/* SPDX-License-Identifier: GPL-2.0-only */
/* Copyright (C) 2000-2002 Joakim Axelsson <gozem@linux.nu>
 *                         Patrick Schaaf <bof@bof.de>
 *                         Martin Josefsson <gandalf@wlug.westbo.se>
 * Copyright (C) 2003-2013 Jozsef Kadlecsik <kadlec@netfilter.org>
 */
#ifndef _IP_SET_H
#define _IP_SET_H

#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/x_tables.h>
#include <linux/stringify.h>
#include <linux/vmalloc.h>
#include <net/netlink.h>
#include <uapi/linux/netfilter/ipset/ip_set.h>

#define _IP_SET_MODULE_DESC(a, b, c)            \
        MODULE_DESCRIPTION(a " type of IP sets, revisions " b "-" c)
#define IP_SET_MODULE_DESC(a, b, c)             \
        _IP_SET_MODULE_DESC(a, __stringify(b), __stringify(c))

/* Set features */
enum ip_set_feature {
        IPSET_TYPE_IP_FLAG = 0,
        IPSET_TYPE_IP = (1 << IPSET_TYPE_IP_FLAG),
        IPSET_TYPE_PORT_FLAG = 1,
        IPSET_TYPE_PORT = (1 << IPSET_TYPE_PORT_FLAG),
        IPSET_TYPE_MAC_FLAG = 2,
        IPSET_TYPE_MAC = (1 << IPSET_TYPE_MAC_FLAG),
        IPSET_TYPE_IP2_FLAG = 3,
        IPSET_TYPE_IP2 = (1 << IPSET_TYPE_IP2_FLAG),
        IPSET_TYPE_NAME_FLAG = 4,
        IPSET_TYPE_NAME = (1 << IPSET_TYPE_NAME_FLAG),
        IPSET_TYPE_IFACE_FLAG = 5,
        IPSET_TYPE_IFACE = (1 << IPSET_TYPE_IFACE_FLAG),
        IPSET_TYPE_MARK_FLAG = 6,
        IPSET_TYPE_MARK = (1 << IPSET_TYPE_MARK_FLAG),
        IPSET_TYPE_NOMATCH_FLAG = 7,
        IPSET_TYPE_NOMATCH = (1 << IPSET_TYPE_NOMATCH_FLAG),
        /* Strictly speaking not a feature, but a flag for dumping:
         * this settype must be dumped last */
        IPSET_DUMP_LAST_FLAG = 8,
        IPSET_DUMP_LAST = (1 << IPSET_DUMP_LAST_FLAG),
};

/* Set extensions */
enum ip_set_extension {
        IPSET_EXT_BIT_TIMEOUT = 0,
        IPSET_EXT_TIMEOUT = (1 << IPSET_EXT_BIT_TIMEOUT),
        IPSET_EXT_BIT_COUNTER = 1,
        IPSET_EXT_COUNTER = (1 << IPSET_EXT_BIT_COUNTER),
        IPSET_EXT_BIT_COMMENT = 2,
        IPSET_EXT_COMMENT = (1 << IPSET_EXT_BIT_COMMENT),
        IPSET_EXT_BIT_SKBINFO = 3,
        IPSET_EXT_SKBINFO = (1 << IPSET_EXT_BIT_SKBINFO),
        /* Mark set with an extension which needs to call destroy */
        IPSET_EXT_BIT_DESTROY = 7,
        IPSET_EXT_DESTROY = (1 << IPSET_EXT_BIT_DESTROY),
};

#define SET_WITH_TIMEOUT(s)     ((s)->extensions & IPSET_EXT_TIMEOUT)
#define SET_WITH_COUNTER(s)     ((s)->extensions & IPSET_EXT_COUNTER)
#define SET_WITH_COMMENT(s)     ((s)->extensions & IPSET_EXT_COMMENT)
#define SET_WITH_SKBINFO(s)     ((s)->extensions & IPSET_EXT_SKBINFO)
#define SET_WITH_FORCEADD(s)    ((s)->flags & IPSET_CREATE_FLAG_FORCEADD)

