[PATCH 3/3] net:ethernet:rmnet: Add support for Mapv5 Uplink packet

@@ -1,5 +1,5 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
-/* Copyright (c) 2013-2014, 2016-2018 The Linux Foundation.
+/* Copyright (c) 2013-2014, 2016-2018, 2021 The Linux Foundation.
  * All rights reserved.
  *
  * RMNET Data configuration engine

@@ -57,6 +57,7 @@ struct rmnet_priv_stats {
 	u64 csum_fragmented_pkt;
 	u64 csum_skipped;
 	u64 csum_sw;
+	u64 csum_hw;
 };
 
 struct rmnet_priv {

@@ -131,8 +131,9 @@ static int rmnet_map_egress_handler(struct sk_buff *skb,
 				    struct rmnet_port *port, u8 mux_id,
 				    struct net_device *orig_dev)
 {
-	int required_headroom, additional_header_len;
+	int required_headroom, additional_header_len, csum_type;
 	struct rmnet_map_header *map_header;
+	csum_type = 0;
 
 	additional_header_len = 0;
 	required_headroom = sizeof(struct rmnet_map_header);

@@ -140,17 +141,25 @@ static int rmnet_map_egress_handler(struct sk_buff *skb,
 	if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV4) {
 		additional_header_len = sizeof(struct rmnet_map_ul_csum_header);
 		required_headroom += additional_header_len;
+		csum_type = RMNET_FLAGS_EGRESS_MAP_CKSUMV4;
+	} else if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV5) {
+		additional_header_len = sizeof(struct rmnet_map_v5_csum_header);
+		csum_type = RMNET_FLAGS_EGRESS_MAP_CKSUMV5;
 	}
 
+	required_headroom += additional_header_len;
+
 	if (skb_headroom(skb) < required_headroom) {
 		if (pskb_expand_head(skb, required_headroom, 0, GFP_ATOMIC))
 			return -ENOMEM;
 	}
 
-	if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV4)
-		rmnet_map_checksum_uplink_packet(skb, orig_dev);
+	if (csum_type) {
+		rmnet_map_checksum_uplink_packet(skb, port, orig_dev,
+						 csum_type);
+	}
 
-	map_header = rmnet_map_add_map_header(skb, additional_header_len, 0);
+	map_header = rmnet_map_add_map_header(skb, additional_header_len, port, 0);
 	if (!map_header)
 		return -ENOMEM;
 

@@ -70,7 +70,9 @@ struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb,
 void rmnet_map_command(struct sk_buff *skb, struct rmnet_port *port);
 int rmnet_map_checksum_downlink_packet(struct sk_buff *skb, u16 len);
 void rmnet_map_checksum_uplink_packet(struct sk_buff *skb,
-				      struct net_device *orig_dev);
+				      struct rmnet_port *port,
+				      struct net_device *orig_dev,
+				      int csum_type);
 int rmnet_map_process_next_hdr_packet(struct sk_buff *skb, u16 len);
 
 static u8 rmnet_map_get_next_hdr_type(struct sk_buff *skb)

@@ -263,12 +263,68 @@ rmnet_map_ipv6_ul_csum_header(void *ip6hdr,
 }
 #endif
 
+void rmnet_map_v5_checksum_uplink_packet(struct sk_buff *skb,
+					 struct rmnet_port *port,
+					 struct net_device *orig_dev)
+{
+	struct rmnet_priv *priv = netdev_priv(orig_dev);
+	struct rmnet_map_v5_csum_header *ul_header;
+
+	if (!(port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV5))
+		return;
+
+	ul_header = (struct rmnet_map_v5_csum_header *)
+		    skb_push(skb, sizeof(*ul_header));
+	memset(ul_header, 0, sizeof(*ul_header));
+	ul_header->header_type = RMNET_MAP_HEADER_TYPE_CSUM_OFFLOAD;
+
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		void *iph = (char *)ul_header + sizeof(*ul_header);
+		__sum16 *check;
+		void *trans;
+		u8 proto;
+
+		if (skb->protocol == htons(ETH_P_IP)) {
+			u16 ip_len = ((struct iphdr *)iph)->ihl * 4;
+
+			proto = ((struct iphdr *)iph)->protocol;
+			trans = iph + ip_len;
+		}
+#if IS_ENABLED(CONFIG_IPV6)
+		else if (skb->protocol == htons(ETH_P_IPV6)) {
+			u16 ip_len = sizeof(struct ipv6hdr);
+
+			proto = ((struct ipv6hdr *)iph)->nexthdr;
+			trans = iph + ip_len;
+		}
+#endif /* CONFIG_IPV6 */
+		else {
+			priv->stats.csum_err_invalid_ip_version++;
+			goto sw_csum;
+		}
+
+		check = rmnet_map_get_csum_field(proto, trans);
+		if (check) {
+			skb->ip_summed = CHECKSUM_NONE;
+			/* Ask for checksum offloading */
+			ul_header->csum_valid_required = 1;
+			priv->stats.csum_hw++;
+			return;
+		}
+	}
+
+sw_csum:
+	priv->stats.csum_sw++;
+}
+
 /* Adds MAP header to front of skb->data
  * Padding is calculated and set appropriately in MAP header. Mux ID is
  * initialized to 0.
  */
 struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb,
-						  int hdrlen, int pad)
+						  int hdrlen,
+						  struct rmnet_port *port,
+						  int pad)
 {
 	struct rmnet_map_header *map_header;
 	u32 padding, map_datalen;

