[dpdk-dev] [PATCH] gro: add missing invalid packet checks

[Jiayu Hu]

Currently, GRO library doesn't check if input packets have
invalid headers. The packets with invalid headers will also
be processed by GRO.

However, GRO shouldn't process invalid packets. This patch adds
missing invalid packet checks.

Fixes: 0d2cbe59b719 ("lib/gro: support TCP/IPv4")
Fixes: 9e0b9d2ec0f4 ("gro: support VxLAN GRO")
Cc: stable at dpdk.org

Signed-off-by: Jiayu Hu <jiayu.hu at intel.com>
---
 lib/librte_gro/gro_tcp4.c       | 10 ++++++++++
 lib/librte_gro/gro_tcp4.h       |  4 ++++
 lib/librte_gro/gro_vxlan_tcp4.c | 13 +++++++++++++
 3 files changed, 27 insertions(+)

diff --git a/lib/librte_gro/gro_tcp4.c b/lib/librte_gro/gro_tcp4.c
index 2fe9aab..0dc0de6 100644
--- a/lib/librte_gro/gro_tcp4.c
+++ b/lib/librte_gro/gro_tcp4.c
@@ -208,6 +208,16 @@ gro_tcp4_reassemble(struct rte_mbuf *pkt,
 	int cmp;
 	uint8_t find;
 
+	/*
+	 * Don't process the packet whose Ethernet, IPv4 and TCP header
+	 * lengths are invalid. In addition, if the IPv4 header contains
+	 * Options, the packet shouldn't be processed.
+	 */
+	if (unlikely(ILLEGAL_ETHER_HDRLEN(pkt->l2_len) ||
+			ILLEGAL_IPV4_HDRLEN(pkt->l3_len) ||
+			ILLEGAL_TCP_HDRLEN(pkt->l4_len)))
+		return -1;
+
 	eth_hdr = rte_pktmbuf_mtod(pkt, struct ether_hdr *);
 	ipv4_hdr = (struct ipv4_hdr *)((char *)eth_hdr + pkt->l2_len);
 	tcp_hdr = (struct tcp_hdr *)((char *)ipv4_hdr + pkt->l3_len);
diff --git a/lib/librte_gro/gro_tcp4.h b/lib/librte_gro/gro_tcp4.h
index 6bb30cd..cab84fd 100644
--- a/lib/librte_gro/gro_tcp4.h
+++ b/lib/librte_gro/gro_tcp4.h
@@ -17,6 +17,10 @@
  */
 #define MAX_IPV4_PKT_LENGTH UINT16_MAX
 
+#define ILLEGAL_ETHER_HDRLEN(len) ((len) < ETHER_HDR_LEN)
+#define ILLEGAL_IPV4_HDRLEN(len) ((len) != 20)
+#define ILLEGAL_TCP_HDRLEN(len) ((len) < 20 || (len) > 60)
+
 /* Header fields representing a TCP/IPv4 flow */
 struct tcp4_flow_key {
 	struct ether_addr eth_saddr;
diff --git a/lib/librte_gro/gro_vxlan_tcp4.c b/lib/librte_gro/gro_vxlan_tcp4.c
index 955ae4b..c499c86 100644
--- a/lib/librte_gro/gro_vxlan_tcp4.c
+++ b/lib/librte_gro/gro_vxlan_tcp4.c
@@ -306,6 +306,19 @@ gro_vxlan_tcp4_reassemble(struct rte_mbuf *pkt,
 	uint16_t hdr_len;
 	uint8_t find;
 
+	/*
+	 * Don't process the packet whose outer Ethernet, outer IPv4,
+	 * inner Ethernet, inner IPv4 and inner TCP header lengths
+	 * are invalid. In addition, if the outer or inner IPv4 header
+	 * contains Options, the packet shouldn't be processed.
+	 */
+	if (unlikely(ILLEGAL_ETHER_HDRLEN(pkt->outer_l2_len) ||
+				ILLEGAL_IPV4_HDRLEN(pkt->outer_l3_len) ||
+				ILLEGAL_ETHER_HDRLEN(pkt->l2_len) ||
+				ILLEGAL_IPV4_HDRLEN(pkt->l3_len) ||
+				ILLEGAL_TCP_HDRLEN(pkt->l4_len)))
+		return -1;
+
 	outer_eth_hdr = rte_pktmbuf_mtod(pkt, struct ether_hdr *);
 	outer_ipv4_hdr = (struct ipv4_hdr *)((char *)outer_eth_hdr +
 			pkt->outer_l2_len);
-- 
2.7.4