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  • Openvswitch原理与代码分析(8): 修改Openvswitch代码添加自定义action

    有时候我们需要自定义一些自己的action，根据包头里面的信息，做一些自己的操作。

     

    例如添加一个action名为handle_example

     

    第一、修改ofp-actions.c文件

     

    首先在ofp-actions.c里面添加Openflow各个版本的这个action

    1. static const struct ofpact_map *
    2. get_ofpact_map(enum ofp_version version)
    3. {
    4.     /* OpenFlow 1.0 actions. */
    5.     static const struct ofpact_map of10[] = {
    6.         { OFPACT_OUTPUT, 0 },
    7.         { OFPACT_SET_VLAN_VID, 1 },
    8.         { OFPACT_SET_VLAN_PCP, 2 },
    9.         { OFPACT_STRIP_VLAN, 3 },
    10.         { OFPACT_SET_ETH_SRC, 4 },
    11.         { OFPACT_SET_ETH_DST, 5 },
    12.         { OFPACT_SET_IPV4_SRC, 6 },
    13.         { OFPACT_SET_IPV4_DST, 7 },
    14.         { OFPACT_SET_IP_DSCP, 8 },
    15.         { OFPACT_SET_L4_SRC_PORT, 9 },
    16.         { OFPACT_SET_L4_DST_PORT, 10 },
    17.         { OFPACT_ENQUEUE, 11 },
    18.         { OFPACT_HANDLE_EXAMPLE, 28 },
    19.         { 0, -1 },
    20.     };
    21.  
    22.     /* OpenFlow 1.1 actions. */
    23.     static const struct ofpact_map of11[] = {
    24.         { OFPACT_OUTPUT, 0 },
    25.         { OFPACT_SET_VLAN_VID, 1 },
    26.         { OFPACT_SET_VLAN_PCP, 2 },
    27.         { OFPACT_SET_ETH_SRC, 3 },
    28.         { OFPACT_SET_ETH_DST, 4 },
    29.         { OFPACT_SET_IPV4_SRC, 5 },
    30.         { OFPACT_SET_IPV4_DST, 6 },
    31.         { OFPACT_SET_IP_DSCP, 7 },
    32.         { OFPACT_SET_IP_ECN, 8 },
    33.         { OFPACT_SET_L4_SRC_PORT, 9 },
    34.         { OFPACT_SET_L4_DST_PORT, 10 },
    35.         /* OFPAT_COPY_TTL_OUT (11) not supported. */
    36.         /* OFPAT_COPY_TTL_IN (12) not supported. */
    37.         { OFPACT_SET_MPLS_LABEL, 13 },
    38.         { OFPACT_SET_MPLS_TC, 14 },
    39.         { OFPACT_SET_MPLS_TTL, 15 },
    40.         { OFPACT_DEC_MPLS_TTL, 16 },
    41.         { OFPACT_PUSH_VLAN, 17 },
    42.         { OFPACT_STRIP_VLAN, 18 },
    43.         { OFPACT_PUSH_MPLS, 19 },
    44.         { OFPACT_POP_MPLS, 20 },
    45.         { OFPACT_SET_QUEUE, 21 },
    46.         { OFPACT_GROUP, 22 },
    47.         { OFPACT_SET_IP_TTL, 23 },
    48.         { OFPACT_DEC_TTL, 24 },
    49.         { OFPACT_HANDLE_EXAMPLE, 28 },
    50.         { 0, -1 },
    51.     };
    52.  
    53.     /* OpenFlow 1.2, 1.3, and 1.4 actions. */
    54.     static const struct ofpact_map of12[] = {
    55.         { OFPACT_OUTPUT, 0 },
    56.         /* OFPAT_COPY_TTL_OUT (11) not supported. */
    57.         /* OFPAT_COPY_TTL_IN (12) not supported. */
    58.         { OFPACT_SET_MPLS_TTL, 15 },
    59.         { OFPACT_DEC_MPLS_TTL, 16 },
    60.         { OFPACT_PUSH_VLAN, 17 },
    61.         { OFPACT_STRIP_VLAN, 18 },
    62.         { OFPACT_PUSH_MPLS, 19 },
    63.         { OFPACT_POP_MPLS, 20 },
    64.         { OFPACT_SET_QUEUE, 21 },
    65.         { OFPACT_GROUP, 22 },
    66.         { OFPACT_SET_IP_TTL, 23 },
    67.         { OFPACT_DEC_TTL, 24 },
    68.         { OFPACT_SET_FIELD, 25 },
    69.         /* OF1.3+ OFPAT_PUSH_PBB (26) not supported. */
    70.         /* OF1.3+ OFPAT_POP_PBB (27) not supported. */
    71.         { OFPACT_HANDLE_EXAMPLE, 28 },
    72.         { 0, -1 },
    73.     };
    74.  
    75.     switch (version) {
    76.     case OFP10_VERSION:
    77.         return of10;
    78.  
    79.     case OFP11_VERSION:
    80.         return of11;
    81.  
    82.     case OFP12_VERSION:
    83.     case OFP13_VERSION:
    84.     case OFP14_VERSION:
    85.     case OFP15_VERSION:
    86.     default:
    87.         return of12;
    88.     }
    89. }

