document krb5_config_*_string

[heimdal.git] / lib / krb5 / config_file.c

/*
 * Copyright (c) 1997 - 2004 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * 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.
 *
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE 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 INSTITUTE 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 "krb5_locl.h"

/* Gaah! I want a portable funopen */
struct fileptr {
    const char *s;
    FILE *f;
};

static char *
config_fgets(char *str, size_t len, struct fileptr *ptr)
{
    /* XXX this is not correct, in that they don't do the same if the
       line is longer than len */
    if(ptr->f != NULL)
        return fgets(str, len, ptr->f);
    else {
        /* this is almost strsep_copy */
        const char *p;
        ssize_t l;
        if(*ptr->s == '\0')
            return NULL;
        p = ptr->s + strcspn(ptr->s, "\n");
        if(*p == '\n')
            p++;
        l = min(len, p - ptr->s);
        if(len > 0) {
            memcpy(str, ptr->s, l);
            str[l] = '\0';
        }
        ptr->s = p;
        return str;
    }
}

static krb5_error_code parse_section(char *p, krb5_config_section **s,
                                     krb5_config_section **res,
                                     const char **error_message);
static krb5_error_code parse_binding(struct fileptr *f, unsigned *lineno, char *p,
                                     krb5_config_binding **b,
                                     krb5_config_binding **parent,
                                     const char **error_message);
static krb5_error_code parse_list(struct fileptr *f, unsigned *lineno,
                                  krb5_config_binding **parent,
                                  const char **error_message);

static krb5_config_section *
get_entry(krb5_config_section **parent, const char *name, int type)
{
    krb5_config_section **q;

    for(q = parent; *q != NULL; q = &(*q)->next)
        if(type == krb5_config_list &&
           type == (*q)->type &&
           strcmp(name, (*q)->name) == 0)
            return *q;
    *q = calloc(1, sizeof(**q));
    if(*q == NULL)
        return NULL;
    (*q)->name = strdup(name);
    (*q)->type = type;
    if((*q)->name == NULL) {
        free(*q);
        *q = NULL;
        return NULL;
    }
    return *q;
}

/*
 * Parse a section:
 *
 * [section]
 *      foo = bar
 *      b = {
 *              a
 *          }
 * ...
 *
 * starting at the line in `p', storing the resulting structure in
 * `s' and hooking it into `parent'.
 * Store the error message in `error_message'.
 */

static krb5_error_code
parse_section(char *p, krb5_config_section **s, krb5_config_section **parent,
              const char **error_message)
{
    char *p1;
    krb5_config_section *tmp;

    p1 = strchr (p + 1, ']');
    if (p1 == NULL) {
        *error_message = "missing ]";
        return KRB5_CONFIG_BADFORMAT;
    }
    *p1 = '\0';
    tmp = get_entry(parent, p + 1, krb5_config_list);
    if(tmp == NULL) {
        *error_message = "out of memory";
        return KRB5_CONFIG_BADFORMAT;
    }
    *s = tmp;
    return 0;
}

/*
 * Parse a brace-enclosed list from `f', hooking in the structure at
 * `parent'.
 * Store the error message in `error_message'.
 */

static krb5_error_code
parse_list(struct fileptr *f, unsigned *lineno, krb5_config_binding **parent,
           const char **error_message)
{
    char buf[BUFSIZ];
    krb5_error_code ret;
    krb5_config_binding *b = NULL;
    unsigned beg_lineno = *lineno;

    while(config_fgets(buf, sizeof(buf), f) != NULL) {
        char *p;

        ++*lineno;
        buf[strcspn(buf, "\r\n")] = '\0';
        p = buf;
        while(isspace((unsigned char)*p))
            ++p;
        if (*p == '#' || *p == ';' || *p == '\0')
            continue;
        while(isspace((unsigned char)*p))
            ++p;
        if (*p == '}')
            return 0;
        if (*p == '\0')
            continue;
        ret = parse_binding (f, lineno, p, &b, parent, error_message);
        if (ret)
            return ret;
    }
    *lineno = beg_lineno;
    *error_message = "unclosed {";
    return KRB5_CONFIG_BADFORMAT;
}

