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Commit 5b7ac017 authored by JINMEI Tatuya's avatar JINMEI Tatuya
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[2091a] added revised version of LabelSequence (de)serialization

parent 9cc4ac55
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src/lib/dns/labelsequence.cc
View file @ 5b7ac017
......@@ -51,6 +51,37 @@ LabelSequence::LabelSequence(const uint8_t* data,
}
}
LabelSequence::LabelSequence(const void* buf) {
if (buf == NULL) {
isc_throw(BadValue,
"Null pointer passed to LabelSequence constructor");
}
const uint8_t* bp = reinterpret_cast<const uint8_t*>(buf);
first_label_ = 0;
const uint8_t offsets_len = *bp++;
if (offsets_len == 0 || offsets_len > Name::MAX_LABELS) {
isc_throw(BadValue,
"Bad offsets len in serialized LabelSequence data: "
<< static_cast<unsigned int>(offsets_len));
}
last_label_ = offsets_len - 1;
offsets_ = bp;
data_ = bp + offsets_len;
// Check the integrity on the offsets and the name data
const uint8_t* dp = data_;
for (size_t cur_offset = 0; cur_offset < offsets_len; ++cur_offset) {
if (offsets_[cur_offset] > Name::MAX_LABELLEN ||
dp - data_ != offsets_[cur_offset]) {
isc_throw(BadValue,
"Broken offset or name data in serialized "
"LabelSequence data");
}
dp += (1 + *dp);
}
}
const uint8_t*
LabelSequence::getData(size_t *len) const {
......@@ -74,6 +105,33 @@ LabelSequence::getDataLength() const {
return (offsets_[last_label_] - offsets_[first_label_] + last_label_len);
}
size_t
LabelSequence::getSerializedLength() const {
return (1 + getLabelCount() + getDataLength());
}
void
LabelSequence::serialize(void* buf, size_t buf_len) const {
const size_t expected_size = getSerializedLength();
if (expected_size > buf_len) {
isc_throw(BadValue, "buffer too short for LabelSequence::serialize");
}
const size_t offsets_len = getLabelCount();
assert(offsets_len < 256); // should be in the 8-bit range
uint8_t* bp = reinterpret_cast<uint8_t*>(buf);
*bp++ = offsets_len;
for (size_t i = 0; i < offsets_len; ++i) {
*bp++ = offsets_[first_label_ + i] - offsets_[first_label_];
}
const size_t ndata_len = getDataLength();
memcpy(bp, &data_[offsets_[first_label_]], ndata_len);
bp += ndata_len;
assert(bp - reinterpret_cast<const uint8_t*>(buf) == expected_size);
}
bool
LabelSequence::equals(const LabelSequence& other, bool case_sensitive) const {
size_t len, other_len;
......
src/lib/dns/labelsequence.h
View file @ 5b7ac017
......@@ -79,6 +79,24 @@ public:
const uint8_t* offsets,
size_t offsets_size);
/// \brief Constructor from serialized image.
///
/// This constructor restores a \c LabelSequence object from a serialized
/// binary image previously generated by \c serialize(). Any other input
/// to this constructor will result in undefined behavior.
///
/// The binary data passed to this constructor MUST remain in scope and
/// MUST NOT be modified during the lifetime of this LabelSequence.
///
/// As long as the data were previously generated by a call to
/// \c serialize() on a valid \c LabelSequence object, this constructor
/// should succeed. While any other case is undefined, this constructor
/// may perform some validity checks internally for safety. Nevertheless,
/// applications must not rely on such checks.
///
/// \param buf Pointer to the serialized image generated by \c serialize().
explicit LabelSequence(const void* buf);
/// \brief Copy constructor.
///
/// \note The associated data MUST remain in scope during the lifetime
......@@ -136,6 +154,52 @@ public:
/// \return The length of the data of the label sequence in octets.
size_t getDataLength() const;
/// \brief Max possible size of serialized image generated by \c serialize
///
/// A fixed length buffer of this size can be always passed to
/// \c serialize() safely. (But the application shouldn't use the
/// specific size value; it must use this constant variable).
static const size_t MAX_SERIALIZED_LENGTH =
Name::MAX_WIRE + Name::MAX_LABELS + 1;
/// \brief Return the size of serialized image of the \c LabelSequence.
///
/// This method calculates the size of necessary storage to store
/// serialized image of this \c LabelSequence (which would be dumped by
/// \c serialize()) and returns it. The size is in bytes.
///
/// \throw none.
///
/// \return The size of serialized image of the \c LabelSequence.
size_t getSerializedLength() const;
/// \brief Serialize the \c LabelSequence object in to a buffer.
///
/// This method dumps a serialized image of this \c LabelSequence
/// that would be restored by the corresponding constructor into the
/// given buffer. The buffer size must be at least equal to
/// the value returned by getSerializedLength() (it can be larger than
/// that).
