net: Refactor IP, UPD, and ICMP header writing functions

ICMP (ping) was reimplementing IP header code... it now shares code.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Acked-by: Simon Glass <sjg@chromium.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>

include/net.h

@@ -457,7 +457,9 @@ extern int	NetEthHdrSize(void);
 extern int NetSetEther(uchar *, uchar *, uint);
 
 /* Set IP header */
-extern void NetSetIP(uchar *, IPaddr_t, int, int, int);
+extern void net_set_ip_header(uchar *pkt, IPaddr_t dest, IPaddr_t source);
+extern void net_set_udp_header(uchar *pkt, IPaddr_t dest, int dport,
+				int sport, int len);
 
 /* Checksum */
 extern int	NetCksumOk(uchar *, int);	/* Return true if cksum OK */

net/bootp.c

@@ -619,9 +619,9 @@ BootpRequest(void)
 	 * determined.
 	 * C. Hallinan, DS4.COM, Inc.
 	 */
-	/* NetSetIP(pkt, 0xFFFFFFFFL, PORT_BOOTPS, PORT_BOOTPC,
+	/* net_set_udp_header(pkt, 0xFFFFFFFFL, PORT_BOOTPS, PORT_BOOTPC,
 		sizeof (struct Bootp_t)); */
-	iphdr = pkt;	/* We need this later for NetSetIP() */
+	iphdr = pkt;	/* We need this later for net_set_udp_header() */
 	pkt += IP_UDP_HDR_SIZE;
 
 	bp = (struct Bootp_t *)pkt;
@@ -663,7 +663,7 @@ BootpRequest(void)
 	pktlen = ((int)(pkt-NetTxPacket)) + BOOTP_HDR_SIZE -
 		sizeof(bp->bp_vend) + ext_len;
 	iplen = BOOTP_HDR_SIZE - sizeof(bp->bp_vend) + ext_len;
-	NetSetIP(iphdr, 0xFFFFFFFFL, PORT_BOOTPS, PORT_BOOTPC, iplen);
+	net_set_udp_header(iphdr, 0xFFFFFFFFL, PORT_BOOTPS, PORT_BOOTPC, iplen);
 	NetSetTimeout(SELECT_TIMEOUT, BootpTimeout);
 
 #if defined(CONFIG_CMD_DHCP)
@@ -844,7 +844,7 @@ static void DhcpSendRequestPkt(struct Bootp_t *bp_offer)
 	pktlen = ((int)(pkt-NetTxPacket)) + BOOTP_HDR_SIZE -
 		sizeof(bp->bp_vend) + extlen;
 	iplen = BOOTP_HDR_SIZE - sizeof(bp->bp_vend) + extlen;
-	NetSetIP(iphdr, 0xFFFFFFFFL, PORT_BOOTPS, PORT_BOOTPC, iplen);
+	net_set_udp_header(iphdr, 0xFFFFFFFFL, PORT_BOOTPS, PORT_BOOTPC, iplen);
 
 	debug("Transmitting DHCPREQUEST packet: len = %d\n", pktlen);
 #ifdef CONFIG_BOOTP_DHCP_REQUEST_DELAY

net/net.c

@@ -618,7 +618,7 @@ int NetSendUDPPacket(uchar *ether, IPaddr_t dest, int dport, int sport,
 		pkt = NetArpWaitTxPacket;
 		pkt += NetSetEther(pkt, NetArpWaitPacketMAC, PROT_IP);
 
-		NetSetIP(pkt, dest, dport, sport, payload_len);
+		net_set_udp_header(pkt, dest, dport, sport, payload_len);
 		memcpy(pkt + IP_UDP_HDR_SIZE, (uchar *)NetTxPacket +
 		       (pkt - (uchar *)NetArpWaitTxPacket) +
 		       IP_UDP_HDR_SIZE, payload_len);
@@ -638,7 +638,7 @@ int NetSendUDPPacket(uchar *ether, IPaddr_t dest, int dport, int sport,
 
 	pkt = (uchar *)NetTxPacket;
 	pkt += NetSetEther(pkt, ether, PROT_IP);
-	NetSetIP(pkt, dest, dport, sport, payload_len);
+	net_set_udp_header(pkt, dest, dport, sport, payload_len);
 	eth_send(NetTxPacket, (pkt - NetTxPacket) + IP_UDP_HDR_SIZE +
 		payload_len);
 
@@ -1245,40 +1245,49 @@ NetSetEther(uchar *xet, uchar * addr, uint prot)
 	}
 }
 
-void NetSetIP(uchar *xip, IPaddr_t dest, int dport, int sport, int len)
+void net_set_ip_header(uchar *pkt, IPaddr_t dest, IPaddr_t source)
 {
-	struct ip_udp_hdr *ip = (struct ip_udp_hdr *)xip;
+	struct ip_udp_hdr *ip = (struct ip_udp_hdr *)pkt;
 
