net/netfilter/ipvs/ip_vs_sync.c

File Facts

System

Linux kernel

Corpus path

net/netfilter/ipvs/ip_vs_sync.c

Extension

.c

Size

55763 bytes

Lines

2062

Domain

Networking Core

Bucket

Sockets, Protocols, Packet Path, And Network Policy

Inferred role

Networking Core: implementation source

Status

source implementation candidate

Why This File Exists

Networking stack implementation surface: socket APIs, protocol dispatch, packet flow, routing, filtering, and network namespaces.

• Networking stack implementation surface: socket APIs, protocol dispatch, packet flow, routing, filtering, and network namespaces.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Allocates kernel memory; connect allocation flags and lifetime to context constraints.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/module.h
• linux/slab.h
• linux/inetdevice.h
• linux/net.h
• linux/completion.h
• linux/delay.h
• linux/skbuff.h
• linux/in.h
• linux/igmp.h
• linux/udp.h
• linux/err.h
• linux/kthread.h
• linux/wait.h
• linux/kernel.h
• linux/sched/signal.h
• linux/unaligned.h
• net/ip.h
• net/sock.h
• net/ip_vs.h

Detected Declarations

• struct ip_vs_sync_conn_v0
• struct ip_vs_sync_conn_options
• struct ip_vs_sync_v4
• struct ip_vs_sync_v6
• struct ip_vs_sync_thread_data
• struct ip_vs_sync_mesg_v0
• struct ip_vs_sync_mesg
• struct ip_vs_sync_buff
• function ntoh_seq
• function hton_seq
• function sb_dequeue
• function ip_vs_sync_buff_create
• function ip_vs_sync_buff_release
• function sb_queue_tail
• function get_curr_sync_buff
• function select_master_thread_id
• function ip_vs_sync_buff_create_v0
• function in_persistence
• function with
• function ip_vs_sync_conn_v0
• function ip_vs_sync_conn
• function ip_vs_conn_fill_param_sync
• function ip_vs_proc_conn
• function ip_vs_process_message_v0
• function ip_vs_proc_seqopt
• function ip_vs_proc_str
• function ip_vs_proc_sync_conn
• function ip_vs_process_message
• function sndbuf
• function set_mcast_loop
• function set_mcast_ttl
• function set_mcast_pmtudisc
• function set_mcast_if
• function join_mcast_group
• function join_mcast_group6
• function bind_mcastif_addr
• function get_mcast_sockaddr
• function make_send_sock
• function make_receive_sock
• function ip_vs_send_async
• function ip_vs_send_sync_msg
• function ip_vs_receive
• function master_wakeup_work_handler
• function next_sync_buff
• function sync_thread_master
• function sync_thread_backup
• function start_sync_thread
• function stop_sync_thread

Annotated Snippet

struct ip_vs_sync_conn_v0 {
	__u8			reserved;

	/* Protocol, addresses and port numbers */
	__u8			protocol;       /* Which protocol (TCP/UDP) */
	__be16			cport;
	__be16                  vport;
	__be16                  dport;
	__be32                  caddr;          /* client address */
	__be32                  vaddr;          /* virtual address */
	__be32                  daddr;          /* destination address */

	/* Flags and state transition */
	__be16                  flags;          /* status flags */
	__be16                  state;          /* state info */

	/* The sequence options start here */
};

struct ip_vs_sync_conn_options {
	struct ip_vs_seq        in_seq;         /* incoming seq. struct */
	struct ip_vs_seq        out_seq;        /* outgoing seq. struct */
};

/*
     Sync Connection format (sync_conn)

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    Type       |    Protocol   | Ver.  |        Size           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                             Flags                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |            State              |         cport                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |            vport              |         dport                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                             fwmark                            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                             timeout  (in sec.)                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                              ...                              |
      |                        IP-Addresses  (v4 or v6)               |
      |                              ...                              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  Optional Parameters.
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | Param. Type    | Param. Length |   Param. data                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               |
      |                              ...                              |
      |                               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                               | Param Type    | Param. Length |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           Param  data                         |
      |         Last Param data should be padded for 32 bit alignment |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/

/*
 *  Type 0, IPv4 sync connection format
 */
struct ip_vs_sync_v4 {
	__u8			type;
	__u8			protocol;	/* Which protocol (TCP/UDP) */
	__be16			ver_size;	/* Version msb 4 bits */
	/* Flags and state transition */
	__be32			flags;		/* status flags */
	__be16			state;		/* state info 	*/
	/* Protocol, addresses and port numbers */
	__be16			cport;
	__be16			vport;
	__be16			dport;
	__be32			fwmark;		/* Firewall mark from skb */
	__be32			timeout;	/* cp timeout */
	__be32			caddr;		/* client address */
	__be32			vaddr;		/* virtual address */
	__be32			daddr;		/* destination address */
	/* The sequence options start here */
	/* PE data padded to 32bit alignment after seq. options */
};
/*
 * Type 2 messages IPv6
 */
struct ip_vs_sync_v6 {
	__u8			type;
	__u8			protocol;	/* Which protocol (TCP/UDP) */
	__be16			ver_size;	/* Version msb 4 bits */
	/* Flags and state transition */
	__be32			flags;		/* status flags */

Annotation

• Immediate include surface: `linux/module.h`, `linux/slab.h`, `linux/inetdevice.h`, `linux/net.h`, `linux/completion.h`, `linux/delay.h`, `linux/skbuff.h`, `linux/in.h`.
• Detected declarations: `struct ip_vs_sync_conn_v0`, `struct ip_vs_sync_conn_options`, `struct ip_vs_sync_v4`, `struct ip_vs_sync_v6`, `struct ip_vs_sync_thread_data`, `struct ip_vs_sync_mesg_v0`, `struct ip_vs_sync_mesg`, `struct ip_vs_sync_buff`, `function ntoh_seq`, `function hton_seq`.
• Atlas domain: Networking Core / Sockets, Protocols, Packet Path, And Network Policy.
• Implementation status: source implementation candidate.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.