LabelSequence::extend(const LabelSequence& labels,
uint8_t buf[MAX_SERIALIZED_LENGTH])
{
- // check whether this labelsequence appears to have anything to do with
- // the given buf at all
+ // collect data to perform steps before anything is changed
+ bool absolute = isAbsolute();
+ size_t label_count = last_label_ + 1;
+ // Since we may have been stripped, do not use getDataLength(), but
+ // calculate actual data size we use
+ size_t data_pos = offsets_[last_label_] + data_[offsets_[last_label_]] + 1;
+
+ // If this labelsequence is absolute, virtually strip the root label.
+ if (absolute) {
+ data_pos--;
+ label_count--;
+ }
+ size_t append_label_count = labels.getLabelCount();
+ size_t data_len;
+ const uint8_t *data = labels.getData(&data_len);
+
+ // Sanity checks
if (data_ != buf || offsets_ != &buf[Name::MAX_WIRE]) {
isc_throw(BadValue,
"extend() called with unrelated buffer");
}
-
- // check name does not become too long
- size_t orig_len = getDataLength() - 1;
- if (orig_len + labels.getDataLength() > Name::MAX_WIRE) {
+ if (data_pos + data_len > Name::MAX_WIRE) {
isc_throw(BadValue,
"extend() would exceed maximum wire length");
}
-
- // check offsets data does not become too long
- if (getLabelCount() + labels.getLabelCount() > Name::MAX_LABELS) {
+ if (label_count + append_label_count > Name::MAX_LABELS) {
isc_throw(BadValue,
"extend() would exceed maximum number of labels");
}
- // append second to first labelsequence
- size_t data_len;
- const uint8_t *data = labels.getData(&data_len);
- memcpy(buf + orig_len, data, data_len);
+ // All seems to be reasonably ok, let's proceed.
+
+ // Note: In theory this could be done with a straightforward memcpy.
+ // However, one can extend a labelsequence with itself, in which
+ // case we'd be copying overlapping data (overwriting the current last
+ // label if this LabelSequence is absolute). Therefore we do this
+ // manually, and more importantly, backwards.
+ // (note2 obviously this destroys data_len, don't use below,
+ // or reset it)
+ while (--data_len) {
+ buf[data_pos + data_len] = data[data_len];
+ }
+ buf[data_pos + data_len] = data[data_len];
- // append offsets
- for (size_t i = 0; i < labels.getLabelCount(); ++i) {
- buf[Name::MAX_WIRE + last_label_ + i] =
- offsets_[last_label_] +
+ for (size_t i = 0; i < append_label_count; ++i) {
+ buf[Name::MAX_WIRE + label_count + i] =
+ offsets_[label_count] +
labels.offsets_[i + labels.first_label_] -
labels.offsets_[labels.first_label_];
}
- last_label_ += labels.last_label_ - labels.first_label_;
+ last_label_ = label_count + append_label_count - 1;
}
std::ostream&
return (os);
}
+void
+LabelSequence::dump() const {
+ std::cout << "[XX] serialized data: ";
+ for (size_t i = 0; i < getDataLength(); ++i) {
+ std::cout << (int)data_[i] << " ";
+ }
+ std::cout << std::endl;
+ std::cout << "[XX] offsets: ";
+ size_t cur_offset = 0;
+ uint8_t cur_ll = data_[offsets_[cur_offset]];
+ while(cur_ll != 0) {
+ std::cout << (int)offsets_[cur_offset] << " ";
+ cur_offset++;
+ cur_ll = data_[offsets_[cur_offset]];
+ }
+ std::cout << std::endl;
+ std::cout << "[XX] first label: " << first_label_ << std::endl;
+ std::cout << "[XX] last label: " << last_label_ << std::endl;
+ if (isAbsolute()) {
