net/ipv4/fou_core.c

File Facts

System

Linux kernel

Corpus path

net/ipv4/fou_core.c

Extension

.c

Size

27324 bytes

Lines

1281

Domain

Networking Core

Bucket

Sockets, Protocols, Packet Path, And Network Policy

Inferred role

Networking Core: exported/initcall integration point

Status

integration 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.
• Exports symbols or registers init work; inspect boot/module ordering and who consumes the exported contract.
• 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/errno.h
• linux/socket.h
• linux/skbuff.h
• linux/ip.h
• linux/icmp.h
• linux/udp.h
• linux/types.h
• linux/kernel.h
• net/genetlink.h
• net/gro.h
• net/gue.h
• net/fou.h
• net/ip.h
• net/protocol.h
• net/udp.h
• net/udp_tunnel.h
• uapi/linux/fou.h
• uapi/linux/genetlink.h
• fou_nl.h

Detected Declarations

• struct fou
• struct fou_cfg
• struct fou_net
• function fou_recv_pull
• function fou_udp_recv
• function gue_control_message
• function gue_udp_recv
• function fou_gro_complete
• function list_for_each_entry
• function gue_gro_complete
• function fou_cfg_cmp
• function fou_add_to_port_list
• function fou_release
• function fou_create
• function fou_destroy
• function parse_nl_config
• function fou_nl_add_doit
• function fou_nl_del_doit
• function fou_fill_info
• function fou_dump_info
• function fou_nl_get_doit
• function fou_nl_get_dumpit
• function fou_encap_hlen
• function gue_encap_hlen
• function __fou_build_header
• function __gue_build_header
• function fou_build_udp
• function fou_build_header
• function gue_build_header
• function gue_err_proto_handler
• function gue_err
• function ip_tunnel_encap_add_fou_ops
• function ip_tunnel_encap_del_fou_ops
• function ip_tunnel_encap_add_fou_ops
• function ip_tunnel_encap_del_fou_ops
• function fou_exit_net
• function fou_init
• function fou_fini
• module init fou_init
• export fou_encap_hlen
• export gue_encap_hlen
• export __fou_build_header
• export __gue_build_header

Annotated Snippet

module_init(fou_init);
module_exit(fou_fini);
MODULE_AUTHOR("Tom Herbert <therbert@google.com>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Foo over UDP");

Annotation

• Immediate include surface: `linux/module.h`, `linux/errno.h`, `linux/socket.h`, `linux/skbuff.h`, `linux/ip.h`, `linux/icmp.h`, `linux/udp.h`, `linux/types.h`.
• Detected declarations: `struct fou`, `struct fou_cfg`, `struct fou_net`, `function fou_recv_pull`, `function fou_udp_recv`, `function gue_control_message`, `function gue_udp_recv`, `function fou_gro_complete`, `function list_for_each_entry`, `function gue_gro_complete`.
• Atlas domain: Networking Core / Sockets, Protocols, Packet Path, And Network Policy.
• Implementation status: integration 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.