/*
* 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 <asm/uaccess.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 <linux/proc_fs.h>
#include <linux/seq_file.h>
#include "udp_impl.h"
int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2)
{
const struct in6_addr *sk_rcv_saddr6 = &inet6_sk(sk)->rcv_saddr;
const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
__be32 sk1_rcv_saddr = sk_rcv_saddr(sk);
__be32 sk2_rcv_saddr = sk_rcv_saddr(sk2);
int sk_ipv6only = ipv6_only_sock(sk);
int sk2_ipv6only = inet_v6_ipv6only(sk2);
int addr_type = ipv6_addr_type(sk_rcv_saddr6);
int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
/* if both are mapped, treat as IPv4 */
if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED)
return (!sk2_ipv6only &&
(!sk1_rcv_saddr || !sk2_rcv_saddr ||
sk1_rcv_saddr == sk2_rcv_saddr));
if (addr_type2 == IPV6_ADDR_ANY &&
!(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
return 1;
if (addr_type == IPV6_ADDR_ANY &&
!(sk_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
return 1;
if (sk2_rcv_saddr6 &&
ipv6_addr_equal(sk_rcv_saddr6, sk2_rcv_saddr6))
return 1;
return 0;
}
static unsigned int udp6_portaddr_hash(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), &inet6_sk(sk)->rcv_saddr, 0);
/* precompute partial secondary hash */
udp_sk(sk)->udp_portaddr_hash = hash2_partial;
return udp_lib_get_port(sk, snum, ipv6_rcv_saddr_equal, hash2_nulladdr);
}
static void udp_v6_rehash(struct sock *sk)
{
u16 new_hash = udp6_portaddr_hash(sock_net(sk),
&inet6_sk(sk)->rcv_saddr,
inet_sk(sk)->inet_num);
udp_lib_rehash(sk, new_hash);
}
static inline int compute_score(struct sock *sk, struct net *net,
unsigned short hnum,
const struct in6_addr *saddr, __be16 sport,
const struct in6_addr *daddr, __be16 dport,
int dif)
{
int score = -1;
if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
sk->sk_family == PF_INET6) {
struct ipv6_pinfo *np = inet6_sk(sk);
struct inet_sock *inet = inet_sk(sk);
score = 0;
if (inet->inet_dport) {
if (inet->inet_dport != sport)
return -1;
score++;
}
if (!ipv6_addr_any(&np->rcv_saddr)) {
if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
return -1;
score++;
}
if (!ipv6_addr_any(&np->daddr)) {
if (!ipv6_addr_equal(&np->daddr, saddr))
return -1;
score++;
}
if (sk->sk_bound_dev_if) {
if (sk->sk_bound_dev_if != dif)
return -1;
score++;
}
}
return score;
}
#define SCORE2_MAX (1 + 1 + 1)
static inline int compute_score2(struct sock *sk, struct net *net,
const struct in6_addr *saddr, __be16 sport,
const struct in6_addr *daddr, unsigned short hnum,
int dif)
{
int score = -1;
if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
sk->sk_family == PF_INET6) {
struct ipv6_pinfo *np = inet6_sk(sk);
struct inet_sock *inet = inet_sk(sk);
if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
return -1;
score = 0;
if (inet->inet_dport) {
if (inet->inet_dport != sport)
return -1;
score++;
}
if (!ipv6_addr_any(&np->daddr)) {
if (!ipv6_addr_equal(&np->daddr, saddr))
return -1;
score++;
}
if (sk->sk_bound_dev_if) {
if (sk->sk_bound_dev_if != dif)
return -1;
score++;
}
}
return score;
}
/* called with read_rcu_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,
struct udp_hslot *hslot2, unsigned int slot2)
{
struct sock *sk, *result;
struct hlist_nulls_node *node;
int score, badness;
begin:
result = NULL;
badness = -1;
udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
score = compute_score2(sk, net, saddr, sport,
daddr, hnum, dif);
if (score > badness) {
result = sk;
badness = score;
if (score == SCORE2_MAX)
goto exact_match;
}
}
/*
* if the nulls value we got at the end of this lookup is
* not the expected one, we must restart lookup.
