ip: extension header parsing fails for fragment header
Refactor and improve boundary checking on IPv6 extension header handling.
Limit parsing of IPv6 extension headers to a maximum of 4 headers and a
depth of 256 bytes.
Type: fix
Signed-off-by: Ole Troan <ot@cisco.com>
Change-Id: Ide40aaa2b482ceef7e92f02fa0caeadb3b8f7556
Signed-off-by: Ole Troan <ot@cisco.com>
diff --git a/src/vnet/ip/reass/ip6_sv_reass.c b/src/vnet/ip/reass/ip6_sv_reass.c
index f18bbe0..fb435ba 100644
--- a/src/vnet/ip/reass/ip6_sv_reass.c
+++ b/src/vnet/ip/reass/ip6_sv_reass.c
@@ -26,6 +26,7 @@
#include <vnet/ip/ip6_to_ip4.h>
#include <vppinfra/bihash_48_8.h>
#include <vnet/ip/reass/ip6_sv_reass.h>
+#include <vnet/ip/ip6_inlines.h>
#define MSEC_PER_SEC 1000
#define IP6_SV_REASS_TIMEOUT_DEFAULT_MS 100
@@ -440,22 +441,18 @@
}
always_inline bool
-ip6_sv_reass_verify_upper_layer_present (vlib_node_runtime_t * node,
- vlib_buffer_t * b,
- ip6_frag_hdr_t * frag_hdr)
+ip6_sv_reass_verify_upper_layer_present (vlib_node_runtime_t *node,
+ vlib_buffer_t *b,
+ ip6_ext_hdr_chain_t *hc)
{
- ip6_ext_header_t *tmp = (ip6_ext_header_t *) frag_hdr;
- while (ip6_ext_hdr (tmp->next_hdr))
+ int nh = hc->eh[hc->length - 1].protocol;
+ /* Checking to see if it's a terminating header */
+ if (ip6_ext_hdr (nh))
{
- tmp = ip6_ext_next_header (tmp);
- }
- if (IP_PROTOCOL_IP6_NONXT == tmp->next_hdr)
- {
- icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
- ICMP6_parameter_problem_first_fragment_has_incomplete_header_chain,
- 0);
+ icmp6_error_set_vnet_buffer (
+ b, ICMP6_parameter_problem,
+ ICMP6_parameter_problem_first_fragment_has_incomplete_header_chain, 0);
b->error = node->errors[IP6_ERROR_REASS_MISSING_UPPER];
-
return false;
}
return true;
@@ -533,16 +530,13 @@
b0 = vlib_get_buffer (vm, bi0);
ip6_header_t *ip0 = vlib_buffer_get_current (b0);
- ip6_frag_hdr_t *frag_hdr = NULL;
- ip6_ext_header_t *prev_hdr;
- if (ip6_ext_hdr (ip0->protocol))
- {
- frag_hdr =
- ip6_ext_header_find (vm, b0, ip0,
- IP_PROTOCOL_IPV6_FRAGMENTATION,
- &prev_hdr);
- }
- if (!frag_hdr)
+ ip6_frag_hdr_t *frag_hdr;
+ ip6_ext_hdr_chain_t hdr_chain;
+
+ int res = ip6_ext_header_walk (
+ b0, ip0, IP_PROTOCOL_IPV6_FRAGMENTATION, &hdr_chain);
+ if (res < 0 ||
+ hdr_chain.eh[res].protocol != IP_PROTOCOL_IPV6_FRAGMENTATION)
{
// this is a regular packet - no fragmentation
if (!ip6_get_port
@@ -571,13 +565,15 @@
}
goto packet_enqueue;
}
+ frag_hdr =
+ ip6_ext_next_header_offset (ip0, hdr_chain.eh[res].offset);
vnet_buffer (b0)->ip.reass.ip6_frag_hdr_offset =
- (u8 *) frag_hdr - (u8 *) ip0;
+ hdr_chain.eh[res].offset;
if (0 == ip6_frag_hdr_offset (frag_hdr))
{
// first fragment - verify upper-layer is present
- if (!ip6_sv_reass_verify_upper_layer_present
- (node, b0, frag_hdr))
+ if (!ip6_sv_reass_verify_upper_layer_present (node, b0,
+ &hdr_chain))
{
next0 = IP6_SV_REASSEMBLY_NEXT_ICMP_ERROR;
goto packet_enqueue;