e = unescaped + strlen (unescaped);
}
+ /* Defang ".." when found as component of path. Remember that path
+ comes from the URL and might contain malicious input. */
+ if (e - b == 2 && b[0] == '.' && b[1] == '.')
+ {
+ b = "%2E%2E";
+ e = b + 6;
+ }
+
/* Walk the PATHEL string and check how many characters we'll need
- to add for file quoting. */
+ to quote. */
quoted = 0;
for (p = b; p < e; p++)
if (FILE_CHAR_TEST (*p, mask))
++quoted;
- /* e-b is the string length. Each quoted char means two additional
+ /* Calculate the length of the output string. e-b is the input
+ string length. Each quoted char introduces two additional
characters in the string, hence 2*quoted. */
outlen = (e - b) + (2 * quoted);
GROW (dest, outlen);
if (!quoted)
{
- /* If there's nothing to quote, we don't need to go through the
- string the second time. */
+ /* If there's nothing to quote, we can simply append the string
+ without processing it again. */
memcpy (TAIL (dest), b, outlen);
}
else
xfree (fname);
return unique;
}
-
-/* Return the length of URL's path. Path is considered to be
- terminated by one of '?', ';', '#', or by the end of the
- string. */
-static int
-path_length (const char *url)
-{
- const char *q = strpbrk_or_eos (url, "?;#");
- return q - url;
-}
-
-/* Find the last occurrence of character C in the range [b, e), or
- NULL, if none are present. This is equivalent to strrchr(b, c),
- except that it accepts an END argument instead of requiring the
- string to be zero-terminated. Why is there no memrchr()? */
-static const char *
-find_last_char (const char *b, const char *e, char c)
-{
- for (; e > b; e--)
- if (*e == c)
- return e;
- return NULL;
-}
\f
/* Resolve "." and ".." elements of PATH by destructively modifying
PATH and return non-zero if PATH has been modified, zero otherwise.
static int
path_simplify (char *path)
{
- char *h, *t, *end;
-
- /* Preserve the leading '/'. */
- if (path[0] == '/')
- ++path;
-
- h = path; /* hare */
- t = path; /* tortoise */
- end = path + strlen (path);
+ char *h = path; /* hare */
+ char *t = path; /* tortoise */
+ char *beg = path; /* boundary for backing the tortoise */
+ char *end = path + strlen (path);
while (h < end)
{
else if (h[0] == '.' && h[1] == '.' && (h[2] == '/' || h[2] == '\0'))
{
/* Handle "../" by retreating the tortoise by one path
- element -- but not past beggining of PATH. */
- if (t > path)
+ element -- but not past beggining. */
+ if (t > beg)
{
/* Move backwards until T hits the beginning of the
previous path element or the beginning of path. */
- for (--t; t > path && t[-1] != '/'; t--)
+ for (--t; t > beg && t[-1] != '/'; t--)
;
}
+ else
+ {
+ /* If we're at the beginning, copy the "../" literally
+ move the beginning so a later ".." doesn't remove
+ it. */
+ beg = t + 3;
+ goto regular;
+ }
h += 3;
}
- else if (*h == '/')
- {
- /* Ignore empty path elements. Supporting them well is hard
- (where do you save "http://x.com///y.html"?), and they
- don't bring any practical gain. Plus, they break our
- filesystem-influenced assumptions: allowing them would
- make "x/y//../z" simplify to "x/y/z", whereas most people
- would expect "x/z". */
- ++h;
- }
else
{
+ regular:
/* A regular path element. If H hasn't advanced past T,
simply skip to the next path element. Otherwise, copy
the path element until the next slash. */
return t != h;
}
\f
+/* Return the length of URL's path. Path is considered to be
+ terminated by one of '?', ';', '#', or by the end of the
+ string. */
+
+static int
+path_length (const char *url)
+{
+ const char *q = strpbrk_or_eos (url, "?;#");
+ return q - url;
+}
+
+/* Find the last occurrence of character C in the range [b, e), or
+ NULL, if none are present. We might want to use memrchr (a GNU
+ extension) under GNU libc. */
+
+static const char *
+find_last_char (const char *b, const char *e, char c)
+{
+ for (; e > b; e--)
+ if (*e == c)
+ return e;
+ return NULL;
+}
+
/* Merge BASE with LINK and return the resulting URI.
Either of the URIs may be absolute or relative, complete with the
foreseeable cases. It only employs minimal URL parsing, without
knowledge of the specifics of schemes.
