net/core/fib_rules.c - kernel/msm-4.19 - Gitiles

 /*
  * net/core/fib_rules.c		Generic Routing Rules
  *
  *	This program is free software; you can redistribute it and/or
  *	modify it under the terms of the GNU General Public License as
  *	published by the Free Software Foundation, version 2.
  *
  * Authors:	Thomas Graf <tgraf@suug.ch>
  */

 #include <linux/config.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <net/fib_rules.h>

 static LIST_HEAD(rules_ops);
 static DEFINE_SPINLOCK(rules_mod_lock);

 static void notify_rule_change(int event, struct fib_rule *rule,
 			       struct fib_rules_ops *ops, struct nlmsghdr *nlh,
 			       u32 pid);

 static struct fib_rules_ops *lookup_rules_ops(int family)
 {
 	struct fib_rules_ops *ops;

 	rcu_read_lock();
 	list_for_each_entry_rcu(ops, &rules_ops, list) {
 		if (ops->family == family) {
 			if (!try_module_get(ops->owner))
 				ops = NULL;
 			rcu_read_unlock();
 			return ops;
 		}
 	}
 	rcu_read_unlock();

 	return NULL;
 }

 static void rules_ops_put(struct fib_rules_ops *ops)
 {
 	if (ops)
 		module_put(ops->owner);
 }

 int fib_rules_register(struct fib_rules_ops *ops)
 {
 	int err = -EEXIST;
 	struct fib_rules_ops *o;

 	if (ops->rule_size < sizeof(struct fib_rule))
 		return -EINVAL;

 	if (ops->match == NULL || ops->configure == NULL ||
 	    ops->compare == NULL || ops->fill == NULL ||
 	    ops->action == NULL)
 		return -EINVAL;

 	spin_lock(&rules_mod_lock);
 	list_for_each_entry(o, &rules_ops, list)
 		if (ops->family == o->family)
 			goto errout;

 	list_add_tail_rcu(&ops->list, &rules_ops);
 	err = 0;
 errout:
 	spin_unlock(&rules_mod_lock);

 	return err;
 }

 EXPORT_SYMBOL_GPL(fib_rules_register);

 static void cleanup_ops(struct fib_rules_ops *ops)
 {
 	struct fib_rule *rule, *tmp;

 	list_for_each_entry_safe(rule, tmp, ops->rules_list, list) {
 		list_del_rcu(&rule->list);
 		fib_rule_put(rule);
 	}
 }

 int fib_rules_unregister(struct fib_rules_ops *ops)
 {
 	int err = 0;
 	struct fib_rules_ops *o;

 	spin_lock(&rules_mod_lock);
 	list_for_each_entry(o, &rules_ops, list) {
 		if (o == ops) {
 			list_del_rcu(&o->list);
 			cleanup_ops(ops);
 			goto out;
 		}
 	}

 	err = -ENOENT;
 out:
 	spin_unlock(&rules_mod_lock);

 	synchronize_rcu();

 	return err;
 }

 EXPORT_SYMBOL_GPL(fib_rules_unregister);

 int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
 		     int flags, struct fib_lookup_arg *arg)
 {
 	struct fib_rule *rule;
 	int err;

 	rcu_read_lock();

 	list_for_each_entry_rcu(rule, ops->rules_list, list) {
 		if (rule->ifindex && (rule->ifindex != fl->iif))
 			continue;

 		if (!ops->match(rule, fl, flags))
 			continue;

 		err = ops->action(rule, fl, flags, arg);
 		if (err != -EAGAIN) {
 			fib_rule_get(rule);
 			arg->rule = rule;
 			goto out;
 		}
 	}

 	err = -ENETUNREACH;
 out:
 	rcu_read_unlock();

 	return err;
 }

 EXPORT_SYMBOL_GPL(fib_rules_lookup);

 int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 {
 	struct fib_rule_hdr *frh = nlmsg_data(nlh);
 	struct fib_rules_ops *ops = NULL;
 	struct fib_rule *rule, *r, *last = NULL;
 	struct nlattr *tb[FRA_MAX+1];
 	int err = -EINVAL;

 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
 		goto errout;

 	ops = lookup_rules_ops(frh->family);
 	if (ops == NULL) {
 		err = EAFNOSUPPORT;
 		goto errout;
 	}

