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 || udp_sk(sk2)->udp_port_hash == num) &&
142 (!sk2->sk_reuse || !sk->sk_reuse) &&
143 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if
144 || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
145 (*saddr_comp)(sk, sk2)) {
147 __set_bit(udp_sk(sk2)->udp_port_hash >> log,
156 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
158 * @sk: socket struct in question
159 * @snum: port number to look up
160 * @saddr_comp: AF-dependent comparison of bound local IP addresses
162 int udp_lib_get_port(struct sock *sk, unsigned short snum,
163 int (*saddr_comp)(const struct sock *sk1,
164 const struct sock *sk2))
166 struct udp_hslot *hslot;
167 struct udp_table *udptable = sk->sk_prot->h.udp_table;
169 struct net *net = sock_net(sk);
172 int low, high, remaining;
174 unsigned short first, last;
175 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
177 inet_get_local_port_range(&low, &high);
178 remaining = (high - low) + 1;
181 first = (((u64)rand * remaining) >> 32) + low;
183 * force rand to be an odd multiple of UDP_HTABLE_SIZE
185 rand = (rand | 1) * (udptable->mask + 1);
186 for (last = first + udptable->mask + 1;
189 hslot = udp_hashslot(udptable, net, first);
190 bitmap_zero(bitmap, PORTS_PER_CHAIN);
191 spin_lock_bh(&hslot->lock);
192 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
193 saddr_comp, udptable->log);
197 * Iterate on all possible values of snum for this hash.
198 * Using steps of an odd multiple of UDP_HTABLE_SIZE
199 * give us randomization and full range coverage.
202 if (low <= snum && snum <= high &&
203 !test_bit(snum >> udptable->log, bitmap))
206 } while (snum != first);
207 spin_unlock_bh(&hslot->lock);
211 hslot = udp_hashslot(udptable, net, snum);
212 spin_lock_bh(&hslot->lock);
213 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk,
218 inet_sk(sk)->inet_num = snum;
219 udp_sk(sk)->udp_port_hash = snum;
220 udp_sk(sk)->udp_portaddr_hash ^= snum;
221 if (sk_unhashed(sk)) {
222 sk_nulls_add_node_rcu(sk, &hslot->head);
224 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
228 spin_unlock_bh(&hslot->lock);
232 EXPORT_SYMBOL(udp_lib_get_port);
234 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
236 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
238 return (!ipv6_only_sock(sk2) &&
239 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr ||
240 inet1->inet_rcv_saddr == inet2->inet_rcv_saddr));
243 static unsigned int udp4_portaddr_hash(struct net *net, __be32 saddr,
246 return jhash_1word(saddr, net_hash_mix(net)) ^ port;
249 int udp_v4_get_port(struct sock *sk, unsigned short snum)
251 /* precompute partial secondary hash */
252 udp_sk(sk)->udp_portaddr_hash =
253 udp4_portaddr_hash(sock_net(sk),
254 inet_sk(sk)->inet_rcv_saddr,
256 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal);
259 static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr,
261 __be16 sport, __be32 daddr, __be16 dport, int dif)
265 if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
266 !ipv6_only_sock(sk)) {
267 struct inet_sock *inet = inet_sk(sk);
269 score = (sk->sk_family == PF_INET ? 1 : 0);
270 if (inet->inet_rcv_saddr) {
271 if (inet->inet_rcv_saddr != daddr)
275 if (inet->inet_daddr) {
276 if (inet->inet_daddr != saddr)
280 if (inet->inet_dport) {
281 if (inet->inet_dport != sport)
285 if (sk->sk_bound_dev_if) {
286 if (sk->sk_bound_dev_if != dif)
294 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
295 * harder than this. -DaveM
297 static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
298 __be16 sport, __be32 daddr, __be16 dport,
299 int dif, struct udp_table *udptable)
301 struct sock *sk, *result;
302 struct hlist_nulls_node *node;
303 unsigned short hnum = ntohs(dport);
304 unsigned int hash = udp_hashfn(net, hnum, udptable->mask);
305 struct udp_hslot *hslot = &udptable->hash[hash];
312 sk_nulls_for_each_rcu(sk, node, &hslot->head) {
313 score = compute_score(sk, net, saddr, hnum, sport,
315 if (score > badness) {
321 * if the nulls value we got at the end of this lookup is
322 * not the expected one, we must restart lookup.
323 * We probably met an item that was moved to another chain.
