net/ipv4/gre_demux.c

Source file repositories/reference/linux-study-clean/net/ipv4/gre_demux.c

File Facts

System: Linux kernel
Corpus path: net/ipv4/gre_demux.c
Extension: .c
Size: 5089 bytes
Lines: 226
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.
Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

linux/module.h
linux/if.h
linux/icmp.h
linux/kernel.h
linux/kmod.h
linux/skbuff.h
linux/in.h
linux/ip.h
linux/netdevice.h
linux/if_tunnel.h
linux/spinlock.h
net/protocol.h
net/gre.h
net/erspan.h
net/icmp.h
net/route.h
net/xfrm.h

Detected Declarations

function gre_add_protocol
function gre_del_protocol
function pskb_may_pull
function gre_rcv
function gre_err
function gre_init
function gre_exit
module init gre_init
export gre_add_protocol
export gre_del_protocol
export gre_parse_header

Annotated Snippet

module_init(gre_init);
module_exit(gre_exit);

MODULE_DESCRIPTION("GRE over IPv4 demultiplexer driver");
MODULE_AUTHOR("D. Kozlov <xeb@mail.ru>");
MODULE_LICENSE("GPL");

Annotation

Immediate include surface: `linux/module.h`, `linux/if.h`, `linux/icmp.h`, `linux/kernel.h`, `linux/kmod.h`, `linux/skbuff.h`, `linux/in.h`, `linux/ip.h`.
Detected declarations: `function gre_add_protocol`, `function gre_del_protocol`, `function pskb_may_pull`, `function gre_rcv`, `function gre_err`, `function gre_init`, `function gre_exit`, `module init gre_init`, `export gre_add_protocol`, `export gre_del_protocol`.
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.