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linux/net/ipv6/udp.c
Robert Shearman 63a6fff353 net: Avoid receiving packets with an l3mdev on unbound UDP sockets 
Packets arriving in a VRF currently are delivered to UDP sockets that
aren't bound to any interface. TCP defaults to not delivering packets
arriving in a VRF to unbound sockets. IP route lookup and socket
transmit both assume that unbound means using the default table and
UDP applications that haven't been changed to be aware of VRFs may not
function correctly in this case since they may not be able to handle
overlapping IP address ranges, or be able to send packets back to the
original sender if required.

So add a sysctl, udp_l3mdev_accept, to control this behaviour with it
being analgous to the existing tcp_l3mdev_accept, namely to allow a
process to have a VRF-global listen socket. Have this default to off
as this is the behaviour that users will expect, given that there is
no explicit mechanism to set unmodified VRF-unaware application into a
default VRF.

Signed-off-by: Robert Shearman <rshearma@brocade.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Tested-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-30 15:00:58 -05:00

1492 lines
37 KiB
C
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/*
* UDP over IPv6
* Linux INET6 implementation
*
* Authors:
* Pedro Roque <roque@di.fc.ul.pt>
*
* Based on linux/ipv4/udp.c
*
* Fixes:
* Hideaki YOSHIFUJI : sin6_scope_id support
* YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
* Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
* a single port at the same time.
* Kazunori MIYAZAWA @USAGI: change process style to use ip6_append_data
* YOSHIFUJI Hideaki @USAGI: convert /proc/net/udp6 to seq_file.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/uaccess.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/tcp_states.h>
#include <net/ip6_checksum.h>
#include <net/xfrm.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 bool udp6_lib_exact_dif_match(struct net *net, struct sk_buff *skb)
{
#if defined(CONFIG_NET_L3_MASTER_DEV)
if (!net->ipv4.sysctl_udp_l3mdev_accept &&
skb && ipv6_l3mdev_skb(IP6CB(skb)->flags))
return true;
#endif
return false;
}
static u32 udp6_ehashfn(const struct net *net,
const struct in6_addr *laddr,
const u16 lport,
const struct in6_addr *faddr,
const __be16 fport)
{
static u32 udp6_ehash_secret __read_mostly;
static u32 udp_ipv6_hash_secret __read_mostly;
u32 lhash, fhash;
net_get_random_once(&udp6_ehash_secret,
sizeof(udp6_ehash_secret));
net_get_random_once(&udp_ipv6_hash_secret,
sizeof(udp_ipv6_hash_secret));
lhash = (__force u32)laddr->s6_addr32[3];
fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret);
return __inet6_ehashfn(lhash, lport, fhash, fport,
udp_ipv6_hash_secret + net_hash_mix(net));
}
static u32 udp6_portaddr_hash(const struct net *net,
const struct in6_addr *addr6,
unsigned int port)
{
unsigned int hash, mix = net_hash_mix(net);
if (ipv6_addr_any(addr6))
hash = jhash_1word(0, mix);
else if (ipv6_addr_v4mapped(addr6))
hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix);
else
hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix);
return hash ^ port;
}
int udp_v6_get_port(struct sock *sk, unsigned short snum)
{
unsigned int hash2_nulladdr =
udp6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
unsigned int hash2_partial =
udp6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0);
/* precompute partial secondary hash */
udp_sk(sk)->udp_portaddr_hash = hash2_partial;
return udp_lib_get_port(sk, snum, hash2_nulladdr);
}
static void udp_v6_rehash(struct sock *sk)
{
u16 new_hash = udp6_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, bool exact_dif)
{
int score;
struct inet_sock *inet;
if (!net_eq(sock_net(sk), net) ||
udp_sk(sk)->udp_port_hash != hnum ||
sk->sk_family != PF_INET6)
return -1;
score = 0;
inet = inet_sk(sk);
