Captures written in the captures directory on the controller

gns3server/controller/link.py

@@ -15,19 +15,24 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import os
 import re
 import uuid
 import asyncio
 
 
+import logging
+log = logging.getLogger(__name__)
+
+
 class Link:
 
-    def __init__(self, project, data_link_type="DLT_EN10MB"):
+    def __init__(self, project):
         self._id = str(uuid.uuid4())
         self._vms = []
         self._project = project
-        self._data_link_type = data_link_type
         self._capturing = False
+        self._capture_file_name = None
 
     @asyncio.coroutine
     def addVM(self, vm, adapter_number, port_number):
@@ -55,29 +60,50 @@ class Link:
         raise NotImplementedError
 
     @asyncio.coroutine
-    def start_capture(self):
+    def start_capture(self, data_link_type="DLT_EN10MB", capture_file_name=None):
         """
         Start capture on the link
 
         :returns: Capture object
         """
-        raise NotImplementedError
+        self._capturing = True
+        self._capture_file_name = capture_file_name
+        self._streaming_pcap = asyncio.async(self._start_streaming_pcap())
+
+    @asyncio.coroutine
+    def _start_streaming_pcap(self):
+        """
+        Dump the pcap file on disk
+        """
+        stream = yield from self.read_pcap_from_source()
+        with open(self.capture_file_path, "wb+") as f:
+            while self._capturing:
+                # We read 1 bytes by 1 otherwise if the traffic stop the remaining data is not read
+                # this is slow
+                data = yield from stream.read(1)
+                if data:
+                    f.write(data)
+                    # Flush to disk otherwise the live is not really live
+                    f.flush()
+                else:
+                    break
+            yield from stream.close()
 
     @asyncio.coroutine
     def stop_capture(self):
         """
         Stop capture on the link
         """
-        raise NotImplementedError
+        self._capturing = False
 
     @asyncio.coroutine
-    def read_pcap(self):
+    def read_pcap_from_source(self):
         """
         Return a FileStream of the Pcap from the compute node
         """
         raise NotImplementedError
 
-    def capture_file_name(self):
+    def default_capture_file_name(self):
         """
         :returns: File name for a capture on this link
         """
@@ -98,6 +124,16 @@ class Link:
     def capturing(self):
         return self._capturing
 
+    @property
+    def capture_file_path(self):
+        """
+        Get the path of the capture
+        """
+        if self._capture_file_name:
+            return os.path.join(self._project.captures_directory, self._capture_file_name)
+        else:
+            return None
+
     def __json__(self):
         res = []
         for side in self._vms:
@@ -106,4 +142,8 @@ class Link:
                 "adapter_number": side["adapter_number"],
                 "port_number": side["port_number"]
             })
-        return {"vms": res, "link_id": self._id, "capturing": self._capturing}
+        return {
+            "vms": res, "link_id": self._id,
+            "capturing": self._capturing,
+            "capture_file_name": self._capture_file_name
+        }

gns3server/controller/udp_link.py

@@ -80,17 +80,19 @@ class UDPLink(Link):
         yield from vm2.delete("/adapters/{adapter_number}/ports/{port_number}/nio".format(adapter_number=adapter_number2, port_number=port_number2))
 
     @asyncio.coroutine
-    def start_capture(self, data_link_type="DLT_EN10MB"):
+    def start_capture(self, data_link_type="DLT_EN10MB", capture_file_name=None):
         """
         Start capture on a link
         """
+        if not capture_file_name:
+            capture_file_name = self.default_capture_file_name()
         self._capture_vm = self._choose_capture_side()
         data = {
-            "capture_file_name": self.capture_file_name(),
+            "capture_file_name": capture_file_name,
             "data_link_type": data_link_type
         }
         yield from self._capture_vm["vm"].post("/adapters/{adapter_number}/ports/{port_number}/start_capture".format(adapter_number=self._capture_vm["adapter_number"], port_number=self._capture_vm["port_number"]), data=data)
-        self._capturing = True
+        yield from super().start_capture(data_link_type=data_link_type, capture_file_name=capture_file_name)
 