* We probably met an item that was moved to another chain.
*/
if (get_nulls_value(node) != slot2)
goto begin;
if (result) {
exact_match:
if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
result = NULL;
else if (unlikely(compute_score2(result, net, saddr, sport,
daddr, hnum, dif) < badness)) {
sock_put(result);
goto begin;
}
}
return result;
}
static 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 sock *sk, *result;
struct hlist_nulls_node *node;
unsigned short hnum = ntohs(dport);
unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
int score, badness;
rcu_read_lock();
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,
hslot2, slot2);
if (!result) {
hash2 = udp6_portaddr_hash(net, &in6addr_any, hnum);
slot2 = hash2 & udptable->mask;
hslot2 = &udptable->hash2[slot2];
if (hslot->count < hslot2->count)
goto begin;
result = udp6_lib_lookup2(net, saddr, sport,
&in6addr_any, hnum, dif,
hslot2, slot2);
}
rcu_read_unlock();
return result;
}
begin:
result = NULL;
badness = -1;
sk_nulls_for_each_rcu(sk, node, &hslot->head) {
score = compute_score(sk, net, hnum, saddr, sport, daddr, dport, dif);
if (score > badness) {
result = sk;
badness = score;
}
}
/*
* if the nulls value we got at the end of this lookup is
* not the expected one, we must restart lookup.
* We probably met an item that was moved to another chain.
*/
if (get_nulls_value(node) != slot)
goto begin;
if (result) {
if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
result = NULL;
else if (unlikely(compute_score(result, net, hnum, saddr, sport,
daddr, dport, dif) < badness)) {
sock_put(result);
goto begin;
}
}
rcu_read_unlock();
return result;
}
static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
__be16 sport, __be16 dport,
struct udp_table *udptable)
{
struct sock *sk;
struct ipv6hdr *iph = ipv6_hdr(skb);
if (unlikely(sk = skb_steal_sock(skb)))
return sk;
return __udp6_lib_lookup(dev_net(skb_dst(skb)->dev), &iph->saddr, sport,
&iph->daddr, dport, inet6_iif(skb),
udptable);
}
struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
const struct in6_addr *daddr, __be16 dport, int dif)
{
return __udp6_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
}
EXPORT_SYMBOL_GPL(udp6_lib_lookup);
/*
* This should be easy, if there is something there we
* return it, otherwise we block.
*/
int udpv6_recvmsg(struct kiocb *iocb, 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;
int peeked;
int err;
int is_udplite = IS_UDPLITE(sk);
int is_udp4;
bool slow;
if (addr_len)
*addr_len=sizeof(struct sockaddr_in6);
if (flags & MSG_ERRQUEUE)
return ipv6_recv_error(sk, msg, len);
if (np->rxpmtu && np->rxopt.bits.rxpmtu)
return ipv6_recv_rxpmtu(sk, msg, len);
try_again:
skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
&peeked, &err);
if (!skb)
goto out;
ulen = skb->len - sizeof(struct udphdr);
if (len > ulen)
len = ulen;
else if (len < 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 (len < ulen || UDP_SKB_CB(skb)->partial_cov) {
if (udp_lib_checksum_complete(skb))
goto csum_copy_err;
}
if (skb_csum_unnecessary(skb))