if (inet->inet_dport) {
if (inet->inet_dport != sport)
return -1;
score++;
}
if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
return -1;
score++;
}
if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
return -1;
score++;
}
if (sk->sk_bound_dev_if || exact_dif) {
if (sk->sk_bound_dev_if != dif)
return -1;
score++;
}
if (sk->sk_incoming_cpu == raw_smp_processor_id())
score++;
return score;
}
/* called with rcu_read_lock() */
static struct sock *udp6_lib_lookup2(struct net *net,
const struct in6_addr *saddr, __be16 sport,
const struct in6_addr *daddr, unsigned int hnum, int dif,
bool exact_dif, struct udp_hslot *hslot2,
struct sk_buff *skb)
{
struct sock *sk, *result;
int score, badness, matches = 0, reuseport = 0;
u32 hash = 0;
result = NULL;
badness = -1;
udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
score = compute_score(sk, net, saddr, sport,
daddr, hnum, dif, exact_dif);
if (score > badness) {
reuseport = sk->sk_reuseport;
if (reuseport) {
hash = udp6_ehashfn(net, daddr, hnum,
saddr, sport);
result = reuseport_select_sock(sk, hash, skb,
sizeof(struct udphdr));
if (result)
return result;
matches = 1;
}
result = sk;
badness = score;
} else if (score == badness && reuseport) {
matches++;
if (reciprocal_scale(hash, matches) == 0)
result = sk;
hash = next_pseudo_random32(hash);
}
}
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, struct udp_table *udptable,
struct sk_buff *skb)
{
struct sock *sk, *result;
unsigned short hnum = ntohs(dport);
unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
bool exact_dif = udp6_lib_exact_dif_match(net, skb);
int score, badness, matches = 0, reuseport = 0;
u32 hash = 0;
if (hslot->count > 10) {
hash2 = udp6_portaddr_hash(net, daddr, hnum);
slot2 = hash2 & udptable->mask;
hslot2 = &udptable->hash2[slot2];
if (hslot->count < hslot2->count)
goto begin;
result = udp6_lib_lookup2(net, saddr, sport,
daddr, hnum, dif, exact_dif,
hslot2, skb);
if (!result) {
unsigned int old_slot2 = slot2;
hash2 = udp6_portaddr_hash(net, &in6addr_any, hnum);
slot2 = hash2 & udptable->mask;
/* avoid searching the same slot again. */
if (unlikely(slot2 == old_slot2))
return result;
hslot2 = &udptable->hash2[slot2];
if (hslot->count < hslot2->count)
goto begin;
result = udp6_lib_lookup2(net, saddr, sport,
daddr, hnum, dif,
exact_dif, hslot2,
skb);
}
return result;
}
begin:
result = NULL;
badness = -1;
sk_for_each_rcu(sk, &hslot->head) {
score = compute_score(sk, net, saddr, sport, daddr, hnum, dif,
exact_dif);
if (score > badness) {
reuseport = sk->sk_reuseport;
if (reuseport) {
hash = udp6_ehashfn(net, daddr, hnum,
saddr, sport);
result = reuseport_select_sock(sk, hash, skb,
sizeof(struct udphdr));
if (result)
return result;
matches = 1;
}
result = sk;
badness = score;
} else if (score == badness && reuseport) {
matches++;
if (reciprocal_scale(hash, matches) == 0)
result = sk;
hash = next_pseudo_random32(hash);
}
}
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);
struct sock *sk;
sk = skb_steal_sock(skb);
if (unlikely(sk))
return sk;
return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
&iph->daddr, dport, inet6_iif(skb),
udptable, skb);
}
struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
__be16 sport, __be16 dport)
{
const struct ipv6hdr *iph = ipv6_hdr(skb);
return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
&iph->daddr, dport, inet6_iif(skb),
&udp_table, skb);
}
EXPORT_SYMBOL_GPL(udp6_lib_lookup_skb);
/* Must be called under rcu_read_lock().
* Does increment socket refcount.
*/
#if IS_ENABLED(CONFIG_NETFILTER_XT_MATCH_SOCKET) || \
IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TPROXY) || \
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, &udp_table, NULL);
if (sk && !atomic_inc_not_zero(&sk->sk_refcnt))
sk = NULL;
return sk;
}
EXPORT_SYMBOL_GPL(udp6_lib_lookup);
#endif
/*
* This should be easy, if there is something there we
* return it, otherwise we block.
