[ovs-dev] [PATCH ovn 4/5] actions: Add new OVN logical fields 'ip.src' and ip.dst'.

Numan Siddique numans at ovn.org
Wed Oct 7 13:26:06 UTC 2020


On Wed, Oct 7, 2020 at 6:19 PM Mark Michelson <mmichels at redhat.com> wrote:
>
> Hi Numan, see below for one finding
>
> On 10/5/20 1:49 PM, numans at ovn.org wrote:
> > From: Numan Siddique <numans at ovn.org>
> >
> > Thee new fields are version independent and these can be used in any
> > OVN action. Right now the usage of these fields are restricted to
> > exchanging the IP source and destination fields.
> >
> > Eg. reject {... ip.src <-> ip.dst ... };
> >
> > "ip.src <-> ip.dst" translates to controller action with "pause" flag set.
> > When pinctrl thread receives the packet in, it checks the IP version of the
> > packet and either does - "ip4.src <-> ip4.dst" or "ip6.src <-> ip6.dst" and
> > resumes the packet to continue with the pipeline.
> >
> > Upcoming patch will make use of these fields.
> >
> > Signed-off-by: Numan Siddique <numans at ovn.org>
> > ---
> >   controller/pinctrl.c         |  49 +++++++++++++++
> >   include/ovn/actions.h        |   4 ++
> >   include/ovn/logical-fields.h |  18 ++++++
> >   lib/actions.c                | 115 +++++++++++++++++++++++++++++++++++
> >   lib/logical-fields.c         |  10 +++
> >   ovn-sb.xml                   |  37 +++++++++++
> >   tests/ovn.at                 |  27 ++++++++
> >   utilities/ovn-trace.c        |  28 +++++++++
> >   8 files changed, 288 insertions(+)
> >
> > diff --git a/controller/pinctrl.c b/controller/pinctrl.c
> > index 631d058458..bc16a82404 100644
> > --- a/controller/pinctrl.c
> > +++ b/controller/pinctrl.c
> > @@ -233,6 +233,11 @@ static void pinctrl_handle_put_icmp_frag_mtu(struct rconn *swconn,
> >                                                struct ofputil_packet_in *pin,
> >                                                struct ofpbuf *userdata,
> >                                                struct ofpbuf *continuation);
> > +static void pinctrl_handle_swap_src_dst_ip(struct rconn *swconn,
> > +                                           const struct flow *in_flow,
> > +                                           struct dp_packet *pkt_in,
> > +                                           struct ofputil_packet_in *pin,
> > +                                           struct ofpbuf *continuation);
> >   static void
> >   pinctrl_handle_event(struct ofpbuf *userdata)
> >       OVS_REQUIRES(pinctrl_mutex);
> > @@ -2835,6 +2840,11 @@ process_packet_in(struct rconn *swconn, const struct ofp_header *msg)
> >           ovs_mutex_unlock(&pinctrl_mutex);
> >           break;
> >
> > +    case ACTION_OPCODE_SWAP_SRC_DST_IP:
> > +        pinctrl_handle_swap_src_dst_ip(swconn, &headers, &packet, &pin,
> > +                                       &continuation);
> > +        break;
> > +
> >       default:
> >           VLOG_WARN_RL(&rl, "unrecognized packet-in opcode %"PRIu32,
> >                        ntohl(ah->opcode));
> > @@ -6508,3 +6518,42 @@ pinctrl_handle_svc_check(struct rconn *swconn, const struct flow *ip_flow,
> >           svc_mon->next_send_time = time_msec() + svc_mon->interval;
> >       }
> >   }
> > +
> > +static void
> > +pinctrl_handle_swap_src_dst_ip(struct rconn *swconn,
> > +                               const struct flow *in_flow,
> > +                               struct dp_packet *pkt_in,
> > +                               struct ofputil_packet_in *pin,
> > +                               struct ofpbuf *continuation)
> > +{
> > +    enum ofp_version version = rconn_get_version(swconn);
> > +    enum ofputil_protocol proto = ofputil_protocol_from_ofp_version(version);
> > +    struct dp_packet *pkt_out;
> > +
> > +    pkt_out = dp_packet_clone(pkt_in);
> > +    pkt_out->l2_5_ofs = pkt_in->l2_5_ofs;
> > +    pkt_out->l2_pad_size = pkt_in->l2_pad_size;
> > +    pkt_out->l3_ofs = pkt_in->l3_ofs;
> > +    pkt_out->l4_ofs = pkt_in->l4_ofs;
> > +
> > +    if (get_dl_type(in_flow) == htons(ETH_TYPE_IP)) {
> > +        /* IPv4 packet. Swap nw_src with nw_dst. */
> > +        packet_set_ipv4(pkt_out, in_flow->nw_dst, in_flow->nw_src,
> > +                        in_flow->nw_tos, in_flow->nw_ttl);
> > +    } else {
> > +        /* IPv6 packet. Swap ip6_src with ip6_dst.
