![Craig Gallek](/assets/img/avatar_default.png)
In order to support fast reuseport lookups in TCP, the hash function defined in struct proto must be capable of returning an error code. This patch changes the function signature of all related hash functions to return an integer and handles or propagates this return value at all call sites. Signed-off-by: Craig Gallek <kraig@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
965 lines
27 KiB
C
965 lines
27 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 INET connection oriented protocols.
|
|
*
|
|
* Authors: See the TCP 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/jhash.h>
|
|
|
|
#include <net/inet_connection_sock.h>
|
|
#include <net/inet_hashtables.h>
|
|
#include <net/inet_timewait_sock.h>
|
|
#include <net/ip.h>
|
|
#include <net/route.h>
|
|
#include <net/tcp_states.h>
|
|
#include <net/xfrm.h>
|
|
#include <net/tcp.h>
|
|
|
|
#ifdef INET_CSK_DEBUG
|
|
const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n";
|
|
EXPORT_SYMBOL(inet_csk_timer_bug_msg);
|
|
#endif
|
|
|
|
void inet_get_local_port_range(struct net *net, int *low, int *high)
|
|
{
|
|
unsigned int seq;
|
|
|
|
do {
|
|
seq = read_seqbegin(&net->ipv4.ip_local_ports.lock);
|
|
|
|
*low = net->ipv4.ip_local_ports.range[0];
|
|
*high = net->ipv4.ip_local_ports.range[1];
|
|
} while (read_seqretry(&net->ipv4.ip_local_ports.lock, seq));
|
|
}
|
|
EXPORT_SYMBOL(inet_get_local_port_range);
|
|
|
|
int inet_csk_bind_conflict(const struct sock *sk,
|
|
const struct inet_bind_bucket *tb, bool relax)
|
|
{
|
|
struct sock *sk2;
|
|
int reuse = sk->sk_reuse;
|
|
int reuseport = sk->sk_reuseport;
|
|
kuid_t uid = sock_i_uid((struct sock *)sk);
|
|
|
|
/*
|
|
* Unlike other sk lookup places we do not check
|
|
* for sk_net here, since _all_ the socks listed
|
|
* in tb->owners list belong to the same net - the
|
|
* one this bucket belongs to.
|
|
*/
|
|
|
|
sk_for_each_bound(sk2, &tb->owners) {
|
|
if (sk != sk2 &&
|
|
!inet_v6_ipv6only(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(sk2))))) {
|
|
|
|
if (!sk2->sk_rcv_saddr || !sk->sk_rcv_saddr ||
|
|
sk2->sk_rcv_saddr == sk->sk_rcv_saddr)
|
|
break;
|
|
}
|
|
if (!relax && reuse && sk2->sk_reuse &&
|
|
sk2->sk_state != TCP_LISTEN) {
|
|
|
|
if (!sk2->sk_rcv_saddr || !sk->sk_rcv_saddr ||
|
|
sk2->sk_rcv_saddr == sk->sk_rcv_saddr)
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
return sk2 != NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
|
|
|
|
/* Obtain a reference to a local port for the given sock,
|
|
* if snum is zero it means select any available local port.
