Refactor how properties are parsed

src/curve_client.cpp

@@ -399,48 +399,17 @@ int zmq::curve_client_t::process_ready (msg_t *msg_)
         return -1;
     }
 
-    rc = parse_property_list (ready_plaintext + crypto_box_ZEROBYTES,
+    rc = parse_properties (ready_plaintext + crypto_box_ZEROBYTES,
                            clen - crypto_box_ZEROBYTES);
     return rc;
 }
 
-int zmq::curve_client_t::parse_property_list (const uint8_t *ptr,
+int zmq::curve_client_t::property (const std::string name,
-    size_t bytes_left)
+                                   const void *value, size_t length)
 {
-    while (bytes_left > 1) {
-        const size_t name_length = static_cast <size_t> (*ptr);
-        ptr += 1;
-        bytes_left -= 1;
-        if (bytes_left < name_length)
-            break;
-
-        const std::string name = std::string ((const char *) ptr, name_length);
-        ptr += name_length;
-        bytes_left -= name_length;
-        if (bytes_left < 4)
-            break;
-
-        const size_t value_length = static_cast <size_t> (get_uint32 (ptr));
-        ptr += 4;
-        bytes_left -= 4;
-        if (bytes_left < value_length)
-            break;
-
-        const uint8_t * const value = ptr;
-        ptr += value_length;
-        bytes_left -= value_length;
-
     if (name == "Socket-Type") {
         //  TODO: Implement socket type checking
     }
-        else
-        if (name == "Identity" && options.recv_identity)
-            set_peer_identity (value, value_length);
-    }
-    if (bytes_left > 0) {
-        errno = EPROTO;
-        return -1;
-    }
     return 0;
 }
 

src/curve_client.hpp

@@ -101,7 +101,8 @@ namespace zmq
         int initiate_msg (msg_t *msg_);
         int process_ready (msg_t *msg_);
 
-        int parse_property_list (const uint8_t *ptr, size_t length);
+        virtual int property (const std::string name,
+                              const void *value, size_t length);
     };
 
 }

src/curve_server.cpp

@@ -441,7 +441,7 @@ int zmq::curve_server_t::process_initiate (msg_t *msg_)
         }
     }
 
-    return parse_property_list (initiate_plaintext + crypto_box_ZEROBYTES + 96,
+    return parse_properties (initiate_plaintext + crypto_box_ZEROBYTES + 96,
                              clen - crypto_box_ZEROBYTES - 96);
 }
 
@@ -543,43 +543,12 @@ void zmq::curve_server_t::send_zap_request (const uint8_t *key)
     errno_assert (rc == 0);
 }
 
-int zmq::curve_server_t::parse_property_list (const uint8_t *ptr,
+int zmq::curve_server_t::property (const std::string name,
-    size_t bytes_left)
+                                   const void *value, size_t length)
 {
-    while (bytes_left > 1) {
-        const size_t name_length = static_cast <size_t> (*ptr);
-        ptr += 1;
-        bytes_left -= 1;
-        if (bytes_left < name_length)
-            break;
-
-        const std::string name = std::string ((const char *) ptr, name_length);
-        ptr += name_length;
-        bytes_left -= name_length;
-        if (bytes_left < 4)
-            break;
-
-        const size_t value_length = static_cast <size_t> (get_uint32 (ptr));
-        ptr += 4;
-        bytes_left -= 4;
-        if (bytes_left < value_length)
-            break;
-
-        const uint8_t * const value = ptr;
-        ptr += value_length;
-        bytes_left -= value_length;
-
     if (name == "Socket-Type") {
         //  TODO: Implement socket type checking
     }
-        else
-        if (name == "Identity" && options.recv_identity)
-            set_peer_identity (value, value_length);
-    }
-    if (bytes_left > 0) {
-        errno = EPROTO;
-        return -1;
-    }
     return 0;
 }
 

src/curve_server.hpp

@@ -107,7 +107,9 @@ namespace zmq
 
         void send_zap_request (const uint8_t *key);
         int receive_and_process_zap_reply ();
-        int parse_property_list (const uint8_t *ptr, size_t length);
+
+        virtual int property (const std::string name,
+                              const void *value, size_t length);
     };
 
