path: root/net/core/fib_rules.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * net/core/fib_rules.c		Generic Routing Rules
 *
 * Authors:	Thomas Graf <tgraf@suug.ch>
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/module.h>
#include <net/net_namespace.h>
#include <net/inet_dscp.h>
#include <net/sock.h>
#include <net/fib_rules.h>
#include <net/ip_tunnels.h>
#include <linux/indirect_call_wrapper.h>

#if defined(CONFIG_IPV6) && defined(CONFIG_IPV6_MULTIPLE_TABLES)
#ifdef CONFIG_IP_MULTIPLE_TABLES
#define INDIRECT_CALL_MT(f, f2, f1, ...) \
	INDIRECT_CALL_INET(f, f2, f1, __VA_ARGS__)
#else
#define INDIRECT_CALL_MT(f, f2, f1, ...) INDIRECT_CALL_1(f, f2, __VA_ARGS__)
#endif
#elif defined(CONFIG_IP_MULTIPLE_TABLES)
#define INDIRECT_CALL_MT(f, f2, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__)
#else
#define INDIRECT_CALL_MT(f, f2, f1, ...) f(__VA_ARGS__)
#endif

static const struct fib_kuid_range fib_kuid_range_unset = {
	KUIDT_INIT(0),
	KUIDT_INIT(~0),
};

bool fib_rule_matchall(const struct fib_rule *rule)
{
	if (rule->iifindex || rule->oifindex || rule->mark || rule->tun_id ||
	    rule->flags)
		return false;
	if (rule->suppress_ifgroup != -1 || rule->suppress_prefixlen != -1)
		return false;
	if (!uid_eq(rule->uid_range.start, fib_kuid_range_unset.start) ||
	    !uid_eq(rule->uid_range.end, fib_kuid_range_unset.end))
		return false;
	if (fib_rule_port_range_set(&rule->sport_range))
		return false;
	if (fib_rule_port_range_set(&rule->dport_range))
		return false;
	return true;
}
EXPORT_SYMBOL_GPL(fib_rule_matchall);

int fib_default_rule_add(struct fib_rules_ops *ops,
			 u32 pref, u32 table)
{
	struct fib_rule *r;

	r = kzalloc(ops->rule_size, GFP_KERNEL_ACCOUNT);
	if (r == NULL)
		return -ENOMEM;

	refcount_set(&r->refcnt, 1);
	r->action = FR_ACT_TO_TBL;
	r->pref = pref;
	r->table = table;
	r->proto = RTPROT_KERNEL;
	r->fr_net = ops->fro_net;
	r->uid_range = fib_kuid_range_unset;

	r->suppress_prefixlen = -1;
	r->suppress_ifgroup = -1;

	/* The lock is not required here, the list in unreachable
	 * at the moment this function is called */
	list_add_tail(&r->list, &ops->rules_list);
	return 0;
}
EXPORT_SYMBOL(fib_default_rule_add);

static u32 fib_default_rule_pref(struct fib_rules_ops *ops)
{
	struct list_head *pos;
	struct fib_rule *rule;

	if (!list_empty(&ops->rules_list)) {
		pos = ops->rules_list.next;
		if (pos