Fetch an indication of whether the interface supports capturing in

monitor mode at the same time that we fetch its list of link-layer
types.  Support fetching that list in monitor mode, as the list may be
different in regular and monitor mode.  If the interface supports
monitor mode, when printing the list of link-layer types, indicate
whether they're fetched in monitor mode or not, as tcpdump 4.1.x does.

svn path=/trunk/; revision=32789

1 files changed, 120 insertions, 26 deletions

diff --git a/dumpcap.c b/dumpcap.c
index 669c96d56b..ef865b97e7 100644
--- a/dumpcap.c
+++ b/dumpcap.c
@@ -502,29 +502,111 @@ create_data_link_info(int dlt)
     return data_link_info;
 }
 
-static GList *
-get_pcap_linktype_list(const char *devname, char **err_str)
+static if_capabilities_t *
+get_if_capabilities(const char *devname, gboolean monitor_mode
+#ifndef HAVE_PCAP_CREATE
+	_U_
+#endif
+, char **err_str)
 {
-    GList *linktype_list = NULL;
+    if_capabilities_t *caps;
+    char errbuf[PCAP_ERRBUF_SIZE];
     pcap_t *pch;
+#ifdef HAVE_PCAP_CREATE
+    int status;
+#endif
     int deflt;
-    char errbuf[PCAP_ERRBUF_SIZE];
 #ifdef HAVE_PCAP_LIST_DATALINKS
     int *linktypes;
     int i, nlt;
 #endif
     data_link_info_t *data_link_info;
 
+    /*
+     * Allocate the interface capabilities structure.
+     */
+    caps = g_malloc(sizeof *caps);
+
 #ifdef HAVE_PCAP_OPEN
     pch = pcap_open(devname, MIN_PACKET_SIZE, 0, 0, NULL, errbuf);
+    caps->can_set_rfmon = FALSE;
+    if (pch == NULL) {
+        if (err_str != NULL)
+            *err_str = g_strdup(errbuf);
+        g_free(caps);
+        return NULL;
+    }
+#elif defined(HAVE_PCAP_CREATE)
+    pch = pcap_create(devname, errbuf);
+    if (pch == NULL) {
+        if (err_str != NULL)
+            *err_str = g_strdup(errbuf);
+        g_free(caps);
+        return NULL;
+    }
+    status = pcap_can_set_rfmon(pch); 
+    switch (status) {
+
+    case 0:
+        caps->can_set_rfmon = FALSE;
+        break;
+
+    case 1:
+        caps->can_set_rfmon = TRUE;
+        if (monitor_mode)
+        	pcap_set_rfmon(pch, 1);
+        break;
+
+    case PCAP_ERROR_NO_SUCH_DEVICE:
+        if (err_str != NULL)
+            *err_str = g_strdup_printf("There is no capture device named \"%s\"", devname);
+        pcap_close(pch);
+        g_free(caps);
+        return NULL;
+
+    case PCAP_ERROR:
+        if (err_str != NULL)
+            *err_str = g_strdup_printf("pcap_can_set_rfmon on \"%s\" failed: %s",
+                                       devname, pcap_geterr(pch));
+        pcap_close(pch);
+        g_free(caps);
+        return NULL;
+
+    default:
+        if (err_str != NULL)
+            *err_str = g_strdup_printf("pcap_can_set_rfmon on \"%s\" failed: %s",
+                                       devname, pcap_statustostr(status));
+        pcap_close(pch);
+        g_free(caps);
+        return NULL;
+    }
+
+    status = pcap_activate(pch);
+    if (status < 0) {
+        /* Error.  We ignore warnings (status > 0). */
+        if (err_str != NULL) {
+            if (status == PCAP_ERROR) {
+                *err_str = g_strdup_printf("pcap_activate on %s failed: %s",
+                                           devname, pcap_geterr(pch));
+            } else {
+                *err_str = g_strdup_printf("pcap_activate on %s failed: %s",
+                                           devname, pcap_statustostr(status));
+            }
+        }
+        pcap_close(pch);
+        g_free(caps);
+        return NULL;
+    }
 #else
     pch = pcap_open_live(devname, MIN_PACKET_SIZE, 0, 0, errbuf);
-#endif
+    caps->can_set_rfmon = FALSE;
     if (pch == NULL) {
         if (err_str != NULL)
             *err_str = g_strdup(errbuf);
-            return NULL;
+        g_free(caps);
+        return NULL;
     }
+#endif
     deflt = get_pcap_linktype(pch, devname);
 #ifdef HAVE_PCAP_LIST_DATALINKS
     nlt = pcap_list_datalinks(pch, &linktypes);
@@ -534,6 +616,7 @@ get_pcap_linktype_list(const char *devname, char **err_str)
             *err_str = NULL; /* an empty list doesn't mean an error */
         return NULL;
     }
+    caps->data_link_types = NULL;
     for (i = 0; i < nlt; i++) {
         data_link_info = create_data_link_info(linktypes[i]);
 
