Create a socketpair() and tie one end to /dev/klog using ioctl LIOCSFD.

This allows us to receive messages direct from programs using the
fd-safe sendsyslog(2), aka. syslog_r(3).  Thanks to guenther for this part
of the solution.
ok beck tedu miod guenther

diff --git a/usr.sbin/syslogd/syslogd.c b/usr.sbin/syslogd/syslogd.c
index 165100e..9d50ff5 100644 (file)
--- a/usr.sbin/syslogd/syslogd.c
+++ b/usr.sbin/syslogd/syslogd.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: syslogd.c,v 1.110 2014/02/04 23:28:05 bluhm Exp $     */
+/*     $OpenBSD: syslogd.c,v 1.111 2014/07/14 04:02:33 deraadt Exp $   */
 
 /*
  * Copyright (c) 1983, 1988, 1993, 1994
@@ -286,7 +286,7 @@ main(int argc, char *argv[])
        socklen_t len;
        char *p, *line;
        char resolve[MAXHOSTNAMELEN];
-       int lockpipe[2] = { -1, -1}, nullfd;
+       int lockpipe[2] = { -1, -1}, pair[2], nullfd;
        struct addrinfo hints, *res, *res0;
        FILE *fp;
 
@@ -436,6 +436,14 @@ main(int argc, char *argv[])
                pfd[PFD_UNIX_0 + i].events = POLLIN;
        }
 
+       nfunix++;
+       if (socketpair(AF_UNIX, SOCK_DGRAM, PF_UNSPEC, pair) == -1)
+               die(0);
+       fd = pair[0];
+       double_rbuf(fd);
+       pfd[PFD_UNIX_0 + i].fd = fd;
+       pfd[PFD_UNIX_0 + i].events = POLLIN;
+
        if (ctlsock_path != NULL) {
                fd = unix_socket(ctlsock_path, SOCK_STREAM, 0600);
                if (fd != -1) {
@@ -456,6 +464,10 @@ main(int argc, char *argv[])
                pfd[PFD_KLOG].events = POLLIN;
        }
 
+       if (ioctl(fd, LIOCSFD, &pair[1]) == -1)
+               dprintf("LIOCSFD errno %d\n", errno);
+       close(pair[1]);
+
        dprintf("off & running....\n");
 
        chdir("/");