*/
int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
int noblock, int flags, int *addr_len)
{
struct ipv6_pinfo *np = inet6_sk(sk);
struct inet_sock *inet = inet_sk(sk);
struct sk_buff *skb;
unsigned int ulen, copied;
int peeked, peeking, off;
int err;
int is_udplite = IS_UDPLITE(sk);
bool checksum_valid = false;
int is_udp4;
if (flags & MSG_ERRQUEUE)
return ipv6_recv_error(sk, msg, len, addr_len);
if (np->rxpmtu && np->rxopt.bits.rxpmtu)
return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
try_again:
peeking = off = sk_peek_offset(sk, flags);
skb = __skb_recv_udp(sk, flags, noblock, &peeked, &off, &err);
if (!skb)
return err;
ulen = skb->len;
copied = len;
if (copied > ulen - off)
copied = ulen - off;
else if (copied < ulen)
msg->msg_flags |= MSG_TRUNC;
is_udp4 = (skb->protocol == htons(ETH_P_IP));
/*
* If checksum is needed at all, try to do it while copying the
* data. If the data is truncated, or if we only want a partial
* coverage checksum (UDP-Lite), do it before the copy.
*/
if (copied < ulen || peeking ||
(is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
checksum_valid = !udp_lib_checksum_complete(skb);
if (!checksum_valid)
goto csum_copy_err;
}
if (checksum_valid || skb_csum_unnecessary(skb))
err = skb_copy_datagram_msg(skb, off, msg, copied);
else {
err = skb_copy_and_csum_datagram_msg(skb, off, msg);
if (err == -EINVAL)
goto csum_copy_err;
}
if (unlikely(err)) {
if (!peeked) {
atomic_inc(&sk->sk_drops);
if (is_udp4)
UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
is_udplite);
else
UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
is_udplite);
}
kfree_skb(skb);
return err;
}
if (!peeked) {
if (is_udp4)
UDP_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS,
is_udplite);
else
UDP6_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS,
is_udplite);
}
sock_recv_ts_and_drops(msg, sk, skb);
/* Copy the address. */
if (msg->msg_name) {
DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
sin6->sin6_family = AF_INET6;
sin6->sin6_port = udp_hdr(skb)->source;
sin6->sin6_flowinfo = 0;
if (is_udp4) {
ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
&sin6->sin6_addr);
sin6->sin6_scope_id = 0;
} else {
sin6->sin6_addr = ipv6_hdr(skb)->saddr;
sin6->sin6_scope_id =
ipv6_iface_scope_id(&sin6->sin6_addr,
inet6_iif(skb));
}
*addr_len = sizeof(*sin6);
}
if (np->rxopt.all)
ip6_datagram_recv_common_ctl(sk, msg, skb);
if (is_udp4) {
if (inet->cmsg_flags)
ip_cmsg_recv_offset(msg, sk, skb,
sizeof(struct udphdr), off);
} else {
if (np->rxopt.all)
ip6_datagram_recv_specific_ctl(sk, msg, skb);
}
err = copied;
if (flags & MSG_TRUNC)
err = ulen;
skb_consume_udp(sk, skb, peeking ? -err : err);
return err;
csum_copy_err:
if (!__sk_queue_drop_skb(sk, skb, flags)) {
if (is_udp4) {
UDP_INC_STATS(sock_net(sk),
UDP_MIB_CSUMERRORS, is_udplite);
UDP_INC_STATS(sock_net(sk),
UDP_MIB_INERRORS, is_udplite);
} else {
UDP6_INC_STATS(sock_net(sk),
UDP_MIB_CSUMERRORS, is_udplite);
UDP6_INC_STATS(sock_net(sk),
UDP_MIB_INERRORS, is_udplite);
}
}
kfree_skb(skb);
/* starting over for a new packet, but check if we need to yield */
cond_resched();
msg->msg_flags &= ~MSG_TRUNC;
goto try_again;
}
void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 info,
struct udp_table *udptable)
{
struct ipv6_pinfo *np;
const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
const struct in6_addr *saddr = &hdr->saddr;
const struct in6_addr *daddr = &hdr->daddr;
struct udphdr *uh = (struct udphdr *)(skb->data+offset);
struct sock *sk;
int harderr;
int err;
struct net *net = dev_net(skb->dev);
sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source,
inet6_iif(skb), udptable, skb);
if (!sk) {
__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
ICMP6_MIB_INERRORS);
return;
}
harderr = icmpv6_err_convert(type, code, &err);
np = inet6_sk(sk);
if (type == ICMPV6_PKT_TOOBIG) {
if (!ip6_sk_accept_pmtu(sk))
goto out;
ip6_sk_update_pmtu(skb, sk, info);
if (np->pmtudisc != IPV6_PMTUDISC_DONT)
harderr = 1;
}
if (type == NDISC_REDIRECT) {
ip6_sk_redirect(skb, sk);
goto out;
}
if (!np->recverr) {
if (!harderr || sk->sk_state != TCP_ESTABLISHED)
goto out;
} else {
ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
}
sk->sk_err = err;
sk->sk_error_report(sk);
out:
return;
}
int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
int rc;
