}
/* if length is in odd bytes */
- if (len == 1)
- sum += *((const uint8_t *)u16_buf);
+ if (len == 1) {
+ uint16_t left = 0;
+ *(uint8_t *)&left = *(const uint8_t *)u16_buf;
+ sum += left;
+ }
return sum;
}
* @param l4_hdr
* The pointer to the beginning of the L4 header.
* @return
- * The complemented checksum to set in the IP packet
- * or 0 on error
+ * The complemented checksum to set in the IP packet.
*/
static inline uint16_t
rte_ipv4_udptcp_cksum(const struct rte_ipv4_hdr *ipv4_hdr, const void *l4_hdr)
cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
cksum = (~cksum) & 0xffff;
- if (cksum == 0)
+ /*
+ * Per RFC 768:If the computed checksum is zero for UDP,
+ * it is transmitted as all ones
+ * (the equivalent in one's complement arithmetic).
+ */
+ if (cksum == 0 && ipv4_hdr->next_proto_id == IPPROTO_UDP)
cksum = 0xffff;
return (uint16_t)cksum;
cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
cksum = (~cksum) & 0xffff;
- if (cksum == 0)
+ /*
+ * Per RFC 768: If the computed checksum is zero for UDP,
+ * it is transmitted as all ones
+ * (the equivalent in one's complement arithmetic).
+ */
+ if (cksum == 0 && ipv6_hdr->proto == IPPROTO_UDP)
cksum = 0xffff;
return (uint16_t)cksum;