/* SPDX-License-Identifier: LGPL-2.1+ */

#include <netinet/in.h>
#include <linux/if_addrlabel.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nf_tables.h>
#include <linux/nexthop.h>
#include <stdbool.h>
#include <unistd.h>

#include "sd-netlink.h"

#include "format-util.h"
#include "netlink-internal.h"
#include "netlink-types.h"
#include "netlink-util.h"
#include "socket-util.h"
#include "util.h"

static int nft_message_new(sd_netlink *nfnl, sd_netlink_message **ret, int family, uint16_t type, uint16_t flags) {
        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
        struct nfgenmsg *nfh;
        const NLType *nl_type;
        size_t size;
        int r;

        assert_return(nfnl, -EINVAL);

        r = type_system_root_get_type(nfnl, &nl_type, NFNL_SUBSYS_NFTABLES);
        if (r < 0)
                return r;

        if (type_get_type(nl_type) != NETLINK_TYPE_NESTED)
                return -EINVAL;

        r = message_new_empty(nfnl, &m);
        if (r < 0)
                return r;

        size = NLMSG_SPACE(type_get_size(nl_type));

        assert(size >= sizeof(struct nlmsghdr));
        m->hdr = malloc0(size);
        if (!m->hdr)
                return -ENOMEM;

        m->hdr->nlmsg_flags = NLM_F_REQUEST | flags;

        type_get_type_system(nl_type, &m->containers[0].type_system);

        r = type_system_get_type_system(m->containers[0].type_system,
                                        &m->containers[0].type_system,
                                        type);
        if (r < 0)
                return r;

        m->hdr->nlmsg_len = size;
        m->hdr->nlmsg_type = NFNL_SUBSYS_NFTABLES << 8 | type;

        nfh = NLMSG_DATA(m->hdr);
        nfh->nfgen_family = family;
        nfh->version = NFNETLINK_V0;
        nfh->res_id = nfnl->serial;

        *ret = TAKE_PTR(m);
        return 0;
}

static int sd_nfnl_message_batch(sd_netlink *nfnl, sd_netlink_message **ret, int v) {
        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
        struct nfgenmsg *nfh;
        int r;

        r = message_new(nfnl, &m, v);
        if (r < 0)
                return r;

        nfh = NLMSG_DATA(m->hdr);
        nfh->nfgen_family = AF_UNSPEC;
        nfh->version = NFNETLINK_V0;
        nfh->res_id = NFNL_SUBSYS_NFTABLES;

        *ret = TAKE_PTR(m);
        return r;
}

int sd_nfnl_message_batch_begin(sd_netlink *nfnl, sd_netlink_message **ret) {
        return sd_nfnl_message_batch(nfnl, ret, NFNL_MSG_BATCH_BEGIN);
}

int sd_nfnl_message_batch_end(sd_netlink *nfnl, sd_netlink_message **ret) {
        return sd_nfnl_message_batch(nfnl, ret, NFNL_MSG_BATCH_END);
}

int sd_nfnl_nft_message_new_basechain(sd_netlink *nfnl, sd_netlink_message **ret,
                                      int family,
                                      const char *table, const char *chain,
                                      const char *type,
                                      uint8_t hook, int prio) {
        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
        int r;

        r = nft_message_new(nfnl, &m, family, NFT_MSG_NEWCHAIN, NLM_F_CREATE | NLM_F_ACK);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_string(m, NFTA_CHAIN_TABLE, table);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_string(m, NFTA_CHAIN_NAME, chain);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_string(m, NFTA_CHAIN_TYPE, type);
        if (r < 0)
                return r;

        r = sd_netlink_message_open_container(m, NFTA_CHAIN_HOOK);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_u32(m, NFTA_HOOK_HOOKNUM, htobe32(hook));
        if (r < 0)
                return r;

        r = sd_netlink_message_append_u32(m, NFTA_HOOK_PRIORITY, htobe32(prio));
        if (r < 0)
                return r;

        r = sd_netlink_message_close_container(m);
        if (r < 0)
                return r;

        *ret = TAKE_PTR(m);
        return 0;
}

int sd_nfnl_nft_message_del_table(sd_netlink *nfnl, sd_netlink_message **ret,
                                  int family, const char *table) {
        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
        int r;

        r = nft_message_new(nfnl, &m, family, NFT_MSG_DELTABLE, NLM_F_CREATE | NLM_F_ACK);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_string(m, NFTA_TABLE_NAME, table);
        if (r < 0)
                return r;

