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authorMarcin Siodelski <marcin@isc.org>2022-10-24 14:51:56 +0200
committerMarcin Siodelski <marcin@isc.org>2023-01-07 11:45:05 +0100
commitce2cf60e342d6a8ddbdf6386cb92bbdefd259075 (patch)
tree07c7ce23bcc3adf62655153ffc384ca61418a6bd /src/lib
parent[#969] Random allocation state added (diff)
downloadkea-ce2cf60e342d6a8ddbdf6386cb92bbdefd259075.tar.xz
kea-ce2cf60e342d6a8ddbdf6386cb92bbdefd259075.zip
[#969] Added ability to reset permutation
Diffstat (limited to 'src/lib')
-rw-r--r--src/lib/dhcpsrv/ip_range_permutation.cc13
-rw-r--r--src/lib/dhcpsrv/ip_range_permutation.h12
-rw-r--r--src/lib/dhcpsrv/tests/ip_range_permutation_unittest.cc29
3 files changed, 50 insertions, 4 deletions
diff --git a/src/lib/dhcpsrv/ip_range_permutation.cc b/src/lib/dhcpsrv/ip_range_permutation.cc
index 8785e54174..ad622d6abd 100644
--- a/src/lib/dhcpsrv/ip_range_permutation.cc
+++ b/src/lib/dhcpsrv/ip_range_permutation.cc
@@ -1,4 +1,4 @@
-// Copyright (C) 2020 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2020-2022 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -17,7 +17,7 @@ namespace dhcp {
IPRangePermutation::IPRangePermutation(const AddressRange& range)
: range_start_(range.start_), step_(1), cursor_(addrsInRange(range_start_, range.end_) - 1),
- state_(), done_(false), generator_() {
+ initial_cursor_(cursor_), state_(), done_(false), generator_() {
std::random_device rd;
generator_.seed(rd());
}
@@ -25,7 +25,7 @@ IPRangePermutation::IPRangePermutation(const AddressRange& range)
IPRangePermutation::IPRangePermutation(const PrefixRange& range)
: range_start_(range.start_), step_(static_cast<uint64_t>(1) << (128 - range.delegated_length_)),
cursor_(prefixesInRange(range.prefix_length_, range.delegated_length_) - 1),
- state_(), done_(false), generator_() {
+ initial_cursor_(cursor_), state_(), done_(false), generator_() {
}
IOAddress
@@ -97,5 +97,12 @@ IPRangePermutation::next(bool& done) {
return (next_loc_address);
}
+void
+IPRangePermutation::reset() {
+ state_.clear();
+ cursor_ = initial_cursor_;
+ done_ = false;
+}
+
} // end of namespace isc::dhcp
} // end of namespace isc
diff --git a/src/lib/dhcpsrv/ip_range_permutation.h b/src/lib/dhcpsrv/ip_range_permutation.h
index c03a471fbf..76868947f8 100644
--- a/src/lib/dhcpsrv/ip_range_permutation.h
+++ b/src/lib/dhcpsrv/ip_range_permutation.h
@@ -1,4 +1,4 @@
-// Copyright (C) 2020-2021 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2020-2022 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -99,6 +99,13 @@ public:
/// prefixes in the range.
asiolink::IOAddress next(bool& done);
+ /// @brief Resets the permutation state.
+ ///
+ /// It effectively causes the permutation to start over the process of
+ /// serving addresses. Any previously returned addresses can be returned
+ /// again after calling this function.
+ void reset();
+
private:
/// Beginning of the range.
@@ -115,6 +122,9 @@ private:
/// is returned.
uint64_t cursor_;
+ /// Keeps the initial cursor position for @c reset function.
+ uint64_t initial_cursor_;
+
/// Keeps the current permutation state. The state associates the
/// swapped IP addresses or delegated prefixes with their positions in
/// the permutation.
diff --git a/src/lib/dhcpsrv/tests/ip_range_permutation_unittest.cc b/src/lib/dhcpsrv/tests/ip_range_permutation_unittest.cc
index 25a45f4397..339f53e3a6 100644
--- a/src/lib/dhcpsrv/tests/ip_range_permutation_unittest.cc
+++ b/src/lib/dhcpsrv/tests/ip_range_permutation_unittest.cc
@@ -137,4 +137,33 @@ TEST(IPRangePermutationTest, pd) {
EXPECT_TRUE(addrs.begin()->isV6Zero());
}
+// This test verifies that it is possible to reset the permutation state.
+TEST(IPRangePermutationTest, reset) {
+ // Create address range with 11 addresses.
+ AddressRange range(IOAddress("192.0.2.10"), IOAddress("192.0.2.20"));
+ IPRangePermutation perm(range);
+
+ // This set will record unique IP addresses generated.
+ std::set<IOAddress> addrs;
+ bool done = false;
+
+ // Call the next() function several times to consume several addresses.
+ for (auto i = 0; i < 5; ++i) {
+ auto next = perm.next(done);
+ EXPECT_FALSE(next.isV4Zero());
+ addrs.insert(next);
+ }
+ EXPECT_EQ(5, addrs.size());
+
+ // Reset the permutation. We should be able to get all addresses again.
+ perm.reset();
+
+ for (auto i = 0; i < 11; ++i) {
+ auto next = perm.next(done);
+ EXPECT_FALSE(next.isV4Zero());
+ addrs.insert(next);
+ }
+ EXPECT_EQ(11, addrs.size());
+}
+
} // end of anonymous namespace