git.notmuchmail.org Git - notmuch/blob - contrib/notmuch-deliver/src/maildiropen.c

   1 /*
   2 ** Copyright 2000 Double Precision, Inc.
   3 ** See COPYING for distribution information.
   4 */
   5
   6 #if HAVE_CONFIG_H
   7 #include "config.h"
   8 #endif
   9
  10 #include        <sys/types.h>
  11 #include        <sys/stat.h>
  12 #include        <string.h>
  13 #include        <stdlib.h>
  14 #include        <time.h>
  15 #if     HAVE_UNISTD_H
  16 #include        <unistd.h>
  17 #endif
  18 #include        <stdio.h>
  19 #include        <ctype.h>
  20 #include        <errno.h>
  21 #include        <fcntl.h>
  22
  23 #include        "maildirmisc.h"
  24
  25 static const char rcsid[]="$Id: maildiropen.c,v 1.8 2003/01/19 16:39:52 mrsam Exp $";
  26
  27 char *maildir_getlink(const char *filename)
  28 {
  29 #if     HAVE_READLINK
  30 size_t  bufsiz;
  31 char    *buf;
  32
  33         bufsiz=0;
  34         buf=0;
  35
  36         for (;;)
  37         {
  38         int     n;
  39
  40                 if (buf)        free(buf);
  41                 bufsiz += 256;
  42                 if ((buf=malloc(bufsiz)) == 0)
  43                 {
  44                         perror("malloc");
  45                         return (0);
  46                 }
  47                 if ((n=readlink(filename, buf, bufsiz)) < 0)
  48                 {
  49                         free(buf);
  50                         return (0);
  51                 }
  52                 if (n < bufsiz)
  53                 {
  54                         buf[n]=0;
  55                         break;
  56                 }
  57         }
  58         return (buf);
  59 #else
  60         return (0);
  61 #endif
  62 }
  63
  64 int maildir_semisafeopen(const char *path, int mode, int perm)
  65 {
  66
  67 #if     HAVE_READLINK
  68
  69 char    *l=maildir_getlink(path);
  70
  71         if (l)
  72         {
  73         int     f;
  74
  75                 if (*l != '/')
  76                 {
  77                 char    *q=malloc(strlen(path)+strlen(l)+2);
  78                 char    *s;
  79
  80                         if (!q)
  81                         {
  82                                 free(l);
  83                                 return (-1);
  84                         }
  85
  86                         strcpy(q, path);
  87                         if ((s=strchr(q, '/')) != 0)
  88                                 s[1]=0;
  89                         else    *q=0;
  90                         strcat(q, l);
  91                         free(l);
  92                         l=q;
  93                 }
  94
  95                 f=maildir_safeopen(l, mode, perm);
  96
  97                 free(l);
  98                 return (f);
  99         }
 100 #endif
 101
 102         return (maildir_safeopen(path, mode, perm));
 103 }
 104
 105 int maildir_safeopen(const char *path, int mode, int perm)
 106 {
 107         struct  stat    stat1;
 108
 109         return maildir_safeopen_stat(path, mode, perm, &stat1);
 110 }
 111
 112 int maildir_safeopen_stat(const char *path, int mode, int perm,
 113                           struct stat *stat1)
 114 {
 115         struct  stat    stat2;
 116
 117         int     fd=open(path, mode
 118 #ifdef  O_NONBLOCK
 119                         | O_NONBLOCK
 120 #else
 121                         | O_NDELAY
 122 #endif
 123                         , perm);
 124
 125         if (fd < 0)     return (fd);
 126         if (fcntl(fd, F_SETFL, (mode & O_APPEND)) || fstat(fd, stat1)
 127             || lstat(path, &stat2))
 128         {
 129                 close(fd);
 130                 return (-1);
 131         }
 132
 133         if (stat1->st_dev != stat2.st_dev || stat1->st_ino != stat2.st_ino)
 134         {
 135                 close(fd);
 136                 errno=ENOENT;
 137                 return (-1);
 138         }
 139
 140         return (fd);
 141 }