1 files changed, 169 insertions, 0 deletions
diff --git a/src/lib/dns/rdata/generic/detail/nsec_bitmap.cc b/src/lib/dns/rdata/generic/detail/nsec_bitmap.cc
new file mode 100644
index 0000000..d02c11d
--- /dev/null
+++ b/src/lib/dns/rdata/generic/detail/nsec_bitmap.cc
@@ -0,0 +1,169 @@
+// Copyright (C) 2011-2015 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
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include <config.h>
+
+#include <exceptions/exceptions.h>
+
+#include <dns/exceptions.h>
+#include <dns/rdata.h>
+#include <dns/rrtype.h>
+
+#include <cassert>
+#include <sstream>
+#include <vector>
+#include <cstring>
+#include <stdint.h>
+
+using namespace std;
+
+namespace isc {
+namespace dns {
+namespace rdata {
+namespace generic {
+namespace detail {
+namespace nsec {
+void
+checkRRTypeBitmaps(const char* const rrtype_name,
+                   const vector<uint8_t>& typebits)
+{
+    bool first = true;
+    unsigned int lastblock = 0;
+    const size_t total_len = typebits.size();
+    size_t i = 0;
+
+    while (i < total_len) {
+        if (i + 2 > total_len) {
+            isc_throw(DNSMessageFORMERR, rrtype_name <<
+                      " RDATA from wire: incomplete bit map field");
+        }
+        const unsigned int block = typebits[i];
+        const size_t len = typebits[i + 1];
+        // Check that bitmap window blocks are in the correct order.
+        if (!first && block <= lastblock) {
+            isc_throw(DNSMessageFORMERR, rrtype_name <<
+                      " RDATA from wire: Disordered window blocks found: "
+                      << lastblock << " then " << block);
+        }
+        // Check for legal length
+        if (len < 1 || len > 32) {
+            isc_throw(DNSMessageFORMERR, rrtype_name <<
+                      " RDATA from wire: Invalid bitmap length: " << len);
+        }
+        // Check for overflow.
+        i += 2;
+        if (i + len > total_len) {
+            isc_throw(DNSMessageFORMERR, rrtype_name <<
+                      " RDATA from wire: bitmap length too large: " << len);
+        }
+        // The last octet of the bitmap must be non zero.
+        if (typebits[i + len - 1] == 0) {
+            isc_throw(DNSMessageFORMERR, rrtype_name <<
+                      " RDATA from wire: bitmap ending an all-zero byte");
+        }
+
+        i += len;
+        lastblock = block;
+        first = false;
+    }
+}
+
+void
+buildBitmapsFromLexer(const char* const rrtype_name,
+                      MasterLexer& lexer, vector<uint8_t>& typebits,
+                      bool allow_empty)
+{
+    uint8_t bitmap[8 * 1024];       // 64k bits
+    memset(bitmap, 0, sizeof(bitmap));
+
+    bool have_rrtypes = false;
+    std::string type_str;
+    while (true) {
+        const MasterToken& token =
+            lexer.getNextToken(MasterToken::STRING, true);
+        if ((token.getType() == MasterToken::END_OF_FILE) ||
+            (token.getType() == MasterToken::END_OF_LINE)) {
+            break;
+        }
+
+        // token is now assured to be of type STRING.
+
+        have_rrtypes = true;
+        token.getString(type_str);
+        try {
+            const int code = RRType(type_str).getCode();
+            bitmap[code / 8] |= (0x80 >> (code % 8));
+        } catch (const InvalidRRType&) {
+            isc_throw(InvalidRdataText, "Invalid RRtype in "
+                      << rrtype_name << " bitmap: " << type_str);
+        }
+    }
+
+    lexer.ungetToken();
+
+    if (!have_rrtypes) {
+         if (allow_empty) {
+              return;
+         }
+         isc_throw(InvalidRdataText,
+                   rrtype_name <<
+                   " record does not end with RR type mnemonic");
+    }
+
+    for (int window = 0; window < 256; ++window) {
+        int octet;
+        for (octet = 31; octet >= 0; octet--) {
+            if (bitmap[window * 32 + octet] != 0) {
+                break;
+            }
+        }
+        if (octet < 0) {
+            continue;
+        }
+        typebits.push_back(window);
+        typebits.push_back(octet + 1);
+        for (int i = 0; i <= octet; ++i) {
+            typebits.push_back(bitmap[window * 32 + i]);
+        }
+    }
+}
+
+void
+bitmapsToText(const vector<uint8_t>& typebits, ostringstream& oss) {
+    // In the following loop we use string::at() rather than operator[].
+    // Since the index calculation is a bit complicated, it will be safer
+    // and easier to find a bug (if any).  Note that this conversion method
+    // is generally not expected to be very efficient, so the slight overhead
+    // of at() should be acceptable.
+    const size_t typebits_len = typebits.size();
+    size_t len = 0;
+    for (size_t i = 0; i < typebits_len; i += len) {
+        assert(i + 2 <= typebits.size());
+        const unsigned int block = typebits.at(i);
+        len = typebits.at(i + 1);
+        assert(len > 0 && len <= 32);
+        i += 2;
+        for (size_t j = 0; j < len; ++j) {
+            if (typebits.at(i + j) == 0) {
+                continue;
+            }
+            for (size_t k = 0; k < 8; ++k) {
+                if ((typebits.at(i + j) & (0x80 >> k)) == 0) {
+                    continue;
+                }
+                const unsigned int t = block * 256 + j * 8 + k;
+                assert(t < 65536);
+                oss << " " << RRType(t);
+            }
+        }
+    }
+}
+}
+}
+}
+}
+}
+}