@@ -33,15 +33,6 @@ typedef struct ODP_PACKED {
uint16be_t chksum; /**< UDP header and data checksum (0 if not used)*/
} odph_udphdr_t;
-/** UDP pseudo header */
-typedef struct ODPH_PACKET {
- uint32be_t src_addr; /**< Source addr */
- uint32be_t dst_addr; /**< Destination addr */
- uint8_t pad; /**< pad byte */
- uint8_t proto; /**< UDP protocol */
- uint16be_t length; /**< data length */
-} odph_udpphdr_t;
-
/**
* UDP checksum
*
@@ -53,10 +44,10 @@ typedef struct ODPH_PACKET {
static inline uint16_t odph_ipv4_udp_chksum(odp_packet_t pkt)
{
uint32_t sum = 0;
- odph_udpphdr_t phdr;
odph_udphdr_t *udph;
odph_ipv4hdr_t *iph;
uint16_t udplen;
+ uint8_t *buf;
if (!odp_packet_l3_offset(pkt))
return 0;
@@ -68,24 +59,22 @@ static inline uint16_t odph_ipv4_udp_chksum(odp_packet_t pkt)
udph = (odph_udphdr_t *)odp_packet_l4_ptr(pkt, NULL);
udplen = odp_be_to_cpu_16(udph->length);
- /* the source ip */
- phdr.src_addr = iph->src_addr;
- /* the dest ip */
- phdr.dst_addr = iph->dst_addr;
- /* proto */
- phdr.pad = 0;
- phdr.proto = ODPH_IPPROTO_UDP;
- /* the length */
- phdr.length = udph->length;
-
- /* calc UDP pseudo header chksum */
- sum = (__odp_force uint32_t) odp_chksum(&phdr, sizeof(odph_udpphdr_t));
- /* calc udp header and data chksum */
- sum += (__odp_force uint32_t) odp_chksum(udph, udplen);
+ /* 32-bit sum of all 16-bit words covered by UDP chksum */
+ sum = (iph->src_addr & 0xFFFF) + (iph->src_addr >> 16) +
+ (iph->dst_addr & 0xFFFF) + (iph->dst_addr >> 16) +
+ (uint16_t) iph->proto + udplen;
+ for (buf = (uint8_t *)udph; udplen > 1; udplen -= 2) {
+ sum += ((*buf << 8) + *(buf + 1));
+ buf += 2;
+ }
/* Fold sum to 16 bits: add carrier to result */
while (sum >> 16)
sum = (sum & 0xFFFF) + (sum >> 16);
+
+ /* 1's complement */
+ sum = ~sum;
+
/* set computation result */
sum = (sum == 0x0) ? 0xFFFF : sum;