|
|
*/
|
|
int inet_csk_get_port(struct sock *sk, unsigned short snum)
|
|
{
|
|
struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
|
|
struct inet_bind_hashbucket *head;
|
|
struct inet_bind_bucket *tb;
|
|
int ret, attempts = 5;
|
|
struct net *net = sock_net(sk);
|
|
int smallest_size = -1, smallest_rover;
|
|
kuid_t uid = sock_i_uid(sk);
|
|
int attempt_half = (sk->sk_reuse == SK_CAN_REUSE) ? 1 : 0;
|
|
|
|
local_bh_disable();
|
|
if (!snum) {
|
|
int remaining, rover, low, high;
|
|
|
|
again:
|
|
inet_get_local_port_range(net, &low, &high);
|
|
if (attempt_half) {
|
|
int half = low + ((high - low) >> 1);
|
|
|
|
if (attempt_half == 1)
|
|
high = half;
|
|
else
|
|
low = half;
|
|
}
|
|
remaining = (high - low) + 1;
|
|
smallest_rover = rover = prandom_u32() % remaining + low;
|
|
|
|
smallest_size = -1;
|
|
do {
|
|
if (inet_is_local_reserved_port(net, rover))
|
|
goto next_nolock;
|
|
head = &hashinfo->bhash[inet_bhashfn(net, rover,
|
|
hashinfo->bhash_size)];
|
|
spin_lock(&head->lock);
|
|
inet_bind_bucket_for_each(tb, &head->chain)
|
|
if (net_eq(ib_net(tb), net) && tb->port == rover) {
|
|
if (((tb->fastreuse > 0 &&
|
|
sk->sk_reuse &&
|
|
sk->sk_state != TCP_LISTEN) ||
|
|
(tb->fastreuseport > 0 &&
|
|
sk->sk_reuseport &&
|
|
uid_eq(tb->fastuid, uid))) &&
|
|
(tb->num_owners < smallest_size || smallest_size == -1)) {
|
|
smallest_size = tb->num_owners;
|
|
smallest_rover = rover;
|
|
}
|
|
if (!inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) {
|
|
snum = rover;
|
|
goto tb_found;
|
|
}
|
|
goto next;
|
|
}
|
|
break;
|
|
next:
|
|
spin_unlock(&head->lock);
|
|
next_nolock:
|
|
if (++rover > high)
|
|
rover = low;
|
|
} while (--remaining > 0);
|
|
|
|
/* Exhausted local port range during search? It is not
|
|
* possible for us to be holding one of the bind hash
|
|
* locks if this test triggers, because if 'remaining'
|
|
* drops to zero, we broke out of the do/while loop at
|
|
* the top level, not from the 'break;' statement.
|
|
*/
|
|
ret = 1;
|
|
if (remaining <= 0) {
|
|
if (smallest_size != -1) {
|
|
snum = smallest_rover;
|
|
goto have_snum;
|
|
}
|
|
if (attempt_half == 1) {
|
|
/* OK we now try the upper half of the range */
|
|
attempt_half = 2;
|
|
goto again;
|
|
}
|
|
goto fail;
|
|
}
|
|
/* OK, here is the one we will use. HEAD is
|
|
* non-NULL and we hold it's mutex.
|
|
*/
|
|
snum = rover;
|
|
} else {
|
|
have_snum:
|
|
head = &hashinfo->bhash[inet_bhashfn(net, snum,
|
|
hashinfo->bhash_size)];
|
|
spin_lock(&head->lock);
|
|
inet_bind_bucket_for_each(tb, &head->chain)
|
|
if (net_eq(ib_net(tb), net) && tb->port == snum)
|
|
goto tb_found;
|
|
}
|
|
tb = NULL;
|
|
goto tb_not_found;
|
|
tb_found:
|
|
if (!hlist_empty(&tb->owners)) {
|
|
if (sk->sk_reuse == SK_FORCE_REUSE)
|
|
goto success;
|
|
|
|
if (((tb->fastreuse > 0 &&
|
|
sk->sk_reuse && sk->sk_state != TCP_LISTEN) ||
|
|
(tb->fastreuseport > 0 &&
|
|
sk->sk_reuseport && uid_eq(tb->fastuid, uid))) &&
|
|
smallest_size == -1) {
|
|
goto success;
|
|
} else {
|
|
ret = 1;
|
|
if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, true)) {
|
|
if (((sk->sk_reuse && sk->sk_state != TCP_LISTEN) ||
|
|
(tb->fastreuseport > 0 &&
|
|
sk->sk_reuseport && uid_eq(tb->fastuid, uid))) &&
|
|
smallest_size != -1 && --attempts >= 0) {
|
|
spin_unlock(&head->lock);
|
|
goto again;
|
|
}
|
|
|
|
goto fail_unlock;
|
|
}
|
|
}
|
|
}
|
|
tb_not_found:
|
|
ret = 1;
|
|
if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep,
|
|
net, head, snum)) == NULL)
|
|
goto fail_unlock;
|
|
if (hlist_empty(&tb->owners)) {
|
|
if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
|
|
tb->fastreuse = 1;
|
|
else
|
|
tb->fastreuse = 0;
|
|
if (sk->sk_reuseport) {
|
|
tb->fastreuseport = 1;
|
|
tb->fastuid = uid;
|
|
} else
|
|
tb->fastreuseport = 0;
|
|
} else {
|
|
if (tb->fastreuse &&
|
|
(!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
|
|
tb->fastreuse = 0;
|
|
if (tb->fastreuseport &&
|
|
(!sk->sk_reuseport || !uid_eq(tb->fastuid, uid)))
|
|
tb->fastreuseport = 0;
|
|
}
|
|
success:
|
|
if (!inet_csk(sk)->icsk_bind_hash)
|
|
inet_bind_hash(sk, tb, snum);
|
|
WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
|
|
ret = 0;
|
|
|
|
fail_unlock:
|
|
spin_unlock(&head->lock);
|
|
fail:
|
|
local_bh_enable();
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_get_port);
|
|
|
|
/*
|
|
* Wait for an incoming connection, avoid race conditions. This must be called
|
|
* with the socket locked.
