Mercurial > hg > nginx
view src/stream/ngx_stream_upstream.c @ 6806:75dbab4ea930
Events: improved error event handling for UDP sockets.
Normally, the epoll module calls the read and write handlers depending
on whether EPOLLIN and EPOLLOUT are reported by epoll_wait(). No error
processing is done in the module, the handlers are expected to get an
error when doing I/O.
If an error event is reported without EPOLLIN and EPOLLOUT, the module
set both EPOLLIN and EPOLLOUT to ensure the error event is handled at
least in one active handler.
This works well unless the error is delivered along with only one of
EPOLLIN or EPOLLOUT, and the corresponding handler does not do any I/O.
For example, it happened when getting EPOLLERR|EPOLLOUT from
epoll_wait() upon receiving "ICMP port unreachable" while proxying UDP.
As the write handler had nothing to send it was not able to detect and
log an error, and did not switch to the next upstream.
The fix is to unconditionally set EPOLLIN and EPOLLOUT in case of an
error event. In the aforementioned case, this causes the read handler
to be called which does recv() and detects an error.
In addition to the epoll module, analogous changes were made in
devpoll/eventport/poll.
author | Dmitry Volyntsev <xeioex@nginx.com> |
---|---|
date | Mon, 21 Nov 2016 16:03:42 +0300 |
parents | 29bf0dbc0a77 |
children | 2a288909abc6 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_stream.h> static ngx_int_t ngx_stream_upstream_add_variables(ngx_conf_t *cf); static ngx_int_t ngx_stream_upstream_addr_variable(ngx_stream_session_t *s, ngx_stream_variable_value_t *v, uintptr_t data); static ngx_int_t ngx_stream_upstream_response_time_variable( ngx_stream_session_t *s, ngx_stream_variable_value_t *v, uintptr_t data); static ngx_int_t ngx_stream_upstream_bytes_variable(ngx_stream_session_t *s, ngx_stream_variable_value_t *v, uintptr_t data); static char *ngx_stream_upstream(ngx_conf_t *cf, ngx_command_t *cmd, void *dummy); static char *ngx_stream_upstream_server(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static void *ngx_stream_upstream_create_main_conf(ngx_conf_t *cf); static char *ngx_stream_upstream_init_main_conf(ngx_conf_t *cf, void *conf); static ngx_command_t ngx_stream_upstream_commands[] = { { ngx_string("upstream"), NGX_STREAM_MAIN_CONF|NGX_CONF_BLOCK|NGX_CONF_TAKE1, ngx_stream_upstream, 0, 0, NULL }, { ngx_string("server"), NGX_STREAM_UPS_CONF|NGX_CONF_1MORE, ngx_stream_upstream_server, NGX_STREAM_SRV_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_stream_module_t ngx_stream_upstream_module_ctx = { ngx_stream_upstream_add_variables, /* preconfiguration */ NULL, /* postconfiguration */ ngx_stream_upstream_create_main_conf, /* create main configuration */ ngx_stream_upstream_init_main_conf, /* init main configuration */ NULL, /* create server configuration */ NULL /* merge server configuration */ }; ngx_module_t ngx_stream_upstream_module = { NGX_MODULE_V1, &ngx_stream_upstream_module_ctx, /* module context */ ngx_stream_upstream_commands, /* module directives */ NGX_STREAM_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_stream_variable_t ngx_stream_upstream_vars[] = { { ngx_string("upstream_addr"), NULL, ngx_stream_upstream_addr_variable, 0, NGX_STREAM_VAR_NOCACHEABLE, 0 }, { ngx_string("upstream_bytes_sent"), NULL, ngx_stream_upstream_bytes_variable, 0, NGX_STREAM_VAR_NOCACHEABLE, 0 }, { ngx_string("upstream_connect_time"), NULL, ngx_stream_upstream_response_time_variable, 2, NGX_STREAM_VAR_NOCACHEABLE, 0 }, { ngx_string("upstream_first_byte_time"), NULL, ngx_stream_upstream_response_time_variable, 1, NGX_STREAM_VAR_NOCACHEABLE, 0 }, { ngx_string("upstream_session_time"), NULL, ngx_stream_upstream_response_time_variable, 0, NGX_STREAM_VAR_NOCACHEABLE, 0 }, { ngx_string("upstream_bytes_received"), NULL, ngx_stream_upstream_bytes_variable, 1, NGX_STREAM_VAR_NOCACHEABLE, 0 }, { ngx_null_string, NULL, NULL, 0, 0, 0 } }; static ngx_int_t ngx_stream_upstream_add_variables(ngx_conf_t *cf) { ngx_stream_variable_t *var, *v; for (v = ngx_stream_upstream_vars; v->name.len; v++) { var = ngx_stream_add_variable(cf, &v->name, v->flags); if (var == NULL) { return NGX_ERROR; } var->get_handler = v->get_handler; var->data = v->data; } return NGX_OK; } static ngx_int_t ngx_stream_upstream_addr_variable(ngx_stream_session_t *s, ngx_stream_variable_value_t *v, uintptr_t data) { u_char *p; size_t len; ngx_uint_t i; ngx_stream_upstream_state_t *state; v->valid = 1; v->no_cacheable = 0; v->not_found = 0; if (s->upstream_states == NULL || s->upstream_states->nelts == 0) { v->not_found = 1; return NGX_OK; } len = 0; state = s->upstream_states->elts; for (i = 0; i < s->upstream_states->nelts; i++) { if (state[i].peer) { len += state[i].peer->len; } len += 2; } p = ngx_pnalloc(s->connection->pool, len); if (p == NULL) { return NGX_ERROR; } v->data = p; i = 0; for ( ;; ) { if (state[i].peer) { p = ngx_cpymem(p, state[i].peer->data, state[i].peer->len); } if (++i == s->upstream_states->nelts) { break; } *p++ = ','; *p++ = ' '; } v->len = p - v->data; return NGX_OK; } static ngx_int_t ngx_stream_upstream_bytes_variable(ngx_stream_session_t *s, ngx_stream_variable_value_t *v, uintptr_t data) { u_char *p; size_t len; ngx_uint_t i; ngx_stream_upstream_state_t *state; v->valid = 1; v->no_cacheable = 0; v->not_found = 0; if (s->upstream_states == NULL || s->upstream_states->nelts == 0) { v->not_found = 1; return NGX_OK; } len = s->upstream_states->nelts * (NGX_OFF_T_LEN + 2); p = ngx_pnalloc(s->connection->pool, len); if (p == NULL) { return NGX_ERROR; } v->data = p; i = 0; state = s->upstream_states->elts; for ( ;; ) { if (data == 1) { p = ngx_sprintf(p, "%O", state[i].bytes_received); } else { p = ngx_sprintf(p, "%O", state[i].bytes_sent); } if (++i == s->upstream_states->nelts) { break; } *p++ = ','; *p++ = ' '; } v->len = p - v->data; return NGX_OK; } static ngx_int_t ngx_stream_upstream_response_time_variable(ngx_stream_session_t *s, ngx_stream_variable_value_t *v, uintptr_t data) { u_char *p; size_t len; ngx_uint_t i; ngx_msec_int_t ms; ngx_stream_upstream_state_t *state; v->valid = 1; v->no_cacheable = 0; v->not_found = 0; if (s->upstream_states == NULL || s->upstream_states->nelts == 0) { v->not_found = 1; return NGX_OK; } len = s->upstream_states->nelts * (NGX_TIME_T_LEN + 4 + 2); p = ngx_pnalloc(s->connection->pool, len); if (p == NULL) { return NGX_ERROR; } v->data = p; i = 0; state = s->upstream_states->elts; for ( ;; ) { if (data == 1) { if (state[i].first_byte_time == (ngx_msec_t) -1) { *p++ = '-'; goto next; } ms = state[i].first_byte_time; } else if (data == 2 && state[i].connect_time != (ngx_msec_t) -1) { ms = state[i].connect_time; } else { ms = state[i].response_time; } ms = ngx_max(ms, 0); p = ngx_sprintf(p, "%T.