        *ret = TAKE_PTR(m);
        return r;
}

int sd_nfnl_nft_message_new_table(sd_netlink *nfnl, sd_netlink_message **ret,
                                  int family, const char *table, uint16_t flags) {
        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
        int r;

        r = nft_message_new(nfnl, &m, family, NFT_MSG_NEWTABLE, NLM_F_CREATE | flags);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_string(m, NFTA_TABLE_NAME, table);
        if (r < 0)
                return r;

        *ret = TAKE_PTR(m);
        return r;
}

int sd_nfnl_nft_message_new_rule(sd_netlink *nfnl, sd_netlink_message **ret,
                                 int family, const char *table, const char *chain) {
        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
        int r;

        r = nft_message_new(nfnl, &m, family, NFT_MSG_NEWRULE, NLM_F_CREATE | NLM_F_ACK);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_string(m, NFTA_RULE_TABLE, table);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_string(m, NFTA_RULE_CHAIN, chain);
        if (r < 0)
                return r;

        *ret = TAKE_PTR(m);
        return r;
}

int sd_nfnl_nft_message_new_set(sd_netlink *nfnl, sd_netlink_message **ret,
                                int family, const char *table, const char *set_name,
                                uint32_t set_id, uint32_t klen) {
        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
        int r;

        r = nft_message_new(nfnl, &m, family, NFT_MSG_NEWSET, NLM_F_CREATE | NLM_F_ACK);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_string(m, NFTA_SET_TABLE, table);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_string(m, NFTA_SET_NAME, set_name);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_u32(m, NFTA_SET_ID, ++set_id);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_u32(m, NFTA_SET_KEY_LEN, htobe32(klen));
        if (r < 0)
                return r;
        *ret = TAKE_PTR(m);
        return r;
}

int sd_nfnl_nft_message_new_setelems_begin(sd_netlink *nfnl, sd_netlink_message **ret,
                                           int family, const char *table, const char *set_name) {
        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
        int r;

        r = nft_message_new(nfnl, &m, family, NFT_MSG_NEWSETELEM, NLM_F_CREATE | NLM_F_ACK);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_string(m, NFTA_SET_ELEM_LIST_TABLE, table);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_string(m, NFTA_SET_ELEM_LIST_SET, set_name);
        if (r < 0)
                return r;

        r = sd_netlink_message_open_container(m, NFTA_SET_ELEM_LIST_ELEMENTS);
        if (r < 0)
                return r;

        *ret = TAKE_PTR(m);
        return r;
}

int sd_nfnl_nft_message_del_setelems_begin(sd_netlink *nfnl, sd_netlink_message **ret,
                                           int family, const char *table, const char *set_name) {
        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
        int r;

        r = nft_message_new(nfnl, &m, family, NFT_MSG_DELSETELEM, NLM_F_ACK);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_string(m, NFTA_SET_ELEM_LIST_TABLE, table);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_string(m, NFTA_SET_ELEM_LIST_SET, set_name);
        if (r < 0)
                return r;

        r = sd_netlink_message_open_container(m, NFTA_SET_ELEM_LIST_ELEMENTS);
        if (r < 0)
                return r;

        *ret = TAKE_PTR(m);
        return r;
}

static int sd_nfnl_add_data(sd_netlink_message *m, uint16_t attr, const void *data, uint32_t dlen) {
        int r = sd_netlink_message_open_container(m, attr);
        if (r < 0)
                return r;

        r = sd_netlink_message_append_data(m, NFTA_DATA_VALUE, data, dlen);
        if (r < 0)
                return r;

        return sd_netlink_message_close_container(m); /* attr */
}

int sd_nfnl_nft_message_add_setelem(sd_netlink_message *m, uint32_t num,
                                    const void *key, uint32_t klen,
                                    const void *data, uint32_t dlen) {
        int r;

        r = sd_netlink_message_open_array(m, num);
        if (r < 0)
                return r;

        r = sd_nfnl_add_data(m, NFTA_SET_ELEM_KEY, key, klen);
        if (r < 0)
                goto cancel;

        if (data) {
                r = sd_nfnl_add_data(m, NFTA_SET_ELEM_DATA, data, dlen);
                if (r < 0)
                        goto cancel;
        }

        return r;
cancel:
        sd_netlink_message_cancel_array(m);
        return r;
}

int sd_nfnl_nft_message_add_setelem_end(sd_netlink_message *m) {
        return sd_netlink_message_close_container(m); /* NFTA_SET_ELEM_LIST_ELEMENTS */
}

int sd_nfnl_socket_open(sd_netlink **ret) {
        return netlink_open_family(ret, NETLINK_NETFILTER);
}