/***

  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 <string.h>

#include <stdarg.h>

#include <assert.h>

#include <stdio.h>

#include <stdlib.h>

#include "strlst.h"

#include "malloc.h"

#include "defs.h"

AvahiStringList*avahi_string_list_add_anonymous(AvahiStringList *l, size_t size) {

    AvahiStringList *n;

    if (!(n = avahi_malloc(sizeof(AvahiStringList) + size)))

        return NULL;

    n->next = l;

    n->size = size;

    /* NUL terminate strings, just to make sure */

    n->text[size] = 0;

    return n;

}

AvahiStringList *avahi_string_list_add_arbitrary(AvahiStringList *l, const uint8_t*text, size_t size) {

    AvahiStringList *n;

    assert(size == 0 || text);

    if (!(n = avahi_string_list_add_anonymous(l, size)))

        return NULL;

    if (size > 0)

        memcpy(n->text, text, size);

    return n;

}

AvahiStringList *avahi_string_list_add(AvahiStringList *l, const char *text) {

    assert(text);

    return avahi_string_list_add_arbitrary(l, (const uint8_t*) text, strlen(text));

}

int avahi_string_list_parse(const void* data, size_t size, AvahiStringList **ret) {

    const uint8_t *c;

    AvahiStringList *r = NULL;

    assert(data);

    assert(ret);

    c = data;

    while (size > 0) {

        size_t k;

        k = *(c++);

        size--;

        if (k > size)

            goto fail; /* Overflow */

        if (k > 0) { /* Ignore empty strings */

            AvahiStringList *n;

            if (!(n = avahi_string_list_add_arbitrary(r, c, k)))

                goto fail; /* OOM */

            r = n;

        }

        c += k;

        size -= k;

    }

    *ret = r;

    return 0;

fail:

    avahi_string_list_free(r);

    return -1;

}

void avahi_string_list_free(AvahiStringList *l) {

    AvahiStringList *n;

    while (l) {

        n = l->next;

        avahi_free(l);

        l = n;

    }

}

AvahiStringList* avahi_string_list_reverse(AvahiStringList *l) {

    AvahiStringList *r = NULL, *n;

    while (l) {

        n = l->next;

        l->next = r;

        r = l;

        l = n;

    }

    return r;

}

/**

 * This routine is used for both human- and machine-readable output of

 * TXT records. As such it must cope with escaping, in order to allow

 * machines to reconstruct the original data.

 *

 * AFAIK no RFC specifies syntax for TXT data other than raw binary,

 * though presumably zonefile syntax would make sense:

 *

 *   - RFC 1035 says that TXT records contain `<character-string>`s, and section

 *     5 says:

 *

 *       <character-string> is expressed in one or two ways: as a contiguous set

 *       of characters without interior spaces, or as a string beginning with a "

 *       and ending with a ".  Inside a " delimited string any character can

 *       occur, except for a " itself, which must be quoted using \ (back slash).

 *

 *     This omits escaping of backslashes (!).

 *

 *   - RFC 1034 doesn't say anything relevant.

 *

 *   - RFC 1464 suggests a specific encoding of information within a TXT

 *     record but does not discuss formatting of TXT records in

 *     general.

 *

 * In order to also escape newlines, which interfere with line-by-line

 * machine processing of records, this routine:

 *

 *   - escapes >>> " <<< to >>> \" <<<

 *   - escapes >>> \ <<< to >>> \\ <<<

 *   - escapes bytes less than 32 to backslash-prefixed 3-digit DECIMAL form

 */

char* avahi_string_list_to_string(AvahiStringList *l) {

    AvahiStringList *n;

    size_t s = 0;

    char *p, *t, *e;

    for (n = l; n; n = n->next) {

        if (n != l)

            s ++; /* for the inter-string separating space */

        for (p = (char*) n->text; ((size_t) (p - (char*) n->text) < n->size); p++) {

            switch (*p) {

              case '"':

              case '\\':

                  s += 2;

                  break;

              default:

                  if (*p < 32) {

                      s += 4;

                  } else {

                      s ++;

                      break;

                  }

            }

        }

        s += 2; /* for the leading and trailing double-quotes */

    }

    if (!(t = e = avahi_new(char, s+1))) /* plus one for the trailing NUL */

        return NULL;

    l = avahi_string_list_reverse(l);

    for (n = l; n; n = n->next) {

        if (n != l)

