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-rw-r--r--net/ipv6/udp.c1825
1 files changed, 1825 insertions, 0 deletions
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
new file mode 100644
index 0000000000..438476a313
--- /dev/null
+++ b/net/ipv6/udp.c
@@ -0,0 +1,1825 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * 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.
+ */
+
+#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 <trace/events/udp.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 <net/gro.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)
+{
+ udp_lib_init_sock(sk);
+ sk->sk_destruct = udpv6_destruct_sock;
+ set_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
+ return 0;
+}
+
+INDIRECT_CALLABLE_SCOPE
+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;
+}
+
+/* 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;
+
+ if (sk->sk_state == TCP_ESTABLISHED) {
+ result = sk;
+ continue;
+ }
+
+ result = inet6_lookup_reuseport(net, sk, skb, sizeof(struct udphdr),
+ saddr, sport, daddr, hnum, udp6_ehashfn);
+ 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;
+}
+
+/* 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) &&
+ udptable == net->ipv4.udp_table) {
+ sk = inet6_lookup_run_sk_lookup(net, IPPROTO_UDP, skb, sizeof(struct udphdr),
+ saddr, sport, daddr, hnum, dif,
+ udp6_ehashfn);
+ 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);
+ struct net *net = dev_net(skb->dev);
+ int iif, sdif;
+
+ inet6_get_iif_sdif(skb, &iif, &sdif);
+
+ return __udp6_lib_lookup(net, &iph->saddr, sport,
+ &iph->daddr, dport, iif,
+ sdif, net->ipv4.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, net->ipv4.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,
+ addr_len);
+ }
+
+ if (udp_test_bit(GRO_ENABLED, sk))
+ 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(inet))
+ 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 || READ_ONCE(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, err, uh->dest,
+ ntohl(info), (u8 *)(uh+1));
+ 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);
+ trace_udp_fail_queue_rcv_skb(rc, sk);
+ 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,
+ dev_net(skb->dev)->ipv4.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) &&
+ READ_ONCE(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 (udp_test_bit(UDPLITE_RECV_CC, sk) && UDP_SKB_CB(skb)->partial_cov) {
+ u16 pcrlen = READ_ONCE(up->pcrlen);
+
+ if (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 < pcrlen) {
+ net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n",
+ UDP_SKB_CB(skb)->cscov, 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, const 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)
+{
+ const 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_get_no_check6_rx(sk))
+ 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 = inet6_steal_sock(net, skb, sizeof(struct udphdr), saddr, uh->source, daddr, uh->dest,
+ &refcounted, udp6_ehashfn);
+ if (IS_ERR(sk))
+ goto no_sk;
+
+ 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_get_no_check6_rx(sk)) {
+ 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_get_no_check6_rx(sk))
+ goto report_csum_error;
+ return udp6_unicast_rcv_skb(sk, skb, uh);
+ }
+no_sk:
+ 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)
+{
+ struct udp_table *udptable = net->ipv4.udp_table;
+ 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 & udptable->mask;
+ hslot2 = &udptable->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, dev_net(skb->dev)->ipv4.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;
+ WRITE_ONCE(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, &addr_len);
+}
+
+/**
+ * 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_get_no_check6_tx(sk)) {
+ 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_get_no_check6_tx(sk)) { /* 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;
+ WRITE_ONCE(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 = udp_test_bit(CORK, sk) || 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 = READ_ONCE(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 (!READ_ONCE(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 (READ_ONCE(up->pending)) {
+ if (READ_ONCE(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,
+ &addr_len,
+ &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;
+ }
+
+ WRITE_ONCE(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)))
+ WRITE_ONCE(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;
+}
+EXPORT_SYMBOL(udpv6_sendmsg);
+
+static void udpv6_splice_eof(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+ struct udp_sock *up = udp_sk(sk);
+
+ if (!READ_ONCE(up->pending) || udp_test_bit(CORK, sk))
+ return;
+
+ lock_sock(sk);
+ if (up->pending && !udp_test_bit(CORK, sk))
+ udp_v6_push_pending_frames(sk);
+ release_sock(sk);
+}
+
+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 (udp_test_bit(ENCAP_ENABLED, sk)) {
+ 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 || level == SOL_SOCKET)
+ 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;
+ const struct inet_sock *inet = inet_sk((const struct sock *)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 = NULL,
+};
+
+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,
+ .splice_eof = udpv6_splice_eof,
+ .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),
+ .ipv6_pinfo_offset = offsetof(struct udp6_sock, inet6),
+ .h.udp_table = NULL,
+ .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);
+}