source/lib/substitute.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 3.0
   4    string substitution functions
   5    Copyright (C) Andrew Tridgell 1992-2000
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22
  23 #include "includes.h"
  24
  25 fstring local_machine="";
  26 fstring remote_arch="UNKNOWN";
  27 userdom_struct current_user_info;
  28 pstring samlogon_user="";
  29 BOOL sam_logon_in_ssb = False;
  30 fstring remote_proto="UNKNOWN";
  31 fstring remote_machine="";
  32
  33
  34 /*******************************************************************
  35  Given a pointer to a %$(NAME) expand it as an environment variable.
  36  Return the number of characters by which the pointer should be advanced.
  37  Based on code by Branko Cibej <branko.cibej@hermes.si>
  38  When this is called p points at the '%' character.
  39 ********************************************************************/
  40
  41 static size_t expand_env_var(char *p, int len)
  42 {
  43         fstring envname;
  44         char *envval;
  45         char *q, *r;
  46         int copylen;
  47
  48         if (p[1] != '$')
  49                 return 1;
  50
  51         if (p[2] != '(')
  52                 return 2;
  53
  54         /*
  55          * Look for the terminating ')'.
  56          */
  57
  58         if ((q = strchr(p,')')) == NULL) {
  59                 DEBUG(0,("expand_env_var: Unterminated environment variable [%s]\n", p));
  60                 return 2;
  61         }
  62
  63         /*
  64          * Extract the name from within the %$(NAME) string.
  65          */
  66
  67         r = p+3;
  68         copylen = MIN((q-r),(sizeof(envname)-1));
  69         strncpy(envname,r,copylen);
  70         envname[copylen] = '\0';
  71
  72         if ((envval = getenv(envname)) == NULL) {
  73                 DEBUG(0,("expand_env_var: Environment variable [%s] not set\n", envname));
  74                 return 2;
  75         }
  76
  77         /*
  78          * Copy the full %$(NAME) into envname so it
  79          * can be replaced.
  80          */
  81
  82         copylen = MIN((q+1-p),(sizeof(envname)-1));
  83         strncpy(envname,p,copylen);
  84         envname[copylen] = '\0';
  85         string_sub(p,envname,envval,len);
  86         return 0; /* Allow the environment contents to be parsed. */
  87 }
  88
  89 /*******************************************************************
  90  Patch from jkf@soton.ac.uk
  91  Added this to implement %p (NIS auto-map version of %H)
  92 *******************************************************************/
  93
  94 static char *automount_path(char *user_name)
  95 {
  96         static pstring server_path;
  97
  98         /* use the passwd entry as the default */
  99         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 100
 101         pstrcpy(server_path, get_user_home_dir(user_name));
 102
 103 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 104
 105         if (lp_nis_home_map()) {
 106                 char *home_path_start;
 107                 char *automount_value = automount_lookup(user_name);
 108
 109                 if(strlen(automount_value) > 0) {
 110                         home_path_start = strchr(automount_value,':');
 111                         if (home_path_start != NULL) {
 112                                 DEBUG(5, ("NIS lookup succeeded.  Home path is: %s\n",
 113                                                 home_path_start?(home_path_start+1):""));
 114                                 pstrcpy(server_path, home_path_start+1);
 115                         }
 116                 } else {
 117                         /* NIS key lookup failed: default to user home directory from password file */
 118                         DEBUG(5, ("NIS lookup failed. Using Home path from passwd file. Home path is: %s\n", server_path ));
 119                 }
 120         }
 121 #endif
 122
 123         DEBUG(4,("Home server path: %s\n", server_path));
 124
 125         return server_path;
 126 }
 127
 128 /*******************************************************************
 129  Patch from jkf@soton.ac.uk
 130  This is Luke's original function with the NIS lookup code
 131  moved out to a separate function.
