Mercurial > hg > nginx
view src/mail/ngx_mail_imap_module.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 | bcb107bb89cd |
children | dc955d274130 |
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/* * 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_imap_module.h> static void *ngx_mail_imap_create_srv_conf(ngx_conf_t *cf); static char *ngx_mail_imap_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_str_t ngx_mail_imap_default_capabilities[] = { ngx_string("IMAP4"), ngx_string("IMAP4rev1"), ngx_string("UIDPLUS"), ngx_null_string }; static ngx_conf_bitmask_t ngx_mail_imap_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_null_string, 0 } }; static ngx_str_t ngx_mail_imap_auth_methods_names[] = { ngx_string("AUTH=PLAIN"), ngx_string("AUTH=LOGIN"), ngx_null_string, /* APOP */ ngx_string("AUTH=CRAM-MD5"), ngx_string("AUTH=EXTERNAL"), ngx_null_string /* NONE */ }; static ngx_mail_protocol_t ngx_mail_imap_protocol = { ngx_string("imap"), { 143, 993, 0, 0 }, NGX_MAIL_IMAP_PROTOCOL, ngx_mail_imap_init_session, ngx_mail_imap_init_protocol, ngx_mail_imap_parse_command, ngx_mail_imap_auth_state, ngx_string("* BAD internal server error" CRLF), ngx_string("* BYE SSL certificate error" CRLF), ngx_string("* BYE No required SSL certificate" CRLF) }; static ngx_command_t ngx_mail_imap_commands[] = { { ngx_string("imap_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_imap_srv_conf_t, client_buffer_size), NULL }, { ngx_string("imap_capabilities"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE, ngx_mail_capabilities, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_imap_srv_conf_t, capabilities), NULL }, { ngx_string("imap_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_imap_srv_conf_t, auth_methods), &ngx_mail_imap_auth_methods }, ngx_null_command }; static ngx_mail_module_t ngx_mail_imap_module_ctx = { &ngx_mail_imap_protocol, /* protocol */ NULL, /* create main configuration */ NULL, /* init main configuration */ ngx_mail_imap_create_srv_conf, /* create server configuration */ ngx_mail_imap_merge_srv_conf /* merge server configuration */ }; ngx_module_t ngx_mail_imap_module = { NGX_MODULE_V1, &ngx_mail_imap_module_ctx, /* module context */ ngx_mail_imap_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_imap_create_srv_conf(ngx_conf_t *cf) { ngx_mail_imap_srv_conf_t *iscf; iscf = ngx_pcalloc(cf->pool, sizeof(ngx_mail_imap_srv_conf_t)); if (iscf == NULL) { return NULL; } iscf->client_buffer_size = NGX_CONF_UNSET_SIZE; if (ngx_array_init(&iscf->capabilities, cf->pool, 4, sizeof(ngx_str_t)) != NGX_OK) { return NULL; } return iscf; } static char * ngx_mail_imap_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_mail_imap_srv_conf_t *prev = parent; ngx_mail_imap_srv_conf_t *conf = child; u_char *p, *auth; size_t size; ngx_str_t *c, *d; ngx_uint_t i, m; ngx_conf_merge_size_value(conf->client_buffer_size, prev->client_buffer_size, (size_t) ngx_pagesize); ngx_conf_merge_bitmask_value(conf->auth_methods, prev->auth_methods, (NGX_CONF_BITMASK_SET |NGX_MAIL_AUTH_PLAIN_ENABLED)); if (conf->capabilities.nelts == 0) { conf->capabilities = prev->capabilities; } if (conf->capabilities.nelts == 0) { for (d = ngx_mail_imap_default_capabilities; d->len; d++) { c = ngx_array_push(&conf->capabilities); if (c == NULL) { return NGX_CONF_ERROR; } *c = *d; } } size = sizeof("* CAPABILITY" CRLF) - 1; c = conf->capabilities.elts; for (i = 0; i < conf->capabilities.nelts; i++) { size += 1 + c[i].len; } 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_imap_auth_methods_names[i].len; } } p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->capability.len = size; conf->capability.data = p; p = ngx_cpymem(p, "* CAPABILITY", sizeof("* CAPABILITY") - 1); for (i = 0; i < conf->capabilities.nelts; i++) { *p++ = ' '; p = ngx_cpymem(p, c[i].data, c[i].len); } auth = p; 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_imap_auth_methods_names[i].data, ngx_mail_imap_auth_methods_names[i].len); } } *p++ = CR; *p = LF; size += sizeof(" STARTTLS") - 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 - (sizeof(CRLF) - 1)); p = ngx_cpymem(p, " STARTTLS", sizeof(" STARTTLS") - 1); *p++ = CR; *p = LF; size = (auth - conf->capability.data) + sizeof(CRLF) - 1 + sizeof(" STARTTLS LOGINDISABLED") - 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); p = ngx_cpymem(p, " STARTTLS LOGINDISABLED", sizeof(" STARTTLS LOGINDISABLED") - 1); *p++ = CR; *p = LF; return NGX_CONF_OK; }