Make list of languages installed discoverable at runtime.

Stop hardcoding Russian in webadmin.
Limit the setting in controlpanel to the known languages, because
untrusted language code might lead to some interesting vulnerabilities.

CMakeLists.txt

@@ -247,6 +247,8 @@ endif()
 
 install(DIRECTORY webskins
 	DESTINATION "${CMAKE_INSTALL_DATADIR}/znc")
+install(DIRECTORY translations
+	DESTINATION "${CMAKE_INSTALL_DATADIR}/znc")
 install(DIRECTORY man/
 	DESTINATION "${CMAKE_INSTALL_MANDIR}/man1"
 	FILES_MATCHING PATTERN "znc*")

include/znc/Translation.h

@@ -20,6 +20,12 @@
 #include <znc/ZNCString.h>
 #include <unordered_map>
 
+struct CTranslationInfo {
+    static std::map<CString, CTranslationInfo> GetTranslations();
+
+    CString sSelfName;
+};
+
 // All instances of modules share single message map using this class stored in
 // CZNC.
 class CTranslation {
@@ -38,6 +44,7 @@ class CTranslation {
     void DelReference(const CString& sDomain);
 
   private:
+    // Domain is either "znc" or "znc-foo" where foo is a module name
     const std::locale& LoadTranslation(const CString& sDomain);
     std::unordered_map<CString /* domain */,
                        std::unordered_map<CString /* language */, std::locale>>

modules/controlpanel.cpp

@@ -276,7 +276,9 @@ class CAdminMod : public CModule {
             PutModule("StatusPrefix = " + pUser->GetStatusPrefix());
 #ifdef HAVE_I18N
         else if (sVar == "language")
-            PutModule("Language = " + pUser->GetLanguage());
+            PutModule("Language = " + (pUser->GetLanguage().empty()
+                                           ? "en"
+                                           : pUser->GetLanguage()));
 #endif
 #ifdef HAVE_ICU
         else if (sVar == "clientencoding")
@@ -453,8 +455,22 @@ class CAdminMod : public CModule {
         }
 #ifdef HAVE_I18N
         else if (sVar == "language") {
-            pUser->SetLanguage(sValue);
-            PutModule("Language = " + pUser->GetLanguage());
+            auto mTranslations = CTranslationInfo::GetTranslations();
+            // TODO: maybe stop special-casing English
+            if (sValue == "en") {
+                pUser->SetLanguage("");
+                PutModule("Language is set to English");
+            } else if (mTranslations.count(sValue)) {
+                pUser->SetLanguage(sValue);
+                PutModule("Language = " + sValue);
+            } else {
+                VCString vsCodes = {"en"};
+                for (const auto it : mTranslations) {
+                    vsCodes.push_back(it.first);
+                }
+                PutModule("Supported languages: " +
+                          CString(", ").Join(vsCodes.begin(), vsCodes.end()));
+            }
         }
 #endif
 #ifdef HAVE_ICU

modules/webadmin.cpp

@@ -316,7 +316,11 @@ class CWebAdminMod : public CModule {
         pNewUser->SetNoTrafficTimeout(uNoTrafficTimeout);
 
 #ifdef HAVE_I18N
-        pNewUser->SetLanguage(WebSock.GetParam("language"));
+        CString sLanguage = WebSock.GetParam("language");
+        if (CTranslationInfo::GetTranslations().count(sLanguage) == 0) {
+            sLanguage = "";
+        }
+        pNewUser->SetLanguage(sLanguage);
 #endif
 #ifdef HAVE_ICU
         CString sEncodingUtf = WebSock.GetParam("encoding_utf");
@@ -1376,13 +1380,15 @@ class CWebAdminMod : public CModule {
 
 #ifdef HAVE_I18N
             Tmpl["HaveI18N"] = "true";
-            // TODO don't have them hardcoded here
+            // TODO maybe stop hardcoding English here
             CTemplate& l_en = Tmpl.AddRow("LanguageLoop");
             l_en["Code"] = "";
             l_en["Name"] = "English";
-            CTemplate& l_ru = Tmpl.AddRow("LanguageLoop");
-            l_ru["Code"] = "ru-RU";
-            l_ru["Name"] = "Russian";
+            for (const auto& it : CTranslationInfo::GetTranslations()) {
+                CTemplate& lang = Tmpl.AddRow("LanguageLoop");
+                lang["Code"] = it.first;
+                lang["Name"] = it.second.sSelfName;
+            }
 #else
             Tmpl["HaveI18N"] = "false";
 #endif

src/Translation.cpp

@@ -15,11 +15,36 @@
  */
 
 #include <znc/Translation.h>
+#include <znc/FileUtils.h>
 
 #ifdef HAVE_I18N
 #include <boost/locale.hpp>
 #endif
 
+namespace {
+std::map<CString, CTranslationInfo> FillTranslations() {
+    std::map<CString, CTranslationInfo> mTranslations;
+    CDir Dir;
+    Dir.Fill(_DATADIR_ "/translations");
+    for (CFile* pFile : Dir) {
+        CString sName = pFile->GetShortName();
+        CTranslationInfo& translation = mTranslations[sName];
+        MCString msData;
+        // TODO: make the file format more sensible than this
+        msData.ReadFromDisk(pFile->GetLongName());
+        translation.sSelfName = msData["SelfName"];
+        // TODO: right-to-left support
+    }
+    return mTranslations;
+}
+}  // namespace
+
+std::map<CString, CTranslationInfo> CTranslationInfo::GetTranslations() {
+    static std::map<CString, CTranslationInfo> mTranslations =
+        FillTranslations();
+    return mTranslations;
+}
+
 CTranslation& CTranslation::Get() {
     static CTranslation translation;
     return translation;

translations/ru-RU

@@ -0,0 +1 @@
+SelfName Русский