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1da177e4 LT |
1 | /* |
2 | * DECnet An implementation of the DECnet protocol suite for the LINUX | |
3 | * operating system. DECnet is implemented using the BSD Socket | |
4 | * interface as the means of communication with the user level. | |
5 | * | |
6 | * DECnet Routing Message Grabulator | |
7 | * | |
8 | * (C) 2000 ChyGwyn Limited - http://www.chygwyn.com/ | |
9 | * This code may be copied under the GPL v.2 or at your option | |
10 | * any later version. | |
11 | * | |
12 | * Author: Steven Whitehouse <steve@chygwyn.com> | |
13 | * | |
14 | */ | |
15 | #include <linux/module.h> | |
16 | #include <linux/skbuff.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/netdevice.h> | |
19 | #include <linux/netfilter.h> | |
20 | #include <linux/spinlock.h> | |
21 | #include <linux/netlink.h> | |
63a1222b | 22 | #include <linux/netfilter_decnet.h> |
1da177e4 LT |
23 | |
24 | #include <net/sock.h> | |
25 | #include <net/flow.h> | |
26 | #include <net/dn.h> | |
27 | #include <net/dn_route.h> | |
28 | ||
1da177e4 LT |
29 | static struct sock *dnrmg = NULL; |
30 | ||
31 | ||
32 | static struct sk_buff *dnrmg_build_message(struct sk_buff *rt_skb, int *errp) | |
33 | { | |
34 | struct sk_buff *skb = NULL; | |
35 | size_t size; | |
27a884dc | 36 | sk_buff_data_t old_tail; |
1da177e4 LT |
37 | struct nlmsghdr *nlh; |
38 | unsigned char *ptr; | |
39 | struct nf_dn_rtmsg *rtm; | |
40 | ||
41 | size = NLMSG_SPACE(rt_skb->len); | |
42 | size += NLMSG_ALIGN(sizeof(struct nf_dn_rtmsg)); | |
43 | skb = alloc_skb(size, GFP_ATOMIC); | |
44 | if (!skb) | |
45 | goto nlmsg_failure; | |
46 | old_tail = skb->tail; | |
47 | nlh = NLMSG_PUT(skb, 0, 0, 0, size - sizeof(*nlh)); | |
48 | rtm = (struct nf_dn_rtmsg *)NLMSG_DATA(nlh); | |
49 | rtm->nfdn_ifindex = rt_skb->dev->ifindex; | |
50 | ptr = NFDN_RTMSG(rtm); | |
51 | memcpy(ptr, rt_skb->data, rt_skb->len); | |
52 | nlh->nlmsg_len = skb->tail - old_tail; | |
53 | return skb; | |
54 | ||
55 | nlmsg_failure: | |
56 | if (skb) | |
57 | kfree_skb(skb); | |
58 | *errp = -ENOMEM; | |
59 | if (net_ratelimit()) | |
60 | printk(KERN_ERR "dn_rtmsg: error creating netlink message\n"); | |
61 | return NULL; | |
62 | } | |
63 | ||
64 | static 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: | |
63a1222b | 73 | group = DNRNG_NLGRP_L1; |
1da177e4 LT |
74 | break; |
75 | case DN_RT_PKT_L2RT: | |
63a1222b | 76 | group = DNRNG_NLGRP_L2; |
1da177e4 LT |
77 | break; |
78 | default: | |
79 | return; | |
80 | } | |
81 | ||
82 | skb2 = dnrmg_build_message(skb, &status); | |
83 | if (skb2 == NULL) | |
84 | return; | |
ac6d439d | 85 | NETLINK_CB(skb2).dst_group = group; |
1da177e4 LT |
86 | netlink_broadcast(dnrmg, skb2, 0, group, GFP_ATOMIC); |
87 | } | |
88 | ||
89 | ||
90 | static unsigned int dnrmg_hook(unsigned int hook, | |
91 | struct sk_buff **pskb, | |
92 | const struct net_device *in, | |
93 | const struct net_device *out, | |
94 | int (*okfn)(struct sk_buff *)) | |
95 | { | |
96 | dnrmg_send_peer(*pskb); | |
97 | return NF_ACCEPT; | |
98 | } | |
99 | ||
100 | ||
101 | #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0) | |
102 | ||
103 | static inline void dnrmg_receive_user_skb(struct sk_buff *skb) | |
104 | { | |
105 | struct nlmsghdr *nlh = (struct nlmsghdr *)skb->data; | |
106 | ||
107 | if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len) | |
108 | return; | |
109 | ||
c7bdb545 | 110 | if (security_netlink_recv(skb, CAP_NET_ADMIN)) |
1da177e4 LT |
111 | RCV_SKB_FAIL(-EPERM); |
112 | ||
113 | /* Eventually we might send routing messages too */ | |
114 | ||
115 | RCV_SKB_FAIL(-EINVAL); | |
116 | } | |
117 | ||
118 | static void dnrmg_receive_user_sk(struct sock *sk, int len) | |
119 | { | |
120 | struct sk_buff *skb; | |
2a0a6ebe | 121 | unsigned int qlen = skb_queue_len(&sk->sk_receive_queue); |
1da177e4 | 122 | |
09e14305 | 123 | for (; qlen && (skb = skb_dequeue(&sk->sk_receive_queue)); qlen--) { |
1da177e4 LT |
124 | dnrmg_receive_user_skb(skb); |
125 | kfree_skb(skb); | |
126 | } | |
127 | } | |
128 | ||
129 | static struct nf_hook_ops dnrmg_ops = { | |
130 | .hook = dnrmg_hook, | |
131 | .pf = PF_DECnet, | |
132 | .hooknum = NF_DN_ROUTE, | |
133 | .priority = NF_DN_PRI_DNRTMSG, | |
134 | }; | |
135 | ||
65b4b4e8 | 136 | static int __init dn_rtmsg_init(void) |
1da177e4 LT |
137 | { |
138 | int rv = 0; | |
139 | ||
06628607 | 140 | dnrmg = netlink_kernel_create(NETLINK_DNRTMSG, DNRNG_NLGRP_MAX, |
429eb0fa | 141 | dnrmg_receive_user_sk, THIS_MODULE); |
1da177e4 LT |
142 | if (dnrmg == NULL) { |
143 | printk(KERN_ERR "dn_rtmsg: Cannot create netlink socket"); | |
144 | return -ENOMEM; | |
145 | } | |
146 | ||
147 | rv = nf_register_hook(&dnrmg_ops); | |
148 | if (rv) { | |
149 | sock_release(dnrmg->sk_socket); | |
150 | } | |
151 | ||
152 | return rv; | |
153 | } | |
154 | ||
65b4b4e8 | 155 | static void __exit dn_rtmsg_fini(void) |
1da177e4 LT |
156 | { |
157 | nf_unregister_hook(&dnrmg_ops); | |
158 | sock_release(dnrmg->sk_socket); | |
159 | } | |
160 | ||
161 | ||
162 | MODULE_DESCRIPTION("DECnet Routing Message Grabulator"); | |
163 | MODULE_AUTHOR("Steven Whitehouse <steve@chygwyn.com>"); | |
164 | MODULE_LICENSE("GPL"); | |
4fdb3bb7 | 165 | MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_DNRTMSG); |
1da177e4 | 166 | |
65b4b4e8 AM |
167 | module_init(dn_rtmsg_init); |
168 | module_exit(dn_rtmsg_fini); | |
1da177e4 | 169 |