| /* |
| * 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; |
| 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) { |
| FD_SET(fd, StaticReadEvent); /* prepare for reading reply */ |
| FD_CLR(fd, StaticWriteEvent); /* nothing more to write */ |
| return 0; |
| } |
| else { |
| s->result = -1; |
| 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; |
| |
| getsockopt(fd, SOL_SOCKET, SO_ERROR, &skerr, &lskerr); |
| if (!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; |
| |
| 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].read = &event_srv_chk_r; |
| fdtab[fd].write = &event_srv_chk_w; |
| fdtab[fd].state = FD_STCONN; /* connection in progress */ |
| FD_SET(fd, StaticWriteEvent); /* for connect status */ |
| #ifdef DEBUG_FULL |
| assert (!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 */ |
| //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; |
| //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: |
| */ |