/* * UDP over IPv6 * Linux INET6 implementation * * Authors: * Pedro Roque <roque@di.fc.ul.pt> * * Based on linux/ipv4/udp.c * * Fixes: * Hideaki YOSHIFUJI : sin6_scope_id support * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind * a single port at the same time. * Kazunori MIYAZAWA @USAGI: change process style to use ip6_append_data * YOSHIFUJI Hideaki @USAGI: convert /proc/net/udp6 to seq_file. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include <linux/errno.h> #include <linux/types.h> #include <linux/socket.h> #include <linux/sockios.h> #include <linux/net.h> #include <linux/in6.h> #include <linux/netdevice.h> #include <linux/if_arp.h> #include <linux/ipv6.h> #include <linux/icmpv6.h> #include <linux/init.h> #include <linux/module.h> #include <linux/skbuff.h> #include <linux/slab.h> #include <asm/uaccess.h> #include <net/ndisc.h> #include <net/protocol.h> #include <net/transp_v6.h> #include <net/ip6_route.h> #include <net/raw.h> #include <net/tcp_states.h> #include <net/ip6_checksum.h> #include <net/xfrm.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include "udp_impl.h" int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2) { const struct in6_addr *sk_rcv_saddr6 = &inet6_sk(sk)->rcv_saddr; const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2); __be32 sk1_rcv_saddr = sk_rcv_saddr(sk); __be32 sk2_rcv_saddr = sk_rcv_saddr(sk2); int sk_ipv6only = ipv6_only_sock(sk); int sk2_ipv6only = inet_v6_ipv6only(sk2); int addr_type = ipv6_addr_type(sk_rcv_saddr6); int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED; /* if both are mapped, treat as IPv4 */ if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED) return (!sk2_ipv6only && (!sk1_rcv_saddr || !sk2_rcv_saddr || sk1_rcv_saddr == sk2_rcv_saddr)); if (addr_type2 == IPV6_ADDR_ANY && !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED)) return 1; if (addr_type == IPV6_ADDR_ANY && !(sk_ipv6only && addr_type2 == IPV6_ADDR_MAPPED)) return 1; if (sk2_rcv_saddr6 && ipv6_addr_equal(sk_rcv_saddr6, sk2_rcv_saddr6)) return 1; return 0; } static unsigned int udp6_portaddr_hash(struct net *net, const struct in6_addr *addr6, unsigned int port) { unsigned int hash, mix = net_hash_mix(net); if (ipv6_addr_any(addr6)) hash = jhash_1word(0, mix); else if (ipv6_addr_v4mapped(addr6)) hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix); else hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix); return hash ^ port; } int udp_v6_get_port(struct sock *sk, unsigned short snum) { unsigned int hash2_nulladdr = udp6_portaddr_hash(sock_net(sk), &in6addr_any, snum); unsigned int hash2_partial = udp6_portaddr_hash(sock_net(sk), &inet6_sk(sk)->rcv_saddr, 0); /* precompute partial secondary hash */ udp_sk(sk)->udp_portaddr_hash = hash2_partial; return udp_lib_get_port(sk, snum, ipv6_rcv_saddr_equal, hash2_nulladdr); } static void udp_v6_rehash(struct sock *sk) { u16 new_hash = udp6_portaddr_hash(sock_net(sk), &inet6_sk(sk)->rcv_saddr, inet_sk(sk)->inet_num); udp_lib_rehash(sk, new_hash); } static inline int compute_score(struct sock *sk, struct net *net, unsigned short hnum, const struct in6_addr *saddr, __be16 sport, const struct in6_addr *daddr, __be16 dport, int dif) { int score = -1; if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum && sk->sk_family == PF_INET6) { struct ipv6_pinfo *np = inet6_sk(sk); struct inet_sock *inet = inet_sk(sk); score = 0; if (inet->inet_dport) { if (inet->inet_dport != sport) return -1; score++; } if (!ipv6_addr_any(&np->rcv_saddr)) { if (!ipv6_addr_equal(&np->rcv_saddr, daddr)) return -1; score++; } if (!ipv6_addr_any(&np->daddr)) { if (!ipv6_addr_equal(&np->daddr, saddr)) return -1; score++; } if (sk->sk_bound_dev_if) { if (sk->sk_bound_dev_if != dif) return -1; score++; } } return score; } #define SCORE2_MAX (1 + 1 + 1) static inline int compute_score2(struct sock *sk, struct net *net, const struct in6_addr *saddr, __be16 sport, const struct in6_addr *daddr, unsigned short hnum, int dif) { int score = -1; if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum && sk->sk_family == PF_INET6) { struct ipv6_pinfo *np = inet6_sk(sk); struct inet_sock *inet = inet_sk(sk); if (!ipv6_addr_equal(&np->rcv_saddr, daddr)) return -1; score = 0; if (inet->inet_dport) { if (inet->inet_dport != sport) return -1; score++; } if (!ipv6_addr_any(&np->daddr)) { if (!ipv6_addr_equal(&np->daddr, saddr)) return -1; score++; } if (sk->sk_bound_dev_if) { if (sk->sk_bound_dev_if != dif) return -1; score++; } } return score; } /* called with read_rcu_lock() */ static struct sock *udp6_lib_lookup2(struct net *net, const struct in6_addr *saddr, __be16 sport, const struct in6_addr *daddr, unsigned int hnum, int dif, struct udp_hslot *hslot2, unsigned int slot2) { struct sock *sk, *result; struct hlist_nulls_node *node; int score, badness; begin: result = NULL; badness = -1; udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) { score = compute_score2(sk, net, saddr, sport, daddr, hnum, dif); if (score > badness) { result = sk; badness = score; if (score == SCORE2_MAX) goto exact_match; } } /* * if the nulls value we got at the end of this lookup is * not the expected one, we must restart lookup. * We probably met an item that was moved to another chain. */ if (get_nulls_value(node) != slot2) goto begin; if (result) { exact_match: if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) result = NULL; else if (unlikely(compute_score2(result, net, saddr, sport, daddr, hnum, dif) < badness)) { sock_put(result); goto begin; } } return result; } static struct sock *__udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, const struct in6_addr *daddr, __be16 dport, int dif, struct udp_table *udptable) { struct sock *sk, *result; struct hlist_nulls_node *node; unsigned short hnum = ntohs(dport); unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; int score, badness; rcu_read_lock(); if (hslot->count > 10) { hash2 = udp6_portaddr_hash(net, daddr, hnum); slot2 = hash2 & udptable->mask; hslot2 = &udptable->hash2[slot2]; if (hslot->count < hslot2->count) goto begin; result = udp6_lib_lookup2(net, saddr, sport, daddr, hnum, dif, hslot2, slot2); if (!result) { hash2 = udp6_portaddr_hash(net, &in6addr_any, hnum); slot2 = hash2 & udptable->mask; hslot2 = &udptable->hash2[slot2]; if (hslot->count < hslot2->count) goto begin; result = udp6_lib_lookup2(net, saddr, sport, &in6addr_any, hnum, dif, hslot2, slot2); } rcu_read_unlock(); return result; } begin: result = NULL; badness = -1; sk_nulls_for_each_rcu(sk, node, &hslot->head) { score = compute_score(sk, net, hnum, saddr, sport, daddr, dport, dif); if (score > badness) { result = sk; badness = score; } } /* * if the nulls value we got at the end of this lookup is * not the expected one, we must restart lookup. * We probably met an item that was moved to another chain. */ if (get_nulls_value(node) != slot) goto begin; if (result) { if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) result = NULL; else if (unlikely(compute_score(result, net, hnum, saddr, sport, daddr, dport, dif) < badness)) { sock_put(result); goto begin; } } rcu_read_unlock(); return result; } static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb, __be16 sport, __be16 dport, struct udp_table *udptable) { struct sock *sk; const struct ipv6hdr *iph = ipv6_hdr(skb); if (unlikely(sk = skb_steal_sock(skb))) return sk; return __udp6_lib_lookup(dev_net(skb_dst(skb)->dev), &iph->saddr, sport, &iph->daddr, dport, inet6_iif(skb), udptable); } struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, const struct in6_addr *daddr, __be16 dport, int dif) { return __udp6_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table); } EXPORT_SYMBOL_GPL(udp6_lib_lookup); /* * This should be easy, if there is something there we * return it, otherwise we block. */ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, size_t len, int noblock, int flags, int *addr_len) { struct ipv6_pinfo *np = inet6_sk(sk); struct inet_sock *inet = inet_sk(sk); struct sk_buff *skb; unsigned int ulen; int peeked; int err; int is_udplite = IS_UDPLITE(sk); int is_udp4; bool slow; if (addr_len) *addr_len=sizeof(struct sockaddr_in6); if (flags & MSG_ERRQUEUE) return ipv6_recv_error(sk, msg, len); if (np->rxpmtu && np->rxopt.bits.rxpmtu) return ipv6_recv_rxpmtu(sk, msg, len); try_again: skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), &peeked, &err); if (!skb) goto out; ulen = skb->len - sizeof(struct udphdr); if (len > ulen) len = ulen; else if (len < ulen) msg->msg_flags |= MSG_TRUNC; is_udp4 = (skb->protocol == htons(ETH_P_IP)); /* * If checksum is needed at all, try to do it while copying the * data. If the data is truncated, or if we only want a partial * coverage checksum (UDP-Lite), do it before the copy. */ if (len < ulen || UDP_SKB_CB(skb)->partial_cov) { if (udp_lib_checksum_complete(skb)) goto csum_copy_err; } if (skb_csum_unnecessary(skb)) err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,len); else { err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov); if (err == -EINVAL) goto csum_copy_err; } if (err) goto out_free; if (!peeked) { if (is_udp4) UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INDATAGRAMS, is_udplite); else UDP6_INC_STATS_USER(sock_net(sk), UDP_MIB_INDATAGRAMS, is_udplite); } sock_recv_ts_and_drops(msg, sk, skb); /* Copy the address. */ if (msg->msg_name) { struct sockaddr_in6 *sin6; sin6 = (struct sockaddr_in6 *) msg->msg_name; sin6->sin6_family = AF_INET6; sin6->sin6_port = udp_hdr(skb)->source; sin6->sin6_flowinfo = 0; sin6->sin6_scope_id = 0; if (is_udp4) ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &sin6->sin6_addr); else { ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr); if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) sin6->sin6_scope_id = IP6CB(skb)->iif; } } if (is_udp4) { if (inet->cmsg_flags) ip_cmsg_recv(msg, skb); } else { if (np->rxopt.all) datagram_recv_ctl(sk, msg, skb); } err = len; if (flags & MSG_TRUNC) err = ulen; out_free: skb_free_datagram_locked(sk, skb); out: return err; csum_copy_err: slow = lock_sock_fast(sk); if (!skb_kill_datagram(sk, skb, flags)) { if (is_udp4) UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite); else UDP6_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite); } unlock_sock_fast(sk, slow); if (flags & MSG_DONTWAIT) return -EAGAIN; goto try_again; } void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt, u8 type, u8 code, int offset, __be32 info, struct udp_table *udptable) { struct ipv6_pinfo *np; const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data; const struct in6_addr *saddr = &hdr->saddr; const struct in6_addr *daddr = &hdr->daddr; struct udphdr *uh = (struct udphdr*)(skb->data+offset); struct sock *sk; int err; sk = __udp6_lib_lookup(dev_net(skb->dev), daddr, uh->dest, saddr, uh->source, inet6_iif(skb), udptable); if (sk == NULL) return; np = inet6_sk(sk); if (!icmpv6_err_convert(type, code, &err) && !np->recverr) goto out; if (sk->sk_state != TCP_ESTABLISHED && !np->recverr) goto out; if (np->recverr) ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1)); sk->sk_err = err; sk->sk_error_report(sk); out: sock_put(sk); } static __inline__ void udpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, u8 type, u8 code, int offset, __be32 info ) { __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table); } int udpv6_queue_rcv_skb(struct sock * sk, struct sk_buff *skb) { struct udp_sock *up = udp_sk(sk); int rc; int is_udplite = IS_UDPLITE(sk); if (!ipv6_addr_any(&inet6_sk(sk)->daddr)) sock_rps_save_rxhash(sk, skb->rxhash); if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) goto drop; /* * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c). */ if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { if (up->pcrlen == 0) { /* full coverage was set */ LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: partial coverage" " %d while full coverage %d requested\n", UDP_SKB_CB(skb)->cscov, skb->len); goto drop; } if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: coverage %d " "too small, need min %d\n", UDP_SKB_CB(skb)->cscov, up->pcrlen); goto drop; } } if (rcu_dereference_raw(sk->sk_filter)) { if (udp_lib_checksum_complete(skb)) goto drop; } if ((rc = ip_queue_rcv_skb(sk, skb)) < 0) { /* Note that an ENOMEM error is charged twice */ if (rc == -ENOMEM) UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, is_udplite); goto drop_no_sk_drops_inc; } return 0; drop: atomic_inc(&sk->sk_drops); drop_no_sk_drops_inc: UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); kfree_skb(skb); return -1; } static struct sock *udp_v6_mcast_next(struct net *net, struct sock *sk, __be16 loc_port, const struct in6_addr *loc_addr, __be16 rmt_port, const struct in6_addr *rmt_addr, int dif) { struct hlist_nulls_node *node; struct