/* Wrapper to see if two symlinks act the same. */
static void
check_same_link (char const *name1, char const *name2)
{
struct stat st1;
struct stat st2;
char *contents1;
char *contents2;
ASSERT (lstat (name1, &st1) == 0);
ASSERT (lstat (name2, &st2) == 0);
contents1 = areadlink_with_size (name1, st1.st_size);
contents2 = areadlink_with_size (name2, st2.st_size);
ASSERT (contents1);
ASSERT (contents2);
ASSERT (strcmp (contents1, contents2) == 0);
if (!LINK_FOLLOWS_SYMLINKS)
ASSERT (SAME_INODE (st1, st2));
free (contents1);
free (contents2);
}
char *
canonicalize_filename_mode (const char *name, canonicalize_mode_t can_mode)
{
char *rname, *dest, *extra_buf = NULL;
char const *start;
char const *end;
char const *rname_limit;
size_t extra_len = 0;
Hash_table *ht = NULL;
int saved_errno;
if (name == NULL)
{
errno = EINVAL;
return NULL;
}
if (name[0] == '\0')
{
errno = ENOENT;
return NULL;
}
if (name[0] != '/')
{
rname = xgetcwd ();
if (!rname)
return NULL;
dest = strchr (rname, '\0');
if (dest - rname < PATH_MAX)
{
char *p = xrealloc (rname, PATH_MAX);
dest = p + (dest - rname);
rname = p;
rname_limit = rname + PATH_MAX;
}
else
{
rname_limit = dest;
}
}
else
{
rname = xmalloc (PATH_MAX);
rname_limit = rname + PATH_MAX;
rname[0] = '/';
dest = rname + 1;
if (DOUBLE_SLASH_IS_DISTINCT_ROOT && name[1] == '/')
*dest++ = '/';
}
for (start = name; *start; start = end)
{
/* Skip sequence of multiple file name separators. */
while (*start == '/')
++start;
/* Find end of component. */
for (end = start; *end && *end != '/'; ++end)
/* Nothing. */;
if (end - start == 0)
break;
else if (end - start == 1 && start[0] == '.')
/* nothing */;
else if (end - start == 2 && start[0] == '.' && start[1] == '.')
{
/* Back up to previous component, ignore if at root already. */
if (dest > rname + 1)
while ((--dest)[-1] != '/');
if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1
&& *dest == '/')
dest++;
}
else
{
struct stat st;
if (dest[-1] != '/')
*dest++ = '/';
if (dest + (end - start) >= rname_limit)
{
ptrdiff_t dest_offset = dest - rname;
size_t new_size = rname_limit - rname;
if (end - start + 1 > PATH_MAX)
new_size += end - start + 1;
else
new_size += PATH_MAX;
rname = xrealloc (rname, new_size);
rname_limit = rname + new_size;
dest = rname + dest_offset;
}
dest = memcpy (dest, start, end - start);
dest += end - start;
*dest = '\0';
if (lstat (rname, &st) != 0)
{
saved_errno = errno;
if (can_mode == CAN_EXISTING)
goto error;
if (can_mode == CAN_ALL_BUT_LAST)
{
if (end[strspn (end, "/")] || saved_errno != ENOENT)
goto error;
continue;
}
st.st_mode = 0;
}
if (S_ISLNK (st.st_mode))
{
char *buf;
size_t n, len;
/* Detect loops. We cannot use the cycle-check module here,
since it's actually possible to encounter the same symlink
more than once in a given traversal. However, encountering
the same symlink,NAME pair twice does indicate a loop. */
if (seen_triple (&ht, name, &st))
{
if (can_mode == CAN_MISSING)
continue;
saved_errno = ELOOP;
goto error;
}
buf = areadlink_with_size (rname, st.st_size);
if (!buf)
{