     

    其次添加raw action type

    1. enum ofp_raw_action_type {
    2. /* ## ----------------- ## */
    3. /* ## Standard actions. ## */
    4. /* ## ----------------- ## */
    5.  
    6.     /* OF1.0(0): struct ofp10_action_output. */
    7.     OFPAT_RAW10_OUTPUT,
    8.     /* OF1.1+(0): struct ofp11_action_output. */
    9.     OFPAT_RAW11_OUTPUT,
    10.  
    11.     /* OF1.0(1): uint16_t. */
    12.     OFPAT_RAW10_SET_VLAN_VID,
    13.     /* OF1.0(2): uint8_t. */
    14.     OFPAT_RAW10_SET_VLAN_PCP,
    15.  
    16.     /* OF1.1(1), OF1.2+(1) is deprecated (use Set-Field): uint16_t.
    17.      *
    18.      * [Semantics differ slightly between the 1.0 and 1.1 versions of the VLAN
    19.      * modification actions: the 1.0 versions push a VLAN header if none is
    20.      * present, but the 1.1 versions do not. That is the only reason that we
    21.      * distinguish their raw action types.] */
    22.     OFPAT_RAW11_SET_VLAN_VID,
    23.     /* OF1.1(2), OF1.2+(2) is deprecated (use Set-Field): uint8_t. */
    24.     OFPAT_RAW11_SET_VLAN_PCP,
    25.  
    26.     /* OF1.1+(17): ovs_be16.
    27.      *
    28.      * [The argument is the Ethertype, e.g. ETH_TYPE_VLAN_8021Q, not the VID or
    29.      * TCI.] */
    30.     OFPAT_RAW11_PUSH_VLAN,
    31.  
    32.     /* OF1.0(3): void. */
    33.     OFPAT_RAW10_STRIP_VLAN,
    34.     /* OF1.1+(18): void. */
    35.     OFPAT_RAW11_POP_VLAN,
    36.  
    37.     /* OF1.0(4), OF1.1(3), OF1.2+(3) is deprecated (use Set-Field): struct
    38.      * ofp_action_dl_addr. */
    39.     OFPAT_RAW_SET_DL_SRC,
    40.  
    41.     /* OF1.0(5), OF1.1(4), OF1.2+(4) is deprecated (use Set-Field): struct
    42.      * ofp_action_dl_addr. */
    43.     OFPAT_RAW_SET_DL_DST,
    44.  
    45.     /* OF1.0(6), OF1.1(5), OF1.2+(5) is deprecated (use Set-Field):
    46.      * ovs_be32. */
    47.     OFPAT_RAW_SET_NW_SRC,
    48.  
    49.     /* OF1.0(7), OF1.1(6), OF1.2+(6) is deprecated (use Set-Field):
    50.      * ovs_be32. */
    51.     OFPAT_RAW_SET_NW_DST,
    52.  
    53.     /* OF1.0(8), OF1.1(7), OF1.2+(7) is deprecated (use Set-Field): uint8_t. */
    54.     OFPAT_RAW_SET_NW_TOS,
    55.  
    56.     /* OF1.1(8), OF1.2+(8) is deprecated (use Set-Field): uint8_t. */
    57.     OFPAT_RAW11_SET_NW_ECN,
    58.  
    59.     /* OF1.0(9), OF1.1(9), OF1.2+(9) is deprecated (use Set-Field):
    60.      * ovs_be16. */
    61.     OFPAT_RAW_SET_TP_SRC,
    62.  
    63.     /* OF1.0(10), OF1.1(10), OF1.2+(10) is deprecated (use Set-Field):
    64.      * ovs_be16. */
    65.     OFPAT_RAW_SET_TP_DST,
    66.  
    67.     /* OF1.0(11): struct ofp10_action_enqueue. */
    68.     OFPAT_RAW10_ENQUEUE,
