add new program to use UDP broadcast packets to find ip.access BTS in the network

src/Makefile.am

@@ -1,7 +1,7 @@
 INCLUDES = $(all_includes) -I$(top_srcdir)/include
 AM_CFLAGS=-Wall
 
-sbin_PROGRAMS = bsc_hack bs11_config
+sbin_PROGRAMS = bsc_hack bs11_config ipaccess-find
 
 bsc_hack_SOURCES = bsc_hack.c abis_rsl.c abis_nm.c gsm_04_08.c gsm_data.c \
 		gsm_subscriber.c msgb.c select.c chan_alloc.c timer.c debug.c db.c \
@@ -11,3 +11,5 @@ bsc_hack_SOURCES = bsc_hack.c abis_rsl.c abis_nm.c gsm_04_08.c gsm_data.c \
 bsc_hack_LDADD = -ldl -ldbi
 
 bs11_config_SOURCES = bs11_config.c abis_nm.c gsm_data.c msgb.c debug.c select.c timer.c rs232.c
+
+ipaccess_find_SOURCES = ipaccess-find.c select.c timer.c

src/ipaccess-find.c

@@ -0,0 +1,149 @@
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+
+#include <openbsc/select.h>
+#include <openbsc/timer.h>
+
+static int udp_sock(void)
+{
+	int fd, rc, bc = 1;
+	struct sockaddr_in sa;
+
+	fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
+	if (fd < 0)
+		return fd;
+
+	sa.sin_family = AF_INET;
+	sa.sin_port = htons(3006);
+	sa.sin_addr.s_addr = INADDR_ANY;
+	inet_aton("192.168.100.11", &sa.sin_addr);
+
+	rc = bind(fd, (struct sockaddr *)&sa, sizeof(sa));
+	if (rc < 0)
+		goto err;
+
+	rc = setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &bc, sizeof(bc));
+	if (rc < 0)
+		goto err;
+
+#if 0
+	rc = connect(fd, (struct sockaddr *)&sa, sizeof(sa));
+	if (rc < 0)
+		goto err;
+#endif		
+	return fd;
+
+err:
+	close(fd);
+	return rc;
+}
+
+const unsigned char find_pkt[] = { 0x00, 0x0b, 0xfe, 0x00, 0x04, 0x01, 0x06, 0x01, 0x07, 0x01, 0x02, 0x01, 0x03, 0x01, 0x08 };
+
+
+static int bcast_find(int fd)
+{
+	struct sockaddr_in sa;
+
+	sa.sin_family = AF_INET;
+	sa.sin_port = htons(3006);
+	inet_aton("255.255.255.255", &sa.sin_addr);
+
+	return sendto(fd, find_pkt, sizeof(find_pkt), 0, (struct sockaddr *) &sa, sizeof(sa));
+}
+
+static int parse_response(unsigned char *buf, int len)
+{
+	u_int8_t t_len;
+	u_int8_t t_tag;
+	u_int8_t *cur = buf;
+
+	cur += 6;
+	
+	while (cur < buf + len) {
+		t_len = *cur++;
+		t_tag = *cur++;
+		
+		printf("tag=0x%02x, val='%s'  ", t_tag, cur);
+
+		cur += t_len;
+	}
+	printf("\n");
+	return 0;
+}
+
+static int read_response(int fd)
+{
+	unsigned char buf[255];
+	struct sockaddr_in sa;
+	int len;
+	socklen_t sa_len = sizeof(sa);
+
+	len = recvfrom(fd, buf, sizeof(buf), 0, (struct sockaddr *)&sa, &sa_len);
+	if (len < 0)
+		return len;
+
+	return parse_response(buf, len);
+}
+
+static int bfd_cb(struct bsc_fd *bfd, unsigned int flags)
+{
+	if (flags & BSC_FD_READ)
+		return read_response(bfd->fd);
+	if (flags & BSC_FD_WRITE) {
+		bfd->when &= ~BSC_FD_WRITE;
+		return bcast_find(bfd->fd);
+	}
+	return 0;
+}
+
+static struct timer_list timer;
+
+static void timer_cb(void *_data)
+{
+	struct bsc_fd *bfd = _data;
+
+	bfd->when |= BSC_FD_WRITE;
+
+	schedule_timer(&timer, 5, 0);
+}
+
+int main(int argc, char **argv)
+{
+	struct bsc_fd bfd;
+	int rc;
+
+	printf("ipaccess-find (C) 2009 by Harald Welte\n");
+	printf("This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY\n\n");
+
+	bfd.cb = bfd_cb;
+	bfd.when = BSC_FD_READ | BSC_FD_WRITE;
+	bfd.fd = udp_sock();
+	if (bfd.fd < 0)
+		exit(2);
+
+	bsc_register_fd(&bfd);
+
+	timer.cb = timer_cb;
+	timer.data = &bfd;
+
+	schedule_timer(&timer, 5, 0);
+
+	printf("Trying to find ip.access BTS by broadcast UDP...\n");
+
+	while (1) {
+		rc = bsc_select_main();
+		if (rc < 0)
+			exit(3);
+	}
+
+	exit(0);
+}
+