1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * File: pn_netlink.c
4 *
5 * Phonet netlink interface
6 *
7 * Copyright (C) 2008 Nokia Corporation.
8 *
9 * Authors: Sakari Ailus <sakari.ailus@nokia.com>
10 * Remi Denis-Courmont
11 */
12
13 #include <linux/kernel.h>
14 #include <linux/netlink.h>
15 #include <linux/phonet.h>
16 #include <linux/slab.h>
17 #include <net/sock.h>
18 #include <net/phonet/pn_dev.h>
19
20 /* Device address handling */
21
22 static int fill_addr(struct sk_buff *skb, struct net_device *dev, u8 addr,
23 u32 portid, u32 seq, int event);
24
phonet_address_notify(int event,struct net_device * dev,u8 addr)25 void phonet_address_notify(int event, struct net_device *dev, u8 addr)
26 {
27 struct sk_buff *skb;
28 int err = -ENOBUFS;
29
30 skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
31 nla_total_size(1), GFP_KERNEL);
32 if (skb == NULL)
33 goto errout;
34 err = fill_addr(skb, dev, addr, 0, 0, event);
35 if (err < 0) {
36 WARN_ON(err == -EMSGSIZE);
37 kfree_skb(skb);
38 goto errout;
39 }
40 rtnl_notify(skb, dev_net(dev), 0,
41 RTNLGRP_PHONET_IFADDR, NULL, GFP_KERNEL);
42 return;
43 errout:
44 rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_IFADDR, err);
45 }
46
47 static const struct nla_policy ifa_phonet_policy[IFA_MAX+1] = {
48 [IFA_LOCAL] = { .type = NLA_U8 },
49 };
50
addr_doit(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)51 static int addr_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
52 struct netlink_ext_ack *extack)
53 {
54 struct net *net = sock_net(skb->sk);
55 struct nlattr *tb[IFA_MAX+1];
56 struct net_device *dev;
57 struct ifaddrmsg *ifm;
58 int err;
59 u8 pnaddr;
60
61 if (!netlink_capable(skb, CAP_NET_ADMIN))
62 return -EPERM;
63
64 if (!netlink_capable(skb, CAP_SYS_ADMIN))
65 return -EPERM;
66
67 ASSERT_RTNL();
68
69 err = nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFA_MAX,
70 ifa_phonet_policy, extack);
71 if (err < 0)
72 return err;
73
74 ifm = nlmsg_data(nlh);
75 if (tb[IFA_LOCAL] == NULL)
76 return -EINVAL;
77 pnaddr = nla_get_u8(tb[IFA_LOCAL]);
78 if (pnaddr & 3)
79 /* Phonet addresses only have 6 high-order bits */
80 return -EINVAL;
81
82 dev = __dev_get_by_index(net, ifm->ifa_index);
83 if (dev == NULL)
84 return -ENODEV;
85
86 if (nlh->nlmsg_type == RTM_NEWADDR)
87 err = phonet_address_add(dev, pnaddr);
88 else
89 err = phonet_address_del(dev, pnaddr);
90 if (!err)
91 phonet_address_notify(nlh->nlmsg_type, dev, pnaddr);
92 return err;
93 }
94
fill_addr(struct sk_buff * skb,struct net_device * dev,u8 addr,u32 portid,u32 seq,int event)95 static int fill_addr(struct sk_buff *skb, struct net_device *dev, u8 addr,
96 u32 portid, u32 seq, int event)
97 {
98 struct ifaddrmsg *ifm;
99 struct nlmsghdr *nlh;
100
101 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*ifm), 0);
102 if (nlh == NULL)
103 return -EMSGSIZE;
104
105 ifm = nlmsg_data(nlh);
106 ifm->ifa_family = AF_PHONET;
107 ifm->ifa_prefixlen = 0;
108 ifm->ifa_flags = IFA_F_PERMANENT;
109 ifm->ifa_scope = RT_SCOPE_LINK;
110 ifm->ifa_index = dev->ifindex;
111 if (nla_put_u8(skb, IFA_LOCAL, addr))
112 goto nla_put_failure;
113 nlmsg_end(skb, nlh);
114 return 0;
115
116 nla_put_failure:
117 nlmsg_cancel(skb, nlh);
118 return -EMSGSIZE;
119 }
120
getaddr_dumpit(struct sk_buff * skb,struct netlink_callback * cb)121 static int getaddr_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
122 {
123 struct phonet_device_list *pndevs;
124 struct phonet_device *pnd;
125 int dev_idx = 0, dev_start_idx = cb->args[0];
126 int addr_idx = 0, addr_start_idx = cb->args[1];
127
128 pndevs = phonet_device_list(sock_net(skb->sk));
129 rcu_read_lock();
130 list_for_each_entry_rcu(pnd, &pndevs->list, list) {
131 u8 addr;
132
133 if (dev_idx > dev_start_idx)
134 addr_start_idx = 0;
135 if (dev_idx++ < dev_start_idx)
136 continue;
137
138 addr_idx = 0;
139 for_each_set_bit(addr, pnd->addrs, 64) {
140 if (addr_idx++ < addr_start_idx)
141 continue;
142
143 if (fill_addr(skb, pnd->netdev, addr << 2,
144 NETLINK_CB(cb->skb).portid,
145 cb->nlh->nlmsg_seq, RTM_NEWADDR) < 0)
146 goto out;
147 }
148 }
149
150 out:
151 rcu_read_unlock();
152 cb->args[0] = dev_idx;
153 cb->args[1] = addr_idx;
154
155 return skb->len;
156 }
157
158 /* Routes handling */
159