|
|
*/
|
|
static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
DEFINE_WAIT(wait);
|
|
int err;
|
|
|
|
/*
|
|
* True wake-one mechanism for incoming connections: only
|
|
* one process gets woken up, not the 'whole herd'.
|
|
* Since we do not 'race & poll' for established sockets
|
|
* anymore, the common case will execute the loop only once.
|
|
*
|
|
* Subtle issue: "add_wait_queue_exclusive()" will be added
|
|
* after any current non-exclusive waiters, and we know that
|
|
* it will always _stay_ after any new non-exclusive waiters
|
|
* because all non-exclusive waiters are added at the
|
|
* beginning of the wait-queue. As such, it's ok to "drop"
|
|
* our exclusiveness temporarily when we get woken up without
|
|
* having to remove and re-insert us on the wait queue.
|
|
*/
|
|
for (;;) {
|
|
prepare_to_wait_exclusive(sk_sleep(sk), &wait,
|
|
TASK_INTERRUPTIBLE);
|
|
release_sock(sk);
|
|
if (reqsk_queue_empty(&icsk->icsk_accept_queue))
|
|
timeo = schedule_timeout(timeo);
|
|
sched_annotate_sleep();
|
|
lock_sock(sk);
|
|
err = 0;
|
|
if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
|
|
break;
|
|
err = -EINVAL;
|
|
if (sk->sk_state != TCP_LISTEN)
|
|
break;
|
|
err = sock_intr_errno(timeo);
|
|
if (signal_pending(current))
|
|
break;
|
|
err = -EAGAIN;
|
|
if (!timeo)
|
|
break;
|
|
}
|
|
finish_wait(sk_sleep(sk), &wait);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* This will accept the next outstanding connection.
|
|
*/
|
|
struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
struct request_sock_queue *queue = &icsk->icsk_accept_queue;
|
|
struct request_sock *req;
|
|
struct sock *newsk;
|
|
int error;
|
|
|
|
lock_sock(sk);
|
|
|
|
/* We need to make sure that this socket is listening,
|
|
* and that it has something pending.
|
|
*/
|
|
error = -EINVAL;
|
|
if (sk->sk_state != TCP_LISTEN)
|
|
goto out_err;
|
|
|
|
/* Find already established connection */
|
|
if (reqsk_queue_empty(queue)) {
|
|
long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
|
|
|
|
/* If this is a non blocking socket don't sleep */
|
|
error = -EAGAIN;
|
|
if (!timeo)
|
|
goto out_err;
|
|
|
|
error = inet_csk_wait_for_connect(sk, timeo);
|
|
if (error)
|
|
goto out_err;
|
|
}
|
|
req = reqsk_queue_remove(queue, sk);
|
|
newsk = req->sk;
|
|
|
|
if (sk->sk_protocol == IPPROTO_TCP &&
|
|
tcp_rsk(req)->tfo_listener) {
|
|
spin_lock_bh(&queue->fastopenq.lock);
|
|
if (tcp_rsk(req)->tfo_listener) {
|
|
/* We are still waiting for the final ACK from 3WHS
|
|
* so can't free req now. Instead, we set req->sk to
|
|
* NULL to signify that the child socket is taken
|
|
* so reqsk_fastopen_remove() will free the req
|
|
* when 3WHS finishes (or is aborted).
|
|
*/
|
|
req->sk = NULL;
|
|
req = NULL;
|
|
}
|
|
spin_unlock_bh(&queue->fastopenq.lock);
|
|
}
|
|
out:
|
|
release_sock(sk);
|
|
if (req)
|
|
reqsk_put(req);
|
|
return newsk;
|
|
out_err:
|
|
newsk = NULL;
|
|
req = NULL;
|
|
*err = error;
|
|
goto out;
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_accept);
|
|
|
|
/*
|
|
* Using different timers for retransmit, delayed acks and probes
|
|
* We may wish use just one timer maintaining a list of expire jiffies
|
|
* to optimize.
