| /* |
| * Backend variables and functions. |
| * |
| * Copyright 2000-2008 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 <stdlib.h> |
| #include <syslog.h> |
| #include <string.h> |
| #include <ctype.h> |
| |
| #include <netinet/tcp.h> |
| |
| #include <common/compat.h> |
| #include <common/config.h> |
| #include <common/debug.h> |
| #include <common/eb32tree.h> |
| #include <common/ticks.h> |
| #include <common/time.h> |
| |
| #include <types/global.h> |
| |
| #include <proto/acl.h> |
| #include <proto/backend.h> |
| #include <proto/client.h> |
| #include <proto/fd.h> |
| #include <proto/httperr.h> |
| #include <proto/log.h> |
| #include <proto/port_range.h> |
| #include <proto/proto_http.h> |
| #include <proto/proto_tcp.h> |
| #include <proto/queue.h> |
| #include <proto/server.h> |
| #include <proto/session.h> |
| #include <proto/stream_sock.h> |
| #include <proto/task.h> |
| |
| static inline void fwrr_remove_from_tree(struct server *s); |
| static inline void fwrr_queue_by_weight(struct eb_root *root, struct server *s); |
| static inline void fwrr_dequeue_srv(struct server *s); |
| static void fwrr_get_srv(struct server *s); |
| static void fwrr_queue_srv(struct server *s); |
| |
| /* This function returns non-zero if a server with the given weight and state |
| * is usable for LB, otherwise zero. |
| */ |
| static inline int srv_is_usable(int state, int weight) |
| { |
| if (!weight) |
| return 0; |
| if (state & SRV_GOINGDOWN) |
| return 0; |
| if (!(state & SRV_RUNNING)) |
| return 0; |
| return 1; |
| } |
| |
| /* |
| * This function recounts the number of usable active and backup servers for |
| * proxy <p>. These numbers are returned into the p->srv_act and p->srv_bck. |
| * This function also recomputes the total active and backup weights. However, |
| * it does not update tot_weight nor tot_used. Use update_backend_weight() for |
| * this. |
| */ |
| static void recount_servers(struct proxy *px) |
| { |
| struct server *srv; |
| |
| px->srv_act = px->srv_bck = 0; |
| px->lbprm.tot_wact = px->lbprm.tot_wbck = 0; |
| px->lbprm.fbck = NULL; |
| for (srv = px->srv; srv != NULL; srv = srv->next) { |
| if (!srv_is_usable(srv->state, srv->eweight)) |
| continue; |
| |
| if (srv->state & SRV_BACKUP) { |
| if (!px->srv_bck && |
| !(px->options & PR_O_USE_ALL_BK)) |
| px->lbprm.fbck = srv; |
| px->srv_bck++; |
| px->lbprm.tot_wbck += srv->eweight; |
| } else { |
| px->srv_act++; |
| px->lbprm.tot_wact += srv->eweight; |
| } |
| } |
| } |
| |
| /* This function simply updates the backend's tot_weight and tot_used values |
| * after servers weights have been updated. It is designed to be used after |
| * recount_servers() or equivalent. |
| */ |
| static void update_backend_weight(struct proxy *px) |
| { |
| if (px->srv_act) { |
| px->lbprm.tot_weight = px->lbprm.tot_wact; |
| px->lbprm.tot_used = px->srv_act; |
| } |
| else if (px->lbprm.fbck) { |
| /* use only the first backup server */ |
| px->lbprm.tot_weight = px->lbprm.fbck->eweight; |
| px->lbprm.tot_used = 1; |
| } |
| else { |
| px->lbprm.tot_weight = px->lbprm.tot_wbck; |
| px->lbprm.tot_used = px->srv_bck; |
| } |
| } |
| |
| /* this function updates the map according to server <srv>'s new state */ |
| static void map_set_server_status_down(struct server *srv) |
| { |
| struct proxy *p = srv->proxy; |
| |
| if (srv->state == srv->prev_state && |
| srv->eweight == srv->prev_eweight) |
| return; |
| |
| if (srv_is_usable(srv->state, srv->eweight)) |
| goto out_update_state; |
| |
| /* FIXME: could be optimized since we know what changed */ |
| recount_servers(p); |
| update_backend_weight(p); |
| p->lbprm.map.state |= PR_MAP_RECALC; |
| out_update_state: |
| srv->prev_state = srv->state; |
| srv->prev_eweight = srv->eweight; |
| } |
| |
| /* This function updates the map according to server <srv>'s new state */ |
| static void map_set_server_status_up(struct server *srv) |
| { |
| struct proxy *p = srv->proxy; |
| |
| if (srv->state == srv->prev_state && |
| srv->eweight == srv->prev_eweight) |
| return; |
| |
| if (!srv_is_usable(srv->state, srv->eweight)) |
| goto out_update_state; |
| |
| /* FIXME: could be optimized since we know what changed */ |
| recount_servers(p); |
| update_backend_weight(p); |
| p->lbprm.map.state |= PR_MAP_RECALC; |
| out_update_state: |
| srv->prev_state = srv->state; |
| srv->prev_eweight = srv->eweight; |
| } |
| |
| /* This function recomputes the server map for proxy px. It relies on |
| * px->lbprm.tot_wact, tot_wbck, tot_used, tot_weight, so it must be |
| * called after recount_servers(). It also expects px->lbprm.map.srv |
| * to be allocated with the largest size needed. It updates tot_weight. |
| */ |
| void recalc_server_map(struct proxy *px) |
| { |
| int o, tot, flag; |
| struct server *cur, *best; |
| |
| switch (px->lbprm.tot_used) { |
| case 0: /* no server */ |
| px->lbprm.map.state &= ~PR_MAP_RECALC; |
| return; |
| case 1: /* only one server, just fill first entry */ |
| tot = 1; |
| break; |
| default: |
| tot = px->lbprm.tot_weight; |
| break; |
| } |
| |
| /* here we *know* that we have some servers */ |
| if (px->srv_act) |
| flag = SRV_RUNNING; |
| else |
| flag = SRV_RUNNING | SRV_BACKUP; |
| |
| /* this algorithm gives priority to the first server, which means that |
| * it will respect the declaration order for equivalent weights, and |
| * that whatever the weights, the first server called will always be |
| * the first declared. This is an important asumption for the backup |
| * case, where we want the first server only. |
| */ |
| for (cur = px->srv; cur; cur = cur->next) |
| cur->wscore = 0; |
| |
| for (o = 0; o < tot; o++) { |
| int max = 0; |
| best = NULL; |
| for (cur = px->srv; cur; cur = cur->next) { |
| if (cur->eweight && |
| flag == (cur->state & |
| (SRV_RUNNING | SRV_GOINGDOWN | SRV_BACKUP))) { |
| int v; |
| |
| /* If we are forced to return only one server, we don't want to |
| * go further, because we would return the wrong one due to |
| * divide overflow. |
| */ |
| if (tot == 1) { |
| best = cur; |
| /* note that best->wscore will be wrong but we don't care */ |
| break; |
| } |
| |
| cur->wscore += cur->eweight; |
| v = (cur->wscore + tot) / tot; /* result between 0 and 3 */ |
| if (best == NULL || v > max) { |
| max = v; |
| best = cur; |
| } |
| } |
| } |
| px->lbprm.map.srv[o] = best; |
| best->wscore -= tot; |
| } |
| px->lbprm.map.state &= ~PR_MAP_RECALC; |
| } |
| |
| /* This function is responsible of building the server MAP for map-based LB |
| * algorithms, allocating the map, and setting p->lbprm.wmult to the GCD of the |
| * weights if applicable. It should be called only once per proxy, at config |
| * time. |
| */ |
| void init_server_map(struct proxy *p) |
| { |
| struct server *srv; |
| int pgcd; |
| int act, bck; |
| |
| p->lbprm.set_server_status_up = map_set_server_status_up; |
| p->lbprm.set_server_status_down = map_set_server_status_down; |
| p->lbprm.update_server_eweight = NULL; |
| |
| if (!p->srv) |
| return; |
| |
| /* We will factor the weights to reduce the table, |
| * using Euclide's largest common divisor algorithm. |
| * Since we may have zero weights, we have to first |
| * find a non-zero weight server. |
| */ |
| pgcd = 1; |
| srv = p->srv; |
| while (srv && !srv->uweight) |
| srv = srv->next; |
| |
| if (srv) { |
| pgcd = srv->uweight; /* note: cannot be zero */ |
| while (pgcd > 1 && (srv = srv->next)) { |
| int w = srv->uweight; |
| while (w) { |
| int t = pgcd % w; |
| pgcd = w; |
| w = t; |
| } |
| } |
| } |
| |
| /* It is sometimes useful to know what factor to apply |
| * to the backend's effective weight to know its real |
| * weight. |
| */ |
| p->lbprm.wmult = pgcd; |
| |
| act = bck = 0; |
| for (srv = p->srv; srv; srv = srv->next) { |
| srv->eweight = srv->uweight / pgcd; |
| srv->prev_eweight = srv->eweight; |
| srv->prev_state = srv->state; |
| if (srv->state & SRV_BACKUP) |
| bck += srv->eweight; |
| else |
| act += srv->eweight; |
| } |
| |
| /* this is the largest map we will ever need for this servers list */ |
| if (act < bck) |
| act = bck; |
| |
| if (!act) |
| act = 1; |
| |
| p->lbprm.map.srv = (struct server **)calloc(act, sizeof(struct server *)); |
| /* recounts servers and their weights */ |
| p->lbprm.map.state = PR_MAP_RECALC; |
| recount_servers(p); |
| update_backend_weight(p); |
| recalc_server_map(p); |
| } |
| |
| /* This function updates the server trees according to server <srv>'s new |
| * state. It should be called when server <srv>'s status changes to down. |
| * It is not important whether the server was already down or not. It is not |
| * important either that the new state is completely down (the caller may not |
| * know all the variables of a server's state). |
| */ |
| static void fwrr_set_server_status_down(struct server *srv) |
| { |
| struct proxy *p = srv->proxy; |
| struct fwrr_group *grp; |
| |
| if (srv->state == srv->prev_state && |
| srv->eweight == srv->prev_eweight) |
| return; |
| |
| if (srv_is_usable(srv->state, srv->eweight)) |
| goto out_update_state; |
| |
| if (!srv_is_usable(srv->prev_state, srv->prev_eweight)) |
| /* server was already down */ |
| goto out_update_backend; |
| |
| grp = (srv->state & SRV_BACKUP) ? &p->lbprm.fwrr.bck : &p->lbprm.fwrr.act; |
