netnamer.c

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/*
 * Copyright (c) 2009, Sun Microsystems, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 * - 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.
 * - Neither the name of Sun Microsystems, Inc. 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 COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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.
 */
 
/*
 * netname utility routines convert from unix names to network names and
 * vice-versa This module is operating system dependent! What we define here
 * will work with any unix system that has adopted the sun NIS domain
 * architecture.
 */
#include <wintirpc.h>
#ifndef _WIN32
#include <sys/param.h>
#include <rpc/rpc.h>
#include "rpc_com.h"
#ifdef YP
#include <rpcsvc/yp_prot.h>
#include <rpcsvc/ypclnt.h>
#endif
#include <ctype.h>
#include <stdio.h>
#include <grp.h>
#include <pwd.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
 
static char    *OPSYS = "unix";
static char    *NETID = "netid.byname";
static char    *NETIDFILE = "/etc/netid";
 
static int getnetid( char *, char * );
static int _getgroups( char *, gid_t * );
 
#ifndef NGROUPS
#define NGROUPS 16
#endif
 
/*
 * Convert network-name into unix credential
 */
int
netname2user(netname, uidp, gidp, gidlenp, gidlist)
    char            netname[MAXNETNAMELEN + 1];
    uid_t            *uidp;
    gid_t            *gidp;
    int            *gidlenp;
    gid_t          *gidlist;
{
    char           *p;
    int             gidlen;
    uid_t           uid;
    long        luid;
    struct passwd  *pwd;
    char            val[1024];
    char           *val1, *val2;
    char           *domain;
    int             vallen;
    int             err;
 
    if (getnetid(netname, val)) {
        char *res = val;
 
        p = strsep(&res, ":");
        if (p == NULL)
            return (0);
        *uidp = (uid_t) atol(p);
        p = strsep(&res, "\n,");
        if (p == NULL) {
            return (0);
        }
        *gidp = (gid_t) atol(p);
        gidlen = 0;
        for (gidlen = 0; gidlen < NGROUPS; gidlen++) {
            p = strsep(&res, "\n,");
            if (p == NULL)
                break;
            gidlist[gidlen] = (gid_t) atol(p);
        }
        *gidlenp = gidlen;
 
        return (1);
    }
    val1 = strchr(netname, '.');
    if (val1 == NULL)
        return (0);
    if (strncmp(netname, OPSYS, (val1-netname)))
        return (0);
    val1++;
    val2 = strchr(val1, '@');
    if (val2 == NULL)
        return (0);
    vallen = val2 - val1;
    if (vallen > (1024 - 1))
        vallen = 1024 - 1;
    (void) strncpy(val, val1, 1024);
    val[vallen] = 0;
 
    err = __rpc_get_default_domain(&domain);    /* change to rpc */
    if (err)
        return (0);
 
    if (strcmp(val2 + 1, domain))
        return (0); /* wrong domain */
 
    if (sscanf(val, "%ld", &luid) != 1)
        return (0);
    uid = luid;
 
    /* use initgroups method */
    pwd = getpwuid(uid);
    if (pwd == NULL)
        return (0);
    *uidp = pwd->pw_uid;
    *gidp = pwd->pw_gid;
    *gidlenp = _getgroups(pwd->pw_name, gidlist);
    return (1);
}
 
/*
 * initgroups
 */
 
static int
_getgroups(uname, groups)
    char           *uname;
    gid_t          groups[NGROUPS];
{
    gid_t           ngroups = 0;
    struct group *grp;
    int    i;
    int    j;
    int             filter;
 
    setgrent();
    while ((grp = getgrent())) {
        for (i = 0; grp->gr_mem[i]; i++)
            if (!strcmp(grp->gr_mem[i], uname)) {
                if (ngroups == NGROUPS) {
#ifdef DEBUG
                    fprintf(stderr,
                "initgroups: %s is in too many groups\n", uname);
#endif
                    goto toomany;
                }
                /* filter out duplicate group entries */
                filter = 0;
                for (j = 0; j < ngroups; j++)
                    if (groups[j] == grp->gr_gid) {
                        filter++;
                        break;
                    }
                if (!filter)
                    groups[ngroups++] = grp->gr_gid;
            }
    }
toomany:
    endgrent();
    return (ngroups);
}
 
