ph10 2005/02/16 15:24:21 GMT
Modified files:
exim-doc/doc-txt ChangeLog
exim-src/src daemon.c
Log:
Fix problem with smtp_max_per_host; test for completed processes before
looking at the count for a new connection.
Revision Changes Path
1.79 +8 -0 exim/exim-doc/doc-txt/ChangeLog
1.8 +81 -55 exim/exim-src/src/daemon.c
Index: ChangeLog
===================================================================
RCS file: /home/cvs/exim/exim-doc/doc-txt/ChangeLog,v
retrieving revision 1.78
retrieving revision 1.79
diff -u -r1.78 -r1.79
--- ChangeLog 15 Feb 2005 09:31:13 -0000 1.78
+++ ChangeLog 16 Feb 2005 15:24:21 -0000 1.79
@@ -1,4 +1,4 @@
-$Cambridge: exim/exim-doc/doc-txt/ChangeLog,v 1.78 2005/02/15 09:31:13 ph10 Exp $
+$Cambridge: exim/exim-doc/doc-txt/ChangeLog,v 1.79 2005/02/16 15:24:21 ph10 Exp $
Change log file for Exim from version 4.21
-------------------------------------------
@@ -366,6 +366,14 @@
for the non-SMTP ACL.
78. Error message wording change in sieve.c.
+
+79. If smtp_accept_max_per_host was set, the number of connections could be
+ restricted to fewer than expected, because the daemon was trying to set up
+ a new connection before checking whether the processes handling previous
+ connections had finished. The check for completed processes is now done
+ earlier. On busy systems, this bug wouldn't be noticed because something
+ else would have woken the daemon, and it would have reaped the completed
+ process earlier.
----------------------------------------------------
Index: daemon.c
===================================================================
RCS file: /home/cvs/exim/exim-src/src/daemon.c,v
retrieving revision 1.7
retrieving revision 1.8
diff -u -r1.7 -r1.8
--- daemon.c 27 Jan 2005 15:15:30 -0000 1.7
+++ daemon.c 16 Feb 2005 15:24:21 -0000 1.8
@@ -1,4 +1,4 @@
-/* $Cambridge: exim/exim-src/src/daemon.c,v 1.7 2005/01/27 15:15:30 ph10 Exp $ */
+/* $Cambridge: exim/exim-src/src/daemon.c,v 1.8 2005/02/16 15:24:21 ph10 Exp $ */
/*************************************************
* Exim - an Internet mail transport agent *
@@ -39,8 +39,8 @@
static BOOL accept_retry_select_failed;
static int queue_run_count = 0;
-static pid_t *queue_pid_slots;
-static smtp_slot *smtp_slots;
+static pid_t *queue_pid_slots = NULL;
+static smtp_slot *smtp_slots = NULL;
static BOOL write_pid = TRUE;
@@ -776,6 +776,72 @@
+/*************************************************
+* Handle terminating subprocesses *
+*************************************************/
+
+/* Handle the termination of child processes. Theoretically, this need be done
+only when sigchld_seen is TRUE, but rumour has it that some systems lose
+SIGCHLD signals at busy times, so to be on the safe side, this function is
+called each time round. It shouldn't be too expensive.
