gso: do not gro on small packets
This has two benefits: fix an issue where small packets can be
padded to 64 bytes by the ethernet layer, and we included these bytes
in the tcp stream; and also if we receive a small packet, it signals
that this tcp stream is likely more latency-sensitive than throughput-
sensitive, and skipping gro buffering should be beneficial.
Type: fix
Change-Id: I165b97673d8cdce95ebf0a66c362ae9f9e6f3f34
Signed-off-by: Aloys Augustin <aloaugus@cisco.com>
diff --git a/test/test_gro.py b/test/test_gro.py
index 33215d6..6c68299 100644
--- a/test/test_gro.py
+++ b/test/test_gro.py
@@ -138,5 +138,107 @@
self.assertEqual(rx[TCP].sport, 1234)
self.assertEqual(rx[TCP].dport, 4321)
+ #
+ # Same test with IPv6
+ #
+ p = []
+ s = 0
+ for n in range(0, 88):
+ p.append((Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
+ IPv6(src=self.pg0.remote_ip6, dst=self.pg2.remote_ip6) /
+ TCP(sport=1234, dport=4321, seq=s, ack=n, flags='A') /
+ Raw(b'\xa5' * 1460)))
+ s += 1460
+ p[-1][TCP].flags = 'AP' # push to flush second packet
+
+ rxs = self.send_and_expect(self.pg0, p, self.pg2, n_rx=2)
+
+ i = 0
+ for rx in rxs:
+ i += 1
+ self.assertEqual(rx[Ether].src, self.pg2.local_mac)
+ self.assertEqual(rx[Ether].dst, self.pg2.remote_mac)
+ self.assertEqual(rx[IPv6].src, self.pg0.remote_ip6)
+ self.assertEqual(rx[IPv6].dst, self.pg2.remote_ip6)
+ self.assertEqual(rx[IPv6].plen, 64260) # 1460 * 44 + 20 < 65536
+ self.assertEqual(rx[TCP].sport, 1234)
+ self.assertEqual(rx[TCP].dport, 4321)
+ self.assertEqual(rx[TCP].ack, (44*i - 1))
+
+ #
+ # Send a series of 1500 bytes packets each followed by a packet with a
+ # PSH flag. Verify that GRO stops everytime a PSH flag is encountered
+ #
+ p = []
+ s = 0
+ for n in range(0, n_packets):
+ p.append((Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
+ IP(src=self.pg0.remote_ip4, dst=self.pg2.remote_ip4,
+ flags='DF') /
+ TCP(sport=1234, dport=4321, seq=s, ack=2*n, flags='A') /
+ Raw(b'\xa5' * 1460)))
+ s += 1460
+ p.append((Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
+ IP(src=self.pg0.remote_ip4, dst=self.pg2.remote_ip4,
+ flags='DF') /
+ TCP(sport=1234, dport=4321, seq=s, ack=2*n+1,
+ flags='AP') /
+ Raw(b'\xa5' * 1340)))
+ s += 1340
+
+ rxs = self.send_and_expect(self.pg0, p, self.pg2, n_rx=n_packets)
+
+ i = 0
+ for rx in rxs:
+ self.assertEqual(rx[Ether].src, self.pg2.local_mac)
+ self.assertEqual(rx[Ether].dst, self.pg2.remote_mac)
+ self.assertEqual(rx[IP].src, self.pg0.remote_ip4)
+ self.assertEqual(rx[IP].dst, self.pg2.remote_ip4)
+ self.assertEqual(rx[IP].len, 40 + 1460 + 1340)
+ self.assertEqual(rx[TCP].sport, 1234)
+ self.assertEqual(rx[TCP].dport, 4321)
+ self.assertEqual(rx[TCP].ack, (2*i + 1))
+ i += 1
+
+ #
+ # Send a series of 1500 bytes packets each followed by a short packet
+ # with padding. Verify that GRO removes the padding and stops on short
+ # packets
+ #
+ p = []
+ s = 0
+ for n in range(0, n_packets):
+ i = self.pg0
+ p.append((Ether(src=i.remote_mac, dst=i.local_mac) /
+ IP(src=i.remote_ip4, dst=self.pg2.remote_ip4,
+ flags='DF') /
+ TCP(sport=1234, dport=4321, seq=s, ack=2*n, flags='A') /
+ Raw(b'\xa5' * 1459)))
+ s += 1459
+ p2 = (Ether(src=i.remote_mac, dst=i.local_mac) /
+ IP(src=i.remote_ip4, dst=self.pg2.remote_ip4,
+ flags='DF', len=41) /
+ TCP(sport=1234, dport=4321, seq=s, ack=2*n+1, flags='A') /
+ Raw(b'\xa5'))
+ # first compute csum of pkt w/o padding to work around scapy bug
+ p2 = Ether(bytes(p2))
+ p.append(p2 / Raw(b'\xa5' * 5)) # 1 byte data + 5 bytes padding
+ s += 1
+
+ rxs = self.send_and_expect(self.pg0, p, self.pg2, n_rx=n_packets)
+
+ i = 0
+ for rx in rxs:
+ self.assertEqual(rx[Ether].src, self.pg2.local_mac)
+ self.assertEqual(rx[Ether].dst, self.pg2.remote_mac)
+ self.assertEqual(rx[IP].src, self.pg0.remote_ip4)
+ self.assertEqual(rx[IP].dst, self.pg2.remote_ip4)
+ self.assertEqual(rx[IP].len, 40 + 1459 + 1)
+ self.assertEqual(rx[TCP].sport, 1234)
+ self.assertEqual(rx[TCP].dport, 4321)
+ self.assertEqual(rx[TCP].ack, (2*i + 1))
+ i += 1
+
+
if __name__ == '__main__':
unittest.main(testRunner=VppTestRunner)