src/proxy.c - haproxy - Gitiles

 /*
  * Proxy variables and functions.
  *
  * Copyright 2000-2007 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 <fcntl.h>
 #include <unistd.h>
 #include <string.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/stat.h>

 #include <common/defaults.h>
 #include <common/compat.h>
 #include <common/config.h>
 #include <common/errors.h>
 #include <common/memory.h>
 #include <common/time.h>

 #include <types/global.h>
 #include <types/polling.h>

 #include <proto/client.h>
 #include <proto/backend.h>
 #include <proto/fd.h>
 #include <proto/log.h>
 #include <proto/protocols.h>
 #include <proto/proto_tcp.h>
 #include <proto/proxy.h>


 int listeners;	/* # of proxy listeners, set by cfgparse, unset by maintain_proxies */
 struct proxy *proxy  = NULL;	/* list of all existing proxies */
 int next_pxid = 1;		/* UUID assigned to next new proxy, 0 reserved */

 /*
  * This function returns a string containing a name describing capabilities to
  * report comprehensible error messages. Specifically, it will return the words
  * "frontend", "backend", "ruleset" when appropriate, or "proxy" for all other
  * cases including the proxies declared in "listen" mode.
  */
 const char *proxy_cap_str(int cap)
 {
 	if ((cap & PR_CAP_LISTEN) != PR_CAP_LISTEN) {
 		if (cap & PR_CAP_FE)
 			return "frontend";
 		else if (cap & PR_CAP_BE)
 			return "backend";
 		else if (cap & PR_CAP_RS)
 			return "ruleset";
 	}
 	return "proxy";
 }

 /*
  * This function returns a string containing the mode of the proxy in a format
  * suitable for error messages.
  */
 const char *proxy_mode_str(int mode) {

 	if (mode == PR_MODE_TCP)
 		return "tcp";
 	else if (mode == PR_MODE_HTTP)
 		return "http";
 	else if (mode == PR_MODE_HEALTH)
 		return "health";
 	else
 		return "unknown";
 }

 /* This function parses a "timeout" statement in a proxy section. It returns
  * -1 if there is any error, 1 for a warning, otherwise zero. If it does not
  * return zero, it may write an error message into the <err> buffer, for at
  * most <errlen> bytes, trailing zero included. The trailing '\n' must not
  * be written. The function must be called with <args> pointing to the first
  * word after "timeout", with <proxy> pointing to the proxy being parsed, and
  * <defpx> to the default proxy or NULL. As a special case for compatibility
  * with older configs, it also accepts "{cli|srv|con}timeout" in args[0].
  */
 int proxy_parse_timeout(const char **args, struct proxy *proxy,
 			struct proxy *defpx, char *err, int errlen)
 {
 	unsigned timeout;
 	int retval, cap;
 	const char *res, *name;
 	struct timeval *tv = NULL;
 	struct timeval *td = NULL;

 	retval = 0;
 	name = args[0];
 	if (!strcmp(args[0], "client") || !strcmp(args[0], "clitimeout")) {
 		name = "client";
 		tv = &proxy->timeout.client;
 		td = &defpx->timeout.client;
 		cap = PR_CAP_FE;
 	} else if (!strcmp(args[0], "tarpit")) {
 		tv = &proxy->timeout.tarpit;
 		td = &defpx->timeout.tarpit;
 		cap = PR_CAP_FE | PR_CAP_BE;
 	} else if (!strcmp(args[0], "http-request")) {
 		tv = &proxy->timeout.httpreq;
 		td = &defpx->timeout.httpreq;
 		cap = PR_CAP_FE;
 	} else if (!strcmp(args[0], "server") || !strcmp(args[0], "srvtimeout")) {
 		name = "server";
 		tv = &proxy->timeout.server;
 		td = &defpx->timeout.server;
 		cap = PR_CAP_BE;
 	} else if (!strcmp(args[0], "connect") || !strcmp(args[0], "contimeout")) {
 		name = "connect";
 		tv = &proxy->timeout.connect;
 		td = &defpx->timeout.connect;
 		cap = PR_CAP_BE;
 	} else if (!strcmp(args[0], "check")) {
 		tv = &proxy->timeout.check;
 		td = &defpx->timeout.check;
 		cap = PR_CAP_BE;
 	} else if (!strcmp(args[0], "appsession")) {
 		tv = &proxy->timeout.appsession;
 		td = &defpx->timeout.appsession;
 		cap = PR_CAP_BE;
 	} else if (!strcmp(args[0], "queue")) {
 		tv = &proxy->timeout.queue;
 		td = &defpx->timeout.queue;
 		cap = PR_CAP_BE;
 	} else {
 		snprintf(err, errlen,
 			 "timeout '%s': must be 'client', 'server', 'connect', 'check', "
 			 "'appsession', 'queue', 'http-request' or 'tarpit'",
 			 args[0]);
 		return -1;
 	}