> > +         * We could also use packet_set_ipv6() here, but that would require
> > +         * to extract the 'tc' and 'label' from in_nh->ip6_flow which seems
> > +         * unnecessary. */
> > +        struct ovs_16aligned_ip6_hdr *out_nh = dp_packet_l3(pkt_out);
> > +        union ovs_16aligned_in6_addr tmp = out_nh->ip6_src;
> > +        out_nh->ip6_src = out_nh->ip6_dst;
> > +        out_nh->ip6_dst = tmp;
> > +    }
> > +
> > +    pin->packet = dp_packet_data(pkt_out);
> > +    pin->packet_len = dp_packet_size(pkt_out);
> > +
> > +    queue_msg(swconn, ofputil_encode_resume(pin, continuation, proto));
> > +    dp_packet_delete(pkt_out);
> > +}
> > diff --git a/include/ovn/actions.h b/include/ovn/actions.h
> > index b4e5acabb9..bf1fe848b7 100644
> > --- a/include/ovn/actions.h
> > +++ b/include/ovn/actions.h
> > @@ -97,6 +97,7 @@ struct ovn_extend_table;
> >       OVNACT(DHCP6_REPLY,       ovnact_null)            \
> >       OVNACT(ICMP6_ERROR,       ovnact_nest)            \
> >       OVNACT(REJECT,            ovnact_nest)            \
> > +    OVNACT(OVNFIELD_EXCHANGE, ovnact_move)            \
> >
> >   /* enum ovnact_type, with a member OVNACT_<ENUM> for each action. */
> >   enum OVS_PACKED_ENUM ovnact_type {
> > @@ -612,6 +613,9 @@ enum action_opcode {
> >        * The actions, in OpenFlow 1.3 format, follow the action_header.
> >        */
> >       ACTION_OPCODE_REJECT,
> > +
> > +    /* ip.src <-> ip.dst */
> > +    ACTION_OPCODE_SWAP_SRC_DST_IP,
> >   };
> >
> >   /* Header. */
> > diff --git a/include/ovn/logical-fields.h b/include/ovn/logical-fields.h
> > index ac6f2f909b..bb6daa50ca 100644
> > --- a/include/ovn/logical-fields.h
> > +++ b/include/ovn/logical-fields.h
> > @@ -116,6 +116,24 @@ enum ovn_field_id {
> >        */
> >       OVN_ICMP6_FRAG_MTU,
> >
> > +    /*
> > +     * Name: "ip.src"
> > +     * Type: be128
> > +     * Description: Sets the field MFF_IPV4_SRC if eth.type == 0x800 (IPv4)
> > +     *              or sets the field MFF_IPV6_SRC if
> > +     *              eth.type == 0x86dd (IPV6).
