Allow index numbers in remote capture.

diff --git a/tcpdump.c b/tcpdump.c
index b8c45966614aedb4445db394e194dd93dff5f414..462202a32b48da6c07eb24604bbad74465e23371 100644 (file)
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -1012,9 +1012,35 @@ read_infile(char *fname)
 static long
 parse_interface_number(const char *device)
 {
+       const char *p;
        long devnum;
        char *end;
 
+       /*
+        * Search for a colon, terminating any scheme at the beginning
+        * of the device.
+        */
+       p = strchr(device, ':');
+       if (p != NULL) {
+               /*
+                * We found it.  Is it followed by "//"?
+                */
+               p++;    /* skip the : */
+               if (strncmp(p, "//", 2) == 0) {
+                       /*
+                        * Yes.  Search for the next /, at the end of the
+                        * authority part of the URL.
+                        */
+                       p += 2; /* skip the // */
+                       p = strchr(p, '/');
+                       if (p != NULL) {
+                               /*
+                                * OK, past the / is the path.
+                                */
+                               device = p + 1;
+                       }
+               }
+       }
        devnum = strtol(device, &end, 10);
        if (device != end && *end == '\0') {
                /*
@@ -1037,14 +1063,54 @@ parse_interface_number(const char *device)
 }
 
 static char *
-find_interface_by_number(long devnum)
+find_interface_by_number(const char *url, long devnum)
 {
        pcap_if_t *dev, *devlist;
        long i;
        char ebuf[PCAP_ERRBUF_SIZE];
        char *device;
+#ifdef HAVE_PCAP_FINDALLDEVS_EX
+       const char *endp;
+       char *host_url;
+#endif
+       int status;
 
-       if (pcap_findalldevs(&devlist, ebuf) < 0)
+#ifdef HAVE_PCAP_FINDALLDEVS_EX
+       /*
+        * Search for a colon, terminating any scheme at the beginning
+        * of the URL.
+        */
+       endp = strchr(url, ':');
+       if (endp != NULL) {
+               /*
+                * We found it.  Is it followed by "//"?
+                */
+               endp++; /* skip the : */
+               if (strncmp(endp, "//", 2) == 0) {
+                       /*
+                        * Yes.  Search for the next /, at the end of the
+                        * authority part of the URL.
+                        */
+                       endp += 2;      /* skip the // */
+                       endp = strchr(endp, '/');
+               } else
+                       endp = NULL;
+       }
+       if (endp != NULL) {
+               /*
+                * OK, everything from device to endp is a URL to hand
+                * to pcap_findalldevs_ex().
+                */
+               endp++; /* Include the trailing / in the URL; pcap_findalldevs_ex() requires it */
+               host_url = malloc(endp - url + 1);
+               memcpy(host_url, url, endp - url);
+               host_url[endp - url] = '\0';
+               status = pcap_findalldevs_ex(host_url, NULL, &devlist, ebuf);
+               free(host_url);
+       } else
+#endif
+       status = pcap_findalldevs(&devlist, ebuf);
+       if (status < 0)
                error("%s", ebuf);
        /*
         * Look for the devnum-th entry in the list of devices (1-based).
@@ -1090,12 +1156,14 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
                    ebuf);
                if (pc == NULL) {
                        /*
-                        * If this failed with "No such device", that means
+                        * If this failed with "No such device" or "The system
+                        * cannot find the device specified", that means
                         * the interface doesn't exist; return NULL, so that
                         * the caller can see whether the device name is
                         * actually an interface index.
                         */
-                       if (strstr(ebuf, "No such device") != NULL)
+                       if (strstr(ebuf, "No such device") != NULL ||
+                           strstr(ebuf, "The system cannot find the device specified") != NULL)
                                return (NULL);
                        error("%s", ebuf);
                }
@@ -1922,7 +1990,7 @@ main(int argc, char **argv)
                         * find_interface_by_number() exits if it
                         * couldn't be found.
                         */
-                       device = find_interface_by_number(devnum);
+                       device = find_interface_by_number(device, devnum);
                        pd = open_interface(device, ndo, ebuf);
                        if (pd == NULL)
                                error("%s", ebuf);