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- // SPDX-License-Identifier: GPL-2.0-or-later
- /*
- * UDP over IPv6
- * Linux INET6 implementation
- *
- * Authors:
- * Pedro Roque <[email protected]>
- *
- * 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.
- */
- #include <linux/bpf-cgroup.h>
- #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 <linux/uaccess.h>
- #include <linux/indirect_call_wrapper.h>
- #include <net/addrconf.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/seg6.h>
- #include <net/tcp_states.h>
- #include <net/ip6_checksum.h>
- #include <net/ip6_tunnel.h>
- #include <net/xfrm.h>
- #include <net/inet_hashtables.h>
- #include <net/inet6_hashtables.h>
- #include <net/busy_poll.h>
- #include <net/sock_reuseport.h>
- #include <linux/proc_fs.h>
- #include <linux/seq_file.h>
- #include <trace/events/skb.h>
- #include "udp_impl.h"
- static void udpv6_destruct_sock(struct sock *sk)
- {
- udp_destruct_common(sk);
- inet6_sock_destruct(sk);
- }
- int udpv6_init_sock(struct sock *sk)
- {
- skb_queue_head_init(&udp_sk(sk)->reader_queue);
- sk->sk_destruct = udpv6_destruct_sock;
- set_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
- return 0;
- }
- 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,
- udp6_ehash_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);
- }
- 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)
- {
- int bound_dev_if, score;
- struct inet_sock *inet;
- bool dev_match;
- if (!net_eq(sock_net(sk), net) ||
- udp_sk(sk)->udp_port_hash != hnum ||
- sk->sk_family != PF_INET6)
- return -1;
- if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
- 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_daddr)) {
- if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
- return -1;
- score++;
- }
- bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
- dev_match = udp_sk_bound_dev_eq(net, bound_dev_if, dif, sdif);
- if (!dev_match)
- return -1;
- if (bound_dev_if)
- score++;
- if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
- score++;
- return score;
- }
- static struct sock *lookup_reuseport(struct net *net, struct sock *sk,
- struct sk_buff *skb,
- const struct in6_addr *saddr,
- __be16 sport,
- const struct in6_addr *daddr,
- unsigned int hnum)
- {
- struct sock *reuse_sk = NULL;
- u32 hash;
- if (sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED) {
- hash = udp6_ehashfn(net, daddr, hnum, saddr, sport);
- reuse_sk = reuseport_select_sock(sk, hash, skb,
- sizeof(struct udphdr));
- }
- return reuse_sk;
- }
- /* 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, struct udp_hslot *hslot2,
- struct sk_buff *skb)
- {
- struct sock *sk, *result;
- int score, badness;
- result = NULL;
- badness = -1;
- udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
- score = compute_score(sk, net, saddr, sport,
- daddr, hnum, dif, sdif);
- if (score > badness) {
- badness = score;
- result = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum);
- if (!result) {
- result = sk;
- continue;
- }
- /* Fall back to scoring if group has connections */
- if (!reuseport_has_conns(sk))
- return result;
- /* Reuseport logic returned an error, keep original score. */
- if (IS_ERR(result))
- continue;
- badness = compute_score(sk, net, saddr, sport,
- daddr, hnum, dif, sdif);
- }
- }
- return result;
- }
- static inline struct sock *udp6_lookup_run_bpf(struct net *net,
- struct udp_table *udptable,
- struct sk_buff *skb,
- const struct in6_addr *saddr,
- __be16 sport,
- const struct in6_addr *daddr,
- u16 hnum, const int dif)
- {
- struct sock *sk, *reuse_sk;
- bool no_reuseport;
- if (udptable != &udp_table)
- return NULL; /* only UDP is supported */
- no_reuseport = bpf_sk_lookup_run_v6(net, IPPROTO_UDP, saddr, sport,
- daddr, hnum, dif, &sk);
- if (no_reuseport || IS_ERR_OR_NULL(sk))
- return sk;
- reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum);
- if (reuse_sk)
- sk = reuse_sk;
- return sk;
- }
- /* 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)
- {
- unsigned short hnum = ntohs(dport);
