/* * UDP over IPv6 * Linux INET6 implementation * * Authors: * Pedro Roque * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "udp_impl.h" static bool udp6_lib_exact_dif_match(struct net *net, struct sk_buff *skb) { #if defined(CONFIG_NET_L3_MASTER_DEV) if (!net->ipv4.sysctl_udp_l3mdev_accept && skb && ipv6_l3mdev_skb(IP6CB(skb)->flags)) return true; #endif return false; } static u32 udp6_ehashfn(const struct net *net, const struct in6_addr *laddr, const u16 lport, const struct in6_addr *faddr, const __be16 fport) { static u32 udp6_ehash_secret __read_mostly; static u32 udp_ipv6_hash_secret __read_mostly; u32 lhash, fhash; net_get_random_once(&udp6_ehash_secret, sizeof(udp6_ehash_secret)); net_get_random_once(&udp_ipv6_hash_secret, sizeof(udp_ipv6_hash_secret)); lhash = (__force u32)laddr->s6_addr32[3]; fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret); return __inet6_ehashfn(lhash, lport, fhash, fport, udp_ipv6_hash_secret + net_hash_mix(net)); } int udp_v6_get_port(struct sock *sk, unsigned short snum) { unsigned int hash2_nulladdr = ipv6_portaddr_hash(sock_net(sk), &in6addr_any, snum); unsigned int hash2_partial = ipv6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0); /* precompute partial secondary hash */ udp_sk(sk)->udp_portaddr_hash = hash2_partial; return udp_lib_get_port(sk, snum, hash2_nulladdr); } static void udp_v6_rehash(struct sock *sk) { u16 new_hash = ipv6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, inet_sk(sk)->inet_num); udp_lib_rehash(sk, new_hash); } static int compute_score(struct sock *sk, struct net *net, const struct in6_addr *saddr, __be16 sport, const struct in6_addr *daddr, unsigned short hnum, int dif, int sdif, bool exact_dif) { int score; struct inet_sock *inet; if (!net_eq(sock_net(sk), net) || udp_sk(sk)->udp_port_hash != hnum || sk->sk_family != PF_INET6) return -1; score = 0; inet = inet_sk(sk); if (inet->inet_dport) { if (inet->inet_dport != sport) return -1; score++; } if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) { if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr)) return -1; score++; } if (!ipv6_addr_any(&sk->sk_v6_daddr)) { if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr)) return -1; score++; } if (sk->sk_bound_dev_if || exact_dif) { bool dev_match = (sk->sk_bound_dev_if == dif || sk->sk_bound_dev_if == sdif); if (!dev_match) return -1; if (sk->sk_bound_dev_if) score++; } if (sk->sk_incoming_cpu == raw_smp_processor_id()) score++; return score; } /* called with rcu_read_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, int sdif, bool exact_dif, struct udp_hslot *hslot2, struct sk_buff *skb) { struct sock *sk, *result; int score, badness; u32 hash = 0; result = NULL; badness = -1; udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { score = compute_score(sk, net, saddr, sport, daddr, hnum, dif, sdif, exact_dif); if (score > badness) { if (sk->sk_reuseport) { hash = udp6_ehashfn(net, daddr, hnum, saddr, sport); result = reuseport_select_sock(sk, hash, skb, sizeof(struct udphdr)); if (result) return result; } result = sk; badness = score; } } return result; } /* rcu_read_lock() must be held */ struct sock *__udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, const struct in6_addr *daddr, __be16 dport, int dif, int sdif, struct udp_table *udptable, struct sk_buff *skb) { struct sock *sk, *result; unsigned short hnum = ntohs(dport); unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; bool exact_dif = udp6_lib_exact_dif_match(net, skb); int score, badness; u32 hash = 0; if (hslot->count > 10) { hash2 = ipv6_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, sdif, exact_dif, hslot2, skb); if (!result) { unsigned int old_slot2 = slot2; hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum); slot2 = hash2 & udptable->mask; /* avoid searching the same slot again. */ if (unlikely(slot2 == old_slot2)) return result; hslot2 = &udptable->hash2[slot2]; if (hslot->count < hslot2->count) goto begin; result = udp6_lib_lookup2(net, saddr, sport, daddr, hnum, dif, sdif, exact_dif, hslot2, skb); } return