This source file includes following definitions.
- ngx_mail_smtp_init_session
- ngx_mail_smtp_resolve_addr_handler
- ngx_mail_smtp_resolve_name
- ngx_mail_smtp_resolve_name_handler
- ngx_mail_smtp_greeting
- ngx_mail_smtp_invalid_pipelining
- ngx_mail_smtp_init_protocol
- ngx_mail_smtp_create_buffer
- ngx_mail_smtp_auth_state
- ngx_mail_smtp_helo
- ngx_mail_smtp_auth
- ngx_mail_smtp_mail
- ngx_mail_smtp_rcpt
- ngx_mail_smtp_rset
- ngx_mail_smtp_starttls
- ngx_mail_smtp_discard_command
- ngx_mail_smtp_log_rejected_command
#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_resolve_addr_handler(ngx_resolver_ctx_t *ctx);
static void ngx_mail_smtp_resolve_name(ngx_event_t *rev);
static void ngx_mail_smtp_resolve_name_handler(ngx_resolver_ctx_t *ctx);
static void ngx_mail_smtp_greeting(ngx_mail_session_t *s, ngx_connection_t *c);
static void ngx_mail_smtp_invalid_pipelining(ngx_event_t *rev);
static ngx_int_t ngx_mail_smtp_create_buffer(ngx_mail_session_t *s,
ngx_connection_t *c);
static ngx_int_t ngx_mail_smtp_helo(ngx_mail_session_t *s, ngx_connection_t *c);
static ngx_int_t ngx_mail_smtp_auth(ngx_mail_session_t *s, ngx_connection_t *c);
static ngx_int_t ngx_mail_smtp_mail(ngx_mail_session_t *s, ngx_connection_t *c);
static ngx_int_t ngx_mail_smtp_starttls(ngx_mail_session_t *s,
ngx_connection_t *c);
static ngx_int_t ngx_mail_smtp_rset(ngx_mail_session_t *s, ngx_connection_t *c);
static ngx_int_t ngx_mail_smtp_rcpt(ngx_mail_session_t *s, ngx_connection_t *c);
static ngx_int_t ngx_mail_smtp_discard_command(ngx_mail_session_t *s,
ngx_connection_t *c, char *err);
static void ngx_mail_smtp_log_rejected_command(ngx_mail_session_t *s,
ngx_connection_t *c, char *err);
static u_char smtp_ok[] = "250 2.0.0 OK" CRLF;
static u_char smtp_bye[] = "221 2.0.0 Bye" CRLF;
static u_char smtp_starttls[] = "220 2.0.0 Start TLS" CRLF;
static u_char smtp_next[] = "334 " CRLF;
static u_char smtp_username[] = "334 VXNlcm5hbWU6" CRLF;
static u_char smtp_password[] = "334 UGFzc3dvcmQ6" CRLF;
static u_char smtp_invalid_command[] = "500 5.5.1 Invalid command" CRLF;
static u_char smtp_invalid_pipelining[] =
"503 5.5.0 Improper use of SMTP command pipelining" CRLF;
static u_char smtp_invalid_argument[] = "501 5.5.4 Invalid argument" CRLF;
static u_char smtp_auth_required[] = "530 5.7.1 Authentication required" CRLF;
static u_char smtp_bad_sequence[] = "503 5.5.1 Bad sequence of commands" CRLF;
static ngx_str_t smtp_unavailable = ngx_string("[UNAVAILABLE]");
static ngx_str_t smtp_tempunavail = ngx_string("[TEMPUNAVAIL]");
void
ngx_mail_smtp_init_session(ngx_mail_session_t *s, ngx_connection_t *c)
{
ngx_resolver_ctx_t *ctx;
ngx_mail_core_srv_conf_t *cscf;
cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);
if (cscf->resolver == NULL) {
s->host = smtp_unavailable;
ngx_mail_smtp_greeting(s, c);
return;
}
#if (NGX_HAVE_UNIX_DOMAIN)
if (c->sockaddr->sa_family == AF_UNIX) {
s->host = smtp_tempunavail;
ngx_mail_smtp_greeting(s, c);
return;
}
#endif
c->log->action = "in resolving client address";
ctx = ngx_resolve_start(cscf->resolver, NULL);
if (ctx == NULL) {
ngx_mail_close_connection(c);
return;
}
ctx->addr.sockaddr = c->sockaddr;
ctx->addr.socklen = c->socklen;
ctx->handler = ngx_mail_smtp_resolve_addr_handler;
ctx->data = s;
ctx->timeout = cscf->resolver_timeout;
if (ngx_resolve_addr(ctx) != NGX_OK) {
