Add dumpcap options to set the name and description for a capture source.

Add --ifname and --ifdescr to allow the name and description for an
interface or pipe to be set; this overrides the specified name or
reported description for an interface, and overrides the pipe path name
and provides a description for a pipe.

Provide those arguments when capturing from an extcap program.

This is mainly for extcaps, so you have something more meaningful than
some random path name as the interface name and something descriptive
for the description.

1 files changed, 53 insertions, 2 deletions

diff --git a/dumpcap.c b/dumpcap.c
index 19cf9f3818..609efa488a 100644
--- a/dumpcap.c
+++ b/dumpcap.c
@@ -367,6 +367,11 @@ print_usage(FILE *output)
                     "                           or for remote capturing, use one of these formats:\n"
                     "                               rpcap://<host>/<interface>\n"
                     "                               TCP@<host>:<port>\n");
+    fprintf(output, "  --ifname <name>          name to use in the capture file for a pipe from which\n");
+    fprintf(output, "                           we're capturing\n");
+    fprintf(output, "  --ifdescr <description>\n");
+    fprintf(output, "                           description to use in the capture file for a pipe\n");
+    fprintf(output, "                           from which we're capturing\n");
     fprintf(output, "  -f <capture filter>      packet filter in libpcap filter syntax\n");
     fprintf(output, "  -s <snaplen>, --snapshot-length <snaplen>\n");
 #ifdef HAVE_PCAP_CREATE
@@ -3146,8 +3151,8 @@ capture_loop_init_pcapng_output(capture_options *capture_opts, loop_data *ld,
                 pcap_src->snaplen = pcap_snapshot(pcap_src->pcap_h);
             }
             successful = pcapng_write_interface_description_block(global_ld.pdh,
-                                                                  NULL,                       /* OPT_COMMENT       1 */
-                                                                  interface_opts->name,       /* IDB_NAME          2 */
+                                                                   NULL,                       /* OPT_COMMENT       1 */
+                                                                  (interface_opts->ifname != NULL) ? interface_opts->ifname : interface_opts->name, /* IDB_NAME          2 */
                                                                   interface_opts->descr,      /* IDB_DESCRIPTION   3 */
                                                                   interface_opts->cfilter,    /* IDB_FILTER       11 */
                                                                   os_info_str->str,           /* IDB_OS           12 */
@@ -4820,6 +4825,9 @@ get_dumpcap_runtime_info(GString *str)
     get_runtime_caplibs_version(str);
 }
 
+#define LONGOPT_IFNAME             LONGOPT_BASE_APPLICATION+1
+#define LONGOPT_IFDESCR            LONGOPT_BASE_APPLICATION+2
+
 /* And now our feature presentation... [ fade to music ] */
 int
 main(int argc, char *argv[])
@@ -4830,6 +4838,8 @@ main(int argc, char *argv[])
         {"help", no_argument, NULL, 'h'},
         {"version", no_argument, NULL, 'v'},
         LONGOPT_CAPTURE_COMMON
+        {"ifname", required_argument, NULL, LONGOPT_IFNAME},
+        {"ifdescr", required_argument, NULL, LONGOPT_IFDESCR},
         {0, 0, 0, 0 }
     };
 
@@ -5190,6 +5200,28 @@ main(int argc, char *argv[])
             }
             break;
             /*** hidden option: Wireshark child mode (using binary output messages) ***/
+        case LONGOPT_IFNAME:
+            if (global_capture_opts.ifaces->len > 0) {
+                interface_options *interface_opts;
+
+                interface_opts = &g_array_index(global_capture_opts.ifaces, interface_options, global_capture_opts.ifaces->len - 1);
+                interface_opts->ifname = g_strdup(optarg);
+            } else {
+                cmdarg_err("--ifname must be specified after a -i option");
+                exit_main(1);
+            }
+            break;
+        case LONGOPT_IFDESCR:
+            if (global_capture_opts.ifaces->len > 0) {
+                interface_options *interface_opts;
+
+                interface_opts = &g_array_index(global_capture_opts.ifaces, interface_options, global_capture_opts.ifaces->len - 1);
+                interface_opts->descr = g_strdup(optarg);
+            } else {
+                cmdarg_err("--ifdescr must be specified after a -i option");
+                exit_main(1);
+            }
+            break;
         case 'Z':
             capture_child = TRUE;
 #ifdef _WIN32
@@ -5530,6 +5562,25 @@ main(int argc, char *argv[])
                         g_string_append_printf(str, "and ");
                     }
                 }
+                if (interface_opts->ifname != NULL) {
+                    /*
+                     * Re-generate the display name based on the strins
+                     * we were handed.
+                     */
+                    g_free(interface_opts->display_name);
+                    if (interface_opts->descr != NULL) {
+#ifdef _WIN32
+                        interface_opts->display_name = g_strdup_printf("%s",
+                            interface_opts->descr);
+#else
+                        interface_opts->display_name = g_strdup_printf("%s: %s",
+                            interface_opts->descr, interface_opts->ifname);
+#endif
+                    } else {
+                        interface_opts->display_name = g_strdup_printf("%s",
+                            interface_opts->ifname);
+                    }
+                }
                 g_string_append_printf(str, "'%s'", interface_opts->display_name);
             }
         } else {