At this point we are sure that this is an ESPinUDP packet,
953 * so we need to remove 'len' bytes from the packet (the UDP
954 * header and optional ESP marker bytes) and then modify the
955 * protocol to ESP, and then call into the transform receiver.
958 /* Now we can update and verify the packet length... */
960 iphlen = iph->ihl << 2;
961 iph->tot_len = htons(ntohs(iph->tot_len) - len);
962 if (skb->len < iphlen + len) {
963 /* packet is too small!?! */
967 /* pull the data buffer up to the ESP header and set the
968 * transport header to point to ESP. Keep UDP on the stack
971 skb->h.raw = skb_pull(skb, len);
973 /* modify the protocol (it's ESP!) */
974 iph->protocol = IPPROTO_ESP;
976 /* and let the caller know to send this into the ESP processor... */
984 * >0: "udp encap" protocol resubmission
986 * Note that in the success and error cases, the skb is assumed to
987 * have either been requeued or freed.
989 static int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
991 struct udp_sock *up = udp_sk(sk);
994 * Charge it to the socket, dropping if the queue is full.
996 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) {
1001 if (up->encap_type) {
1003 * This is an encapsulation socket, so let's see if this is
1004 * an encapsulated packet.
1005 * If it's a keepalive packet, then just eat it.
1006 * If it's an encapsulateed packet, then pass it to the
1007 * IPsec xfrm input and return the response
1008 * appropriately. Otherwise, just fall through and
1009 * pass this up the UDP socket.
1013 ret = udp_encap_rcv(sk, skb);
1015 /* Eat the packet .. */
1020 /* process the ESP packet */
1021 ret = xfrm4_rcv_encap(skb, up->encap_type);
1022 UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS);
1025 /* FALLTHROUGH -- it's a UDP Packet */
1028 if (sk->sk_filter && skb->ip_summed != CHECKSUM_UNNECESSARY) {
1029 if (__udp_checksum_complete(skb)) {
1030 UDP_INC_STATS_BH(UDP_MIB_INERRORS);
1034 skb->ip_summed = CHECKSUM_UNNECESSARY;
1037 if (sock_queue_rcv_skb(sk,skb)<0) {
1038 UDP_INC_STATS_BH(UDP_MIB_INERRORS);
1042 UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS);
1047 * Multicasts and broadcasts go to each listener.
1049 * Note: called only from the BH handler context,
1050 * so we don't need to lock the hashes.
1052 static int udp_v4_mcast_deliver(struct sk_buff *skb, struct udphdr *uh,
1053 u32 saddr, u32 daddr)
1058 read_lock(&udp_hash_lock);
1059 sk = sk_head(&udp_hash[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]);
1060 dif = skb->dev->ifindex;
1061 sk = udp_v4_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif);
1063 struct sock *sknext = NULL;
1066 struct sk_buff *skb1 = skb;
1068 sknext = udp_v4_mcast_next(sk_next(sk), uh->dest, daddr,
1069 uh->source, saddr, dif);
1071 skb1 = skb_clone(skb, GFP_ATOMIC);
1074 int ret = udp_queue_rcv_skb(sk, skb1);
1076 /* we should probably re-process instead
1077 * of dropping packets here. */
1084 read_unlock(&udp_hash_lock);
1088 /* Initialize UDP checksum. If exited with zero value (success),
1089 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1090 * Otherwise, csum completion requires chacksumming packet body,
1091 * including udp header and folding it to skb->csum.
1093 static int udp_checksum_init(struct sk_buff *skb, struct udphdr *uh,
1094 unsigned short ulen, u32 saddr, u32 daddr)
1096 if (uh->check == 0) {
1097 skb->ip_summed = CHECKSUM_UNNECESSARY;
1098 } else if (skb->ip_summed == CHECKSUM_HW) {
1099 skb->ip_summed = CHECKSUM_UNNECESSARY;
1100 if (!udp_check(uh, ulen, saddr, daddr, skb->csum))
1102 NETDEBUG(if (net_ratelimit()) printk(KERN_DEBUG "udp v4 hw csum failure.\n"));
1103 skb->ip_summed = CHECKSUM_NONE;
1105 if (skb->ip_summed != CHECKSUM_UNNECESSARY)
1106 skb->csum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
1107 /* Probably, we should checksum udp header (it should be in cache
1108 * in any case) and data in tiny packets (< rx copybreak).
1114 * All we need to do is get the socket, and then do a checksum.
1117 int udp_rcv(struct sk_buff *skb)
1121 unsigned short ulen;
1122 struct rtable *rt = (struct rtable*)skb->dst;
1123 u32 saddr = skb->nh.iph->saddr;
1124 u32 daddr = skb->nh.iph->daddr;
1128 * Validate the packet and the UDP length.