 132 *******************************************************************/
 133
 134 static char *automount_server(char *user_name)
 135 {
 136         extern pstring global_myname;
 137         static pstring server_name;
 138
 139         /* use the local machine name as the default */
 140         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 141         if (*local_machine)
 142                 pstrcpy(server_name, local_machine);
 143         else
 144                 pstrcpy(server_name, global_myname);
 145
 146 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 147
 148         if (lp_nis_home_map()) {
 149                 int home_server_len;
 150                 char *automount_value = automount_lookup(user_name);
 151                 home_server_len = strcspn(automount_value,":");
 152                 DEBUG(5, ("NIS lookup succeeded.  Home server length: %d\n",home_server_len));
 153                 if (home_server_len > sizeof(pstring))
 154                         home_server_len = sizeof(pstring);
 155                 strncpy(server_name, automount_value, home_server_len);
 156                 server_name[home_server_len] = '\0';
 157         }
 158 #endif
 159
 160         DEBUG(4,("Home server: %s\n", server_name));
 161
 162         return server_name;
 163 }
 164
 165 /****************************************************************************
 166  Do some standard substitutions in a string.
 167 ****************************************************************************/
 168
 169 void standard_sub_basic(char *str)
 170 {
 171         char *p, *s;
 172         fstring pidstr;
 173         struct passwd *pass;
 174
 175         for (s=str; (p=strchr(s, '%'));s=p) {
 176                 fstring tmp_str;
 177
 178                 int l = sizeof(pstring) - (int)(p-str);
 179
 180                 switch (*(p+1)) {
 181                 case 'U' :
 182                         fstrcpy(tmp_str, sam_logon_in_ssb?samlogon_user:current_user_info.smb_name);
 183                         strlower(tmp_str);
 184                         string_sub(p,"%U",tmp_str,l);
 185                         break;
 186                 case 'G' :
 187                         fstrcpy(tmp_str, sam_logon_in_ssb?samlogon_user:current_user_info.smb_name);
 188                         if ((pass = Get_Pwnam(tmp_str, False))!=NULL) {
 189                                 string_sub(p,"%G",gidtoname(pass->pw_gid),l);
 190                         } else {
 191                                 p += 2;
 192                         }
 193                         break;
 194                 case 'D' :
 195                         fstrcpy(tmp_str, current_user_info.domain);
 196                         strupper(tmp_str);
 197                         string_sub(p,"%D", tmp_str,l);
 198                         break;
 199                 case 'I' : string_sub(p,"%I", client_addr(),l); break;
 200                 case 'L' : string_sub(p,"%L", local_machine,l); break;
 201                 case 'M' : string_sub(p,"%M", client_name(),l); break;
 202                 case 'R' : string_sub(p,"%R", remote_proto,l); break;
 203                 case 'T' : string_sub(p,"%T", timestring(False),l); break;
 204                 case 'a' : string_sub(p,"%a", remote_arch,l); break;
 205                 case 'd' :
 206                         slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)sys_getpid());
 207                         string_sub(p,"%d", pidstr,l);
 208                         break;
 209                 case 'h' : string_sub(p,"%h", myhostname(),l); break;
 210                 case 'm' : string_sub(p,"%m", remote_machine,l); break;
 211                 case 'v' : string_sub(p,"%v", VERSION,l); break;
 212                 case '$' : p += expand_env_var(p,l); break; /* Expand environment variables */
 213                 case '\0':
 214                         p++;
 215                         break; /* don't run off the end of the string */
 216
 217                 default: p+=2;
 218                         break;
 219                 }
 220         }
 221 }
 222
 223 /****************************************************************************