|
|
*/
|
|
void inet_csk_init_xmit_timers(struct sock *sk,
|
|
void (*retransmit_handler)(unsigned long),
|
|
void (*delack_handler)(unsigned long),
|
|
void (*keepalive_handler)(unsigned long))
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
|
|
setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler,
|
|
(unsigned long)sk);
|
|
setup_timer(&icsk->icsk_delack_timer, delack_handler,
|
|
(unsigned long)sk);
|
|
setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk);
|
|
icsk->icsk_pending = icsk->icsk_ack.pending = 0;
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_init_xmit_timers);
|
|
|
|
void inet_csk_clear_xmit_timers(struct sock *sk)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
|
|
icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
|
|
|
|
sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
|
|
sk_stop_timer(sk, &icsk->icsk_delack_timer);
|
|
sk_stop_timer(sk, &sk->sk_timer);
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
|
|
|
|
void inet_csk_delete_keepalive_timer(struct sock *sk)
|
|
{
|
|
sk_stop_timer(sk, &sk->sk_timer);
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
|
|
|
|
void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
|
|
{
|
|
sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
|
|
|
|
struct dst_entry *inet_csk_route_req(const struct sock *sk,
|
|
struct flowi4 *fl4,
|
|
const struct request_sock *req)
|
|
{
|
|
const struct inet_request_sock *ireq = inet_rsk(req);
|
|
struct net *net = read_pnet(&ireq->ireq_net);
|
|
struct ip_options_rcu *opt = ireq->opt;
|
|
struct rtable *rt;
|
|
|
|
flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
|
|
RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
|
|
sk->sk_protocol, inet_sk_flowi_flags(sk),
|
|
(opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
|
|
ireq->ir_loc_addr, ireq->ir_rmt_port,
|
|
htons(ireq->ir_num));
|
|
security_req_classify_flow(req, flowi4_to_flowi(fl4));
|
|
rt = ip_route_output_flow(net, fl4, sk);
|
|
if (IS_ERR(rt))
|
|
goto no_route;
|
|
if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
|
|
goto route_err;
|
|
return &rt->dst;
|
|
|
|
route_err:
|
|
ip_rt_put(rt);
|
|
no_route:
|
|
IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_route_req);
|
|
|
|
struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
|
|
struct sock *newsk,
|
|
const struct request_sock *req)
|
|
{
|
|
const struct inet_request_sock *ireq = inet_rsk(req);
|
|
struct net *net = read_pnet(&ireq->ireq_net);
|
|
struct inet_sock *newinet = inet_sk(newsk);
|
|
struct ip_options_rcu *opt;
|
|
struct flowi4 *fl4;
|
|
struct rtable *rt;
|
|
|
|
fl4 = &newinet->cork.fl.u.ip4;
|
|
|
|
rcu_read_lock();
|
|
opt = rcu_dereference(newinet->inet_opt);
|
|
flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark,
|
|
RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
|
|
sk->sk_protocol, inet_sk_flowi_flags(sk),
|
|
(opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr,
|
|
ireq->ir_loc_addr, ireq->ir_rmt_port,
|
|
htons(ireq->ir_num));
|
|
security_req_classify_flow(req, flowi4_to_flowi(fl4));
|
|
rt = ip_route_output_flow(net, fl4, sk);
|
|
if (IS_ERR(rt))
|
|
goto no_route;
|
|
if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway)
|
|
goto route_err;
|
|
rcu_read_unlock();
|
|
return &rt->dst;
|
|
|
|
route_err:
|
|
ip_rt_put(rt);
|
|
no_route:
|
|
rcu_read_unlock();
|
|
IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_route_child_sock);
|
|
|
|
#if IS_ENABLED(CONFIG_IPV6)
|
|
#define AF_INET_FAMILY(fam) ((fam) == AF_INET)
|
|
#else
|
|
#define AF_INET_FAMILY(fam) true
|
|
#endif
|
|
|
|
/* Decide when to expire the request and when to resend SYN-ACK */
|
|
static inline void syn_ack_recalc(struct request_sock *req, const int thresh,
|
|
const int max_retries,
|
|
const u8 rskq_defer_accept,
|
|
int *expire, int *resend)
|
|
{
|
|
if (!rskq_defer_accept) {
|
|
*expire = req->num_timeout >= thresh;
|
|
*resend = 1;
|
|
return;
|
|
}
|
|
*expire = req->num_timeout >= thresh &&
|
|
(!inet_rsk(req)->acked || req->num_timeout >= max_retries);
|
|
/*
|
|
* Do not resend while waiting for data after ACK,
|
|
* start to resend on end of deferring period to give
|
|
* last chance for data or ACK to create established socket.
