Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 | /*
* DECnet An implementation of the DECnet protocol suite for the LINUX
* operating system. DECnet is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* DECnet Routing Message Grabulator
*
* (C) 2000 ChyGwyn Limited - http://www.chygwyn.com/
* This code may be copied under the GPL v.2 or at your option
* any later version.
*
* Author: Steven Whitehouse <steve@chygwyn.com>
*
*/
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/netfilter.h>
#include <linux/spinlock.h>
#include <linux/netlink.h>
#include <linux/netfilter_decnet.h>
#include <net/sock.h>
#include <net/flow.h>
#include <net/dn.h>
#include <net/dn_route.h>
static struct sock *dnrmg = NULL;
static struct sk_buff *dnrmg_build_message(struct sk_buff *rt_skb, int *errp)
{
struct sk_buff *skb = NULL;
size_t size;
sk_buff_data_t old_tail;
struct nlmsghdr *nlh;
unsigned char *ptr;
struct nf_dn_rtmsg *rtm;
size = NLMSG_SPACE(rt_skb->len);
size += NLMSG_ALIGN(sizeof(struct nf_dn_rtmsg));
skb = alloc_skb(size, GFP_ATOMIC);
if (!skb)
goto nlmsg_failure;
old_tail = skb->tail;
nlh = NLMSG_PUT(skb, 0, 0, 0, size - sizeof(*nlh));
rtm = (struct nf_dn_rtmsg *)NLMSG_DATA(nlh);
rtm->nfdn_ifindex = rt_skb->dev->ifindex;
ptr = NFDN_RTMSG(rtm);
skb_copy_from_linear_data(rt_skb, ptr, rt_skb->len);
nlh->nlmsg_len = skb->tail - old_tail;
return skb;
nlmsg_failure:
if (skb)
kfree_skb(skb);
*errp = -ENOMEM;
if (net_ratelimit())
printk(KERN_ERR "dn_rtmsg: error creating netlink message\n");
return NULL;
}
static void dnrmg_send_peer(struct sk_buff *skb)
{
struct sk_buff *skb2;
int status = 0;
int group = 0;
unsigned char flags = *skb->data;
switch (flags & DN_RT_CNTL_MSK) {
case DN_RT_PKT_L1RT:
group = DNRNG_NLGRP_L1;
break;
case DN_RT_PKT_L2RT:
group = DNRNG_NLGRP_L2;
break;
default:
return;
}
skb2 = dnrmg_build_message(skb, &status);
if (skb2 == NULL)
return;
NETLINK_CB(skb2).dst_group = group;
netlink_broadcast(dnrmg, skb2, 0, group, GFP_ATOMIC);
}
static unsigned int dnrmg_hook(unsigned int hook,
struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
dnrmg_send_peer(skb);
return NF_ACCEPT;
}
#define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
static inline void dnrmg_receive_user_skb(struct sk_buff *skb)
{
struct nlmsghdr *nlh = nlmsg_hdr(skb);
if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len)
return;
if (!capable(CAP_NET_ADMIN))
RCV_SKB_FAIL(-EPERM);
/* Eventually we might send routing messages too */
RCV_SKB_FAIL(-EINVAL);
}
static struct nf_hook_ops dnrmg_ops __read_mostly = {
.hook = dnrmg_hook,
.pf = PF_DECnet,
.hooknum = NF_DN_ROUTE,
.priority = NF_DN_PRI_DNRTMSG,
};
static int __init dn_rtmsg_init(void)
{
int rv = 0;
dnrmg = netlink_kernel_create(&init_net,
NETLINK_DNRTMSG, DNRNG_NLGRP_MAX,
dnrmg_receive_user_skb,
NULL, THIS_MODULE);
if (dnrmg == NULL) {
printk(KERN_ERR "dn_rtmsg: Cannot create netlink socket");
return -ENOMEM;
}
rv = nf_register_hook(&dnrmg_ops);
if (rv) {
netlink_kernel_release(dnrmg);
}
return rv;
}
static void __exit dn_rtmsg_fini(void)
{
nf_unregister_hook(&dnrmg_ops);
netlink_kernel_release(dnrmg);
}
MODULE_DESCRIPTION("DECnet Routing Message Grabulator");
MODULE_AUTHOR("Steven Whitehouse <steve@chygwyn.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_DNRTMSG);
module_init(dn_rtmsg_init);
module_exit(dn_rtmsg_fini);
|