blob: 91dd5319d9b5a733b7dd947544fb312e5cacbc94 [file] [log] [blame]
/*
* Health-checks 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 <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/standard.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/proto_http.h>
#include <proto/proxy.h>
#include <proto/server.h>
#include <proto/task.h>
#ifdef CONFIG_HAP_CTTPROXY
#include <import/ip_tproxy.h>
#endif
/* 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.
*/
static 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->be->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 */
http_flush_cookie_flags(&sess->txn);
pendconn_free(pc);
task_wakeup(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("%s '%s' has no server available !\n", proxy_type_str(s->proxy), s->proxy->id);
send_log(s->proxy, LOG_EMERG, "%s %s has no server available !\n", proxy_type_str(s->proxy), 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 in s->result if the
* socket is OK, or -1 if an error occured.
* The function itself returns 0 if it needs some polling before being called
* again, otherwise 1.
*/
static int event_srv_chk_w(int fd)
{
__label__ out_wakeup, out_nowake, out_poll, out_error;
struct task *t = fdtab[fd].owner;
struct server *s = t->context;
if (unlikely(fdtab[fd].state == FD_STERROR || (fdtab[fd].ev & FD_POLL_ERR)))
goto out_error;
/* here, we know that the connection is established */
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) ||
(s->proxy->options & PR_O_SMTP_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) {
EV_FD_SET(fd, DIR_RD); /* prepare for reading reply */
goto out_nowake;
}
else if (ret == 0 || errno == EAGAIN)
goto out_poll;
else
goto out_error;
}
else {
/* We have no data to send to check the connection, and
* getsockopt() will not inform us whether the connection
* is still pending. So we'll reuse connect() to check the
* state of the socket. This has the advantage of givig us
* the following info :
* - error
* - connecting (EALREADY, EINPROGRESS)
* - connected (EISCONN, 0)
*/
struct sockaddr_in sa;
sa = (s->check_addr.sin_addr.s_addr) ? s->check_addr : s->addr;
sa.sin_port = htons(s->check_port);
if (connect(fd, (struct sockaddr *)&sa, sizeof(sa)) == 0)
errno = 0;
if (errno == EALREADY || errno == EINPROGRESS)
goto out_poll;
if (errno && errno != EISCONN)
goto out_error;
/* good TCP connection is enough */
s->result = 1;
goto out_wakeup;
}
}
out_wakeup:
task_wakeup(t);
out_nowake:
EV_FD_CLR(fd, DIR_WR); /* nothing more to write */
fdtab[fd].ev &= ~FD_POLL_WR;
return 1;
out_poll:
/* The connection is still pending. We'll have to poll it
* before attempting to go further. */
fdtab[fd].ev &= ~FD_POLL_WR;
return 0;
out_error:
s->result = -1;
fdtab[fd].state = FD_STERROR;
goto out_wakeup;
}
/*
* 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 if it needs to be called again after some
* polling, otherwise non-zero..
*/
static int event_srv_chk_r(int fd)
{
__label__ out_wakeup;
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 (unlikely(fdtab[fd].state == FD_STERROR ||
(fdtab[fd].ev & FD_POLL_ERR) ||
(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;
goto out_wakeup;
}
#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 (unlikely(len < 0 && errno == EAGAIN)) {
/* we want some polling to happen first */
fdtab[fd].ev &= ~FD_POLL_RD;
return 0;
}
if ((s->proxy->options & PR_O_HTTP_CHK) && (len >= sizeof("HTTP/1.0 000")) &&
(memcmp(reply, "HTTP/1.", 7) == 0) && (reply[9] == '2' || reply[9] == '3')) {
/* HTTP/1.X 2xx or 3xx */
result = 1;
}
else if ((s->proxy->options & PR_O_SSL3_CHK) && (len >= 5) &&
(reply[0] == 0x15 || reply[0] == 0x16)) {
/* SSLv3 alert or handshake */
result = 1;
}
else if ((s->proxy->options & PR_O_SMTP_CHK) && (len >= 3) &&
(reply[0] == '2')) /* 2xx (should be 250) */ {
result = 1;
}
if (result == -1)
fdtab[fd].state = FD_STERROR;
if (s->result != -1)
s->result = result;
out_wakeup:
EV_FD_CLR(fd, DIR_RD);
task_wakeup(t);
fdtab[fd].ev &= ~FD_POLL_RD;
return 1;
}
/*
* manages a server health-check. Returns
* the time the task accepts to wait, or TIME_ETERNITY for infinity.