 	if (*args[1] == 0) {
 		snprintf(err, errlen, "%s timeout expects an integer value (in milliseconds)", name);
 		return -1;
 	}

 	res = parse_time_err(args[1], &timeout, TIME_UNIT_MS);
 	if (res) {
 		snprintf(err, errlen, "unexpected character '%c' in %s timeout", *err, name);
 		return -1;
 	}

 	if (!(proxy->cap & cap)) {
 		snprintf(err, errlen, "%s timeout will be ignored because %s '%s' has no %s capability",
 			 name, proxy_type_str(proxy), proxy->id,
 			 (cap & PR_CAP_BE) ? "backend" : "frontend");
 		retval = 1;
 	}
 	else if (defpx && !__tv_iseq(tv, td)) {
 		snprintf(err, errlen, "overwriting %s timeout which was already specified", name);
 		retval = 1;
 	}

 	if (timeout)
 		__tv_from_ms(tv, timeout);
 	else
 		tv_eternity(tv);

 	return retval;
 }

 /*
  * This function finds a proxy with matching name, mode and with satisfying
  * capabilities. It also checks if there are more matching proxies with
  * requested name as this often leads into unexpected situations.
  */

 struct proxy *findproxy(const char *name, int mode, int cap) {

 	struct proxy *curproxy, *target=NULL;

 	for (curproxy = proxy; curproxy; curproxy = curproxy->next) {
 		if ((curproxy->cap & cap)!=cap || strcmp(curproxy->id, name))
 			continue;

 		if (curproxy->mode != mode) {
 			Alert("Unable to use proxy '%s' with wrong mode, required: %s, has: %s.\n",
 				name, proxy_mode_str(mode), proxy_mode_str(curproxy->mode));
 			Alert("You may want to use 'mode %s'.\n", proxy_mode_str(mode));
 			return NULL;
 		}

 		if (!target) {
 			target = curproxy;
 			continue;
 		}

 		Alert("Refusing to use duplicated proxy '%s' with overlapping capabilities: %s/%s!\n",
 			name, proxy_type_str(curproxy), proxy_type_str(target));

 		return NULL;
 	}

 	return target;
 }

 /*
  * This function creates all proxy sockets. It should be done very early,
  * typically before privileges are dropped. The sockets will be registered
  * but not added to any fd_set, in order not to loose them across the fork().
  * The proxies also start in IDLE state, meaning that it will be
  * maintain_proxies that will finally complete their loading.
  *
  * Its return value is composed from ERR_NONE, ERR_RETRYABLE and ERR_FATAL.
  * Retryable errors will only be printed if <verbose> is not zero.
  */
 int start_proxies(int verbose)
 {
 	struct proxy *curproxy;
 	struct listener *listener;
 	int lerr, err = ERR_NONE;
 	int pxerr;
 	char msg[100];

 	for (curproxy = proxy; curproxy != NULL; curproxy = curproxy->next) {
 		if (curproxy->state != PR_STNEW)
 			continue; /* already initialized */

 		pxerr = 0;
 		for (listener = curproxy->listen; listener != NULL; listener = listener->next) {
 			if (listener->state != LI_ASSIGNED)
 				continue; /* already started */

 			lerr = tcp_bind_listener(listener, msg, sizeof(msg));

