linux/net/ipv6/inet6_connection_sock.c
Eric Dumazet b282705336 net: convert syn_wait_lock to a spinlock
This is a low hanging fruit, as we'll get rid of syn_wait_lock eventually.

We hold syn_wait_lock for such small sections, that it makes no sense to use
a read/write lock. A spin lock is simply faster.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-23 16:52:26 -04:00

262 lines
7.3 KiB
C

/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* Support for INET6 connection oriented protocols.
*
* Authors: See the TCPv6 sources
*
* 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/module.h>
#include <linux/in6.h>
#include <linux/ipv6.h>
#include <linux/jhash.h>
#include <linux/slab.h>
#include <net/addrconf.h>
#include <net/inet_connection_sock.h>
#include <net/inet_ecn.h>
#include <net/inet_hashtables.h>
#include <net/ip6_route.h>
#include <net/sock.h>
#include <net/inet6_connection_sock.h>
int inet6_csk_bind_conflict(const struct sock *sk,
const struct inet_bind_bucket *tb, bool relax)
{
const struct sock *sk2;
int reuse = sk->sk_reuse;
int reuseport = sk->sk_reuseport;
kuid_t uid = sock_i_uid((struct sock *)sk);
/* We must walk the whole port owner list in this case. -DaveM */
/*
* See comment in inet_csk_bind_conflict about sock lookup
* vs net namespaces issues.
*/
sk_for_each_bound(sk2, &tb->owners) {
if (sk != sk2 &&
(!sk->sk_bound_dev_if ||
!sk2->sk_bound_dev_if ||
sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
if ((!reuse || !sk2->sk_reuse ||
sk2->sk_state == TCP_LISTEN) &&
(!reuseport || !sk2->sk_reuseport ||
(sk2->sk_state != TCP_TIME_WAIT &&
!uid_eq(uid,
sock_i_uid((struct sock *)sk2))))) {
if (ipv6_rcv_saddr_equal(sk, sk2))
break;
}
if (!relax && reuse && sk2->sk_reuse &&
sk2->sk_state != TCP_LISTEN &&
ipv6_rcv_saddr_equal(sk, sk2))
break;
}
}
return sk2 != NULL;
}
EXPORT_SYMBOL_GPL(inet6_csk_bind_conflict);
struct dst_entry *inet6_csk_route_req(struct sock *sk,
struct flowi6 *fl6,
const struct request_sock *req)
{
struct inet_request_sock *ireq = inet_rsk(req);
struct ipv6_pinfo *np = inet6_sk(sk);
struct in6_addr *final_p, final;
struct dst_entry *dst;
memset(fl6, 0, sizeof(*fl6));
fl6->flowi6_proto = IPPROTO_TCP;
fl6->daddr = ireq->ir_v6_rmt_addr;
final_p = fl6_update_dst(fl6, np->opt, &final);
fl6->saddr = ireq->ir_v6_loc_addr;
fl6->flowi6_oif = ireq->ir_iif;
fl6->flowi6_mark = ireq->ir_mark;
fl6->fl6_dport = ireq->ir_rmt_port;
fl6->fl6_sport = htons(ireq->ir_num);
security_req_classify_flow(req, flowi6_to_flowi(fl6));
dst = ip6_dst_lookup_flow(sk, fl6, final_p);
if (IS_ERR(dst))
return NULL;
return dst;
}
/*
* request_sock (formerly open request) hash tables.
*/
static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport,
const u32 rnd, const u32 synq_hsize)
{
u32 c;
c = jhash_3words((__force u32)raddr->s6_addr32[0],
(__force u32)raddr->s6_addr32[1],
(__force u32)raddr->s6_addr32[2],
rnd);
c = jhash_2words((__force u32)raddr->s6_addr32[3],
(__force u32)rport,
c);
return c & (synq_hsize - 1);
}
struct request_sock *inet6_csk_search_req(struct sock *sk,
const __be16 rport,
const struct in6_addr *raddr,
const struct in6_addr *laddr,
const int iif)
{
struct inet_connection_sock *icsk = inet_csk(sk);
struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
struct request_sock *req;
u32 hash = inet6_synq_hash(raddr, rport, lopt->hash_rnd,
lopt->nr_table_entries);
spin_lock(&icsk->icsk_accept_queue.syn_wait_lock);
for (req = lopt->syn_table[hash]; req != NULL; req = req->dl_next) {
