Allow bigger snapshot lengths for D-Bus captures.

Use WTAP_MAX_PACKET_SIZE_STANDARD, set to 256KB, for everything except
for D-Bus captures.  Use WTAP_MAX_PACKET_SIZE_DBUS, set to 128MB, for
them, because that's the largest possible D-Bus message size.  See

	https://bugs.freedesktop.org/show_bug.cgi?id=100220

for an example of the problems caused by limiting the snapshot length to
256KB for D-Bus.

Have a snapshot length of 0 in a capture_file structure mean "there is
no snapshot length for the file"; we don't need the has_snap field in
that case, a value of 0 mean "no, we don't have a snapshot length".

In dumpcap, start out with a pipe buffer size of 2KB, and grow it as
necessary.  When checking for a too-big packet from a pipe, check
against the appropriate maximum - 128MB for DLT_DBUS, 256KB for
everything else.

Change-Id: Ib2ce7a0cf37b971fbc0318024fd011e18add8b20
Reviewed-on: https://code.wireshark.org/review/21952
Petri-Dish: Guy Harris <guy@alum.mit.edu>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Guy Harris <guy@alum.mit.edu>

6 files changed, 15 insertions, 15 deletions

diff --git a/ui/qt/capture_file_properties_dialog.cpp b/ui/qt/capture_file_properties_dialog.cpp
index 0cf0404fd0..dd53edfd32 100644
--- a/ui/qt/capture_file_properties_dialog.cpp
+++ b/ui/qt/capture_file_properties_dialog.cpp
@@ -192,7 +192,7 @@ QString CaptureFilePropertiesDialog::summaryToHtml()
         << table_data_tmpl.arg(encaps_str)
         << table_row_end;
 
-    if (summary.has_snap) {
+    if (summary.snap != 0) {
         out << table_row_begin
             << table_vheader_tmpl.arg(tr("Snapshot length"))
             << table_data_tmpl.arg(summary.snap)
diff --git a/ui/qt/capture_interfaces_dialog.cpp b/ui/qt/capture_interfaces_dialog.cpp
index 3148e4fccc..d2969c0df7 100644
--- a/ui/qt/capture_interfaces_dialog.cpp
+++ b/ui/qt/capture_interfaces_dialog.cpp
@@ -704,10 +704,10 @@ void CaptureInterfacesDialog::updateInterfaces()
             if (capture_dev_user_snaplen_find(device->name, &hassnap, &snaplen)) {
                 /* Default snap length set in preferences */
                 device->snaplen = snaplen;
-                device->has_snaplen = snaplen == WTAP_MAX_PACKET_SIZE ? FALSE : hassnap;
+                device->has_snaplen = snaplen == WTAP_MAX_PACKET_SIZE_STANDARD ? FALSE : hassnap;
             } else {
                 /* No preferences set yet, use default values */
-                device->snaplen = WTAP_MAX_PACKET_SIZE;
+                device->snaplen = WTAP_MAX_PACKET_SIZE_STANDARD;
                 device->has_snaplen = FALSE;
             }
 
@@ -1009,7 +1009,7 @@ bool CaptureInterfacesDialog::saveOptionsToPreferences()
                 snaplen_list << QString("%1:%2(%3)")
                                 .arg(device->name)
                                 .arg(device->has_snaplen)
-                                .arg(device->has_snaplen ? device->snaplen : WTAP_MAX_PACKET_SIZE);
+                                .arg(device->has_snaplen ? device->snaplen : WTAP_MAX_PACKET_SIZE_STANDARD);
             }
             g_free(prefs.capture_devices_snaplen);
             prefs.capture_devices_snaplen = qstring_strdup(snaplen_list.join(","));
@@ -1197,7 +1197,7 @@ QWidget* InterfaceTreeDelegate::createEditor(QWidget *parent, const QStyleOption
 #ifdef SHOW_BUFFER_COLUMN
     gint buffer = DEFAULT_CAPTURE_BUFFER_SIZE;
 #endif
-    guint snap = WTAP_MAX_PACKET_SIZE;
+    guint snap = WTAP_MAX_PACKET_SIZE_STANDARD;
     GList *links = NULL;
 
