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
22static int fill_addr(struct sk_buff *skb, u32 ifindex, u8 addr,
23 u32 portid, u32 seq, int event);
24
25void phonet_address_notify(struct net *net, int event, u32 ifindex, 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(payload: 1), GFP_KERNEL);
32 if (skb == NULL)
33 goto errout;
34
35 err = fill_addr(skb, ifindex, addr, portid: 0, seq: 0, event);
36 if (err < 0) {
37 WARN_ON(err == -EMSGSIZE);
38 kfree_skb(skb);
39 goto errout;
40 }
41
42 rtnl_notify(skb, net, pid: 0, RTNLGRP_PHONET_IFADDR, NULL, GFP_KERNEL);
43 return;
44errout:
45 rtnl_set_sk_err(net, RTNLGRP_PHONET_IFADDR, error: err);
46}
47
48static const struct nla_policy ifa_phonet_policy[IFA_MAX+1] = {
49 [IFA_LOCAL] = { .type = NLA_U8 },
50};
51
52static int addr_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
53 struct netlink_ext_ack *extack)
54{
55 struct net *net = sock_net(sk: skb->sk);
56 struct nlattr *tb[IFA_MAX+1];
57 struct net_device *dev;
58 struct ifaddrmsg *ifm;
59 int err;
60 u8 pnaddr;
61
62 if (!netlink_capable(skb, CAP_NET_ADMIN))
63 return -EPERM;
64
65 if (!netlink_capable(skb, CAP_SYS_ADMIN))
66 return -EPERM;
67
68 err = nlmsg_parse_deprecated(nlh, hdrlen: sizeof(*ifm), tb, IFA_MAX,
69 policy: ifa_phonet_policy, extack);
70 if (err < 0)
71 return err;
72
73 ifm = nlmsg_data(nlh);
74 if (tb[IFA_LOCAL] == NULL)
75 return -EINVAL;
76 pnaddr = nla_get_u8(nla: tb[IFA_LOCAL]);
77 if (pnaddr & 3)
78 /* Phonet addresses only have 6 high-order bits */
79 return -EINVAL;
80
81 rcu_read_lock();
82
83 dev = dev_get_by_index_rcu(net, ifindex: ifm->ifa_index);
84 if (!dev) {
85 rcu_read_unlock();
86 return -ENODEV;
87 }
88
89 if (nlh->nlmsg_type == RTM_NEWADDR)
90 err = phonet_address_add(dev, addr: pnaddr);
91 else
92 err = phonet_address_del(dev, addr: pnaddr);
93
94 rcu_read_unlock();
95
96 if (!err)
97 phonet_address_notify(net, event: nlh->nlmsg_type, ifindex: ifm->ifa_index, addr: pnaddr);
98
99 return err;
100}
101
102static int fill_addr(struct sk_buff *skb, u32 ifindex, u8 addr,
103 u32 portid, u32 seq, int event)
104{
105 struct ifaddrmsg *ifm;
106 struct nlmsghdr *nlh;
107
108 nlh = nlmsg_put(skb, portid, seq, type: event, payload: sizeof(*ifm), flags: 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 = ifindex;
118 if (nla_put_u8(skb, attrtype: IFA_LOCAL, value: addr))
119 goto nla_put_failure;
120 nlmsg_end(skb, nlh);
121 return 0;
122
123nla_put_failure:
124 nlmsg_cancel(skb, nlh);
125 return -EMSGSIZE;
126}
127
128static int getaddr_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
129{
130 int addr_idx = 0, addr_start_idx = cb->args[1];
131 int dev_idx = 0, dev_start_idx = cb->args[0];
132 struct phonet_device_list *pndevs;
133 struct phonet_device *pnd;
134 int err = 0;
135
