From 7eb9d9608b5b47b95f4860b2c470411658f7cdac Mon Sep 17 00:00:00 2001 From: Ole Troan Date: Fri, 10 Aug 2018 14:39:48 +0200 Subject: [PATCH] IP fragmentation buffer chains, part 2. Change-Id: I8d1072cf9ff9f502302fd906c5590e0f3698dc60 Signed-off-by: Ole Troan --- src/vnet/ip/ip_frag.c | 40 ++++++++++++++++--------------- test/test_ipip.py | 66 +++++++++++++++++++++++++++++++++++++++++---------- 2 files changed, 75 insertions(+), 31 deletions(-) diff --git a/src/vnet/ip/ip_frag.c b/src/vnet/ip/ip_frag.c index 667a92bbfa5..630948723cd 100644 --- a/src/vnet/ip/ip_frag.c +++ b/src/vnet/ip/ip_frag.c @@ -128,7 +128,6 @@ ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u32 ** buffer, if (!vlib_buffer_alloc (vm, &to_bi, 1)) { *error = IP_FRAG_ERROR_MEMORY; - /* XXX: Free already allocated buffers? */ return; } vec_add1 (*buffer, to_bi); @@ -152,12 +151,22 @@ ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u32 ** buffer, to_ip4 = vlib_buffer_get_current (to_b) + offset; to_data = (void *) (to_ip4 + 1); - /* Spin through buffer chain copying data */ - // XXX: Make sure we don't overflow source buffer!!! - if (len > left_in_from_buffer) + /* Spin through from buffers filling up the to buffer */ + u16 to_ptr = 0; + u16 bytes_to_copy, left_in_to_buffer = len; + while (1) { - clib_memcpy (to_data, from_data + ptr, left_in_from_buffer); - + /* Figure out how many bytes we can safely copy */ + bytes_to_copy = left_in_to_buffer <= left_in_from_buffer ? + left_in_to_buffer : left_in_from_buffer; + clib_memcpy (to_data + to_ptr, from_data + ptr, bytes_to_copy); + left_in_to_buffer -= bytes_to_copy; + ptr += bytes_to_copy; + left_in_from_buffer -= bytes_to_copy; + if (left_in_to_buffer == 0) + break; + + ASSERT (left_in_from_buffer == 0); /* Move buffer */ if (!(from_b->flags & VLIB_BUFFER_NEXT_PRESENT)) { @@ -166,18 +175,11 @@ ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u32 ** buffer, } from_b = vlib_get_buffer (vm, from_b->next_buffer); from_data = (u8 *) vlib_buffer_get_current (from_b); - clib_memcpy (to_data + left_in_from_buffer, from_data, - len - left_in_from_buffer); - ptr = len - left_in_from_buffer; - left_in_from_buffer = - from_b->current_length - (len - left_in_from_buffer); - } - else - { - clib_memcpy (to_data, from_data + ptr, len); - left_in_from_buffer -= len; - ptr += len; + ptr = 0; + left_in_from_buffer = from_b->current_length; + to_ptr += bytes_to_copy; } + to_b->current_length = offset + len + sizeof (ip4_header_t); to_ip4->fragment_id = ip_frag_id; @@ -209,8 +211,6 @@ ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u32 ** buffer, rem -= len; fo += len; } - /* Free original packet chain */ - vlib_buffer_free_one (vm, from_bi); } void @@ -287,6 +287,8 @@ ip4_frag (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) if (error0 == IP_FRAG_ERROR_NONE) { + /* Free original buffer chain */ + vlib_buffer_free_one (vm, pi0); frag_sent += vec_len (buffer); small_packets += (vec_len (buffer) == 1); } diff --git a/test/test_ipip.py b/test/test_ipip.py index 582ab5be84c..8d99f83e6c2 100644 --- a/test/test_ipip.py +++ b/test/test_ipip.py @@ -3,7 +3,7 @@ import unittest from scapy.layers.inet6 import IPv6, Ether, IP, UDP -from scapy.all import fragment +from scapy.all import fragment, RandShort from framework import VppTestCase, VppTestRunner from vpp_ip_route import VppIpRoute, VppRoutePath, DpoProto from socket import AF_INET, AF_INET6, inet_pton @@ -60,6 +60,18 @@ class TestIPIP(VppTestCase): def validate(self, rx, expected): self.assertEqual(rx, expected.