3 * Linux INET6 implementation
6 * Pedro Roque <roque@di.fc.ul.pt>
8 * Based on linux/ipv4/udp.c
11 * Hideaki YOSHIFUJI : sin6_scope_id support
12 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
13 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
14 * a single port at the same time.
15 * Kazunori MIYAZAWA @USAGI: change process style to use ip6_append_data
16 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/udp6 to seq_file.
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
24 #include <linux/errno.h>
25 #include <linux/types.h>
26 #include <linux/socket.h>
27 #include <linux/sockios.h>
28 #include <linux/net.h>
29 #include <linux/in6.h>
30 #include <linux/netdevice.h>
31 #include <linux/if_arp.h>
32 #include <linux/ipv6.h>
33 #include <linux/icmpv6.h>
34 #include <linux/init.h>
35 #include <linux/module.h>
36 #include <linux/skbuff.h>
37 #include <linux/slab.h>
38 #include <linux/uaccess.h>
40 #include <net/addrconf.h>
41 #include <net/ndisc.h>
42 #include <net/protocol.h>
43 #include <net/transp_v6.h>
44 #include <net/ip6_route.h>
46 #include <net/tcp_states.h>
47 #include <net/ip6_checksum.h>
49 #include <net/inet_hashtables.h>
50 #include <net/inet6_hashtables.h>
51 #include <net/busy_poll.h>
52 #include <net/sock_reuseport.h>
54 #include <linux/proc_fs.h>
55 #include <linux/seq_file.h>
56 #include <trace/events/skb.h>
59 static bool udp6_lib_exact_dif_match(struct net *net, struct sk_buff *skb)
61 #if defined(CONFIG_NET_L3_MASTER_DEV)
62 if (!net->ipv4.sysctl_udp_l3mdev_accept &&
63 skb && ipv6_l3mdev_skb(IP6CB(skb)->flags))
69 static u32 udp6_ehashfn(const struct net *net,
70 const struct in6_addr *laddr,
72 const struct in6_addr *faddr,
75 static u32 udp6_ehash_secret __read_mostly;
76 static u32 udp_ipv6_hash_secret __read_mostly;
80 net_get_random_once(&udp6_ehash_secret,
81 sizeof(udp6_ehash_secret));
82 net_get_random_once(&udp_ipv6_hash_secret,
83 sizeof(udp_ipv6_hash_secret));
85 lhash = (__force u32)laddr->s6_addr32[3];
86 fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret);
88 return __inet6_ehashfn(lhash, lport, fhash, fport,
89 udp_ipv6_hash_secret + net_hash_mix(net));
92 int udp_v6_get_port(struct sock *sk, unsigned short snum)
94 unsigned int hash2_nulladdr =
95 ipv6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
96 unsigned int hash2_partial =
97 ipv6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0);
99 /* precompute partial secondary hash */
100 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
101 return udp_lib_get_port(sk, snum, hash2_nulladdr);
104 static void udp_v6_rehash(struct sock *sk)
106 u16 new_hash = ipv6_portaddr_hash(sock_net(sk),
107 &sk->sk_v6_rcv_saddr,
108 inet_sk(sk)->inet_num);
110 udp_lib_rehash(sk, new_hash);
113 static int compute_score(struct sock *sk, struct net *net,
114 const struct in6_addr *saddr, __be16 sport,
115 const struct in6_addr *daddr, unsigned short hnum,
116 int dif, int sdif, bool exact_dif)
119 struct inet_sock *inet;
121 if (!net_eq(sock_net(sk), net) ||
122 udp_sk(sk)->udp_port_hash != hnum ||
123 sk->sk_family != PF_INET6)
129 if (inet->inet_dport) {
130 if (inet->inet_dport != sport)
135 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
136 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
141 if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
142 if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
147 if (sk->sk_bound_dev_if || exact_dif) {
148 bool dev_match = (sk->sk_bound_dev_if == dif ||
149 sk->sk_bound_dev_if == sdif);
153 if (sk->sk_bound_dev_if)
157 if (sk->sk_incoming_cpu == raw_smp_processor_id())
163 /* called with rcu_read_lock() */
164 static struct sock *udp6_lib_lookup2(struct net *net,
165 const struct in6_addr *saddr, __be16 sport,
166 const struct in6_addr *daddr, unsigned int hnum,
167 int dif, int sdif, bool exact_dif,
168 struct udp_hslot *hslot2, struct sk_buff *skb)
170 struct sock *sk, *result;
176 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
177 score = compute_score(sk, net, saddr, sport,
178 daddr, hnum, dif, sdif, exact_dif);
179 if (score > badness) {
180 if (sk->sk_reuseport) {
181 hash = udp6_ehashfn(net, daddr, hnum,
