[U-Boot] [PATCH 24/28] net: Don't copy every packet that waits for an ARP

Joe Hershberger joe.hershberger at ni.com
Fri Jan 20 01:53:27 CET 2012


Use the NetArpTxPacket for the ARP packet, not to hold what used to be
   in NetTxPacket
This saves a copy and makes the code easier to understand
Generalize the formation of the ARP packet

Signed-off-by: Joe Hershberger <joe.hershberger at ni.com>
Cc: Joe Hershberger <joe.hershberger at gmail.com>
Cc: Wolfgang Denk <wd at denx.de>
---
 net/arp.c  |   44 ++++++++++++++++++++++++--------------------
 net/arp.h  |    4 ++--
 net/net.c  |   24 ++++++------------------
 net/ping.c |    5 ++---
 4 files changed, 34 insertions(+), 43 deletions(-)

diff --git a/net/arp.c b/net/arp.c
index b3be0a6..938db59 100644
--- a/net/arp.c
+++ b/net/arp.c
@@ -30,25 +30,26 @@ IPaddr_t	NetArpWaitPacketIP;
 IPaddr_t	NetArpWaitReplyIP;
 /* MAC address of waiting packet's destination */
 uchar	       *NetArpWaitPacketMAC;
-/* THE transmit packet */
-uchar	       *NetArpWaitTxPacket;
 int		NetArpWaitTxPacketSize;
-uchar		NetArpWaitPacketBuf[PKTSIZE_ALIGN + PKTALIGN];
 ulong		NetArpWaitTimerStart;
 int		NetArpWaitTry;
 
+uchar	       *NetArpTxPacket;	/* THE ARP transmit packet */
+uchar		NetArpPacketBuf[PKTSIZE_ALIGN + PKTALIGN];
+
 void ArpInit(void)
 {
 	/* XXX problem with bss workaround */
 	NetArpWaitPacketMAC = NULL;
 	NetArpWaitPacketIP = 0;
 	NetArpWaitReplyIP = 0;
-	NetArpWaitTxPacket = &NetArpWaitPacketBuf[0] + (PKTALIGN - 1);
-	NetArpWaitTxPacket -= (ulong)NetArpWaitTxPacket % PKTALIGN;
 	NetArpWaitTxPacketSize = 0;
+	NetArpTxPacket = &NetArpPacketBuf[0] + (PKTALIGN - 1);
+	NetArpTxPacket -= (ulong)NetArpTxPacket % PKTALIGN;
 }
 
-void ArpRequest(void)
+void ArpRawRequest(IPaddr_t sourceIP, const uchar *targetEther,
+	IPaddr_t targetIP)
 {
 	uchar *pkt;
 	struct ARP_t *arp;
@@ -56,7 +57,7 @@ void ArpRequest(void)
 
 	debug("ARP broadcast %d\n", NetArpWaitTry);
 
-	pkt = NetTxPacket;
+	pkt = NetArpTxPacket;
 
 	eth_hdr_size = NetSetEther(pkt, NetBcastAddr, PROT_ARP);
 	pkt += eth_hdr_size;
@@ -69,12 +70,16 @@ void ArpRequest(void)
 	arp->ar_pln = ARP_PLEN;
 	arp->ar_op = htons(ARPOP_REQUEST);
 
-	/* source ET addr */
-	memcpy(&arp->ar_sha, NetOurEther, ARP_HLEN);
-	/* source IP addr */
-	NetWriteIP(&arp->ar_spa, NetOurIP);
-	/* dest ET addr = 0 */
-	memset(&arp->ar_tha, 0, ARP_HLEN);
+	memcpy(&arp->ar_sha, NetOurEther, ARP_HLEN);	/* source ET addr */
+	NetWriteIP(&arp->ar_spa, sourceIP);		/* source IP addr */
+	memcpy(&arp->ar_tha, targetEther, ARP_HLEN);	/* target ET addr */
+	NetWriteIP(&arp->ar_tpa, targetIP);		/* target IP addr */
+
+	NetSendPacket(NetArpTxPacket, eth_hdr_size + ARP_HDR_SIZE);
+}
+
+void ArpRequest(void)
+{
 	if ((NetArpWaitPacketIP & NetOurSubnetMask) !=
 	    (NetOurIP & NetOurSubnetMask)) {
 		if (NetOurGatewayIP == 0) {
@@ -87,8 +92,7 @@ void ArpRequest(void)
 		NetArpWaitReplyIP = NetArpWaitPacketIP;
 	}
 
-	NetWriteIP(&arp->ar_tpa, NetArpWaitReplyIP);
-	NetSendPacket(NetTxPacket, eth_hdr_size + ARP_HDR_SIZE);
+	ArpRawRequest(NetOurIP, NetEtherNullAddr, NetArpWaitReplyIP);
 }
 
 void ArpTimeoutCheck(void)
@@ -197,11 +201,11 @@ void ArpReceive(struct Ethernet_t *et, struct IP_UDP_t *ip, int len)
 				NetGetARPHandler()((uchar *)arp, 0,
 					reply_ip_addr, 0, len);
 