    69.  
    70.     /* NX1.0(30), OF1.1(13), OF1.2+(13) is deprecated (use Set-Field):
    71.      * ovs_be32. */
    72.     OFPAT_RAW_SET_MPLS_LABEL,
    73.  
    74.     /* NX1.0(31), OF1.1(14), OF1.2+(14) is deprecated (use Set-Field):
    75.      * uint8_t. */
    76.     OFPAT_RAW_SET_MPLS_TC,
    77.  
    78.     /* NX1.0(25), OF1.1(15), OF1.2+(15) is deprecated (use Set-Field):
    79.      * uint8_t. */
    80.     OFPAT_RAW_SET_MPLS_TTL,
    81.  
    82.     /* NX1.0(26), OF1.1+(16): void. */
    83.     OFPAT_RAW_DEC_MPLS_TTL,
    84.  
    85.     /* NX1.0(23), OF1.1+(19): ovs_be16.
    86.      *
    87.      * [The argument is the Ethertype, e.g. ETH_TYPE_MPLS, not the label.] */
    88.     OFPAT_RAW_PUSH_MPLS,
    89.  
    90.     /* NX1.0(24), OF1.1+(20): ovs_be16.
    91.      *
    92.      * [The argument is the Ethertype, e.g. ETH_TYPE_IPV4 if at BoS or
    93.      * ETH_TYPE_MPLS otherwise, not the label.] */
    94.     OFPAT_RAW_POP_MPLS,
    95.  
    96.     /* NX1.0(4), OF1.1+(21): uint32_t. */
    97.     OFPAT_RAW_SET_QUEUE,
    98.  
    99.     /* OF1.1+(22): uint32_t. */
    100.     OFPAT_RAW11_GROUP,
    101.  
    102.     /* OF1.1+(23): uint8_t. */
    103.     OFPAT_RAW11_SET_NW_TTL,
    104.  
    105.     /* NX1.0(18), OF1.1+(24): void. */
    106.     OFPAT_RAW_DEC_NW_TTL,
    107.     /* NX1.0+(21): struct nx_action_cnt_ids, ... */
    108.     NXAST_RAW_DEC_TTL_CNT_IDS,
    109.  
    110.     /* OF1.2-1.4(25): struct ofp12_action_set_field, ... */
    111.     OFPAT_RAW12_SET_FIELD,
    112.     /* OF1.5+(25): struct ofp12_action_set_field, ... */
    113.     OFPAT_RAW15_SET_FIELD,
    114.  
    115.     /* OF1.0(28): void. */
    116.     OFPAT_RAW10_HANDLE_EXAMPLE,
    117.  
    118.     /* OF1.1(28): void. */
    119.     OFPAT_RAW11_HANDLE_EXAMPLE,
    120.  
    121.     /* OF1.2-1.4(28): void. */
    122.     OFPAT_RAW12_HANDLE_EXAMPLE,
    123.  
    124.     /* NX1.0-1.4(7): struct nx_action_reg_load.
    125.      *
    126.      * [In OpenFlow 1.5, set_field is a superset of reg_load functionality, so
    127.      * we drop reg_load.] */
    128.     NXAST_RAW_REG_LOAD,
    129.     /* NX1.0-1.4(33): struct nx_action_reg_load2, ...
    130.      *
    131.      * [In OpenFlow 1.5, set_field is a superset of reg_load2 functionality, so
    132.      * we drop reg_load2.] */
    133.     NXAST_RAW_REG_LOAD2,
    134.  
    135.     /* OF1.5+(28): struct ofp15_action_copy_field, ... */
    136.     OFPAT_RAW15_COPY_FIELD,
    137.     /* ONF1.3-1.4(3200): struct onf_action_copy_field, ... */
    138.     ONFACT_RAW13_COPY_FIELD,
    139.     /* NX1.0-1.4(6): struct nx_action_reg_move, ... */
