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bfb3e5dd RA |
1 | /* |
2 | * Copyright (c) 2014, Ericsson AB | |
3 | * All rights reserved. | |
4 | * | |
5 | * Redistribution and use in source and binary forms, with or without | |
6 | * modification, are permitted provided that the following conditions are met: | |
7 | * | |
8 | * 1. Redistributions of source code must retain the above copyright | |
9 | * notice, this list of conditions and the following disclaimer. | |
10 | * 2. Redistributions in binary form must reproduce the above copyright | |
11 | * notice, this list of conditions and the following disclaimer in the | |
12 | * documentation and/or other materials provided with the distribution. | |
13 | * 3. Neither the names of the copyright holders nor the names of its | |
14 | * contributors may be used to endorse or promote products derived from | |
15 | * this software without specific prior written permission. | |
16 | * | |
17 | * Alternatively, this software may be distributed under the terms of the | |
18 | * GNU General Public License ("GPL") version 2 as published by the Free | |
19 | * Software Foundation. | |
20 | * | |
21 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | |
22 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE | |
25 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
26 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
27 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
28 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | |
29 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
30 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
31 | * POSSIBILITY OF SUCH DAMAGE. | |
32 | */ | |
33 | ||
34 | #include "core.h" | |
35 | #include "config.h" | |
d0796d1e | 36 | #include "bearer.h" |
bfb3e5dd RA |
37 | #include <net/genetlink.h> |
38 | #include <linux/tipc_config.h> | |
39 | ||
d0796d1e RA |
40 | /* The legacy API had an artificial message length limit called |
41 | * ULTRA_STRING_MAX_LEN. | |
42 | */ | |
43 | #define ULTRA_STRING_MAX_LEN 32768 | |
44 | ||
45 | #define TIPC_SKB_MAX TLV_SPACE(ULTRA_STRING_MAX_LEN) | |
46 | ||
47 | #define REPLY_TRUNCATED "<truncated>\n" | |
48 | ||
49 | struct tipc_nl_compat_msg { | |
50 | u16 cmd; | |
51 | int rep_size; | |
52 | struct sk_buff *rep; | |
53 | struct tlv_desc *req; | |
54 | struct sock *dst_sk; | |
55 | }; | |
56 | ||
57 | struct tipc_nl_compat_cmd_dump { | |
58 | int (*dumpit)(struct sk_buff *, struct netlink_callback *); | |
59 | int (*format)(struct tipc_nl_compat_msg *msg, struct nlattr **attrs); | |
60 | }; | |
61 | ||
62 | static int tipc_skb_tailroom(struct sk_buff *skb) | |
63 | { | |
64 | int tailroom; | |
65 | int limit; | |
66 | ||
67 | tailroom = skb_tailroom(skb); | |
68 | limit = TIPC_SKB_MAX - skb->len; | |
69 | ||
70 | if (tailroom < limit) | |
71 | return tailroom; | |
72 | ||
73 | return limit; | |
74 | } | |
75 | ||
76 | static int tipc_add_tlv(struct sk_buff *skb, u16 type, void *data, u16 len) | |
