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alistair23-linux/net/ipv6/udp.c
Shawn Bohrer 005ec97433 udp: Only allow busy read/poll on connected sockets 
UDP sockets can receive packets from multiple endpoints and thus may be
received on multiple receive queues.  Since packets packets can arrive
on multiple receive queues we should not mark the napi_id for all
packets.  This makes busy read/poll only work for connected UDP sockets.

This additionally enables busy read/poll for UDP multicast packets as
long as the socket is connected by moving the check into
__udp_queue_rcv_skb().

Signed-off-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Suggested-by: Eric Dumazet <edumazet@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-08 16:27:33 -04:00

1492 lines
37 KiB
C
Raw Blame History

/*
* 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 <net/inet6_hashtables.h>
#include <net/busy_poll.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <trace/events/skb.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);
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 &&
(!sk->sk_rcv_saddr || !sk2->sk_rcv_saddr ||
sk->sk_rcv_saddr == sk2->sk_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, matches = 0, reuseport = 0;
u32 hash = 0;
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;
reuseport = sk->sk_reuseport;
if (reuseport) {
hash = inet6_ehashfn(net, daddr, hnum,
saddr, sport);
matches = 1;
} else if (score == SCORE2_MAX)
goto exact_match;
} else if (score == badness && reuseport) {
matches++;
if (((u64)hash * matches) >> 32 == 0)
result = sk;
hash = next_pseudo_random32(hash);
}
}
/*
* 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;
}
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, matches = 0, reuseport = 0;
u32 hash = 0;
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;
reuseport = sk->sk_reuseport;
if (reuseport) {
hash = inet6_ehashfn(net, daddr, hnum,
saddr, sport);
matches = 1;
}
} else if (score == badness && reuseport) {
matches++;
if (((u64)hash * matches) >> 32 == 0)
result = sk;
hash = next_pseudo_random32(hash);
}
}
/*
* 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;
}
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)
{
struct sock *sk;
const 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, copied;
int peeked, off = 0;
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, &off, &err);
if (!skb)
goto out;
ulen = skb->len - sizeof(struct udphdr);
copied = len;
if (copied > ulen)
copied = ulen;
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 || 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, copied);
else {
err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
if (err == -EINVAL)
goto csum_copy_err;
}
if (unlikely(err)) {
trace_kfree_skb(skb, udpv6_recvmsg);
if (!peeked) {
atomic_inc(&sk->sk_drops);
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);
}
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;
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,
IP6CB(skb)->iif);
}
}
if (is_udp4) {
if (inet->cmsg_flags)
ip_cmsg_recv(msg, skb);
} else {
if (np->rxopt.all)
ip6_datagram_recv_ctl(sk, msg, skb);
}
err = copied;
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_CSUMERRORS, is_udplite);
UDP_INC_STATS_USER(sock_net(sk),
UDP_MIB_INERRORS, is_udplite);
} else {
UDP6_INC_STATS_USER(sock_net(sk),
UDP_MIB_CSUMERRORS, is_udplite);
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;
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 err;
sk = __udp6_lib_lookup(dev_net(skb->dev), daddr, uh->dest,
saddr, uh->source, inet6_iif(skb), udptable);
if (sk == NULL)
return;
if (type == ICMPV6_PKT_TOOBIG)
ip6_sk_update_pmtu(skb, sk, info);
if (type == NDISC_REDIRECT) {
ip6_sk_redirect(skb, sk);
goto out;
}
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 int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
int rc;
if (!ipv6_addr_any(&inet6_sk(sk)->daddr)) {
sock_rps_save_rxhash(sk, skb);
sk_mark_napi_id(sk, skb);
}
rc = sock_queue_rcv_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_BH(sock_net(sk),
UDP_MIB_RCVBUFERRORS, is_udplite);
UDP6_INC_STATS_BH(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 rc;
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 (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
int ret;
ret = encap_rcv(sk, skb);
if (ret <= 0) {
UDP_INC_STATS_BH(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 */
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_access_pointer(sk->sk_filter)) {
if (udp_lib_checksum_complete(skb))
goto csum_error;
}
if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf))
goto drop;
skb_dst_drop(skb);
bh_lock_sock(sk);
rc = 0;
if (!sock_owned_by_user(sk))
rc = __udpv6_queue_rcv_skb(sk, skb);
else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
bh_unlock_sock(sk);
goto drop;
}
bh_unlock_sock(sk);
return rc;
csum_error:
UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
drop:
UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
atomic_inc(&sk->sk_drops);
kfree_skb(skb);
return -1;
}
static struct sock *udp_v6_mcast_next(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)
{
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)
{
struct sk_buff *skb1 = NULL;
struct sock *sk;
unsigned int i;
for (i = 0; i < count; i++) {
sk = stack[i];
if (likely(skb1 == NULL))
skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
if (!skb1) {
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));
}
if (skb1 && udpv6_queue_rcv_skb(sk, skb1) <= 0)
skb1 = NULL;
}
if (unlikely(skb1))
kfree_skb(skb1);
}
/*
* 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)
{
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;
}
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;
const 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 csum_error;
/*
* 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) {
int ret;
ret = udpv6_queue_rcv_skb(sk, skb);
sock_put(sk);
/* a return value > 0 means to resubmit the input, but
* it wants the return to be -protocol, or 0
*/
if (ret > 0)
return -ret;
return 0;
}
if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
goto discard;
if (udp_lib_checksum_complete(skb))
goto csum_error;
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;
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));
goto discard;
csum_error:
UDP6_INC_STATS_BH(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
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;
int err = 0;
int is_udplite = IS_UDPLITE(sk);
__wsum csum = 0;
if (up->pending == AF_INET)
return udp_push_pending_frames(sk);
fl6 = &inet->cork.fl.u.ip6;
/* 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_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 = &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 = ip6_datagram_send_ctl(sock_net(sk), 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))
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));
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)
{
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 */
void udp_v6_clear_sk(struct sock *sk, int size)
{
struct inet_sock *inet = inet_sk(sk);
/* we do not want to clear pinet6 field, because of RCU lookups */
sk_prot_clear_portaddr_nulls(sk, offsetof(struct inet_sock, pinet6));
size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
memset(&inet->pinet6 + 1, 0, size);
}
/* ------------------------------------------------------------------------ */
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 = udp_v6_clear_sk,
};
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);
}
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