lib/glibc
1
0
Fork 0
mirror of https://sourceware.org/git/glibc.git synced 2025-08-07 06:43:00 +03:00
Code Activity

resolv: Support an exactly sized buffer in ns_name_pack [BZ #21359]

Browse Source 
This bug did not affect name resolution because those functions
indirectly call ns_name_pack with a buffer which is always larger
than the generated query packet, even in the case of the
longest-possible domain name.
This commit is contained in:
Florian Weimer
2017-04-13 11:56:28 +02:00
parent a7ff1da823
commit c803cb9b24
6 changed files with 260 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

139
resolv/tst-ns_name.c
View File

@@ -195,6 +195,7 @@ print_hex (const char *label, struct buffer buffer)
static void
run_test_case (struct test_case *t)
{
/* Test ns_name_unpack. */
unsigned char *unpacked = xmalloc (NS_MAXCDNAME);
int consumed = ns_name_unpack
(t->input.data, t->input.data + t->input.length,
@@ -211,16 +212,19 @@ run_test_case (struct test_case *t)
}
if (consumed != -1)
{
if (memcmp (unpacked, t->unpack_output.data, consumed) != 0)
if (memcmp (unpacked, t->unpack_output.data,
t->unpack_output.length) != 0)
{
support_record_failure ();
printf ("%s:%zu: error: wrong data from ns_name_unpack\n",
t->path, t->lineno);
print_hex ("expected:", t->unpack_output);
print_hex ("actual: ", (struct buffer) { unpacked, consumed });
print_hex ("actual: ",
(struct buffer) { unpacked, t->unpack_output.length });
return;
}
/* Test ns_name_ntop. */
char *text = xmalloc (NS_MAXDNAME);
int ret = ns_name_ntop (unpacked, text, NS_MAXDNAME);
if (ret != t->ntop_result)
@@ -243,6 +247,137 @@ run_test_case (struct test_case *t)
printf (" actual: \"%s\"\n", text);
return;
}
/* Test ns_name_pton. Unpacking does not check the
NS_MAXCDNAME limit, but packing does, so we need to
adjust the expected result. */
int expected;
if (t->unpack_output.length > NS_MAXCDNAME)
expected = -1;
else if (strcmp (text, ".") == 0)
/* The root domain is fully qualified. */
expected = 1;
else
/* The domain name is never fully qualified. */
expected = 0;
unsigned char *repacked = xmalloc (NS_MAXCDNAME);
ret = ns_name_pton (text, repacked, NS_MAXCDNAME);
if (ret != expected)
{
support_record_failure ();
printf ("%s:%zu: error: wrong result from ns_name_pton\n"
" expected: %d\n"
" actual: %d\n",
t->path, t->lineno, expected, ret);
return;
}
if (ret >= 0
&& memcmp (repacked, unpacked, t->unpack_output.length) != 0)
{
support_record_failure ();
printf ("%s:%zu: error: wrong data from ns_name_pton\n",
t->path, t->lineno);
print_hex ("expected:", t->unpack_output);
print_hex ("actual: ",
(struct buffer) { repacked, t->unpack_output.length });
return;
}
/* Test ns_name_compress, no compression case. */
if (t->unpack_output.length > NS_MAXCDNAME)
expected = -1;
else
expected = t->unpack_output.length;
memset (repacked, '$', NS_MAXCDNAME);
{
enum { ptr_count = 5 };
const unsigned char *dnptrs[ptr_count] = { repacked, };
ret = ns_name_compress (text, repacked, NS_MAXCDNAME,
dnptrs, dnptrs + ptr_count);
if (ret != expected)
{
support_record_failure ();
printf ("%s:%zu: error: wrong result from ns_name_compress\n"
" expected: %d\n"
" actual: %d\n",
t->path, t->lineno, expected, ret);
return;
}
if (ret < 0)
{
TEST_VERIFY (dnptrs[0] == repacked);
TEST_VERIFY (dnptrs[1] == NULL);
}
else
{
if (memcmp (repacked, unpacked, t->unpack_output.length) != 0)
{
support_record_failure ();
printf ("%s:%zu: error: wrong data from ns_name_compress\n",
t->path, t->lineno);
print_hex ("expected:", t->unpack_output);
print_hex ("actual: ", (struct buffer) { repacked, ret });
return;
}
TEST_VERIFY (dnptrs[0] == repacked);
if (unpacked[0] == '\0')
/* The root domain is not a compression target. */
TEST_VERIFY (dnptrs[1] == NULL);
else
{
TEST_VERIFY (dnptrs[1] == repacked);
TEST_VERIFY (dnptrs[2] == NULL);
}
}
}
/* Test ns_name_compress, full compression case. Skip this
test for invalid names and the root domain. */
if (expected >= 0 && unpacked[0] != '\0')
{
/* The destination buffer needs additional room for the
offset, the initial name, and the compression
reference. */
enum { name_offset = 259 };
size_t target_offset = name_offset + t->unpack_output.length;
size_t repacked_size = target_offset + 2;
repacked = xrealloc (repacked, repacked_size);
memset (repacked, '@', repacked_size);
memcpy (repacked + name_offset,
t->unpack_output.data, t->unpack_output.length);
enum { ptr_count = 5 };
const unsigned char *dnptrs[ptr_count]
= { repacked, repacked + name_offset, };
ret = ns_name_compress
(text, repacked + target_offset, NS_MAXCDNAME,
dnptrs, dnptrs + ptr_count);
if (ret != 2)
{
support_record_failure ();
printf ("%s:%zu: error: wrong result from ns_name_compress"
" (2)\n"
" expected: 2\n"
" actual: %d\n",
t->path, t->lineno, ret);
return;
}
if (memcmp (repacked + target_offset, "\xc1\x03", 2) != 0)
{
support_record_failure ();
printf ("%s:%zu: error: wrong data from ns_name_compress"
" (2)\n"
" expected: C103\n",
t->path, t->lineno);
print_hex ("actual: ",
(struct buffer) { repacked + target_offset, ret });
return;
}
TEST_VERIFY (dnptrs[0] == repacked);
TEST_VERIFY (dnptrs[1] == repacked + name_offset);
TEST_VERIFY (dnptrs[2] == NULL);
}
free (repacked);
}
free (text);
}