[dpdk-dev] [PATCH v2] gro: add missing invalid packet checks

[Jiayu Hu <jiayu.hu@intel.com>]

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@dpdk.org

Signed-off-by: Jiayu Hu <jiayu.hu@intel.com>
---
changes in v2:
- fix VxLAN header length check bug for VxLAN GRO;
- fix ethernet header length check bug;
- use sizeof() and macro to present valid header length;
- add VLAN related comments since GRO cannot process VLAN tagged packets.

 lib/librte_gro/gro_tcp4.c       | 12 ++++++++++++
 lib/librte_gro/gro_tcp4.h       | 10 ++++++++++
 lib/librte_gro/gro_vxlan_tcp4.c | 15 +++++++++++++++
 3 files changed, 37 insertions(+)

diff --git a/lib/librte_gro/gro_tcp4.c b/lib/librte_gro/gro_tcp4.c
index 2fe9aab..48076e0 100644
--- a/lib/librte_gro/gro_tcp4.c
+++ b/lib/librte_gro/gro_tcp4.c
@@ -208,6 +208,18 @@ 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, GRO doesn't process the packet that is VLAN
+	 * tagged or whose the IPv4 header contains Options.
+	 */
+	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..65bcae8 100644
--- a/lib/librte_gro/gro_tcp4.h
+++ b/lib/librte_gro/gro_tcp4.h
@@ -17,6 +17,16 @@
  */
 #define MAX_IPV4_PKT_LENGTH UINT16_MAX
 
+/* The maximum TCP header length */
+#define TCP_MAX_HLEN 60
+
+#define ILLEGAL_ETHER_HDRLEN(len) ((len) != ETHER_HDR_LEN)
+#define ILLEGAL_ETHER_VXLAN_HDRLEN(len) \
+	((len) != (ETHER_VXLAN_HLEN + ETHER_HDR_LEN))
+#define ILLEGAL_IPV4_HDRLEN(len) ((len) != sizeof(struct ipv4_hdr))
+#define ILLEGAL_TCP_HDRLEN(len) \
+	(((len) < sizeof(struct tcp_hdr)) || ((len) > TCP_MAX_HLEN))
+
 /* 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..72d63bc 100644
--- a/lib/librte_gro/gro_vxlan_tcp4.c
+++ b/lib/librte_gro/gro_vxlan_tcp4.c
@@ -306,6 +306,21 @@ 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,
+	 * VxLAN header, inner Ethernet, inner IPv4 and inner TCP
+	 * header lengths are invalid.
+	 *
+	 * In addition, GRO doesn't process the packet that is VLAN
+	 * tagged or whose IPv4 header contains Options.
+	 */
+	if (unlikely(ILLEGAL_ETHER_HDRLEN(pkt->outer_l2_len) ||
+				ILLEGAL_IPV4_HDRLEN(pkt->outer_l3_len) ||
+				ILLEGAL_ETHER_VXLAN_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