ngx_mail_close_connection(c);
}
}
static void
ngx_mail_smtp_resolve_addr_handler(ngx_resolver_ctx_t *ctx)
{
ngx_connection_t *c;
ngx_mail_session_t *s;
s = ctx->data;
c = s->connection;
if (ctx->state) {
ngx_log_error(NGX_LOG_ERR, c->log, 0,
"%V could not be resolved (%i: %s)",
&c->addr_text, ctx->state,
ngx_resolver_strerror(ctx->state));
if (ctx->state == NGX_RESOLVE_NXDOMAIN) {
s->host = smtp_unavailable;
} else {
s->host = smtp_tempunavail;
}
ngx_resolve_addr_done(ctx);
ngx_mail_smtp_greeting(s, s->connection);
return;
}
c->log->action = "in resolving client hostname";
s->host.data = ngx_pstrdup(c->pool, &ctx->name);
if (s->host.data == NULL) {
ngx_resolve_addr_done(ctx);
ngx_mail_close_connection(c);
return;
}
s->host.len = ctx->name.len;
ngx_resolve_addr_done(ctx);
ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
"address resolved: %V", &s->host);
c->read->handler = ngx_mail_smtp_resolve_name;
ngx_post_event(c->read, &ngx_posted_events);
}
static void
ngx_mail_smtp_resolve_name(ngx_event_t *rev)
{
ngx_connection_t *c;
ngx_mail_session_t *s;
ngx_resolver_ctx_t *ctx;
ngx_mail_core_srv_conf_t *cscf;
c = rev->data;
s = c->data;
cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);
ctx = ngx_resolve_start(cscf->resolver, NULL);
if (ctx == NULL) {
ngx_mail_close_connection(c);
return;
}
ctx->name = s->host;
ctx->handler = ngx_mail_smtp_resolve_name_handler;
ctx->data = s;
ctx->timeout = cscf->resolver_timeout;
if (ngx_resolve_name(ctx) != NGX_OK) {
ngx_mail_close_connection(c);
}
}
static void
ngx_mail_smtp_resolve_name_handler(ngx_resolver_ctx_t *ctx)
{
ngx_uint_t i;
ngx_connection_t *c;
ngx_mail_session_t *s;
s = ctx->data;
c = s->connection;
if (ctx->state) {
ngx_log_error(NGX_LOG_ERR, c->log, 0,
"\"%V\" could not be resolved (%i: %s)",
&ctx->name, ctx->state,
ngx_resolver_strerror(ctx->state));
if (ctx->state == NGX_RESOLVE_NXDOMAIN) {
s->host = smtp_unavailable;
} else {
s->host = smtp_tempunavail;
}
} else {
#if (NGX_DEBUG)
{
u_char text[NGX_SOCKADDR_STRLEN];
ngx_str_t addr;
addr.data = text;
for (i = 0; i < ctx->naddrs; i++) {
addr.len = ngx_sock_ntop(ctx->addrs[i].sockaddr,
ctx->addrs[i].socklen,
text, NGX_SOCKADDR_STRLEN, 0);
ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
"name was resolved to %V", &addr);
}
}
#endif
for (i = 0; i < ctx->naddrs; i++) {
if (ngx_cmp_sockaddr(ctx->addrs[i].sockaddr, ctx->addrs[i].socklen,
c->sockaddr, c->socklen, 0)
== NGX_OK)
{
goto found;
}
}
s->host = smtp_unavailable;
}
found:
ngx_resolve_name_done(ctx);
ngx_mail_smtp_greeting(s, c);
}
static void
ngx_mail_smtp_greeting(ngx_mail_session_t *s, ngx_connection_t *c)
{
ngx_msec_t timeout;
ngx_mail_core_srv_conf_t *cscf;
ngx_mail_smtp_srv_conf_t *sscf;
ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
"smtp greeting for \"%V\"", &s->host);
cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);
sscf = ngx_mail_get_module_srv_conf(s, ngx_mail_smtp_module);
timeout = sscf->greeting_delay ? sscf->greeting_delay : cscf->timeout;
ngx_add_timer(c->read, timeout);
if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
ngx_mail_close_connection(c);
}
if (sscf->greeting_delay) {
c->read->handler = ngx_mail_smtp_invalid_pipelining;
return;
}
c->read->handler = ngx_mail_smtp_init_protocol;
s->out = sscf->greeting;
ngx_mail_send(c->write);
}
static void
