(libT): added an ACL tester to tr_sessionSetRPCACL() and return an error string if the ACL can't be parsed.

libtransmission/rpc-server.c

@@ -175,19 +175,72 @@ tr_rpcGetPort( const tr_rpc_server * server )
     return server->port;
 }
 
-void
-tr_rpcSetACL( tr_rpc_server * server, const char * acl )
+/*
+ * DELIM_CHARS, FOR_EACH_WORD_IN_LIST, isbyte, and testACL are from, or modified from,
+ * shttpd, written by Sergey Lyubka under this license:
+ * "THE BEER-WARE LICENSE" (Revision 42):
+ * Sergey Lyubka wrote this file.  As long as you retain this notice you
+ * can do whatever you want with this stuff. If we meet some day, and you think
+ * this stuff is worth it, you can buy me a beer in return.
+ */
+
+#define  DELIM_CHARS " ," /* Separators for lists */
+
+#define FOR_EACH_WORD_IN_LIST(s,len)                                    \
+        for (; s != NULL && (len = strcspn(s, DELIM_CHARS)) != 0;       \
+                        s += len, s+= strspn(s, DELIM_CHARS))
+
+static int isbyte(int n) { return (n >= 0 && n <= 255); }
+
+static char*
+testACL( const char * s )
+{
+    int len;
+
+    FOR_EACH_WORD_IN_LIST(s, len)
+    {
+
+        char flag;
+        int  a, b, c, d, n, mask;
+
+        if( sscanf(s, "%c%d.%d.%d.%d%n",&flag,&a,&b,&c,&d,&n) != 5 )
+            return tr_strdup_printf( _( "[%s]: subnet must be [+|-]x.x.x.x[/x]" ), s );
+        if( flag != '+' && flag != '-')
+            return tr_strdup_printf( _( "[%s]: flag must be + or -" ), s );
+        if( !isbyte(a) || !isbyte(b) || !isbyte(c) || !isbyte(d) )
+            return tr_strdup_printf( _( "[%s]: bad ip address" ), s );
+        if( sscanf(s + n, "/%d", &mask) == 1 && ( mask<0 || mask>32 ) )
+            return tr_strdup_printf( _( "[%s]: bad subnet mask %d" ), s, n );
+    }
+
+    return NULL;
+}
+
+int
+tr_rpcSetACL( tr_rpc_server * server, const char * acl, char ** setme_errmsg )
 {
     const int isRunning = server->ctx != NULL;
+    int ret = 0;
+    char * errmsg = testACL( acl );
 
-    if( isRunning )
-        stopServer( server );
+    if( errmsg )
+    {
+        *setme_errmsg = errmsg;
+        ret = -1;
+    }
+    else
+    {
+        if( isRunning )
+            stopServer( server );
 
-    tr_free( server->acl );
-    server->acl = tr_strdup( acl );
+        tr_free( server->acl );
+        server->acl = tr_strdup( acl );
 
-    if( isRunning )
-        startServer( server );
+        if( isRunning )
+            startServer( server );
+    }
+
+    return ret;
 }
 
 const char*

libtransmission/rpc-server.h

@@ -32,8 +32,9 @@ void        tr_rpcSetPort   ( tr_rpc_server          * server,
 
 int         tr_rpcGetPort   ( const tr_rpc_server    * server );
 
-void        tr_rpcSetACL    ( tr_rpc_server          * server,
-                              const char             * acl );
+int         tr_rpcSetACL    ( tr_rpc_server          * server,
+                              const char             * acl,
+                              char                  ** allocme_errmsg );
 
 const char* tr_rpcGetACL    ( const tr_rpc_server    * server );
 

libtransmission/session.c

@@ -775,10 +775,12 @@ tr_sessionSetRPCCallback( tr_handle    * session,
     session->rpc_func_user_data = user_data;
 }
 
-void
-tr_sessionSetRPCACL( tr_handle * session, const char * acl )
+int
+tr_sessionSetRPCACL( tr_handle    * session,
+                     const char   * acl,
+                     char        ** allocme_errmsg )
 {
-    tr_rpcSetACL( session->rpcServer, acl );
+    return tr_rpcSetACL( session->rpcServer, acl, allocme_errmsg );
 }
 
 const char*

libtransmission/transmission.h

@@ -300,15 +300,19 @@ int tr_sessionGetRPCPort( const tr_handle * );
  *
  * The default string is "+127.0.0.1"
  *
- * IMPORTANT: a malformed ACL is likely to cause Transmission to crash.
- * Client applications need to validate user input, or better yet
- * generate it from a higher-level interface that doesn't allow user error,
- * before calling this function.
+ * @param acl the new ACL to use.
+ * @param allocme_errmsg If the ACL can't be parsed, this is set to a
+ *                       newly-allocated error string describing the problem.
+ *                       The client should tr_free() this string when done.
+ *
+ * @return 0 on success, -1 on failure due to an unparseable ACL.
  *
  * @see tr_sessionInitFull
  * @see tr_sessionGetRPCACL
  */
-void tr_sessionSetRPCACL( tr_handle *, const char * acl );
+int tr_sessionSetRPCACL( tr_handle   * session,
+                         const char  * acl,
+                         char       ** allocme_errmsg );
 
 /** Returns the Access Control List for allowing/denying RPC requests.
     @see tr_sessionInitFull

libtransmission/utils-test.c

@@ -3,7 +3,7 @@
 #include "transmission.h"
 #include "utils.h"
 
-#define VERBOSE 1
+#define VERBOSE 0
 #define NUM_LOOPS 1
 #define SPEED_TEST 0