/* Extension id, in size order */
enum ip_set_ext_id {
        IPSET_EXT_ID_COUNTER = 0,
        IPSET_EXT_ID_TIMEOUT,
        IPSET_EXT_ID_SKBINFO,
        IPSET_EXT_ID_COMMENT,
        IPSET_EXT_ID_MAX,
};

struct ip_set;

/* Extension type */
struct ip_set_ext_type {
        /* Destroy extension private data (can be NULL) */
        void (*destroy)(struct ip_set *set, void *ext);
        enum ip_set_extension type;
        enum ipset_cadt_flags flag;
        /* Size and minimal alignment */
        u8 len;
        u8 align;
};

extern const struct ip_set_ext_type ip_set_extensions[];

struct ip_set_counter {
        atomic64_t bytes;
        atomic64_t packets;
};

struct ip_set_comment_rcu {
        struct rcu_head rcu;
        char str[];
};

struct ip_set_comment {
        struct ip_set_comment_rcu __rcu *c;
};

struct ip_set_skbinfo {
        u32 skbmark;
        u32 skbmarkmask;
        u32 skbprio;
        u16 skbqueue;
        u16 __pad;
};

struct ip_set_ext {
        struct ip_set_skbinfo skbinfo;
        u64 packets;
        u64 bytes;
        char *comment;
        u32 timeout;
        u8 packets_op;
        u8 bytes_op;
        bool target;
};

#define ext_timeout(e, s)       \
((unsigned long *)(((void *)(e)) + (s)->offset[IPSET_EXT_ID_TIMEOUT]))
#define ext_counter(e, s)       \
((struct ip_set_counter *)(((void *)(e)) + (s)->offset[IPSET_EXT_ID_COUNTER]))
#define ext_comment(e, s)       \
((struct ip_set_comment *)(((void *)(e)) + (s)->offset[IPSET_EXT_ID_COMMENT]))
#define ext_skbinfo(e, s)       \
((struct ip_set_skbinfo *)(((void *)(e)) + (s)->offset[IPSET_EXT_ID_SKBINFO]))

typedef int (*ipset_adtfn)(struct ip_set *set, void *value,
                           const struct ip_set_ext *ext,
                           struct ip_set_ext *mext, u32 cmdflags);

/* Kernel API function options */
struct ip_set_adt_opt {
        u8 family;              /* Actual protocol family */
        u8 dim;                 /* Dimension of match/target */
        u8 flags;               /* Direction and negation flags */
        u32 cmdflags;           /* Command-like flags */
        struct ip_set_ext ext;  /* Extensions */
};

/* Set type, variant-specific part */
struct ip_set_type_variant {
        /* Kernelspace: test/add/del entries
         *              returns negative error code,
         *                      zero for no match/success to add/delete
         *                      positive for matching element */
        int (*kadt)(struct ip_set *set, const struct sk_buff *skb,
                    const struct xt_action_param *par,
                    enum ipset_adt adt, struct ip_set_adt_opt *opt);

        /* Userspace: test/add/del entries
         *              returns negative error code,
         *                      zero for no match/success to add/delete
         *                      positive for matching element */
        int (*uadt)(struct ip_set *set, struct nlattr *tb[],
                    enum ipset_adt adt, u32 *lineno, u32 flags, bool retried);

        /* Low level add/del/test functions */
        ipset_adtfn adt[IPSET_ADT_MAX];

        /* When adding entries and set is full, try to resize the set */
        int (*resize)(struct ip_set *set, bool retried);
        /* Destroy the set */
        void (*destroy)(struct ip_set *set);
        /* Flush the elements */
        void (*flush)(struct ip_set *set);
        /* Expire entries before listing */
        void (*expire)(struct ip_set *set);
        /* List set header data */
        int (*head)(struct ip_set *set, struct sk_buff *skb);
        /* List elements */
        int (*list)(const struct ip_set *set, struct sk_buff *skb,
                    struct netlink_callback *cb);
        /* Keep listing private when resizing runs parallel */
        void (*uref)(struct ip_set *set, struct netlink_callback *cb,
                     bool start);