- unsigned int hash2, slot2;
- struct udp_hslot *hslot2;
- struct sock *result, *sk;
- hash2 = ipv6_portaddr_hash(net, daddr, hnum);
- slot2 = hash2 & udptable->mask;
- hslot2 = &udptable->hash2[slot2];
- /* Lookup connected or non-wildcard sockets */
- result = udp6_lib_lookup2(net, saddr, sport,
- daddr, hnum, dif, sdif,
- hslot2, skb);
- if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED)
- goto done;
- /* Lookup redirect from BPF */
- if (static_branch_unlikely(&bpf_sk_lookup_enabled)) {
- sk = udp6_lookup_run_bpf(net, udptable, skb,
- saddr, sport, daddr, hnum, dif);
- if (sk) {
- result = sk;
- goto done;
- }
- }
- /* Got non-wildcard socket or error on first lookup */
- if (result)
- goto done;
- /* Lookup wildcard sockets */
- hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
- slot2 = hash2 & udptable->mask;
- hslot2 = &udptable->hash2[slot2];
- result = udp6_lib_lookup2(net, saddr, sport,
- &in6addr_any, hnum, dif, sdif,
- hslot2, skb);
- done:
- if (IS_ERR(result))
- return NULL;
- 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(const 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, NULL);
- }
- /* 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 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 off, err, peeking = flags & MSG_PEEK;
- int is_udplite = IS_UDPLITE(sk);
- struct udp_mib __percpu *mib;
- 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:
- off = sk_peek_offset(sk, flags);
- skb = __skb_recv_udp(sk, flags, &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));
- mib = __UDPX_MIB(sk, is_udp4);
- /*
- * 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 (!peeking) {
- atomic_inc(&sk->sk_drops);
- SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
- }
- kfree_skb(skb);
- return err;
- }
- if (!peeking)
- SNMP_INC_STATS(mib, UDP_MIB_INDATAGRAMS);
- sock_recv_cmsgs(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);
- BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk,
- (struct sockaddr *)sin6);
- }
- if (udp_sk(sk)->gro_enabled)
- udp_cmsg_recv(msg, sk, skb);
- 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)) {
- SNMP_INC_STATS(mib, UDP_MIB_CSUMERRORS);
- SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
- }
- 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;
- }
- DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
- void udpv6_encap_enable(void)
- {
- static_branch_inc(&udpv6_encap_needed_key);
- }
- EXPORT_SYMBOL(udpv6_encap_enable);
- /* Handler for tunnels with arbitrary destination ports: no socket lookup, go
- * through error handlers in encapsulations looking for a match.
- */
- static int __udp6_lib_err_encap_no_sk(struct sk_buff *skb,
- struct inet6_skb_parm *opt,
- u8 type, u8 code, int offset, __be32 info)
- {
- int i;
- for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
- int (*handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
- u8 type, u8 code, int offset, __be32 info);
- const struct ip6_tnl_encap_ops *encap;
- encap = rcu_dereference(ip6tun_encaps[i]);
- if (!encap)
- continue;
- handler = encap->err_handler;
- if (handler && !handler(skb, opt, type, code, offset, info))
- return 0;
- }
- return -ENOENT;
- }
- /* Try to match ICMP errors to UDP tunnels by looking up a socket without
- * reversing source and destination port: this will match tunnels that force the
- * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
- * lwtunnels might actually break this assumption by being configured with
- * different destination ports on endpoints, in this case we won't be able to
- * trace ICMP messages back to them.
- *
- * If this doesn't match any socket, probe tunnels with arbitrary destination
- * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
- * we've sent packets to won't necessarily match the local destination port.
- *
- * Then ask the tunnel implementation to match the error against a valid
- * association.
- *
- * Return an error if we can't find a match, the socket if we need further
- * processing, zero otherwise.
