Mail: IMAP pipelining support.

The change is mostly the same as the SMTP one (04e43d03e153 and 3f5d0af4e40a),
and ensures that nginx is able to properly handle or reject multiple IMAP
commands.  The s->cmd field is not really used and set for consistency.

Non-synchronizing literals handling in invalid/unknown commands is limited,
so when a non-synchronizing literal is detected at the end of a discarded
line, the connection is closed.

diff --git a/src/mail/ngx_mail.h b/src/mail/ngx_mail.h
index 0a0bde2908e10dcb4aebf1f86c5de5836e079856..07104df68556eacc27946f3e2282acebf77e0ca4 100644 (file)
--- a/src/mail/ngx_mail.h
+++ b/src/mail/ngx_mail.h
@@ -236,6 +236,7 @@ typedef struct {
     /* used to parse POP3/IMAP/SMTP command */
 
     ngx_uint_t              state;
+    u_char                 *tag_start;
     u_char                 *cmd_start;
     u_char                 *arg_start;
     ngx_uint_t              literal_len;

diff --git a/src/mail/ngx_mail_imap_handler.c b/src/mail/ngx_mail_imap_handler.c
index ba66b898c42f151493a34416a6de80c373fbe74f..291e87a4deba134ba0faad127704200389ef1a53 100644 (file)
--- a/src/mail/ngx_mail_imap_handler.c
+++ b/src/mail/ngx_mail_imap_handler.c
@@ -226,6 +226,10 @@ ngx_mail_imap_auth_state(ngx_event_t *rev)
         ngx_str_set(&s->out, imap_next);
     }
 
+    if (s->buffer->pos < s->buffer->last) {
+        s->blocked = 1;
+    }
+
     switch (rc) {
 
     case NGX_DONE:
@@ -275,13 +279,14 @@ ngx_mail_imap_auth_state(ngx_event_t *rev)
 
         if (s->state) {
             /* preserve tag */
-            s->arg_start = s->buffer->start + s->tag.len;
-            s->buffer->pos = s->arg_start;
-            s->buffer->last = s->arg_start;
+            s->arg_start = s->buffer->pos;
 
         } else {
-            s->buffer->pos = s->buffer->start;
-            s->buffer->last = s->buffer->start;
+            if (s->buffer->pos == s->buffer->last) {
+                s->buffer->pos = s->buffer->start;
+                s->buffer->last = s->buffer->start;
+            }
+
             s->tag.len = 0;
         }
     }
@@ -459,6 +464,8 @@ ngx_mail_imap_starttls(ngx_mail_session_t *s, ngx_connection_t *c)
     if (c->ssl == NULL) {
         sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);
         if (sslcf->starttls) {
+            s->buffer->pos = s->buffer->start;
+            s->buffer->last = s->buffer->start;
             c->read->handler = ngx_mail_starttls_handler;
             return NGX_OK;
         }

diff --git a/src/mail/ngx_mail_parse.c b/src/mail/ngx_mail_parse.c
index 47c9e3a90747589cb7adc3bbebccc30153e81985..4db1f18d30e3482ac944a9709741c1804c033dc0 100644 (file)
--- a/src/mail/ngx_mail_parse.c
+++ b/src/mail/ngx_mail_parse.c
@@ -231,6 +231,8 @@ ngx_mail_imap_parse_command(ngx_mail_session_t *s)
     ngx_str_t  *arg;
     enum {
         sw_start = 0,
+        sw_tag,
+        sw_invalid,
         sw_spaces_before_command,
         sw_command,
         sw_spaces_before_argument,
@@ -253,18 +255,21 @@ ngx_mail_imap_parse_command(ngx_mail_session_t *s)
 
         /* IMAP tag */
         case sw_start:
+            s->tag_start = p;
+            state = sw_tag;
+
+            /* fall through */
+
+        case sw_tag:
             switch (ch) {
             case ' ':
-                s->tag.len = p - s->buffer->start + 1;
-                s->tag.data = s->buffer->start;
+                s->tag.len = p - s->tag_start + 1;
+                s->tag.data = s->tag_start;
                 state = sw_spaces_before_command;
                 break;
             case CR:
-                s->state = sw_start;
-                return NGX_MAIL_PARSE_INVALID_COMMAND;
             case LF:
-                s->state = sw_start;
-                return NGX_MAIL_PARSE_INVALID_COMMAND;
+                goto invalid;
             default:
                 if ((ch < 'A' || ch > 'Z') && (ch < 'a' || ch > 'z')
                     && (ch < '0' || ch > '9') && ch != '-' && ch != '.'
@@ -272,23 +277,23 @@ ngx_mail_imap_parse_command(ngx_mail_session_t *s)
                 {
                     goto invalid;
                 }
-                if (p - s->buffer->start > 31) {
+                if (p - s->tag_start > 31) {
                     goto invalid;
                 }
                 break;
             }
             break;
 
+        case sw_invalid:
+            goto invalid;
+
         case sw_spaces_before_command:
             switch (ch) {
             case ' ':
                 break;
             case CR:
-                s->state = sw_start;
-                return NGX_MAIL_PARSE_INVALID_COMMAND;
             case LF:
-                s->state = sw_start;
-                return NGX_MAIL_PARSE_INVALID_COMMAND;
+                goto invalid;
             default:
                 s->cmd_start = p;
                 state = sw_command;
@@ -408,6 +413,9 @@ ngx_mail_imap_parse_command(ngx_mail_session_t *s)
                     goto invalid;
                 }
 
+                s->cmd.data = s->cmd_start;
+                s->cmd.len = p - s->cmd_start;
+
                 switch (ch) {
                 case ' ':
                     state = sw_spaces_before_argument;
@@ -631,13 +639,40 @@ done:
 
 invalid:
 
-    s->state = sw_start;
+    s->state = sw_invalid;
     s->quoted = 0;
     s->backslash = 0;
     s->no_sync_literal = 0;
     s->literal_len = 0;
 
-    return NGX_MAIL_PARSE_INVALID_COMMAND;
+    /* skip invalid command till LF */
+
+    for ( /* void */ ; p < s->buffer->last; p++) {
+        if (*p == LF) {
+            s->state = sw_start;
+            s->buffer->pos = p + 1;
+
+            /* detect non-synchronizing literals */
+
+            if ((size_t) (p - s->buffer->start) > sizeof("{1+}") - 1) {
+                p--;
+
+                if (*p == CR) {
+                    p--;
+                }
+
+                if (*p == '}' && *(p - 1) == '+') {
+                    s->quit = 1;
+                }
+            }
+
+            return NGX_MAIL_PARSE_INVALID_COMMAND;
+        }
+    }
+
+    s->buffer->pos = p;
+
+    return NGX_AGAIN;
 }
 
 

diff --git a/src/mail/ngx_mail_proxy_module.c b/src/mail/ngx_mail_proxy_module.c
index 0f56d299e2abe1a3fd71dca990d7b8617268667b..a7ab0776e0febb1267ea39623c372f8e06f2c74c 100644 (file)
--- a/src/mail/ngx_mail_proxy_module.c
+++ b/src/mail/ngx_mail_proxy_module.c
@@ -486,6 +486,10 @@ ngx_mail_proxy_imap_handler(ngx_event_t *rev)
         c->log->action = NULL;
         ngx_log_error(NGX_LOG_INFO, c->log, 0, "client logged in");
 
+        if (s->buffer->pos < s->buffer->last) {
+            ngx_post_event(c->write, &ngx_posted_events);
+        }
+
         ngx_mail_proxy_handler(s->connection->write);
 
         return;