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 <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"
109 struct udp_table udp_table __read_mostly;
110 EXPORT_SYMBOL(udp_table);
112 int sysctl_udp_mem[3] __read_mostly;
113 EXPORT_SYMBOL(sysctl_udp_mem);
115 int sysctl_udp_rmem_min __read_mostly;
116 EXPORT_SYMBOL(sysctl_udp_rmem_min);
118 int sysctl_udp_wmem_min __read_mostly;
119 EXPORT_SYMBOL(sysctl_udp_wmem_min);
121 atomic_t udp_memory_allocated;
122 EXPORT_SYMBOL(udp_memory_allocated);
124 #define MAX_UDP_PORTS 65536
125 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
127 static int udp_lib_lport_inuse(struct net *net, __u16 num,
128 const struct udp_hslot *hslot,
129 unsigned long *bitmap,
131 int (*saddr_comp)(const struct sock *sk1,
132 const struct sock *sk2),
136 struct hlist_nulls_node *node;
138 sk_nulls_for_each(sk2, node, &hslot->head)
139 if (net_eq(sock_net(sk2), net) &&
141 (bitmap || sk2->sk_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)) {
147 __set_bit(sk2->sk_hash >> log, bitmap);
155 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
157 * @sk: socket struct in question
158 * @snum: port number to look up
159 * @saddr_comp: AF-dependent comparison of bound local IP addresses
161 int udp_lib_get_port(struct sock *sk, unsigned short snum,
162 int (*saddr_comp)(const struct sock *sk1,
163 const struct sock *sk2))
165 struct udp_hslot *hslot;
166 struct udp_table *udptable = sk->sk_prot->h.udp_table;
168 struct net *net = sock_net(sk);
171 int low, high, remaining;
173 unsigned short first, last;
174 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
176 inet_get_local_port_range(&low, &high);
177 remaining = (high - low) + 1;
180 first = (((u64)rand * remaining) >> 32) + low;
182 * force rand to be an odd multiple of UDP_HTABLE_SIZE
184 rand = (rand | 1) * (udptable->mask + 1);
185 for (last = first + udptable->mask + 1;
188 hslot = udp_hashslot(udptable, net, first);
189 bitmap_zero(bitmap, PORTS_PER_CHAIN);
190 spin_lock_bh(&hslot->lock);
191 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
192 saddr_comp, udptable->log);
196 * Iterate on all possible values of snum for this hash.
197 * Using steps of an odd multiple of UDP_HTABLE_SIZE
198 * give us randomization and full range coverage.
201 if (low <= snum && snum <= high &&
202 !test_bit(snum >> udptable->log, bitmap))
205 } while (snum != first);
206 spin_unlock_bh(&hslot->lock);
210 hslot = udp_hashslot(udptable, net, snum);
211 spin_lock_bh(&hslot->lock);
212 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk,
217 inet_sk(sk)->inet_num = snum;
219 if (sk_unhashed(sk)) {
220 sk_nulls_add_node_rcu(sk, &hslot->head);
221 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
225 spin_unlock_bh(&hslot->lock);
229 EXPORT_SYMBOL(udp_lib_get_port);
231 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
233 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
235 return (!ipv6_only_sock(sk2) &&
236 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr ||
237 inet1->inet_rcv_saddr == inet2->inet_rcv_saddr));
240 int udp_v4_get_port(struct sock *sk, unsigned short snum)
242 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal);
245 static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr,
247 __be16 sport, __be32 daddr, __be16 dport, int dif)
251 if (net_eq(sock_net(sk), net) && sk->sk_hash == hnum &&
252 !ipv6_only_sock(sk)) {
253 struct inet_sock *inet = inet_sk(sk);
255 score = (sk->sk_family == PF_INET ? 1 : 0);
256 if (inet->inet_rcv_saddr) {
257 if (inet->inet_rcv_saddr != daddr)
261 if (inet->inet_daddr) {
262 if (inet->inet_daddr != saddr)
266 if (inet->inet_dport) {
267 if (inet->inet_dport != sport)
271 if (sk->sk_bound_dev_if) {
272 if (sk->sk_bound_dev_if != dif)
280 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
281 * harder than this. -DaveM
283 static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
284 __be16 sport, __be32 daddr, __be16 dport,
285 int dif, struct udp_table *udptable)
287 struct sock *sk, *result;
288 struct hlist_nulls_node *node;
289 unsigned short hnum = ntohs(dport);
290 unsigned int hash = udp_hashfn(net, hnum, udptable->mask);
291 struct udp_hslot *hslot = &udptable->hash[hash];
298 sk_nulls_for_each_rcu(sk, node, &hslot->head) {
299 score = compute_score(sk, net, saddr, hnum, sport,
301 if (score > badness) {
307 * if the nulls value we got at the end of this lookup is
308 * not the expected one, we must restart lookup.
309 * We probably met an item that was moved to another chain.
