Commit | Line | Data |
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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> | |
5a0e3ad6 | 17 | #include <linux/slab.h> |
1da177e4 LT |
18 | #include <linux/init.h> |
19 | #include <linux/netdevice.h> | |
20 | #include <linux/netfilter.h> | |
21 | #include <linux/spinlock.h> | |
22 | #include <linux/netlink.h> | |
63a1222b | 23 | #include <linux/netfilter_decnet.h> |
1da177e4 LT |
24 | |
25 | #include <net/sock.h> | |
26 | #include <net/flow.h> | |
27 | #include <net/dn.h> | |
28 | #include <net/dn_route.h> | |
29 | ||
1da177e4 LT |
30 | static struct sock *dnrmg = NULL; |
31 | ||
32 | ||
33 | static struct sk_buff *dnrmg_build_message(struct sk_buff *rt_skb, int *errp) | |
34 | { | |
35 | struct sk_buff *skb = NULL; | |
36 | size_t size; | |
27a884dc | 37 | sk_buff_data_t old_tail; |
1da177e4 LT |
38 | struct nlmsghdr *nlh; |
39 | unsigned char *ptr; | |
40 | struct nf_dn_rtmsg *rtm; | |
41 | ||
42 | size = NLMSG_SPACE(rt_skb->len); | |
43 | size += NLMSG_ALIGN(sizeof(struct nf_dn_rtmsg)); | |
44 | skb = alloc_skb(size, GFP_ATOMIC); | |
45 | if (!skb) | |
46 | goto nlmsg_failure; | |
47 | old_tail = skb->tail; | |
48 | nlh = NLMSG_PUT(skb, 0, 0, 0, size - sizeof(*nlh)); | |
49 | rtm = (struct nf_dn_rtmsg *)NLMSG_DATA(nlh); | |
50 | rtm->nfdn_ifindex = rt_skb->dev->ifindex; | |
51 | ptr = NFDN_RTMSG(rtm); | |
1a4e2d09 | 52 | skb_copy_from_linear_data(rt_skb, ptr, rt_skb->len); |
1da177e4 LT |
53 | nlh->nlmsg_len = skb->tail - old_tail; |
54 | return skb; | |
55 | ||
56 | nlmsg_failure: | |
57 | if (skb) | |
58 | kfree_skb(skb); | |
59 | *errp = -ENOMEM; | |
60 | if (net_ratelimit()) | |
61 | printk(KERN_ERR "dn_rtmsg: error creating netlink message\n"); | |
62 | return NULL; | |
63 | } | |
64 | ||
65 | static void dnrmg_send_peer(struct sk_buff *skb) | |
66 | { | |
67 | struct sk_buff *skb2; | |
68 | int status = 0; | |
69 | int group = 0; | |
70 | unsigned char flags = *skb->data; | |
71 | ||
72 | switch(flags & DN_RT_CNTL_MSK) { | |
73 | case DN_RT_PKT_L1RT: | |
63a1222b | 74 | group = DNRNG_NLGRP_L1; |
1da177e4 LT |
75 | break; |
76 | case DN_RT_PKT_L2RT: | |
63a1222b | 77 | group = DNRNG_NLGRP_L2; |
1da177e4 LT |
78 | break; |
79 | default: | |
80 | return; | |
81 | } | |
82 | ||
83 | skb2 = dnrmg_build_message(skb, &status); | |
84 | if (skb2 == NULL) | |
85 | return; | |
ac6d439d | 86 | NETLINK_CB(skb2).dst_group = group; |
1da177e4 LT |
87 | netlink_broadcast(dnrmg, skb2, 0, group, GFP_ATOMIC); |
88 | } | |
89 | ||
90 | ||
91 | static unsigned int dnrmg_hook(unsigned int hook, | |
3db05fea | 92 | struct sk_buff *skb, |
1da177e4 LT |
93 | const struct net_device *in, |
94 | const struct net_device *out, | |
95 | int (*okfn)(struct sk_buff *)) | |
96 | { | |
3db05fea | 97 | dnrmg_send_peer(skb); |
1da177e4 LT |
98 | return NF_ACCEPT; |
99 | } | |
100 | ||
101 | ||
102 | #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0) | |
103 | ||
104 | static inline void dnrmg_receive_user_skb(struct sk_buff *skb) | |
105 | { | |
b529ccf2 | 106 | struct nlmsghdr *nlh = nlmsg_hdr(skb); |
1da177e4 LT |
107 | |
108 | if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len) | |
109 | return; | |
110 | ||
c7bdb545 | 111 | if (security_netlink_recv(skb, CAP_NET_ADMIN)) |
1da177e4 LT |
112 | RCV_SKB_FAIL(-EPERM); |
113 | ||
114 | /* Eventually we might send routing messages too */ | |
115 | ||
116 | RCV_SKB_FAIL(-EINVAL); | |
117 | } | |
118 | ||
1999414a | 119 | static struct nf_hook_ops dnrmg_ops __read_mostly = { |
1da177e4 LT |
120 | .hook = dnrmg_hook, |
121 | .pf = PF_DECnet, | |
122 | .hooknum = NF_DN_ROUTE, | |
123 | .priority = NF_DN_PRI_DNRTMSG, | |
124 | }; | |
125 | ||
65b4b4e8 | 126 | static int __init dn_rtmsg_init(void) |
1da177e4 LT |
127 | { |
128 | int rv = 0; | |
129 | ||
b4b51029 EB |
130 | dnrmg = netlink_kernel_create(&init_net, |
131 | NETLINK_DNRTMSG, DNRNG_NLGRP_MAX, | |
cd40b7d3 DL |
132 | dnrmg_receive_user_skb, |
133 | NULL, THIS_MODULE); | |
1da177e4 LT |
134 | if (dnrmg == NULL) { |
135 | printk(KERN_ERR "dn_rtmsg: Cannot create netlink socket"); | |
136 | return -ENOMEM; | |
137 | } | |
138 | ||
139 | rv = nf_register_hook(&dnrmg_ops); | |
140 | if (rv) { | |
b7c6ba6e | 141 | netlink_kernel_release(dnrmg); |
1da177e4 LT |
142 | } |
143 | ||
144 | return rv; | |
145 | } | |
146 | ||
65b4b4e8 | 147 | static void __exit dn_rtmsg_fini(void) |
1da177e4 LT |
148 | { |
149 | nf_unregister_hook(&dnrmg_ops); | |
b7c6ba6e | 150 | netlink_kernel_release(dnrmg); |
1da177e4 LT |
151 | } |
152 | ||
153 | ||
154 | MODULE_DESCRIPTION("DECnet Routing Message Grabulator"); | |
155 | MODULE_AUTHOR("Steven Whitehouse <steve@chygwyn.com>"); | |
156 | MODULE_LICENSE("GPL"); | |
4fdb3bb7 | 157 | MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_DNRTMSG); |
1da177e4 | 158 | |
65b4b4e8 AM |
159 | module_init(dn_rtmsg_init); |
160 | module_exit(dn_rtmsg_fini); | |
1da177e4 | 161 |