From 78daf86eb3b224825be812aad673c6c0f7184589 Mon Sep 17 00:00:00 2001
From: lda <lda@freetards.xyz>
Date: Wed, 29 Nov 2023 12:57:42 +0100
Subject: [PATCH] [MOD/WIP] Start doing checks on room alias

NOTE: Currently UNTESTED.
---
 src/Parser.c                     |  2 ++
 src/Routes/RouteAliasDirectory.c | 41 ++++++++++++++++++++++++++++----
 src/include/Parser.h             |  8 +++++--
 3 files changed, 44 insertions(+), 7 deletions(-)

diff --git a/src/Parser.c b/src/Parser.c
index 3dda8a0..e514c6d 100644
--- a/src/Parser.c
+++ b/src/Parser.c
@@ -267,6 +267,8 @@ ParseCommonID(char *str, CommonID *id)
     
     switch (sigil)
     {
+        case '#': /* It seems like the localpart should be the same as the 
+                     user's: everything, except ':'. */
         case '@':
             if (!ParseUserLocalpart(&str, &id->local))
             {
diff --git a/src/Routes/RouteAliasDirectory.c b/src/Routes/RouteAliasDirectory.c
index b1ae042..7a4772f 100644
--- a/src/Routes/RouteAliasDirectory.c
+++ b/src/Routes/RouteAliasDirectory.c
@@ -27,6 +27,9 @@
 
 #include <Cytoplasm/Json.h>
 #include <Cytoplasm/Str.h>
+
+#include <Config.h>
+#include <Parser.h>
 #include <User.h>
 
 ROUTE_IMPL(RouteAliasDirectory, path, argp)
@@ -43,15 +46,33 @@ ROUTE_IMPL(RouteAliasDirectory, path, argp)
     JsonValue *val;
 
     char *token;
+    char *msg;
     User *user = NULL;
 
-    /* TODO: Return HTTP 400 M_INVALID_PARAM if alias is invalid */
+    CommonID commonID;
+    Config *config;
+
+    commonID.sigil = '\0';
+    commonID.local = NULL;
+    commonID.server.hostname = NULL;
+    commonID.server.port = NULL;
+
+    config = ConfigLock(db);
+
+    if (!ParseCommonID(alias, &commonID) || commonID.sigil != '#')
+    {
+        msg = "Invalid room alias.";
+        HttpResponseStatus(args->context, HTTP_BAD_REQUEST);
+        response = MatrixErrorCreate(M_INVALID_PARAM, msg);
+        goto finish;
+    }
 
     ref = DbLock(db, 1, "aliases");
     if (!ref && !(ref = DbCreate(db, 1, "aliases")))
     {
+        msg = "Unable to access alias database.",
         HttpResponseStatus(args->context, HTTP_INTERNAL_SERVER_ERROR);
-        response = MatrixErrorCreate(M_UNKNOWN, "Unable to access alias database.");
+        response = MatrixErrorCreate(M_UNKNOWN, msg);
         goto finish;
     }
 
@@ -69,8 +90,9 @@ ROUTE_IMPL(RouteAliasDirectory, path, argp)
             }
             else
             {
+                msg = "There is no mapped room ID for this room alias.";
                 HttpResponseStatus(args->context, HTTP_NOT_FOUND);
-                response = MatrixErrorCreate(M_NOT_FOUND, "There is no mapped room ID for this room alias.");
+                response = MatrixErrorCreate(M_NOT_FOUND, msg);
             }
             break;
         case HTTP_PUT:
@@ -93,8 +115,15 @@ ROUTE_IMPL(RouteAliasDirectory, path, argp)
             {
                 HashMap *newAlias;
 
-                /* TODO: Validate alias domain and make sure it matches
-                 * server name and is well formed. */
+                /* Check for server name. 
+                 * TODO: Take the port into account, that might need a 
+                 * refactor for it to use a ServerPart */
+                if (!StrEquals(commonID.server.hostname, config->serverName))
+                {
+                    HttpResponseStatus(args->context, HTTP_BAD_REQUEST);
+                    response = MatrixErrorCreate(M_INVALID_PARAM, "Invalid servername");
+                    goto finish;
+                }
 
                 if (JsonGet(aliases, 2, "alias", alias))
                 {
@@ -156,6 +185,8 @@ ROUTE_IMPL(RouteAliasDirectory, path, argp)
     }
 
 finish:
+    CommonIDFree(commonID);
+    ConfigUnlock(config);
     UserUnlock(user);
     DbUnlock(db, ref);
     JsonFree(request);
diff --git a/src/include/Parser.h b/src/include/Parser.h
index 788f92f..68853b5 100644
--- a/src/include/Parser.h
+++ b/src/include/Parser.h
@@ -44,8 +44,8 @@ typedef struct ServerPart {
     char *port;
 } ServerPart;
 /**
- * A common identifier in the form '&local[:server]', where 
- * & determines the *type* of the identifier.
+ * A common identifier in the form '&local[:server]', where & determines the 
+ * *type* of the identifier.
  */
 typedef struct CommonID {
     char sigil;
@@ -59,5 +59,9 @@ typedef struct CommonID {
  */
 extern int ParseCommonID(char *, CommonID *);
 
+/** 
+ * Frees a CommonID's values. Note that it doesn't free the CommonID itself. */
+extern void CommonIDFree(CommonID id);
+
 
 #endif                             /* TELODENDRIA_PARSER_H */