diff options
Diffstat (limited to 'test/vpp_pg_interface.py')
| -rw-r--r-- | test/vpp_pg_interface.py | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/test/vpp_pg_interface.py b/test/vpp_pg_interface.py index 81737c6d..d6e66849 100644 --- a/test/vpp_pg_interface.py +++ b/test/vpp_pg_interface.py @@ -1,6 +1,7 @@ import os import time import socket +import struct from traceback import format_exc, format_stack from scapy.utils import wrpcap, rdpcap, PcapReader from scapy.plist import PacketList @@ -283,6 +284,37 @@ class VppPGInterface(VppInterface): return False return True + def wait_for_packet_data(self, deadline): + """ + Wait until enough data is available in the file handled by internal + pcap reader so that a whole packet can be read. + + :param deadline: timestamp by which the data must arrive + :raises Exception: if not enough data by deadline + """ + orig_pos = self._pcap_reader.f.tell() # save file position + enough_data = False + while time.time() < deadline: + # read packet header from pcap + hdr = self._pcap_reader.f.read(16) + if len(hdr) < 16: + time.sleep(0) # yield + continue # cannot read full header, continue looping + # find the capture length - caplen + sec, usec, caplen, wirelen = struct.unpack( + self._pcap_reader.endian + "IIII", hdr) + self._pcap_reader.f.seek(0, 2) # seek to end of file + end_pos = self._pcap_reader.f.tell() # get position at end + if end_pos >= orig_pos + len(hdr) + caplen: + enough_data = True # yay, we have enough data + break + self.test.logger.debug("Partial packet data in pcap") + time.sleep(0) # yield + self._pcap_reader.f.seek(orig_pos, 0) # restore original position + if not enough_data: + raise Exception( + "Not enough data to read a full packet within deadline") + def wait_for_packet(self, timeout, filter_out_fn=is_ipv6_misc): """ Wait for next packet captured with a timeout @@ -311,6 +343,7 @@ class VppPGInterface(VppInterface): self.test.logger.debug("Waiting for packet") while time.time() < deadline: + self.wait_for_packet_data(deadline) p = self._pcap_reader.recv() if p is not None: if filter_out_fn is not None and filter_out_fn(p): |