# HG changeset patch
# User Maxim Dounin <mdounin@mdounin.ru>
# Date 1621383195 -10800
# Node ID 6a81d96d3733515253697f7d7b4615c37bcd4e3e
# Parent  c72d8839f427d4e026bc09e91916d46833640c30
Mail: fixed handling of invalid SMTP commands split between reads.

Previously, if an invalid SMTP command was split between reads, nginx failed
to wait for LF before returning an error, and interpreted the rest of the
command received later as a separate command.

The sw_invalid state in ngx_mail_smtp_parse_command(), introduced in
04e43d03e153, did not work, since ngx_mail_smtp_auth_state() clears
s->state when returning an error due to NGX_MAIL_PARSE_INVALID_COMMAND.
And not clearing s->state will introduce another problem: the rest
of the command would trigger duplicate error when rest of the command is
received.

Fix is to return NGX_AGAIN from ngx_mail_smtp_parse_command() until full
command is received.

diff --git a/src/mail/ngx_mail_parse.c b/src/mail/ngx_mail_parse.c
--- a/src/mail/ngx_mail_parse.c
+++ b/src/mail/ngx_mail_parse.c
@@ -846,14 +846,14 @@ invalid:
     for (p = s->buffer->pos; p < s->buffer->last; p++) {
         if (*p == LF) {
             s->state = sw_start;
-            p++;
-            break;
+            s->buffer->pos = p + 1;
+            return NGX_MAIL_PARSE_INVALID_COMMAND;
         }
     }
 
     s->buffer->pos = p;
 
-    return NGX_MAIL_PARSE_INVALID_COMMAND;
+    return NGX_AGAIN;
 }