if (can_mode == CAN_MISSING && errno != ENOMEM)
continue;
saved_errno = errno;
goto error;
}
n = strlen (buf);
len = strlen (end);
if (!extra_len)
{
extra_len =
((n + len + 1) > PATH_MAX) ? (n + len + 1) : PATH_MAX;
extra_buf = xmalloc (extra_len);
}
else if ((n + len + 1) > extra_len)
{
extra_len = n + len + 1;
extra_buf = xrealloc (extra_buf, extra_len);
}
/* Careful here, end may be a pointer into extra_buf... */
memmove (&extra_buf[n], end, len + 1);
name = end = memcpy (extra_buf, buf, n);
if (buf[0] == '/')
{
dest = rname + 1; /* It's an absolute symlink */
if (DOUBLE_SLASH_IS_DISTINCT_ROOT && buf[1] == '/')
*dest++ = '/';
}
else
{
/* Back up to previous component, ignore if at root
already: */
if (dest > rname + 1)
while ((--dest)[-1] != '/');
if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1
&& *dest == '/')
dest++;
}
free (buf);
}
else
{
if (!S_ISDIR (st.st_mode) && *end && (can_mode != CAN_MISSING))
{
saved_errno = ENOTDIR;
goto error;
}
}
}
}
if (dest > rname + 1 && dest[-1] == '/')
--dest;
if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1 && *dest == '/')
dest++;
*dest = '\0';
if (rname_limit != dest + 1)
rname = xrealloc (rname, dest - rname + 1);
free (extra_buf);
if (ht)
hash_free (ht);
return rname;
error:
free (extra_buf);
free (rname);
if (ht)
hash_free (ht);
errno = saved_errno;
return NULL;
}
char *
canonicalize_filename_mode (const char *name, canonicalize_mode_t can_mode)
{
char *rname, *dest, *extra_buf = NULL;
char const *start;
char const *end;
char const *rname_limit;
size_t extra_len = 0;
Hash_table *ht = NULL;
int saved_errno;
int can_flags = can_mode & ~CAN_MODE_MASK;
bool logical = can_flags & CAN_NOLINKS;
size_t prefix_len;
can_mode &= CAN_MODE_MASK;
if (MULTIPLE_BITS_SET (can_mode))
{
errno = EINVAL;
return NULL;
}
if (name == NULL)
{
errno = EINVAL;
return NULL;
}
if (name[0] == '\0')
{
errno = ENOENT;
return NULL;
}
/* This is always zero for Posix hosts, but can be 2 for MS-Windows
and MS-DOS X:/foo/bar file names. */
prefix_len = FILE_SYSTEM_PREFIX_LEN (name);
if (!IS_ABSOLUTE_FILE_NAME (name))
{
rname = xgetcwd ();
if (!rname)
return NULL;
dest = strchr (rname, '\0');
if (dest - rname < PATH_MAX)
{
char *p = xrealloc (rname, PATH_MAX);
dest = p + (dest - rname);
rname = p;
rname_limit = rname + PATH_MAX;
}
else
{
rname_limit = dest;
}
start = name;
prefix_len = FILE_SYSTEM_PREFIX_LEN (rname);
}
else
{
rname = xmalloc (PATH_MAX);
rname_limit = rname + PATH_MAX;
dest = rname;
if (prefix_len)
{
memcpy (rname, name, prefix_len);
dest += prefix_len;
}
*dest++ = '/';
if (DOUBLE_SLASH_IS_DISTINCT_ROOT)
{
if (ISSLASH (name[1]) && !ISSLASH (name[2]) && !prefix_len)
*dest++ = '/';
*dest = '\0';
}
start = name + prefix_len;
}
for ( ; *start; start = end)
{
/* Skip sequence of multiple file name separators. */
while (ISSLASH (*start))
++start;
/* Find end of component. */
for (end = start; *end && !ISSLASH (*end); ++end)
/* Nothing. */;
if (end - start == 0)
break;
else if (end - start == 1 && start[0] == '.')
/* nothing */;
else if (end - start == 2 && start[0] == '.' && start[1] == '.')
