[ovs-dev,1/4] Userspace: Software fallback for UDP encapsulated TCP segmentation.

When sending packets that are flagged as requiring segmentation to an
interface that doens't support this feature, send the packet to the TSO
software fallback instead of dropping it.

Signed-off-by: Mike Pattrick <mkp@redhat.com>

---
Note: Previously this patch failed gitlab ci, however, I was not able to
reproduce that failure in my VM. I'm resubmitting to see if the failure
was a fluke.

---
 lib/dp-packet-gso.c     | 73 +++++++++++++++++++++++++++++++++--------
 lib/dp-packet.h         | 26 +++++++++++++++
 lib/netdev-native-tnl.c |  8 +++++
 lib/netdev.c            | 19 -----------
 tests/system-traffic.at | 48 +++++++++++++++++++++++++++
 5 files changed, 142 insertions(+), 32 deletions(-)

On 2/12/24 09:13, Mike Pattrick wrote:
> When sending packets that are flagged as requiring segmentation to an
> interface that doens't support this feature, send the packet to the TSO
> software fallback instead of dropping it.
> 
> Signed-off-by: Mike Pattrick <mkp@redhat.com>
> 
> ---
> Note: Previously this patch failed gitlab ci, however, I was not able to
> reproduce that failure in my VM. I'm resubmitting to see if the failure
> was a fluke.

Doesn't look like a fluke.  Tests seem to fail consistently...