 			/* errors are reported if <verbose> is set or if they are fatal */
 			if (verbose || (lerr & (ERR_FATAL | ERR_ABORT))) {
 				if (lerr & ERR_ALERT)
 					Alert("Starting %s %s: %s\n",
 					      proxy_type_str(curproxy), curproxy->id, msg);
 				else if (lerr & ERR_WARN)
 					Warning("Starting %s %s: %s\n",
 						proxy_type_str(curproxy), curproxy->id, msg);
 			}

 			err |= lerr;
 			if (lerr & (ERR_ABORT | ERR_FATAL)) {
 				pxerr |= 1;
 				break;
 			}
 			else if (lerr & ERR_CODE) {
 				pxerr |= 1;
 				continue;
 			}
 		}

 		if (!pxerr) {
 			curproxy->state = PR_STIDLE;
 			send_log(curproxy, LOG_NOTICE, "Proxy %s started.\n", curproxy->id);
 		}

 		if (err & ERR_ABORT)
 			break;
 	}

 	return err;
 }


 /*
  * this function enables proxies when there are enough free sessions,
  * or stops them when the table is full. It is designed to be called from the
  * select_loop(). It returns the date of next expiration event during stop
  * time, ETERNITY otherwise.
  */
 void maintain_proxies(struct timeval *next)
 {
 	struct proxy *p;
 	struct listener *l;

 	p = proxy;
 	tv_eternity(next);

 	/* if there are enough free sessions, we'll activate proxies */
 	if (actconn < global.maxconn) {
 		while (p) {
 			if (p->feconn < p->maxconn) {
 				if (p->state == PR_STIDLE) {
 					for (l = p->listen; l != NULL; l = l->next)
 						enable_listener(l);
 					p->state = PR_STRUN;
 				}
 			}
 			else {
 				if (p->state == PR_STRUN) {
 					for (l = p->listen; l != NULL; l = l->next)
 						disable_listener(l);
 					p->state = PR_STIDLE;
 				}
 			}
 			p = p->next;
 		}
 	}
 	else {  /* block all proxies */
 		while (p) {
 			if (p->state == PR_STRUN) {
 				for (l = p->listen; l != NULL; l = l->next)
 					disable_listener(l);
 				p->state = PR_STIDLE;
 			}
 			p = p->next;
 		}
 	}

 	if (stopping) {
 		p = proxy;
 		while (p) {
 			if (p->state != PR_STSTOPPED) {
 				int t;
 				t = tv_ms_remain2(&now, &p->stop_time);
 				if (t == 0) {
 					Warning("Proxy %s stopped.\n", p->id);
 					send_log(p, LOG_WARNING, "Proxy %s stopped.\n", p->id);

 					for (l = p->listen; l != NULL; l = l->next) {
 						unbind_listener(l);
 						if (l->state >= LI_ASSIGNED) {
 							delete_listener(l);
 							listeners--;
 						}
 					}
 					p->state = PR_STSTOPPED;
 					/* try to free more memory */
 					pool_gc2();
 				}
 				else {
 					tv_bound(next, &p->stop_time);
 				}
 			}
 			p = p->next;
 		}
 	}
 	return;
 }


