examples/ip_pipeline/tap.c

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2018 Intel Corporation
 */

#include <netinet/in.h>
#ifdef RTE_EXEC_ENV_LINUX
#include <linux/if.h>
#include <linux/if_tun.h>
#endif
#include <sys/ioctl.h>

#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <rte_string_fns.h>

#include "tap.h"

#define TAP_DEV                                            "/dev/net/tun"

static struct tap_list tap_list;

int
tap_init(void)
{
    TAILQ_INIT(&tap_list);

    return 0;
}

struct tap *
tap_find(const char *name)
{
    struct tap *tap;

    if (name == NULL)
        return NULL;

    TAILQ_FOREACH(tap, &tap_list, node)
        if (strcmp(tap->name, name) == 0)
            return tap;

    return NULL;
}

#ifndef RTE_EXEC_ENV_LINUX

struct tap *
tap_create(const char *name __rte_unused)
{
    return NULL;
}

#else

struct tap *
tap_create(const char *name)
{
    struct tap *tap;
    struct ifreq ifr;
    int fd, status;

    /* Check input params */
    if ((name == NULL) ||
        tap_find(name))
        return NULL;

    /* Resource create */
    fd = open(TAP_DEV, O_RDWR | O_NONBLOCK);
    if (fd < 0)
        return NULL;

    memset(&ifr, 0, sizeof(ifr));
    ifr.ifr_flags = IFF_TAP | IFF_NO_PI; /* No packet information */
    strlcpy(ifr.ifr_name, name, IFNAMSIZ);

    status = ioctl(fd, TUNSETIFF, (void *) &ifr);
    if (status < 0) {
        close(fd);
        return NULL;
    }

    /* Node allocation */
    tap = calloc(1, sizeof(struct tap));
    if (tap == NULL) {
        close(fd);
        return NULL;
    }
    /* Node fill in */
    strlcpy(tap->name, name, sizeof(tap->name));
    tap->fd = fd;

    /* Node add to list */
    TAILQ_INSERT_TAIL(&tap_list, tap, node);

    return tap;
}

#endif