err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
msg->msg_iov,len);
else {
err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
if (err == -EINVAL)
goto csum_copy_err;
}
if (err)
goto out_free;
if (!peeked) {
if (is_udp4)
UDP_INC_STATS_USER(sock_net(sk),
UDP_MIB_INDATAGRAMS, is_udplite);
else
UDP6_INC_STATS_USER(sock_net(sk),
UDP_MIB_INDATAGRAMS, is_udplite);
}
sock_recv_ts_and_drops(msg, sk, skb);
/* Copy the address. */
if (msg->msg_name) {
struct sockaddr_in6 *sin6;
sin6 = (struct sockaddr_in6 *) msg->msg_name;
sin6->sin6_family = AF_INET6;
sin6->sin6_port = udp_hdr(skb)->source;
sin6->sin6_flowinfo = 0;
sin6->sin6_scope_id = 0;
if (is_udp4)
ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
&sin6->sin6_addr);
else {
ipv6_addr_copy(&sin6->sin6_addr,
&ipv6_hdr(skb)->saddr);
if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
sin6->sin6_scope_id = IP6CB(skb)->iif;
}
}
if (is_udp4) {
if (inet->cmsg_flags)
ip_cmsg_recv(msg, skb);
} else {
if (np->rxopt.all)
datagram_recv_ctl(sk, msg, skb);
}
err = len;
if (flags & MSG_TRUNC)
err = ulen;
out_free:
skb_free_datagram_locked(sk, skb);
out:
return err;
csum_copy_err:
slow = lock_sock_fast(sk);
if (!skb_kill_datagram(sk, skb, flags)) {
if (is_udp4)
UDP_INC_STATS_USER(sock_net(sk),
UDP_MIB_INERRORS, is_udplite);
else
UDP6_INC_STATS_USER(sock_net(sk),
UDP_MIB_INERRORS, is_udplite);
}
unlock_sock_fast(sk, slow);
if (noblock)
return -EAGAIN;
/* starting over for a new packet */
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;
struct ipv6hdr *hdr = (struct ipv6hdr*)skb->data;
struct in6_addr *saddr = &hdr->saddr;
struct in6_addr *daddr = &hdr->daddr;
struct udphdr *uh = (struct udphdr*)(skb->data+offset);
struct sock *sk;
int err;
sk = __udp6_lib_lookup(dev_net(skb->dev), daddr, uh->dest,
saddr, uh->source, inet6_iif(skb), udptable);
if (sk == NULL)
return;
np = inet6_sk(sk);
if (!icmpv6_err_convert(type, code, &err) && !np->recverr)
goto out;
if (sk->sk_state != TCP_ESTABLISHED && !np->recverr)
goto out;
if (np->recverr)
ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
sk->sk_err = err;
sk->sk_error_report(sk);
out:
sock_put(sk);
}
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);
}
int udpv6_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
{
struct udp_sock *up = udp_sk(sk);
int rc;
int is_udplite = IS_UDPLITE(sk);
if (!ipv6_addr_any(&inet6_sk(sk)->daddr))
sock_rps_save_rxhash(sk, skb->rxhash);
if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
goto drop;
/*
* 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 */
LIMIT_NETDEBUG(KERN_WARNING "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) {
LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: coverage %d "
"too small, need min %d\n",
UDP_SKB_CB(skb)->cscov, up->pcrlen);
goto drop;
}
}
if (rcu_dereference_raw(sk->sk_filter)) {
if (udp_lib_checksum_complete(skb))
goto drop;
}
if ((rc = ip_queue_rcv_skb(sk, skb)) < 0) {
/* Note that an ENOMEM error is charged twice */
if (rc == -ENOMEM)
UDP6_INC_STATS_BH(sock_net(sk),
UDP_MIB_RCVBUFERRORS, is_udplite);
goto drop_no_sk_drops_inc;
}
return 0;
drop:
atomic_inc(&sk->sk_drops);
drop_no_sk_drops_inc:
UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
kfree_skb(skb);
return -1;
}
static struct sock *udp_v6_mcast_next(struct net *net, struct sock *sk,
__be16 loc_port, struct in6_addr *loc_addr,
__be16 rmt_port, struct in6_addr *rmt_addr,
int dif)
{
struct hlist_nulls_node *node;
struct sock *s = sk;
unsigned short num = ntohs(loc_port);
sk_nulls_for_each_from(s, node) {
struct inet_sock *inet = inet_sk(s);
if (!net_eq(sock_net(s), net))
continue;
if (udp_sk(s)->udp_port_hash == num &&
s->sk_family == PF_INET6) {
struct ipv6_pinfo *np = inet6_sk(s);
if (inet->inet_dport) {
if (inet->inet_dport != rmt_port)
continue;
}
if (!ipv6_addr_any(&np->daddr) &&
!ipv6_addr_equal(&np->daddr, rmt_addr))
continue;
if (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)
continue;
if (!ipv6_addr_any(&np->rcv_saddr)) {
if (!ipv6_addr_equal(&np->rcv_saddr, loc_addr))
continue;
}
if (!inet6_mc_check(s, loc_addr, rmt_addr))
continue;
return s;
}
}
return NULL;
}
static void flush_stack(struct sock **stack, unsigned int count,
struct sk_buff *skb, unsigned int final)
{
unsigned int i;
struct sock *sk;
struct sk_buff *skb1;
for (i = 0; i < count; i++) {
skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
sk = stack[i];
if (skb1) {
if (sk_rcvqueues_full(sk, skb1)) {
kfree_skb(skb1);
goto drop;
}
bh_lock_sock(sk);
if (!sock_owned_by_user(sk))
udpv6_queue_rcv_skb(sk, skb1);
else if (sk_add_backlog(sk, skb1)) {
kfree_skb(skb1);
bh_unlock_sock(sk);
goto drop;
}
bh_unlock_sock(sk);
continue;
}
drop:
atomic_inc(&sk->sk_drops);
UDP6_INC_STATS_BH(sock_net(sk),
UDP_MIB_RCVBUFERRORS, IS_UDPLITE(sk));
UDP6_INC_STATS_BH(sock_net(sk),
UDP_MIB_INERRORS, IS_UDPLITE(sk));
}
}
/*
* 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,
struct in6_addr *saddr, struct in6_addr *daddr,
struct udp_table *udptable)
{
struct sock *sk, *stack[256 / sizeof(struct sock *)];
const struct udphdr *uh = udp_hdr(skb);
struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
int dif;
unsigned int i, count = 0;
spin_lock(&hslot->lock);
sk = sk_nulls_head(&hslot->head);
dif = inet6_iif(skb);
sk = udp_v6_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
while (sk) {
stack[count++] = sk;
sk = udp_v6_mcast_next(net, sk_nulls_next(sk), uh->dest, daddr,
uh->source, saddr, dif);
if (unlikely(count == ARRAY_SIZE(stack))) {
if (!sk)
break;
flush_stack(stack, count, skb, ~0);
count = 0;
}
}
/*
* before releasing the lock, we must take reference on sockets
*/
for (i = 0; i < count; i++)
sock_hold(stack[i]);
spin_unlock(&hslot->lock);
if (count) {
flush_stack(stack, count, skb, count - 1);
for (i = 0; i < count; i++)
sock_put(stack[i]);
} else {
kfree_skb(skb);
}
return 0;
}
static inline int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh,
int proto)
{
int err;
UDP_SKB_CB(skb)->partial_cov = 0;
UDP_SKB_CB(skb)->cscov = skb->len;
if (proto == IPPROTO_UDPLITE) {
err = udplite_checksum_init(skb, uh);
if (err)
return err;
}
if (uh->check == 0) {
/* RFC 2460 section 8.1 says that we SHOULD log
this error. Well, it is reasonable.
