source: rtems-libbsd/dhcpcd/platform-linux.c @ 2017a6d

/*
 * dhcpcd - DHCP client daemon
 * Copyright (c) 2006-2013 Roy Marples <roy@marples.name>
 * All rights reserved

 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>

#include "common.h"
#include "dhcpcd.h"
#include "if-options.h"
#include "platform.h"

static const char *mproc =
#if defined(__alpha__)
        "system type"
#elif defined(__arm__)
        "Hardware"
#elif defined(__avr32__)
        "cpu family"
#elif defined(__bfin__)
        "BOARD Name"
#elif defined(__cris__)
        "cpu model"
#elif defined(__frv__)
        "System"
#elif defined(__i386__) || defined(__x86_64__)
        "vendor_id"
#elif defined(__ia64__)
        "vendor"
#elif defined(__hppa__)
        "model"
#elif defined(__m68k__)
        "MMU"
#elif defined(__mips__)
        "system type"
#elif defined(__powerpc__) || defined(__powerpc64__)
        "machine"
#elif defined(__s390__) || defined(__s390x__)
        "Manufacturer"
#elif defined(__sh__)
        "machine"
#elif defined(sparc) || defined(__sparc__)
        "cpu"
#elif defined(__vax__)
        "cpu"
#else
        NULL
#endif
        ;

#ifdef INET6
static char **restore;
static ssize_t nrestore;
#endif

char *
hardware_platform(void)
{
        FILE *fp;
        char *buf, *p;

        if (mproc == NULL) {
                errno = EINVAL;
                return NULL;
        }

        fp = fopen("/proc/cpuinfo", "r");
        if (fp == NULL)
                return NULL;

        p = NULL;
        while ((buf = get_line(fp))) {
                if (strncmp(buf, mproc, strlen(mproc)) == 0) {
                        p = strchr(buf, ':');
                        if (p != NULL && ++p != NULL) {
                                while (*p == ' ')
                                        p++;
                                break;
                        }
                }
        }
        fclose(fp);

        if (p == NULL)
                errno = ESRCH;
        return p;
}

#ifdef INET6
static int
check_proc_int(const char *path)
{
        FILE *fp;
        char *buf;

        fp = fopen(path, "r");
        if (fp == NULL)
                return -1;
        buf = get_line(fp);
        fclose(fp);
        if (buf == NULL)
                return -1;
        return atoi(buf);
}

static ssize_t
write_path(const char *path, const char *val)
{
        FILE *fp;
        ssize_t r;

        fp = fopen(path, "w");
        if (fp == NULL)
                return -1;
        r = fprintf(fp, "%s\n", val);
        fclose(fp);
        return r;
}

static const char *prefix = "/proc/sys/net/ipv6/conf";

static void
restore_kernel_ra(void)
{
        char path[256];

#ifndef DEBUG_MEMORY
        if (options & DHCPCD_FORKED)
                return;
#endif

        for (nrestore--; nrestore >= 0; nrestore--) {
#ifdef DEBUG_MEMORY
                if (!(options & DHCPCD_FORKED)) {
#endif
                syslog(LOG_INFO, "%s: restoring Kernel IPv6 RA support",
                       restore[nrestore]);
                snprintf(path, sizeof(path), "%s/%s/accept_ra",
                         prefix, restore[nrestore]);
                if (write_path(path, "1") == -1 && errno != ENOENT)
                        syslog(LOG_ERR, "write_path: %s: %m", path);
#ifdef DEBUG_MEMORY
                }
                free(restore[nrestore]);
#endif
        }
#ifdef DEBUG_MEMORY
        free(restore);
#endif
}

int
check_ipv6(const char *ifname, int own)
{
        static int ipv6_checked = 0;
        int ra, ex, i;
        char path[256], *p, **nrest;

        if (ifname == NULL) {
                if (ipv6_checked)
                        return 1;
                ipv6_checked = 1;
                ifname = "all";
                ex = 1;
        } else
                ex = 0;

        snprintf(path, sizeof(path), "%s/%s/autoconf", prefix, ifname);
        i = check_proc_int(path);
        if (i != 1) {
                syslog(LOG_WARNING, "%s: IPv6 kernel autoconf disabled",
                    ifname);
                return -1;
        }

        snprintf(path, sizeof(path), "%s/%s/accept_ra", prefix, ifname);
        ra = check_proc_int(path);
        if (ra == -1)
                /* The sysctl probably doesn't exist, but this isn't an
                 * error as such so just log it and continue */
                syslog(errno == ENOENT ? LOG_DEBUG : LOG_WARNING,
                    "%s: %m", path);
        else if (ra != 0 && own) {
                syslog(LOG_INFO, "%s: disabling Kernel IPv6 RA support",
                    ifname);
                if (write_path(path, "0") == -1) {
                        syslog(LOG_ERR, "write_path: %s: %m", path);
                        return ra;
                }
                for (i = 0; i < nrestore; i++)
                        if (strcmp(restore[i], ifname) == 0)
                                break;
                if (i == nrestore) {
                        p = strdup(ifname);
                        if (p == NULL) {
                                syslog(LOG_ERR, "%s: %m", __func__);
                                return ra;
                        }
                        nrest = realloc(restore,
                            (nrestore + 1) * sizeof(char *));
                        if (nrest == NULL) {
                                syslog(LOG_ERR, "%s: %m", __func__);
                                return ra;
                        }
                        restore = nrest;
                        restore[nrestore++] = p;

                }
                if (ex)
                        atexit(restore_kernel_ra);
        }

        return ra;
}

int
ipv6_dadtransmits(const char *ifname)
{
        char path[256];
        int r;

        if (ifname == NULL)
                ifname = "default";

        snprintf(path, sizeof(path), "%s/%s/dad_transmits", prefix, ifname);
        r = check_proc_int(path);
        return r < 0 ? 0 : r;
}
#endif