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| author | Martin Schwenke <martin@meltin.net> | 2018-08-10 18:38:23 +1000 |
|---|---|---|
| committer | Amitay Isaacs <amitay@samba.org> | 2018-08-30 04:48:58 +0200 |
| commit | ca0db67df9a122528a37558ddfe8f9a34e7ff684 (patch) | |
| tree | e1a3757f2324e7aa4dba0478f531ce633a8f53fa /ctdb/common | |
| parent | 6b1e9a43dcd0e4aa158f1e03351b9fefc2db1162 (diff) | |
| download | samba-ca0db67df9a122528a37558ddfe8f9a34e7ff684.tar.gz | |
ctdb-common: Clarify offset and packet length calculations
Calculate each offset from the beginning of the buffer and explicitly
use the sizes of structures.
Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>
Diffstat (limited to 'ctdb/common')
| -rw-r--r-- | ctdb/common/system_socket.c | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/ctdb/common/system_socket.c b/ctdb/common/system_socket.c index a6c5f5c093d..b528b89af8f 100644 --- a/ctdb/common/system_socket.c +++ b/ctdb/common/system_socket.c @@ -216,12 +216,12 @@ static int arp_build(uint8_t *buffer, memcpy(eh->ether_shost, hwaddr, ETH_ALEN); eh->ether_type = htons(ETHERTYPE_ARP); - ea = (struct ether_arp *)&buffer[sizeof(struct ether_header)]; + ea = (struct ether_arp *)(buffer + sizeof(struct ether_header)); ah = &ea->ea_hdr; ah->ar_hrd = htons(ARPHRD_ETHER); ah->ar_pro = htons(ETH_P_IP); ah->ar_hln = ETH_ALEN; - ah->ar_pln = 4; + ah->ar_pln = sizeof(ea->arp_spa); if (! reply) { ah->ar_op = htons(ARPOP_REQUEST); @@ -277,9 +277,9 @@ static int ip6_na_build(uint8_t *buffer, memcpy(eh->ether_shost, hwaddr, ETH_ALEN); eh->ether_type = htons(ETHERTYPE_IP6); - ip6 = (struct ip6_hdr *)(eh+1); + ip6 = (struct ip6_hdr *)(buffer + sizeof(struct ether_header)); ip6->ip6_vfc = 0x60; - ip6->ip6_plen = htons(sizeof(*nd_na) + + ip6->ip6_plen = htons(sizeof(struct nd_neighbor_advert) + sizeof(struct nd_opt_hdr) + ETH_ALEN); ip6->ip6_nxt = IPPROTO_ICMPV6; @@ -292,17 +292,27 @@ static int ip6_na_build(uint8_t *buffer, return EIO; } - nd_na = (struct nd_neighbor_advert *)(ip6+1); + nd_na = (struct nd_neighbor_advert *)(buffer + + sizeof(struct ether_header) + + sizeof(struct ip6_hdr)); nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; nd_na->nd_na_code = 0; nd_na->nd_na_flags_reserved = ND_NA_FLAG_OVERRIDE; nd_na->nd_na_target = addr->sin6_addr; + /* Option: Target link-layer address */ - nd_oh = (struct nd_opt_hdr *)(nd_na+1); + nd_oh = (struct nd_opt_hdr *)(buffer + + sizeof(struct ether_header) + + sizeof(struct ip6_hdr) + + sizeof(struct nd_neighbor_advert)); nd_oh->nd_opt_type = ND_OPT_TARGET_LINKADDR; - nd_oh->nd_opt_len = 1; + nd_oh->nd_opt_len = 1; /* multiple of 8 octets */ - ea = (struct ether_addr *)(nd_oh+1); + ea = (struct ether_addr *)(buffer + + sizeof(struct ether_header) + + sizeof(struct ip6_hdr) + + sizeof(struct nd_neighbor_advert) + + sizeof(struct nd_opt_hdr)); memcpy(ea, hwaddr, ETH_ALEN); nd_na->nd_na_cksum = ip6_checksum((uint16_t *)nd_na, |