xref: /openbmc/linux/net/phonet/pn_netlink.c (revision b6dcefde)
1 /*
2  * File: pn_netlink.c
3  *
4  * Phonet netlink interface
5  *
6  * Copyright (C) 2008 Nokia Corporation.
7  *
8  * Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
9  * Original author: Sakari Ailus <sakari.ailus@nokia.com>
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 <net/sock.h>
30 #include <net/phonet/pn_dev.h>
31 
32 /* Device address handling */
33 
34 static int fill_addr(struct sk_buff *skb, struct net_device *dev, u8 addr,
35 		     u32 pid, u32 seq, int event);
36 
37 void phonet_address_notify(int event, struct net_device *dev, u8 addr)
38 {
39 	struct sk_buff *skb;
40 	int err = -ENOBUFS;
41 
42 	skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
43 			nla_total_size(1), GFP_KERNEL);
44 	if (skb == NULL)
45 		goto errout;
46 	err = fill_addr(skb, dev, addr, 0, 0, event);
47 	if (err < 0) {
48 		WARN_ON(err == -EMSGSIZE);
49 		kfree_skb(skb);
50 		goto errout;
51 	}
52 	rtnl_notify(skb, dev_net(dev), 0,
53 		    RTNLGRP_PHONET_IFADDR, NULL, GFP_KERNEL);
54 	return;
55 errout:
56 	rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_IFADDR, err);
57 }
58 
59 static const struct nla_policy ifa_phonet_policy[IFA_MAX+1] = {
60 	[IFA_LOCAL] = { .type = NLA_U8 },
61 };
62 
63 static int addr_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *attr)
64 {
65 	struct net *net = sock_net(skb->sk);
66 	struct nlattr *tb[IFA_MAX+1];
67 	struct net_device *dev;
68 	struct ifaddrmsg *ifm;
69 	int err;
70 	u8 pnaddr;
71 
72 	if (!capable(CAP_SYS_ADMIN))
73 		return -EPERM;
74 
75 	ASSERT_RTNL();
76 
77 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_phonet_policy);
78 	if (err < 0)
79 		return err;
80 
81 	ifm = nlmsg_data(nlh);
82 	if (tb[IFA_LOCAL] == NULL)
83 		return -EINVAL;
84 	pnaddr = nla_get_u8(tb[IFA_LOCAL]);
85 	if (pnaddr & 3)
86 		/* Phonet addresses only have 6 high-order bits */
87 		return -EINVAL;
88 
89 	dev = __dev_get_by_index(net, ifm->ifa_index);
90 	if (dev == NULL)
91 		return -ENODEV;
92 
93 	if (nlh->nlmsg_type == RTM_NEWADDR)
94 		err = phonet_address_add(dev, pnaddr);
95 	else
96 		err = phonet_address_del(dev, pnaddr);
97 	if (!err)
98 		phonet_address_notify(nlh->nlmsg_type, dev, pnaddr);
99 	return err;
100 }
101 
102 static int fill_addr(struct sk_buff *skb, struct net_device *dev, u8 addr,
103 			u32 pid, u32 seq, int event)
104 {
105 	struct ifaddrmsg *ifm;
106 	struct nlmsghdr *nlh;
107 
108 	nlh = nlmsg_put(skb, pid, seq, event, sizeof(*ifm), 0);
109 	if (nlh == NULL)
110 		return -EMSGSIZE;
111 
112 	ifm = nlmsg_data(nlh);
113 	ifm->ifa_family = AF_PHONET;
114 	ifm->ifa_prefixlen = 0;
115 	ifm->ifa_flags = IFA_F_PERMANENT;
116 	ifm->ifa_scope = RT_SCOPE_LINK;
117 	ifm->ifa_index = dev->ifindex;
118 	NLA_PUT_U8(skb, IFA_LOCAL, addr);
119 	return nlmsg_end(skb, nlh);
120 
121 nla_put_failure:
122 	nlmsg_cancel(skb, nlh);
123 	return -EMSGSIZE;
124 }
125 
126 static int getaddr_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
127 {
128 	struct phonet_device_list *pndevs;
129 	struct phonet_device *pnd;
130 	int dev_idx = 0, dev_start_idx = cb->args[0];
131 	int addr_idx = 0, addr_start_idx = cb->args[1];
132 
133 	pndevs = phonet_device_list(sock_net(skb->sk));
134 	rcu_read_lock();
135 	list_for_each_entry_rcu(pnd, &pndevs->list, list) {
136 		u8 addr;
137 
138 		if (dev_idx > dev_start_idx)
139 			addr_start_idx = 0;
140 		if (dev_idx++ < dev_start_idx)
141 			continue;
142 
143 		addr_idx = 0;
144 		for (addr = find_first_bit(pnd->addrs, 64); addr < 64;
145 			addr = find_next_bit(pnd->addrs, 64, 1+addr)) {
146 			if (addr_idx++ < addr_start_idx)
147 				continue;
148 
149 			if (fill_addr(skb, pnd->netdev, addr << 2,
150 					 NETLINK_CB(cb->skb).pid,
151 					cb->nlh->nlmsg_seq, RTM_NEWADDR) < 0)
152 				goto out;
153 		}
154 	}
155 
156 out:
157 	rcu_read_unlock();
158 	cb->args[0] = dev_idx;
159 	cb->args[1] = addr_idx;
160 
161 	return skb->len;
162 }
