[dpdk-stable] [PATCH v3] app/testpmd: fix l4 sw csum over multi segments
Xiaoyun Li
xiaoyun.li at intel.com
Wed Oct 20 12:10:58 CEST 2021
In csum forwarding mode, software UDP/TCP csum calculation only takes
the first segment into account while using the whole packet length so
the calculation will read invalid memory region with multi-segments
packets and will get wrong value.
This patch fixes this issue.
Fixes: af75078fece3 ("first public release")
Cc: stable at dpdk.org
Signed-off-by: Xiaoyun Li <xiaoyun.li at intel.com>
---
v3:
* Use rte_raw_cksum() for multi-segs case instead of copying the whole
* packet.
v2:
* Use static stack memory instead of dynamic allocating in datapath
---
app/test-pmd/csumonly.c | 68 ++++++++++++++++++++++++++++++++---------
1 file changed, 53 insertions(+), 15 deletions(-)
diff --git a/app/test-pmd/csumonly.c b/app/test-pmd/csumonly.c
index 090797318a..f3e60eb3c3 100644
--- a/app/test-pmd/csumonly.c
+++ b/app/test-pmd/csumonly.c
@@ -91,12 +91,41 @@ struct simple_gre_hdr {
} __rte_packed;
static uint16_t
-get_udptcp_checksum(void *l3_hdr, void *l4_hdr, uint16_t ethertype)
+get_udptcp_checksum(void *l3_hdr, struct rte_mbuf *m, uint16_t l4_off,
+ uint16_t ethertype)
{
+ uint16_t off = l4_off;
+ uint32_t cksum = 0;
+ char *buf;
+
+ while (m != NULL) {
+ buf = rte_pktmbuf_mtod_offset(m, char *, off);
+ cksum += rte_raw_cksum(buf, m->data_len - off);
+ off = 0;
+ m = m->next;
+ }
if (ethertype == _htons(RTE_ETHER_TYPE_IPV4))
- return rte_ipv4_udptcp_cksum(l3_hdr, l4_hdr);
+ cksum += rte_ipv4_phdr_cksum(l3_hdr, 0);
else /* assume ethertype == RTE_ETHER_TYPE_IPV6 */
- return rte_ipv6_udptcp_cksum(l3_hdr, l4_hdr);
+ cksum += rte_ipv6_phdr_cksum(l3_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
+ * (the equivalent in one's complement arithmetic).
+ */
+ if (cksum == 0 && ethertype == _htons(RTE_ETHER_TYPE_IPV4) &&
+ ((struct rte_ipv4_hdr *)l3_hdr)->next_proto_id == IPPROTO_UDP)
+ cksum = 0xffff;
+
+ if (cksum == 0 && ethertype == _htons(RTE_ETHER_TYPE_IPV6) &&
+ ((struct rte_ipv6_hdr *)l3_hdr)->proto == IPPROTO_UDP)
+ cksum = 0xffff;
+
+ return (uint16_t)cksum;
}
/* Parse an IPv4 header to fill l3_len, l4_len, and l4_proto */
@@ -455,7 +484,7 @@ parse_encap_ip(void *encap_ip, struct testpmd_offload_info *info)
* depending on the testpmd command line configuration */
static uint64_t
process_inner_cksums(void *l3_hdr, const struct testpmd_offload_info *info,
- uint64_t tx_offloads)
+ uint64_t tx_offloads, struct rte_mbuf *m)
{
struct rte_ipv4_hdr *ipv4_hdr = l3_hdr;
struct rte_udp_hdr *udp_hdr;
@@ -463,6 +492,7 @@ process_inner_cksums(void *l3_hdr, const struct testpmd_offload_info *info,
struct rte_sctp_hdr *sctp_hdr;
uint64_t ol_flags = 0;
uint32_t max_pkt_len, tso_segsz = 0;
+ uint16_t l4_off;
/* ensure packet is large enough to require tso */
if (!info->is_tunnel) {
@@ -505,9 +535,15 @@ process_inner_cksums(void *l3_hdr, const struct testpmd_offload_info *info,
if (tx_offloads & DEV_TX_OFFLOAD_UDP_CKSUM) {
ol_flags |= PKT_TX_UDP_CKSUM;
} else {
+ if (info->is_tunnel)
+ l4_off = info->l2_len +
+ info->outer_l3_len +
+ info->l2_len + info->l3_len;
+ else
+ l4_off = info->l2_len + info->l3_len;
udp_hdr->dgram_cksum = 0;
udp_hdr->dgram_cksum =
- get_udptcp_checksum(l3_hdr, udp_hdr,
+ get_udptcp_checksum(l3_hdr, m, l4_off,
info->ethertype);
}
}
@@ -520,9 +556,14 @@ process_inner_cksums(void *l3_hdr, const struct testpmd_offload_info *info,
else if (tx_offloads & DEV_TX_OFFLOAD_TCP_CKSUM) {
ol_flags |= PKT_TX_TCP_CKSUM;
} else {
+ if (info->is_tunnel)
+ l4_off = info->l2_len + info->outer_l3_len +
+ info->l2_len + info->l3_len;
+ else
+ l4_off = info->l2_len + info->l3_len;
tcp_hdr->cksum = 0;
tcp_hdr->cksum =
- get_udptcp_checksum(l3_hdr, tcp_hdr,
+ get_udptcp_checksum(l3_hdr, m, l4_off,
info->ethertype);
}
if (info->gso_enable)
@@ -548,7 +589,7 @@ process_inner_cksums(void *l3_hdr, const struct testpmd_offload_info *info,
/* Calculate the checksum of outer header */
static uint64_t
process_outer_cksums(void *outer_l3_hdr, struct testpmd_offload_info *info,
- uint64_t tx_offloads, int tso_enabled)
+ uint64_t tx_offloads, int tso_enabled, struct rte_mbuf *m)
{
struct rte_ipv4_hdr *ipv4_hdr = outer_l3_hdr;
struct rte_ipv6_hdr *ipv6_hdr = outer_l3_hdr;
@@ -602,12 +643,9 @@ process_outer_cksums(void *outer_l3_hdr, struct testpmd_offload_info *info,
/* do not recalculate udp cksum if it was 0 */
if (udp_hdr->dgram_cksum != 0) {
udp_hdr->dgram_cksum = 0;
- if (info->outer_ethertype == _htons(RTE_ETHER_TYPE_IPV4))
- udp_hdr->dgram_cksum =
- rte_ipv4_udptcp_cksum(ipv4_hdr, udp_hdr);
- else
- udp_hdr->dgram_cksum =
- rte_ipv6_udptcp_cksum(ipv6_hdr, udp_hdr);
+ udp_hdr->dgram_cksum = get_udptcp_checksum(outer_l3_hdr,
+ m, info->l2_len + info->outer_l3_len,
+ info->outer_ethertype);
}
return ol_flags;
@@ -942,7 +980,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
/* process checksums of inner headers first */
tx_ol_flags |= process_inner_cksums(l3_hdr, &info,
- tx_offloads);
+ tx_offloads, m);
/* Then process outer headers if any. Note that the software
* checksum will be wrong if one of the inner checksums is
@@ -950,7 +988,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
if (info.is_tunnel == 1) {
tx_ol_flags |= process_outer_cksums(outer_l3_hdr, &info,
tx_offloads,
- !!(tx_ol_flags & PKT_TX_TCP_SEG));
+ !!(tx_ol_flags & PKT_TX_TCP_SEG), m);
}
/* step 3: fill the mbuf meta data (flags and header lengths) */
--
2.25.1
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