325 if (get_nulls_value(node) != hash)
329 if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
331 else if (unlikely(compute_score(result, net, saddr, hnum, sport,
332 daddr, dport, dif) < badness)) {
341 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
342 __be16 sport, __be16 dport,
343 struct udp_table *udptable)
346 const struct iphdr *iph = ip_hdr(skb);
348 if (unlikely(sk = skb_steal_sock(skb)))
351 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport,
352 iph->daddr, dport, inet_iif(skb),
356 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
357 __be32 daddr, __be16 dport, int dif)
359 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
361 EXPORT_SYMBOL_GPL(udp4_lib_lookup);
363 static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
364 __be16 loc_port, __be32 loc_addr,
365 __be16 rmt_port, __be32 rmt_addr,
368 struct hlist_nulls_node *node;
370 unsigned short hnum = ntohs(loc_port);
372 sk_nulls_for_each_from(s, node) {
373 struct inet_sock *inet = inet_sk(s);
375 if (!net_eq(sock_net(s), net) ||
376 udp_sk(s)->udp_port_hash != hnum ||
377 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
378 (inet->inet_dport != rmt_port && inet->inet_dport) ||
379 (inet->inet_rcv_saddr &&
380 inet->inet_rcv_saddr != loc_addr) ||
382 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
384 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
394 * This routine is called by the ICMP module when it gets some
395 * sort of error condition. If err < 0 then the socket should
396 * be closed and the error returned to the user. If err > 0
397 * it's just the icmp type << 8 | icmp code.
398 * Header points to the ip header of the error packet. We move
399 * on past this. Then (as it used to claim before adjustment)
400 * header points to the first 8 bytes of the udp header. We need
401 * to find the appropriate port.
404 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
406 struct inet_sock *inet;
407 struct iphdr *iph = (struct iphdr *)skb->data;
408 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
409 const int type = icmp_hdr(skb)->type;
410 const int code = icmp_hdr(skb)->code;
414 struct net *net = dev_net(skb->dev);
416 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
417 iph->saddr, uh->source, skb->dev->ifindex, udptable);
419 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
420 return; /* No socket for error */
429 case ICMP_TIME_EXCEEDED:
432 case ICMP_SOURCE_QUENCH:
434 case ICMP_PARAMETERPROB:
438 case ICMP_DEST_UNREACH:
439 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
440 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
448 if (code <= NR_ICMP_UNREACH) {
449 harderr = icmp_err_convert[code].fatal;
450 err = icmp_err_convert[code].errno;
456 * RFC1122: OK. Passes ICMP errors back to application, as per
459 if (!inet->recverr) {
460 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
463 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
466 sk->sk_error_report(sk);
471 void udp_err(struct sk_buff *skb, u32 info)
473 __udp4_lib_err(skb, info, &udp_table);
477 * Throw away all pending data and cancel the corking. Socket is locked.
479 void udp_flush_pending_frames(struct sock *sk)
481 struct udp_sock *up = udp_sk(sk);
486 ip_flush_pending_frames(sk);
489 EXPORT_SYMBOL(udp_flush_pending_frames);
492 * udp4_hwcsum_outgoing - handle outgoing HW checksumming
493 * @sk: socket we are sending on
494 * @skb: sk_buff containing the filled-in UDP header
495 * (checksum field must be zeroed out)
497 static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
498 __be32 src, __be32 dst, int len)
501 struct udphdr *uh = udp_hdr(skb);
504 if (skb_queue_len(&sk->sk_write_queue) == 1) {
506 * Only one fragment on the socket.
508 skb->csum_start = skb_transport_header(skb) - skb->head;
509 skb->csum_offset = offsetof(struct udphdr, check);
510 uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0);
513 * HW-checksum won't work as there are two or more
514 * fragments on the socket so that all csums of sk_buffs
517 offset = skb_transport_offset(skb);
518 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
520 skb->ip_summed = CHECKSUM_NONE;
522 skb_queue_walk(&sk->sk_write_queue, skb) {
523 csum = csum_add(csum, skb->csum);
526 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
528 uh->check = CSUM_MANGLED_0;
533 * Push out all pending data as one UDP datagram. Socket is locked.
535 static int udp_push_pending_frames(struct sock *sk)
537 struct udp_sock *up = udp_sk(sk);
538 struct inet_sock *inet = inet_sk(sk);
539 struct flowi *fl = &inet->cork.fl;
543 int is_udplite = IS_UDPLITE(sk);
546 /* Grab the skbuff where UDP header space exists. */
547 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
551 * Create a UDP header
554 uh->source = fl->fl_ip_sport;
555 uh->dest = fl->fl_ip_dport;
556 uh->len = htons(up->len);
559 if (is_udplite) /* UDP-Lite */
560 csum = udplite_csum_outgoing(sk, skb);
562 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */
564 skb->ip_summed = CHECKSUM_NONE;
567 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
569 udp4_hwcsum_outgoing(sk, skb, fl->fl4_src, fl->fl4_dst, up->len);
572 } else /* `normal' UDP */
573 csum = udp_csum_outgoing(sk, skb);
575 /* add protocol-dependent pseudo-header */
576 uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len,
577 sk->sk_protocol, csum);
579 uh->check = CSUM_MANGLED_0;
582 err = ip_push_pending_frames(sk);
584 if (err == -ENOBUFS && !inet->recverr) {
585 UDP_INC_STATS_USER(sock_net(sk),
586 UDP_MIB_SNDBUFERRORS, is_udplite);
590 UDP_INC_STATS_USER(sock_net(sk),
591 UDP_MIB_OUTDATAGRAMS, is_udplite);
598 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
601 struct inet_sock *inet = inet_sk(sk);
602 struct udp_sock *up = udp_sk(sk);
604 struct ipcm_cookie ipc;
605 struct rtable *rt = NULL;
608 __be32 daddr, faddr, saddr;
611 int err, is_udplite = IS_UDPLITE(sk);
612 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
613 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
622 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
630 * There are pending frames.