/*
 *
 */

static krb5_error_code
parse_binding(struct fileptr *f, unsigned *lineno, char *p,
              krb5_config_binding **b, krb5_config_binding **parent,
              const char **error_message)
{
    krb5_config_binding *tmp;
    char *p1, *p2;
    krb5_error_code ret = 0;

    p1 = p;
    while (*p && *p != '=' && !isspace((unsigned char)*p))
        ++p;
    if (*p == '\0') {
        *error_message = "missing =";
        return KRB5_CONFIG_BADFORMAT;
    }
    p2 = p;
    while (isspace((unsigned char)*p))
        ++p;
    if (*p != '=') {
        *error_message = "missing =";
        return KRB5_CONFIG_BADFORMAT;
    }
    ++p;
    while(isspace((unsigned char)*p))
        ++p;
    *p2 = '\0';
    if (*p == '{') {
        tmp = get_entry(parent, p1, krb5_config_list);
        if (tmp == NULL) {
            *error_message = "out of memory";
            return KRB5_CONFIG_BADFORMAT;
        }
        ret = parse_list (f, lineno, &tmp->u.list, error_message);
    } else {
        tmp = get_entry(parent, p1, krb5_config_string);
        if (tmp == NULL) {
            *error_message = "out of memory";
            return KRB5_CONFIG_BADFORMAT;
        }
        p1 = p;
        p = p1 + strlen(p1);
        while(p > p1 && isspace((unsigned char)*(p-1)))
            --p;
        *p = '\0';
        tmp->u.string = strdup(p1);
    }
    *b = tmp;
    return ret;
}

/*
 * Parse the config file `fname', generating the structures into `res'
 * returning error messages in `error_message'
 */

static krb5_error_code
krb5_config_parse_debug (struct fileptr *f,
                         krb5_config_section **res,
                         unsigned *lineno,
                         const char **error_message)
{
    krb5_config_section *s = NULL;
    krb5_config_binding *b = NULL;
    char buf[BUFSIZ];
    krb5_error_code ret;

    while (config_fgets(buf, sizeof(buf), f) != NULL) {
        char *p;

        ++*lineno;
        buf[strcspn(buf, "\r\n")] = '\0';
        p = buf;
        while(isspace((unsigned char)*p))
            ++p;
        if (*p == '#' || *p == ';')
            continue;
        if (*p == '[') {
            ret = parse_section(p, &s, res, error_message);
            if (ret)
                return ret;
            b = NULL;
        } else if (*p == '}') {
            *error_message = "unmatched }";
            return EINVAL;      /* XXX */
        } else if(*p != '\0') {
            if (s == NULL) {
                *error_message = "binding before section";
                return EINVAL;
            }
            ret = parse_binding(f, lineno, p, &b, &s->u.list, error_message);
            if (ret)
                return ret;
        }
    }
    return 0;
}

krb5_error_code KRB5_LIB_FUNCTION
krb5_config_parse_string_multi(krb5_context context,
                               const char *string,
                               krb5_config_section **res)
{
    const char *str;
    unsigned lineno = 0;
    krb5_error_code ret;
    struct fileptr f;
    f.f = NULL;
    f.s = string;

    ret = krb5_config_parse_debug (&f, res, &lineno, &str);
    if (ret) {
        krb5_set_error_message (context, ret, "%s:%u: %s",
                                "<constant>", lineno, str);
        return ret;
    }
    return 0;
}

