path: root/drivers/net/netdevsim/fib.c

/*
 * Copyright (c) 2018 Cumulus Networks. All rights reserved.
 * Copyright (c) 2018 David Ahern <dsa@cumulusnetworks.com>
 *
 * This software is licensed under the GNU General License Version 2,
 * June 1991 as shown in the file COPYING in the top-level directory of this
 * source tree.
 *
 * THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS"
 * WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
 * OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
 * THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
 */

#include <linux/in6.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/rhashtable.h>
#include <linux/spinlock_types.h>
#include <linux/types.h>
#include <net/fib_notifier.h>
#include <net/ip_fib.h>
#include <net/ip6_fib.h>
#include <net/fib_rules.h>
#include <net/net_namespace.h>
#include <net/nexthop.h>
#include <linux/debugfs.h>

#include "netdevsim.h"

struct nsim_fib_entry {
	u64 max;
	atomic64_t num;
};

struct nsim_per_fib_data {
	struct nsim_fib_entry fib;
	struct nsim_fib_entry rules;
};

struct nsim_fib_data {
	struct notifier_block fib_nb;
	struct nsim_per_fib_data ipv4;
	struct nsim_per_fib_data ipv6;
	struct nsim_fib_entry nexthops;
	struct rhashtable fib_rt_ht;
	struct list_head fib_rt_list;
	struct mutex fib_lock; /* Protects hashtable and list */
	struct notifier_block nexthop_nb;
	struct rhashtable nexthop_ht;
	struct devlink *devlink;
	struct work_struct fib_event_work;
	struct list_head fib_event_queue;
	spinlock_t fib_event_queue_lock; /* Protects fib event queue list */
	struct dentry *ddir;
	bool fail_route_offload;
};

struct nsim_fib_rt_key {
	unsigned char addr[sizeof(struct in6_addr)];
	unsigned char prefix_len;
	int family;
	u32 tb_id;
};

struct nsim_fib_rt {
	struct nsim_fib_rt_key key;
	struct rhash_head ht_node;
	struct list_head list;	/* Member of fib_rt_list */
};

struct nsim_fib4_rt {
	struct nsim_fib_rt common;
	struct fib_info *fi;
	u8 tos;
	u8 type;
};

struct nsim_fib6_rt {
	struct nsim_fib_rt common;
	struct list_head nh_list;
	unsigned int nhs;
};

struct nsim_fib6_rt_nh {
	struct list_head list;	/* Member of nh_list */
	struct fib6_info *rt;
};

struct nsim_fib6_event {
	struct fib6_info **rt_arr;
	unsigned int nrt6;
};

struct nsim_fib_event {
	struct list_head list; /* node in fib queue */
	union {
		struct fib_entry_notifier_info fen_info;
		struct nsim_fib6_event fib6_event;
	};
	struct nsim_fib_data *data;
	unsigned long event;
	int family;
};

static const struct rhashtable_params nsim_fib_rt_ht_params = {
	.key_offset = offsetof(struct nsim_fib_rt, key),
	.head_offset = offsetof(struct nsim_fib_rt, ht_node),
	.key_len = sizeof(struct nsim_fib_rt_key),
	.automatic_shrinking = true,
};

struct nsim_nexthop {
	struct rhash_head ht_node;
	u64 occ;
	u32 id;
};

static const struct rhashtable_params nsim_nexthop_ht_params = {
	.key_offset = offsetof(struct nsim_nexthop, id),
	.head_offset = offsetof(struct nsim_nexthop, ht_node),
	.key_len = sizeof(u32),
	.automatic_shrinking = true,
};

u64 nsim_fib_get_val(struct nsim_fib_data *fib_data,
		     enum nsim_resource_id res_id, bool max)
{
	struct nsim_fib_entry *entry;

	switch (res_id) {
	case NSIM_RESOURCE_IPV4_FIB:
		entry = &fib_data->ipv4.fib;
		break;
	case NSIM_RESOURCE_IPV4_FIB_RULES:
		entry = &fib_data->ipv4.rules;
		break;
	case NSIM_RESOURCE_IPV6_FIB:
		entry = &fib_data->ipv6.fib;
		break;
	case NSIM_RESOURCE_IPV6_FIB_RULES:
		entry = &fib_data->ipv6.rules;
		break;
	case NSIM_RESOURCE_NEXTHOPS:
		entry = &fib_data->nexthops;
		break;
	default:
		return 0;
	}

	return max ? entry->max : atomic64_read(&entry->num);
}

static void nsim_fib_set_max(struct nsim_fib_data *fib_data,
			     enum nsim_resource_id res_id, u64 val)
{
	struct nsim_fib_entry *entry;

	switch (res_id) {
	case NSIM_RESOURCE_IPV4_FIB:
		entry = &fib_data->ipv4.fib;
		break;
	case NSIM_RESOURCE_IPV4_FIB_RULES:
		entry = &fib_data->ipv4.rules;
		break;
	case NSIM_RESOURCE_IPV6_FIB:
		entry = &fib_data->ipv6.fib;
		break;
	case NSIM_RESOURCE_IPV6_FIB_RULES:
		entry = &fib_data->ipv6.rules;
		break;
	case NSIM_RESOURCE_NEXTHOPS:
		entry = &fib_data->nexthops;
		break;
	default:
		WARN_ON(1);
		return;
	}
	entry->max = val;
}

