net/llc/llc_if.c

File Facts

System

Linux kernel

Corpus path

net/llc/llc_if.c

Extension

.c

Size

4363 bytes

Lines

152

Domain

Networking Core

Bucket

Sockets, Protocols, Packet Path, And Network Policy

Inferred role

Networking Core: implementation source

Status

source 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.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/gfp.h
• linux/module.h
• linux/kernel.h
• linux/netdevice.h
• linux/errno.h
• net/llc_if.h
• net/llc_sap.h
• net/llc_s_ev.h
• net/llc_conn.h
• net/sock.h
• net/llc_c_ev.h
• net/llc_c_ac.h
• net/llc_c_st.h
• net/tcp_states.h

Detected Declarations

• function Copyright
• function llc_establish_connection
• function llc_send_disc

Annotated Snippet

if (existing->sk_state == TCP_ESTABLISHED) {
			sk = existing;
			goto out_put;
		} else
			sock_put(existing);
	}
	sock_hold(sk);
	rc = -ENOMEM;
	skb = alloc_skb(0, GFP_ATOMIC);
	if (skb) {
		struct llc_conn_state_ev *ev = llc_conn_ev(skb);

		ev->type      = LLC_CONN_EV_TYPE_PRIM;
		ev->prim      = LLC_CONN_PRIM;
		ev->prim_type = LLC_PRIM_TYPE_REQ;
		skb_set_owner_w(skb, sk);
		rc = llc_conn_state_process(sk, skb);
	}
out_put:
	sock_put(sk);
	return rc;
}

/**
 *	llc_send_disc - Called by upper layer to close a connection
 *	@sk: connection to be closed
 *
 *	Upper layer calls this when it wants to close an established LLC
 *	connection with a remote machine. This function packages a proper event
 *	and sends it to connection component state machine. Returns 0 for
 *	success, 1 otherwise.
 */
int llc_send_disc(struct sock *sk)
{
	u16 rc = 1;
	struct llc_conn_state_ev *ev;
	struct sk_buff *skb;

	sock_hold(sk);
	if (sk->sk_type != SOCK_STREAM || sk->sk_state != TCP_ESTABLISHED ||
	    llc_sk(sk)->state == LLC_CONN_STATE_ADM ||
	    llc_sk(sk)->state == LLC_CONN_OUT_OF_SVC)
		goto out;
	/*
	 * Postpone unassigning the connection from its SAP and returning the
	 * connection until all ACTIONs have been completely executed
	 */
	skb = alloc_skb(0, GFP_ATOMIC);
	if (!skb)
		goto out;
	skb_set_owner_w(skb, sk);
	sk->sk_state  = TCP_CLOSING;
	ev	      = llc_conn_ev(skb);
	ev->type      = LLC_CONN_EV_TYPE_PRIM;
	ev->prim      = LLC_DISC_PRIM;
	ev->prim_type = LLC_PRIM_TYPE_REQ;
	rc = llc_conn_state_process(sk, skb);
out:
	sock_put(sk);
	return rc;
}

Annotation

• Immediate include surface: `linux/gfp.h`, `linux/module.h`, `linux/kernel.h`, `linux/netdevice.h`, `linux/errno.h`, `net/llc_if.h`, `net/llc_sap.h`, `net/llc_s_ev.h`.
• Detected declarations: `function Copyright`, `function llc_establish_connection`, `function llc_send_disc`.
• Atlas domain: Networking Core / Sockets, Protocols, Packet Path, And Network Policy.
• Implementation status: source implementation candidate.

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.