Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / staging / gdm724x / netlink_k.c

diff --git a/kernel/drivers/staging/gdm724x/netlink_k.c b/kernel/drivers/staging/gdm724x/netlink_k.c
new file mode 100644 (file)
index 0000000..59a1830
--- /dev/null
+++ b/kernel/drivers/staging/gdm724x/netlink_k.c
@@ -0,0 +1,150 @@
+/*
+ * 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;
+}