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MTU: IP fragmentation added to ip4-rewrite and ip6-rewrite

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Change-Id: Ibae260273f25a319153be37470aed49ff73e957a
Signed-off-by: Ole Troan <ot@cisco.com>
This commit is contained in:
Ole Troan
2018-04-10 16:02:51 +02:00
committed by Florin Coras
parent aa2f59bbd3
commit 313f7e2fea
4 changed files with 59 additions and 19 deletions
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12
src/vnet/ip/ip4_forward.c
View File

@ -39,6 +39,7 @@
#include <vnet/vnet.h>
#include <vnet/ip/ip.h>
#include <vnet/ip/ip_frag.h>
#include <vnet/ethernet/ethernet.h> /* for ethernet_header_t */
#include <vnet/ethernet/arp_packet.h> /* for ethernet_arp_header_t */
#include <vnet/ppp/ppp.h>
@ -2013,6 +2014,8 @@ typedef enum
{
IP4_REWRITE_NEXT_DROP,
IP4_REWRITE_NEXT_ICMP_ERROR,
IP4_REWRITE_NEXT_FRAGMENT,
IP4_REWRITE_N_NEXT /* Last */
} ip4_rewrite_next_t;
/**
@ -2042,8 +2045,10 @@ ip4_mtu_check (vlib_buffer_t * b, u16 packet_len,
}
else
{
/* Add support for fragmentation here */
*next = IP4_REWRITE_NEXT_DROP;
/* IP fragmentation */
ip_frag_set_vnet_buffer (b, 0, adj_packet_bytes,
IP4_FRAG_NEXT_IP4_LOOKUP, 0);
*next = IP4_REWRITE_NEXT_FRAGMENT;
}
}
}
@ -2539,10 +2544,11 @@ VLIB_REGISTER_NODE (ip4_rewrite_node) = {
.format_trace = format_ip4_rewrite_trace,
.n_next_nodes = 2,
.n_next_nodes = IP4_REWRITE_N_NEXT,
.next_nodes = {
[IP4_REWRITE_NEXT_DROP] = "ip4-drop",
[IP4_REWRITE_NEXT_ICMP_ERROR] = "ip4-icmp-error",
[IP4_REWRITE_NEXT_FRAGMENT] = "ip4-frag",
},
};
VLIB_NODE_FUNCTION_MULTIARCH (ip4_rewrite_node, ip4_rewrite)

