From: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Date: Wed, 11 Dec 2013 02:52:11 +0000 (-0500)
Subject: activate: clean up inherited descriptors
X-Git-Tag: v209~1032
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=c099716487df4a4f5394e57e7ca14da1d358166a

activate: clean up inherited descriptors

> [simon@troela server]$ /usr/lib/systemd/systemd-activate -l 9000 main.js
> Assertion 'fd == 3 + count' failed at src/activate/activate.c:115,
> function open_sockets(). Aborting.
> Aborted (core dumped)

> after a bit debuging i found the problem:
> slim appears to leak an fd into all of its children:
> stat /proc/14004/fd/3  (14004 is the pid a random process in my session)
>  File: '/proc/14004/fd/3' -> '/var/log/slim.log'

systemd-activate should be robust against the shell (or anything else) leaking
descriptors. Now everything except stdin/stdout/stderr and received sockets
will be closed.
---

diff --git a/src/activate/activate.c b/src/activate/activate.c
index 5263969fc..d73c16e8a 100644
--- a/src/activate/activate.c
+++ b/src/activate/activate.c
@@ -99,6 +99,17 @@ static int open_sockets(int *epoll_fd, bool accept) {
                 }
         }
 
+        /* Close logging and all other descriptors */
+        if (arg_listen) {
+                int except[3 + n];
+
+                for (fd = 0; fd < SD_LISTEN_FDS_START + n; fd++)
+                        except[fd] = fd;
+
+                log_close();
+                close_all_fds(except, 3 + n);
+        }
+
         /** Note: we leak some fd's on error here. I doesn't matter
          *  much, since the program will exit immediately anyway, but
          *  would be a pain to fix.
@@ -108,6 +119,7 @@ static int open_sockets(int *epoll_fd, bool accept) {
 
                 fd = make_socket_fd(*address, SOCK_STREAM | (arg_accept*SOCK_CLOEXEC));
                 if (fd < 0) {
+                        log_open();
                         log_error("Failed to open '%s': %s", *address, strerror(-fd));
                         return fd;
                 }
@@ -116,6 +128,9 @@ static int open_sockets(int *epoll_fd, bool accept) {
                 count ++;
         }
 
+        if (arg_listen)
+                log_open();
+
         *epoll_fd = epoll_create1(EPOLL_CLOEXEC);
         if (*epoll_fd < 0) {
                 log_error("Failed to create epoll object: %m");
@@ -270,10 +285,10 @@ static void sigchld_hdl(int sig, siginfo_t *t, void *data) {
 
 static int install_chld_handler(void) {
         int r;
-        struct sigaction act;
-        zero(act);
-        act.sa_flags = SA_SIGINFO;
-        act.sa_sigaction = sigchld_hdl;
+        struct sigaction act = {
+                .sa_flags = SA_SIGINFO,
+                .sa_sigaction = sigchld_hdl,
+        };
 
         r = sigaction(SIGCHLD, &act, 0);
         if (r < 0)