> > +     */
> > +    OVN_IP_SRC,
> > +
> > +    /*
> > +     * Name: "ip.dst"
> > +     * Type: be128
> > +     * Description: Sets the field MFF_IPV4_DST if eth.type == 0x800 (IPv4)
> > +     *              or sets the field MFF_IPV6_DST if
> > +     *              eth.type == 0x86dd (IPV6).
> > +     */
> > +    OVN_IP_DST,
> > +
> >       OVN_FIELD_N_IDS
> >   };
> >
> > diff --git a/lib/actions.c b/lib/actions.c
> > index 1e1bdeff24..da583f9c93 100644
> > --- a/lib/actions.c
> > +++ b/lib/actions.c
> > @@ -371,12 +371,35 @@ ovnact_next_free(struct ovnact_next *a OVS_UNUSED)
> >   {
> >   }
> >
> > +static bool
> > +check_ovnfield_load(struct action_context *ctx, const struct expr_field *field)
> > +{
> > +    switch (field->symbol->ovn_field->id) {
> > +    case OVN_ICMP4_FRAG_MTU:
> > +    case OVN_ICMP6_FRAG_MTU:
> > +        return true;
> > +
> > +    case OVN_IP_SRC:
> > +    case OVN_IP_DST:
> > +        lexer_error(ctx->lexer, "Can't load a value to ovn field (%s).",
> > +                    field->symbol->name);
> > +        return false;
> > +
> > +    case OVN_FIELD_N_IDS:
> > +    default:
> > +        OVS_NOT_REACHED();
> > +    }
> > +}
> > +
> >   static void
> >   parse_LOAD(struct action_context *ctx, const struct expr_field *lhs)
> >   {
> >       size_t ofs = ctx->ovnacts->size;
> >       struct ovnact_load *load;
> >       if (lhs->symbol->ovn_field) {
> > +        if (!check_ovnfield_load(ctx, lhs)) {
> > +            return;
> > +        }
> >           load = ovnact_put_OVNFIELD_LOAD(ctx->ovnacts);
> >       } else {
> >           load = ovnact_put_LOAD(ctx->ovnacts);
> > @@ -474,6 +497,43 @@ format_EXCHANGE(const struct ovnact_move *move, struct ds *s)
> >       format_assignment(move, "<->", s);
> >   }
> >
> > +static void
> > +parse_ovnfield_exchange(struct action_context *ctx,
> > +                        const struct expr_field *lhs,
> > +                        const struct expr_field *rhs)
> > +{
> > +    if (!lhs->symbol->ovn_field || !rhs->symbol->ovn_field) {
> > +        lexer_error(ctx->lexer,
> > +                    "Can't exchange ovn field with non ovn field (%s <-> %s).",
> > +                    lhs->symbol->name, rhs->symbol->name);
> > +        return;
> > +    }
> > +
> > +    if (lhs->symbol->ovn_field->id != OVN_IP_SRC &&
> > +            lhs->symbol->ovn_field->id != OVN_IP_DST) {
> > +        lexer_error(ctx->lexer,
> > +                    "Can't exchange ovn field (%s) with ovn field (%s).",
> > +                    lhs->symbol->name, rhs->symbol->name);
>
> Should this (and all the other if statements in this function) return?
> Otherwise, the lexer will report the error but still put the move into
> ctx->ovnacts.
>

Thanks Mark for spotting this. I think it's better to return. I'll
address this in the next
version.

