net/l2tp/l2tp_core.c

File Facts

System

Linux kernel

Corpus path

net/l2tp/l2tp_core.c

Extension

.c

Size

52556 bytes

Lines

1955

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/string.h
• linux/list.h
• linux/rculist.h
• linux/uaccess.h
• linux/kernel.h
• linux/spinlock.h
• linux/kthread.h
• linux/sched.h
• linux/slab.h
• linux/errno.h
• linux/jiffies.h
• linux/netdevice.h
• linux/net.h
• linux/inetdevice.h
• linux/skbuff.h
• linux/init.h
• linux/in.h
• linux/ip.h
• linux/udp.h
• linux/l2tp.h
• linux/sort.h
• linux/file.h
• linux/nsproxy.h
• net/net_namespace.h
• net/netns/generic.h
• net/dst.h
• net/ip.h
• net/udp.h
• net/udp_tunnel.h
• net/inet_common.h
• net/xfrm.h

Detected Declarations

• struct l2tp_skb_cb
• struct l2tp_net
• function l2tp_v2_session_key
• function l2tp_v3_session_hashkey
• function l2tp_sk_is_v6
• function l2tp_tunnel_free
• function l2tp_session_free
• function l2tp_tunnel_put
• function l2tp_session_put
• function refcount_inc_not_zero
• function hash_for_each_possible_rcu
• function hash_for_each_possible_rcu
• function l2tp_session_coll_list_add
• function l2tp_session_collision_add
• function l2tp_session_collision_del
• function l2tp_session_register
• function l2tp_recv_queue_skb
• function l2tp_recv_dequeue_skb
• function l2tp_recv_dequeue
• function l2tp_seq_check_rx_window
• function l2tp_recv_data_seq
• function data
• function l2tp_session_queue_purge
• function l2tp_udp_encap_recv
• function l2tp_udp_encap_err_recv
• function l2tp_build_l2tpv2_header
• function l2tp_build_l2tpv3_header
• function l2tp_xmit_queue
• function l2tp_xmit_core
• function l2tp_xmit_skb
• function l2tp_session_unhash
• function l2tp_tunnel_closeall
• function l2tp_udp_encap_destroy
• function l2tp_tunnel_remove
• function l2tp_tunnel_del_work
• function l2tp_tunnel_sock_create
• function l2tp_tunnel_create
• function l2tp_validate_socket
• function l2tp_tunnel_register
• function l2tp_tunnel_delete
• function l2tp_session_delete
• function l2tp_session_del_work
• function l2tp_session_set_header_len
• function l2tp_init_net
• function l2tp_pre_exit_net
• function l2tp_idr_item_unexpected
• function l2tp_exit_net
• function l2tp_init

Annotated Snippet

module_init(l2tp_init);
module_exit(l2tp_exit);

MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
MODULE_DESCRIPTION("L2TP core");
MODULE_LICENSE("GPL");
MODULE_VERSION(L2TP_DRV_VERSION);

Annotation

• Immediate include surface: `linux/module.h`, `linux/string.h`, `linux/list.h`, `linux/rculist.h`, `linux/uaccess.h`, `linux/kernel.h`, `linux/spinlock.h`, `linux/kthread.h`.
• Detected declarations: `struct l2tp_skb_cb`, `struct l2tp_net`, `function l2tp_v2_session_key`, `function l2tp_v3_session_hashkey`, `function l2tp_sk_is_v6`, `function l2tp_tunnel_free`, `function l2tp_session_free`, `function l2tp_tunnel_put`, `function l2tp_session_put`, `function refcount_inc_not_zero`.
• 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.