__class__(str(expected))) + def generate_frags(self, payload_length, fragment_size): + p_ether = Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) + p_payload = UDP(sport=1234, dport=1234) / self.payload(payload_length) + p_ip4 = IP(src="1.2.3.4", dst=self.pg0.remote_ip4) + outer_ip4 = (p_ether / IP(src=self.pg1.remote_ip4, + id=RandShort(), + dst=self.pg0.local_ip4) / p_ip4 / p_payload) + frags = fragment(outer_ip4, fragment_size) + p4_reply = (p_ip4 / p_payload) + p4_reply.ttl -= 1 + return frags, p4_reply + def test_ipip4(self): """ ip{v4,v6} over ip4 test """ p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) @@ -142,29 +154,48 @@ class TestIPIP(VppTestCase): for p in rx: self.validate(p[1], p6_reply) + # # Fragmentation / Reassembly and Re-fragmentation + # rv = self.vapi.ip_reassembly_enable_disable( sw_if_index=self.pg1.sw_if_index, enable_ip4=1) - # Decapsulation - p_ether = Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) - p_payload = UDP(sport=1234, dport=1234) / self.payload(3123) - p_ip4 = IP(src="1.2.3.4", dst=self.pg0.remote_ip4) - outer_ip4 = (p_ether / IP(src=self.pg1.remote_ip4, - dst=self.pg0.local_ip4) / p_ip4 / p_payload) - frags = fragment(outer_ip4, 1400) - p4_reply = (p_ip4 / p_payload) - p4_reply.ttl -= 1 + # Send lots of fragments, verify reassembled packet + frags, p4_reply = self.generate_frags(3131, 1400) + f = [] + for i in range(0, 1000): + f.extend(frags) + self.pg1.add_stream(f) self.pg_enable_capture() - self.pg1.add_stream(frags) self.pg_start() - rx = self.pg0.get_capture(1) + rx = self.pg0.get_capture(1000) + for p in rx: self.validate(p[1], p4_reply) + f = [] + r = [] + for i in range(1, 90): + frags, p4_reply = self.generate_frags(i * 100, 1000) + f.extend(frags) + r.extend(p4_reply) + self.pg_enable_capture() + self.pg1.add_stream(f) + self.pg_start() + rx = self.pg0.get_capture(89) + i = 0 + for p in rx: + self.validate(p[1], r[i]) + i += 1 + # Now try with re-fragmentation + # + # Send fragments to tunnel head-end, for the tunnel head end + # to reassemble and then refragment + # self.vapi.sw_interface_set_mtu(self.pg0.sw_if_index, [576, 0, 0, 0]) + frags, p4_reply = self.generate_frags(3123, 1200) self.pg_enable_capture() self.pg1.add_stream(frags) self.pg_start() @@ -174,6 +205,17 @@ class TestIPIP(VppTestCase): p4_reply.id = 256 self.validate(reass_pkt, p4_reply) + self.vapi.sw_interface_set_mtu(self.pg0.sw_if_index, [1600, 0, 0, 0]) + frags, p4_reply = self.generate_frags(3123, 1200) + self.pg_enable_capture() + self.pg1.add_stream(frags) + self.pg_start() + rx = self.pg0.get_capture(2) + reass_pkt = reassemble(rx) + p4_reply.ttl -= 1 + p4_reply.id = 512 + self.validate(reass_pkt, p4_reply) + def test_ipip6(self): """ ip{v4,v6} over ip6 test """ p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) -- 2.16.6