Dumpcap+Qt: Add support for `-a packets:NUM` and `-b packets:NUM`.

Add the ability to rotate files after a specified number of packets (`-b
packets:NUM`). Move some condition checks to capture_loop_write_packet_cb.

Add `-a packets:NUM` in order to be consistent. It is functionally
equivalent to the `-c` flag.

Add a corresponding "packets" option to the Capture Interfaces dialog
Output tab.

Add initial tests for autostop and ringbuffer conditions.

Change-Id: I66eb968927ed287deb8edb96db96d7c73526c257
Reviewed-on: https://code.wireshark.org/review/30534
Reviewed-by: Gerald Combs <gerald@wireshark.org>
Petri-Dish: Gerald Combs <gerald@wireshark.org>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>

2 files changed, 88 insertions, 47 deletions

diff --git a/ui/qt/capture_interfaces_dialog.cpp b/ui/qt/capture_interfaces_dialog.cpp
index 0bef6cba84..b9dc86ff9c 100644
--- a/ui/qt/capture_interfaces_dialog.cpp
+++ b/ui/qt/capture_interfaces_dialog.cpp
@@ -549,6 +549,10 @@ void CaptureInterfacesDialog::updateInterfaces()
     }
 
     ui->gbNewFileAuto->setChecked(global_capture_opts.multi_files_on);
+    ui->PktCheckBox->setChecked(global_capture_opts.has_file_packets);
+    if (global_capture_opts.has_file_packets) {
+        ui->PktSpinBox->setValue(global_capture_opts.file_packets);
+    }
     ui->MBCheckBox->setChecked(global_capture_opts.has_autostop_filesize);
     ui->SecsCheckBox->setChecked(global_capture_opts.has_file_interval);
     if (global_capture_opts.has_autostop_filesize) {
@@ -850,6 +854,10 @@ bool CaptureInterfacesDialog::saveOptionsToPreferences()
                 break;
             }
          }
+         global_capture_opts.has_file_packets = ui->PktCheckBox->isChecked();
+         if (global_capture_opts.has_file_packets) {
+             global_capture_opts.file_packets = ui->PktSpinBox->value();
+         }
          global_capture_opts.has_autostop_filesize = ui->MBCheckBox->isChecked();
          if (global_capture_opts.has_autostop_filesize) {
              global_capture_opts.autostop_filesize = ui->MBSpinBox->value();
@@ -878,9 +886,12 @@ bool CaptureInterfacesDialog::saveOptionsToPreferences()
              QMessageBox::warning(this, tr("Error"),
                                       tr("Multiple files: No capture file name given. You must specify a filename if you want to use multiple files."));
              return false;
-         } else if (!global_capture_opts.has_autostop_filesize && !global_capture_opts.has_file_interval) {
+         } else if (!global_capture_opts.has_autostop_filesize &&
+                    !global_capture_opts.has_file_interval &&
+                    !global_capture_opts.has_file_duration &&
+                    !global_capture_opts.has_file_packets) {
              QMessageBox::warning(this, tr("Error"),
-                                      tr("Multiple files: No file limit given. You must specify a file size or interval at which is switched to the next capture file\n if you want to use multiple files."));
+                                      tr("Multiple files: No file limit given. You must specify a file size, interval, or number of packets for each file."));
              g_free(global_capture_opts.save_file);
              global_capture_opts.save_file = NULL;
              return false;
diff --git a/ui/qt/capture_interfaces_dialog.ui b/ui/qt/capture_interfaces_dialog.ui
index 7d3c416f27..181f5df332 100644
--- a/ui/qt/capture_interfaces_dialog.ui
+++ b/ui/qt/capture_interfaces_dialog.ui
@@ -262,10 +262,38 @@
           <bool>true</bool>
          </property>
          <layout class="QGridLayout" name="gridLayout">
-          <item row="1" column="1">
-           <widget class="QSpinBox" name="MBSpinBox">
+          <item row="0" column="3" rowspan="4">
+           <spacer name="horizontalSpacer_8">
+            <property name="orientation">
+             <enum>Qt::Horizontal</enum>
+            </property>
+            <property name="sizeHint" stdset="0">
+             <size>
+              <width>40</width>
+              <height>20</height>
+             </size>
+            </property>
+           </spacer>
+          </item>
+          <item row="2" column="0">
+           <widget class="QCheckBox" name="MBCheckBox">
+            <property name="text">
+             <string/>
+            </property>
+           </widget>
+          </item>
+          <item row="3" column="0">
+           <widget class="QCheckBox" name="SecsCheckBox">
+            <property name="text">
+             <string/>
+            </property>
+           </widget>
+          </item>
+          <item row="3" column="1">
+           <widget class="QSpinBox" name="SecsSpinBox">
             <property name="toolTip">