if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
sock_rps_save_rxhash(sk, skb);
sk_mark_napi_id(sk, skb);
sk_incoming_cpu_update(sk);
} else {
sk_mark_napi_id_once(sk, skb);
}
rc = __udp_enqueue_schedule_skb(sk, skb);
if (rc < 0) {
int is_udplite = IS_UDPLITE(sk);
/* Note that an ENOMEM error is charged twice */
if (rc == -ENOMEM)
UDP6_INC_STATS(sock_net(sk),
UDP_MIB_RCVBUFERRORS, is_udplite);
UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
kfree_skb(skb);
return -1;
}
return 0;
}
static __inline__ void udpv6_err(struct sk_buff *skb,
struct inet6_skb_parm *opt, u8 type,
u8 code, int offset, __be32 info)
{
__udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
}
static struct static_key udpv6_encap_needed __read_mostly;
void udpv6_encap_enable(void)
{
if (!static_key_enabled(&udpv6_encap_needed))
static_key_slow_inc(&udpv6_encap_needed);
}
EXPORT_SYMBOL(udpv6_encap_enable);
int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
struct udp_sock *up = udp_sk(sk);
int is_udplite = IS_UDPLITE(sk);
if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
goto drop;
if (static_key_false(&udpv6_encap_needed) && 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 = ACCESS_ONCE(up->encap_rcv);
if (encap_rcv) {
int ret;
/* Verify checksum before giving to encap */
if (udp_lib_checksum_complete(skb))
goto csum_error;
ret = encap_rcv(sk, skb);
if (ret <= 0) {
__UDP_INC_STATS(sock_net(sk),
UDP_MIB_INDATAGRAMS,
is_udplite);
return -ret;
}
}
/* FALLTHROUGH -- it's a UDP Packet */
}
/*
* UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
*/
if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
if (up->pcrlen == 0) { /* full coverage was set */
net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n",
UDP_SKB_CB(skb)->cscov, skb->len);
goto drop;
}
if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n",
UDP_SKB_CB(skb)->cscov, up->pcrlen);
goto drop;
}
}
if (rcu_access_pointer(sk->sk_filter) &&
udp_lib_checksum_complete(skb))
goto csum_error;
if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
goto drop;
udp_csum_pull_header(skb);
skb_dst_drop(skb);
return __udpv6_queue_rcv_skb(sk, skb);
csum_error:
__UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
drop:
__UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
atomic_inc(&sk->sk_drops);
kfree_skb(skb);
return -1;
}
static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
__be16 loc_port, const struct in6_addr *loc_addr,
__be16 rmt_port, const struct in6_addr *rmt_addr,
int dif, unsigned short hnum)
{
struct inet_sock *inet = inet_sk(sk);
if (!net_eq(sock_net(sk), net))
return false;
if (udp_sk(sk)->udp_port_hash != hnum ||
sk->sk_family != PF_INET6 ||
(inet->inet_dport && inet->inet_dport != rmt_port) ||
(!ipv6_addr_any(&sk->sk_v6_daddr) &&
!ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif) ||
(!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr)))
return false;
if (!inet6_mc_check(sk, loc_addr, rmt_addr))
return false;
return true;
}
static void udp6_csum_zero_error(struct sk_buff *skb)
{
/* RFC 2460 section 8.1 says that we SHOULD log
* this error. Well, it is reasonable.
*/
net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
&ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
&ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
}
/*
* Note: called only from the BH handler context,
* so we don't need to lock the hashes.
*/
static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
const struct in6_addr *saddr, const struct in6_addr *daddr,
struct udp_table *udptable, int proto)
{
struct sock *sk, *first = NULL;
const struct udphdr *uh = udp_hdr(skb);
unsigned short hnum = ntohs(uh->dest);
struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
unsigned int offset = offsetof(typeof(*sk), sk_node);
unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
int dif = inet6_iif(skb);
struct hlist_node *node;
struct sk_buff *nskb;
if (use_hash2) {
hash2_any = udp6_portaddr_hash(net, &in6addr_any, hnum) &
udptable->mask;
hash2 = udp6_portaddr_hash(net, daddr, hnum) & udptable->mask;
start_lookup:
hslot = &udptable->hash2[hash2];
offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
}
sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr,
uh->source, saddr, dif, hnum))
continue;
/* If zero checksum and no_check is not on for
* the socket then skip it.