311 if (get_nulls_value(node) != hash)
315 if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
317 else if (unlikely(compute_score(result, net, saddr, hnum, sport,
318 daddr, dport, dif) < badness)) {
327 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
328 __be16 sport, __be16 dport,
329 struct udp_table *udptable)
332 const struct iphdr *iph = ip_hdr(skb);
334 if (unlikely(sk = skb_steal_sock(skb)))
337 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport,
338 iph->daddr, dport, inet_iif(skb),
342 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
343 __be32 daddr, __be16 dport, int dif)
345 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
347 EXPORT_SYMBOL_GPL(udp4_lib_lookup);
349 static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
350 __be16 loc_port, __be32 loc_addr,
351 __be16 rmt_port, __be32 rmt_addr,
354 struct hlist_nulls_node *node;
356 unsigned short hnum = ntohs(loc_port);
358 sk_nulls_for_each_from(s, node) {
359 struct inet_sock *inet = inet_sk(s);
361 if (!net_eq(sock_net(s), net) ||
362 s->sk_hash != hnum ||
363 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
364 (inet->inet_dport != rmt_port && inet->inet_dport) ||
365 (inet->inet_rcv_saddr &&
366 inet->inet_rcv_saddr != loc_addr) ||
368 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
370 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
380 * This routine is called by the ICMP module when it gets some
381 * sort of error condition. If err < 0 then the socket should
382 * be closed and the error returned to the user. If err > 0
383 * it's just the icmp type << 8 | icmp code.
384 * Header points to the ip header of the error packet. We move
385 * on past this. Then (as it used to claim before adjustment)
386 * header points to the first 8 bytes of the udp header. We need
387 * to find the appropriate port.
390 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
392 struct inet_sock *inet;
393 struct iphdr *iph = (struct iphdr *)skb->data;
394 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
395 const int type = icmp_hdr(skb)->type;
396 const int code = icmp_hdr(skb)->code;
400 struct net *net = dev_net(skb->dev);
402 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
403 iph->saddr, uh->source, skb->dev->ifindex, udptable);
405 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
406 return; /* No socket for error */
415 case ICMP_TIME_EXCEEDED:
418 case ICMP_SOURCE_QUENCH:
420 case ICMP_PARAMETERPROB:
424 case ICMP_DEST_UNREACH:
425 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
426 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
434 if (code <= NR_ICMP_UNREACH) {
435 harderr = icmp_err_convert[code].fatal;
436 err = icmp_err_convert[code].errno;
442 * RFC1122: OK. Passes ICMP errors back to application, as per
445 if (!inet->recverr) {
446 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
449 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
452 sk->sk_error_report(sk);
457 void udp_err(struct sk_buff *skb, u32 info)
459 __udp4_lib_err(skb, info, &udp_table);
463 * Throw away all pending data and cancel the corking. Socket is locked.
465 void udp_flush_pending_frames(struct sock *sk)
467 struct udp_sock *up = udp_sk(sk);
472 ip_flush_pending_frames(sk);
475 EXPORT_SYMBOL(udp_flush_pending_frames);
478 * udp4_hwcsum_outgoing - handle outgoing HW checksumming
479 * @sk: socket we are sending on
480 * @skb: sk_buff containing the filled-in UDP header
481 * (checksum field must be zeroed out)
483 static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
484 __be32 src, __be32 dst, int len)
487 struct udphdr *uh = udp_hdr(skb);
490 if (skb_queue_len(&sk->sk_write_queue) == 1) {
492 * Only one fragment on the socket.
494 skb->csum_start = skb_transport_header(skb) - skb->head;
495 skb->csum_offset = offsetof(struct udphdr, check);
496 uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0);
499 * HW-checksum won't work as there are two or more
500 * fragments on the socket so that all csums of sk_buffs
503 offset = skb_transport_offset(skb);
504 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
506 skb->ip_summed = CHECKSUM_NONE;
508 skb_queue_walk(&sk->sk_write_queue, skb) {
509 csum = csum_add(csum, skb->csum);
512 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
514 uh->check = CSUM_MANGLED_0;
519 * Push out all pending data as one UDP datagram. Socket is locked.
521 static int udp_push_pending_frames(struct sock *sk)
523 struct udp_sock *up = udp_sk(sk);
524 struct inet_sock *inet = inet_sk(sk);
525 struct flowi *fl = &inet->cork.fl;
529 int is_udplite = IS_UDPLITE(sk);
532 /* Grab the skbuff where UDP header space exists. */
533 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
537 * Create a UDP header
540 uh->source = fl->fl_ip_sport;
541 uh->dest = fl->fl_ip_dport;
542 uh->len = htons(up->len);
545 if (is_udplite) /* UDP-Lite */
546 csum = udplite_csum_outgoing(sk, skb);
548 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */
550 skb->ip_summed = CHECKSUM_NONE;
553 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
555 udp4_hwcsum_outgoing(sk, skb, fl->fl4_src, fl->fl4_dst, up->len);
558 } else /* `normal' UDP */
559 csum = udp_csum_outgoing(sk, skb);
561 /* add protocol-dependent pseudo-header */
562 uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len,
563 sk->sk_protocol, csum);
565 uh->check = CSUM_MANGLED_0;
568 err = ip_push_pending_frames(sk);
570 if (err == -ENOBUFS && !inet->recverr) {
571 UDP_INC_STATS_USER(sock_net(sk),
572 UDP_MIB_SNDBUFERRORS, is_udplite);
576 UDP_INC_STATS_USER(sock_net(sk),
577 UDP_MIB_OUTDATAGRAMS, is_udplite);
584 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
587 struct inet_sock *inet = inet_sk(sk);
588 struct udp_sock *up = udp_sk(sk);
590 struct ipcm_cookie ipc;
591 struct rtable *rt = NULL;
594 __be32 daddr, faddr, saddr;
597 int err, is_udplite = IS_UDPLITE(sk);
598 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
599 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
608 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
616 * There are pending frames.