 /*
  * this function disables health-check servers so that the process will quickly be ignored
  * by load balancers. Note that if a proxy was already in the PAUSED state, then its grace
  * time will not be used since it would already not listen anymore to the socket.
  */
 void soft_stop(void)
 {
 	struct proxy *p;

 	stopping = 1;
 	p = proxy;
 	tv_now(&now); /* else, the old time before select will be used */
 	while (p) {
 		if (p->state != PR_STSTOPPED) {
 			Warning("Stopping proxy %s in %d ms.\n", p->id, p->grace);
 			send_log(p, LOG_WARNING, "Stopping proxy %s in %d ms.\n", p->id, p->grace);
 			tv_ms_add(&p->stop_time, &now, p->grace);
 		}
 		p = p->next;
 	}
 }


 /*
  * 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.
  * If disabling at least one listener returns an error, then the proxy
  * state is set to PR_STERROR because we don't know how to resume from this.
  */
 void pause_proxy(struct proxy *p)
 {
 	struct listener *l;
 	for (l = p->listen; l != NULL; l = l->next) {
 		if (shutdown(l->fd, SHUT_WR) == 0 &&
 		    listen(l->fd, p->backlog ? p->backlog : p->maxconn) == 0 &&
 		    shutdown(l->fd, SHUT_RD) == 0) {
 			EV_FD_CLR(l->fd, DIR_RD);
 			if (p->state != PR_STERROR)
 				p->state = PR_STPAUSED;
 		}
 		else
 			p->state = PR_STERROR;
 	}
 }

 /*
  * This function temporarily disables listening so that another new instance
  * can start listening. It is designed to be called upon reception of a
  * SIGTTOU, after which either a SIGUSR1 can be sent to completely stop
  * the proxy, or a SIGTTIN can be sent to listen again.
  */
 void pause_proxies(void)
 {
 	int err;
 	struct proxy *p;

 	err = 0;
 	p = proxy;
 	tv_now(&now); /* else, the old time before select will be used */
 	while (p) {
 		if (p->state != PR_STERROR &&
 		    p->state != PR_STSTOPPED &&
 		    p->state != PR_STPAUSED) {
 			Warning("Pausing proxy %s.\n", p->id);
 			send_log(p, LOG_WARNING, "Pausing proxy %s.\n", p->id);
 			pause_proxy(p);
 			if (p->state != PR_STPAUSED) {
 				err |= 1;
 				Warning("Proxy %s failed to enter pause mode.\n", p->id);
 				send_log(p, LOG_WARNING, "Proxy %s failed to enter pause mode.\n", p->id);
 			}
 		}
 		p = p->next;
 	}
 	if (err) {
 		Warning("Some proxies refused to pause, performing soft stop now.\n");
 		send_log(p, LOG_WARNING, "Some proxies refused to pause, performing soft stop now.\n");
 		soft_stop();
 	}
 }


 /*
  * This function reactivates listening. This can be used after a call to
  * sig_pause(), for example when a new instance has failed starting up.
  * It is designed to be called upon reception of a SIGTTIN.
  */
 void listen_proxies(void)
 {
 	struct proxy *p;
 	struct listener *l;

 	p = proxy;
 	tv_now(&now); /* else, the old time before select will be used */
 	while (p) {
 		if (p->state == PR_STPAUSED) {
 			Warning("Enabling proxy %s.\n", p->id);
 			send_log(p, LOG_WARNING, "Enabling proxy %s.\n", p->id);

 			for (l = p->listen; l != NULL; l = l->next) {
 				if (listen(l->fd, p->backlog ? p->backlog : p->maxconn) == 0) {
 					if (actconn < global.maxconn && p->feconn < p->maxconn) {
 						EV_FD_SET(l->fd, DIR_RD);
 						p->state = PR_STRUN;
 					}
 					else
 						p->state = PR_STIDLE;
 				} else {
 					int port;

 					if (l->addr.ss_family == AF_INET6)
 						port = ntohs(((struct sockaddr_in6 *)(&l->addr))->sin6_port);
 					else
 						port = ntohs(((struct sockaddr_in *)(&l->addr))->sin_port);

