Mercurial > hg > nginx-quic
view src/mail/ngx_mail_proxy_module.c @ 8366:6df9d7df2784
gRPC: fixed handling of padding on DATA frames.
The response size check introduced in 39501ce97e29 did not take into
account possible padding on DATA frames, resulting in incorrect
"upstream sent response body larger than indicated content length" errors
if upstream server used padding in responses with known length.
Fix is to check the actual size of response buffers produced by the code,
similarly to how it is done in other protocols, instead of checking
the size of DATA frames.
Reported at:
http://mailman.nginx.org/pipermail/nginx-devel/2021-March/013907.html
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Tue, 23 Mar 2021 16:52:23 +0300 |
parents | 4b8f23a36ebf |
children | c72d8839f427 |
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_event_connect.h> #include <ngx_mail.h> typedef struct { ngx_flag_t enable; ngx_flag_t pass_error_message; ngx_flag_t xclient; ngx_flag_t smtp_auth; ngx_flag_t proxy_protocol; size_t buffer_size; ngx_msec_t timeout; } ngx_mail_proxy_conf_t; static void ngx_mail_proxy_block_read(ngx_event_t *rev); static void ngx_mail_proxy_pop3_handler(ngx_event_t *rev); static void ngx_mail_proxy_imap_handler(ngx_event_t *rev); static void ngx_mail_proxy_smtp_handler(ngx_event_t *rev); static void ngx_mail_proxy_write_handler(ngx_event_t *wev); static ngx_int_t ngx_mail_proxy_send_proxy_protocol(ngx_mail_session_t *s); static ngx_int_t ngx_mail_proxy_read_response(ngx_mail_session_t *s, ngx_uint_t state); static void ngx_mail_proxy_handler(ngx_event_t *ev); static void ngx_mail_proxy_upstream_error(ngx_mail_session_t *s); static void ngx_mail_proxy_internal_server_error(ngx_mail_session_t *s); static void ngx_mail_proxy_close_session(ngx_mail_session_t *s); static void *ngx_mail_proxy_create_conf(ngx_conf_t *cf); static char *ngx_mail_proxy_merge_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_command_t ngx_mail_proxy_commands[] = { { ngx_string("proxy"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_proxy_conf_t, enable), NULL }, { ngx_string("proxy_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_proxy_conf_t, buffer_size), NULL }, { ngx_string("proxy_timeout"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_msec_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_proxy_conf_t, timeout), NULL }, { ngx_string("proxy_pass_error_message"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_proxy_conf_t, pass_error_message), NULL }, { ngx_string("xclient"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_proxy_conf_t, xclient), NULL }, { ngx_string("proxy_smtp_auth"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_proxy_conf_t, smtp_auth), NULL }, { ngx_string("proxy_protocol"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_proxy_conf_t, proxy_protocol), NULL }, ngx_null_command }; static ngx_mail_module_t ngx_mail_proxy_module_ctx = { NULL, /* protocol */ NULL, /* create main configuration */ NULL, /* init main configuration */ ngx_mail_proxy_create_conf, /* create server configuration */ ngx_mail_proxy_merge_conf /* merge server configuration */ }; ngx_module_t ngx_mail_proxy_module = { NGX_MODULE_V1, &ngx_mail_proxy_module_ctx, /* module context */ ngx_mail_proxy_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 u_char smtp_auth_ok[] = "235 2.0.0 OK" CRLF; void ngx_mail_proxy_init(ngx_mail_session_t *s, ngx_addr_t *peer) { ngx_int_t rc; ngx_mail_proxy_ctx_t *p; ngx_mail_proxy_conf_t *pcf; ngx_mail_core_srv_conf_t *cscf; s->connection->log->action = "connecting to upstream"; cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); p = ngx_pcalloc(s->connection->pool, sizeof(ngx_mail_proxy_ctx_t)); if (p == NULL) { ngx_mail_session_internal_server_error(s); return; } s->proxy = p; p->upstream.sockaddr = peer->sockaddr; p->upstream.socklen = peer->socklen; p->upstream.name = &peer->name; p->upstream.get = ngx_event_get_peer; p->upstream.log = s->connection->log; p->upstream.log_error = NGX_ERROR_ERR; rc = ngx_event_connect_peer(&p->upstream); if (rc == NGX_ERROR || rc == NGX_BUSY || rc == NGX_DECLINED) { ngx_mail_proxy_internal_server_error(s); return; } ngx_add_timer(p->upstream.connection->read, cscf->timeout); p->upstream.connection->data = s; p->upstream.connection->pool = s->connection->pool; s->connection->read->handler = ngx_mail_proxy_block_read; p->upstream.connection->write->handler = ngx_mail_proxy_write_handler; pcf = ngx_mail_get_module_srv_conf(s, ngx_mail_proxy_module); s->proxy->buffer = ngx_create_temp_buf(s->connection->pool, pcf->buffer_size); if (s->proxy->buffer == NULL) { ngx_mail_proxy_internal_server_error(s); return; } s->proxy->proxy_protocol = pcf->proxy_protocol; s->out.len = 0; switch (s->protocol) { case NGX_MAIL_POP3_PROTOCOL: p->upstream.connection->read->handler = ngx_mail_proxy_pop3_handler; s->mail_state = ngx_pop3_start; break; case NGX_MAIL_IMAP_PROTOCOL: p->upstream.connection->read->handler = ngx_mail_proxy_imap_handler; s->mail_state = ngx_imap_start; break; default: /* NGX_MAIL_SMTP_PROTOCOL */ p->upstream.connection->read->handler = ngx_mail_proxy_smtp_handler; s->mail_state = ngx_smtp_start; break; } if (rc == NGX_AGAIN) { return; } ngx_mail_proxy_write_handler(p->upstream.connection->write); } static void ngx_mail_proxy_block_read(ngx_event_t *rev) { ngx_connection_t *c; ngx_mail_session_t *s; ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy block read"); if (ngx_handle_read_event(rev, 0) != NGX_OK) { c = rev->data; s = c->data; ngx_mail_proxy_close_session(s); } } static void ngx_mail_proxy_pop3_handler(ngx_event_t *rev) { u_char *p; ngx_int_t rc; ngx_str_t line; ngx_connection_t *c; ngx_mail_session_t *s; ngx_mail_proxy_conf_t *pcf; ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy pop3 auth handler"); c = rev->data; s = c->data; if (rev->timedout) { ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "upstream timed out"); c->timedout = 1; ngx_mail_proxy_internal_server_error(s); return; } if (s->proxy->proxy_protocol) { ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail proxy pop3 busy"); if (ngx_handle_read_event(c->read, 0) != NGX_OK) { ngx_mail_proxy_internal_server_error(s); return; } return; } rc = ngx_mail_proxy_read_response(s, 0); if (rc == NGX_AGAIN) { if (ngx_handle_read_event(c->read, 0) != NGX_OK) { ngx_mail_proxy_internal_server_error(s); return; } return; } if (rc == NGX_ERROR) { ngx_mail_proxy_upstream_error(s); return; } switch (s->mail_state) { case ngx_pop3_start: ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy send user"); s->connection->log->action = "sending user name to upstream"; line.len = sizeof("USER ") - 1 + s->login.len + 2; line.data = ngx_pnalloc(c->pool, line.len); if (line.data == NULL) { ngx_mail_proxy_internal_server_error(s); return; } p = ngx_cpymem(line.data, "USER ", sizeof("USER ") - 1); p = ngx_cpymem(p, s->login.data, s->login.len); *p++ = CR; *p = LF; s->mail_state = ngx_pop3_user; break; case ngx_pop3_user: ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy send pass"); s->connection->log->action = "sending password to upstream"; line.len = sizeof("PASS ") - 1 + s->passwd.len + 2; line.data = ngx_pnalloc(c->pool, line.len); if (line.data == NULL) { ngx_mail_proxy_internal_server_error(s); return; } p = ngx_cpymem(line.data, "PASS ", sizeof("PASS ") - 1); p = ngx_cpymem(p, s->passwd.data, s->passwd.len); *p++ = CR; *p = LF; s->mail_state = ngx_pop3_passwd; break; case ngx_pop3_passwd: s->connection->read->handler = ngx_mail_proxy_handler; s->connection->write->handler = ngx_mail_proxy_handler; rev->handler = ngx_mail_proxy_handler; c->write->handler = ngx_mail_proxy_handler; pcf = ngx_mail_get_module_srv_conf(s, ngx_mail_proxy_module); ngx_add_timer(s->connection->read, pcf->timeout); ngx_del_timer(c->read); c->log->action = NULL; ngx_log_error(NGX_LOG_INFO, c->log, 0, "client logged in"); ngx_mail_proxy_handler(s->connection->write); return; default: #if (NGX_SUPPRESS_WARN) ngx_str_null(&line); #endif break; } if (c->send(c, line.data, line.len) < (ssize_t) line.len) { /* * we treat the incomplete sending as NGX_ERROR * because it is very strange here */ ngx_mail_proxy_internal_server_error(s); return; } if (ngx_handle_read_event(c->read, 0) != NGX_OK) { ngx_mail_proxy_internal_server_error(s); return; } s->proxy->buffer->pos = s->proxy->buffer->start; s->proxy->buffer->last = s->proxy->buffer->start; } static void ngx_mail_proxy_imap_handler(ngx_event_t *rev) { u_char *p; ngx_int_t rc; ngx_str_t line; ngx_connection_t *c; ngx_mail_session_t *s; ngx_mail_proxy_conf_t *pcf; ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy imap auth handler"); c = rev->data; s = c->data; if (rev->timedout) { ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "upstream timed out"); c->timedout = 1; ngx_mail_proxy_internal_server_error(s); return; } if (s->proxy->proxy_protocol) { ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail proxy imap busy"); if (ngx_handle_read_event(c->read, 0) != NGX_OK) { ngx_mail_proxy_internal_server_error(s); return; } return; } rc = ngx_mail_proxy_read_response(s, s->mail_state); if (rc == NGX_AGAIN) { if (ngx_handle_read_event(c->read, 0) != NGX_OK) { ngx_mail_proxy_internal_server_error(s); return; } return; } if (rc == NGX_ERROR) { ngx_mail_proxy_upstream_error(s); return; } switch (s->mail_state) { case ngx_imap_start: ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy send login"); s->connection->log->action = "sending LOGIN command to upstream"; line.len = s->tag.len + sizeof("LOGIN ") - 1 + 1 + NGX_SIZE_T_LEN + 1 + 2; line.data = ngx_pnalloc(c->pool, line.len); if (line.data == NULL) { ngx_mail_proxy_internal_server_error(s); return; } line.len = ngx_sprintf(line.data, "%VLOGIN {%uz}" CRLF, &s->tag, s->login.len) - line.data; s->mail_state = ngx_imap_login; break; case ngx_imap_login: ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy send user"); s->connection->log->action = "sending user name to upstream"; line.len = s->login.len + 1 + 1 + NGX_SIZE_T_LEN + 1 + 2; line.data = ngx_pnalloc(c->pool, line.len); if (line.data == NULL) { ngx_mail_proxy_internal_server_error(s); return; } line.len = ngx_sprintf(line.data, "%V {%uz}" CRLF, &s->login, s->passwd.len) - line.data; s->mail_state = ngx_imap_user; break; case ngx_imap_user: ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy send passwd"); s->connection->log->action = "sending password to upstream"; line.len = s->passwd.len + 2; line.data = ngx_pnalloc(c->pool, line.len); if (line.data == NULL) { ngx_mail_proxy_internal_server_error(s); return; } p = ngx_cpymem(line.data, s->passwd.data, s->passwd.len); *p++ = CR; *p = LF; s->mail_state = ngx_imap_passwd; break; case ngx_imap_passwd: s->connection->read->handler = ngx_mail_proxy_handler; s->connection->write->handler = ngx_mail_proxy_handler; rev->handler = ngx_mail_proxy_handler; c->write->handler = ngx_mail_proxy_handler; pcf = ngx_mail_get_module_srv_conf(s, ngx_mail_proxy_module); ngx_add_timer(s->connection->read, pcf->timeout); ngx_del_timer(c->read); c->log->action = NULL; ngx_log_error(NGX_LOG_INFO, c->log, 0, "client logged in"); ngx_mail_proxy_handler(s->connection->write); return; default: #if (NGX_SUPPRESS_WARN) ngx_str_null(&line); #endif break; } if (c->send(c, line.data, line.len) < (ssize_t) line.len) { /* * we treat the incomplete sending as NGX_ERROR * because it is very strange here */ ngx_mail_proxy_internal_server_error(s); return; } if (ngx_handle_read_event(c->read, 0) != NGX_OK) { ngx_mail_proxy_internal_server_error(s); return; } s->proxy->buffer->pos = s->proxy->buffer->start; s->proxy->buffer->last = s->proxy->buffer->start; } static void ngx_mail_proxy_smtp_handler(ngx_event_t *rev) { u_char *p; ngx_int_t rc; ngx_str_t line, auth, encoded; ngx_buf_t *b; ngx_connection_t *c; ngx_mail_session_t *s; ngx_mail_proxy_conf_t *pcf; ngx_mail_core_srv_conf_t *cscf; ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy smtp auth handler"); c = rev->data; s = c->data; if (rev->timedout) { ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "upstream timed out"); c->timedout = 1; ngx_mail_proxy_internal_server_error(s); return; } if (s->proxy->proxy_protocol) { ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail proxy smtp busy"); if (ngx_handle_read_event(c->read, 0) != NGX_OK) { ngx_mail_proxy_internal_server_error(s); return; } return; } rc = ngx_mail_proxy_read_response(s, s->mail_state); if (rc == NGX_AGAIN) { if (ngx_handle_read_event(c->read, 0) != NGX_OK) { ngx_mail_proxy_internal_server_error(s); return; } return; } if (rc == NGX_ERROR) { ngx_mail_proxy_upstream_error(s); return; } switch (s->mail_state) { case ngx_smtp_start: ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy send ehlo"); s->connection->log->action = "sending HELO/EHLO to upstream"; cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); line.len = sizeof("HELO ") - 1 + cscf->server_name.len + 2; line.data = ngx_pnalloc(c->pool, line.len); if (line.data == NULL) { ngx_mail_proxy_internal_server_error(s); return; } pcf = ngx_mail_get_module_srv_conf(s, ngx_mail_proxy_module); p = ngx_cpymem(line.data, ((s->esmtp || pcf->xclient) ? "EHLO " : "HELO "), sizeof("HELO ") - 1); p = ngx_cpymem(p, cscf->server_name.data, cscf->server_name.len); *p++ = CR; *p = LF; if (pcf->xclient) { s->mail_state = ngx_smtp_helo_xclient; } else if (s->auth_method == NGX_MAIL_AUTH_NONE) { s->mail_state = ngx_smtp_helo_from; } else if (pcf->smtp_auth) { s->mail_state = ngx_smtp_helo_auth; } else { s->mail_state = ngx_smtp_helo; } break; case ngx_smtp_helo_xclient: ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy send xclient"); s->connection->log->action = "sending XCLIENT to upstream"; line.len = sizeof("XCLIENT ADDR= LOGIN= NAME=" CRLF) - 1 + s->connection->addr_text.len + s->login.len + s->host.len; #if (NGX_HAVE_INET6) if (s->connection->sockaddr->sa_family == AF_INET6) { line.len += sizeof("IPV6:") - 1; } #endif line.data = ngx_pnalloc(c->pool, line.len); if (line.data == NULL) { ngx_mail_proxy_internal_server_error(s); return; } p = ngx_cpymem(line.data, "XCLIENT ADDR=", sizeof("XCLIENT ADDR=") - 1); #if (NGX_HAVE_INET6) if (s->connection->sockaddr->sa_family == AF_INET6) { p = ngx_cpymem(p, "IPV6:", sizeof("IPV6:") - 