net/lapb/lapb_out.c

File Facts

System

Linux kernel

Corpus path

net/lapb/lapb_out.c

Extension

.c

Size

4800 bytes

Lines

206

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/errno.h
• linux/types.h
• linux/socket.h
• linux/in.h
• linux/kernel.h
• linux/timer.h
• linux/string.h
• linux/sockios.h
• linux/net.h
• linux/inet.h
• linux/skbuff.h
• linux/slab.h
• net/sock.h
• linux/uaccess.h
• linux/fcntl.h
• linux/mm.h
• linux/interrupt.h
• net/lapb.h

Detected Declarations

• function lapb_send_iframe
• function lapb_kick
• function lapb_transmit_buffer
• function lapb_establish_data_link
• function lapb_enquiry_response
• function lapb_timeout_response
• function lapb_check_iframes_acked
• function lapb_check_need_response

Annotated Snippet

if (!skbn) {
				skb_queue_head(&lapb->write_queue, skb);
				break;
			}

			if (skb->sk)
				skb_set_owner_w(skbn, skb->sk);

			/*
			 * Transmit the frame copy.
			 */
			lapb_send_iframe(lapb, skbn, LAPB_POLLOFF);

			lapb->vs = (lapb->vs + 1) % modulus;

			/*
			 * Requeue the original data frame.
			 */
			skb_queue_tail(&lapb->ack_queue, skb);

		} while (lapb->vs != end && (skb = skb_dequeue(&lapb->write_queue)) != NULL);

		lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;

		if (!lapb_t1timer_running(lapb))
			lapb_start_t1timer(lapb);
	}
}

void lapb_transmit_buffer(struct lapb_cb *lapb, struct sk_buff *skb, int type)
{
	unsigned char *ptr;

	ptr = skb_push(skb, 1);

	if (lapb->mode & LAPB_MLP) {
		if (lapb->mode & LAPB_DCE) {
			if (type == LAPB_COMMAND)
				*ptr = LAPB_ADDR_C;
			if (type == LAPB_RESPONSE)
				*ptr = LAPB_ADDR_D;
		} else {
			if (type == LAPB_COMMAND)
				*ptr = LAPB_ADDR_D;
			if (type == LAPB_RESPONSE)
				*ptr = LAPB_ADDR_C;
		}
	} else {
		if (lapb->mode & LAPB_DCE) {
			if (type == LAPB_COMMAND)
				*ptr = LAPB_ADDR_A;
			if (type == LAPB_RESPONSE)
				*ptr = LAPB_ADDR_B;
		} else {
			if (type == LAPB_COMMAND)
				*ptr = LAPB_ADDR_B;
			if (type == LAPB_RESPONSE)
				*ptr = LAPB_ADDR_A;
		}
	}

	lapb_dbg(2, "(%p) S%d TX %3ph\n", lapb->dev, lapb->state, skb->data);

	if (!lapb_data_transmit(lapb, skb))
		kfree_skb(skb);
}

void lapb_establish_data_link(struct lapb_cb *lapb)
{
	lapb->condition = 0x00;
	lapb->n2count   = 0;

	if (lapb->mode & LAPB_EXTENDED) {
		lapb_dbg(1, "(%p) S%d TX SABME(1)\n", lapb->dev, lapb->state);
		lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND);
	} else {
		lapb_dbg(1, "(%p) S%d TX SABM(1)\n", lapb->dev, lapb->state);
		lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND);
	}

	lapb_start_t1timer(lapb);
	lapb_stop_t2timer(lapb);
}

void lapb_enquiry_response(struct lapb_cb *lapb)
{
	lapb_dbg(1, "(%p) S%d TX RR(1) R%d\n",
		 lapb->dev, lapb->state, lapb->vr);

	lapb_send_control(lapb, LAPB_RR, LAPB_POLLON, LAPB_RESPONSE);

Annotation

• Immediate include surface: `linux/errno.h`, `linux/types.h`, `linux/socket.h`, `linux/in.h`, `linux/kernel.h`, `linux/timer.h`, `linux/string.h`, `linux/sockios.h`.
• Detected declarations: `function lapb_send_iframe`, `function lapb_kick`, `function lapb_transmit_buffer`, `function lapb_establish_data_link`, `function lapb_enquiry_response`, `function lapb_timeout_response`, `function lapb_check_iframes_acked`, `function lapb_check_need_response`.
• 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.