617 * The socket lock must be held while it's corked.
620 if (likely(up->pending)) {
621 if (unlikely(up->pending != AF_INET)) {
629 ulen += sizeof(struct udphdr);
632 * Get and verify the address.
635 struct sockaddr_in * usin = (struct sockaddr_in *)msg->msg_name;
636 if (msg->msg_namelen < sizeof(*usin))
638 if (usin->sin_family != AF_INET) {
639 if (usin->sin_family != AF_UNSPEC)
640 return -EAFNOSUPPORT;
643 daddr = usin->sin_addr.s_addr;
644 dport = usin->sin_port;
648 if (sk->sk_state != TCP_ESTABLISHED)
649 return -EDESTADDRREQ;
650 daddr = inet->inet_daddr;
651 dport = inet->inet_dport;
652 /* Open fast path for connected socket.
653 Route will not be used, if at least one option is set.
657 ipc.addr = inet->inet_saddr;
659 ipc.oif = sk->sk_bound_dev_if;
660 err = sock_tx_timestamp(msg, sk, &ipc.shtx);
663 if (msg->msg_controllen) {
664 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
675 ipc.addr = faddr = daddr;
677 if (ipc.opt && ipc.opt->srr) {
680 faddr = ipc.opt->faddr;
683 tos = RT_TOS(inet->tos);
684 if (sock_flag(sk, SOCK_LOCALROUTE) ||
685 (msg->msg_flags & MSG_DONTROUTE) ||
686 (ipc.opt && ipc.opt->is_strictroute)) {
691 if (ipv4_is_multicast(daddr)) {
693 ipc.oif = inet->mc_index;
695 saddr = inet->mc_addr;
700 rt = (struct rtable *)sk_dst_check(sk, 0);
703 struct flowi fl = { .oif = ipc.oif,
709 .proto = sk->sk_protocol,
710 .flags = inet_sk_flowi_flags(sk),
712 { .sport = inet->inet_sport,
713 .dport = dport } } };
714 struct net *net = sock_net(sk);
716 security_sk_classify_flow(sk, &fl);
717 err = ip_route_output_flow(net, &rt, &fl, sk, 1);
719 if (err == -ENETUNREACH)
720 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
725 if ((rt->rt_flags & RTCF_BROADCAST) &&
726 !sock_flag(sk, SOCK_BROADCAST))
729 sk_dst_set(sk, dst_clone(&rt->u.dst));
732 if (msg->msg_flags&MSG_CONFIRM)
738 daddr = ipc.addr = rt->rt_dst;
741 if (unlikely(up->pending)) {
742 /* The socket is already corked while preparing it. */
743 /* ... which is an evident application bug. --ANK */
746 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
751 * Now cork the socket to pend data.
753 inet->cork.fl.fl4_dst = daddr;
754 inet->cork.fl.fl_ip_dport = dport;
755 inet->cork.fl.fl4_src = saddr;
756 inet->cork.fl.fl_ip_sport = inet->inet_sport;
757 up->pending = AF_INET;
761 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
762 err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
763 sizeof(struct udphdr), &ipc, &rt,
764 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
766 udp_flush_pending_frames(sk);
768 err = udp_push_pending_frames(sk);
769 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
780 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
781 * ENOBUFS might not be good (it's not tunable per se), but otherwise
782 * we don't have a good statistic (IpOutDiscards but it can be too many
783 * things). We could add another new stat but at least for now that
784 * seems like overkill.
786 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
787 UDP_INC_STATS_USER(sock_net(sk),
788 UDP_MIB_SNDBUFERRORS, is_udplite);
793 dst_confirm(&rt->u.dst);
794 if (!(msg->msg_flags&MSG_PROBE) || len)
795 goto back_from_confirm;
799 EXPORT_SYMBOL(udp_sendmsg);
801 int udp_sendpage(struct sock *sk, struct page *page, int offset,
802 size_t size, int flags)
804 struct udp_sock *up = udp_sk(sk);
808 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
810 /* Call udp_sendmsg to specify destination address which
811 * sendpage interface can't pass.
812 * This will succeed only when the socket is connected.