@@ -543,9 +626,11 @@ get_pcap_linktype_list(const char *devname, char **err_str)
          * device has as the default?
          */
         if (linktypes[i] == deflt)
-            linktype_list = g_list_prepend(linktype_list, data_link_info);
+            caps->data_link_types = g_list_prepend(caps->data_link_types,
+                                                   data_link_info);
         else
-            linktype_list = g_list_append(linktype_list, data_link_info);
+            caps->data_link_types = g_list_append(caps->data_link_types,
+                                                  data_link_info);
     }
 #ifdef HAVE_PCAP_FREE_DATALINKS
     pcap_free_datalinks(linktypes);
@@ -575,14 +660,15 @@ get_pcap_linktype_list(const char *devname, char **err_str)
 #else /* HAVE_PCAP_LIST_DATALINKS */
 
     data_link_info = create_data_link_info(deflt);
-    linktype_list = g_list_append(linktype_list, data_link_info);
+    caps->data_link_types = g_list_append(caps->data_link_types,
+                                          data_link_info);
 #endif /* HAVE_PCAP_LIST_DATALINKS */
 
     pcap_close(pch);
 
     if (err_str != NULL)
         *err_str = NULL;
-    return linktype_list;
+    return caps;
 }
 
 #define ADDRSTRLEN 46 /* Covers IPv4 & IPv6 */
@@ -652,16 +738,21 @@ print_machine_readable_interfaces(GList *if_list)
 
 /*
  * If you change the machine-readable output format of this function,
- * you MUST update capture_sync.c:sync_linktype_list_open() accordingly!
+ * you MUST update capture_ifinfo.c:capture_get_if_capabilities() accordingly!
  */
 static void
-print_machine_readable_link_layer_types(GList *lt_list)
+print_machine_readable_if_capabilities(if_capabilities_t *caps)
 {
     GList *lt_entry;
     data_link_info_t *data_link_info;
     const gchar *desc_str;
 
-    for (lt_entry = lt_list; lt_entry != NULL; lt_entry = g_list_next(lt_entry)) {
+    if (caps->can_set_rfmon)
+        printf("1\n");
+    else
+        printf("0\n");
+    for (lt_entry = caps->data_link_types; lt_entry != NULL;
+         lt_entry = g_list_next(lt_entry)) {
       data_link_info = (data_link_info_t *)lt_entry->data;
       if (data_link_info->description != NULL)
         desc_str = data_link_info->description;
@@ -3381,25 +3472,28 @@ main(int argc, char *argv[])
     exit_main(0);
   } else if (list_link_layer_types) {
     /* Get the list of link-layer types for the capture device. */
-    GList *lt_list;
+    if_capabilities_t *caps;
     gchar *err_str;
 
-    lt_list = get_pcap_linktype_list(global_capture_opts.iface, &err_str);
-    if (lt_list == NULL) {
-      if (err_str != NULL) {
-        cmdarg_err("The list of data link types for the capture device \"%s\" could not be obtained (%s)."
-         "Please check to make sure you have sufficient permissions, and that\n"
-         "you have the proper interface or pipe specified.\n", global_capture_opts.iface, err_str);
-        g_free(err_str);
-      } else
-        cmdarg_err("The capture device \"%s\" has no data link types.", global_capture_opts.iface);
+    caps = get_if_capabilities(global_capture_opts.iface,
+                               global_capture_opts.monitor_mode, &err_str);
+    if (caps == NULL) {
+      cmdarg_err("The capabilities of the capture device \"%s\" could not be obtained (%s)."
+       "Please check to make sure you have sufficient permissions, and that\n"
+       "you have the proper interface or pipe specified.\n", global_capture_opts.iface, err_str);
+      g_free(err_str);
+      exit_main(2);
+    }
+    if (caps->data_link_types == NULL) {
+      cmdarg_err("The capture device \"%s\" has no data link types.", global_capture_opts.iface);
       exit_main(2);
     }
     if (machine_readable)      /* tab-separated values to stdout */
-      print_machine_readable_link_layer_types(lt_list);
+      print_machine_readable_if_capabilities(caps);
     else
-      capture_opts_print_link_layer_types(lt_list);
-    free_pcap_linktype_list(lt_list);
+      capture_opts_print_if_capabilities(caps,
+                                         global_capture_opts.monitor_mode);
+    free_if_capabilities(caps);
     exit_main(0);
   } else if (print_statistics) {
     status = print_statistics_loop(machine_readable);