X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/b01dd148c3a5f3a70817b08e41ad21aeee1d8f28..fa32850be0d9e605da1b33305c122f7a59a24650:/src/src/daemon.c

diff --git a/src/src/daemon.c b/src/src/daemon.c
index 4c6c90878..3db9be374 100644
--- a/src/src/daemon.c
+++ b/src/src/daemon.c
@@ -1,10 +1,10 @@
-/* $Cambridge: exim/src/src/daemon.c,v 1.22 2007/01/23 14:34:02 ph10 Exp $ */
+/* $Cambridge: exim/src/src/daemon.c,v 1.27 2009/11/16 19:50:36 nm4 Exp $ */
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
-/* Copyright (c) University of Cambridge 1995 - 2007 */
+/* Copyright (c) University of Cambridge 1995 - 2009 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* Functions concerned with running Exim as a daemon */
@@ -241,7 +241,7 @@ subprocess because it might take time. */
 
 if (smtp_load_reserve >= 0)
   {
-  load_average = os_getloadavg();
+  load_average = OS_GETLOADAVG();
   if (smtp_reserve_hosts == NULL && load_average > smtp_load_reserve)
     {
     DEBUG(D_any) debug_printf("rejecting SMTP connection: load average = %.2f\n",
@@ -365,6 +365,7 @@ if (pid == 0)
   int old_pool = store_pool;
   int save_debug_selector = debug_selector;
   BOOL local_queue_only;
+  BOOL session_local_queue_only;
   #ifdef SA_NOCLDWAIT
   struct sigaction act;
   #endif
@@ -413,7 +414,7 @@ if (pid == 0)
   /* Initialize the queueing flags */
 
   queue_check_only();
-  local_queue_only = queue_only;
+  session_local_queue_only = queue_only;
 
   /* Close the listening sockets, and set the SIGCHLD handler to SIG_IGN.
   We also attempt to set things up so that children are automatically reaped,
@@ -424,6 +425,13 @@ if (pid == 0)
 
   for (i = 0; i < listen_socket_count; i++) (void)close(listen_sockets[i]);
 
+  /* Set FD_CLOEXEC on the SMTP socket. We don't want any rogue child processes
+  to be able to communicate with them, under any circumstances. */
+  (void)fcntl(accept_socket, F_SETFD,
+              fcntl(accept_socket, F_GETFD) | FD_CLOEXEC);
+  (void)fcntl(dup_accept_socket, F_SETFD,
+              fcntl(dup_accept_socket, F_GETFD) | FD_CLOEXEC);
+
   #ifdef SA_NOCLDWAIT
   act.sa_handler = SIG_IGN;
   sigemptyset(&(act.sa_mask));
@@ -457,13 +465,15 @@ if (pid == 0)
   if (debug_daemon) debug_selector = 0;
 
   /* If there are too many child processes for immediate delivery,
-  set the local_queue_only flag, which is initialized from the
+  set the session_local_queue_only flag, which is initialized from the
   configured value and may therefore already be TRUE. Leave logging
-  till later so it will have a message id attached. */
+  till later so it will have a message id attached. Note that there is no
+  possibility of re-calculating this per-message, because the value of
+  smtp_accept_count does not change in this subprocess. */
 
   if (smtp_accept_queue > 0 && smtp_accept_count > smtp_accept_queue)
     {
-    local_queue_only = TRUE;
+    session_local_queue_only = TRUE;
     queue_only_reason = 1;
     }
 
@@ -550,26 +560,37 @@ if (pid == 0)
     store_reset(reset_point);
 
     /* If queue_only is set or if there are too many incoming connections in
-    existence, local_queue_only will be TRUE. If it is not, check whether we
-    have received too many messages in this session for immediate delivery. If
-    not, and queue_only_load is set, check that the load average is below it.
-    Note that, once set, local_queue_only remains set for any subsequent
-    messages on the same SMTP connection. This is a deliberate choice; even
-    though the load average may fall, it doesn't seem right to deliver later
-    messages on the same call when not delivering earlier ones. */
-
-    if (!local_queue_only)
+    existence, session_local_queue_only will be TRUE. If it is not, check
+    whether we have received too many messages in this session for immediate
+    delivery. */
+
+    if (!session_local_queue_only &&
+        smtp_accept_queue_per_connection > 0 &&
+        receive_messagecount > smtp_accept_queue_per_connection)
       {
-      if (smtp_accept_queue_per_connection > 0 &&
-          receive_messagecount > smtp_accept_queue_per_connection)
-        {
-        local_queue_only = TRUE;
-        queue_only_reason = 2;
-        }
-      else if (queue_only_load >= 0)
+      session_local_queue_only = TRUE;
+      queue_only_reason = 2;
+      }
+
+    /* Initialize local_queue_only from session_local_queue_only. If it is not
+    true, and queue_only_load is set, check that the load average is below it.
+    If local_queue_only is set by this means, we also set if for the session if
+    queue_only_load_latch is true (the default). This means that, once set,
+    local_queue_only remains set for any subsequent messages on the same SMTP
+    connection. This is a deliberate choice; even though the load average may
+    fall, it doesn't seem right to deliver later messages on the same call when
+    not delivering earlier ones. However, the are special circumstances such as
+    very long-lived connections from scanning appliances where this is not the
+    best strategy. In such cases, queue_only_load_latch should be set false. */
+
+    local_queue_only = session_local_queue_only;
+    if (!local_queue_only && queue_only_load >= 0)
+      {
+      local_queue_only = (load_average = OS_GETLOADAVG()) > queue_only_load;
+      if (local_queue_only)
         {
-        local_queue_only = (load_average = os_getloadavg()) > queue_only_load;
-        if (local_queue_only) queue_only_reason = 3;
+        queue_only_reason = 3;
+        if (queue_only_load_latch) session_local_queue_only = TRUE;
         }
       }
 
@@ -881,6 +902,7 @@ There are no arguments to this function, and it never returns. */
 void
 daemon_go(void)
 {
+struct passwd *pw;
 int *listen_sockets = NULL;
 int listen_socket_count = 0;
 ip_address_item *addresses = NULL;
@@ -1453,6 +1475,14 @@ cannot do this. */
 
 exim_setugid(exim_uid, exim_gid, geteuid()==root_uid, US"running as a daemon");
 
+/* Update the originator_xxx fields so that received messages as listed as
+coming from Exim, not whoever started the daemon. */
+
+originator_uid = exim_uid;
+originator_gid = exim_gid;
+originator_login = ((pw = getpwuid(exim_uid)) != NULL)?
+  string_copy_malloc(US pw->pw_name) : US"exim";
+
 /* Get somewhere to keep the list of queue-runner pids if we are keeping track
 of them (and also if we are doing queue runs). */
 
@@ -1590,7 +1620,7 @@ for (;;)
   struct sockaddr_in accepted;
   #endif
 
-  EXIM_SOCKLEN_T len = sizeof(accepted);
+  EXIM_SOCKLEN_T len;
   pid_t pid;
 
   /* This code is placed first in the loop, so that it gets obeyed at the
@@ -1638,7 +1668,7 @@ for (;;)
           {
           uschar opt[8];
           uschar *p = opt;
-          uschar *extra[4];
+          uschar *extra[5];
           int extracount = 1;
 
           signal(SIGALRM, SIG_DFL);
@@ -1785,6 +1815,7 @@ for (;;)
           {
           if (FD_ISSET(listen_sockets[sk], &select_listen))
             {
+            len = sizeof(accepted);
             accept_socket = accept(listen_sockets[sk],
               (struct sockaddr *)&accepted, &len);
             FD_CLR(listen_sockets[sk], &select_listen);