70 require host header in each request

[u413-284-si]

Overview

1. Check for missing host header
2. Check for empty host header value
3. Check for multiple host headers in request
4. Determine if host value is ip (w or w/o port) or a hostname
5. Check for valid ip (w or w/o port)
6. Check for valid hostname
7. Code restructure
8. Check for not allowed method
9. Tests

re 1.

• simple check if Host header is present in std::map<std::string, std::string> headers, if not throw

re 2.

• simple check if the value of the Host header is empty, if yes throw

re 3.

• during parsing of the respective headers, check if there is more than one host header in the request, if yes throw

re 4.

• Host value can be either a hostname or an ip address (with or without a port)
• implemented check to differentiate

re 5.

• use Chris' methods to check for valid ip address and/or port
• therefore moved isIpAddressValid() and isPortValid() to utilities as it is shared

re 6.

• if is not an ip address, then see if it is a valid hostname
• criteria follow RFC 1035, 1123 and 3986
• detailed description in code documentation

re 7.

• as mentioned moved Chris' methods
• restructured RequestParser to align with header file and its structure

re 8.

• create new method to check for allowed methods if there is a body
• set httpStatus to StatusMethodNotAllowed instead of general StatusBadRequest -> general check should be performed to specify status code

re 9.

• add new unittests to test various valid and invalid host headers

closes #70