treewide: Standardise variable names for various packet lengths

At various points we need to track the lengths of a packet including or
excluding various different sets of headers.  We don't always use the same
variable names for doing so.  Worse in some places we use the same name
for different things: e.g. tcp_fill_headers[46]() use ip_len for the
length including the IP headers, but then tcp_send_flag() which calls it
uses it to mean the IP payload length only.

To improve clarity, standardise on these names:
   dlen:		L4 protocol payload length ("data length")
   l4len:		plen + length of L4 protocol header
   l3len:		l4len + length of IPv4/IPv6 header
   l2len:		l3len + length of L2 (ethernet) header

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 23 insertions, 23 deletions

diff --git a/checksum.c b/checksum.c
index b330e1e..006614f 100644
--- a/checksum.c
+++ b/checksum.c
@@ -116,19 +116,19 @@ uint16_t csum_fold(uint32_t sum)
 
 /**
  * csum_ip4_header() - Calculate IPv4 header checksum
- * @tot_len:	IPv4 packet length (data + IP header, host order)
+ * @l3len:	IPv4 packet length (host order)
  * @protocol:	Protocol number
  * @saddr:	IPv4 source address
  * @daddr:	IPv4 destination address
  *
  * Return: 16-bit folded sum of the IPv4 header
  */
-uint16_t csum_ip4_header(uint16_t tot_len, uint8_t protocol,
+uint16_t csum_ip4_header(uint16_t l3len, uint8_t protocol,
 			 struct in_addr saddr, struct in_addr daddr)
 {
 	uint32_t sum = L2_BUF_IP4_PSUM(protocol);
 
-	sum += htons(tot_len);
+	sum += htons(l3len);
 	sum += (saddr.s_addr >> 16) & 0xffff;
 	sum += saddr.s_addr & 0xffff;
 	sum += (daddr.s_addr >> 16) & 0xffff;
@@ -140,13 +140,13 @@ uint16_t csum_ip4_header(uint16_t tot_len, uint8_t protocol,
 /**
  * proto_ipv4_header_psum() - Calculates the partial checksum of an
  * 			      IPv4 header for UDP or TCP
- * @tot_len:	IPv4 Payload length (host order)
+ * @l4len:	IPv4 Payload length (host order)
  * @proto:	Protocol number
  * @saddr:	Source address
  * @daddr:	Destination address
  * Returns:	Partial checksum of the IPv4 header
  */
-uint32_t proto_ipv4_header_psum(uint16_t tot_len, uint8_t protocol,
+uint32_t proto_ipv4_header_psum(uint16_t l4len, uint8_t protocol,
 				struct in_addr saddr, struct in_addr daddr)
 {
 	uint32_t psum = htons(protocol);
@@ -155,7 +155,7 @@ uint32_t proto_ipv4_header_psum(uint16_t tot_len, uint8_t protocol,
 	psum += saddr.s_addr & 0xffff;
 	psum += (daddr.s_addr >> 16) & 0xffff;
 	psum += daddr.s_addr & 0xffff;
-	psum += htons(tot_len);
+	psum += htons(l4len);
 
 	return psum;
 }
@@ -165,22 +165,22 @@ uint32_t proto_ipv4_header_psum(uint16_t tot_len, uint8_t protocol,
  * @udp4hr:	UDP header, initialised apart from checksum
  * @saddr:	IPv4 source address
  * @daddr:	IPv4 destination address
- * @payload:	ICMPv4 packet payload
- * @len:	Length of @payload (not including UDP)
+ * @payload:	UDP packet payload
+ * @dlen:	Length of @payload (not including UDP header)
  */
 void csum_udp4(struct udphdr *udp4hr,
 	       struct in_addr saddr, struct in_addr daddr,
-	       const void *payload, size_t len)
+	       const void *payload, size_t dlen)
 {
 	/* UDP checksums are optional, so don't bother */
 	udp4hr->check = 0;
 
 	if (UDP4_REAL_CHECKSUMS) {
-		uint16_t tot_len = len + sizeof(struct udphdr);
-		uint32_t psum = proto_ipv4_header_psum(tot_len, IPPROTO_UDP,
+		uint16_t l4len = dlen + sizeof(struct udphdr);
+		uint32_t psum = proto_ipv4_header_psum(l4len, IPPROTO_UDP,
 						       saddr, daddr);
 		psum = csum_unfolded(udp4hr, sizeof(struct udphdr), psum);
-		udp4hr->check = csum(payload, len, psum);
+		udp4hr->check = csum(payload, dlen, psum);
 	}
 }
 
