diff options
Diffstat (limited to 'src/libsystemd-network/dhcp-packet.c')
| -rw-r--r-- | src/libsystemd-network/dhcp-packet.c | 51 |
1 files changed, 39 insertions, 12 deletions
diff --git a/src/libsystemd-network/dhcp-packet.c b/src/libsystemd-network/dhcp-packet.c index 102ed096af..fba9c46ef2 100644 --- a/src/libsystemd-network/dhcp-packet.c +++ b/src/libsystemd-network/dhcp-packet.c @@ -59,21 +59,48 @@ int dhcp_message_init(DHCPMessage *message, uint8_t op, uint32_t xid, return 0; } -uint16_t dhcp_packet_checksum(void *buf, int len) { - uint32_t sum; - uint16_t *check; - int i; - uint8_t *odd; +uint16_t dhcp_packet_checksum(void *buf, size_t len) { + uint64_t *buf_64 = buf; + uint64_t *end_64 = (uint64_t*)buf + (len / sizeof(uint64_t)); + uint32_t *buf_32; + uint16_t *buf_16; + uint8_t *buf_8; + uint64_t sum = 0; + + while (buf_64 < end_64) { + sum += *buf_64; + if (sum < *buf_64) + sum++; + + buf_64 ++; + } + + buf_32 = (uint32_t*)buf_64; + + if (len & sizeof(uint32_t)) { + sum += *buf_32; + if (sum < *buf_32) + sum++; + + buf_32 ++; + } + + buf_16 = (uint16_t*)buf_32; - sum = 0; - check = buf; + if (len & sizeof(uint16_t)) { + sum += *buf_16; + if (sum < *buf_16) + sum ++; + + buf_16 ++; + } - for (i = 0; i < len / 2 ; i++) - sum += check[i]; + buf_8 = (uint8_t*)buf_16; - if (len & 0x01) { - odd = buf; - sum += odd[len - 1]; + if (len & sizeof(uint8_t)) { + sum += *buf_8; + if (sum < *buf_8) + sum++; } while (sum >> 16) |