*/
void process_chk(struct task *t, struct timeval *next)
{
__label__ new_chk, out;
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_isle(&t->expire, &now)) { /* not good time yet */
task_queue(t); /* restore t to its place in the task list */
*next = t->expire;
goto out;
}
/* 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_isle(&t->expire, &now))
tv_ms_add(&t->expire, &t->expire, s->inter);
task_queue(t); /* restore t to its place in the task list */
*next = t->expire;
goto out;
}
/* 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");
if (s->check_addr.sin_addr.s_addr)
/* we'll connect to the check addr specified on the server */
sa = s->check_addr;
else
/* we'll connect to the addr on the server */
sa = s->addr;
/* we'll connect to the check port on the server */
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;
}
#ifdef CONFIG_HAP_CTTPROXY
if ((s->state & SRV_TPROXY_MASK) == SRV_TPROXY_ADDR) {
struct in_tproxy itp1, itp2;
memset(&itp1, 0, sizeof(itp1));
itp1.op = TPROXY_ASSIGN;
itp1.v.addr.faddr = s->tproxy_addr.sin_addr;
itp1.v.addr.fport = s->tproxy_addr.sin_port;
/* set connect flag on socket */
itp2.op = TPROXY_FLAGS;
itp2.v.flags = ITP_CONNECT | ITP_ONCE;
if (setsockopt(fd, SOL_IP, IP_TPROXY, &itp1, sizeof(itp1)) == -1 ||
setsockopt(fd, SOL_IP, IP_TPROXY, &itp2, sizeof(itp2)) == -1) {
Alert("Cannot bind to tproxy source address before connect() for server %s/%s. Aborting.\n",
s->proxy->id, s->id);
s->result = -1;
}
}
#endif
}
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 %s '%s'. Aborting.\n",
proxy_type_str(s->proxy), s->proxy->id);
s->result = -1;
}
#ifdef CONFIG_HAP_CTTPROXY
if ((s->proxy->options & PR_O_TPXY_MASK) == PR_O_TPXY_ADDR) {
struct in_tproxy itp1, itp2;
memset(&itp1, 0, sizeof(itp1));
itp1.op = TPROXY_ASSIGN;
itp1.v.addr.faddr = s->tproxy_addr.sin_addr;
itp1.v.addr.fport = s->tproxy_addr.sin_port;
/* set connect flag on socket */
itp2.op = TPROXY_FLAGS;
itp2.v.flags = ITP_CONNECT | ITP_ONCE;
if (setsockopt(fd, SOL_IP, IP_TPROXY, &itp1, sizeof(itp1)) == -1 ||
setsockopt(fd, SOL_IP, IP_TPROXY, &itp2, sizeof(itp2)) == -1) {
Alert("Cannot bind to tproxy source address before connect() for %s '%s'. Aborting.\n",
proxy_type_str(s->proxy), s->proxy->id);
s->result = -1;
}
}
#endif
}
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 ;-) */
fd_insert(fd);
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 */
fdtab[fd].ev = 0;
EV_FD_SET(fd, DIR_WR); /* for connect status */
#ifdef DEBUG_FULL
assert (!EV_FD_ISSET(fd, DIR_RD));
#endif
/* FIXME: we allow up to <inter> for a connection to establish, but we should use another parameter */
tv_ms_add(&t->expire, &now, s->inter);
task_queue(t); /* restore t to its place in the task list */
*next = 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_isle(&t->expire, &now))
tv_ms_add(&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_isle(&t->expire, &now))
tv_ms_add(&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(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 */
fd_delete(fd);
while (tv_isle(&t->expire, &now))
tv_ms_add(&t->expire, &t->expire, s->inter);
goto new_chk;
}
else if (s->result < 0 || tv_isle(&t->expire, &now)) {
//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;
fd_delete(fd);
while (tv_isle(&t->expire, &now))
tv_ms_add(&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 */
*next = t->expire;
out:
return;
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/