abisip-find: Add option to bind to a specific source address
When the BTS answers, it uses the src addr used by abisip-find to send
the boardcast packets. This way a different IP than the one
automatically specified by default routing can be used.
An extra benefit: more than one abisip-find process can now be run in
parallel on the same interface.
Change-Id: I6b805f22d261003239d7002d9e568ea4797a2b0b
diff --git a/src/ipaccess/abisip-find.c b/src/ipaccess/abisip-find.c
index 0f398b4..a4ed93e 100644
--- a/src/ipaccess/abisip-find.c
+++ b/src/ipaccess/abisip-find.c
@@ -39,11 +39,13 @@
static struct {
const char *ifname;
+ const char *bind_ip;
int send_interval;
bool list_view;
time_t list_view_timeout;
} cmdline_opts = {
.ifname = NULL,
+ .bind_ip = NULL,
.send_interval = 5,
.list_view = false,
.list_view_timeout = 10,
@@ -55,6 +57,8 @@
printf("Usage: abisip-find [-l] [<interface-name>]\n");
printf(" <interface-name> Specify the outgoing network interface,\n"
" e.g. 'eth0'\n");
+ printf(" -b --bind-ip <ip> Specify the local IP to bind to,\n"
+ " e.g. '192.168.1.10'\n");
printf(" -i --interval <s> Send broadcast frames every <s> seconds.\n");
printf(" -l --list-view Instead of printing received responses,\n"
" output a sorted list of currently present\n"
@@ -70,13 +74,14 @@
int option_index = 0, c;
static struct option long_options[] = {
{"help", 0, 0, 'h'},
+ {"bind-ip", 1, 0, 'b'},
{"send-interval", 1, 0, 'i'},
{"list-view", 0, 0, 'l'},
{"timeout", 1, 0, 't'},
{0, 0, 0, 0}
};
- c = getopt_long(argc, argv, "hi:lt:",
+ c = getopt_long(argc, argv, "hb:i:lt:",
long_options, &option_index);
if (c == -1)
break;
@@ -85,6 +90,9 @@
case 'h':
print_help();
exit(EXIT_SUCCESS);
+ case 'b':
+ cmdline_opts.bind_ip = optarg;
+ break;
case 'i':
errno = 0;
cmdline_opts.send_interval = strtoul(optarg, NULL, 10);
@@ -122,7 +130,7 @@
}
}
-static int udp_sock(const char *ifname)
+static int udp_sock(const char *ifname, const char *bind_ip)
{
int fd, rc, bc = 1;
struct sockaddr_in sa;
@@ -146,7 +154,15 @@
memset(&sa, 0, sizeof(sa));
sa.sin_family = AF_INET;
sa.sin_port = htons(3006);
- sa.sin_addr.s_addr = INADDR_ANY;
+ if (bind_ip) {
+ rc = inet_pton(AF_INET, bind_ip, &sa.sin_addr);
+ if (rc != 1) {
+ fprintf(stderr, "bind ip addr: inet_pton failed, returned %d\n", rc);
+ goto err;
+ }
+ } else {
+ sa.sin_addr.s_addr = INADDR_ANY;
+ }
rc = bind(fd, (struct sockaddr *)&sa, sizeof(sa));
if (rc < 0)
@@ -395,7 +411,7 @@
bfd.cb = bfd_cb;
bfd.when = BSC_FD_READ | BSC_FD_WRITE;
- bfd.fd = udp_sock(cmdline_opts.ifname);
+ bfd.fd = udp_sock(cmdline_opts.ifname, cmdline_opts.bind_ip);
if (bfd.fd < 0) {
perror("Cannot create local socket for broadcast udp");
exit(1);