From 8fcf1af559f2a716ebcfb8277668d6539fd432f0 Mon Sep 17 00:00:00 2001 From: Martin Schwenke Date: Fri, 17 Aug 2018 12:30:19 +1000 Subject: ctdb-common: Avoid magic numbers when building TCP packets Most packet sizes and offsets are multiples of 32-bit words. The IPv6 payload length is in octets. The IPv6 version is the top 4 bits of the relevant field. Signed-off-by: Martin Schwenke Reviewed-by: Amitay Isaacs --- ctdb/common/system_socket.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'ctdb/common') diff --git a/ctdb/common/system_socket.c b/ctdb/common/system_socket.c index 7f08b817084..41037ce1ec6 100644 --- a/ctdb/common/system_socket.c +++ b/ctdb/common/system_socket.c @@ -528,7 +528,7 @@ static int tcp4_build(uint8_t *buf, memset(ip4pkt, 0, l); ip4pkt->ip.ip_v = 4; - ip4pkt->ip.ip_hl = sizeof(ip4pkt->ip)/4; + ip4pkt->ip.ip_hl = sizeof(ip4pkt->ip)/sizeof(uint32_t); ip4pkt->ip.ip_len = htons(sizeof(ip4pkt)); ip4pkt->ip.ip_ttl = 255; ip4pkt->ip.ip_p = IPPROTO_TCP; @@ -545,7 +545,7 @@ static int tcp4_build(uint8_t *buf, if (rst) { ip4pkt->tcp.th_flags |= TH_RST; } - ip4pkt->tcp.th_off = sizeof(ip4pkt->tcp)/4; + ip4pkt->tcp.th_off = sizeof(ip4pkt->tcp)/sizeof(uint32_t); /* this makes it easier to spot in a sniffer */ ip4pkt->tcp.th_win = htons(1234); ip4pkt->tcp.th_sum = ip_checksum((uint16_t *)&ip4pkt->tcp, @@ -582,8 +582,8 @@ static int tcp6_build(uint8_t *buf, ip6pkt = (void *)buf; memset(ip6pkt, 0, l); - ip6pkt->ip6.ip6_vfc = 0x60; - ip6pkt->ip6.ip6_plen = htons(20); + ip6pkt->ip6.ip6_vfc = 6 << 4; + ip6pkt->ip6.ip6_plen = htons(sizeof(struct tcphdr)); ip6pkt->ip6.ip6_nxt = IPPROTO_TCP; ip6pkt->ip6.ip6_hlim = 64; ip6pkt->ip6.ip6_src = src->sin6_addr; @@ -598,7 +598,7 @@ static int tcp6_build(uint8_t *buf, if (rst) { ip6pkt->tcp.th_flags |= TH_RST; } - ip6pkt->tcp.th_off = sizeof(ip6pkt->tcp)/4; + ip6pkt->tcp.th_off = sizeof(ip6pkt->tcp)/sizeof(uint32_t); /* this makes it easier to spot in a sniffer */ ip6pkt->tcp.th_win = htons(1234); ip6pkt->tcp.th_sum = ip6_checksum((uint16_t *)&ip6pkt->tcp, -- cgit v1.2.1