-             <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;If the selected file size is exceeded, capturing switches to the next file.&lt;/p&gt;&lt;p&gt;PLEASE NOTE: One option MUST be selected.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+             <string>If the selected file size is exceeded, capturing switches to the next file.
+PLEASE NOTE: One option MUST be selected.</string>
             </property>
             <property name="wrapping">
              <bool>true</bool>
@@ -284,30 +312,7 @@
             </property>
            </widget>
           </item>
-          <item row="1" column="2">
-           <widget class="QComboBox" name="MBComboBox">
-            <property name="toolTip">
-             <string>If the selected file size is exceeded, capturing switches to the next file.
-PLEASE NOTE: One option MUST be selected.</string>
-            </property>
-            <item>
-             <property name="text">
-              <string>kilobytes</string>
-             </property>
-            </item>
-            <item>
-             <property name="text">
-              <string>megabytes</string>
-             </property>
-            </item>
-            <item>
-             <property name="text">
-              <string>gigabytes</string>
-             </property>
-            </item>
-           </widget>
-          </item>
-          <item row="2" column="2">
+          <item row="3" column="2">
            <widget class="QComboBox" name="SecsComboBox">
             <property name="toolTip">
              <string>If the selected file size is exceeded, capturing switches to the next file.
@@ -331,10 +336,9 @@ PLEASE NOTE: One option MUST be selected.</string>
            </widget>
           </item>
           <item row="2" column="1">
-           <widget class="QSpinBox" name="SecsSpinBox">
+           <widget class="QSpinBox" name="MBSpinBox">
             <property name="toolTip">
-             <string>If the selected file size is exceeded, capturing switches to the next file.
-PLEASE NOTE: One option MUST be selected.</string>
+             <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;If the selected file size is exceeded, capturing switches to the next file.&lt;/p&gt;&lt;p&gt;PLEASE NOTE: One option MUST be selected.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
             </property>
             <property name="wrapping">
              <bool>true</bool>
@@ -353,30 +357,56 @@ PLEASE NOTE: One option MUST be selected.</string>
             </property>
            </widget>
           </item>
-          <item row="0" column="3" rowspan="3">
-           <spacer name="horizontalSpacer_8">
-            <property name="orientation">
-             <enum>Qt::Horizontal</enum>
-            </property>
-            <property name="sizeHint" stdset="0">
-             <size>
-              <width>40</width>
-              <height>20</height>
-             </size>
+          <item row="2" column="2">
+           <widget class="QComboBox" name="MBComboBox">
+            <property name="toolTip">
+             <string>If the selected file size is exceeded, capturing switches to the next file.
+PLEASE NOTE: One option MUST be selected.</string>
             </property>
-           </spacer>
+            <item>
+             <property name="text">
+              <string>kilobytes</string>
+             </property>
+            </item>
+            <item>
+             <property name="text">
+              <string>megabytes</string>
+             </property>
+            </item>
+            <item>
+             <property name="text">
+              <string>gigabytes</string>
+             </property>
+            </item>
+           </widget>
           </item>
           <item row="1" column="0">
-           <widget class="QCheckBox" name="MBCheckBox">
+           <widget class="QCheckBox" name="PktCheckBox">
             <property name="text">
              <string/>
             </property>
            </widget>
           </item>
-          <item row="2" column="0">
-           <widget class="QCheckBox" name="SecsCheckBox">
+          <item row="1" column="1">
+           <widget class="QSpinBox" name="PktSpinBox">
+            <property name="toolTip">
+             <string>Switch to the next file after the specified number of packets have been captured.</string>
+            </property>
+            <property name="buttonSymbols">
+             <enum>QAbstractSpinBox::PlusMinus</enum>
+            </property>
+            <property name="maximum">
+             <number>2147483647</number>
+            </property>
+            <property name="value">
+             <number>100000</number>
+            </property>
+           </widget>
+          </item>
+          <item row="1" column="2">
+           <widget class="QLabel" name="PktLabel">
             <property name="text">
-             <string/>
+             <string>packets</string>
             </property>
            </widget>
           </item>