*/
LIMIT_NETDEBUG(KERN_INFO "IPv6: udp checksum is 0\n");
return 1;
}
if (skb->ip_summed == CHECKSUM_COMPLETE &&
!csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
skb->len, proto, skb->csum))
skb->ip_summed = CHECKSUM_UNNECESSARY;
if (!skb_csum_unnecessary(skb))
skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
&ipv6_hdr(skb)->daddr,
skb->len, proto, 0));
return 0;
}
int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
int proto)
{
struct net *net = dev_net(skb->dev);
struct sock *sk;
struct udphdr *uh;
struct in6_addr *saddr, *daddr;
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 discard;
/*
* Multicast receive code
*/
if (ipv6_addr_is_multicast(daddr))
return __udp6_lib_mcast_deliver(net, skb,
saddr, daddr, udptable);
/* 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 == NULL) {
if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
goto discard;
if (udp_lib_checksum_complete(skb))
goto discard;
UDP6_INC_STATS_BH(net, UDP_MIB_NOPORTS,
proto == IPPROTO_UDPLITE);
icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
kfree_skb(skb);
return 0;
}
/* deliver */
if (sk_rcvqueues_full(sk, skb)) {
sock_put(sk);
goto discard;
}
bh_lock_sock(sk);
if (!sock_owned_by_user(sk))
udpv6_queue_rcv_skb(sk, skb);
else if (sk_add_backlog(sk, skb)) {
atomic_inc(&sk->sk_drops);
bh_unlock_sock(sk);
sock_put(sk);
goto discard;
}
bh_unlock_sock(sk);
sock_put(sk);
return 0;
short_packet:
LIMIT_NETDEBUG(KERN_DEBUG "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));
discard:
UDP6_INC_STATS_BH(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);
__wsum csum = 0;
if (skb_queue_len(&sk->sk_write_queue) == 1) {
/* 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;
skb_queue_walk(&sk->sk_write_queue, skb) {
csum = csum_add(csum, skb->csum);
}
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_push_pending_frames(struct sock *sk)
{
struct sk_buff *skb;
struct udphdr *uh;
struct udp_sock *up = udp_sk(sk);
struct inet_sock *inet = inet_sk(sk);
struct flowi6 *fl6 = &inet->cork.fl.u.ip6;
int err = 0;
int is_udplite = IS_UDPLITE(sk);
__wsum csum = 0;
/* Grab the skbuff where UDP header space exists. */
if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
goto out;
/*
* Create a UDP header
*/
uh = udp_hdr(skb);
uh->source = fl6->fl6_sport;
uh->dest = fl6->fl6_dport;
uh->len = htons(up->len);
uh->check = 0;
if (is_udplite)
csum = udplite_csum_outgoing(sk, skb);
else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr,
up->len);
goto send;
} else
csum = udp_csum_outgoing(sk, skb);
/* add protocol-dependent pseudo-header */
uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
up->len, fl6->flowi6_proto, csum);
if (uh->check == 0)
uh->check = CSUM_MANGLED_0;
send:
err = ip6_push_pending_frames(sk);
if (err) {
if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
UDP6_INC_STATS_USER(sock_net(sk),
UDP_MIB_SNDBUFERRORS, is_udplite);
err = 0;
}
} else
UDP6_INC_STATS_USER(sock_net(sk),
UDP_MIB_OUTDATAGRAMS, is_udplite);
out:
up->len = 0;
up->pending = 0;
return err;
}
int udpv6_sendmsg(struct kiocb *iocb, 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);
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) msg->msg_name;
struct in6_addr *daddr, *final_p, final;
struct ipv6_txoptions *opt = NULL;
struct ip6_flowlabel *flowlabel = NULL;
struct flowi6 fl6;
struct dst_entry *dst;
int addr_len = msg->msg_namelen;
int ulen = len;
int hlimit = -1;
int tclass = -1;
int dontfrag = -1;
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 *);
/* 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 = &np->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(iocb, sk, msg, len);
}
}
if (up->pending == AF_INET)
return udp_sendmsg(iocb, 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;
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 == NULL)
return -EINVAL;
daddr = &flowlabel->dst;
}
}
/*
* Otherwise it will be difficult to maintain
* sk->sk_dst_cache.
