| 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 | #include <linux/module.h> |
| 15 | #include <linux/etherdevice.h> |
| 16 | #include <linux/netlink.h> |
| 17 | #include <asm/byteorder.h> |
| 18 | #include <net/sock.h> |
| 19 | |
| 20 | #if !defined(NLMSG_HDRLEN) |
| 21 | #define NLMSG_HDRLEN ((int) NLMSG_ALIGN(sizeof(struct nlmsghdr))) |
| 22 | #endif |
| 23 | |
| 24 | #define ND_MAX_GROUP 30 |
| 25 | #define ND_IFINDEX_LEN sizeof(int) |
| 26 | #define ND_NLMSG_SPACE(len) (NLMSG_SPACE(len) + ND_IFINDEX_LEN) |
| 27 | #define ND_NLMSG_DATA(nlh) \ |
| 28 | ((void *)((char *)NLMSG_DATA(nlh) + ND_IFINDEX_LEN)) |
| 29 | #define ND_NLMSG_S_LEN(len) (len+ND_IFINDEX_LEN) |
| 30 | #define ND_NLMSG_R_LEN(nlh) (nlh->nlmsg_len-ND_IFINDEX_LEN) |
| 31 | #define ND_NLMSG_IFIDX(nlh) NLMSG_DATA(nlh) |
| 32 | #define ND_MAX_MSG_LEN 8096 |
| 33 | |
| 34 | #if defined(DEFINE_MUTEX) |
| 35 | static DEFINE_MUTEX(netlink_mutex); |
| 36 | #else |
| 37 | static struct semaphore netlink_mutex; |
| 38 | #define mutex_lock(x) down(x) |
| 39 | #define mutex_unlock(x) up(x) |
| 40 | #endif |
| 41 | |
| 42 | static void (*rcv_cb)(struct net_device *dev, u16 type, void *msg, int len); |
| 43 | |
| 44 | static void netlink_rcv_cb(struct sk_buff *skb) |
| 45 | { |
| 46 | struct nlmsghdr *nlh; |
| 47 | struct net_device *dev; |
| 48 | u32 mlen; |
| 49 | void *msg; |
| 50 | int ifindex; |
| 51 | |
| 52 | if (skb->len >= NLMSG_SPACE(0)) { |
| 53 | nlh = (struct nlmsghdr *)skb->data; |
| 54 | |
| 55 | if (skb->len < nlh->nlmsg_len || |
| 56 | nlh->nlmsg_len > ND_MAX_MSG_LEN) { |
| 57 | printk(KERN_ERR "Invalid length (%d,%d)\n", skb->len, |
| 58 | nlh->nlmsg_len); |
| 59 | return; |
| 60 | } |
| 61 | |
| 62 | memcpy(&ifindex, ND_NLMSG_IFIDX(nlh), ND_IFINDEX_LEN); |
| 63 | msg = ND_NLMSG_DATA(nlh); |
| 64 | mlen = ND_NLMSG_R_LEN(nlh); |
| 65 | |
| 66 | if (rcv_cb) { |
| 67 | dev = dev_get_by_index(&init_net, ifindex); |
| 68 | if (dev) { |
| 69 | rcv_cb(dev, nlh->nlmsg_type, msg, mlen); |
| 70 | dev_put(dev); |
| 71 | } else |
| 72 | printk(KERN_ERR "dev_get_by_index(%d) " |
| 73 | "is not found.\n", ifindex); |
| 74 | } else |
| 75 | printk(KERN_ERR "Unregistered Callback\n"); |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | static void netlink_rcv(struct sk_buff *skb) |
| 80 | { |
| 81 | mutex_lock(&netlink_mutex); |
| 82 | netlink_rcv_cb(skb); |
| 83 | mutex_unlock(&netlink_mutex); |
| 84 | } |
| 85 | |
| 86 | struct sock *netlink_init(int unit, void (*cb)(struct net_device *dev, u16 type, |
| 87 | void *msg, int len)) |
| 88 | { |
| 89 | struct sock *sock; |
| 90 | struct netlink_kernel_cfg cfg = { |
| 91 | .input = netlink_rcv, |
| 92 | }; |
| 93 | |
| 94 | #if !defined(DEFINE_MUTEX) |
| 95 | init_MUTEX(&netlink_mutex); |
| 96 | #endif |
| 97 | |
| 98 | sock = netlink_kernel_create(&init_net, unit, &cfg); |
| 99 | |
| 100 | if (sock) |
| 101 | rcv_cb = cb; |
| 102 | |
| 103 | return sock; |
| 104 | } |
| 105 | |
| 106 | void netlink_exit(struct sock *sock) |
| 107 | { |
| 108 | netlink_kernel_release(sock); |
| 109 | } |
| 110 | |
| 111 | int netlink_send(struct sock *sock, int group, u16 type, void *msg, int len) |
| 112 | { |
| 113 | static u32 seq; |
| 114 | struct sk_buff *skb = NULL; |
| 115 | struct nlmsghdr *nlh; |
| 116 | int ret = 0; |
| 117 | |
| 118 | if (group > ND_MAX_GROUP) { |
| 119 | printk(KERN_ERR "Group %d is invalied.\n", group); |
| 120 | printk(KERN_ERR "Valid group is 0 ~ %d.\n", ND_MAX_GROUP); |
| 121 | return -EINVAL; |
| 122 | } |
| 123 | |
| 124 | skb = alloc_skb(NLMSG_SPACE(len), GFP_ATOMIC); |
| 125 | if (!skb) { |
| 126 | printk(KERN_ERR "netlink_broadcast ret=%d\n", ret); |
| 127 | return -ENOMEM; |
| 128 | } |
| 129 | |
| 130 | seq++; |
| 131 | nlh = nlmsg_put(skb, 0, seq, type, len, 0); |
| 132 | if (!nlh) { |
| 133 | kfree_skb(skb); |
| 134 | return -EMSGSIZE; |
| 135 | } |
| 136 | memcpy(nlmsg_data(nlh), msg, len); |
| 137 | |
| 138 | NETLINK_CB(skb).portid = 0; |
| 139 | NETLINK_CB(skb).dst_group = 0; |
| 140 | |
| 141 | ret = netlink_broadcast(sock, skb, 0, group+1, GFP_ATOMIC); |
| 142 | |
| 143 | if (!ret) |
| 144 | return len; |
| 145 | else { |
| 146 | if (ret != -ESRCH) { |
| 147 | printk(KERN_ERR "netlink_broadcast g=%d, t=%d, l=%d, r=%d\n", |
| 148 | group, type, len, ret); |
| 149 | } |
| 150 | ret = 0; |
| 151 | } |
| 152 | return ret; |
| 153 | } |