blob: 92f2c6772fa8d4c57d7466c8aea9940a738604f9 [file] [log] [blame]
/*
* Protocol registration and listener management functions.
*
* Copyright 2000-2010 Willy Tarreau <w@1wt.eu>
*
* 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 <stdio.h>
#include <string.h>
#include <common/config.h>
#include <common/errors.h>
#include <common/mini-clist.h>
#include <common/standard.h>
#include <proto/acl.h>
#include <proto/fd.h>
/* List head of all registered protocols */
static struct list protocols = LIST_HEAD_INIT(protocols);
/* This function adds the specified listener's file descriptor to the polling
* lists if it is in the LI_LISTEN state. The listener enters LI_READY or
* LI_FULL state depending on its number of connections.
*/
void enable_listener(struct listener *listener)
{
if (listener->state == LI_LISTEN) {
if (listener->nbconn < listener->maxconn) {
EV_FD_SET(listener->fd, DIR_RD);
listener->state = LI_READY;
} else {
listener->state = LI_FULL;
}
}
}
/* This function removes the specified listener's file descriptor from the
* polling lists if it is in the LI_READY or in the LI_FULL state. The listener
* enters LI_LISTEN.
*/
void disable_listener(struct listener *listener)
{
if (listener->state < LI_READY)
return;
if (listener->state == LI_READY)
EV_FD_CLR(listener->fd, DIR_RD);
if (listener->state == LI_LIMITED)
LIST_DEL(&listener->wait_queue);
listener->state = LI_LISTEN;
}
/* This function tries to temporarily disable a listener, depending on the OS
* capabilities. Linux unbinds the listen socket after a SHUT_RD, and ignores
* SHUT_WR. Solaris refuses either shutdown(). OpenBSD ignores SHUT_RD but
* closes upon SHUT_WR and refuses to rebind. So a common validation path
* involves SHUT_WR && listen && SHUT_RD. In case of success, the FD's polling
* is disabled. It normally returns non-zero, unless an error is reported.
*/
int pause_listener(struct listener *l)
{
if (l->state <= LI_PAUSED)
return 1;
if (shutdown(l->fd, SHUT_WR) != 0)
return 0; /* Solaris dies here */
if (listen(l->fd, l->backlog ? l->backlog : l->maxconn) != 0)
return 0; /* OpenBSD dies here */
if (shutdown(l->fd, SHUT_RD) != 0)
return 0; /* should always be OK */
if (l->state == LI_LIMITED)
LIST_DEL(&l->wait_queue);
EV_FD_CLR(l->fd, DIR_RD);
l->state = LI_PAUSED;
return 1;
}
/* This function tries to resume a temporarily disabled listener. Paused, full,
* limited and disabled listeners are handled, which means that this function
* may replace enable_listener(). The resulting state will either be LI_READY
* or LI_FULL. 0 is returned in case of failure to resume (eg: dead socket).
*/
int resume_listener(struct listener *l)
{
if (l->state < LI_PAUSED)
return 0;
if (l->state == LI_PAUSED &&
listen(l->fd, l->backlog ? l->backlog : l->maxconn) != 0)
return 0;
if (l->state == LI_READY)
return 1;
if (l->state == LI_LIMITED)
LIST_DEL(&l->wait_queue);
if (l->nbconn >= l->maxconn) {
l->state = LI_FULL;
return 1;
}
EV_FD_SET(l->fd, DIR_RD);
l->state = LI_READY;
return 1;
}
/* Marks a ready listener as full so that the session code tries to re-enable
* it upon next close() using resume_listener().
*/
void listener_full(struct listener *l)
{
if (l->state >= LI_READY) {
if (l->state == LI_LIMITED)
LIST_DEL(&l->wait_queue);
EV_FD_CLR(l->fd, DIR_RD);
l->state = LI_FULL;
}
}
/* Marks a ready listener as limited so that we only try to re-enable it when
* resources are free again. It will be queued into the specified queue.
*/
void limit_listener(struct listener *l, struct list *list)
{
if (l->state == LI_READY) {
LIST_ADDQ(list, &l->wait_queue);
EV_FD_CLR(l->fd, DIR_RD);
l->state = LI_LIMITED;
}
}
/* This function adds all of the protocol's listener's file descriptors to the
* polling lists when they are in the LI_LISTEN state. It is intended to be
* used as a protocol's generic enable_all() primitive, for use after the
* fork(). It puts the listeners into LI_READY or LI_FULL states depending on
* their number of connections. It always returns ERR_NONE.
*/
int enable_all_listeners(struct protocol *proto)
{
struct listener *listener;
list_for_each_entry(listener, &proto->listeners, proto_list)
enable_listener(listener);
return ERR_NONE;
}
/* This function removes all of the protocol's listener's file descriptors from
* the polling lists when they are in the LI_READY or LI_FULL states. It is
* intended to be used as a protocol's generic disable_all() primitive. It puts
* the listeners into LI_LISTEN, and always returns ERR_NONE.
*/
int disable_all_listeners(struct protocol *proto)
{
struct listener *listener;
list_for_each_entry(listener, &proto->listeners, proto_list)
disable_listener(listener);
return ERR_NONE;
}
/* Dequeues all of the listeners waiting for a resource in wait queue <queue>. */
void dequeue_all_listeners(struct list *list)
{
struct listener *listener, *l_back;
list_for_each_entry_safe(listener, l_back, list, wait_queue) {
/* This cannot fail because the listeners are by definition in
* the LI_LIMITED state. The function also removes the entry
* from the queue.