> 
> ---
>  lib/dp-packet-gso.c     | 73 +++++++++++++++++++++++++++++++++--------
>  lib/dp-packet.h         | 26 +++++++++++++++
>  lib/netdev-native-tnl.c |  8 +++++
>  lib/netdev.c            | 19 -----------
>  tests/system-traffic.at | 48 +++++++++++++++++++++++++++
>  5 files changed, 142 insertions(+), 32 deletions(-)
> 
> diff --git a/lib/dp-packet-gso.c b/lib/dp-packet-gso.c
> index 847685ad9..f25abf436 100644
> --- a/lib/dp-packet-gso.c
> +++ b/lib/dp-packet-gso.c
> @@ -47,6 +47,8 @@ dp_packet_gso_seg_new(const struct dp_packet *p, size_t hdr_len,
>      seg->l2_5_ofs = p->l2_5_ofs;
>      seg->l3_ofs = p->l3_ofs;
>      seg->l4_ofs = p->l4_ofs;
> +    seg->inner_l3_ofs = p->inner_l3_ofs;
> +    seg->inner_l4_ofs = p->inner_l4_ofs;
>  
>      /* The protocol headers remain the same, so preserve hash and mark. */
>      *dp_packet_rss_ptr(seg) = *dp_packet_rss_ptr(p);
> @@ -71,7 +73,12 @@ dp_packet_gso_nr_segs(struct dp_packet *p)
>      const char *data_tail;
>      const char *data_pos;
>  
> -    data_pos = dp_packet_get_tcp_payload(p);
> +    if (dp_packet_hwol_is_tunnel_vxlan(p) ||
> +        dp_packet_hwol_is_tunnel_geneve(p)) {
> +        data_pos = dp_packet_get_inner_tcp_payload(p);
> +    } else {
> +        data_pos = dp_packet_get_tcp_payload(p);
> +    }
>      data_tail = (char *) dp_packet_tail(p) - dp_packet_l2_pad_size(p);
>  
>      return DIV_ROUND_UP(data_tail - data_pos, segsz);
> @@ -91,12 +98,15 @@ dp_packet_gso(struct dp_packet *p, struct dp_packet_batch **batches)
>      struct tcp_header *tcp_hdr;
>      struct ip_header *ip_hdr;
>      struct dp_packet *seg;
> +    const char *data_pos;
>      uint16_t tcp_offset;
>      uint16_t tso_segsz;
> +    uint16_t ip_id = 0;
>      uint32_t tcp_seq;
> -    uint16_t ip_id;
> +    bool outer_ipv4;
>      int hdr_len;
>      int seg_len;
> +    bool tnl;
>  
>      tso_segsz = dp_packet_get_tso_segsz(p);
>      if (!tso_segsz) {
> @@ -105,20 +115,35 @@ dp_packet_gso(struct dp_packet *p, struct dp_packet_batch **batches)
>          return false;
>      }
>  
> -    tcp_hdr = dp_packet_l4(p);
> -    tcp_offset = TCP_OFFSET(tcp_hdr->tcp_ctl);
> -    tcp_seq = ntohl(get_16aligned_be32(&tcp_hdr->tcp_seq));
> -    hdr_len = ((char *) dp_packet_l4(p) - (char *) dp_packet_eth(p))
> -              + tcp_offset * 4;
> -    ip_id = 0;
> -    if (dp_packet_hwol_is_ipv4(p)) {
> +    if (dp_packet_hwol_is_tunnel_vxlan(p) ||
> +            dp_packet_hwol_is_tunnel_geneve(p)) {
> +        data_pos =  dp_packet_get_inner_tcp_payload(p);
> +        outer_ipv4 = dp_packet_hwol_is_outer_ipv4(p);
> +        tcp_hdr = dp_packet_inner_l4(p);
> +        ip_hdr = dp_packet_inner_l3(p);
> +        tnl = true;
> +        if (outer_ipv4) {
> +            ip_id = ntohs(((struct ip_header *) dp_packet_l3(p))->ip_id);
> +        } else if (dp_packet_hwol_is_ipv4(p)) {
> +            ip_id = ntohs(ip_hdr->ip_id);
> +        }
> +    } else {
> +        data_pos = dp_packet_get_tcp_payload(p);
> +        outer_ipv4 = dp_packet_hwol_is_ipv4(p);
> +        tcp_hdr = dp_packet_l4(p);
>          ip_hdr = dp_packet_l3(p);
> -        ip_id = ntohs(ip_hdr->ip_id);
> +        tnl = false;
> +        if (outer_ipv4) {
> +            ip_id = ntohs(ip_hdr->ip_id);
> +        }
>      }
>  
> +    tcp_offset = TCP_OFFSET(tcp_hdr->tcp_ctl);
> +    tcp_seq = ntohl(get_16aligned_be32(&tcp_hdr->tcp_seq));
> +    hdr_len = ((char *) tcp_hdr - (char *) dp_packet_eth(p))
> +              + tcp_offset * 4;
>      const char *data_tail = (char *) dp_packet_tail(p)
>                              - dp_packet_l2_pad_size(p);
> -    const char *data_pos = dp_packet_get_tcp_payload(p);
>      int n_segs = dp_packet_gso_nr_segs(p);
>  
>      for (int i = 0; i < n_segs; i++) {
> @@ -130,8 +155,26 @@ dp_packet_gso(struct dp_packet *p, struct dp_packet_batch **batches)
