Adding multithreaded example from issue #3054 (by airween)

- Rewritten to use C++ libModSecurity API and std::thread (instead of
  pthreads)

examples/multithread/Makefile.am

@@ -0,0 +1,54 @@
+
+
+noinst_PROGRAMS = multithread
+
+multithread_SOURCES = \
+	multithread.cc
+
+multithread_LDADD = \
+	$(CURL_LDADD) \
+	$(GEOIP_LDADD) \
+	$(GLOBAL_LDADD) \
+	$(LIBXML2_LDADD) \
+	$(LMDB_LDADD) \
+	$(MAXMIND_LDADD) \
+	$(LUA_LDADD) \
+	$(PCRE_LDADD) \
+	$(SSDEEP_LDADD) \
+	$(YAJL_LDADD)
+
+multithread_LDFLAGS = \
+	-L$(top_builddir)/src/.libs/ \
+	$(GEOIP_LDFLAGS) \
+	-lmodsecurity \
+	-lm \
+	-lstdc++ \
+	$(LMDB_LDFLAGS) \
+	$(LUA_LDFLAGS) \
+	$(MAXMIND_LDFLAGS) \
+	$(SSDEEP_LDFLAGS) \
+	$(YAJL_LDFLAGS)
+
+multithread_CPPFLAGS = \
+	$(GLOBAL_CFLAGS) \
+	-I$(top_builddir)/headers \
+	-I$(top_builddir) \
+	-g \
+	-I../others \
+	-fPIC \
+	-O3 \
+	$(CURL_CFLAGS) \
+	$(GEOIP_CFLAGS) \
+	$(GLOBAL_CPPFLAGS) \
+	$(MODSEC_NO_LOGS) \
+	$(YAJL_CFLAGS) \
+	$(LMDB_CFLAGS) \
+	$(LUA_CFLAGS) \
+	$(PCRE_CFLAGS) \
+	$(LIBXML2_CFLAGS)
+
+
+MAINTAINERCLEANFILES = \
+	Makefile.in
+
+

examples/multithread/basic_rules.conf

@@ -0,0 +1,14 @@
+SecDebugLog debug.log
+SecDebugLogLevel 9
+
+
+SecRule REQUEST_HEADERS:User-Agent ".*" "id:1,phase:1,t:sha1,t:hexEncode,setvar:tx.ua_hash=%{MATCHED_VAR}"
+
+SecAction "id:2,phase:2,initcol:ip=%{REMOTE_ADDR}_%{tx.ua_hash}"
+
+SecRule REQUEST_HEADERS:User-Agent "@rx .*" "id:3,phase:2,setvar:ip.auth_attempt=+1"
+
+SecRule ARGS:foo "@rx herewego" "id:4,phase:2,setvar:ip.foo=bar,expirevar:ip.foo=2"
+#SecRule ARGS:foo "@rx herewego" "id:4,phase:2,setvar:ip.foo=bar"
+SecRule IP "@rx bar" "id:5,phase:2,pass"
+SecRule IP:auth_attempt "@rx bar" "id:6,phase:2,pass"

examples/multithread/multithread.cc

@@ -0,0 +1,68 @@
+#include <iostream>
+#include <thread>
+#include <array>
+
+#include <modsecurity/modsecurity.h>
+#include <modsecurity/transaction.h>
+#include <modsecurity/rules_set.h>
+
+static void process_request(modsecurity::ModSecurity *modsec, modsecurity::RulesSet *rules, int tid) {
+    std::cout << "Hello World! It's me, thread #" << tid << std::endl;
+
+    for(int i = 0; i != 1'000; i++) {
+        auto modsecTransaction = std::make_unique<modsecurity::Transaction>(modsec, rules, nullptr);
+
+        modsecTransaction->processConnection("127.0.0.1", 12345, "127.0.0.1", 80);
+        modsecTransaction->processURI(
+            "https://www.modsecurity.org/test?foo=herewego",
+            "GET", "1.1");
+
+        modsecTransaction->addRequestHeader("User-Agent",
+            "Basic ModSecurity example");
+        modsecTransaction->processRequestHeaders();
+        modsecTransaction->processRequestBody();
+
+        modsecTransaction->addResponseHeader("HTTP/1.1",
+            "200 OK");
+        modsecTransaction->processResponseHeaders(200, "HTTP 1.2");
+        modsecTransaction->processResponseBody();
+
+        modsecTransaction->processLogging();
+
+        std::this_thread::sleep_for(std::chrono::microseconds(100));
+    }
+
+    std::cout << "Thread #" << tid << " exits" << std::endl;
+}
+
+int main (int argc, char *argv[]) {
+    auto modsec = std::make_unique<modsecurity::ModSecurity>();
+    modsec->setConnectorInformation("ModSecurity-test v0.0.1-alpha (Simple " \
+        "example on how to use ModSecurity API");
+
+    char main_rule_uri[] = "basic_rules.conf";
+    auto rules = std::make_unique<modsecurity::RulesSet>();
+    if (rules->loadFromUri(main_rule_uri) < 0) {
+        std::cerr << "Problems loading the rules..." << std::endl;
+        std::cerr << rules->m_parserError.str() << std::endl;
+        return -1;
+    }
+
+    constexpr auto NUM_THREADS = 100;
+    std::array<std::thread, NUM_THREADS> threads;
+
+    for (auto i = 0; i != threads.size(); ++i) {
+        threads[i] = std::thread(
+            [&modsec, &rules, i]() {
+                process_request(modsec.get(), rules.get(), i);
+            });
+    }
+
+    std::this_thread::sleep_for(std::chrono::microseconds(10000));
+
+    for (auto i = 0; i != threads.size(); ++i) {
+        threads[i].join();
+    }
+
+    return 0;
+}