1/* 2 * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved. 3 * 4 * This software is licensed under the terms of the GNU General Public 5 * License version 2, as published by the Free Software Foundation, and 6 * may be copied, distributed, and modified under those terms. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 */ 13 14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 15 16#include <linux/module.h> 17#include <linux/etherdevice.h> 18#include <net/netlink.h> 19#include <asm/byteorder.h> 20#include <net/sock.h> 21#include "netlink_k.h" 22 23#if !defined(NLMSG_HDRLEN) 24#define NLMSG_HDRLEN ((int) NLMSG_ALIGN(sizeof(struct nlmsghdr))) 25#endif 26 27#define ND_MAX_GROUP 30 28#define ND_IFINDEX_LEN sizeof(int) 29#define ND_NLMSG_SPACE(len) (nlmsg_total_size(len) + ND_IFINDEX_LEN) 30#define ND_NLMSG_DATA(nlh) \ 31 ((void *)((char *)nlmsg_data(nlh) + ND_IFINDEX_LEN)) 32#define ND_NLMSG_S_LEN(len) (len+ND_IFINDEX_LEN) 33#define ND_NLMSG_R_LEN(nlh) (nlh->nlmsg_len-ND_IFINDEX_LEN) 34#define ND_NLMSG_IFIDX(nlh) nlmsg_data(nlh) 35#define ND_MAX_MSG_LEN 8096 36 37#if defined(DEFINE_MUTEX) 38static DEFINE_MUTEX(netlink_mutex); 39#else 40static struct semaphore netlink_mutex; 41#define mutex_lock(x) down(x) 42#define mutex_unlock(x) up(x) 43#endif 44 45static void (*rcv_cb)(struct net_device *dev, u16 type, void *msg, int len); 46 47static void netlink_rcv_cb(struct sk_buff *skb) 48{ 49 struct nlmsghdr *nlh; 50 struct net_device *dev; 51 u32 mlen; 52 void *msg; 53 int ifindex; 54 55 if (skb->len >= NLMSG_HDRLEN) { 56 nlh = (struct nlmsghdr *)skb->data; 57 58 if (skb->len < nlh->nlmsg_len || 59 nlh->nlmsg_len > ND_MAX_MSG_LEN) { 60 netdev_err(skb->dev, "Invalid length (%d,%d)\n", 61 skb->len, nlh->nlmsg_len); 62 return; 63 } 64 65 memcpy(&ifindex, ND_NLMSG_IFIDX(nlh), ND_IFINDEX_LEN); 66 msg = ND_NLMSG_DATA(nlh); 67 mlen = ND_NLMSG_R_LEN(nlh); 68 69 if (rcv_cb) { 70 dev = dev_get_by_index(&init_net, ifindex); 71 if (dev) { 72 rcv_cb(dev, nlh->nlmsg_type, msg, mlen); 73 dev_put(dev); 74 } else 75 netdev_err(skb->dev, 76 "dev_get_by_index(%d) is not found.\n", 77 ifindex); 78 } else { 79 netdev_err(skb->dev, "Unregistered Callback\n"); 80 } 81 } 82} 83 84static void netlink_rcv(struct sk_buff *skb) 85{ 86 mutex_lock(&netlink_mutex); 87 netlink_rcv_cb(skb); 88 mutex_unlock(&netlink_mutex); 89} 90 91struct sock *netlink_init(int unit, void (*cb)(struct net_device *dev, u16 type, 92 void *msg, int len)) 93{ 94 struct sock *sock; 95 struct netlink_kernel_cfg cfg = { 96 .input = netlink_rcv, 97 }; 98 99#if !defined(DEFINE_MUTEX) 100 init_MUTEX(&netlink_mutex); 101#endif 102 103 sock = netlink_kernel_create(&init_net, unit, &cfg); 104 105 if (sock) 106 rcv_cb = cb; 107 108 return sock; 109} 110 111void netlink_exit(struct sock *sock) 112{ 113 netlink_kernel_release(sock); 114} 115 116int netlink_send(struct sock *sock, int group, u16 type, void *msg, int len) 117{ 118 static u32 seq; 119 struct sk_buff *skb = NULL; 120 struct nlmsghdr *nlh; 121 int ret = 0; 122 123 if (group > ND_MAX_GROUP) { 124 pr_err("Group %d is invalied.\n", group); 125 pr_err("Valid group is 0 ~ %d.\n", ND_MAX_GROUP); 126 return -EINVAL; 127 } 128 129 skb = nlmsg_new(len, GFP_ATOMIC); 130 if (!skb) { 131 pr_err("netlink_broadcast ret=%d\n", ret); 132 return -ENOMEM; 133 } 134 135 seq++; 136 nlh = nlmsg_put(skb, 0, seq, type, len, 0); 137 if (!nlh) { 138 kfree_skb(skb); 139 return -EMSGSIZE; 140 } 141 memcpy(nlmsg_data(nlh), msg, len); 142 143 NETLINK_CB(skb).portid = 0; 144 NETLINK_CB(skb).dst_group = 0; 145 146 ret = netlink_broadcast(sock, skb, 0, group+1, GFP_ATOMIC); 147 148 if (!ret) 149 return len; 150 if (ret != -ESRCH) { 151 pr_err("netlink_broadcast g=%d, t=%d, l=%d, r=%d\n", 152 group, type, len, ret); 153 } 154 ret = 0; 155 return ret; 156} 157