>          seg = dp_packet_gso_seg_new(p, hdr_len, data_pos, seg_len);
>          data_pos += seg_len;
>  
> +        if (tnl) {
> +            /* Update tunnel L3 header. */
> +            if (dp_packet_hwol_is_ipv4(seg)) {
> +                ip_hdr = dp_packet_inner_l3(seg);
> +                ip_hdr->ip_tot_len = htons(sizeof *ip_hdr +
> +                                           dp_packet_inner_l4_size(seg));
> +                ip_hdr->ip_id = htons(ip_id);
> +                ip_hdr->ip_csum = 0;
> +                ip_id++;
> +            } else {
> +                struct ovs_16aligned_ip6_hdr *ip6_hdr;
> +
> +                ip6_hdr = dp_packet_inner_l3(seg);
> +                ip6_hdr->ip6_ctlun.ip6_un1.ip6_un1_plen
> +                    = htons(dp_packet_inner_l3_size(seg) - sizeof *ip6_hdr);
> +            }
> +        }
> +
>          /* Update L3 header. */
> -        if (dp_packet_hwol_is_ipv4(seg)) {
> +        if (outer_ipv4) {
>              ip_hdr = dp_packet_l3(seg);
>              ip_hdr->ip_tot_len = htons(sizeof *ip_hdr +
>                                         dp_packet_l4_size(seg));
> @@ -146,7 +189,11 @@ dp_packet_gso(struct dp_packet *p, struct dp_packet_batch **batches)
>          }
>  
>          /* Update L4 header. */
> -        tcp_hdr = dp_packet_l4(seg);
> +        if (tnl) {
> +            tcp_hdr = dp_packet_inner_l4(seg);
> +        } else {
> +            tcp_hdr = dp_packet_l4(seg);
> +        }
>          put_16aligned_be32(&tcp_hdr->tcp_seq, htonl(tcp_seq));
>          tcp_seq += seg_len;
>          if (OVS_LIKELY(i < (n_segs - 1))) {
> diff --git a/lib/dp-packet.h b/lib/dp-packet.h
> index dceb701e8..338d2a014 100644
> --- a/lib/dp-packet.h
> +++ b/lib/dp-packet.h
> @@ -529,6 +529,16 @@ dp_packet_inner_l3(const struct dp_packet *b)
>             : NULL;
>  }
>  
> +static inline size_t
> +dp_packet_inner_l3_size(const struct dp_packet *b)
> +{
> +    return OVS_LIKELY(b->inner_l3_ofs != UINT16_MAX)
> +           ? (const char *) dp_packet_tail(b)
> +           - (const char *) dp_packet_inner_l3(b)
> +           - dp_packet_l2_pad_size(b)
> +           : 0;
> +}
> +
>  static inline void *
>  dp_packet_inner_l4(const struct dp_packet *b)
>  {
> @@ -563,6 +573,22 @@ dp_packet_get_tcp_payload(const struct dp_packet *b)
>      return NULL;
>  }
>  
> +static inline const void *
> +dp_packet_get_inner_tcp_payload(const struct dp_packet *b)
> +{
> +    size_t l4_size = dp_packet_inner_l4_size(b);
> +
> +    if (OVS_LIKELY(l4_size >= TCP_HEADER_LEN)) {
> +        struct tcp_header *tcp = dp_packet_inner_l4(b);
> +        int tcp_len = TCP_OFFSET(tcp->tcp_ctl) * 4;
> +
> +        if (OVS_LIKELY(tcp_len >= TCP_HEADER_LEN && tcp_len <= l4_size)) {
> +            return (const char *) tcp + tcp_len;
> +        }
> +    }
> +    return NULL;
> +}
> +
>  static inline uint32_t
>  dp_packet_get_tcp_payload_length(const struct dp_packet *pkt)
>  {
> diff --git a/lib/netdev-native-tnl.c b/lib/netdev-native-tnl.c
> index 0d6d803fe..76aaa41c9 100644
> --- a/lib/netdev-native-tnl.c
> +++ b/lib/netdev-native-tnl.c
> @@ -342,6 +342,14 @@ netdev_tnl_push_udp_header(const struct netdev *netdev OVS_UNUSED,
>      if (l4_ofs != UINT16_MAX) {
>          packet->inner_l4_ofs = l4_ofs + data->header_len;
>      }
> +
> +    if (dp_packet_hwol_is_tso(packet)) {
> +        uint16_t tso_segsz = dp_packet_get_tso_segsz(packet);
> +        if (tso_segsz > data->header_len) {
> +            tso_segsz -= data->header_len;
> +            dp_packet_set_tso_segsz(packet, tso_segsz);
> +        }
> +    }
>  }
>  
>  static void *
> diff --git a/lib/netdev.c b/lib/netdev.c
> index f2d921ed6..fc61ab1fd 100644
> --- a/lib/netdev.c
> +++ b/lib/netdev.c
> @@ -69,8 +69,6 @@ COVERAGE_DEFINE(netdev_received);
>  COVERAGE_DEFINE(netdev_sent);
>  COVERAGE_DEFINE(netdev_add_router);