static int nsim_fib_rule_account(struct nsim_fib_entry *entry, bool add,
				 struct netlink_ext_ack *extack)
{
	int err = 0;

	if (add) {
		if (!atomic64_add_unless(&entry->num, 1, entry->max)) {
			err = -ENOSPC;
			NL_SET_ERR_MSG_MOD(extack, "Exceeded number of supported fib rule entries");
		}
	} else {
		atomic64_dec_if_positive(&entry->num);
	}

	return err;
}

static int nsim_fib_rule_event(struct nsim_fib_data *data,
			       struct fib_notifier_info *info, bool add)
{
	struct netlink_ext_ack *extack = info->extack;
	int err = 0;

	switch (info->family) {
	case AF_INET:
		err = nsim_fib_rule_account(&data->ipv4.rules, add, extack);
		break;
	case AF_INET6:
		err = nsim_fib_rule_account(&data->ipv6.rules, add, extack);
		break;
	}

	return err;
}

static int nsim_fib_account(struct nsim_fib_entry *entry, bool add)
{
	int err = 0;

	if (add) {
		if (!atomic64_add_unless(&entry->num, 1, entry->max))
			err = -ENOSPC;
	} else {
		atomic64_dec_if_positive(&entry->num);
	}

	return err;
}

static void nsim_fib_rt_init(struct nsim_fib_data *data,
			     struct nsim_fib_rt *fib_rt, const void *addr,
			     size_t addr_len, unsigned int prefix_len,
			     int family, u32 tb_id)
{
	memcpy(fib_rt->key.addr, addr, addr_len);
	fib_rt->key.prefix_len = prefix_len;
	fib_rt->key.family = family;
	fib_rt->key.tb_id = tb_id;
	list_add(&fib_rt->list, &data->fib_rt_list);
}

static void nsim_fib_rt_fini(struct nsim_fib_rt *fib_rt)
{
	list_del(&fib_rt->list);
}

static struct nsim_fib_rt *nsim_fib_rt_lookup(struct rhashtable *fib_rt_ht,
					      const void *addr, size_t addr_len,
					      unsigned int prefix_len,
					      int family, u32 tb_id)
{
	struct nsim_fib_rt_key key;

	memset(&key, 0, sizeof(key));
	memcpy(key.addr, addr, addr_len);
	key.prefix_len = prefix_len;
	key.family = family;
	key.tb_id = tb_id;

	return rhashtable_lookup_fast(fib_rt_ht, &key, nsim_fib_rt_ht_params);
}

static struct nsim_fib4_rt *
nsim_fib4_rt_create(struct nsim_fib_data *data,
		    struct fib_entry_notifier_info *fen_info)
{
	struct nsim_fib4_rt *fib4_rt;

	fib4_rt = kzalloc(sizeof(*fib4_rt), GFP_KERNEL);
	if (!fib4_rt)
		return NULL;

	nsim_fib_rt_init(data, &fib4_rt->common, &fen_info->dst, sizeof(u32),
			 fen_info->dst_len, AF_INET, fen_info->tb_id);

	fib4_rt->fi = fen_info->fi;
	fib_info_hold(fib4_rt->fi);
	fib4_rt->tos = fen_info->tos;
	fib4_rt->type = fen_info->type;

	return fib4_rt;
}

static void nsim_fib4_rt_destroy(struct nsim_fib4_rt *fib4_rt)
{
	fib_info_put(fib4_rt->fi);
	nsim_fib_rt_fini(&fib4_rt->common);
	kfree(fib4_rt);
}

static struct nsim_fib4_rt *
nsim_fib4_rt_lookup(struct rhashtable *fib_rt_ht,
		    const struct fib_entry_notifier_info *fen_info)
{
	struct nsim_fib_rt *fib_rt;

	fib_rt = nsim_fib_rt_lookup(fib_rt_ht, &fen_info->dst, sizeof(u32),
				    fen_info->dst_len, AF_INET,
				    fen_info->tb_id);
	if (!fib_rt)
		return NULL;

	return container_of(fib_rt, struct nsim_fib4_rt, common);
}

static void
nsim_fib4_rt_offload_failed_flag_set(struct net *net,
				     struct fib_entry_notifier_info *fen_info)
{
	u32 *p_dst = (u32 *)&fen_info->dst;
	struct fib_rt_info fri;

	fri.fi = fen_info->fi;
	fri.tb_id = fen_info->tb_id;
	fri.dst = cpu_to_be32(*p_dst);
	fri.dst_len = fen_info->dst_len;
	fri.tos = fen_info->tos;
	fri.type = fen_info->type;
	fri.offload = false;
	fri.trap = false;
	fri.offload_failed = true;
	fib_alias_hw_flags_set(net, &fri);
}

static void nsim_fib4_rt_hw_flags_set(struct net *net,
				      const struct nsim_fib4_rt *fib4_rt,
				      bool trap)
{
	u32 *p_dst = (u32 *) fib4_rt->common.key.addr;
	int dst_len = fib4_rt->