77 | { | |
78 | struct tlv_desc *tlv = (struct tlv_desc *)skb_tail_pointer(skb); | |
79 | ||
80 | if (tipc_skb_tailroom(skb) < TLV_SPACE(len)) | |
81 | return -EMSGSIZE; | |
82 | ||
83 | skb_put(skb, TLV_SPACE(len)); | |
84 | tlv->tlv_type = htons(type); | |
85 | tlv->tlv_len = htons(TLV_LENGTH(len)); | |
86 | if (len && data) | |
87 | memcpy(TLV_DATA(tlv), data, len); | |
88 | ||
89 | return 0; | |
90 | } | |
91 | ||
92 | static struct sk_buff *tipc_tlv_alloc(int size) | |
93 | { | |
94 | int hdr_len; | |
95 | struct sk_buff *buf; | |
96 | ||
97 | size = TLV_SPACE(size); | |
98 | hdr_len = nlmsg_total_size(GENL_HDRLEN + TIPC_GENL_HDRLEN); | |
99 | ||
100 | buf = alloc_skb(hdr_len + size, GFP_KERNEL); | |
101 | if (!buf) | |
102 | return NULL; | |
103 | ||
104 | skb_reserve(buf, hdr_len); | |
105 | ||
106 | return buf; | |
107 | } | |
108 | ||
109 | static struct sk_buff *tipc_get_err_tlv(char *str) | |
110 | { | |
111 | int str_len = strlen(str) + 1; | |
112 | struct sk_buff *buf; | |
113 | ||
114 | buf = tipc_tlv_alloc(TLV_SPACE(str_len)); | |
115 | if (buf) | |
116 | tipc_add_tlv(buf, TIPC_TLV_ERROR_STRING, str, str_len); | |
117 | ||
118 | return buf; | |
119 | } | |
120 | ||
121 | static int __tipc_nl_compat_dumpit(struct tipc_nl_compat_cmd_dump *cmd, | |
122 | struct tipc_nl_compat_msg *msg, | |
123 | struct sk_buff *arg) | |
124 | { | |
125 | int len = 0; | |
126 | int err; | |
127 | struct sk_buff *buf; | |
128 | struct nlmsghdr *nlmsg; | |
129 | struct netlink_callback cb; | |
130 | ||
131 | memset(&cb, 0, sizeof(cb)); | |
132 | cb.nlh = (struct nlmsghdr *)arg->data; | |
133 | cb.skb = arg; | |
134 | ||
135 | buf = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL); | |
136 | if (!buf) | |
137 | return -ENOMEM; | |
138 | ||
139 | buf->sk = msg->dst_sk; | |
140 | ||
141 | do { | |
142 | int rem; | |
143 | ||
144 | len = (*cmd->dumpit)(buf, &cb); | |
145 | ||
146 | nlmsg_for_each_msg(nlmsg, nlmsg_hdr(buf), len, rem) { | |
147 | struct nlattr **attrs; | |
148 | ||
149 | err = tipc_nlmsg_parse(nlmsg, &attrs); | |
150 | if (err) | |
151 | goto err_out; | |
152 | ||
153 | err = (*cmd->format)(msg, attrs); | |
154 | if (err) | |
155 | goto err_out; | |
156 | ||
157 | if (tipc_skb_tailroom(msg->rep) <= 1) { | |
158 | err = -EMSGSIZE; | |
159 | goto err_out; | |
160 | } | |
161 | } | |
162 | ||
163 | skb_reset_tail_pointer(buf); | |
164 | buf->len = 0; | |
165 | ||
166 | } while (len); | |
167 | ||
168 | err = 0; | |
169 | ||
170 | err_out: | |
171 | kfree_skb(buf); | |
172 | ||
173 | if (err == -EMSGSIZE) { | |
174 | /* The legacy API only considered messages filling | |
175 | * "ULTRA_STRING_MAX_LEN" to be truncated. | |
176 | */ | |
177 | if ((TIPC_SKB_MAX - msg->rep->len) <= 1) { | |
178 | char *tail = skb_tail_pointer(msg->rep); | |
179 | ||
180 | if (*tail != '\0') | |
181 | sprintf(tail - sizeof(REPLY_TRUNCATED) - 1, | |
182 | REPLY_TRUNCATED); | |
183 | } | |
