usr.sbin/cron/lib/compat.c

   1 /* Copyright 1988,1990,1993,1994 by Paul Vixie
   2  * All rights reserved
   3  *
   4  * Distribute freely, except: don't remove my name from the source or
   5  * documentation (don't take credit for my work), mark your changes (don't
   6  * get me blamed for your possible bugs), don't alter or remove this
   7  * notice.  May be sold if buildable source is provided to buyer.  No
   8  * warrantee of any kind, express or implied, is included with this
   9  * software; use at your own risk, responsibility for damages (if any) to
  10  * anyone resulting from the use of this software rests entirely with the
  11  * user.
  12  *
  13  * Send bug reports, bug fixes, enhancements, requests, flames, etc., and
  14  * I'll try to keep a version up to date.  I can be reached as follows:
  15  * Paul Vixie          <paul@vix.com>          uunet!decwrl!vixie!paul
  16  *
  17  * $FreeBSD: src/usr.sbin/cron/lib/compat.c,v 1.6.2.1 2000/12/11 01:03:31 obrien Exp $
  18  * $DragonFly: src/usr.sbin/cron/lib/compat.c,v 1.4 2004/12/18 22:48:03 swildner Exp $
  19  */
  20
  21 /* vix 30dec93 [broke this out of misc.c - see RCS log for history]
  22  * vix 15jan87 [added TIOCNOTTY, thanks csg@pyramid]
  23  */
  24
  25
  26 #include "cron.h"
  27 #ifdef NEED_GETDTABLESIZE
  28 # include <limits.h>
  29 #endif
  30 #if defined(NEED_SETSID) && defined(BSD)
  31 # include <sys/ioctl.h>
  32 #endif
  33 #include <errno.h>
  34 #include <paths.h>
  35
  36
  37 /* the code does not depend on any of vfork's
  38  * side-effects; it just uses it as a quick
  39  * fork-and-exec.
  40  */
  41 #ifdef NEED_VFORK
  42 PID_T
  43 vfork(void)
  44 {
  45         return (fork());
  46 }
  47 #endif
  48
  49
  50 #ifdef NEED_STRDUP
  51 char *
  52 strdup(char *str)
  53 {
  54         char    *temp;
  55
  56         if ((temp = malloc(strlen(str) + 1)) == NULL) {
  57                 errno = ENOMEM;
  58                 return NULL;
  59         }
  60         strcpy(temp, str);
  61         return temp;
  62 }
  63 #endif
  64
  65
  66 #ifdef NEED_STRERROR
  67 char *
  68 strerror(int error)
  69 {
  70         extern char *sys_errlist[];
  71         extern int sys_nerr;
  72         static char buf[32];
  73
  74         if ((error <= sys_nerr) && (error > 0)) {
  75                 return sys_errlist[error];
  76         }
  77
  78         sprintf(buf, "Unknown error: %d", error);
  79         return buf;
  80 }
  81 #endif
  82
  83
  84 #ifdef NEED_STRCASECMP
  85 int
  86 strcasecmp(char *left, char *right)
  87 {
  88         while (*left && (MkLower(*left) == MkLower(*right))) {
  89                 left++;
  90                 right++;
  91         }
  92         return MkLower(*left) - MkLower(*right);
  93 }
  94 #endif
  95
  96
  97 #ifdef NEED_SETSID
  98 int
  99 setsid(void)
 100 {
 101         int     newpgrp;
 102 # if defined(BSD)
 103         int     fd;
 104 #  if defined(POSIX)
 105         newpgrp = setpgid((pid_t)0, getpid());
 106 #  else
 107         newpgrp = setpgrp(0, getpid());
 108 #  endif
 109         if ((fd = open(_PATH_TTY, 2)) >= 0)
 110         {
 111                 ioctl(fd, TIOCNOTTY, NULL);
 112                 close(fd);
 113         }
 114 # else /*BSD*/
 115         newpgrp = setpgrp();
 116
 117         close(STDIN);   open(_PATH_DEVNULL, 0);
 118         close(STDOUT);  open(_PATH_DEVNULL, 1);
 119         close(STDERR);  open(_PATH_DEVNULL, 2);
 120 # endif /*BSD*/
