usr/src/lib/libc/port/nsl/netname.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
  27 /* All Rights Reserved */
  28 /*
  29  * Portions of this source code were derived from Berkeley
  30  * 4.3 BSD under license from the Regents of the University of
  31  * California.
  32  */
  33 /*
  34  * ==== hack-attack:  possibly MT-safe but definitely not MT-hot.
  35  * ==== turn this into a real switch frontend and backends
  36  *
  37  * Well, at least the API doesn't involve pointers-to-static.
  38  */
  39
  40 /*
  41  * netname utility routines (getnetname, user2netname, host2netname).
  42  *
  43  * Convert from unix names (uid, gid) to network wide names.
  44  * This module is operating system dependent!
  45  * What we define here will work with any unix system that has adopted
  46  * the Sun NIS domain architecture.
  47  */
  48
  49 #include "mt.h"
  50 #include "rpc_mt.h"
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <unistd.h>
  54 #include <sys/types.h>
  55 #include <ctype.h>
  56 #include <string.h>
  57 #include <syslog.h>
  58 #include <sys/param.h>
  59 #include <rpc/rpc.h>
  60 #include <rpcsvc/nis.h>
  61 #include <rpcsvc/nis_dhext.h>
  62 #include <nsswitch.h>
  63 #include <syslog.h>
  64 #include <errno.h>
  65
  66 #ifndef MAXHOSTNAMELEN
  67 #define MAXHOSTNAMELEN 256
  68 #endif
  69 #ifndef NGROUPS
  70 #define NGROUPS 16
  71 #endif
  72
  73 /*
  74  * the value for NOBODY_UID is set by the SVID. The following define also
  75  * appears in netnamer.c
  76  */
  77
  78 #define NOBODY_UID 60001
  79
  80 extern int getdomainname();
  81 extern int key_call();
  82 #define OPSYS_LEN 4
  83 static const char *OPSYS = "unix";
  84
  85 /*
  86  * default publickey policy:
  87  *      publickey: nis [NOTFOUND = return] files
  88  */
  89
  90
  91 /*      NSW_NOTSUCCESS  NSW_NOTFOUND   NSW_UNAVAIL    NSW_TRYAGAIN */
  92 #define DEF_ACTION {__NSW_RETURN, __NSW_RETURN, __NSW_CONTINUE, __NSW_CONTINUE}
  93
  94 static struct __nsw_lookup lookup_files = {"files", DEF_ACTION, NULL, NULL},
  95                 lookup_nis = {"nis", DEF_ACTION, NULL, &lookup_files};
  96 static struct __nsw_switchconfig publickey_default =
  97                         {0, "publickey", 2, &lookup_nis};
  98
  99 static mutex_t serialize_netname = ERRORCHECKMUTEX;
 100
 101
 102 #define MAXIPRINT       (11)    /* max length of printed integer */
 103
 104 /*
 105  * Convert unix cred to network-name by concatenating the
 106  * 3 pieces of information <opsys type> <uid> <domain>.
 107  */
 108
 109 static int
 110 user2netname_nis(int *err, char netname[MAXNETNAMELEN + 1], uid_t uid,
 111     char *domain)
 112 {
 113         int i;
 114         char *dfltdom;
 115         if (domain == NULL) {
 116                 if (__rpc_get_default_domain(&dfltdom) != 0) {
 117                         *err = __NSW_UNAVAIL;
 118                         return (0);
 119                 }
 120                 domain = dfltdom;
 121         }
 122         if ((strlen(domain) + OPSYS_LEN + 3 + MAXIPRINT) >
 123             (size_t)MAXNETNAMELEN) {
 124                 *err = __NSW_UNAVAIL;
 125                 return (0);
 126         }
 127         (void) snprintf(netname, MAXNETNAMELEN + 1,
 128             "%s.%d@%s", OPSYS, (int)uid, domain);
 129         i = strlen(netname);
 130         if (netname[i-1] == '.')
 131                 netname[i-1] = '\0';
 132         *err = __NSW_SUCCESS;
 133         return (1);
 134 }
 135
 136 /*
 137  * Figure out my fully qualified network name
 138  */
 139 int
 140 getnetname(char name[MAXNETNAMELEN + 1])
 141 {
 142         uid_t uid;
 143
 144         uid = geteuid();
 145         if (uid == 0)
 146                 return (host2netname(name, NULL, NULL));
 147         return (user2netname(name, uid, NULL));
 148 }
 149
 150
 151 /*
 152  * Figure out the fully qualified network name for the given uid.
 153  * This is a private interface.
 154  */
 155 int
 156 __getnetnamebyuid(char name[MAXNETNAMELEN + 1], uid_t uid)
 157 {
 158         if (uid == 0)
 159                 return (host2netname(name, NULL, NULL));
 160         return (user2netname(name, uid, NULL));
 161 }
 162
 163 /*
 164  * Convert unix cred to network-name
 165  *
 166  * It uses the publickey policy in the /etc/nsswitch.conf file
 167  * (Unless the netname is "nobody", which is special cased).
 168  * If there is no publickey policy in /etc/nsswitch.conf,
 169  * the default publickey policy is used, which is
 170  *      publickey: nis [NOTFOUND=return] files
 171  * Note that for the non-nisplus case, there is no failover
 172  * so only the first entry would be relevant for those cases.
 173  */
 174 int
 175 user2netname(char netname[MAXNETNAMELEN + 1], const uid_t uid,
 176     const char *domain)
 177 {
 178         struct __nsw_switchconfig *conf;
 179         struct __nsw_lookup *look;
 180         int needfree = 1, res = 0;
 181         enum __nsw_parse_err perr;
 182         int err;
 183
 184         /*
 185          * Take care of the special case of "nobody". If the uid is
 186          * the value assigned by the SVID for nobody, return the string
 187          * "nobody".
