// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (C) 2003-2013 Jozsef Kadlecsik <kadlec@netfilter.org> */

/* Kernel module implementing an IP set type: the bitmap:port type */

#include <linux/module.h>
#include <linux/ip.h>
#include <linux/skbuff.h>
#include <linux/errno.h>
#include <linux/netlink.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <net/netlink.h>

#include <linux/netfilter/ipset/ip_set.h>
#include <linux/netfilter/ipset/ip_set_bitmap.h>
#include <linux/netfilter/ipset/ip_set_getport.h>

#define IPSET_TYPE_REV_MIN      0
/*                              1          Counter support added */
/*                              2          Comment support added */
#define IPSET_TYPE_REV_MAX      3       /* skbinfo support added */

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@netfilter.org>");
IP_SET_MODULE_DESC("bitmap:port", IPSET_TYPE_REV_MIN, IPSET_TYPE_REV_MAX);
MODULE_ALIAS("ip_set_bitmap:port");

#define MTYPE           bitmap_port

/* Type structure */
struct bitmap_port {
        unsigned long *members; /* the set members */
        u16 first_port;         /* host byte order, included in range */
        u16 last_port;          /* host byte order, included in range */
        u32 elements;           /* number of max elements in the set */
        size_t memsize;         /* members size */
        struct timer_list gc;   /* garbage collection */
        struct ip_set *set;     /* attached to this ip_set */
        unsigned char extensions[]      /* data extensions */
                __aligned(__alignof__(u64));
};

/* ADT structure for generic function args */
struct bitmap_port_adt_elem {
        u16 id;
};

static u16
port_to_id(const struct bitmap_port *m, u16 port)
{
        return port - m->first_port;
}

/* Common functions */

static int
bitmap_port_do_test(const struct bitmap_port_adt_elem *e,
                    const struct bitmap_port *map, size_t dsize)
{
        return !!test_bit(e->id, map->members);
}

static int
bitmap_port_gc_test(u16 id, const struct bitmap_port *map, size_t dsize)
{
        return !!test_bit(id, map->members);
}

static int
bitmap_port_do_add(const struct bitmap_port_adt_elem *e,
                   struct bitmap_port *map, u32 flags, size_t dsize)
{
        return !!test_bit(e->id, map->members);
}

static int
bitmap_port_do_del(const struct bitmap_port_adt_elem *e,
                   struct bitmap_port *map)
{
        return !test_and_clear_bit(e->id, map->members);
}

static int
bitmap_port_do_list(struct sk_buff *skb, const struct bitmap_port *map, u32 id,
                    size_t dsize)
{
        return nla_put_net16(skb, IPSET_ATTR_PORT,
                             htons(map->first_port + id));
}

static int
bitmap_port_do_head(struct sk_buff *skb, const struct bitmap_port *map)
{
        return nla_put_net16(skb, IPSET_ATTR_PORT, htons(map->first_port)) ||
               nla_put_net16(skb, IPSET_ATTR_PORT_TO, htons(map->last_port));
}

static bool
ip_set_get_ip_port(const struct sk_buff *skb, u8 pf, bool src, __be16 *port)
{
        bool ret;
        u8 proto;

        switch (pf) {
        case NFPROTO_IPV4:
                ret = ip_set_get_ip4_port(skb, src, port, &proto);
                break;
        case NFPROTO_IPV6:
                ret = ip_set_get_ip6_port(skb, src, port, &proto);
                break;
        default:
                return false;
        }
        if (!ret)
                return ret;
        switch (proto) {
        case IPPROTO_TCP:
        case IPPROTO_UDP:
                return true;
        default:
                return false;
        }
}

static int
bitmap_port_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)
{
        struct bitmap_port *map = set->data;
        ipset_adtfn adtfn = set->variant->adt[adt];
        struct bitmap_port_adt_elem e = { .id = 0 };
        struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
        __be16 __port;
        u16 port = 0;

        if (!ip_set_get_ip_port(skb, opt->family,
                                opt->flags & IPSET_DIM_ONE_SRC, &__port))
                return -EINVAL;

        port = ntohs(__port);

        if (port < map->first_port || port > map->last_port)
                return -IPSET_ERR_BITMAP_RANGE;

        e.id = port_to_id(map, port);

        return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
}

static int
bitmap_port_uadt(struct ip_set *set, struct nlattr *tb[],
                 enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
{
        struct bitmap_port *map = set->data;
        ipset_adtfn adtfn = set->variant->adt[adt];
        struct bitmap_port_adt_elem e = { .id = 0 };
        struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
        u32 port;       /* wraparound */
        u16 port_to;
        int ret = 0;

        if (tb[IPSET_ATTR_LINENO])
                *lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);

        if (unlikely(!ip_set_attr_netorder(tb, IPSET_ATTR_PORT) ||
                     !ip_set_optattr_netorder(tb, IPSET_ATTR_PORT_TO)))
                return -IPSET_ERR_PROTOCOL;

        port = ip_set_get_h16(tb[IPSET_ATTR_PORT]);
        if (port < map->first_port || port > map->last_port)
                return -IPSET_ERR_BITMAP_RANGE;
        ret = ip_set_get_extensions(set, tb, &ext);
        if (ret)
                return ret;

        if (adt == IPSET_TEST) {
                e.id = port_to_id(map, port);
                return adtfn(set, &e, &ext, &ext, flags);
        }