184 result = reuseport_select_sock(sk, hash, skb,
185 sizeof(struct udphdr));
196 /* rcu_read_lock() must be held */
197 struct sock *__udp6_lib_lookup(struct net *net,
198 const struct in6_addr *saddr, __be16 sport,
199 const struct in6_addr *daddr, __be16 dport,
200 int dif, int sdif, struct udp_table *udptable,
203 struct sock *sk, *result;
204 unsigned short hnum = ntohs(dport);
205 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
206 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
207 bool exact_dif = udp6_lib_exact_dif_match(net, skb);
211 if (hslot->count > 10) {
212 hash2 = ipv6_portaddr_hash(net, daddr, hnum);
213 slot2 = hash2 & udptable->mask;
214 hslot2 = &udptable->hash2[slot2];
215 if (hslot->count < hslot2->count)
218 result = udp6_lib_lookup2(net, saddr, sport,
219 daddr, hnum, dif, sdif, exact_dif,
222 unsigned int old_slot2 = slot2;
223 hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
224 slot2 = hash2 & udptable->mask;
225 /* avoid searching the same slot again. */
226 if (unlikely(slot2 == old_slot2))
229 hslot2 = &udptable->hash2[slot2];
230 if (hslot->count < hslot2->count)
233 result = udp6_lib_lookup2(net, saddr, sport,
234 daddr, hnum, dif, sdif,
238 if (unlikely(IS_ERR(result)))
245 sk_for_each_rcu(sk, &hslot->head) {
246 score = compute_score(sk, net, saddr, sport, daddr, hnum, dif,
248 if (score > badness) {
249 if (sk->sk_reuseport) {
250 hash = udp6_ehashfn(net, daddr, hnum,
252 result = reuseport_select_sock(sk, hash, skb,
253 sizeof(struct udphdr));
254 if (unlikely(IS_ERR(result)))
265 EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
267 static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
268 __be16 sport, __be16 dport,
269 struct udp_table *udptable)
271 const struct ipv6hdr *iph = ipv6_hdr(skb);
273 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
274 &iph->daddr, dport, inet6_iif(skb),
275 inet6_sdif(skb), udptable, skb);
278 struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
279 __be16 sport, __be16 dport)
281 const struct ipv6hdr *iph = ipv6_hdr(skb);
283 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
284 &iph->daddr, dport, inet6_iif(skb),
285 inet6_sdif(skb), &udp_table, skb);
287 EXPORT_SYMBOL_GPL(udp6_lib_lookup_skb);
289 /* Must be called under rcu_read_lock().
290 * Does increment socket refcount.
292 #if IS_ENABLED(CONFIG_NF_TPROXY_IPV6) || IS_ENABLED(CONFIG_NF_SOCKET_IPV6)
293 struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
294 const struct in6_addr *daddr, __be16 dport, int dif)
298 sk = __udp6_lib_lookup(net, saddr, sport, daddr, dport,
299 dif, 0, &udp_table, NULL);
300 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
304 EXPORT_SYMBOL_GPL(udp6_lib_lookup);
307 /* do not use the scratch area len for jumbogram: their length execeeds the
308 * scratch area space; note that the IP6CB flags is still in the first
309 * cacheline, so checking for jumbograms is cheap
311 static int udp6_skb_len(struct sk_buff *skb)
313 return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb);
317 * This should be easy, if there is something there we
318 * return it, otherwise we block.
321 int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
322 int noblock, int flags, int *addr_len)
324 struct ipv6_pinfo *np = inet6_sk(sk);
325 struct inet_sock *inet = inet_sk(sk);
327 unsigned int ulen, copied;
328 int peeked, peeking, off;
330 int is_udplite = IS_UDPLITE(sk);
331 bool checksum_valid = false;
334 if (flags & MSG_ERRQUEUE)
335 return ipv6_recv_error(sk, msg, len, addr_len);
337 if (np->rxpmtu && np->rxopt.bits.rxpmtu)
338 return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
341 peeking = flags & MSG_PEEK;
342 off = sk_peek_offset(sk, flags);
343 skb = __skb_recv_udp(sk, flags, noblock, &peeked, &off, &err);
347 ulen = udp6_skb_len(skb);
349 if (copied > ulen - off)
351 else if (copied < ulen)
352 msg->msg_flags |= MSG_TRUNC;
354 is_udp4 = (skb->protocol == htons(ETH_P_IP));
357 * If checksum is needed at all, try to do it while copying the
358 * data. If the data is truncated, or if we only want a partial
359 * coverage checksum (UDP-Lite), do it before the copy.
