net: ipv4: Add IPv4 options length to net pkt

IPv4 header options length will be stored in ipv4_opts_len
in net_pkt structure. Now IPv4 header length will be in
net_pkt ip_hdr_len + ipv4_opts_len. So modified relevant
places of ip header length calculation for IPv4.

Signed-off-by: Ravi kumar Veeramally <ravikumar.veeramally@linux.intel.com>

include/net/net_pkt.h

@@ -188,6 +188,15 @@ struct net_pkt {
 		u8_t ipv4_ttl;
 	};
 
+	union {
+#if defined(CONFIG_NET_IPV4)
+		u8_t ipv4_opts_len; /* Length if IPv4 Header Options */
+#endif
+#if defined(CONFIG_NET_IPV6)
+		u16_t ipv6_ext_len; /* length of extension headers */
+#endif
+	};
+
 #if NET_TC_COUNT > 1
 	/** Network packet priority, can be left out in which case packet
 	 * is not prioritised.
@@ -205,8 +214,6 @@ struct net_pkt {
 #endif /* CONFIG_NET_VLAN */
 
 #if defined(CONFIG_NET_IPV6)
-	u16_t ipv6_ext_len;	/* length of extension headers */
-
 	/* Where is the start of the last header before payload data
 	 * in IPv6 packet. This is offset value from start of the IPv6
 	 * packet. Note that this value should be updated by who ever
@@ -387,6 +394,17 @@ static inline void net_pkt_set_ipv4_ttl(struct net_pkt *pkt,
 {
 	pkt->ipv4_ttl = ttl;
 }
+
+static inline u8_t net_pkt_ipv4_opts_len(struct net_pkt *pkt)
+{
+	return pkt->ipv4_opts_len;
+}
+
+static inline void net_pkt_set_ipv4_opts_len(struct net_pkt *pkt,
+					     u8_t opts_len)
+{
+	pkt->ipv4_opts_len = opts_len;
+}
 #else
 static inline u8_t net_pkt_ipv4_ttl(struct net_pkt *pkt)
 {
@@ -401,6 +419,19 @@ static inline void net_pkt_set_ipv4_ttl(struct net_pkt *pkt,
 	ARG_UNUSED(pkt);
 	ARG_UNUSED(ttl);
 }
+
+static inline u8_t net_pkt_ipv4_opts_len(struct net_pkt *pkt)
+{
+	ARG_UNUSED(pkt);
+	return 0;
+}
+
+static inline void net_pkt_set_ipv4_opts_len(struct net_pkt *pkt,
+					     u8_t opts_len)
+{
+	ARG_UNUSED(pkt);
+	ARG_UNUSED(opts_len);
+}
 #endif
 
 #if defined(CONFIG_NET_IPV6)
@@ -526,6 +557,19 @@ static inline void net_pkt_set_ipv6_hop_limit(struct net_pkt *pkt,
 }
 #endif /* CONFIG_NET_IPV6 */
 
+static inline u16_t net_pkt_ip_opts_len(struct net_pkt *pkt)
+{
+#if defined(CONFIG_NET_IPV6)
+	return pkt->ipv6_ext_len;
+#elif defined(CONFIG_NET_IPV4)
+	return pkt->ipv4_opts_len;
+#else
+	ARG_UNUSED(pkt);
+
+	return 0;
+#endif
+}
+
 #if defined(CONFIG_NET_IPV6_FRAGMENT)
 static inline u16_t net_pkt_ipv6_fragment_start(struct net_pkt *pkt)
 {

subsys/net/ip/ipv4.c

@@ -79,6 +79,12 @@ int net_ipv4_finalize(struct net_pkt *pkt, u8_t next_header_proto)
 		return -ENOBUFS;
 	}
 
+	if (net_pkt_ipv4_opts_len(pkt)) {
+		ipv4_hdr->vhl = 0x40 | (0x0F &
+				 ((net_pkt_ip_hdr_len(pkt) +
+				   net_pkt_ipv4_opts_len(pkt)) / 4U));
+	}
+
 	ipv4_hdr->len   = htons(net_pkt_get_len(pkt));
 	ipv4_hdr->proto = next_header_proto;
 