814 ret = udp_sendmsg(NULL, sk, &msg, 0);
821 if (unlikely(!up->pending)) {
824 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n");
828 ret = ip_append_page(sk, page, offset, size, flags);
829 if (ret == -EOPNOTSUPP) {
831 return sock_no_sendpage(sk->sk_socket, page, offset,
835 udp_flush_pending_frames(sk);
840 if (!(up->corkflag || (flags&MSG_MORE)))
841 ret = udp_push_pending_frames(sk);
851 * first_packet_length - return length of first packet in receive queue
854 * Drops all bad checksum frames, until a valid one is found.
855 * Returns the length of found skb, or 0 if none is found.
857 static unsigned int first_packet_length(struct sock *sk)
859 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue;
863 __skb_queue_head_init(&list_kill);
865 spin_lock_bh(&rcvq->lock);
866 while ((skb = skb_peek(rcvq)) != NULL &&
867 udp_lib_checksum_complete(skb)) {
868 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
870 __skb_unlink(skb, rcvq);
871 __skb_queue_tail(&list_kill, skb);
873 res = skb ? skb->len : 0;
874 spin_unlock_bh(&rcvq->lock);
876 if (!skb_queue_empty(&list_kill)) {
878 __skb_queue_purge(&list_kill);
879 sk_mem_reclaim_partial(sk);
886 * IOCTL requests applicable to the UDP protocol
889 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
894 int amount = sk_wmem_alloc_get(sk);
896 return put_user(amount, (int __user *)arg);
901 unsigned int amount = first_packet_length(sk);
905 * We will only return the amount
906 * of this packet since that is all
909 amount -= sizeof(struct udphdr);
911 return put_user(amount, (int __user *)arg);
920 EXPORT_SYMBOL(udp_ioctl);
923 * This should be easy, if there is something there we
924 * return it, otherwise we block.
927 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
928 size_t len, int noblock, int flags, int *addr_len)
930 struct inet_sock *inet = inet_sk(sk);
931 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
933 unsigned int ulen, copied;
936 int is_udplite = IS_UDPLITE(sk);
939 * Check any passed addresses
942 *addr_len = sizeof(*sin);
944 if (flags & MSG_ERRQUEUE)
945 return ip_recv_error(sk, msg, len);
948 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
953 ulen = skb->len - sizeof(struct udphdr);
957 else if (copied < ulen)
958 msg->msg_flags |= MSG_TRUNC;
961 * If checksum is needed at all, try to do it while copying the
962 * data. If the data is truncated, or if we only want a partial
963 * coverage checksum (UDP-Lite), do it before the copy.
966 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
967 if (udp_lib_checksum_complete(skb))
971 if (skb_csum_unnecessary(skb))
972 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
973 msg->msg_iov, copied);
975 err = skb_copy_and_csum_datagram_iovec(skb,
976 sizeof(struct udphdr),
987 UDP_INC_STATS_USER(sock_net(sk),
988 UDP_MIB_INDATAGRAMS, is_udplite);
990 sock_recv_ts_and_drops(msg, sk, skb);
992 /* Copy the address. */
994 sin->sin_family = AF_INET;
995 sin->sin_port = udp_hdr(skb)->source;
996 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
997 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
999 if (inet->cmsg_flags)
1000 ip_cmsg_recv(msg, skb);
1003 if (flags & MSG_TRUNC)
1008 skb_free_datagram(sk, skb);
1015 if (!skb_kill_datagram(sk, skb, flags))
1016 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1025 int udp_disconnect(struct sock *sk, int flags)
1027 struct inet_sock *inet = inet_sk(sk);
1029 * 1003.1g - break association.
1032 sk->sk_state = TCP_CLOSE;
1033 inet->inet_daddr = 0;
1034 inet->inet_dport = 0;
1035 sk->sk_bound_dev_if = 0;
1036 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1037 inet_reset_saddr(sk);
1039 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1040 sk->sk_prot->unhash(sk);
1041 inet->inet_sport = 0;
1046 EXPORT_SYMBOL(udp_disconnect);
1048 void udp_lib_unhash(struct sock *sk)
1050 if (sk_hashed(sk)) {
1051 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1052 struct udp_hslot *hslot = udp_hashslot(udptable, sock_net(sk),
1055 spin_lock_bh(&hslot->lock);
1056 if (sk_nulls_del_node_init_rcu(sk)) {
1057 inet_sk(sk)->inet_num = 0;
1058 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1060 spin_unlock_bh(&hslot->lock);
1063 EXPORT_SYMBOL(udp_lib_unhash);
1065 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1067 int rc = sock_queue_rcv_skb(sk, skb);
1070 int is_udplite = IS_UDPLITE(sk);
1072 /* Note that an ENOMEM error is charged twice */
1074 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1076 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1088 * >0: "udp encap" protocol resubmission
1090 * Note that in the success and error cases, the skb is assumed to
1091 * have either been requeued or freed.
1093 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1095 struct udp_sock *up = udp_sk(sk);
1097 int is_udplite = IS_UDPLITE(sk);
1100 * Charge it to the socket, dropping if the queue is full.