     if (idx.column() > 1 && idx.data().toString().compare(UTF8_EM_DASH)) {
@@ -1247,7 +1247,7 @@ QWidget* InterfaceTreeDelegate::createEditor(QWidget *parent, const QStyleOption
         case col_snaplen_:
         {
             QSpinBox *sb = new QSpinBox(parent);
-            sb->setRange(1, WTAP_MAX_PACKET_SIZE);
+            sb->setRange(1, WTAP_MAX_PACKET_SIZE_STANDARD);
             sb->setValue(snap);
             sb->setWrapping(true);
             connect(sb, SIGNAL(valueChanged(int)), this, SLOT(snapshotLengthChanged(int)));
@@ -1258,7 +1258,7 @@ QWidget* InterfaceTreeDelegate::createEditor(QWidget *parent, const QStyleOption
         case col_buffer_:
         {
             QSpinBox *sb = new QSpinBox(parent);
-            sb->setRange(1, WTAP_MAX_PACKET_SIZE);
+            sb->setRange(1, WTAP_MAX_PACKET_SIZE_STANDARD);
             sb->setValue(buffer);
             sb->setWrapping(true);
             connect(sb, SIGNAL(valueChanged(int)), this, SLOT(bufferSizeChanged(int)));
@@ -1332,12 +1332,12 @@ void InterfaceTreeDelegate::snapshotLengthChanged(int value)
     if (!device) {
         return;
     }
-    if (value != WTAP_MAX_PACKET_SIZE) {
+    if (value != WTAP_MAX_PACKET_SIZE_STANDARD) {
         device->has_snaplen = true;
         device->snaplen = value;
     } else {
         device->has_snaplen = false;
-        device->snaplen = WTAP_MAX_PACKET_SIZE;
+        device->snaplen = WTAP_MAX_PACKET_SIZE_STANDARD;
     }
 }
 
diff --git a/ui/qt/compiled_filter_output.cpp b/ui/qt/compiled_filter_output.cpp
index ca718259a4..fda2332a33 100644
--- a/ui/qt/compiled_filter_output.cpp
+++ b/ui/qt/compiled_filter_output.cpp
@@ -88,7 +88,7 @@ void CompiledFilterOutput::compileFilter()
             if (interfaces.compare(device.display_name)) {
                 continue;
             } else {
-                pcap_t *pd = pcap_open_dead(device.active_dlt, WTAP_MAX_PACKET_SIZE);
+                pcap_t *pd = pcap_open_dead(device.active_dlt, WTAP_MAX_PACKET_SIZE_STANDARD);
                 if (pd == NULL)
                     break;
                 g_mutex_lock(pcap_compile_mtx);
diff --git a/ui/qt/gsm_map_summary_dialog.cpp b/ui/qt/gsm_map_summary_dialog.cpp
index 4b8c50747d..a13b116047 100644
--- a/ui/qt/gsm_map_summary_dialog.cpp
+++ b/ui/qt/gsm_map_summary_dialog.cpp
@@ -128,7 +128,7 @@ QString GsmMapSummaryDialog::summaryToHtml()
         << table_data_tmpl.arg(format_str)
         << table_row_end;
 
-    if (summary.has_snap) {
+    if (summary.snap != 0) {
         out << table_row_begin
             << table_vheader_tmpl.arg(tr("Snapshot length"))
             << table_data_tmpl.arg(summary.snap)
diff --git a/ui/qt/interface_tree_cache_model.cpp b/ui/qt/interface_tree_cache_model.cpp
index e89e266868..5447f80332 100644
--- a/ui/qt/interface_tree_cache_model.cpp
+++ b/ui/qt/interface_tree_cache_model.cpp
@@ -210,7 +210,7 @@ void InterfaceTreeCacheModel::save()
                 else if ( col == IFTREE_COL_SNAPLEN )
                 {
                     int iVal = saveValue.toInt();
-                    if ( iVal != WTAP_MAX_PACKET_SIZE )
+                    if ( iVal != WTAP_MAX_PACKET_SIZE_STANDARD )
                     {
                         device.has_snaplen = true;
                         device.snaplen = iVal;
@@ -218,7 +218,7 @@ void InterfaceTreeCacheModel::save()
                     else
                     {
                         device.has_snaplen = false;
-                        device.snaplen = WTAP_MAX_PACKET_SIZE;
+                        device.snaplen = WTAP_MAX_PACKET_SIZE_STANDARD;
                     }
                 }
 #ifdef CAN_SET_CAPTURE_BUFFER_SIZE
@@ -270,7 +270,7 @@ void InterfaceTreeCacheModel::save()
                 prefStorage[&prefs.capture_devices_snaplen]  <<
                         QString("%1:%2(%3)").arg(device.name).
                         arg(device.has_snaplen ? 1 : 0).
-                        arg(device.has_snaplen ? value : WTAP_MAX_PACKET_SIZE);
+                        arg(device.has_snaplen ? value : WTAP_MAX_PACKET_SIZE_STANDARD);
             }
 
 #ifdef CAN_SET_CAPTURE_BUFFER_SIZE
diff --git a/ui/qt/mtp3_summary_dialog.cpp b/ui/qt/mtp3_summary_dialog.cpp
index 62fcc7107c..3affcc94b2 100644
--- a/ui/qt/mtp3_summary_dialog.cpp
+++ b/ui/qt/mtp3_summary_dialog.cpp
@@ -133,7 +133,7 @@ QString Mtp3SummaryDialog::summaryToHtml()
         << table_data_tmpl.arg(format_str)
         << table_row_end;
 
-    if (summary.has_snap) {
+    if (summary.snap != 0) {
         out << table_row_begin
             << table_vheader_tmpl.arg(tr("Snapshot length"))
             << table_data_tmpl.arg(summary.snap)