    140.     NXAST_RAW_REG_MOVE,
    141.  
    142. /* ## ------------------------- ## */
    143. /* ## Nicira extension actions. ## */
    144. /* ## ------------------------- ## */
    145.  
    146. /* Actions similar to standard actions are listed with the standard actions. */
    147.  
    148.     /* NX1.0+(1): uint16_t. */
    149.     NXAST_RAW_RESUBMIT,
    150.     /* NX1.0+(14): struct nx_action_resubmit. */
    151.     NXAST_RAW_RESUBMIT_TABLE,
    152.  
    153.     /* NX1.0+(2): uint32_t. */
    154.     NXAST_RAW_SET_TUNNEL,
    155.     /* NX1.0+(9): uint64_t. */
    156.     NXAST_RAW_SET_TUNNEL64,
    157.  
    158.     /* NX1.0+(5): void. */
    159.     NXAST_RAW_POP_QUEUE,
    160.  
    161.     /* NX1.0+(8): struct nx_action_note, ... */
    162.     NXAST_RAW_NOTE,
    163.  
    164.     /* NX1.0+(10): struct nx_action_multipath. */
    165.     NXAST_RAW_MULTIPATH,
    166.  
    167.     /* NX1.0+(12): struct nx_action_bundle, ... */
    168.     NXAST_RAW_BUNDLE,
    169.     /* NX1.0+(13): struct nx_action_bundle, ... */
    170.     NXAST_RAW_BUNDLE_LOAD,
    171.  
    172.     /* NX1.0+(15): struct nx_action_output_reg. */
    173.     NXAST_RAW_OUTPUT_REG,
    174.     /* NX1.0+(32): struct nx_action_output_reg2. */
    175.     NXAST_RAW_OUTPUT_REG2,
    176.  
    177.     /* NX1.0+(16): struct nx_action_learn, ... */
    178.     NXAST_RAW_LEARN,
    179.  
    180.     /* NX1.0+(17): void. */
    181.     NXAST_RAW_EXIT,
    182.  
    183.     /* NX1.0+(19): struct nx_action_fin_timeout. */
    184.     NXAST_RAW_FIN_TIMEOUT,
    185.  
    186.     /* NX1.0+(20): struct nx_action_controller. */
    187.     NXAST_RAW_CONTROLLER,
    188.  
    189.     /* NX1.0+(22): struct nx_action_write_metadata. */
    190.     NXAST_RAW_WRITE_METADATA,
    191.  
    192.     /* NX1.0+(27): struct nx_action_stack. */
    193.     NXAST_RAW_STACK_PUSH,
    194.  
    195.     /* NX1.0+(28): struct nx_action_stack. */
    196.     NXAST_RAW_STACK_POP,
    197.  
    198.     /* NX1.0+(29): struct nx_action_sample. */
    199.     NXAST_RAW_SAMPLE,
    200.  
    201.     /* NX1.0+(34): struct nx_action_conjunction. */
    202.     NXAST_RAW_CONJUNCTION,
    203.  
    204.     /* NX1.0+(35): struct nx_action_conntrack, ... */
    205.     NXAST_RAW_CT,
    206.  
    207. /* ## ------------------ ## */
    208. /* ## Debugging actions. ## */
    209. /* ## ------------------ ## */
    210.  
    211. /* These are intentionally undocumented, subject to change, and ovs-vswitchd */
    212. /* accepts them only if started with --enable-dummy. */
    213.  
    214.     /* NX1.0+(255): void. */
    215.     NXAST_RAW_DEBUG_RECIRC,
    216. };

