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authorNeale Ranns <neale@graphiant.com>2022-03-04 11:45:41 +0000
committerNeale Ranns <neale@graphiant.com>2022-03-07 09:02:01 +0000
commitec5371e3e31b7860d6b3996fd10420566a4377f2 (patch)
tree13c540d79e88d940e35e776b8c288d2642ce1ea5
parent7e721954d4ea31a26ad44872acc199c91b9595e6 (diff)
ip: Fixes for IPv6 and MPLS fragmentation
Type: fix - IPv6 fragmentation did not work if the packet spaneed multiple buffers, because the 'len' calculation to did max out at the size of a buffer - IPv6 fragmentation did not work when the l2unfragmentable size was non-zero, it was not used in the correct places - IPv6oMPLS fragmentation would fragment all IPv6, it should do so only for link local - IPv6oMPLS should send back TooBig ICMP6 for non locally generated Signed-off-by: Neale Ranns <neale@graphiant.com> Change-Id: Ie8f02cdfdd7b7e8474e62b6d0acda8f20c371184
-rw-r--r--src/vnet/ip/ip_frag.c23
-rw-r--r--src/vnet/mpls/mpls_output.c105
-rw-r--r--test/test_ip6.py7
-rw-r--r--test/test_ipip.py53
-rw-r--r--test/test_mpls.py56
5 files changed, 191 insertions, 53 deletions
diff --git a/src/vnet/ip/ip_frag.c b/src/vnet/ip/ip_frag.c
index b9bc90dcc11..9c223c3d0ae 100644
--- a/src/vnet/ip/ip_frag.c
+++ b/src/vnet/ip/ip_frag.c
@@ -25,10 +25,10 @@
typedef struct
{
- u8 ipv6;
u16 mtu;
u8 next;
u16 n_fragments;
+ u16 pkt_size;
} ip_frag_trace_t;
static u8 *
@@ -37,8 +37,8 @@ format_ip_frag_trace (u8 * s, va_list * args)
CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
ip_frag_trace_t *t = va_arg (*args, ip_frag_trace_t *);
- s = format (s, "IPv%s mtu: %u fragments: %u next: %d",
- t->ipv6 ? "6" : "4", t->mtu, t->n_fragments, t->next);
+ s = format (s, "mtu: %u pkt-size: %u fragments: %u next: %d", t->mtu,
+ t->pkt_size, t->n_fragments, t->next);
return s;
}
@@ -286,7 +286,7 @@ frag_node_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
ip_frag_trace_t *tr =
vlib_add_trace (vm, node, p0, sizeof (*tr));
tr->mtu = mtu;
- tr->ipv6 = is_ip6 ? 1 : 0;
+ tr->pkt_size = vlib_buffer_length_in_chain (vm, p0);
tr->n_fragments = vec_len (buffer);
tr->next = vnet_buffer (p0)->ip_frag.next_index;
}
@@ -385,13 +385,17 @@ ip6_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u16 mtu,
ip6_header_t *ip6;
u16 len, max, rem, ip_frag_id;
u8 *org_from_packet;
+ u16 head_bytes;
from_b = vlib_get_buffer (vm, from_bi);
org_from_packet = vlib_buffer_get_current (from_b);
ip6 = vlib_buffer_get_current (from_b) + l2unfragmentablesize;
+ head_bytes =
+ (sizeof (ip6_header_t) + sizeof (ip6_frag_hdr_t) + l2unfragmentablesize);
rem = clib_net_to_host_u16 (ip6->payload_length);
- max = (mtu - sizeof (ip6_header_t) - sizeof (ip6_frag_hdr_t)) & ~0x7; // TODO: Is max correct??