        /* Return true if "b" set is the same as "a"
         * according to the create set parameters */
        bool (*same_set)(const struct ip_set *a, const struct ip_set *b);
        /* Cancel ongoing garbage collectors before destroying the set*/
        void (*cancel_gc)(struct ip_set *set);
        /* Region-locking is used */
        bool region_lock;
};

struct ip_set_region {
        spinlock_t lock;        /* Region lock */
        size_t ext_size;        /* Size of the dynamic extensions */
        u32 elements;           /* Number of elements vs timeout */
};

/* Max range where every element is added/deleted in one step */
#define IPSET_MAX_RANGE         (1<<14)

/* The max revision number supported by any set type + 1 */
#define IPSET_REVISION_MAX      9

/* The core set type structure */
struct ip_set_type {
        struct list_head list;

        /* Typename */
        char name[IPSET_MAXNAMELEN];
        /* Protocol version */
        u8 protocol;
        /* Set type dimension */
        u8 dimension;
        /*
         * Supported family: may be NFPROTO_UNSPEC for both
         * NFPROTO_IPV4/NFPROTO_IPV6.
         */
        u8 family;
        /* Type revisions */
        u8 revision_min, revision_max;
        /* Revision-specific supported (create) flags */
        u8 create_flags[IPSET_REVISION_MAX+1];
        /* Set features to control swapping */
        u16 features;

        /* Create set */
        int (*create)(struct net *net, struct ip_set *set,
                      struct nlattr *tb[], u32 flags);

        /* Attribute policies */
        const struct nla_policy create_policy[IPSET_ATTR_CREATE_MAX + 1];
        const struct nla_policy adt_policy[IPSET_ATTR_ADT_MAX + 1];

        /* Set this to THIS_MODULE if you are a module, otherwise NULL */
        struct module *me;
};

/* register and unregister set type */
extern int ip_set_type_register(struct ip_set_type *set_type);
extern void ip_set_type_unregister(struct ip_set_type *set_type);

/* A generic IP set */
struct ip_set {
        /* For call_cru in destroy */
        struct rcu_head rcu;
        /* The name of the set */
        char name[IPSET_MAXNAMELEN];
        /* Lock protecting the set data */
        spinlock_t lock;
        /* References to the set */
        u32 ref;
        /* References to the set for netlink events like dump,
         * ref can be swapped out by ip_set_swap
         */
        u32 ref_netlink;
        /* The core set type */
        struct ip_set_type *type;
        /* The type variant doing the real job */
        const struct ip_set_type_variant *variant;
        /* The actual INET family of the set */
        u8 family;
        /* The type revision */
        u8 revision;
        /* Extensions */
        u8 extensions;
        /* Create flags */
        u8 flags;
        /* Default timeout value, if enabled */
        u32 timeout;
        /* Number of elements (vs timeout) */
        u32 elements;
        /* Size of the dynamic extensions (vs timeout) */
        size_t ext_size;
        /* Element data size */
        size_t dsize;
        /* Offsets to extensions in elements */
        size_t offset[IPSET_EXT_ID_MAX];
        /* The type specific data */
        void *data;
};

static inline void
ip_set_ext_destroy(struct ip_set *set, void *data)
{
        /* Check that the extension is enabled for the set and
         * call it's destroy function for its extension part in data.
         */
        if (SET_WITH_COMMENT(set)) {
                struct ip_set_comment *c = ext_comment(data, set);

                ip_set_extensions[IPSET_EXT_ID_COMMENT].destroy(set, c);
        }
}

int ip_set_put_flags(struct sk_buff *skb, struct ip_set *set);

/* Netlink CB args */
enum {
        IPSET_CB_NET = 0,       /* net namespace */
        IPSET_CB_PROTO,         /* ipset protocol */
        IPSET_CB_DUMP,          /* dump single set/all sets */
        IPSET_CB_INDEX,         /* set index */
        IPSET_CB_PRIVATE,       /* set private data */
        IPSET_CB_ARG0,          /* type specific */
};

/* register and unregister set references */
extern ip_set_id_t ip_set_get_byname(struct net *net,
                                     const struct nlattr *name, struct ip_set **set);
extern void ip_set_put_byindex(struct net *net, ip_set_id_t index);
extern void ip_set_name_byindex(struct net *net, ip_set_id_t index, char *name);
extern ip_set_id_t ip_set_nfnl_get_byindex(struct net *net, ip_set_id_t index);
extern void ip_set_nfnl_put(struct net *net, ip_set_id_t index);