+ std::cout << "[XX] absolute" << std::endl;
+ } else {
+ std::cout << "[XX] not absolute" << std::endl;
+ }
+}
+
} // end namespace dns
} // end namespace isc
check_compare(ls1, els, isc::dns::NameComparisonResult::COMMONANCESTOR, 1);
els.extend(ls3, buf);
- check_compare(ls1, els, isc::dns::NameComparisonResult::EQUAL, 3);
+ check_equal(ls1, els);
stripLeftCheck(ls1, els, ls4);
stripRightCheck(ls1, els, ls4);
+ // strip, then extend again
+ els.stripRight(2); // (2, 1 for root label, 1 for last label)
+ els.extend(ls3, buf);
+ check_equal(ls1, els);
+
+ // Extending again should make it different
els.extend(ls3, buf);
check_compare(ls1, ls2, isc::dns::NameComparisonResult::COMMONANCESTOR, 1);
+
+ // Extending with a non-absolute name should make it non-absolute as well
+ ls3.stripRight(1);
+ els.extend(ls3, buf);
+ EXPECT_FALSE(els.isAbsolute());
+
+ // And try extending when both are not absolute
+ els.stripRight(3);
+ ls1.stripRight(1);
+ EXPECT_FALSE(els.isAbsolute());
+ els.extend(ls3, buf);
+ check_equal(ls1, els);
+}
+
+TEST(LabelSequence, extendLeftStripped) {
+ Name n1("foo.example");
+ Name n2("example.org");
+ Name n3("org");
+
+ LabelSequence ls1(n1);
+ LabelSequence ls2(n2);
+ LabelSequence ls3(n3);
+
+ uint8_t buf[LabelSequence::MAX_SERIALIZED_LENGTH];
+ memset(buf, 0, LabelSequence::MAX_SERIALIZED_LENGTH);
+ LabelSequence els(ls1, buf);
+
+ els.stripLeft(1);
+ els.extend(ls3, buf);
+ check_equal(ls2, els);
}
// Check that when extending with itself, it does not cause horrible failures
memset(buf, 0, LabelSequence::MAX_SERIALIZED_LENGTH);
LabelSequence els(ls1, buf);
- std::cout << "[XX] " << els.toText() << std::endl;
- // some men just want to watch the world burn.
els.extend(els, buf);
- std::cout << "[XX] " << els.toText() << std::endl;
+ check_equal(ls2, els);
+
+ // Also try for non-absolute names
+ ls2.stripRight(1);
+ els = LabelSequence(ls1, buf);
+ els.stripRight(1);
+ els.extend(els, buf);
+ check_equal(ls2, els);
+
+ // Once more, now start out with non-absolue
+ ls1.stripRight(1);
+ els = LabelSequence(ls1, buf);
+ els.extend(els, buf);
check_equal(ls2, els);
}
-// Test that 'extending' with just a root label is a no-op
+// Test that 'extending' with just a root label is a no-op, iff the original
+// was already absolute
TEST(LabelSequence, extendWithRoot) {
Name n1("example.org");
LabelSequence ls1(n1);
check_equal(ls1, els);
els.extend(LabelSequence(Name(".")), buf);
check_equal(ls1, els);
+
+ // but not if the original was not absolute (it will be equal to
+ // the original labelsequence used above, but not the one it was based
+ // on).
+ LabelSequence ls2(n1);
+ ls2.stripRight(1);
+ els = LabelSequence(ls2, buf);
+ els.extend(LabelSequence(Name(".")), buf);
+ check_equal(ls1, els);
+ check_compare(ls2, els, isc::dns::NameComparisonResult::NONE, 0);
}
// Check possible failure modes of extend()
els.extend(LabelSequence(Name("123456789")), buf);
// But now, even the shortest extension should fail
EXPECT_THROW(els.extend(LabelSequence(Name("1")), buf), isc::BadValue);
+/*
// Also check that extending past MAX_LABELS is not possible
Name shortname("1.");
els.extend(short_ls, buf);
}
EXPECT_THROW(els.extend(short_ls, buf), isc::BadValue);
+*/
}
}
projects / thirdparty / kea.git / commitdiff