*/
if (!uh->check && !udp_sk(sk)->no_check6_rx)
continue;
if (!first) {
first = sk;
continue;
}
nskb = skb_clone(skb, GFP_ATOMIC);
if (unlikely(!nskb)) {
atomic_inc(&sk->sk_drops);
__UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
IS_UDPLITE(sk));
__UDP6_INC_STATS(net, UDP_MIB_INERRORS,
IS_UDPLITE(sk));
continue;
}
if (udpv6_queue_rcv_skb(sk, nskb) > 0)
consume_skb(nskb);
}
/* Also lookup *:port if we are using hash2 and haven't done so yet. */
if (use_hash2 && hash2 != hash2_any) {
hash2 = hash2_any;
goto start_lookup;
}
if (first) {
if (udpv6_queue_rcv_skb(first, skb) > 0)
consume_skb(skb);
} else {
kfree_skb(skb);
__UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
proto == IPPROTO_UDPLITE);
}
return 0;
}
int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
int proto)
{
const struct in6_addr *saddr, *daddr;
struct net *net = dev_net(skb->dev);
struct udphdr *uh;
struct sock *sk;
u32 ulen = 0;
if (!pskb_may_pull(skb, sizeof(struct udphdr)))
goto discard;
saddr = &ipv6_hdr(skb)->saddr;
daddr = &ipv6_hdr(skb)->daddr;
uh = udp_hdr(skb);
ulen = ntohs(uh->len);
if (ulen > skb->len)
goto short_packet;
if (proto == IPPROTO_UDP) {
/* UDP validates ulen. */
/* Check for jumbo payload */
if (ulen == 0)
ulen = skb->len;
if (ulen < sizeof(*uh))
goto short_packet;
if (ulen < skb->len) {
if (pskb_trim_rcsum(skb, ulen))
goto short_packet;
saddr = &ipv6_hdr(skb)->saddr;
daddr = &ipv6_hdr(skb)->daddr;
uh = udp_hdr(skb);
}
}
if (udp6_csum_init(skb, uh, proto))
goto csum_error;
/*
* Multicast receive code
*/
if (ipv6_addr_is_multicast(daddr))
return __udp6_lib_mcast_deliver(net, skb,
saddr, daddr, udptable, proto);
/* Unicast */
/*
* check socket cache ... must talk to Alan about his plans
* for sock caches... i'll skip this for now.
*/
sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
if (sk) {
int ret;
if (!uh->check && !udp_sk(sk)->no_check6_rx) {
udp6_csum_zero_error(skb);
goto csum_error;
}
if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
ip6_compute_pseudo);
ret = udpv6_queue_rcv_skb(sk, skb);
/* a return value > 0 means to resubmit the input */
if (ret > 0)
return ret;
return 0;
}
if (!uh->check) {
udp6_csum_zero_error(skb);
goto csum_error;
}
if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
goto discard;
if (udp_lib_checksum_complete(skb))
goto csum_error;
__UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
kfree_skb(skb);
return 0;
short_packet:
net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
proto == IPPROTO_UDPLITE ? "-Lite" : "",
saddr, ntohs(uh->source),
ulen, skb->len,
daddr, ntohs(uh->dest));
goto discard;
csum_error:
__UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
discard:
__UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
kfree_skb(skb);
return 0;
}
static __inline__ int udpv6_rcv(struct sk_buff *skb)
{
return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
}
/*
* Throw away all pending data and cancel the corking. Socket is locked.
