1 files changed, 30 insertions, 6 deletions

diff --git a/networking/libiproute/ll_map.c b/networking/libiproute/ll_map.c
index 48775122c..a14fa4e42 100644
--- a/networking/libiproute/ll_map.c
+++ b/networking/libiproute/ll_map.c
@@ -17,8 +17,11 @@
 #include "libnetlink.h"
 #include "ll_map.h"
 
-struct idxmap
-{
+#include <sys/socket.h> /* socket() */
+#include <net/if.h>     /* struct ifreq and co. */
+#include <sys/ioctl.h>  /* ioctl() & SIOCGIFINDEX */
+
+struct idxmap {
         struct idxmap * next;
         int             index;
         int             type;
@@ -129,6 +132,7 @@ int ll_name_to_index(char *name)
         static char ncache[16];
         static int icache;
         struct idxmap *im;
+        int sock_fd;
         int i;
 
         if (name == NULL)
@@ -144,19 +148,39 @@ int ll_name_to_index(char *name)
                         }
                 }
         }
+        /* We have not found the interface in our cache, but the kernel
+         * may still know about it. One reason is that we may be using
+         * module on-demand loading, which means that the kernel will
+         * load the module and make the interface exist only when
+         * we explicitely request it (check for dev_load() in net/core/dev.c).
+         * I can think of other similar scenario, but they are less common...
+         * Jean II */
+        sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
+        if (sock_fd) {
+                struct ifreq ifr;
+                int ret;
+                strncpy(ifr.ifr_name, name, IFNAMSIZ);
+                ifr.ifr_ifindex = -1;
+                ret = ioctl(sock_fd, SIOCGIFINDEX, &ifr);
+                close(sock_fd);
+                if (ret >= 0)
+                        /* In theory, we should redump the interface list
+                         * to update our cache, this is left as an exercise
+                         * to the reader... Jean II */
+                        return ifr.ifr_ifindex;
+        }
+        
         return 0;
 }
 
 int ll_init_map(struct rtnl_handle *rth)
 {
         if (rtnl_wilddump_request(rth, AF_UNSPEC, RTM_GETLINK) < 0) {
-                perror("Cannot send dump request");
-                exit(1);
+                bb_perror_msg_and_die("cannot send dump request");
         }
 
         if (rtnl_dump_filter(rth, ll_remember_index, &idxmap, NULL, NULL) < 0) {
-                fprintf(stderr, "Dump terminated\n");
-                exit(1);
+                bb_error_msg_and_die("dump terminated");
         }
         return 0;
 }