blob: 06424c62c13411dbd9897f16ae1534e2a4e045ee [file] [log] [blame]
/*
* 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 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->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:
*/