>  COVERAGE_DEFINE(netdev_get_stats);
> -COVERAGE_DEFINE(netdev_vxlan_tso_drops);
> -COVERAGE_DEFINE(netdev_geneve_tso_drops);
>  COVERAGE_DEFINE(netdev_push_header_drops);
>  COVERAGE_DEFINE(netdev_soft_seg_good);
>  COVERAGE_DEFINE(netdev_soft_seg_drops);
> @@ -914,23 +912,6 @@ netdev_send(struct netdev *netdev, int qid, struct dp_packet_batch *batch,
>          !(netdev_flags & NETDEV_TX_OFFLOAD_TCP_TSO)) {
>          DP_PACKET_BATCH_FOR_EACH (i, packet, batch) {
>              if (dp_packet_hwol_is_tso(packet)) {
> -                if (dp_packet_hwol_is_tunnel_vxlan(packet)
> -                    && !(netdev_flags & NETDEV_TX_VXLAN_TNL_TSO)) {
> -                        VLOG_WARN_RL(&rl, "%s: No VXLAN TSO support",
> -                                     netdev_get_name(netdev));
> -                        COVERAGE_INC(netdev_vxlan_tso_drops);
> -                        dp_packet_delete_batch(batch, true);
> -                        return false;
> -                }
> -
> -                if (dp_packet_hwol_is_tunnel_geneve(packet)
> -                    && !(netdev_flags & NETDEV_TX_GENEVE_TNL_TSO)) {
> -                        VLOG_WARN_RL(&rl, "%s: No GENEVE TSO support",
> -                                     netdev_get_name(netdev));
> -                        COVERAGE_INC(netdev_geneve_tso_drops);
> -                        dp_packet_delete_batch(batch, true);
> -                        return false;
> -                }
>                  return netdev_send_tso(netdev, qid, batch, concurrent_txq);
>              }
>          }
> diff --git a/tests/system-traffic.at b/tests/system-traffic.at
> index 4fd5dbe59..07af87143 100644
> --- a/tests/system-traffic.at
> +++ b/tests/system-traffic.at
> @@ -341,6 +341,54 @@ AT_CHECK([diff -q payload.bin data], [0])
>  OVS_TRAFFIC_VSWITCHD_STOP
>  AT_CLEANUP
>  
> +AT_SETUP([datapath - tcp over vxlan tunnel with software fallback])
> +AT_SKIP_IF([test $HAVE_NC = no])
> +OVS_CHECK_VXLAN()
> +
> +OVS_TRAFFIC_VSWITCHD_START()
> +ADD_BR([br-underlay])
> +
> +AT_CHECK([ovs-ofctl add-flow br0 "actions=normal"])
> +AT_CHECK([ovs-ofctl add-flow br-underlay "actions=normal"])
> +
> +ADD_NAMESPACES(at_ns0)
> +
> +dnl Set up underlay link from host into the namespace using veth pair.
> +ADD_VETH(p0, at_ns0, br-underlay, "172.31.1.1/24")
> +AT_CHECK([ip addr add dev br-underlay "172.31.1.100/24"])
> +AT_CHECK([ip link set dev br-underlay up])
> +
> +dnl Test the case where only one side has all checksum and tso offload disabled.
> +AT_CHECK([ethtool -K ovs-p0 tso off], [0], [ignore], [ignore])
> +AT_CHECK([ethtool -K ovs-p0 sg off], [0], [ignore], [ignore])
> +
> +dnl Reinitialize.
> +AT_CHECK([ovs-vsctl del-port ovs-p0])
> +AT_CHECK([ovs-vsctl add-port br-underlay ovs-p0])
> +
> +dnl Set up tunnel endpoints on OVS outside the namespace and with a native
> +dnl linux device inside the namespace.
> +ADD_OVS_TUNNEL([vxlan], [br0], [at_vxlan0], [172.31.1.1], [10.1.1.100/24])
> +ADD_NATIVE_TUNNEL([vxlan], [at_vxlan1], [at_ns0], [172.31.1.100], [10.1.1.1/24],
> +                  [id 0 dstport 4789])
> +
> +dnl First, check the underlay.
> +NS_CHECK_EXEC([at_ns0], [ping -q -c 3 -i 0.3 -W 2 172.31.1.100 | FORMAT_PING], [0], [dnl
> +3 packets transmitted, 3 received, 0% packet loss, time 0ms
> +])
> +
> +dnl Large TCP transfer aimed towards ovs-p0, which has TSO disabled.
> +AT_CHECK([dd if=/dev/urandom of=payload.bin bs=60000 count=1 2> /dev/null])
> +NETNS_DAEMONIZE([at_ns0], [nc -l 10.1.1.1 1234 > data2], [nc2.pid])
> +AT_CHECK([nc $NC_EOF_OPT 10.1.1.1 1234 < payload.bin])
> +
> +dnl Wait until transfer completes before checking.
> +OVS_WAIT_WHILE([kill -0 $(cat nc2.pid)])
> +AT_CHECK([diff -q payload.bin data2], [0])
> +
> +OVS_TRAFFIC_VSWITCHD_STOP
> +AT_CLEANUP
> +
>  AT_SETUP([datapath - ping vlan over vxlan tunnel])
>  OVS_CHECK_TUNNEL_TSO()
>  OVS_CHECK_VXLAN()