- */
- static struct sock *__udp6_lib_err_encap(struct net *net,
- const struct ipv6hdr *hdr, int offset,
- struct udphdr *uh,
- struct udp_table *udptable,
- struct sock *sk,
- struct sk_buff *skb,
- struct inet6_skb_parm *opt,
- u8 type, u8 code, __be32 info)
- {
- int (*lookup)(struct sock *sk, struct sk_buff *skb);
- int network_offset, transport_offset;
- struct udp_sock *up;
- network_offset = skb_network_offset(skb);
- transport_offset = skb_transport_offset(skb);
- /* Network header needs to point to the outer IPv6 header inside ICMP */
- skb_reset_network_header(skb);
- /* Transport header needs to point to the UDP header */
- skb_set_transport_header(skb, offset);
- if (sk) {
- up = udp_sk(sk);
- lookup = READ_ONCE(up->encap_err_lookup);
- if (lookup && lookup(sk, skb))
- sk = NULL;
- goto out;
- }
- sk = __udp6_lib_lookup(net, &hdr->daddr, uh->source,
- &hdr->saddr, uh->dest,
- inet6_iif(skb), 0, udptable, skb);
- if (sk) {
- up = udp_sk(sk);
- lookup = READ_ONCE(up->encap_err_lookup);
- if (!lookup || lookup(sk, skb))
- sk = NULL;
- }
- out:
- if (!sk) {
- sk = ERR_PTR(__udp6_lib_err_encap_no_sk(skb, opt, type, code,
- offset, info));
- }
- skb_set_transport_header(skb, transport_offset);
- skb_set_network_header(skb, network_offset);
- return sk;
- }
- int __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 = seg6_get_daddr(skb, opt) ? : &hdr->daddr;
- struct udphdr *uh = (struct udphdr *)(skb->data+offset);
- bool tunnel = false;
- 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), inet6_sdif(skb), udptable, NULL);
- if (!sk || udp_sk(sk)->encap_type) {
- /* No socket for error: try tunnels before discarding */
- if (static_branch_unlikely(&udpv6_encap_needed_key)) {
- sk = __udp6_lib_err_encap(net, hdr, offset, uh,
- udptable, sk, skb,
- opt, type, code, info);
- if (!sk)
- return 0;
- } else
- sk = ERR_PTR(-ENOENT);
- if (IS_ERR(sk)) {
- __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
- ICMP6_MIB_INERRORS);
- return PTR_ERR(sk);
- }
- tunnel = true;
- }
- 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) {
- if (tunnel) {
- ip6_redirect(skb, sock_net(sk), inet6_iif(skb),
- READ_ONCE(sk->sk_mark), sk->sk_uid);
- } else {
- ip6_sk_redirect(skb, sk);
- }
- goto out;
- }
- /* Tunnels don't have an application socket: don't pass errors back */
- if (tunnel) {
- if (udp_sk(sk)->encap_err_rcv)
- udp_sk(sk)->encap_err_rcv(sk, skb, offset);
- 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_error_report(sk);
- out:
- return 0;
- }
- 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);
- enum skb_drop_reason drop_reason;
- /* Note that an ENOMEM error is charged twice */
- if (rc == -ENOMEM) {
- UDP6_INC_STATS(sock_net(sk),
- UDP_MIB_RCVBUFERRORS, is_udplite);
- drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
- } else {
- UDP6_INC_STATS(sock_net(sk),
- UDP_MIB_MEMERRORS, is_udplite);
- drop_reason = SKB_DROP_REASON_PROTO_MEM;
- }
- UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
- kfree_skb_reason(skb, drop_reason);
- return -1;
- }
- return 0;
- }
- static __inline__ int udpv6_err(struct sk_buff *skb,
- struct inet6_skb_parm *opt, u8 type,
- u8 code, int offset, __be32 info)
- {
- return __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
- }
- static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
- {
- enum skb_drop_reason drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
- struct udp_sock *up = udp_sk(sk);
- int is_udplite = IS_UDPLITE(sk);
- if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
- drop_reason = SKB_DROP_REASON_XFRM_POLICY;
- goto drop;
- }
- nf_reset_ct(skb);
- 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) {
- __UDP6_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 ((up->pcflag & 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))) {
- drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
- goto drop;
- }
- udp_csum_pull_header(skb);
- skb_dst_drop(skb);
- return __udpv6_queue_rcv_skb(sk, skb);
- csum_error:
- drop_reason = SKB_DROP_REASON_UDP_CSUM;
- __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_reason(skb, drop_reason);
- return -1;
- }
- static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
- {
- struct sk_buff *next, *segs;
- int ret;
- if (likely(!udp_unexpected_gso(sk, skb)))
- return udpv6_queue_rcv_one_skb(sk, skb);
- __skb_push(skb, -skb_mac_offset(skb));
- segs = udp_rcv_segment(sk, skb, false);
- skb_list_walk_safe(segs, skb, next) {
- __skb_pull(skb, skb_transport_offset(skb));
- udp_post_segment_fix_csum(skb);
- ret = udpv6_queue_rcv_one_skb(sk, skb);
- if (ret > 0)
- ip6_protocol_deliver_rcu(dev_net(skb->dev), skb, ret,
- true);
- }
- return 0;
- }
- 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, int sdif, 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)) ||
- !udp_sk_bound_dev_eq(net, READ_ONCE(sk->sk_bound_dev_if), dif, sdif) ||
