udhcp[cd]: fix binding to network aliases. Closes 5432, 5438

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/networking/udhcp/socket.c b/networking/udhcp/socket.c
index a5220ba..a421069 100644 (file)
--- a/networking/udhcp/socket.c
+++ b/networking/udhcp/socket.c
@@ -80,6 +80,7 @@ int FAST_FUNC udhcp_listen_socket(/*uint32_t ip,*/ int port, const char *inf)
 {
        int fd;
        struct sockaddr_in addr;
+       char *colon;
 
        log1("Opening listen socket on *:%d %s", port, inf);
        fd = xsocket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
@@ -88,10 +89,17 @@ int FAST_FUNC udhcp_listen_socket(/*uint32_t ip,*/ int port, const char *inf)
        if (setsockopt_broadcast(fd) == -1)
                bb_perror_msg_and_die("SO_BROADCAST");
 
-       /* NB: bug 1032 says this doesn't work on ethernet aliases (ethN:M) */
+       /* SO_BINDTODEVICE doesn't work on ethernet aliases (ethN:M) */
+       colon = strrchr(inf, ':');
+       if (colon)
+               *colon = '\0';
+
        if (setsockopt_bindtodevice(fd, inf))
                xfunc_die(); /* warning is already printed */
 
+       if (colon)
+               *colon = ':';
+
        memset(&addr, 0, sizeof(addr));
        addr.sin_family = AF_INET;
        addr.sin_port = htons(port);