 }

src/mechanism.cpp

@@ -71,3 +71,53 @@ size_t zmq::mechanism_t::add_property (unsigned char *ptr, const char *name,
 
     return 1 + name_len + 4 + value_len;
 }
+
+int zmq::mechanism_t::parse_properties (const unsigned char *ptr_,
+                                        size_t length_)
+{
+    size_t bytes_left = length_;
+
+    while (bytes_left > 1) {
+        const size_t name_length = static_cast <size_t> (*ptr_);
+        ptr_ += 1;
+        bytes_left -= 1;
+        if (bytes_left < name_length)
+            break;
+
+        const std::string name = std::string ((char *) ptr_, name_length);
+        ptr_ += name_length;
+        bytes_left -= name_length;
+        if (bytes_left < 4)
+            break;
+
+        const size_t value_length = static_cast <size_t> (get_uint32 (ptr_));
+        ptr_ += 4;
+        bytes_left -= 4;
+        if (bytes_left < value_length)
+            break;
+
+        const uint8_t *value = ptr_;
+        ptr_ += value_length;
+        bytes_left -= value_length;
+
+        const int rc = property (name, value, value_length);
+        if (rc == -1)
+            return -1;
+
+        if (name == "Identity" && options.recv_identity)
+            set_peer_identity (value, value_length);
+    }
+    if (bytes_left > 0) {
+        errno = EPROTO;
+        return -1;
+    }
+    return 0;
+}
+
+int zmq::mechanism_t::property (const std::string name_,
+                                const void *value_, size_t length_)
+{
+    //  Default implementation does not check
+    //  property values and returns 0 to signal success.
+    return 0;
+}

src/mechanism.hpp

@@ -69,6 +69,20 @@ namespace zmq
         size_t add_property (unsigned char *ptr, const char *name,
             const void *value, size_t value_len) const;
 
+        //  Parse a list of properties. Returns 0 on success
+        //  and -1 on error, in which case errno is set.
+        int parse_properties (const unsigned char *ptr_, size_t length);
+
+        //  This is called by parse_property method whenever it
+        //  parses a new property. The function should return 0
+        //  on success and -1 on error, in which case it should
+        //  set errno. Signaling error prevetns parser from
+        //  parsing remaining data.
+        //  Derived classes are supposed to override this
+        //  method to handle custom processing.
+        virtual int property (const std::string name_,
+                              const void *value_, size_t length_);
+
         options_t options;
 
     private:

src/null_mechanism.cpp

@@ -99,54 +99,29 @@ int zmq::null_mechanism_t::process_handshake_message (msg_t *msg_)
     ptr += 8;
     bytes_left -= 8;
 
-    //  Parse the property list
+    int rc = parse_properties (ptr, bytes_left);
-    while (bytes_left > 1) {
+    if (rc == 0) {
-        const size_t name_length = static_cast <size_t> (*ptr);
-        ptr += 1;
-        bytes_left -= 1;
-
-        if (bytes_left < name_length)
-            break;
-        const std::string name = std::string((const char *) ptr, name_length);
-        ptr += name_length;
-        bytes_left -= name_length;
-
-        if (bytes_left < 4)
-            break;
-        const size_t value_length = static_cast <size_t> (get_uint32 (ptr));
-        ptr += 4;
-        bytes_left -= 4;
-
-        if (bytes_left < value_length)
-            break;
-        const unsigned char * const value = ptr;
-        ptr += value_length;
-        bytes_left -= value_length;
-
-        if (name == "Socket-Type") {
-            //  TODO: Implement socket type checking
-        }
-        else
-        if (name == "Identity" && options.recv_identity)
-            set_peer_identity (value, value_length);
-    }
-
-    if (bytes_left > 0) {
-        errno = EPROTO;
-        return -1;
-    }
-
         int rc = msg_->close ();
         errno_assert (rc == 0);
         rc = msg_->init ();
         errno_assert (rc == 0);
+    }
 
     ready_command_received = true;
 