%03M", (time_t) ms / 1000, ms % 1000); next: if (++i == s->upstream_states->nelts) { break; } *p++ = ','; *p++ = ' '; } v->len = p - v->data; return NGX_OK; } static char * ngx_stream_upstream(ngx_conf_t *cf, ngx_command_t *cmd, void *dummy) { char *rv; void *mconf; ngx_str_t *value; ngx_url_t u; ngx_uint_t m; ngx_conf_t pcf; ngx_stream_module_t *module; ngx_stream_conf_ctx_t *ctx, *stream_ctx; ngx_stream_upstream_srv_conf_t *uscf; ngx_memzero(&u, sizeof(ngx_url_t)); value = cf->args->elts; u.host = value[1]; u.no_resolve = 1; u.no_port = 1; uscf = ngx_stream_upstream_add(cf, &u, NGX_STREAM_UPSTREAM_CREATE |NGX_STREAM_UPSTREAM_WEIGHT |NGX_STREAM_UPSTREAM_MAX_CONNS |NGX_STREAM_UPSTREAM_MAX_FAILS |NGX_STREAM_UPSTREAM_FAIL_TIMEOUT |NGX_STREAM_UPSTREAM_DOWN |NGX_STREAM_UPSTREAM_BACKUP); if (uscf == NULL) { return NGX_CONF_ERROR; } ctx = ngx_pcalloc(cf->pool, sizeof(ngx_stream_conf_ctx_t)); if (ctx == NULL) { return NGX_CONF_ERROR; } stream_ctx = cf->ctx; ctx->main_conf = stream_ctx->main_conf; /* the upstream{}'s srv_conf */ ctx->srv_conf = ngx_pcalloc(cf->pool, sizeof(void *) * ngx_stream_max_module); if (ctx->srv_conf == NULL) { return NGX_CONF_ERROR; } ctx->srv_conf[ngx_stream_upstream_module.ctx_index] = uscf; uscf->srv_conf = ctx->srv_conf; for (m = 0; cf->cycle->modules[m]; m++) { if (cf->cycle->modules[m]->type != NGX_STREAM_MODULE) { continue; } module = cf->cycle->modules[m]->ctx; if (module->create_srv_conf) { mconf = module->create_srv_conf(cf); if (mconf == NULL) { return NGX_CONF_ERROR; } ctx->srv_conf[cf->cycle->modules[m]->ctx_index] = mconf; } } uscf->servers = ngx_array_create(cf->pool, 4, sizeof(ngx_stream_upstream_server_t)); if (uscf->servers == NULL) { return NGX_CONF_ERROR; } /* parse inside upstream{} */ pcf = *cf; cf->ctx = ctx; cf->cmd_type = NGX_STREAM_UPS_CONF; rv = ngx_conf_parse(cf, NULL); *cf = pcf; if (rv != NGX_CONF_OK) { return rv; } if (uscf->servers->nelts == 0) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "no servers are inside upstream"); return NGX_CONF_ERROR; } return rv; } static char * ngx_stream_upstream_server(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_stream_upstream_srv_conf_t *uscf = conf; time_t fail_timeout; ngx_str_t *value, s; ngx_url_t u; ngx_int_t weight, max_conns, max_fails; ngx_uint_t i; ngx_stream_upstream_server_t *us; us = ngx_array_push(uscf->servers); if (us == NULL) { return NGX_CONF_ERROR; } ngx_memzero(us, sizeof(ngx_stream_upstream_server_t)); value = cf->args->elts; weight = 1; max_conns = 0; max_fails = 1; fail_timeout = 10; for (i = 2; i < cf->args->nelts; i++) { if (ngx_strncmp(value[i].data, "weight=", 7) == 0) { if (!(uscf->flags & NGX_STREAM_UPSTREAM_WEIGHT)) { goto not_supported; } weight = ngx_atoi(&value[i].data[7], value[i].len - 7); if (weight == NGX_ERROR || weight == 0) { goto invalid; } continue; } if (ngx_strncmp(value[i].data, "max_conns=", 10) == 0) { if (!(uscf->flags & NGX_STREAM_UPSTREAM_MAX_CONNS)) { goto not_supported; } max_conns = ngx_atoi(&value[i].data[10], value[i].len - 10); if (max_conns == NGX_ERROR) { goto invalid; } continue; } if (ngx_strncmp(value[i].data, "max_fails=", 10) == 0) { if (!(uscf->flags & NGX_STREAM_UPSTREAM_MAX_FAILS)) { goto not_supported; } max_fails = ngx_atoi(&value[i].data[10], value[i].len - 10); if (max_fails == NGX_ERROR) { goto invalid; } continue; } if (ngx_strncmp(value[i].data, "fail_timeout=", 13) == 0) { if (!(uscf->flags & NGX_STREAM_UPSTREAM_FAIL_TIMEOUT)) { goto not_supported; } s.len = value[i].len - 13; s.data = &value[i].data[13]; fail_timeout = ngx_parse_time(&s, 1); if (fail_timeout == (time_t) NGX_ERROR) { goto invalid; } continue; } if (ngx_strcmp(value[i].data, "backup") == 0) { if (!(uscf->flags & NGX_STREAM_UPSTREAM_BACKUP)) { goto not_supported; } us->backup = 1; continue; } if (ngx_strcmp(value[i].data, "down") == 0) { if (!