///
/// The serialized image would be as follows:
/// - olen: number of offsets (1 byte)
/// - binary sequence of offsets (olen bytes, verbatim copy of offsets_
/// of this size)
/// - binary sequence of name data (length determined by itself, verbatim
/// copy of data_ of the corresponding size)
///
/// Applications must use the resulting image opaque value and must not
/// use it for other purposes than input to the corresponding constructor
/// to restore it. Application behavior that assumes the specific
/// organization of the image is not guaranteed.
///
/// \throw isc::BadValue buf_len is too short (this method never throws
/// otherwise)
///
/// \param buf Pointer to the placeholder to dump the serialized image
/// \param buf_len The size of available region in \c buf
void serialize(void* buf, size_t buf_len) const;
/// \brief Compares two label sequences for equality.
///
/// Performs a (optionally case-insensitive) comparison between this
......
src/lib/dns/tests/labelsequence_unittest.cc
View file @ 5b7ac017
......@@ -21,11 +21,17 @@
#include <boost/functional/hash.hpp>
#include <string>
#include <vector>
#include <utility>
#include <set>
using namespace isc::dns;
using namespace std;
// XXX: this is defined as class static constants, but some compilers
// seemingly cannot find the symbols when used in the EXPECT_xxx macros.
const size_t LabelSequence::MAX_SERIALIZED_LENGTH;
namespace {
class LabelSequenceTest : public ::testing::Test {
......@@ -38,6 +44,13 @@ public:
n10("\\000xample.org"),
n11("\\000xample.com"),
n12("\\000xamplE.com"),
n_maxlabel("0.1.2.3.4.5.6.7.8.9.0.1.2.3.4.5.6.7.8.9."
"0.1.2.3.4.5.6.7.8.9.0.1.2.3.4.5.6.7.8.9."
"0.1.2.3.4.5.6.7.8.9.0.1.2.3.4.5.6.7.8.9."
"0.1.2.3.4.5.6.7.8.9.0.1.2.3.4.5.6.7.8.9."
"0.1.2.3.4.5.6.7.8.9.0.1.2.3.4.5.6.7.8.9."
"0.1.2.3.4.5.6.7.8.9.0.1.2.3.4.5.6.7.8.9."
"0.1.2.3.4.5.6"),
ls1(n1), ls2(n2), ls3(n3), ls4(n4), ls5(n5),
ls6(n6), ls7(n7), ls8(n8),
ls9(n9), ls10(n10), ls11(n11), ls12(n12)
......@@ -46,6 +59,7 @@ public:
// the labelsequences
Name n1, n2, n3, n4, n5, n6, n7, n8;
Name n9, n10, n11, n12;
const Name n_maxlabel;
LabelSequence ls1, ls2, ls3, ls4, ls5, ls6, ls7, ls8;
LabelSequence ls9, ls10, ls11, ls12;
......@@ -654,14 +668,7 @@ TEST_F(LabelSequenceTest, toText) {
"012345678901234567890123456789"
"0123456789012345678901234567890", ls_long1.toText());
Name n_long2("0.1.2.3.4.5.6.7.8.9.0.1.2.3.4.5.6.7.8.9."
"0.1.2.3.4.5.6.7.8.9.0.1.2.3.4.5.6.7.8.9."
"0.1.2.3.4.5.6.7.8.9.0.1.2.3.4.5.6.7.8.9."
"0.1.2.3.4.5.6.7.8.9.0.1.2.3.4.5.6.7.8.9."
"0.1.2.3.4.5.6.7.8.9.0.1.2.3.4.5.6.7.8.9."
"0.1.2.3.4.5.6.7.8.9.0.1.2.3.4.5.6.7.8.9."
"0.1.2.3.4.5.6");
LabelSequence ls_long2(n_long2);
LabelSequence ls_long2(n_maxlabel);
EXPECT_EQ("0.1.2.3.4.5.6.7.8.9.0.1.2.3.4.5.6.7.8.9."
"0.1.2.3.4.5.6.7.8.9.0.1.2.3.4.5.6.7.8.9."
......@@ -843,4 +850,120 @@ TEST(LabelSequence, badRawConstruction) {
EXPECT_THROW(LabelSequence(data, offsets_noincrease, 3), isc::BadValue);
}
TEST_F(LabelSequenceTest, serializedLength) {
// Initially, the labels are "example.org."
const size_t base_size = n1.getLength() + n1.getLabelCount() + 1;
EXPECT_EQ(base_size, ls1.getSerializedLength());
// Strip off the trailing dot. We'll lose 1 label and 1-byte data
LabelSequence ls1_stripped = ls1;
ls1_stripped.stripRight(1);
EXPECT_EQ(base_size - 2, ls1_stripped.getSerializedLength());
// Strip off the leftmost label (example). We'll lose 1 label and
// 8-byte data (1 + len('example')).
ls1_stripped = ls1;
ls1_stripped.stripLeft(1);
EXPECT_EQ(base_size - 9, ls1_stripped.getSerializedLength());
// Longest possible serialized length. Confirm there's indeed such a case.