ngx_mail_smtp_invalid_pipelining(ngx_event_t *rev)
{
ngx_connection_t *c;
ngx_mail_session_t *s;
ngx_mail_core_srv_conf_t *cscf;
ngx_mail_smtp_srv_conf_t *sscf;
c = rev->data;
s = c->data;
c->log->action = "in delay pipelining state";
if (rev->timedout) {
ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "delay greeting");
rev->timedout = 0;
cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);
c->read->handler = ngx_mail_smtp_init_protocol;
ngx_add_timer(c->read, cscf->timeout);
if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
ngx_mail_close_connection(c);
return;
}
sscf = ngx_mail_get_module_srv_conf(s, ngx_mail_smtp_module);
s->out = sscf->greeting;
} else {
ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "invalid pipelining");
if (s->buffer == NULL) {
if (ngx_mail_smtp_create_buffer(s, c) != NGX_OK) {
return;
}
}
if (ngx_mail_smtp_discard_command(s, c,
"client was rejected before greeting: \"%V\"")
!= NGX_OK)
{
return;
}
ngx_str_set(&s->out, smtp_invalid_pipelining);
s->quit = 1;
}
ngx_mail_send(c->write);
}
void
ngx_mail_smtp_init_protocol(ngx_event_t *rev)
{
ngx_connection_t *c;
ngx_mail_session_t *s;
c = rev->data;
c->log->action = "in auth state";
if (rev->timedout) {
ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
c->timedout = 1;
ngx_mail_close_connection(c);
return;
}
s = c->data;
if (s->buffer == NULL) {
if (ngx_mail_smtp_create_buffer(s, c) != NGX_OK) {
return;
}
}
s->mail_state = ngx_smtp_start;
c->read->handler = ngx_mail_smtp_auth_state;
ngx_mail_smtp_auth_state(rev);
}
static ngx_int_t
ngx_mail_smtp_create_buffer(ngx_mail_session_t *s, ngx_connection_t *c)
{
ngx_mail_smtp_srv_conf_t *sscf;
if (ngx_array_init(&s->args, c->pool, 2, sizeof(ngx_str_t)) == NGX_ERROR) {
ngx_mail_session_internal_server_error(s);
return NGX_ERROR;
}
sscf = ngx_mail_get_module_srv_conf(s, ngx_mail_smtp_module);
s->buffer = ngx_create_temp_buf(c->pool, sscf->client_buffer_size);
if (s->buffer == NULL) {
ngx_mail_session_internal_server_error(s);
return NGX_ERROR;
}
return NGX_OK;
}
void
ngx_mail_smtp_auth_state(ngx_event_t *rev)
{
ngx_int_t rc;
ngx_connection_t *c;
ngx_mail_session_t *s;
c = rev->data;
s = c->data;
ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "smtp auth state");
if (rev->timedout) {
ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
c->timedout = 1;
ngx_mail_close_connection(c);
return;
}
if (s->out.len) {
ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "smtp send handler busy");
s->blocked = 1;
return;
}
s->blocked = 0;
rc = ngx_mail_read_command(s, c);
if (rc == NGX_AGAIN || rc == NGX_ERROR) {
return;
}
ngx_str_set(&s->out, smtp_ok);
if (rc == NGX_OK) {
switch (s->mail_state) {
case ngx_smtp_start:
switch (s->command) {
case NGX_SMTP_HELO:
case NGX_SMTP_EHLO:
rc = ngx_mail_smtp_helo(s, c);
break;
case NGX_SMTP_AUTH:
rc = ngx_mail_smtp_auth(s, c);
break;
case NGX_SMTP_QUIT:
s->quit = 1;
ngx_str_set(&s->out, smtp_bye);
break;
case NGX_SMTP_MAIL:
rc = ngx_mail_smtp_mail(s, c);
break;
case NGX_SMTP_RCPT:
rc = ngx_mail_smtp_rcpt(s, c);
break;
case NGX_SMTP_RSET:
rc = ngx_mail_smtp_rset(s, c);
break;
case NGX_SMTP_NOOP:
break;
case NGX_SMTP_STARTTLS:
rc = ngx_mail_smtp_starttls(s, c);
ngx_str_set(&s->out, smtp_starttls);
break;
default:
rc = NGX_MAIL_PARSE_INVALID_COMMAND;
break;
}
break;
case ngx_smtp_auth_login_username:
