1 files changed, 114 insertions, 0 deletions
diff --git a/newlib/libc/sys/linux/gethostid.c b/newlib/libc/sys/linux/gethostid.c
new file mode 100644
index 000000000..bf801c74a
--- /dev/null
+++ b/newlib/libc/sys/linux/gethostid.c
@@ -0,0 +1,114 @@
+/* Copyright (C) 1995,1996,1998,1999,2000,2001 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <alloca.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <netdb.h>
+
+#define HOSTIDFILE "/etc/hostid"
+#define OLD_HOSTIDFILE "/etc/hostid"
+
+#if !defined(_ELIX_LEVEL) || _ELIX_LEVEL >= 2
+# define OPEN __open64
+#else
+# define OPEN __open
+#endif
+
+#ifdef SET_PROCEDURE
+int
+sethostid (id)
+     long int id;
+{
+  int fd;
+  ssize_t written;
+
+  /* Open file for writing.  Everybody is allowed to read this file.  */
+  fd = OPEN (HOSTIDFILE, O_CREAT|O_WRONLY|O_TRUNC, 0644);
+  if (fd < 0)
+    return -1;
+
+  written = __write (fd, &id, sizeof (id));
+
+  __close (fd);
+
+  return written != sizeof (id) ? -1 : 0;
+}
+
+#else
+# include <string.h>
+# include <sys/param.h>
+# include <netdb.h>
+# include <netinet/in.h>
+
+long int
+gethostid ()
+{
+  char hostname[MAXHOSTNAMELEN + 1];
+  size_t buflen;
+  char *buffer;
+  struct hostent hostbuf, *hp;
+  unsigned long int id;
+  struct in_addr in;
+  int herr;
+  int fd;
+
+  /* First try to get the ID from a former invocation of sethostid.  */
+  fd = OPEN (HOSTIDFILE, O_RDONLY);
+  if (fd >= 0)
+    {
+      ssize_t n = __read (fd, &id, sizeof (id));
+
+      __close (fd);
+
+      if (n == sizeof (id))
+	return id;
+    }
+
+  /* Getting from the file was not successful.  An intelligent guess for
+     a unique number of a host is its IP address.  Return this.  */
+  if (__gethostname (hostname, MAXHOSTNAMELEN) < 0 || hostname[0] == '\0')
+    /* This also fails.  Return and arbitrary value.  */
+    return 0;
+
+  buflen = 1024;
+  buffer = alloca (buflen);
+
+  /* To get the IP address we need to know the host name.  */
+  while (__gethostbyname_r (hostname, &hostbuf, buffer, buflen, &hp, &herr)
+	 != 0
+	 || hp == NULL)
+    if (herr != NETDB_INTERNAL || errno != ERANGE)
+      return 0;
+    else
+      {
+	/* Enlarge buffer.  */
+	buflen *= 2;
+	buffer = alloca (buflen);
+      }
+
+  in.s_addr = 0;
+  memcpy (&in, hp->h_addr,
+	  (int) sizeof (in) < hp->h_length ? sizeof (in) : hp->h_length);
+
+  /* For the return value to be not exactly the IP address we do some
+     bit fiddling.  */
+  return in.s_addr << 16 | in.s_addr >> 16;
+}
+#endif