Add hardware timestamping support

pcap provides a pcap_set_tstamp_type function, which can be used to request
hardware timestamps from a supporting kernel.

This patch adds support for aforementioned function as well as two new
command line options to dumpcap, wireshark and tshark:

    --list-time-stamp-types
                             List time stamp types supported for the interface
    --time-stamp-type <type>
                             Change the interface's timestamp method

Name choice mimics those used by tcpdump(1), which already supports this
feature. However, unlike tcpdump, we provide both options unconditionally.
If Wireshark was configured without pcap_set_tstamp_type being available,
--list-time-stamp-types reports an empty list.

Change-Id: I418a4b2b84cb01949cd262aad0ad8427f5ac0652
Signed-off-by: Ahmad Fatoum <ahmad.fatoum@siemens.com>
Reviewed-on: https://code.wireshark.org/review/23113
Petri-Dish: Guy Harris <guy@alum.mit.edu>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 68 insertions, 30 deletions

diff --git a/dumpcap.c b/dumpcap.c
index cc248ff781..14c96e6fb9 100644
--- a/dumpcap.c
+++ b/dumpcap.c
@@ -493,8 +493,10 @@ print_usage(FILE *output)
     fprintf(output, "  -B <buffer size>         size of kernel buffer in MiB (def: %dMiB)\n", DEFAULT_CAPTURE_BUFFER_SIZE);
 #endif
     fprintf(output, "  -y <link type>           link layer type (def: first appropriate)\n");
+    fprintf(output, "  --time-stamp-type <type> timestamp method for interface\n");
     fprintf(output, "  -D                       print list of interfaces and exit\n");
     fprintf(output, "  -L                       print list of link-layer types of iface and exit\n");
+    fprintf(output, "  --list-time-stamp-types  print list of timestamp types for iface and exit\n");
 #ifdef HAVE_BPF_IMAGE
     fprintf(output, "  -d                       print generated BPF code for capture filter\n");
 #endif
@@ -906,10 +908,9 @@ print_machine_readable_interfaces(GList *if_list)
  * you MUST update capture_ifinfo.c:capture_get_if_capabilities() accordingly!
  */
 static void
-print_machine_readable_if_capabilities(if_capabilities_t *caps)
+print_machine_readable_if_capabilities(if_capabilities_t *caps, int queries)
 {
-    GList *lt_entry;
-    data_link_info_t *data_link_info;
+    GList *lt_entry, *ts_entry;
     const gchar *desc_str;
 
     if (capture_child) {
@@ -917,19 +918,33 @@ print_machine_readable_if_capabilities(if_capabilities_t *caps)
         pipe_write_block(2, SP_SUCCESS, NULL);
     }
 
-    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;
-      else
-        desc_str = "(not supported)";
-      printf("%d\t%s\t%s\n", data_link_info->dlt, data_link_info->name,
-             desc_str);
+    if (queries & CAPS_QUERY_LINK_TYPES) {
+        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_t *data_link_info = (data_link_info_t *)lt_entry->data;
+          if (data_link_info->description != NULL)
+            desc_str = data_link_info->description;
+          else
+            desc_str = "(not supported)";
+          printf("%d\t%s\t%s\n", data_link_info->dlt, data_link_info->name,
+                 desc_str);
+        }
+    }
+    printf("\n");
+    if (queries & CAPS_QUERY_TIMESTAMP_TYPES) {
+        for (ts_entry = caps->timestamp_types; ts_entry != NULL;
+             ts_entry = g_list_next(ts_entry)) {
+          timestamp_info_t *timestamp = (timestamp_info_t *)ts_entry->data;
+          if (timestamp->description != NULL)
+            desc_str = timestamp->description;
+          else
+            desc_str = "(none)";
+          printf("%s\t%s\n", timestamp->name, desc_str);
+        }
     }
 }
 