sock *s = sk; unsigned short num = ntohs(loc_port); sk_nulls_for_each_from(s, node) { struct inet_sock *inet = inet_sk(s); if (!net_eq(sock_net(s), net)) continue; if (udp_sk(s)->udp_port_hash == num && s->sk_family == PF_INET6) { struct ipv6_pinfo *np = inet6_sk(s); if (inet->inet_dport) { if (inet->inet_dport != rmt_port) continue; } if (!ipv6_addr_any(&np->daddr) && !ipv6_addr_equal(&np->daddr, rmt_addr)) continue; if (s->sk_bound_dev_if && s->sk_bound_dev_if != dif) continue; if (!ipv6_addr_any(&np->rcv_saddr)) { if (!ipv6_addr_equal(&np->rcv_saddr, loc_addr)) continue; } if (!inet6_mc_check(s, loc_addr, rmt_addr)) continue; return s; } } return NULL; } static void flush_stack(struct sock **stack, unsigned int count, struct sk_buff *skb, unsigned int final) { unsigned int i; struct sock *sk; struct sk_buff *skb1; for (i = 0; i < count; i++) { skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC); sk = stack[i]; if (skb1) { if (sk_rcvqueues_full(sk, skb1)) { kfree_skb(skb1); goto drop; } bh_lock_sock(sk); if (!sock_owned_by_user(sk)) udpv6_queue_rcv_skb(sk, skb1); else if (sk_add_backlog(sk, skb1)) { kfree_skb(skb1); bh_unlock_sock(sk); goto drop; } bh_unlock_sock(sk); continue; } drop: atomic_inc(&sk->sk_drops); UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, IS_UDPLITE(sk)); UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, IS_UDPLITE(sk)); } } /* * Note: called only from the BH handler context, * so we don't need to lock the hashes. */ static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb, const struct in6_addr *saddr, const struct in6_addr *daddr, struct udp_table *udptable) { struct sock *sk, *stack[256 / sizeof(struct sock *)]; const struct udphdr *uh = udp_hdr(skb); struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest)); int dif; unsigned int i, count = 0; spin_lock(&hslot->lock); sk = sk_nulls_head(&hslot->head); dif = inet6_iif(skb); sk = udp_v6_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif); while (sk) { stack[count++] = sk; sk = udp_v6_mcast_next(net, sk_nulls_next(sk), uh->dest, daddr, uh->source, saddr, dif); if (unlikely(count == ARRAY_SIZE(stack))) { if (!sk) break; flush_stack(stack, count, skb, ~0); count = 0; } } /* * before releasing the lock, we must take reference on sockets */ for (i = 0; i < count; i++) sock_hold(stack[i]); spin_unlock(&hslot->lock); if (count) { flush_stack(stack, count, skb, count - 1); for (i = 0; i < count; i++) sock_put(stack[i]); } else { kfree_skb(skb); } return 0; } static inline int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto) { int err; UDP_SKB_CB(skb)->partial_cov = 0; UDP_SKB_CB(skb)->cscov = skb->len; if (proto == IPPROTO_UDPLITE) { err = udplite_checksum_init(skb, uh); if (err) return err; } if (uh->check == 0) { /* RFC 2460 section 8.1 says that we SHOULD log this error. Well, it is reasonable. */ LIMIT_NETDEBUG(KERN_INFO "IPv6: udp checksum is 0\n"); return 1; } if (skb->ip_summed == CHECKSUM_COMPLETE && !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr, skb->len, proto, skb->csum)) skb->ip_summed = CHECKSUM_UNNECESSARY; if (!skb_csum_unnecessary(skb)) skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr, skb->len, proto, 0)); return 0; } int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, int proto) { struct net *net = dev_net(skb->dev); struct sock *sk; struct udphdr *uh; const struct in6_addr *saddr, *daddr; u32 ulen = 0; if (!pskb_may_pull(skb, sizeof(struct udphdr))) goto discard; saddr = &ipv6_hdr(skb)->saddr; daddr = &ipv6_hdr(skb)->daddr; uh = udp_hdr(skb); ulen = ntohs(uh->len); if (ulen > skb->len) goto short_packet; if (proto == IPPROTO_UDP) { /* UDP validates ulen. */ /* Check for jumbo payload */ if (ulen == 0) ulen = skb->len; if (ulen < sizeof(*uh)) goto short_packet; if (ulen < skb->len) { if (pskb_trim_rcsum(skb, ulen)) goto short_packet; saddr = &ipv6_hdr(skb)->saddr; daddr = &ipv6_hdr(skb)->daddr; uh = udp_hdr(skb); } } if (udp6_csum_init(skb, uh, proto)) goto discard; /* * Multicast receive code */ if (ipv6_addr_is_multicast(daddr)) return __udp6_lib_mcast_deliver(net, skb, saddr, daddr, udptable); /* Unicast */ /* * check socket cache ... must talk to Alan about his plans * for sock caches... i'll skip this for now. */ sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable); if (sk == NULL) { if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) goto discard; if (udp_lib_checksum_complete(skb)) goto discard; UDP6_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0); kfree_skb(skb); return 0; } /* deliver */ if (sk_rcvqueues_full(sk, skb)) { sock_put(sk); goto discard; } bh_lock_sock(sk); if (!sock_owned_by_user(sk)) udpv6_queue_rcv_skb(sk, skb); else if (sk_add_backlog(sk, skb)) { atomic_inc(&sk->sk_drops); bh_unlock_sock(sk); sock_put(sk); goto discard; } bh_unlock_sock(sk); sock_put(sk); return 0; short_packet: LIMIT_NETDEBUG(KERN_DEBUG "UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n", proto == IPPROTO_UDPLITE ? "-Lite" : "", saddr, ntohs(uh->source), ulen, skb->len, daddr, ntohs(uh->dest)); discard: UDP6_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); kfree_skb(skb); return 0; } static __inline__ int udpv6_rcv(struct sk_buff *skb) { return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP); } /* * Throw away all pending data and cancel the corking. Socket is locked. */ static void udp_v6_flush_pending_frames(struct sock *sk) { struct udp_sock *up = udp_sk(sk); if (up->pending == AF_INET) udp_flush_pending_frames(sk); else if (up->pending) { up->len = 0; up->pending = 0; ip6_flush_pending_frames(sk); } } /** * udp6_hwcsum_outgoing - handle outgoing HW checksumming * @sk: socket we are sending on * @skb: sk_buff containing the filled-in UDP header * (checksum field must be zeroed out) */ static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb, const struct in6_addr *saddr, const struct in6_addr *daddr, int len) { unsigned int offset; struct udphdr *uh = udp_hdr(skb); __wsum csum = 0; if (skb_queue_len(&sk->sk_write_queue) == 1) { /* Only one fragment on the socket. */ skb->csum_start = skb_transport_header(skb) - skb->head; skb->csum_offset = offsetof(struct udphdr, check); uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0); } else { /* * HW-checksum won't work as there are two or more * fragments on the socket so that all csums of sk_buffs * should be together */ offset = skb_transport_offset(skb); skb->csum = skb_checksum(skb, offset, skb->len - offset, 0); skb->ip_summed = CHECKSUM_NONE; skb_queue_walk(&sk->sk_write_queue, skb) { csum = csum_add(csum, skb->csum); } uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, csum); if (uh->check == 0) uh->check = CSUM_MANGLED_0; } } /* * Sending */ static int udp_v6_push_pending_frames(struct sock *sk) { struct sk_buff *skb; struct udphdr *uh; struct udp_sock *up = udp_sk(sk); struct inet_sock *inet = inet_sk(sk); struct flowi6 *fl6 = &inet->cork.fl.u.ip6; int err = 0; int is_udplite = IS_UDPLITE(sk); __wsum csum = 0; /* Grab the skbuff where UDP header space exists. */ if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) goto out; /* * Create a UDP header */ uh = udp_hdr(skb); uh->source = fl6->fl6_sport; uh->dest = fl6->fl6_dport; uh->len = htons(up->len); uh->check = 0; if (is_udplite) csum = udplite_csum_outgoing(sk, skb); else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, up->len); goto send; } else csum = udp_csum_outgoing(sk, skb); /* add protocol-dependent pseudo-header */ uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr, up->len, fl6->flowi6_proto, csum); if (uh->check == 0) uh->check = CSUM_MANGLED_0; send: err = ip6_push_pending_frames(sk); if (err) { if (err == -ENOBUFS && !inet6_sk(sk)->recverr) { UDP6_INC_STATS_USER(sock_net(sk), UDP_MIB_SNDBUFERRORS, is_udplite); err = 0; } } else UDP6_INC_STATS_USER(sock_net(sk), UDP_MIB_OUTDATAGRAMS, is_udplite); out: up->len = 0; up->pending = 0; return err; } int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, size_t len) { struct ipv6_txoptions opt_space; struct udp_sock *up = udp_sk(sk); struct inet_sock *inet = inet_sk(sk); struct ipv6_pinfo *np = inet6_sk(sk); struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) msg->msg_name; struct in6_addr *daddr, *final_p, final; struct ipv6_txoptions *opt = NULL; struct ip6_flowlabel *flowlabel = NULL; struct flowi6 fl6; struct dst_entry *dst; int addr_len = msg->msg_namelen; int ulen = len; int hlimit = -1; int tclass = -1; int dontfrag = -1; int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; int