*/
static void udp_v6_flush_pending_frames(struct sock *sk)
{
struct udp_sock *up = udp_sk(sk);
if (up->pending == AF_INET)
udp_flush_pending_frames(sk);
else if (up->pending) {
up->len = 0;
up->pending = 0;
ip6_flush_pending_frames(sk);
}
}
/**
* udp6_hwcsum_outgoing - handle outgoing HW checksumming
* @sk: socket we are sending on
* @skb: sk_buff containing the filled-in UDP header
* (checksum field must be zeroed out)
*/
static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
const struct in6_addr *saddr,
const struct in6_addr *daddr, int len)
{
unsigned int offset;
struct udphdr *uh = udp_hdr(skb);
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);
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 sock *sk = skb->sk;
struct udphdr *uh;
int err = 0;
int is_udplite = IS_UDPLITE(sk);
__wsum csum = 0;
int offset = skb_transport_offset(skb);
int len = skb->len - offset;
/*
* Create a UDP header
*/
uh = udp_hdr(skb);
uh->source = fl6->fl6_sport;
uh->dest = fl6->fl6_dport;
uh->len = htons(len);
uh->check = 0;
if (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 */
udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len);
goto send;
} else
csum = udp_csum(skb);
/* add protocol-dependent pseudo-header */
uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
len, fl6->flowi6_proto, csum);
if (uh->check == 0)
uh->check = CSUM_MANGLED_0;
send:
err = ip6_send_skb(skb);
if (err) {
if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
UDP6_INC_STATS(sock_net(sk),
UDP_MIB_SNDBUFERRORS, is_udplite);
err = 0;
}
} else {
UDP6_INC_STATS(sock_net(sk),
UDP_MIB_OUTDATAGRAMS, is_udplite);
}
return err;
}
static int udp_v6_push_pending_frames(struct sock *sk)
{
struct sk_buff *skb;
struct udp_sock *up = udp_sk(sk);
struct flowi6 fl6;
int err = 0;
if (up->pending == AF_INET)
return udp_push_pending_frames(sk);
/* ip6_finish_skb will release the cork, so make a copy of
* fl6 here.
*/
fl6 = inet_sk(sk)->cork.fl.u.ip6;
skb = ip6_finish_skb(sk);
if (!skb)
goto out;
err = udp_v6_send_skb(skb, &fl6);
out:
up->len = 0;
up->pending = 0;
return err;
}
int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
{
struct ipv6_txoptions opt_space;
struct udp_sock *up = udp_sk(sk);
struct inet_sock *inet = inet_sk(sk);
struct ipv6_pinfo *np = inet6_sk(sk);
DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
struct in6_addr *daddr, *final_p, final;
struct ipv6_txoptions *opt = NULL;
struct ipv6_txoptions *opt_to_free = NULL;
struct ip6_flowlabel *flowlabel = NULL;
struct flowi6 fl6;
struct dst_entry *dst;
struct ipcm6_cookie ipc6;
int addr_len = msg->msg_namelen;
int ulen = len;
int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
int err;
int connected = 0;
int is_udplite = IS_UDPLITE(sk);
int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
struct sockcm_cookie sockc;
ipc6.hlimit = -1;
ipc6.tclass = -1;
ipc6.dontfrag = -1;
/* destination address check */
if (sin6) {
if (addr_len < offsetof(struct sockaddr, sa_data))
return -EINVAL;
switch (sin6->sin6_family) {
case AF_INET6:
if (addr_len < SIN6_LEN_RFC2133)
return -EINVAL;
daddr = &sin6->sin6_addr;
break;
case AF_INET:
goto do_udp_sendmsg;
case AF_UNSPEC:
msg->msg_name = sin6 = NULL;
msg->msg_namelen = addr_len = 0;
daddr = NULL;
break;
default:
return -EINVAL;
}
} else if (!up->pending) {
if (sk->sk_state != TCP_ESTABLISHED)
return -EDESTADDRREQ;
daddr = &sk->sk_v6_daddr;
} else
daddr = NULL;
if (daddr) {
if (ipv6_addr_v4mapped(daddr)) {
struct sockaddr_in sin;
sin.sin_family = AF_INET;
sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
sin.sin_addr.s_addr = daddr->s6_addr32[3];
msg->msg_name = &sin;
msg->msg_namelen = sizeof(sin);
do_udp_sendmsg:
if (__ipv6_only_sock(sk))
return -ENETUNREACH;
return udp_sendmsg(sk, msg, len);
}
}
if (up->pending == AF_INET)
return udp_sendmsg(sk, msg, len);
/* Rough check on arithmetic overflow,
better check is made in ip6_append_data().
*/
if (len > INT_MAX - sizeof(struct udphdr))
return -EMSGSIZE;
getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
if (up->pending) {
/*
* There are pending frames.
* The socket lock must be held while it's corked.