362 if (copied < ulen || peeking ||
363 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
364 checksum_valid = udp_skb_csum_unnecessary(skb) ||
365 !__udp_lib_checksum_complete(skb);
370 if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
371 if (udp_skb_is_linear(skb))
372 err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
374 err = skb_copy_datagram_msg(skb, off, msg, copied);
376 err = skb_copy_and_csum_datagram_msg(skb, off, msg);
382 atomic_inc(&sk->sk_drops);
384 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
387 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
395 UDP_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS,
398 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS,
402 sock_recv_ts_and_drops(msg, sk, skb);
404 /* Copy the address. */
406 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
407 sin6->sin6_family = AF_INET6;
408 sin6->sin6_port = udp_hdr(skb)->source;
409 sin6->sin6_flowinfo = 0;
412 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
414 sin6->sin6_scope_id = 0;
416 sin6->sin6_addr = ipv6_hdr(skb)->saddr;
417 sin6->sin6_scope_id =
418 ipv6_iface_scope_id(&sin6->sin6_addr,
421 *addr_len = sizeof(*sin6);
425 ip6_datagram_recv_common_ctl(sk, msg, skb);
428 if (inet->cmsg_flags)
429 ip_cmsg_recv_offset(msg, sk, skb,
430 sizeof(struct udphdr), off);
433 ip6_datagram_recv_specific_ctl(sk, msg, skb);
437 if (flags & MSG_TRUNC)
440 skb_consume_udp(sk, skb, peeking ? -err : err);
444 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
445 udp_skb_destructor)) {
447 UDP_INC_STATS(sock_net(sk),
448 UDP_MIB_CSUMERRORS, is_udplite);
449 UDP_INC_STATS(sock_net(sk),
450 UDP_MIB_INERRORS, is_udplite);
452 UDP6_INC_STATS(sock_net(sk),
453 UDP_MIB_CSUMERRORS, is_udplite);
454 UDP6_INC_STATS(sock_net(sk),
455 UDP_MIB_INERRORS, is_udplite);
460 /* starting over for a new packet, but check if we need to yield */
462 msg->msg_flags &= ~MSG_TRUNC;
466 void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
467 u8 type, u8 code, int offset, __be32 info,
468 struct udp_table *udptable)
470 struct ipv6_pinfo *np;
471 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
472 const struct in6_addr *saddr = &hdr->saddr;
473 const struct in6_addr *daddr = &hdr->daddr;
474 struct udphdr *uh = (struct udphdr *)(skb->data+offset);
478 struct net *net = dev_net(skb->dev);
480 sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source,
481 inet6_iif(skb), 0, udptable, skb);
483 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
488 harderr = icmpv6_err_convert(type, code, &err);
491 if (type == ICMPV6_PKT_TOOBIG) {
492 if (!ip6_sk_accept_pmtu(sk))
494 ip6_sk_update_pmtu(skb, sk, info);
495 if (np->pmtudisc != IPV6_PMTUDISC_DONT)
498 if (type == NDISC_REDIRECT) {
499 ip6_sk_redirect(skb, sk);
504 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
507 ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
511 sk->sk_error_report(sk);
516 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
520 if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
521 sock_rps_save_rxhash(sk, skb);
522 sk_mark_napi_id(sk, skb);
523 sk_incoming_cpu_update(sk);
525 sk_mark_napi_id_once(sk, skb);
528 rc = __udp_enqueue_schedule_skb(sk, skb);
530 int is_udplite = IS_UDPLITE(sk);
532 /* Note that an ENOMEM error is charged twice */
534 UDP6_INC_STATS(sock_net(sk),
535 UDP_MIB_RCVBUFERRORS, is_udplite);
536 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
544 static __inline__ void udpv6_err(struct sk_buff *skb,
545 struct inet6_skb_parm *opt, u8 type,
546 u8 code, int offset, __be32 info)
548 __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
551 static DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
552 void udpv6_encap_enable(void)
554 static_branch_enable(&udpv6_encap_needed_key);
556 EXPORT_SYMBOL(udpv6_encap_enable);
558 static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
560 struct udp_sock *up = udp_sk(sk);
561 int is_udplite = IS_UDPLITE(sk);
563 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
566 if (static_branch_unlikely(&udpv6_encap_needed_key) && up->encap_type) {
567 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
570 * This is an encapsulation socket so pass the skb to
571 * the socket's udp_encap_rcv() hook. Otherwise, just
572 * fall through and pass this up the UDP socket.
573 * up->encap_rcv() returns the following value:
574 * =0 if skb was successfully passed to the encap
575 * handler or was discarded by it.
576 * >0 if skb should be passed on to UDP.