/* API for iptables set match, and SET target */

extern int ip_set_add(ip_set_id_t id, const struct sk_buff *skb,
                      const struct xt_action_param *par,
                      struct ip_set_adt_opt *opt);
extern int ip_set_del(ip_set_id_t id, const struct sk_buff *skb,
                      const struct xt_action_param *par,
                      struct ip_set_adt_opt *opt);
extern int ip_set_test(ip_set_id_t id, const struct sk_buff *skb,
                       const struct xt_action_param *par,
                       struct ip_set_adt_opt *opt);

/* Utility functions */
extern void *ip_set_alloc(size_t size);
extern void ip_set_free(void *members);
extern int ip_set_get_ipaddr4(struct nlattr *nla,  __be32 *ipaddr);
extern int ip_set_get_ipaddr6(struct nlattr *nla, union nf_inet_addr *ipaddr);
extern size_t ip_set_elem_len(struct ip_set *set, struct nlattr *tb[],
                              size_t len, size_t align);
extern int ip_set_get_extensions(struct ip_set *set, struct nlattr *tb[],
                                 struct ip_set_ext *ext);
extern int ip_set_put_extensions(struct sk_buff *skb, const struct ip_set *set,
                                 const void *e, bool active);
extern bool ip_set_match_extensions(struct ip_set *set,
                                    const struct ip_set_ext *ext,
                                    struct ip_set_ext *mext,
                                    u32 flags, void *data);

static inline int
ip_set_get_hostipaddr4(struct nlattr *nla, u32 *ipaddr)
{
        __be32 ip;
        int ret = ip_set_get_ipaddr4(nla, &ip);

        if (ret)
                return ret;
        *ipaddr = ntohl(ip);
        return 0;
}

/* Ignore IPSET_ERR_EXIST errors if asked to do so? */
static inline bool
ip_set_eexist(int ret, u32 flags)
{
        return ret == -IPSET_ERR_EXIST && (flags & IPSET_FLAG_EXIST);
}

/* Match elements marked with nomatch */
static inline bool
ip_set_enomatch(int ret, u32 flags, enum ipset_adt adt, struct ip_set *set)
{
        return adt == IPSET_TEST &&
               (set->type->features & IPSET_TYPE_NOMATCH) &&
               ((flags >> 16) & IPSET_FLAG_NOMATCH) &&
               (ret > 0 || ret == -ENOTEMPTY);
}

/* Check the NLA_F_NET_BYTEORDER flag */
static inline bool
ip_set_attr_netorder(struct nlattr *tb[], int type)
{
        return tb[type] && (tb[type]->nla_type & NLA_F_NET_BYTEORDER);
}

static inline bool
ip_set_optattr_netorder(struct nlattr *tb[], int type)
{
        return !tb[type] || (tb[type]->nla_type & NLA_F_NET_BYTEORDER);
}

/* Useful converters */
static inline u32
ip_set_get_h32(const struct nlattr *attr)
{
        return ntohl(nla_get_be32(attr));
}

static inline u16
ip_set_get_h16(const struct nlattr *attr)
{
        return ntohs(nla_get_be16(attr));
}

static inline int nla_put_ipaddr4(struct sk_buff *skb, int type, __be32 ipaddr)
{
        struct nlattr *__nested = nla_nest_start(skb, type);
        int ret;

        if (!__nested)
                return -EMSGSIZE;
        ret = nla_put_in_addr(skb, IPSET_ATTR_IPADDR_IPV4, ipaddr);
        if (!ret)
                nla_nest_end(skb, __nested);
        return ret;
}

static inline int nla_put_ipaddr6(struct sk_buff *skb, int type,
                                  const struct in6_addr *ipaddrptr)
{
        struct nlattr *__nested = nla_nest_start(skb, type);
        int ret;

        if (!__nested)
                return -EMSGSIZE;
        ret = nla_put_in6_addr(skb, IPSET_ATTR_IPADDR_IPV6, ipaddrptr);
        if (!ret)
                nla_nest_end(skb, __nested);
        return ret;
}