| grp->next_weight -= srv->prev_eweight; |
| |
| if (srv->state & SRV_BACKUP) { |
| p->lbprm.tot_wbck = p->lbprm.fwrr.bck.next_weight; |
| p->srv_bck--; |
| |
| if (srv == p->lbprm.fbck) { |
| /* we lost the first backup server in a single-backup |
| * configuration, we must search another one. |
| */ |
| struct server *srv2 = p->lbprm.fbck; |
| do { |
| srv2 = srv2->next; |
| } while (srv2 && |
| !((srv2->state & SRV_BACKUP) && |
| srv_is_usable(srv2->state, srv2->eweight))); |
| p->lbprm.fbck = srv2; |
| } |
| } else { |
| p->lbprm.tot_wact = p->lbprm.fwrr.act.next_weight; |
| p->srv_act--; |
| } |
| |
| fwrr_dequeue_srv(srv); |
| fwrr_remove_from_tree(srv); |
| |
| out_update_backend: |
| /* check/update tot_used, tot_weight */ |
| update_backend_weight(p); |
| out_update_state: |
| srv->prev_state = srv->state; |
| srv->prev_eweight = srv->eweight; |
| } |
| |
| /* This function updates the server trees according to server <srv>'s new |
| * state. It should be called when server <srv>'s status changes to up. |
| * It is not important whether the server was already down or not. It is not |
| * important either that the new state is completely UP (the caller may not |
| * know all the variables of a server's state). This function will not change |
| * the weight of a server which was already up. |
| */ |
| static void fwrr_set_server_status_up(struct server *srv) |
| { |
| struct proxy *p = srv->proxy; |
| struct fwrr_group *grp; |
| |
| if (srv->state == srv->prev_state && |
| srv->eweight == srv->prev_eweight) |
| return; |
| |
| if (!srv_is_usable(srv->state, srv->eweight)) |
| goto out_update_state; |
| |
| if (srv_is_usable(srv->prev_state, srv->prev_eweight)) |
| /* server was already up */ |
| goto out_update_backend; |
| |
| grp = (srv->state & SRV_BACKUP) ? &p->lbprm.fwrr.bck : &p->lbprm.fwrr.act; |
| grp->next_weight += srv->eweight; |
| |
| if (srv->state & SRV_BACKUP) { |
| p->lbprm.tot_wbck = p->lbprm.fwrr.bck.next_weight; |
| p->srv_bck++; |
| |
| if (!(p->options & PR_O_USE_ALL_BK)) { |
| if (!p->lbprm.fbck) { |
| /* there was no backup server anymore */ |
| p->lbprm.fbck = srv; |
| } else { |
| /* we may have restored a backup server prior to fbck, |
| * in which case it should replace it. |
| */ |
| struct server *srv2 = srv; |
| do { |
| srv2 = srv2->next; |
| } while (srv2 && (srv2 != p->lbprm.fbck)); |
| if (srv2) |
| p->lbprm.fbck = srv; |
| } |
| } |
| } else { |
| p->lbprm.tot_wact = p->lbprm.fwrr.act.next_weight; |
| p->srv_act++; |
| } |
| |
| /* note that eweight cannot be 0 here */ |
| fwrr_get_srv(srv); |
| srv->npos = grp->curr_pos + (grp->next_weight + grp->curr_weight - grp->curr_pos) / srv->eweight; |
| fwrr_queue_srv(srv); |
| |
| out_update_backend: |
| /* check/update tot_used, tot_weight */ |
| update_backend_weight(p); |
| out_update_state: |
| srv->prev_state = srv->state; |
| srv->prev_eweight = srv->eweight; |
| } |
| |
| /* This function must be called after an update to server <srv>'s effective |
| * weight. It may be called after a state change too. |
| */ |
| static void fwrr_update_server_weight(struct server *srv) |
| { |
| int old_state, new_state; |
| struct proxy *p = srv->proxy; |
| struct fwrr_group *grp; |
| |
| if (srv->state == srv->prev_state && |
| srv->eweight == srv->prev_eweight) |
| return; |
| |
| /* If changing the server's weight changes its state, we simply apply |
| * the procedures we already have for status change. If the state |
| * remains down, the server is not in any tree, so it's as easy as |
| * updating its values. If the state remains up with different weights, |
| * there are some computations to perform to find a new place and |
| * possibly a new tree for this server. |
| */ |
| |
| old_state = srv_is_usable(srv->prev_state, srv->prev_eweight); |
| new_state = srv_is_usable(srv->state, srv->eweight); |
| |
| if (!old_state && !new_state) { |
| srv->prev_state = srv->state; |
| srv->prev_eweight = srv->eweight; |
| return; |
| } |
| else if (!old_state && new_state) { |
| fwrr_set_server_status_up(srv); |
| return; |
| } |
| else if (old_state && !new_state) { |
| fwrr_set_server_status_down(srv); |
| return; |
| } |
| |
| grp = (srv->state & SRV_BACKUP) ? &p->lbprm.fwrr.bck : &p->lbprm.fwrr.act; |
| grp->next_weight = grp->next_weight - srv->prev_eweight + srv->eweight; |
| |
| p->lbprm.tot_wact = p->lbprm.fwrr.act.next_weight; |
| p->lbprm.tot_wbck = p->lbprm.fwrr.bck.next_weight; |
| |
| if (srv->lb_tree == grp->init) { |
| fwrr_dequeue_srv(srv); |
| fwrr_queue_by_weight(grp->init, srv); |
| } |
| else if (!srv->lb_tree) { |
| /* FIXME: server was down. This is not possible right now but |
| * may be needed soon for slowstart or graceful shutdown. |
| */ |
| fwrr_dequeue_srv(srv); |
| fwrr_get_srv(srv); |
| srv->npos = grp->curr_pos + (grp->next_weight + grp->curr_weight - grp->curr_pos) / srv->eweight; |
| fwrr_queue_srv(srv); |
| } else { |
| /* The server is either active or in the next queue. If it's |
| * still in the active queue and it has not consumed all of its |
| * places, let's adjust its next position. |
| */ |
| fwrr_get_srv(srv); |
| |
| if (srv->eweight > 0) { |
| int prev_next = srv->npos; |
| int step = grp->next_weight / srv->eweight; |
| |
| srv->npos = srv->lpos + step; |
| srv->rweight = 0; |
| |
| if (srv->npos > prev_next) |
| srv->npos = prev_next; |
| if (srv->npos < grp->curr_pos + 2) |
| srv->npos = grp->curr_pos + step; |
| } else { |
| /* push it into the next tree */ |
| srv->npos = grp->curr_pos + grp->curr_weight; |
| } |
| |
| fwrr_dequeue_srv(srv); |
| fwrr_queue_srv(srv); |
| } |
| |
| update_backend_weight(p); |
| srv->prev_state = srv->state; |
| srv->prev_eweight = srv->eweight; |
| } |
| |
| /* Remove a server from a tree. It must have previously been dequeued. This |
| * function is meant to be called when a server is going down or has its |
| * weight disabled. |
| */ |
| static inline void fwrr_remove_from_tree(struct server *s) |
| { |
| s->lb_tree = NULL; |
| } |
| |
| /* Queue a server in the weight tree <root>, assuming the weight is >0. |
| * We want to sort them by inverted weights, because we need to place |
| * heavy servers first in order to get a smooth distribution. |
| */ |
| static inline void fwrr_queue_by_weight(struct eb_root *root, struct server *s) |
| { |
| s->lb_node.key = SRV_EWGHT_MAX - s->eweight; |
| eb32_insert(root, &s->lb_node); |
| s->lb_tree = root; |
| } |
| |
| /* This function is responsible for building the weight trees in case of fast |
| * weighted round-robin. It also sets p->lbprm.wdiv to the eweight to uweight |
| * ratio. Both active and backup groups are initialized. |
| */ |
| void fwrr_init_server_groups(struct proxy *p) |
| { |
| struct server *srv; |
| struct eb_root init_head = EB_ROOT; |
| |
| p->lbprm.set_server_status_up = fwrr_set_server_status_up; |
| p->lbprm.set_server_status_down = fwrr_set_server_status_down; |
| p->lbprm.update_server_eweight = fwrr_update_server_weight; |
| |
| p->lbprm.wdiv = BE_WEIGHT_SCALE; |
| for (srv = p->srv; srv; srv = srv->next) { |
| srv->prev_eweight = srv->eweight = srv->uweight * BE_WEIGHT_SCALE; |
| srv->prev_state = srv->state; |
| } |
| |
| recount_servers(p); |
| update_backend_weight(p); |
| |
| /* prepare the active servers group */ |
| p->lbprm.fwrr.act.curr_pos = p->lbprm.fwrr.act.curr_weight = |
| p->lbprm.fwrr.act.next_weight = p->lbprm.tot_wact; |
| p->lbprm.fwrr.act.curr = p->lbprm.fwrr.act.t0 = |
| p->lbprm.fwrr.act.t1 = init_head; |
| p->lbprm.fwrr.act.init = &p->lbprm.fwrr.act.t0; |
| p->lbprm.fwrr.act.next = &p->lbprm.fwrr.act.t1; |
| |
| /* prepare the backup servers group */ |
| p->lbprm.fwrr.bck.curr_pos = p->lbprm.fwrr.bck.curr_weight = |
| p->lbprm.fwrr.bck.next_weight = p->lbprm.tot_wbck; |
| p->lbprm.fwrr.bck.curr = p->lbprm.fwrr.bck.t0 = |
| p->lbprm.fwrr.bck.t1 = init_head; |
| p->lbprm.fwrr.bck.init = &p->lbprm.fwrr.bck.t0; |
| p->lbprm.fwrr.bck.next = &p->lbprm.fwrr.bck.t1; |
| |
| /* queue active and backup servers in two distinct groups */ |
| for (srv = p->srv; srv; srv = srv->next) { |
| if (!srv_is_usable(srv->state, srv->eweight)) |
| continue; |
| fwrr_queue_by_weight((srv->state & SRV_BACKUP) ? |
| p->lbprm.fwrr.bck.init : |
| p->lbprm.fwrr.act.init, |
| srv); |
| } |
| } |
| |
| /* simply removes a server from a weight tree */ |
| static inline void fwrr_dequeue_srv(struct server *s) |
| { |
| eb32_delete(&s->lb_node); |
| } |
| |
| /* queues a server into the appropriate group and tree depending on its |
| * backup status, and ->npos. If the server is disabled, simply assign |
| * it to the NULL tree. |
| */ |
| static void fwrr_queue_srv(struct server *s) |
| { |
| struct proxy *p = s->proxy; |
| struct fwrr_group *grp; |
| |
| grp = (s->state & SRV_BACKUP) ? &p->lbprm.fwrr.bck : &p->lbprm.fwrr.act; |
| |
| /* Delay everything which does not fit into the window and everything |
| * which does not fit into the theorical new window. |
| */ |
| if (!srv_is_usable(s->state, s->eweight)) { |
| fwrr_remove_from_tree(s); |
| } |
| else if (s->eweight <= 0 || |
| s->npos >= 2 * grp->curr_weight || |
| s->npos >= grp->curr_weight + grp->next_weight) { |
| /* put into next tree, and readjust npos in case we could |