1102 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1106 if (up->encap_type) {
1108 * This is an encapsulation socket so pass the skb to
1109 * the socket's udp_encap_rcv() hook. Otherwise, just
1110 * fall through and pass this up the UDP socket.
1111 * up->encap_rcv() returns the following value:
1112 * =0 if skb was successfully passed to the encap
1113 * handler or was discarded by it.
1114 * >0 if skb should be passed on to UDP.
1115 * <0 if skb should be resubmitted as proto -N
1118 /* if we're overly short, let UDP handle it */
1119 if (skb->len > sizeof(struct udphdr) &&
1120 up->encap_rcv != NULL) {
1123 ret = (*up->encap_rcv)(sk, skb);
1125 UDP_INC_STATS_BH(sock_net(sk),
1126 UDP_MIB_INDATAGRAMS,
1132 /* FALLTHROUGH -- it's a UDP Packet */
1136 * UDP-Lite specific tests, ignored on UDP sockets
1138 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1141 * MIB statistics other than incrementing the error count are
1142 * disabled for the following two types of errors: these depend
1143 * on the application settings, not on the functioning of the
1144 * protocol stack as such.
1146 * RFC 3828 here recommends (sec 3.3): "There should also be a
1147 * way ... to ... at least let the receiving application block
1148 * delivery of packets with coverage values less than a value
1149 * provided by the application."
1151 if (up->pcrlen == 0) { /* full coverage was set */
1152 LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage "
1153 "%d while full coverage %d requested\n",
1154 UDP_SKB_CB(skb)->cscov, skb->len);
1157 /* The next case involves violating the min. coverage requested
1158 * by the receiver. This is subtle: if receiver wants x and x is
1159 * greater than the buffersize/MTU then receiver will complain
1160 * that it wants x while sender emits packets of smaller size y.
1161 * Therefore the above ...()->partial_cov statement is essential.
1163 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1164 LIMIT_NETDEBUG(KERN_WARNING
1165 "UDPLITE: coverage %d too small, need min %d\n",
1166 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1171 if (sk->sk_filter) {
1172 if (udp_lib_checksum_complete(skb))
1179 if (!sock_owned_by_user(sk))
1180 rc = __udp_queue_rcv_skb(sk, skb);
1182 sk_add_backlog(sk, skb);
1188 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1194 * Multicasts and broadcasts go to each listener.
1196 * Note: called only from the BH handler context,
1197 * so we don't need to lock the hashes.
1199 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1201 __be32 saddr, __be32 daddr,
1202 struct udp_table *udptable)
1205 struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
1208 spin_lock(&hslot->lock);
1209 sk = sk_nulls_head(&hslot->head);
1210 dif = skb->dev->ifindex;
1211 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
1213 struct sock *sknext = NULL;
1216 struct sk_buff *skb1 = skb;
1218 sknext = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest,
1219 daddr, uh->source, saddr,
1222 skb1 = skb_clone(skb, GFP_ATOMIC);
1225 int ret = udp_queue_rcv_skb(sk, skb1);
1227 /* we should probably re-process instead
1228 * of dropping packets here. */
1235 spin_unlock(&hslot->lock);
1239 /* Initialize UDP checksum. If exited with zero value (success),
1240 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1241 * Otherwise, csum completion requires chacksumming packet body,
1242 * including udp header and folding it to skb->csum.
1244 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
1247 const struct iphdr *iph;
1250 UDP_SKB_CB(skb)->partial_cov = 0;
1251 UDP_SKB_CB(skb)->cscov = skb->len;
1253 if (proto == IPPROTO_UDPLITE) {
1254 err = udplite_checksum_init(skb, uh);
1260 if (uh->check == 0) {
1261 skb->ip_summed = CHECKSUM_UNNECESSARY;
1262 } else if (skb->ip_summed == CHECKSUM_COMPLETE) {
1263 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1265 skb->ip_summed = CHECKSUM_UNNECESSARY;
1267 if (!skb_csum_unnecessary(skb))
1268 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
1269 skb->len, proto, 0);
1270 /* Probably, we should checksum udp header (it should be in cache
1271 * in any case) and data in tiny packets (< rx copybreak).
1278 * All we need to do is get the socket, and then do a checksum.
1281 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1286 unsigned short ulen;
1287 struct rtable *rt = skb_rtable(skb);
1288 __be32 saddr, daddr;
1289 struct net *net = dev_net(skb->dev);
1292 * Validate the packet.
1294 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1295 goto drop; /* No space for header. */
1298 ulen = ntohs(uh->len);
1299 if (ulen > skb->len)
1302 if (proto == IPPROTO_UDP) {
1303 /* UDP validates ulen. */
1304 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
1309 if (udp4_csum_init(skb, uh, proto))
1312 saddr = ip_hdr(skb)->saddr;
1313 daddr = ip_hdr(skb)->daddr;
1315 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1316 return __udp4_lib_mcast_deliver(net, skb, uh,
1317 saddr, daddr, udptable);
1319 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1322 int ret = udp_queue_rcv_skb(sk, skb);
1325 /* a return value > 0 means to resubmit the input, but
1326 * it wants the return to be -protocol, or 0
1333 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1337 /* No socket. Drop packet silently, if checksum is wrong */
1338 if (udp_lib_checksum_complete(skb))
1341 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1342 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
1345 * Hmm. We got an UDP packet to a port to which we
1346 * don't wanna listen. Ignore it.