{
/* Back up to previous component, ignore if at root already. */
if (dest > rname + prefix_len + 1)
for (--dest; dest > rname && !ISSLASH (dest[-1]); --dest)
continue;
if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1
&& !prefix_len && ISSLASH (*dest) && !ISSLASH (dest[1]))
dest++;
}
else
{
struct stat st;
if (!ISSLASH (dest[-1]))
*dest++ = '/';
if (dest + (end - start) >= rname_limit)
{
ptrdiff_t dest_offset = dest - rname;
size_t new_size = rname_limit - rname;
if (end - start + 1 > PATH_MAX)
new_size += end - start + 1;
else
new_size += PATH_MAX;
rname = xrealloc (rname, new_size);
rname_limit = rname + new_size;
dest = rname + dest_offset;
}
dest = memcpy (dest, start, end - start);
dest += end - start;
*dest = '\0';
if (logical && (can_mode == CAN_MISSING))
{
/* Avoid the stat in this case as it's inconsequential.
i.e. we're neither resolving symlinks or testing
component existence. */
st.st_mode = 0;
}
else if ((logical ? stat (rname, &st) : lstat (rname, &st)) != 0)
{
saved_errno = errno;
if (can_mode == CAN_EXISTING)
goto error;
if (can_mode == CAN_ALL_BUT_LAST)
{
if (end[strspn (end, SLASHES)] || saved_errno != ENOENT)
goto error;
continue;
}
st.st_mode = 0;
}
if (S_ISLNK (st.st_mode))
{
char *buf;
size_t n, len;
/* Detect loops. We cannot use the cycle-check module here,
since it's actually possible to encounter the same symlink
more than once in a given traversal. However, encountering
the same symlink,NAME pair twice does indicate a loop. */
if (seen_triple (&ht, name, &st))
{
if (can_mode == CAN_MISSING)
continue;
saved_errno = ELOOP;
goto error;
}
buf = areadlink_with_size (rname, st.st_size);
if (!buf)
{
if (can_mode == CAN_MISSING && errno != ENOMEM)
continue;
saved_errno = errno;
goto error;
}
n = strlen (buf);
len = strlen (end);
if (!extra_len)
{
extra_len =
((n + len + 1) > PATH_MAX) ? (n + len + 1) : PATH_MAX;
extra_buf = xmalloc (extra_len);
}
else if ((n + len + 1) > extra_len)
{
extra_len = n + len + 1;
extra_buf = xrealloc (extra_buf, extra_len);
}
/* Careful here, end may be a pointer into extra_buf... */
memmove (&extra_buf[n], end, len + 1);
name = end = memcpy (extra_buf, buf, n);
if (IS_ABSOLUTE_FILE_NAME (buf))
{
size_t pfxlen = FILE_SYSTEM_PREFIX_LEN (buf);
if (pfxlen)
memcpy (rname, buf, pfxlen);
dest = rname + pfxlen;
*dest++ = '/'; /* It's an absolute symlink */
if (DOUBLE_SLASH_IS_DISTINCT_ROOT)
{
if (ISSLASH (buf[1]) && !ISSLASH (buf[2]) && !pfxlen)
*dest++ = '/';
*dest = '\0';
}
/* Install the new prefix to be in effect hereafter. */
prefix_len = pfxlen;
}
else
{
/* Back up to previous component, ignore if at root
already: */
if (dest > rname + prefix_len + 1)
for (--dest; dest > rname && !ISSLASH (dest[-1]); --dest)
continue;
if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1
&& ISSLASH (*dest) && !ISSLASH (dest[1]) && !prefix_len)
dest++;
}
free (buf);
}
else
{
if (!S_ISDIR (st.st_mode) && *end && (can_mode != CAN_MISSING))
{
saved_errno = ENOTDIR;
goto error;
}
}
}
}
if (dest > rname + prefix_len + 1 && ISSLASH (dest[-1]))
--dest;
if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1 && !prefix_len
&& ISSLASH (*dest) && !ISSLASH (dest[1]))
dest++;
*dest = '\0';
if (rname_limit != dest + 1)
rname = xrealloc (rname, dest - rname + 1);
free (extra_buf);
if (ht)
hash_free (ht);
return rname;
error:
free (extra_buf);
free (rname);
if (ht)
hash_free (ht);
errno = saved_errno;
return NULL;
}