Numan

> > +    }
> > +
> > +    if (rhs->symbol->ovn_field->id != OVN_IP_SRC &&
> > +            rhs->symbol->ovn_field->id != OVN_IP_DST) {
> > +        lexer_error(ctx->lexer,
> > +                    "Can't exchange ovn field (%s) with ovn field (%s).",
> > +                    lhs->symbol->name, rhs->symbol->name);
> > +    }
> > +
> > +    if (lhs->symbol->ovn_field->id == rhs->symbol->ovn_field->id) {
> > +        lexer_error(ctx->lexer,
> > +                    "Can't exchange ovn field (%s) with ovn field (%s).",
> > +                    lhs->symbol->name, rhs->symbol->name);
> > +    }
> > +
> > +    struct ovnact_move *move = ovnact_put_OVNFIELD_EXCHANGE(ctx->ovnacts);
> > +    move->lhs = *lhs;
> > +    move->rhs = *rhs;
> > +}
> > +
> >   static void
> >   parse_assignment_action(struct action_context *ctx, bool exchange,
> >                           const struct expr_field *lhs)
> > @@ -483,6 +543,11 @@ parse_assignment_action(struct action_context *ctx, bool exchange,
> >           return;
> >       }
> >
> > +    if (exchange && (lhs->symbol->ovn_field || rhs.symbol->ovn_field)) {
> > +        parse_ovnfield_exchange(ctx, lhs, &rhs);
> > +        return;
> > +    }
> > +
> >       const struct expr_symbol *ls = lhs->symbol;
> >       const struct expr_symbol *rs = rhs.symbol;
> >       if ((ls->width != 0) != (rs->width != 0)) {
> > @@ -3128,6 +3193,8 @@ format_OVNFIELD_LOAD(const struct ovnact_load *load , struct ds *s)
> >                         ntohs(load->imm.value.be16_int));
> >           break;
> >
> > +    case OVN_IP_SRC:
> > +    case OVN_IP_DST:
> >       case OVN_FIELD_N_IDS:
> >       default:
> >           OVS_NOT_REACHED();
> > @@ -3157,6 +3224,9 @@ encode_OVNFIELD_LOAD(const struct ovnact_load *load,
> >           encode_finish_controller_op(oc_offset, ofpacts);
> >           break;
> >       }
> > +
> > +    case OVN_IP_SRC:
> > +    case OVN_IP_DST:
> >       case OVN_FIELD_N_IDS:
> >       default:
> >           OVS_NOT_REACHED();
> > @@ -3451,6 +3521,51 @@ ovnact_fwd_group_free(struct ovnact_fwd_group *fwd_group)
> >       free(fwd_group->child_ports);
> >   }
> >
> > +static void
> > +format_OVNFIELD_EXCHANGE(const struct ovnact_move *move , struct ds *s)
> > +{
> > +    const struct ovn_field *lhs = ovn_field_from_name(move->lhs.symbol->name);
> > +    const struct ovn_field *rhs = ovn_field_from_name(move->rhs.symbol->name);
> > +    switch (lhs->id) {
> > +    case OVN_IP_SRC:
> > +    case OVN_IP_DST:
> > +        break;
> > +
> > +    case OVN_ICMP4_FRAG_MTU:
> > +    case OVN_ICMP6_FRAG_MTU:
> > +    case OVN_FIELD_N_IDS:
> > +    default:
> > +        OVS_NOT_REACHED();
> > +    }
> > +
> > +    switch (rhs->id) {
> > +    case OVN_IP_SRC:
> > +    case OVN_IP_DST:
> > +        break;
> > +
> > +    case OVN_ICMP4_FRAG_MTU:
> > +    case OVN_ICMP6_FRAG_MTU:
> > +    case OVN_FIELD_N_IDS:
> > +    default:
> > +        OVS_NOT_REACHED();
> > +    }
> > +
> > +    ds_put_format(s, "%s <-> %s;", lhs->name, rhs->name);
> > +}
> > +
> > +static void
> > +encode_OVNFIELD_EXCHANGE(const struct ovnact_move *move OVS_UNUSED,
> > +                         const struct ovnact_encode_params *ep OVS_UNUSED,
> > +                         struct ofpbuf *ofpacts OVS_UNUSED)
> > +{
> > +    /* Right now we only support exchanging the IPs in
> > +     * OVN fields (ip.src <-> ip.dst). */
