/***

  This file is part of avahi.

  avahi 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; either version 2.1 of the

  License, or (at your option) any later version.

  avahi is distributed in the hope that it will be useful, but WITHOUT

  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY

  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General

  Public License for more details.

  You should have received a copy of the GNU Lesser General Public

  License along with avahi; if not, write to the Free Software

  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307

  USA.

***/

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <stdlib.h>

#include <assert.h>

#include <string.h>

#include <unistd.h>

#include <ctype.h>

#include <sys/utsname.h>

#include <stdio.h>

#include <avahi-common/malloc.h>

#include "log.h"

#include "domain-util.h"

#include "util.h"

static void strip_bad_chars(char *s) {

    char *p, *d;

    s[strcspn(s, ".")] = 0;

    for (p = s, d = s; *p; p++)

        if ((*p >= 'a' && *p <= 'z') ||

            (*p >= 'A' && *p <= 'Z') ||

            (*p >= '0' && *p <= '9') ||

            *p == '-')

            *(d++) = *p;

    *d = 0;

}

#ifdef __linux__

static int load_id(char *ret_s, size_t size, const char *filename, const char *field) {

    FILE *f;

    size_t flen;

    assert(ret_s);

    assert(size > 0);

    assert(filename);

    assert(field);

    assert(strchr(field, '='));

    if (!(f = fopen(filename, "r")))

        return -1;

    flen = strlen(field);

    while (!feof(f)) {

        char ln[256], *p;

        if (!fgets(ln, sizeof(ln), f))

            break;

        if (strncmp(ln, field, flen))

            continue;

        p = ln + flen;

        p += strspn(p, "\"");

        p[strcspn(p, "\"")] = 0;

        snprintf(ret_s, size, "%s", p);

        fclose(f);

        return 0;

    }

    fclose(f);

    return -1;

}

static int load_lsb_distrib_id(char *ret_s, size_t size) {

    return load_id(ret_s, size, "/etc/lsb-release", "DISTRIB_ID=");

}

static int load_os_hostname(char *ret_s, size_t size) {

    int r;

    r = load_id(ret_s, size, "/etc/os-release", "DEFAULT_HOSTNAME=");

    if (r < 0)

        r = load_id(ret_s, size, "/etc/os-release", "ID=");

    return r;

}

#endif

char *avahi_get_host_name(char *ret_s, size_t size) {

    assert(ret_s);

    assert(size > 0);

    if (gethostname(ret_s, size) >= 0) {

        ret_s[size-1] = 0;

        strip_bad_chars(ret_s);

    } else

        *ret_s = 0;

    if (strcmp(ret_s, "localhost") == 0 || strncmp(ret_s, "localhost.", 10) == 0) {

        *ret_s = 0;

        avahi_log_warn("System host name is set to 'localhost'. This is not a suitable mDNS host name, looking for alternatives.");

    }

    if (*ret_s == 0) {

        /* No hostname was set, so let's take the OS name */

#ifdef __linux__

        /* Try os-release or LSB distribution name first */

        if (load_os_hostname(ret_s, size) >= 0 || load_lsb_distrib_id(ret_s, size) >= 0) {

            strip_bad_chars(ret_s);

            avahi_strdown(ret_s);

        }

        if (*ret_s == 0)

#endif

        {

            /* Try uname() second */

            struct utsname utsname;

            if (uname(&utsname) >= 0) {

                snprintf(ret_s, size, "%s", utsname.sysname);

                strip_bad_chars(ret_s);

                avahi_strdown(ret_s);

            }

            /* Give up */

            if (*ret_s == 0)

                snprintf(ret_s, size, "unnamed");

        }

    }

    if (size >= AVAHI_LABEL_MAX)

  ret_s[AVAHI_LABEL_MAX-1] = 0;

    return ret_s;

}

char *avahi_get_host_name_strdup(void) {

    char t[AVAHI_DOMAIN_NAME_MAX];

    if (!(avahi_get_host_name(t, sizeof(t))))

        return NULL;

    return avahi_strdup(t);

}

int avahi_binary_domain_cmp(const char *a, const char *b) {

    assert(a);

    assert(b);

    if (a == b)

        return 0;

    for (;;) {

        char ca[AVAHI_LABEL_MAX], cb[AVAHI_LABEL_MAX], *p;

        int r;

        p = avahi_unescape_label(&a, ca, sizeof(ca));

        assert(p);

        p = avahi_unescape_label(&b, cb, sizeof(cb));

        assert(p);

        if ((r = strcmp(ca, cb)))

            return r;

        if (!*a && !*b)

            return 0;

    }

}

int avahi_domain_ends_with(const char *domain, const char *suffix) {

    assert(domain);

    assert(suffix);

    for (;;) {

        char dummy[AVAHI_LABEL_MAX], *r;

        if (*domain == 0)

            return 0;

        if (avahi_domain_equal(domain, suffix))

            return 1;

        r = avahi_unescape_label(&domain, dummy, sizeof(dummy));

        assert(r);

    }

}