| * finally take this back to current. */ |
| s->npos -= grp->curr_weight; |
| fwrr_queue_by_weight(grp->next, s); |
| } |
| else { |
| /* The sorting key is stored in units of s->npos * user_weight |
| * in order to avoid overflows. As stated in backend.h, the |
| * lower the scale, the rougher the weights modulation, and the |
| * higher the scale, the lower the number of servers without |
| * overflow. With this formula, the result is always positive, |
| * so we can use eb3é_insert(). |
| */ |
| s->lb_node.key = SRV_UWGHT_RANGE * s->npos + |
| (unsigned)(SRV_EWGHT_MAX + s->rweight - s->eweight) / BE_WEIGHT_SCALE; |
| |
| eb32_insert(&grp->curr, &s->lb_node); |
| s->lb_tree = &grp->curr; |
| } |
| } |
| |
| /* prepares a server when extracting it from the "init" tree */ |
| static inline void fwrr_get_srv_init(struct server *s) |
| { |
| s->npos = s->rweight = 0; |
| } |
| |
| /* prepares a server when extracting it from the "next" tree */ |
| static inline void fwrr_get_srv_next(struct server *s) |
| { |
| struct fwrr_group *grp = (s->state & SRV_BACKUP) ? |
| &s->proxy->lbprm.fwrr.bck : |
| &s->proxy->lbprm.fwrr.act; |
| |
| s->npos += grp->curr_weight; |
| } |
| |
| /* prepares a server when it was marked down */ |
| static inline void fwrr_get_srv_down(struct server *s) |
| { |
| struct fwrr_group *grp = (s->state & SRV_BACKUP) ? |
| &s->proxy->lbprm.fwrr.bck : |
| &s->proxy->lbprm.fwrr.act; |
| |
| s->npos = grp->curr_pos; |
| } |
| |
| /* prepares a server when extracting it from its tree */ |
| static void fwrr_get_srv(struct server *s) |
| { |
| struct proxy *p = s->proxy; |
| struct fwrr_group *grp = (s->state & SRV_BACKUP) ? |
| &p->lbprm.fwrr.bck : |
| &p->lbprm.fwrr.act; |
| |
| if (s->lb_tree == grp->init) { |
| fwrr_get_srv_init(s); |
| } |
| else if (s->lb_tree == grp->next) { |
| fwrr_get_srv_next(s); |
| } |
| else if (s->lb_tree == NULL) { |
| fwrr_get_srv_down(s); |
| } |
| } |
| |
| /* switches trees "init" and "next" for FWRR group <grp>. "init" should be empty |
| * when this happens, and "next" filled with servers sorted by weights. |
| */ |
| static inline void fwrr_switch_trees(struct fwrr_group *grp) |
| { |
| struct eb_root *swap; |
| swap = grp->init; |
| grp->init = grp->next; |
| grp->next = swap; |
| grp->curr_weight = grp->next_weight; |
| grp->curr_pos = grp->curr_weight; |
| } |
| |
| /* return next server from the current tree in FWRR group <grp>, or a server |
| * from the "init" tree if appropriate. If both trees are empty, return NULL. |
| */ |
| static struct server *fwrr_get_server_from_group(struct fwrr_group *grp) |
| { |
| struct eb32_node *node; |
| struct server *s; |
| |
| node = eb32_first(&grp->curr); |
| s = eb32_entry(node, struct server, lb_node); |
| |
| if (!node || s->npos > grp->curr_pos) { |
| /* either we have no server left, or we have a hole */ |
| struct eb32_node *node2; |
| node2 = eb32_first(grp->init); |
| if (node2) { |
| node = node2; |
| s = eb32_entry(node, struct server, lb_node); |
| fwrr_get_srv_init(s); |
| if (s->eweight == 0) /* FIXME: is it possible at all ? */ |
| node = NULL; |
| } |
| } |
| if (node) |
| return s; |
| else |
| return NULL; |
| } |
| |
| /* Computes next position of server <s> in the group. It is mandatory for <s> |
| * to have a non-zero, positive eweight. |
| */ |
| static inline void fwrr_update_position(struct fwrr_group *grp, struct server *s) |
| { |
| if (!s->npos) { |
| /* first time ever for this server */ |
| s->lpos = grp->curr_pos; |
| s->npos = grp->curr_pos + grp->next_weight / s->eweight; |
| s->rweight += grp->next_weight % s->eweight; |
| |
| if (s->rweight >= s->eweight) { |
| s->rweight -= s->eweight; |
| s->npos++; |
| } |
| } else { |
| s->lpos = s->npos; |
| s->npos += grp->next_weight / s->eweight; |
| s->rweight += grp->next_weight % s->eweight; |
| |
| if (s->rweight >= s->eweight) { |
| s->rweight -= s->eweight; |
| s->npos++; |
| } |
| } |
| } |
| |
| /* Return next server from the current tree in backend <p>, or a server from |
| * the init tree if appropriate. If both trees are empty, return NULL. |
| * Saturated servers are skipped and requeued. |
| */ |
| static struct server *fwrr_get_next_server(struct proxy *p, struct server *srvtoavoid) |
| { |
| struct server *srv, *full, *avoided; |
| struct fwrr_group *grp; |
| int switched; |
| |
| if (p->srv_act) |
| grp = &p->lbprm.fwrr.act; |
| else if (p->lbprm.fbck) |
| return p->lbprm.fbck; |
| else if (p->srv_bck) |
| grp = &p->lbprm.fwrr.bck; |
| else |
| return NULL; |
| |
| switched = 0; |
| avoided = NULL; |
| full = NULL; /* NULL-terminated list of saturated servers */ |
| while (1) { |
| /* if we see an empty group, let's first try to collect weights |
| * which might have recently changed. |
| */ |
| if (!grp->curr_weight) |
| grp->curr_pos = grp->curr_weight = grp->next_weight; |
| |
| /* get first server from the "current" tree. When the end of |
| * the tree is reached, we may have to switch, but only once. |
| */ |
| while (1) { |
| srv = fwrr_get_server_from_group(grp); |
| if (srv) |
| break; |
| if (switched) { |
| if (avoided) { |
| srv = avoided; |
| break; |
| } |
| goto requeue_servers; |
| } |
| switched = 1; |
| fwrr_switch_trees(grp); |
| |
| } |
| |
| /* OK, we have a server. However, it may be saturated, in which |
| * case we don't want to reconsider it for now. We'll update |
| * its position and dequeue it anyway, so that we can move it |
| * to a better place afterwards. |
| */ |
| fwrr_update_position(grp, srv); |
| fwrr_dequeue_srv(srv); |
| grp->curr_pos++; |
| if (!srv->maxconn || (!srv->nbpend && srv->served < srv_dynamic_maxconn(srv))) { |
| /* make sure it is not the server we are trying to exclude... */ |
| if (srv != srvtoavoid || avoided) |
| break; |
| |
| avoided = srv; /* ...but remember that is was selected yet avoided */ |
| } |
| |
| /* the server is saturated or avoided, let's chain it for later reinsertion */ |
| srv->next_full = full; |
| full = srv; |
| } |
| |
| /* OK, we got the best server, let's update it */ |
| fwrr_queue_srv(srv); |
| |
| requeue_servers: |
| /* Requeue all extracted servers. If full==srv then it was |
| * avoided (unsucessfully) and chained, omit it now. |
| */ |
| if (unlikely(full != NULL)) { |
| if (switched) { |
| /* the tree has switched, requeue all extracted servers |
| * into "init", because their place was lost, and only |
| * their weight matters. |
| */ |
| do { |
| if (likely(full != srv)) |
| fwrr_queue_by_weight(grp->init, full); |
| full = full->next_full; |
| } while (full); |
| } else { |
| /* requeue all extracted servers just as if they were consumed |
| * so that they regain their expected place. |
| */ |
| do { |
| if (likely(full != srv)) |
| fwrr_queue_srv(full); |
| full = full->next_full; |
| } while (full); |
| } |
| } |
| return srv; |
| } |
| |
| /* Remove a server from a tree. It must have previously been dequeued. This |
| * function is meant to be called when a server is going down or has its |
| * weight disabled. |
| */ |
| static inline void fwlc_remove_from_tree(struct server *s) |
| { |
| s->lb_tree = NULL; |
| } |
| |
| /* simply removes a server from a tree */ |
| static inline void fwlc_dequeue_srv(struct server *s) |
| { |
| eb32_delete(&s->lb_node); |
| } |
| |
| /* Queue a server in its associated tree, assuming the weight is >0. |
| * Servers are sorted by #conns/weight. To ensure maximum accuracy, |
| * we use #conns*SRV_EWGHT_MAX/eweight as the sorting key. |
| */ |
| static inline void fwlc_queue_srv(struct server *s) |
| { |
| s->lb_node.key = s->served * SRV_EWGHT_MAX / s->eweight; |
| eb32_insert(s->lb_tree, &s->lb_node); |
| } |
| |
| /* Re-position the server in the FWLC tree after it has been assigned one |
| * connection or after it has released one. Note that it is possible that |
| * the server has been moved out of the tree due to failed health-checks. |
| */ |
| static void fwlc_srv_reposition(struct server *s) |
| { |
| if (!s->lb_tree) |
| return; |
| fwlc_dequeue_srv(s); |
| fwlc_queue_srv(s); |
| } |
| |
| /* This function updates the server trees according to server <srv>'s new |
| * state. It should be called when server <srv>'s status changes to down. |
| * It is not important whether the server was already down or not. It is not |
| * important either that the new state is completely down (the caller may not |
| * know all the variables of a server's state). |
| */ |
| static void fwlc_set_server_status_down(struct server *srv) |
| { |
| struct proxy *p = srv->proxy; |
| |
| if (srv->state == srv->prev_state && |
| srv->eweight == srv->prev_eweight) |
| return; |
| |
| if (srv_is_usable(srv->state, srv->eweight)) |
| goto out_update_state; |
| |
| if (!srv_is_usable(srv->prev_state, srv->prev_eweight)) |
| /* server was already down */ |
| goto out_update_backend; |
| |
| if (srv->state & SRV_BACKUP) { |
| p->lbprm.tot_wbck -= srv->prev_eweight; |
| p->srv_bck--; |
| |
| if (srv == p->lbprm.fbck) { |
| /* we lost the first backup server in a single-backup |
| * configuration, we must search another one. |
| */ |
| struct server *srv2 = p->lbprm.fbck; |
| do { |
| srv2 = srv2->next; |
| } while (srv2 && |
| !((srv2->state & SRV_BACKUP) && |