 	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
 	if (err < 0)
 		goto errout;

 	if (tb[FRA_IFNAME] && nla_len(tb[FRA_IFNAME]) > IFNAMSIZ)
 		goto errout;

 	rule = kzalloc(ops->rule_size, GFP_KERNEL);
 	if (rule == NULL) {
 		err = -ENOMEM;
 		goto errout;
 	}

 	if (tb[FRA_PRIORITY])
 		rule->pref = nla_get_u32(tb[FRA_PRIORITY]);

 	if (tb[FRA_IFNAME]) {
 		struct net_device *dev;

 		rule->ifindex = -1;
 		if (nla_strlcpy(rule->ifname, tb[FRA_IFNAME],
 				IFNAMSIZ) >= IFNAMSIZ)
 			goto errout_free;

 		dev = __dev_get_by_name(rule->ifname);
 		if (dev)
 			rule->ifindex = dev->ifindex;
 	}

 	rule->action = frh->action;
 	rule->flags = frh->flags;
 	rule->table = frh_get_table(frh, tb);

 	if (!rule->pref && ops->default_pref)
 		rule->pref = ops->default_pref();

 	err = ops->configure(rule, skb, nlh, frh, tb);
 	if (err < 0)
 		goto errout_free;

 	list_for_each_entry(r, ops->rules_list, list) {
 		if (r->pref > rule->pref)
 			break;
 		last = r;
 	}

 	fib_rule_get(rule);

 	if (last)
 		list_add_rcu(&rule->list, &last->list);
 	else
 		list_add_rcu(&rule->list, ops->rules_list);

 	notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).pid);
 	rules_ops_put(ops);
 	return 0;

 errout_free:
 	kfree(rule);
 errout:
 	rules_ops_put(ops);
 	return err;
 }

 int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 {
 	struct fib_rule_hdr *frh = nlmsg_data(nlh);
 	struct fib_rules_ops *ops = NULL;
 	struct fib_rule *rule;
 	struct nlattr *tb[FRA_MAX+1];
 	int err = -EINVAL;

 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
 		goto errout;

 	ops = lookup_rules_ops(frh->family);
 	if (ops == NULL) {
 		err = EAFNOSUPPORT;
 		goto errout;
 	}

 	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
 	if (err < 0)
 		goto errout;

 	list_for_each_entry(rule, ops->rules_list, list) {
 		if (frh->action && (frh->action != rule->action))
 			continue;

 		if (frh->table && (frh_get_table(frh, tb) != rule->table))
 			continue;

 		if (tb[FRA_PRIORITY] &&
 		    (rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
 			continue;

 		if (tb[FRA_IFNAME] &&
 		    nla_strcmp(tb[FRA_IFNAME], rule->ifname))
 			continue;

 		if (!ops->compare(rule, frh, tb))
 			continue;

 		if (rule->flags & FIB_RULE_PERMANENT) {
 			err = -EPERM;
 			goto errout;
 		}

 		list_del_rcu(&rule->list);
 		synchronize_rcu();
 		notify_rule_change(RTM_DELRULE, rule, ops, nlh,
 				   NETLINK_CB(skb).pid);
 		fib_rule_put(rule);
 		rules_ops_put(ops);
 		return 0;
 	}

 	err = -ENOENT;
 errout:
 	rules_ops_put(ops);
 	return err;
 }

 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
 			    u32 pid, u32 seq, int type, int flags,
 			    struct fib_rules_ops *ops)
 {
 	struct nlmsghdr *nlh;
 	struct fib_rule_hdr *frh;

 	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
 	if (nlh == NULL)
 		return -1;

 	frh = nlmsg_data(nlh);
 	frh->table = rule->table;
 	NLA_PUT_U32(skb, FRA_TABLE, rule->table);
 	frh->res1 = 0;
 	frh->res2 = 0;
 	frh->action = rule->action;
 	frh->flags = rule->flags;

 	if (rule->ifname[0])
 		NLA_PUT_STRING(skb, FRA_IFNAME, rule->ifname);

 	if (rule->pref)
 		NLA_PUT_U32(skb, FRA_PRIORITY, rule->pref);

 	if (ops->fill(rule, skb, nlh, frh) < 0)
 		goto nla_put_failure;

 	return nlmsg_end(skb, nlh);

 nla_put_failure:
 	return nlmsg_cancel(skb, nlh);
 }

 int fib_rules_dump(struct sk_buff *skb, struct netlink_callback *cb, int family)
 {
 	int idx = 0;
 	struct fib_rule *rule;
 	struct fib_rules_ops *ops;

 	ops = lookup_rules_ops(family);
 	if (ops == NULL)
 		return -EAFNOSUPPORT;

 	rcu_read_lock();
 	list_for_each_entry(rule, ops->rules_list, list) {
 		if (idx < cb->args[0])
 			goto skip;