     @asyncio.coroutine
     def stop_capture(self):
@@ -100,7 +102,7 @@ class UDPLink(Link):
         if self._capture_vm:
             yield from self._capture_vm["vm"].post("/adapters/{adapter_number}/ports/{port_number}/stop_capture".format(adapter_number=self._capture_vm["adapter_number"], port_number=self._capture_vm["port_number"]))
             self._capture_vm = None
-            self._capturing = False
+        yield from super().stop_capture()
 
     def _choose_capture_side(self):
         """
@@ -124,10 +126,10 @@ class UDPLink(Link):
         raise aiohttp.web.HTTPConflict(text="Capture is not supported for this link")
 
     @asyncio.coroutine
-    def read_pcap(self):
+    def read_pcap_from_source(self):
         """
         Return a FileStream of the Pcap from the compute node
         """
         if self._capture_vm:
             compute = self._capture_vm["vm"].compute
-            return compute.streamFile(self._project, "tmp/captures/" + self.capture_file_name())
+            return compute.streamFile(self._project, "tmp/captures/" + self._capture_file_name)

gns3server/handlers/api/controller/link_handler.py

@@ -73,7 +73,7 @@ class LinkHandler:
         controller = Controller.instance()
         project = controller.getProject(request.match_info["project_id"])
         link = project.getLink(request.match_info["link_id"])
-        yield from link.start_capture(request.json.get("data_link_type", "DLT_EN10MB"))
+        yield from link.start_capture(data_link_type=request.json.get("data_link_type", "DLT_EN10MB"), capture_file_name=request.json.get("capture_file_name"))
         response.set_status(204)
 
     @classmethod
@@ -136,20 +136,24 @@ class LinkHandler:
         project = controller.getProject(request.match_info["project_id"])
         link = project.getLink(request.match_info["link_id"])
 
-        content = yield from link.read_pcap()
-        if content is None:
+        if link.capture_file_path is None:
             raise aiohttp.web.HTTPNotFound(text="pcap file not found")
 
-        response.content_type = "application/vnd.tcpdump.pcap"
-        response.set_status(200)
-        response.enable_chunked_encoding()
-        # Very important: do not send a content length otherwise QT close the connection but curl can consume the Feed
-        response.content_length = None
+        try:
+            print(link.capture_file_path)
+            with open(link.capture_file_path, "rb") as f:
 
-        response.start(request)
+                response.content_type = "application/vnd.tcpdump.pcap"
+                response.set_status(200)
+                response.enable_chunked_encoding()
+                # Very important: do not send a content length otherwise QT close the connection but curl can consume the Feed
+                response.content_length = None
+                response.start(request)
 
-        while True:
-            chunk = yield from content.read(4096)
-            if not chunk:
-                yield from asyncio.sleep(0.1)
-            yield from response.write(chunk)
+                while True:
+                    chunk = f.read(4096)
+                    if not chunk:
+                        break
+                    yield from response.write(chunk)
+        except OSError:
+            raise aiohttp.web.HTTPNotFound(text="pcap file {} not found or not accessible".format(link.capture_file_path))

gns3server/schemas/link.py

@@ -55,9 +55,13 @@ LINK_OBJECT_SCHEMA = {
             }
         },
         "capturing": {
-            "description": "Read only propertie. Is a capture running on the link",
+            "description": "Read only propertie. True if a capture running on the link",
             "type": "boolean"
         },
+        "capture_file_name": {
+            "description": "Read only propertie. The name of the capture file if capture is running",
+            "type": ["string", "null"]
+        }
     },
     "required": ["vms"],
     "additionalProperties": False
@@ -72,6 +76,10 @@ LINK_CAPTURE_SCHEMA = {
         "data_link_type": {
             "description": "PCAP data link type (http://www.tcpdump.org/linktypes.html)",
             "enum": ["DLT_ATM_RFC1483", "DLT_EN10MB", "DLT_FRELAY", "DLT_C_HDLC"]
+        },
+        "capture_file_name": {
+            "description": "Read only propertie. The name of the capture file if capture is running",
+            "type": "string"
         }
     },
     "additionalProperties": False