X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=lib%2Fdropin.c;h=c92c0b81ebb65d9c39fe8dc3c51021e157c56b48;hp=faa2314bd90749ce7f948c0265dc2922122fc319;hb=0e945413315c9d15a3eb013fa3731dd978a8c7b8;hpb=c94f7637427f4c89d56c41fe4c75f2970b664a63 diff --git a/lib/dropin.c b/lib/dropin.c index faa2314b..c92c0b81 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 , - 2000 Guus Sliepen + Copyright (C) 2000-2003 Ivo Timmermans , + 2000-2003 Guus Sliepen 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 @@ -17,85 +17,145 @@ 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 1.1.2.17 2003/07/28 22:06:09 guus Exp $ */ -#include "config.h" +#include "system.h" -#include -#include -#include -#include -#include - -#include +#include "xalloc.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); +#ifdef HAVE_FORK + 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; +#else + return -1; +#endif +} +#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 +#ifndef HAVE_GETTIMEOFDAY +int gettimeofday(struct timeval *tv, void *tz) { + tv->tv_sec = time(NULL); + tv->tv_usec = 0; + return 0; +} #endif