Mercurial > hg > nginx
view src/mail/ngx_mail_imap_module.c @ 8018:5119c8150478
Fixed runtime handling of systems without EPOLLRDHUP support.
In 7583:efd71d49bde0 (nginx 1.17.5) along with introduction of the
ioctl(FIONREAD) support proper handling of systems without EPOLLRDHUP
support in the kernel (but with EPOLLRDHUP in headers) was broken.
Before the change, rev->available was never set to 0 unless
ngx_use_epoll_rdhup was also set (that is, runtime test for EPOLLRDHUP
introduced in 6536:f7849bfb6d21 succeeded). After the change,
rev->available might reach 0 on systems without runtime EPOLLRDHUP
support, stopping further reading in ngx_readv_chain() and ngx_unix_recv().
And, if EOF happened to be already reported along with the last event,
it is not reported again by epoll_wait(), leading to connection hangs
and timeouts on such systems.
This affects Linux kernels before 2.6.17 if nginx was compiled
with newer headers, and, more importantly, emulation layers, such as
DigitalOcean's App Platform's / gVisor's epoll emulation layer.
Fix is to explicitly check ngx_use_epoll_rdhup before the corresponding
rev->pending_eof tests in ngx_readv_chain() and ngx_unix_recv().
author | Marcus Ball <marcus.ball@live.com> |
---|---|
date | Mon, 30 May 2022 02:38:07 +0300 |
parents | dc955d274130 |
children |
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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"), ngx_string("\x04imap"), { 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; }