/* Get address from skbuff */
static inline __be32
ip4addr(const struct sk_buff *skb, bool src)
{
        return src ? ip_hdr(skb)->saddr : ip_hdr(skb)->daddr;
}

static inline void
ip4addrptr(const struct sk_buff *skb, bool src, __be32 *addr)
{
        *addr = src ? ip_hdr(skb)->saddr : ip_hdr(skb)->daddr;
}

static inline void
ip6addrptr(const struct sk_buff *skb, bool src, struct in6_addr *addr)
{
        memcpy(addr, src ? &ipv6_hdr(skb)->saddr : &ipv6_hdr(skb)->daddr,
               sizeof(*addr));
}

/* How often should the gc be run by default */
#define IPSET_GC_TIME                   (3 * 60)

/* Timeout period depending on the timeout value of the given set */
#define IPSET_GC_PERIOD(timeout) \
        ((timeout/3) ? min_t(u32, (timeout)/3, IPSET_GC_TIME) : 1)

/* Entry is set with no timeout value */
#define IPSET_ELEM_PERMANENT    0

/* Set is defined with timeout support: timeout value may be 0 */
#define IPSET_NO_TIMEOUT        UINT_MAX

/* Max timeout value, see msecs_to_jiffies() in jiffies.h */
#define IPSET_MAX_TIMEOUT       (UINT_MAX >> 1)/MSEC_PER_SEC

#define ip_set_adt_opt_timeout(opt, set)        \
((opt)->ext.timeout != IPSET_NO_TIMEOUT ? (opt)->ext.timeout : (set)->timeout)

static inline unsigned int
ip_set_timeout_uget(struct nlattr *tb)
{
        unsigned int timeout = ip_set_get_h32(tb);

        /* Normalize to fit into jiffies */
        if (timeout > IPSET_MAX_TIMEOUT)
                timeout = IPSET_MAX_TIMEOUT;

        return timeout;
}

static inline bool
ip_set_timeout_expired(const unsigned long *t)
{
        return *t != IPSET_ELEM_PERMANENT && time_is_before_jiffies(*t);
}

static inline void
ip_set_timeout_set(unsigned long *timeout, u32 value)
{
        unsigned long t;

        if (!value) {
                *timeout = IPSET_ELEM_PERMANENT;
                return;
        }

        t = msecs_to_jiffies(value * MSEC_PER_SEC) + jiffies;
        if (t == IPSET_ELEM_PERMANENT)
                /* Bingo! :-) */
                t--;
        *timeout = t;
}

void ip_set_init_comment(struct ip_set *set, struct ip_set_comment *comment,
                         const struct ip_set_ext *ext);

static inline void
ip_set_init_counter(struct ip_set_counter *counter,
                    const struct ip_set_ext *ext)
{
        if (ext->bytes != ULLONG_MAX)
                atomic64_set(&(counter)->bytes, (long long)(ext->bytes));
        if (ext->packets != ULLONG_MAX)
                atomic64_set(&(counter)->packets, (long long)(ext->packets));
}

static inline void
ip_set_init_skbinfo(struct ip_set_skbinfo *skbinfo,
                    const struct ip_set_ext *ext)
{
        *skbinfo = ext->skbinfo;
}

static inline void
nf_inet_addr_mask_inplace(union nf_inet_addr *a1,
                          const union nf_inet_addr *mask)
{
        a1->all[0] &= mask->all[0];
        a1->all[1] &= mask->all[1];
        a1->all[2] &= mask->all[2];
        a1->all[3] &= mask->all[3];
}

#define IP_SET_INIT_KEXT(skb, opt, set)                 \
        { .bytes = (skb)->len, .packets = 1, .target = true,\
          .timeout = ip_set_adt_opt_timeout(opt, set) }

#define IP_SET_INIT_UEXT(set)                           \
        { .bytes = ULLONG_MAX, .packets = ULLONG_MAX,   \
          .timeout = (set)->timeout }

#define IPSET_CONCAT(a, b)              a##b
#define IPSET_TOKEN(a, b)               IPSET_CONCAT(a, b)

#endif /*_IP_SET_H */