From ae446f56223420b3a137e717b2c6a95636bf26d4 Mon Sep 17 00:00:00 2001 From: Joe Hershberger Date: Wed, 23 May 2012 07:59:10 +0000 Subject: [PATCH] net: Refactor bootp packet length computations Eliminate pointer subtraction that recovers values computed earlier Signed-off-by: Joe Hershberger Acked-by: Simon Glass --- net/bootp.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/net/bootp.c b/net/bootp.c index 7346993e2f..84ac8a027d 100644 --- a/net/bootp.c +++ b/net/bootp.c @@ -581,7 +581,8 @@ BootpRequest(void) { 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 @@ BootpRequest(void) 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 @@ BootpRequest(void) /* 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 @@ BootpRequest(void) * 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 @@ static void DhcpSendRequestPkt(struct Bootp_t *bp_offer) 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 @@ static void DhcpSendRequestPkt(struct Bootp_t *bp_offer) 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); -- 2.30.2