1); } #endif p = ngx_copy(p, s->connection->addr_text.data, s->connection->addr_text.len); pcf = ngx_mail_get_module_srv_conf(s, ngx_mail_proxy_module); if (s->login.len && !pcf->smtp_auth) { p = ngx_cpymem(p, " LOGIN=", sizeof(" LOGIN=") - 1); p = ngx_copy(p, s->login.data, s->login.len); } p = ngx_cpymem(p, " NAME=", sizeof(" NAME=") - 1); p = ngx_copy(p, s->host.data, s->host.len); *p++ = CR; *p++ = LF; line.len = p - line.data; if (s->smtp_helo.len) { s->mail_state = ngx_smtp_xclient_helo; } else if (s->auth_method == NGX_MAIL_AUTH_NONE) { s->mail_state = ngx_smtp_xclient_from; } else if (pcf->smtp_auth) { s->mail_state = ngx_smtp_xclient_auth; } else { s->mail_state = ngx_smtp_xclient; } break; case ngx_smtp_xclient_helo: ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy send client ehlo"); s->connection->log->action = "sending client HELO/EHLO to upstream"; line.len = sizeof("HELO " CRLF) - 1 + s->smtp_helo.len; line.data = ngx_pnalloc(c->pool, line.len); if (line.data == NULL) { ngx_mail_proxy_internal_server_error(s); return; } line.len = ngx_sprintf(line.data, ((s->esmtp) ? "EHLO %V" CRLF : "HELO %V" CRLF), &s->smtp_helo) - line.data; pcf = ngx_mail_get_module_srv_conf(s, ngx_mail_proxy_module); if (s->auth_method == NGX_MAIL_AUTH_NONE) { s->mail_state = ngx_smtp_helo_from; } else if (pcf->smtp_auth) { s->mail_state = ngx_smtp_helo_auth; } else { s->mail_state = ngx_smtp_helo; } break; case ngx_smtp_helo_auth: case ngx_smtp_xclient_auth: ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy send auth"); s->connection->log->action = "sending AUTH to upstream"; if (s->passwd.data == NULL) { ngx_log_error(NGX_LOG_ERR, s->connection->log, 0, "no password available"); ngx_mail_proxy_internal_server_error(s); return; } auth.len = 1 + s->login.len + 1 + s->passwd.len; auth.data = ngx_pnalloc(c->pool, auth.len); if (auth.data == NULL) { ngx_mail_proxy_internal_server_error(s); return; } auth.len = ngx_sprintf(auth.data, "%Z%V%Z%V", &s->login, &s->passwd) - auth.data; line.len = sizeof("AUTH PLAIN " CRLF) - 1 + ngx_base64_encoded_length(auth.len); line.data = ngx_pnalloc(c->pool, line.len); if (line.data == NULL) { ngx_mail_proxy_internal_server_error(s); return; } encoded.data = ngx_cpymem(line.data, "AUTH PLAIN ", sizeof("AUTH PLAIN ") - 1); ngx_encode_base64(&encoded, &auth); p = encoded.data + encoded.len; *p++ = CR; *p = LF; s->mail_state = ngx_smtp_auth_plain; break; case ngx_smtp_helo_from: case ngx_smtp_xclient_from: ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy send mail from"); s->connection->log->action = "sending MAIL FROM to upstream"; line.len = s->smtp_from.len + sizeof(CRLF) - 1; line.data = ngx_pnalloc(c->pool, line.len); if (line.data == NULL) { ngx_mail_proxy_internal_server_error(s); return; } p = ngx_cpymem(line.data, s->smtp_from.data, s->smtp_from.len); *p++ = CR; *p = LF; s->mail_state = ngx_smtp_from; break; case ngx_smtp_from: ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy send rcpt to"); s->connection->log->action = "sending RCPT TO to upstream"; line.len = s->smtp_to.len + sizeof(CRLF) - 1; line.data = ngx_pnalloc(c->pool, line.len); if (line.data == NULL) { ngx_mail_proxy_internal_server_error(s); return; } p = ngx_cpymem(line.data, s->smtp_to.data, s->smtp_to.len); *p++ = CR; *p = LF; s->mail_state = ngx_smtp_to; break; case ngx_smtp_helo: case ngx_smtp_xclient: case ngx_smtp_auth_plain: case ngx_smtp_to: b = s->proxy->buffer; if (s->auth_method == NGX_MAIL_AUTH_NONE) { b->pos = b->start; } else { ngx_memcpy(b->start, smtp_auth_ok, sizeof(smtp_auth_ok) - 