631 * The socket lock must be held while it's corked.
634 if (likely(up->pending)) {
635 if (unlikely(up->pending != AF_INET)) {
643 ulen += sizeof(struct udphdr);
646 * Get and verify the address.
649 struct sockaddr_in * usin = (struct sockaddr_in *)msg->msg_name;
650 if (msg->msg_namelen < sizeof(*usin))
652 if (usin->sin_family != AF_INET) {
653 if (usin->sin_family != AF_UNSPEC)
654 return -EAFNOSUPPORT;
657 daddr = usin->sin_addr.s_addr;
658 dport = usin->sin_port;
662 if (sk->sk_state != TCP_ESTABLISHED)
663 return -EDESTADDRREQ;
664 daddr = inet->inet_daddr;
665 dport = inet->inet_dport;
666 /* Open fast path for connected socket.
667 Route will not be used, if at least one option is set.
671 ipc.addr = inet->inet_saddr;
673 ipc.oif = sk->sk_bound_dev_if;
674 err = sock_tx_timestamp(msg, sk, &ipc.shtx);
677 if (msg->msg_controllen) {
678 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
689 ipc.addr = faddr = daddr;
691 if (ipc.opt && ipc.opt->srr) {
694 faddr = ipc.opt->faddr;
697 tos = RT_TOS(inet->tos);
698 if (sock_flag(sk, SOCK_LOCALROUTE) ||
699 (msg->msg_flags & MSG_DONTROUTE) ||
700 (ipc.opt && ipc.opt->is_strictroute)) {
705 if (ipv4_is_multicast(daddr)) {
707 ipc.oif = inet->mc_index;
709 saddr = inet->mc_addr;
714 rt = (struct rtable *)sk_dst_check(sk, 0);
717 struct flowi fl = { .oif = ipc.oif,
723 .proto = sk->sk_protocol,
724 .flags = inet_sk_flowi_flags(sk),
726 { .sport = inet->inet_sport,
727 .dport = dport } } };
728 struct net *net = sock_net(sk);
730 security_sk_classify_flow(sk, &fl);
731 err = ip_route_output_flow(net, &rt, &fl, sk, 1);
733 if (err == -ENETUNREACH)
734 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
739 if ((rt->rt_flags & RTCF_BROADCAST) &&
740 !sock_flag(sk, SOCK_BROADCAST))
743 sk_dst_set(sk, dst_clone(&rt->u.dst));
746 if (msg->msg_flags&MSG_CONFIRM)
752 daddr = ipc.addr = rt->rt_dst;
755 if (unlikely(up->pending)) {
756 /* The socket is already corked while preparing it. */
757 /* ... which is an evident application bug. --ANK */
760 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
765 * Now cork the socket to pend data.
767 inet->cork.fl.fl4_dst = daddr;
768 inet->cork.fl.fl_ip_dport = dport;
769 inet->cork.fl.fl4_src = saddr;
770 inet->cork.fl.fl_ip_sport = inet->inet_sport;
771 up->pending = AF_INET;
775 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
776 err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
777 sizeof(struct udphdr), &ipc, &rt,
778 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
780 udp_flush_pending_frames(sk);
782 err = udp_push_pending_frames(sk);
783 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
794 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
795 * ENOBUFS might not be good (it's not tunable per se), but otherwise
796 * we don't have a good statistic (IpOutDiscards but it can be too many
797 * things). We could add another new stat but at least for now that
798 * seems like overkill.
800 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
801 UDP_INC_STATS_USER(sock_net(sk),
802 UDP_MIB_SNDBUFERRORS, is_udplite);
807 dst_confirm(&rt->u.dst);
808 if (!(msg->msg_flags&MSG_PROBE) || len)
809 goto back_from_confirm;
813 EXPORT_SYMBOL(udp_sendmsg);
815 int udp_sendpage(struct sock *sk, struct page *page, int offset,
816 size_t size, int flags)
818 struct udp_sock *up = udp_sk(sk);
822 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
824 /* Call udp_sendmsg to specify destination address which
825 * sendpage interface can't pass.
826 * This will succeed only when the socket is connected.
828 ret = udp_sendmsg(NULL, sk, &msg, 0);
835 if (unlikely(!up->pending)) {
838 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n");
842 ret = ip_append_page(sk, page, offset, size, flags);
843 if (ret == -EOPNOTSUPP) {
845 return sock_no_sendpage(sk->sk_socket, page, offset,
849 udp_flush_pending_frames(sk);
854 if (!(up->corkflag || (flags&MSG_MORE)))
855 ret = udp_push_pending_frames(sk);
865 * first_packet_length - return length of first packet in receive queue
868 * Drops all bad checksum frames, until a valid one is found.