(uscf->flags & NGX_STREAM_UPSTREAM_DOWN)) { goto not_supported; } us->down = 1; continue; } goto invalid; } ngx_memzero(&u, sizeof(ngx_url_t)); u.url = value[1]; if (ngx_parse_url(cf->pool, &u) != NGX_OK) { if (u.err) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "%s in upstream \"%V\"", u.err, &u.url); } return NGX_CONF_ERROR; } if (u.no_port) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "no port in upstream \"%V\"", &u.url); return NGX_CONF_ERROR; } us->name = u.url; us->addrs = u.addrs; us->naddrs = u.naddrs; us->weight = weight; us->max_conns = max_conns; us->max_fails = max_fails; us->fail_timeout = fail_timeout; return NGX_CONF_OK; invalid: ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid parameter \"%V\"", &value[i]); return NGX_CONF_ERROR; not_supported: ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "balancing method does not support parameter \"%V\"", &value[i]); return NGX_CONF_ERROR; } ngx_stream_upstream_srv_conf_t * ngx_stream_upstream_add(ngx_conf_t *cf, ngx_url_t *u, ngx_uint_t flags) { ngx_uint_t i; ngx_stream_upstream_server_t *us; ngx_stream_upstream_srv_conf_t *uscf, **uscfp; ngx_stream_upstream_main_conf_t *umcf; if (!(flags & NGX_STREAM_UPSTREAM_CREATE)) { if (ngx_parse_url(cf->pool, u) != NGX_OK) { if (u->err) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "%s in upstream \"%V\"", u->err, &u->url); } return NULL; } } umcf = ngx_stream_conf_get_module_main_conf(cf, ngx_stream_upstream_module); uscfp = umcf->upstreams.elts; for (i = 0; i < umcf->upstreams.nelts; i++) { if (uscfp[i]->host.len != u->host.len || ngx_strncasecmp(uscfp[i]->host.data, u->host.data, u->host.len) != 0) { continue; } if ((flags & NGX_STREAM_UPSTREAM_CREATE) && (uscfp[i]->flags & NGX_STREAM_UPSTREAM_CREATE)) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "duplicate upstream \"%V\"", &u->host); return NULL; } if ((uscfp[i]->flags & NGX_STREAM_UPSTREAM_CREATE) && !u->no_port) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "upstream \"%V\" may not have port %d", &u->host, u->port); return NULL; } if ((flags & NGX_STREAM_UPSTREAM_CREATE) && !uscfp[i]->no_port) { ngx_log_error(NGX_LOG_EMERG, cf->log, 0, "upstream \"%V\" may not have port %d in %s:%ui", &u->host, uscfp[i]->port, uscfp[i]->file_name, uscfp[i]->line); return NULL; } if (uscfp[i]->port != u->port) { continue; } if (flags & NGX_STREAM_UPSTREAM_CREATE) { uscfp[i]->flags = flags; } return uscfp[i]; } uscf = ngx_pcalloc(cf->pool, sizeof(ngx_stream_upstream_srv_conf_t)); if (uscf == NULL) { return NULL; } uscf->flags = flags; uscf->host = u->host; uscf->file_name = cf->conf_file->file.name.data; uscf->line = cf->conf_file->line; uscf->port = u->port; uscf->no_port = u->no_port; if (u->naddrs == 1 && (u->port || u->family == AF_UNIX)) { uscf->servers = ngx_array_create(cf->pool, 1, sizeof(ngx_stream_upstream_server_t)); if (uscf->servers == NULL) { return NULL; } us = ngx_array_push(uscf->servers); if (us == NULL) { return NULL; } ngx_memzero(us, sizeof(ngx_stream_upstream_server_t)); us->addrs = u->addrs; us->naddrs = 1; } uscfp = ngx_array_push(&umcf->upstreams); if (uscfp == NULL) { return NULL; } *uscfp = uscf; return uscf; } static void * ngx_stream_upstream_create_main_conf(ngx_conf_t *cf) { ngx_stream_upstream_main_conf_t *umcf; umcf = ngx_pcalloc(cf->pool, sizeof(ngx_stream_upstream_main_conf_t)); if (umcf == NULL) { return NULL; } if (ngx_array_init(&umcf->upstreams, cf->pool, 4, sizeof(ngx_stream_upstream_srv_conf_t *)) != NGX_OK) { return NULL; } return umcf; } static char * ngx_stream_upstream_init_main_conf(ngx_conf_t *cf, void *conf) { ngx_stream_upstream_main_conf_t *umcf = conf; ngx_uint_t i; ngx_stream_upstream_init_pt init; ngx_stream_upstream_srv_conf_t **uscfp; uscfp = umcf->upstreams.elts; for (i = 0; i < umcf->upstreams.nelts; i++) { init = uscfp[i]->peer.init_upstream ? uscfp[i]->peer.init_upstream : ngx_stream_upstream_init_round_robin; if (init(cf, uscfp[i]) != NGX_OK) { return NGX_CONF_ERROR; } } return NGX_CONF_OK; }