On Mon, Feb 12, 2024 at 7:52 AM Ilya Maximets <i.maximets@ovn.org> wrote:
>
> On 2/12/24 09:13, Mike Pattrick wrote:
> > When sending packets that are flagged as requiring segmentation to an
> > interface that doens't support this feature, send the packet to the TSO
> > software fallback instead of dropping it.
> >
> > Signed-off-by: Mike Pattrick <mkp@redhat.com>
> >
> > ---
> > Note: Previously this patch failed gitlab ci, however, I was not able to
> > reproduce that failure in my VM. I'm resubmitting to see if the failure
> > was a fluke.
>
> Doesn't look like a fluke.  Tests seem to fail consistently...

Yes. I'll continue to look into this. I've tried different
kernel/compiler versions but it consistently passes for me.

-M

>
> >
> > ---
> >  lib/dp-packet-gso.c     | 73 +++++++++++++++++++++++++++++++++--------
> >  lib/dp-packet.h         | 26 +++++++++++++++
> >  lib/netdev-native-tnl.c |  8 +++++
> >  lib/netdev.c            | 19 -----------
> >  tests/system-traffic.at | 48 +++++++++++++++++++++++++++
> >  5 files changed, 142 insertions(+), 32 deletions(-)
> >
> > diff --git a/lib/dp-packet-gso.c b/lib/dp-packet-gso.c
> > index 847685ad9..f25abf436 100644
> > --- a/lib/dp-packet-gso.c
> > +++ b/lib/dp-packet-gso.c
> > @@ -47,6 +47,8 @@ dp_packet_gso_seg_new(const struct dp_packet *p, size_t hdr_len,
> >      seg->l2_5_ofs = p->l2_5_ofs;
> >      seg->l3_ofs = p->l3_ofs;
> >      seg->l4_ofs = p->l4_ofs;
> > +    seg->inner_l3_ofs = p->inner_l3_ofs;
> > +    seg->inner_l4_ofs = p->inner_l4_ofs;
> >
> >      /* The protocol headers remain the same, so preserve hash and mark. */
> >      *dp_packet_rss_ptr(seg) = *dp_packet_rss_ptr(p);
> > @@ -71,7 +73,12 @@ dp_packet_gso_nr_segs(struct dp_packet *p)
> >      const char *data_tail;
> >      const char *data_pos;
> >
> > -    data_pos = dp_packet_get_tcp_payload(p);
> > +    if (dp_packet_hwol_is_tunnel_vxlan(p) ||
> > +        dp_packet_hwol_is_tunnel_geneve(p)) {
> > +        data_pos = dp_packet_get_inner_tcp_payload(p);
> > +    } else {
> > +        data_pos = dp_packet_get_tcp_payload(p);
> > +    }
> >      data_tail = (char *) dp_packet_tail(p) - dp_packet_l2_pad_size(p);
> >
> >      return DIV_ROUND_UP(data_tail - data_pos, segsz);
> > @@ -91,12 +98,15 @@ dp_packet_gso(struct dp_packet *p, struct dp_packet_batch **batches)
> >      struct tcp_header *tcp_hdr;
> >      struct ip_header *ip_hdr;
> >      struct dp_packet *seg;
> > +    const char *data_pos;
> >      uint16_t tcp_offset;
> >      uint16_t tso_segsz;
> > +    uint16_t ip_id = 0;
> >      uint32_t tcp_seq;
> > -    uint16_t ip_id;
> > +    bool outer_ipv4;
> >      int hdr_len;
> >      int seg_len;
> > +    bool tnl;
> >
> >      tso_segsz = dp_packet_get_tso_segsz(p);
> >      if (!tso_segsz) {
> > @@ -105,20 +115,35 @@ dp_packet_gso(struct dp_packet *p, struct dp_packet_batch **batches)
> >          return false;
> >      }
> >
> > -    tcp_hdr = dp_packet_l4(p);
> > -    tcp_offset = TCP_OFFSET(tcp_hdr->tcp_ctl);
> > -    tcp_seq = ntohl(get_16aligned_be32(&tcp_hdr->tcp_seq));
> > -    hdr_len = ((char *) dp_packet_l4(p) - (char *) dp_packet_eth(p))
> > -              + tcp_offset * 4;
> > -    ip_id = 0;
> > -    if (dp_packet_hwol_is_ipv4(p)) {
> > +    if (dp_packet_hwol_is_tunnel_vxlan(p) ||
> > +            dp_packet_hwol_is_tunnel_geneve(p)) {
> > +        data_pos =  dp_packet_get_inner_tcp_payload(p);
> > +        outer_ipv4 = dp_packet_hwol_is_outer_ipv4(p);
> > +        tcp_hdr = dp_packet_inner_l4(p);
> > +        ip_hdr = dp_packet_inner_l3(p);
> > +        tnl = true;
> > +        if (outer_ipv4) {
> > +            ip_id = ntohs(((struct ip_header *) dp_packet_l3(p))->ip_id);
> > +        } else if (dp_packet_hwol_is_ipv4(p)) {
> > +            ip_id = ntohs(ip_hdr->ip_id);
> > +        }
> > +    } else {
> > +        data_pos = dp_packet_get_tcp_payload(p);
> > +        outer_ipv4 = dp_packet_hwol_is_ipv4(p);
> > +        tcp_hdr = dp_packet_l4(p);
> >          ip_hdr = dp_packet_l3(p);
> > -        ip_id = ntohs(ip_hdr->ip_id);
> > +        tnl = false;
> > +        if (outer_ipv4) {
> > +            ip_id = ntohs(ip_hdr->ip_id);
> > +        }
> >      }
> >
> > +    tcp_offset = TCP_OFFSET(tcp_hdr->tcp_ctl);
> > +    tcp_seq = ntohl(get_16aligned_be32(&tcp_hdr->tcp_seq));