163 
164 /* Routes handling */
165 
166 static int fill_route(struct sk_buff *skb, struct net_device *dev, u8 dst,
167 			u32 pid, u32 seq, int event)
168 {
169 	struct rtmsg *rtm;
170 	struct nlmsghdr *nlh;
171 
172 	nlh = nlmsg_put(skb, pid, seq, event, sizeof(*rtm), 0);
173 	if (nlh == NULL)
174 		return -EMSGSIZE;
175 
176 	rtm = nlmsg_data(nlh);
177 	rtm->rtm_family = AF_PHONET;
178 	rtm->rtm_dst_len = 6;
179 	rtm->rtm_src_len = 0;
180 	rtm->rtm_tos = 0;
181 	rtm->rtm_table = RT_TABLE_MAIN;
182 	rtm->rtm_protocol = RTPROT_STATIC;
183 	rtm->rtm_scope = RT_SCOPE_UNIVERSE;
184 	rtm->rtm_type = RTN_UNICAST;
185 	rtm->rtm_flags = 0;
186 	NLA_PUT_U8(skb, RTA_DST, dst);
187 	NLA_PUT_U32(skb, RTA_OIF, dev->ifindex);
188 	return nlmsg_end(skb, nlh);
189 
190 nla_put_failure:
191 	nlmsg_cancel(skb, nlh);
192 	return -EMSGSIZE;
193 }
194 
195 void rtm_phonet_notify(int event, struct net_device *dev, u8 dst)
196 {
197 	struct sk_buff *skb;
198 	int err = -ENOBUFS;
199 
200 	skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
201 			nla_total_size(1) + nla_total_size(4), GFP_KERNEL);
202 	if (skb == NULL)
203 		goto errout;
204 	err = fill_route(skb, dev, dst, 0, 0, event);
205 	if (err < 0) {
206 		WARN_ON(err == -EMSGSIZE);
207 		kfree_skb(skb);
208 		goto errout;
209 	}
210 	rtnl_notify(skb, dev_net(dev), 0,
211 			  RTNLGRP_PHONET_ROUTE, NULL, GFP_KERNEL);
212 	return;
213 errout:
214 	rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_ROUTE, err);
215 }
216 
217 static const struct nla_policy rtm_phonet_policy[RTA_MAX+1] = {
218 	[RTA_DST] = { .type = NLA_U8 },
219 	[RTA_OIF] = { .type = NLA_U32 },
220 };
221 
222 static int route_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *attr)
223 {
224 	struct net *net = sock_net(skb->sk);
225 	struct nlattr *tb[RTA_MAX+1];
226 	struct net_device *dev;
227 	struct rtmsg *rtm;
228 	int err;
229 	u8 dst;
230 
231 	if (!capable(CAP_SYS_ADMIN))
232 		return -EPERM;
233 
234 	ASSERT_RTNL();
235 
236 	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_phonet_policy);
237 	if (err < 0)
238 		return err;
239 
240 	rtm = nlmsg_data(nlh);
241 	if (rtm->rtm_table != RT_TABLE_MAIN || rtm->rtm_type != RTN_UNICAST)
242 		return -EINVAL;
243 	if (tb[RTA_DST] == NULL || tb[RTA_OIF] == NULL)
244 		return -EINVAL;
245 	dst = nla_get_u8(tb[RTA_DST]);
246 	if (dst & 3) /* Phonet addresses only have 6 high-order bits */
247 		return -EINVAL;
248 
249 	dev = __dev_get_by_index(net, nla_get_u32(tb[RTA_OIF]));
250 	if (dev == NULL)
251 		return -ENODEV;
252 
253 	if (nlh->nlmsg_type == RTM_NEWROUTE)
254 		err = phonet_route_add(dev, dst);
255 	else
256 		err = phonet_route_del(dev, dst);
257 	if (!err)
258 		rtm_phonet_notify(nlh->nlmsg_type, dev, dst);
259 	return err;
260 }
261 
262 static int route_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
263 {
264 	struct net *net = sock_net(skb->sk);
265 	u8 addr, addr_idx = 0, addr_start_idx = cb->args[0];
266 
267 	for (addr = 0; addr < 64; addr++) {
268 		struct net_device *dev;
269 
270 		dev = phonet_route_get(net, addr << 2);
271 		if (!dev)
272 			continue;
273 
274 		if (addr_idx++ < addr_start_idx)
275 			continue;
276 		if (fill_route(skb, dev, addr << 2, NETLINK_CB(cb->skb).pid,
277 				cb->nlh->nlmsg_seq, RTM_NEWROUTE))
278 			goto out;
279 	}
280 
281 out:
282 	cb->args[0] = addr_idx;
283 	cb->args[1] = 0;
284 
285 	return skb->len;
286 }
287 
288 int __init phonet_netlink_register(void)
289 {
290 	int err = __rtnl_register(PF_PHONET, RTM_NEWADDR, addr_doit, NULL);
291 	if (err)
292 		return err;
293 
294 	/* Further __rtnl_register() cannot fail */
295 	__rtnl_register(PF_PHONET, RTM_DELADDR, addr_doit, NULL);
296 	__rtnl_register(PF_PHONET, RTM_GETADDR, NULL, getaddr_dumpit);
297 	__rtnl_register(PF_PHONET, RTM_NEWROUTE, route_doit, NULL);
298 	__rtnl_register(PF_PHONET, RTM_DELROUTE, route_doit, NULL);
299 	__rtnl_register(PF_PHONET, RTM_GETROUTE, NULL, route_dumpit);
300 	return 0;
301 }
302