port/gen/getpwnam_r.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include "lint.h"
#include <sys/types.h>
#include <pwd.h>
#include <nss_dbdefs.h>
#include <stdio.h>
#include <synch.h>
#include <sys/param.h>
#include <string.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <errno.h>

int str2passwd(const char *, int, void *,
    char *, int);

static DEFINE_NSS_DB_ROOT(db_root);
static DEFINE_NSS_GETENT(context);

void
_nss_initf_passwd(nss_db_params_t *p)
{
    p->name = NSS_DBNAM_PASSWD;
    p->default_config = NSS_DEFCONF_PASSWD;
}

#include <getxby_door.h>

struct passwd *
_uncached_getpwuid_r(uid_t uid, struct passwd *result, char *buffer,
    int buflen);

struct passwd *
_uncached_getpwnam_r(const char *name, struct passwd *result, char *buffer,
    int buflen);

/*
 * POSIX.1c Draft-6 version of the function getpwnam_r.
 * It was implemented by Solaris 2.3.
 */
struct passwd *
getpwnam_r(const char *name, struct passwd *result, char *buffer, int buflen)
{
    nss_XbyY_args_t arg;

    if (name == (const char *)NULL) {
        errno = ERANGE;
        return (NULL);
    }
    NSS_XbyY_INIT(&arg, result, buffer, buflen, str2passwd);
    arg.key.name = name;
    (void) nss_search(&db_root, _nss_initf_passwd, NSS_DBOP_PASSWD_BYNAME,
        &arg);
    return ((struct passwd *)NSS_XbyY_FINI(&arg));
}

/*
 * POSIX.1c Draft-6 version of the function getpwuid_r.
 * It was implemented by Solaris 2.3.
 */
struct passwd *
getpwuid_r(uid_t uid, struct passwd *result, char *buffer, int buflen)
{
    nss_XbyY_args_t arg;

    NSS_XbyY_INIT(&arg, result, buffer, buflen, str2passwd);
    arg.key.uid = uid;
    (void) nss_search(&db_root, _nss_initf_passwd, NSS_DBOP_PASSWD_BYUID,
        &arg);
    return ((struct passwd *)NSS_XbyY_FINI(&arg));
}


struct passwd *
_uncached_getpwuid_r(uid_t uid, struct passwd *result, char *buffer,
    int buflen)
{
    nss_XbyY_args_t arg;

    NSS_XbyY_INIT(&arg, result, buffer, buflen, str2passwd);
    arg.key.uid = uid;
    (void) nss_search(&db_root, _nss_initf_passwd, NSS_DBOP_PASSWD_BYUID,
        &arg);
    return ((struct passwd *)NSS_XbyY_FINI(&arg));
}


/*
 * POSIX.1c standard version of the function getpwuid_r.
 * User gets it via static getpwuid_r from the header file.
 */
int
__posix_getpwuid_r(uid_t uid, struct passwd *pwd, char *buffer,
    size_t bufsize, struct passwd **result)
{
    int nerrno = 0;
    int oerrno = errno;

    errno = 0;
    if ((*result = getpwuid_r(uid, pwd, buffer, (uintptr_t)bufsize))
        == NULL) {
            nerrno = errno;
    }
    errno = oerrno;
    return (nerrno);
}

struct passwd *
_uncached_getpwnam_r(const char *name, struct passwd *result, char *buffer,
    int buflen)
{
    nss_XbyY_args_t arg;

    NSS_XbyY_INIT(&arg, result, buffer, buflen, str2passwd);
    arg.key.name = name;
    (void) nss_search(&db_root, _nss_initf_passwd, NSS_DBOP_PASSWD_BYNAME,
        &arg);
    return ((struct passwd *)NSS_XbyY_FINI(&arg));
}

/*
 * POSIX.1c standard version of the function getpwnam_r.
 * User gets it via static getpwnam_r from the header file.
 */
int
__posix_getpwnam_r(const char *name, struct passwd *pwd, char *buffer,
    size_t bufsize, struct passwd **result)
{
    int nerrno = 0;
    int oerrno = errno;

    errno = 0;
    if ((*result = getpwnam_r(name, pwd, buffer, (uintptr_t)bufsize))
        == NULL) {
            nerrno = errno;
    }
    errno = oerrno;
    return (nerrno);
}

void
setpwent(void)
{
    nss_setent(&db_root, _nss_initf_passwd, &context);
}

void
endpwent(void)
{
    nss_endent(&db_root, _nss_initf_passwd, &context);
    nss_delete(&db_root);
}

struct passwd *
getpwent_r(struct passwd *result, char *buffer, int buflen)
{
    nss_XbyY_args_t arg;
    char        *nam;

    /* In getXXent_r(), protect the unsuspecting caller from +/- entries */

    do {
        NSS_XbyY_INIT(&arg, result, buffer, buflen, str2passwd);
        /* No key to fill in */
        (void) nss_getent(&db_root, _nss_initf_passwd, &context, &arg);
    } while (arg.returnval != 0 &&
        (nam = ((struct passwd *)arg.returnval)->pw_name) != 0 &&
        (*nam == '+' || *nam == '-'));

    return ((struct passwd *)NSS_XbyY_FINI(&arg));
}

struct passwd *
fgetpwent_r(FILE *f, struct passwd *result, char *buffer, int buflen)
{
    extern void _nss_XbyY_fgets(FILE *, nss_XbyY_args_t *);
    nss_XbyY_args_t arg;