-    return 0;
+    return rc;
 }
 
 bool zmq::null_mechanism_t::is_handshake_complete () const
 {
     return ready_command_received && ready_command_sent;
 }
+
+int zmq::null_mechanism_t::property (const std::string name,
+                                     const void *value, size_t length)
+{
+    if (name == "Socket-Type") {
+        //  TODO: Implement socket type checking
+    }
+    return 0;
+}

src/null_mechanism.hpp

@@ -40,6 +40,10 @@ namespace zmq
         virtual int process_handshake_message (msg_t *msg_);
         virtual bool is_handshake_complete () const;
 
+    protected:
+
+        virtual int property (const std::string name,
+                              const void *value, size_t length);
     private:
 
         bool ready_command_sent;

src/plain_mechanism.cpp

@@ -285,7 +285,7 @@ int zmq::plain_mechanism_t::process_initiate_command (msg_t *msg_)
         errno = EPROTO;
         return -1;
     }
-    return parse_property_list (ptr + 8, bytes_left - 8);
+    return parse_properties (ptr + 8, bytes_left - 8);
 }
 
 int zmq::plain_mechanism_t::ready_command (msg_t *msg_) const
@@ -329,7 +329,7 @@ int zmq::plain_mechanism_t::process_ready_command (msg_t *msg_)
         errno = EPROTO;
         return -1;
     }
-    return parse_property_list (ptr + 8, bytes_left - 8);
+    return parse_properties (ptr + 8, bytes_left - 8);
 }
 
 void zmq::plain_mechanism_t::send_zap_request (const std::string &username,
@@ -451,42 +451,11 @@ error:
     return rc;
 }
 
-int zmq::plain_mechanism_t::parse_property_list (const unsigned char *ptr,
+int zmq::plain_mechanism_t::property (const std::string name,
-    size_t bytes_left)
+                                      const void *value, size_t length)
 {
-    while (bytes_left > 1) {
-        const size_t name_length = static_cast <size_t> (*ptr);
-        ptr += 1;
-        bytes_left -= 1;
-        if (bytes_left < name_length)
-            break;
-
-        const std::string name = std::string ((const char *) ptr, name_length);
-        ptr += name_length;
-        bytes_left -= name_length;
-        if (bytes_left < 4)
-            break;
-
-        const size_t value_length = static_cast <size_t> (get_uint32 (ptr));
-        ptr += 4;
-        bytes_left -= 4;
-        if (bytes_left < value_length)
-            break;
-
-        const unsigned char * const value = ptr;
-        ptr += value_length;
-        bytes_left -= value_length;
-
     if (name == "Socket-Type") {
         //  TODO: Implement socket type checking
     }
-        else
-        if (name == "Identity" && options.recv_identity)
-            set_peer_identity (value, value_length);
-    }
-    if (bytes_left > 0) {
-        errno = EPROTO;
-        return -1;
-    }
     return 0;
 }

src/plain_mechanism.hpp

@@ -43,6 +43,11 @@ namespace zmq
         virtual int zap_msg_available ();
         virtual bool is_handshake_complete () const;
 
+    protected:
+
+        virtual int property (const std::string name,
+                              const void *value, size_t length);
+
     private:
 
         enum state_t {
@@ -78,8 +83,6 @@ namespace zmq
         void send_zap_request (const std::string &username,
                                const std::string &password);
         int receive_and_process_zap_reply ();
-
-        int parse_property_list (const unsigned char *ptr, size_t length);
     };
 
 }