*/
if (sk->sk_state == TCP_ESTABLISHED &&
ipv6_addr_equal(daddr, &np->daddr))
daddr = &np->daddr;
if (addr_len >= sizeof(struct sockaddr_in6) &&
sin6->sin6_scope_id &&
ipv6_addr_type(daddr)&IPV6_ADDR_LINKLOCAL)
fl6.flowi6_oif = sin6->sin6_scope_id;
} else {
if (sk->sk_state != TCP_ESTABLISHED)
return -EDESTADDRREQ;
fl6.fl6_dport = inet->inet_dport;
daddr = &np->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;
if (msg->msg_controllen) {
opt = &opt_space;
memset(opt, 0, sizeof(struct ipv6_txoptions));
opt->tot_len = sizeof(*opt);
err = datagram_send_ctl(sock_net(sk), msg, &fl6, opt, &hlimit,
&tclass, &dontfrag);
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 == NULL)
return -EINVAL;
}
if (!(opt->opt_nflen|opt->opt_flen))
opt = NULL;
connected = 0;
}
if (opt == NULL)
opt = np->opt;
if (flowlabel)
opt = fl6_merge_options(&opt_space, flowlabel, opt);
opt = ipv6_fixup_options(&opt_space, opt);
fl6.flowi6_proto = sk->sk_protocol;
if (!ipv6_addr_any(daddr))
ipv6_addr_copy(&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))
ipv6_addr_copy(&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;
}
security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, true);
if (IS_ERR(dst)) {
err = PTR_ERR(dst);
dst = NULL;
goto out;
}
if (hlimit < 0) {
if (ipv6_addr_is_multicast(&fl6.daddr))
hlimit = np->mcast_hops;
else
hlimit = np->hop_limit;
if (hlimit < 0)
hlimit = ip6_dst_hoplimit(dst);
}
if (tclass < 0)
tclass = np->tclass;
if (dontfrag < 0)
dontfrag = np->dontfrag;
if (msg->msg_flags&MSG_CONFIRM)
goto do_confirm;
back_from_confirm:
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);
LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
err = -EINVAL;
goto out;
}
up->pending = AF_INET6;
do_append_data:
up->len += ulen;
getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
err = ip6_append_data(sk, getfrag, msg->msg_iov, ulen,
sizeof(struct udphdr), hlimit, tclass, opt, &fl6,
(struct rt6_info*)dst,
corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags, dontfrag);
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 (dst) {
if (connected) {
ip6_dst_store(sk, dst,
ipv6_addr_equal(&fl6.daddr, &np->daddr) ?
&np->daddr : NULL,
#ifdef CONFIG_IPV6_SUBTREES
ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
&np->saddr :
#endif
NULL);
} else {
dst_release(dst);
}
dst = NULL;
}
if (err > 0)
err = np->recverr ? net_xmit_errno(err) : 0;
release_sock(sk);
out:
dst_release(dst);
fl6_sock_release(flowlabel);
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_USER(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)
{
lock_sock(sk);
udp_v6_flush_pending_frames(sk);
release_sock(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 int udp6_ufo_send_check(struct sk_buff *skb)
{
struct ipv6hdr *ipv6h;
struct udphdr *uh;
if (!pskb_may_pull(skb, sizeof(*uh)))
return -EINVAL;
ipv6h = ipv6_hdr(skb);
uh = udp_hdr(skb);
uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
IPPROTO_UDP, 0);
skb->csum_start = skb_transport_header(skb) - skb->head;
skb->csum_offset = offsetof(struct udphdr, check);
skb->ip_summed = CHECKSUM_PARTIAL;
return 0;
}
static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, u32 features)
{
struct sk_buff *segs = ERR_PTR(-EINVAL);
unsigned int mss;
unsigned int unfrag_ip6hlen, unfrag_len;
struct frag_hdr *fptr;
u8 *mac_start, *prevhdr;
u8 nexthdr;
u8 frag_hdr_sz = sizeof(struct frag_hdr);
int offset;
__wsum csum;
mss = skb_shinfo(skb)->gso_size;
if (unlikely(skb->len <= mss))
goto out;
if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
/* Packet is from an untrusted source, reset gso_segs. */
int type = skb_shinfo(skb)->gso_type;
if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) ||
!(type & (SKB_GSO_UDP))))
goto out;
skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
segs = NULL;
goto out;
}
/* Do software UFO. Complete and fill in the UDP checksum as HW cannot
* do checksum of UDP packets sent as multiple IP fragments.
*/
offset = skb->csum_start - skb_headroom(skb);
csum = skb_checksum(skb, offset, skb->len- offset, 0);
offset += skb->csum_offset;
*(__sum16 *)(skb->data + offset) = csum_fold(csum);
skb->ip_summed = CHECKSUM_NONE;
/* Check if there is enough headroom to insert fragment header. */
if ((skb_mac_header(skb) < skb->head + frag_hdr_sz) &&
pskb_expand_head(skb, frag_hdr_sz, 0, GFP_ATOMIC))
goto out;
/* Find the unfragmentable header and shift it left by frag_hdr_sz
* bytes to insert fragment header.
