The rte_raw_cksum_mbuf function is used to compute

the raw checksum of a packet.

If the packet payload stored in multi mbuf, the function

will goto the hard case. In hard case,

the variable 'tmp' is a type of uint32_t,

so rte_bswap16 will drop high 16 bit.

Meanwhile, the variable 'sum' is a type of uint32_t,

so 'sum += tmp' will drop the carry when overflow.

Both drop will make cksum incorrect.

This commit fixes the above bug.

Signed-off-by: Su Sai <susai.ss@bytedance.com>

---

 .mailmap            |  1 +

 lib/net/rte_cksum.h | 26 +++++++++++++++++++++++---

 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/.mailmap b/.mailmap

index 34a99f93a1..838b544a97 100644

--- a/.mailmap

+++ b/.mailmap

@@ -1891,3 +1891,4 @@ Zoltan Kiss <zoltan.kiss@schaman.hu> <zoltan.kiss@linaro.org>

 Zorik Machulsky <zorik@amazon.com>

 Zyta Szpak <zyta@marvell.com> <zr@semihalf.com>

 Zyta Szpak <zyta@marvell.com> <zyta.szpak@semihalf.com>

+Su Sai <susai.ss@bytedance.com>

diff --git a/lib/net/rte_cksum.h b/lib/net/rte_cksum.h

index a8e8927952..aa584d5f8d 100644

--- a/lib/net/rte_cksum.h

+++ b/lib/net/rte_cksum.h

@@ -80,6 +80,25 @@ __rte_raw_cksum_reduce(uint32_t sum)

         return (uint16_t)sum;

 }

+/**

+ * @internal Reduce a sum to the non-complemented checksum.

+ * Helper routine for the rte_raw_cksum_mbuf().

+ *

+ * @param sum

+ *   Value of the sum.

+ * @return

+ *   The non-complemented checksum.

+ */

+static inline uint16_t

+__rte_raw_cksum_reduce_u64(uint64_t sum)

+{

+        uint32_t tmp;

+

+        tmp = __rte_raw_cksum_reduce((uint32_t)sum);

+        tmp += __rte_raw_cksum_reduce((uint32_t)(sum >> 32));

+        return __rte_raw_cksum_reduce(tmp);

+}

+

 /**

  * Process the non-complemented checksum of a buffer.

  *

@@ -119,8 +138,9 @@ rte_raw_cksum_mbuf(const struct rte_mbuf *m, uint32_t off, uint32_t len,

 {

         const struct rte_mbuf *seg;

         const char *buf;

-        uint32_t sum, tmp;

+        uint32_t tmp;

         uint32_t seglen, done;

+        uint64_t sum;

         /* easy case: all data in the first segment */

         if (off + len <= rte_pktmbuf_data_len(m)) {

@@ -157,7 +177,7 @@ rte_raw_cksum_mbuf(const struct rte_mbuf *m, uint32_t off, uint32_t len,

         for (;;) {

                 tmp = __rte_raw_cksum(buf, seglen, 0);

                 if (done & 1)

-                        tmp = rte_bswap16((uint16_t)tmp);

+                        tmp = rte_bswap32(tmp);

                 sum += tmp;

                 done += seglen;

                 if (done == len)

@@ -169,7 +189,7 @@ rte_raw_cksum_mbuf(const struct rte_mbuf *m, uint32_t off, uint32_t len,

                         seglen = len - done;

         }

-        *cksum = __rte_raw_cksum_reduce(sum);

+        *cksum = __rte_raw_cksum_reduce_u64(sum);

         return 0;

 }

-- 

2.39.2 (Apple Git-143)