X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=lib%2Fdropin.c;h=24d25ca50a3049d2c3566062d063f50058e054aa;hp=faa2314bd90749ce7f948c0265dc2922122fc319;hb=085d33e6265e139bb08cdfda3d7498993190d187;hpb=c94f7637427f4c89d56c41fe4c75f2970b664a63

diff --git a/lib/dropin.c b/lib/dropin.c
index faa2314b..24d25ca5 100644
--- a/lib/dropin.c
+++ b/lib/dropin.c
@@ -1,7 +1,7 @@
 /*
     dropin.c -- a set of drop-in replacements for libc functions
-    Copyright (C) 2000 Ivo Timmermans <itimmermans@bigfoot.com>,
-                  2000 Guus Sliepen <guus@sliepen.warande.net>
+    Copyright (C) 2000-2003 Ivo Timmermans <ivo@o2w.nl>,
+                  2000-2003 Guus Sliepen <guus@sliepen.eu.org>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -17,7 +17,7 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: dropin.c,v 1.1.2.1 2000/11/28 23:23:41 zarq Exp $
+    $Id: dropin.c,v 1.1.2.14 2003/07/12 17:48:38 guus Exp $
 */
 
 #include "config.h"
@@ -27,75 +27,134 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+
+#include <xalloc.h>
 
 #include <system.h>
+#include <errno.h>
 
 #ifndef HAVE_DAEMON
+/*
+  Replacement for the daemon() function.
+  
+  The daemon() function is for programs wishing to detach themselves
+  from the controlling terminal and run in the background as system
+  daemons.
+
+  Unless the argument nochdir is non-zero, daemon() changes the
+  current working directory to the root (``/'').
+
+  Unless the argument noclose is non-zero, daemon() will redirect
+  standard input, standard output and standard error to /dev/null.
+*/
 int daemon(int nochdir, int noclose)
 {
-  pid_t pid;
-  int fd;
-  
-  pid = fork();
-  
-  /* Check if forking failed */
-    
-  if(pid < 0)
-    {
-      perror("fork");
-      exit(-1);
-    }
-
-  /* If we are the parent, terminate */
-  
-  if(pid)
-    exit(0);
+	pid_t pid;
+	int fd;
+
+	pid = fork();
+
+	/* Check if forking failed */
+	if(pid < 0) {
+		perror("fork");
+		exit(-1);
+	}
+
+	/* If we are the parent, terminate */
+	if(pid)
+		exit(0);
+
+	/* Detach by becoming the new process group leader */
+	if(setsid() < 0) {
+		perror("setsid");
+		return -1;
+	}
+
+	/* Change working directory to the root (to avoid keeping mount
+	   points busy) */
+	if(!nochdir) {
+		chdir("/");
+	}
+
+	/* Redirect stdin/out/err to /dev/null */
+	if(!noclose) {
+		fd = open("/dev/null", O_RDWR);
+
+		if(fd < 0) {
+			perror("opening /dev/null");
+			return -1;
+		} else {
+			dup2(fd, 0);
+			dup2(fd, 1);
+			dup2(fd, 2);
+		}
+	}
+
+	return 0;
+}
+#endif
 
-  /* Detach by becoming the new process group leader */
-  
-  if(setsid() < 0)
-    {
-      perror("setsid");
-      return -1;
-    }
-  
-  /* Change working directory to the root (to avoid keeping mount points busy) */
-  
-  if(!nochdir)
-    {
-      chdir("/");
-    }
-    
-  /* Redirect stdin/out/err to /dev/null */
-
-  if(!noclose)
-    {
-      fd = open("/dev/null", O_RDWR);
-
-      if(fd < 0)
-        {
-          perror("opening /dev/null");
-          return -1;
-        }
-        else
-        {
-          dup2(fd, 0);
-          dup2(fd, 1);
-          dup2(fd, 2);
-        }
-    }
+#ifndef HAVE_GET_CURRENT_DIR_NAME
+/*
+  Replacement for the GNU get_current_dir_name function:
+
+  get_current_dir_name will malloc(3) an array big enough to hold the
+  current directory name.  If the environment variable PWD is set, and
+  its value is correct, then that value will be returned.
+*/
+char *get_current_dir_name(void)
+{
+	size_t size;
+	char *buf;
+	char *r;
+
+	/* Start with 100 bytes.  If this turns out to be insufficient to
+	   contain the working directory, double the size.  */
+	size = 100;
+	buf = xmalloc(size);
+
+	errno = 0;					/* Success */
+	r = getcwd(buf, size);
+
+	/* getcwd returns NULL and sets errno to ERANGE if the bufferspace
+	   is insufficient to contain the entire working directory.  */
+	while(r == NULL && errno == ERANGE) {
+		free(buf);
+		size <<= 1;				/* double the size */
+		buf = xmalloc(size);
+		r = getcwd(buf, size);
+	}
+
+	return buf;
 }
 #endif
 
+#ifndef HAVE_ASPRINTF
+int asprintf(char **buf, const char *fmt, ...)
+{
+	int status;
+	va_list ap;
+	int len;
 
+	len = 4096;
+	*buf = xmalloc(len);
 
+	va_start(ap, fmt);
+	status = vsnprintf(*buf, len, fmt, ap);
+	va_end(ap);
 
+	if(status >= 0)
+		*buf = xrealloc(*buf, status);
 
-#ifndef HAVE_GET_CURRENT_DIR_NAME
+	if(status > len - 1) {
+		len = status;
+		va_start(ap, fmt);
+		status = vsnprintf(*buf, len, fmt, ap);
+		va_end(ap);
+	}
 
-char *get_current_dir_name(void)
-{
-  return ".";
+	return status;
 }
-
 #endif