| srv_is_usable(srv2->state, srv2->eweight))); |
| p->lbprm.fbck = srv2; |
| } |
| } else { |
| p->lbprm.tot_wact -= srv->prev_eweight; |
| p->srv_act--; |
| } |
| |
| fwlc_dequeue_srv(srv); |
| fwlc_remove_from_tree(srv); |
| |
| out_update_backend: |
| /* check/update tot_used, tot_weight */ |
| update_backend_weight(p); |
| out_update_state: |
| srv->prev_state = srv->state; |
| srv->prev_eweight = srv->eweight; |
| } |
| |
| /* This function updates the server trees according to server <srv>'s new |
| * state. It should be called when server <srv>'s status changes to up. |
| * It is not important whether the server was already down or not. It is not |
| * important either that the new state is completely UP (the caller may not |
| * know all the variables of a server's state). This function will not change |
| * the weight of a server which was already up. |
| */ |
| static void fwlc_set_server_status_up(struct server *srv) |
| { |
| struct proxy *p = srv->proxy; |
| |
| if (srv->state == srv->prev_state && |
| srv->eweight == srv->prev_eweight) |
| return; |
| |
| if (!srv_is_usable(srv->state, srv->eweight)) |
| goto out_update_state; |
| |
| if (srv_is_usable(srv->prev_state, srv->prev_eweight)) |
| /* server was already up */ |
| goto out_update_backend; |
| |
| if (srv->state & SRV_BACKUP) { |
| srv->lb_tree = &p->lbprm.fwlc.bck; |
| p->lbprm.tot_wbck += srv->eweight; |
| p->srv_bck++; |
| |
| if (!(p->options & PR_O_USE_ALL_BK)) { |
| if (!p->lbprm.fbck) { |
| /* there was no backup server anymore */ |
| p->lbprm.fbck = srv; |
| } else { |
| /* we may have restored a backup server prior to fbck, |
| * in which case it should replace it. |
| */ |
| struct server *srv2 = srv; |
| do { |
| srv2 = srv2->next; |
| } while (srv2 && (srv2 != p->lbprm.fbck)); |
| if (srv2) |
| p->lbprm.fbck = srv; |
| } |
| } |
| } else { |
| srv->lb_tree = &p->lbprm.fwlc.act; |
| p->lbprm.tot_wact += srv->eweight; |
| p->srv_act++; |
| } |
| |
| /* note that eweight cannot be 0 here */ |
| fwlc_queue_srv(srv); |
| |
| out_update_backend: |
| /* check/update tot_used, tot_weight */ |
| update_backend_weight(p); |
| out_update_state: |
| srv->prev_state = srv->state; |
| srv->prev_eweight = srv->eweight; |
| } |
| |
| /* This function must be called after an update to server <srv>'s effective |
| * weight. It may be called after a state change too. |
| */ |
| static void fwlc_update_server_weight(struct server *srv) |
| { |
| int old_state, new_state; |
| struct proxy *p = srv->proxy; |
| |
| if (srv->state == srv->prev_state && |
| srv->eweight == srv->prev_eweight) |
| return; |
| |
| /* If changing the server's weight changes its state, we simply apply |
| * the procedures we already have for status change. If the state |
| * remains down, the server is not in any tree, so it's as easy as |
| * updating its values. If the state remains up with different weights, |
| * there are some computations to perform to find a new place and |
| * possibly a new tree for this server. |
| */ |
| |
| old_state = srv_is_usable(srv->prev_state, srv->prev_eweight); |
| new_state = srv_is_usable(srv->state, srv->eweight); |
| |
| if (!old_state && !new_state) { |
| srv->prev_state = srv->state; |
| srv->prev_eweight = srv->eweight; |
| return; |
| } |
| else if (!old_state && new_state) { |
| fwlc_set_server_status_up(srv); |
| return; |
| } |
| else if (old_state && !new_state) { |
| fwlc_set_server_status_down(srv); |
| return; |
| } |
| |
| if (srv->lb_tree) |
| fwlc_dequeue_srv(srv); |
| |
| if (srv->state & SRV_BACKUP) { |
| p->lbprm.tot_wbck += srv->eweight - srv->prev_eweight; |
| srv->lb_tree = &p->lbprm.fwlc.bck; |
| } else { |
| p->lbprm.tot_wact += srv->eweight - srv->prev_eweight; |
| srv->lb_tree = &p->lbprm.fwlc.act; |
| } |
| |
| fwlc_queue_srv(srv); |
| |
| update_backend_weight(p); |
| srv->prev_state = srv->state; |
| srv->prev_eweight = srv->eweight; |
| } |
| |
| /* This function is responsible for building the trees in case of fast |
| * weighted least-conns. It also sets p->lbprm.wdiv to the eweight to |
| * uweight ratio. Both active and backup groups are initialized. |
| */ |
| void fwlc_init_server_tree(struct proxy *p) |
| { |
| struct server *srv; |
| struct eb_root init_head = EB_ROOT; |
| |
| p->lbprm.set_server_status_up = fwlc_set_server_status_up; |
| p->lbprm.set_server_status_down = fwlc_set_server_status_down; |
| p->lbprm.update_server_eweight = fwlc_update_server_weight; |
| p->lbprm.server_take_conn = fwlc_srv_reposition; |
| p->lbprm.server_drop_conn = fwlc_srv_reposition; |
| |
| p->lbprm.wdiv = BE_WEIGHT_SCALE; |
| for (srv = p->srv; srv; srv = srv->next) { |
| srv->prev_eweight = srv->eweight = srv->uweight * BE_WEIGHT_SCALE; |
| srv->prev_state = srv->state; |
| } |
| |
| recount_servers(p); |
| update_backend_weight(p); |
| |
| p->lbprm.fwlc.act = init_head; |
| p->lbprm.fwlc.bck = init_head; |
| |
| /* queue active and backup servers in two distinct groups */ |
| for (srv = p->srv; srv; srv = srv->next) { |
| if (!srv_is_usable(srv->state, srv->eweight)) |
| continue; |
| srv->lb_tree = (srv->state & SRV_BACKUP) ? &p->lbprm.fwlc.bck : &p->lbprm.fwlc.act; |
| fwlc_queue_srv(srv); |
| } |
| } |
| |
| /* Return next server from the FWLC tree in backend <p>. If the tree is empty, |
| * return NULL. Saturated servers are skipped. |
| */ |
| static struct server *fwlc_get_next_server(struct proxy *p, struct server *srvtoavoid) |
| { |
| struct server *srv, *avoided; |
| struct eb32_node *node; |
| |
| srv = avoided = NULL; |
| |
| if (p->srv_act) |
| node = eb32_first(&p->lbprm.fwlc.act); |
| else if (p->lbprm.fbck) |
| return p->lbprm.fbck; |
| else if (p->srv_bck) |
| node = eb32_first(&p->lbprm.fwlc.bck); |
| else |
| return NULL; |
| |
| while (node) { |
| /* OK, we have a server. However, it may be saturated, in which |
| * case we don't want to reconsider it for now, so we'll simply |
| * skip it. Same if it's the server we try to avoid, in which |
| * case we simply remember it for later use if needed. |
| */ |
| struct server *s; |
| |
| s = eb32_entry(node, struct server, lb_node); |
| if (!s->maxconn || (!s->nbpend && s->served < srv_dynamic_maxconn(s))) { |
| if (s != srvtoavoid) { |
| srv = s; |
| break; |
| } |
| avoided = s; |
| } |
| node = eb32_next(node); |
| } |
| |
| if (!srv) |
| srv = avoided; |
| |
| return srv; |
| } |
| |
| /* |
| * This function tries to find a running server for the proxy <px> following |
| * the URL parameter hash method. It looks for a specific parameter in the |
| * URL and hashes it to compute the server ID. This is useful to optimize |
| * performance by avoiding bounces between servers in contexts where sessions |
| * are shared but cookies are not usable. If the parameter is not found, NULL |
| * is returned. If any server is found, it will be returned. If no valid server |
| * is found, NULL is returned. |
| */ |
| struct server *get_server_ph(struct proxy *px, const char *uri, int uri_len) |
| { |
| unsigned long hash = 0; |
| const char *p; |
| const char *params; |
| int plen; |
| |
| /* when tot_weight is 0 then so is srv_count */ |
| if (px->lbprm.tot_weight == 0) |
| return NULL; |
| |
| if ((p = memchr(uri, '?', uri_len)) == NULL) |
| return NULL; |
| |
| if (px->lbprm.map.state & PR_MAP_RECALC) |
| recalc_server_map(px); |
| |
| p++; |
| |
| uri_len -= (p - uri); |
| plen = px->url_param_len; |
| params = p; |
| |
| while (uri_len > plen) { |
| /* Look for the parameter name followed by an equal symbol */ |
| if (params[plen] == '=') { |
| if (memcmp(params, px->url_param_name, plen) == 0) { |
| /* OK, we have the parameter here at <params>, and |
| * the value after the equal sign, at <p> |
| * skip the equal symbol |
| */ |
| p += plen + 1; |
| uri_len -= plen + 1; |
| |
| while (uri_len && *p != '&') { |
| hash = *p + (hash << 6) + (hash << 16) - hash; |
| uri_len--; |
| p++; |
| } |
| return px->lbprm.map.srv[hash % px->lbprm.tot_weight]; |
| } |
| } |
| /* skip to next parameter */ |
| p = memchr(params, '&', uri_len); |
| if (!p) |
| return NULL; |
| p++; |
| uri_len -= (p - params); |
| params = p; |
| } |
| return NULL; |
| } |
| |
| /* |
| * this does the same as the previous server_ph, but check the body contents |
| */ |
| struct server *get_server_ph_post(struct session *s) |
| { |
| unsigned long hash = 0; |
| struct http_txn *txn = &s->txn; |
| struct buffer *req = s->req; |
| struct http_msg *msg = &txn->req; |
| struct proxy *px = s->be; |
| unsigned int plen = px->url_param_len; |
| unsigned long body; |
| unsigned long len; |
| const char *params; |
| struct hdr_ctx ctx; |
| const char *p; |
| |
| /* tot_weight appears to mean srv_count */ |
| if (px->lbprm.tot_weight == 0) |
| return NULL; |
| |
| body = msg->sol[msg->eoh] == '\r' ? msg->eoh + 2 : msg->eoh + 1; |
| len = req->l - body; |
| params = req->data + body; |
| |
| if ( len == 0 ) |
| return NULL; |
| |
| if (px->lbprm.map.state & PR_MAP_RECALC) |
| recalc_server_map(px); |
| |
| ctx.idx = 0; |
| |
| /* if the message is chunked, we skip the chunk size, but use the value as len */ |
| http_find_header2("Transfer-Encoding", 17, msg->sol, &txn->hdr_idx, &ctx); |
| if (ctx.idx && ctx.vlen >= 7 && strncasecmp(ctx.line+ctx.val, "chunked", 7) == 0) { |
