diff options
| -rw-r--r-- | src/vnet/ip/ip_frag.c | 5 | ||||
| -rw-r--r-- | test/test_ip4.py | 50 |
2 files changed, 53 insertions, 2 deletions
diff --git a/src/vnet/ip/ip_frag.c b/src/vnet/ip/ip_frag.c index 628d9d66474..8de4dfc5d58 100644 --- a/src/vnet/ip/ip_frag.c +++ b/src/vnet/ip/ip_frag.c @@ -101,7 +101,8 @@ ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u32 ** buffer, ip4 = (ip4_header_t *) vlib_buffer_get_current (from_b); rem = clib_net_to_host_u16 (ip4->length) - sizeof (ip4_header_t); - max = (mtu - sizeof (ip4_header_t)) & ~0x7; + max = + (clib_min (mtu, VLIB_BUFFER_DATA_SIZE) - sizeof (ip4_header_t)) & ~0x7; if (rem > (vlib_buffer_length_in_chain (vm, from_b) - sizeof (ip4_header_t))) @@ -152,7 +153,7 @@ ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u32 ** buffer, ip4_header_t *to_ip4; u8 *to_data; - len = (rem > (mtu - sizeof (ip4_header_t)) ? max : rem); + len = (rem > max ? max : rem); if (len != rem) /* Last fragment does not need to divisible by 8 */ len &= ~0x7; if ((to_b = frag_buffer_alloc (org_from_b, &to_bi)) == 0) diff --git a/test/test_ip4.py b/test/test_ip4.py index e9ec71a2830..ca461f1d276 100644 --- a/test/test_ip4.py +++ b/test/test_ip4.py @@ -1554,5 +1554,55 @@ class TestIPLPM(VppTestCase): rx = self.send_and_expect(self.pg0, p_24 * 65, self.pg1) +class TestIPv4Frag(VppTestCase): + """ IPv4 fragmentation """ + + @classmethod + def setUpClass(cls): + super(TestIPv4Frag, cls).setUpClass() + + cls.create_pg_interfaces([0, 1]) + cls.src_if = cls.pg0 + cls.dst_if = cls.pg1 + + # setup all interfaces + for i in cls.pg_interfaces: + i.admin_up() + i.config_ip4() + i.resolve_arp() + + def test_frag_large_packets(self): + """ Fragmentation of large packets """ + + p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) / + IP(src=self.src_if.remote_ip4, dst=self.dst_if.remote_ip4) / + UDP(sport=1234, dport=5678) / Raw()) + self.extend_packet(p, 6000, "abcde") + saved_payload = p[Raw].load + + # Force fragmentation by setting MTU of output interface + # lower than packet size + self.vapi.sw_interface_set_mtu(self.dst_if.sw_if_index, + [5000, 0, 0, 0]) + + self.pg_enable_capture() + self.src_if.add_stream(p) + self.pg_start() + + # Expecting 3 fragments because size of created fragments currently + # cannot be larger then VPP buffer size (which is 2048) + packets = self.dst_if.get_capture(3) + + # Assume VPP sends the fragments in order + payload = '' + for p in packets: + payload_offset = p.frag * 8 + if payload_offset > 0: + payload_offset -= 8 # UDP header is not in payload + self.assert_equal(payload_offset, len(payload)) + payload += p[Raw].load + self.assert_equal(payload, saved_payload, "payload") + + if __name__ == '__main__': unittest.main(testRunner=VppTestRunner) |