577 * <0 if skb should be resubmitted as proto -N
580 /* if we're overly short, let UDP handle it */
581 encap_rcv = READ_ONCE(up->encap_rcv);
585 /* Verify checksum before giving to encap */
586 if (udp_lib_checksum_complete(skb))
589 ret = encap_rcv(sk, skb);
591 __UDP_INC_STATS(sock_net(sk),
598 /* FALLTHROUGH -- it's a UDP Packet */
602 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
604 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
606 if (up->pcrlen == 0) { /* full coverage was set */
607 net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n",
608 UDP_SKB_CB(skb)->cscov, skb->len);
611 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
612 net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n",
613 UDP_SKB_CB(skb)->cscov, up->pcrlen);
618 prefetch(&sk->sk_rmem_alloc);
619 if (rcu_access_pointer(sk->sk_filter) &&
620 udp_lib_checksum_complete(skb))
623 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
626 udp_csum_pull_header(skb);
630 return __udpv6_queue_rcv_skb(sk, skb);
633 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
635 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
636 atomic_inc(&sk->sk_drops);
641 static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
642 __be16 loc_port, const struct in6_addr *loc_addr,
643 __be16 rmt_port, const struct in6_addr *rmt_addr,
644 int dif, unsigned short hnum)
646 struct inet_sock *inet = inet_sk(sk);
648 if (!net_eq(sock_net(sk), net))
651 if (udp_sk(sk)->udp_port_hash != hnum ||
652 sk->sk_family != PF_INET6 ||
653 (inet->inet_dport && inet->inet_dport != rmt_port) ||
654 (!ipv6_addr_any(&sk->sk_v6_daddr) &&
655 !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
656 (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif) ||
657 (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
658 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr)))
660 if (!inet6_mc_check(sk, loc_addr, rmt_addr))
665 static void udp6_csum_zero_error(struct sk_buff *skb)
667 /* RFC 2460 section 8.1 says that we SHOULD log
668 * this error. Well, it is reasonable.
670 net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
671 &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
672 &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
676 * Note: called only from the BH handler context,
677 * so we don't need to lock the hashes.
679 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
680 const struct in6_addr *saddr, const struct in6_addr *daddr,
681 struct udp_table *udptable, int proto)
683 struct sock *sk, *first = NULL;
684 const struct udphdr *uh = udp_hdr(skb);
685 unsigned short hnum = ntohs(uh->dest);
686 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
687 unsigned int offset = offsetof(typeof(*sk), sk_node);
688 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
689 int dif = inet6_iif(skb);
690 struct hlist_node *node;
691 struct sk_buff *nskb;
694 hash2_any = ipv6_portaddr_hash(net, &in6addr_any, hnum) &
696 hash2 = ipv6_portaddr_hash(net, daddr, hnum) & udptable->mask;
698 hslot = &udptable->hash2[hash2];
699 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
702 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
703 if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr,
704 uh->source, saddr, dif, hnum))
706 /* If zero checksum and no_check is not on for
707 * the socket then skip it.
709 if (!uh->check && !udp_sk(sk)->no_check6_rx)
715 nskb = skb_clone(skb, GFP_ATOMIC);
716 if (unlikely(!nskb)) {
717 atomic_inc(&sk->sk_drops);
718 __UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
720 __UDP6_INC_STATS(net, UDP_MIB_INERRORS,
725 if (udpv6_queue_rcv_skb(sk, nskb) > 0)
729 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
730 if (use_hash2 && hash2 != hash2_any) {
736 if (udpv6_queue_rcv_skb(first, skb) > 0)
740 __UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
741 proto == IPPROTO_UDPLITE);
746 static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
748 if (udp_sk_rx_dst_set(sk, dst)) {
749 const struct rt6_info *rt = (const struct rt6_info *)dst;
751 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
755 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
756 * return code conversion for ip layer consumption
758 static int udp6_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
763 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
764 skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
767 ret = udpv6_queue_rcv_skb(sk, skb);
769 /* a return value > 0 means to resubmit the input, but
770 * it wants the return to be -protocol, or 0
777 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