/**
 * Parse a configuration file and add the result into res. This
 * interface can be used to parse several configuration files into one
 * resulting krb5_config_section by calling it repeatably.
 *
 * @param context a Kerberos 5 context.
 * @param fname a file name to a Kerberos configuration file
 * @param res the returned result, must be free with krb5_free_config_files().
 * @return Return an error code or 0, see krb5_get_error_message().
 *
 * @ingroup krb5_support
 */

krb5_error_code KRB5_LIB_FUNCTION
krb5_config_parse_file_multi (krb5_context context,
                              const char *fname,
                              krb5_config_section **res)
{
    const char *str;
    char *newfname = NULL;
    unsigned lineno = 0;
    krb5_error_code ret;
    struct fileptr f;

    /**
     * If the fname starts with "~/" parse configuration file in the
     * current users home directory. The behavior can be disabled and
     * enabled by calling krb5_set_home_dir_access().
     */
    if (_krb5_homedir_access(context) && fname[0] == '~' && fname[1] == '/') {
        const char *home = NULL;

        if(!issuid())
            home = getenv("HOME");

        if (home == NULL) {
            struct passwd *pw = getpwuid(getuid());     
            if(pw != NULL)
                home = pw->pw_dir;
        }
        if (home) {
            asprintf(&newfname, "%s%s", home, &fname[1]);
            if (newfname == NULL) {
                krb5_set_error_message(context, ENOMEM,
                                       N_("malloc: out of memory", ""));
                return ENOMEM;
            }
            fname = newfname;
        }
    }

    f.f = fopen(fname, "r");
    f.s = NULL;
    if(f.f == NULL) {
        ret = errno;
        krb5_set_error_message (context, ret, "open %s: %s",
                                fname, strerror(ret));
        if (newfname)
            free(newfname);
        return ret;
    }

    ret = krb5_config_parse_debug (&f, res, &lineno, &str);
    fclose(f.f);
    if (ret) {
        krb5_set_error_message (context, ret, "%s:%u: %s", fname, lineno, str);
        if (newfname)
            free(newfname);
        return ret;
    }
    if (newfname)
        free(newfname);
    return 0;
}

krb5_error_code KRB5_LIB_FUNCTION
krb5_config_parse_file (krb5_context context,
                        const char *fname,
                        krb5_config_section **res)
{
    *res = NULL;
    return krb5_config_parse_file_multi(context, fname, res);
}

static void
free_binding (krb5_context context, krb5_config_binding *b)
{
    krb5_config_binding *next_b;

    while (b) {
        free (b->name);
        if (b->type == krb5_config_string)
            free (b->u.string);
        else if (b->type == krb5_config_list)
            free_binding (context, b->u.list);
        else
            krb5_abortx(context, "unknown binding type (%d) in free_binding",
                        b->type);
        next_b = b->next;
        free (b);
        b = next_b;
    }
}

/**
 * Free configuration file section, the result of
 * krb5_config_parse_file() and krb5_config_parse_file_multi().
 *
 * @param context A Kerberos 5 context
 * @param s the configuration section to free
 *
 * @return returns 0 on successes, otherwise an error code, see
 *          krb5_get_error_message()
 *
 * @ingroup krb5_support
 */

krb5_error_code KRB5_LIB_FUNCTION
krb5_config_file_free (krb5_context context, krb5_config_section *s)
{
    free_binding (context, s);
    return 0;
}

#ifndef HEIMDAL_SMALLER

krb5_error_code
_krb5_config_copy(krb5_context context,
                  krb5_config_section *c,
                  krb5_config_section **head)
{
    krb5_config_binding *d, *previous = NULL;