+
+Arguments: none
+Returns: nothing
+*/
+
+static void
+handle_ending_processes(void)
+{
+int status;
+pid_t pid;
+
+while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
+ {
+ int i;
+ DEBUG(D_any) debug_printf("child %d ended: status=0x%x\n", (int)pid,
+ status);
+
+ /* If it's a listening daemon for which we are keeping track of individual
+ subprocesses, deal with an accepting process that has terminated. */
+
+ if (smtp_slots != NULL)
+ {
+ for (i = 0; i < smtp_accept_max; i++)
+ {
+ if (smtp_slots[i].pid == pid)
+ {
+ if (smtp_slots[i].host_address != NULL)
+ store_free(smtp_slots[i].host_address);
+ smtp_slots[i] = empty_smtp_slot;
+ if (--smtp_accept_count < 0) smtp_accept_count = 0;
+ DEBUG(D_any) debug_printf("%d SMTP accept process%s now running\n",
+ smtp_accept_count, (smtp_accept_count == 1)? "" : "es");
+ break;
+ }
+ }
+ if (i < smtp_accept_max) continue; /* Found an accepting process */
+ }
+
+ /* If it wasn't an accepting process, see if it was a queue-runner
+ process that we are tracking. */
+
+ if (queue_pid_slots != NULL)
+ {
+ for (i = 0; i < queue_run_max; i++)
+ {
+ if (queue_pid_slots[i] == pid)
+ {
+ queue_pid_slots[i] = 0;
+ if (--queue_run_count < 0) queue_run_count = 0;
+ DEBUG(D_any) debug_printf("%d queue-runner process%s now running\n",
+ queue_run_count, (queue_run_count == 1)? "" : "es");
+ break;
+ }
+ }
+ }
+ }
+}
+
/*************************************************
@@ -1513,7 +1579,6 @@
#endif
SOCKLEN_T len = sizeof(accepted);
- int status;
pid_t pid;
/* This code is placed first in the loop, so that it gets obeyed at the
@@ -1622,7 +1687,7 @@
if (daemon_listen)
{
- int sk, lcount;
+ int sk, lcount, select_errno;
int max_socket = 0;
BOOL select_failed = FALSE;
fd_set select_listen;
@@ -1660,6 +1725,17 @@
lcount = 1;
}
+ /* Clean up any subprocesses that may have terminated. We need to do this
+ here so that smtp_accept_max_per_host works when a connection to that host
+ has completed, and we are about to accept a new one. When this code was
+ later in the sequence, a new connection could be rejected, even though an
+ old one had just finished. Preserve the errno from any select() failure for
+ the use of the common select/accept error processing below. */
+
+ select_errno = errno;
+ handle_ending_processes();
+ errno = select_errno;
+
/* Loop for all the sockets that are currently ready to go. If select
actually failed, we have set the count to 1 and select_failed=TRUE, so as
to use the common error code for select/accept below. */
@@ -1754,57 +1830,7 @@
tv.tv_sec = queue_interval;
tv.tv_usec = 0;
select(0, NULL, NULL, NULL, &tv);
- }
-
- /* Handle the termination of a child process. Theoretically, this need
- be done only when sigchld_seen is TRUE, but rumour has it that some systems
- lose SIGCHLD signals at busy times, so to be on the safe side, just
- do it each time round. It shouldn't be too expensive. */
-
- while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
- {
- int i;
- DEBUG(D_any) debug_printf("child %d ended: status=0x%x\n", (int)pid,
- status);
-
- /* If it's a listening daemon, deal with an accepting process that has
- terminated. */
-
- if (daemon_listen)
- {
- for (i = 0; i < smtp_accept_max; i++)
- {
- if (smtp_slots[i].pid == pid)
- {
- if (smtp_slots[i].host_address != NULL)
- store_free(smtp_slots[i].host_address);
- smtp_slots[i] = empty_smtp_slot;
- if (--smtp_accept_count < 0) smtp_accept_count = 0;
- DEBUG(D_any) debug_printf("%d SMTP accept process%s now running\n",
- smtp_accept_count, (smtp_accept_count == 1)? "" : "es");
- break;
- }
- }
- if (i < smtp_accept_max) continue; /* Found an accepting process */
- }
-
- /* If it wasn't an accepting process, see if it was a queue-runner
- process, if we are keeping track of them. */
-
- if (queue_interval > 0)
- {
- for (i = 0; i < queue_run_max; i++)
- {
- if (queue_pid_slots[i] == pid)
- {
- queue_pid_slots[i] = 0;
- if (--queue_run_count < 0) queue_run_count = 0;
- DEBUG(D_any) debug_printf("%d queue-runner process%s now running\n",
- queue_run_count, (queue_run_count == 1)? "" : "es");
- break;
- }
- }
- }
+ handle_ending_processes();
}
/* Re-enable the SIGCHLD handler if it has been run. It can't do it