+ max = (clib_min (mtu, vlib_buffer_get_default_data_size (vm)) - head_bytes) &
+ ~0x7;
if (rem >
(vlib_buffer_length_in_chain (vm, from_b) - sizeof (ip6_header_t)))
@@ -423,9 +427,7 @@ ip6_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u16 mtu,
ip6_frag_hdr_t *to_frag_hdr;
u8 *to_data;
- len =
- (rem >
- (mtu - sizeof (ip6_header_t) - sizeof (ip6_frag_hdr_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)
@@ -438,7 +440,7 @@ ip6_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u16 mtu,
/* Copy ip6 header */
clib_memcpy_fast (to_b->data, org_from_packet,
l2unfragmentablesize + sizeof (ip6_header_t));
- to_ip6 = vlib_buffer_get_current (to_b);
+ to_ip6 = vlib_buffer_get_current (to_b) + l2unfragmentablesize;
to_frag_hdr = (ip6_frag_hdr_t *) (to_ip6 + 1);
to_data = (void *) (to_frag_hdr + 1);
@@ -484,8 +486,7 @@ ip6_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u16 mtu,
to_ptr += bytes_to_copy;
}
- to_b->current_length =
- len + sizeof (ip6_header_t) + sizeof (ip6_frag_hdr_t);
+ to_b->current_length = len + head_bytes;
to_ip6->payload_length =
clib_host_to_net_u16 (len + sizeof (ip6_frag_hdr_t));
to_ip6->protocol = IP_PROTOCOL_IPV6_FRAGMENTATION;
diff --git a/src/vnet/mpls/mpls_output.c b/src/vnet/mpls/mpls_output.c
index 3699163a155..faeba748e89 100644
--- a/src/vnet/mpls/mpls_output.c
+++ b/src/vnet/mpls/mpls_output.c
@@ -377,11 +377,12 @@ typedef struct mpls_frag_trace_t_
typedef enum
{
- MPLS_FRAG_NEXT_REWRITE,
- MPLS_FRAG_NEXT_REWRITE_MIDCHAIN,
- MPLS_FRAG_NEXT_ICMP_ERROR,
- MPLS_FRAG_NEXT_DROP,
- MPLS_FRAG_N_NEXT,
+ MPLS_FRAG_NEXT_REWRITE,
+ MPLS_FRAG_NEXT_REWRITE_MIDCHAIN,
+ MPLS_FRAG_NEXT_ICMP4_ERROR,
+ MPLS_FRAG_NEXT_ICMP6_ERROR,
+ MPLS_FRAG_NEXT_DROP,
+ MPLS_FRAG_N_NEXT,
} mpls_frag_next_t;
static uword
@@ -390,9 +391,7 @@ mpls_frag (vlib_main_t * vm,
vlib_frame_t * frame)
{
u32 n_left_from, next_index, * from, * to_next, n_left_to_next, *frags;
- vlib_node_runtime_t * error_node;
- error_node = vlib_node_get_runtime (vm, mpls_output_node.index);
from = vlib_frame_vector_args (frame);
n_left_from = frame->n_vectors;
next_index = node->cached_next_index;
@@ -410,8 +409,7 @@ mpls_frag (vlib_main_t * vm,
mpls_frag_next_t next0;
u32 pi0, adj_index0;
ip_frag_error_t error0 = IP_FRAG_ERROR_NONE;
- i16 encap_size;
- u16 mtu;
+ i16 encap_size, mtu;
u8 is_ip4;
pi0 = to_next[0] = from[0];
@@ -422,6 +420,7 @@ mpls_frag (vlib_main_t * vm,
adj_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_TX];
adj0 = adj_get (adj_index0);
+
/* the size of the MPLS stack */
encap_size = vnet_buffer (p0)->l3_hdr_offset - p0->current_data;
mtu = adj0->rewrite_header.max_l3_packet_bytes - encap_size;
@@ -430,7 +429,18 @@ mpls_frag (vlib_main_t * vm,
if (is_ip4)
error0 = ip4_frag_do_fragment (vm, pi0, mtu, encap_size, &frags);
else
- error0 = ip6_frag_do_fragment (vm, pi0, mtu, encap_size, &frags);
+ {
+ if (!(p0->flags & VNET_BUFFER_F_LOCALLY_ORIGINATED))
+ {
+ /* only fragment locally generated IPv6 */
+ error0 = IP_FRAG_ERROR_DONT_FRAGMENT_SET;
+ }
+ else
+ {
+ error0 =
+ ip6_frag_do_fragment (vm, pi0, mtu, encap_size, &frags);
+ }
+ }
if (PREDICT_FALSE (p0->flags & VLIB_BUFFER_IS_TRACED))
{
@@ -443,24 +453,41 @@ mpls_frag (vlib_main_t * vm,
if (PREDICT_TRUE (error0 == IP_FRAG_ERROR_NONE))
{
/* Free original buffer chain */
- vlib_buffer_free_one (vm, pi0); /* Free original packet */
+ vlib_buffer_free_one (vm, pi0);
next0 = (IP_LOOKUP_NEXT_MIDCHAIN == adj0->lookup_next_index ?
