add FEATURE_UNIX_LOCAL. By Ingo van Lil (inguin AT gmx.de)

libbb/xconnect.c

@@ -9,6 +9,7 @@
 
 #include <netinet/in.h>
 #include <net/if.h>
+#include <sys/un.h>
 #include "libbb.h"
 
 void FAST_FUNC setsockopt_reuseaddr(int fd)
@@ -160,13 +161,26 @@ IF_FEATURE_IPV6(sa_family_t af,)
 		int ai_flags)
 {
 	int rc;
-	len_and_sockaddr *r = NULL;
+	len_and_sockaddr *r;
 	struct addrinfo *result = NULL;
 	struct addrinfo *used_res;
 	const char *org_host = host; /* only for error msg */
 	const char *cp;
 	struct addrinfo hint;
 
+	if (ENABLE_FEATURE_UNIX_LOCAL && strncmp(host, "local:", 6) == 0) {
+		struct sockaddr_un *sun;
+
+		r = xzalloc(LSA_LEN_SIZE + sizeof(struct sockaddr_un));
+		r->len = sizeof(struct sockaddr_un);
+		r->u.sa.sa_family = AF_UNIX;
+		sun = (struct sockaddr_un *)&r->u.sa;
+		safe_strncpy(sun->sun_path, host + 6, sizeof(sun->sun_path));
+		return r;
+	}
+
+	r = NULL;
+
 	/* Ugly parsing of host:addr */
 	if (ENABLE_FEATURE_IPV6 && host[0] == '[') {
 		/* Even uglier parsing of [xx]:nn */
@@ -188,6 +202,7 @@ IF_FEATURE_IPV6(sa_family_t af,)
 	}
 	if (cp) { /* points to ":" or "]:" */
 		int sz = cp - host + 1;
+
 		host = safe_strncpy(alloca(sz), host, sz);
 		if (ENABLE_FEATURE_IPV6 && *cp != ':') {
 			cp++; /* skip ']' */
@@ -371,6 +386,13 @@ static char* FAST_FUNC sockaddr2str(const struct sockaddr *sa, int flags)
 	int rc;
 	socklen_t salen;
 
+	if (ENABLE_FEATURE_UNIX_LOCAL && sa->sa_family == AF_UNIX) {
+		struct sockaddr_un *sun = (struct sockaddr_un *)sa;
+		return xasprintf("local:%.*s",
+				(int) sizeof(sun->sun_path),
+				sun->sun_path);
+	}
+
 	salen = LSA_SIZEOF_SA;
 #if ENABLE_FEATURE_IPV6
 	if (sa->sa_family == AF_INET)

networking/Config.in

@@ -12,6 +12,13 @@ config FEATURE_IPV6
 	  Enable IPv6 support in busybox.
 	  This adds IPv6 support in the networking applets.
 
+config FEATURE_UNIX_LOCAL
+	bool "Enable Unix domain socket support"
+	default n
+	help
+	  Enable Unix domain socket support in all busybox networking
+	  applets.
+
 config FEATURE_PREFER_IPV4_ADDRESS
 	bool "Prefer IPv4 addresses from DNS queries"
 	default y

networking/nc.c

@@ -34,7 +34,6 @@ int nc_main(int argc, char **argv)
 	IF_NOT_NC_EXTRA (const) unsigned delay = 0;
 	IF_NOT_NC_EXTRA (const int execparam = 0;)
 	IF_NC_EXTRA     (char **execparam = NULL;)
-	len_and_sockaddr *lsa;
 	fd_set readfds, testfds;
 	int opt; /* must be signed (getopt returns -1) */
 
@@ -80,9 +79,12 @@ int nc_main(int argc, char **argv)
 		argc -= optind;
 		// -l and -f don't mix
 		if (do_listen && cfd) bb_show_usage();
-		// Listen or file modes need zero arguments, client mode needs 2
-		if (do_listen || cfd) {
+		// File mode needs need zero arguments, listen mode needs zero or one,
+		// client mode needs one or two
+		if (cfd) {
 			if (argc) bb_show_usage();
+		} else if (do_listen) {
+			if (argc > 1) bb_show_usage();
 		} else {
 			if (!argc || argc > 2) bb_show_usage();
 		}
@@ -99,24 +101,20 @@ int nc_main(int argc, char **argv)
 
 	if (!cfd) {
 		if (do_listen) {
-			/* create_and_bind_stream_or_die(NULL, lport)
-			 * would've work wonderfully, but we need
-			 * to know lsa */
-			sfd = xsocket_stream(&lsa);
-			if (lport)
-				set_nport(lsa, htons(lport));
-			setsockopt_reuseaddr(sfd);
-			xbind(sfd, &lsa->u.sa, lsa->len);
+			sfd = create_and_bind_stream_or_die(argv[0], lport);
 			xlisten(sfd, do_listen); /* can be > 1 */
+#if 0  /* nc-1.10 does not do this (without -v) */
 			/* If we didn't specify a port number,
 			 * query and print it after listen() */
 			if (!lport) {
-				getsockname(sfd, &lsa->u.sa, &lsa->len);
-				lport = get_nport(&lsa->u.sa);
+				len_and_sockaddr lsa;
+				lsa.len = LSA_SIZEOF_SA;
+				getsockname(sfd, &lsa.u.sa, &lsa.len);
+				lport = get_nport(&lsa.u.sa);
 				fdprintf(2, "%d\n", ntohs(lport));
 			}
+#endif
 			close_on_exec_on(sfd);
-			free(lsa);
  accept_again:
 			cfd = accept(sfd, NULL, 0);
 			if (cfd < 0)

networking/nc_bloaty.c

@@ -377,9 +377,7 @@ create new one, and bind() it. TODO */
 		socklen_t x = sizeof(optbuf);
 
 		rr = getsockopt(netfd, IPPROTO_IP, IP_OPTIONS, optbuf, &x);
-		if (rr < 0)
-			bb_perror_msg("getsockopt failed");
-		else if (x) {    /* we've got options, lessee em... */
+		if (rr >= 0 && x) {    /* we've got options, lessee em... */
 			bin2hex(bigbuf_net, optbuf, x);
 			bigbuf_net[2*x] = '\0';
 			fprintf(stderr, "IP options: %s\n", bigbuf_net);
@@ -603,7 +601,10 @@ Debug("got %d from the net, errno %d", rr, errno);
 	 mobygrams are kinda fun and exercise the reassembler. */
 			if (rr <= 0) {                        /* at end, or fukt, or ... */
 				FD_CLR(STDIN_FILENO, &ding1);                /* disable and close stdin */
-				close(0);
+				close(STDIN_FILENO);
+// Does it make sense to shutdown(net_fd, SHUT_WR)
+// to let other side know that we won't write anything anymore?
+// (and what about keeping compat if we do that?)
 			} else {
 				rzleft = rr;
 				zp = bigbuf_in;
@@ -768,7 +769,12 @@ int nc_main(int argc, char **argv)
 	setsockopt_reuseaddr(netfd);
 	if (o_udpmode)
 		socket_want_pktinfo(netfd);
+	if (!ENABLE_FEATURE_UNIX_LOCAL
+	 || o_listen
+	 || ouraddr->u.sa.sa_family != AF_UNIX
+	) {
 		xbind(netfd, &ouraddr->u.sa, ouraddr->len);
+	}
 #if 0
 	setsockopt(netfd, SOL_SOCKET, SO_RCVBUF, &o_rcvbuf, sizeof o_rcvbuf);
 	setsockopt(netfd, SOL_SOCKET, SO_SNDBUF, &o_sndbuf, sizeof o_sndbuf);