--- a/rvinterf/lowlevel/Makefile	Sat Nov 23 07:40:13 2013 +0000
+++ b/rvinterf/lowlevel/Makefile	Sat Nov 23 20:15:02 2013 +0000
@@ -5,8 +5,8 @@
 
 RVTDUMP_OBJS=	format.o format_g23.o openport.o output.o packetrx.o rvtdump.o
 
-RVINTERF_OBJS=	format.o format_g23.o logsent.o openport.o output.o packetrx.o \
-		packettx.o rvifmain.o
+RVINTERF_OBJS=	format.o format_g23.o localsock.o logsent.o openport.o output.o\
+		packetrx.o packettx.o rvifmain.o
 
 all:	${PROGS}
 

--- a/rvinterf/lowlevel/client.h	Sat Nov 23 07:40:13 2013 +0000
+++ b/rvinterf/lowlevel/client.h	Sat Nov 23 20:15:02 2013 +0000
@@ -9,7 +9,6 @@
 
 struct client {
 	struct	client *next;
-	struct	client **backptr;
 	int	fd;
 	int	rx_state;
 	u_char	rx_buf[LOCALSOCK_MAX_MSG];

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rvinterf/lowlevel/localsock.c	Sat Nov 23 20:15:02 2013 +0000
@@ -0,0 +1,141 @@
+/*
+ * This rvinterf module handles the local UNIX domain socket interface
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <stdio.h>
+#include <string.h>
+#include <strings.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "../localsock.h"
+#include "client.h"
+
+static char sockpath[] = "/tmp/rvinterf_socket";
+
+int listener;
+
+extern struct client *client_head;
+extern int max_fd;
+
+create_listener_socket()
+{
+	/* local socket binding voodoo copied from osmocon */
+	struct sockaddr_un local;
+	unsigned int namelen;
+	int rc;
+
+	listener = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (listener < 0) {
+		perror("socket(AF_UNIX, SOCK_STREAM, 0)");
+		exit(1);
+	}
+
+	local.sun_family = AF_UNIX;
+	strncpy(local.sun_path, sockpath, sizeof(local.sun_path));
+	local.sun_path[sizeof(local.sun_path) - 1] = '\0';
+	unlink(local.sun_path);
+
+	/* we use the same magic that X11 uses in Xtranssock.c for
+	 * calculating the proper length of the sockaddr */
+#if defined(BSD44SOCKETS) || defined(__UNIXWARE__)
+	local.sun_len = strlen(local.sun_path);
+#endif
+#if defined(BSD44SOCKETS) || defined(SUN_LEN)
+	namelen = SUN_LEN(&local);
+#else
+	namelen = strlen(local.sun_path) +
+		  offsetof(struct sockaddr_un, sun_path) + 1;
+#endif
+
+	rc = bind(listener, (struct sockaddr *) &local, namelen);
+	if (rc != 0) {
+		perror("bind on local socket");
+		exit(1);
+	}
+	rc = listen(listener, 3);
+	if (rc != 0) {
+		perror("listen");
+		exit(1);
+	}
+
+	if (listener > max_fd)
+		max_fd = listener;
+	return(0);
+}
+
+static void
+prep_for_length_rx(cli)
+	struct client *cli;
+{
+	cli->rx_state = 0;
+	cli->rx_ptr = cli->rx_buf;
+	cli->rx_left = 2;
+}
+
+static void
+prep_for_message_rx(cli)
+	struct client *cli;
+{
+	cli->rx_state = 1;
+	cli->rx_ptr = cli->rx_buf;
+	cli->rx_left = cli->rx_msglen;
+}
+
+handle_listener_select()
+{
+	struct sockaddr_un un_addr;
+	socklen_t len;
+	int rc;
+	struct client *newcli;
+
+	len = sizeof(un_addr);
+	rc = accept(listener, (struct sockaddr *) &un_addr, &len);
+	if (rc < 0) {
+		perror("rvinterf: accept");
+		exit(1);
+	}
+	newcli = malloc(sizeof(struct client));
+	if (!newcli) {
+		perror("rvinterf: malloc for new client");
+		exit(1);
+	}
+	bzero(newcli, sizeof(struct client));
+	newcli->fd = rc;
+	newcli->next = client_head;
+	client_head = newcli;
+	prep_for_length_rx(newcli);
+	return(0);
+}
+
+void
+handle_client_select(cli)
+	struct client *cli;
+{
+	int cc;
+
+	cc = read(cli->fd, cli->rx_ptr, cli->rx_left);
+	if (cc <= 0) {
+		/* normal client exit condition */
+close_socket:	cli->rx_state = 2;
+		return;
+	}
+	cli->rx_ptr += cc;
+	cli->rx_left -= cc;
+	if (cli->rx_left)
+		return;
+	/* got the thing, process it */
+	if (cli->rx_state) {
+		prep_for_length_rx(cli);
+		/* process_msg_from_client(cli); */
+	} else {
+		cli->rx_msglen = *(u_short *)cli->rx_buf;
+		if (cli->rx_msglen < 1 || cli->rx_msglen > LOCALSOCK_MAX_MSG) {
+			/* TODO: report invalid length to the client */
+			goto close_socket;
+		}
+		prep_for_message_rx(cli);
+	}
+}

