net: Refactor bootp packet length computations
Eliminate pointer subtraction that recovers values computed earlier
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/net/bootp.c b/net/bootp.c
index 7346993..84ac8a0 100644
--- a/net/bootp.c
+++ b/net/bootp.c
@@ -581,7 +581,8 @@
{
uchar *pkt, *iphdr;
struct Bootp_t *bp;
- int ext_len, pktlen, iplen;
+ int extlen, pktlen, iplen;
+ int eth_hdr_size;
#ifdef CONFIG_BOOTP_RANDOM_DELAY
ulong i, rand_ms;
#endif
@@ -610,7 +611,8 @@
pkt = NetTxPacket;
memset((void *)pkt, 0, PKTSIZE);
- pkt += NetSetEther(pkt, NetBcastAddr, PROT_IP);
+ eth_hdr_size = NetSetEther(pkt, NetBcastAddr, PROT_IP);
+ pkt += eth_hdr_size;
/*
* Next line results in incorrect packet size being transmitted,
@@ -639,9 +641,9 @@
/* Request additional information from the BOOTP/DHCP server */
#if defined(CONFIG_CMD_DHCP)
- ext_len = DhcpExtended((u8 *)bp->bp_vend, DHCP_DISCOVER, 0, 0);
+ extlen = DhcpExtended((u8 *)bp->bp_vend, DHCP_DISCOVER, 0, 0);
#else
- ext_len = BootpExtended((u8 *)bp->bp_vend);
+ extlen = BootpExtended((u8 *)bp->bp_vend);
#endif
/*
@@ -660,9 +662,8 @@
* Calculate proper packet lengths taking into account the
* variable size of the options field
*/
- pktlen = ((int)(pkt-NetTxPacket)) + BOOTP_HDR_SIZE -
- sizeof(bp->bp_vend) + ext_len;
- iplen = BOOTP_HDR_SIZE - sizeof(bp->bp_vend) + ext_len;
+ iplen = BOOTP_HDR_SIZE - OPT_FIELD_SIZE + extlen;
+ pktlen = eth_hdr_size + IP_UDP_HDR_SIZE + iplen;
net_set_udp_header(iphdr, 0xFFFFFFFFL, PORT_BOOTPS, PORT_BOOTPC, iplen);
NetSetTimeout(SELECT_TIMEOUT, BootpTimeout);
@@ -798,13 +799,15 @@
uchar *pkt, *iphdr;
struct Bootp_t *bp;
int pktlen, iplen, extlen;
+ int eth_hdr_size;
IPaddr_t OfferedIP;
debug("DhcpSendRequestPkt: Sending DHCPREQUEST\n");
pkt = NetTxPacket;
memset((void *)pkt, 0, PKTSIZE);
- pkt += NetSetEther(pkt, NetBcastAddr, PROT_IP);
+ eth_hdr_size = NetSetEther(pkt, NetBcastAddr, PROT_IP);
+ pkt += eth_hdr_size;
iphdr = pkt; /* We'll need this later to set proper pkt size */
pkt += IP_UDP_HDR_SIZE;
@@ -841,9 +844,8 @@
extlen = DhcpExtended((u8 *)bp->bp_vend, DHCP_REQUEST,
NetDHCPServerIP, OfferedIP);
- pktlen = ((int)(pkt-NetTxPacket)) + BOOTP_HDR_SIZE -
- sizeof(bp->bp_vend) + extlen;
- iplen = BOOTP_HDR_SIZE - sizeof(bp->bp_vend) + extlen;
+ iplen = BOOTP_HDR_SIZE - OPT_FIELD_SIZE + extlen;
+ pktlen = eth_hdr_size + IP_UDP_HDR_SIZE + iplen;
net_set_udp_header(iphdr, 0xFFFFFFFFL, PORT_BOOTPS, PORT_BOOTPC, iplen);
debug("Transmitting DHCPREQUEST packet: len = %d\n", pktlen);