net/ipv4/inet_timewait_sock.c

File Facts

System

Linux kernel

Corpus path

net/ipv4/inet_timewait_sock.c

Extension

.c

Size

10792 bytes

Lines

361

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/kernel.h
• linux/slab.h
• linux/module.h
• net/inet_hashtables.h
• net/inet_timewait_sock.h
• net/ip.h
• net/tcp.h
• net/psp.h

Detected Declarations

• function inet_twsk_put
• function inet_twsk_kill
• function inet_twsk_free
• function inet_twsk_put
• function inet_twsk_schedule
• function inet_twsk_hashdance_schedule
• function tw_timer_handler
• function inet_twsk_deschedule_put
• function __inet_twsk_schedule
• function inet_twsk_purge
• function sk_nulls_for_each_rcu
• export inet_twsk_put
• export inet_twsk_deschedule_put

Annotated Snippet

sk_nulls_for_each_rcu(sk, node, &head->chain) {
			int state = inet_sk_state_load(sk);

			if ((1 << state) & ~(TCPF_TIME_WAIT |
					     TCPF_NEW_SYN_RECV))
				continue;

			if (check_net(sock_net(sk)))
				continue;

			if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
				continue;

			if (check_net(sock_net(sk))) {
				sock_gen_put(sk);
				goto restart;
			}

			rcu_read_unlock();
			local_bh_disable();
			if (state == TCP_TIME_WAIT) {
				inet_twsk_deschedule_put(inet_twsk(sk));
			} else {
				struct request_sock *req = inet_reqsk(sk);

				inet_csk_reqsk_queue_drop_and_put(req->rsk_listener,
								  req);
			}
			local_bh_enable();
			goto restart_rcu;
		}
		/* If the nulls value we got at the end of this lookup is
		 * not the expected one, we must restart lookup.
		 * We probably met an item that was moved to another chain.
		 */
		if (get_nulls_value(node) != slot)
			goto restart;
		rcu_read_unlock();
	}
}

Annotation

• Immediate include surface: `linux/kernel.h`, `linux/slab.h`, `linux/module.h`, `net/inet_hashtables.h`, `net/inet_timewait_sock.h`, `net/ip.h`, `net/tcp.h`, `net/psp.h`.
• Detected declarations: `function inet_twsk_put`, `function inet_twsk_kill`, `function inet_twsk_free`, `function inet_twsk_put`, `function inet_twsk_schedule`, `function inet_twsk_hashdance_schedule`, `function tw_timer_handler`, `function inet_twsk_deschedule_put`, `function __inet_twsk_schedule`, `function inet_twsk_purge`.
• 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.