 		if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).pid,
 				     cb->nlh->nlmsg_seq, RTM_NEWRULE,
 				     NLM_F_MULTI, ops) < 0)
 			break;
 skip:
 		idx++;
 	}
 	rcu_read_unlock();
 	cb->args[0] = idx;
 	rules_ops_put(ops);

 	return skb->len;
 }

 EXPORT_SYMBOL_GPL(fib_rules_dump);

 static void notify_rule_change(int event, struct fib_rule *rule,
 			       struct fib_rules_ops *ops, struct nlmsghdr *nlh,
 			       u32 pid)
 {
 	struct sk_buff *skb;
 	int err = -ENOBUFS;

 	skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
 	if (skb == NULL)
 		goto errout;

 	err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
 	if (err < 0) {
 		kfree_skb(skb);
 		goto errout;
 	}

 	err = rtnl_notify(skb, pid, ops->nlgroup, nlh, GFP_KERNEL);
 errout:
 	if (err < 0)
 		rtnl_set_sk_err(ops->nlgroup, err);
 }

 static void attach_rules(struct list_head *rules, struct net_device *dev)
 {
 	struct fib_rule *rule;

 	list_for_each_entry(rule, rules, list) {
 		if (rule->ifindex == -1 &&
 		    strcmp(dev->name, rule->ifname) == 0)
 			rule->ifindex = dev->ifindex;
 	}
 }

 static void detach_rules(struct list_head *rules, struct net_device *dev)
 {
 	struct fib_rule *rule;

 	list_for_each_entry(rule, rules, list)
 		if (rule->ifindex == dev->ifindex)
 			rule->ifindex = -1;
 }


 static int fib_rules_event(struct notifier_block *this, unsigned long event,
 			    void *ptr)
 {
 	struct net_device *dev = ptr;
 	struct fib_rules_ops *ops;

 	ASSERT_RTNL();
 	rcu_read_lock();

 	switch (event) {
 	case NETDEV_REGISTER:
 		list_for_each_entry(ops, &rules_ops, list)
 			attach_rules(ops->rules_list, dev);
 		break;

 	case NETDEV_UNREGISTER:
 		list_for_each_entry(ops, &rules_ops, list)
 			detach_rules(ops->rules_list, dev);
 		break;
 	}

 	rcu_read_unlock();

 	return NOTIFY_DONE;
 }

 static struct notifier_block fib_rules_notifier = {
 	.notifier_call = fib_rules_event,
 };

 static int __init fib_rules_init(void)
 {
 	return register_netdevice_notifier(&fib_rules_notifier);
 }

 subsys_initcall(fib_rules_init);
	/*
	* net/core/fib_rules.c Generic Routing Rules
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License as
	* published by the Free Software Foundation, version 2.
	*
	* Authors: Thomas Graf <tgraf@suug.ch>
	*/

	#include <linux/config.h>
	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <linux/list.h>
	#include <net/fib_rules.h>

	static LIST_HEAD(rules_ops);
	static DEFINE_SPINLOCK(rules_mod_lock);

	static void notify_rule_change(int event, struct fib_rule *rule,
	struct fib_rules_ops ops, struct nlmsghdr nlh,
	u32 pid);

	static struct fib_rules_ops *lookup_rules_ops(int family)
	{
	struct fib_rules_ops *ops;

	rcu_read_lock();
	list_for_each_entry_rcu(ops, &rules_ops, list) {
	if (ops->family == family) {
	if (!try_module_get(ops->owner))
	ops = NULL;
	rcu_read_unlock();
	return ops;
	}
	}
	rcu_read_unlock();

	return NULL;
	}

	static void rules_ops_put(struct fib_rules_ops *ops)
	{
	if (ops)
	module_put(ops->owner);
	}

	int fib_rules_register(struct fib_rules_ops *ops)
	{
	int err = -EEXIST;
	struct fib_rules_ops *o;

	if (ops->rule_size < sizeof(struct fib_rule))
	return -EINVAL;

	if (ops->match == NULL \|\| ops->configure == NULL \|\|
	ops->compare == NULL \|\| ops->fill == NULL \|\|
	ops->action == NULL)
	return -EINVAL;

	spin_lock(&rules_mod_lock);
	list_for_each_entry(o, &rules_ops, list)
	if (ops->family == o->family)
	goto errout;

	list_add_tail_rcu(&ops->list, &rules_ops);
	err = 0;
	errout:
	spin_unlock(&rules_mod_lock);

	return err;
	}

	EXPORT_SYMBOL_GPL(fib_rules_register);

	static void cleanup_ops(struct fib_rules_ops *ops)
	{
	struct fib_rule rule, tmp;