 					Warning("Port %d busy while trying to enable proxy %s.\n",
 						port, p->id);
 					send_log(p, LOG_WARNING, "Port %d busy while trying to enable proxy %s.\n",
 						 port, p->id);
 					/* Another port might have been enabled. Let's stop everything. */
 					pause_proxy(p);
 					break;
 				}
 			}
 		}
 		p = p->next;
 	}
 }


 /*
  * Local variables:
  *  c-indent-level: 8
  *  c-basic-offset: 8
  * End:
  */
	/*
	* Proxy variables and functions.
	*
	* Copyright 2000-2007 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 <fcntl.h>
	#include <unistd.h>
	#include <string.h>
	#include <sys/types.h>
	#include <sys/socket.h>
	#include <sys/stat.h>

	#include <common/defaults.h>
	#include <common/compat.h>
	#include <common/config.h>
	#include <common/errors.h>
	#include <common/memory.h>
	#include <common/time.h>

	#include <types/global.h>
	#include <types/polling.h>

	#include <proto/client.h>
	#include <proto/backend.h>
	#include <proto/fd.h>
	#include <proto/log.h>
	#include <proto/protocols.h>
	#include <proto/proto_tcp.h>
	#include <proto/proxy.h>


	int listeners; /* # of proxy listeners, set by cfgparse, unset by maintain_proxies */
	struct proxy proxy = NULL; / list of all existing proxies */
	int next_pxid = 1; /* UUID assigned to next new proxy, 0 reserved */

	/*
	* This function returns a string containing a name describing capabilities to
	* report comprehensible error messages. Specifically, it will return the words
	* "frontend", "backend", "ruleset" when appropriate, or "proxy" for all other
	* cases including the proxies declared in "listen" mode.
	*/
	const char *proxy_cap_str(int cap)
	{
	if ((cap & PR_CAP_LISTEN) != PR_CAP_LISTEN) {
	if (cap & PR_CAP_FE)
	return "frontend";
	else if (cap & PR_CAP_BE)
	return "backend";
	else if (cap & PR_CAP_RS)
	return "ruleset";
	}
	return "proxy";
	}

	/*
	* This function returns a string containing the mode of the proxy in a format
	* suitable for error messages.
	*/
	const char *proxy_mode_str(int mode) {

	if (mode == PR_MODE_TCP)
	return "tcp";
	else if (mode == PR_MODE_HTTP)
	return "http";
	else if (mode == PR_MODE_HEALTH)
	return "health";
	else
	return "unknown";
	}

	/* This function parses a "timeout" statement in a proxy section. It returns
	* -1 if there is any error, 1 for a warning, otherwise zero. If it does not
	* return zero, it may write an error message into the <err> buffer, for at
	* most <errlen> bytes, trailing zero included. The trailing '\n' must not
	* be written. The function must be called with <args> pointing to the first
	* word after "timeout", with <proxy> pointing to the proxy being parsed, and
	* <defpx> to the default proxy or NULL. As a special case for compatibility
	* with older configs, it also accepts "{cli\|srv\|con}timeout" in args[0].
	*/
	int proxy_parse_timeout(const char *args, struct proxy proxy,
	struct proxy defpx, char err, int errlen)
	{
	unsigned timeout;
	int retval, cap;
	const char res, name;
	struct timeval *tv = NULL;
	struct timeval *td = NULL;