1352 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1353 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1364 * RFC1122: OK. Discards the bad packet silently (as far as
1365 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1367 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1368 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1375 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1380 int udp_rcv(struct sk_buff *skb)
1382 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1385 void udp_destroy_sock(struct sock *sk)
1388 udp_flush_pending_frames(sk);
1393 * Socket option code for UDP
1395 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1396 char __user *optval, unsigned int optlen,
1397 int (*push_pending_frames)(struct sock *))
1399 struct udp_sock *up = udp_sk(sk);
1402 int is_udplite = IS_UDPLITE(sk);
1404 if (optlen < sizeof(int))
1407 if (get_user(val, (int __user *)optval))
1417 (*push_pending_frames)(sk);
1425 case UDP_ENCAP_ESPINUDP:
1426 case UDP_ENCAP_ESPINUDP_NON_IKE:
1427 up->encap_rcv = xfrm4_udp_encap_rcv;
1429 case UDP_ENCAP_L2TPINUDP:
1430 up->encap_type = val;
1439 * UDP-Lite's partial checksum coverage (RFC 3828).
1441 /* The sender sets actual checksum coverage length via this option.
1442 * The case coverage > packet length is handled by send module. */
1443 case UDPLITE_SEND_CSCOV:
1444 if (!is_udplite) /* Disable the option on UDP sockets */
1445 return -ENOPROTOOPT;
1446 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
1448 else if (val > USHORT_MAX)
1451 up->pcflag |= UDPLITE_SEND_CC;
1454 /* The receiver specifies a minimum checksum coverage value. To make
1455 * sense, this should be set to at least 8 (as done below). If zero is
1456 * used, this again means full checksum coverage. */
1457 case UDPLITE_RECV_CSCOV:
1458 if (!is_udplite) /* Disable the option on UDP sockets */
1459 return -ENOPROTOOPT;
1460 if (val != 0 && val < 8) /* Avoid silly minimal values. */
1462 else if (val > USHORT_MAX)
1465 up->pcflag |= UDPLITE_RECV_CC;
1475 EXPORT_SYMBOL(udp_lib_setsockopt);
1477 int udp_setsockopt(struct sock *sk, int level, int optname,
1478 char __user *optval, unsigned int optlen)
1480 if (level == SOL_UDP || level == SOL_UDPLITE)
1481 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1482 udp_push_pending_frames);
1483 return ip_setsockopt(sk, level, optname, optval, optlen);
1486 #ifdef CONFIG_COMPAT
1487 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
1488 char __user *optval, unsigned int optlen)
1490 if (level == SOL_UDP || level == SOL_UDPLITE)
1491 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1492 udp_push_pending_frames);
1493 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
1497 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
1498 char __user *optval, int __user *optlen)
1500 struct udp_sock *up = udp_sk(sk);
1503 if (get_user(len, optlen))
1506 len = min_t(unsigned int, len, sizeof(int));
1517 val = up->encap_type;
1520 /* The following two cannot be changed on UDP sockets, the return is
1521 * always 0 (which corresponds to the full checksum coverage of UDP). */
1522 case UDPLITE_SEND_CSCOV:
1526 case UDPLITE_RECV_CSCOV:
1531 return -ENOPROTOOPT;
1534 if (put_user(len, optlen))
1536 if (copy_to_user(optval, &val, len))
1540 EXPORT_SYMBOL(udp_lib_getsockopt);
1542 int udp_getsockopt(struct sock *sk, int level, int optname,
1543 char __user *optval, int __user *optlen)
1545 if (level == SOL_UDP || level == SOL_UDPLITE)
1546 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1547 return ip_getsockopt(sk, level, optname, optval, optlen);
1550 #ifdef CONFIG_COMPAT
1551 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
1552 char __user *optval, int __user *optlen)
1554 if (level == SOL_UDP || level == SOL_UDPLITE)
1555 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1556 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
1560 * udp_poll - wait for a UDP event.
1561 * @file - file struct
1563 * @wait - poll table
1565 * This is same as datagram poll, except for the special case of
1566 * blocking sockets. If application is using a blocking fd
1567 * and a packet with checksum error is in the queue;
1568 * then it could get return from select indicating data available
1569 * but then block when reading it. Add special case code
1570 * to work around these arguably broken applications.