        if (tb[IPSET_ATTR_PORT_TO]) {
                port_to = ip_set_get_h16(tb[IPSET_ATTR_PORT_TO]);
                if (port > port_to) {
                        swap(port, port_to);
                        if (port < map->first_port)
                                return -IPSET_ERR_BITMAP_RANGE;
                }
        } else {
                port_to = port;
        }

        if (port_to > map->last_port)
                return -IPSET_ERR_BITMAP_RANGE;

        for (; port <= port_to; port++) {
                e.id = port_to_id(map, port);
                ret = adtfn(set, &e, &ext, &ext, flags);

                if (ret && !ip_set_eexist(ret, flags))
                        return ret;

                ret = 0;
        }
        return ret;
}

static bool
bitmap_port_same_set(const struct ip_set *a, const struct ip_set *b)
{
        const struct bitmap_port *x = a->data;
        const struct bitmap_port *y = b->data;

        return x->first_port == y->first_port &&
               x->last_port == y->last_port &&
               a->timeout == b->timeout &&
               a->extensions == b->extensions;
}

/* Plain variant */

struct bitmap_port_elem {
};

#include "ip_set_bitmap_gen.h"

/* Create bitmap:ip type of sets */

static bool
init_map_port(struct ip_set *set, struct bitmap_port *map,
              u16 first_port, u16 last_port)
{
        map->members = bitmap_zalloc(map->elements, GFP_KERNEL | __GFP_NOWARN);
        if (!map->members)
                return false;
        map->first_port = first_port;
        map->last_port = last_port;
        set->timeout = IPSET_NO_TIMEOUT;

        map->set = set;
        set->data = map;
        set->family = NFPROTO_UNSPEC;

        return true;
}

static int
bitmap_port_create(struct net *net, struct ip_set *set, struct nlattr *tb[],
                   u32 flags)
{
        struct bitmap_port *map;
        u16 first_port, last_port;
        u32 elements;

        if (unlikely(!ip_set_attr_netorder(tb, IPSET_ATTR_PORT) ||
                     !ip_set_attr_netorder(tb, IPSET_ATTR_PORT_TO) ||
                     !ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT) ||
                     !ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
                return -IPSET_ERR_PROTOCOL;

        first_port = ip_set_get_h16(tb[IPSET_ATTR_PORT]);
        last_port = ip_set_get_h16(tb[IPSET_ATTR_PORT_TO]);
        if (first_port > last_port)
                swap(first_port, last_port);

        elements = last_port - first_port + 1;
        set->dsize = ip_set_elem_len(set, tb, 0, 0);
        map = ip_set_alloc(sizeof(*map) + elements * set->dsize);
        if (!map)
                return -ENOMEM;

        map->elements = elements;
        map->memsize = BITS_TO_LONGS(elements) * sizeof(unsigned long);
        set->variant = &bitmap_port;
        if (!init_map_port(set, map, first_port, last_port)) {
                ip_set_free(map);
                return -ENOMEM;
        }
        if (tb[IPSET_ATTR_TIMEOUT]) {
                set->timeout = ip_set_timeout_uget(tb[IPSET_ATTR_TIMEOUT]);
                bitmap_port_gc_init(set, bitmap_port_gc);
        }
        return 0;
}

static struct ip_set_type bitmap_port_type = {
        .name           = "bitmap:port",
        .protocol       = IPSET_PROTOCOL,
        .features       = IPSET_TYPE_PORT,
        .dimension      = IPSET_DIM_ONE,
        .family         = NFPROTO_UNSPEC,
        .revision_min   = IPSET_TYPE_REV_MIN,
        .revision_max   = IPSET_TYPE_REV_MAX,
        .create         = bitmap_port_create,
        .create_policy  = {
                [IPSET_ATTR_PORT]       = { .type = NLA_U16 },
                [IPSET_ATTR_PORT_TO]    = { .type = NLA_U16 },
                [IPSET_ATTR_TIMEOUT]    = { .type = NLA_U32 },
                [IPSET_ATTR_CADT_FLAGS] = { .type = NLA_U32 },
        },
        .adt_policy     = {
                [IPSET_ATTR_PORT]       = { .type = NLA_U16 },
                [IPSET_ATTR_PORT_TO]    = { .type = NLA_U16 },
                [IPSET_ATTR_TIMEOUT]    = { .type = NLA_U32 },
                [IPSET_ATTR_LINENO]     = { .type = NLA_U32 },
                [IPSET_ATTR_BYTES]      = { .type = NLA_U64 },
                [IPSET_ATTR_PACKETS]    = { .type = NLA_U64 },
                [IPSET_ATTR_COMMENT]    = { .type = NLA_NUL_STRING,
                                            .len  = IPSET_MAX_COMMENT_SIZE },
                [IPSET_ATTR_SKBMARK]    = { .type = NLA_U64 },
                [IPSET_ATTR_SKBPRIO]    = { .type = NLA_U32 },
                [IPSET_ATTR_SKBQUEUE]   = { .type = NLA_U16 },
        },
        .me             = THIS_MODULE,
};

static int __init
bitmap_port_init(void)
{
        return ip_set_type_register(&bitmap_port_type);
}

static void __exit
bitmap_port_fini(void)
{
        rcu_barrier();
        ip_set_type_unregister(&bitmap_port_type);
}

module_init(bitmap_port_init);
module_exit(bitmap_port_fini);