 	/*
-	 *	If the data is an odd number of bytes, zero the
-	 *	byte after the last byte so that the checksum
-	 *	will work.
-	 */
-	if (len & 1)
-		xip[IP_UDP_HDR_SIZE + len] = 0;
-
-	/*
-	 *	Construct an IP and UDP header.
-	 *	(need to set no fragment bit - XXX)
+	 *	Construct an IP header.
 	 */
 	/* IP_HDR_SIZE / 4 (not including UDP) */
 	ip->ip_hl_v  = 0x45;
 	ip->ip_tos   = 0;
-	ip->ip_len   = htons(IP_UDP_HDR_SIZE + len);
+	ip->ip_len   = htons(IP_HDR_SIZE);
 	ip->ip_id    = htons(NetIPID++);
 	ip->ip_off   = htons(IP_FLAGS_DFRAG);	/* Don't fragment */
 	ip->ip_ttl   = 255;
-	ip->ip_p     = 17;		/* UDP */
 	ip->ip_sum   = 0;
 	/* already in network byte order */
-	NetCopyIP((void *)&ip->ip_src, &NetOurIP);
-	/* - "" - */
+	NetCopyIP((void *)&ip->ip_src, &source);
+	/* already in network byte order */
 	NetCopyIP((void *)&ip->ip_dst, &dest);
+}
+
+void net_set_udp_header(uchar *pkt, IPaddr_t dest, int dport, int sport,
+			int len)
+{
+	struct ip_udp_hdr *ip = (struct ip_udp_hdr *)pkt;
+
+	/*
+	 *	If the data is an odd number of bytes, zero the
+	 *	byte after the last byte so that the checksum
+	 *	will work.
+	 */
+	if (len & 1)
+		pkt[IP_UDP_HDR_SIZE + len] = 0;
+
+	net_set_ip_header(pkt, dest, NetOurIP);
+	ip->ip_len   = htons(IP_UDP_HDR_SIZE + len);
+	ip->ip_p     = IPPROTO_UDP;
+	ip->ip_sum   = ~NetCksum((uchar *)ip, IP_HDR_SIZE >> 1);
+
 	ip->udp_src  = htons(sport);
 	ip->udp_dst  = htons(dport);
 	ip->udp_len  = htons(UDP_HDR_SIZE + len);
 	ip->udp_xsum = 0;
-	ip->ip_sum   = ~NetCksum((uchar *)ip, IP_HDR_SIZE / 2);
 }
 
 void copy_filename(char *dst, const char *src, int size)

net/ping.c

@@ -16,11 +16,31 @@ static ushort PingSeqNo;
 /* The ip address to ping */
 IPaddr_t NetPingIP;
 
+static void set_icmp_header(uchar *pkt, IPaddr_t 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, NetOurIP);
+
+	ip->ip_len   = htons(IP_ICMP_HDR_SIZE);
+	ip->ip_p     = IPPROTO_ICMP;
+	ip->ip_sum   = ~NetCksum((uchar *)ip, IP_HDR_SIZE >> 1);
+
+	icmp->type = ICMP_ECHO_REQUEST;
+	icmp->code = 0;
+	icmp->checksum = 0;
+	icmp->un.echo.id = 0;
+	icmp->un.echo.sequence = htons(PingSeqNo++);
+	icmp->checksum = ~NetCksum((uchar *)icmp, ICMP_HDR_SIZE	>> 1);
+}
+
 static int ping_send(void)
 {
 	static uchar mac[6];
-	struct ip_udp_hdr *ip;
-	ushort *s;
 	uchar *pkt;
 
 	/* XXX always send arp request */
@@ -35,33 +55,7 @@ static int ping_send(void)
 	pkt = NetArpWaitTxPacket;
 	pkt += NetSetEther(pkt, mac, PROT_IP);
 
-	ip = (struct ip_udp_hdr *)pkt;
-
-	/*
-	 * Construct an IP and ICMP header.
-	 * (need to set no fragment bit - XXX)
-	 */
-	/* IP_HDR_SIZE / 4 (not including UDP) */
-	ip->ip_hl_v  = 0x45;
-	ip->ip_tos   = 0;
-	ip->ip_len   = htons(IP_HDR_SIZE + 8);
-	ip->ip_id    = htons(NetIPID++);
-	ip->ip_off   = htons(IP_FLAGS_DFRAG);	/* Don't fragment */
-	ip->ip_ttl   = 255;
-	ip->ip_p     = 0x01;		/* ICMP */
-	ip->ip_sum   = 0;
-	/* already in network byte order */
-	NetCopyIP((void *)&ip->ip_src, &NetOurIP);
-	/* - "" - */
-	NetCopyIP((void *)&ip->ip_dst, &NetPingIP);
-	ip->ip_sum   = ~NetCksum((uchar *)ip, IP_HDR_SIZE / 2);
-
-	s = &ip->udp_src;		/* XXX ICMP starts here */
-	s[0] = htons(0x0800);		/* echo-request, code */
-	s[1] = 0;			/* checksum */
-	s[2] = 0;			/* identifier */
-	s[3] = htons(PingSeqNo++);	/* sequence number */
-	s[1] = ~NetCksum((uchar *)s, 8/2);
+	set_icmp_header(pkt, NetPingIP);
 
 	/* size of the waiting packet */
 	NetArpWaitTxPacketSize =