> > +    size_t oc_offset =
> > +        encode_start_controller_op(ACTION_OPCODE_SWAP_SRC_DST_IP,
> > +                                   true, NX_CTLR_NO_METER, ofpacts);
> > +    encode_finish_controller_op(oc_offset, ofpacts);
> > +}
> > +
> >   /* Parses an assignment or exchange or put_dhcp_opts action. */
> >   static void
> >   parse_set_action(struct action_context *ctx)
> > diff --git a/lib/logical-fields.c b/lib/logical-fields.c
> > index bf61df7719..d6f1981f52 100644
> > --- a/lib/logical-fields.c
> > +++ b/lib/logical-fields.c
> > @@ -33,6 +33,14 @@ const struct ovn_field ovn_fields[OVN_FIELD_N_IDS] = {
> >           OVN_ICMP6_FRAG_MTU,
> >           "icmp6.frag_mtu",
> >           4, 32,
> > +    }, {
> > +        OVN_IP_SRC,
> > +        "ip.src",
> > +        16, 128,
> > +    }, {
> > +        OVN_IP_DST,
> > +        "ip.dst",
> > +        16, 128,
> >       },
> >   };
> >
> > @@ -271,6 +279,8 @@ ovn_init_symtab(struct shash *symtab)
> >
> >       expr_symtab_add_ovn_field(symtab, "icmp4.frag_mtu", OVN_ICMP4_FRAG_MTU);
> >       expr_symtab_add_ovn_field(symtab, "icmp6.frag_mtu", OVN_ICMP6_FRAG_MTU);
> > +    expr_symtab_add_ovn_field(symtab, "ip.src", OVN_IP_SRC);
> > +    expr_symtab_add_ovn_field(symtab, "ip.dst", OVN_IP_DST);
> >   }
> >
> >   const char *
> > diff --git a/ovn-sb.xml b/ovn-sb.xml
> > index 2fc84f54ee..73ee543bfe 100644
> > --- a/ovn-sb.xml
> > +++ b/ovn-sb.xml
> > @@ -1258,6 +1258,43 @@
> >               except that the two values are exchanged instead of copied.  Both
> >               <var>field1</var> and <var>field2</var> must modifiable.
> >             </p>
> > +
> > +          <p>
> > +            <code>OVN</code> supports exchange of below OVN logical fields.
> > +          </p>
> > +
> > +          <ul>
> > +            <li>
> > +              <code>ip.src</code>
> > +              <code>ip.dst</code>
> > +              <p>
> > +                These fields can be used to refer to IP source and destination
> > +                fields which are IP version independent. These fields can be
> > +                used only for exchange of values.
> > +              </p>
> > +            </li>
> > +
> > +            <li>
> > +              <p>
> > +                Below are few examples:
> > +              </p>
> > +
> > +              <p>
> > +                match = "ip && tcp"
> > +                action = "ip.src <-> ip.dst; next;"
> > +              </p>
> > +
> > +              <p>
> > +                match = "ip4 || ip6"
> > +                action = reject { ip.src <-> ip.dst; } next;"
> > +              </p>
> > +
> > +              <p>
> > +                match = "ip && (tcp || udp)"
> > +                action = "ip.src <-> ip.dst; next;"
> > +              </p>
> > +            </li>
> > +          </ul>
> >           </dd>
> >
> >           <dt><code>ip.ttl--;</code></dt>
> > diff --git a/tests/ovn.at b/tests/ovn.at
> > index d849425f00..9fb22c03d3 100644
> > --- a/tests/ovn.at
> > +++ b/tests/ovn.at
> > @@ -1605,6 +1605,33 @@ reject { };
> >       formats as reject { drop; };
> >       encodes as controller(userdata=00.00.00.16.00.00.00.00)
> >
> > +ip.src <-> ip.dst;
> > +    encodes as controller(userdata=00.00.00.17.00.00.00.00,pause)
> > +
> > +ip.src <-> ip.dst
> > +    Syntax error at end of input expecting `;'.