> > +    hdr_len = ((char *) tcp_hdr - (char *) dp_packet_eth(p))
> > +              + tcp_offset * 4;
> >      const char *data_tail = (char *) dp_packet_tail(p)
> >                              - dp_packet_l2_pad_size(p);
> > -    const char *data_pos = dp_packet_get_tcp_payload(p);
> >      int n_segs = dp_packet_gso_nr_segs(p);
> >
> >      for (int i = 0; i < n_segs; i++) {
> > @@ -130,8 +155,26 @@ dp_packet_gso(struct dp_packet *p, struct dp_packet_batch **batches)
> >          seg = dp_packet_gso_seg_new(p, hdr_len, data_pos, seg_len);
> >          data_pos += seg_len;
> >
> > +        if (tnl) {
> > +            /* Update tunnel L3 header. */
> > +            if (dp_packet_hwol_is_ipv4(seg)) {
> > +                ip_hdr = dp_packet_inner_l3(seg);
> > +                ip_hdr->ip_tot_len = htons(sizeof *ip_hdr +
> > +                                           dp_packet_inner_l4_size(seg));
> > +                ip_hdr->ip_id = htons(ip_id);
> > +                ip_hdr->ip_csum = 0;
> > +                ip_id++;
> > +            } else {
> > +                struct ovs_16aligned_ip6_hdr *ip6_hdr;
> > +
> > +                ip6_hdr = dp_packet_inner_l3(seg);
> > +                ip6_hdr->ip6_ctlun.ip6_un1.ip6_un1_plen
> > +                    = htons(dp_packet_inner_l3_size(seg) - sizeof *ip6_hdr);
> > +            }
> > +        }
> > +
> >          /* Update L3 header. */
> > -        if (dp_packet_hwol_is_ipv4(seg)) {
> > +        if (outer_ipv4) {
> >              ip_hdr = dp_packet_l3(seg);
> >              ip_hdr->ip_tot_len = htons(sizeof *ip_hdr +
> >                                         dp_packet_l4_size(seg));
> > @@ -146,7 +189,11 @@ dp_packet_gso(struct dp_packet *p, struct dp_packet_batch **batches)
> >          }
> >
> >          /* Update L4 header. */
> > -        tcp_hdr = dp_packet_l4(seg);
> > +        if (tnl) {
> > +            tcp_hdr = dp_packet_inner_l4(seg);
> > +        } else {
> > +            tcp_hdr = dp_packet_l4(seg);
> > +        }
> >          put_16aligned_be32(&tcp_hdr->tcp_seq, htonl(tcp_seq));
> >          tcp_seq += seg_len;
> >          if (OVS_LIKELY(i < (n_segs - 1))) {
> > diff --git a/lib/dp-packet.h b/lib/dp-packet.h
> > index dceb701e8..338d2a014 100644
> > --- a/lib/dp-packet.h
> > +++ b/lib/dp-packet.h
> > @@ -529,6 +529,16 @@ dp_packet_inner_l3(const struct dp_packet *b)
> >             : NULL;
> >  }
> >
> > +static inline size_t
> > +dp_packet_inner_l3_size(const struct dp_packet *b)
> > +{
> > +    return OVS_LIKELY(b->inner_l3_ofs != UINT16_MAX)
> > +           ? (const char *) dp_packet_tail(b)
> > +           - (const char *) dp_packet_inner_l3(b)
> > +           - dp_packet_l2_pad_size(b)
> > +           : 0;
> > +}
> > +
> >  static inline void *
> >  dp_packet_inner_l4(const struct dp_packet *b)
> >  {
> > @@ -563,6 +573,22 @@ dp_packet_get_tcp_payload(const struct dp_packet *b)
> >      return NULL;
> >  }
> >
> > +static inline const void *
> > +dp_packet_get_inner_tcp_payload(const struct dp_packet *b)
> > +{
> > +    size_t l4_size = dp_packet_inner_l4_size(b);
> > +
> > +    if (OVS_LIKELY(l4_size >= TCP_HEADER_LEN)) {
> > +        struct tcp_header *tcp = dp_packet_inner_l4(b);
> > +        int tcp_len = TCP_OFFSET(tcp->tcp_ctl) * 4;
> > +
> > +        if (OVS_LIKELY(tcp_len >= TCP_HEADER_LEN && tcp_len <= l4_size)) {
> > +            return (const char *) tcp + tcp_len;
> > +        }
> > +    }
> > +    return NULL;
> > +}
> > +
> >  static inline uint32_t
> >  dp_packet_get_tcp_payload_length(const struct dp_packet *pkt)
> >  {
> > diff --git a/lib/netdev-native-tnl.c b/lib/netdev-native-tnl.c
> > index 0d6d803fe..76aaa41c9 100644
> > --- a/lib/netdev-native-tnl.c
> > +++ b/lib/netdev-native-tnl.c
> > @@ -342,6 +342,14 @@ netdev_tnl_push_udp_header(const struct netdev *netdev OVS_UNUSED,
> >      if (l4_ofs != UINT16_MAX) {
> >          packet->inner_l4_ofs = l4_ofs + data->header_len;
> >      }
> > +
> > +    if (dp_packet_hwol_is_tso(packet)) {
> > +        uint16_t tso_segsz = dp_packet_get_tso_segsz(packet);
> > +        if (tso_segsz > data->header_len) {
> > +            tso_segsz -= data->header_len;
> > +            dp_packet_set_tso_segsz(packet, tso_segsz);
> > +        }
> > +    }
> >  }
> >
> >  static void *
