From d21d855464ff05d65ce160264eac1e52eb319574 Mon Sep 17 00:00:00 2001
From: Olivier Matz <olivier.matz@6wind.com>
Date: Mon, 3 Oct 2016 10:38:51 +0200
Subject: [PATCH] net: support GRE in software packet type parser

Add support of Gre tunnels in rte_net_get_ptype().

Signed-off-by: Jean Dao <jean.dao@6wind.com>
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
---
 lib/librte_net/rte_net.c | 40 ++++++++++++++++++++++++++++++++++++----
 lib/librte_net/rte_net.h |  2 +-
 2 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/lib/librte_net/rte_net.c b/lib/librte_net/rte_net.c
index 87294bba9a..66db2c833c 100644
--- a/lib/librte_net/rte_net.c
+++ b/lib/librte_net/rte_net.c
@@ -41,6 +41,7 @@
 #include <rte_tcp.h>
 #include <rte_udp.h>
 #include <rte_sctp.h>
+#include <rte_gre.h>
 #include <rte_net.h>
 
 /* get l3 packet type from ip6 next protocol */
@@ -150,11 +151,40 @@ ptype_inner_l4(uint8_t proto)
 	return ptype_inner_l4_proto[proto];
 }
 
-/* get the tunnel packet type if any, update proto. */
+/* get the tunnel packet type if any, update proto and off. */
 static uint32_t
-ptype_tunnel(uint16_t *proto)
+ptype_tunnel(uint16_t *proto, const struct rte_mbuf *m,
+	uint32_t *off)
 {
 	switch (*proto) {
+	case IPPROTO_GRE: {
+		static const uint8_t opt_len[16] = {
+			[0x0] = 4,
+			[0x1] = 8,
+			[0x2] = 8,
+			[0x8] = 8,
+			[0x3] = 12,
+			[0x9] = 12,
+			[0xa] = 12,
+			[0xb] = 16,
+		};
+		const struct gre_hdr *gh;
+		struct gre_hdr gh_copy;
+		uint16_t flags;
+
+		gh = rte_pktmbuf_read(m, *off, sizeof(*gh), &gh_copy);
+		if (unlikely(gh == NULL))
+			return 0;
+
+		flags = rte_be_to_cpu_16(*(const uint16_t *)gh);
+		flags >>= 12;
+		if (opt_len[flags] == 0)
+			return 0;
+
+		*off += opt_len[flags];
+		*proto = gh->proto;
+		return RTE_PTYPE_TUNNEL_GRE;
+	}
 	case IPPROTO_IPIP:
 		*proto = rte_cpu_to_be_16(ETHER_TYPE_IPv4);
 		return RTE_PTYPE_TUNNEL_IP;
@@ -332,9 +362,11 @@ uint32_t rte_net_get_ptype(const struct rte_mbuf *m,
 		hdr_lens->l4_len = sizeof(struct sctp_hdr);
 		return pkt_type;
 	} else {
+		uint32_t prev_off = off;
+
 		hdr_lens->l4_len = 0;
-		pkt_type |= ptype_tunnel(&proto);
-		hdr_lens->tunnel_len = 0;
+		pkt_type |= ptype_tunnel(&proto, m, &off);
+		hdr_lens->tunnel_len = off - prev_off;
 	}
 
 	/* same job for inner header: we need to duplicate the code
diff --git a/lib/librte_net/rte_net.h b/lib/librte_net/rte_net.h
index f43338926f..4a72b1b2d4 100644
--- a/lib/librte_net/rte_net.h
+++ b/lib/librte_net/rte_net.h
@@ -68,7 +68,7 @@ struct rte_net_hdr_lens {
  *   L2: Ether, Vlan, QinQ
  *   L3: IPv4, IPv6
  *   L4: TCP, UDP, SCTP
- *   Tunnels: IPv4, IPv6
+ *   Tunnels: IPv4, IPv6, Gre
  *
  * @param m
  *   The packet mbuf to be parsed.
-- 
2.20.1