| unsigned int chunk = 0; |
| while ( params < (req->data+req->max_len) && !HTTP_IS_CRLF(*params)) { |
| char c = *params; |
| if (ishex(c)) { |
| unsigned int hex = toupper(c) - '0'; |
| if ( hex > 9 ) |
| hex -= 'A' - '9' - 1; |
| chunk = (chunk << 4) | hex; |
| } |
| else |
| return NULL; |
| params++; |
| len--; |
| } |
| /* spec says we get CRLF */ |
| if (HTTP_IS_CRLF(*params) && HTTP_IS_CRLF(params[1])) |
| params += 2; |
| else |
| return NULL; |
| /* ok we have some encoded length, just inspect the first chunk */ |
| len = chunk; |
| } |
| |
| p = params; |
| |
| while (len > plen) { |
| /* Look for the parameter name followed by an equal symbol */ |
| if (params[plen] == '=') { |
| if (memcmp(params, px->url_param_name, plen) == 0) { |
| /* OK, we have the parameter here at <params>, and |
| * the value after the equal sign, at <p> |
| * skip the equal symbol |
| */ |
| p += plen + 1; |
| len -= plen + 1; |
| |
| while (len && *p != '&') { |
| if (unlikely(!HTTP_IS_TOKEN(*p))) { |
| /* if in a POST, body must be URI encoded or its not a URI. |
| * Do not interprete any possible binary data as a parameter. |
| */ |
| if (likely(HTTP_IS_LWS(*p))) /* eol, uncertain uri len */ |
| break; |
| return NULL; /* oh, no; this is not uri-encoded. |
| * This body does not contain parameters. |
| */ |
| } |
| hash = *p + (hash << 6) + (hash << 16) - hash; |
| len--; |
| p++; |
| /* should we break if vlen exceeds limit? */ |
| } |
| return px->lbprm.map.srv[hash % px->lbprm.tot_weight]; |
| } |
| } |
| /* skip to next parameter */ |
| p = memchr(params, '&', len); |
| if (!p) |
| return NULL; |
| p++; |
| len -= (p - params); |
| params = p; |
| } |
| return NULL; |
| } |
| |
| |
| /* |
| * This function tries to find a running server for the proxy <px> following |
| * the Header parameter hash method. It looks for a specific parameter in the |
| * URL and hashes it to compute the server ID. This is useful to optimize |
| * performance by avoiding bounces between servers in contexts where sessions |
| * are shared but cookies are not usable. If the parameter is not found, NULL |
| * is returned. If any server is found, it will be returned. If no valid server |
| * is found, NULL is returned. |
| */ |
| struct server *get_server_hh(struct session *s) |
| { |
| unsigned long hash = 0; |
| struct http_txn *txn = &s->txn; |
| struct http_msg *msg = &txn->req; |
| struct proxy *px = s->be; |
| unsigned int plen = px->hh_len; |
| unsigned long len; |
| struct hdr_ctx ctx; |
| const char *p; |
| |
| /* tot_weight appears to mean srv_count */ |
| if (px->lbprm.tot_weight == 0) |
| return NULL; |
| |
| if (px->lbprm.map.state & PR_MAP_RECALC) |
| recalc_server_map(px); |
| |
| ctx.idx = 0; |
| |
| /* if the message is chunked, we skip the chunk size, but use the value as len */ |
| http_find_header2(px->hh_name, plen, msg->sol, &txn->hdr_idx, &ctx); |
| |
| /* if the header is not found or empty, let's fallback to round robin */ |
| if (!ctx.idx || !ctx.vlen) |
| return NULL; |
| |
| /* Found a the hh_name in the headers. |
| * we will compute the hash based on this value ctx.val. |
| */ |
| len = ctx.vlen; |
| p = (char *)ctx.line + ctx.val; |
| if (!px->hh_match_domain) { |
| while (len) { |
| hash = *p + (hash << 6) + (hash << 16) - hash; |
| len--; |
| p++; |
| } |
| } else { |
| int dohash = 0; |
| p += len - 1; |
| /* special computation, use only main domain name, not tld/host |
| * going back from the end of string, start hashing at first |
| * dot stop at next. |
| * This is designed to work with the 'Host' header, and requires |
| * a special option to activate this. |
| */ |
| while (len) { |
| if (*p == '.') { |
| if (!dohash) |
| dohash = 1; |
| else |
| break; |
| } else { |
| if (dohash) |
| hash = *p + (hash << 6) + (hash << 16) - hash; |
| } |
| len--; |
| p--; |
| } |
| } |
| return px->lbprm.map.srv[hash % px->lbprm.tot_weight]; |
| } |
| |
| struct server *get_server_rch(struct session *s) |
| { |
| unsigned long hash = 0; |
| struct proxy *px = s->be; |
| unsigned long len; |
| const char *p; |
| int ret; |
| struct acl_expr expr; |
| struct acl_test test; |
| |
| /* tot_weight appears to mean srv_count */ |
| if (px->lbprm.tot_weight == 0) |
| return NULL; |
| |
| if (px->lbprm.map.state & PR_MAP_RECALC) |
| recalc_server_map(px); |
| |
| memset(&expr, 0, sizeof(expr)); |
| memset(&test, 0, sizeof(test)); |
| |
| expr.arg.str = px->hh_name; |
| expr.arg_len = px->hh_len; |
| |
| ret = acl_fetch_rdp_cookie(px, s, NULL, ACL_DIR_REQ, &expr, &test); |
| if (ret == 0 || (test.flags & ACL_TEST_F_MAY_CHANGE) || test.len == 0) |
| return NULL; |
| |
| /* Found a the hh_name in the headers. |
| * we will compute the hash based on this value ctx.val. |
| */ |
| len = test.len; |
| p = (char *)test.ptr; |
| while (len) { |
| hash = *p + (hash << 6) + (hash << 16) - hash; |
| len--; |
| p++; |
| } |
| |
| return px->lbprm.map.srv[hash % px->lbprm.tot_weight]; |
| } |
| |
| /* |
| * This function applies the load-balancing algorithm to the session, as |
| * defined by the backend it is assigned to. The session is then marked as |
| * 'assigned'. |
| * |
| * This function MAY NOT be called with SN_ASSIGNED already set. If the session |
| * had a server previously assigned, it is rebalanced, trying to avoid the same |
| * server. |
| * The function tries to keep the original connection slot if it reconnects to |
| * the same server, otherwise it releases it and tries to offer it. |
| * |
| * It is illegal to call this function with a session in a queue. |
| * |
| * It may return : |
| * SRV_STATUS_OK if everything is OK. Session assigned to ->srv |
| * SRV_STATUS_NOSRV if no server is available. Session is not ASSIGNED |
| * SRV_STATUS_FULL if all servers are saturated. Session is not ASSIGNED |
| * SRV_STATUS_INTERNAL for other unrecoverable errors. |
| * |
| * Upon successful return, the session flag SN_ASSIGNED is set to indicate that |
| * it does not need to be called anymore. This means that s->srv can be trusted |
| * in balance and direct modes. |
| * |
| */ |
| |
| int assign_server(struct session *s) |
| { |
| |
| struct server *conn_slot; |
| int err; |
| |
| #ifdef DEBUG_FULL |
| fprintf(stderr,"assign_server : s=%p\n",s); |
| #endif |
| |
| err = SRV_STATUS_INTERNAL; |
| if (unlikely(s->pend_pos || s->flags & SN_ASSIGNED)) |
| goto out_err; |
| |
| s->prev_srv = s->prev_srv; |
| conn_slot = s->srv_conn; |
| |
| /* We have to release any connection slot before applying any LB algo, |
| * otherwise we may erroneously end up with no available slot. |
| */ |
| if (conn_slot) |
| sess_change_server(s, NULL); |
| |
| /* We will now try to find the good server and store it into <s->srv>. |
| * Note that <s->srv> may be NULL in case of dispatch or proxy mode, |
| * as well as if no server is available (check error code). |
| */ |
| |
| s->srv = NULL; |
| if (s->be->lbprm.algo & BE_LB_ALGO) { |
| int len; |
| /* we must check if we have at least one server available */ |
| if (!s->be->lbprm.tot_weight) { |
| err = SRV_STATUS_NOSRV; |
| goto out; |
| } |
| |
| switch (s->be->lbprm.algo & BE_LB_ALGO) { |
| case BE_LB_ALGO_RR: |
| s->srv = fwrr_get_next_server(s->be, s->prev_srv); |
| if (!s->srv) { |
| err = SRV_STATUS_FULL; |
| goto out; |
| } |
| break; |
| case BE_LB_ALGO_LC: |
| s->srv = fwlc_get_next_server(s->be, s->prev_srv); |
| if (!s->srv) { |
| err = SRV_STATUS_FULL; |
| goto out; |
| } |
| break; |
| case BE_LB_ALGO_SH: |
| if (s->cli_addr.ss_family == AF_INET) |
| len = 4; |
| else if (s->cli_addr.ss_family == AF_INET6) |
| len = 16; |
| else { |
| /* unknown IP family */ |
| err = SRV_STATUS_INTERNAL; |
| goto out; |
| } |
| |
| s->srv = get_server_sh(s->be, |
| (void *)&((struct sockaddr_in *)&s->cli_addr)->sin_addr, |
| len); |
| break; |
| case BE_LB_ALGO_UH: |
| /* URI hashing */ |
| s->srv = get_server_uh(s->be, |
| s->txn.req.sol + s->txn.req.sl.rq.u, |
| s->txn.req.sl.rq.u_l); |
| break; |
| case BE_LB_ALGO_PH: |
| /* URL Parameter hashing */ |
| if (s->txn.meth == HTTP_METH_POST && |
| memchr(s->txn.req.sol + s->txn.req.sl.rq.u, '&', |
| s->txn.req.sl.rq.u_l ) == NULL) |
| s->srv = get_server_ph_post(s); |
| else |
| s->srv = get_server_ph(s->be, |
| s->txn.req.sol + s->txn.req.sl.rq.u, |
| s->txn.req.sl.rq.u_l); |
| |
| if (!s->srv) { |
| /* parameter not found, fall back to round robin on the map */ |
| s->srv = get_server_rr_with_conns(s->be, s->prev_srv); |
| if (!s->srv) { |
| err = SRV_STATUS_FULL; |
| goto out; |
| } |
| } |
| break; |
| case BE_LB_ALGO_HH: |
| /* Header Parameter hashing */ |
| s->srv = get_server_hh(s); |
| |
| if (!s->srv) { |
| /* parameter not found, fall back to round robin on the map */ |
| s->srv = get_server_rr_with_conns(s->be, s->prev_srv); |
| if (!s->srv) { |
| err = SRV_STATUS_FULL; |
| goto out; |
| } |
| } |
| break; |
| case BE_LB_ALGO_RCH: |
| /* RDP Cookie hashing */ |
| s->srv = get_server_rch(s); |
| |
| if (!s->srv) { |
| /* parameter not found, fall back to round robin on the map */ |
| s->srv = get_server_rr_with_conns(s->be, s->prev_srv); |
| if (!s->srv) { |
| err = SRV_STATUS_FULL; |
| goto out; |
| } |
| } |
| break; |
| default: |
| /* unknown balancing algorithm */ |
