sunrpc/netname.c

   1 /* Copyright (C) 1997-2022 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <stdio.h>
  19 #include <unistd.h>
  20 #include <string.h>
  21 #include <rpc/rpc.h>
  22 #include <shlib-compat.h>
  23
  24 #include "nsswitch.h"
  25
  26 #define OPSYS_LEN 4
  27 #define MAXIPRINT (11)          /* max length of printed integer */
  28 static const char OPSYS[] = "unix";
  29
  30 int
  31 user2netname (char netname[MAXNETNAMELEN + 1], const uid_t uid,
  32               const char *domain)
  33 {
  34   char dfltdom[MAXNETNAMELEN + 1];
  35   size_t i;
  36
  37   if (domain == NULL)
  38     {
  39       if (getdomainname (dfltdom, sizeof (dfltdom)) < 0)
  40         return 0;
  41     }
  42   else
  43     {
  44       strncpy (dfltdom, domain, MAXNETNAMELEN);
  45       dfltdom[MAXNETNAMELEN] = '\0';
  46     }
  47
  48   if ((strlen (dfltdom) + OPSYS_LEN + 3 + MAXIPRINT) > (size_t) MAXNETNAMELEN)
  49     return 0;
  50
  51   sprintf (netname, "%s.%d@%s", OPSYS, uid, dfltdom);
  52   i = strlen (netname);
  53   if (netname[i - 1] == '.')
  54     netname[i - 1] = '\0';
  55   return 1;
  56 }
  57 libc_hidden_nolink_sunrpc (user2netname, GLIBC_2_1)
  58
  59 int
  60 host2netname (char netname[MAXNETNAMELEN + 1], const char *host,
  61               const char *domain)
  62 {
  63   char *p;
  64   char hostname[MAXHOSTNAMELEN + 1];
  65   char domainname[MAXHOSTNAMELEN + 1];
  66   char *dot_in_host;
  67   size_t i;
  68
  69   netname[0] = '\0';            /* make null first (no need for memset) */
  70
  71   if (host == NULL)
  72     __gethostname (hostname, MAXHOSTNAMELEN);
  73   else
  74     {
  75       strncpy (hostname, host, MAXHOSTNAMELEN);
  76       hostname[MAXHOSTNAMELEN] = '\0';
  77     }
  78
  79   dot_in_host = strchr (hostname, '.');
  80   if (domain == NULL)
  81     {
  82       p = dot_in_host;
  83       if (p)
  84         {
  85           ++p;
  86           strncpy (domainname, p, MAXHOSTNAMELEN);
  87           domainname[MAXHOSTNAMELEN] = '\0';
  88         }
  89       else
  90         {
  91           domainname[0] = 0;
  92           getdomainname (domainname, MAXHOSTNAMELEN);
  93         }
  94     }
  95   else
  96     {
  97       strncpy (domainname, domain, MAXHOSTNAMELEN);
  98       domainname[MAXHOSTNAMELEN] = '\0';
  99     }
 100
 101   i = strlen (domainname);
 102   if (i == 0)
 103     /* No domainname */
 104     return 0;
 105   if (domainname[i - 1] == '.')
 106     domainname[i - 1] = 0;
 107
 108   if (dot_in_host)              /* strip off rest of name */
 109     *dot_in_host = '\0';
 110
 111   if ((strlen (domainname) + strlen (hostname) + OPSYS_LEN + 3)
 112       > MAXNETNAMELEN)
 113     return 0;
 114
 115   sprintf (netname, "%s.%s@%s", OPSYS, hostname, domainname);
 116   return 1;
 117 }
 118 #ifdef EXPORT_RPC_SYMBOLS
 119 libc_hidden_def (host2netname)
 120 #else
 121 libc_hidden_nolink_sunrpc (host2netname, GLIBC_2_1)
 122 #endif
 123
 124 int
 125 getnetname (char name[MAXNETNAMELEN + 1])
 126 {
 127   uid_t uid;
 128   int dummy;
 129
 130   uid = __geteuid ();
 131   if (uid == 0)
 132     dummy = host2netname (name, NULL, NULL);
 133   else
 134     dummy = user2netname (name, uid, NULL);
 135   return (dummy);
 136 }
 137 libc_hidden_nolink_sunrpc (getnetname, GLIBC_2_1)
 138
 139 /* Type of the lookup function for netname2user.  */
 140 typedef int (*netname2user_function) (const char netname[MAXNETNAMELEN + 1],
 141                                       uid_t *, gid_t *, int *, gid_t *);
 142
 143 int
 144 netname2user (const char *netname, uid_t * uidp, gid_t * gidp,
 145               int *gidlenp, gid_t * gidlist)
 146 {
 147   nss_action_list nip;
 148   union
 149   {
 150     netname2user_function f;
 151     void *ptr;
 152   } fct;
 153   enum nss_status status = NSS_STATUS_UNAVAIL;
 154   int no_more;
 155
 156   no_more = __nss_publickey_lookup2 (&nip, "netname2user", NULL, &fct.ptr);
 157
 158   while (!no_more)
 159     {
 160       status = (*fct.f) (netname, uidp, gidp, gidlenp, gidlist);
 161
 162       no_more = __nss_next2 (&nip, "netname2user", NULL, &fct.ptr, status, 0);
 163     }
 164
 165   return status == NSS_STATUS_SUCCESS;
 166 }
 167 #ifdef EXPORT_RPC_SYMBOLS
 168 libc_hidden_def (netname2user)
 169 #else
 170 libc_hidden_nolink_sunrpc (netname2user, GLIBC_2_1)
 171 #endif
 172
 173 int
 174 netname2host (const char *netname, char *hostname, const int hostlen)
 175 {
 176   char *p1, *p2;
 177
 178   p1 = strchr (netname, '.');
 179   if (p1 == NULL)
 180     return 0;
 181   p1++;
 182
 183   p2 = strchr (p1, '@');
 184   if (p2 == NULL)
 185     return 0;
 186   *p2 = '\0';
 187
 188   if (hostlen > MAXNETNAMELEN)
 189     return 0;
 190
 191   strncpy (hostname, p1, hostlen);
 192   hostname[hostlen] = '\0';
 193
 194   return 1;
 195 }
 196 libc_hidden_nolink_sunrpc (netname2host, GLIBC_2_1)