SECURITY: rework BDAT receive function handling

[exim.git] / src / src / smtp_in.c

diff --git a/src/src/smtp_in.c b/src/src/smtp_in.c
index 5888b8037036691c5f24d575103d49f5d83f05b4..eb032bb52ee2ee7d8ead36faa4a0cd53fdc024f1 100644 (file)
--- a/src/src/smtp_in.c
+++ b/src/src/smtp_in.c
@@ -624,9 +624,7 @@ for(;;)
   if (chunking_data_left > 0)
     return lwr_receive_getc(chunking_data_left--);
 
-  receive_getc = lwr_receive_getc;
-  receive_getbuf = lwr_receive_getbuf;
-  receive_ungetc = lwr_receive_ungetc;
+  bdat_pop_receive_functions();
 #ifndef DISABLE_DKIM
   dkim_save = dkim_collect_input;
   dkim_collect_input = 0;
@@ -730,9 +728,7 @@ next_cmd:
          goto repeat_until_rset;
          }
 
-      receive_getc = bdat_getc;
-      receive_getbuf = bdat_getbuf;    /* r~getbuf is never actually used */
-      receive_ungetc = bdat_ungetc;
+      bdat_push_receive_functions();
 #ifndef DISABLE_DKIM
       dkim_collect_input = dkim_save;
 #endif
@@ -765,9 +761,7 @@ while (chunking_data_left)
   if (!bdat_getbuf(&n)) break;
   }
 
-receive_getc = lwr_receive_getc;
-receive_getbuf = lwr_receive_getbuf;
-receive_ungetc = lwr_receive_ungetc;
+bdat_pop_receive_functions();
 
 if (chunking_state != CHUNKING_LAST)
   {
@@ -777,7 +771,35 @@ if (chunking_state != CHUNKING_LAST)
 }
 
 
+void
+bdat_push_receive_functions(void)
+{
+/* push the current receive_* function on the "stack", and
+replace them by bdat_getc(), which in turn will use the lwr_receive_*
+functions to do the dirty work. */
+if (lwr_receive_getc == NULL)
+  {
+  lwr_receive_getc = receive_getc;
+  lwr_receive_getbuf = receive_getbuf;
+  lwr_receive_ungetc = receive_ungetc;
+  }
+else
+  {
+  DEBUG(D_receive) debug_printf("chunking double-push receive functions\n");
+  }
+
+receive_getc = bdat_getc;
+receive_ungetc = bdat_ungetc;
+}
 
+void
+bdat_pop_receive_functions(void)
+{
+receive_getc = lwr_receive_getc;
+receive_getbuf = lwr_receive_getbuf;
+receive_ungetc = lwr_receive_ungetc;
+lwr_receive_getc = lwr_receive_getbuf = lwr_receive_ungetc = NULL;
+}
 
 /*************************************************
 *          SMTP version of ungetc()              *
@@ -1969,12 +1991,13 @@ extract_option(uschar **name, uschar **value)
 uschar *n;
 uschar *v = smtp_cmd_data + Ustrlen(smtp_cmd_data) - 1;
 while (isspace(*v)) v--;
-v[1] = 0;
+v[1] = '\0';
 while (v > smtp_cmd_data && *v != '=' && !isspace(*v))
   {
   /* Take care to not stop at a space embedded in a quoted local-part */
 
-  if (*v == '"') do v--; while (*v != '"' && v > smtp_cmd_data+1);
+  if ((*v == '"') && (v > smtp_cmd_data + 1))
+    do v--; while (*v != '"' && v > smtp_cmd_data+1);
   v--;
   }
 
@@ -2527,6 +2550,7 @@ receive_ungetc = smtp_ungetc;
 receive_feof = smtp_feof;
 receive_ferror = smtp_ferror;
 receive_smtp_buffered = smtp_buffered;
+lwr_receive_getc = lwr_receive_getbuf = lwr_receive_ungetc = NULL;
 smtp_inptr = smtp_inend = smtp_inbuffer;
 smtp_had_eof = smtp_had_error = 0;
 
