1. api

1.1. Introduction

This module is not a node.

1.2. Interface

Initial function is lb_api_init().

And support below API messages:

/* List of message types that this plugin understands */
#define foreach_lb_plugin_api_msg            \
_(LB_CONF, lb_conf)                          \
_(LB_ADD_DEL_VIP, lb_add_del_vip)            \
_(LB_ADD_DEL_AS, lb_add_del_as)              \
_(LB_FLUSH_VIP, lb_flush_vip)

2. cli

2.1. Introduction

This module is not a node.

2.2. Command

lb vip <prefix> 
[protocol (tcp|udp) port <n>] 
[encap (gre6|gre4|l3dsr|nat4|nat6)] 
[dscp <n>] 
[type (nodeport|clusterip) target_port <n>] 
[new_len <n>] [del]

lb as <vip-prefix> [protocol (tcp|udp) port <n>]
 [<address> [<address> [...]]] [del] [flush]

lb conf [ip4-src-address <addr>] [ip6-src-address <addr>] [buckets <n>] [timeout <s>]

show lb

show lb vips [verbose]

lb set interface nat4 in <intfc> [del]

lb set interface nat6 in <intfc> [del]

lb flush vip <prefix> 
[protocol (tcp|udp) port <n>]

test lb flowtable flush

3. lb_test

3.1. Introduction

This is not a node.

4. lb

4.1. Introduction

This module is not a node, and it registers load balancer plugin.

There is garbage collection mechanism to remove entry without reference.

4.2. Interface

Initial function is lb_init()

5. node

5.1. Introduction

There are 16 nodes:

• lb6_gre6_node
• lb6_gre4_node
• lb4_gre6_node
• lb4_gre4_node
• lb6_gre6_port_node
• lb6_gre4_port_node
• lb4_gre6_port_node
• lb4_gre4_port_node
• lb4_l3dsr_port_node
• lb4_l3dsr_node
• lb6_nat6_port_node
• lb4_nat4_port_node
• lb4_nodeport_node
• lb6_nodeport_node
• lb_nat4_in2out_node
• lb_nat6_in2out_node

5.2. Detail

5.2.1. lb6_gre6_node

This node is using lb_node_fn(), is_input_v4 is 0, encap_type is LB_ENCAP_TYPE_GRE6, per_port_vip is 0.

• Call lb_node_get_hash() to compute hash value.
• If input is IPv4, get IPv4 header and header length.
• If input is IPv6, get IPv6 header and header length.
• Call lb_hash_get() to search load balancer hash table.
  • timeout entry will be taken here.
• If found an existing entry, do nothing.
• If there is an available slot for a new flow.
  • Update reference counter.
  • Call lb_hash_put() to add hash entry.
• If could not store new entry in the table, use conflict entry.
• If encap_type is LB_ENCAP_TYPE_GRE4.
  • Source address is load balancer source address.
  • Destination address is application server address.
  • Update some other field.
  • IP protocol is IP_PROTOCOL_GRE.
  • Update IP checksum.
  • protocol is 0x0800.
• If encap_type is LB_ENCAP_TYPE_GRE6.
  • Source address is load balancer source address.
  • Destination address is application server address.
  • Update some other field.
  • IP protocol is IP_PROTOCOL_GRE.
  • protocol is 0x86DD.
• If encap_type is LB_ENCAP_TYPE_L3DSR.
  • Replace destination address with application server address.
  • Replace tos with VIP dscp value.
  • Update IP checksum.
  • Recomputing L4 checksum after dst-IP modifying.
• encap_type is LB_ENCAP_TYPE_NAT4.
  • If is_input_v4 is 1.
    • Replace destination address with application server address.
    • Update IP checksum.
    • If IP protocol is UDP.
      • Replace destination port with target port.
      • Update UDP checksum.
• encap_type is LB_ENCAP_TYPE_NAT6.
  • If is_input_v4 is 0.
    • Replace destination address with application server address.
    • If IP protocol is UDP.
      • Replace destination port with target port.
      • Update UDP checksum.

5.2.2. lb6_gre4_node

This node is using lb_node_fn(), is_input_v4 is 0, encap_type is LB_ENCAP_TYPE_GRE4, per_port_vip is 0.

5.2.3. lb4_gre6_node

This node is using lb_node_fn(), is_input_v4 is 1, encap_type is LB_ENCAP_TYPE_GRE6, per_port_vip is 0.

5.2.4. lb4_gre4_node

This node is using lb_node_fn(), is_input_v4 is 1, encap_type is LB_ENCAP_TYPE_GRE4, per_port_vip is 0.

5.2.5. lb6_gre6_port_node

This node is using lb_node_fn(), is_input_v4 is 0, encap_type is LB_ENCAP_TYPE_GRE6, per_port_vip is 1.

5.2.6. lb6_gre4_port_node

This node is using lb_node_fn(), is_input_v4 is 0, encap_type is LB_ENCAP_TYPE_GRE4, per_port_vip is 1.

5.2.7. lb4_gre6_port_node

This node is using lb_node_fn(), is_input_v4 is 1, encap_type is LB_ENCAP_TYPE_GRE6, per_port_vip is 1.

5.2.8. lb4_gre4_port_node

This node is using lb_node_fn(), is_input_v4 is 1, encap_type is LB_ENCAP_TYPE_GRE4, per_port_vip is 1.

5.2.9. lb4_l3dsr_port_node

This node is using lb_node_fn(), is_input_v4 is 1, encap_type is LB_ENCAP_TYPE_L3DSR, per_port_vip is 1.

5.2.10. lb4_l3dsr_node

This node is using lb_node_fn(), is_input_v4 is 1, encap_type is LB_ENCAP_TYPE_L3DSR, per_port_vip is 0.

5.2.11. lb6_nat6_port_node

This node is using lb_node_fn(), is_input_v4 is 0, encap_type is LB_ENCAP_TYPE_NAT6, per_port_vip is 1.

5.2.12. lb4_nat4_port_node

This node is using lb_node_fn(), is_input_v4 is 1, encap_type is LB_ENCAP_TYPE_NAT4, per_port_vip is 1.

5.2.13. lb4_nodeport_node

This node is used before lb4-nat4-port.

This node is using lb_nodeport_node_fn(), is_input_v4 is 1.

• If is_input_v4 is 1, get IPv4 header and UDP header.
• If is_input_v4 is 0, get IPv6 header and UDP header.
• Call hash_get_mem() to get hash entry.
  • Key is UDP destination port.
• Enqueue to next.

5.2.14. lb6_nodeport_node

This node is used before lb6-nat6-port.

This node is using lb_nodeport_node_fn(), is_input_v4 is 0.

5.2.15. lb_nat4_in2out_node

This node is used before ip4-lookup.

This node is using lb_nat_in2out_node_fn(), is_nat4 is 1.

• If is_nat4 is 1.
  • Call lb_nat44_mapping_match() to get mapping.
    • Search mapping_by_as4 table.
  • Replace source address and update IP checksum.
  • If IP protocol is TCP.
    • Replace source port and update TCP checksum.
  • If IP protocol is UDP.
    • Replace source port and update UDP checksum.
• If is_nat4 is 0.
  • Call lb_nat66_mapping_match() to get mapping.
    • Search mapping_by_as6 table.
  • Replace source address.
  • If IP protocol is TCP.
    • Replace source port and update TCP checksum.
  • If IP protocol is UDP.
    • Replace source port and update UDP checksum.

5.2.16. lb_nat6_in2out_node

This node is used before ip6-lookup.

This node is using lb_nat_in2out_node_fn(), is_nat4 is 0.

6. util

6.1. Introduction

This module is not a node.