Move binpac code into the main Zeek repository

This is based on commit 48f75b5f6415fe9d597e3e991cec635b1bc400dc from
the binpac repository.

tools/binpac/lib/binpac_regex.h

@@ -0,0 +1,72 @@
+#ifndef binpac_regex_h
+#define binpac_regex_h
+
+#include "zeek/RE.h"
+
+#include "binpac.h"
+
+namespace zeek {
+class RE_Matcher;
+}
+
+namespace binpac {
+
+// Must be called before any binpac functionality is used.
+//
+// Note, this must be declared/defined here, and inline, because the RE
+// functionality can only be used when compiling from inside Zeek.
+// A copy is made of any FlowBuffer policy struct data passed.
+inline void init(FlowBuffer::Policy* fbp = 0);
+
+// Internal vector recording not yet compiled matchers.
+extern std::vector<zeek::RE_Matcher*>* uncompiled_re_matchers;
+
+class RegExMatcher {
+public:
+    RegExMatcher(const char* pattern) : pattern_(pattern) {
+        if ( ! uncompiled_re_matchers )
+            uncompiled_re_matchers = new std::vector<zeek::RE_Matcher*>;
+
+        re_matcher_ = new zeek::RE_Matcher(pattern_.c_str());
+        uncompiled_re_matchers->push_back(re_matcher_);
+    }
+
+    ~RegExMatcher() { delete re_matcher_; }
+
+    // Returns the length of longest match, or -1 on mismatch.
+    int MatchPrefix(const_byteptr data, int len) { return re_matcher_->MatchPrefix(data, len); }
+
+private:
+    friend void ::binpac::init(FlowBuffer::Policy*);
+
+    // Function, and state, for compiling matchers.
+    static void init();
+
+    string pattern_;
+    zeek::RE_Matcher* re_matcher_;
+};
+
+inline void RegExMatcher::init() {
+    if ( ! uncompiled_re_matchers )
+        return;
+
+    for ( size_t i = 0; i < uncompiled_re_matchers->size(); ++i ) {
+        if ( ! (*uncompiled_re_matchers)[i]->Compile() ) {
+            fprintf(stderr, "binpac: cannot compile regular expression\n");
+            exit(1);
+        }
+    }
+
+    uncompiled_re_matchers->clear();
+}
+
+inline void init(FlowBuffer::Policy* fbp) {
+    RegExMatcher::init();
+
+    if ( fbp )
+        FlowBuffer::init(*fbp);
+}
+
+} // namespace binpac
+
+#endif // binpac_regex_h