|
|
*/
|
|
*resend = !inet_rsk(req)->acked ||
|
|
req->num_timeout >= rskq_defer_accept - 1;
|
|
}
|
|
|
|
int inet_rtx_syn_ack(const struct sock *parent, struct request_sock *req)
|
|
{
|
|
int err = req->rsk_ops->rtx_syn_ack(parent, req);
|
|
|
|
if (!err)
|
|
req->num_retrans++;
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(inet_rtx_syn_ack);
|
|
|
|
/* return true if req was found in the ehash table */
|
|
static bool reqsk_queue_unlink(struct request_sock_queue *queue,
|
|
struct request_sock *req)
|
|
{
|
|
struct inet_hashinfo *hashinfo = req_to_sk(req)->sk_prot->h.hashinfo;
|
|
bool found = false;
|
|
|
|
if (sk_hashed(req_to_sk(req))) {
|
|
spinlock_t *lock = inet_ehash_lockp(hashinfo, req->rsk_hash);
|
|
|
|
spin_lock(lock);
|
|
found = __sk_nulls_del_node_init_rcu(req_to_sk(req));
|
|
spin_unlock(lock);
|
|
}
|
|
if (timer_pending(&req->rsk_timer) && del_timer_sync(&req->rsk_timer))
|
|
reqsk_put(req);
|
|
return found;
|
|
}
|
|
|
|
void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req)
|
|
{
|
|
if (reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req)) {
|
|
reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
|
|
reqsk_put(req);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_reqsk_queue_drop);
|
|
|
|
void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req)
|
|
{
|
|
inet_csk_reqsk_queue_drop(sk, req);
|
|
reqsk_put(req);
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_reqsk_queue_drop_and_put);
|
|
|
|
static void reqsk_timer_handler(unsigned long data)
|
|
{
|
|
struct request_sock *req = (struct request_sock *)data;
|
|
struct sock *sk_listener = req->rsk_listener;
|
|
struct net *net = sock_net(sk_listener);
|
|
struct inet_connection_sock *icsk = inet_csk(sk_listener);
|
|
struct request_sock_queue *queue = &icsk->icsk_accept_queue;
|
|
int qlen, expire = 0, resend = 0;
|
|
int max_retries, thresh;
|
|
u8 defer_accept;
|
|
|
|
if (sk_state_load(sk_listener) != TCP_LISTEN)
|
|
goto drop;
|
|
|
|
max_retries = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_synack_retries;
|
|
thresh = max_retries;
|
|
/* Normally all the openreqs are young and become mature
|
|
* (i.e. converted to established socket) for first timeout.
|
|
* If synack was not acknowledged for 1 second, it means
|
|
* one of the following things: synack was lost, ack was lost,
|
|
* rtt is high or nobody planned to ack (i.e. synflood).
|
|
* When server is a bit loaded, queue is populated with old
|
|
* open requests, reducing effective size of queue.
|
|
* When server is well loaded, queue size reduces to zero
|
|
* after several minutes of work. It is not synflood,
|
|
* it is normal operation. The solution is pruning
|
|
* too old entries overriding normal timeout, when
|
|
* situation becomes dangerous.
|
|
*
|
|
* Essentially, we reserve half of room for young
|
|
* embrions; and abort old ones without pity, if old
|
|
* ones are about to clog our table.
|
|
*/
|
|
qlen = reqsk_queue_len(queue);
|
|
if ((qlen << 1) > max(8U, sk_listener->sk_max_ack_backlog)) {
|
|
int young = reqsk_queue_len_young(queue) << 1;
|
|
|
|
while (thresh > 2) {
|
|
if (qlen < young)
|
|
break;
|
|
thresh--;
|
|
young <<= 1;
|
|
}
|
|
}
|
|
defer_accept = READ_ONCE(queue->rskq_defer_accept);
|
|
if (defer_accept)
|
|
max_retries = defer_accept;
|
|
syn_ack_recalc(req, thresh, max_retries, defer_accept,
|
|
&expire, &resend);
|
|
req->rsk_ops->syn_ack_timeout(req);
|
|
if (!expire &&
|
|
(!resend ||
|
|
!inet_rtx_syn_ack(sk_listener, req) ||
|
|
inet_rsk(req)->acked)) {
|
|
unsigned long timeo;
|
|
|
|
if (req->num_timeout++ == 0)
|
|
atomic_dec(&queue->young);
|
|
timeo = min(TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX);
|
|
mod_timer_pinned(&req->rsk_timer, jiffies + timeo);
|
|
return;
|
|
}
|
|
drop:
|
|
inet_csk_reqsk_queue_drop_and_put(sk_listener, req);
|
|
}
|
|
|
|
static void reqsk_queue_hash_req(struct request_sock *req,
|
|
unsigned long timeout)
|
|
{
|
|
req->num_retrans = 0;
|
|
req->num_timeout = 0;
|
|
req->sk = NULL;
|
|
|
|
setup_timer(&req->rsk_timer, reqsk_timer_handler, (unsigned long)req);
|
|
mod_timer_pinned(&req->rsk_timer, jiffies + timeout);
|
|
|
|
inet_ehash_insert(req_to_sk(req), NULL);
|
|
/* before letting lookups find us, make sure all req fields
|
|
* are committed to memory and refcnt initialized.