869 * Returns the length of found skb, or 0 if none is found.
871 static unsigned int first_packet_length(struct sock *sk)
873 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue;
877 __skb_queue_head_init(&list_kill);
879 spin_lock_bh(&rcvq->lock);
880 while ((skb = skb_peek(rcvq)) != NULL &&
881 udp_lib_checksum_complete(skb)) {
882 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
884 atomic_inc(&sk->sk_drops);
885 __skb_unlink(skb, rcvq);
886 __skb_queue_tail(&list_kill, skb);
888 res = skb ? skb->len : 0;
889 spin_unlock_bh(&rcvq->lock);
891 if (!skb_queue_empty(&list_kill)) {
893 __skb_queue_purge(&list_kill);
894 sk_mem_reclaim_partial(sk);
901 * IOCTL requests applicable to the UDP protocol
904 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
909 int amount = sk_wmem_alloc_get(sk);
911 return put_user(amount, (int __user *)arg);
916 unsigned int amount = first_packet_length(sk);
920 * We will only return the amount
921 * of this packet since that is all
924 amount -= sizeof(struct udphdr);
926 return put_user(amount, (int __user *)arg);
935 EXPORT_SYMBOL(udp_ioctl);
938 * This should be easy, if there is something there we
939 * return it, otherwise we block.
942 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
943 size_t len, int noblock, int flags, int *addr_len)
945 struct inet_sock *inet = inet_sk(sk);
946 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
948 unsigned int ulen, copied;
951 int is_udplite = IS_UDPLITE(sk);
954 * Check any passed addresses
957 *addr_len = sizeof(*sin);
959 if (flags & MSG_ERRQUEUE)
960 return ip_recv_error(sk, msg, len);
963 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
968 ulen = skb->len - sizeof(struct udphdr);
972 else if (copied < ulen)
973 msg->msg_flags |= MSG_TRUNC;
976 * If checksum is needed at all, try to do it while copying the
977 * data. If the data is truncated, or if we only want a partial
978 * coverage checksum (UDP-Lite), do it before the copy.
981 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
982 if (udp_lib_checksum_complete(skb))
986 if (skb_csum_unnecessary(skb))
987 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
988 msg->msg_iov, copied);
990 err = skb_copy_and_csum_datagram_iovec(skb,
991 sizeof(struct udphdr),
1002 UDP_INC_STATS_USER(sock_net(sk),
1003 UDP_MIB_INDATAGRAMS, is_udplite);
1005 sock_recv_ts_and_drops(msg, sk, skb);
1007 /* Copy the address. */
1009 sin->sin_family = AF_INET;
1010 sin->sin_port = udp_hdr(skb)->source;
1011 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1012 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1014 if (inet->cmsg_flags)
1015 ip_cmsg_recv(msg, skb);
1018 if (flags & MSG_TRUNC)
1022 skb_free_datagram_locked(sk, skb);
1028 if (!skb_kill_datagram(sk, skb, flags))
1029 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1038 int udp_disconnect(struct sock *sk, int flags)
1040 struct inet_sock *inet = inet_sk(sk);
1042 * 1003.1g - break association.
1045 sk->sk_state = TCP_CLOSE;
1046 inet->inet_daddr = 0;
1047 inet->inet_dport = 0;
1048 sk->sk_bound_dev_if = 0;
1049 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1050 inet_reset_saddr(sk);
1052 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1053 sk->sk_prot->unhash(sk);
1054 inet->inet_sport = 0;
1059 EXPORT_SYMBOL(udp_disconnect);
1061 void udp_lib_unhash(struct sock *sk)
1063 if (sk_hashed(sk)) {
1064 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1065 struct udp_hslot *hslot = udp_hashslot(udptable, sock_net(sk),
1066 udp_sk(sk)->udp_port_hash);
1068 spin_lock_bh(&hslot->lock);
1069 if (sk_nulls_del_node_init_rcu(sk)) {
1071 inet_sk(sk)->inet_num = 0;
1072 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1074 spin_unlock_bh(&hslot->lock);
1077 EXPORT_SYMBOL(udp_lib_unhash);
1079 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1081 int rc = sock_queue_rcv_skb(sk, skb);
1084 int is_udplite = IS_UDPLITE(sk);
1086 /* Note that an ENOMEM error is charged twice */
1088 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1090 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1102 * >0: "udp encap" protocol resubmission
1104 * Note that in the success and error cases, the skb is assumed to
1105 * have either been requeued or freed.
1107 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1109 struct udp_sock *up = udp_sk(sk);
1111 int is_udplite = IS_UDPLITE(sk);
1114 * Charge it to the socket, dropping if the queue is full.
1116 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1120 if (up->encap_type) {
1122 * This is an encapsulation socket so pass the skb to
1123 * the socket's udp_encap_rcv() hook. Otherwise, just
1124 * fall through and pass this up the UDP socket.
