queue.c

/*
 * lib/netfilter/queue.c        Netfilter Queue
 *
 *      This library is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU Lesser General Public
 *      License as published by the Free Software Foundation version 2.1
 *      of the License.
 *
 * Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net>
 */

/**
 * @ingroup nfnl
 * @defgroup queue Queue
 * @brief
 * @{
 */

#include <sys/types.h>
#include <linux/netfilter/nfnetlink_queue.h>

#include <netlink-private/netlink.h>
#include <netlink/attr.h>
#include <netlink/netfilter/nfnl.h>
#include <netlink/netfilter/queue.h>

struct nl_sock *nfnl_queue_socket_alloc(void)
{
        struct nl_sock *nlsk;

        nlsk = nl_socket_alloc();
        if (nlsk)
                nl_socket_disable_auto_ack(nlsk);
        return nlsk;
}

static int send_queue_request(struct nl_sock *sk, struct nl_msg *msg)
{
        int err;

        err = nl_send_auto_complete(sk, msg);
        nlmsg_free(msg);
        if (err < 0)
                return err;

        return wait_for_ack(sk);
}

/**
 * @name Queue Commands
 * @{
 */

static int build_queue_cmd_request(uint8_t family, uint16_t queuenum,
                                   uint8_t command, struct nl_msg **result)
{
        struct nl_msg *msg;
        struct nfqnl_msg_config_cmd cmd;

        msg = nfnlmsg_alloc_simple(NFNL_SUBSYS_QUEUE, NFQNL_MSG_CONFIG, 0,
                                   family, queuenum);
        if (msg == NULL)
                return -NLE_NOMEM;

        cmd.pf = htons(family);
        cmd._pad = 0;
        cmd.command = command;
        if (nla_put(msg, NFQA_CFG_CMD, sizeof(cmd), &cmd) < 0)
                goto nla_put_failure;

        *result = msg;
        return 0;

nla_put_failure:
        nlmsg_free(msg);
        return -NLE_MSGSIZE;
}

int nfnl_queue_build_pf_bind(uint8_t pf, struct nl_msg **result)
{
        return build_queue_cmd_request(pf, 0, NFQNL_CFG_CMD_PF_BIND, result);
}

int nfnl_queue_pf_bind(struct nl_sock *nlh, uint8_t pf)
{
        struct nl_msg *msg;
        int err;

        if ((err = nfnl_queue_build_pf_bind(pf, &msg)) < 0)
                return err;

        return send_queue_request(nlh, msg);
}

int nfnl_queue_build_pf_unbind(uint8_t pf, struct nl_msg **result)
{
        return build_queue_cmd_request(pf, 0, NFQNL_CFG_CMD_PF_UNBIND, result);
}

int nfnl_queue_pf_unbind(struct nl_sock *nlh, uint8_t pf)
{
        struct nl_msg *msg;
        int err;

        if ((err = nfnl_queue_build_pf_unbind(pf, &msg)) < 0)
                return err;

        return send_queue_request(nlh, msg);
}

static int nfnl_queue_build_request(const struct nfnl_queue *queue,
                                    struct nl_msg **result)
{
        struct nl_msg *msg;

        if (!nfnl_queue_test_group(queue))
                return -NLE_MISSING_ATTR;

        msg = nfnlmsg_alloc_simple(NFNL_SUBSYS_QUEUE, NFQNL_MSG_CONFIG, 0,
                                   0, nfnl_queue_get_group(queue));
        if (msg == NULL)
                return -NLE_NOMEM;

        if (nfnl_queue_test_maxlen(queue) &&
            nla_put_u32(msg, NFQA_CFG_QUEUE_MAXLEN,
                        htonl(nfnl_queue_get_maxlen(queue))) < 0)
                goto nla_put_failure;

        /* This sucks, the nfnetlink_queue interface always expects both
         * parameters to be present. Needs to be done properly.
         */
        if (nfnl_queue_test_copy_mode(queue)) {
                struct nfqnl_msg_config_params params;

                switch (nfnl_queue_get_copy_mode(queue)) {
                case NFNL_QUEUE_COPY_NONE:
                        params.copy_mode = NFQNL_COPY_NONE;
                        break;
                case NFNL_QUEUE_COPY_META:
                        params.copy_mode = NFQNL_COPY_META;
                        break;
                case NFNL_QUEUE_COPY_PACKET:
                        params.copy_mode = NFQNL_COPY_PACKET;
                        break;
                }
                params.copy_range = htonl(nfnl_queue_get_copy_range(queue));

                if (nla_put(msg, NFQA_CFG_PARAMS, sizeof(params), &params) < 0)
                        goto nla_put_failure;
        }

        *result = msg;
        return 0;

nla_put_failure:
        nlmsg_free(msg);
        return -NLE_MSGSIZE;
}

int nfnl_queue_build_create_request(const struct nfnl_queue *queue,
                                    struct nl_msg **result)
{
        struct nfqnl_msg_config_cmd cmd;
        int err;

        if ((err = nfnl_queue_build_request(queue, result)) < 0)
                return err;

        cmd.pf = 0;
        cmd._pad = 0;
        cmd.command = NFQNL_CFG_CMD_BIND;

        NLA_PUT(*result, NFQA_CFG_CMD, sizeof(cmd), &cmd);

        return 0;

nla_put_failure:
        nlmsg_free(*result);
        return -NLE_MSGSIZE;
}

int nfnl_queue_create(struct nl_sock *nlh, const struct nfnl_queue *queue)
{
        struct nl_msg *msg;
        int err;

        if ((err = nfnl_queue_build_create_request(queue, &msg)) < 0)
                return err;

        return send_queue_request(nlh, msg);
}

int nfnl_queue_build_change_request(const struct nfnl_queue *queue,
                                    struct nl_msg **result)
{
        return nfnl_queue_build_request(queue, result);
}

int nfnl_queue_change(struct nl_sock *nlh, const struct nfnl_queue *queue)
{
        struct nl_msg *msg;
        int err;

        if ((err = nfnl_queue_build_change_request(queue, &msg)) < 0)
                return err;

        return send_queue_request(nlh, msg);
}

int nfnl_queue_build_delete_request(const struct nfnl_queue *queue,
                                    struct nl_msg **result)
{
        if (!nfnl_queue_test_group(queue))
                return -NLE_MISSING_ATTR;

        return build_queue_cmd_request(0, nfnl_queue_get_group(queue),
                                       NFQNL_CFG_CMD_UNBIND, result);
}

int nfnl_queue_delete(struct nl_sock *nlh, const struct nfnl_queue *queue)
{
        struct nl_msg *msg;
        int err;

        if ((err = nfnl_queue_build_delete_request(queue, &msg)) < 0)
                return err;

        return send_queue_request(nlh, msg);
}

/** @} */

static struct nl_cache_ops nfnl_queue_ops = {
        .co_name                = "netfilter/queue",
        .co_obj_ops             = &queue_obj_ops,
        .co_msgtypes            = {
                END_OF_MSGTYPES_LIST,
        },
};

static void __init nfnl_queue_init(void)
{
        nl_cache_mngt_register(&nfnl_queue_ops);
}

static void __exit nfnl_queue_exit(void)
{
        nl_cache_mngt_unregister(&nfnl_queue_ops);
}

/** @} */