	list_for_each_entry_safe(rule, tmp, ops->rules_list, list) {
	list_del_rcu(&rule->list);
	fib_rule_put(rule);
	}
	}

	int fib_rules_unregister(struct fib_rules_ops *ops)
	{
	int err = 0;
	struct fib_rules_ops *o;

	spin_lock(&rules_mod_lock);
	list_for_each_entry(o, &rules_ops, list) {
	if (o == ops) {
	list_del_rcu(&o->list);
	cleanup_ops(ops);
	goto out;
	}
	}

	err = -ENOENT;
	out:
	spin_unlock(&rules_mod_lock);

	synchronize_rcu();

	return err;
	}

	EXPORT_SYMBOL_GPL(fib_rules_unregister);

	int fib_rules_lookup(struct fib_rules_ops ops, struct flowi fl,
	int flags, struct fib_lookup_arg *arg)
	{
	struct fib_rule *rule;
	int err;

	rcu_read_lock();

	list_for_each_entry_rcu(rule, ops->rules_list, list) {
	if (rule->ifindex && (rule->ifindex != fl->iif))
	continue;

	if (!ops->match(rule, fl, flags))
	continue;

	err = ops->action(rule, fl, flags, arg);
	if (err != -EAGAIN) {
	fib_rule_get(rule);
	arg->rule = rule;
	goto out;
	}
	}

	err = -ENETUNREACH;
	out:
	rcu_read_unlock();

	return err;
	}

	EXPORT_SYMBOL_GPL(fib_rules_lookup);

	int fib_nl_newrule(struct sk_buff skb, struct nlmsghdr nlh, void *arg)
	{
	struct fib_rule_hdr *frh = nlmsg_data(nlh);
	struct fib_rules_ops *ops = NULL;
	struct fib_rule rule, r, *last = NULL;
	struct nlattr *tb[FRA_MAX+1];
	int err = -EINVAL;

	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
	goto errout;

	ops = lookup_rules_ops(frh->family);
	if (ops == NULL) {
	err = EAFNOSUPPORT;
	goto errout;
	}

	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
	if (err < 0)
	goto errout;

	if (tb[FRA_IFNAME] && nla_len(tb[FRA_IFNAME]) > IFNAMSIZ)
	goto errout;

	rule = kzalloc(ops->rule_size, GFP_KERNEL);
	if (rule == NULL) {
	err = -ENOMEM;
	goto errout;
	}

	if (tb[FRA_PRIORITY])
	rule->pref = nla_get_u32(tb[FRA_PRIORITY]);

	if (tb[FRA_IFNAME]) {
	struct net_device *dev;

	rule->ifindex = -1;
	if (nla_strlcpy(rule->ifname, tb[FRA_IFNAME],
	IFNAMSIZ) >= IFNAMSIZ)
	goto errout_free;

	dev = __dev_get_by_name(rule->ifname);
	if (dev)
	rule->ifindex = dev->ifindex;
	}

	rule->action = frh->action;
	rule->flags = frh->flags;
	rule->table = frh_get_table(frh, tb);

	if (!rule->pref && ops->default_pref)
	rule->pref = ops->default_pref();

	err = ops->configure(rule, skb, nlh, frh, tb);
	if (err < 0)
	goto errout_free;

	list_for_each_entry(r, ops->rules_list, list) {
	if (r->pref > rule->pref)
	break;
	last = r;
	}

	fib_rule_get(rule);

	if (last)
	list_add_rcu(&rule->list, &last->list);
	else
	list_add_rcu(&rule->list, ops->rules_list);

	notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).pid);
	rules_ops_put(ops);
	return 0;

	errout_free:
	kfree(rule);
	errout:
	rules_ops_put(ops);
	return err;
	}

	int fib_nl_delrule(struct sk_buff skb, struct nlmsghdr nlh, void *arg)
	{
	struct fib_rule_hdr *frh = nlmsg_data(nlh);
	struct fib_rules_ops *ops = NULL;
	struct fib_rule *rule;
	struct nlattr *tb[FRA_MAX+1];
	int err = -EINVAL;

	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
	goto errout;

	ops = lookup_rules_ops(frh->family);
	if (ops == NULL) {
	err = EAFNOSUPPORT;
	goto errout;
	}