1125 * up->encap_rcv() returns the following value:
1126 * =0 if skb was successfully passed to the encap
1127 * handler or was discarded by it.
1128 * >0 if skb should be passed on to UDP.
1129 * <0 if skb should be resubmitted as proto -N
1132 /* if we're overly short, let UDP handle it */
1133 if (skb->len > sizeof(struct udphdr) &&
1134 up->encap_rcv != NULL) {
1137 ret = (*up->encap_rcv)(sk, skb);
1139 UDP_INC_STATS_BH(sock_net(sk),
1140 UDP_MIB_INDATAGRAMS,
1146 /* FALLTHROUGH -- it's a UDP Packet */
1150 * UDP-Lite specific tests, ignored on UDP sockets
1152 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1155 * MIB statistics other than incrementing the error count are
1156 * disabled for the following two types of errors: these depend
1157 * on the application settings, not on the functioning of the
1158 * protocol stack as such.
1160 * RFC 3828 here recommends (sec 3.3): "There should also be a
1161 * way ... to ... at least let the receiving application block
1162 * delivery of packets with coverage values less than a value
1163 * provided by the application."
1165 if (up->pcrlen == 0) { /* full coverage was set */
1166 LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage "
1167 "%d while full coverage %d requested\n",
1168 UDP_SKB_CB(skb)->cscov, skb->len);
1171 /* The next case involves violating the min. coverage requested
1172 * by the receiver. This is subtle: if receiver wants x and x is
1173 * greater than the buffersize/MTU then receiver will complain
1174 * that it wants x while sender emits packets of smaller size y.
1175 * Therefore the above ...()->partial_cov statement is essential.
1177 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1178 LIMIT_NETDEBUG(KERN_WARNING
1179 "UDPLITE: coverage %d too small, need min %d\n",
1180 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1185 if (sk->sk_filter) {
1186 if (udp_lib_checksum_complete(skb))
1193 if (!sock_owned_by_user(sk))
1194 rc = __udp_queue_rcv_skb(sk, skb);
1196 sk_add_backlog(sk, skb);
1202 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1203 atomic_inc(&sk->sk_drops);
1209 * Multicasts and broadcasts go to each listener.
1211 * Note: called only from the BH handler context,
1212 * so we don't need to lock the hashes.
1214 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1216 __be32 saddr, __be32 daddr,
1217 struct udp_table *udptable)
1220 struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
1223 spin_lock(&hslot->lock);
1224 sk = sk_nulls_head(&hslot->head);
1225 dif = skb->dev->ifindex;
1226 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
1228 struct sock *sknext = NULL;
1231 struct sk_buff *skb1 = skb;
1233 sknext = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest,
1234 daddr, uh->source, saddr,
1237 skb1 = skb_clone(skb, GFP_ATOMIC);
1240 int ret = udp_queue_rcv_skb(sk, skb1);
1242 /* we should probably re-process instead
1243 * of dropping packets here. */
1250 spin_unlock(&hslot->lock);
1254 /* Initialize UDP checksum. If exited with zero value (success),
1255 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1256 * Otherwise, csum completion requires chacksumming packet body,
1257 * including udp header and folding it to skb->csum.
1259 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
1262 const struct iphdr *iph;
1265 UDP_SKB_CB(skb)->partial_cov = 0;
1266 UDP_SKB_CB(skb)->cscov = skb->len;
1268 if (proto == IPPROTO_UDPLITE) {
1269 err = udplite_checksum_init(skb, uh);
1275 if (uh->check == 0) {
1276 skb->ip_summed = CHECKSUM_UNNECESSARY;
1277 } else if (skb->ip_summed == CHECKSUM_COMPLETE) {
1278 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1280 skb->ip_summed = CHECKSUM_UNNECESSARY;
1282 if (!skb_csum_unnecessary(skb))
1283 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
1284 skb->len, proto, 0);
1285 /* Probably, we should checksum udp header (it should be in cache
1286 * in any case) and data in tiny packets (< rx copybreak).
1293 * All we need to do is get the socket, and then do a checksum.
1296 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1301 unsigned short ulen;
1302 struct rtable *rt = skb_rtable(skb);
1303 __be32 saddr, daddr;
1304 struct net *net = dev_net(skb->dev);
1307 * Validate the packet.
1309 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1310 goto drop; /* No space for header. */
1313 ulen = ntohs(uh->len);
1314 if (ulen > skb->len)
1317 if (proto == IPPROTO_UDP) {
1318 /* UDP validates ulen. */
1319 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
1324 if (udp4_csum_init(skb, uh, proto))
1327 saddr = ip_hdr(skb)->saddr;
1328 daddr = ip_hdr(skb)->daddr;
1330 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1331 return __udp4_lib_mcast_deliver(net, skb, uh,
1332 saddr, daddr, udptable);
1334 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1337 int ret = udp_queue_rcv_skb(sk, skb);
1340 /* a return value > 0 means to resubmit the input, but
1341 * it wants the return to be -protocol, or 0
1348 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1352 /* No socket. Drop packet silently, if checksum is wrong */
1353 if (udp_lib_checksum_complete(skb))
1356 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1357 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
1360 * Hmm. We got an UDP packet to a port to which we
1361 * don't wanna listen. Ignore it.
