[dpdk-stable] [PATCH v3] ip_frag: recalculate data length of fragment

[Yicai Lu <luyicai@huawei.com>]

In some situations, we would get several ip fragments, which total
data length is less than minimum frame(64) and padding with zeros.
Examples: Second Fragment "a0a1 a2a3 a4a5 a6a7 0000 0000 ..."
and Third Fragment "a8a9 aaab acad aeaf b0b1 b2b3 ...".
Finally, we would reassemble Second and Third Fragment like this
"a0a1 a2a3 a4a5 a6a7 0000 0000 ... a8a9 aaab acad aeaf b0b1 ...",
which is not correct!
So, we need recalculate data length of fragment to remove padings!

Fixes: 7f0983ee331c ("ip_frag: check fragment length of incoming packet")
Cc: stable@dpdk.org

Signed-off-by: Yicai Lu <luyicai@huawei.com>
---
v2 -> v3: Update the comments.
---
 lib/librte_ip_frag/rte_ipv4_reassembly.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/librte_ip_frag/rte_ipv4_reassembly.c b/lib/librte_ip_frag/rte_ipv4_reassembly.c
index 1dda8aca0..9a9fe3703 100644
--- a/lib/librte_ip_frag/rte_ipv4_reassembly.c
+++ b/lib/librte_ip_frag/rte_ipv4_reassembly.c
@@ -117,6 +117,7 @@ rte_ipv4_frag_reassemble_packet(struct rte_ip_frag_tbl *tbl,
 
 	ip_ofs *= RTE_IPV4_HDR_OFFSET_UNITS;
 	ip_len = rte_be_to_cpu_16(ip_hdr->total_length) - mb->l3_len;
+	mb->data_len = ip_len + mb->l3_len + mb->l2_len;
 
 	IP_FRAG_LOG(DEBUG, "%s:%d:\n"
 		"mbuf: %p, tms: %" PRIu64
-- 
2.28.0.windows.1