     

    第三，添加handle example的action的处理函数

    1. /* handle gtp actions. */
    2. static enum ofperr
    3. decode_OFPAT_RAW10_HANDLE_EXAMPLE(struct ofpbuf *out)
    4. {
    5.     ofpact_put_HANDLE_EXAMPLE(out)->ofpact.raw = OFPAT_RAW10_HANDLE_EXAMPLE;
    6.     return 0;
    7. }
    8.  
    9. static enum ofperr
    10. decode_OFPAT_RAW11_HANDLE_EXAMPLE(struct ofpbuf *out)
    11. {
    12.     ofpact_put_HANDLE_EXAMPLE(out)->ofpact.raw = OFPAT_RAW11_HANDLE_EXAMPLE;
    13.     return 0;
    14. }
    15.  
    16. static enum ofperr
    17. decode_OFPAT_RAW12_HANDLE_EXAMPLE(struct ofpbuf *out)
    18. {
    19.     ofpact_put_HANDLE_EXAMPLE(out)->ofpact.raw = OFPAT_RAW12_HANDLE_EXAMPLE;
    20.     return 0;
    21. }
    22.  
    23. static void
    24. encode_HANDLE_EXAMPLE(const struct ofpact_null *null OVS_UNUSED,
    25.                   enum ofp_version ofp_version, struct ofpbuf *out)
    26. {
    27.     if (ofp_version == OFP10_VERSION) {
    28.         put_OFPAT10_HANDLE_EXAMPLE(out);
    29.     } else if (ofp_version == OFP11_VERSION) {
    30.         put_OFPAT11_HANDLE_EXAMPLE(out);
    31.     } else {
    32.         put_OFPAT12_HANDLE_EXAMPLE(out);
    33.     }
    34. }
    35.  
    36. static char * OVS_WARN_UNUSED_RESULT
    37. parse_HANDLE_EXAMPLE(char *arg OVS_UNUSED, struct ofpbuf *ofpacts,
    38.                  enum ofputil_protocol *usable_protocols OVS_UNUSED)
    39. {
    40.     ofpact_put_HANDLE_EXAMPLE(ofpacts)->ofpact.raw = OFPAT_RAW10_HANDLE_EXAMPLE;
    41.     return NULL;
    42. }
    43.  
    44. static void
    45. format_HANDLE_EXAMPLE(const struct ofpact_null *a OVS_UNUSED, struct ds *s)
    46. {
    47.     ds_put_cstr(s, "handle_example");
    48. }

     

    1. struct ofpact *
    2. ofpact_next_flattened(const struct ofpact *ofpact)
    3. {
    4. switch (ofpact->type) {
    5. case OFPACT_HANDLE_EXAMPLE:

     

    1. static bool
    2. ofpact_is_set_or_move_action(const struct ofpact *a)
    3. {
    4.     switch (a->type) {
    5.     case OFPACT_HANDLE_EXAMPLE:
    6. return true;

     

    1. static bool
    2. ofpact_is_allowed_in_actions_set(const struct ofpact *a)
    3. {
    4.     switch (a->type) {
    5.     case OFPACT_HANDLE_EXAMPLE:
    6. return true;

     

    1. enum ovs_instruction_type
    2. ovs_instruction_type_from_ofpact_type(enum ofpact_type type)
    3. {
    4.     switch (type) {
    5.     case OFPACT_HANDLE_EXAMPLE:

     

    1. static enum ofperr
    2. ofpact_check__(enum ofputil_protocol *usable_protocols, struct ofpact *a,
    3.                struct flow *flow, ofp_port_t max_ports,
    4.                uint8_t table_id, uint8_t n_tables)
    5. {
    6.     const struct ofpact_enqueue *enqueue;
    7.     const struct mf_field *mf;
    8.  
    9.     switch (a->type) {
    10.     case OFPACT_HANDLE_EXAMPLE:
    11.         return 0;

     

    1. static bool
    2. ofpact_outputs_to_port(const struct ofpact *ofpact, ofp_port_t port)
    3. {
    4.     switch (ofpact->type) {
    5.     case OFPACT_HANDLE_EXAMPLE:
    6.     default:
    7.         return false;

     

    第二，修改文件ofp-actions.h

     