result; } begin: result = NULL; badness = -1; sk_for_each_rcu(sk, &hslot->head) { score = compute_score(sk, net, saddr, sport, daddr, hnum, dif, sdif, exact_dif); if (score > badness) { if (sk->sk_reuseport) { hash = udp6_ehashfn(net, daddr, hnum, saddr, sport); result = reuseport_select_sock(sk, hash, skb, sizeof(struct udphdr)); if (result) return result; } result = sk; badness = score; } } return result; } EXPORT_SYMBOL_GPL(__udp6_lib_lookup); static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb, __be16 sport, __be16 dport, struct udp_table *udptable) { const struct ipv6hdr *iph = ipv6_hdr(skb); return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport, &iph->daddr, dport, inet6_iif(skb), inet6_sdif(skb), udptable, skb); } struct sock *udp6_lib_lookup_skb(struct sk_buff *skb, __be16 sport, __be16 dport) { const struct ipv6hdr *iph = ipv6_hdr(skb); return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport, &iph->daddr, dport, inet6_iif(skb), inet6_sdif(skb), &udp_table, skb); } EXPORT_SYMBOL_GPL(udp6_lib_lookup_skb); /* Must be called under rcu_read_lock(). * Does increment socket refcount. */ #if IS_ENABLED(CONFIG_NF_TPROXY_IPV6) || IS_ENABLED(CONFIG_NF_SOCKET_IPV6) 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 sock *sk; sk = __udp6_lib_lookup(net, saddr, sport, daddr, dport, dif, 0, &udp_table, NULL); if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) sk = NULL; return sk; } EXPORT_SYMBOL_GPL(udp6_lib_lookup); #endif /* do not use the scratch area len for jumbogram: their length execeeds the * scratch area space; note that the IP6CB flags is still in the first * cacheline, so checking for jumbograms is cheap */ static int udp6_skb_len(struct sk_buff *skb) { return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb); } /* * This should be easy, if there is something there we * return it, otherwise we block. */ int udpv6_recvmsg(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, copied; int peeked, peeking, off; int err; int is_udplite = IS_UDPLITE(sk); bool checksum_valid = false; int is_udp4; if (flags & MSG_ERRQUEUE) return ipv6_recv_error(sk, msg, len, addr_len); if (np->rxpmtu && np->rxopt.bits.rxpmtu) return ipv6_recv_rxpmtu(sk, msg, len, addr_len); try_again: peeking = flags & MSG_PEEK; off = sk_peek_offset(sk, flags); skb = __skb_recv_udp(sk, flags, noblock, &peeked, &off, &err); if (!skb) return err; ulen = udp6_skb_len(skb); copied = len; if (copied > ulen - off) copied = ulen - off; else if (copied < 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 (copied < ulen || peeking || (is_udplite && UDP_SKB_CB(skb)->partial_cov)) { checksum_valid = udp_skb_csum_unnecessary(skb) || !__udp_lib_checksum_complete(skb); if (!checksum_valid) goto csum_copy_err; } if (checksum_valid || udp_skb_csum_unnecessary(skb)) { if (udp_skb_is_linear(skb)) err = copy_linear_skb(skb, copied, off, &msg->msg_iter); else err = skb_copy_datagram_msg(skb, off, msg, copied); } else { err = skb_copy_and_csum_datagram_msg(skb, off, msg); if (err == -EINVAL) goto csum_copy_err; } if (unlikely(err)) { if (!peeked) { atomic_inc(&sk->sk_drops); if (is_udp4) UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); else UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); } kfree_skb(skb); return err; } if (!peeked) { if (is_udp4) UDP_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS, is_udplite); else UDP6_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS, is_udplite); } sock_recv_ts_and_drops(msg, sk, skb); /* Copy the address. */ if (msg->msg_name) { DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); sin6->sin6_family = AF_INET6; sin6->sin6_port = udp_hdr(skb)->source; sin6->sin6_flowinfo = 0; if (is_udp4) { ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &sin6->sin6_addr); sin6->sin6_scope_id = 0; } else { sin6->sin6_addr = ipv6_hdr(skb)->saddr; sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr, inet6_iif(skb)); } *addr_len = sizeof(*sin6); } if (np->rxopt.all) ip6_datagram_recv_common_ctl(sk, msg, skb); if (is_udp4) { if (inet->cmsg_flags) ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off); } else { if (np->rxopt.all) ip6_datagram_recv_specific_ctl(sk, msg, skb); } err = copied; if (flags & MSG_TRUNC) err = ulen; skb_consume_udp(sk, skb, peeking ? -err : err); return err; csum_copy_err: if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags, udp_skb_destructor)) { if (is_udp4) { UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); } else { UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); } } kfree_skb(skb); /* starting over for a new packet, but check if we need to yield */ cond_resched(); msg->msg_flags &= ~MSG_TRUNC; 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 harderr; int err; struct net *net = dev_net(skb->dev); sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source, inet6_iif(skb), 0, udptable, skb); if (!sk) { __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS); return; } harderr = icmpv6_err_convert(type, code, &err); np = inet6_sk(sk); if (type == ICMPV6_PKT_TOOBIG) { if (!ip6_sk_accept_pmtu(sk)) goto out; ip6_sk_update_pmtu(skb, sk, info); if (np->pmtudisc != IPV6_PMTUDISC_DONT) harderr = 1; } if (type == NDISC_REDIRECT) { ip6_sk_redirect(skb, sk); goto out; } if (!np->recverr) { if (!harderr || sk->sk_state != TCP_ESTABLISHED) goto out; } else { ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1)); } sk->sk_err = err; sk->sk_error_report(sk); out: return; } static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) { int rc; if (!ipv6_addr_any(&sk->sk_v6_daddr)) { sock_rps_save_rxhash(sk, skb); sk_mark_napi_id(sk, skb); sk_incoming_cpu_update(sk); } else { sk_mark_napi_id_once(sk, skb); } rc = __udp_enqueue_schedule_skb(sk, skb); if (rc < 0) { int is_udplite = IS_UDPLITE(sk); /* Note that an ENOMEM error is charged twice */ if (rc == -ENOMEM) UDP6_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS, is_udplite); UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); kfree_skb(skb); return -1; } return 0; } 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); } static DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key); void udpv6_encap_enable(void) { static_branch_enable(&udpv6_encap_needed_key); } EXPORT_SYMBOL(udpv6_encap_enable); static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) { struct udp_sock *up = udp_sk(sk); int is_udplite = IS_UDPLITE(sk); if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) goto drop; if (static_branch_unlikely(&udpv6_encap_needed_key) && up->encap_type) { int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); /* * This is an encapsulation socket so pass the skb to * the socket's udp_encap_rcv() hook. Otherwise, just * fall through and pass this up the UDP socket. * up->encap_rcv() returns the following value: * =0 if skb was successfully passed to the encap * handler or was discarded by it. * >0 if skb should be passed on to UDP. * <0 if skb should be resubmitted as proto -N */ /* if we're overly short, let UDP handle it */ encap_rcv = READ_ONCE(up->encap_rcv); if (encap_rcv) { int ret; /* Verify checksum before giving to encap */ if (udp_lib_checksum_complete(skb)) goto csum_error; ret = encap_rcv(sk, skb); if (ret <= 0) { __UDP_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS, is_udplite); return -ret; } } /* FALLTHROUGH -- it's a UDP Packet */ } /* * 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 */ net_dbg_ratelimited("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) { net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n", UDP_SKB_CB(skb)->cscov, up->pcrlen); goto drop; } } prefetch(&sk->sk_rmem_alloc); if (rcu_access_pointer(sk->sk_filter) && udp_lib_checksum_complete(skb)) goto csum_error; if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) goto drop; udp_csum_pull_header(skb); skb_dst_drop(skb); return __udpv6_queue_rcv_skb(sk, skb); csum_error: __UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); drop: __UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); atomic_inc(&sk->sk_drops); kfree_skb(skb); return -1; } static bool __udp_v6_is_mcast_sock(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, unsigned short hnum) { struct inet_sock *inet = inet_sk(sk); if (!net_eq(sock_net(sk), net)) return false; if (udp_sk(sk)->udp_port_hash != hnum || sk->sk_family != PF_INET6 || (inet->inet_dport && inet->inet_dport != rmt_port) || (!ipv6_addr_any(&sk->sk_v6_daddr) && !