net: Consolidate UDP header functions

Make it possible to add TCP versions of the same, while reusing
IP portions. This patch should not change any behavior.

Signed-off-by: Duncan Hare <DH@Synoia.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

include/net.h

@@ -597,7 +597,8 @@ int net_set_ether(uchar *xet, const uchar *dest_ethaddr, uint prot);
 int net_update_ether(struct ethernet_hdr *et, uchar *addr, uint prot);
 
 /* Set IP header */
-void net_set_ip_header(uchar *pkt, struct in_addr dest, struct in_addr source);
+void net_set_ip_header(uchar *pkt, struct in_addr dest, struct in_addr source,
+		       u16 pkt_len, u8 proto);
 void net_set_udp_header(uchar *pkt, struct in_addr dest, int dport,
 				int sport, int len);
 
@@ -680,6 +681,9 @@ static inline void net_send_packet(uchar *pkt, int len)
  * @param sport Source UDP port
  * @param payload_len Length of data after the UDP header
  */
+int net_send_ip_packet(uchar *ether, struct in_addr dest, int dport, int sport,
+		       int payload_len, int proto, u8 action, u32 tcp_seq_num,
+		       u32 tcp_ack_num);
 int net_send_udp_packet(uchar *ether, struct in_addr dest, int dport,
 			int sport, int payload_len);
 

net/net.c

@@ -810,6 +810,14 @@ uchar *net_get_async_tx_pkt_buf(void)
 int net_send_udp_packet(uchar *ether, struct in_addr dest, int dport, int sport,
 		int payload_len)
 {
+	return net_send_ip_packet(ether, dest, dport, sport, payload_len,
+				  IPPROTO_UDP, 0, 0, 0);
+}
+
+int net_send_ip_packet(uchar *ether, struct in_addr dest, int dport, int sport,
+		       int payload_len, int proto, u8 action, u32 tcp_seq_num,
+		       u32 tcp_ack_num)
+{
 	uchar *pkt;
 	int eth_hdr_size;
 	int pkt_hdr_size;
@@ -830,9 +838,16 @@ int net_send_udp_packet(uchar *ether, struct in_addr dest, int dport, int sport,
 	pkt = (uchar *)net_tx_packet;
 
 	eth_hdr_size = net_set_ether(pkt, ether, PROT_IP);
-	pkt += eth_hdr_size;
+
-	net_set_udp_header(pkt, dest, dport, sport, payload_len);
+	switch (proto) {
-	pkt_hdr_size = eth_hdr_size + IP_UDP_HDR_SIZE;
+	case IPPROTO_UDP:
+		net_set_udp_header(pkt + eth_hdr_size, dest, dport, sport,
+				   payload_len);
+		pkt_hdr_size = eth_hdr_size + IP_UDP_HDR_SIZE;
+		break;
+	default:
+		return -EINVAL;
+	}
 
 	/* if MAC address was not discovered yet, do an ARP request */
 	if (memcmp(ether, net_null_ethaddr, 6) == 0) {
@@ -1463,7 +1478,8 @@ int net_update_ether(struct ethernet_hdr *et, uchar *addr, uint prot)
 	}
 }
 
-void net_set_ip_header(uchar *pkt, struct in_addr dest, struct in_addr source)
+void net_set_ip_header(uchar *pkt, struct in_addr dest, struct in_addr source,
+		       u16 pkt_len, u8 proto)
 {
 	struct ip_udp_hdr *ip = (struct ip_udp_hdr *)pkt;
 
@@ -1473,7 +1489,8 @@ void net_set_ip_header(uchar *pkt, struct in_addr dest, struct in_addr source)
 	/* IP_HDR_SIZE / 4 (not including UDP) */
 	ip->ip_hl_v  = 0x45;
 	ip->ip_tos   = 0;
-	ip->ip_len   = htons(IP_HDR_SIZE);
+	ip->ip_len   = htons(pkt_len);
+	ip->ip_p     = proto;
 	ip->ip_id    = htons(net_ip_id++);
 	ip->ip_off   = htons(IP_FLAGS_DFRAG);	/* Don't fragment */
 	ip->ip_ttl   = 255;
@@ -1482,6 +1499,8 @@ void net_set_ip_header(uchar *pkt, struct in_addr dest, struct in_addr source)
 	net_copy_ip((void *)&ip->ip_src, &source);
 	/* already in network byte order */
 	net_copy_ip((void *)&ip->ip_dst, &dest);
+
+	ip->ip_sum   = compute_ip_checksum(ip, IP_HDR_SIZE);
 }
 
 void net_set_udp_header(uchar *pkt, struct in_addr dest, int dport, int sport,
@@ -1497,10 +1516,8 @@ void net_set_udp_header(uchar *pkt, struct in_addr dest, int dport, int sport,
 	if (len & 1)
 		pkt[IP_UDP_HDR_SIZE + len] = 0;
 
-	net_set_ip_header(pkt, dest, net_ip);
+	net_set_ip_header(pkt, dest, net_ip, IP_UDP_HDR_SIZE + len,
-	ip->ip_len   = htons(IP_UDP_HDR_SIZE + len);
+			  IPPROTO_UDP);
-	ip->ip_p     = IPPROTO_UDP;
-	ip->ip_sum   = compute_ip_checksum(ip, IP_HDR_SIZE);
 
 	ip->udp_src  = htons(sport);
 	ip->udp_dst  = htons(dport);

net/ping.c

@@ -22,14 +22,9 @@ static void set_icmp_header(uchar *pkt, struct in_addr dest)
 	/*
 	 *	Construct an IP and ICMP header.
 	 */
-	struct ip_hdr *ip = (struct ip_hdr *)pkt;
 	struct icmp_hdr *icmp = (struct icmp_hdr *)(pkt + IP_HDR_SIZE);
 
-	net_set_ip_header(pkt, dest, net_ip);
+	net_set_ip_header(pkt, dest, net_ip, IP_ICMP_HDR_SIZE, IPPROTO_ICMP);
-
-	ip->ip_len   = htons(IP_ICMP_HDR_SIZE);
-	ip->ip_p     = IPPROTO_ICMP;
-	ip->ip_sum   = compute_ip_checksum(ip, IP_HDR_SIZE);
 
 	icmp->type = ICMP_ECHO_REQUEST;
 	icmp->code = 0;