| err = SRV_STATUS_INTERNAL; |
| goto out; |
| } |
| if (s->srv != s->prev_srv) { |
| s->be->cum_lbconn++; |
| s->srv->cum_lbconn++; |
| } |
| } |
| else if (s->be->options & PR_O_HTTP_PROXY) { |
| if (!s->srv_addr.sin_addr.s_addr) { |
| err = SRV_STATUS_NOSRV; |
| goto out; |
| } |
| } |
| else if (!*(int *)&s->be->dispatch_addr.sin_addr && |
| !(s->be->options & PR_O_TRANSP)) { |
| err = SRV_STATUS_NOSRV; |
| goto out; |
| } |
| |
| s->flags |= SN_ASSIGNED; |
| err = SRV_STATUS_OK; |
| out: |
| |
| /* Either we take back our connection slot, or we offer it to someone |
| * else if we don't need it anymore. |
| */ |
| if (conn_slot) { |
| if (conn_slot == s->srv) { |
| sess_change_server(s, s->srv); |
| } else { |
| if (may_dequeue_tasks(conn_slot, s->be)) |
| process_srv_queue(conn_slot); |
| } |
| } |
| |
| out_err: |
| return err; |
| } |
| |
| |
| /* |
| * This function assigns a server address to a session, and sets SN_ADDR_SET. |
| * The address is taken from the currently assigned server, or from the |
| * dispatch or transparent address. |
| * |
| * It may return : |
| * SRV_STATUS_OK if everything is OK. |
| * SRV_STATUS_INTERNAL for other unrecoverable errors. |
| * |
| * Upon successful return, the session flag SN_ADDR_SET is set. This flag is |
| * not cleared, so it's to the caller to clear it if required. |
| * |
| */ |
| int assign_server_address(struct session *s) |
| { |
| #ifdef DEBUG_FULL |
| fprintf(stderr,"assign_server_address : s=%p\n",s); |
| #endif |
| |
| if ((s->flags & SN_DIRECT) || (s->be->lbprm.algo & BE_LB_ALGO)) { |
| /* A server is necessarily known for this session */ |
| if (!(s->flags & SN_ASSIGNED)) |
| return SRV_STATUS_INTERNAL; |
| |
| s->srv_addr = s->srv->addr; |
| |
| /* if this server remaps proxied ports, we'll use |
| * the port the client connected to with an offset. */ |
| if (s->srv->state & SRV_MAPPORTS) { |
| if (!(s->be->options & PR_O_TRANSP) && !(s->flags & SN_FRT_ADDR_SET)) |
| get_frt_addr(s); |
| if (s->frt_addr.ss_family == AF_INET) { |
| s->srv_addr.sin_port = htons(ntohs(s->srv_addr.sin_port) + |
| ntohs(((struct sockaddr_in *)&s->frt_addr)->sin_port)); |
| } else { |
| s->srv_addr.sin_port = htons(ntohs(s->srv_addr.sin_port) + |
| ntohs(((struct sockaddr_in6 *)&s->frt_addr)->sin6_port)); |
| } |
| } |
| } |
| else if (*(int *)&s->be->dispatch_addr.sin_addr) { |
| /* connect to the defined dispatch addr */ |
| s->srv_addr = s->be->dispatch_addr; |
| } |
| else if (s->be->options & PR_O_TRANSP) { |
| /* in transparent mode, use the original dest addr if no dispatch specified */ |
| if (!(s->flags & SN_FRT_ADDR_SET)) |
| get_frt_addr(s); |
| |
| memcpy(&s->srv_addr, &s->frt_addr, MIN(sizeof(s->srv_addr), sizeof(s->frt_addr))); |
| /* when we support IPv6 on the backend, we may add other tests */ |
| //qfprintf(stderr, "Cannot get original server address.\n"); |
| //return SRV_STATUS_INTERNAL; |
| } |
| else if (s->be->options & PR_O_HTTP_PROXY) { |
| /* If HTTP PROXY option is set, then server is already assigned |
| * during incoming client request parsing. */ |
| } |
| else { |
| /* no server and no LB algorithm ! */ |
| return SRV_STATUS_INTERNAL; |
| } |
| |
| s->flags |= SN_ADDR_SET; |
| return SRV_STATUS_OK; |
| } |
| |
| |
| /* This function assigns a server to session <s> if required, and can add the |
| * connection to either the assigned server's queue or to the proxy's queue. |
| * If ->srv_conn is set, the session is first released from the server. |
| * It may also be called with SN_DIRECT and/or SN_ASSIGNED though. It will |
| * be called before any connection and after any retry or redispatch occurs. |
| * |
| * It is not allowed to call this function with a session in a queue. |
| * |
| * Returns : |
| * |
| * SRV_STATUS_OK if everything is OK. |
| * SRV_STATUS_NOSRV if no server is available. s->srv = NULL. |
| * SRV_STATUS_QUEUED if the connection has been queued. |
| * SRV_STATUS_FULL if the server(s) is/are saturated and the |
| * connection could not be queued in s->srv, |
| * which may be NULL if we queue on the backend. |
| * SRV_STATUS_INTERNAL for other unrecoverable errors. |
| * |
| */ |
| int assign_server_and_queue(struct session *s) |
| { |
| struct pendconn *p; |
| int err; |
| |
| if (s->pend_pos) |
| return SRV_STATUS_INTERNAL; |
| |
| err = SRV_STATUS_OK; |
| if (!(s->flags & SN_ASSIGNED)) { |
| err = assign_server(s); |
| if (s->prev_srv) { |
| /* This session was previously assigned to a server. We have to |
| * update the session's and the server's stats : |
| * - if the server changed : |
| * - set TX_CK_DOWN if txn.flags was TX_CK_VALID |
| * - set SN_REDISP if it was successfully redispatched |
| * - increment srv->redispatches and be->redispatches |
| * - if the server remained the same : update retries. |
| */ |
| |
| if (s->prev_srv != s->srv) { |
| if ((s->txn.flags & TX_CK_MASK) == TX_CK_VALID) { |
| s->txn.flags &= ~TX_CK_MASK; |
| s->txn.flags |= TX_CK_DOWN; |
| } |
| s->flags |= SN_REDISP; |
| s->prev_srv->redispatches++; |
| s->be->redispatches++; |
| } else { |
| s->prev_srv->retries++; |
| s->be->retries++; |
| } |
| } |
| } |
| |
| switch (err) { |
| case SRV_STATUS_OK: |
| /* we have SN_ASSIGNED set */ |
| if (!s->srv) |
| return SRV_STATUS_OK; /* dispatch or proxy mode */ |
| |
| /* If we already have a connection slot, no need to check any queue */ |
| if (s->srv_conn == s->srv) |
| return SRV_STATUS_OK; |
| |
| /* OK, this session already has an assigned server, but no |
| * connection slot yet. Either it is a redispatch, or it was |
| * assigned from persistence information (direct mode). |
| */ |
| if ((s->flags & SN_REDIRECTABLE) && s->srv->rdr_len) { |
| /* server scheduled for redirection, and already assigned. We |
| * don't want to go further nor check the queue. |
| */ |
| sess_change_server(s, s->srv); /* not really needed in fact */ |
| return SRV_STATUS_OK; |
| } |
| |
| /* We might have to queue this session if the assigned server is full. |
| * We know we have to queue it into the server's queue, so if a maxqueue |
| * is set on the server, we must also check that the server's queue is |
| * not full, in which case we have to return FULL. |
| */ |
| if (s->srv->maxconn && |
| (s->srv->nbpend || s->srv->served >= srv_dynamic_maxconn(s->srv))) { |
| |
| if (s->srv->maxqueue > 0 && s->srv->nbpend >= s->srv->maxqueue) |
| return SRV_STATUS_FULL; |
| |
| p = pendconn_add(s); |
| if (p) |
| return SRV_STATUS_QUEUED; |
| else |
| return SRV_STATUS_INTERNAL; |
| } |
| |
| /* OK, we can use this server. Let's reserve our place */ |
| sess_change_server(s, s->srv); |
| return SRV_STATUS_OK; |
| |
| case SRV_STATUS_FULL: |
| /* queue this session into the proxy's queue */ |
| p = pendconn_add(s); |
| if (p) |
| return SRV_STATUS_QUEUED; |
| else |
| return SRV_STATUS_INTERNAL; |
| |
| case SRV_STATUS_NOSRV: |
| return err; |
| |
| case SRV_STATUS_INTERNAL: |
| return err; |
| |
| default: |
| return SRV_STATUS_INTERNAL; |
| } |
| } |
| |
| /* |
| * This function initiates a connection to the server assigned to this session |
| * (s->srv, s->srv_addr). It will assign a server if none is assigned yet. |
| * It can return one of : |
| * - SN_ERR_NONE if everything's OK |
| * - SN_ERR_SRVTO if there are no more servers |
| * - SN_ERR_SRVCL if the connection was refused by the server |
| * - SN_ERR_PRXCOND if the connection has been limited by the proxy (maxconn) |
| * - SN_ERR_RESOURCE if a system resource is lacking (eg: fd limits, ports, ...) |
| * - SN_ERR_INTERNAL for any other purely internal errors |
| * Additionnally, in the case of SN_ERR_RESOURCE, an emergency log will be emitted. |
| */ |
| int connect_server(struct session *s) |
| { |
| int fd, err; |
| |
| if (!(s->flags & SN_ADDR_SET)) { |
| err = assign_server_address(s); |
| if (err != SRV_STATUS_OK) |
| return SN_ERR_INTERNAL; |
| } |
| |
| if ((fd = s->req->cons->fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1) { |
| qfprintf(stderr, "Cannot get a server socket.\n"); |
| |
| if (errno == ENFILE) |
| send_log(s->be, LOG_EMERG, |
| "Proxy %s reached system FD limit at %d. Please check system tunables.\n", |
| s->be->id, maxfd); |
| else if (errno == EMFILE) |
| send_log(s->be, LOG_EMERG, |
| "Proxy %s reached process FD limit at %d. Please check 'ulimit-n' and restart.\n", |
| s->be->id, maxfd); |
| else if (errno == ENOBUFS || errno == ENOMEM) |
| send_log(s->be, LOG_EMERG, |
| "Proxy %s reached system memory limit at %d sockets. Please check system tunables.\n", |
| s->be->id, maxfd); |
| /* this is a resource error */ |
| return SN_ERR_RESOURCE; |
| } |
| |
| if (fd >= global.maxsock) { |
| /* do not log anything there, it's a normal condition when this option |
| * is used to serialize connections to a server ! |
| */ |
| Alert("socket(): not enough free sockets. Raise -n argument. Giving up.\n"); |
| close(fd); |
| return SN_ERR_PRXCOND; /* it is a configuration limit */ |
| } |
| |
| if ((fcntl(fd, F_SETFL, O_NONBLOCK)==-1) || |
| (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, (char *) &one, sizeof(one)) == -1)) { |
| qfprintf(stderr,"Cannot set client socket to non blocking mode.\n"); |
| close(fd); |
| return SN_ERR_INTERNAL; |
| } |
| |
| if (s->be->options & PR_O_TCP_SRV_KA) |
| setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (char *) &one, sizeof(one)); |
| |
| if (s->be->options & PR_O_TCP_NOLING) |
| setsockopt(fd, SOL_SOCKET, SO_LINGER, (struct linger *) &nolinger, sizeof(struct linger)); |
| |
| /* allow specific binding : |
| * - server-specific at first |
| * - proxy-specific next |
| */ |
| if (s->srv != NULL && s->srv->state & SRV_BIND_SRC) { |
| struct sockaddr_in *remote = NULL; |
| int ret, flags = 0; |
| |
| #if defined(CONFIG_HAP_CTTPROXY) || defined(CONFIG_HAP_LINUX_TPROXY) |
| switch (s->srv->state & SRV_TPROXY_MASK) { |
| case SRV_TPROXY_ADDR: |
| remote = (struct sockaddr_in *)&s->srv->tproxy_addr; |
| flags = 3; |
| break; |
| case SRV_TPROXY_CLI: |
| flags |= 2; |
| /* fall through */ |
| case SRV_TPROXY_CIP: |
| /* FIXME: what can we do if the client connects in IPv6 ? */ |
| flags |= 1; |
| remote = (struct sockaddr_in *)&s->cli_addr; |
| break; |
| } |
| #endif |
| #ifdef SO_BINDTODEVICE |
| /* Note: this might fail if not CAP_NET_RAW */ |
| if (s->srv->iface_name) |
| setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, s->srv->iface_name, s->srv->iface_len + 1); |
| #endif |
| |
| if (s->srv->sport_range) { |
| int attempts = 10; /* should be more than enough to find a spare port */ |
| struct sockaddr_in src; |
| |
| ret = 1; |
| src = s->srv->source_addr; |
| |
| do { |
| /* note: in case of retry, we may have to release a previously |
| * allocated port, hence this loop's construct. |
| */ |
| port_range_release_port(fdtab[fd].port_range, fdtab[fd].local_port); |
| fdtab[fd].port_range = NULL; |
| |
| if (!attempts) |
| break; |
| attempts--; |
| |
| fdtab[fd].local_port = port_range_alloc_port(s->srv->sport_range); |
| if (!fdtab[fd].local_port) |
| break; |
| |
| fdtab[fd].port_range = s->srv->sport_range; |
| src.sin_port = htons(fdtab[fd].local_port); |
| |
| ret = tcpv4_bind_socket(fd, flags, &src, remote); |
| } while (ret != 0); /* binding NOK */ |
| } |
| else { |
| ret = tcpv4_bind_socket(fd, flags, &s->srv->source_addr, remote); |
| } |
| |
| if (ret) { |
| port_range_release_port(fdtab[fd].port_range, fdtab[fd].local_port); |
| fdtab[fd].port_range = NULL; |
| close(fd); |
| |
| if (ret == 1) { |
| Alert("Cannot bind to source address before connect() for server %s/%s. Aborting.\n", |
| s->be->id, s->srv->id); |
| send_log(s->be, LOG_EMERG, |
| "Cannot bind to source address before connect() for server %s/%s.\n", |
| s->be->id, s->srv->id); |
| } else { |
| Alert("Cannot bind to tproxy source address before connect() for server %s/%s. Aborting.\n", |
| s->be->id, s->srv->id); |
| send_log(s->be, LOG_EMERG, |
| "Cannot bind to tproxy source address before connect() for server %s/%s.\n", |
| s->be->id, s->srv->id); |
| } |
| return SN_ERR_RESOURCE; |
| } |
| } |
| else if (s->be->options & PR_O_BIND_SRC) { |
| struct sockaddr_in *remote = NULL; |
| int ret, flags = 0; |
| |
| #if defined(CONFIG_HAP_CTTPROXY) || defined(CONFIG_HAP_LINUX_TPROXY) |
| switch (s->be->options & PR_O_TPXY_MASK) { |
| case PR_O_TPXY_ADDR: |
| remote = (struct sockaddr_in *)&s->be->tproxy_addr; |
| flags = 3; |
| break; |
| case PR_O_TPXY_CLI: |
| flags |= 2; |
| /* fall through */ |
| case PR_O_TPXY_CIP: |
| /* FIXME: what can we do if the client connects in IPv6 ? */ |
| flags |= 1; |
| remote = (struct sockaddr_in *)&s->cli_addr; |
| break; |
| } |
| #endif |
| #ifdef SO_BINDTODEVICE |
| /* Note: this might fail if not CAP_NET_RAW */ |
| if (s->be->iface_name) |
| setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, s->be->iface_name, s->be->iface_len + 1); |
| #endif |
| ret = tcpv4_bind_socket(fd, flags, &s->be->source_addr, remote); |
| if (ret) { |
| close(fd); |
| if (ret == 1) { |
| Alert("Cannot bind to source address before connect() for proxy %s. Aborting.\n", |
| s->be->id); |
| send_log(s->be, LOG_EMERG, |
| "Cannot bind to source address before connect() for proxy %s.\n", |
| s->be->id); |
| } else { |
| Alert("Cannot bind to tproxy source address before connect() for proxy %s. Aborting.\n", |
| s->be->id); |
| send_log(s->be, LOG_EMERG, |
| "Cannot bind to tproxy source address before connect() for proxy %s.\n", |
| s->be->id); |
| } |
| return SN_ERR_RESOURCE; |
| } |
| } |
| |
| #ifdef TCP_QUICKACK |
| /* disabling tcp quick ack now allows the first request to leave the |
| * machine with the first ACK. We only do this if there are pending |
| * data in the buffer. |
| */ |
| if ((s->be->options2 & PR_O2_SMARTCON) && s->req->send_max) |
| setsockopt(fd, SOL_TCP, TCP_QUICKACK, (char *) &zero, sizeof(zero)); |
| #endif |
| |
| if ((connect(fd, (struct sockaddr *)&s->srv_addr, sizeof(s->srv_addr)) == -1) && |
| (errno != EINPROGRESS) && (errno != EALREADY) && (errno != EISCONN)) { |
| |
| if (errno == EAGAIN || errno == EADDRINUSE) { |
| char *msg; |
| if (errno == EAGAIN) /* no free ports left, try again later */ |
| msg = "no free ports"; |
| else |
| msg = "local address already in use"; |
| |
| qfprintf(stderr,"Cannot connect: %s.\n",msg); |
| port_range_release_port(fdtab[fd].port_range, fdtab[fd].local_port); |
| fdtab[fd].port_range = NULL; |
| close(fd); |
| send_log(s->be, LOG_EMERG, |
| "Connect() failed for server %s/%s: %s.\n", |
| s->be->id, s->srv->id, msg); |
| return SN_ERR_RESOURCE; |
| } else if (errno == ETIMEDOUT) { |
| //qfprintf(stderr,"Connect(): ETIMEDOUT"); |
| port_range_release_port(fdtab[fd].port_range, fdtab[fd].local_port); |
| fdtab[fd].port_range = NULL; |
| close(fd); |
| return SN_ERR_SRVTO; |
| } else { |
| // (errno == ECONNREFUSED || errno == ENETUNREACH || errno == EACCES || errno == EPERM) |
| //qfprintf(stderr,"Connect(): %d", errno); |
| port_range_release_port(fdtab[fd].port_range, fdtab[fd].local_port); |
| fdtab[fd].port_range = NULL; |
| close(fd); |
| return SN_ERR_SRVCL; |
| } |
| } |
| |
| fdtab[fd].owner = s->req->cons; |
| fdtab[fd].state = FD_STCONN; /* connection in progress */ |
| fdtab[fd].flags = FD_FL_TCP | FD_FL_TCP_NODELAY; |
| fdtab[fd].cb[DIR_RD].f = &stream_sock_read; |
| fdtab[fd].cb[DIR_RD].b = s->rep; |
| fdtab[fd].cb[DIR_WR].f = &stream_sock_write; |
| fdtab[fd].cb[DIR_WR].b = s->req; |
| |
| fdtab[fd].peeraddr = (struct sockaddr *)&s->srv_addr; |
| fdtab[fd].peerlen = sizeof(s->srv_addr); |
| |
| fd_insert(fd); |
| EV_FD_SET(fd, DIR_WR); /* for connect status */ |
| |
| s->req->cons->state = SI_ST_CON; |
| s->req->cons->flags |= SI_FL_CAP_SPLTCP; /* TCP supports splicing */ |
| if (s->srv) { |
| s->flags |= SN_CURR_SESS; |
| s->srv->cur_sess++; |
| if (s->srv->cur_sess > s->srv->cur_sess_max) |
| s->srv->cur_sess_max = s->srv->cur_sess; |
| if (s->be->lbprm.server_take_conn) |
| s->be->lbprm.server_take_conn(s->srv); |
| } |
| |
| s->req->cons->exp = tick_add_ifset(now_ms, s->be->timeout.connect); |
| return SN_ERR_NONE; /* connection is OK */ |
| } |
| |
| |
| /* This function performs the "redispatch" part of a connection attempt. It |
| * will assign a server if required, queue the connection if required, and |
| * handle errors that might arise at this level. It can change the server |
| * state. It will return 1 if it encounters an error, switches the server |
| * state, or has to queue a connection. Otherwise, it will return 0 indicating |
| * that the connection is ready to use. |
| */ |
| |
| int srv_redispatch_connect(struct session *t) |
| { |
| int conn_err; |
| |
| /* We know that we don't have any connection pending, so we will |
| * try to get a new one, and wait in this state if it's queued |
| */ |
| redispatch: |
| conn_err = assign_server_and_queue(t); |
| switch (conn_err) { |
| case SRV_STATUS_OK: |
| break; |
| |
| case SRV_STATUS_FULL: |
| /* The server has reached its maxqueue limit. Either PR_O_REDISP is set |
| * and we can redispatch to another server, or it is not and we return |
| * 503. This only makes sense in DIRECT mode however, because normal LB |
| * algorithms would never select such a server, and hash algorithms |
| * would bring us on the same server again. Note that t->srv is set in |
| * this case. |
| */ |
| if ((t->flags & SN_DIRECT) && (t->be->options & PR_O_REDISP)) { |
| t->flags &= ~(SN_DIRECT | SN_ASSIGNED | SN_ADDR_SET); |
| t->prev_srv = t->srv; |
| goto redispatch; |
| } |
| |
| if (!t->req->cons->err_type) { |
| t->req->cons->err_type = SI_ET_QUEUE_ERR; |
| t->req->cons->err_loc = t->srv; |
| } |
| |
| t->srv->failed_conns++; |
| t->be->failed_conns++; |
| return 1; |
| |
| case SRV_STATUS_NOSRV: |
| /* note: it is guaranteed that t->srv == NULL here */ |
| if (!t->req->cons->err_type) { |
| t->req->cons->err_type = SI_ET_CONN_ERR; |
| t->req->cons->err_loc = NULL; |
| } |
| |
| t->be->failed_conns++; |
| return 1; |
| |
| case SRV_STATUS_QUEUED: |
| t->req->cons->exp = tick_add_ifset(now_ms, t->be->timeout.queue); |
| t->req->cons->state = SI_ST_QUE; |
| /* do nothing else and do not wake any other session up */ |
| return 1; |
| |
| case SRV_STATUS_INTERNAL: |
| default: |
| if (!t->req->cons->err_type) { |
| t->req->cons->err_type = SI_ET_CONN_OTHER; |
| t->req->cons->err_loc = t->srv; |
| } |
| |
| if (t->srv) |
| srv_inc_sess_ctr(t->srv); |
| if (t->srv) |
| t->srv->failed_conns++; |
| t->be->failed_conns++; |
| |
| /* release other sessions waiting for this server */ |