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) || (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif) || (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr))) return false; if (!inet6_mc_check(sk, loc_addr, rmt_addr)) return false; return true; } static void udp6_csum_zero_error(struct sk_buff *skb) { /* RFC 2460 section 8.1 says that we SHOULD log * this error. Well, it is reasonable. */ net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n", &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source), &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest)); } /* * 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, int proto) { struct sock *sk, *first = NULL; const struct udphdr *uh = udp_hdr(skb); unsigned short hnum = ntohs(uh->dest); struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); unsigned int offset = offsetof(typeof(*sk), sk_node); unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); int dif = inet6_iif(skb); struct hlist_node *node; struct sk_buff *nskb; if (use_hash2) { hash2_any = ipv6_portaddr_hash(net, &in6addr_any, hnum) & udptable->mask; hash2 = ipv6_portaddr_hash(net, daddr, hnum) & udptable->mask; start_lookup: hslot = &udptable->hash2[hash2]; offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); } sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) { if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr, uh->source, saddr, dif, hnum)) continue; /* If zero checksum and no_check is not on for * the socket then skip it. */ if (!uh->check && !udp_sk(sk)->no_check6_rx) continue; if (!first) { first = sk; continue; } nskb = skb_clone(skb, GFP_ATOMIC); if (unlikely(!nskb)) { atomic_inc(&sk->sk_drops); __UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS, IS_UDPLITE(sk)); __UDP6_INC_STATS(net, UDP_MIB_INERRORS, IS_UDPLITE(sk)); continue; } if (udpv6_queue_rcv_skb(sk, nskb) > 0) consume_skb(nskb); } /* Also lookup *:port if we are using hash2 and haven't done so yet. */ if (use_hash2 && hash2 != hash2_any) { hash2 = hash2_any; goto start_lookup; } if (first) { if (udpv6_queue_rcv_skb(first, skb) > 0) consume_skb(skb); } else { kfree_skb(skb); __UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI, proto == IPPROTO_UDPLITE); } return 0; } static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) { if (udp_sk_rx_dst_set(sk, dst)) { const struct rt6_info *rt = (const struct rt6_info *)dst; inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt); } } int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, int proto) { const struct in6_addr *saddr, *daddr; struct net *net = dev_net(skb->dev); struct udphdr *uh; struct sock *sk; 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 csum_error; /* Check if the socket is already available, e.g. due to early demux */ sk = skb_steal_sock(skb); if (sk) { struct dst_entry *dst = skb_dst(skb); int ret; if (unlikely(sk->sk_rx_dst != dst)) udp6_sk_rx_dst_set(sk, dst); ret = udpv6_queue_rcv_skb(sk, skb); sock_put(sk); /* a return value > 0 means to resubmit the input */ if (ret > 0) return ret; return 0; } /* * Multicast receive code */ if (ipv6_addr_is_multicast(daddr)) return __udp6_lib_mcast_deliver(net, skb, saddr, daddr, udptable, proto); /* Unicast */ sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable); if (sk) { int ret; if (!uh->check && !udp_sk(sk)->no_check6_rx) { udp6_csum_zero_error(skb); goto csum_error; } if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk)) skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check, ip6_compute_pseudo); ret = udpv6_queue_rcv_skb(sk, skb); /* a return value > 0 means to resubmit the input */ if (ret > 