| /* |
| * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved. |
| * |
| * This software is licensed under the terms of the GNU General Public |
| * License version 2, as published by the Free Software Foundation, and |
| * may be copied, distributed, and modified under those terms. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/export.h> |
| #include <linux/etherdevice.h> |
| #include <linux/netlink.h> |
| #include <asm/byteorder.h> |
| #include <net/sock.h> |
| |
| #include "netlink_k.h" |
| |
| #if defined(DEFINE_MUTEX) |
| static DEFINE_MUTEX(netlink_mutex); |
| #else |
| static struct semaphore netlink_mutex; |
| #define mutex_lock(x) down(x) |
| #define mutex_unlock(x) up(x) |
| #endif |
| |
| #define ND_MAX_GROUP 30 |
| #define ND_IFINDEX_LEN sizeof(int) |
| #define ND_NLMSG_SPACE(len) (NLMSG_SPACE(len) + ND_IFINDEX_LEN) |
| #define ND_NLMSG_DATA(nlh) ((void *)((char *)NLMSG_DATA(nlh) + \ |
| ND_IFINDEX_LEN)) |
| #define ND_NLMSG_S_LEN(len) (len + ND_IFINDEX_LEN) |
| #define ND_NLMSG_R_LEN(nlh) (nlh->nlmsg_len - ND_IFINDEX_LEN) |
| #define ND_NLMSG_IFIDX(nlh) NLMSG_DATA(nlh) |
| #define ND_MAX_MSG_LEN (1024 * 32) |
| |
| static void (*rcv_cb)(struct net_device *dev, u16 type, void *msg, int len); |
| |
| static void netlink_rcv_cb(struct sk_buff *skb) |
| { |
| struct nlmsghdr *nlh; |
| struct net_device *dev; |
| u32 mlen; |
| void *msg; |
| int ifindex; |
| |
| if (!rcv_cb) { |
| pr_err("nl cb - unregistered\n"); |
| return; |
| } |
| |
| if (skb->len < NLMSG_HDRLEN) { |
| pr_err("nl cb - invalid skb length\n"); |
| return; |
| } |
| |
| nlh = (struct nlmsghdr *)skb->data; |
| |
| if (skb->len < nlh->nlmsg_len || nlh->nlmsg_len > ND_MAX_MSG_LEN) { |
| pr_err("nl cb - invalid length (%d,%d)\n", |
| skb->len, nlh->nlmsg_len); |
| return; |
| } |
| |
| memcpy(&ifindex, ND_NLMSG_IFIDX(nlh), ND_IFINDEX_LEN); |
| msg = ND_NLMSG_DATA(nlh); |
| mlen = ND_NLMSG_R_LEN(nlh); |
| |
| dev = dev_get_by_index(&init_net, ifindex); |
| if (dev) { |
| rcv_cb(dev, nlh->nlmsg_type, msg, mlen); |
| dev_put(dev); |
| } else { |
| pr_err("nl cb - dev (%d) not found\n", ifindex); |
| } |
| } |
| |
| static void netlink_rcv(struct sk_buff *skb) |
| { |
| mutex_lock(&netlink_mutex); |
| netlink_rcv_cb(skb); |
| mutex_unlock(&netlink_mutex); |
| } |
| |
| struct sock *netlink_init(int unit, |
| void (*cb)(struct net_device *dev, u16 type, void *msg, int len)) |
| { |
| struct sock *sock; |
| struct netlink_kernel_cfg cfg = { |
| .input = netlink_rcv, |
| }; |
| |
| #if !defined(DEFINE_MUTEX) |
| init_MUTEX(&netlink_mutex); |
| #endif |
| |
| sock = netlink_kernel_create(&init_net, unit, &cfg); |
| |
| if (sock) |
| rcv_cb = cb; |
| |
| return sock; |
| } |
| |
| void netlink_exit(struct sock *sock) |
| { |
| sock_release(sock->sk_socket); |
| } |
| |
| int netlink_send(struct sock *sock, int group, u16 type, void *msg, int len) |
| { |
| static u32 seq; |
| struct sk_buff *skb = NULL; |
| struct nlmsghdr *nlh; |
| int ret = 0; |
| |
| if (group > ND_MAX_GROUP) |
| return -EINVAL; |
| |
| if (!netlink_has_listeners(sock, group + 1)) |
| return -ESRCH; |
| |
| skb = alloc_skb(NLMSG_SPACE(len), GFP_ATOMIC); |
| if (!skb) |
| return -ENOMEM; |
| |
| seq++; |
| |
| nlh = nlmsg_put(skb, 0, seq, type, len, 0); |
| memcpy(NLMSG_DATA(nlh), msg, len); |
| NETLINK_CB(skb).portid = 0; |
| NETLINK_CB(skb).dst_group = 0; |
| |
| ret = netlink_broadcast(sock, skb, 0, group + 1, GFP_ATOMIC); |
| if (!ret) |
| return len; |
| |
| if (ret != -ESRCH) |
| pr_err("nl broadcast g=%d, t=%d, l=%d, r=%d\n", |
| group, type, len, ret); |
| else if (netlink_has_listeners(sock, group + 1)) |
| return -EAGAIN; |
| |
| return ret; |
| } |