|
|
*/
|
|
smp_wmb();
|
|
atomic_set(&req->rsk_refcnt, 2 + 1);
|
|
}
|
|
|
|
void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
|
|
unsigned long timeout)
|
|
{
|
|
reqsk_queue_hash_req(req, timeout);
|
|
inet_csk_reqsk_queue_added(sk);
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
|
|
|
|
/**
|
|
* inet_csk_clone_lock - clone an inet socket, and lock its clone
|
|
* @sk: the socket to clone
|
|
* @req: request_sock
|
|
* @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
|
|
*
|
|
* Caller must unlock socket even in error path (bh_unlock_sock(newsk))
|
|
*/
|
|
struct sock *inet_csk_clone_lock(const struct sock *sk,
|
|
const struct request_sock *req,
|
|
const gfp_t priority)
|
|
{
|
|
struct sock *newsk = sk_clone_lock(sk, priority);
|
|
|
|
if (newsk) {
|
|
struct inet_connection_sock *newicsk = inet_csk(newsk);
|
|
|
|
newsk->sk_state = TCP_SYN_RECV;
|
|
newicsk->icsk_bind_hash = NULL;
|
|
|
|
inet_sk(newsk)->inet_dport = inet_rsk(req)->ir_rmt_port;
|
|
inet_sk(newsk)->inet_num = inet_rsk(req)->ir_num;
|
|
inet_sk(newsk)->inet_sport = htons(inet_rsk(req)->ir_num);
|
|
newsk->sk_write_space = sk_stream_write_space;
|
|
|
|
newsk->sk_mark = inet_rsk(req)->ir_mark;
|
|
atomic64_set(&newsk->sk_cookie,
|
|
atomic64_read(&inet_rsk(req)->ir_cookie));
|
|
|
|
newicsk->icsk_retransmits = 0;
|
|
newicsk->icsk_backoff = 0;
|
|
newicsk->icsk_probes_out = 0;
|
|
|
|
/* Deinitialize accept_queue to trap illegal accesses. */
|
|
memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
|
|
|
|
security_inet_csk_clone(newsk, req);
|
|
}
|
|
return newsk;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_clone_lock);
|
|
|
|
/*
|
|
* At this point, there should be no process reference to this
|
|
* socket, and thus no user references at all. Therefore we
|
|
* can assume the socket waitqueue is inactive and nobody will
|
|
* try to jump onto it.
|
|
*/
|
|
void inet_csk_destroy_sock(struct sock *sk)
|
|
{
|
|
WARN_ON(sk->sk_state != TCP_CLOSE);
|
|
WARN_ON(!sock_flag(sk, SOCK_DEAD));
|
|
|
|
/* It cannot be in hash table! */
|
|
WARN_ON(!sk_unhashed(sk));
|
|
|
|
/* If it has not 0 inet_sk(sk)->inet_num, it must be bound */
|
|
WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash);
|
|
|
|
sk->sk_prot->destroy(sk);
|
|
|
|
sk_stream_kill_queues(sk);
|
|
|
|
xfrm_sk_free_policy(sk);
|
|
|
|
sk_refcnt_debug_release(sk);
|
|
|
|
percpu_counter_dec(sk->sk_prot->orphan_count);
|
|
sock_put(sk);
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_destroy_sock);
|
|
|
|
/* This function allows to force a closure of a socket after the call to
|
|
* tcp/dccp_create_openreq_child().