> > diff --git a/lib/netdev.c b/lib/netdev.c
> > index f2d921ed6..fc61ab1fd 100644
> > --- a/lib/netdev.c
> > +++ b/lib/netdev.c
> > @@ -69,8 +69,6 @@ COVERAGE_DEFINE(netdev_received);
> >  COVERAGE_DEFINE(netdev_sent);
> >  COVERAGE_DEFINE(netdev_add_router);
> >  COVERAGE_DEFINE(netdev_get_stats);
> > -COVERAGE_DEFINE(netdev_vxlan_tso_drops);
> > -COVERAGE_DEFINE(netdev_geneve_tso_drops);
> >  COVERAGE_DEFINE(netdev_push_header_drops);
> >  COVERAGE_DEFINE(netdev_soft_seg_good);
> >  COVERAGE_DEFINE(netdev_soft_seg_drops);
> > @@ -914,23 +912,6 @@ netdev_send(struct netdev *netdev, int qid, struct dp_packet_batch *batch,
> >          !(netdev_flags & NETDEV_TX_OFFLOAD_TCP_TSO)) {
> >          DP_PACKET_BATCH_FOR_EACH (i, packet, batch) {
> >              if (dp_packet_hwol_is_tso(packet)) {
> > -                if (dp_packet_hwol_is_tunnel_vxlan(packet)
> > -                    && !(netdev_flags & NETDEV_TX_VXLAN_TNL_TSO)) {
> > -                        VLOG_WARN_RL(&rl, "%s: No VXLAN TSO support",
> > -                                     netdev_get_name(netdev));
> > -                        COVERAGE_INC(netdev_vxlan_tso_drops);
> > -                        dp_packet_delete_batch(batch, true);
> > -                        return false;
> > -                }
> > -
> > -                if (dp_packet_hwol_is_tunnel_geneve(packet)
> > -                    && !(netdev_flags & NETDEV_TX_GENEVE_TNL_TSO)) {
> > -                        VLOG_WARN_RL(&rl, "%s: No GENEVE TSO support",
> > -                                     netdev_get_name(netdev));
> > -                        COVERAGE_INC(netdev_geneve_tso_drops);
> > -                        dp_packet_delete_batch(batch, true);
> > -                        return false;
> > -                }
> >                  return netdev_send_tso(netdev, qid, batch, concurrent_txq);
> >              }
> >          }
> > diff --git a/tests/system-traffic.at b/tests/system-traffic.at
> > index 4fd5dbe59..07af87143 100644
> > --- a/tests/system-traffic.at
> > +++ b/tests/system-traffic.at
> > @@ -341,6 +341,54 @@ AT_CHECK([diff -q payload.bin data], [0])
> >  OVS_TRAFFIC_VSWITCHD_STOP
> >  AT_CLEANUP
> >
> > +AT_SETUP([datapath - tcp over vxlan tunnel with software fallback])
> > +AT_SKIP_IF([test $HAVE_NC = no])
> > +OVS_CHECK_VXLAN()
> > +
> > +OVS_TRAFFIC_VSWITCHD_START()
> > +ADD_BR([br-underlay])
> > +
> > +AT_CHECK([ovs-ofctl add-flow br0 "actions=normal"])
> > +AT_CHECK([ovs-ofctl add-flow br-underlay "actions=normal"])
> > +
> > +ADD_NAMESPACES(at_ns0)
> > +
> > +dnl Set up underlay link from host into the namespace using veth pair.
> > +ADD_VETH(p0, at_ns0, br-underlay, "172.31.1.1/24")
> > +AT_CHECK([ip addr add dev br-underlay "172.31.1.100/24"])
> > +AT_CHECK([ip link set dev br-underlay up])
> > +
> > +dnl Test the case where only one side has all checksum and tso offload disabled.
> > +AT_CHECK([ethtool -K ovs-p0 tso off], [0], [ignore], [ignore])
> > +AT_CHECK([ethtool -K ovs-p0 sg off], [0], [ignore], [ignore])
> > +
> > +dnl Reinitialize.
> > +AT_CHECK([ovs-vsctl del-port ovs-p0])
> > +AT_CHECK([ovs-vsctl add-port br-underlay ovs-p0])
> > +
> > +dnl Set up tunnel endpoints on OVS outside the namespace and with a native
> > +dnl linux device inside the namespace.
> > +ADD_OVS_TUNNEL([vxlan], [br0], [at_vxlan0], [172.31.1.1], [10.1.1.100/24])
> > +ADD_NATIVE_TUNNEL([vxlan], [at_vxlan1], [at_ns0], [172.31.1.100], [10.1.1.1/24],
> > +                  [id 0 dstport 4789])
> > +
> > +dnl First, check the underlay.
> > +NS_CHECK_EXEC([at_ns0], [ping -q -c 3 -i 0.3 -W 2 172.31.1.100 | FORMAT_PING], [0], [dnl
> > +3 packets transmitted, 3 received, 0% packet loss, time 0ms
> > +])
> > +
> > +dnl Large TCP transfer aimed towards ovs-p0, which has TSO disabled.
> > +AT_CHECK([dd if=/dev/urandom of=payload.bin bs=60000 count=1 2> /dev/null])
> > +NETNS_DAEMONIZE([at_ns0], [nc -l 10.1.1.1 1234 > data2], [nc2.pid])
> > +AT_CHECK([nc $NC_EOF_OPT 10.1.1.1 1234 < payload.bin])
> > +
> > +dnl Wait until transfer completes before checking.
> > +OVS_WAIT_WHILE([kill -0 $(cat nc2.pid)])
> > +AT_CHECK([diff -q payload.bin data2], [0])
> > +
> > +OVS_TRAFFIC_VSWITCHD_STOP
> > +AT_CLEANUP
> > +
> >  AT_SETUP([datapath - ping vlan over vxlan tunnel])
> >  OVS_CHECK_TUNNEL_TSO()
> >  OVS_CHECK_VXLAN()
>