	retval = 0;
	name = args[0];
	if (!strcmp(args[0], "client") \|\| !strcmp(args[0], "clitimeout")) {
	name = "client";
	tv = &proxy->timeout.client;
	td = &defpx->timeout.client;
	cap = PR_CAP_FE;
	} else if (!strcmp(args[0], "tarpit")) {
	tv = &proxy->timeout.tarpit;
	td = &defpx->timeout.tarpit;
	cap = PR_CAP_FE \| PR_CAP_BE;
	} else if (!strcmp(args[0], "http-request")) {
	tv = &proxy->timeout.httpreq;
	td = &defpx->timeout.httpreq;
	cap = PR_CAP_FE;
	} else if (!strcmp(args[0], "server") \|\| !strcmp(args[0], "srvtimeout")) {
	name = "server";
	tv = &proxy->timeout.server;
	td = &defpx->timeout.server;
	cap = PR_CAP_BE;
	} else if (!strcmp(args[0], "connect") \|\| !strcmp(args[0], "contimeout")) {
	name = "connect";
	tv = &proxy->timeout.connect;
	td = &defpx->timeout.connect;
	cap = PR_CAP_BE;
	} else if (!strcmp(args[0], "check")) {
	tv = &proxy->timeout.check;
	td = &defpx->timeout.check;
	cap = PR_CAP_BE;
	} else if (!strcmp(args[0], "appsession")) {
	tv = &proxy->timeout.appsession;
	td = &defpx->timeout.appsession;
	cap = PR_CAP_BE;
	} else if (!strcmp(args[0], "queue")) {
	tv = &proxy->timeout.queue;
	td = &defpx->timeout.queue;
	cap = PR_CAP_BE;
	} else {
	snprintf(err, errlen,
	"timeout '%s': must be 'client', 'server', 'connect', 'check', "
	"'appsession', 'queue', 'http-request' or 'tarpit'",
	args[0]);
	return -1;
	}

	if (*args[1] == 0) {
	snprintf(err, errlen, "%s timeout expects an integer value (in milliseconds)", name);
	return -1;
	}

	res = parse_time_err(args[1], &timeout, TIME_UNIT_MS);
	if (res) {
	snprintf(err, errlen, "unexpected character '%c' in %s timeout", *err, name);
	return -1;
	}

	if (!(proxy->cap & cap)) {
	snprintf(err, errlen, "%s timeout will be ignored because %s '%s' has no %s capability",
	name, proxy_type_str(proxy), proxy->id,
	(cap & PR_CAP_BE) ? "backend" : "frontend");
	retval = 1;
	}
	else if (defpx && !__tv_iseq(tv, td)) {
	snprintf(err, errlen, "overwriting %s timeout which was already specified", name);
	retval = 1;
	}

	if (timeout)
	__tv_from_ms(tv, timeout);
	else
	tv_eternity(tv);

	return retval;
	}

	/*
	* This function finds a proxy with matching name, mode and with satisfying
	* capabilities. It also checks if there are more matching proxies with
	* requested name as this often leads into unexpected situations.
	*/

	struct proxy findproxy(const char name, int mode, int cap) {

	struct proxy curproxy, target=NULL;

	for (curproxy = proxy; curproxy; curproxy = curproxy->next) {
	if ((curproxy->cap & cap)!=cap \|\| strcmp(curproxy->id, name))
	continue;

	if (curproxy->mode != mode) {
	Alert("Unable to use proxy '%s' with wrong mode, required: %s, has: %s.\n",
	name, proxy_mode_str(mode), proxy_mode_str(curproxy->mode));
	Alert("You may want to use 'mode %s'.\n", proxy_mode_str(mode));
	return NULL;
	}

	if (!target) {
	target = curproxy;
	continue;
	}

	Alert("Refusing to use duplicated proxy '%s' with overlapping capabilities: %s/%s!\n",
	name, proxy_type_str(curproxy), proxy_type_str(target));

	return NULL;
	}

	return target;
	}

	/*
	* This function creates all proxy sockets. It should be done very early,
	* typically before privileges are dropped. The sockets will be registered
	* but not added to any fd_set, in order not to loose them across the fork().
	* The proxies also start in IDLE state, meaning that it will be
	* maintain_proxies that will finally complete their loading.
	*
	* Its return value is composed from ERR_NONE, ERR_RETRYABLE and ERR_FATAL.
	* Retryable errors will only be printed if <verbose> is not zero.
	*/
	int start_proxies(int verbose)
	{
	struct proxy *curproxy;
	struct listener *listener;
	int lerr, err = ERR_NONE;
	int pxerr;
	char msg[100];

	for (curproxy = proxy; curproxy != NULL; curproxy = curproxy->next) {
	if (curproxy->state != PR_STNEW)
	continue; /* already initialized */

	pxerr = 0;
	for (listener = curproxy->listen; listener != NULL; listener = listener->next) {
	if (listener->state != LI_ASSIGNED)
	continue; /* already started */

	lerr = tcp_bind_listener(listener, msg, sizeof(msg));