@@ -188,9 +188,9 @@ void csum_udp4(struct udphdr *udp4hr,
  * csum_icmp4() - Calculate and set checksum for an ICMP packet
  * @icmp4hr:	ICMP header, initialised apart from checksum
  * @payload:	ICMP packet payload
- * @len:	Length of @payload (not including ICMP header)
+ * @dlen:	Length of @payload (not including ICMP header)
  */
-void csum_icmp4(struct icmphdr *icmp4hr, const void *payload, size_t len)
+void csum_icmp4(struct icmphdr *icmp4hr, const void *payload, size_t dlen)
 {
 	uint32_t psum;
 
@@ -199,7 +199,7 @@ void csum_icmp4(struct icmphdr *icmp4hr, const void *payload, size_t len)
 	/* Partial checksum for ICMP header alone */
 	psum = sum_16b(icmp4hr, sizeof(*icmp4hr));
 
-	icmp4hr->checksum = csum(payload, len, psum);
+	icmp4hr->checksum = csum(payload, dlen, psum);
 }
 
 /**
@@ -227,18 +227,18 @@ uint32_t proto_ipv6_header_psum(uint16_t payload_len, uint8_t protocol,
  * csum_udp6() - Calculate and set checksum for a UDP over IPv6 packet
  * @udp6hr:	UDP header, initialised apart from checksum
  * @payload:	UDP packet payload
- * @len:	Length of @payload (not including UDP header)
+ * @dlen:	Length of @payload (not including UDP header)
  */
 void csum_udp6(struct udphdr *udp6hr,
 	       const struct in6_addr *saddr, const struct in6_addr *daddr,
-	       const void *payload, size_t len)
+	       const void *payload, size_t dlen)
 {
-	uint32_t psum = proto_ipv6_header_psum(len + sizeof(struct udphdr),
+	uint32_t psum = proto_ipv6_header_psum(dlen + sizeof(struct udphdr),
 					       IPPROTO_UDP, saddr, daddr);
 	udp6hr->check = 0;
 
 	psum = csum_unfolded(udp6hr, sizeof(struct udphdr), psum);
-	udp6hr->check = csum(payload, len, psum);
+	udp6hr->check = csum(payload, dlen, psum);
 }
 
 /**
@@ -247,19 +247,19 @@ void csum_udp6(struct udphdr *udp6hr,
  * @saddr:	IPv6 source address
  * @daddr:	IPv6 destination address
  * @payload:	ICMP packet payload
- * @len:	Length of @payload (not including ICMPv6 header)
+ * @dlen:	Length of @payload (not including ICMPv6 header)
  */
 void csum_icmp6(struct icmp6hdr *icmp6hr,
 		const struct in6_addr *saddr, const struct in6_addr *daddr,
-		const void *payload, size_t len)
+		const void *payload, size_t dlen)
 {
-	uint32_t psum = proto_ipv6_header_psum(len + sizeof(*icmp6hr),
+	uint32_t psum = proto_ipv6_header_psum(dlen + sizeof(*icmp6hr),
 					       IPPROTO_ICMPV6, saddr, daddr);
 
 	icmp6hr->icmp6_cksum = 0;
 	/* Add in partial checksum for the ICMPv6 header alone */
 	psum += sum_16b(icmp6hr, sizeof(*icmp6hr));
-	icmp6hr->icmp6_cksum = csum(payload, len, psum);
+	icmp6hr->icmp6_cksum = csum(payload, dlen, psum);
 }
 
 #ifdef __AVX2__