@@ -279,6 +335,11 @@ struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb,
 			skb_push(skb, sizeof(struct rmnet_map_header));
 	memset(map_header, 0, sizeof(struct rmnet_map_header));
 
+	/* Set next_hdr bit for csum offload packets */
+	if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV5) {
+		map_header->next_hdr = 1;
+	}
+
 	if (pad == RMNET_MAP_NO_PAD_BYTES) {
 		map_header->pkt_len = htons(map_datalen);
 		return map_header;

@@ -395,11 +456,8 @@ int rmnet_map_checksum_downlink_packet(struct sk_buff *skb, u16 len)
 	return 0;
 }
 
-/* Generates UL checksum meta info header for IPv4 and IPv6 over TCP and UDP
- * packets that are supported for UL checksum offload.
- */
-void rmnet_map_checksum_uplink_packet(struct sk_buff *skb,
-				      struct net_device *orig_dev)
+void rmnet_map_v4_checksum_uplink_packet(struct sk_buff *skb,
+					 struct net_device *orig_dev)
 {
 	struct rmnet_priv *priv = netdev_priv(orig_dev);
 	struct rmnet_map_ul_csum_header *ul_header;

@@ -418,10 +476,12 @@ void rmnet_map_checksum_uplink_packet(struct sk_buff *skb,
 
 		if (skb->protocol == htons(ETH_P_IP)) {
 			rmnet_map_ipv4_ul_csum_header(iphdr, ul_header, skb);
+			priv->stats.csum_hw++;
 			return;
 		} else if (skb->protocol == htons(ETH_P_IPV6)) {
 #if IS_ENABLED(CONFIG_IPV6)
 			rmnet_map_ipv6_ul_csum_header(iphdr, ul_header, skb);
+			priv->stats.csum_hw++;
 			return;
 #else
 			priv->stats.csum_err_invalid_ip_version++;

@@ -441,6 +501,26 @@ void rmnet_map_checksum_uplink_packet(struct sk_buff *skb,
 	priv->stats.csum_sw++;
 }
 
+/* Generates UL checksum meta info header for IPv4 and IPv6 over TCP and UDP
+ * packets that are supported for UL checksum offload.
+ */
+void rmnet_map_checksum_uplink_packet(struct sk_buff *skb,
+				      struct rmnet_port *port,
+				      struct net_device *orig_dev,
+				      int csum_type)
+{
+	switch (csum_type) {
+	case RMNET_FLAGS_EGRESS_MAP_CKSUMV4:
+		rmnet_map_v4_checksum_uplink_packet(skb, orig_dev);
+		break;
+	case RMNET_FLAGS_EGRESS_MAP_CKSUMV5:
+		rmnet_map_v5_checksum_uplink_packet(skb, port, orig_dev);
+		break;
+	default:
+		break;
+	}
+}
+
 /* Process a MAPv5 packet header */
 int rmnet_map_process_next_hdr_packet(struct sk_buff *skb,
 				      u16 len)

@@ -1234,6 +1234,7 @@ enum {
 #define RMNET_FLAGS_INGRESS_MAP_CKSUMV4           (1U << 2)
 #define RMNET_FLAGS_EGRESS_MAP_CKSUMV4            (1U << 3)
 #define RMNET_FLAGS_INGRESS_MAP_CKSUMV5           (1U << 4)
+#define RMNET_FLAGS_EGRESS_MAP_CKSUMV5            (1U << 5)
 
 enum {
 	IFLA_RMNET_UNSPEC,