MPLS_FRAG_NEXT_REWRITE_MIDCHAIN :
MPLS_FRAG_NEXT_REWRITE);
}
- else if (is_ip4 && error0 == IP_FRAG_ERROR_DONT_FRAGMENT_SET)
- {
- icmp4_error_set_vnet_buffer (
- p0, ICMP4_destination_unreachable,
- ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
- vnet_buffer (p0)->ip_frag.mtu);
- next0 = MPLS_FRAG_NEXT_ICMP_ERROR;
- }
else
{
- vlib_error_count (vm, mpls_output_node.index, error0, 1);
- vec_add1 (frags, pi0); /* Get rid of the original buffer */
- next0 = MPLS_FRAG_NEXT_DROP;
+ vlib_error_count (vm, node->node_index, error0, 1);
+
+ if (error0 == IP_FRAG_ERROR_DONT_FRAGMENT_SET)
+ {
+ vlib_buffer_advance (p0, encap_size);
+ if (is_ip4)
+ {
+ icmp4_error_set_vnet_buffer (
+ p0, ICMP4_destination_unreachable,
+ ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
+ vnet_buffer (p0)->ip_frag.mtu);
+ next0 = MPLS_FRAG_NEXT_ICMP4_ERROR;
+ }
+ else
+ {
+ icmp6_error_set_vnet_buffer (
+ p0, ICMP6_packet_too_big, 0,
+ adj0->rewrite_header.max_l3_packet_bytes);
+ next0 = MPLS_FRAG_NEXT_ICMP6_ERROR;
+ }
+ }
+ else
+ {
+ next0 = MPLS_FRAG_NEXT_DROP;
+ }
+
+ /* Get rid of the original buffer */
+ vec_add1 (frags, pi0);
}
/* Send fragments that were added in the frame */
@@ -480,9 +507,6 @@ mpls_frag (vlib_main_t * vm,
to_next += 1;
n_left_to_next -= 1;
- p0 = vlib_get_buffer (vm, i);
- p0->error = error_node->errors[error0];
-
vlib_validate_buffer_enqueue_x1 (
vm, node, next_index, to_next, n_left_to_next, i, next0);
}
@@ -511,22 +535,21 @@ format_mpls_frag_trace (u8 * s, va_list * args)
}
VLIB_REGISTER_NODE (mpls_frag_node) = {
- .function = mpls_frag,
- .name = "mpls-frag",
- .vector_size = sizeof (u32),
- .format_trace = format_mpls_frag_trace,
- .type = VLIB_NODE_TYPE_INTERNAL,
-
- .n_errors = IP_FRAG_N_ERROR,
- .error_strings = mpls_frag_error_strings,
-
- .n_next_nodes = MPLS_FRAG_N_NEXT,
- .next_nodes = {
- [MPLS_FRAG_NEXT_REWRITE] = "mpls-output",
- [MPLS_FRAG_NEXT_REWRITE_MIDCHAIN] = "mpls-midchain",
- [MPLS_FRAG_NEXT_ICMP_ERROR] = "ip4-icmp-error",
- [MPLS_FRAG_NEXT_DROP] = "mpls-drop"
- },
+ .function = mpls_frag,
+ .name = "mpls-frag",
+ .vector_size = sizeof (u32),
+ .format_trace = format_mpls_frag_trace,
+ .type = VLIB_NODE_TYPE_INTERNAL,
+
+ .n_errors = IP_FRAG_N_ERROR,
+ .error_strings = mpls_frag_error_strings,
+
+ .n_next_nodes = MPLS_FRAG_N_NEXT,
+ .next_nodes = { [MPLS_FRAG_NEXT_REWRITE] = "mpls-output",
+ [MPLS_FRAG_NEXT_REWRITE_MIDCHAIN] = "mpls-midchain",
+ [MPLS_FRAG_NEXT_ICMP4_ERROR] = "ip4-icmp-error",
+ [MPLS_FRAG_NEXT_ICMP6_ERROR] = "ip6-icmp-error",
+ [MPLS_FRAG_NEXT_DROP] = "mpls-drop" },