@@ -3847,9 +3871,18 @@ if (*user_msgp)
 else
   smtp_printf("221 %s closing connection\r\n", FALSE, smtp_active_hostname);
 
-#ifndef DISABLE_TLS
+#ifdef SERVERSIDE_CLOSE_NOWAIT
+# ifndef DISABLE_TLS
+tls_close(NULL, TLS_SHUTDOWN_NOWAIT);
+# endif
+
+log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT",
+  smtp_get_connection_info());
+#else
+
+# ifndef DISABLE_TLS
 tls_close(NULL, TLS_SHUTDOWN_WAIT);
-#endif
+# endif
 
 log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT",
   smtp_get_connection_info());
@@ -3866,6 +3899,7 @@ The socket should become readble (though with no data) */
   FD_SET(fd, &fds);
   (void) select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &t_limit);
   }
+#endif /*!DAEMON_CLOSE_NOWAIT*/
 }
 
 
@@ -3943,6 +3977,14 @@ cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE;
 cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = TRUE;
 #endif
 
+if (lwr_receive_getc != NULL)
+  {
+  /* This should have already happened, but if we've gotten confused,
+  force a reset here. */
+  DEBUG(D_receive) debug_printf("WARNING: smtp_setup_msg had to restore receive functions to lowers\n");
+  bdat_pop_receive_functions();
+  }
+
 /* Set the local signal handler for SIGTERM - it tries to end off tidily */
 
 had_command_sigterm = 0;
@@ -4336,6 +4378,19 @@ while (done <= 0)
          g = string_catn(g, US"-SIZE\r\n", 7);
          }
 
+#ifdef EXPERIMENTAL_ESMTP_LIMITS
+       if (  (mailmax > 0 || recipients_max)
+          && verify_check_host(&limits_advertise_hosts) == OK)
+         {
+         g = string_fmt_append(g, "%.3s-LIMITS", smtp_code);
+         if (mailmax > 0)
+           g = string_fmt_append(g, " MAILMAX=%d", mailmax);
+         if (recipients_max)
+           g = string_fmt_append(g, " RCPTMAX=%d", recipients_max);
+         g = string_catn(g, US"\r\n", 2);
+         }
+#endif
+
        /* Exim does not do protocol conversion or data conversion. It is 8-bit
        clean; if it has an 8-bit character in its hand, it just sends it. It
        cannot therefore specify 8BITMIME and remain consistent with the RFCs.
@@ -5264,16 +5319,7 @@ while (done <= 0)
       DEBUG(D_receive) debug_printf("chunking state %d, %d bytes\n",
                                    (int)chunking_state, chunking_data_left);
 
-      /* push the current receive_* function on the "stack", and
-      replace them by bdat_getc(), which in turn will use the lwr_receive_*
-      functions to do the dirty work. */
-      lwr_receive_getc = receive_getc;
-      lwr_receive_getbuf = receive_getbuf;
-      lwr_receive_ungetc = receive_ungetc;
-
-      receive_getc = bdat_getc;
-      receive_ungetc = bdat_ungetc;
-
+      f.bdat_readers_wanted = TRUE;
       f.dot_ends = FALSE;
 
       goto DATA_BDAT;
@@ -5282,6 +5328,7 @@ while (done <= 0)
     case DATA_CMD:
       HAD(SCH_DATA);
       f.dot_ends = TRUE;
+      f.bdat_readers_wanted = FALSE
 
     DATA_BDAT:         /* Common code for DATA and BDAT */
 #ifndef DISABLE_PIPE_CONNECT
@@ -5310,7 +5357,10 @@ while (done <= 0)
            : US"valid RCPT command must precede BDAT");
 
        if (chunking_state > CHUNKING_OFFERED)
+         {
+         bdat_push_receive_functions();
          bdat_flush_data();
+         }
        break;
        }
 
@@ -5349,6 +5399,9 @@ while (done <= 0)
            }
          }
 
+       if (f.bdat_readers_wanted)
+         bdat_push_receive_functions();
+
        if (user_msg)
          smtp_user_msg(US"354", user_msg);
        else