- (!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);
- int sdif = inet6_sdif(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, sdif,
- 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;
- sk->sk_rx_dst_cookie = rt6_get_cookie(rt);
- }
- }
- /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
- * return code conversion for ip layer consumption
- */
- static int udp6_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
- struct udphdr *uh)
- {
- int ret;
- if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
- skb_checksum_try_convert(skb, IPPROTO_UDP, 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;
- }
- int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
- int proto)
- {
- enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
- const struct in6_addr *saddr, *daddr;
- struct net *net = dev_net(skb->dev);
- struct udphdr *uh;
- struct sock *sk;
- bool refcounted;
- 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, &refcounted);
- if (sk) {
- struct dst_entry *dst = skb_dst(skb);
- int ret;
- if (unlikely(rcu_dereference(sk->sk_rx_dst) != dst))
- udp6_sk_rx_dst_set(sk, dst);
- if (!uh->check && !udp_sk(sk)->no_check6_rx) {
- if (refcounted)
- sock_put(sk);
- goto report_csum_error;
- }
- ret = udp6_unicast_rcv_skb(sk, skb, uh);
- if (refcounted)
- sock_put(sk);
- return ret;
- }
- /*
- * 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) {
- if (!uh->check && !udp_sk(sk)->no_check6_rx)
- goto report_csum_error;
- return udp6_unicast_rcv_skb(sk, skb, uh);
- }
- reason = SKB_DROP_REASON_NO_SOCKET;
- if (!uh->check)
- goto report_csum_error;
- if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
- goto discard;
- nf_reset_ct(skb);
- 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_reason(skb, reason);
- return 0;
- short_packet:
- if (reason == SKB_DROP_REASON_NOT_SPECIFIED)
- reason = SKB_DROP_REASON_PKT_TOO_SMALL;
- 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;
- report_csum_error:
- udp6_csum_zero_error(skb);
- csum_error:
- if (reason == SKB_DROP_REASON_NOT_SPECIFIED)
- reason = SKB_DROP_REASON_UDP_CSUM;
- __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
- discard:
- __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
- kfree_skb_reason(skb, reason);
- 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, slot2;
- struct udp_hslot *hslot2;
- __portpair ports;
- struct sock *sk;
- hash2 = ipv6_portaddr_hash(net, loc_addr, hnum);
- slot2 = hash2 & udp_table.mask;
- hslot2 = &udp_table.hash2[slot2];
- ports = INET_COMBINED_PORTS(rmt_port, hnum);
- udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
- if (sk->sk_state == TCP_ESTABLISHED &&
- inet6_match(net, sk, rmt_addr, loc_addr, ports, dif, sdif))
- return sk;
- /* Only check first socket in chain */
- break;
- }
- return NULL;
- }
- 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 = rcu_dereference(sk->sk_rx_dst);
- if (dst)
- dst = dst_check(dst, 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);
- }
- }
- INDIRECT_CALLABLE_SCOPE 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)
- {
- if (addr_len < offsetofend(struct sockaddr, sa_family))
- return -EINVAL;
- /* 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)
- * @saddr: source address
- * @daddr: destination address
- * @len: length of packet
- */
- 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;
- int datalen = len - sizeof(*uh);
- /*
- * 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) {
- kfree_skb(skb);
- return -EINVAL;
- }
- if (datalen > cork->gso_size * UDP_MAX_SEGMENTS) {
- kfree_skb(skb);
- return -EINVAL;
- }
- if (udp_sk(sk)->no_check6_tx) {
- kfree_skb(skb);
- return -EINVAL;
- }
- if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite ||
- dst_xfrm(skb_dst(skb))) {
- kfree_skb(skb);
- return -EIO;
- }
- if (datalen > cork->gso_size) {
- skb_shinfo(skb)->gso_size = cork->gso_size;
- skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
- skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen,
- cork->gso_size);
- }
- 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);
- int err = 0;
- if (up->pending == AF_INET)
- return udp_push_pending_frames(sk);
- skb = ip6_finish_skb(sk);
- if (!skb)
- goto out;
- err = udp_v6_send_skb(skb, &inet_sk(sk)->cork.fl.u.ip6,
- &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 inet_cork_full cork;
- struct flowi6 *fl6 = &cork.fl.u.ip6;
- struct dst_entry *dst;
- struct ipcm6_cookie ipc6;
- int addr_len = msg->msg_namelen;
- bool connected = false;
- int ulen = len;
- int corkreq = READ_ONCE(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 *);
- ipcm6_init(&ipc6);
- ipc6.gso_size = READ_ONCE(up->gso_size);
- ipc6.sockc.tsflags = sk->sk_tsflags;
- ipc6.sockc.mark = READ_ONCE(sk->sk_mark);
- /* 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:
- err = ipv6_only_sock(sk) ?