|
|
*/
|
|
void inet_csk_prepare_forced_close(struct sock *sk)
|
|
__releases(&sk->sk_lock.slock)
|
|
{
|
|
/* sk_clone_lock locked the socket and set refcnt to 2 */
|
|
bh_unlock_sock(sk);
|
|
sock_put(sk);
|
|
|
|
/* The below has to be done to allow calling inet_csk_destroy_sock */
|
|
sock_set_flag(sk, SOCK_DEAD);
|
|
percpu_counter_inc(sk->sk_prot->orphan_count);
|
|
inet_sk(sk)->inet_num = 0;
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_prepare_forced_close);
|
|
|
|
int inet_csk_listen_start(struct sock *sk, int backlog)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
int err = -EADDRINUSE;
|
|
|
|
reqsk_queue_alloc(&icsk->icsk_accept_queue);
|
|
|
|
sk->sk_max_ack_backlog = backlog;
|
|
sk->sk_ack_backlog = 0;
|
|
inet_csk_delack_init(sk);
|
|
|
|
/* There is race window here: we announce ourselves listening,
|
|
* but this transition is still not validated by get_port().
|
|
* It is OK, because this socket enters to hash table only
|
|
* after validation is complete.
|
|
*/
|
|
sk_state_store(sk, TCP_LISTEN);
|
|
if (!sk->sk_prot->get_port(sk, inet->inet_num)) {
|
|
inet->inet_sport = htons(inet->inet_num);
|
|
|
|
sk_dst_reset(sk);
|
|
err = sk->sk_prot->hash(sk);
|
|
|
|
if (likely(!err))
|
|
return 0;
|
|
}
|
|
|
|
sk->sk_state = TCP_CLOSE;
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_listen_start);
|
|
|
|
static void inet_child_forget(struct sock *sk, struct request_sock *req,
|
|
struct sock *child)
|
|
{
|
|
sk->sk_prot->disconnect(child, O_NONBLOCK);
|
|
|
|
sock_orphan(child);
|
|
|
|
percpu_counter_inc(sk->sk_prot->orphan_count);
|
|
|
|
if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) {
|
|
BUG_ON(tcp_sk(child)->fastopen_rsk != req);
|
|
BUG_ON(sk != req->rsk_listener);
|
|
|
|
/* Paranoid, to prevent race condition if
|
|
* an inbound pkt destined for child is
|
|
* blocked by sock lock in tcp_v4_rcv().
|
|
* Also to satisfy an assertion in
|
|
* tcp_v4_destroy_sock().
|
|
*/
|
|
tcp_sk(child)->fastopen_rsk = NULL;
|
|
}
|
|
inet_csk_destroy_sock(child);
|
|
reqsk_put(req);
|
|
}
|
|
|
|
void inet_csk_reqsk_queue_add(struct sock *sk, struct request_sock *req,
|
|
struct sock *child)
|
|
{
|
|
struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
|
|
|
|
spin_lock(&queue->rskq_lock);
|
|
if (unlikely(sk->sk_state != TCP_LISTEN)) {
|
|
inet_child_forget(sk, req, child);
|
|
} else {
|
|
req->sk = child;
|
|
req->dl_next = NULL;
|
|
if (queue->rskq_accept_head == NULL)
|
|
queue->rskq_accept_head = req;
|
|
else
|
|
queue->rskq_accept_tail->dl_next = req;
|
|
queue->rskq_accept_tail = req;
|
|
sk_acceptq_added(sk);
|
|
}
|
|
spin_unlock(&queue->rskq_lock);
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_reqsk_queue_add);
|
|
|
|
struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
|
|
struct request_sock *req, bool own_req)
|
|
{
|
|
if (own_req) {
|
|
inet_csk_reqsk_queue_drop(sk, req);
|
|
reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req);
|
|
inet_csk_reqsk_queue_add(sk, req, child);
|
|
/* Warning: caller must not call reqsk_put(req);
|
|
* child stole last reference on it.
|
|
*/
|
|
return child;
|
|
}
|
|
/* Too bad, another child took ownership of the request, undo. */
|
|
bh_unlock_sock(child);
|
|
sock_put(child);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(inet_csk_complete_hashdance);
|
|
|
|
/*
|
|
* This routine closes sockets which have been at least partially
|
|
* opened, but not yet accepted.
|
|
*/
|
|
void inet_csk_listen_stop(struct sock *sk)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
struct request_sock_queue *queue = &icsk->icsk_accept_queue;
|
|
struct request_sock *next, *req;
|
|
|
|
/* Following specs, it would be better either to send FIN
|
|
* (and enter FIN-WAIT-1, it is normal close)
|
|
* or to send active reset (abort).
