src/proxy.c - haproxy - Gitiles

 /*
  * Proxy variables and functions.
  *
  * Copyright 2000-2006 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 <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/time.h>

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

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


 int listeners;	/* # of listeners */
 struct proxy *proxy  = NULL;	/* list of all existing proxies */

 /*
  * This function returns a string containing the type of the proxy in a format
  * suitable for error messages, from its capabilities.
  */
 const char *proxy_type_str(struct proxy *proxy)
 {
 	int cap = proxy->cap;
 	if ((cap & PR_CAP_LISTEN) == PR_CAP_LISTEN)
 		return "listener";
 	else if (cap & PR_CAP_FE)
 		return "frontend";
 	else if (cap & PR_CAP_BE)
 		return "backend";
 	else if (cap & PR_CAP_RS)
 		return "ruleset";
 	else
 		return "proxy";
 }


 /*
  * this function starts all the proxies. 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 err = ERR_NONE;
 	int fd, pxerr;

 	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->fd != -1)
 				continue; /* already initialized */

 			if ((fd = socket(listener->addr.ss_family, SOCK_STREAM, IPPROTO_TCP)) == -1) {
 				if (verbose)
 					Alert("cannot create listening socket for proxy %s. Aborting.\n",
 					      curproxy->id);
 				err |= ERR_RETRYABLE;
 				pxerr |= 1;
 				continue;
 			}

 			if (fd >= global.maxsock) {
 				Alert("socket(): not enough free sockets for proxy %s. Raise -n argument. Aborting.\n",
 				      curproxy->id);
 				close(fd);
 				err |= ERR_FATAL;
 				pxerr |= 1;
 				break;
 			}

 			if ((fcntl(fd, F_SETFL, O_NONBLOCK) == -1) ||
 			    (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY,
 					(char *) &one, sizeof(one)) == -1)) {
 				Alert("cannot make socket non-blocking for proxy %s. Aborting.\n",
 				      curproxy->id);
 				close(fd);
 				err |= ERR_FATAL;
 				pxerr |= 1;
 				break;
 			}

 			if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *) &one, sizeof(one)) == -1) {
 				Alert("cannot do so_reuseaddr for proxy %s. Continuing.\n",
 				      curproxy->id);
 			}

 #ifdef SO_REUSEPORT
 			/* OpenBSD supports this. As it's present in old libc versions of Linux,
 			 * it might return an error that we will silently ignore.
 			 */
 			setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, (char *) &one, sizeof(one));
 #endif
 			if (bind(fd,
 				 (struct sockaddr *)&listener->addr,
 				 listener->addr.ss_family == AF_INET6 ?
 				 sizeof(struct sockaddr_in6) :
 				 sizeof(struct sockaddr_in)) == -1) {
 				if (verbose)
 					Alert("cannot bind socket for proxy %s. Aborting.\n",
 					      curproxy->id);
 				close(fd);
 				err |= ERR_RETRYABLE;
 				pxerr |= 1;
 				continue;
 			}

 			if (listen(fd, curproxy->maxconn) == -1) {
 				if (verbose)
 					Alert("cannot listen to socket for proxy %s. Aborting.\n",
 					      curproxy->id);
 				close(fd);
 				err |= ERR_RETRYABLE;
 				pxerr |= 1;
 				continue;
 			}

 			/* the socket is ready */
 			listener->fd = fd;

 			/* the function for the accept() event */
 			fdtab[fd].cb[DIR_RD].f  = &event_accept;
 			fdtab[fd].cb[DIR_WR].f = NULL; /* never called */
 			fdtab[fd].cb[DIR_RD].b = fdtab[fd].cb[DIR_WR].b = NULL;
 			fdtab[fd].owner = (struct task *)curproxy; /* reference the proxy instead of a task */
 			fdtab[fd].state = FD_STLISTEN;
 			EV_FD_SET(fd, DIR_RD);
 			fd_insert(fd);
 			listeners++;
 		}

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

 	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 time left before next expiration event
  * during stop time, TIME_ETERNITY otherwise.
  */
 int maintain_proxies(void)
 {
 	struct proxy *p;
 	struct listener *l;
 	int tleft; /* time left */

 	p = proxy;
 	tleft = TIME_ETERNITY; /* infinite time */

 	/* 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) {
 						EV_FD_SET(l->fd, DIR_RD);
 					}
 					p->state = PR_STRUN;
 				}
 			}
 			else {
 				if (p->state == PR_STRUN) {
 					for (l = p->listen; l != NULL; l = l->next) {
 						EV_FD_CLR(l->fd, DIR_RD);
 					}
 					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) {
 					EV_FD_CLR(l->fd, DIR_RD);
 				}
 				p->state = PR_STIDLE;
 			}
 			p = p->next;
 		}
 	}

 	if (stopping) {
 		p = proxy;
 		while (p) {
 			if (p->state != PR_STSTOPPED) {
 				int t;
 				t = tv_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) {
 						fd_delete(l->fd);
 						listeners--;
 					}
 					p->state = PR_STSTOPPED;
 				}
 				else {
 					tleft = MINTIME(t, tleft);
 				}
 			}
 			p = p->next;
 		}
 	}
 	return tleft;
 }


