X-Git-Url: https://vcs.fsf.org/?p=exim.git;a=blobdiff_plain;f=src%2Fsrc%2Fdaemon.c;h=4ac34332b84a20b01412cc283e57fa4d52e94022;hp=81c32020e7ba4debe136c730e45deb38503e31f9;hb=d6cc7c78f624e505bb889c8ccd2879706d6dc9e1;hpb=b4ed4da0f525ab98c05797e15df0045e49ae3618 diff --git a/src/src/daemon.c b/src/src/daemon.c index 81c32020e..4ac34332b 100644 --- a/src/src/daemon.c +++ b/src/src/daemon.c @@ -1,10 +1,8 @@ -/* $Cambridge: exim/src/src/daemon.c,v 1.20 2007/01/15 15:59:22 ph10 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 */ @@ -31,8 +29,8 @@ static smtp_slot empty_smtp_slot = { 0, NULL }; * Local static variables * *************************************************/ -static volatile BOOL sigchld_seen; -static volatile BOOL sighup_seen; +static SIGNAL_BOOL sigchld_seen; +static SIGNAL_BOOL sighup_seen; static int accept_retry_count = 0; static int accept_retry_errno; @@ -241,7 +239,7 @@ 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", @@ -365,10 +363,13 @@ 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 + smtp_accept_count++; /* So that it includes this process */ + /* May have been modified for the subprocess */ log_write_selector = use_log_write_selector; @@ -411,7 +412,7 @@ 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, @@ -422,6 +423,13 @@ 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)); @@ -455,20 +463,27 @@ 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) + if (smtp_accept_queue > 0 && smtp_accept_count > smtp_accept_queue) { - local_queue_only = TRUE; + session_local_queue_only = TRUE; queue_only_reason = 1; } /* Handle the start of the SMTP session, then loop, accepting incoming messages from the SMTP connection. The end will come at the QUIT command, when smtp_setup_msg() returns 0. A break in the connection causes the - process to die (see accept.c). */ + process to die (see accept.c). + + NOTE: We do *not* call smtp_log_no_mail() if smtp_start_session() fails, + because a log line has already been written for all its failure exists + (usually "connection refused: ") and writing another one is + unnecessary clutter. */ if (!smtp_start_session()) { @@ -543,26 +558,37 @@ 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; } } @@ -874,6 +900,7 @@ 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; @@ -1446,6 +1473,14 @@ 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). */ @@ -1583,7 +1618,7 @@ 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 @@ -1631,7 +1666,7 @@ for (;;) { uschar opt[8]; uschar *p = opt; - uschar *extra[4]; + uschar *extra[5]; int extracount = 1; signal(SIGALRM, SIG_DFL); @@ -1778,6 +1813,7 @@ 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);