diff options
| -rw-r--r-- | include/inspircd.h | 6 | ||||
| -rw-r--r-- | src/helperfuncs.cpp | 59 |
2 files changed, 65 insertions, 0 deletions
diff --git a/include/inspircd.h b/include/inspircd.h index a7f19f483..447fb8441 100644 --- a/include/inspircd.h +++ b/include/inspircd.h @@ -381,6 +381,12 @@ class CoreExport InspIRCd */ static bool DefaultIsChannel(const std::string& channel); + /** Determines whether a hostname is valid according to RFC 5891 rules. + * @param host The hostname to validate. + * @return True if the hostname is valid; otherwise, false. + */ + static bool IsHost(const std::string& host); + /** Return true if str looks like a server ID * @param sid string to check against */ diff --git a/src/helperfuncs.cpp b/src/helperfuncs.cpp index 111e1363f..8ced78ae8 100644 --- a/src/helperfuncs.cpp +++ b/src/helperfuncs.cpp @@ -267,6 +267,65 @@ bool InspIRCd::DefaultIsIdent(const std::string& n) return true; } +bool InspIRCd::IsHost(const std::string& host) +{ + // Hostnames must be non-empty and shorter than the maximum hostname length. + if (host.empty() || host.length() > ServerInstance->Config->Limits.MaxHost) + return false; + + unsigned int numdashes = 0; + unsigned int numdots = 0; + bool seendot = false; + const std::string::const_iterator hostend = host.end() - 1; + for (std::string::const_iterator iter = host.begin(); iter != host.end(); ++iter) + { + unsigned char chr = static_cast<unsigned char>(*iter); + + // If the current character is a label separator. + if (chr == '.') + { + numdots++; + + // Consecutive separators are not allowed and dashes can not exist at the start or end + // of labels and separators must only exist between labels. + if (seendot || numdashes || iter == host.begin() || iter == hostend) + return false; + + seendot = true; + continue; + } + + // If this point is reached then the character is not a dot. + seendot = false; + + // If the current character is a dash. + if (chr == '-') + { + // Consecutive separators are not allowed and dashes can not exist at the start or end + // of labels and separators must only exist between labels. + if (seendot || numdashes >= 2 || iter == host.begin() || iter == hostend) + return false; + + numdashes += 1; + continue; + } + + // If this point is reached then the character is not a dash. + numdashes = 0; + + // Alphanumeric characters are allowed at any position. + if ((chr >= '0' && chr <= '9') || (chr >= 'A' && chr <= 'Z') || (chr >= 'a' && chr <= 'z')) + continue; + + return false; + } + + // Whilst simple hostnames (e.g. localhost) are valid we do not allow the server to use + // them to prevent issues with clients that differentiate between short client and server + // prefixes by checking whether the nickname contains a dot. + return numdots; +} + bool InspIRCd::IsSID(const std::string &str) { /* Returns true if the string given is exactly 3 characters long, |