 121         return newpgrp;
 122 }
 123 #endif /*NEED_SETSID*/
 124
 125
 126 #ifdef NEED_GETDTABLESIZE
 127 int
 128 getdtablesize(void)
 129 {
 130 #ifdef _SC_OPEN_MAX
 131         return sysconf(_SC_OPEN_MAX);
 132 #else
 133         return _POSIX_OPEN_MAX;
 134 #endif
 135 }
 136 #endif
 137
 138
 139 #ifdef NEED_FLOCK
 140 /* The following flock() emulation snarfed intact *) from the HP-UX
 141  * "BSD to HP-UX porting tricks" maintained by
 142  * system@alchemy.chem.utoronto.ca (System Admin (Mike Peterson))
 143  * from the version "last updated: 11-Jan-1993"
 144  * Snarfage done by Jarkko Hietaniemi <Jarkko.Hietaniemi@hut.fi>
 145  * *) well, almost, had to K&R the function entry, HPUX "cc"
 146  * does not grok ANSI function prototypes */
 147
 148 /*
 149  * flock (fd, operation)
 150  *
 151  * This routine performs some file locking like the BSD 'flock'
 152  * on the object described by the int file descriptor 'fd',
 153  * which must already be open.
 154  *
 155  * The operations that are available are:
 156  *
 157  * LOCK_SH  -  get a shared lock.
 158  * LOCK_EX  -  get an exclusive lock.
 159  * LOCK_NB  -  don't block (must be ORed with LOCK_SH or LOCK_EX).
 160  * LOCK_UN  -  release a lock.
 161  *
 162  * Return value: 0 if lock successful, -1 if failed.
 163  *
 164  * Note that whether the locks are enforced or advisory is
 165  * controlled by the presence or absence of the SETGID bit on
 166  * the executable.
 167  *
 168  * Note that there is no difference between shared and exclusive
 169  * locks, since the 'lockf' system call in SYSV doesn't make any
 170  * distinction.
 171  *
 172  * The file "<sys/file.h>" should be modified to contain the definitions
 173  * of the available operations, which must be added manually (see below
 174  * for the values).
 175  */
 176
 177 /* this code has been reformatted by vixie */
 178
 179 int
 180 flock(int fd, int operation)
 181 {
 182         int i;
 183
 184         switch (operation) {
 185         case LOCK_SH:           /* get a shared lock */
 186         case LOCK_EX:           /* get an exclusive lock */
 187                 i = lockf (fd, F_LOCK, 0);
 188                 break;
 189
 190         case LOCK_SH|LOCK_NB:   /* get a non-blocking shared lock */
 191         case LOCK_EX|LOCK_NB:   /* get a non-blocking exclusive lock */
 192                 i = lockf (fd, F_TLOCK, 0);
 193                 if (i == -1)
 194                         if ((errno == EAGAIN) || (errno == EACCES))
 195                                 errno = EWOULDBLOCK;
 196                 break;
 197
 198         case LOCK_UN:           /* unlock */
 199                 i = lockf (fd, F_ULOCK, 0);
 200                 break;
 201
 202         default:                /* can't decipher operation */
 203                 i = -1;
 204                 errno = EINVAL;
 205                 break;
 206         }
 207
 208         return (i);
 209 }
 210 #endif /*NEED_FLOCK*/
 211
 212
 213 #ifdef NEED_SETENV
 214 int
 215 setenv(char *name, char *value, int overwrite)
 216 {
 217         char *tmp;
 218
 219         if (overwrite && getenv(name))
 220                 return -1;
 221
 222         if (!(tmp = malloc(strlen(name) + strlen(value) + 2))) {
 223                 errno = ENOMEM;
 224                 return -1;
 225         }
 226
 227         sprintf(tmp, "%s=%s", name, value);
 228         return putenv(tmp);     /* intentionally orphan 'tmp' storage */
 229 }
 230 #endif