};
/*
diff --git a/test/test_ip6.py b/test/test_ip6.py
index bac50a3df98..2e972db5dd3 100644
--- a/test/test_ip6.py
+++ b/test/test_ip6.py
@@ -3170,6 +3170,12 @@ class TestIPv6PathMTU(VppTestCase):
self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index,
[2800, 0, 0, 0])
+ p_6k = (Ether(dst=self.pg0.local_mac,
+ src=self.pg0.remote_mac) /
+ IPv6(src=self.pg0.remote_ip6,
+ dst=tun.remote_ip6) /
+ UDP(sport=1234, dport=5678) /
+ Raw(b'0xa' * 2000))
p_2k = (Ether(dst=self.pg0.local_mac,
src=self.pg0.remote_mac) /
IPv6(src=self.pg0.remote_ip6,
@@ -3189,6 +3195,7 @@ class TestIPv6PathMTU(VppTestCase):
self.pg1.remote_ip6).add_vpp_config()
# this is now the interface MTU frags
+ self.send_and_expect(self.pg0, [p_6k], self.pg1, n_rx=4)
self.send_and_expect(self.pg0, [p_2k], self.pg1, n_rx=2)
self.send_and_expect(self.pg0, [p_1k], self.pg1)
diff --git a/test/test_ipip.py b/test/test_ipip.py
index 83395e0bd72..8e16c80f05f 100644
--- a/test/test_ipip.py
+++ b/test/test_ipip.py
@@ -1150,6 +1150,59 @@ class TestIPIP6(VppTestCase):
p6_reply.id = 256
self.validate(reass_pkt, p6_reply)
+ def test_ip6_mpls_frag(self):
+ """ Test fragmenting IPv6 over MPLS """
+
+ # IPv6 packets must be locally generated to be fragmented
+ # the use of tunnel encaps
+ tun_dst = VppIpRoute(
+ self, "1000::1", 128,
+ [VppRoutePath(self.pg1.remote_ip6,
+ self.pg1.sw_if_index,
+ labels=[VppMplsLabel(32)])]).add_vpp_config()
+
+ tun = VppIpIpTunInterface(
+ self,
+ self.pg0,
+ self.pg0.local_ip6,
+ "1000::1").add_vpp_config()
+
+ tun.admin_up()
+ tun.config_ip6()
+ tun.config_ip4()
+
+ self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index,
+ [2000, 0, 0, 0])
+
+ p_6k = (Ether(dst=self.pg0.local_mac,
+ src=self.pg0.remote_mac) /
+ IPv6(src=self.pg0.remote_ip6,
+ dst=tun.remote_ip6) /
+ UDP(sport=1234, dport=5678) /
+ Raw(b'0xa' * 2000))
+ p_2k = (Ether(dst=self.pg0.local_mac,
+ src=self.pg0.remote_mac) /
+ IPv6(src=self.pg0.remote_ip6,
+ dst=tun.remote_ip6) /
+ UDP(sport=1234, dport=5678) /
+ Raw(b'0xa' * 1000))
+ p_1k = (Ether(dst=self.pg0.local_mac,
+ src=self.pg0.remote_mac) /
+ IPv6(src=self.pg0.remote_ip6,
+ dst=tun.remote_ip6) /
+ UDP(sport=1234, dport=5678) /
+ Raw(b'0xa' * 600))
+
+ # this is now the interface MTU frags
+ rxs = self.send_and_expect(self.pg0, [p_6k], self.pg1, n_rx=4)
+ self.assertEqual(rxs[0][UDP].dport, 5678)
+ for rx in rxs:
+ self.assertEqual(rx[MPLS].label, 32)
+ self.assertEqual(rx[IPv6].dst, "1000::1")
+ self.assertEqual(rx[IPv6].dst, "1000::1")
+ self.send_and_expect(self.pg0, [p_2k], self.pg1, n_rx=2)