    *head = NULL;

    while (c) {
        d = calloc(1, sizeof(*d));

        if (*head == NULL)
            *head = d;

        d->name = strdup(c->name);
        d->type = c->type;
        if (d->type == krb5_config_string)
            d->u.string = strdup(c->u.string);
        else if (d->type == krb5_config_list)
            _krb5_config_copy (context, c->u.list, &d->u.list);
        else
            krb5_abortx(context,
                        "unknown binding type (%d) in krb5_config_copy",
                        d->type);
        if (previous)
            previous->next = d;

        previous = d;
        c = c->next;
    }
    return 0;
}

#endif /* HEIMDAL_SMALLER */

const void *
krb5_config_get_next (krb5_context context,
                      const krb5_config_section *c,
                      const krb5_config_binding **pointer,
                      int type,
                      ...)
{
    const char *ret;
    va_list args;

    va_start(args, type);
    ret = krb5_config_vget_next (context, c, pointer, type, args);
    va_end(args);
    return ret;
}

static const void *
vget_next(krb5_context context,
          const krb5_config_binding *b,
          const krb5_config_binding **pointer,
          int type,
          const char *name,
          va_list args)
{
    const char *p = va_arg(args, const char *);
    while(b != NULL) {
        if(strcmp(b->name, name) == 0) {
            if(b->type == type && p == NULL) {
                *pointer = b;
                return b->u.generic;
            } else if(b->type == krb5_config_list && p != NULL) {
                return vget_next(context, b->u.list, pointer, type, p, args);
            }
        }
        b = b->next;
    }
    return NULL;
}

const void *
krb5_config_vget_next (krb5_context context,
                       const krb5_config_section *c,
                       const krb5_config_binding **pointer,
                       int type,
                       va_list args)
{
    const krb5_config_binding *b;
    const char *p;

    if(c == NULL)
        c = context->cf;

    if (c == NULL)
        return NULL;

    if (*pointer == NULL) {
        /* first time here, walk down the tree looking for the right
           section */
        p = va_arg(args, const char *);
        if (p == NULL)
            return NULL;
        return vget_next(context, c, pointer, type, p, args);
    }

    /* we were called again, so just look for more entries with the
       same name and type */
    for (b = (*pointer)->next; b != NULL; b = b->next) {
        if(strcmp(b->name, (*pointer)->name) == 0 && b->type == type) {
            *pointer = b;
            return b->u.generic;
        }
    }
    return NULL;
}

const void *
krb5_config_get (krb5_context context,
                 const krb5_config_section *c,
                 int type,
                 ...)
{
    const void *ret;
    va_list args;

    va_start(args, type);
    ret = krb5_config_vget (context, c, type, args);
    va_end(args);
    return ret;
}

const void *
krb5_config_vget (krb5_context context,
                  const krb5_config_section *c,
                  int type,
                  va_list args)
{
    const krb5_config_binding *foo = NULL;

    return krb5_config_vget_next (context, c, &foo, type, args);
}

const krb5_config_binding *
krb5_config_get_list (krb5_context context,
                      const krb5_config_section *c,
                      ...)
{
    const krb5_config_binding *ret;
    va_list args;

    va_start(args, c);
    ret = krb5_config_vget_list (context, c, args);
    va_end(args);
    return ret;
}

const krb5_config_binding *
krb5_config_vget_list (krb5_context context,
                       const krb5_config_section *c,
                       va_list args)
{
    return krb5_config_vget (context, c, krb5_config_list, args);
}

/**
 * Returns a "const char *" to a string in the configuration database.
 * The string may not be valid after a reload of the configuration
 * database so a caller should make a local copy if it needs to keep
 * the string.
 *
 * @param context A Kerberos 5 context.
 * @param c a configuration section, or NULL to use the section from context
 * @param ... a list of names, terminated with NULL.
 *
 * @return NULL if configuration string not found, a string otherwise
 *
 * @ingroup krb5_support
 */
 
const char* KRB5_LIB_FUNCTION
krb5_config_get_string (krb5_context context,
                        const krb5_config_section *c,
                        ...)
{
    const char *ret;
    va_list args;

    va_start(args, c);
    ret = krb5_config_vget_string (context, c, args);
    va_end(args);
    return ret;
}