err; int connected = 0; int is_udplite = IS_UDPLITE(sk); int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); /* destination address check */ if (sin6) { if (addr_len < offsetof(struct sockaddr, sa_data)) return -EINVAL; switch (sin6->sin6_family) { case AF_INET6: if (addr_len < SIN6_LEN_RFC2133) return -EINVAL; daddr = &sin6->sin6_addr; break; case AF_INET: goto do_udp_sendmsg; case AF_UNSPEC: msg->msg_name = sin6 = NULL; msg->msg_namelen = addr_len = 0; daddr = NULL; break; default: return -EINVAL; } } else if (!up->pending) { if (sk->sk_state != TCP_ESTABLISHED) return -EDESTADDRREQ; daddr = &np->daddr; } else daddr = NULL; if (daddr) { if (ipv6_addr_v4mapped(daddr)) { struct sockaddr_in sin; sin.sin_family = AF_INET; sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport; sin.sin_addr.s_addr = daddr->s6_addr32[3]; msg->msg_name = &sin; msg->msg_namelen = sizeof(sin); do_udp_sendmsg: if (__ipv6_only_sock(sk)) return -ENETUNREACH; return udp_sendmsg(iocb, sk, msg, len); } } if (up->pending == AF_INET) return udp_sendmsg(iocb, sk, msg, len); /* Rough check on arithmetic overflow, better check is made in ip6_append_data(). */ if (len > INT_MAX - sizeof(struct udphdr)) return -EMSGSIZE; if (up->pending) { /* * There are pending frames. * The socket lock must be held while it's corked. */ lock_sock(sk); if (likely(up->pending)) { if (unlikely(up->pending != AF_INET6)) { release_sock(sk); return -EAFNOSUPPORT; } dst = NULL; goto do_append_data; } release_sock(sk); } ulen += sizeof(struct udphdr); memset(&fl6, 0, sizeof(fl6)); if (sin6) { if (sin6->sin6_port == 0) return -EINVAL; fl6.fl6_dport = sin6->sin6_port; daddr = &sin6->sin6_addr; if (np->sndflow) { fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK; if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); if (flowlabel == NULL) return -EINVAL; daddr = &flowlabel->dst; } } /* * Otherwise it will be difficult to maintain * sk->sk_dst_cache. */ if (sk->sk_state == TCP_ESTABLISHED && ipv6_addr_equal(daddr, &np->daddr)) daddr = &np->daddr; if (addr_len >= sizeof(struct sockaddr_in6) && sin6->sin6_scope_id && ipv6_addr_type(daddr)&IPV6_ADDR_LINKLOCAL) fl6.flowi6_oif = sin6->sin6_scope_id; } else { if (sk->sk_state != TCP_ESTABLISHED) return -EDESTADDRREQ; fl6.fl6_dport = inet->inet_dport; daddr = &np->daddr; fl6.flowlabel = np->flow_label; connected = 1; } if (!fl6.flowi6_oif) fl6.flowi6_oif = sk->sk_bound_dev_if; if (!fl6.flowi6_oif) fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex; fl6.flowi6_mark = sk->sk_mark; if (msg->msg_controllen) { opt = &opt_space; memset(opt, 0, sizeof(struct ipv6_txoptions)); opt->tot_len = sizeof(*opt); err = datagram_send_ctl(sock_net(sk), msg, &fl6, opt, &hlimit, &tclass, &dontfrag); if (err < 0) { fl6_sock_release(flowlabel); return err; } if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) { flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); if (flowlabel == NULL) return -EINVAL; } if (!(opt->opt_nflen|opt->opt_flen)) opt = NULL; connected = 0; } if (opt == NULL) opt = np->opt; if (flowlabel) opt = fl6_merge_options(&opt_space, flowlabel, opt); opt = ipv6_fixup_options(&opt_space, opt); fl6.flowi6_proto = sk->sk_protocol; if (!ipv6_addr_any(daddr)) ipv6_addr_copy(&fl6.daddr, daddr); else fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) ipv6_addr_copy(&fl6.saddr, &np->saddr); fl6.fl6_sport = inet->inet_sport; final_p = fl6_update_dst(&fl6, opt, &final); if (final_p) connected = 0; if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) { fl6.flowi6_oif = np->mcast_oif; connected = 0; } security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, true); if (IS_ERR(dst)) { err = PTR_ERR(dst); dst = NULL; goto out; } if (hlimit < 0) { if (ipv6_addr_is_multicast(&fl6.daddr)) hlimit = np->mcast_hops; else hlimit = np->hop_limit; if (hlimit < 0) hlimit = ip6_dst_hoplimit(dst); } if (tclass < 0) tclass = np->tclass; if (dontfrag < 0) dontfrag = np->dontfrag; if (msg->msg_flags&MSG_CONFIRM) goto do_confirm; back_from_confirm: lock_sock(sk); if (unlikely(up->pending)) { /* The socket is already corked while preparing it. */ /* ... which is an evident application bug. --ANK */ release_sock(sk); LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n"); err = -EINVAL; goto