1); b->last = b->start + sizeof(smtp_auth_ok) - 1; } s->connection->read->handler = ngx_mail_proxy_handler; s->connection->write->handler = ngx_mail_proxy_handler; rev->handler = ngx_mail_proxy_handler; c->write->handler = ngx_mail_proxy_handler; pcf = ngx_mail_get_module_srv_conf(s, ngx_mail_proxy_module); ngx_add_timer(s->connection->read, pcf->timeout); ngx_del_timer(c->read); c->log->action = NULL; ngx_log_error(NGX_LOG_INFO, c->log, 0, "client logged in"); if (s->buffer->pos == s->buffer->last) { ngx_mail_proxy_handler(s->connection->write); } else { ngx_mail_proxy_handler(c->write); } return; default: #if (NGX_SUPPRESS_WARN) ngx_str_null(&line); #endif break; } if (c->send(c, line.data, line.len) < (ssize_t) line.len) { /* * we treat the incomplete sending as NGX_ERROR * because it is very strange here */ ngx_mail_proxy_internal_server_error(s); return; } if (ngx_handle_read_event(c->read, 0) != NGX_OK) { ngx_mail_proxy_internal_server_error(s); return; } s->proxy->buffer->pos = s->proxy->buffer->start; s->proxy->buffer->last = s->proxy->buffer->start; } static void ngx_mail_proxy_write_handler(ngx_event_t *wev) { ngx_connection_t *c; ngx_mail_session_t *s; ngx_log_debug0(NGX_LOG_DEBUG_MAIL, wev->log, 0, "mail proxy write handler"); c = wev->data; s = c->data; if (s->proxy->proxy_protocol) { if (ngx_mail_proxy_send_proxy_protocol(s) != NGX_OK) { return; } s->proxy->proxy_protocol = 0; } if (ngx_handle_write_event(wev, 0) != NGX_OK) { ngx_mail_proxy_internal_server_error(s); } if (c->read->ready) { ngx_post_event(c->read, &ngx_posted_events); } } static ngx_int_t ngx_mail_proxy_send_proxy_protocol(ngx_mail_session_t *s) { u_char *p; ssize_t n, size; ngx_connection_t *c; u_char buf[NGX_PROXY_PROTOCOL_MAX_HEADER]; s->connection->log->action = "sending PROXY protocol header to upstream"; ngx_log_debug0(NGX_LOG_DEBUG_MAIL, s->connection->log, 0, "mail proxy send PROXY protocol header"); p = ngx_proxy_protocol_write(s->connection, buf, buf + NGX_PROXY_PROTOCOL_MAX_HEADER); if (p == NULL) { ngx_mail_proxy_internal_server_error(s); return NGX_ERROR; } c = s->proxy->upstream.connection; size = p - buf; n = c->send(c, buf, size); if (n == NGX_AGAIN) { if (ngx_handle_write_event(c->write, 0) != NGX_OK) { ngx_mail_proxy_internal_server_error(s); return NGX_ERROR; } return NGX_AGAIN; } if (n == NGX_ERROR) { ngx_mail_proxy_internal_server_error(s); return NGX_ERROR; } if (n != size) { /* * PROXY protocol specification: * The sender must always ensure that the header * is sent at once, so that the transport layer * maintains atomicity along the path to the receiver. */ ngx_log_error(NGX_LOG_ERR, s->connection->log, 0, "could not send PROXY protocol header at once"); ngx_mail_proxy_internal_server_error(s); return NGX_ERROR; } return NGX_OK; } static ngx_int_t ngx_mail_proxy_read_response(ngx_mail_session_t *s, ngx_uint_t state) { u_char *p, *m; ssize_t n; ngx_buf_t *b; ngx_mail_proxy_conf_t *pcf; s->connection->log->action = "reading response from upstream"; b = s->proxy->buffer; n = s->proxy->upstream.connection->recv(s->proxy->upstream.connection, b->last, b->end - b->last); if (n == NGX_ERROR || n == 0) { return NGX_ERROR; } if (n == NGX_AGAIN) { return NGX_AGAIN; } b->last += n; if (b->last - b->pos < 4) { return NGX_AGAIN; } if (*(b->last - 2) != CR || *(b->last - 1) != LF) { if (b->last == b->end) { *(b->last - 1) = '\0'; ngx_log_error(NGX_LOG_ERR, s->connection->log, 0, "upstream sent too long response line: \"%s\"", b->pos); return NGX_ERROR; } return NGX_AGAIN; } p = b->pos; switch (s->protocol) { case NGX_MAIL_POP3_PROTOCOL: if (p[0] == '+' && p[1] == 'O' && p[2] == 'K') { return NGX_OK; } break; case NGX_MAIL_IMAP_PROTOCOL: switch (state) { case ngx_imap_start: if (p[0] == '*' && p[1] == ' ' && p[2] == 'O' && p[3] == 'K') { return NGX_OK; } break; case ngx_imap_login: case ngx_imap_user: if (p[0] == '+') { return NGX_OK; } break; case ngx_imap_passwd: if (ngx_strncmp(p, s->tag.data, s->tag.len) == 0) { p += s->tag.len; if (p[0] == 'O' && p[1] == 'K') { return NGX_OK; } } break; } break; default: /* NGX_MAIL_SMTP_PROTOCOL */ if (p[3] == '-') { /* multiline reply, check if we got last line */ m = b->last - (sizeof(CRLF "200" CRLF) - 1); while (m > p) { if (m[0] == CR && m[1] == LF) { break; } m--; } if (m <= p || m[5] == '-') { return NGX_AGAIN; } } switch (state) { case ngx_smtp_start: if (p[0] == '2' && p[1] == '2' && p[2] == '0') { return NGX_OK; } break; case ngx_smtp_helo: case ngx_smtp_helo_xclient: case ngx_smtp_helo_from: case ngx_smtp_helo_auth: case ngx_smtp_from: if (p[0] == '2' && p[1] == '5' && p[2] == '0') { return NGX_OK; } break; case ngx_smtp_xclient: case ngx_smtp_xclient_from: case ngx_smtp_xclient_helo: case ngx_smtp_xclient_auth: if (p[0] == '2' && (p[1] == '2' || p[1] == '5') && p[2] == '0') { return NGX_OK; } break; case ngx_smtp_auth_plain: if (p[0] == '2' && p[1] == '3' && p[2] == '5') { return NGX_OK; } break; case ngx_smtp_to: return NGX_OK; } break; } pcf = ngx_mail_get_module_srv_conf(s, ngx_mail_proxy_module); if (pcf->pass_error_message == 0) { *(b->last - 2) = '\0'; ngx_log_error(NGX_LOG_ERR, s->connection->log, 0, "upstream sent invalid response: \"%s\"", p); return NGX_ERROR; } s->out.len = b->last - p - 2; s->out.data = p; ngx_log_error(NGX_LOG_INFO, s->connection->log, 0, "upstream sent invalid response: \"%V\"", &s->out); s->out.len = b->last - b->pos; s->out.data = b->pos; return NGX_ERROR; } static void ngx_mail_proxy_handler(ngx_event_t *ev) { char *action, *recv_action, *send_action; size_t size; ssize_t n; ngx_buf_t *b; ngx_uint_t do_write; ngx_connection_t *c, *src, *dst; ngx_mail_session_t *s; ngx_mail_proxy_conf_t *pcf; c = ev->data; s = c->data; if (ev->timedout || c->close) { c->log->action = "proxying"; if (c->close) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "shutdown timeout"); } else if (c == s->connection) { ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out"); c->timedout = 1; } else { ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "upstream timed out"); } ngx_mail_proxy_close_session(s); return; } if (c == s->connection) { if (ev->write) { recv_action = "proxying and reading from upstream"; send_action = "proxying and sending to client"; src = s->proxy->upstream.connection; dst = c; b = s->proxy->buffer; } else { recv_action = "proxying and reading from client"; send_action = "proxying and sending to upstream"; src = c; dst = s->proxy->upstream.connection; b = s->buffer; } } else { if (ev->write) { recv_action = "proxying and reading from client"; send_action = "proxying and sending to upstream"; src = s->connection; dst = c; b = s->buffer; } else { recv_action = "proxying and reading from upstream"; send_action = "proxying and sending to client"; src = c; dst = s->connection; b = s->proxy->buffer; } } do_write = ev->write ? 