-			/* modify header, and transmit it */
-			memcpy(((struct Ethernet_t *)NetArpWaitTxPacket)->
-				et_dest, &arp->ar_sha, ARP_HLEN);
-			NetSendPacket(NetArpWaitTxPacket,
-					NetArpWaitTxPacketSize);
+			/* set the mac address in the waiting packet's header
+			   and transmit it */
+			memcpy(((struct Ethernet_t *)NetTxPacket)->et_dest,
+				&arp->ar_sha, ARP_HLEN);
+			NetSendPacket(NetTxPacket, NetArpWaitTxPacketSize);
 
 			/* no arp request pending now */
 			NetArpWaitPacketIP = 0;
diff --git a/net/arp.h b/net/arp.h
index d9ce03d..9657e67 100644
--- a/net/arp.h
+++ b/net/arp.h
@@ -16,14 +16,14 @@
 extern IPaddr_t	NetArpWaitPacketIP;
 /* MAC address of waiting packet's destination */
 extern uchar *NetArpWaitPacketMAC;
-/* THE transmit packet */
-extern uchar *NetArpWaitTxPacket;
 extern int NetArpWaitTxPacketSize;
 extern ulong NetArpWaitTimerStart;
 extern int NetArpWaitTry;
 
 void ArpInit(void);
 void ArpRequest(void);
+void ArpRawRequest(IPaddr_t sourceIP, const uchar *targetEther,
+	IPaddr_t targetIP);
 void ArpTimeoutCheck(void);
 void ArpReceive(struct Ethernet_t *et, struct IP_UDP_t *ip, int len);
 
diff --git a/net/net.c b/net/net.c
index 59ac167..fe4e528 100644
--- a/net/net.c
+++ b/net/net.c
@@ -444,6 +444,9 @@ restart:
 		 *	Abort if ctrl-c was pressed.
 		 */
 		if (ctrlc()) {
+			/* cancel any ARP that may not have completed */
+			NetArpWaitPacketIP = 0;
+
 			NetCleanupLoop();
 			eth_halt();
 			puts("\nAbort\n");
@@ -638,7 +641,6 @@ NetSendUDPPacket(uchar *ether, IPaddr_t dest, int dport, int sport,
 		int payload_len)
 {
 	uchar *pkt;
-	int need_arp = 0;
 	int eth_hdr_size;
 	int pkt_hdr_size;
 
@@ -656,35 +658,21 @@ NetSendUDPPacket(uchar *ether, IPaddr_t dest, int dport, int sport,
 	if (dest == 0xFFFFFFFF)
 		ether = NetBcastAddr;
 
-	/*
-	 * if MAC address was not discovered yet, save the packet and do
-	 * an ARP request
-	 */
-	if (memcmp(ether, NetEtherNullAddr, 6) == 0) {
-		need_arp = 1;
-		pkt = NetArpWaitTxPacket;
-	} else
-		pkt = (uchar *)NetTxPacket;
+	pkt = (uchar *)NetTxPacket;
 
 	eth_hdr_size = NetSetEther(pkt, ether, PROT_IP);
 	pkt += eth_hdr_size;
 	NetSetUDPHeader(pkt, dest, dport, sport, payload_len);
 	pkt_hdr_size = eth_hdr_size + IP_UDP_HDR_SIZE;
 
-	if (need_arp) {
+	/* if MAC address was not discovered yet, do an ARP request */
+	if (memcmp(ether, NetEtherNullAddr, 6) == 0) {
 		debug("sending ARP for %pI4\n", &dest);
 
 		/* save the ip and eth addr for the packet to send after arp */
 		NetArpWaitPacketIP = dest;
 		NetArpWaitPacketMAC = ether;
 
-		/*
-		 * Copy the packet data from the NetTxPacket into the
-		 *   NetArpWaitTxPacket to send after arp
-		 */
-		memcpy(pkt + IP_UDP_HDR_SIZE, (uchar *)NetTxPacket +
-			pkt_hdr_size, payload_len);
-
 		/* size of the waiting packet */
 		NetArpWaitTxPacketSize = pkt_hdr_size + payload_len;
 
diff --git a/net/ping.c b/net/ping.c
index 687c5aa..8332c88 100644
--- a/net/ping.c
+++ b/net/ping.c
@@ -49,9 +49,8 @@ static int PingSend(void)
 
 	NetArpWaitPacketIP = NetPingIP;
 
-	eth_hdr_size = NetSetEther(NetArpWaitTxPacket, NetEtherNullAddr,
-		PROT_IP);
-	pkt = NetArpWaitTxPacket + eth_hdr_size;
+	eth_hdr_size = NetSetEther(NetTxPacket, NetEtherNullAddr, PROT_IP);
+	pkt = (uchar *)NetTxPacket + eth_hdr_size;
 
 	SetICMPHeader(pkt, NetPingIP);
 
-- 
1.6.0.2



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