            *(e++) = ' ';

        *(e++) = '"';

        for (p = (char*) n->text; ((size_t) (p - (char*) n->text) < n->size); p++) {

            switch (*p) {

              case '"':

              case '\\':

                  *(e++) = '\\';

                  /* FALL THROUGH */

              default:

                  if (*p < 32) {

                      *(e++) = '\\';

                      *(e++) = '0' + (char)  ((uint8_t) *p / 100);

                      *(e++) = '0' + (char) (((uint8_t) *p / 10) % 10);

                      *(e++) = '0' + (char)  ((uint8_t) *p % 10);

                  } else {

                      *(e++) = *p;

                  }

            }

        }

        *(e++) = '"';

        assert(e);

    }

    l = avahi_string_list_reverse(l);

    *e = 0;

    return t;

}

size_t avahi_string_list_serialize(AvahiStringList *l, void *data, size_t size) {

    size_t used = 0;

    if (data) {

        AvahiStringList *n;

        uint8_t *c;

        l = avahi_string_list_reverse(l);

        c = data;

        for (n = l; size > 1 && n; n = n->next) {

            size_t k;

            if ((k = n->size) == 0)

                /* Skip empty strings */

                continue;

            if (k > 255)

                /* Truncate strings at 255 characters */

                k = 255;

            if (k > size-1)

                /* Make sure this string fits in */

                k = size-1;

            *(c++) = (uint8_t) k;

            memcpy(c, n->text, k);

            c += k;

            used += 1 + k;

            size -= 1 + k;

        }

        l = avahi_string_list_reverse(l);

        if (used == 0 && size > 0) {

            /* Empty lists are treated specially. To comply with

             * section 6.1 of the DNS-SD spec, we return a single

             * empty string (i.e. a NUL byte)*/

            *(uint8_t*) data = 0;

            used = 1;

        }

    } else {

        AvahiStringList *n;

        for (n = l; n; n = n->next) {

            size_t k;

            if ((k = n->size) == 0)

                continue;

            if (k > 255)

                k = 255;

            used += 1+k;

        }

        if (used == 0)

            used = 1;

    }

    return used;

}

int avahi_string_list_equal(const AvahiStringList *a, const AvahiStringList *b) {

    for (;;) {

        if (!a && !b)

            return 1;

        if (!a || !b)

            return 0;

        if (a->size != b->size)

            return 0;

        if (a->size != 0 && memcmp(a->text, b->text, a->size) != 0)

            return 0;

        a = a->next;

        b = b->next;

    }

}

AvahiStringList *avahi_string_list_add_many(AvahiStringList *r, ...) {

    va_list va;

    va_start(va, r);

    r = avahi_string_list_add_many_va(r, va);

    va_end(va);

    return r;

}

AvahiStringList *avahi_string_list_add_many_va(AvahiStringList *r, va_list va) {

    const char *txt;

    while ((txt = va_arg(va, const char*)))

        r = avahi_string_list_add(r, txt);

    return r;

}

AvahiStringList *avahi_string_list_new(const char *txt, ...) {

    va_list va;

    AvahiStringList *r = NULL;

    if (txt) {

        r = avahi_string_list_add(r, txt);

        va_start(va, txt);

        r = avahi_string_list_add_many_va(r, va);

        va_end(va);

    }

    return r;

}

AvahiStringList *avahi_string_list_new_va(va_list va) {

    return avahi_string_list_add_many_va(NULL, va);

}

AvahiStringList *avahi_string_list_copy(const AvahiStringList *l) {

    AvahiStringList *r = NULL;

    for (; l; l = l->next)

        if (!(r = avahi_string_list_add_arbitrary(r, l->text, l->size))) {

            avahi_string_list_free(r);

            return NULL;

        }

    return avahi_string_list_reverse(r);

}

AvahiStringList *avahi_string_list_new_from_array(const char *array[], int length) {

    AvahiStringList *r = NULL;

    int i;

    assert(array);

    for (i = 0; length >= 0 ? i < length : !!array[i]; i++)

        r = avahi_string_list_add(r, array[i]);

    return r;

}

unsigned avahi_string_list_length(const AvahiStringList *l) {

    unsigned n = 0;

    for (; l; l = l->next)

        n++;

    return n;

