1/*
2 * File: pn_netlink.c
3 *
4 * Phonet netlink interface
5 *
6 * Copyright (C) 2008 Nokia Corporation.
7 *
8 * Authors: Sakari Ailus <sakari.ailus@nokia.com>
9 *          Remi Denis-Courmont
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * version 2 as published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
23 * 02110-1301 USA
24 */
25
26#include <linux/kernel.h>
27#include <linux/netlink.h>
28#include <linux/phonet.h>
29#include <linux/slab.h>
30#include <net/sock.h>
31#include <net/phonet/pn_dev.h>
32
33/* Device address handling */
34
35static int fill_addr(struct sk_buff *skb, struct net_device *dev, u8 addr,
36		     u32 portid, u32 seq, int event);
37
38void phonet_address_notify(int event, struct net_device *dev, u8 addr)
39{
40	struct sk_buff *skb;
41	int err = -ENOBUFS;
42
43	skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
44			nla_total_size(1), GFP_KERNEL);
45	if (skb == NULL)
46		goto errout;
47	err = fill_addr(skb, dev, addr, 0, 0, event);
48	if (err < 0) {
49		WARN_ON(err == -EMSGSIZE);
50		kfree_skb(skb);
51		goto errout;
52	}
53	rtnl_notify(skb, dev_net(dev), 0,
54		    RTNLGRP_PHONET_IFADDR, NULL, GFP_KERNEL);
55	return;
56errout:
57	rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_IFADDR, err);
58}
59
60static const struct nla_policy ifa_phonet_policy[IFA_MAX+1] = {
61	[IFA_LOCAL] = { .type = NLA_U8 },
62};
63
64static int addr_doit(struct sk_buff *skb, struct nlmsghdr *nlh)
65{
66	struct net *net = sock_net(skb->sk);
67	struct nlattr *tb[IFA_MAX+1];
68	struct net_device *dev;
69	struct ifaddrmsg *ifm;
70	int err;
71	u8 pnaddr;
72
73	if (!netlink_capable(skb, CAP_NET_ADMIN))
74		return -EPERM;
75
76	if (!netlink_capable(skb, CAP_SYS_ADMIN))
77		return -EPERM;
78
79	ASSERT_RTNL();
80
81	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_phonet_policy);
82	if (err < 0)
83		return err;
84
85	ifm = nlmsg_data(nlh);
86	if (tb[IFA_LOCAL] == NULL)
87		return -EINVAL;
88	pnaddr = nla_get_u8(tb[IFA_LOCAL]);
89	if (pnaddr & 3)
90		/* Phonet addresses only have 6 high-order bits */
91		return -EINVAL;
92
93	dev = __dev_get_by_index(net, ifm->ifa_index);
94	if (dev == NULL)
95		return -ENODEV;
96
97	if (nlh->nlmsg_type == RTM_NEWADDR)
98		err = phonet_address_add(dev, pnaddr);
99	else
100		err = phonet_address_del(dev, pnaddr);
101	if (!err)
102		phonet_address_notify(nlh->nlmsg_type, dev, pnaddr);
103	return err;
104}
105
106static int fill_addr(struct sk_buff *skb, struct net_device *dev, u8 addr,
107			u32 portid, u32 seq, int event)
108{
109	struct ifaddrmsg *ifm;
110	struct nlmsghdr *nlh;
111
112	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*ifm), 0);
113	if (nlh == NULL)
114		return -EMSGSIZE;
115
116	ifm = nlmsg_data(nlh);
117	ifm->ifa_family = AF_PHONET;
118	ifm->ifa_prefixlen = 0;
119	ifm->ifa_flags = IFA_F_PERMANENT;
120	ifm->ifa_scope = RT_SCOPE_LINK;
121	ifm->ifa_index = dev->ifindex;
122	if (nla_put_u8(skb, IFA_LOCAL, addr))
123		goto nla_put_failure;
124	nlmsg_end(skb, nlh);
125	return 0;
126
127nla_put_failure:
128	nlmsg_cancel(skb, nlh);
129	return -EMSGSIZE;
130}
131
132static int getaddr_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
133{
134	struct phonet_device_list *pndevs;
135	struct phonet_device *pnd;
136	int dev_idx = 0, dev_start_idx = cb->args[0];
137	int addr_idx = 0, addr_start_idx = cb->args[1];
138
139	pndevs = phonet_device_list(sock_net(skb->sk));
140	rcu_read_lock();
141	list_for_each_entry_rcu(pnd, &pndevs->list, list) {
142		u8 addr;
143
144		if (dev_idx > dev_start_idx)
145			addr_start_idx = 0;
146		if (dev_idx++ < dev_start_idx)
147			continue;
148
149		addr_idx = 0;
150		for_each_set_bit(addr, pnd->addrs, 64) {
151			if (addr_idx++ < addr_start_idx)
152				continue;
153
154			if (fill_addr(skb, pnd->netdev, addr << 2,
155					 NETLINK_CB(cb->skb).portid,
156					cb->nlh->nlmsg_seq, RTM_NEWADDR) < 0)
157				goto out;
158		}
159	}
160
161out:
162	rcu_read_unlock();
163	cb->args[0] = dev_idx;
164	cb->args[1] = addr_idx;