1572 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
1574 unsigned int mask = datagram_poll(file, sock, wait);
1575 struct sock *sk = sock->sk;
1577 /* Check for false positives due to checksum errors */
1578 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
1579 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk))
1580 mask &= ~(POLLIN | POLLRDNORM);
1585 EXPORT_SYMBOL(udp_poll);
1587 struct proto udp_prot = {
1589 .owner = THIS_MODULE,
1590 .close = udp_lib_close,
1591 .connect = ip4_datagram_connect,
1592 .disconnect = udp_disconnect,
1594 .destroy = udp_destroy_sock,
1595 .setsockopt = udp_setsockopt,
1596 .getsockopt = udp_getsockopt,
1597 .sendmsg = udp_sendmsg,
1598 .recvmsg = udp_recvmsg,
1599 .sendpage = udp_sendpage,
1600 .backlog_rcv = __udp_queue_rcv_skb,
1601 .hash = udp_lib_hash,
1602 .unhash = udp_lib_unhash,
1603 .get_port = udp_v4_get_port,
1604 .memory_allocated = &udp_memory_allocated,
1605 .sysctl_mem = sysctl_udp_mem,
1606 .sysctl_wmem = &sysctl_udp_wmem_min,
1607 .sysctl_rmem = &sysctl_udp_rmem_min,
1608 .obj_size = sizeof(struct udp_sock),
1609 .slab_flags = SLAB_DESTROY_BY_RCU,
1610 .h.udp_table = &udp_table,
1611 #ifdef CONFIG_COMPAT
1612 .compat_setsockopt = compat_udp_setsockopt,
1613 .compat_getsockopt = compat_udp_getsockopt,
1616 EXPORT_SYMBOL(udp_prot);
1618 /* ------------------------------------------------------------------------ */
1619 #ifdef CONFIG_PROC_FS
1621 static struct sock *udp_get_first(struct seq_file *seq, int start)
1624 struct udp_iter_state *state = seq->private;
1625 struct net *net = seq_file_net(seq);
1627 for (state->bucket = start; state->bucket <= state->udp_table->mask;
1629 struct hlist_nulls_node *node;
1630 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
1632 if (hlist_nulls_empty(&hslot->head))
1635 spin_lock_bh(&hslot->lock);
1636 sk_nulls_for_each(sk, node, &hslot->head) {
1637 if (!net_eq(sock_net(sk), net))
1639 if (sk->sk_family == state->family)
1642 spin_unlock_bh(&hslot->lock);
1649 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
1651 struct udp_iter_state *state = seq->private;
1652 struct net *net = seq_file_net(seq);
1655 sk = sk_nulls_next(sk);
1656 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
1659 if (state->bucket <= state->udp_table->mask)
1660 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
1661 return udp_get_first(seq, state->bucket + 1);
1666 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
1668 struct sock *sk = udp_get_first(seq, 0);
1671 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
1673 return pos ? NULL : sk;
1676 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
1678 struct udp_iter_state *state = seq->private;
1679 state->bucket = MAX_UDP_PORTS;
1681 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1684 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1688 if (v == SEQ_START_TOKEN)
1689 sk = udp_get_idx(seq, 0);
1691 sk = udp_get_next(seq, v);
1697 static void udp_seq_stop(struct seq_file *seq, void *v)
1699 struct udp_iter_state *state = seq->private;
1701 if (state->bucket <= state->udp_table->mask)
1702 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
1705 static int udp_seq_open(struct inode *inode, struct file *file)
1707 struct udp_seq_afinfo *afinfo = PDE(inode)->data;
1708 struct udp_iter_state *s;
1711 err = seq_open_net(inode, file, &afinfo->seq_ops,
1712 sizeof(struct udp_iter_state));
1716 s = ((struct seq_file *)file->private_data)->private;
1717 s->family = afinfo->family;
1718 s->udp_table = afinfo->udp_table;
1722 /* ------------------------------------------------------------------------ */
1723 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
1725 struct proc_dir_entry *p;
1728 afinfo->seq_fops.open = udp_seq_open;
1729 afinfo->seq_fops.read = seq_read;
1730 afinfo->seq_fops.llseek = seq_lseek;
1731 afinfo->seq_fops.release = seq_release_net;
1733 afinfo->seq_ops.start = udp_seq_start;
1734 afinfo->seq_ops.next = udp_seq_next;
1735 afinfo->seq_ops.stop = udp_seq_stop;
1737 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1738 &afinfo->seq_fops, afinfo);
1743 EXPORT_SYMBOL(udp_proc_register);
1745 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
1747 proc_net_remove(net, afinfo->name);
1749 EXPORT_SYMBOL(udp_proc_unregister);
1751 /* ------------------------------------------------------------------------ */
1752 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
1753 int bucket, int *len)
1755 struct inet_sock *inet = inet_sk(sp);
1756 __be32 dest = inet->inet_daddr;
1757 __be32 src = inet->inet_rcv_saddr;
1758 __u16 destp = ntohs(inet->inet_dport);