	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
	if (err < 0)
	goto errout;

	list_for_each_entry(rule, ops->rules_list, list) {
	if (frh->action && (frh->action != rule->action))
	continue;

	if (frh->table && (frh_get_table(frh, tb) != rule->table))
	continue;

	if (tb[FRA_PRIORITY] &&
	(rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
	continue;

	if (tb[FRA_IFNAME] &&
	nla_strcmp(tb[FRA_IFNAME], rule->ifname))
	continue;

	if (!ops->compare(rule, frh, tb))
	continue;

	if (rule->flags & FIB_RULE_PERMANENT) {
	err = -EPERM;
	goto errout;
	}

	list_del_rcu(&rule->list);
	synchronize_rcu();
	notify_rule_change(RTM_DELRULE, rule, ops, nlh,
	NETLINK_CB(skb).pid);
	fib_rule_put(rule);
	rules_ops_put(ops);
	return 0;
	}

	err = -ENOENT;
	errout:
	rules_ops_put(ops);
	return err;
	}

	static int fib_nl_fill_rule(struct sk_buff skb, struct fib_rule rule,
	u32 pid, u32 seq, int type, int flags,
	struct fib_rules_ops *ops)
	{
	struct nlmsghdr *nlh;
	struct fib_rule_hdr *frh;

	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
	if (nlh == NULL)
	return -1;

	frh = nlmsg_data(nlh);
	frh->table = rule->table;
	NLA_PUT_U32(skb, FRA_TABLE, rule->table);
	frh->res1 = 0;
	frh->res2 = 0;
	frh->action = rule->action;
	frh->flags = rule->flags;

	if (rule->ifname[0])
	NLA_PUT_STRING(skb, FRA_IFNAME, rule->ifname);

	if (rule->pref)
	NLA_PUT_U32(skb, FRA_PRIORITY, rule->pref);

	if (ops->fill(rule, skb, nlh, frh) < 0)
	goto nla_put_failure;

	return nlmsg_end(skb, nlh);

	nla_put_failure:
	return nlmsg_cancel(skb, nlh);
	}

	int fib_rules_dump(struct sk_buff skb, struct netlink_callback cb, int family)
	{
	int idx = 0;
	struct fib_rule *rule;
	struct fib_rules_ops *ops;

	ops = lookup_rules_ops(family);
	if (ops == NULL)
	return -EAFNOSUPPORT;

	rcu_read_lock();
	list_for_each_entry(rule, ops->rules_list, list) {
	if (idx < cb->args[0])
	goto skip;

	if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).pid,
	cb->nlh->nlmsg_seq, RTM_NEWRULE,
	NLM_F_MULTI, ops) < 0)
	break;
	skip:
	idx++;
	}
	rcu_read_unlock();
	cb->args[0] = idx;
	rules_ops_put(ops);

	return skb->len;
	}

	EXPORT_SYMBOL_GPL(fib_rules_dump);

	static void notify_rule_change(int event, struct fib_rule *rule,
	struct fib_rules_ops ops, struct nlmsghdr nlh,
	u32 pid)
	{
	struct sk_buff *skb;
	int err = -ENOBUFS;

	skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
	if (skb == NULL)
	goto errout;

	err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
	if (err < 0) {
	kfree_skb(skb);
	goto errout;
	}

	err = rtnl_notify(skb, pid, ops->nlgroup, nlh, GFP_KERNEL);
	errout:
	if (err < 0)
	rtnl_set_sk_err(ops->nlgroup, err);
	}

	static void attach_rules(struct list_head rules, struct net_device dev)
	{
	struct fib_rule *rule;

	list_for_each_entry(rule, rules, list) {
	if (rule->ifindex == -1 &&
	strcmp(dev->name, rule->ifname) == 0)
	rule->ifindex = dev->ifindex;
	}
	}

	static void detach_rules(struct list_head rules, struct net_device dev)
	{
	struct fib_rule *rule;

	list_for_each_entry(rule, rules, list)
	if (rule->ifindex == dev->ifindex)
	rule->ifindex = -1;
	}


	static int fib_rules_event(struct notifier_block *this, unsigned long event,
	void *ptr)
	{
	struct net_device *dev = ptr;
	struct fib_rules_ops *ops;

	ASSERT_RTNL();
	rcu_read_lock();

	switch (event) {
	case NETDEV_REGISTER:
	list_for_each_entry(ops, &rules_ops, list)
	attach_rules(ops->rules_list, dev);
	break;

	case NETDEV_UNREGISTER:
	list_for_each_entry(ops, &rules_ops, list)
	detach_rules(ops->rules_list, dev);
	break;
	}

	rcu_read_unlock();

	return NOTIFY_DONE;
	}

	static struct notifier_block fib_rules_notifier = {
	.notifier_call = fib_rules_event,
	};

	static int __init fib_rules_init(void)
	{
	return register_netdevice_notifier(&fib_rules_notifier);
	}

	subsys_initcall(fib_rules_init);