0) return ret; return 0; } if (!uh->check) { udp6_csum_zero_error(skb); goto csum_error; } if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) goto discard; if (udp_lib_checksum_complete(skb)) goto csum_error; __UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0); kfree_skb(skb); return 0; short_packet: net_dbg_ratelimited("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)); goto discard; csum_error: __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); discard: __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); kfree_skb(skb); return 0; } static struct sock *__udp6_lib_demux_lookup(struct net *net, __be16 loc_port, const struct in6_addr *loc_addr, __be16 rmt_port, const struct in6_addr *rmt_addr, int dif, int sdif) { unsigned short hnum = ntohs(loc_port); unsigned int hash2 = ipv6_portaddr_hash(net, loc_addr, hnum); unsigned int slot2 = hash2 & udp_table.mask; struct udp_hslot *hslot2 = &udp_table.hash2[slot2]; const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum); struct sock *sk; udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { if (sk->sk_state == TCP_ESTABLISHED && INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif, sdif)) return sk; /* Only check first socket in chain */ break; } return NULL; } static void udp_v6_early_demux(struct sk_buff *skb) { struct net *net = dev_net(skb->dev); const struct udphdr *uh; struct sock *sk; struct dst_entry *dst; int dif = skb->dev->ifindex; int sdif = inet6_sdif(skb); if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr))) return; uh = udp_hdr(skb); if (skb->pkt_type == PACKET_HOST) sk = __udp6_lib_demux_lookup(net, uh->dest, &ipv6_hdr(skb)->daddr, uh->source, &ipv6_hdr(skb)->saddr, dif, sdif); else return; if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) return; skb->sk = sk; skb->destructor = sock_efree; dst = READ_ONCE(sk->sk_rx_dst); if (dst) dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie); if (dst) { /* set noref for now. * any place which wants to hold dst has to call * dst_hold_safe() */ skb_dst_set_noref(skb, dst); } } 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); } } static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) { /* The following checks are replicated from __ip6_datagram_connect() * and intended to prevent BPF program called below from accessing * bytes that are out of the bound specified by user in addr_len. */ if (uaddr->sa_family == AF_INET) { if (__ipv6_only_sock(sk)) return -EAFNOSUPPORT; return udp_pre_connect(sk, uaddr, addr_len); } if (addr_len < SIN6_LEN_RFC2133) return -EINVAL; return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr); } /** * 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); struct sk_buff *frags = skb_shinfo(skb)->frag_list; __wsum csum = 0; if (!frags) { /* 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); csum = skb->csum; skb->ip_summed = CHECKSUM_NONE; do { csum = csum_add(csum, frags->csum); } while ((frags = frags->next)); 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_send_skb(struct sk_buff *skb, struct flowi6 *fl6, struct inet_cork *cork) { struct sock *sk = skb->sk; struct udphdr *uh; int err = 0; int is_udplite = IS_UDPLITE(sk); __wsum csum = 0; int offset = skb_transport_offset(skb); int len = skb->len - offset; /* * Create a UDP header */ uh = udp_hdr(skb); uh->source = fl6->fl6_sport; uh->dest = fl6->fl6_dport; uh->len = htons(len); uh->check = 0; if (cork->gso_size) { const int hlen = skb_network_header_len(skb) + sizeof(struct udphdr); if (hlen + cork->gso_size > cork->fragsize) return -EINVAL; if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) return -EINVAL; if (udp_sk(sk)->no_check6_tx) return -EINVAL; if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite || dst_xfrm(skb_dst(skb))) return -EIO; skb_shinfo(skb)->gso_size = cork->gso_size; skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4; goto csum_partial; } if (is_udplite) csum = udplite_csum(skb); else if (udp_sk(sk)->no_check6_tx) { /* UDP csum disabled */ skb->ip_summed = CHECKSUM_NONE; goto send; } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ csum_partial: udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len); goto send; } else csum = udp_csum(skb); /* add protocol-dependent pseudo-header */ uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr, len, fl6->flowi6_proto, csum); if (uh->check == 0) uh->check = CSUM_MANGLED_0; send: err = ip6_send_skb(skb); if (err) { if (err == -ENOBUFS && !inet6_sk(sk)->recverr) { UDP6_INC_STATS(sock_net(sk), UDP_MIB_SNDBUFERRORS, is_udplite); err = 0; } } else { UDP6_INC_STATS(sock_net(sk), UDP_MIB_OUTDATAGRAMS, is_udplite); } return err; } static int udp_v6_push_pending_frames(struct sock *sk) { struct sk_buff *skb; struct udp_sock *up = udp_sk(sk); struct flowi6 fl6; int err = 0; if (up->pending == AF_INET) return udp_push_pending_frames(sk); /* ip6_finish_skb will release the cork, so make a copy of * fl6 here. */ fl6 = inet_sk(sk)->cork.fl.u.ip6; skb = ip6_finish_skb(sk); if (!skb) goto out; err = udp_v6_send_skb(skb, &fl6, &inet_sk(sk)->cork.base); out: up->len = 0; up->pending = 0; return err; } int udpv6_sendmsg(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); DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); struct in6_addr *daddr, *final_p, final; struct ipv6_txoptions *opt = NULL; struct ipv6_txoptions *opt_to_free = NULL; struct ip6_flowlabel *flowlabel = NULL; struct flowi6 fl6; struct dst_entry *dst; struct ipcm6_cookie ipc6; int addr_len = msg->msg_namelen; bool connected = false; int ulen = len; int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; int err; int is_udplite = IS_UDPLITE(sk); int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); struct sockcm_cookie sockc; ipc6.hlimit = -1; ipc6.tclass = -1; ipc6.dontfrag = -1; ipc6.gso_size = up->gso_size; sockc.tsflags = sk->sk_tsflags; /* 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; if (ipv6_addr_any(daddr) && ipv6_addr_v4mapped(&np->saddr)) ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK), daddr); 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 = &sk->sk_v6_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(sk, msg, len); } } if (up->pending == AF_INET) return udp_sendmsg(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; getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 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) return -EINVAL; } } /* * Otherwise it will be difficult to maintain * sk->sk_dst_cache. */ if (sk->sk_state == TCP_ESTABLISHED && ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) daddr = &sk->sk_v6_daddr; if (addr_len >= sizeof(struct sockaddr_in6) && sin6->sin6_scope_id && __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr))) fl6.flowi6_oif = sin6->sin6_scope_id; } else { if (sk->sk_state != TCP_ESTABLISHED) return -EDESTADDRREQ; fl6.fl6_dport = inet->inet_dport; daddr = &sk->sk_v6_daddr; fl6.flowlabel = np->flow_label; connected = true; } 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; fl6.flowi6_uid = sk->sk_uid; if (msg->msg_controllen) { opt = &opt_space; memset(opt, 0, sizeof(struct ipv6_txoptions)); opt->tot_len = sizeof(*opt); ipc6.opt = opt; err = udp_cmsg_send(sk, msg, &ipc6.gso_size); if (err > 0) err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, &sockc); 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) return -EINVAL; } if (!(opt->opt_nflen|opt->opt_flen)) opt = NULL; connected = false; } if (!opt) { opt = txopt_get(np); opt_to_free = opt; } if (flowlabel) opt = fl6_merge_options(&opt_space, flowlabel, opt); opt = ipv6_fixup_options(&opt_space, opt); ipc6.opt = opt; fl6.flowi6_proto = sk->sk_protocol; if (!ipv6_addr_any(daddr)) 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)) fl6.saddr = np->saddr; fl6.fl6_sport = inet->inet_sport; final_p = fl6_update_dst(&fl6, opt, &final); if (final_p) connected = false; if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) { fl6.flowi6_oif = np->mcast_oif; connected = false; } else if (!fl6.flowi6_oif) fl6.flowi6_oif = np->ucast_oif; security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); if (ipc6.tclass < 0) ipc6.tclass = np->tclass; fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, connected); if (IS_ERR(dst)) { err = PTR_ERR(dst); dst = NULL; goto out; } if (ipc6.hlimit < 0) ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); if (msg->msg_flags&MSG_CONFIRM) goto do_confirm; back_from_confirm: /* Lockless fast path for the non-corking case */ if (!corkreq) { struct inet_cork_full cork; struct sk_buff *skb; skb = ip6_make_skb(sk, getfrag, msg, ulen, sizeof(struct udphdr), &ipc6, &fl6, (struct rt6_info *)dst, msg->msg_flags, &cork, &sockc); err = PTR_ERR(skb); if (!IS_ERR_OR_NULL(skb)) err = udp_v6_send_skb(skb, &fl6, &cork.base); goto out; } 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); net_dbg_ratelimited("udp cork app bug 2\n"); err = -EINVAL; goto out; } up->pending = AF_INET6; do_append_data: if (ipc6.dontfrag < 0) ipc6.dontfrag = np->dontfrag; up->len += ulen; err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr), &ipc6, &fl6, (struct rt6_info *)dst, corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags, &sockc); 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 (err > 0) err = np->recverr ? net_xmit_errno(err) : 0; release_sock(sk); out: dst_release(dst); fl6_sock_release(flowlabel); txopt_put(opt_to_free); 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(sock_net(sk), UDP_MIB_SNDBUFERRORS, is_udplite); } return err; do_confirm: if (msg->msg_flags & MSG_PROBE) dst_confirm_neigh(dst, &fl6.daddr); if (!(msg->msg_flags&MSG_PROBE) || len) goto back_from_confirm; err = 0; goto out; } void udpv6_destroy_sock(struct sock *sk) { struct udp_sock *up = udp_sk(sk); lock_sock(sk); udp_v6_flush_pending_frames(sk); release_sock(sk); if (static_branch_unlikely(&udpv6_encap_needed_key) && up->encap_type) { void (*encap_destroy)(struct sock *sk); encap_destroy = READ_ONCE(up->encap_destroy); if (encap_destroy) encap_destroy(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 /* thinking of making this const? Don't. * early_demux can change based on sysctl. */ static struct inet6_protocol udpv6_protocol = { .early_demux = udp_v6_early_demux, .early_demux_handler = udp_v6_early_demux, .handler = udpv6_rcv, .err_handler = udpv6_err, .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, }; /* ------------------------------------------------------------------------ */ #ifdef CONFIG_PROC_FS int udp6_seq_show(struct seq_file *seq, void *v) { if (v == SEQ_START_TOKEN) { seq_puts(seq, IPV6_SEQ_DGRAM_HEADER); } else { int bucket = ((struct udp_iter_state *)seq->private)->bucket; struct inet_sock *inet = inet_sk(v); __u16 srcp = ntohs(inet->inet_sport); __u16 destp = ntohs(inet->inet_dport); ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket); } return 0; } static const struct file_operations udp6_afinfo_seq_fops = { .open = udp_seq_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release_net }; static struct udp_seq_afinfo udp6_seq_afinfo = { .name = "udp6", .family = AF_INET6, .udp_table = &udp_table, .seq_fops = &udp6_afinfo_seq_fops, .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, .pre_connect = udpv6_pre_connect, .connect = ip6_datagram_connect, .disconnect = udp_disconnect, .ioctl = udp_ioctl, .init = udp_init_sock, .destroy = udpv6_destroy_sock, .setsockopt = udpv6_setsockopt, .getsockopt = udpv6_getsockopt, .sendmsg = udpv6_sendmsg, .recvmsg = udpv6_recvmsg, .release_cb = ip6_datagram_release_cb, .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_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min), .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min), .obj_size = sizeof(struct udp6_sock), .h.udp_table = &udp_table, #ifdef CONFIG_COMPAT .compat_setsockopt = compat_udpv6_setsockopt, .compat_getsockopt = compat_udpv6_getsockopt, #endif .diag_destroy = udp_abort, }; static struct inet_protosw udpv6_protosw = { .type = SOCK_DGRAM, .protocol = IPPROTO_UDP, .prot = &udpv6_prot, .ops = &inet6_dgram_ops, .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); }