}

AvahiStringList *avahi_string_list_add_vprintf(AvahiStringList *l, const char *format, va_list va) {

    size_t len = 80;

    AvahiStringList *r;

    assert(format);

    if (!(r = avahi_malloc(sizeof(AvahiStringList) + len)))

        return NULL;

    for (;;) {

        int n;

        AvahiStringList *nr;

        va_list va2;

        va_copy(va2, va);

        n = vsnprintf((char*) r->text, len, format, va2);

        va_end(va2);

        if (n >= 0 && n < (int) len)

            break;

        if (n >= 0)

            len = n+1;

        else

            len *= 2;

        if (!(nr = avahi_realloc(r, sizeof(AvahiStringList) + len))) {

            avahi_free(r);

            return NULL;

        }

        r = nr;

    }

    r->next = l;

    r->size = strlen((char*) r->text);

    return r;

}

AvahiStringList *avahi_string_list_add_printf(AvahiStringList *l, const char *format, ...) {

    va_list va;

    assert(format);

    va_start(va, format);

    l  = avahi_string_list_add_vprintf(l, format, va);

    va_end(va);

    return l;

}

AvahiStringList *avahi_string_list_find(AvahiStringList *l, const char *key) {

    size_t n;

    assert(key);

    n = strlen(key);

    for (; l; l = l->next) {

        if (strcasecmp((char*) l->text, key) == 0)

            return l;

        if (strncasecmp((char*) l->text, key, n) == 0 && l->text[n] == '=')

            return l;

    }

    return NULL;

}

AvahiStringList *avahi_string_list_add_pair(AvahiStringList *l, const char *key, const char *value) {

    assert(key);

    if (value)

        return avahi_string_list_add_printf(l, "%s=%s", key, value);

    else

        return avahi_string_list_add(l, key);

}

AvahiStringList *avahi_string_list_add_pair_arbitrary(AvahiStringList *l, const char *key, const uint8_t *value, size_t size) {

    size_t n;

    assert(key);

    if (!value)

        return avahi_string_list_add(l, key);

    n = strlen(key);

    if (!(l = avahi_string_list_add_anonymous(l, n + 1 + size)))

        return NULL;

    memcpy(l->text, key, n);

    l->text[n] = '=';

    memcpy(l->text + n + 1, value, size);

    return l;

}

int avahi_string_list_get_pair(AvahiStringList *l, char **key, char **value, size_t *size) {

    char *e;

    assert(l);

    if (!(e = memchr(l->text, '=', l->size))) {

        if (key)

            if (!(*key = avahi_strdup((char*) l->text)))

                return -1;

        if (value)

            *value = NULL;

        if (size)

            *size = 0;

    } else {

        size_t n;

        if (key)

            if (!(*key = avahi_strndup((char*) l->text, e - (char *) l->text)))

                return -1;

        e++; /* Advance after '=' */

        n = l->size - (e - (char*) l->text);

        if (value) {

            if (!(*value = avahi_memdup(e, n+1))) {

                if (key)

                    avahi_free(*key);

                return -1;

            }

            (*value)[n] = 0;

        }

        if (size)

            *size = n;

    }

    return 0;

}

AvahiStringList *avahi_string_list_get_next(AvahiStringList *l) {

    assert(l);

    return l->next;

}

uint8_t *avahi_string_list_get_text(AvahiStringList *l) {

    assert(l);

    return l->text;

}

size_t avahi_string_list_get_size(AvahiStringList *l) {

    assert(l);

    return l->size;

}

uint32_t avahi_string_list_get_service_cookie(AvahiStringList *l) {

    AvahiStringList *f;

    char *value = NULL, *end = NULL;

    uint32_t ret;

    if (!(f = avahi_string_list_find(l, AVAHI_SERVICE_COOKIE)))

        return AVAHI_SERVICE_COOKIE_INVALID;

    if (avahi_string_list_get_pair(f, NULL, &value, NULL) < 0 || !value)

        return AVAHI_SERVICE_COOKIE_INVALID;

    ret = (uint32_t) strtoll(value, &end, 0);

    if (*value && end && *end != 0) {

        avahi_free(value);

        return AVAHI_SERVICE_COOKIE_INVALID;

    }

    avahi_free(value);

    return ret;

}