    /* ... but in fgetXXent_r, the caller deserves any +/- entry he gets */

    /* No key to fill in */
    NSS_XbyY_INIT(&arg, result, buffer, buflen, str2passwd);
    _nss_XbyY_fgets(f, &arg);
    return ((struct passwd *)NSS_XbyY_FINI(&arg));
}

static char *
gettok(char **nextpp)
{
    char    *p = *nextpp;
    char    *q = p;
    char    c;

    if (p == 0)
        return (0);

    while ((c = *q) != '\0' && c != ':')
        q++;

    if (c == '\0')
        *nextpp = 0;
    else {
        *q++ = '\0';
        *nextpp = q;
    }
    return (p);
}

/*
 * Return values: 0 = success, 1 = parse error, 2 = erange ...
 * The structure pointer passed in is a structure in the caller's space
 * wherein the field pointers would be set to areas in the buffer if
 * need be. instring and buffer should be separate areas.
 */
int
str2passwd(const char *instr, int lenstr, void *ent, char *buffer, int buflen)
{
    struct passwd   *passwd = (struct passwd *)ent;
    char        *p, *next;
    int     black_magic;    /* "+" or "-" entry */
    ulong_t     tmp;

    if (lenstr + 1 > buflen)
        return (NSS_STR_PARSE_ERANGE);

    /*
     * We copy the input string into the output buffer and
     * operate on it in place.
     */
    if (instr != buffer) {
        /* Overlapping buffer copies are OK */
        (void) memmove(buffer, instr, lenstr);
        buffer[lenstr] = '\0';
    }

    /* quick exit do not entry fill if not needed */
    if (ent == (void *)NULL)
        return (NSS_STR_PARSE_SUCCESS);

    next = buffer;

    passwd->pw_name = p = gettok(&next);        /* username */
    if (*p == '\0') {
        /* Empty username;  not allowed */
        return (NSS_STR_PARSE_PARSE);
    }
    black_magic = (*p == '+' || *p == '-');
    if (black_magic) {
        passwd->pw_uid = UID_NOBODY;
        passwd->pw_gid = GID_NOBODY;
        /*
         *  pwconv tests pw_passwd and pw_age == NULL
         */
        passwd->pw_passwd  = "";
        passwd->pw_age  = "";
        /*
         * the rest of the passwd entry is "optional"
         */
        passwd->pw_comment = "";
        passwd->pw_gecos = "";
        passwd->pw_dir  = "";
        passwd->pw_shell = "";
    }

    passwd->pw_passwd = p = gettok(&next);      /* password */
    if (p == 0) {
        if (black_magic)
            return (NSS_STR_PARSE_SUCCESS);
        else
            return (NSS_STR_PARSE_PARSE);
    }
    for (; *p != '\0';  p++) {          /* age */
        if (*p == ',') {
            *p++ = '\0';
            break;
        }
    }
    passwd->pw_age = p;

    p = next;                   /* uid */
    if (p == 0 || *p == '\0') {
        if (black_magic)
            return (NSS_STR_PARSE_SUCCESS);
        else
            return (NSS_STR_PARSE_PARSE);
    }
    if (!black_magic) {
        /*
         * strtoul returns unsigned long which is
         * 8 bytes on a 64-bit system. We don't want
         * to assign it directly to passwd->pw_uid
         * which is 4 bytes or else we will end up
         * truncating the value.
         */
        errno = 0;
        tmp = strtoul(p, &next, 10);
        if (next == p || errno != 0) {
            /* uid field should be nonempty */
            /* also check errno from strtoul */
            return (NSS_STR_PARSE_PARSE);
        }
        /*
         * The old code (in 2.0 through 2.5) would check
         * for the uid being negative, or being greater
         * than 60001 (the rfs limit).  If it met either of
         * these conditions, the uid was translated to 60001.
         *
         * Now we just check for -1 (UINT32_MAX); anything else
         * is administrative policy
         */
        if (tmp >= UINT32_MAX)
            passwd->pw_uid = UID_NOBODY;
        else
            passwd->pw_uid = (uid_t)tmp;
    }
    if (*next++ != ':') {
        if (black_magic)
            (void) gettok(&next);
        else
            return (NSS_STR_PARSE_PARSE);
    }
    p = next;                   /* gid */
    if (p == 0 || *p == '\0') {
        if (black_magic)
            return (NSS_STR_PARSE_SUCCESS);
        else
            return (NSS_STR_PARSE_PARSE);
    }
    if (!black_magic) {
        errno = 0;
        tmp = strtoul(p, &next, 10);
        if (next == p || errno != 0) {
            /* gid field should be nonempty */
            /* also check errno from strtoul */
            return (NSS_STR_PARSE_PARSE);
        }
        /*
         * gid should not be -1; anything else
         * is administrative policy.
         */
        if (tmp >= UINT32_MAX)
            passwd->pw_gid = GID_NOBODY;
        else
            passwd->pw_gid = (gid_t)tmp;
    }
    if (*next++ != ':') {
        if (black_magic)
            (void) gettok(&next);
        else
            return (NSS_STR_PARSE_PARSE);
    }

    passwd->pw_gecos = passwd->pw_comment = p = gettok(&next);
    if (p == 0) {
        if (black_magic)
            return (NSS_STR_PARSE_SUCCESS);
        else
            return (NSS_STR_PARSE_PARSE);
    }

    passwd->pw_dir = p = gettok(&next);
    if (p == 0) {
        if (black_magic)
            return (NSS_STR_PARSE_SUCCESS);
        else
            return (NSS_STR_PARSE_PARSE);
    }

    passwd->pw_shell = p = gettok(&next);
    if (p == 0) {
        if (black_magic)
            return (NSS_STR_PARSE_SUCCESS);
        else
            return (NSS_STR_PARSE_PARSE);
    }

    /* Better not be any more fields... */
    if (next == 0) {
        /* Successfully parsed and stored */
        return (NSS_STR_PARSE_SUCCESS);
    }
    return (NSS_STR_PARSE_PARSE);
}