out; } up->pending = AF_INET6; do_append_data: up->len += ulen; getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; err = ip6_append_data(sk, getfrag, msg->msg_iov, ulen, sizeof(struct udphdr), hlimit, tclass, opt, &fl6, (struct rt6_info*)dst, corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags, dontfrag); if (err) udp_v6_flush_pending_frames(sk); else if (!corkreq) err = udp_v6_push_pending_frames(sk); else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) up->pending = 0; if (dst) { if (connected) { ip6_dst_store(sk, dst, ipv6_addr_equal(&fl6.daddr, &np->daddr) ? &np->daddr : NULL, #ifdef CONFIG_IPV6_SUBTREES ipv6_addr_equal(&fl6.saddr, &np->saddr) ? &np->saddr : #endif NULL); } else { dst_release(dst); } dst = NULL; } if (err > 0) err = np->recverr ? net_xmit_errno(err) : 0; release_sock(sk); out: dst_release(dst); fl6_sock_release(flowlabel); if (!err) return len; /* * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting * ENOBUFS might not be good (it's not tunable per se), but otherwise * we don't have a good statistic (IpOutDiscards but it can be too many * things). We could add another new stat but at least for now that * seems like overkill. */ if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { UDP6_INC_STATS_USER(sock_net(sk), UDP_MIB_SNDBUFERRORS, is_udplite); } return err; do_confirm: dst_confirm(dst); if (!(msg->msg_flags&MSG_PROBE) || len) goto back_from_confirm; err = 0; goto out; } void udpv6_destroy_sock(struct sock *sk) { lock_sock(sk); udp_v6_flush_pending_frames(sk); release_sock(sk); inet6_destroy_sock(sk); } /* * Socket option code for UDP */ int udpv6_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen) { if (level == SOL_UDP || level == SOL_UDPLITE) return udp_lib_setsockopt(sk, level, optname, optval, optlen, udp_v6_push_pending_frames); return ipv6_setsockopt(sk, level, optname, optval, optlen); } #ifdef CONFIG_COMPAT int compat_udpv6_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen) { if (level == SOL_UDP || level == SOL_UDPLITE) return udp_lib_setsockopt(sk, level, optname, optval, optlen, udp_v6_push_pending_frames); return compat_ipv6_setsockopt(sk, level, optname, optval, optlen); } #endif int udpv6_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen) { if (level == SOL_UDP || level == SOL_UDPLITE) return udp_lib_getsockopt(sk, level, optname, optval, optlen); return ipv6_getsockopt(sk, level, optname, optval, optlen); } #ifdef CONFIG_COMPAT int compat_udpv6_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen) { if (level == SOL_UDP || level == SOL_UDPLITE) return udp_lib_getsockopt(sk, level, optname, optval, optlen); return compat_ipv6_getsockopt(sk, level, optname, optval, optlen); } #endif static int udp6_ufo_send_check(struct sk_buff *skb) { const struct ipv6hdr *ipv6h; struct udphdr *uh; if (!pskb_may_pull(skb, sizeof(*uh))) return -EINVAL; ipv6h = ipv6_hdr(skb); uh = udp_hdr(skb); uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len, IPPROTO_UDP, 0); skb->csum_start = skb_transport_header(skb) - skb->head; skb->csum_offset = offsetof(struct udphdr, check); skb->ip_summed = CHECKSUM_PARTIAL; return 0; } static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, u32 features) { struct sk_buff *segs = ERR_PTR(-EINVAL); unsigned int mss; unsigned int unfrag_ip6hlen, unfrag_len; struct frag_hdr *fptr; u8 *mac_start, *prevhdr; u8 nexthdr; u8 frag_hdr_sz = sizeof(struct frag_hdr); int offset; __wsum csum; mss = skb_shinfo(skb)->gso_size; if (unlikely(skb->len <= mss)) goto out; if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { /* Packet is from an untrusted source, reset gso_segs. */ int type = skb_shinfo(skb)->gso_type; if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) || !