source4/lib/system.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Samba system utilities
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Jeremy Allison 1998-2002
   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 #include "includes.h"
  23 #include "system/network.h"
  24 #include "system/wait.h"
  25 #include "system/filesys.h"
  26 #include "pstring.h"
  27
  28 /*
  29    The idea is that this file will eventually have wrappers around all
  30    important system calls in samba. The aims are:
  31
  32    - to enable easier porting by putting OS dependent stuff in here
  33
  34    - to allow for hooks into other "pseudo-filesystems"
  35
  36    - to allow easier integration of things like the japanese extensions
  37
  38    - to support the philosophy of Samba to expose the features of
  39      the OS within the SMB model. In general whatever file/printer/variable
  40      expansions/etc make sense to the OS should be acceptable to Samba.
  41 */
  42
  43
  44
  45 /*******************************************************************
  46  A wrapper for usleep in case we don't have one.
  47 ********************************************************************/
  48
  49 int sys_usleep(long usecs)
  50 {
  51 #ifndef HAVE_USLEEP
  52         struct timeval tval;
  53 #endif
  54
  55         /*
  56          * We need this braindamage as the glibc usleep
  57          * is not SPEC1170 complient... grumble... JRA.
  58          */
  59
  60         if(usecs < 0 || usecs > 1000000) {
  61                 errno = EINVAL;
  62                 return -1;
  63         }
  64
  65 #if HAVE_USLEEP
  66         usleep(usecs);
  67         return 0;
  68 #else /* HAVE_USLEEP */
  69         /*
  70          * Fake it with select...
  71          */
  72         tval.tv_sec = 0;
  73         tval.tv_usec = usecs/1000;
  74         select(0,NULL,NULL,NULL,&tval);
  75         return 0;
  76 #endif /* HAVE_USLEEP */
  77 }
  78
  79
  80 /*******************************************************************
  81  System wrapper for getwd
  82 ********************************************************************/
  83 char *sys_getwd(char *s)
  84 {
  85         char *wd;
  86 #ifdef HAVE_GETCWD
  87         wd = (char *)getcwd(s, sizeof (pstring));
  88 #else
  89         wd = (char *)getwd(s);
  90 #endif
  91         return wd;
  92 }
  93
  94 /*******************************************************************
  95 A read wrapper that will deal with EINTR.
  96 ********************************************************************/
  97
  98 ssize_t sys_read(int fd, void *buf, size_t count)
  99 {
 100         ssize_t ret;
 101
 102         do {
 103                 ret = read(fd, buf, count);
 104         } while (ret == -1 && errno == EINTR);
 105         return ret;
 106 }
 107
 108 /*******************************************************************
 109 A write wrapper that will deal with EINTR.
 110 ********************************************************************/
 111
 112 ssize_t sys_write(int fd, const void *buf, size_t count)
 113 {
 114         ssize_t ret;
 115
 116         do {
 117                 ret = write(fd, buf, count);
 118         } while (ret == -1 && errno == EINTR);
 119         return ret;
 120 }
 121
 122
 123
 124 /*******************************************************************
 125 os/2 also doesn't have chroot
 126 ********************************************************************/
 127 int sys_chroot(const char *dname)
 128 {
 129 #ifndef HAVE_CHROOT
 130         static int done;
 131         if (!done) {
 132                 DEBUG(1,("WARNING: no chroot!\n"));
 133                 done=1;
 134         }
 135         errno = ENOSYS;
 136         return -1;
 137 #else
 138         return(chroot(dname));
 139 #endif
 140 }
 141
 142 /**************************************************************************
 143 A wrapper for gethostbyname() that tries avoids looking up hostnames
 144 in the root domain, which can cause dial-on-demand links to come up for no
 145 apparent reason.
 146 ****************************************************************************/
 147
 148 struct hostent *sys_gethostbyname(const char *name)
 149 {
 150 #ifdef REDUCE_ROOT_DNS_LOOKUPS
 151         char query[256], hostname[256];
 152         char *domain;
 153
 154         /* Does this name have any dots in it? If so, make no change */
 155
 156         if (strchr_m(name, '.'))
 157                 return(gethostbyname(name));
 158
 159         /* Get my hostname, which should have domain name
 160                 attached. If not, just do the gethostname on the
 161                 original string.
 162         */
 163
 164         gethostname(hostname, sizeof(hostname) - 1);
 165         hostname[sizeof(hostname) - 1] = 0;
 166         if ((domain = strchr_m(hostname, '.')) == NULL)
 167                 return(gethostbyname(name));
 168
 169         /* Attach domain name to query and do modified query.
 170                 If names too large, just do gethostname on the
 171                 original string.
 172         */
 173
 174         if((strlen(name) + strlen(domain)) >= sizeof(query))
 175                 return(gethostbyname(name));
 176
 177         slprintf(query, sizeof(query)-1, "%s%s", name, domain);
 178         return(gethostbyname(query));
 179 #else /* REDUCE_ROOT_DNS_LOOKUPS */
 180         return(gethostbyname(name));
 181 #endif /* REDUCE_ROOT_DNS_LOOKUPS */
 182 }
 183
 184
 185
 186 /**************************************************************************
 187  Wrappers for dlopen, dlsym, dlclose.
 188 ****************************************************************************/
 189
 190 void *sys_dlopen(const char *name, int flags)
 191 {
 192 #if defined(HAVE_DLOPEN)
 193         return dlopen(name, flags);
 194 #else
 195         return NULL;
 196 #endif
 197 }
 198
 199 void *sys_dlsym(void *handle, const char *symbol)
 200 {
 201 #if defined(HAVE_DLSYM)
 202     return dlsym(handle, symbol);
 203 #else
 204     return NULL;
 205 #endif
 206 }
 207
 208 const char *sys_dlerror(void)
 209 {
 210 #if defined(HAVE_DLERROR)
 211         return dlerror();
 212 #else
 213         return NULL;
 214 #endif
 215 }
 216
 217 const char *sys_inet_ntoa(struct ipv4_addr in)
 218 {
 219         struct in_addr in2;
 220         in2.s_addr = in.addr;
 221         return inet_ntoa(in2);
 222 }
 223
 224 uint32_t sys_inet_addr(const char *s)
 225 {
 226         return inet_addr(s);
 227 }
 228
 229 struct ipv4_addr sys_inet_makeaddr(int net, int host)
 230 {
 231         struct in_addr in;
 232         struct ipv4_addr in2;
 233         in = inet_makeaddr(net, host);
 234         in2.addr = in.s_addr;
 235         return in2;
 236 }
 237