    1. #define OFPACTS
    2.     /* Output. */
    3.     OFPACT(OUTPUT, ofpact_output, ofpact, "output")
    4.     OFPACT(GROUP, ofpact_group, ofpact, "group")
    5.     OFPACT(CONTROLLER, ofpact_controller, ofpact, "controller")
    6.     OFPACT(ENQUEUE, ofpact_enqueue, ofpact, "enqueue")
    7.     OFPACT(OUTPUT_REG, ofpact_output_reg, ofpact, "output_reg")
    8.     OFPACT(BUNDLE, ofpact_bundle, slaves, "bundle")
    9.                                                                         
    10.     /* Header changes. */
    11.     OFPACT(SET_FIELD, ofpact_set_field, ofpact, "set_field")
    12.     OFPACT(HANDLE_EXAMPLE, ofpact_null, ofpact, "handle_example")
    13.     OFPACT(SET_VLAN_VID, ofpact_vlan_vid, ofpact, "set_vlan_vid")
    14.     OFPACT(SET_VLAN_PCP, ofpact_vlan_pcp, ofpact, "set_vlan_pcp")
    15.     OFPACT(STRIP_VLAN, ofpact_null, ofpact, "strip_vlan")
    16.     OFPACT(PUSH_VLAN, ofpact_null, ofpact, "push_vlan")
    17.     OFPACT(SET_ETH_SRC, ofpact_mac, ofpact, "mod_dl_src")
    18.     OFPACT(SET_ETH_DST, ofpact_mac, ofpact, "mod_dl_dst")
    19.     OFPACT(SET_IPV4_SRC, ofpact_ipv4, ofpact, "mod_nw_src")
    20.     OFPACT(SET_IPV4_DST, ofpact_ipv4, ofpact, "mod_nw_dst")
    21.     OFPACT(SET_IP_DSCP, ofpact_dscp, ofpact, "mod_nw_tos")
    22.     OFPACT(SET_IP_ECN, ofpact_ecn, ofpact, "mod_nw_ecn")
    23.     OFPACT(SET_IP_TTL, ofpact_ip_ttl, ofpact, "mod_nw_ttl")
    24.     OFPACT(SET_L4_SRC_PORT, ofpact_l4_port, ofpact, "mod_tp_src")
    25.     OFPACT(SET_L4_DST_PORT, ofpact_l4_port, ofpact, "mod_tp_dst")
    26.     OFPACT(REG_MOVE, ofpact_reg_move, ofpact, "move")
    27.     OFPACT(STACK_PUSH, ofpact_stack, ofpact, "push")
    28.     OFPACT(STACK_POP, ofpact_stack, ofpact, "pop")
    29.     OFPACT(DEC_TTL, ofpact_cnt_ids, cnt_ids, "dec_ttl")
    30.     OFPACT(SET_MPLS_LABEL, ofpact_mpls_label, ofpact, "set_mpls_label")
    31.     OFPACT(SET_MPLS_TC, ofpact_mpls_tc, ofpact, "set_mpls_tc")
    32.     OFPACT(SET_MPLS_TTL, ofpact_mpls_ttl, ofpact, "set_mpls_ttl")
    33.     OFPACT(DEC_MPLS_TTL, ofpact_null, ofpact, "dec_mpls_ttl")
    34.     OFPACT(PUSH_MPLS, ofpact_push_mpls, ofpact, "push_mpls")
    35.     OFPACT(POP_MPLS, ofpact_pop_mpls, ofpact, "pop_mpls")
    36.                                                                         
    37.     /* Metadata. */
    38.     OFPACT(SET_TUNNEL, ofpact_tunnel, ofpact, "set_tunnel")
    39.     OFPACT(SET_QUEUE, ofpact_queue, ofpact, "set_queue")
    40.     OFPACT(POP_QUEUE, ofpact_null, ofpact, "pop_queue")
    41.     OFPACT(FIN_TIMEOUT, ofpact_fin_timeout, ofpact, "fin_timeout")
    42.                                                                         
    43.     /* Flow table interaction. */
    44.     OFPACT(RESUBMIT, ofpact_resubmit, ofpact, "resubmit")
    45.     OFPACT(LEARN, ofpact_learn, specs, "learn")
    46.     OFPACT(CONJUNCTION, ofpact_conjunction, ofpact, "conjunction")
    47.                                                                         
    48.     /* Arithmetic. */
    49.     OFPACT(MULTIPATH, ofpact_multipath, ofpact, "multipath")
    50.                                                                         
    51.     /* Other. */
    52.     OFPACT(NOTE, ofpact_note, data, "note")
    53.     OFPACT(EXIT, ofpact_null, ofpact, "exit")
    54.     OFPACT(SAMPLE, ofpact_sample, ofpact, "sample")
    55.     OFPACT(UNROLL_XLATE, ofpact_unroll_xlate, ofpact, "unroll_xlate")
    56.     OFPACT(CT, ofpact_conntrack, ofpact, "ct")
    57.                                                                         
    58.     /* Debugging actions.
    59.      *
    60.      * These are intentionally undocumented, subject to change, and
    61.      * only accepted if ovs-vswitchd is started with --enable-dummy. */
    62.     OFPACT(DEBUG_RECIRC, ofpact_null, ofpact, "debug_recirc")
    63.                                                                         
    64.     /* Instructions. */
    65.     OFPACT(METER, ofpact_meter, ofpact, "meter")
    66.     OFPACT(CLEAR_ACTIONS, ofpact_null, ofpact, "clear_actions")
    67.     OFPACT(WRITE_ACTIONS, ofpact_nest, ofpact, "write_actions")
    68.     OFPACT(WRITE_METADATA, ofpact_metadata, ofpact, "write_metadata")
    69.     OFPACT(GOTO_TABLE, ofpact_goto_table, ofpact, "goto_table")