|
|
* Certainly, it is pretty dangerous while synflood, but it is
|
|
* bad justification for our negligence 8)
|
|
* To be honest, we are not able to make either
|
|
* of the variants now. --ANK
|
|
*/
|
|
while ((req = reqsk_queue_remove(queue, sk)) != NULL) {
|
|
struct sock *child = req->sk;
|
|
|
|
local_bh_disable();
|
|
bh_lock_sock(child);
|
|
WARN_ON(sock_owned_by_user(child));
|
|
sock_hold(child);
|
|
|
|
inet_child_forget(sk, req, child);
|
|
bh_unlock_sock(child);
|
|
local_bh_enable();
|
|
sock_put(child);
|
|
|
|
cond_resched();
|
|
}
|
|
if (queue->fastopenq.rskq_rst_head) {
|
|
/* Free all the reqs queued in rskq_rst_head. */
|
|
spin_lock_bh(&queue->fastopenq.lock);
|
|
req = queue->fastopenq.rskq_rst_head;
|
|
queue->fastopenq.rskq_rst_head = NULL;
|
|
spin_unlock_bh(&queue->fastopenq.lock);
|
|
while (req != NULL) {
|
|
next = req->dl_next;
|
|
reqsk_put(req);
|
|
req = next;
|
|
}
|
|
}
|
|
WARN_ON_ONCE(sk->sk_ack_backlog);
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
|
|
|
|
void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
|
|
{
|
|
struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
|
|
const struct inet_sock *inet = inet_sk(sk);
|
|
|
|
sin->sin_family = AF_INET;
|
|
sin->sin_addr.s_addr = inet->inet_daddr;
|
|
sin->sin_port = inet->inet_dport;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
|
|
char __user *optval, int __user *optlen)
|
|
{
|
|
const struct inet_connection_sock *icsk = inet_csk(sk);
|
|
|
|
if (icsk->icsk_af_ops->compat_getsockopt)
|
|
return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
|
|
optval, optlen);
|
|
return icsk->icsk_af_ops->getsockopt(sk, level, optname,
|
|
optval, optlen);
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
|
|
|
|
int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
|
|
char __user *optval, unsigned int optlen)
|
|
{
|
|
const struct inet_connection_sock *icsk = inet_csk(sk);
|
|
|
|
if (icsk->icsk_af_ops->compat_setsockopt)
|
|
return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
|
|
optval, optlen);
|
|
return icsk->icsk_af_ops->setsockopt(sk, level, optname,
|
|
optval, optlen);
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
|
|
#endif
|
|
|
|
static struct dst_entry *inet_csk_rebuild_route(struct sock *sk, struct flowi *fl)
|
|
{
|
|
const struct inet_sock *inet = inet_sk(sk);
|
|
const struct ip_options_rcu *inet_opt;
|
|
__be32 daddr = inet->inet_daddr;
|
|
struct flowi4 *fl4;
|
|
struct rtable *rt;
|
|
|
|
rcu_read_lock();
|
|
inet_opt = rcu_dereference(inet->inet_opt);
|
|
if (inet_opt && inet_opt->opt.srr)
|
|
daddr = inet_opt->opt.faddr;
|
|
fl4 = &fl->u.ip4;
|
|
rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr,
|
|
inet->inet_saddr, inet->inet_dport,
|
|
inet->inet_sport, sk->sk_protocol,
|
|
RT_CONN_FLAGS(sk), sk->sk_bound_dev_if);
|
|
if (IS_ERR(rt))
|
|
rt = NULL;
|
|
if (rt)
|
|
sk_setup_caps(sk, &rt->dst);
|
|
rcu_read_unlock();
|
|
|
|
return &rt->dst;
|
|
}
|
|
|
|
struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu)
|
|
{
|
|
struct dst_entry *dst = __sk_dst_check(sk, 0);
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
|
|
if (!dst) {
|
|
dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
|
|
if (!dst)
|
|
goto out;
|
|
}
|
|
dst->ops->update_pmtu(dst, sk, NULL, mtu);
|
|
|
|
dst = __sk_dst_check(sk, 0);
|
|
if (!dst)
|
|
dst = inet_csk_rebuild_route(sk, &inet->cork.fl);
|
|
out:
|
|
return dst;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_csk_update_pmtu);
|