Right now reassembly code relies on src_dst[] being all zeroes to
determine is it free/occupied entry in the fragments table.
This is suboptimal and error prone - user can crash DPDK ip_reassembly
app by something like the following scapy script:
x=Ether(src=...,dst=...)/IP(dst='0.0.0.0',src='0.0.0.0',id=0)/('X'*1000)
frags=fragment(x, fragsize=500)
sendp(frags, iface=...)
To overcome that issue and reduce overhead of
'key invalidate' and 'key is empty' operations -
add key_len into keys comparision procedure.
Fixes: 4f1a8f633862 ("ip_frag: add IPv6 reassembly")
Cc: sta...@dpdk.org
Reported-by: Ryan E Hall <ryan.e.h...@intel.com>
Reported-by: Alexander V Gutkin <alexander.v.gut...@intel.com>
Signed-off-by: Konstantin Ananyev <konstantin.anan...@intel.com>
---
lib/librte_ip_frag/ip_frag_common.h | 14 ++++----------
lib/librte_ip_frag/rte_ip_frag.h | 14 +++++++++++---
2 files changed, 15 insertions(+), 13 deletions(-)
diff --git a/lib/librte_ip_frag/ip_frag_common.h
b/lib/librte_ip_frag/ip_frag_common.h
index 0f62e2e16..a17a74076 100644
--- a/lib/librte_ip_frag/ip_frag_common.h
+++ b/lib/librte_ip_frag/ip_frag_common.h
@@ -58,20 +58,14 @@ struct rte_mbuf *ipv6_frag_reassemble(struct ip_frag_pkt
*fp);
static inline int
ip_frag_key_is_empty(const struct ip_frag_key * key)
{
- uint32_t i;
- for (i = 0; i < RTE_MIN(key->key_len, RTE_DIM(key->src_dst)); i++)
- if (key->src_dst[i] != 0)
- return 0;
- return 1;
+ return (key->key_len == 0);
}
-/* empty the key */
+/* invalidate the key */
static inline void
ip_frag_key_invalidate(struct ip_frag_key * key)
{
- uint32_t i;
- for (i = 0; i < key->key_len; i++)
- key->src_dst[i] = 0;
+ key->key_len = 0;
}
/* compare two keys */
@@ -80,7 +74,7 @@ ip_frag_key_cmp(const struct ip_frag_key * k1, const struct
ip_frag_key * k2)
{
uint32_t i;
uint64_t val;
- val = k1->id ^ k2->id;
+ val = k1->id_key_len ^ k2->id_key_len;
for (i = 0; i < k1->key_len; i++)
val |= k1->src_dst[i] ^ k2->src_dst[i];
return val;
diff --git a/lib/librte_ip_frag/rte_ip_frag.h b/lib/librte_ip_frag/rte_ip_frag.h
index 7f425f610..a4ccaf9d1 100644
--- a/lib/librte_ip_frag/rte_ip_frag.h
+++ b/lib/librte_ip_frag/rte_ip_frag.h
@@ -44,9 +44,17 @@ struct ip_frag {
/** @internal <src addr, dst_addr, id> to uniquely identify fragmented
datagram. */
struct ip_frag_key {
- uint64_t src_dst[4]; /**< src address, first 8 bytes used for IPv4
*/
- uint32_t id; /**< dst address */
- uint32_t key_len; /**< src/dst key length */
+ uint64_t src_dst[4];
+ /**< src and dst address, only first 8 bytes used for IPv4 */
+ RTE_STD_C11
+ union {
+ uint64_t id_key_len; /**< combined for easy fetch */
+ __extension__
+ struct {
+ uint32_t id; /**< packet id */
+ uint32_t key_len; /**< src/dst key length */
+ };
+ };
};
/**
--
2.17.1