1130 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1135 ulen = ntohs(uh->len);
1137 if (ulen > len || ulen < sizeof(*uh))
1140 if (pskb_trim(skb, ulen))
1143 if (udp_checksum_init(skb, uh, ulen, saddr, daddr) < 0)
1146 if(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1147 return udp_v4_mcast_deliver(skb, uh, saddr, daddr);
1149 sk = udp_v4_lookup(saddr, uh->source, daddr, uh->dest, skb->dev->ifindex);
1152 int ret = udp_queue_rcv_skb(sk, skb);
1155 /* a return value > 0 means to resubmit the input, but
1156 * it it wants the return to be -protocol, or 0
1163 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1166 /* No socket. Drop packet silently, if checksum is wrong */
1167 if (udp_checksum_complete(skb))
1170 UDP_INC_STATS_BH(UDP_MIB_NOPORTS);
1171 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
1174 * Hmm. We got an UDP packet to a port to which we
1175 * don't wanna listen. Ignore it.
1181 NETDEBUG(if (net_ratelimit())
1182 printk(KERN_DEBUG "UDP: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n",
1190 UDP_INC_STATS_BH(UDP_MIB_INERRORS);
1196 * RFC1122: OK. Discards the bad packet silently (as far as
1197 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1199 NETDEBUG(if (net_ratelimit())
1200 printk(KERN_DEBUG "UDP: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n",
1207 UDP_INC_STATS_BH(UDP_MIB_INERRORS);
1212 static int udp_destroy_sock(struct sock *sk)
1215 udp_flush_pending_frames(sk);
1221 * Socket option code for UDP
1223 static int udp_setsockopt(struct sock *sk, int level, int optname,
1224 char __user *optval, int optlen)
1226 struct udp_sock *up = udp_sk(sk);
1230 if (level != SOL_UDP)
1231 return ip_setsockopt(sk, level, optname, optval, optlen);
1233 if(optlen<sizeof(int))
1236 if (get_user(val, (int __user *)optval))
1246 udp_push_pending_frames(sk, up);
1254 case UDP_ENCAP_ESPINUDP:
1255 case UDP_ENCAP_ESPINUDP_NON_IKE:
1256 up->encap_type = val;
1272 static int udp_getsockopt(struct sock *sk, int level, int optname,
1273 char __user *optval, int __user *optlen)
1275 struct udp_sock *up = udp_sk(sk);
1278 if (level != SOL_UDP)
1279 return ip_getsockopt(sk, level, optname, optval, optlen);
1281 if(get_user(len,optlen))
1284 len = min_t(unsigned int, len, sizeof(int));
1295 val = up->encap_type;
1299 return -ENOPROTOOPT;
1302 if(put_user(len, optlen))
1304 if(copy_to_user(optval, &val,len))
1310 * udp_poll - wait for a UDP event.
1311 * @file - file struct
1313 * @wait - poll table
1315 * This is same as datagram poll, except for the special case of
1316 * blocking sockets. If application is using a blocking fd
1317 * and a packet with checksum error is in the queue;
1318 * then it could get return from select indicating data available
1319 * but then block when reading it. Add special case code
1320 * to work around these arguably broken applications.
1322 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
1324 unsigned int mask = datagram_poll(file, sock, wait);
1325 struct sock *sk = sock->sk;
1327 /* Check for false positives due to checksum errors */
1328 if ( (mask & POLLRDNORM) &&
1329 !(file->f_flags & O_NONBLOCK) &&
1330 !(sk->sk_shutdown & RCV_SHUTDOWN)){
1331 struct sk_buff_head *rcvq = &sk->sk_receive_queue;
1332 struct sk_buff *skb;
1334 spin_lock_irq(&rcvq->lock);
1335 while ((skb = skb_peek(rcvq)) != NULL) {
1336 if (udp_checksum_complete(skb)) {
1337 UDP_INC_STATS_BH(UDP_MIB_INERRORS);
1338 __skb_unlink(skb, rcvq);
1341 skb->ip_summed = CHECKSUM_UNNECESSARY;
1345 spin_unlock_irq(&rcvq->lock);
1347 /* nothing to see, move along */
1349 mask &= ~(POLLIN | POLLRDNORM);
1356 struct proto udp_prot = {
1358 .owner = THIS_MODULE,
1360 .connect = ip4_datagram_connect,
1361 .disconnect = udp_disconnect,
1363 .destroy = udp_destroy_sock,
1364 .setsockopt = udp_setsockopt,
1365 .getsockopt = udp_getsockopt,
1366 .sendmsg = udp_sendmsg,
1367 .recvmsg = udp_recvmsg,
1368 .sendpage = udp_sendpage,
1369 .backlog_rcv = udp_queue_rcv_skb,
1370 .hash = udp_v4_hash,
1371 .unhash = udp_v4_unhash,
1372 .get_port = udp_v4_get_port,
1373 .slab_obj_size = sizeof(struct udp_sock),
1376 /* ------------------------------------------------------------------------ */
