MXS-1220: Add HTTP parser

The HTTP parser parses HTTP/1.1 messages into easily manageable data
structures. This should make it easier to map the HTTP requests into
actual commands in MaxScale.

server/core/httpparser.cc

@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 2016 MariaDB Corporation Ab
+ *
+ * Use of this software is governed by the Business Source License included
+ * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
+ *
+ * Change Date: 2019-07-01
+ *
+ * On the date above, in accordance with the Business Source License, use
+ * of this software will be governed by version 2 or later of the General
+ * Public License.
+ */
+
+#include "maxscale/httpparser.hh"
+
+#include <ctype.h>
+
+static enum http_verb string_to_http_verb(string& verb)
+{
+    if (verb == "GET")
+    {
+        return HTTP_GET;
+    }
+    else if (verb == "POST")
+    {
+        return HTTP_POST;
+    }
+    else if (verb == "PUT")
+    {
+        return HTTP_PUT;
+    }
+    else if (verb == "PATCH")
+    {
+        return HTTP_PATCH;
+    }
+    else if (verb == "OPTIONS")
+    {
+        return HTTP_OPTIONS;
+    }
+
+    return HTTP_UNKNOWN;
+}
+
+HttpParser* HttpParser::parse(string request)
+{
+    size_t pos = request.find("\r\n");
+    string request_line = request.substr(0, pos);
+    request.erase(0, pos + 2);
+
+    pos = request_line.find(" ");
+    string verb = request_line.substr(0, pos);
+    request_line.erase(0, pos + 1);
+
+    pos = request_line.find(" ");
+    string uri = request_line.substr(0, pos);
+    request_line.erase(0, pos + 1);
+
+    pos = request_line.find("\r\n");
+    string http_version = request_line.substr(0, pos);
+    request_line.erase(0, pos + 2);
+
+    map<string, string> headers;
+
+    while ((pos = request.find("\r\n")) != string::npos)
+    {
+        string header_line = request.substr(0, pos);
+        request.erase(0, pos + 2);
+
+        if (header_line.length() == 0)
+        {
+            /** End of headers */
+            break;
+        }
+
+        if ((pos = header_line.find(":")) != string::npos)
+        {
+            string key = header_line.substr(0, pos);
+            header_line.erase(0, pos + 1);
+
+            while (isspace(header_line[0]))
+            {
+                header_line.erase(0, 1);
+            }
+
+            headers[key] = header_line;
+        }
+    }
+
+    HttpParser* parser = NULL;
+    enum http_verb verb_value = string_to_http_verb(verb);
+
+    if (http_version == "HTTP/1.1" && verb_value != HTTP_UNKNOWN)
+    {
+        parser = new HttpParser();
+        parser->m_verb = verb_value;
+        parser->m_resource = uri;
+        parser->m_headers = headers;
+        parser->m_body = request;
+    }
+
+    return parser;
+}
+
+HttpParser::HttpParser()
+{
+
+}
+
+HttpParser::~HttpParser()
+{
+
+}