| if (may_dequeue_tasks(t->srv, t->be)) |
| process_srv_queue(t->srv); |
| return 1; |
| } |
| /* if we get here, it's because we got SRV_STATUS_OK, which also |
| * means that the connection has not been queued. |
| */ |
| return 0; |
| } |
| |
| int be_downtime(struct proxy *px) { |
| if (px->lbprm.tot_weight && px->last_change < now.tv_sec) // ignore negative time |
| return px->down_time; |
| |
| return now.tv_sec - px->last_change + px->down_time; |
| } |
| |
| /* This function parses a "balance" statement in a backend section describing |
| * <curproxy>. It returns -1 if there is any error, otherwise zero. If it |
| * returns -1, it may write an error message into ther <err> buffer, for at |
| * most <errlen> bytes, trailing zero included. The trailing '\n' will not be |
| * written. The function must be called with <args> pointing to the first word |
| * after "balance". |
| */ |
| int backend_parse_balance(const char **args, char *err, int errlen, struct proxy *curproxy) |
| { |
| if (!*(args[0])) { |
| /* if no option is set, use round-robin by default */ |
| curproxy->lbprm.algo &= ~BE_LB_ALGO; |
| curproxy->lbprm.algo |= BE_LB_ALGO_RR; |
| return 0; |
| } |
| |
| if (!strcmp(args[0], "roundrobin")) { |
| curproxy->lbprm.algo &= ~BE_LB_ALGO; |
| curproxy->lbprm.algo |= BE_LB_ALGO_RR; |
| } |
| else if (!strcmp(args[0], "leastconn")) { |
| curproxy->lbprm.algo &= ~BE_LB_ALGO; |
| curproxy->lbprm.algo |= BE_LB_ALGO_LC; |
| } |
| else if (!strcmp(args[0], "source")) { |
| curproxy->lbprm.algo &= ~BE_LB_ALGO; |
| curproxy->lbprm.algo |= BE_LB_ALGO_SH; |
| } |
| else if (!strcmp(args[0], "uri")) { |
| int arg = 1; |
| |
| curproxy->lbprm.algo &= ~BE_LB_ALGO; |
| curproxy->lbprm.algo |= BE_LB_ALGO_UH; |
| |
| while (*args[arg]) { |
| if (!strcmp(args[arg], "len")) { |
| if (!*args[arg+1] || (atoi(args[arg+1]) <= 0)) { |
| snprintf(err, errlen, "'balance uri len' expects a positive integer (got '%s').", args[arg+1]); |
| return -1; |
| } |
| curproxy->uri_len_limit = atoi(args[arg+1]); |
| arg += 2; |
| } |
| else if (!strcmp(args[arg], "depth")) { |
| if (!*args[arg+1] || (atoi(args[arg+1]) <= 0)) { |
| snprintf(err, errlen, "'balance uri depth' expects a positive integer (got '%s').", args[arg+1]); |
| return -1; |
| } |
| /* hint: we store the position of the ending '/' (depth+1) so |
| * that we avoid a comparison while computing the hash. |
| */ |
| curproxy->uri_dirs_depth1 = atoi(args[arg+1]) + 1; |
| arg += 2; |
| } |
| else { |
| snprintf(err, errlen, "'balance uri' only accepts parameters 'len' and 'depth' (got '%s').", args[arg]); |
| return -1; |
| } |
| } |
| } |
| else if (!strcmp(args[0], "url_param")) { |
| if (!*args[1]) { |
| snprintf(err, errlen, "'balance url_param' requires an URL parameter name."); |
| return -1; |
| } |
| curproxy->lbprm.algo &= ~BE_LB_ALGO; |
| curproxy->lbprm.algo |= BE_LB_ALGO_PH; |
| |
| free(curproxy->url_param_name); |
| curproxy->url_param_name = strdup(args[1]); |
| curproxy->url_param_len = strlen(args[1]); |
| if (*args[2]) { |
| if (strcmp(args[2], "check_post")) { |
| snprintf(err, errlen, "'balance url_param' only accepts check_post modifier."); |
| return -1; |
| } |
| if (*args[3]) { |
| /* TODO: maybe issue a warning if there is no value, no digits or too long */ |
| curproxy->url_param_post_limit = str2ui(args[3]); |
| } |
| /* if no limit, or faul value in args[3], then default to a moderate wordlen */ |
| if (!curproxy->url_param_post_limit) |
| curproxy->url_param_post_limit = 48; |
| else if ( curproxy->url_param_post_limit < 3 ) |
| curproxy->url_param_post_limit = 3; /* minimum example: S=3 or \r\nS=6& */ |
| } |
| } |
| else if (!strncmp(args[0], "hdr(", 4)) { |
| const char *beg, *end; |
| |
| beg = args[0] + 4; |
| end = strchr(beg, ')'); |
| |
| if (!end || end == beg) { |
| snprintf(err, errlen, "'balance hdr(name)' requires an http header field name."); |
| return -1; |
| } |
| |
| curproxy->lbprm.algo &= ~BE_LB_ALGO; |
| curproxy->lbprm.algo |= BE_LB_ALGO_HH; |
| |
| free(curproxy->hh_name); |
| curproxy->hh_len = end - beg; |
| curproxy->hh_name = my_strndup(beg, end - beg); |
| curproxy->hh_match_domain = 0; |
| |
| if (*args[1]) { |
| if (strcmp(args[1], "use_domain_only")) { |
| snprintf(err, errlen, "'balance hdr(name)' only accepts 'use_domain_only' modifier."); |
| return -1; |
| } |
| curproxy->hh_match_domain = 1; |
| } |
| |
| } |
| else if (!strncmp(args[0], "rdp-cookie", 10)) { |
| curproxy->lbprm.algo &= ~BE_LB_ALGO; |
| curproxy->lbprm.algo |= BE_LB_ALGO_RCH; |
| |
| if ( *(args[0] + 10 ) == '(' ) { /* cookie name */ |
| const char *beg, *end; |
| |
| beg = args[0] + 11; |
| end = strchr(beg, ')'); |
| |
| if (!end || end == beg) { |
| snprintf(err, errlen, "'balance rdp-cookie(name)' requires an rdp cookie name."); |
| return -1; |
| } |
| |
| free(curproxy->hh_name); |
| curproxy->hh_name = my_strndup(beg, end - beg); |
| curproxy->hh_len = end - beg; |
| } |
| else if ( *(args[0] + 10 ) == '\0' ) { /* default cookie name 'mstshash' */ |
| free(curproxy->hh_name); |
| curproxy->hh_name = strdup("mstshash"); |
| curproxy->hh_len = strlen(curproxy->hh_name); |
| } |
| else { /* syntax */ |
| snprintf(err, errlen, "'balance rdp-cookie(name)' requires an rdp cookie name."); |
| return -1; |
| } |
| } |
| else { |
| snprintf(err, errlen, "'balance' only supports 'roundrobin', 'leastconn', 'source', 'uri', 'url_param', 'hdr(name)' and 'rdp-cookie(name)' options."); |
| return -1; |
| } |
| return 0; |
| } |
| |
| |
| /************************************************************************/ |
| /* All supported keywords must be declared here. */ |
| /************************************************************************/ |
| |
| /* set test->i to the number of enabled servers on the proxy */ |
| static int |
| acl_fetch_nbsrv(struct proxy *px, struct session *l4, void *l7, int dir, |
| struct acl_expr *expr, struct acl_test *test) |
| { |
| test->flags = ACL_TEST_F_VOL_TEST; |
| if (expr->arg_len) { |
| /* another proxy was designated, we must look for it */ |
| for (px = proxy; px; px = px->next) |
| if ((px->cap & PR_CAP_BE) && !strcmp(px->id, expr->arg.str)) |
| break; |
| } |
| if (!px) |
| return 0; |
| |
| if (px->srv_act) |
| test->i = px->srv_act; |
| else if (px->lbprm.fbck) |
| test->i = 1; |
| else |
| test->i = px->srv_bck; |
| |
| return 1; |
| } |
| |
| /* set test->i to the number of enabled servers on the proxy */ |
| static int |
| acl_fetch_connslots(struct proxy *px, struct session *l4, void *l7, int dir, |
| struct acl_expr *expr, struct acl_test *test) |
| { |
| struct server *iterator; |
| test->flags = ACL_TEST_F_VOL_TEST; |
| if (expr->arg_len) { |
| /* another proxy was designated, we must look for it */ |
| for (px = proxy; px; px = px->next) |
| if ((px->cap & PR_CAP_BE) && !strcmp(px->id, expr->arg.str)) |
| break; |
| } |
| if (!px) |
| return 0; |
| |
| test->i = 0; |
| iterator = px->srv; |
| while (iterator) { |
| if ((iterator->state & 1) == 0) { |
| iterator = iterator->next; |
| continue; |
| } |
| if (iterator->maxconn == 0 || iterator->maxqueue == 0) { |
| test->i = -1; |
| return 1; |
| } |
| |
| test->i += (iterator->maxconn - iterator->cur_sess) |
| + (iterator->maxqueue - iterator->nbpend); |
| iterator = iterator->next; |
| } |
| |
| return 1; |
| } |
| |
| /* set test->i to the number of connections per second reaching the frontend */ |
| static int |
| acl_fetch_fe_sess_rate(struct proxy *px, struct session *l4, void *l7, int dir, |
| struct acl_expr *expr, struct acl_test *test) |
| { |
| test->flags = ACL_TEST_F_VOL_TEST; |
| if (expr->arg_len) { |
| /* another proxy was designated, we must look for it */ |
| for (px = proxy; px; px = px->next) |
| if ((px->cap & PR_CAP_FE) && !strcmp(px->id, expr->arg.str)) |
| break; |
| } |
| if (!px) |
| return 0; |
| |
| test->i = read_freq_ctr(&px->fe_sess_per_sec); |
| return 1; |
| } |
| |
| /* set test->i to the number of connections per second reaching the backend */ |
| static int |
| acl_fetch_be_sess_rate(struct proxy *px, struct session *l4, void *l7, int dir, |
| struct acl_expr *expr, struct acl_test *test) |
| { |
| test->flags = ACL_TEST_F_VOL_TEST; |
| if (expr->arg_len) { |
| /* another proxy was designated, we must look for it */ |
| for (px = proxy; px; px = px->next) |
| if ((px->cap & PR_CAP_BE) && !strcmp(px->id, expr->arg.str)) |
| break; |
| } |
| if (!px) |
| return 0; |
| |
| test->i = read_freq_ctr(&px->be_sess_per_sec); |
| return 1; |
| } |
| |
| |
| /* Note: must not be declared <const> as its list will be overwritten */ |
| static struct acl_kw_list acl_kws = {{ },{ |
| { "nbsrv", acl_parse_int, acl_fetch_nbsrv, acl_match_int, ACL_USE_NOTHING }, |
| { "connslots", acl_parse_int, acl_fetch_connslots, acl_match_int, ACL_USE_NOTHING }, |
| { "fe_sess_rate", acl_parse_int, acl_fetch_fe_sess_rate, acl_match_int, ACL_USE_NOTHING }, |
| { "be_sess_rate", acl_parse_int, acl_fetch_be_sess_rate, acl_match_int, ACL_USE_NOTHING }, |
| { NULL, NULL, NULL, NULL }, |
| }}; |
| |
| |
| __attribute__((constructor)) |
| static void __backend_init(void) |
| { |
| acl_register_keywords(&acl_kws); |
| } |
| |
| |
| /* |
| * Local variables: |
| * c-indent-level: 8 |
| * c-basic-offset: 8 |
| * End: |
| */ |