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61e12104 WK |
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 | ||
0ec473b5 JP |
14 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
15 | ||
61e12104 | 16 | #include <linux/export.h> |
bf5cad61 | 17 | #include <linux/mutex.h> |
61e12104 WK |
18 | #include <linux/etherdevice.h> |
19 | #include <linux/netlink.h> | |
20 | #include <asm/byteorder.h> | |
21 | #include <net/sock.h> | |
22 | ||
23 | #include "netlink_k.h" | |
24 | ||
61e12104 | 25 | static DEFINE_MUTEX(netlink_mutex); |
61e12104 WK |
26 | |
27 | #define ND_MAX_GROUP 30 | |
28 | #define ND_IFINDEX_LEN sizeof(int) | |
29 | #define ND_NLMSG_SPACE(len) (NLMSG_SPACE(len) + ND_IFINDEX_LEN) | |
a6708372 DN |
30 | #define ND_NLMSG_DATA(nlh) ((void *)((char *)NLMSG_DATA(nlh) + \ |
31 | ND_IFINDEX_LEN)) | |
ba7f55b7 IC |
32 | #define ND_NLMSG_S_LEN(len) (len + ND_IFINDEX_LEN) |
33 | #define ND_NLMSG_R_LEN(nlh) (nlh->nlmsg_len - ND_IFINDEX_LEN) | |
61e12104 WK |
34 | #define ND_NLMSG_IFIDX(nlh) NLMSG_DATA(nlh) |
35 | #define ND_MAX_MSG_LEN (1024 * 32) | |
36 | ||
37 | static void (*rcv_cb)(struct net_device *dev, u16 type, void *msg, int len); | |
38 | ||
39 | static void netlink_rcv_cb(struct sk_buff *skb) | |
40 | { | |
41 | struct nlmsghdr *nlh; | |
42 | struct net_device *dev; | |
43 | u32 mlen; | |
44 | void *msg; | |
45 | int ifindex; | |
46 | ||
47 | if (!rcv_cb) { | |
0ec473b5 | 48 | pr_err("nl cb - unregistered\n"); |
61e12104 WK |
49 | return; |
50 | } | |
51 | ||
58419939 | 52 | if (skb->len < NLMSG_HDRLEN) { |
0ec473b5 | 53 | pr_err("nl cb - invalid skb length\n"); |
61e12104 WK |
54 | return; |
55 | } | |
56 | ||
57 | nlh = (struct nlmsghdr *)skb->data; | |
58 | ||
59 | if (skb->len < nlh->nlmsg_len || nlh->nlmsg_len > ND_MAX_MSG_LEN) { | |
0ec473b5 | 60 | pr_err("nl cb - invalid length (%d,%d)\n", |
61e12104 WK |
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 | dev = dev_get_by_index(&init_net, ifindex); | |
70 | if (dev) { | |
71 | rcv_cb(dev, nlh->nlmsg_type, msg, mlen); | |
72 | dev_put(dev); | |
73 | } else { | |
0ec473b5 | 74 | pr_err("nl cb - dev (%d) not found\n", ifindex); |
61e12104 WK |
75 | } |
76 | } | |
77 | ||
78 | static void netlink_rcv(struct sk_buff *skb) | |
79 | { | |
80 | mutex_lock(&netlink_mutex); | |
81 | netlink_rcv_cb(skb); | |
82 | mutex_unlock(&netlink_mutex); | |
83 | } | |
84 | ||
85 | struct sock *netlink_init(int unit, | |
47678e37 BC |
86 | void (*cb)(struct net_device *dev, u16 type, |
87 | void *msg, int len)) | |
61e12104 WK |
88 | { |
89 | struct sock *sock; | |
61e12104 WK |
90 | struct netlink_kernel_cfg cfg = { |
91 | .input = netlink_rcv, | |
92 | }; | |
61e12104 | 93 | |
61e12104 | 94 | sock = netlink_kernel_create(&init_net, unit, &cfg); |
61e12104 WK |
95 | |
96 | if (sock) | |
97 | rcv_cb = cb; | |
98 | ||
99 | return sock; | |
100 | } | |
101 | ||
61e12104 WK |
102 | int netlink_send(struct sock *sock, int group, u16 type, void *msg, int len) |
103 | { | |
104 | static u32 seq; | |
105 | struct sk_buff *skb = NULL; | |
106 | struct nlmsghdr *nlh; | |
107 | int ret = 0; | |
108 | ||
109 | if (group > ND_MAX_GROUP) | |
110 | return -EINVAL; | |
111 | ||
b6f6fd8a | 112 | if (!netlink_has_listeners(sock, group + 1)) |
61e12104 WK |
113 | return -ESRCH; |
114 | ||
115 | skb = alloc_skb(NLMSG_SPACE(len), GFP_ATOMIC); | |
116 | if (!skb) | |
117 | return -ENOMEM; | |
118 | ||
119 | seq++; | |
120 | ||
121 | nlh = nlmsg_put(skb, 0, seq, type, len, 0); | |
122 | memcpy(NLMSG_DATA(nlh), msg, len); | |
61e12104 | 123 | NETLINK_CB(skb).portid = 0; |
61e12104 WK |
124 | NETLINK_CB(skb).dst_group = 0; |
125 | ||
ba7f55b7 | 126 | ret = netlink_broadcast(sock, skb, 0, group + 1, GFP_ATOMIC); |
61e12104 WK |
127 | if (!ret) |
128 | return len; | |
129 | ||
130 | if (ret != -ESRCH) | |
0ec473b5 | 131 | pr_err("nl broadcast g=%d, t=%d, l=%d, r=%d\n", |
61e12104 | 132 | group, type, len, ret); |
ba7f55b7 | 133 | else if (netlink_has_listeners(sock, group + 1)) |
61e12104 WK |
134 | return -EAGAIN; |
135 | ||
136 | return ret; | |
137 | } |