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15#include <linux/module.h>
16#include <linux/skbuff.h>
17#include <linux/slab.h>
18#include <linux/init.h>
19#include <linux/netdevice.h>
20#include <linux/netfilter.h>
21#include <linux/spinlock.h>
22#include <net/netlink.h>
23#include <linux/netfilter_decnet.h>
24
25#include <net/sock.h>
26#include <net/flow.h>
27#include <net/dn.h>
28#include <net/dn_route.h>
29
30static struct sock *dnrmg = NULL;
31
32
33static struct sk_buff *dnrmg_build_message(struct sk_buff *rt_skb, int *errp)
34{
35 struct sk_buff *skb = NULL;
36 size_t size;
37 sk_buff_data_t old_tail;
38 struct nlmsghdr *nlh;
39 unsigned char *ptr;
40 struct nf_dn_rtmsg *rtm;
41
42 size = NLMSG_ALIGN(rt_skb->len) +
43 NLMSG_ALIGN(sizeof(struct nf_dn_rtmsg));
44 skb = nlmsg_new(size, GFP_ATOMIC);
45 if (!skb) {
46 *errp = -ENOMEM;
47 return NULL;
48 }
49 old_tail = skb->tail;
50 nlh = nlmsg_put(skb, 0, 0, 0, size, 0);
51 if (!nlh) {
52 kfree_skb(skb);
53 *errp = -ENOMEM;
54 return NULL;
55 }
56 rtm = (struct nf_dn_rtmsg *)nlmsg_data(nlh);
57 rtm->nfdn_ifindex = rt_skb->dev->ifindex;
58 ptr = NFDN_RTMSG(rtm);
59 skb_copy_from_linear_data(rt_skb, ptr, rt_skb->len);
60 nlh->nlmsg_len = skb->tail - old_tail;
61 return skb;
62}
63
64static void dnrmg_send_peer(struct sk_buff *skb)
65{
66 struct sk_buff *skb2;
67 int status = 0;
68 int group = 0;
69 unsigned char flags = *skb->data;
70
71 switch (flags & DN_RT_CNTL_MSK) {
72 case DN_RT_PKT_L1RT:
73 group = DNRNG_NLGRP_L1;
74 break;
75 case DN_RT_PKT_L2RT:
76 group = DNRNG_NLGRP_L2;
77 break;
78 default:
79 return;
80 }
81
82 skb2 = dnrmg_build_message(skb, &status);
83 if (skb2 == NULL)
84 return;
85 NETLINK_CB(skb2).dst_group = group;
86 netlink_broadcast(dnrmg, skb2, 0, group, GFP_ATOMIC);
87}
88
89
90static unsigned int dnrmg_hook(void *priv,
91 struct sk_buff *skb,
92 const struct nf_hook_state *state)
93{
94 dnrmg_send_peer(skb);
95 return NF_ACCEPT;
96}
97
98
99#define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
100
101static inline void dnrmg_receive_user_skb(struct sk_buff *skb)
102{
103 struct nlmsghdr *nlh = nlmsg_hdr(skb);
104
105 if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len)
106 return;
107
108 if (!netlink_capable(skb, CAP_NET_ADMIN))
109 RCV_SKB_FAIL(-EPERM);
110
111
112
113 RCV_SKB_FAIL(-EINVAL);
114}
115
116static struct nf_hook_ops dnrmg_ops __read_mostly = {
117 .hook = dnrmg_hook,
118 .pf = NFPROTO_DECNET,
119 .hooknum = NF_DN_ROUTE,
120 .priority = NF_DN_PRI_DNRTMSG,
121};
122
123static int __init dn_rtmsg_init(void)
124{
125 int rv = 0;
126 struct netlink_kernel_cfg cfg = {
127 .groups = DNRNG_NLGRP_MAX,
128 .input = dnrmg_receive_user_skb,
129 };
130
131 dnrmg = netlink_kernel_create(&init_net, NETLINK_DNRTMSG, &cfg);
132 if (dnrmg == NULL) {
133 printk(KERN_ERR "dn_rtmsg: Cannot create netlink socket");
134 return -ENOMEM;
135 }
136
137 rv = nf_register_hook(&dnrmg_ops);
138 if (rv) {
139 netlink_kernel_release(dnrmg);
140 }
141
142 return rv;
143}
144
145static void __exit dn_rtmsg_fini(void)
146{
147 nf_unregister_hook(&dnrmg_ops);
148 netlink_kernel_release(dnrmg);
149}
150
151
152MODULE_DESCRIPTION("DECnet Routing Message Grabulator");
153MODULE_AUTHOR("Steven Whitehouse <steve@chygwyn.com>");
154MODULE_LICENSE("GPL");
155MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_DNRTMSG);
156
157module_init(dn_rtmsg_init);
158module_exit(dn_rtmsg_fini);
159
160