net/phonet/datagram.c

Source file repositories/reference/linux-study-clean/net/phonet/datagram.c

File Facts

System
Linux kernel
Corpus path
net/phonet/datagram.c
Extension
.c
Size
4102 bytes
Lines
197
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.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 * File: datagram.c
 *
 * Datagram (ISI) Phonet sockets
 *
 * Copyright (C) 2008 Nokia Corporation.
 *
 * Authors: Sakari Ailus <sakari.ailus@nokia.com>
 *          Rémi Denis-Courmont
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/socket.h>
#include <asm/ioctls.h>
#include <net/sock.h>

#include <linux/phonet.h>
#include <linux/export.h>
#include <net/phonet/phonet.h>

static int pn_backlog_rcv(struct sock *sk, struct sk_buff *skb);

/* associated socket ceases to exist */
static void pn_sock_close(struct sock *sk, long timeout)
{
	sk_common_release(sk);
}

static int pn_ioctl(struct sock *sk, int cmd, int *karg)
{
	struct sk_buff *skb;

	switch (cmd) {
	case SIOCINQ:
		spin_lock_bh(&sk->sk_receive_queue.lock);
		skb = skb_peek(&sk->sk_receive_queue);
		*karg = skb ? skb->len : 0;
		spin_unlock_bh(&sk->sk_receive_queue.lock);
		return 0;

	case SIOCPNADDRESOURCE:
	case SIOCPNDELRESOURCE: {
			u32 res = *karg;
			if (res >= 256)
				return -EINVAL;
			if (cmd == SIOCPNADDRESOURCE)
				return pn_sock_bind_res(sk, res);
			else
				return pn_sock_unbind_res(sk, res);
		}
	}

	return -ENOIOCTLCMD;
}

/* Destroy socket. All references are gone. */
static void pn_destruct(struct sock *sk)
{
	skb_queue_purge(&sk->sk_receive_queue);
}

static int pn_init(struct sock *sk)
{
	sk->sk_destruct = pn_destruct;
	return 0;
}

static int pn_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
{
	DECLARE_SOCKADDR(struct sockaddr_pn *, target, msg->msg_name);
	struct sk_buff *skb;
	int err;

	if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
				MSG_CMSG_COMPAT))
		return -EOPNOTSUPP;

	if (target == NULL)
		return -EDESTADDRREQ;

	if (msg->msg_namelen < sizeof(struct sockaddr_pn))
		return -EINVAL;

	if (target->spn_family != AF_PHONET)
		return -EAFNOSUPPORT;

	skb = sock_alloc_send_skb(sk, MAX_PHONET_HEADER + len,
					msg->msg_flags & MSG_DONTWAIT, &err);

Annotation

Implementation Notes