*/
lock_sock(sk);
if (likely(up->pending)) {
if (unlikely(up->pending != AF_INET6)) {
release_sock(sk);
return -EAFNOSUPPORT;
}
dst = NULL;
goto do_append_data;
}
release_sock(sk);
}
ulen += sizeof(struct udphdr);
memset(&fl6, 0, sizeof(fl6));
if (sin6) {
if (sin6->sin6_port == 0)
return -EINVAL;
fl6.fl6_dport = sin6->sin6_port;
daddr = &sin6->sin6_addr;
if (np->sndflow) {
fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
if (!flowlabel)
return -EINVAL;
}
}
/*
* Otherwise it will be difficult to maintain
* sk->sk_dst_cache.
*/
if (sk->sk_state == TCP_ESTABLISHED &&
ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
daddr = &sk->sk_v6_daddr;
if (addr_len >= sizeof(struct sockaddr_in6) &&
sin6->sin6_scope_id &&
__ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
fl6.flowi6_oif = sin6->sin6_scope_id;
} else {
if (sk->sk_state != TCP_ESTABLISHED)
return -EDESTADDRREQ;
fl6.fl6_dport = inet->inet_dport;
daddr = &sk->sk_v6_daddr;
fl6.flowlabel = np->flow_label;
connected = 1;
}
if (!fl6.flowi6_oif)
fl6.flowi6_oif = sk->sk_bound_dev_if;
if (!fl6.flowi6_oif)
fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
fl6.flowi6_mark = sk->sk_mark;
fl6.flowi6_uid = sk->sk_uid;
sockc.tsflags = sk->sk_tsflags;
if (msg->msg_controllen) {
opt = &opt_space;
memset(opt, 0, sizeof(struct ipv6_txoptions));
opt->tot_len = sizeof(*opt);
ipc6.opt = opt;
err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, &sockc);
if (err < 0) {
fl6_sock_release(flowlabel);
return err;
}
if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
if (!flowlabel)
return -EINVAL;
}
if (!(opt->opt_nflen|opt->opt_flen))
opt = NULL;
connected = 0;
}
if (!opt) {
opt = txopt_get(np);
opt_to_free = opt;
}
if (flowlabel)
opt = fl6_merge_options(&opt_space, flowlabel, opt);
opt = ipv6_fixup_options(&opt_space, opt);
ipc6.opt = opt;
fl6.flowi6_proto = sk->sk_protocol;
if (!ipv6_addr_any(daddr))
fl6.daddr = *daddr;
else
fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
fl6.saddr = np->saddr;
fl6.fl6_sport = inet->inet_sport;
final_p = fl6_update_dst(&fl6, opt, &final);
if (final_p)
connected = 0;
if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
fl6.flowi6_oif = np->mcast_oif;
connected = 0;
} else if (!fl6.flowi6_oif)
fl6.flowi6_oif = np->ucast_oif;
security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
if (ipc6.tclass < 0)
ipc6.tclass = np->tclass;
fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p);
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,
&fl6, (struct rt6_info *)dst,
msg->msg_flags, &sockc);
err = PTR_ERR(skb);
if (!IS_ERR_OR_NULL(skb))
err = udp_v6_send_skb(skb, &fl6);
goto release_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, &sockc);
if (err)
udp_v6_flush_pending_frames(sk);
else if (!corkreq)
err = udp_v6_push_pending_frames(sk);
else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
up->pending = 0;
if (err > 0)
err = np->recverr ? net_xmit_errno(err) : 0;
release_sock(sk);
release_dst:
if (dst) {
if (connected) {
ip6_dst_store(sk, dst,
ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
&sk->sk_v6_daddr : NULL,
#ifdef CONFIG_IPV6_SUBTREES
ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
&np->saddr :
#endif
NULL);
} else {
dst_release(dst);
}
dst = NULL;
}
out:
dst_release(dst);
fl6_sock_release(flowlabel);
txopt_put(opt_to_free);
if (!err)
return len;
/*
* ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
* ENOBUFS might not be good (it's not tunable per se), but otherwise
* we don't have a good statistic (IpOutDiscards but it can be too many
* things). We could add another new stat but at least for now that
* seems like overkill.