- Perhaps this function should call path_simplify so that the callers
- don't have to call url_parse unconditionally. */
+ I briefly considered making this function call path_simplify after
+ the merging process, as rfc1738 seems to suggest. This is a bad
+ idea for several reasons: 1) it complexifies the code, and 2)
+ url_parse has to simplify path anyway, so it's wasteful to boot. */
char *
uri_merge (const char *base, const char *link)
const char *last_slash = find_last_char (base, end, '/');
if (!last_slash)
{
- /* No slash found at all. Append LINK to what we have,
- but we'll need a slash as a separator.
-
- Example: if base == "foo" and link == "qux/xyzzy", then
- we cannot just append link to base, because we'd get
- "fooqux/xyzzy", whereas what we want is
- "foo/qux/xyzzy".
-
- To make sure the / gets inserted, we set
- need_explicit_slash to 1. We also set start_insert
- to end + 1, so that the length calculations work out
- correctly for one more (slash) character. Accessing
- that character is fine, since it will be the
- delimiter, '\0' or '?'. */
- /* example: "foo?..." */
- /* ^ ('?' gets changed to '/') */
- start_insert = end + 1;
- need_explicit_slash = 1;
+ /* No slash found at all. Replace what we have with LINK. */
+ start_insert = base;
}
else if (last_slash && last_slash >= base + 2
&& last_slash[-2] == ':' && last_slash[-1] == '/')
if (modified != expected_change)
{
if (expected_change == 1)
- printf ("Expected no modification with path_simplify(\"%s\").\n",
+ printf ("Expected modification with path_simplify(\"%s\").\n",
test);
else
- printf ("Expected modification with path_simplify(\"%s\").\n",
+ printf ("Expected no modification with path_simplify(\"%s\").\n",
test);
}
xfree (test_copy);
char *test, *result;
int should_modify;
} tests[] = {
- { "", "", 0 },
- { ".", "", 1 },
- { "..", "", 1 },
- { "foo", "foo", 0 },
- { "foo/bar", "foo/bar", 0 },
- { "foo///bar", "foo/bar", 1 },
- { "foo/.", "foo/", 1 },
- { "foo/./", "foo/", 1 },
- { "foo./", "foo./", 0 },
- { "foo/../bar", "bar", 1 },
- { "foo/../bar/", "bar/", 1 },
- { "foo/bar/..", "foo/", 1 },
- { "foo/bar/../x", "foo/x", 1 },
- { "foo/bar/../x/", "foo/x/", 1 },
- { "foo/..", "", 1 },
- { "foo/../..", "", 1 },
- { "a/b/../../c", "c", 1 },
- { "./a/../b", "b", 1 }
+ { "", "", 0 },
+ { ".", "", 1 },
+ { "./", "", 1 },
+ { "..", "..", 0 },
+ { "../", "../", 0 },
+ { "foo", "foo", 0 },
+ { "foo/bar", "foo/bar", 0 },
+ { "foo///bar", "foo///bar", 0 },
+ { "foo/.", "foo/", 1 },
+ { "foo/./", "foo/", 1 },
+ { "foo./", "foo./", 0 },
+ { "foo/../bar", "bar", 1 },
+ { "foo/../bar/", "bar/", 1 },
+ { "foo/bar/..", "foo/", 1 },
+ { "foo/bar/../x", "foo/x", 1 },
+ { "foo/bar/../x/", "foo/x/", 1 },
+ { "foo/..", "", 1 },
+ { "foo/../..", "..", 1 },
+ { "foo/../../..", "../..", 1 },
+ { "foo/../../bar/../../baz", "../../baz", 1 },
+ { "a/b/../../c", "c", 1 },
+ { "./a/../b", "b", 1 }
};
int i;
int expected_change = tests[i].should_modify;
run_test (test, expected_result, expected_change);
}
-
- /* Now run all the tests with a leading slash before the test case,
- to prove that the slash is being preserved. */
- for (i = 0; i < countof (tests); i++)
- {
- char *test, *expected_result;
- int expected_change = tests[i].should_modify;
-
- test = xmalloc (1 + strlen (tests[i].test) + 1);
- sprintf (test, "/%s", tests[i].test);
-
- expected_result = xmalloc (1 + strlen (tests[i].result) + 1);
- sprintf (expected_result, "/%s", tests[i].result);
-
- run_test (test, expected_result, expected_change);
-
- xfree (test);
- xfree (expected_result);
- }
}
#endif
projects / wget / commitdiff