Give inetd the ability to manage unix domain sockets. Details of

how to use this feature are in the man page. This is based on work
by Lyndon Nerenberg.

(The only difficult part about this patch is the fact that you
can't fchown a unix domain socket, which means the sockets must be
put in a secure directory).

Reviewed by:	dillon

1 files changed, 95 insertions, 10 deletions

diff --git a/usr.sbin/inetd/inetd.c b/usr.sbin/inetd/inetd.c
index eca4749..61945dc 100644
--- a/usr.sbin/inetd/inetd.c
+++ b/usr.sbin/inetd/inetd.c
@@ -68,10 +68,11 @@ static const char rcsid[] =
  * order shown below.  Continuation lines for an entry must begin with
  * a space or tab.  All fields must be present in each entry.
  *
- *	service name			must be in /etc/services or must
- *					name a tcpmux service
+ *	service name			must be in /etc/services
+ *					or name a tcpmux service 
+ *					or specify a unix domain socket
  *	socket type			stream/dgram/raw/rdm/seqpacket
- *	protocol			tcp[4][6][/faith,ttcp], udp[4][6]
+ *	protocol			tcp[4][6][/faith,ttcp], udp[4][6], unix
  *	wait/nowait			single-threaded/multi-threaded
  *	user				user to run daemon as
  *	server program			full path name
@@ -115,6 +116,8 @@ static const char rcsid[] =
 #include <sys/wait.h>
 #include <sys/time.h>
 #include <sys/resource.h>
+#include <sys/stat.h>
+#include <sys/un.h>
 
 #include <netinet/in.h>
 #include <netinet/tcp.h>
@@ -169,6 +172,7 @@ static const char rcsid[] =
 
 #define ISWRAP(sep)	\
 	   ( ((wrap_ex && !(sep)->se_bi) || (wrap_bi && (sep)->se_bi)) \
+	&& (sep->se_family == AF_INET || sep->se_family == AF_INET6) \
 	&& ( ((sep)->se_accept && (sep)->se_socktype == SOCK_STREAM) \
 	    || (sep)->se_socktype == SOCK_DGRAM))
 
@@ -226,6 +230,9 @@ int	signalpipe[2];
 #ifdef SANITY_CHECK
 int	nsock;
 #endif
+uid_t	euid;
+gid_t	egid;
+mode_t	mask;
 
 struct	servtab *servtab;
 
@@ -403,6 +410,10 @@ main(argc, argv, envp)
 		exit(EX_USAGE);
 	}
 
+	euid = geteuid();
+	egid = getegid();
+	umask(mask = umask(0777));
+
 	argc -= optind;
 	argv += optind;
 
@@ -898,6 +909,7 @@ void config()
 		for (sep = servtab; sep; sep = sep->se_next)
 			if (strcmp(sep->se_service, new->se_service) == 0 &&
 			    strcmp(sep->se_proto, new->se_proto) == 0 &&
+			    sep->se_socktype == new->se_socktype &&
 			    sep->se_family == new->se_family)
 				break;
 		if (sep != 0) {
@@ -978,12 +990,14 @@ void config()
 #endif
 		}
 		if (!sep->se_rpc) {
-			sp = getservbyname(sep->se_service, sep->se_proto);
-			if (sp == 0) {
-				syslog(LOG_ERR, "%s/%s: unknown service",
-				sep->se_service, sep->se_proto);
-				sep->se_checked = 0;
-				continue;
+			if (sep->se_family != AF_UNIX) {
+				sp = getservbyname(sep->se_service, sep->se_proto);
+				if (sp == 0) {
+					syslog(LOG_ERR, "%s/%s: unknown service",
+					sep->se_service, sep->se_proto);
+					sep->se_checked = 0;
+					continue;
+				}
 			}
 			switch (sep->se_family) {
 			case AF_INET:
@@ -1154,6 +1168,10 @@ setsockopt(fd, SOL_SOCKET, opt, (char *)&on, sizeof (on))
 #ifdef IPSEC
 	ipsecsetup(sep);
 #endif
+	if (sep->se_family == AF_UNIX) {
+		(void) unlink(sep->se_ctrladdr_un.sun_path);
+		umask(0777); /* Make socket with conservative permissions */
+	}
 	if (bind(sep->se_fd, (struct sockaddr *)&sep->se_ctrladdr,
 	    sep->se_ctrladdr_size) < 0) {
 		if (debug)
@@ -1167,8 +1185,18 @@ setsockopt(fd, SOL_SOCKET, opt, (char *)&on, sizeof (on))
 			timingout = 1;
 			alarm(RETRYTIME);
 		}
+		if (sep->se_family == AF_UNIX)
+			umask(mask);
 		return;
 	}
+	if (sep->se_family == AF_UNIX) {
+		/* Ick - fch{own,mod} don't work on Unix domain sockets */
+		if (chown(sep->se_service, sep->se_sockuid, sep->se_sockgid) < 0)
+			syslog(LOG_ERR, "chown socket: %m");
+		if (chmod(sep->se_service, sep->se_sockmode) < 0)
+			syslog(LOG_ERR, "chmod socket: %m");
+		umask(mask);
+	}
         if (sep->se_rpc) {
 		int i;
 		socklen_t len = sep->se_ctrladdr_size;
@@ -1301,9 +1329,15 @@ int
 matchservent(name1, name2, proto)
 	char *name1, *name2, *proto;
 {
-	char **alias;
+	char **alias, *p;
 	struct servent *se;
 
