microudp.c: avoid redundant accesses into multi-level structures

This commit is contained in:
Werner Almesberger 2013-04-16 13:55:20 -03:00 committed by Sebastien Bourdeauducq
parent 0d21711c1b
commit 65b807b63f

View file

@ -128,39 +128,42 @@ static unsigned int cached_ip;
static void process_arp(void)
{
const struct arp_frame *rx_arp = &rxbuffer->frame.contents.arp;
struct arp_frame *tx_arp = &txbuffer->frame.contents.arp;
if(rxlen < 68) return;
if(rxbuffer->frame.contents.arp.hwtype != ARP_HWTYPE_ETHERNET) return;
if(rxbuffer->frame.contents.arp.proto != ARP_PROTO_IP) return;
if(rxbuffer->frame.contents.arp.hwsize != 6) return;
if(rxbuffer->frame.contents.arp.protosize != 4) return;
if(rxbuffer->frame.contents.arp.opcode == ARP_OPCODE_REPLY) {
if(rxbuffer->frame.contents.arp.sender_ip == cached_ip) {
if(rx_arp->hwtype != ARP_HWTYPE_ETHERNET) return;
if(rx_arp->proto != ARP_PROTO_IP) return;
if(rx_arp->hwsize != 6) return;
if(rx_arp->protosize != 4) return;
if(rx_arp->opcode == ARP_OPCODE_REPLY) {
if(rx_arp->sender_ip == cached_ip) {
int i;
for(i=0;i<6;i++)
cached_mac[i] = rxbuffer->frame.contents.arp.sender_mac[i];
cached_mac[i] = rx_arp->sender_mac[i];
}
return;
}
if(rxbuffer->frame.contents.arp.opcode == ARP_OPCODE_REQUEST) {
if(rxbuffer->frame.contents.arp.target_ip == my_ip) {
if(rx_arp->opcode == ARP_OPCODE_REQUEST) {
if(rx_arp->target_ip == my_ip) {
int i;
fill_eth_header(&txbuffer->frame.eth_header,
rxbuffer->frame.contents.arp.sender_mac,
rx_arp->sender_mac,
my_mac,
ETHERTYPE_ARP);
txlen = 68;
txbuffer->frame.contents.arp.hwtype = ARP_HWTYPE_ETHERNET;
txbuffer->frame.contents.arp.proto = ARP_PROTO_IP;
txbuffer->frame.contents.arp.hwsize = 6;
txbuffer->frame.contents.arp.protosize = 4;
txbuffer->frame.contents.arp.opcode = ARP_OPCODE_REPLY;
txbuffer->frame.contents.arp.sender_ip = my_ip;
tx_arp->hwtype = ARP_HWTYPE_ETHERNET;
tx_arp->proto = ARP_PROTO_IP;
tx_arp->hwsize = 6;
tx_arp->protosize = 4;
tx_arp->opcode = ARP_OPCODE_REPLY;
tx_arp->sender_ip = my_ip;
for(i=0;i<6;i++)
txbuffer->frame.contents.arp.sender_mac[i] = my_mac[i];
txbuffer->frame.contents.arp.target_ip = rxbuffer->frame.contents.arp.sender_ip;
tx_arp->sender_mac[i] = my_mac[i];
tx_arp->target_ip = rx_arp->sender_ip;
for(i=0;i<6;i++)
txbuffer->frame.contents.arp.target_mac[i] = rxbuffer->frame.contents.arp.sender_mac[i];
tx_arp->target_mac[i] = rx_arp->sender_mac[i];
send_packet();
}
return;
@ -171,6 +174,7 @@ static const unsigned char broadcast[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
int microudp_arp_resolve(unsigned int ip)
{
struct arp_frame *arp = &txbuffer->frame.contents.arp;
int i;
int tries;
int timeout;
@ -190,17 +194,17 @@ int microudp_arp_resolve(unsigned int ip)
my_mac,
ETHERTYPE_ARP);
txlen = 68;
txbuffer->frame.contents.arp.hwtype = ARP_HWTYPE_ETHERNET;
txbuffer->frame.contents.arp.proto = ARP_PROTO_IP;
txbuffer->frame.contents.arp.hwsize = 6;
txbuffer->frame.contents.arp.protosize = 4;
txbuffer->frame.contents.arp.opcode = ARP_OPCODE_REQUEST;
txbuffer->frame.contents.arp.sender_ip = my_ip;
arp->hwtype = ARP_HWTYPE_ETHERNET;
arp->proto = ARP_PROTO_IP;
arp->hwsize = 6;
arp->protosize = 4;
arp->opcode = ARP_OPCODE_REQUEST;
arp->sender_ip = my_ip;
for(i=0;i<6;i++)
txbuffer->frame.contents.arp.sender_mac[i] = my_mac[i];
txbuffer->frame.contents.arp.target_ip = ip;
arp->sender_mac[i] = my_mac[i];
arp->target_ip = ip;
for(i=0;i<6;i++)
txbuffer->frame.contents.arp.target_mac[i] = 0;
arp->target_mac[i] = 0;
send_packet();
/* Do we get a reply ? */