blob: 9643a2b0d6f9eab8757b1187ad48540376628641 [file] [log] [blame]
/*
* Health-checks 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 <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <common/compat.h>
#include <common/config.h>
#include <common/mini-clist.h>
#include <common/time.h>
#include <types/global.h>
#include <types/polling.h>
#include <types/proxy.h>
#include <types/session.h>
#include <proto/backend.h>
#include <proto/fd.h>
#include <proto/log.h>
#include <proto/queue.h>
#include <proto/server.h>
#include <proto/task.h>
/* Sets server <s> down, notifies by all available means, recounts the
* remaining servers on the proxy and transfers queued sessions whenever
* possible to other servers.
*/
void set_server_down(struct server *s)
{
struct pendconn *pc, *pc_bck, *pc_end;
struct session *sess;
int xferred;
s->state &= ~SRV_RUNNING;
if (s->health == s->rise) {
recount_servers(s->proxy);
recalc_server_map(s->proxy);
/* we might have sessions queued on this server and waiting for
* a connection. Those which are redispatchable will be queued
* to another server or to the proxy itself.
*/
xferred = 0;
FOREACH_ITEM_SAFE(pc, pc_bck, &s->pendconns, pc_end, struct pendconn *, list) {
sess = pc->sess;
if ((sess->proxy->options & PR_O_REDISP)) {
/* The REDISP option was specified. We will ignore
* cookie and force to balance or use the dispatcher.
*/
sess->flags &= ~(SN_DIRECT | SN_ASSIGNED | SN_ADDR_SET);
sess->srv = NULL; /* it's left to the dispatcher to choose a server */
if ((sess->flags & SN_CK_MASK) == SN_CK_VALID) {
sess->flags &= ~SN_CK_MASK;
sess->flags |= SN_CK_DOWN;
}
pendconn_free(pc);
task_wakeup(&rq, sess->task);
xferred++;
}
}
sprintf(trash, "%sServer %s/%s is DOWN. %d active and %d backup servers left.%s"
" %d sessions active, %d requeued, %d remaining in queue.\n",
s->state & SRV_BACKUP ? "Backup " : "",
s->proxy->id, s->id, s->proxy->srv_act, s->proxy->srv_bck,
(s->proxy->srv_bck && !s->proxy->srv_act) ? " Running on backup." : "",
s->cur_sess, xferred, s->nbpend);
Warning("%s", trash);
send_log(s->proxy, LOG_ALERT, "%s", trash);
if (s->proxy->srv_bck == 0 && s->proxy->srv_act == 0) {
Alert("Proxy %s has no server available !\n", s->proxy->id);
send_log(s->proxy, LOG_EMERG, "Proxy %s has no server available !\n", s->proxy->id);
}
s->down_trans++;
}
s->health = 0; /* failure */
}
/*
* This function is used only for server health-checks. It handles
* the connection acknowledgement. If the proxy requires HTTP health-checks,
* it sends the request. In other cases, it returns 1 if the socket is OK,
* or -1 if an error occured.
*/
int event_srv_chk_w(int fd)
{
struct task *t = fdtab[fd].owner;
struct server *s = t->context;
int skerr;
socklen_t lskerr = sizeof(skerr);
skerr = 1;
if ((getsockopt(fd, SOL_SOCKET, SO_ERROR, &skerr, &lskerr) == -1)
|| (skerr != 0)) {
/* in case of TCP only, this tells us if the connection failed */
s->result = -1;
fdtab[fd].state = FD_STERROR;
MY_FD_CLR(fd, StaticWriteEvent);
}
else if (s->result != -1) {
/* we don't want to mark 'UP' a server on which we detected an error earlier */
if ((s->proxy->options & PR_O_HTTP_CHK) ||
(s->proxy->options & PR_O_SSL3_CHK)) {
int ret;
/* we want to check if this host replies to HTTP or SSLv3 requests
* so we'll send the request, and won't wake the checker up now.