	/* errors are reported if <verbose> is set or if they are fatal */
	if (verbose \|\| (lerr & (ERR_FATAL \| ERR_ABORT))) {
	if (lerr & ERR_ALERT)
	Alert("Starting %s %s: %s\n",
	proxy_type_str(curproxy), curproxy->id, msg);
	else if (lerr & ERR_WARN)
	Warning("Starting %s %s: %s\n",
	proxy_type_str(curproxy), curproxy->id, msg);
	}

	err \|= lerr;
	if (lerr & (ERR_ABORT \| ERR_FATAL)) {
	pxerr \|= 1;
	break;
	}
	else if (lerr & ERR_CODE) {
	pxerr \|= 1;
	continue;
	}
	}

	if (!pxerr) {
	curproxy->state = PR_STIDLE;
	send_log(curproxy, LOG_NOTICE, "Proxy %s started.\n", curproxy->id);
	}

	if (err & ERR_ABORT)
	break;
	}

	return err;
	}


	/*
	* this function enables proxies when there are enough free sessions,
	* or stops them when the table is full. It is designed to be called from the
	* select_loop(). It returns the date of next expiration event during stop
	* time, ETERNITY otherwise.
	*/
	void maintain_proxies(struct timeval *next)
	{
	struct proxy *p;
	struct listener *l;

	p = proxy;
	tv_eternity(next);

	/* if there are enough free sessions, we'll activate proxies */
	if (actconn < global.maxconn) {
	while (p) {
	if (p->feconn < p->maxconn) {
	if (p->state == PR_STIDLE) {
	for (l = p->listen; l != NULL; l = l->next)
	enable_listener(l);
	p->state = PR_STRUN;
	}
	}
	else {
	if (p->state == PR_STRUN) {
	for (l = p->listen; l != NULL; l = l->next)
	disable_listener(l);
	p->state = PR_STIDLE;
	}
	}
	p = p->next;
	}
	}
	else { /* block all proxies */
	while (p) {
	if (p->state == PR_STRUN) {
	for (l = p->listen; l != NULL; l = l->next)
	disable_listener(l);
	p->state = PR_STIDLE;
	}
	p = p->next;
	}
	}

	if (stopping) {
	p = proxy;
	while (p) {
	if (p->state != PR_STSTOPPED) {
	int t;
	t = tv_ms_remain2(&now, &p->stop_time);
	if (t == 0) {
	Warning("Proxy %s stopped.\n", p->id);
	send_log(p, LOG_WARNING, "Proxy %s stopped.\n", p->id);

	for (l = p->listen; l != NULL; l = l->next) {
	unbind_listener(l);
	if (l->state >= LI_ASSIGNED) {
	delete_listener(l);
	listeners--;
	}
	}
	p->state = PR_STSTOPPED;
	/* try to free more memory */
	pool_gc2();
	}
	else {
	tv_bound(next, &p->stop_time);
	}
	}
	p = p->next;
	}
	}
	return;
	}


	/*
	* this function disables health-check servers so that the process will quickly be ignored
	* by load balancers. Note that if a proxy was already in the PAUSED state, then its grace
	* time will not be used since it would already not listen anymore to the socket.
	*/
	void soft_stop(void)
	{
	struct proxy *p;

	stopping = 1;
	p = proxy;
	tv_now(&now); /* else, the old time before select will be used */
	while (p) {
	if (p->state != PR_STSTOPPED) {
	Warning("Stopping proxy %s in %d ms.\n", p->id, p->grace);
	send_log(p, LOG_WARNING, "Stopping proxy %s in %d ms.\n", p->id, p->grace);
	tv_ms_add(&p->stop_time, &now, p->grace);
	}
	p = p->next;
	}
	}