780 const struct in6_addr *saddr, *daddr;
781 struct net *net = dev_net(skb->dev);
786 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
789 saddr = &ipv6_hdr(skb)->saddr;
790 daddr = &ipv6_hdr(skb)->daddr;
793 ulen = ntohs(uh->len);
797 if (proto == IPPROTO_UDP) {
798 /* UDP validates ulen. */
800 /* Check for jumbo payload */
804 if (ulen < sizeof(*uh))
807 if (ulen < skb->len) {
808 if (pskb_trim_rcsum(skb, ulen))
810 saddr = &ipv6_hdr(skb)->saddr;
811 daddr = &ipv6_hdr(skb)->daddr;
816 if (udp6_csum_init(skb, uh, proto))
819 /* Check if the socket is already available, e.g. due to early demux */
820 sk = skb_steal_sock(skb);
822 struct dst_entry *dst = skb_dst(skb);
825 if (unlikely(sk->sk_rx_dst != dst))
826 udp6_sk_rx_dst_set(sk, dst);
828 if (!uh->check && !udp_sk(sk)->no_check6_rx) {
830 goto report_csum_error;
833 ret = udp6_unicast_rcv_skb(sk, skb, uh);
839 * Multicast receive code
841 if (ipv6_addr_is_multicast(daddr))
842 return __udp6_lib_mcast_deliver(net, skb,
843 saddr, daddr, udptable, proto);
846 sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
848 if (!uh->check && !udp_sk(sk)->no_check6_rx)
849 goto report_csum_error;
850 return udp6_unicast_rcv_skb(sk, skb, uh);
854 goto report_csum_error;
856 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
859 if (udp_lib_checksum_complete(skb))
862 __UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
863 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
869 net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
870 proto == IPPROTO_UDPLITE ? "-Lite" : "",
871 saddr, ntohs(uh->source),
873 daddr, ntohs(uh->dest));
877 udp6_csum_zero_error(skb);
879 __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
881 __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
887 static struct sock *__udp6_lib_demux_lookup(struct net *net,
888 __be16 loc_port, const struct in6_addr *loc_addr,
889 __be16 rmt_port, const struct in6_addr *rmt_addr,
892 unsigned short hnum = ntohs(loc_port);
893 unsigned int hash2 = ipv6_portaddr_hash(net, loc_addr, hnum);
894 unsigned int slot2 = hash2 & udp_table.mask;
895 struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
896 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
899 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
900 if (sk->sk_state == TCP_ESTABLISHED &&
901 INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif, sdif))
903 /* Only check first socket in chain */
909 static void udp_v6_early_demux(struct sk_buff *skb)
911 struct net *net = dev_net(skb->dev);
912 const struct udphdr *uh;
914 struct dst_entry *dst;
915 int dif = skb->dev->ifindex;
916 int sdif = inet6_sdif(skb);
918 if (!pskb_may_pull(skb, skb_transport_offset(skb) +
919 sizeof(struct udphdr)))
924 if (skb->pkt_type == PACKET_HOST)
925 sk = __udp6_lib_demux_lookup(net, uh->dest,
926 &ipv6_hdr(skb)->daddr,
927 uh->source, &ipv6_hdr(skb)->saddr,
932 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
936 skb->destructor = sock_efree;
937 dst = READ_ONCE(sk->sk_rx_dst);
940 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
942 /* set noref for now.
943 * any place which wants to hold dst has to call
946 skb_dst_set_noref(skb, dst);
950 static __inline__ int udpv6_rcv(struct sk_buff *skb)
952 return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
956 * Throw away all pending data and cancel the corking. Socket is locked.
958 static void udp_v6_flush_pending_frames(struct sock *sk)
960 struct udp_sock *up = udp_sk(sk);
962 if (up->pending == AF_INET)
963 udp_flush_pending_frames(sk);
964 else if (up->pending) {
967 ip6_flush_pending_frames(sk);
971 static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
974 /* The following checks are replicated from __ip6_datagram_connect()
975 * and intended to prevent BPF program called below from accessing
976 * bytes that are out of the bound specified by user in addr_len.
978 if (uaddr->sa_family == AF_INET) {
979 if (__ipv6_only_sock(sk))
980 return -EAFNOSUPPORT;
981 return udp_pre_connect(sk, uaddr, addr_len);
984 if (addr_len < SIN6_LEN_RFC2133)
987 return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr);
991 * udp6_hwcsum_outgoing - handle outgoing HW checksumming
992 * @sk: socket we are sending on
993 * @skb: sk_buff containing the filled-in UDP header
994 * (checksum field must be zeroed out)
996 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
997 const struct in6_addr *saddr,
998 const struct in6_addr *daddr, int len)
1000 unsigned int offset;
1001 struct udphdr *uh = udp_hdr(skb);
1002 struct sk_buff *frags = skb_shinfo(skb)->frag_list;
1006 /* Only one fragment on the socket. */
