sftp: more flexibility on channels

Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

include/libssh/sftp.h

@@ -133,6 +133,7 @@ struct sftp_client_message_struct {
     ssh_buffer attrbuf; /* used by sftp_reply_attrs */
     ssh_string data; /* can be newpath of rename() */
     ssh_buffer complete_message; /* complete message in case of retransmission*/
+    char *str_data; /* cstring version of data */
 };
 
 struct sftp_request_queue_struct {
@@ -203,6 +204,19 @@ struct sftp_statvfs_struct {
  */
 LIBSSH_API sftp_session sftp_new(ssh_session session);
 
+/**
+ * @brief Start a new sftp session with an existing channel.
+ *
+ * @param session       The ssh session to use.
+ * @param channel		An open session channel with subsystem already allocated
+ *
+ * @return              A new sftp session or NULL on error.
+ *
+ * @see sftp_free()
+ */
+LIBSSH_API sftp_session sftp_new_channel(ssh_session session, ssh_channel channel);
+
+
 /**
  * @brief Close and deallocate a sftp session.
  *
@@ -830,7 +844,7 @@ LIBSSH_API void sftp_client_message_free(sftp_client_message msg);
 LIBSSH_API uint8_t sftp_client_message_get_type(sftp_client_message msg);
 LIBSSH_API const char *sftp_client_message_get_filename(sftp_client_message msg);
 LIBSSH_API void sftp_client_message_set_filename(sftp_client_message msg, const char *newname);
-LIBSSH_API char *sftp_client_message_get_data(sftp_client_message msg);
+LIBSSH_API const char *sftp_client_message_get_data(sftp_client_message msg);
 LIBSSH_API uint32_t sftp_client_message_get_flags(sftp_client_message msg);
 LIBSSH_API int sftp_send_client_message(sftp_session sftp, sftp_client_message msg);
 int sftp_reply_name(sftp_client_message msg, const char *name,

src/sftp.c

@@ -149,6 +149,37 @@ sftp_session sftp_new(ssh_session session){
   return sftp;
 }
 
+sftp_session sftp_new_channel(ssh_session session, ssh_channel channel){
+  sftp_session sftp;
+
+  if (session == NULL) {
+    return NULL;
+  }
+  enter_function();
+
+  sftp = malloc(sizeof(struct sftp_session_struct));
+  if (sftp == NULL) {
+    ssh_set_error_oom(session);
+    leave_function();
+    return NULL;
+  }
+  ZERO_STRUCTP(sftp);
+
+  sftp->ext = sftp_ext_new();
+  if (sftp->ext == NULL) {
+    ssh_set_error_oom(session);
+    SAFE_FREE(sftp);
+    leave_function();
+    return NULL;
+  }
+
+  sftp->session = session;
+  sftp->channel = channel;
+
+  leave_function();
+  return sftp;
+}
+
 #ifdef WITH_SERVER
 sftp_session sftp_server_new(ssh_session session, ssh_channel chan){
   sftp_session sftp = NULL;

src/sftpserver.c

@@ -263,9 +263,10 @@ void sftp_client_message_set_filename(sftp_client_message msg, const char *newna
 	msg->filename = strdup(newname);
 }
 
-char *sftp_client_message_get_data(sftp_client_message msg){
-	char *str = ssh_string_to_char(msg->data);
-	return str;
+const char *sftp_client_message_get_data(sftp_client_message msg){
+	if (msg->str_data == NULL)
+		msg->str_data = ssh_string_to_char(msg->data);
+	return msg->str_data;
 }
 
 uint32_t sftp_client_message_get_flags(sftp_client_message msg){
@@ -282,6 +283,7 @@ void sftp_client_message_free(sftp_client_message msg) {
   ssh_string_free(msg->handle);
   sftp_attributes_free(msg->attr);
   ssh_buffer_free(msg->complete_message);
+  SAFE_FREE(msg->str_data);
   ZERO_STRUCTP(msg);
   SAFE_FREE(msg);
 }