136 pndevs = phonet_device_list(net: sock_net(sk: skb->sk));
137
138 rcu_read_lock();
139 list_for_each_entry_rcu(pnd, &pndevs->list, list) {
140 DECLARE_BITMAP(addrs, 64);
141 u8 addr;
142
143 if (dev_idx > dev_start_idx)
144 addr_start_idx = 0;
145 if (dev_idx++ < dev_start_idx)
146 continue;
147
148 addr_idx = 0;
149 memcpy(addrs, pnd->addrs, sizeof(pnd->addrs));
150
151 for_each_set_bit(addr, addrs, 64) {
152 if (addr_idx++ < addr_start_idx)
153 continue;
154
155 err = fill_addr(skb, READ_ONCE(pnd->netdev->ifindex),
156 addr: addr << 2, NETLINK_CB(cb->skb).portid,
157 seq: cb->nlh->nlmsg_seq, RTM_NEWADDR);
158 if (err < 0)
159 goto out;
160 }
161 }
162out:
163 rcu_read_unlock();
164
165 cb->args[0] = dev_idx;
166 cb->args[1] = addr_idx;
167
168 return err;
169}
170
171/* Routes handling */
172
173static int fill_route(struct sk_buff *skb, u32 ifindex, u8 dst,
174 u32 portid, u32 seq, int event)
175{
176 struct rtmsg *rtm;
177 struct nlmsghdr *nlh;
178
179 nlh = nlmsg_put(skb, portid, seq, type: event, payload: sizeof(*rtm), flags: 0);
180 if (nlh == NULL)
181 return -EMSGSIZE;
182
183 rtm = nlmsg_data(nlh);
184 rtm->rtm_family = AF_PHONET;
185 rtm->rtm_dst_len = 6;
186 rtm->rtm_src_len = 0;
187 rtm->rtm_tos = 0;
188 rtm->rtm_table = RT_TABLE_MAIN;
189 rtm->rtm_protocol = RTPROT_STATIC;
190 rtm->rtm_scope = RT_SCOPE_UNIVERSE;
191 rtm->rtm_type = RTN_UNICAST;
192 rtm->rtm_flags = 0;
193 if (nla_put_u8(skb, attrtype: RTA_DST, value: dst) || nla_put_u32(skb, attrtype: RTA_OIF, value: ifindex))
194 goto nla_put_failure;
195 nlmsg_end(skb, nlh);
196 return 0;
197
198nla_put_failure:
199 nlmsg_cancel(skb, nlh);
200 return -EMSGSIZE;
201}
202
203void rtm_phonet_notify(struct net *net, int event, u32 ifindex, u8 dst)
204{
205 struct sk_buff *skb;
206 int err = -ENOBUFS;
207
208 skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct rtmsg)) +
209 nla_total_size(payload: 1) + nla_total_size(payload: 4), GFP_KERNEL);
210 if (skb == NULL)
211 goto errout;
212
213 err = fill_route(skb, ifindex, dst, portid: 0, seq: 0, event);
214 if (err < 0) {
215 WARN_ON(err == -EMSGSIZE);
216 kfree_skb(skb);
217 goto errout;
218 }
219
220 rtnl_notify(skb, net, pid: 0, RTNLGRP_PHONET_ROUTE, NULL, GFP_KERNEL);
221 return;
222errout:
223 rtnl_set_sk_err(net, RTNLGRP_PHONET_ROUTE, error: err);
224}
225
226static const struct nla_policy rtm_phonet_policy[RTA_MAX+1] = {
227 [RTA_DST] = { .type = NLA_U8 },
228 [RTA_OIF] = { .type = NLA_U32 },
229};
230
231static int route_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
232 struct netlink_ext_ack *extack)
233{
234 struct net *net = sock_net(sk: skb->sk);
235 struct nlattr *tb[RTA_MAX+1];
236 bool sync_needed = false;
237 struct net_device *dev;
238 struct rtmsg *rtm;
239 u32 ifindex;
240 int err;
241 u8 dst;
242
243 if (!netlink_capable(skb, CAP_NET_ADMIN))
