sunrpc/netname.c

   1 /* Copyright (C) 1997-2021 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.de>, 1997.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <stdio.h>
  20 #include <unistd.h>
  21 #include <string.h>
  22 #include <rpc/rpc.h>
  23 #include <shlib-compat.h>
  24
  25 #include "nsswitch.h"
  26
  27 #define OPSYS_LEN 4
  28 #define MAXIPRINT (11)          /* max length of printed integer */
  29 static const char OPSYS[] = "unix";
  30
  31 int
  32 user2netname (char netname[MAXNETNAMELEN + 1], const uid_t uid,
  33               const char *domain)
  34 {
  35   char dfltdom[MAXNETNAMELEN + 1];
  36   size_t i;
  37
  38   if (domain == NULL)
  39     {
  40       if (getdomainname (dfltdom, sizeof (dfltdom)) < 0)
  41         return 0;
  42     }
  43   else
  44     {
  45       strncpy (dfltdom, domain, MAXNETNAMELEN);
  46       dfltdom[MAXNETNAMELEN] = '\0';
  47     }
  48
  49   if ((strlen (dfltdom) + OPSYS_LEN + 3 + MAXIPRINT) > (size_t) MAXNETNAMELEN)
  50     return 0;
  51
  52   sprintf (netname, "%s.%d@%s", OPSYS, uid, dfltdom);
  53   i = strlen (netname);
  54   if (netname[i - 1] == '.')
  55     netname[i - 1] = '\0';
  56   return 1;
  57 }
  58 libc_hidden_nolink_sunrpc (user2netname, GLIBC_2_1)
  59
  60 int
  61 host2netname (char netname[MAXNETNAMELEN + 1], const char *host,
  62               const char *domain)
  63 {
  64   char *p;
  65   char hostname[MAXHOSTNAMELEN + 1];
  66   char domainname[MAXHOSTNAMELEN + 1];
  67   char *dot_in_host;
  68   size_t i;
  69
  70   netname[0] = '\0';            /* make null first (no need for memset) */
  71
  72   if (host == NULL)
  73     __gethostname (hostname, MAXHOSTNAMELEN);
  74   else
  75     {
  76       strncpy (hostname, host, MAXHOSTNAMELEN);
  77       hostname[MAXHOSTNAMELEN] = '\0';
  78     }
  79
  80   dot_in_host = strchr (hostname, '.');
  81   if (domain == NULL)
  82     {
  83       p = dot_in_host;
  84       if (p)
  85         {
  86           ++p;
  87           strncpy (domainname, p, MAXHOSTNAMELEN);
  88           domainname[MAXHOSTNAMELEN] = '\0';
  89         }
  90       else
  91         {
  92           domainname[0] = 0;
  93           getdomainname (domainname, MAXHOSTNAMELEN);
  94         }
  95     }
  96   else
  97     {
  98       strncpy (domainname, domain, MAXHOSTNAMELEN);
  99       domainname[MAXHOSTNAMELEN] = '\0';
 100     }
 101
 102   i = strlen (domainname);
 103   if (i == 0)
 104     /* No domainname */
 105     return 0;
 106   if (domainname[i - 1] == '.')
 107     domainname[i - 1] = 0;
 108
 109   if (dot_in_host)              /* strip off rest of name */
 110     *dot_in_host = '\0';
 111
 112   if ((strlen (domainname) + strlen (hostname) + OPSYS_LEN + 3)
 113       > MAXNETNAMELEN)
 114     return 0;
 115
 116   sprintf (netname, "%s.%s@%s", OPSYS, hostname, domainname);
 117   return 1;
 118 }
 119 #ifdef EXPORT_RPC_SYMBOLS
 120 libc_hidden_def (host2netname)
 121 #else
 122 libc_hidden_nolink_sunrpc (host2netname, GLIBC_2_1)
 123 #endif
 124
 125 int
 126 getnetname (char name[MAXNETNAMELEN + 1])
 127 {
 128   uid_t uid;
 129   int dummy;
 130
 131   uid = __geteuid ();
 132   if (uid == 0)
 133     dummy = host2netname (name, NULL, NULL);
 134   else
 135     dummy = user2netname (name, uid, NULL);
 136   return (dummy);
 137 }
 138 libc_hidden_nolink_sunrpc (getnetname, GLIBC_2_1)
 139
 140 /* Type of the lookup function for netname2user.  */
 141 typedef int (*netname2user_function) (const char netname[MAXNETNAMELEN + 1],
 142                                       uid_t *, gid_t *, int *, gid_t *);
 143
 144 int
 145 netname2user (const char *netname, uid_t * uidp, gid_t * gidp,
 146               int *gidlenp, gid_t * gidlist)
 147 {
 148   nss_action_list nip;
 149   union
 150   {
 151     netname2user_function f;
 152     void *ptr;
 153   } fct;
 154   enum nss_status status = NSS_STATUS_UNAVAIL;
 155   int no_more;
 156
 157   no_more = __nss_publickey_lookup2 (&nip, "netname2user", NULL, &fct.ptr);
 158
 159   while (!no_more)
 160     {
 161       status = (*fct.f) (netname, uidp, gidp, gidlenp, gidlist);
 162
 163       no_more = __nss_next2 (&nip, "netname2user", NULL, &fct.ptr, status, 0);
 164     }
 165
 166   return status == NSS_STATUS_SUCCESS;
 167 }
 168 #ifdef EXPORT_RPC_SYMBOLS
 169 libc_hidden_def (netname2user)
 170 #else
 171 libc_hidden_nolink_sunrpc (netname2user, GLIBC_2_1)
 172 #endif
 173
 174 int
 175 netname2host (const char *netname, char *hostname, const int hostlen)
 176 {
 177   char *p1, *p2;
 178
 179   p1 = strchr (netname, '.');
 180   if (p1 == NULL)
 181     return 0;
 182   p1++;
 183
 184   p2 = strchr (p1, '@');
 185   if (p2 == NULL)
 186     return 0;
 187   *p2 = '\0';
 188
 189   if (hostlen > MAXNETNAMELEN)
 190     return 0;
 191
 192   strncpy (hostname, p1, hostlen);
 193   hostname[hostlen] = '\0';
 194
 195   return 1;
 196 }
 197 libc_hidden_nolink_sunrpc (netname2host, GLIBC_2_1)