1007 skb->csum_start = skb_transport_header(skb) - skb->head;
1008 skb->csum_offset = offsetof(struct udphdr, check);
1009 uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
1012 * HW-checksum won't work as there are two or more
1013 * fragments on the socket so that all csums of sk_buffs
1014 * should be together
1016 offset = skb_transport_offset(skb);
1017 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
1020 skb->ip_summed = CHECKSUM_NONE;
1023 csum = csum_add(csum, frags->csum);
1024 } while ((frags = frags->next));
1026 uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
1029 uh->check = CSUM_MANGLED_0;
1037 static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6,
1038 struct inet_cork *cork)
1040 struct sock *sk = skb->sk;
1043 int is_udplite = IS_UDPLITE(sk);
1045 int offset = skb_transport_offset(skb);
1046 int len = skb->len - offset;
1049 * Create a UDP header
1052 uh->source = fl6->fl6_sport;
1053 uh->dest = fl6->fl6_dport;
1054 uh->len = htons(len);
1057 if (cork->gso_size) {
1058 const int hlen = skb_network_header_len(skb) +
1059 sizeof(struct udphdr);
1061 if (hlen + cork->gso_size > cork->fragsize)
1063 if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS)
1065 if (udp_sk(sk)->no_check6_tx)
1067 if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite ||
1068 dst_xfrm(skb_dst(skb)))
1071 skb_shinfo(skb)->gso_size = cork->gso_size;
1072 skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
1077 csum = udplite_csum(skb);
1078 else if (udp_sk(sk)->no_check6_tx) { /* UDP csum disabled */
1079 skb->ip_summed = CHECKSUM_NONE;
1081 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
1083 udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len);
1086 csum = udp_csum(skb);
1088 /* add protocol-dependent pseudo-header */
1089 uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
1090 len, fl6->flowi6_proto, csum);
1092 uh->check = CSUM_MANGLED_0;
1095 err = ip6_send_skb(skb);
1097 if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
1098 UDP6_INC_STATS(sock_net(sk),
1099 UDP_MIB_SNDBUFERRORS, is_udplite);
1103 UDP6_INC_STATS(sock_net(sk),
1104 UDP_MIB_OUTDATAGRAMS, is_udplite);
1109 static int udp_v6_push_pending_frames(struct sock *sk)
1111 struct sk_buff *skb;
1112 struct udp_sock *up = udp_sk(sk);
1116 if (up->pending == AF_INET)
1117 return udp_push_pending_frames(sk);
1119 /* ip6_finish_skb will release the cork, so make a copy of
1122 fl6 = inet_sk(sk)->cork.fl.u.ip6;
1124 skb = ip6_finish_skb(sk);
1128 err = udp_v6_send_skb(skb, &fl6, &inet_sk(sk)->cork.base);
1136 int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1138 struct ipv6_txoptions opt_space;
1139 struct udp_sock *up = udp_sk(sk);
1140 struct inet_sock *inet = inet_sk(sk);
1141 struct ipv6_pinfo *np = inet6_sk(sk);
1142 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
1143 struct in6_addr *daddr, *final_p, final;
1144 struct ipv6_txoptions *opt = NULL;
1145 struct ipv6_txoptions *opt_to_free = NULL;
1146 struct ip6_flowlabel *flowlabel = NULL;
1148 struct dst_entry *dst;
1149 struct ipcm6_cookie ipc6;
1150 int addr_len = msg->msg_namelen;
1151 bool connected = false;
1153 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
1155 int is_udplite = IS_UDPLITE(sk);
1156 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1159 ipc6.gso_size = up->gso_size;
1160 ipc6.sockc.tsflags = sk->sk_tsflags;
1162 /* destination address check */
1164 if (addr_len < offsetof(struct sockaddr, sa_data))
1167 switch (sin6->sin6_family) {
1169 if (addr_len < SIN6_LEN_RFC2133)
1171 daddr = &sin6->sin6_addr;
1172 if (ipv6_addr_any(daddr) &&
1173 ipv6_addr_v4mapped(&np->saddr))
1174 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
1178 goto do_udp_sendmsg;
1180 msg->msg_name = sin6 = NULL;
1181 msg->msg_namelen = addr_len = 0;
1187 } else if (!up->pending) {
1188 if (sk->sk_state != TCP_ESTABLISHED)
1189 return -EDESTADDRREQ;
1190 daddr = &sk->sk_v6_daddr;
1195 if (ipv6_addr_v4mapped(daddr)) {
1196 struct sockaddr_in sin;
1197 sin.sin_family = AF_INET;
1198 sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1199 sin.sin_addr.s_addr = daddr->s6_addr32[3];
1200 msg->msg_name = &sin;
1201 msg->msg_namelen = sizeof(sin);
1203 if (__ipv6_only_sock(sk))
1204 return -ENETUNREACH;
1205 return udp_sendmsg(sk, msg, len);
1209 if (up->pending == AF_INET)
1210 return udp_sendmsg(sk, msg, len);
1212 /* Rough check on arithmetic overflow,
1213 better check is made in ip6_append_data().
1215 if (len > INT_MAX - sizeof(struct udphdr))
1218 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
1221 * There are pending frames.
1222 * The socket lock must be held while it's corked.