/**
 * Like krb5_config_get_string(), but uses a va_list instead of ...
 *
 * @param context A Kerberos 5 context.
 * @param c a configuration section, or NULL to use the section from context
 * @param def_value the default value to return if no configuration
 *        found in the database.
 * @param args a va_list of arguments
 *
 * @return NULL if configuration string not found, a string otherwise
 *
 * @ingroup krb5_support
 */

const char* KRB5_LIB_FUNCTION
krb5_config_vget_string (krb5_context context,
                         const krb5_config_section *c,
                         va_list args)
{
    return krb5_config_vget (context, c, krb5_config_string, args);
}

/**
 * Like krb5_config_vget_string(), but instead of returning NULL,
 * instead return a default value.
 *
 * @param context A Kerberos 5 context.
 * @param c a configuration section, or NULL to use the section from context
 * @param def_value the default value to return if no configuration
 *        found in the database.
 * @param args a va_list of arguments
 *
 * @return a configuration string
 *
 * @ingroup krb5_support
 */

const char* KRB5_LIB_FUNCTION
krb5_config_vget_string_default (krb5_context context,
                                 const krb5_config_section *c,
                                 const char *def_value,
                                 va_list args)
{
    const char *ret;

    ret = krb5_config_vget_string (context, c, args);
    if (ret == NULL)
        ret = def_value;
    return ret;
}

/**
 * Like krb5_config_get_string(), but instead of returning NULL,
 * instead return a default value.
 *
 * @param context A Kerberos 5 context.
 * @param c a configuration section, or NULL to use the section from context
 * @param def_value the default value to return if no configuration
 *        found in the database.
 * @param ... a list of names, terminated with NULL.
 *
 * @return a configuration string
 *
 * @ingroup krb5_support
 */

const char* KRB5_LIB_FUNCTION
krb5_config_get_string_default (krb5_context context,
                                const krb5_config_section *c,
                                const char *def_value,
                                ...)
{
    const char *ret;
    va_list args;

    va_start(args, def_value);
    ret = krb5_config_vget_string_default (context, c, def_value, args);
    va_end(args);
    return ret;
}

char ** KRB5_LIB_FUNCTION
krb5_config_vget_strings(krb5_context context,
                         const krb5_config_section *c,
                         va_list args)
{
    char **strings = NULL;
    int nstr = 0;
    const krb5_config_binding *b = NULL;
    const char *p;

    while((p = krb5_config_vget_next(context, c, &b,
                                     krb5_config_string, args))) {
        char *tmp = strdup(p);
        char *pos = NULL;
        char *s;
        if(tmp == NULL)
            goto cleanup;
        s = strtok_r(tmp, " \t", &pos);
        while(s){
            char **tmp2 = realloc(strings, (nstr + 1) * sizeof(*strings));
            if(tmp2 == NULL)
                goto cleanup;
            strings = tmp2;
            strings[nstr] = strdup(s);
            nstr++;
            if(strings[nstr-1] == NULL)
                goto cleanup;
            s = strtok_r(NULL, " \t", &pos);
        }
        free(tmp);
    }
    if(nstr){
        char **tmp = realloc(strings, (nstr + 1) * sizeof(*strings));
        if(tmp == NULL)
            goto cleanup;
        strings = tmp;
        strings[nstr] = NULL;
    }
    return strings;
cleanup:
    while(nstr--)
        free(strings[nstr]);
    free(strings);
    return NULL;

}

char**
krb5_config_get_strings(krb5_context context,
                        const krb5_config_section *c,
                        ...)
{
    va_list ap;
    char **ret;
    va_start(ap, c);
    ret = krb5_config_vget_strings(context, c, ap);
    va_end(ap);
    return ret;
}

void KRB5_LIB_FUNCTION
krb5_config_free_strings(char **strings)
{
    char **s = strings;
    while(s && *s){
        free(*s);
        s++;
    }
    free(strings);
}