1759 __u16 srcp = ntohs(inet->inet_sport);
1761 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1762 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d%n",
1763 bucket, src, srcp, dest, destp, sp->sk_state,
1764 sk_wmem_alloc_get(sp),
1765 sk_rmem_alloc_get(sp),
1766 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
1767 atomic_read(&sp->sk_refcnt), sp,
1768 atomic_read(&sp->sk_drops), len);
1771 int udp4_seq_show(struct seq_file *seq, void *v)
1773 if (v == SEQ_START_TOKEN)
1774 seq_printf(seq, "%-127s\n",
1775 " sl local_address rem_address st tx_queue "
1776 "rx_queue tr tm->when retrnsmt uid timeout "
1777 "inode ref pointer drops");
1779 struct udp_iter_state *state = seq->private;
1782 udp4_format_sock(v, seq, state->bucket, &len);
1783 seq_printf(seq, "%*s\n", 127 - len, "");
1788 /* ------------------------------------------------------------------------ */
1789 static struct udp_seq_afinfo udp4_seq_afinfo = {
1792 .udp_table = &udp_table,
1794 .owner = THIS_MODULE,
1797 .show = udp4_seq_show,
1801 static int udp4_proc_init_net(struct net *net)
1803 return udp_proc_register(net, &udp4_seq_afinfo);
1806 static void udp4_proc_exit_net(struct net *net)
1808 udp_proc_unregister(net, &udp4_seq_afinfo);
1811 static struct pernet_operations udp4_net_ops = {
1812 .init = udp4_proc_init_net,
1813 .exit = udp4_proc_exit_net,
1816 int __init udp4_proc_init(void)
1818 return register_pernet_subsys(&udp4_net_ops);
1821 void udp4_proc_exit(void)
1823 unregister_pernet_subsys(&udp4_net_ops);
1825 #endif /* CONFIG_PROC_FS */
1827 static __initdata unsigned long uhash_entries;
1828 static int __init set_uhash_entries(char *str)
1832 uhash_entries = simple_strtoul(str, &str, 0);
1833 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
1834 uhash_entries = UDP_HTABLE_SIZE_MIN;
1837 __setup("uhash_entries=", set_uhash_entries);
1839 void __init udp_table_init(struct udp_table *table, const char *name)
1843 if (!CONFIG_BASE_SMALL)
1844 table->hash = alloc_large_system_hash(name,
1845 sizeof(struct udp_hslot),
1847 21, /* one slot per 2 MB */
1853 * Make sure hash table has the minimum size
1855 if (CONFIG_BASE_SMALL || table->mask < UDP_HTABLE_SIZE_MIN - 1) {
1856 table->hash = kmalloc(UDP_HTABLE_SIZE_MIN *
1857 sizeof(struct udp_hslot), GFP_KERNEL);
1860 table->log = ilog2(UDP_HTABLE_SIZE_MIN);
1861 table->mask = UDP_HTABLE_SIZE_MIN - 1;
1863 for (i = 0; i <= table->mask; i++) {
1864 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
1865 spin_lock_init(&table->hash[i].lock);
1869 void __init udp_init(void)
1871 unsigned long nr_pages, limit;
1873 udp_table_init(&udp_table, "UDP");
1874 /* Set the pressure threshold up by the same strategy of TCP. It is a
1875 * fraction of global memory that is up to 1/2 at 256 MB, decreasing
1876 * toward zero with the amount of memory, with a floor of 128 pages.
1878 nr_pages = totalram_pages - totalhigh_pages;
1879 limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
1880 limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
1881 limit = max(limit, 128UL);
1882 sysctl_udp_mem[0] = limit / 4 * 3;
1883 sysctl_udp_mem[1] = limit;
1884 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
1886 sysctl_udp_rmem_min = SK_MEM_QUANTUM;
1887 sysctl_udp_wmem_min = SK_MEM_QUANTUM;
1890 int udp4_ufo_send_check(struct sk_buff *skb)
1892 const struct iphdr *iph;
1895 if (!pskb_may_pull(skb, sizeof(*uh)))
1901 uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1903 skb->csum_start = skb_transport_header(skb) - skb->head;
1904 skb->csum_offset = offsetof(struct udphdr, check);
1905 skb->ip_summed = CHECKSUM_PARTIAL;
1909 struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, int features)
1911 struct sk_buff *segs = ERR_PTR(-EINVAL);
1916 mss = skb_shinfo(skb)->gso_size;
1917 if (unlikely(skb->len <= mss))
1920 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
1921 /* Packet is from an untrusted source, reset gso_segs. */
1922 int type = skb_shinfo(skb)->gso_type;
1924 if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) ||
1925 !(type & (SKB_GSO_UDP))))
1928 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
1934 /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
1935 * do checksum of UDP packets sent as multiple IP fragments.
1937 offset = skb->csum_start - skb_headroom(skb);
1938 csum = skb_checksum(skb, offset, skb->len - offset, 0);
1939 offset += skb->csum_offset;
1940 *(__sum16 *)(skb->data + offset) = csum_fold(csum);
1941 skb->ip_summed = CHECKSUM_NONE;
1943 /* Fragment the skb. IP headers of the fragments are updated in
1944 * inet_gso_segment()
1946 segs = skb_segment(skb, features);