(type & (SKB_GSO_UDP)))) goto out; skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); segs = NULL; goto out; } /* Do software UFO. Complete and fill in the UDP checksum as HW cannot * do checksum of UDP packets sent as multiple IP fragments. */ offset = skb_checksum_start_offset(skb); csum = skb_checksum(skb, offset, skb->len- offset, 0); offset += skb->csum_offset; *(__sum16 *)(skb->data + offset) = csum_fold(csum); skb->ip_summed = CHECKSUM_NONE; /* Check if there is enough headroom to insert fragment header. */ if ((skb_mac_header(skb) < skb->head + frag_hdr_sz) && pskb_expand_head(skb, frag_hdr_sz, 0, GFP_ATOMIC)) goto out; /* Find the unfragmentable header and shift it left by frag_hdr_sz * bytes to insert fragment header. */ unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr); nexthdr = *prevhdr; *prevhdr = NEXTHDR_FRAGMENT; unfrag_len = skb_network_header(skb) - skb_mac_header(skb) + unfrag_ip6hlen; mac_start = skb_mac_header(skb); memmove(mac_start-frag_hdr_sz, mac_start, unfrag_len); skb->mac_header -= frag_hdr_sz; skb->network_header -= frag_hdr_sz; fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen); fptr->nexthdr = nexthdr; fptr->reserved = 0; ipv6_select_ident(fptr); /* Fragment the skb. ipv6 header and the remaining fields of the * fragment header are updated in ipv6_gso_segment() */ segs = skb_segment(skb, features); out: return segs; } static const struct inet6_protocol udpv6_protocol = { .handler = udpv6_rcv, .err_handler = udpv6_err, .gso_send_check = udp6_ufo_send_check, .gso_segment = udp6_ufo_fragment, .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, }; /* ------------------------------------------------------------------------ */ #ifdef CONFIG_PROC_FS static void udp6_sock_seq_show(struct seq_file *seq, struct sock *sp, int bucket) { struct inet_sock *inet = inet_sk(sp); struct ipv6_pinfo *np = inet6_sk(sp); const struct in6_addr *dest, *src; __u16 destp, srcp; dest = &np->daddr; src = &np->rcv_saddr; destp = ntohs(inet->inet_dport); srcp = ntohs(inet->inet_sport); seq_printf(seq, "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d\n", bucket, src->s6_addr32[0], src->s6_addr32[1], src->s6_addr32[2], src->s6_addr32[3], srcp, dest->s6_addr32[0], dest->s6_addr32[1], dest->s6_addr32[2], dest->s6_addr32[3], destp, sp->sk_state, sk_wmem_alloc_get(sp), sk_rmem_alloc_get(sp), 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp), atomic_read(&sp->sk_refcnt), sp, atomic_read(&sp->sk_drops)); } int udp6_seq_show(struct seq_file *seq, void *v) { if (v == SEQ_START_TOKEN) seq_printf(seq, " sl " "local_address " "remote_address " "st tx_queue rx_queue tr tm->when retrnsmt" " uid timeout inode ref pointer drops\n"); else udp6_sock_seq_show(seq, v, ((struct udp_iter_state *)seq->private)->bucket); return 0; } static struct udp_seq_afinfo udp6_seq_afinfo = { .name = "udp6", .family = AF_INET6, .udp_table = &udp_table, .seq_fops = { .owner = THIS_MODULE, }, .seq_ops = { .show = udp6_seq_show, }, }; int __net_init udp6_proc_init(struct net *net) { return udp_proc_register(net, &udp6_seq_afinfo); } void udp6_proc_exit(struct net *net) { udp_proc_unregister(net, &udp6_seq_afinfo); } #endif /* CONFIG_PROC_FS */ /* ------------------------------------------------------------------------ */ struct proto udpv6_prot = { .name = "UDPv6", .owner = THIS_MODULE, .close = udp_lib_close, .connect = ip6_datagram_connect, .disconnect = udp_disconnect, .ioctl = udp_ioctl, .destroy = udpv6_destroy_sock, .setsockopt = udpv6_setsockopt, .getsockopt = udpv6_getsockopt, .sendmsg = udpv6_sendmsg, .recvmsg = udpv6_recvmsg, .backlog_rcv = udpv6_queue_rcv_skb, .hash = udp_lib_hash, .unhash = udp_lib_unhash, .rehash = udp_v6_rehash, .get_port = udp_v6_get_port, .memory_allocated = &udp_memory_allocated, .sysctl_mem = sysctl_udp_mem, .sysctl_wmem = &sysctl_udp_wmem_min, .sysctl_rmem = &sysctl_udp_rmem_min, .obj_size = sizeof(struct udp6_sock), .slab_flags = SLAB_DESTROY_BY_RCU, .h.udp_table = &udp_table, #ifdef CONFIG_COMPAT .compat_setsockopt = compat_udpv6_setsockopt, .compat_getsockopt = compat_udpv6_getsockopt, #endif .clear_sk = sk_prot_clear_portaddr_nulls, }; static struct inet_protosw udpv6_protosw = { .type = SOCK_DGRAM, .protocol = IPPROTO_UDP, .prot = &udpv6_prot, .ops = &inet6_dgram_ops, .no_check = UDP_CSUM_DEFAULT, .flags = INET_PROTOSW_PERMANENT, }; int __init udpv6_init(void) { int ret; ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP); if (ret) goto out; ret = inet6_register_protosw(&udpv6_protosw); if (ret) goto out_udpv6_protocol; out: return ret; out_udpv6_protocol: inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP); goto out; } void udpv6_exit(void) { inet6_unregister_protosw(&udpv6_protosw); inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP); }