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linuxdebug/net/ipv6/udp.c

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null pointer error
2024-07-16 15:50:57 +02:00
// 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 <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);
}