net/netfilter/nf_conntrack_proto_generic.c

Source file repositories/reference/linux-study-clean/net/netfilter/nf_conntrack_proto_generic.c

File Facts

System
Linux kernel
Corpus path
net/netfilter/nf_conntrack_proto_generic.c
Extension
.c
Size
2019 bytes
Lines
81
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
/* (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
 */

#include <linux/types.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <linux/netfilter.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_timeout.h>

static const unsigned int nf_ct_generic_timeout = 600*HZ;

#ifdef CONFIG_NF_CONNTRACK_TIMEOUT

#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_cttimeout.h>

static int generic_timeout_nlattr_to_obj(struct nlattr *tb[],
					 struct net *net, void *data)
{
	struct nf_generic_net *gn = nf_generic_pernet(net);
	unsigned int *timeout = data;

	if (!timeout)
		timeout = &gn->timeout;

	if (tb[CTA_TIMEOUT_GENERIC_TIMEOUT])
		*timeout =
		    ntohl(nla_get_be32(tb[CTA_TIMEOUT_GENERIC_TIMEOUT])) * HZ;
	else {
		/* Set default generic timeout. */
		*timeout = gn->timeout;
	}

	return 0;
}

static int
generic_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
{
	const unsigned int *timeout = data;

	if (nla_put_be32(skb, CTA_TIMEOUT_GENERIC_TIMEOUT, htonl(*timeout / HZ)))
		goto nla_put_failure;

	return 0;

nla_put_failure:
        return -ENOSPC;
}

static const struct nla_policy
generic_timeout_nla_policy[CTA_TIMEOUT_GENERIC_MAX+1] = {
	[CTA_TIMEOUT_GENERIC_TIMEOUT]	= { .type = NLA_U32 },
};
#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */

void nf_conntrack_generic_init_net(struct net *net)
{
	struct nf_generic_net *gn = nf_generic_pernet(net);

	gn->timeout = nf_ct_generic_timeout;
}

const struct nf_conntrack_l4proto nf_conntrack_l4proto_generic =
{
	.l4proto		= 255,
	.allow_clash            = true,
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
	.ctnl_timeout		= {
		.nlattr_to_obj	= generic_timeout_nlattr_to_obj,
		.obj_to_nlattr	= generic_timeout_obj_to_nlattr,
		.nlattr_max	= CTA_TIMEOUT_GENERIC_MAX,
		.obj_size	= sizeof(unsigned int),
		.nla_policy	= generic_timeout_nla_policy,
	},
#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
};

Annotation

Implementation Notes