fill_route(struct sk_buff * skb,struct net_device * dev,u8 dst,u32 portid,u32 seq,int event)160 static int fill_route(struct sk_buff *skb, struct net_device *dev, u8 dst,
161 u32 portid, u32 seq, int event)
162 {
163 struct rtmsg *rtm;
164 struct nlmsghdr *nlh;
165
166 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), 0);
167 if (nlh == NULL)
168 return -EMSGSIZE;
169
170 rtm = nlmsg_data(nlh);
171 rtm->rtm_family = AF_PHONET;
172 rtm->rtm_dst_len = 6;
173 rtm->rtm_src_len = 0;
174 rtm->rtm_tos = 0;
175 rtm->rtm_table = RT_TABLE_MAIN;
176 rtm->rtm_protocol = RTPROT_STATIC;
177 rtm->rtm_scope = RT_SCOPE_UNIVERSE;
178 rtm->rtm_type = RTN_UNICAST;
179 rtm->rtm_flags = 0;
180 if (nla_put_u8(skb, RTA_DST, dst) ||
181 nla_put_u32(skb, RTA_OIF, READ_ONCE(dev->ifindex)))
182 goto nla_put_failure;
183 nlmsg_end(skb, nlh);
184 return 0;
185
186 nla_put_failure:
187 nlmsg_cancel(skb, nlh);
188 return -EMSGSIZE;
189 }
190
rtm_phonet_notify(int event,struct net_device * dev,u8 dst)191 void rtm_phonet_notify(int event, struct net_device *dev, u8 dst)
192 {
193 struct sk_buff *skb;
194 int err = -ENOBUFS;
195
196 skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct rtmsg)) +
197 nla_total_size(1) + nla_total_size(4), GFP_KERNEL);
198 if (skb == NULL)
199 goto errout;
200 err = fill_route(skb, dev, dst, 0, 0, event);
201 if (err < 0) {
202 WARN_ON(err == -EMSGSIZE);
203 kfree_skb(skb);
204 goto errout;
205 }
206 rtnl_notify(skb, dev_net(dev), 0,
207 RTNLGRP_PHONET_ROUTE, NULL, GFP_KERNEL);
208 return;
209 errout:
210 rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_ROUTE, err);
211 }
212
213 static const struct nla_policy rtm_phonet_policy[RTA_MAX+1] = {
214 [RTA_DST] = { .type = NLA_U8 },
215 [RTA_OIF] = { .type = NLA_U32 },
216 };
217
route_doit(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)218 static int route_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
219 struct netlink_ext_ack *extack)
220 {
221 struct net *net = sock_net(skb->sk);
222 struct nlattr *tb[RTA_MAX+1];
223 struct net_device *dev;
224 struct rtmsg *rtm;
225 int err;
226 u8 dst;
227
228 if (!netlink_capable(skb, CAP_NET_ADMIN))
229 return -EPERM;
230
231 if (!netlink_capable(skb, CAP_SYS_ADMIN))
232 return -EPERM;
233
234 ASSERT_RTNL();
235
236 err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
237 rtm_phonet_policy, extack);
238 if (err < 0)
239 return err;
240
241 rtm = nlmsg_data(nlh);
242 if (rtm->rtm_table != RT_TABLE_MAIN || rtm->rtm_type != RTN_UNICAST)
243 return -EINVAL;
244 if (tb[RTA_DST] == NULL || tb[RTA_OIF] == NULL)
245 return -EINVAL;
246 dst = nla_get_u8(tb[RTA_DST]);
247 if (dst & 3) /* Phonet addresses only have 6 high-order bits */
248 return -EINVAL;
249
250 dev = __dev_get_by_index(net, nla_get_u32(tb[RTA_OIF]));
251 if (dev == NULL)
252 return -ENODEV;
253
254 if (nlh->nlmsg_type == RTM_NEWROUTE)
255 err = phonet_route_add(dev, dst);
256 else
257 err = phonet_route_del(dev, dst);
258 if (!err)
259 rtm_phonet_notify(nlh->nlmsg_type, dev, dst);
260 return err;
261 }
262
route_dumpit(struct sk_buff * skb,struct netlink_callback * cb)263 static int route_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
264 {
265 struct net *net = sock_net(skb->sk);
266 int err = 0;
267 u8 addr;
268
269 rcu_read_lock();
270 for (addr = cb->args[0]; addr < 64; addr++) {
271 struct net_device *dev = phonet_route_get_rcu(net, addr << 2);
272
273 if (!dev)
274 continue;
275
276 err = fill_route(skb, dev, addr << 2,
277 NETLINK_CB(cb->skb).portid,
278 cb->nlh->nlmsg_seq, RTM_NEWROUTE);
279 if (err < 0)
280 break;
281 }
282 rcu_read_unlock();
283 cb->args[0] = addr;
284
285 return err;
286 }
287
288 static const struct rtnl_msg_handler phonet_rtnl_msg_handlers[] __initdata_or_module = {
289 {THIS_MODULE, PF_PHONET, RTM_NEWADDR, addr_doit, NULL, 0},
290 {THIS_MODULE, PF_PHONET, RTM_DELADDR, addr_doit, NULL, 0},
291 {THIS_MODULE, PF_PHONET, RTM_GETADDR, NULL, getaddr_dumpit, 0},
292 {THIS_MODULE, PF_PHONET, RTM_NEWROUTE, route_doit, NULL, 0},
293 {THIS_MODULE, PF_PHONET, RTM_DELROUTE, route_doit, NULL, 0},
294 {THIS_MODULE, PF_PHONET, RTM_GETROUTE, NULL, route_dumpit,
295 RTNL_FLAG_DUMP_UNLOCKED},
296 };
297
phonet_netlink_register(void)298 int __init phonet_netlink_register(void)
299 {
300 return rtnl_register_many(phonet_rtnl_msg_handlers);
301 }
302