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_LINUXAPP
#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_LINUXAPP

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 */
        snprintf(ifr.ifr_name, IFNAMSIZ, "%s", name);

        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