1 : 0; ngx_log_debug3(NGX_LOG_DEBUG_MAIL, ev->log, 0, "mail proxy handler: %ui, #%d > #%d", do_write, src->fd, dst->fd); for ( ;; ) { if (do_write) { size = b->last - b->pos; if (size && dst->write->ready) { c->log->action = send_action; n = dst->send(dst, b->pos, size); if (n == NGX_ERROR) { ngx_mail_proxy_close_session(s); return; } if (n > 0) { b->pos += n; if (b->pos == b->last) { b->pos = b->start; b->last = b->start; } } } } size = b->end - b->last; if (size && src->read->ready) { c->log->action = recv_action; n = src->recv(src, b->last, size); if (n == NGX_AGAIN || n == 0) { break; } if (n > 0) { do_write = 1; b->last += n; continue; } if (n == NGX_ERROR) { src->read->eof = 1; } } break; } c->log->action = "proxying"; if ((s->connection->read->eof && s->buffer->pos == s->buffer->last) || (s->proxy->upstream.connection->read->eof && s->proxy->buffer->pos == s->proxy->buffer->last) || (s->connection->read->eof && s->proxy->upstream.connection->read->eof)) { action = c->log->action; c->log->action = NULL; ngx_log_error(NGX_LOG_INFO, c->log, 0, "proxied session done"); c->log->action = action; ngx_mail_proxy_close_session(s); return; } if (ngx_handle_write_event(dst->write, 0) != NGX_OK) { ngx_mail_proxy_close_session(s); return; } if (ngx_handle_read_event(dst->read, 0) != NGX_OK) { ngx_mail_proxy_close_session(s); return; } if (ngx_handle_write_event(src->write, 0) != NGX_OK) { ngx_mail_proxy_close_session(s); return; } if (ngx_handle_read_event(src->read, 0) != NGX_OK) { ngx_mail_proxy_close_session(s); return; } if (c == s->connection) { pcf = ngx_mail_get_module_srv_conf(s, ngx_mail_proxy_module); ngx_add_timer(c->read, pcf->timeout); } } static void ngx_mail_proxy_upstream_error(ngx_mail_session_t *s) { if (s->proxy->upstream.connection) { ngx_log_debug1(NGX_LOG_DEBUG_MAIL, s->connection->log, 0, "close mail proxy connection: %d", s->proxy->upstream.connection->fd); ngx_close_connection(s->proxy->upstream.connection); } if (s->out.len == 0) { ngx_mail_session_internal_server_error(s); return; } s->quit = 1; ngx_mail_send(s->connection->write); } static void ngx_mail_proxy_internal_server_error(ngx_mail_session_t *s) { if (s->proxy->upstream.connection) { ngx_log_debug1(NGX_LOG_DEBUG_MAIL, s->connection->log, 0, "close mail proxy connection: %d", s->proxy->upstream.connection->fd); ngx_close_connection(s->proxy->upstream.connection); } ngx_mail_session_internal_server_error(s); } static void ngx_mail_proxy_close_session(ngx_mail_session_t *s) { if (s->proxy->upstream.connection) { ngx_log_debug1(NGX_LOG_DEBUG_MAIL, s->connection->log, 0, "close mail proxy connection: %d", s->proxy->upstream.connection->fd); ngx_close_connection(s->proxy->upstream.connection); } ngx_mail_close_connection(s->connection); } static void * ngx_mail_proxy_create_conf(ngx_conf_t *cf) { ngx_mail_proxy_conf_t *pcf; pcf = ngx_pcalloc(cf->pool, sizeof(ngx_mail_proxy_conf_t)); if (pcf == NULL) { return NULL; } pcf->enable = NGX_CONF_UNSET; pcf->pass_error_message = NGX_CONF_UNSET; pcf->xclient = NGX_CONF_UNSET; pcf->smtp_auth = NGX_CONF_UNSET; pcf->proxy_protocol = NGX_CONF_UNSET; pcf->buffer_size = NGX_CONF_UNSET_SIZE; pcf->timeout = NGX_CONF_UNSET_MSEC; return pcf; } static char * ngx_mail_proxy_merge_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_mail_proxy_conf_t *prev = parent; ngx_mail_proxy_conf_t *conf = child; ngx_conf_merge_value(conf->enable, prev->enable, 0); ngx_conf_merge_value(conf->pass_error_message, prev->pass_error_message, 0); ngx_conf_merge_value(conf->xclient, prev->xclient, 1); ngx_conf_merge_value(conf->smtp_auth, prev->smtp_auth, 0); ngx_conf_merge_value(conf->proxy_protocol, prev->proxy_protocol, 0); ngx_conf_merge_size_value(conf->buffer_size, prev->buffer_size, (size_t) ngx_pagesize); ngx_conf_merge_msec_value(conf->timeout, prev->timeout, 24 * 60 * 60000); return NGX_CONF_OK; }