Mercurial > hg > nginx-quic
view src/http/modules/ngx_http_realip_module.c @ 4667:d05ab8793a69 stable-1.2
Merge of r4622, r4623: balancing changes.
*) Upstream: smooth weighted round-robin balancing.
For edge case weights like { 5, 1, 1 } we now produce { a, a, b, a, c, a, a }
sequence instead of { c, b, a, a, a, a, a } produced previously.
Algorithm is as follows: on each peer selection we increase current_weight
of each eligible peer by its weight, select peer with greatest current_weight
and reduce its current_weight by total number of weight points distributed
among peers.
In case of { 5, 1, 1 } weights this gives the following sequence of
current_weight's:
a b c
0 0 0 (initial state)
5 1 1 (a selected)
-2 1 1
3 2 2 (a selected)
-4 2 2
1 3 3 (b selected)
1 -4 3
6 -3 4 (a selected)
-1 -3 4
4 -2 5 (c selected)
4 -2 -2
9 -1 -1 (a selected)
2 -1 -1
7 0 0 (a selected)
0 0 0
To preserve weight reduction in case of failures the effective_weight
variable was introduced, which usually matches peer's weight, but is
reduced temporarily on peer failures.
This change also fixes loop with backup servers and proxy_next_upstream
http_404 (ticket #47), and skipping alive upstreams in some cases if there
are multiple dead ones (ticket #64).
*) Upstream: fixed ip_hash rebalancing with the "down" flag.
Due to weight being set to 0 for down peers, order of peers after sorting
wasn't the same as without the "down" flag (with down peers at the end),
resulting in client rebalancing for clients on other servers. The only
rebalancing which should happen after adding "down" to a server is one
for clients on the server.
The problem was introduced in r1377 (which fixed endless loop by setting
weight to 0 for down servers). The loop is no longer possible with new
smooth algorithm, so preserving original weight is safe.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 04 Jun 2012 11:21:58 +0000 |
parents | b1950b0a9550 |
children | df93068953c0 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> #define NGX_HTTP_REALIP_XREALIP 0 #define NGX_HTTP_REALIP_XFWD 1 #define NGX_HTTP_REALIP_HEADER 2 typedef struct { ngx_array_t *from; /* array of ngx_in_cidr_t */ ngx_uint_t type; ngx_uint_t hash; ngx_str_t header; #if (NGX_HAVE_UNIX_DOMAIN) ngx_uint_t unixsock; /* unsigned unixsock:2; */ #endif } ngx_http_realip_loc_conf_t; typedef struct { ngx_connection_t *connection; struct sockaddr *sockaddr; socklen_t socklen; ngx_str_t addr_text; } ngx_http_realip_ctx_t; static ngx_int_t ngx_http_realip_handler(ngx_http_request_t *r); static ngx_int_t ngx_http_realip_set_addr(ngx_http_request_t *r, u_char *ip, size_t len); static void ngx_http_realip_cleanup(void *data); static char *ngx_http_realip_from(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_http_realip(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static void *ngx_http_realip_create_loc_conf(ngx_conf_t *cf); static char *ngx_http_realip_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_int_t ngx_http_realip_init(ngx_conf_t *cf); static ngx_command_t ngx_http_realip_commands[] = { { ngx_string("set_real_ip_from"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1, ngx_http_realip_from, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, { ngx_string("real_ip_header"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1, ngx_http_realip, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_realip_module_ctx = { NULL, /* preconfiguration */ ngx_http_realip_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_realip_create_loc_conf, /* create location configuration */ ngx_http_realip_merge_loc_conf /* merge location configuration */ }; ngx_module_t ngx_http_realip_module = { NGX_MODULE_V1, &ngx_http_realip_module_ctx, /* module context */ ngx_http_realip_commands, /* module directives */ NGX_HTTP_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static ngx_int_t ngx_http_realip_handler(ngx_http_request_t *r) { u_char *ip, *p; size_t len; ngx_uint_t i, hash; ngx_list_part_t *part; ngx_table_elt_t *header; struct sockaddr_in *sin; ngx_in_cidr_t *from; ngx_connection_t *c; ngx_http_realip_ctx_t *ctx; ngx_http_realip_loc_conf_t *rlcf; ctx = ngx_http_get_module_ctx(r, ngx_http_realip_module); if (ctx) { return NGX_DECLINED; } rlcf = ngx_http_get_module_loc_conf(r, ngx_http_realip_module); if (rlcf->from == NULL #if (NGX_HAVE_UNIX_DOMAIN) && !rlcf->unixsock #endif ) { return NGX_DECLINED; } switch (rlcf->type) { case NGX_HTTP_REALIP_XREALIP: if (r->headers_in.x_real_ip == NULL) { return NGX_DECLINED; } len = r->headers_in.x_real_ip->value.len; ip = r->headers_in.x_real_ip->value.data; break; case NGX_HTTP_REALIP_XFWD: if (r->headers_in.x_forwarded_for == NULL) { return NGX_DECLINED; } len = r->headers_in.x_forwarded_for->value.len; ip = r->headers_in.x_forwarded_for->value.data; for (p = ip + len - 1; p > ip; p--) { if (*p == ' ' || *p == ',') { p++; len -= p - ip; ip = p; break; } } break; default: /* NGX_HTTP_REALIP_HEADER */ part = &r->headers_in.headers.part; header = part->elts; hash = rlcf->hash; len = rlcf->header.len; p = rlcf->header.data; for (i = 0; /* void */ ; i++) { if (i >= part->nelts) { if (part->next == NULL) { break; } part = part->next; header = part->elts; i = 0; } if (hash == header[i].hash && len == header[i].key.len && ngx_strncmp(p, header[i].lowcase_key, len) == 0) { len = header[i].value.len; ip = header[i].value.data; goto found; } } return NGX_DECLINED; } found: c = r->connection; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0, "realip: \"%s\"", ip); /* AF_INET only */ if (c->sockaddr->sa_family == AF_INET) { sin = (struct sockaddr_in *) c->sockaddr; from = rlcf->from->elts; for (i = 0; i < rlcf->from->nelts; i++) { ngx_log_debug3(NGX_LOG_DEBUG_HTTP, c->log, 0, "realip: %08XD %08XD %08XD", sin->sin_addr.s_addr, from[i].mask, from[i].addr); if ((sin->sin_addr.s_addr & from[i].mask) == from[i].addr) { return ngx_http_realip_set_addr(r, ip, len); } } } #if (NGX_HAVE_UNIX_DOMAIN) if (c->sockaddr->sa_family == AF_UNIX && rlcf->unixsock) { return ngx_http_realip_set_addr(r, ip, len); } #endif return NGX_DECLINED; } static ngx_int_t ngx_http_realip_set_addr(ngx_http_request_t *r, u_char *ip, size_t len) { u_char *p; ngx_int_t rc; ngx_addr_t addr; ngx_connection_t *c; ngx_pool_cleanup_t *cln; ngx_http_realip_ctx_t *ctx; cln = ngx_pool_cleanup_add(r->pool, sizeof(ngx_http_realip_ctx_t)); if (cln == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } ctx = cln->data; ngx_http_set_ctx(r, ctx, ngx_http_realip_module); c = r->connection; rc = ngx_parse_addr(c->pool, &addr, ip, len); switch (rc) { case NGX_DECLINED: return NGX_DECLINED; case NGX_ERROR: return NGX_HTTP_INTERNAL_SERVER_ERROR; default: /* NGX_OK */ break; } p = ngx_pnalloc(c->pool, len); if (p == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } ngx_memcpy(p, ip, len); cln->handler = ngx_http_realip_cleanup; ctx->connection = c; ctx->sockaddr = c->sockaddr; ctx->socklen = c->socklen; ctx->addr_text = c->addr_text; c->sockaddr = addr.sockaddr; c->socklen = addr.socklen; c->addr_text.len = len; c->addr_text.data = p; return NGX_DECLINED; } static void ngx_http_realip_cleanup(void *data) { ngx_http_realip_ctx_t *ctx = data; ngx_connection_t *c; c = ctx->connection; c->sockaddr = ctx->sockaddr; c->socklen = ctx->socklen; c->addr_text = ctx->addr_text; } static char * ngx_http_realip_from(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_realip_loc_conf_t *rlcf = conf; ngx_int_t rc; ngx_str_t *value; ngx_cidr_t cidr; ngx_in_cidr_t *from; value = cf->args->elts; #if (NGX_HAVE_UNIX_DOMAIN) if (ngx_strcmp(value[1].data, "unix:") == 0) { rlcf->unixsock = 1; return NGX_CONF_OK; } #endif if (rlcf->from == NULL) { rlcf->from = ngx_array_create(cf->pool, 2, sizeof(ngx_in_cidr_t)); if (rlcf->from == NULL) { return NGX_CONF_ERROR; } } from = ngx_array_push(rlcf->from); if (from == NULL) { return NGX_CONF_ERROR; } rc = ngx_ptocidr(&value[1], &cidr); if (rc == NGX_ERROR) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid parameter \"%V\"", &value[1]); return NGX_CONF_ERROR; } if (cidr.family != AF_INET) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "\"set_real_ip_from\" supports IPv4 only"); return NGX_CONF_ERROR; } if (rc == NGX_DONE) { ngx_conf_log_error(NGX_LOG_WARN, cf, 0, "low address bits of %V are meaningless", &value[1]); } from->mask = cidr.u.in.mask; from->addr = cidr.u.in.addr; return NGX_CONF_OK; } static char * ngx_http_realip(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_realip_loc_conf_t *rlcf = conf; ngx_str_t *value; value = cf->args->elts; if (ngx_strcmp(value[1].data, "X-Real-IP") == 0) { rlcf->type = NGX_HTTP_REALIP_XREALIP; return NGX_CONF_OK; } if (ngx_strcmp(value[1].data, "X-Forwarded-For") == 0) { rlcf->type = NGX_HTTP_REALIP_XFWD; return NGX_CONF_OK; } rlcf->type = NGX_HTTP_REALIP_HEADER; rlcf->hash = ngx_hash_strlow(value[1].data, value[1].data, value[1].len); rlcf->header = value[1]; return NGX_CONF_OK; } static void * ngx_http_realip_create_loc_conf(ngx_conf_t *cf) { ngx_http_realip_loc_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_realip_loc_conf_t)); if (conf == NULL) { return NULL; } /* * set by ngx_pcalloc(): * * conf->from = NULL; * conf->hash = 0; * conf->header = { 0, NULL }; */ conf->type = NGX_CONF_UNSET_UINT; #if (NGX_HAVE_UNIX_DOMAIN) conf->unixsock = 2; #endif return conf; } static char * ngx_http_realip_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_realip_loc_conf_t *prev = parent; ngx_http_realip_loc_conf_t *conf = child; if (conf->from == NULL) { conf->from = prev->from; } #if (NGX_HAVE_UNIX_DOMAIN) if (conf->unixsock == 2) { conf->unixsock = (prev->unixsock == 2) ? 0 : prev->unixsock; } #endif ngx_conf_merge_uint_value(conf->type, prev->type, NGX_HTTP_REALIP_XREALIP); if (conf->header.len == 0) { conf->hash = prev->hash; conf->header = prev->header; } return NGX_CONF_OK; } static ngx_int_t ngx_http_realip_init(ngx_conf_t *cf) { ngx_http_handler_pt *h; ngx_http_core_main_conf_t *cmcf; cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module); h = ngx_array_push(&cmcf->phases[NGX_HTTP_POST_READ_PHASE].handlers); if (h == NULL) { return NGX_ERROR; } *h = ngx_http_realip_handler; h = ngx_array_push(&cmcf->phases[NGX_HTTP_PREACCESS_PHASE].handlers); if (h == NULL) { return NGX_ERROR; } *h = ngx_http_realip_handler; return NGX_OK; }