1367 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1368 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1379 * RFC1122: OK. Discards the bad packet silently (as far as
1380 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1382 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1383 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1390 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1395 int udp_rcv(struct sk_buff *skb)
1397 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1400 void udp_destroy_sock(struct sock *sk)
1403 udp_flush_pending_frames(sk);
1408 * Socket option code for UDP
1410 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1411 char __user *optval, unsigned int optlen,
1412 int (*push_pending_frames)(struct sock *))
1414 struct udp_sock *up = udp_sk(sk);
1417 int is_udplite = IS_UDPLITE(sk);
1419 if (optlen < sizeof(int))
1422 if (get_user(val, (int __user *)optval))
1432 (*push_pending_frames)(sk);
1440 case UDP_ENCAP_ESPINUDP:
1441 case UDP_ENCAP_ESPINUDP_NON_IKE:
1442 up->encap_rcv = xfrm4_udp_encap_rcv;
1444 case UDP_ENCAP_L2TPINUDP:
1445 up->encap_type = val;
1454 * UDP-Lite's partial checksum coverage (RFC 3828).
1456 /* The sender sets actual checksum coverage length via this option.
1457 * The case coverage > packet length is handled by send module. */
1458 case UDPLITE_SEND_CSCOV:
1459 if (!is_udplite) /* Disable the option on UDP sockets */
1460 return -ENOPROTOOPT;
1461 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
1463 else if (val > USHORT_MAX)
1466 up->pcflag |= UDPLITE_SEND_CC;
1469 /* The receiver specifies a minimum checksum coverage value. To make
1470 * sense, this should be set to at least 8 (as done below). If zero is
1471 * used, this again means full checksum coverage. */
1472 case UDPLITE_RECV_CSCOV:
1473 if (!is_udplite) /* Disable the option on UDP sockets */
1474 return -ENOPROTOOPT;
1475 if (val != 0 && val < 8) /* Avoid silly minimal values. */
1477 else if (val > USHORT_MAX)
1480 up->pcflag |= UDPLITE_RECV_CC;
1490 EXPORT_SYMBOL(udp_lib_setsockopt);
1492 int udp_setsockopt(struct sock *sk, int level, int optname,
1493 char __user *optval, unsigned int optlen)
1495 if (level == SOL_UDP || level == SOL_UDPLITE)
1496 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1497 udp_push_pending_frames);
1498 return ip_setsockopt(sk, level, optname, optval, optlen);
1501 #ifdef CONFIG_COMPAT
1502 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
1503 char __user *optval, unsigned int optlen)
1505 if (level == SOL_UDP || level == SOL_UDPLITE)
1506 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1507 udp_push_pending_frames);
1508 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
1512 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
1513 char __user *optval, int __user *optlen)
1515 struct udp_sock *up = udp_sk(sk);
1518 if (get_user(len, optlen))
1521 len = min_t(unsigned int, len, sizeof(int));
1532 val = up->encap_type;
1535 /* The following two cannot be changed on UDP sockets, the return is
1536 * always 0 (which corresponds to the full checksum coverage of UDP). */
1537 case UDPLITE_SEND_CSCOV:
1541 case UDPLITE_RECV_CSCOV:
1546 return -ENOPROTOOPT;
1549 if (put_user(len, optlen))
1551 if (copy_to_user(optval, &val, len))
1555 EXPORT_SYMBOL(udp_lib_getsockopt);
1557 int udp_getsockopt(struct sock *sk, int level, int optname,
1558 char __user *optval, int __user *optlen)
1560 if (level == SOL_UDP || level == SOL_UDPLITE)
1561 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1562 return ip_getsockopt(sk, level, optname, optval, optlen);
1565 #ifdef CONFIG_COMPAT
1566 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
1567 char __user *optval, int __user *optlen)
1569 if (level == SOL_UDP || level == SOL_UDPLITE)
1570 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1571 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
1575 * udp_poll - wait for a UDP event.
1576 * @file - file struct
1578 * @wait - poll table
1580 * This is same as datagram poll, except for the special case of
1581 * blocking sockets. If application is using a blocking fd
1582 * and a packet with checksum error is in the queue;
1583 * then it could get return from select indicating data available
1584 * but then block when reading it. Add special case code
1585 * to work around these arguably broken applications.
