diff options
Diffstat (limited to 'drivers/staging/gdm724x/netlink_k.c')
-rw-r--r-- | drivers/staging/gdm724x/netlink_k.c | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/drivers/staging/gdm724x/netlink_k.c b/drivers/staging/gdm724x/netlink_k.c new file mode 100644 index 000000000..8f39cc561 --- /dev/null +++ b/drivers/staging/gdm724x/netlink_k.c @@ -0,0 +1,128 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved. */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/export.h> +#include <linux/mutex.h> +#include <linux/etherdevice.h> +#include <linux/netlink.h> +#include <asm/byteorder.h> +#include <net/sock.h> + +#include "netlink_k.h" + +static DEFINE_MUTEX(netlink_mutex); + +#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, + }; + + sock = netlink_kernel_create(&init_net, unit, &cfg); + + if (sock) + rcv_cb = cb; + + return sock; +} + +int netlink_send(struct sock *sock, int group, u16 type, void *msg, int len, + struct net_device *dev) +{ + 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) + netdev_err(dev, "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; +} |