+ self.send_and_expect(self.pg0, [p_1k], self.pg1)
+
def test_ipip_create(self):
""" ipip create / delete interface test """
rv = ipip_add_tunnel(self, '1.2.3.4', '2.3.4.5')
diff --git a/test/test_mpls.py b/test/test_mpls.py
index 4cc7a0759f2..d94676b67da 100644
--- a/test/test_mpls.py
+++ b/test/test_mpls.py
@@ -18,7 +18,8 @@ import scapy.compat
from scapy.packet import Raw
from scapy.layers.l2 import Ether, ARP
from scapy.layers.inet import IP, UDP, ICMP
-from scapy.layers.inet6 import IPv6, ICMPv6TimeExceeded, ICMPv6EchoRequest
+from scapy.layers.inet6 import IPv6, ICMPv6TimeExceeded, ICMPv6EchoRequest, \
+ ICMPv6PacketTooBig
from scapy.contrib.mpls import MPLS
NUM_PKTS = 67
@@ -425,6 +426,31 @@ class TestMPLS(VppTestCase):
except:
raise
+ def verify_capture_fragmented_labelled_ip6(self, src_if, capture, sent,
+ mpls_labels, ip_ttl=None):
+ try:
+ capture = verify_filter(capture, sent)
+
+ for i in range(len(capture)):
+ tx = sent[0]
+ rx = capture[i]
+ tx_ip = tx[IPv6]
+ rx.show()
+ rx_ip = IPv6(rx[MPLS].payload)
+ rx_ip.show()
+
+ verify_mpls_stack(self, rx, mpls_labels)
+
+ self.assertEqual(rx_ip.src, tx_ip.src)
+ self.assertEqual(rx_ip.dst, tx_ip.dst)
+ if not ip_ttl:
+ # IP processing post pop has decremented the hop-limit
+ self.assertEqual(rx_ip.hlim + 1, tx_ip.hlim)
+ else:
+ self.assertEqual(rx_ip.hlim, ip_ttl)
+ except:
+ raise
+
def test_swap(self):
""" MPLS label swap tests """
@@ -908,6 +934,11 @@ class TestMPLS(VppTestCase):
self.pg0.sw_if_index,
labels=[VppMplsLabel(32)])])
route_10_0_0_1.add_vpp_config()
+ route_1000_1 = VppIpRoute(self, "1000::1", 128,
+ [VppRoutePath(self.pg0.remote_ip6,
+ self.pg0.sw_if_index,
+ labels=[VppMplsLabel(32)])])
+ route_1000_1.add_vpp_config()
#
# a stream that matches the route for 10.0.0.1
@@ -924,6 +955,29 @@ class TestMPLS(VppTestCase):
self.verify_capture_fragmented_labelled_ip4(self.pg0, rx, tx,
[VppMplsLabel(32)])
+ # packets with DF bit set generate ICMP
+ for t in tx:
+ t[IP].flags = 'DF'
+ rxs = self.send_and_expect_some(self.pg0, tx, self.pg0)
+
+ for rx in rxs:
+ rx[ICMP].code = "fragmentation-needed"
+
+ self.assertEqual(self.statistics.get_err_counter(
+ "/err/mpls-frag/can't fragment this packet"),
+ len(tx))
+ #
+ # a stream that matches the route for 1000::1/128
+ # PG0 is in the default table
+ #
+ tx = self.create_stream_ip6(self.pg0, "1000::1")
+ for i in range(0, 257):
+ self.extend_packet(tx[i], 10000)
+
+ rxs = self.send_and_expect_some(self.pg0, tx, self.pg0)
+ for rx in rxs:
+ rx[ICMPv6PacketTooBig].mtu = 9000
+
#
# cleanup
#