244 return -EPERM;
245
246 if (!netlink_capable(skb, CAP_SYS_ADMIN))
247 return -EPERM;
248
249 err = nlmsg_parse_deprecated(nlh, hdrlen: sizeof(*rtm), tb, RTA_MAX,
250 policy: rtm_phonet_policy, extack);
251 if (err < 0)
252 return err;
253
254 rtm = nlmsg_data(nlh);
255 if (rtm->rtm_table != RT_TABLE_MAIN || rtm->rtm_type != RTN_UNICAST)
256 return -EINVAL;
257 if (tb[RTA_DST] == NULL || tb[RTA_OIF] == NULL)
258 return -EINVAL;
259 dst = nla_get_u8(nla: tb[RTA_DST]);
260 if (dst & 3) /* Phonet addresses only have 6 high-order bits */
261 return -EINVAL;
262
263 ifindex = nla_get_u32(nla: tb[RTA_OIF]);
264
265 rcu_read_lock();
266
267 dev = dev_get_by_index_rcu(net, ifindex);
268 if (!dev) {
269 rcu_read_unlock();
270 return -ENODEV;
271 }
272
273 if (nlh->nlmsg_type == RTM_NEWROUTE) {
274 err = phonet_route_add(dev, daddr: dst);
275 } else {
276 err = phonet_route_del(dev, daddr: dst);
277 if (!err)
278 sync_needed = true;
279 }
280
281 rcu_read_unlock();
282
283 if (sync_needed) {
284 synchronize_rcu();
285 dev_put(dev);
286 }
287 if (!err)
288 rtm_phonet_notify(net, event: nlh->nlmsg_type, ifindex, dst);
289
290 return err;
291}
292
293static int route_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
294{
295 struct net *net = sock_net(sk: skb->sk);
296 int err = 0;
297 u8 addr;
298
299 rcu_read_lock();
300 for (addr = cb->args[0]; addr < 64; addr++) {
301 struct net_device *dev = phonet_route_get_rcu(net, daddr: addr << 2);
302
303 if (!dev)
304 continue;
305
306 err = fill_route(skb, READ_ONCE(dev->ifindex), dst: addr << 2,
307 NETLINK_CB(cb->skb).portid,
308 seq: cb->nlh->nlmsg_seq, RTM_NEWROUTE);
309 if (err < 0)
310 break;
311 }
312 rcu_read_unlock();
313 cb->args[0] = addr;
314
315 return err;
316}
317
318static const struct rtnl_msg_handler phonet_rtnl_msg_handlers[] __initdata_or_module = {
319 {.owner = THIS_MODULE, .protocol = PF_PHONET, .msgtype = RTM_NEWADDR,
320 .doit = addr_doit, .flags = RTNL_FLAG_DOIT_UNLOCKED},
321 {.owner = THIS_MODULE, .protocol = PF_PHONET, .msgtype = RTM_DELADDR,
322 .doit = addr_doit, .flags = RTNL_FLAG_DOIT_UNLOCKED},
323 {.owner = THIS_MODULE, .protocol = PF_PHONET, .msgtype = RTM_GETADDR,
324 .dumpit = getaddr_dumpit, .flags = RTNL_FLAG_DUMP_UNLOCKED},
325 {.owner = THIS_MODULE, .protocol = PF_PHONET, .msgtype = RTM_NEWROUTE,
326 .doit = route_doit, .flags = RTNL_FLAG_DOIT_UNLOCKED},
327 {.owner = THIS_MODULE, .protocol = PF_PHONET, .msgtype = RTM_DELROUTE,
328 .doit = route_doit, .flags = RTNL_FLAG_DOIT_UNLOCKED},
329 {.owner = THIS_MODULE, .protocol = PF_PHONET, .msgtype = RTM_GETROUTE,
330 .dumpit = route_dumpit, .flags = RTNL_FLAG_DUMP_UNLOCKED},
331};
332
333int __init phonet_netlink_register(void)
334{
335 return rtnl_register_many(phonet_rtnl_msg_handlers);
336}
337

source code of linux/net/phonet/pn_netlink.c