1225 if (likely(up->pending)) {
1226 if (unlikely(up->pending != AF_INET6)) {
1228 return -EAFNOSUPPORT;
1231 goto do_append_data;
1235 ulen += sizeof(struct udphdr);
1237 memset(&fl6, 0, sizeof(fl6));
1240 if (sin6->sin6_port == 0)
1243 fl6.fl6_dport = sin6->sin6_port;
1244 daddr = &sin6->sin6_addr;
1247 fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1248 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
1249 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1256 * Otherwise it will be difficult to maintain
1259 if (sk->sk_state == TCP_ESTABLISHED &&
1260 ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
1261 daddr = &sk->sk_v6_daddr;
1263 if (addr_len >= sizeof(struct sockaddr_in6) &&
1264 sin6->sin6_scope_id &&
1265 __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1266 fl6.flowi6_oif = sin6->sin6_scope_id;
1268 if (sk->sk_state != TCP_ESTABLISHED)
1269 return -EDESTADDRREQ;
1271 fl6.fl6_dport = inet->inet_dport;
1272 daddr = &sk->sk_v6_daddr;
1273 fl6.flowlabel = np->flow_label;
1277 if (!fl6.flowi6_oif)
1278 fl6.flowi6_oif = sk->sk_bound_dev_if;
1280 if (!fl6.flowi6_oif)
1281 fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1283 fl6.flowi6_mark = sk->sk_mark;
1284 fl6.flowi6_uid = sk->sk_uid;
1286 if (msg->msg_controllen) {
1288 memset(opt, 0, sizeof(struct ipv6_txoptions));
1289 opt->tot_len = sizeof(*opt);
1292 err = udp_cmsg_send(sk, msg, &ipc6.gso_size);
1294 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6,
1297 fl6_sock_release(flowlabel);
1300 if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1301 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1305 if (!(opt->opt_nflen|opt->opt_flen))
1310 opt = txopt_get(np);
1314 opt = fl6_merge_options(&opt_space, flowlabel, opt);
1315 opt = ipv6_fixup_options(&opt_space, opt);
1318 fl6.flowi6_proto = sk->sk_protocol;
1319 if (!ipv6_addr_any(daddr))
1322 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1323 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
1324 fl6.saddr = np->saddr;
1325 fl6.fl6_sport = inet->inet_sport;
1327 if (cgroup_bpf_enabled && !connected) {
1328 err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk,
1329 (struct sockaddr *)sin6, &fl6.saddr);
1333 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
1334 /* BPF program rewrote IPv6-only by IPv4-mapped
1335 * IPv6. It's currently unsupported.
1340 if (sin6->sin6_port == 0) {
1341 /* BPF program set invalid port. Reject it. */
1345 fl6.fl6_dport = sin6->sin6_port;
1346 fl6.daddr = sin6->sin6_addr;
1350 final_p = fl6_update_dst(&fl6, opt, &final);
1354 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
1355 fl6.flowi6_oif = np->mcast_oif;
1357 } else if (!fl6.flowi6_oif)
1358 fl6.flowi6_oif = np->ucast_oif;
1360 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
1362 if (ipc6.tclass < 0)
1363 ipc6.tclass = np->tclass;
1365 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
1367 dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, connected);
1374 if (ipc6.hlimit < 0)
1375 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
1377 if (msg->msg_flags&MSG_CONFIRM)
1381 /* Lockless fast path for the non-corking case */
1383 struct inet_cork_full cork;
1384 struct sk_buff *skb;
1386 skb = ip6_make_skb(sk, getfrag, msg, ulen,
1387 sizeof(struct udphdr), &ipc6,
1388 &fl6, (struct rt6_info *)dst,
1389 msg->msg_flags, &cork);
1391 if (!IS_ERR_OR_NULL(skb))
1392 err = udp_v6_send_skb(skb, &fl6, &cork.base);
1397 if (unlikely(up->pending)) {
1398 /* The socket is already corked while preparing it. */
1399 /* ... which is an evident application bug. --ANK */
1402 net_dbg_ratelimited("udp cork app bug 2\n");
1407 up->pending = AF_INET6;
1410 if (ipc6.dontfrag < 0)
1411 ipc6.dontfrag = np->dontfrag;
1413 err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr),
1414 &ipc6, &fl6, (struct rt6_info *)dst,
1415 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1417 udp_v6_flush_pending_frames(sk);
1419 err = udp_v6_push_pending_frames(sk);
1420 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1424 err = np->recverr ? net_xmit_errno(err) : 0;
1430 fl6_sock_release(flowlabel);
1431 txopt_put(opt_to_free);
1435 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1436 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1437 * we don't have a good statistic (IpOutDiscards but it can be too many
1438 * things). We could add another new stat but at least for now that
1439 * seems like overkill.