 224  Do some standard substitutions in a string.
 225 ****************************************************************************/
 226
 227 void standard_sub_advanced(int snum, char *user, char *connectpath, gid_t gid, char *str)
 228 {
 229         char *p, *s, *home;
 230
 231         for (s=str; (p=strchr(s, '%'));s=p) {
 232                 int l = sizeof(pstring) - (int)(p-str);
 233
 234                 switch (*(p+1)) {
 235                 case 'N' : string_sub(p,"%N", automount_server(user),l); break;
 236                 case 'H':
 237                         if ((home = get_user_home_dir(user))) {
 238                                 string_sub(p,"%H",home, l);
 239                         } else {
 240                                 p += 2;
 241                         }
 242                         break;
 243                 case 'P':
 244                         string_sub(p,"%P", connectpath, l);
 245                         break;
 246
 247                 case 'S':
 248                         string_sub(p,"%S", lp_servicename(snum), l);
 249                         break;
 250
 251                 case 'g':
 252                         string_sub(p,"%g", gidtoname(gid), l);
 253                         break;
 254                 case 'u':
 255                         string_sub(p,"%u", user, l);
 256                         break;
 257
 258                         /* Patch from jkf@soton.ac.uk Left the %N (NIS
 259                          * server name) in standard_sub_basic as it is
 260                          * a feature for logon servers, hence uses the
 261                          * username.  The %p (NIS server path) code is
 262                          * here as it is used instead of the default
 263                          * "path =" string in [homes] and so needs the
 264                          * service name, not the username.  */
 265                 case 'p':
 266                         string_sub(p,"%p", automount_path(lp_servicename(snum)), l);
 267                         break;
 268                 case '\0':
 269                         p++;
 270                         break; /* don't run off the end of the string */
 271
 272                 default: p+=2;
 273                         break;
 274                 }
 275         }
 276
 277         standard_sub_basic(str);
 278 }
 279
 280 /****************************************************************************
 281  Do some standard substitutions in a string.
 282 ****************************************************************************/
 283
 284 void standard_sub_conn(connection_struct *conn, char *str)
 285 {
 286         standard_sub_advanced(SNUM(conn), conn->user, conn->connectpath, conn->gid, str);
 287 }
 288
 289 /****************************************************************************
 290  Like standard_sub but for a homes share where snum still points to the [homes]
 291  share. No user specific snum created yet so servicename should be the username.
 292 ****************************************************************************/
 293
 294 void standard_sub_home(int snum, char *user, char *str)
 295 {
 296         char *p, *s;
 297
 298         for (s=str; (p=strchr(s, '%'));s=p) {
 299                 int l = sizeof(pstring) - (int)(p-str);
 300
 301                 switch (*(p+1)) {
 302                 case 'S':
 303                         string_sub(p,"%S", user, l);
 304                         break;
 305                 case 'p':
 306                         string_sub(p,"%p", automount_path(user), l);
 307                         break;
 308                 case '\0':
 309                         p++;
 310                         break; /* don't run off the end of the string */
 311
 312                 default: p+=2;
 313                         break;
 314                 }
 315         }
 316
 317         standard_sub_advanced(snum, user, "", -1, str);
 318 }
 319
 320 /****************************************************************************
 321  Like standard_sub but by snum.
 322 ****************************************************************************/
 323
 324 void standard_sub_snum(int snum, char *str)
 325 {
 326         extern struct current_user current_user;
 327         static uid_t cached_uid = -1;
 328         static fstring cached_user;
 329         /* calling uidtoname() on every substitute would be too expensive, so
 330            we cache the result here as nearly every call is for the same uid */
 331
 332         if (cached_uid != current_user.uid) {
 333                 fstrcpy(cached_user, uidtoname(current_user.uid));
 334                 cached_uid = current_user.uid;
 335         }
 336
 337         standard_sub_advanced(snum, cached_user, "", -1, str);
 338 }
 339
 340 /*******************************************************************
 341  Substitute strings with useful parameters.
 342 ********************************************************************/
 343
 344 void standard_sub_vuser(char *str, user_struct *vuser)
 345 {
 346         standard_sub_advanced(-1, vuser->user.unix_name, "", -1, str);
 347 }
 348
 349 /*******************************************************************
 350  Substitute strings with useful parameters.
 351 ********************************************************************/
 352
 353 void standard_sub_vsnum(char *str, user_struct *vuser, int snum)
 354 {
 355         standard_sub_advanced(snum, vuser->user.unix_name, "", -1, str);
 356 }