1587 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
1589 unsigned int mask = datagram_poll(file, sock, wait);
1590 struct sock *sk = sock->sk;
1592 /* Check for false positives due to checksum errors */
1593 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
1594 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk))
1595 mask &= ~(POLLIN | POLLRDNORM);
1600 EXPORT_SYMBOL(udp_poll);
1602 struct proto udp_prot = {
1604 .owner = THIS_MODULE,
1605 .close = udp_lib_close,
1606 .connect = ip4_datagram_connect,
1607 .disconnect = udp_disconnect,
1609 .destroy = udp_destroy_sock,
1610 .setsockopt = udp_setsockopt,
1611 .getsockopt = udp_getsockopt,
1612 .sendmsg = udp_sendmsg,
1613 .recvmsg = udp_recvmsg,
1614 .sendpage = udp_sendpage,
1615 .backlog_rcv = __udp_queue_rcv_skb,
1616 .hash = udp_lib_hash,
1617 .unhash = udp_lib_unhash,
1618 .get_port = udp_v4_get_port,
1619 .memory_allocated = &udp_memory_allocated,
1620 .sysctl_mem = sysctl_udp_mem,
1621 .sysctl_wmem = &sysctl_udp_wmem_min,
1622 .sysctl_rmem = &sysctl_udp_rmem_min,
1623 .obj_size = sizeof(struct udp_sock),
1624 .slab_flags = SLAB_DESTROY_BY_RCU,
1625 .h.udp_table = &udp_table,
1626 #ifdef CONFIG_COMPAT
1627 .compat_setsockopt = compat_udp_setsockopt,
1628 .compat_getsockopt = compat_udp_getsockopt,
1631 EXPORT_SYMBOL(udp_prot);
1633 /* ------------------------------------------------------------------------ */
1634 #ifdef CONFIG_PROC_FS
1636 static struct sock *udp_get_first(struct seq_file *seq, int start)
1639 struct udp_iter_state *state = seq->private;
1640 struct net *net = seq_file_net(seq);
1642 for (state->bucket = start; state->bucket <= state->udp_table->mask;
1644 struct hlist_nulls_node *node;
1645 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
1647 if (hlist_nulls_empty(&hslot->head))
1650 spin_lock_bh(&hslot->lock);
1651 sk_nulls_for_each(sk, node, &hslot->head) {
1652 if (!net_eq(sock_net(sk), net))
1654 if (sk->sk_family == state->family)
1657 spin_unlock_bh(&hslot->lock);
1664 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
1666 struct udp_iter_state *state = seq->private;
1667 struct net *net = seq_file_net(seq);
1670 sk = sk_nulls_next(sk);
1671 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
1674 if (state->bucket <= state->udp_table->mask)
1675 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
1676 return udp_get_first(seq, state->bucket + 1);
1681 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
1683 struct sock *sk = udp_get_first(seq, 0);
1686 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
1688 return pos ? NULL : sk;
1691 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
1693 struct udp_iter_state *state = seq->private;
1694 state->bucket = MAX_UDP_PORTS;
1696 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1699 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1703 if (v == SEQ_START_TOKEN)
1704 sk = udp_get_idx(seq, 0);
1706 sk = udp_get_next(seq, v);
1712 static void udp_seq_stop(struct seq_file *seq, void *v)
1714 struct udp_iter_state *state = seq->private;
1716 if (state->bucket <= state->udp_table->mask)
1717 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
1720 static int udp_seq_open(struct inode *inode, struct file *file)
1722 struct udp_seq_afinfo *afinfo = PDE(inode)->data;
1723 struct udp_iter_state *s;
1726 err = seq_open_net(inode, file, &afinfo->seq_ops,
1727 sizeof(struct udp_iter_state));
1731 s = ((struct seq_file *)file->private_data)->private;
1732 s->family = afinfo->family;
1733 s->udp_table = afinfo->udp_table;
1737 /* ------------------------------------------------------------------------ */
1738 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
1740 struct proc_dir_entry *p;
1743 afinfo->seq_fops.open = udp_seq_open;
1744 afinfo->seq_fops.read = seq_read;
1745 afinfo->seq_fops.llseek = seq_lseek;
1746 afinfo->seq_fops.release = seq_release_net;
1748 afinfo->seq_ops.start = udp_seq_start;
1749 afinfo->seq_ops.next = udp_seq_next;
1750 afinfo->seq_ops.stop = udp_seq_stop;
1752 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1753 &afinfo->seq_fops, afinfo);
1758 EXPORT_SYMBOL(udp_proc_register);
1760 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
1762 proc_net_remove(net, afinfo->name);
1764 EXPORT_SYMBOL(udp_proc_unregister);
1766 /* ------------------------------------------------------------------------ */
1767 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
1768 int bucket, int *len)
1770 struct inet_sock *inet = inet_sk(sp);
1771 __be32 dest = inet->inet_daddr;
1772 __be32 src = inet->inet_rcv_saddr;
1773 __u16 destp = ntohs(inet->inet_dport);
