Improve a tcpdump error message, free device list before exiting.

If an adapter index that's greater than the number of adapters is
specified by the user, mention the incorrect adapter index, and the
total number of adapters (the former being greater than the latter), in
the error message.

Free the adapter list before reporting the error and exiting, to
suppress complaints from leak detectots (not that the memory spends much
time leaked, as exiting destroys the entire address space, but...).

Fixes issue #1208.

diff --git a/tcpdump.c b/tcpdump.c
index d6b8e600c83bec68a62bc0ac37d3b3231059fbb3..bddf963fa5e14a7fc0edc2a787a286e02e8bd50d 100644 (file)
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -1171,8 +1171,11 @@ _U_
        for (i = 0, dev = devlist; i < devnum-1 && dev != NULL;
            i++, dev = dev->next)
                ;
-       if (dev == NULL)
-               error("Invalid adapter index");
+       if (dev == NULL) {
+               pcap_freealldevs(devlist);
+               error("Invalid adapter index %ld: only %ld interfaces found",
+                   devnum, i);
+       }
        device = strdup(dev->name);
        pcap_freealldevs(devlist);
        return (device);