const struct inet_request_sock *ireq = inet_rsk(req);
if (ireq->ir_rmt_port == rport &&
req->rsk_ops->family == AF_INET6 &&
ipv6_addr_equal(&ireq->ir_v6_rmt_addr, raddr) &&
ipv6_addr_equal(&ireq->ir_v6_loc_addr, laddr) &&
(!ireq->ir_iif || ireq->ir_iif == iif)) {
atomic_inc(&req->rsk_refcnt);
WARN_ON(req->sk != NULL);
break;
}
}
spin_unlock(&icsk->icsk_accept_queue.syn_wait_lock);
return req;
}
EXPORT_SYMBOL_GPL(inet6_csk_search_req);
void inet6_csk_reqsk_queue_hash_add(struct sock *sk,
struct request_sock *req,
const unsigned long timeout)
{
struct inet_connection_sock *icsk = inet_csk(sk);
struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
const u32 h = inet6_synq_hash(&inet_rsk(req)->ir_v6_rmt_addr,
inet_rsk(req)->ir_rmt_port,
lopt->hash_rnd, lopt->nr_table_entries);
reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
inet_csk_reqsk_queue_added(sk, timeout);
}
EXPORT_SYMBOL_GPL(inet6_csk_reqsk_queue_hash_add);
void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
{
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
sin6->sin6_family = AF_INET6;
sin6->sin6_addr = sk->sk_v6_daddr;
sin6->sin6_port = inet_sk(sk)->inet_dport;
/* We do not store received flowlabel for TCP */
sin6->sin6_flowinfo = 0;
sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr,
sk->sk_bound_dev_if);
}
EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
static inline
void __inet6_csk_dst_store(struct sock *sk, struct dst_entry *dst,
const struct in6_addr *daddr,
const struct in6_addr *saddr)
{
__ip6_dst_store(sk, dst, daddr, saddr);
}
static inline
struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
{
return __sk_dst_check(sk, cookie);
}
static struct dst_entry *inet6_csk_route_socket(struct sock *sk,
struct flowi6 *fl6)
{
struct inet_sock *inet = inet_sk(sk);
struct ipv6_pinfo *np = inet6_sk(sk);
struct in6_addr *final_p, final;
struct dst_entry *dst;
memset(fl6, 0, sizeof(*fl6));
fl6->flowi6_proto = sk->sk_protocol;
fl6->daddr = sk->sk_v6_daddr;
fl6->saddr = np->saddr;
fl6->flowlabel = np->flow_label;
IP6_ECN_flow_xmit(sk, fl6->flowlabel);
fl6->flowi6_oif = sk->sk_bound_dev_if;
fl6->flowi6_mark = sk->sk_mark;
fl6->fl6_sport = inet->inet_sport;
fl6->fl6_dport = inet->inet_dport;
security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
final_p = fl6_update_dst(fl6, np->opt, &final);
dst = __inet6_csk_dst_check(sk, np->dst_cookie);
if (!dst) {
dst = ip6_dst_lookup_flow(sk, fl6, final_p);
if (!IS_ERR(dst))
__inet6_csk_dst_store(sk, dst, NULL, NULL);
}
return dst;
}
int inet6_csk_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl_unused)
{
struct ipv6_pinfo *np = inet6_sk(sk);
struct flowi6 fl6;
struct dst_entry *dst;
int res;
dst = inet6_csk_route_socket(sk, &fl6);
if (IS_ERR(dst)) {
sk->sk_err_soft = -PTR_ERR(dst);
sk->sk_route_caps = 0;
kfree_skb(skb);
return PTR_ERR(dst);
}
rcu_read_lock();
skb_dst_set_noref(skb, dst);
/* Restore final destination back after routing done */
fl6.daddr = sk->sk_v6_daddr;
res = ip6_xmit(sk, skb, &fl6, np->opt, np->tclass);
rcu_read_unlock();
return res;
}
EXPORT_SYMBOL_GPL(inet6_csk_xmit);
struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu)
{
struct flowi6 fl6;
struct dst_entry *dst = inet6_csk_route_socket(sk, &fl6);
if (IS_ERR(dst))
return NULL;
dst->ops->update_pmtu(dst, sk, NULL, mtu);
dst = inet6_csk_route_socket(sk, &fl6);
return IS_ERR(dst) ? NULL : dst;
}
EXPORT_SYMBOL_GPL(inet6_csk_update_pmtu);