diff options
Diffstat (limited to 'kernel/net/decnet/netfilter/dn_rtmsg.c')
-rw-r--r-- | kernel/net/decnet/netfilter/dn_rtmsg.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/kernel/net/decnet/netfilter/dn_rtmsg.c b/kernel/net/decnet/netfilter/dn_rtmsg.c new file mode 100644 index 000000000..af34fc9bd --- /dev/null +++ b/kernel/net/decnet/netfilter/dn_rtmsg.c @@ -0,0 +1,159 @@ +/* + * 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 <net/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_ALIGN(rt_skb->len) + + NLMSG_ALIGN(sizeof(struct nf_dn_rtmsg)); + skb = nlmsg_new(size, GFP_ATOMIC); + if (!skb) { + *errp = -ENOMEM; + return NULL; + } + old_tail = skb->tail; + nlh = nlmsg_put(skb, 0, 0, 0, size, 0); + if (!nlh) { + kfree_skb(skb); + *errp = -ENOMEM; + return NULL; + } + 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; +} + +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(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + 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 (!netlink_capable(skb, 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 = NFPROTO_DECNET, + .hooknum = NF_DN_ROUTE, + .priority = NF_DN_PRI_DNRTMSG, +}; + +static int __init dn_rtmsg_init(void) +{ + int rv = 0; + struct netlink_kernel_cfg cfg = { + .groups = DNRNG_NLGRP_MAX, + .input = dnrmg_receive_user_skb, + }; + + dnrmg = netlink_kernel_create(&init_net, NETLINK_DNRTMSG, &cfg); + 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); + |