stdlib/FreeBSD/realpath.c.patch

   1 --- realpath.c.orig     2003-08-15 19:22:17.000000000 -0700
   2 +++ realpath.c  2004-12-04 14:47:52.000000000 -0800
   3 @@ -35,13 +35,35 @@
   4  #include "namespace.h"
   5  #include <sys/param.h>
   6  #include <sys/stat.h>
   7 +#include <sys/mount.h>
   8
   9  #include <errno.h>
  10  #include <stdlib.h>
  11  #include <string.h>
  12  #include <unistd.h>
  13 +#include <sys/attr.h>
  14 +#include <sys/vnode.h>
  15  #include "un-namespace.h"
  16
  17 +struct attrs {
  18 +       u_int32_t len;
  19 +       attrreference_t name;
  20 +       dev_t dev;
  21 +       fsobj_type_t type;
  22 +       fsobj_id_t id;
  23 +       char buf[PATH_MAX];
  24 +};
  25 +
  26 +static struct attrlist alist = {
  27 +       ATTR_BIT_MAP_COUNT,
  28 +       0,
  29 +       ATTR_CMN_NAME | ATTR_CMN_DEVID | ATTR_CMN_OBJTYPE | ATTR_CMN_OBJID,
  30 +       0,
  31 +       0,
  32 +       0,
  33 +       0,
  34 +};
  35 +
  36  /*
  37   * char *realpath(const char *path, char resolved[PATH_MAX]);
  38   *
  39 @@ -52,13 +74,25 @@
  40  char *
  41  realpath(const char *path, char resolved[PATH_MAX])
  42  {
  43 +       struct attrs attrs;
  44         struct stat sb;
  45         char *p, *q, *s;
  46 -       size_t left_len, resolved_len;
  47 +       size_t left_len, resolved_len, save_resolved_len;
  48         unsigned symlinks;
  49 -       int serrno, slen;
  50 +       int serrno, slen, useattrs, islink;
  51         char left[PATH_MAX], next_token[PATH_MAX], symlink[PATH_MAX];
  52 +       dev_t dev, lastdev;
  53 +       struct statfs sfs;
  54 +       static dev_t rootdev;
  55 +       static int rootdev_inited = 0;
  56 +       ino_t inode;
  57
  58 +       if (!rootdev_inited) {
  59 +               rootdev_inited = 1;
  60 +               if (stat("/", &sb) < 0)
  61 +                       return (NULL);
  62 +               rootdev = sb.st_dev;
  63 +       }
  64         serrno = errno;
  65         symlinks = 0;
  66         if (path[0] == '/') {
  67 @@ -80,6 +114,12 @@
  68                 errno = ENAMETOOLONG;
  69                 return (NULL);
  70         }
  71 +       if (resolved_len > 1) {
  72 +               if (stat(resolved, &sb) < 0)
  73 +                       return (NULL);
  74 +               lastdev = sb.st_dev;
  75 +       } else
  76 +               lastdev = rootdev;
  77
  78         /*
  79          * Iterate over path components in `left'.
  80 @@ -127,6 +167,13 @@
  81                 }
  82
  83                 /*
  84 +                * Save resolved_len, so that we can later null out
  85 +                * the the appended next_token, and replace with the
  86 +                * real name (matters on case-insensitive filesystems).
  87 +                */
  88 +               save_resolved_len = resolved_len;
  89 +
  90 +               /*
  91                  * Append the next path component and lstat() it. If
  92                  * lstat() fails we still can return successfully if
  93                  * there are no more path components left.
  94 @@ -136,14 +183,72 @@
  95                         errno = ENAMETOOLONG;
  96                         return (NULL);
  97                 }
  98 -               if (lstat(resolved, &sb) != 0) {
  99 +               if (getattrlist(resolved, &alist, &attrs, sizeof(attrs), FSOPT_NOFOLLOW) == 0) {
 100 +                       useattrs = 1;
 101 +                       islink = (attrs.type == VLNK);
 102 +                       dev = attrs.dev;
 103 +                       inode = attrs.id.fid_objno;
 104 +               } else if (errno == EOPNOTSUPP || errno == EINVAL) {
 105 +                       if ((useattrs = lstat(resolved, &sb)) == 0) {
 106 +                               islink = S_ISLNK(sb.st_mode);
 107 +                               dev = sb.st_dev;
 108 +                               inode = sb.st_ino;
 109 +                       }
 110 +               } else
 111 +                       useattrs = -1;
 112 +               if (useattrs < 0) {
 113                         if (errno == ENOENT && p == NULL) {
 114                                 errno = serrno;
 115                                 return (resolved);
 116                         }
 117                         return (NULL);
 118                 }
 119 -               if (S_ISLNK(sb.st_mode)) {
 120 +               if (dev != lastdev) {
 121 +                       /*
 122 +                        * We have crossed a mountpoint.  For volumes like UDF
 123 +                        * the getattrlist name may not match the actual
 124 +                        * mountpoint, so we just copy the mountpoint directly.