+	if (strcmp(proto, "unix") == 0) {
+		if ((p = strrchr(name1, '/')) != NULL)
+			name1 = p + 1;
+		if ((p = strrchr(name2, '/')) != NULL)
+			name2 = p + 1;
+	}
 	if (strcmp(name1, name2) == 0)
 		return(1);
 	if ((se = getservbyname(name1, proto)) != NULL) {
@@ -1483,6 +1517,42 @@ more:
 		/* got an empty line containing just blanks/tabs. */
 		goto more;
 	}
+	if (arg[0] == ':') { /* :user:group:perm: */
+		char *user, *group, *perm;
+		struct passwd *pw;
+		struct group *gr;
+		user = arg+1;
+		if ((group = strchr(user, ':')) == NULL) {
+			syslog(LOG_ERR, "no group after user '%s'", user);
+			goto more;
+		}
+		*group++ = '\0';
+		if ((perm = strchr(group, ':')) == NULL) {
+			syslog(LOG_ERR, "no mode after group '%s'", group);
+			goto more;
+		}
+		*perm++ = '\0';
+		if ((pw = getpwnam(user)) == NULL) {
+			syslog(LOG_ERR, "no such user '%s'", user);
+			goto more;
+		}
+		sep->se_sockuid = pw->pw_uid;
+		if ((gr = getgrnam(group)) == NULL) {
+			syslog(LOG_ERR, "no such user '%s'", group);
+			goto more;
+		}
+		sep->se_sockgid = gr->gr_gid;
+		sep->se_sockmode = strtol(perm, &arg, 8);
+		if (*arg != ':') {
+			syslog(LOG_ERR, "bad mode '%s'", perm);
+			goto more;
+		}
+		*arg++ = '\0';
+	} else {
+		sep->se_sockuid = euid;
+		sep->se_sockgid = egid;
+		sep->se_sockmode = 0200;
+	}
 	if (strncmp(arg, TCPMUX_TOKEN, MUX_LEN) == 0) {
 		char *c = arg + MUX_LEN;
 		if (*c == '+') {
@@ -1589,6 +1659,9 @@ more:
 		freeconfig(sep);
 		goto more;
 	}
+	if (strcmp(sep->se_proto, "unix") == 0) {
+	        sep->se_family = AF_UNIX;
+	} else
 #ifdef INET6
 	if (v6bind != 0) {
 		sep->se_family = AF_INET6;
@@ -1619,6 +1692,18 @@ more:
 		sep->se_ctrladdr_size =	sizeof(sep->se_ctrladdr6);
 		break;
 #endif
+	case AF_UNIX:
+		if (strlen(sep->se_service) >= sizeof(sep->se_ctrladdr_un.sun_path)) {
+			syslog(LOG_ERR, 
+			    "domain socket pathname too long for service %s",
+			    sep->se_service);
+			goto more;
+		}
+		memset(&sep->se_ctrladdr, 0, sizeof(sep->se_ctrladdr));
+		sep->se_ctrladdr_un.sun_family = sep->se_family;
+		sep->se_ctrladdr_un.sun_len = strlen(sep->se_service);
+		strcpy(sep->se_ctrladdr_un.sun_path, sep->se_service);
+		sep->se_ctrladdr_size = SUN_LEN(&sep->se_ctrladdr_un);
 	}
 	arg = sskip(&cp);
 	if (!strncmp(arg, "wait", 4))