rc = ngx_mail_auth_login_username(s, c, 0);
ngx_str_set(&s->out, smtp_password);
s->mail_state = ngx_smtp_auth_login_password;
break;
case ngx_smtp_auth_login_password:
rc = ngx_mail_auth_login_password(s, c);
break;
case ngx_smtp_auth_plain:
rc = ngx_mail_auth_plain(s, c, 0);
break;
case ngx_smtp_auth_cram_md5:
rc = ngx_mail_auth_cram_md5(s, c);
break;
}
}
if (s->buffer->pos < s->buffer->last) {
s->blocked = 1;
}
switch (rc) {
case NGX_DONE:
ngx_mail_auth(s, c);
return;
case NGX_ERROR:
ngx_mail_session_internal_server_error(s);
return;
case NGX_MAIL_PARSE_INVALID_COMMAND:
s->mail_state = ngx_smtp_start;
s->state = 0;
ngx_str_set(&s->out, smtp_invalid_command);
case NGX_OK:
s->args.nelts = 0;
if (s->buffer->pos == s->buffer->last) {
s->buffer->pos = s->buffer->start;
s->buffer->last = s->buffer->start;
}
if (s->state) {
s->arg_start = s->buffer->pos;
}
ngx_mail_send(c->write);
}
}
static ngx_int_t
ngx_mail_smtp_helo(ngx_mail_session_t *s, ngx_connection_t *c)
{
ngx_str_t *arg;
ngx_mail_smtp_srv_conf_t *sscf;
if (s->args.nelts != 1) {
ngx_str_set(&s->out, smtp_invalid_argument);
s->state = 0;
return NGX_OK;
}
arg = s->args.elts;
s->smtp_helo.len = arg[0].len;
s->smtp_helo.data = ngx_pnalloc(c->pool, arg[0].len);
if (s->smtp_helo.data == NULL) {
return NGX_ERROR;
}
ngx_memcpy(s->smtp_helo.data, arg[0].data, arg[0].len);
ngx_str_null(&s->smtp_from);
ngx_str_null(&s->smtp_to);
sscf = ngx_mail_get_module_srv_conf(s, ngx_mail_smtp_module);
if (s->command == NGX_SMTP_HELO) {
s->out = sscf->server_name;
} else {
s->esmtp = 1;
#if (NGX_MAIL_SSL)
if (c->ssl == NULL) {
ngx_mail_ssl_conf_t *sslcf;
sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);
if (sslcf->starttls == NGX_MAIL_STARTTLS_ON) {
s->out = sscf->starttls_capability;
return NGX_OK;
}
if (sslcf->starttls == NGX_MAIL_STARTTLS_ONLY) {
s->out = sscf->starttls_only_capability;
return NGX_OK;
}
}
#endif
s->out = sscf->capability;
}
return NGX_OK;
}
static ngx_int_t
ngx_mail_smtp_auth(ngx_mail_session_t *s, ngx_connection_t *c)
{
ngx_int_t rc;
ngx_mail_core_srv_conf_t *cscf;
ngx_mail_smtp_srv_conf_t *sscf;
#if (NGX_MAIL_SSL)
if (ngx_mail_starttls_only(s, c)) {
return NGX_MAIL_PARSE_INVALID_COMMAND;
}
#endif
if (s->args.nelts == 0) {
ngx_str_set(&s->out, smtp_invalid_argument);
s->state = 0;
return NGX_OK;
}
rc = ngx_mail_auth_parse(s, c);
switch (rc) {
case NGX_MAIL_AUTH_LOGIN:
ngx_str_set(&s->out, smtp_username);
s->mail_state = ngx_smtp_auth_login_username;
return NGX_OK;
case NGX_MAIL_AUTH_LOGIN_USERNAME:
ngx_str_set(&s->out, smtp_password);
s->mail_state = ngx_smtp_auth_login_password;
return ngx_mail_auth_login_username(s, c, 1);
case NGX_MAIL_AUTH_PLAIN:
ngx_str_set(&s->out, smtp_next);
s->mail_state = ngx_smtp_auth_plain;
return NGX_OK;
case NGX_MAIL_AUTH_CRAM_MD5:
sscf = ngx_mail_get_module_srv_conf(s, ngx_mail_smtp_module);
if (!(sscf->auth_methods & NGX_MAIL_AUTH_CRAM_MD5_ENABLED)) {
return NGX_MAIL_PARSE_INVALID_COMMAND;
}
if (s->salt.data == NULL) {
cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);
if (ngx_mail_salt(s, c, cscf) != NGX_OK) {
return NGX_ERROR;
}
}
if (ngx_mail_auth_cram_md5_salt(s, c, "334 ", 4) == NGX_OK) {
s->mail_state = ngx_smtp_auth_cram_md5;
return NGX_OK;
}
return NGX_ERROR;
}
return rc;
}
static ngx_int_t
ngx_mail_smtp_mail(ngx_mail_session_t *s, ngx_connection_t *c)
{
ngx_str_t *arg, cmd;