1377 #ifdef CONFIG_PROC_FS
1379 static struct sock *udp_get_first(struct seq_file *seq)
1382 struct udp_iter_state *state = seq->private;
1384 for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
1385 struct hlist_node *node;
1386 sk_for_each(sk, node, &udp_hash[state->bucket]) {
1387 if (sk->sk_family == state->family)
1396 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
1398 struct udp_iter_state *state = seq->private;
1404 } while (sk && sk->sk_family != state->family);
1406 if (!sk && ++state->bucket < UDP_HTABLE_SIZE) {
1407 sk = sk_head(&udp_hash[state->bucket]);
1413 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
1415 struct sock *sk = udp_get_first(seq);
1418 while(pos && (sk = udp_get_next(seq, sk)) != NULL)
1420 return pos ? NULL : sk;
1423 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
1425 read_lock(&udp_hash_lock);
1426 return *pos ? udp_get_idx(seq, *pos-1) : (void *)1;
1429 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1434 sk = udp_get_idx(seq, 0);
1436 sk = udp_get_next(seq, v);
1442 static void udp_seq_stop(struct seq_file *seq, void *v)
1444 read_unlock(&udp_hash_lock);
1447 static int udp_seq_open(struct inode *inode, struct file *file)
1449 struct udp_seq_afinfo *afinfo = PDE(inode)->data;
1450 struct seq_file *seq;
1452 struct udp_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
1456 memset(s, 0, sizeof(*s));
1457 s->family = afinfo->family;
1458 s->seq_ops.start = udp_seq_start;
1459 s->seq_ops.next = udp_seq_next;
1460 s->seq_ops.show = afinfo->seq_show;
1461 s->seq_ops.stop = udp_seq_stop;
1463 rc = seq_open(file, &s->seq_ops);
1467 seq = file->private_data;
1476 /* ------------------------------------------------------------------------ */
1477 int udp_proc_register(struct udp_seq_afinfo *afinfo)
1479 struct proc_dir_entry *p;
1484 afinfo->seq_fops->owner = afinfo->owner;
1485 afinfo->seq_fops->open = udp_seq_open;
1486 afinfo->seq_fops->read = seq_read;
1487 afinfo->seq_fops->llseek = seq_lseek;
1488 afinfo->seq_fops->release = seq_release_private;
1490 p = proc_net_fops_create(afinfo->name, S_IRUGO, afinfo->seq_fops);
1498 void udp_proc_unregister(struct udp_seq_afinfo *afinfo)
1502 proc_net_remove(afinfo->name);
1503 memset(afinfo->seq_fops, 0, sizeof(*afinfo->seq_fops));
1506 /* ------------------------------------------------------------------------ */
1507 static void udp4_format_sock(struct sock *sp, char *tmpbuf, int bucket)
1509 struct inet_sock *inet = inet_sk(sp);
1510 unsigned int dest = inet->daddr;
1511 unsigned int src = inet->rcv_saddr;
1512 __u16 destp = ntohs(inet->dport);
1513 __u16 srcp = ntohs(inet->sport);
1515 sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"
1516 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p",
1517 bucket, src, srcp, dest, destp, sp->sk_state,
1518 atomic_read(&sp->sk_wmem_alloc),
1519 atomic_read(&sp->sk_rmem_alloc),
1520 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
1521 atomic_read(&sp->sk_refcnt), sp);
1524 static int udp4_seq_show(struct seq_file *seq, void *v)
1526 if (v == SEQ_START_TOKEN)
1527 seq_printf(seq, "%-127s\n",
1528 " sl local_address rem_address st tx_queue "
1529 "rx_queue tr tm->when retrnsmt uid timeout "
1533 struct udp_iter_state *state = seq->private;
1535 udp4_format_sock(v, tmpbuf, state->bucket);
1536 seq_printf(seq, "%-127s\n", tmpbuf);
1541 /* ------------------------------------------------------------------------ */
1542 static struct file_operations udp4_seq_fops;
1543 static struct udp_seq_afinfo udp4_seq_afinfo = {
1544 .owner = THIS_MODULE,
1547 .seq_show = udp4_seq_show,
1548 .seq_fops = &udp4_seq_fops,
1551 int __init udp4_proc_init(void)
1553 return udp_proc_register(&udp4_seq_afinfo);
1556 void udp4_proc_exit(void)
1558 udp_proc_unregister(&udp4_seq_afinfo);
1560 #endif /* CONFIG_PROC_FS */
1562 EXPORT_SYMBOL(udp_disconnect);
1563 EXPORT_SYMBOL(udp_hash);
1564 EXPORT_SYMBOL(udp_hash_lock);
1565 EXPORT_SYMBOL(udp_ioctl);
1566 EXPORT_SYMBOL(udp_port_rover);
1567 EXPORT_SYMBOL(udp_prot);
1568 EXPORT_SYMBOL(udp_sendmsg);
1569 EXPORT_SYMBOL(udp_poll);
1571 #ifdef CONFIG_PROC_FS
1572 EXPORT_SYMBOL(udp_proc_register);
1573 EXPORT_SYMBOL(udp_proc_unregister);