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/*
** Copyright 2000 Double Precision, Inc.
** See COPYING for distribution information.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include "maildirmisc.h"
static const char rcsid[]="$Id: maildiropen.c,v 1.7 2000/12/10 04:43:44 mrsam Exp $";
char *maildir_getlink(const char *filename)
{
#if HAVE_READLINK
size_t bufsiz;
char *buf;
bufsiz=0;
buf=0;
for (;;)
{
int n;
if (buf) free(buf);
bufsiz += 256;
if ((buf=malloc(bufsiz)) == 0)
{
perror("malloc");
return (0);
}
if ((n=readlink(filename, buf, bufsiz)) < 0)
{
free(buf);
return (0);
}
if (n < bufsiz)
{
buf[n]=0;
break;
}
}
return (buf);
#else
return (0);
#endif
}
int maildir_semisafeopen(const char *path, int mode, int perm)
{
#if HAVE_READLINK
char *l=maildir_getlink(path);
if (l)
{
int f;
if (*l != '/')
{
char *q=malloc(strlen(path)+strlen(l)+2);
char *s;
if (!q)
{
free(l);
return (-1);
}
strcpy(q, path);
if ((s=strchr(q, '/')) != 0)
s[1]=0;
else *q=0;
strcat(q, l);
free(l);
l=q;
}
f=maildir_safeopen(l, mode, perm);
free(l);
return (f);
}
#endif
return (maildir_safeopen(path, mode, perm));
}
int maildir_safeopen(const char *path, int mode, int perm)
{
struct stat stat1, stat2;
int fd=open(path, mode
#ifdef O_NONBLOCK
| O_NONBLOCK
#else
| O_NDELAY
#endif
, perm);
if (fd < 0) return (fd);
if (fcntl(fd, F_SETFL, (mode & O_APPEND)) || fstat(fd, &stat1)
|| lstat(path, &stat2))
{
close(fd);
return (-1);
}
if (stat1.st_dev != stat2.st_dev || stat1.st_ino != stat2.st_ino)
{
close(fd);
errno=ENOENT;
return (-1);
}
return (fd);
}
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