@@ -112,6 +118,7 @@ enum net_verdict net_ipv4_input(struct net_pkt *pkt)
 	struct net_ipv4_hdr *hdr;
 	union net_ip_header ip;
 	u8_t hdr_len;
+	u8_t opts_len;
 	int pkt_len;
 
 	net_stats_update_ipv4_recv(net_pkt_iface(pkt));
@@ -140,7 +147,10 @@ enum net_verdict net_ipv4_input(struct net_pkt *pkt)
 		goto drop;
 	}
 
-	net_pkt_set_ip_hdr_len(pkt, hdr_len);
+	net_pkt_set_ip_hdr_len(pkt, sizeof(struct net_ipv4_hdr));
+
+	opts_len = hdr_len - sizeof(struct net_ipv4_hdr);
+	net_pkt_set_ipv4_opts_len(pkt, opts_len);
 
 	pkt_len = ntohs(hdr->len);
 	if (real_len < pkt_len) {
@@ -188,9 +198,9 @@ enum net_verdict net_ipv4_input(struct net_pkt *pkt)
 
 	net_pkt_acknowledge_data(pkt, &ipv4_access);
 
-	if (hdr_len > sizeof(struct net_ipv4_hdr)) {
+	if (opts_len) {
-		/* There are probably options, let's skip them */
+		/* Only few options are handled in EchoRequest, rest skipped */
-		if (net_pkt_skip(pkt, hdr_len - sizeof(struct net_ipv4_hdr))) {
+		if (net_pkt_skip(pkt, opts_len)) {
 			NET_DBG("Header too big? %u", hdr_len);
 			goto drop;
 		}

subsys/net/ip/net_pkt.c

@@ -1704,6 +1704,8 @@ static void clone_pkt_attributes(struct net_pkt *pkt, struct net_pkt *clone_pkt)
 
 	if (IS_ENABLED(CONFIG_NET_IPV4) && net_pkt_family(pkt) == AF_INET) {
 		net_pkt_set_ipv4_ttl(clone_pkt, net_pkt_ipv4_ttl(pkt));
+		net_pkt_set_ipv4_opts_len(clone_pkt,
+					  net_pkt_ipv4_opts_len(pkt));
 	} else if (IS_ENABLED(CONFIG_NET_IPV6) &&
 		   net_pkt_family(pkt) == AF_INET6) {
 		net_pkt_set_ipv6_hop_limit(clone_pkt,

subsys/net/ip/tcp.c

@@ -873,7 +873,7 @@ int net_tcp_send_pkt(struct net_pkt *pkt)
 	net_pkt_set_overwrite(pkt, true);
 
 	if (net_pkt_skip(pkt, net_pkt_ip_hdr_len(pkt) +
-			 net_pkt_ipv6_ext_len(pkt))) {
+			 net_pkt_ip_opts_len(pkt))) {
 		return -EMSGSIZE;
 	}
 
@@ -908,7 +908,7 @@ int net_tcp_send_pkt(struct net_pkt *pkt)
 	if (calc_chksum) {
 		net_pkt_cursor_init(pkt);
 		net_pkt_skip(pkt, net_pkt_ip_hdr_len(pkt) +
-			     net_pkt_ipv6_ext_len(pkt));
+			     net_pkt_ip_opts_len(pkt));
 
 		/* No need to get tcp_hdr again */
 		tcp_hdr->chksum = net_calc_chksum_tcp(pkt);
@@ -1076,7 +1076,7 @@ bool net_tcp_ack_received(struct net_context *ctx, u32_t ack)
 		net_pkt_set_overwrite(pkt, true);
 
 		if (net_pkt_skip(pkt, net_pkt_ip_hdr_len(pkt) +
-			 net_pkt_ipv6_ext_len(pkt))) {
+				 net_pkt_ip_opts_len(pkt))) {
 			sys_slist_remove(list, NULL, head);
 			net_pkt_unref(pkt);
 			continue;

subsys/net/ip/udp.c

@@ -39,16 +39,16 @@ int net_udp_finalize(struct net_pkt *pkt)
 {
 	NET_PKT_DATA_ACCESS_DEFINE(udp_access, struct net_udp_hdr);
 	struct net_udp_hdr *udp_hdr;
-	u16_t length;
+	u16_t length = 0;
 
 	udp_hdr = (struct net_udp_hdr *)net_pkt_get_data(pkt, &udp_access);
 	if (!udp_hdr) {
 		return -ENOBUFS;
 	}
 