krb5_boolean KRB5_LIB_FUNCTION
krb5_config_vget_bool_default (krb5_context context,
                               const krb5_config_section *c,
                               krb5_boolean def_value,
                               va_list args)
{
    const char *str;
    str = krb5_config_vget_string (context, c, args);
    if(str == NULL)
        return def_value;
    if(strcasecmp(str, "yes") == 0 ||
       strcasecmp(str, "true") == 0 ||
       atoi(str)) return TRUE;
    return FALSE;
}

krb5_boolean KRB5_LIB_FUNCTION
krb5_config_vget_bool  (krb5_context context,
                        const krb5_config_section *c,
                        va_list args)
{
    return krb5_config_vget_bool_default (context, c, FALSE, args);
}

krb5_boolean KRB5_LIB_FUNCTION
krb5_config_get_bool_default (krb5_context context,
                              const krb5_config_section *c,
                              krb5_boolean def_value,
                              ...)
{
    va_list ap;
    krb5_boolean ret;
    va_start(ap, def_value);
    ret = krb5_config_vget_bool_default(context, c, def_value, ap);
    va_end(ap);
    return ret;
}

krb5_boolean KRB5_LIB_FUNCTION
krb5_config_get_bool (krb5_context context,
                      const krb5_config_section *c,
                      ...)
{
    va_list ap;
    krb5_boolean ret;
    va_start(ap, c);
    ret = krb5_config_vget_bool (context, c, ap);
    va_end(ap);
    return ret;
}

int KRB5_LIB_FUNCTION
krb5_config_vget_time_default (krb5_context context,
                               const krb5_config_section *c,
                               int def_value,
                               va_list args)
{
    const char *str;
    krb5_deltat t;

    str = krb5_config_vget_string (context, c, args);
    if(str == NULL)
        return def_value;
    if (krb5_string_to_deltat(str, &t))
        return def_value;
    return t;
}

int KRB5_LIB_FUNCTION
krb5_config_vget_time  (krb5_context context,
                        const krb5_config_section *c,
                        va_list args)
{
    return krb5_config_vget_time_default (context, c, -1, args);
}

int KRB5_LIB_FUNCTION
krb5_config_get_time_default (krb5_context context,
                              const krb5_config_section *c,
                              int def_value,
                              ...)
{
    va_list ap;
    int ret;
    va_start(ap, def_value);
    ret = krb5_config_vget_time_default(context, c, def_value, ap);
    va_end(ap);
    return ret;
}

int KRB5_LIB_FUNCTION
krb5_config_get_time (krb5_context context,
                      const krb5_config_section *c,
                      ...)
{
    va_list ap;
    int ret;
    va_start(ap, c);
    ret = krb5_config_vget_time (context, c, ap);
    va_end(ap);
    return ret;
}


int KRB5_LIB_FUNCTION
krb5_config_vget_int_default (krb5_context context,
                              const krb5_config_section *c,
                              int def_value,
                              va_list args)
{
    const char *str;
    str = krb5_config_vget_string (context, c, args);
    if(str == NULL)
        return def_value;
    else {
        char *endptr;
        long l;
        l = strtol(str, &endptr, 0);
        if (endptr == str)
            return def_value;
        else
            return l;
    }
}

int KRB5_LIB_FUNCTION
krb5_config_vget_int  (krb5_context context,
                       const krb5_config_section *c,
                       va_list args)
{
    return krb5_config_vget_int_default (context, c, -1, args);
}

int KRB5_LIB_FUNCTION
krb5_config_get_int_default (krb5_context context,
                             const krb5_config_section *c,
                             int def_value,
                             ...)
{
    va_list ap;
    int ret;
    va_start(ap, def_value);
    ret = krb5_config_vget_int_default(context, c, def_value, ap);
    va_end(ap);
    return ret;
}

int KRB5_LIB_FUNCTION
krb5_config_get_int (krb5_context context,
                     const krb5_config_section *c,
                     ...)
{
    va_list ap;
    int ret;
    va_start(ap, c);
    ret = krb5_config_vget_int (context, c, ap);
    va_end(ap);
    return ret;
}