 /*
  * 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_delayfrom(&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->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->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 2000-2006 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 <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/time.h>

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

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


	int listeners; /* # of listeners */
	struct proxy proxy = NULL; / list of all existing proxies */

	/*
	* This function returns a string containing the type of the proxy in a format
	* suitable for error messages, from its capabilities.
	*/
	const char proxy_type_str(struct proxy proxy)
	{
	int cap = proxy->cap;
	if ((cap & PR_CAP_LISTEN) == PR_CAP_LISTEN)
	return "listener";
	else if (cap & PR_CAP_FE)
	return "frontend";
	else if (cap & PR_CAP_BE)
	return "backend";
	else if (cap & PR_CAP_RS)
	return "ruleset";
	else
	return "proxy";
	}


	/*
	* this function starts all the proxies. 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 err = ERR_NONE;
	int fd, pxerr;

	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->fd != -1)
	continue; /* already initialized */

	if ((fd = socket(listener->addr.ss_family, SOCK_STREAM, IPPROTO_TCP)) == -1) {
	if (verbose)
	Alert("cannot create listening socket for proxy %s. Aborting.\n",
	curproxy->id);
	err \|= ERR_RETRYABLE;
	pxerr \|= 1;
	continue;
	}

	if (fd >= global.maxsock) {
	Alert("socket(): not enough free sockets for proxy %s. Raise -n argument. Aborting.\n",
	curproxy->id);
	close(fd);
	err \|= ERR_FATAL;
	pxerr \|= 1;
	break;
	}

	if ((fcntl(fd, F_SETFL, O_NONBLOCK) == -1) \|\|
	(setsockopt(fd, IPPROTO_TCP, TCP_NODELAY,
	(char *) &one, sizeof(one)) == -1)) {
	Alert("cannot make socket non-blocking for proxy %s. Aborting.\n",
	curproxy->id);
	close(fd);
	err \|= ERR_FATAL;
	pxerr \|= 1;
	break;
	}

	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *) &one, sizeof(one)) == -1) {
	Alert("cannot do so_reuseaddr for proxy %s. Continuing.\n",
	curproxy->id);
	}

	#ifdef SO_REUSEPORT
	/* OpenBSD supports this. As it's present in old libc versions of Linux,
	* it might return an error that we will silently ignore.
	*/
	setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, (char *) &one, sizeof(one));
	#endif
	if (bind(fd,
	(struct sockaddr *)&listener->addr,
	listener->addr.ss_family == AF_INET6 ?
	sizeof(struct sockaddr_in6) :
	sizeof(struct sockaddr_in)) == -1) {
	if (verbose)
	Alert("cannot bind socket for proxy %s. Aborting.\n",
	curproxy->id);
	close(fd);
	err \|= ERR_RETRYABLE;
	pxerr \|= 1;
	continue;
	}

	if (listen(fd, curproxy->maxconn) == -1) {
	if (verbose)
	Alert("cannot listen to socket for proxy %s. Aborting.\n",
	curproxy->id);
	close(fd);
	err \|= ERR_RETRYABLE;
	pxerr \|= 1;
	continue;
	}

	/* the socket is ready */
	listener->fd = fd;

	/* the function for the accept() event */
	fdtab[fd].cb[DIR_RD].f = &event_accept;
	fdtab[fd].cb[DIR_WR].f = NULL; /* never called */
	fdtab[fd].cb[DIR_RD].b = fdtab[fd].cb[DIR_WR].b = NULL;
	fdtab[fd].owner = (struct task )curproxy; / reference the proxy instead of a task */
	fdtab[fd].state = FD_STLISTEN;
	EV_FD_SET(fd, DIR_RD);
	fd_insert(fd);
	listeners++;
	}

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

	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 time left before next expiration event
	* during stop time, TIME_ETERNITY otherwise.
	*/
	int maintain_proxies(void)
	{
	struct proxy *p;
	struct listener *l;
	int tleft; /* time left */

	p = proxy;
	tleft = TIME_ETERNITY; /* infinite time */

	/* 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) {
	EV_FD_SET(l->fd, DIR_RD);
	}
	p->state = PR_STRUN;
	}
	}
	else {
	if (p->state == PR_STRUN) {
	for (l = p->listen; l != NULL; l = l->next) {
	EV_FD_CLR(l->fd, DIR_RD);
	}
	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) {
	EV_FD_CLR(l->fd, DIR_RD);
	}
	p->state = PR_STIDLE;
	}
	p = p->next;
	}
	}

	if (stopping) {
	p = proxy;
	while (p) {
	if (p->state != PR_STSTOPPED) {
	int t;
	t = tv_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) {
	fd_delete(l->fd);
	listeners--;
	}
	p->state = PR_STSTOPPED;
	}
	else {
	tleft = MINTIME(t, tleft);
	}
	}
	p = p->next;
	}
	}
	return tleft;
	}


	/*
	* 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_delayfrom(&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->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->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:
	*/