EXPECT_EQ(LabelSequence::MAX_SERIALIZED_LENGTH,
LabelSequence(n_maxlabel).getSerializedLength());
}
TEST_F(LabelSequenceTest, serialize) {
// placeholder for serialized data
uint8_t labels_buf[LabelSequence::MAX_SERIALIZED_LENGTH];
// vector to store expected and actual data
vector<LabelSequence> actual_labelseqs;
typedef pair<size_t, const uint8_t*> DataPair;
vector<DataPair> expected;
// An absolute sequence directly constructed from a valid name.
// labels = 3, offset sequence = 0, 8, 12, data = "example.com."
actual_labelseqs.push_back(ls1);
const uint8_t const expected_data1[] = {
3, 0, 8, 12, 7, 'e', 'x', 'a', 'm', 'p', 'l', 'e',
3, 'o', 'r', 'g', 0 };
expected.push_back(DataPair(sizeof(expected_data1), expected_data1));
// Strip the original one from right.
// labels = 2, offset sequence = 0, 8, data = "example.com" (non absolute)
LabelSequence ls_rstripped = ls1;
ls_rstripped.stripRight(1);
actual_labelseqs.push_back(ls_rstripped);
const uint8_t const expected_data2[] = {
2, 0, 8, 7, 'e', 'x', 'a', 'm', 'p', 'l', 'e',
3, 'o', 'r', 'g'};
expected.push_back(DataPair(sizeof(expected_data2), expected_data2));
// Strip the original one from left.
// labels = 2, offset sequence = 0, 4, data = "com."
// Note that offsets are adjusted so that they begin with 0.
LabelSequence ls_lstripped = ls1;
ls_lstripped.stripLeft(1);
actual_labelseqs.push_back(ls_lstripped);
const uint8_t const expected_data3[] = {
2, 0, 4, 3, 'o', 'r', 'g', 0 };
expected.push_back(DataPair(sizeof(expected_data3), expected_data3));
// Root label.
LabelSequence ls_root(Name::ROOT_NAME());
actual_labelseqs.push_back(ls_root);
const uint8_t const expected_data4[] = { 1, 0, 0 };
expected.push_back(DataPair(sizeof(expected_data4), expected_data4));
// Non absolute single-label.
LabelSequence ls_single = ls_rstripped;
ls_single.stripRight(1);
actual_labelseqs.push_back(ls_single);
const uint8_t const expected_data5[] = {
1, 0, 7, 'e', 'x', 'a', 'm', 'p', 'l', 'e' };
expected.push_back(DataPair(sizeof(expected_data5), expected_data5));
// For each data set, serialize the labels and compare the data to the
// expected one.
vector<DataPair>::const_iterator it = expected.begin();
vector<LabelSequence>::const_iterator itl = actual_labelseqs.begin();
for (; it != expected.end(); ++it, ++itl) {
SCOPED_TRACE(itl->toText());
const size_t serialized_len = itl->getSerializedLength();
ASSERT_GE(LabelSequence::MAX_SERIALIZED_LENGTH, serialized_len);
itl->serialize(labels_buf, serialized_len);
EXPECT_EQ(it->first, serialized_len);
EXPECT_EQ(0, memcmp(it->second, labels_buf, serialized_len));
EXPECT_EQ(NameComparisonResult::EQUAL,
LabelSequence(labels_buf).compare(*itl).getRelation());
}
EXPECT_THROW(ls1.serialize(labels_buf, ls1.getSerializedLength() - 1),
isc::BadValue);
}
TEST_F(LabelSequenceTest, badDeserialize) {
EXPECT_THROW(LabelSequence(NULL), isc::BadValue);
const uint8_t const zero_offsets[] = { 0 };
EXPECT_THROW(LabelSequence ls(zero_offsets), isc::BadValue);
const uint8_t const toomany_offsets[] = { Name::MAX_LABELS + 1 };
EXPECT_THROW(LabelSequence ls(toomany_offsets), isc::BadValue);
// exceed MAX_LABEL_LEN
const uint8_t const offsets_toolonglabel[] = { 2, 0, 64 };
EXPECT_THROW(LabelSequence ls(offsets_toolonglabel), isc::BadValue);
// Inconsistent data: an offset is lower than the previous offset
const uint8_t const offsets_lower[] = { 3, // # of offsets
0, 2, 1, // offsets
1, 'a', 1, 'b', 0};
EXPECT_THROW(LabelSequence ls(offsets_lower), isc::BadValue);
// Inconsistent data: an offset is equal to the previous offset
const uint8_t const offsets_noincrease[] = { 2, 0, 0, 0, 0 };
EXPECT_THROW(LabelSequence ls(offsets_noincrease), isc::BadValue);
}
}
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