*/
unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
nexthdr = *prevhdr;
*prevhdr = NEXTHDR_FRAGMENT;
unfrag_len = skb_network_header(skb) - skb_mac_header(skb) +
unfrag_ip6hlen;
mac_start = skb_mac_header(skb);
memmove(mac_start-frag_hdr_sz, mac_start, unfrag_len);
skb->mac_header -= frag_hdr_sz;
skb->network_header -= frag_hdr_sz;
fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen);
fptr->nexthdr = nexthdr;
fptr->reserved = 0;
ipv6_select_ident(fptr);
/* Fragment the skb. ipv6 header and the remaining fields of the
* fragment header are updated in ipv6_gso_segment()
*/
segs = skb_segment(skb, features);
out:
return segs;
}
static const struct inet6_protocol udpv6_protocol = {
.handler = udpv6_rcv,
.err_handler = udpv6_err,
.gso_send_check = udp6_ufo_send_check,
.gso_segment = udp6_ufo_fragment,
.flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
};
/* ------------------------------------------------------------------------ */
#ifdef CONFIG_PROC_FS
static void udp6_sock_seq_show(struct seq_file *seq, struct sock *sp, int bucket)
{
struct inet_sock *inet = inet_sk(sp);
struct ipv6_pinfo *np = inet6_sk(sp);
struct in6_addr *dest, *src;
__u16 destp, srcp;
dest = &np->daddr;
src = &np->rcv_saddr;
destp = ntohs(inet->inet_dport);
srcp = ntohs(inet->inet_sport);
seq_printf(seq,
"%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
"%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d\n",
bucket,
src->s6_addr32[0], src->s6_addr32[1],
src->s6_addr32[2], src->s6_addr32[3], srcp,
dest->s6_addr32[0], dest->s6_addr32[1],
dest->s6_addr32[2], dest->s6_addr32[3], destp,
sp->sk_state,
sk_wmem_alloc_get(sp),
sk_rmem_alloc_get(sp),
0, 0L, 0,
sock_i_uid(sp), 0,
sock_i_ino(sp),
atomic_read(&sp->sk_refcnt), sp,
atomic_read(&sp->sk_drops));
}
int udp6_seq_show(struct seq_file *seq, void *v)
{
if (v == SEQ_START_TOKEN)
seq_printf(seq,
" sl "
"local_address "
"remote_address "
"st tx_queue rx_queue tr tm->when retrnsmt"
" uid timeout inode ref pointer drops\n");
else
udp6_sock_seq_show(seq, v, ((struct udp_iter_state *)seq->private)->bucket);
return 0;
}
static struct udp_seq_afinfo udp6_seq_afinfo = {
.name = "udp6",
.family = AF_INET6,
.udp_table = &udp_table,
.seq_fops = {
.owner = THIS_MODULE,
},
.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,
.destroy = udpv6_destroy_sock,
.setsockopt = udpv6_setsockopt,
.getsockopt = udpv6_getsockopt,
.sendmsg = udpv6_sendmsg,
.recvmsg = udpv6_recvmsg,
.backlog_rcv = udpv6_queue_rcv_skb,
.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),
.slab_flags = SLAB_DESTROY_BY_RCU,
.h.udp_table = &udp_table,
#ifdef CONFIG_COMPAT
.compat_setsockopt = compat_udpv6_setsockopt,
.compat_getsockopt = compat_udpv6_getsockopt,
#endif
.clear_sk = sk_prot_clear_portaddr_nulls,
};
static struct inet_protosw udpv6_protosw = {
.type = SOCK_DGRAM,
.protocol = IPPROTO_UDP,
.prot = &udpv6_prot,
.ops = &inet6_dgram_ops,
.no_check = UDP_CSUM_DEFAULT,
.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);
}