	/*
	* 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.
	* If disabling at least one listener returns an error, then the proxy
	* state is set to PR_STERROR because we don't know how to resume from this.
	*/
	void pause_proxy(struct proxy *p)
	{
	struct listener *l;
	for (l = p->listen; l != NULL; l = l->next) {
	if (shutdown(l->fd, SHUT_WR) == 0 &&
	listen(l->fd, p->backlog ? p->backlog : p->maxconn) == 0 &&
	shutdown(l->fd, SHUT_RD) == 0) {
	EV_FD_CLR(l->fd, DIR_RD);
	if (p->state != PR_STERROR)
	p->state = PR_STPAUSED;
	}
	else
	p->state = PR_STERROR;
	}
	}

	/*
	* This function temporarily disables listening so that another new instance
	* can start listening. It is designed to be called upon reception of a
	* SIGTTOU, after which either a SIGUSR1 can be sent to completely stop
	* the proxy, or a SIGTTIN can be sent to listen again.
	*/
	void pause_proxies(void)
	{
	int err;
	struct proxy *p;

	err = 0;
	p = proxy;
	tv_now(&now); /* else, the old time before select will be used */
	while (p) {
	if (p->state != PR_STERROR &&
	p->state != PR_STSTOPPED &&
	p->state != PR_STPAUSED) {
	Warning("Pausing proxy %s.\n", p->id);
	send_log(p, LOG_WARNING, "Pausing proxy %s.\n", p->id);
	pause_proxy(p);
	if (p->state != PR_STPAUSED) {
	err \|= 1;
	Warning("Proxy %s failed to enter pause mode.\n", p->id);
	send_log(p, LOG_WARNING, "Proxy %s failed to enter pause mode.\n", p->id);
	}
	}
	p = p->next;
	}
	if (err) {
	Warning("Some proxies refused to pause, performing soft stop now.\n");
	send_log(p, LOG_WARNING, "Some proxies refused to pause, performing soft stop now.\n");
	soft_stop();
	}
	}


	/*
	* This function reactivates listening. This can be used after a call to
	* sig_pause(), for example when a new instance has failed starting up.
	* It is designed to be called upon reception of a SIGTTIN.
	*/
	void listen_proxies(void)
	{
	struct proxy *p;
	struct listener *l;

	p = proxy;
	tv_now(&now); /* else, the old time before select will be used */
	while (p) {
	if (p->state == PR_STPAUSED) {
	Warning("Enabling proxy %s.\n", p->id);
	send_log(p, LOG_WARNING, "Enabling proxy %s.\n", p->id);

	for (l = p->listen; l != NULL; l = l->next) {
	if (listen(l->fd, p->backlog ? p->backlog : p->maxconn) == 0) {
	if (actconn < global.maxconn && p->feconn < p->maxconn) {
	EV_FD_SET(l->fd, DIR_RD);
	p->state = PR_STRUN;
	}
	else
	p->state = PR_STIDLE;
	} else {
	int port;

	if (l->addr.ss_family == AF_INET6)
	port = ntohs(((struct sockaddr_in6 *)(&l->addr))->sin6_port);
	else
	port = ntohs(((struct sockaddr_in *)(&l->addr))->sin_port);

	Warning("Port %d busy while trying to enable proxy %s.\n",
	port, p->id);
	send_log(p, LOG_WARNING, "Port %d busy while trying to enable proxy %s.\n",
	port, p->id);
	/* Another port might have been enabled. Let's stop everything. */
	pause_proxy(p);
	break;
	}
	}
	}
	p = p->next;
	}
	}


	/*
	* Local variables:
	* c-indent-level: 8
	* c-basic-offset: 8
	* End:
	*/