 125 +                        * (3703138).  However, the mountpoint may not be
 126 +                        * accessible, as when chroot-ed, so check first.
 127 +                        * There may be a file on the chroot-ed volume with
 128 +                        * the same name as the mountpoint, so compare device
 129 +                        * and inode numbers.
 130 +                        */
 131 +                       lastdev = dev;
 132 +                       if (statfs(resolved, &sfs) == 0 && lstat(sfs.f_mntonname, &sb) == 0 && dev == sb.st_dev && inode == sb.st_ino) {
 133 +                               /*
 134 +                                * However, it's possible that the mountpoint
 135 +                                * path matches, even though it isn't the real
 136 +                                * path in the chroot-ed environment, so check
 137 +                                * that each component of the mountpoint
 138 +                                * is a directory (and not a symlink)
 139 +                                */
 140 +                               char temp[MNAMELEN];
 141 +                               char *cp;
 142 +                               int ok = 1;
 143 +
 144 +                               strcpy(temp, sfs.f_mntonname);
 145 +                               for(;;) {
 146 +                                       if ((cp = strrchr(temp, '/')) == NULL) {
 147 +                                               ok = 0;
 148 +                                               break;
 149 +                                       }
 150 +                                       if (cp <= temp)
 151 +                                               break;
 152 +                                       *cp = 0;
 153 +                                       if (lstat(temp, &sb) < 0 || (sb.st_mode & S_IFMT) != S_IFDIR) {
 154 +                                               ok = 0;
 155 +                                               break;
 156 +                                       }
 157 +                               }
 158 +                               if (ok) {
 159 +                                       resolved_len = strlcpy(resolved, sfs.f_mntonname, PATH_MAX);
 160 +                                       continue;
 161 +                               }
 162 +                       }
 163 +                       /* if we fail, use the other methods. */
 164 +               }
 165 +               if (islink) {
 166                         if (symlinks++ > MAXSYMLINKS) {
 167                                 errno = ELOOP;
 168                                 return (NULL);
 169 @@ -155,6 +260,7 @@
 170                         if (symlink[0] == '/') {
 171                                 resolved[1] = 0;
 172                                 resolved_len = 1;
 173 +                               lastdev = rootdev;
 174                         } else if (resolved_len > 1) {
 175                                 /* Strip the last path component. */
 176                                 resolved[resolved_len - 1] = '\0';
 177 @@ -184,7 +290,30 @@
 178                                 }
 179                         }
 180                         left_len = strlcpy(left, symlink, sizeof(left));
 181 +               } else if (useattrs) {
 182 +                       /*
 183 +                        * attrs already has the real name.
 184 +                        */
 185 +
 186 +                       resolved[save_resolved_len] = '\0';
 187 +                       resolved_len = strlcat(resolved, (const char *)&attrs.name + attrs.name.attr_dataoffset, PATH_MAX);
 188 +                       if (resolved_len >= PATH_MAX) {
 189 +                               errno = ENAMETOOLONG;
 190 +                               return (NULL);
 191 +                       }
 192                 }
 193 +               /*
 194 +                * For the case of useattrs == 0, we could scan the directory
 195 +                * and try to match the inode.  There are many problems with
 196 +                * this: (1) the directory may not be readable, (2) for multiple
 197 +                * hard links, we would find the first, but not necessarily
 198 +                * the one specified in the path, (3) we can't try to do
 199 +                * a case-insensitive search to match the right one in (2),
 200 +                * because the underlying filesystem may do things like
 201 +                * decompose composed characters.  For most cases, doing
 202 +                * nothing is the right thing when useattrs == 0, so we punt
 203 +                * for now.
 204 +                */
 205         }
 206
 207         /*