/*
 * Convert network-name to hostname
 */
int
netname2host(netname, hostname, hostlen)
    char            netname[MAXNETNAMELEN + 1];
    char           *hostname;
    int             hostlen;
{
    int             err;
    char            valbuf[1024];
    char           *val;
    char           *val2;
    int             vallen;
    char           *domain;
 
    if (getnetid(netname, valbuf)) {
        val = valbuf;
        if ((*val == '0') && (val[1] == ':')) {
            (void) strncpy(hostname, val + 2, hostlen);
            return (1);
        }
    }
    val = strchr(netname, '.');
    if (val == NULL)
        return (0);
    if (strncmp(netname, OPSYS, (val - netname)))
        return (0);
    val++;
    val2 = strchr(val, '@');
    if (val2 == NULL)
        return (0);
    vallen = val2 - val;
    if (vallen > (hostlen - 1))
        vallen = hostlen - 1;
    (void) strncpy(hostname, val, vallen);
    hostname[vallen] = 0;
 
    err = __rpc_get_default_domain(&domain);    /* change to rpc */
    if (err)
        return (0);
 
    if (strcmp(val2 + 1, domain))
        return (0); /* wrong domain */
    else
        return (1);
}
 
/*
 * reads the file /etc/netid looking for a + to optionally go to the
 * network information service.
 */
int
getnetid(key, ret)
    char           *key, *ret;
{
    char            buf[1024];  /* big enough */
    char           *res;
    char           *mkey;
    char           *mval;
    FILE           *fd;
#ifdef YP
    char           *domain;
    int             err;
    char           *lookup;
    int             len;
#endif
 
    fd = fopen(NETIDFILE, "r");
    if (fd == NULL) {
#ifdef YP
        res = "+";
        goto getnetidyp;
#else
        return (0);
#endif
    }
    for (;;) {
        if (fd == NULL)
            return (0); /* getnetidyp brings us here */
        res = fgets(buf, sizeof(buf), fd);
        if (res == NULL) {
            fclose(fd);
            return (0);
        }
        if (res[0] == '#')
            continue;
        else if (res[0] == '+') {
#ifdef YP
    getnetidyp:
            err = yp_get_default_domain(&domain);
            if (err) {
                continue;
            }
            lookup = NULL;
            err = yp_match(domain, NETID, key,
                strlen(key), &lookup, &len);
            if (err) {
#ifdef DEBUG
                fprintf(stderr, "match failed error %d\n", err);
#endif
                continue;
            }
            lookup[len] = 0;
            strcpy(ret, lookup);
            free(lookup);
            if (fd != NULL)
                fclose(fd);
            return (2);
#else   /* YP */
#ifdef DEBUG
            fprintf(stderr,
"Bad record in %s '+' -- NIS not supported in this library copy\n",
                NETIDFILE);
#endif
            continue;
#endif  /* YP */
        } else {
            mkey = strsep(&res, "\t ");
            if (mkey == NULL) {
                fprintf(stderr,
        "Bad record in %s -- %s", NETIDFILE, buf);
                continue;
            }
            do {
                mval = strsep(&res, " \t#\n");
            } while (mval != NULL && !*mval);
            if (mval == NULL) {
                fprintf(stderr,
        "Bad record in %s val problem - %s", NETIDFILE, buf);
                continue;
            }
            if (strcmp(mkey, key) == 0) {
                strcpy(ret, mval);
                fclose(fd);
                return (1);
 
            }
        }
    }
}
#endif  /* !_WIN32 */