Since commit
d5df2ae0428a ("net: fix unneeded replacement of TCP
checksum 0"), the functions rte_ipv4_udptcp_cksum() and
rte_ipv6_udptcp_cksum() can return either 0x0000 or 0xffff when used to
verify a packet containing a valid checksum.
Since these functions should be used to calculate the checksum to set in
a packet, introduce 2 new helpers for checksum verification. They return
0 if the checksum is valid in the packet.
Use this new helper in net/tap driver.
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
- cksum = rte_ipv4_udptcp_cksum(l3_hdr, l4_hdr);
+ cksum_ok = !rte_ipv4_udptcp_cksum_verify(l3_hdr, l4_hdr);
} else { /* l3 == RTE_PTYPE_L3_IPV6, checked above */
} else { /* l3 == RTE_PTYPE_L3_IPV6, checked above */
- cksum = rte_ipv6_udptcp_cksum(l3_hdr, l4_hdr);
+ cksum_ok = !rte_ipv6_udptcp_cksum_verify(l3_hdr, l4_hdr);
- cksum_ok = (cksum == 0) || (cksum == 0xffff);
mbuf->ol_flags |= cksum_ok ?
PKT_RX_L4_CKSUM_GOOD : PKT_RX_L4_CKSUM_BAD;
}
mbuf->ol_flags |= cksum_ok ?
PKT_RX_L4_CKSUM_GOOD : PKT_RX_L4_CKSUM_BAD;
}
- * Process the IPv4 UDP or TCP checksum.
- *
- * The IP and layer 4 checksum must be set to 0 in the packet by
- * the caller.
- *
- * @param ipv4_hdr
- * The pointer to the contiguous IPv4 header.
- * @param l4_hdr
- * The pointer to the beginning of the L4 header.
- * @return
- * The complemented checksum to set in the IP packet.
+ * @internal Calculate the non-complemented IPv4 L4 checksum
*/
static inline uint16_t
*/
static inline uint16_t
-rte_ipv4_udptcp_cksum(const struct rte_ipv4_hdr *ipv4_hdr, const void *l4_hdr)
+__rte_ipv4_udptcp_cksum(const struct rte_ipv4_hdr *ipv4_hdr, const void *l4_hdr)
{
uint32_t cksum;
uint32_t l3_len, l4_len;
{
uint32_t cksum;
uint32_t l3_len, l4_len;
cksum += rte_ipv4_phdr_cksum(ipv4_hdr, 0);
cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
cksum += rte_ipv4_phdr_cksum(ipv4_hdr, 0);
cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
- cksum = (~cksum) & 0xffff;
+
+ return cksum;
+}
+
+/**
+ * Process the IPv4 UDP or TCP checksum.
+ *
+ * The IP and layer 4 checksum must be set to 0 in the packet by
+ * the caller.
+ *
+ * @param ipv4_hdr
+ * The pointer to the contiguous IPv4 header.
+ * @param l4_hdr
+ * The pointer to the beginning of the L4 header.
+ * @return
+ * 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)
+{
+ uint16_t cksum = __rte_ipv4_udptcp_cksum(ipv4_hdr, l4_hdr);
+
+ cksum = ~cksum;
+
- * Per RFC 768:If the computed checksum is zero for UDP,
+ * Per RFC 768: If the computed checksum is zero for UDP,
* it is transmitted as all ones
* (the equivalent in one's complement arithmetic).
*/
* it is transmitted as all ones
* (the equivalent in one's complement arithmetic).
*/
return (uint16_t)cksum;
}
return (uint16_t)cksum;
}
+/**
+ * Validate the IPv4 UDP or TCP checksum.
+ *
+ * @param ipv4_hdr
+ * The pointer to the contiguous IPv4 header.
+ * @param l4_hdr
+ * The pointer to the beginning of the L4 header.
+ * @return
+ * Return 0 if the checksum is correct, else -1.
+ */
+static inline int
+rte_ipv4_udptcp_cksum_verify(const struct rte_ipv4_hdr *ipv4_hdr, const void *l4_hdr)
+{
+ uint16_t cksum = __rte_ipv4_udptcp_cksum(ipv4_hdr, l4_hdr);
+
+ if (cksum != 0xffff)
+ return -1;
+
+ return 0;
+}
+
return __rte_raw_cksum_reduce(sum);
}
return __rte_raw_cksum_reduce(sum);
}
+/**
+ * @internal Calculate the non-complemented IPv4 L4 checksum
+ */
+static inline uint16_t
+__rte_ipv6_udptcp_cksum(const struct rte_ipv6_hdr *ipv6_hdr, const void *l4_hdr)
+{
+ uint32_t cksum;
+ uint32_t l4_len;
+
+ l4_len = rte_be_to_cpu_16(ipv6_hdr->payload_len);
+
+ cksum = rte_raw_cksum(l4_hdr, l4_len);
+ cksum += rte_ipv6_phdr_cksum(ipv6_hdr, 0);
+
+ cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
+
+ return cksum;
+}
+
/**
* Process the IPv6 UDP or TCP checksum.
*
/**
* Process the IPv6 UDP or TCP checksum.
*
static inline uint16_t
rte_ipv6_udptcp_cksum(const struct rte_ipv6_hdr *ipv6_hdr, const void *l4_hdr)
{
static inline uint16_t
rte_ipv6_udptcp_cksum(const struct rte_ipv6_hdr *ipv6_hdr, const void *l4_hdr)
{
- uint32_t cksum;
- uint32_t l4_len;
+ uint16_t cksum = __rte_ipv6_udptcp_cksum(ipv6_hdr, l4_hdr);
- l4_len = rte_be_to_cpu_16(ipv6_hdr->payload_len);
- cksum = rte_raw_cksum(l4_hdr, l4_len);
- cksum += rte_ipv6_phdr_cksum(ipv6_hdr, 0);
-
- cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
- cksum = (~cksum) & 0xffff;
/*
* Per RFC 768: If the computed checksum is zero for UDP,
* it is transmitted as all ones
/*
* Per RFC 768: If the computed checksum is zero for UDP,
* it is transmitted as all ones
return (uint16_t)cksum;
}
return (uint16_t)cksum;
}
+/**
+ * Validate the IPv6 UDP or TCP checksum.
+ *
+ * The function accepts a 0 checksum, since it can exceptionally happen. See 8.1
+ * (Upper-Layer Checksums) in RFC 8200.
+ *
+ * @param ipv6_hdr
+ * The pointer to the contiguous IPv6 header.
+ * @param l4_hdr
+ * The pointer to the beginning of the L4 header.
+ * @return
+ * Return 0 if the checksum is correct, else -1.
+ */
+static inline int
+rte_ipv6_udptcp_cksum_verify(const struct rte_ipv6_hdr *ipv6_hdr, const void *l4_hdr)
+{
+ uint16_t cksum;
+
+ cksum = __rte_ipv6_udptcp_cksum(ipv6_hdr, l4_hdr);
+ if (cksum != 0xffff)
+ return -1;
+
+ return 0;
+}
+
/** IPv6 fragment extension header. */
#define RTE_IPV6_EHDR_MF_SHIFT 0
#define RTE_IPV6_EHDR_MF_MASK 1
/** IPv6 fragment extension header. */
#define RTE_IPV6_EHDR_MF_SHIFT 0
#define RTE_IPV6_EHDR_MF_MASK 1