ngx_mail_smtp_srv_conf_t *sscf;
sscf = ngx_mail_get_module_srv_conf(s, ngx_mail_smtp_module);
if (!(sscf->auth_methods & NGX_MAIL_AUTH_NONE_ENABLED)) {
ngx_mail_smtp_log_rejected_command(s, c, "client was rejected: \"%V\"");
ngx_str_set(&s->out, smtp_auth_required);
return NGX_OK;
}
if (s->smtp_from.len) {
ngx_str_set(&s->out, smtp_bad_sequence);
return NGX_OK;
}
if (s->args.nelts == 0) {
ngx_str_set(&s->out, smtp_invalid_argument);
return NGX_OK;
}
arg = s->args.elts;
arg += s->args.nelts - 1;
cmd.len = arg->data + arg->len - s->cmd.data;
cmd.data = s->cmd.data;
s->smtp_from.len = cmd.len;
s->smtp_from.data = ngx_pnalloc(c->pool, cmd.len);
if (s->smtp_from.data == NULL) {
return NGX_ERROR;
}
ngx_memcpy(s->smtp_from.data, cmd.data, cmd.len);
ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
"smtp mail from:\"%V\"", &s->smtp_from);
ngx_str_set(&s->out, smtp_ok);
return NGX_OK;
}
static ngx_int_t
ngx_mail_smtp_rcpt(ngx_mail_session_t *s, ngx_connection_t *c)
{
ngx_str_t *arg, cmd;
if (s->smtp_from.len == 0) {
ngx_str_set(&s->out, smtp_bad_sequence);
return NGX_OK;
}
if (s->args.nelts == 0) {
ngx_str_set(&s->out, smtp_invalid_argument);
return NGX_OK;
}
arg = s->args.elts;
arg += s->args.nelts - 1;
cmd.len = arg->data + arg->len - s->cmd.data;
cmd.data = s->cmd.data;
s->smtp_to.len = cmd.len;
s->smtp_to.data = ngx_pnalloc(c->pool, cmd.len);
if (s->smtp_to.data == NULL) {
return NGX_ERROR;
}
ngx_memcpy(s->smtp_to.data, cmd.data, cmd.len);
ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
"smtp rcpt to:\"%V\"", &s->smtp_to);
s->auth_method = NGX_MAIL_AUTH_NONE;
return NGX_DONE;
}
static ngx_int_t
ngx_mail_smtp_rset(ngx_mail_session_t *s, ngx_connection_t *c)
{
ngx_str_null(&s->smtp_from);
ngx_str_null(&s->smtp_to);
ngx_str_set(&s->out, smtp_ok);
return NGX_OK;
}
static ngx_int_t
ngx_mail_smtp_starttls(ngx_mail_session_t *s, ngx_connection_t *c)
{
#if (NGX_MAIL_SSL)
ngx_mail_ssl_conf_t *sslcf;
if (c->ssl == NULL) {
sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);
if (sslcf->starttls) {
ngx_str_null(&s->smtp_helo);
ngx_str_null(&s->smtp_from);
ngx_str_null(&s->smtp_to);
s->buffer->pos = s->buffer->start;
s->buffer->last = s->buffer->start;
c->read->handler = ngx_mail_starttls_handler;
return NGX_OK;
}
}
#endif
return NGX_MAIL_PARSE_INVALID_COMMAND;
}
static ngx_int_t
ngx_mail_smtp_discard_command(ngx_mail_session_t *s, ngx_connection_t *c,
char *err)
{
ssize_t n;
n = c->recv(c, s->buffer->last, s->buffer->end - s->buffer->last);
if (n == NGX_ERROR || n == 0) {
ngx_mail_close_connection(c);
return NGX_ERROR;
}
if (n > 0) {
s->buffer->last += n;
}
if (n == NGX_AGAIN) {
if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
ngx_mail_session_internal_server_error(s);
return NGX_ERROR;
}
return NGX_AGAIN;
}
ngx_mail_smtp_log_rejected_command(s, c, err);
s->buffer->pos = s->buffer->start;
s->buffer->last = s->buffer->start;
return NGX_OK;
}
static void
ngx_mail_smtp_log_rejected_command(ngx_mail_session_t *s, ngx_connection_t *c,
char *err)
{
u_char ch;
ngx_str_t cmd;
ngx_uint_t i;
if (c->log->log_level < NGX_LOG_INFO) {
return;
}
cmd.len = s->buffer->last - s->buffer->start;
cmd.data = s->buffer->start;
for (i = 0; i < cmd.len; i++) {
ch = cmd.data[i];
if (ch != CR && ch != LF) {
continue;
}
cmd.data[i] = '_';
}
cmd.len = i;
ngx_log_error(NGX_LOG_INFO, c->log, 0, err, &cmd);
}