net/ipv4/esp4.c

File Facts

System

Linux kernel

Corpus path

net/ipv4/esp4.c

Extension

.c

Size

28144 bytes

Lines

1219

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

• crypto/aead.h
• crypto/authenc.h
• linux/err.h
• linux/module.h
• net/ip.h
• net/xfrm.h
• net/esp.h
• linux/scatterlist.h
• linux/kernel.h
• linux/pfkeyv2.h
• linux/rtnetlink.h
• linux/slab.h
• linux/spinlock.h
• linux/in6.h
• net/icmp.h
• net/protocol.h
• net/udp.h
• net/tcp.h
• net/espintcp.h
• linux/skbuff_ref.h
• linux/highmem.h

Detected Declarations

• struct esp_skb_cb
• struct esp_output_extra
• function esp_ssg_unref
• function esp_output_tcp_finish
• function esp_output_tcp_encap_cb
• function esp_output_tail_tcp
• function esp_output_tail_tcp
• function esp_output_done
• function esp_restore_header
• function esp_output_restore_header
• function esp_output_done_esn
• function esp_output_encap
• function esp_output_head
• function esp_output_tail
• function esp_output
• function esp_remove_trailer
• function esp_input_done2
• function esp_input_done
• function esp_input_restore_header
• function esp_input_set_header
• function esp_input_done_esn
• function esp_input
• function esp4_err
• function esp_destroy
• function esp_init_aead
• function esp_init_authenc
• function esp_init_state
• function esp4_rcv_cb
• function esp4_init
• function esp4_fini
• module init esp4_init
• export esp_output_head
• export esp_output_tail
• export esp_input_done2

Annotated Snippet

module_init(esp4_init);
module_exit(esp4_fini);
MODULE_DESCRIPTION("IPv4 ESP transformation library");
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);

Annotation

• Immediate include surface: `crypto/aead.h`, `crypto/authenc.h`, `linux/err.h`, `linux/module.h`, `net/ip.h`, `net/xfrm.h`, `net/esp.h`, `linux/scatterlist.h`.
• Detected declarations: `struct esp_skb_cb`, `struct esp_output_extra`, `function esp_ssg_unref`, `function esp_output_tcp_finish`, `function esp_output_tcp_encap_cb`, `function esp_output_tail_tcp`, `function esp_output_tail_tcp`, `function esp_output_done`, `function esp_restore_header`, `function esp_output_restore_header`.
• 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.