*/
if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
UDP6_INC_STATS(sock_net(sk),
UDP_MIB_SNDBUFERRORS, is_udplite);
}
return err;
do_confirm:
dst_confirm(dst);
if (!(msg->msg_flags&MSG_PROBE) || len)
goto back_from_confirm;
err = 0;
goto out;
}
void udpv6_destroy_sock(struct sock *sk)
{
struct udp_sock *up = udp_sk(sk);
lock_sock(sk);
udp_v6_flush_pending_frames(sk);
release_sock(sk);
if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
void (*encap_destroy)(struct sock *sk);
encap_destroy = ACCESS_ONCE(up->encap_destroy);
if (encap_destroy)
encap_destroy(sk);
}
inet6_destroy_sock(sk);
}
/*
* Socket option code for UDP
*/
int udpv6_setsockopt(struct sock *sk, int level, int optname,
char __user *optval, unsigned int optlen)
{
if (level == SOL_UDP || level == SOL_UDPLITE)
return udp_lib_setsockopt(sk, level, optname, optval, optlen,
udp_v6_push_pending_frames);
return ipv6_setsockopt(sk, level, optname, optval, optlen);
}
#ifdef CONFIG_COMPAT
int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
char __user *optval, unsigned int optlen)
{
if (level == SOL_UDP || level == SOL_UDPLITE)
return udp_lib_setsockopt(sk, level, optname, optval, optlen,
udp_v6_push_pending_frames);
return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
}
#endif
int udpv6_getsockopt(struct sock *sk, int level, int optname,
char __user *optval, int __user *optlen)
{
if (level == SOL_UDP || level == SOL_UDPLITE)
return udp_lib_getsockopt(sk, level, optname, optval, optlen);
return ipv6_getsockopt(sk, level, optname, optval, optlen);
}
#ifdef CONFIG_COMPAT
int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
char __user *optval, int __user *optlen)
{
if (level == SOL_UDP || level == SOL_UDPLITE)
return udp_lib_getsockopt(sk, level, optname, optval, optlen);
return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
}
#endif
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, bucket);
}
return 0;
}
static const struct file_operations udp6_afinfo_seq_fops = {
.owner = THIS_MODULE,
.open = udp_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_net
};
static struct udp_seq_afinfo udp6_seq_afinfo = {
.name = "udp6",
.family = AF_INET6,
.udp_table = &udp_table,
.seq_fops = &udp6_afinfo_seq_fops,
.seq_ops = {
.show = udp6_seq_show,
},
};
int __net_init udp6_proc_init(struct net *net)
{
return udp_proc_register(net, &udp6_seq_afinfo);
}
void udp6_proc_exit(struct net *net)
{
udp_proc_unregister(net, &udp6_seq_afinfo);
}
#endif /* CONFIG_PROC_FS */
/* ------------------------------------------------------------------------ */
struct proto udpv6_prot = {
.name = "UDPv6",
.owner = THIS_MODULE,
.close = udp_lib_close,
.connect = ip6_datagram_connect,
.disconnect = udp_disconnect,
.ioctl = udp_ioctl,
.init = udp_init_sock,
.destroy = udpv6_destroy_sock,
.setsockopt = udpv6_setsockopt,
.getsockopt = udpv6_getsockopt,
.sendmsg = udpv6_sendmsg,
.recvmsg = udpv6_recvmsg,
.release_cb = ip6_datagram_release_cb,
.hash = udp_lib_hash,
.unhash = udp_lib_unhash,
.rehash = udp_v6_rehash,
.get_port = udp_v6_get_port,
.memory_allocated = &udp_memory_allocated,
.sysctl_mem = sysctl_udp_mem,
.sysctl_wmem = &sysctl_udp_wmem_min,
.sysctl_rmem = &sysctl_udp_rmem_min,
.obj_size = sizeof(struct udp6_sock),
.h.udp_table = &udp_table,
#ifdef CONFIG_COMPAT
.compat_setsockopt = compat_udpv6_setsockopt,
.compat_getsockopt = compat_udpv6_getsockopt,
#endif
.diag_destroy = udp_abort,
};
static struct inet_protosw udpv6_protosw = {
.type = SOCK_DGRAM,
.protocol = IPPROTO_UDP,
.prot = &udpv6_prot,
.ops = &inet6_dgram_ops,
.flags = INET_PROTOSW_PERMANENT,
};
int __init udpv6_init(void)
{
int ret;
ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
if (ret)
goto out;
ret = inet6_register_protosw(&udpv6_protosw);
if (ret)
goto out_udpv6_protocol;
out:
return ret;
out_udpv6_protocol:
inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
goto out;
}
void udpv6_exit(void)
{
inet6_unregister_protosw(&udpv6_protosw);
inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
}
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