> > +
> > +ip.src = 10.0.0.10;
> > +    Can't load a value to ovn field (ip.src).
> > +
> > +ip.dst = aef0::4;
> > +    Can't load a value to ovn field (ip.dst).
> > +
> > +ip.src <-> ip4.dst;
> > +    Can't exchange ovn field with non ovn field (ip.src <-> ip4.dst).
> > +
> > +ip6.src <-> ip.dst;
> > +    Can't exchange ovn field with non ovn field (ip6.src <-> ip.dst).
> > +
> > +ip.src <-> icmp4.frag_mtu;
> > +    Can't exchange ovn field (ip.src) with ovn field (icmp4.frag_mtu).
> > +
> > +icmp6.frag_mtu <-> ip.dst;
> > +    Can't exchange ovn field (icmp6.frag_mtu) with ovn field (ip.dst).
> > +
> > +ip.src <-> ip.src;
> > +    Can't exchange ovn field (ip.src) with ovn field (ip.src).
> > +
> >   # trigger_event
> >   trigger_event(event = "empty_lb_backends", vip = "10.0.0.1:80", protocol = "tcp", load_balancer = "12345678-abcd-9876-fedc-11119f8e7d6c");
> >       encodes as controller(userdata=00.00.00.0f.00.00.00.00.00.00.00.00.00.01.00.0b.31.30.2e.30.2e.30.2e.31.3a.38.30.00.02.00.03.74.63.70.00.03.00.24.31.32.33.34.35.36.37.38.2d.61.62.63.64.2d.39.38.37.36.2d.66.65.64.63.2d.31.31.31.31.39.66.38.65.37.64.36.63)
> > diff --git a/utilities/ovn-trace.c b/utilities/ovn-trace.c
> > index 38aee6081b..ed7d8bf278 100644
> > --- a/utilities/ovn-trace.c
> > +++ b/utilities/ovn-trace.c
> > @@ -2147,12 +2147,35 @@ execute_ovnfield_load(const struct ovnact_load *load,
> >                                ntohs(load->imm.value.be16_int));
> >           break;
> >       }
> > +
> > +    case OVN_IP_SRC:
> > +    case OVN_IP_DST:
> >       case OVN_FIELD_N_IDS:
> >       default:
> >           OVS_NOT_REACHED();
> >       }
> >   }
> >
> > +static void
> > +execute_ovnfield_exchange(const struct ovnact_move *move OVS_UNUSED,
> > +                          struct flow *uflow,
> > +                          struct ovs_list *super)
> > +{
> > +    /* Right now we support exchanging of ip.src with ip.dst. */
> > +    ovntrace_node_append(super, OVNTRACE_NODE_MODIFY,
> > +                         "ip.src <-> ip.dst");
> > +
> > +    if (get_dl_type(uflow) == htons(ETH_TYPE_IP)) {
> > +        ovs_be32 tmp = uflow->nw_dst;
> > +        uflow->nw_dst = uflow->nw_src;
> > +        uflow->nw_src = tmp;
> > +    } else {
> > +        struct in6_addr tmp = uflow->ipv6_dst;
> > +        uflow->ipv6_dst = uflow->ipv6_src;
> > +        uflow->ipv6_src = tmp;
> > +    }
> > +}
> > +
> >   static void
> >   trace_actions(const struct ovnact *ovnacts, size_t ovnacts_len,
> >                 const struct ovntrace_datapath *dp, struct flow *uflow,
> > @@ -2369,6 +2392,11 @@ trace_actions(const struct ovnact *ovnacts, size_t ovnacts_len,
> >                              pipeline, super);
> >               break;
> >
> > +        case OVNACT_OVNFIELD_EXCHANGE:
> > +            execute_ovnfield_exchange(ovnact_get_OVNFIELD_EXCHANGE(a),
> > +                                      uflow, super);
> > +            break;
> > +
> >           case OVNACT_TRIGGER_EVENT:
> >               break;
> >
> >
>
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