 188          */
 189
 190         if (uid == NOBODY_UID) {
 191                 (void) strlcpy(netname, "nobody", MAXNETNAMELEN + 1);
 192                 return (1);
 193         }
 194
 195         netname[0] = '\0';  /* make null first (no need for memset) */
 196
 197         if (mutex_lock(&serialize_netname) == EDEADLK) {
 198                 /*
 199                  * This thread already holds this lock. This scenario
 200                  * occurs when a process requires a netname which
 201                  * itself requires a netname to look up. As we clearly
 202                  * can't continue like this we return 'nobody'.
 203                  */
 204                 (void) strlcpy(netname, "nobody", MAXNETNAMELEN + 1);
 205                 return (1);
 206         }
 207
 208         conf = __nsw_getconfig("publickey", &perr);
 209         if (!conf) {
 210                 conf = &publickey_default;
 211                 needfree = 0;
 212         }
 213
 214         for (look = conf->lookups; look; look = look->next) {
 215                 /* ldap, nis, and files all do the same thing. */
 216                 if (strcmp(look->service_name, "ldap") == 0 ||
 217                     strcmp(look->service_name, "nis") == 0 ||
 218                     strcmp(look->service_name, "files") == 0)
 219                         res = user2netname_nis(&err,
 220                             netname, uid, (char *)domain);
 221                 else {
 222                         syslog(LOG_INFO,
 223                             "user2netname: unknown nameservice \
 224                                         for publickey info '%s'\n",
 225                             look->service_name);
 226                         err = __NSW_UNAVAIL;
 227                 }
 228                 switch (look->actions[err]) {
 229                         case __NSW_CONTINUE :
 230                                 break;
 231                         case __NSW_RETURN :
 232                                 if (needfree)
 233                                         (void) __nsw_freeconfig(conf);
 234                                 (void) mutex_unlock(&serialize_netname);
 235                                 return (res);
 236                         default :
 237                                 syslog(LOG_ERR,
 238                         "user2netname: Unknown action for nameservice '%s'",
 239                                     look->service_name);
 240                         }
 241         }
 242         if (needfree)
 243                 (void) __nsw_freeconfig(conf);
 244         (void) mutex_unlock(&serialize_netname);
 245         return (0);
 246 }
 247
 248
 249 /*
 250  * Convert host to network-name
 251  * This routine returns following netnames given the host and domain
 252  * arguments defined below: (domainname=y.z)
 253  *        Arguments
 254  *      host    domain          netname
 255  *      ----    ------          -------
 256  *      -       -               unix.m@y.z (hostname=m)
 257  *      -       a.b             unix.m@a.b (hostname=m)
 258  *      -       -               unix.m@y.z (hostname=m.w.x)
 259  *      -       a.b             unix.m@a.b (hostname=m.w.x)
 260  *      h       -               unix.h@y.z
 261  *      h       a.b             unix.h@a.b
 262  *      h.w.x   -               unix.h@w.x
 263  *      h.w.x   a.b             unix.h@a.b
 264  */
 265 int
 266 host2netname(char netname[MAXNETNAMELEN + 1], const char *host,
 267     const char *domain)
 268 {
 269         char *p;
 270         char hostname[MAXHOSTNAMELEN + 1];
 271         char domainname[MAXHOSTNAMELEN + 1];
 272         char *dot_in_host;
 273         int i;
 274         size_t len;
 275
 276         netname[0] = '\0';  /* make null first (no need for memset) */
 277
 278         if (host == NULL) {
 279                 (void) strncpy(hostname, nis_local_host(), sizeof (hostname));
 280                 p = (char *)strchr(hostname, '.');
 281                 if (p) {
 282                         *p++ = '\0';
 283                         /* if no domain passed, use tail of nis_local_host() */
 284                         if (domain == NULL) {
 285                                 domain = p;
 286                         }
 287                 }
 288         } else {
 289                 len = strlen(host);
 290                 if (len >= sizeof (hostname)) {
 291                         return (0);
 292                 }
 293                 (void) strcpy(hostname, host);
 294         }
 295
 296         dot_in_host = (char *)strchr(hostname, '.');
 297         if (domain == NULL) {
 298                 p = dot_in_host;
 299                 if (p) {
 300                         p = (char *)nis_domain_of(hostname);
 301                         len = strlen(p);
 302                         if (len >= sizeof (domainname)) {
 303                                 return (0);
 304                         }
 305                         (void) strcpy(domainname, p);
 306                 } else {
 307                         domainname[0] = '\0';
 308                         if (getdomainname(domainname, MAXHOSTNAMELEN) < 0)
 309                                 return (0);
 310                 }
 311         } else {
 312                 len = strlen(domain);
 313                 if (len >= sizeof (domainname)) {
 314                         return (0);
 315                 }
 316                 (void) strcpy(domainname, domain);
 317         }
 318
 319         i = strlen(domainname);
 320         if (i == 0)
 321                 /* No domainname */
 322                 return (0);
 323         if (domainname[i - 1] == '.')
 324                 domainname[i - 1] = 0;
 325
 326         if (dot_in_host) {  /* strip off rest of name */
 327                 *dot_in_host = '\0';
 328         }
 329
 330         if ((strlen(domainname) + strlen(hostname) + OPSYS_LEN + 3)
 331             > (size_t)MAXNETNAMELEN) {
 332                 return (0);
 333         }
 334
 335         (void) snprintf(netname, MAXNETNAMELEN + 1,
 336             "%s.%s@%s", OPSYS, hostname, domainname);
 337         return (1);
 338 }