*/
if (s->proxy->options & PR_O_SSL3_CHK) {
/* SSL requires that we put Unix time in the request */
int gmt_time = htonl(now.tv_sec);
memcpy(s->proxy->check_req + 11, &gmt_time, 4);
}
#ifndef MSG_NOSIGNAL
ret = send(fd, s->proxy->check_req, s->proxy->check_len, MSG_DONTWAIT);
#else
ret = send(fd, s->proxy->check_req, s->proxy->check_len, MSG_DONTWAIT | MSG_NOSIGNAL);
#endif
if (ret == s->proxy->check_len) {
MY_FD_SET(fd, StaticReadEvent); /* prepare for reading reply */
MY_FD_CLR(fd, StaticWriteEvent); /* nothing more to write */
return 0;
}
else {
s->result = -1;
MY_FD_CLR(fd, StaticWriteEvent);
}
}
else {
/* good TCP connection is enough */
s->result = 1;
}
}
task_wakeup(&rq, t);
return 0;
}
/*
* This function is used only for server health-checks. It handles the server's
* reply to an HTTP request or SSL HELLO. It returns 1 in s->result if the
* server replies HTTP 2xx or 3xx (valid responses), or if it returns at least
* 5 bytes in response to SSL HELLO. The principle is that this is enough to
* distinguish between an SSL server and a pure TCP relay. All other cases will
* return -1. The function returns 0.
*/
int event_srv_chk_r(int fd)
{
char reply[64];
int len, result;
struct task *t = fdtab[fd].owner;
struct server *s = t->context;
int skerr;
socklen_t lskerr = sizeof(skerr);
result = len = -1;
if (!getsockopt(fd, SOL_SOCKET, SO_ERROR, &skerr, &lskerr) && !skerr) {
#ifndef MSG_NOSIGNAL
len = recv(fd, reply, sizeof(reply), 0);
#else
/* Warning! Linux returns EAGAIN on SO_ERROR if data are still available
* but the connection was closed on the remote end. Fortunately, recv still
* works correctly and we don't need to do the getsockopt() on linux.
*/
len = recv(fd, reply, sizeof(reply), MSG_NOSIGNAL);
#endif
if (((s->proxy->options & PR_O_HTTP_CHK) &&
(len >= sizeof("HTTP/1.0 000")) &&
!memcmp(reply, "HTTP/1.", 7) &&
(reply[9] == '2' || reply[9] == '3')) /* 2xx or 3xx */
|| ((s->proxy->options & PR_O_SSL3_CHK) && (len >= 5) &&
(reply[0] == 0x15 || reply[0] == 0x16))) /* alert or handshake */
result = 1;
}
if (result == -1)
fdtab[fd].state = FD_STERROR;
if (s->result != -1)
s->result = result;
MY_FD_CLR(fd, StaticReadEvent);
task_wakeup(&rq, t);
return 0;
}
/*
* manages a server health-check. Returns
* the time the task accepts to wait, or TIME_ETERNITY for infinity.
*/
int process_chk(struct task *t)
{
struct server *s = t->context;
struct sockaddr_in sa;
int fd;
//fprintf(stderr, "process_chk: task=%p\n", t);
new_chk:
fd = s->curfd;
if (fd < 0) { /* no check currently running */
//fprintf(stderr, "process_chk: 2\n");
if (tv_cmp2_ms(&t->expire, &now) > 0) { /* not good time yet */
task_queue(t); /* restore t to its place in the task list */
return tv_remain2(&now, &t->expire);
}
/* we don't send any health-checks when the proxy is stopped or when
* the server should not be checked.
*/
if (!(s->state & SRV_CHECKED) || s->proxy->state == PR_STSTOPPED) {
while (tv_cmp2_ms(&t->expire, &now) <= 0)
tv_delayfrom(&t->expire, &t->expire, s->inter);
task_queue(t); /* restore t to its place in the task list */
return tv_remain2(&now, &t->expire);
}
/* we'll initiate a new check */
s->result = 0; /* no result yet */
if ((fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) != -1) {
if ((fd < global.maxsock) &&
(fcntl(fd, F_SETFL, O_NONBLOCK) != -1) &&
(setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, (char *) &one, sizeof(one)) != -1)) {
//fprintf(stderr, "process_chk: 3\n");
/* we'll connect to the check port on the server */
sa = s->addr;
sa.sin_port = htons(s->check_port);
/* allow specific binding :
* - server-specific at first
* - proxy-specific next
*/
if (s->state & SRV_BIND_SRC) {
setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *) &one, sizeof(one));
if (bind(fd, (struct sockaddr *)&s->source_addr, sizeof(s->source_addr)) == -1) {
Alert("Cannot bind to source address before connect() for server %s/%s. Aborting.\n",
s->proxy->id, s->id);
s->result = -1;
}
}
else if (s->proxy->options & PR_O_BIND_SRC) {
setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *) &one, sizeof(one));
if (bind(fd, (struct sockaddr *)&s->proxy->source_addr, sizeof(s->proxy->source_addr)) == -1) {
Alert("Cannot bind to source address before connect() for proxy %s. Aborting.\n",
s->proxy->id);
s->result = -1;
}
}
if (!s->result) {
if ((connect(fd, (struct sockaddr *)&sa, sizeof(sa)) != -1) || (errno == EINPROGRESS)) {
/* OK, connection in progress or established */
//fprintf(stderr, "process_chk: 4\n");
s->curfd = fd; /* that's how we know a test is in progress ;-) */
fdtab[fd].owner = t;
fdtab[fd].cb[DIR_RD].f = &event_srv_chk_r;
fdtab[fd].cb[DIR_RD].b = NULL;
fdtab[fd].cb[DIR_WR].f = &event_srv_chk_w;
fdtab[fd].cb[DIR_WR].b = NULL;
fdtab[fd].state = FD_STCONN; /* connection in progress */
MY_FD_SET(fd, StaticWriteEvent); /* for connect status */
#ifdef DEBUG_FULL
assert (!MY_FD_ISSET(fd, StaticReadEvent));
#endif
fd_insert(fd);
/* FIXME: we allow up to <inter> for a connection to establish, but we should use another parameter */
tv_delayfrom(&t->expire, &now, s->inter);
task_queue(t); /* restore t to its place in the task list */
return tv_remain(&now, &t->expire);
}
else if (errno != EALREADY && errno != EISCONN && errno != EAGAIN) {
s->result = -1; /* a real error */
}
}
}
close(fd); /* socket creation error */
}
if (!s->result) { /* nothing done */
//fprintf(stderr, "process_chk: 6\n");
while (tv_cmp2_ms(&t->expire, &now) <= 0)
tv_delayfrom(&t->expire, &t->expire, s->inter);
goto new_chk; /* may be we should initialize a new check */
}
/* here, we have seen a failure */
if (s->health > s->rise) {
s->health--; /* still good */
s->failed_checks++;
}
else
set_server_down(s);
//fprintf(stderr, "process_chk: 7\n");
/* FIXME: we allow up to <inter> for a connection to establish, but we should use another parameter */
while (tv_cmp2_ms(&t->expire, &now) <= 0)
tv_delayfrom(&t->expire, &t->expire, s->inter);
goto new_chk;
}
else {
//fprintf(stderr, "process_chk: 8\n");
/* there was a test running */
if (s->result > 0) { /* good server detected */
//fprintf(stderr, "process_chk: 9\n");
s->health++; /* was bad, stays for a while */
if (s->health >= s->rise) {
s->state |= SRV_RUNNING;
if (s->health == s->rise) {
int xferred;
recount_servers(s->proxy);
recalc_server_map(s->proxy);
/* check if we can handle some connections queued at the proxy. We
* will take as many as we can handle.
*/
for (xferred = 0; !s->maxconn || xferred < srv_dynamic_maxconn(s); xferred++) {
struct session *sess;
struct pendconn *p;
p = pendconn_from_px(s->proxy);
if (!p)
break;
p->sess->srv = s;
sess = p->sess;
pendconn_free(p);
task_wakeup(&rq, sess->task);
}
sprintf(trash,
"%sServer %s/%s is UP. %d active and %d backup servers online.%s"
" %d sessions requeued, %d total in queue.\n",
s->state & SRV_BACKUP ? "Backup " : "",
s->proxy->id, s->id, s->proxy->srv_act, s->proxy->srv_bck,
(s->proxy->srv_bck && !s->proxy->srv_act) ? " Running on backup." : "",
xferred, s->nbpend);
Warning("%s", trash);
send_log(s->proxy, LOG_NOTICE, "%s", trash);
}
s->health = s->rise + s->fall - 1; /* OK now */
}
s->curfd = -1; /* no check running anymore */
//MY_FD_CLR(fd, StaticWriteEvent);
fd_delete(fd);
while (tv_cmp2_ms(&t->expire, &now) <= 0)
tv_delayfrom(&t->expire, &t->expire, s->inter);
goto new_chk;
}
else if (s->result < 0 || tv_cmp2_ms(&t->expire, &now) <= 0) {
//fprintf(stderr, "process_chk: 10\n");
/* failure or timeout detected */
if (s->health > s->rise) {
s->health--; /* still good */
s->failed_checks++;
}
else
set_server_down(s);
s->curfd = -1;
//MY_FD_CLR(fd, StaticWriteEvent);
fd_delete(fd);
while (tv_cmp2_ms(&t->expire, &now) <= 0)
tv_delayfrom(&t->expire, &t->expire, s->inter);
goto new_chk;
}
/* if result is 0 and there's no timeout, we have to wait again */
}
//fprintf(stderr, "process_chk: 11\n");
s->result = 0;
task_queue(t); /* restore t to its place in the task list */
return tv_remain2(&now, &t->expire);
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/