-	length = net_pkt_get_len(pkt) -
+	length = net_pkt_get_len(pkt) - net_pkt_ip_hdr_len(pkt) -
-		net_pkt_ip_hdr_len(pkt) -
+		 net_pkt_ip_opts_len(pkt);
-		net_pkt_ipv6_ext_len(pkt);
+
 	udp_hdr->len = htons(length);
 
 	if (net_if_need_calc_tx_checksum(net_pkt_iface(pkt))) {
@@ -75,7 +75,7 @@ struct net_udp_hdr *net_udp_get_hdr(struct net_pkt *pkt,
 	net_pkt_cursor_init(pkt);
 
 	if (net_pkt_skip(pkt, net_pkt_ip_hdr_len(pkt) +
-			 net_pkt_ipv6_ext_len(pkt))) {
+			 net_pkt_ip_opts_len(pkt))) {
 		udp_hdr = NULL;
 		goto out;
 	}
@@ -104,7 +104,7 @@ struct net_udp_hdr *net_udp_set_hdr(struct net_pkt *pkt,
 	net_pkt_cursor_init(pkt);
 
 	if (net_pkt_skip(pkt, net_pkt_ip_hdr_len(pkt) +
-			 net_pkt_ipv6_ext_len(pkt))) {
+			 net_pkt_ip_opts_len(pkt))) {
 		udp_hdr = NULL;
 		goto out;
 	}
@@ -156,7 +156,7 @@ struct net_udp_hdr *net_udp_input(struct net_pkt *pkt,
 
 	if (ntohs(udp_hdr->len) != (net_pkt_get_len(pkt) -
 				    net_pkt_ip_hdr_len(pkt) -
-				    net_pkt_ipv6_ext_len(pkt))) {
+				    net_pkt_ip_opts_len(pkt))) {
 		NET_DBG("DROP: Invalid hdr length");
 		goto drop;
 	}

subsys/net/ip/utils.c

@@ -566,7 +566,8 @@ u16_t net_calc_chksum(struct net_pkt *pkt, u8_t proto)
 		if (proto != IPPROTO_ICMP) {
 			len = 2 * sizeof(struct in_addr);
 			sum = net_pkt_get_len(pkt) -
-				net_pkt_ip_hdr_len(pkt) + proto;
+				net_pkt_ip_hdr_len(pkt) -
+				net_pkt_ipv4_opts_len(pkt) + proto;
 		}
 	} else if (IS_ENABLED(CONFIG_NET_IPV6) &&
 		   net_pkt_family(pkt) == AF_INET6) {
@@ -588,8 +589,7 @@ u16_t net_calc_chksum(struct net_pkt *pkt, u8_t proto)
 	net_pkt_skip(pkt, net_pkt_ip_hdr_len(pkt) - len);
 
 	sum = calc_chksum(sum, pkt->cursor.pos, len);
-
+	net_pkt_skip(pkt, len + net_pkt_ip_opts_len(pkt));
-	net_pkt_skip(pkt, len + net_pkt_ipv6_ext_len(pkt));
 
 	sum = pkt_calc_chksum(pkt, sum);
 
@@ -607,7 +607,9 @@ u16_t net_calc_chksum_ipv4(struct net_pkt *pkt)
 {
 	u16_t sum;
 
-	sum = calc_chksum(0, pkt->buffer->data, net_pkt_ip_hdr_len(pkt));
+	sum = calc_chksum(0, pkt->buffer->data,
+			  net_pkt_ip_hdr_len(pkt) +
+			  net_pkt_ipv4_opts_len(pkt));
 
 	sum = (sum == 0U) ? 0xffff : htons(sum);
 

subsys/net/lib/sockets/sockets.c

@@ -644,7 +644,9 @@ static int sock_get_pkt_src_addr(struct net_pkt *pkt,
 
 		ipv4_hdr = (struct net_ipv4_hdr *)net_pkt_get_data(
 							pkt, &ipv4_access);
-		if (!ipv4_hdr || net_pkt_acknowledge_data(pkt, &ipv4_access)) {
+		if (!ipv4_hdr ||
+		    net_pkt_acknowledge_data(pkt, &ipv4_access) ||
+		    net_pkt_skip(pkt, net_pkt_ipv4_opts_len(pkt))) {
 			ret = -ENOBUFS;
 			goto error;
 		}