/*
 * Copyright (C) 2017 Netronome Systems, Inc.
 *
 * 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/device.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/u64_stats_sync.h>
#include <net/devlink.h>
#include <net/xdp.h>

#define DRV_NAME	"netdevsim"

#define NSIM_XDP_MAX_MTU	4000

#define NSIM_EA(extack, msg)	NL_SET_ERR_MSG_MOD((extack), msg)

#define NSIM_IPSEC_MAX_SA_COUNT		33
#define NSIM_IPSEC_VALID		BIT(31)

struct nsim_sa {
	struct xfrm_state *xs;
	__be32 ipaddr[4];
	u32 key[4];
	u32 salt;
	bool used;
	bool crypt;
	bool rx;
};

struct nsim_ipsec {
	struct nsim_sa sa[NSIM_IPSEC_MAX_SA_COUNT];
	struct dentry *pfile;
	u32 count;
	u32 tx;
	u32 ok;
};

struct netdevsim {
	struct net_device *netdev;
	struct nsim_dev *nsim_dev;
	struct nsim_dev_port *nsim_dev_port;

	u64 tx_packets;
	u64 tx_bytes;
	struct u64_stats_sync syncp;

	struct nsim_bus_dev *nsim_bus_dev;

	struct bpf_prog	*bpf_offloaded;
	u32 bpf_offloaded_id;

	struct xdp_attachment_info xdp;
	struct xdp_attachment_info xdp_hw;

	bool bpf_tc_accept;
	bool bpf_tc_non_bound_accept;
	bool bpf_xdpdrv_accept;
	bool bpf_xdpoffload_accept;

	bool bpf_map_accept;
	struct nsim_ipsec ipsec;
};

struct netdevsim *
nsim_create(struct nsim_dev *nsim_dev, struct nsim_dev_port *nsim_dev_port);
void nsim_destroy(struct netdevsim *ns);

#ifdef CONFIG_BPF_SYSCALL
int nsim_bpf_dev_init(struct nsim_dev *nsim_dev);
void nsim_bpf_dev_exit(struct nsim_dev *nsim_dev);
int nsim_bpf_init(struct netdevsim *ns);
void nsim_bpf_uninit(struct netdevsim *ns);
int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf);
int nsim_bpf_disable_tc(struct netdevsim *ns);
int nsim_bpf_setup_tc_block_cb(enum tc_setup_type type,
			       void *type_data, void *cb_priv);
#else

static inline int nsim_bpf_dev_init(struct nsim_dev *nsim_dev)
{
	return 0;
}

static inline void nsim_bpf_dev_exit(struct nsim_dev *nsim_dev)
{
}
static inline int nsim_bpf_init(struct netdevsim *ns)
{
	return 0;
}

static inline void nsim_bpf_uninit(struct netdevsim *ns)
{
}

static inline int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf)
{
	return bpf->command == XDP_QUERY_PROG ? 0 : -EOPNOTSUPP;
}

static inline int nsim_bpf_disable_tc(struct netdevsim *ns)
{
	return 0;
}

static inline int
nsim_bpf_setup_tc_block_cb(enum tc_setup_type type, void *type_data,
			   void *cb_priv)
{
	return -EOPNOTSUPP;
}
#endif

enum nsim_resource_id {
	NSIM_RESOURCE_NONE,   /* DEVLINK_RESOURCE_ID_PARENT_TOP */
	NSIM_RESOURCE_IPV4,
	NSIM_RESOURCE_IPV4_FIB,
	NSIM_RESOURCE_IPV4_FIB_RULES,
	NSIM_RESOURCE_IPV6,
	NSIM_RESOURCE_IPV6_FIB,
	NSIM_RESOURCE_IPV6_FIB_RULES,
};

struct nsim_dev_port {
	struct list_head list;
	struct devlink_port devlink_port;
	unsigned int port_index;
	struct dentry *ddir;
	struct netdevsim *ns;
};

struct nsim_dev {
	struct nsim_bus_dev *nsim_bus_dev;
	struct nsim_fib_data *fib_data;
	struct dentry *ddir;
	struct dentry *ports_ddir;
	struct bpf_offload_dev *bpf_dev;
	bool bpf_bind_accept;
	u32 bpf_bind_verifier_delay;
	struct dentry *ddir_bpf_bound_progs;
	u32 prog_id_gen;
	struct list_head bpf_bound_progs;
	struct list_head bpf_bound_maps;
	struct netdev_phys_item_id switch_id;
	struct list_head port_list;
	struct mutex port_list_lock; /* protects port list */
};

int nsim_dev_init(void);
void nsim_dev_exit(void);
int nsim_dev_probe(struct nsim_bus_dev *nsim_bus_dev);
void nsim_dev_remove(struct nsim_bus_dev *nsim_bus_dev);
int nsim_dev_port_add(struct nsim_bus_dev *nsim_bus_dev,
		      unsigned int port_index);
int nsim_dev_port_del(struct nsim_bus_dev *nsim_bus_dev,
		      unsigned int port_index);

struct nsim_fib_data *nsim_fib_create(void);
void nsim_fib_destroy(struct nsim_fib_data *fib_data);
u64 nsim_fib_get_val(struct nsim_fib_data *fib_data,
		     enum nsim_resource_id res_id, bool max);
int nsim_fib_set_max(struct nsim_fib_data *fib_data,
		     enum nsim_resource_id res_id, u64 val,
		     struct netlink_ext_ack *extack);

#if IS_ENABLED(CONFIG_XFRM_OFFLOAD)
void nsim_ipsec_init(struct netdevsim *ns);
void nsim_ipsec_teardown(struct netdevsim *ns);
bool nsim_ipsec_tx(struct netdevsim *ns, struct sk_buff *skb);
#else
static inline void nsim_ipsec_init(struct netdevsim *ns)
{
}

static inline void nsim_ipsec_teardown(struct netdevsim *ns)
{
}

static inline bool nsim_ipsec_tx(struct netdevsim *ns, struct sk_buff *skb)
{
	return true;
}
#endif

struct nsim_vf_config {
	int link_state;
	u16 min_tx_rate;
	u16 max_tx_rate;
	u16 vlan;
	__be16 vlan_proto;
	u16 qos;
	u8 vf_mac[ETH_ALEN];
	bool spoofchk_enabled;
	bool trusted;
	bool rss_query_enabled;
};

struct nsim_bus_dev {
	struct device dev;
	struct list_head list;
	unsigned int port_count;
	unsigned int num_vfs;
	struct nsim_vf_config *vfconfigs;
};

int nsim_bus_init(void);
void nsim_bus_exit(void);