Mini Shell
/*
* 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");
if (s->buffer->pos < s->buffer->last
|| s->connection->read->ready)
{
ngx_post_event(c->write, &ngx_posted_events);
}
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");
if (s->buffer->pos < s->buffer->last
|| s->connection->read->ready)
{
ngx_post_event(c->write, &ngx_posted_events);
}
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
|| s->connection->read->ready)
{
ngx_post_event(c->write, &ngx_posted_events);
}
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_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_V1_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_V1_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;
}
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