@@ -3888,7 +3903,7 @@ main(int argc, char *argv[])
     struct pcap_stat  stats;
     GLogLevelFlags    log_flags;
     gboolean          list_interfaces       = FALSE;
-    gboolean          list_link_layer_types = FALSE;
+    int               caps_queries          = 0;
 #ifdef HAVE_BPF_IMAGE
     gboolean          print_bpf_code        = FALSE;
 #endif
@@ -4241,6 +4256,7 @@ main(int argc, char *argv[])
         case 'f':        /* capture filter */
         case 'g':        /* enable group read access on file(s) */
         case 'i':        /* Use interface x */
+        case LONGOPT_SET_TSTAMP_TYPE: /* Set capture timestamp type */
         case 'n':        /* Use pcapng format */
         case 'p':        /* Don't capture in promiscuous mode */
         case 'P':        /* Use pcap format */
@@ -4306,11 +4322,14 @@ main(int argc, char *argv[])
             }
             break;
         case 'L':        /* Print list of link-layer types and exit */
-            if (!list_link_layer_types) {
-                list_link_layer_types = TRUE;
+            if (!(caps_queries & CAPS_QUERY_LINK_TYPES)) {
+                caps_queries |= CAPS_QUERY_LINK_TYPES;
                 run_once_args++;
             }
             break;
+        case LONGOPT_LIST_TSTAMP_TYPES:
+                caps_queries |= CAPS_QUERY_TIMESTAMP_TYPES;
+        break;
 #ifdef HAVE_BPF_IMAGE
         case 'd':        /* Print BPF code for capture filter and exit */
             if (!print_bpf_code) {
@@ -4387,9 +4406,9 @@ main(int argc, char *argv[])
 
     if (run_once_args > 1) {
 #ifdef HAVE_BPF_IMAGE
-        cmdarg_err("Only one of -D, -L, -d, -k, or -S may be supplied.");
+        cmdarg_err("Only one of -D, -L, -d, -k or -S may be supplied.");
 #else
-        cmdarg_err("Only one of -D, -L, -k, or -S may be supplied.");
+        cmdarg_err("Only one of -D, -L, -k or -S may be supplied.");
 #endif
         exit_main(1);
     } else if (run_once_args == 1) {
@@ -4452,7 +4471,7 @@ main(int argc, char *argv[])
         int    err;
         gchar *err_str;
 
-        if_list = capture_interface_list(&err, &err_str,NULL);
+        if_list = capture_interface_list(&err, &err_str, NULL);
         if (if_list == NULL) {
             if (err == 0) {
                 /*
@@ -4512,13 +4531,14 @@ main(int argc, char *argv[])
         exit_main(status);
     }
 
-    if (list_link_layer_types) {
-        /* Get the list of link-layer types for the capture device. */
+    if (caps_queries) {
+        /* Get the list of link-layer and/or timestamp types for the capture device. */
         if_capabilities_t *caps;
         gchar *err_str;
         guint  ii;
 
         for (ii = 0; ii < global_capture_opts.ifaces->len; ii++) {
+            int if_caps_queries = caps_queries;
             interface_options interface_opts;
 
             interface_opts = g_array_index(global_capture_opts.ifaces, interface_options, ii);
@@ -4531,22 +4551,40 @@ main(int argc, char *argv[])
                 g_free(err_str);
                 exit_main(2);
             }
-            if (caps->data_link_types == NULL) {
+            if ((if_caps_queries & CAPS_QUERY_LINK_TYPES) && caps->data_link_types == NULL) {
                 cmdarg_err("The capture device \"%s\" has no data link types.", interface_opts.name);
                 exit_main(2);
-            }
+            } /* No timestamp types is no big deal. So we will just ignore it */
+
+            if (interface_opts.monitor_mode)
+                if_caps_queries |= CAPS_MONITOR_MODE;
+
             if (machine_readable)      /* tab-separated values to stdout */
-                /* XXX: We need to change the format and adopt consumers */
-                print_machine_readable_if_capabilities(caps);
+                /* XXX: We need to change the format and adapt consumers */
+                print_machine_readable_if_capabilities(caps, if_caps_queries);
             else
                 /* XXX: We might want to print also the interface name */
-                capture_opts_print_if_capabilities(caps, interface_opts.name,
-                                                   interface_opts.monitor_mode);
+                capture_opts_print_if_capabilities(caps, interface_opts.name, if_caps_queries);
             free_if_capabilities(caps);
         }
         exit_main(0);
     }
 
+#ifdef HAVE_PCAP_SET_TSTAMP_TYPE
+    for (j = 0; j < global_capture_opts.ifaces->len; j++) {
+        interface_options *interface_opts;
+
+        interface_opts = &g_array_index(global_capture_opts.ifaces, interface_options, j);
+        if (interface_opts->timestamp_type) {
+            interface_opts->timestamp_type_id = pcap_tstamp_type_name_to_val(interface_opts->timestamp_type);
+            if (interface_opts->timestamp_type_id < 0) {
+                cmdarg_err("Invalid argument to option: --time-stamp-type=%s", interface_opts->timestamp_type);
+                exit_main(1);
+            }
+        }
+    }
+#endif
+
     /* We're supposed to do a capture, or print the BPF code for a filter. */
 
     /* Let the user know what interfaces were chosen. */