1441 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1442 UDP6_INC_STATS(sock_net(sk),
1443 UDP_MIB_SNDBUFERRORS, is_udplite);
1448 if (msg->msg_flags & MSG_PROBE)
1449 dst_confirm_neigh(dst, &fl6.daddr);
1450 if (!(msg->msg_flags&MSG_PROBE) || len)
1451 goto back_from_confirm;
1456 void udpv6_destroy_sock(struct sock *sk)
1458 struct udp_sock *up = udp_sk(sk);
1460 udp_v6_flush_pending_frames(sk);
1463 if (static_branch_unlikely(&udpv6_encap_needed_key) && up->encap_type) {
1464 void (*encap_destroy)(struct sock *sk);
1465 encap_destroy = READ_ONCE(up->encap_destroy);
1470 inet6_destroy_sock(sk);
1474 * Socket option code for UDP
1476 int udpv6_setsockopt(struct sock *sk, int level, int optname,
1477 char __user *optval, unsigned int optlen)
1479 if (level == SOL_UDP || level == SOL_UDPLITE)
1480 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1481 udp_v6_push_pending_frames);
1482 return ipv6_setsockopt(sk, level, optname, optval, optlen);
1485 #ifdef CONFIG_COMPAT
1486 int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
1487 char __user *optval, unsigned int optlen)
1489 if (level == SOL_UDP || level == SOL_UDPLITE)
1490 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1491 udp_v6_push_pending_frames);
1492 return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
1496 int udpv6_getsockopt(struct sock *sk, int level, int optname,
1497 char __user *optval, int __user *optlen)
1499 if (level == SOL_UDP || level == SOL_UDPLITE)
1500 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1501 return ipv6_getsockopt(sk, level, optname, optval, optlen);
1504 #ifdef CONFIG_COMPAT
1505 int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
1506 char __user *optval, int __user *optlen)
1508 if (level == SOL_UDP || level == SOL_UDPLITE)
1509 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1510 return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
1514 /* thinking of making this const? Don't.
1515 * early_demux can change based on sysctl.
1517 static struct inet6_protocol udpv6_protocol = {
1518 .early_demux = udp_v6_early_demux,
1519 .early_demux_handler = udp_v6_early_demux,
1520 .handler = udpv6_rcv,
1521 .err_handler = udpv6_err,
1522 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1525 /* ------------------------------------------------------------------------ */
1526 #ifdef CONFIG_PROC_FS
1527 int udp6_seq_show(struct seq_file *seq, void *v)
1529 if (v == SEQ_START_TOKEN) {
1530 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1532 int bucket = ((struct udp_iter_state *)seq->private)->bucket;
1533 struct inet_sock *inet = inet_sk(v);
1534 __u16 srcp = ntohs(inet->inet_sport);
1535 __u16 destp = ntohs(inet->inet_dport);
1536 __ip6_dgram_sock_seq_show(seq, v, srcp, destp,
1537 udp_rqueue_get(v), bucket);
1542 const struct seq_operations udp6_seq_ops = {
1543 .start = udp_seq_start,
1544 .next = udp_seq_next,
1545 .stop = udp_seq_stop,
1546 .show = udp6_seq_show,
1548 EXPORT_SYMBOL(udp6_seq_ops);
1550 static struct udp_seq_afinfo udp6_seq_afinfo = {
1552 .udp_table = &udp_table,
1555 int __net_init udp6_proc_init(struct net *net)
1557 if (!proc_create_net_data("udp6", 0444, net->proc_net, &udp6_seq_ops,
1558 sizeof(struct udp_iter_state), &udp6_seq_afinfo))
1563 void udp6_proc_exit(struct net *net)
1565 remove_proc_entry("udp6", net->proc_net);
1567 #endif /* CONFIG_PROC_FS */
1569 /* ------------------------------------------------------------------------ */
1571 struct proto udpv6_prot = {
1573 .owner = THIS_MODULE,
1574 .close = udp_lib_close,
1575 .pre_connect = udpv6_pre_connect,
1576 .connect = ip6_datagram_connect,
1577 .disconnect = udp_disconnect,
1579 .init = udp_init_sock,
1580 .destroy = udpv6_destroy_sock,
1581 .setsockopt = udpv6_setsockopt,
1582 .getsockopt = udpv6_getsockopt,
1583 .sendmsg = udpv6_sendmsg,
1584 .recvmsg = udpv6_recvmsg,
1585 .release_cb = ip6_datagram_release_cb,
1586 .hash = udp_lib_hash,
1587 .unhash = udp_lib_unhash,
1588 .rehash = udp_v6_rehash,
1589 .get_port = udp_v6_get_port,
1590 .memory_allocated = &udp_memory_allocated,
1591 .sysctl_mem = sysctl_udp_mem,
1592 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
1593 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
1594 .obj_size = sizeof(struct udp6_sock),
1595 .h.udp_table = &udp_table,
1596 #ifdef CONFIG_COMPAT
1597 .compat_setsockopt = compat_udpv6_setsockopt,
1598 .compat_getsockopt = compat_udpv6_getsockopt,
1600 .diag_destroy = udp_abort,
1603 static struct inet_protosw udpv6_protosw = {
1605 .protocol = IPPROTO_UDP,
1606 .prot = &udpv6_prot,
1607 .ops = &inet6_dgram_ops,
1608 .flags = INET_PROTOSW_PERMANENT,
1611 int __init udpv6_init(void)
1615 ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1619 ret = inet6_register_protosw(&udpv6_protosw);
1621 goto out_udpv6_protocol;
1626 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1630 void udpv6_exit(void)
1632 inet6_unregister_protosw(&udpv6_protosw);
1633 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);