On 2/12/24 15:19, Mike Pattrick wrote:
> On Mon, Feb 12, 2024 at 7:52 AM Ilya Maximets <i.maximets@ovn.org> wrote:
>>
>> On 2/12/24 09:13, Mike Pattrick wrote:
>>> When sending packets that are flagged as requiring segmentation to an
>>> interface that doens't support this feature, send the packet to the TSO
>>> software fallback instead of dropping it.
>>>
>>> Signed-off-by: Mike Pattrick <mkp@redhat.com>
>>>
>>> ---
>>> Note: Previously this patch failed gitlab ci, however, I was not able to
>>> reproduce that failure in my VM. I'm resubmitting to see if the failure
>>> was a fluke.
>>
>> Doesn't look like a fluke.  Tests seem to fail consistently...
> 
> Yes. I'll continue to look into this. I've tried different
> kernel/compiler versions but it consistently passes for me.

There is always an option to add some debug stuff into the test and
run GHA in your fork.  But that's the most annoying way of debugging,
I agree.

Best regards, Ilya Maximets.

On Mon, Feb 12, 2024 at 10:04 AM Ilya Maximets <i.maximets@ovn.org> wrote:
>
> On 2/12/24 15:19, Mike Pattrick wrote:
> > On Mon, Feb 12, 2024 at 7:52 AM Ilya Maximets <i.maximets@ovn.org> wrote:
> >>
> >> On 2/12/24 09:13, Mike Pattrick wrote:
> >>> When sending packets that are flagged as requiring segmentation to an
> >>> interface that doens't support this feature, send the packet to the TSO
> >>> software fallback instead of dropping it.
> >>>
> >>> Signed-off-by: Mike Pattrick <mkp@redhat.com>
> >>>
> >>> ---
> >>> Note: Previously this patch failed gitlab ci, however, I was not able to
> >>> reproduce that failure in my VM. I'm resubmitting to see if the failure
> >>> was a fluke.
> >>
> >> Doesn't look like a fluke.  Tests seem to fail consistently...
> >
> > Yes. I'll continue to look into this. I've tried different
> > kernel/compiler versions but it consistently passes for me.
>
> There is always an option to add some debug stuff into the test and
> run GHA in your fork.  But that's the most annoying way of debugging,
> I agree.

That was a good idea, I never would have guessed the issue on my own.

-M

>
> Best regards, Ilya Maximets.
>