Order rule traversal in RuleMatcher::Match() operations by Rule index

This ordering fixes a test failure we're seeing on Alpine for the
signatures/tcp-end-of-match btest, since discrepancies in rule match traversal
could lead to discrepancies in corresponding event ordering.

It looks safe to rely on across platforms since the index is driven by signature
load order, which shouldn't deviate. If this somehow doesn't hold in the future,
we'll only wind up with a test failure, not incorrect match behavior.

(Correction to 2e03fbb8b0, which I pushed
accidentally.)

src/Rule.h

@@ -59,9 +59,6 @@ public:
 
     void PrintDebug();
 
-    bool operator==(const Rule& other) { return strcmp(ID(), other.ID()) == 0; }
-    bool operator<(const Rule& other) { return strcmp(ID(), other.ID()) < 0; }
-
     static const char* TypeToString(Rule::PatternType type);
 
 private:

src/RuleMatcher.cc

@@ -657,8 +657,7 @@ RuleMatcher::MIME_Matches* RuleMatcher::Match(RuleFileMagicState* state, const u
     }
 
     // Find rules for which patterns have matched.
-    auto cmp = [](Rule* a, Rule* b) { return *a < *b; };
+    map<decltype(Rule::idx), Rule*> rule_matches;
-    set<Rule*, decltype(cmp)> rule_matches(cmp);
 
     for ( AcceptingMatchSet::const_iterator it = accepted_matches.begin(); it != accepted_matches.end(); ++it ) {
         auto [aidx, mpos] = *it;
@@ -666,11 +665,11 @@ RuleMatcher::MIME_Matches* RuleMatcher::Match(RuleFileMagicState* state, const u
         Rule* r = Rule::rule_table[aidx - 1];
 
         if ( AllRulePatternsMatched(r, mpos, accepted_matches) )
-            rule_matches.insert(r);
+            rule_matches[r->Index()] = r;
     }
 
-    for ( set<Rule*>::const_iterator it = rule_matches.begin(); it != rule_matches.end(); ++it ) {
+    for ( const auto& entry : rule_matches ) {
-        Rule* r = *it;
+        Rule* r = entry.second;
 
         for ( const auto& action : r->actions ) {
             const RuleActionMIME* ram = dynamic_cast<const RuleActionMIME*>(action);
@@ -842,12 +841,7 @@ void RuleMatcher::Match(RuleEndpointState* state, Rule::PatternType type, const
     // matched patterns per connection (which is a plausible assumption).
 
     // Find rules for which patterns have matched.
-    auto cmp = [](pair<Rule*, MatchPos> a, pair<Rule*, MatchPos> b) {
+    map<decltype(Rule::idx), std::pair<Rule*, MatchPos>> rule_matches;
-        if ( *a.first == *b.first )
-            return a.second < b.second;
-        return *a.first < *b.first;
-    };
-    set<pair<Rule*, MatchPos>, decltype(cmp)> rule_matches(cmp);
 
     for ( AcceptingMatchSet::const_iterator it = accepted_matches.begin(); it != accepted_matches.end(); ++it ) {
         AcceptIdx aidx = it->first;
@@ -856,13 +850,12 @@ void RuleMatcher::Match(RuleEndpointState* state, Rule::PatternType type, const
         Rule* r = Rule::rule_table[aidx - 1];
 
         if ( AllRulePatternsMatched(r, mpos, accepted_matches) )
-            rule_matches.insert(make_pair(r, mpos));
+            rule_matches[r->Index()] = make_pair(r, mpos);
     }
 
     // Check which of the matching rules really belong to any of our nodes.
-
+    for ( const auto& entry : rule_matches ) {
-    for ( set<pair<Rule*, MatchPos>>::const_iterator it = rule_matches.begin(); it != rule_matches.end(); ++it ) {
+        auto [r, match_end_pos] = entry.second;
-        auto [r, match_end_pos] = *it;
 
         DBG_LOG(DBG_RULES, "Accepted rule: %s", r->id);
 

testing/btest/Baseline/signatures.tcp-end-of-match/.stdout

@@ -1,7 +1,7 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+signature_match, message, 1448
+signature_match with end_of_match, message, 1448,    rather than all. (Robin Sommer)\x0a\x0a  * Fix parallel make portability
 portability_match with end_of_match, 1448,    rather than all. (Robin Sommer)\x0a\x0a  * Fix parallel make portability
 portability_match, 1448
 portability_match_with_msg with end_of_match, custom message, 1448, 69,    rather than all. (Robin Sommer)\x0a\x0a  * Fix parallel make portability
 portability_match_with_msg, custom message, 1448
-signature_match, message, 1448
-signature_match with end_of_match, message, 1448,    rather than all. (Robin Sommer)\x0a\x0a  * Fix parallel make portability