     

    第三、修改ofprotoofproto-dpif-xlate.c文件

     

    1. static void
    2. recirc_unroll_actions(const struct ofpact *ofpacts, size_t ofpacts_len,
    3.                       struct xlate_ctx *ctx)
    4. {
    5.     const struct ofpact *a;
    6.  
    7.     OFPACT_FOR_EACH (a, ofpacts, ofpacts_len) {
    8.         switch (a->type) {
    9.         case OFPACT_OPERATE_EXAMPLE:
    10.             /* These may not generate PACKET INs. */
    11.             break;

     

    1. static void
    2. do_xlate_actions(const struct ofpact *ofpacts, size_t ofpacts_len,
    3.                  struct xlate_ctx *ctx)
    4. {
    5.     struct flow_wildcards *wc = ctx->wc;
    6.     struct flow *flow = &ctx->xin->flow;
    7.     const struct ofpact *a;
    8.  
    9.     if (ovs_native_tunneling_is_on(ctx->xbridge->ofproto)) {
    10.         tnl_neigh_snoop(flow, wc, ctx->xbridge->name);
    11.     }
    12.     /* dl_type already in the mask, not set below. */
    13.  
    14.     OFPACT_FOR_EACH (a, ofpacts, ofpacts_len) {
    15.         struct ofpact_controller *controller;
    16.         const struct ofpact_metadata *metadata;
    17.         const struct ofpact_set_field *set_field;
    18.         const struct mf_field *mf;
    19.  
    20.         if (ctx->error) {
    21.             break;
    22.         }
    23.  
    24.         if (ctx->exit) {
    25.             /* Check if need to store the remaining actions for later
    26.              * execution. */
    27.             if (exit_recirculates(ctx)) {
    28.                 recirc_unroll_actions(a, OFPACT_ALIGN(ofpacts_len -
    29.                                                       ((uint8_t *)a -
    30.                                                        (uint8_t *)ofpacts)),
    31.                                       ctx);
    32.             }
    33.             break;
    34.         }
    35.  
    36.         switch (a->type) {
    37.    case OFPACT_HANDLE_EXAMPLE:
    38.             VLOG_INFO("OFPACT_HANDLE_EXAMPLE");
    39.             CHECK_MPLS_RECIRCULATION();
    40.             handle_example(flow, wc, ctx->xin->packet, ctx);
    41.             break;

     

    最最重要的就是handle_example的实现，为你自己实现的逻辑，对于包头的修改可以通过修改flow来进行，也可以进一步解析ctx->xin->packet，也即解析网络包的正文。
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  • 原文地址：https://www.cnblogs.com/popsuper1982/p/5906722.html
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