47
src/vnet/ip/ip6_forward.c
View File

@ -39,6 +39,7 @@
#include <vnet/vnet.h>
#include <vnet/ip/ip.h>
#include <vnet/ip/ip_frag.h>
#include <vnet/ip/ip6_neighbor.h>
#include <vnet/ethernet/ethernet.h> /* for ethernet_header_t */
#include <vnet/srp/srp.h> /* for srp_hw_interface_class */
@ -1542,6 +1543,8 @@ typedef enum
{
IP6_REWRITE_NEXT_DROP,
IP6_REWRITE_NEXT_ICMP_ERROR,
IP6_REWRITE_NEXT_FRAGMENT,
IP6_REWRITE_N_NEXT /* Last */
} ip6_rewrite_next_t;
/**
@ -1552,14 +1555,25 @@ typedef enum
always_inline void
ip6_mtu_check (vlib_buffer_t * b, u16 packet_bytes,
u16 adj_packet_bytes, u32 * next, u32 * error)
u16 adj_packet_bytes, bool is_locally_generated,
u32 * next, u32 * error)
{
if (adj_packet_bytes >= 1280 && packet_bytes > adj_packet_bytes)
{
*error = IP6_ERROR_MTU_EXCEEDED;
icmp6_error_set_vnet_buffer (b, ICMP6_packet_too_big, 0,
adj_packet_bytes);
*next = IP6_REWRITE_NEXT_ICMP_ERROR;
if (is_locally_generated)
{
/* IP fragmentation */
ip_frag_set_vnet_buffer (b, 0, adj_packet_bytes,
IP6_FRAG_NEXT_IP6_LOOKUP, 0);
*next = IP6_REWRITE_NEXT_FRAGMENT;
}
else
{
*error = IP6_ERROR_MTU_EXCEEDED;
icmp6_error_set_vnet_buffer (b, ICMP6_packet_too_big, 0,
adj_packet_bytes);
*next = IP6_REWRITE_NEXT_ICMP_ERROR;
}
}
}
@ -1591,6 +1605,7 @@ ip6_rewrite_inline (vlib_main_t * vm,
u32 pi0, rw_len0, next0, error0, adj_index0;
u32 pi1, rw_len1, next1, error1, adj_index1;
u32 tx_sw_if_index0, tx_sw_if_index1;
bool is_locally_originated0, is_locally_originated1;
/* Prefetch next iteration. */
{
@ -1629,7 +1644,9 @@ ip6_rewrite_inline (vlib_main_t * vm,
error0 = error1 = IP6_ERROR_NONE;
next0 = next1 = IP6_REWRITE_NEXT_DROP;
if (PREDICT_TRUE (!(p0->flags & VNET_BUFFER_F_LOCALLY_ORIGINATED)))
is_locally_originated0 =
p0->flags & VNET_BUFFER_F_LOCALLY_ORIGINATED;
if (PREDICT_TRUE (!is_locally_originated0))
{
i32 hop_limit0 = ip0->hop_limit;
@ -1658,7 +1675,9 @@ ip6_rewrite_inline (vlib_main_t * vm,
{
p0->flags &= ~VNET_BUFFER_F_LOCALLY_ORIGINATED;
}
if (PREDICT_TRUE (!(p1->flags & VNET_BUFFER_F_LOCALLY_ORIGINATED)))
is_locally_originated1 =
p1->flags & VNET_BUFFER_F_LOCALLY_ORIGINATED;
if (PREDICT_TRUE (!is_locally_originated1))
{
i32 hop_limit1 = ip1->hop_limit;
@ -1711,11 +1730,11 @@ ip6_rewrite_inline (vlib_main_t * vm,
ip6_mtu_check (p0, clib_net_to_host_u16 (ip0->payload_length) +
sizeof (ip6_header_t),
adj0[0].rewrite_header.max_l3_packet_bytes,
&next0, &error0);
is_locally_originated0, &next0, &error0);
ip6_mtu_check (p1, clib_net_to_host_u16 (ip1->payload_length) +
sizeof (ip6_header_t),
adj1[0].rewrite_header.max_l3_packet_bytes,
&next1, &error1);
is_locally_originated1, &next1, &error1);
/* Don't adjust the buffer for hop count issue; icmp-error node
* wants to see the IP headerr */
@ -1789,6 +1808,7 @@ ip6_rewrite_inline (vlib_main_t * vm,
u32 pi0, rw_len0;
u32 adj_index0, next0, error0;
u32 tx_sw_if_index0;
bool is_locally_originated0;
pi0 = to_next[0] = from[0];
@ -1804,7 +1824,9 @@ ip6_rewrite_inline (vlib_main_t * vm,
next0 = IP6_REWRITE_NEXT_DROP;
/* Check hop limit */
if (PREDICT_TRUE (!(p0->flags & VNET_BUFFER_F_LOCALLY_ORIGINATED)))
is_locally_originated0 =
p0->flags & VNET_BUFFER_F_LOCALLY_ORIGINATED;
if (PREDICT_TRUE (!is_locally_originated0))
{
i32 hop_limit0 = ip0->hop_limit;
@ -1852,7 +1874,7 @@ ip6_rewrite_inline (vlib_main_t * vm,
ip6_mtu_check (p0, clib_net_to_host_u16 (ip0->payload_length) +
sizeof (ip6_header_t),
adj0[0].rewrite_header.max_l3_packet_bytes,
&next0, &error0);
is_locally_originated0, &next0, &error0);
/* Don't adjust the buffer for hop count issue; icmp-error node
* wants to see the IP header */
@ -1968,11 +1990,12 @@ VLIB_REGISTER_NODE (ip6_rewrite_node) =
.name = "ip6-rewrite",
.vector_size = sizeof (u32),
.format_trace = format_ip6_rewrite_trace,
.n_next_nodes = 2,
.n_next_nodes = IP6_REWRITE_N_NEXT,
.next_nodes =
{
[IP6_REWRITE_NEXT_DROP] = "ip6-drop",
[IP6_REWRITE_NEXT_ICMP_ERROR] = "ip6-icmp-error",
[IP6_REWRITE_NEXT_FRAGMENT] = "ip6-frag",
},
};
/* *INDENT-ON* */

12
src/vnet/ip/ip_frag.c
View File

@ -85,6 +85,12 @@ ip4_frag_do_fragment (vlib_main_t * vm, u32 pi, u32 ** buffer,
return;
}
if (p->flags & VLIB_BUFFER_NEXT_PRESENT)
{
*error = IP_FRAG_ERROR_MALFORMED;
return;
}
if (ip4_is_fragment (ip4))
{
ip_frag_id = ip4->fragment_id;
@ -342,6 +348,12 @@ ip6_frag_do_fragment (vlib_main_t * vm, u32 pi, u32 ** buffer,
return;
}
if (p->flags & VLIB_BUFFER_NEXT_PRESENT)
{
*error = IP_FRAG_ERROR_MALFORMED;
return;
}
u8 has_more;
u16 initial_offset;
if (*next_header == IP_PROTOCOL_IPV6_FRAGMENTATION)

7
test/test_mtu.py
View File

@ -119,7 +119,6 @@ class TestMTU(VppTestCase):
# n.show2()
self.validate_bytes(str(p[1]), icmp4_reply)
'''
# Now with DF off. Expect fragments.
# First go with 1500 byte packets.
p_payload = UDP(sport=1234, dport=1234) / self.payload(
@ -127,19 +126,18 @@ class TestMTU(VppTestCase):
p4 = p_ether / p_ip4 / p_payload
p4.flags = 0
p4_reply = p_ip4 / p_payload
p4_reply.ttl = 62 # check this
p4_reply.ttl = 62 # check this
p4_reply.flags = 0
p4_reply.id = 256
self.pg_enable_capture()
self.pg0.add_stream(p4*1)
self.pg_start()
rx = self.pg1.get_capture(3)
print('RX', len(rx))
reass_pkt = reassemble(rx)
self.validate(reass_pkt, p4_reply)
'''
# Now what happens with a 9K frame
'''
p_payload = UDP(sport=1234, dport=1234) / self.payload(
current_mtu - 20 - 8)
p4 = p_ether / p_ip4 / p_payload
@ -158,6 +156,7 @@ class TestMTU(VppTestCase):
p4_reply.show2()
self.validate(reass_pkt, p4_reply)
'''
# Reset MTU
self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index,
[current_mtu, 0, 0, 0])