--- a/rvinterf/lowlevel/rvifmain.c	Sat Nov 23 07:40:13 2013 +0000
+++ b/rvinterf/lowlevel/rvifmain.c	Sat Nov 23 20:15:02 2013 +0000
@@ -9,17 +9,22 @@
 #include <unistd.h>
 #include <time.h>
 #include "../pktmux.h"
+#include "../localsock.h"
+#include "client.h"
 
-extern int target_fd;
+extern int target_fd, listener;
 extern char *baudrate_name;
 
 extern u_char rxpkt[];
 extern size_t rxpkt_len;
 
+struct client *client_head;
+
 char *logfname;
 FILE *logF;
 time_t logtime;
 int background;
+int max_fd;
 
 main(argc, argv)
 	char **argv;
@@ -28,6 +33,7 @@
 	extern int optind;
 	int c;
 	fd_set fds;
+	struct client *cli, **clip;
 
 	while ((c = getopt(argc, argv, "bB:d:l:")) != EOF)
 		switch (c) {
@@ -54,6 +60,7 @@
 			goto usage;
 		open_target_serial(argv[optind]);
 	}
+	max_fd = target_fd;
 
 	set_serial_nonblock(0);
 	setlinebuf(stdout);
@@ -66,6 +73,7 @@
 		fprintf(logF, "*** Log of rvinterf session ***\n");
 		setlinebuf(logF);
 	}
+	create_listener_socket();
 	if (background) {
 		c = fork();
 		if (c < 0) {
@@ -80,7 +88,18 @@
 	for (;;) {
 		FD_ZERO(&fds);
 		FD_SET(target_fd, &fds);
-		c = select(target_fd+1, &fds, 0, 0, 0);
+		FD_SET(listener, &fds);
+		for (clip = &client_head; cli = *clip; ) {
+			if (cli->rx_state == 2) {
+				close(cli->fd);
+				*clip = cli->next;
+				free(cli);
+				continue;
+			}
+			FD_SET(cli->fd, &fds);
+			clip = &cli->next;
+		}
+		c = select(max_fd+1, &fds, 0, 0, 0);
 		time(&logtime);
 		if (c < 0) {
 			if (errno == EINTR)
@@ -90,6 +109,11 @@
 		}
 		if (FD_ISSET(target_fd, &fds))
 			process_serial_rx();
+		if (FD_ISSET(listener, &fds))
+			handle_listener_select();
+		for (cli = client_head; cli; cli = cli->next)
+			if (FD_ISSET(cli->fd, &fds))
+				handle_client_select(cli);
 	}
 }