- -ENETUNREACH : udp_sendmsg(sk, msg, len);
- msg->msg_name = sin6;
- msg->msg_namelen = addr_len;
- return err;
- }
- }
- /* 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) {
- if (up->pending == AF_INET)
- return udp_sendmsg(sk, msg, len);
- /*
- * 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 (IS_ERR(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 = READ_ONCE(sk->sk_bound_dev_if);
- if (!fl6->flowi6_oif)
- fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
- 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);
- if (err < 0) {
- fl6_sock_release(flowlabel);
- return err;
- }
- if ((fl6->flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
- flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
- if (IS_ERR(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;
- fl6->flowi6_mark = ipc6.sockc.mark;
- fl6->daddr = *daddr;
- if (ipv6_addr_any(&fl6->saddr) && !ipv6_addr_any(&np->saddr))
- fl6->saddr = np->saddr;
- fl6->fl6_sport = inet->inet_sport;
- if (cgroup_bpf_enabled(CGROUP_UDP6_SENDMSG) && !connected) {
- err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk,
- (struct sockaddr *)sin6,
- &fl6->saddr);
- if (err)
- goto out_no_dst;
- if (sin6) {
- if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
- /* BPF program rewrote IPv6-only by IPv4-mapped
- * IPv6. It's currently unsupported.
- */
- err = -ENOTSUPP;
- goto out_no_dst;
- }
- if (sin6->sin6_port == 0) {
- /* BPF program set invalid port. Reject it. */
- err = -EINVAL;
- goto out_no_dst;
- }
- fl6->fl6_dport = sin6->sin6_port;
- fl6->daddr = sin6->sin6_addr;
- }
- }
- if (ipv6_addr_any(&fl6->daddr))
- fl6->daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
- 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_common(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 sk_buff *skb;
- skb = ip6_make_skb(sk, getfrag, msg, ulen,
- sizeof(struct udphdr), &ipc6,
- (struct rt6_info *)dst,
- msg->msg_flags, &cork);
- err = PTR_ERR(skb);
- if (!IS_ERR_OR_NULL(skb))
- err = udp_v6_send_skb(skb, fl6, &cork.base);
- /* ip6_make_skb steals dst reference */
- goto out_no_dst;
- }
- 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);
- 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);
- out_no_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);
- /* protects from races with udp_abort() */
- sock_set_flag(sk, SOCK_DEAD);
- udp_v6_flush_pending_frames(sk);
- release_sock(sk);
- if (static_branch_unlikely(&udpv6_encap_needed_key)) {
- if (up->encap_type) {
- void (*encap_destroy)(struct sock *sk);
- encap_destroy = READ_ONCE(up->encap_destroy);
- if (encap_destroy)
- encap_destroy(sk);
- }
- if (up->encap_enabled) {
- static_branch_dec(&udpv6_encap_needed_key);
- udp_encap_disable();
- }
- }
- }
- /*
- * Socket option code for UDP
- */
- int udpv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t 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);
- }
- 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);
- }
- static const struct inet6_protocol udpv6_protocol = {
- .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,
- udp_rqueue_get(v), bucket);
- }
- return 0;
- }
- const struct seq_operations udp6_seq_ops = {
- .start = udp_seq_start,
- .next = udp_seq_next,
- .stop = udp_seq_stop,
- .show = udp6_seq_show,
- };
- EXPORT_SYMBOL(udp6_seq_ops);
- static struct udp_seq_afinfo udp6_seq_afinfo = {
- .family = AF_INET6,
- .udp_table = &udp_table,
- };
- int __net_init udp6_proc_init(struct net *net)
- {
- if (!proc_create_net_data("udp6", 0444, net->proc_net, &udp6_seq_ops,
- sizeof(struct udp_iter_state), &udp6_seq_afinfo))
- return -ENOMEM;
- return 0;
- }
- void udp6_proc_exit(struct net *net)
- {
- remove_proc_entry("udp6", net->proc_net);
- }
- #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 = udpv6_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,
- .put_port = udp_lib_unhash,
- #ifdef CONFIG_BPF_SYSCALL
- .psock_update_sk_prot = udp_bpf_update_proto,
- #endif
- .memory_allocated = &udp_memory_allocated,
- .per_cpu_fw_alloc = &udp_memory_per_cpu_fw_alloc,
- .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,
- .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);
- }
|