1a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown/* 2a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * Copyright 2012 Daniel Drown <dan-android@drown.org> 3a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * 4a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * Licensed under the Apache License, Version 2.0 (the "License"); 5a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * you may not use this file except in compliance with the License. 6a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * You may obtain a copy of the License at 7a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * 8a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * http://www.apache.org/licenses/LICENSE-2.0 9a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * 10a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * Unless required by applicable law or agreed to in writing, software 11a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * distributed under the License is distributed on an "AS IS" BASIS, 12a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * See the License for the specific language governing permissions and 14a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * limitations under the License. 15a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * 16a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * netlink_callbacks.c - generic callbacks for netlink responses 17a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown */ 18a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown#include <netinet/in.h> 19a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown#include <net/if.h> 20a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown 21a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown#include <linux/rtnetlink.h> 22a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown#include <netlink/handlers.h> 23a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown#include <netlink/msg.h> 24a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown 25a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown/* function: ack_handler 26a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * generic netlink callback for ack messages 27a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * msg - netlink message 28a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * data - pointer to an int, stores the success code 29a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown */ 3056ec161d47856212008f47676577882f30853312Lorenzo Colittistatic int ack_handler(__attribute__((unused)) struct nl_msg *msg, void *data) { 31a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown int *retval = data; 32a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown *retval = 0; 33a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown return NL_OK; 34a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown} 35a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown 36a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown/* function: error_handler 37a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * generic netlink callback for error messages 38a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * nla - error source 39a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * err - netlink error message 40a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * arg - pointer to an int, stores the error code 41a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown */ 4256ec161d47856212008f47676577882f30853312Lorenzo Colittistatic int error_handler(__attribute__((unused)) struct sockaddr_nl *nla, 4356ec161d47856212008f47676577882f30853312Lorenzo Colitti struct nlmsgerr *err, void *arg) { 44a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown int *retval = arg; 45a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown if(err->error < 0) { 46a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown *retval = err->error; 47a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown } else { 48a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown *retval = 0; // NLMSG_ERROR used as reply type on no error 49a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown } 50a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown return NL_OK; 51a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown} 52a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown 53a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown/* function: alloc_ack_callbacks 54a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * allocates a set of netlink callbacks. returns NULL on failure. callbacks will modify retval with <0 meaning failure 55a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown * retval - shared state between caller and callback functions 56a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown */ 57a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drownstruct nl_cb *alloc_ack_callbacks(int *retval) { 58a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown struct nl_cb *callbacks; 59a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown 60a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown callbacks = nl_cb_alloc(NL_CB_DEFAULT); 61a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown if(!callbacks) { 62a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown return NULL; 63a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown } 64a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown nl_cb_set(callbacks, NL_CB_ACK, NL_CB_CUSTOM, ack_handler, retval); 65a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown nl_cb_err(callbacks, NL_CB_CUSTOM, error_handler, retval); 66a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown return callbacks; 67a45056e35c1af2a0f0a6eed258fd5fdf4846a79fDaniel Drown} 68