1774 __u16 srcp = ntohs(inet->inet_sport);
1776 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1777 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d%n",
1778 bucket, src, srcp, dest, destp, sp->sk_state,
1779 sk_wmem_alloc_get(sp),
1780 sk_rmem_alloc_get(sp),
1781 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
1782 atomic_read(&sp->sk_refcnt), sp,
1783 atomic_read(&sp->sk_drops), len);
1786 int udp4_seq_show(struct seq_file *seq, void *v)
1788 if (v == SEQ_START_TOKEN)
1789 seq_printf(seq, "%-127s\n",
1790 " sl local_address rem_address st tx_queue "
1791 "rx_queue tr tm->when retrnsmt uid timeout "
1792 "inode ref pointer drops");
1794 struct udp_iter_state *state = seq->private;
1797 udp4_format_sock(v, seq, state->bucket, &len);
1798 seq_printf(seq, "%*s\n", 127 - len, "");
1803 /* ------------------------------------------------------------------------ */
1804 static struct udp_seq_afinfo udp4_seq_afinfo = {
1807 .udp_table = &udp_table,
1809 .owner = THIS_MODULE,
1812 .show = udp4_seq_show,
1816 static int udp4_proc_init_net(struct net *net)
1818 return udp_proc_register(net, &udp4_seq_afinfo);
1821 static void udp4_proc_exit_net(struct net *net)
1823 udp_proc_unregister(net, &udp4_seq_afinfo);
1826 static struct pernet_operations udp4_net_ops = {
1827 .init = udp4_proc_init_net,
1828 .exit = udp4_proc_exit_net,
1831 int __init udp4_proc_init(void)
1833 return register_pernet_subsys(&udp4_net_ops);
1836 void udp4_proc_exit(void)
1838 unregister_pernet_subsys(&udp4_net_ops);
1840 #endif /* CONFIG_PROC_FS */
1842 static __initdata unsigned long uhash_entries;
1843 static int __init set_uhash_entries(char *str)
1847 uhash_entries = simple_strtoul(str, &str, 0);
1848 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
1849 uhash_entries = UDP_HTABLE_SIZE_MIN;
1852 __setup("uhash_entries=", set_uhash_entries);
1854 void __init udp_table_init(struct udp_table *table, const char *name)
1858 if (!CONFIG_BASE_SMALL)
1859 table->hash = alloc_large_system_hash(name,
1860 sizeof(struct udp_hslot),
1862 21, /* one slot per 2 MB */
1868 * Make sure hash table has the minimum size
1870 if (CONFIG_BASE_SMALL || table->mask < UDP_HTABLE_SIZE_MIN - 1) {
1871 table->hash = kmalloc(UDP_HTABLE_SIZE_MIN *
1872 sizeof(struct udp_hslot), GFP_KERNEL);
1875 table->log = ilog2(UDP_HTABLE_SIZE_MIN);
1876 table->mask = UDP_HTABLE_SIZE_MIN - 1;
1878 for (i = 0; i <= table->mask; i++) {
1879 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
1880 table->hash[i].count = 0;
1881 spin_lock_init(&table->hash[i].lock);
1885 void __init udp_init(void)
1887 unsigned long nr_pages, limit;
1889 udp_table_init(&udp_table, "UDP");
1890 /* Set the pressure threshold up by the same strategy of TCP. It is a
1891 * fraction of global memory that is up to 1/2 at 256 MB, decreasing
1892 * toward zero with the amount of memory, with a floor of 128 pages.
1894 nr_pages = totalram_pages - totalhigh_pages;
1895 limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
1896 limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
1897 limit = max(limit, 128UL);
1898 sysctl_udp_mem[0] = limit / 4 * 3;
1899 sysctl_udp_mem[1] = limit;
1900 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
1902 sysctl_udp_rmem_min = SK_MEM_QUANTUM;
1903 sysctl_udp_wmem_min = SK_MEM_QUANTUM;
1906 int udp4_ufo_send_check(struct sk_buff *skb)
1908 const struct iphdr *iph;
1911 if (!pskb_may_pull(skb, sizeof(*uh)))
1917 uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1919 skb->csum_start = skb_transport_header(skb) - skb->head;
1920 skb->csum_offset = offsetof(struct udphdr, check);
1921 skb->ip_summed = CHECKSUM_PARTIAL;
1925 struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, int features)
1927 struct sk_buff *segs = ERR_PTR(-EINVAL);
1932 mss = skb_shinfo(skb)->gso_size;
1933 if (unlikely(skb->len <= mss))
1936 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
1937 /* Packet is from an untrusted source, reset gso_segs. */
1938 int type = skb_shinfo(skb)->gso_type;
1940 if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) ||
1941 !(type & (SKB_GSO_UDP))))
1944 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
1950 /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
1951 * do checksum of UDP packets sent as multiple IP fragments.
1953 offset = skb->csum_start - skb_headroom(skb);
1954 csum = skb_checksum(skb, offset, skb->len - offset, 0);
1955 offset += skb->csum_offset;
1956 *(__sum16 *)(skb->data + offset) = csum_fold(csum);
1957 skb->ip_summed = CHECKSUM_NONE;
1959 /* Fragment the skb. IP headers of the fragments are updated in
1960 * inet_gso_segment()
1962 segs = skb_segment(skb, features);