*/
resume_listener(listener);
}
}
/* This function closes the listening socket for the specified listener,
* provided that it's already in a listening state. The listener enters the
* LI_ASSIGNED state. It always returns ERR_NONE. This function is intended
* to be used as a generic function for standard protocols.
*/
int unbind_listener(struct listener *listener)
{
if (listener->state == LI_READY)
EV_FD_CLR(listener->fd, DIR_RD);
if (listener->state == LI_LIMITED)
LIST_DEL(&listener->wait_queue);
if (listener->state >= LI_PAUSED) {
fd_delete(listener->fd);
listener->state = LI_ASSIGNED;
}
return ERR_NONE;
}
/* This function closes all listening sockets bound to the protocol <proto>,
* and the listeners end in LI_ASSIGNED state if they were higher. It does not
* detach them from the protocol. It always returns ERR_NONE.
*/
int unbind_all_listeners(struct protocol *proto)
{
struct listener *listener;
list_for_each_entry(listener, &proto->listeners, proto_list)
unbind_listener(listener);
return ERR_NONE;
}
/* Delete a listener from its protocol's list of listeners. The listener's
* state is automatically updated from LI_ASSIGNED to LI_INIT. The protocol's
* number of listeners is updated. Note that the listener must have previously
* been unbound. This is the generic function to use to remove a listener.
*/
void delete_listener(struct listener *listener)
{
if (listener->state != LI_ASSIGNED)
return;
listener->state = LI_INIT;
LIST_DEL(&listener->proto_list);
listener->proto->nb_listeners--;
}
/* Registers the protocol <proto> */
void protocol_register(struct protocol *proto)
{
LIST_ADDQ(&protocols, &proto->list);
}
/* Unregisters the protocol <proto>. Note that all listeners must have
* previously been unbound.
*/
void protocol_unregister(struct protocol *proto)
{
LIST_DEL(&proto->list);
LIST_INIT(&proto->list);
}
/* binds all listeners of all registered protocols. Returns a composition
* of ERR_NONE, ERR_RETRYABLE, ERR_FATAL.
*/
int protocol_bind_all(char *errmsg, int errlen)
{
struct protocol *proto;
int err;
err = 0;
list_for_each_entry(proto, &protocols, list) {
if (proto->bind_all) {
err |= proto->bind_all(proto, errmsg, errlen);
if ( err & ERR_ABORT )
break;
}
}
return err;
}
/* unbinds all listeners of all registered protocols. They are also closed.
* This must be performed before calling exit() in order to get a chance to
* remove file-system based sockets and pipes.
* Returns a composition of ERR_NONE, ERR_RETRYABLE, ERR_FATAL, ERR_ABORT.
*/
int protocol_unbind_all(void)
{
struct protocol *proto;
int err;
err = 0;
list_for_each_entry(proto, &protocols, list) {
if (proto->unbind_all) {
err |= proto->unbind_all(proto);
}
}
return err;
}
/* enables all listeners of all registered protocols. This is intended to be
* used after a fork() to enable reading on all file descriptors. Returns a
* composition of ERR_NONE, ERR_RETRYABLE, ERR_FATAL.
*/
int protocol_enable_all(void)
{
struct protocol *proto;
int err;
err = 0;
list_for_each_entry(proto, &protocols, list) {
if (proto->enable_all) {
err |= proto->enable_all(proto);
}
}
return err;
}
/* disables all listeners of all registered protocols. This may be used before
* a fork() to avoid duplicating poll lists. Returns a composition of ERR_NONE,
* ERR_RETRYABLE, ERR_FATAL.
*/
int protocol_disable_all(void)
{
struct protocol *proto;
int err;
err = 0;
list_for_each_entry(proto, &protocols, list) {
if (proto->disable_all) {
err |= proto->disable_all(proto);
}
}
return err;
}
/************************************************************************/
/* All supported ACL keywords must be declared here. */
/************************************************************************/
/* set temp integer to the number of connexions to the same listening socket */
static int
acl_fetch_dconn(struct proxy *px, struct session *l4, void *l7, int dir,
struct acl_expr *expr, struct acl_test *test)
{
temp_pattern.data.integer = l4->listener->nbconn;
return 1;
}
/* set temp integer to the id of the socket (listener) */
static int
acl_fetch_so_id(struct proxy *px, struct session *l4, void *l7, int dir,
struct acl_expr *expr, struct acl_test *test) {
test->flags = ACL_TEST_F_READ_ONLY;
temp_pattern.data.integer = l4->listener->luid;
return 1;
}
/* Note: must not be declared <const> as its list will be overwritten */
static struct acl_kw_list acl_kws = {{ },{
{ "dst_conn", acl_parse_int, acl_fetch_dconn, acl_match_int, ACL_USE_NOTHING },
{ "so_id", acl_parse_int, acl_fetch_so_id, acl_match_int, ACL_USE_NOTHING },
{ NULL, NULL, NULL, NULL },
}};
__attribute__((constructor))
static void __protocols_init(void)
{
acl_register_keywords(&acl_kws);
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/