Mercurial > hg > nginx
view src/mail/ngx_mail_smtp_module.c @ 7281:bd6563e81cea
Limit req: improved handling of negative times.
Negative times can appear since workers only update time on an event
loop iteration start. If a worker was blocked for a long time during
an event loop iteration, it is possible that another worker already
updated the time stored in the node. As such, time since last update
of the node (ms) will be negative.
Previous code used ngx_abs(ms) in the calculations. That is, negative
times were effectively treated as positive ones. As a result, it was
not possible to maintain high request rates, where the same node can be
updated multiple times from during an event loop iteration.
In particular, this affected setups with many SSL handshakes, see
http://mailman.nginx.org/pipermail/nginx/2018-May/056291.html.
Fix is to only update the last update time stored in the node if the
new time is larger than previously stored one. If a future time is
stored in the node, we preserve this time as is.
To prevent breaking things on platforms without monotonic time available
if system time is updated backwards, a safety limit of 60 seconds is
used. If the time stored in the node is more than 60 seconds in the future,
we assume that the time was changed backwards and update lr->last
to the current time.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Wed, 30 May 2018 15:40:34 +0300 |
parents | f18c285c2e59 |
children | dc955d274130 |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #include <ngx_mail.h> #include <ngx_mail_smtp_module.h> static void *ngx_mail_smtp_create_srv_conf(ngx_conf_t *cf); static char *ngx_mail_smtp_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_conf_bitmask_t ngx_mail_smtp_auth_methods[] = { { ngx_string("plain"), NGX_MAIL_AUTH_PLAIN_ENABLED }, { ngx_string("login"), NGX_MAIL_AUTH_LOGIN_ENABLED }, { ngx_string("cram-md5"), NGX_MAIL_AUTH_CRAM_MD5_ENABLED }, { ngx_string("external"), NGX_MAIL_AUTH_EXTERNAL_ENABLED }, { ngx_string("none"), NGX_MAIL_AUTH_NONE_ENABLED }, { ngx_null_string, 0 } }; static ngx_str_t ngx_mail_smtp_auth_methods_names[] = { ngx_string("PLAIN"), ngx_string("LOGIN"), ngx_null_string, /* APOP */ ngx_string("CRAM-MD5"), ngx_string("EXTERNAL"), ngx_null_string /* NONE */ }; static ngx_mail_protocol_t ngx_mail_smtp_protocol = { ngx_string("smtp"), { 25, 465, 587, 0 }, NGX_MAIL_SMTP_PROTOCOL, ngx_mail_smtp_init_session, ngx_mail_smtp_init_protocol, ngx_mail_smtp_parse_command, ngx_mail_smtp_auth_state, ngx_string("451 4.3.2 Internal server error" CRLF), ngx_string("421 4.7.1 SSL certificate error" CRLF), ngx_string("421 4.7.1 No required SSL certificate" CRLF) }; static ngx_command_t ngx_mail_smtp_commands[] = { { ngx_string("smtp_client_buffer"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_size_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_smtp_srv_conf_t, client_buffer_size), NULL }, { ngx_string("smtp_greeting_delay"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_msec_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_smtp_srv_conf_t, greeting_delay), NULL }, { ngx_string("smtp_capabilities"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE, ngx_mail_capabilities, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_smtp_srv_conf_t, capabilities), NULL }, { ngx_string("smtp_auth"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE, ngx_conf_set_bitmask_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_smtp_srv_conf_t, auth_methods), &ngx_mail_smtp_auth_methods }, ngx_null_command }; static ngx_mail_module_t ngx_mail_smtp_module_ctx = { &ngx_mail_smtp_protocol, /* protocol */ NULL, /* create main configuration */ NULL, /* init main configuration */ ngx_mail_smtp_create_srv_conf, /* create server configuration */ ngx_mail_smtp_merge_srv_conf /* merge server configuration */ }; ngx_module_t ngx_mail_smtp_module = { NGX_MODULE_V1, &ngx_mail_smtp_module_ctx, /* module context */ ngx_mail_smtp_commands, /* module directives */ NGX_MAIL_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 void * ngx_mail_smtp_create_srv_conf(ngx_conf_t *cf) { ngx_mail_smtp_srv_conf_t *sscf; sscf = ngx_pcalloc(cf->pool, sizeof(ngx_mail_smtp_srv_conf_t)); if (sscf == NULL) { return NULL; } sscf->client_buffer_size = NGX_CONF_UNSET_SIZE; sscf->greeting_delay = NGX_CONF_UNSET_MSEC; if (ngx_array_init(&sscf->capabilities, cf->pool, 4, sizeof(ngx_str_t)) != NGX_OK) { return NULL; } return sscf; } static char * ngx_mail_smtp_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_mail_smtp_srv_conf_t *prev = parent; ngx_mail_smtp_srv_conf_t *conf = child; u_char *p, *auth, *last; size_t size; ngx_str_t *c; ngx_uint_t i, m, auth_enabled; ngx_mail_core_srv_conf_t *cscf; ngx_conf_merge_size_value(conf->client_buffer_size, prev->client_buffer_size, (size_t) ngx_pagesize); ngx_conf_merge_msec_value(conf->greeting_delay, prev->greeting_delay, 0); ngx_conf_merge_bitmask_value(conf->auth_methods, prev->auth_methods, (NGX_CONF_BITMASK_SET |NGX_MAIL_AUTH_PLAIN_ENABLED |NGX_MAIL_AUTH_LOGIN_ENABLED)); cscf = ngx_mail_conf_get_module_srv_conf(cf, ngx_mail_core_module); size = sizeof("220 ESMTP ready" CRLF) - 1 + cscf->server_name.len; p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->greeting.len = size; conf->greeting.data = p; *p++ = '2'; *p++ = '2'; *p++ = '0'; *p++ = ' '; p = ngx_cpymem(p, cscf->server_name.data, cscf->server_name.len); ngx_memcpy(p, " ESMTP ready" CRLF, sizeof(" ESMTP ready" CRLF) - 1); size = sizeof("250 " CRLF) - 1 + cscf->server_name.len; p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->server_name.len = size; conf->server_name.data = p; *p++ = '2'; *p++ = '5'; *p++ = '0'; *p++ = ' '; p = ngx_cpymem(p, cscf->server_name.data, cscf->server_name.len); *p++ = CR; *p = LF; if (conf->capabilities.nelts == 0) { conf->capabilities = prev->capabilities; } size = sizeof("250-") - 1 + cscf->server_name.len + sizeof(CRLF) - 1; c = conf->capabilities.elts; for (i = 0; i < conf->capabilities.nelts; i++) { size += sizeof("250 ") - 1 + c[i].len + sizeof(CRLF) - 1; } auth_enabled = 0; for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0; m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED; m <<= 1, i++) { if (m & conf->auth_methods) { size += 1 + ngx_mail_smtp_auth_methods_names[i].len; auth_enabled = 1; } } if (auth_enabled) { size += sizeof("250 AUTH") - 1 + sizeof(CRLF) - 1; } p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->capability.len = size; conf->capability.data = p; last = p; *p++ = '2'; *p++ = '5'; *p++ = '0'; *p++ = '-'; p = ngx_cpymem(p, cscf->server_name.data, cscf->server_name.len); *p++ = CR; *p++ = LF; for (i = 0; i < conf->capabilities.nelts; i++) { last = p; *p++ = '2'; *p++ = '5'; *p++ = '0'; *p++ = '-'; p = ngx_cpymem(p, c[i].data, c[i].len); *p++ = CR; *p++ = LF; } auth = p; if (auth_enabled) { last = p; *p++ = '2'; *p++ = '5'; *p++ = '0'; *p++ = ' '; *p++ = 'A'; *p++ = 'U'; *p++ = 'T'; *p++ = 'H'; for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0; m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED; m <<= 1, i++) { if (m & conf->auth_methods) { *p++ = ' '; p = ngx_cpymem(p, ngx_mail_smtp_auth_methods_names[i].data, ngx_mail_smtp_auth_methods_names[i].len); } } *p++ = CR; *p = LF; } else { last[3] = ' '; } size += sizeof("250 STARTTLS" CRLF) - 1; p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->starttls_capability.len = size; conf->starttls_capability.data = p; p = ngx_cpymem(p, conf->capability.data, conf->capability.len); ngx_memcpy(p, "250 STARTTLS" CRLF, sizeof("250 STARTTLS" CRLF) - 1); p = conf->starttls_capability.data + (last - conf->capability.data) + 3; *p = '-'; size = (auth - conf->capability.data) + sizeof("250 STARTTLS" CRLF) - 1; p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->starttls_only_capability.len = size; conf->starttls_only_capability.data = p; p = ngx_cpymem(p, conf->capability.data, auth - conf->capability.data); ngx_memcpy(p, "250 STARTTLS" CRLF, sizeof("250 STARTTLS" CRLF) - 1); if (last < auth) { p = conf->starttls_only_capability.data + (last - conf->capability.data) + 3; *p = '-'; } return NGX_CONF_OK; }