165
166	return skb->len;
167}
168
169/* Routes handling */
170
171static int fill_route(struct sk_buff *skb, struct net_device *dev, u8 dst,
172			u32 portid, u32 seq, int event)
173{
174	struct rtmsg *rtm;
175	struct nlmsghdr *nlh;
176
177	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), 0);
178	if (nlh == NULL)
179		return -EMSGSIZE;
180
181	rtm = nlmsg_data(nlh);
182	rtm->rtm_family = AF_PHONET;
183	rtm->rtm_dst_len = 6;
184	rtm->rtm_src_len = 0;
185	rtm->rtm_tos = 0;
186	rtm->rtm_table = RT_TABLE_MAIN;
187	rtm->rtm_protocol = RTPROT_STATIC;
188	rtm->rtm_scope = RT_SCOPE_UNIVERSE;
189	rtm->rtm_type = RTN_UNICAST;
190	rtm->rtm_flags = 0;
191	if (nla_put_u8(skb, RTA_DST, dst) ||
192	    nla_put_u32(skb, RTA_OIF, dev->ifindex))
193		goto nla_put_failure;
194	nlmsg_end(skb, nlh);
195	return 0;
196
197nla_put_failure:
198	nlmsg_cancel(skb, nlh);
199	return -EMSGSIZE;
200}
201
202void rtm_phonet_notify(int event, struct net_device *dev, u8 dst)
203{
204	struct sk_buff *skb;
205	int err = -ENOBUFS;
206
207	skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
208			nla_total_size(1) + nla_total_size(4), GFP_KERNEL);
209	if (skb == NULL)
210		goto errout;
211	err = fill_route(skb, dev, dst, 0, 0, event);
212	if (err < 0) {
213		WARN_ON(err == -EMSGSIZE);
214		kfree_skb(skb);
215		goto errout;
216	}
217	rtnl_notify(skb, dev_net(dev), 0,
218			  RTNLGRP_PHONET_ROUTE, NULL, GFP_KERNEL);
219	return;
220errout:
221	rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_ROUTE, err);
222}
223
224static const struct nla_policy rtm_phonet_policy[RTA_MAX+1] = {
225	[RTA_DST] = { .type = NLA_U8 },
226	[RTA_OIF] = { .type = NLA_U32 },
227};
228
229static int route_doit(struct sk_buff *skb, struct nlmsghdr *nlh)
230{
231	struct net *net = sock_net(skb->sk);
232	struct nlattr *tb[RTA_MAX+1];
233	struct net_device *dev;
234	struct rtmsg *rtm;
235	int err;
236	u8 dst;
237
238	if (!netlink_capable(skb, CAP_NET_ADMIN))
239		return -EPERM;
240
241	if (!netlink_capable(skb, CAP_SYS_ADMIN))
242		return -EPERM;
243
244	ASSERT_RTNL();
245
246	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_phonet_policy);
247	if (err < 0)
248		return err;
249
250	rtm = nlmsg_data(nlh);
251	if (rtm->rtm_table != RT_TABLE_MAIN || rtm->rtm_type != RTN_UNICAST)
252		return -EINVAL;
253	if (tb[RTA_DST] == NULL || tb[RTA_OIF] == NULL)
254		return -EINVAL;
255	dst = nla_get_u8(tb[RTA_DST]);
256	if (dst & 3) /* Phonet addresses only have 6 high-order bits */
257		return -EINVAL;
258
259	dev = __dev_get_by_index(net, nla_get_u32(tb[RTA_OIF]));
260	if (dev == NULL)
261		return -ENODEV;
262
263	if (nlh->nlmsg_type == RTM_NEWROUTE)
264		err = phonet_route_add(dev, dst);
265	else
266		err = phonet_route_del(dev, dst);
267	if (!err)
268		rtm_phonet_notify(nlh->nlmsg_type, dev, dst);
269	return err;
270}
271
272static int route_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
273{
274	struct net *net = sock_net(skb->sk);
275	u8 addr;
276
277	rcu_read_lock();
278	for (addr = cb->args[0]; addr < 64; addr++) {
279		struct net_device *dev = phonet_route_get_rcu(net, addr << 2);
280
281		if (!dev)
282			continue;
283
284		if (fill_route(skb, dev, addr << 2, NETLINK_CB(cb->skb).portid,
285			       cb->nlh->nlmsg_seq, RTM_NEWROUTE) < 0)
286			goto out;
287	}
288
289out:
290	rcu_read_unlock();
291	cb->args[0] = addr;
292
293	return skb->len;
294}
295
296int __init phonet_netlink_register(void)
297{
298	int err = __rtnl_register(PF_PHONET, RTM_NEWADDR, addr_doit,
299				  NULL, NULL);
300	if (err)
301		return err;
302
303	/* Further __rtnl_register() cannot fail */
304	__rtnl_register(PF_PHONET, RTM_DELADDR, addr_doit, NULL, NULL);
305	__rtnl_register(PF_PHONET, RTM_GETADDR, NULL, getaddr_dumpit, NULL);
306	__rtnl_register(PF_PHONET, RTM_NEWROUTE, route_doit, NULL, NULL);
307	__rtnl_register(PF_PHONET, RTM_DELROUTE, route_doit, NULL, NULL);
308	__rtnl_register(PF_PHONET, RTM_GETROUTE, NULL, route_dumpit, NULL);
309	return 0;
310}
311