184 | ||
185 | return 0; | |
186 | } | |
187 | ||
188 | return err; | |
189 | } | |
190 | ||
191 | static int tipc_nl_compat_dumpit(struct tipc_nl_compat_cmd_dump *cmd, | |
192 | struct tipc_nl_compat_msg *msg) | |
193 | { | |
194 | int err; | |
195 | struct sk_buff *arg; | |
196 | ||
197 | msg->rep = tipc_tlv_alloc(msg->rep_size); | |
198 | if (!msg->rep) | |
199 | return -ENOMEM; | |
200 | ||
201 | arg = nlmsg_new(0, GFP_KERNEL); | |
202 | if (!arg) { | |
203 | kfree_skb(msg->rep); | |
204 | return -ENOMEM; | |
205 | } | |
206 | ||
207 | err = __tipc_nl_compat_dumpit(cmd, msg, arg); | |
208 | if (err) | |
209 | kfree_skb(msg->rep); | |
210 | ||
211 | kfree_skb(arg); | |
212 | ||
213 | return err; | |
214 | } | |
215 | ||
216 | static int tipc_nl_compat_bearer_dump(struct tipc_nl_compat_msg *msg, | |
217 | struct nlattr **attrs) | |
218 | { | |
219 | struct nlattr *bearer[TIPC_NLA_BEARER_MAX + 1]; | |
220 | ||
221 | nla_parse_nested(bearer, TIPC_NLA_BEARER_MAX, attrs[TIPC_NLA_BEARER], | |
222 | NULL); | |
223 | ||
224 | return tipc_add_tlv(msg->rep, TIPC_TLV_BEARER_NAME, | |
225 | nla_data(bearer[TIPC_NLA_BEARER_NAME]), | |
226 | nla_len(bearer[TIPC_NLA_BEARER_NAME])); | |
227 | } | |
228 | ||
229 | static int tipc_nl_compat_handle(struct tipc_nl_compat_msg *msg) | |
230 | { | |
231 | struct tipc_nl_compat_cmd_dump dump; | |
232 | ||
233 | memset(&dump, 0, sizeof(dump)); | |
234 | ||
235 | switch (msg->cmd) { | |
236 | case TIPC_CMD_GET_BEARER_NAMES: | |
237 | msg->rep_size = MAX_BEARERS * TLV_SPACE(TIPC_MAX_BEARER_NAME); | |
238 | dump.dumpit = tipc_nl_bearer_dump; | |
239 | dump.format = tipc_nl_compat_bearer_dump; | |
240 | return tipc_nl_compat_dumpit(&dump, msg); | |
241 | } | |
242 | ||
243 | return -EOPNOTSUPP; | |
244 | } | |
245 | ||
246 | static int tipc_nl_compat_recv(struct sk_buff *skb, struct genl_info *info) | |
247 | { | |
248 | int err; | |
249 | int len; | |
250 | struct tipc_nl_compat_msg msg; | |
251 | struct nlmsghdr *req_nlh; | |
252 | struct nlmsghdr *rep_nlh; | |
253 | struct tipc_genlmsghdr *req_userhdr = info->userhdr; | |
254 | struct net *net = genl_info_net(info); | |
255 | ||
256 | memset(&msg, 0, sizeof(msg)); | |
257 | ||
258 | req_nlh = (struct nlmsghdr *)skb->data; | |
259 | msg.req = nlmsg_data(req_nlh) + GENL_HDRLEN + TIPC_GENL_HDRLEN; | |
260 | msg.cmd = req_userhdr->cmd; | |
261 | msg.dst_sk = info->dst_sk; | |
262 | ||
263 | if ((msg.cmd & 0xC000) && (!netlink_net_capable(skb, CAP_NET_ADMIN))) { | |
264 | msg.rep = tipc_get_err_tlv(TIPC_CFG_NOT_NET_ADMIN); | |
265 | err = -EACCES; | |
266 | goto send; | |
267 | } | |
268 | ||
269 | len = nlmsg_attrlen(req_nlh, GENL_HDRLEN + TIPC_GENL_HDRLEN); | |
270 | if (TLV_GET_LEN(msg.req) && !TLV_OK(msg.req, len)) { | |
271 | msg.rep = tipc_get_err_tlv(TIPC_CFG_NOT_SUPPORTED); | |
272 | err = -EOPNOTSUPP; | |
273 | goto send; | |
274 | } | |
275 | ||
276 | err = tipc_nl_compat_handle(&msg); | |
277 | if (err == -EOPNOTSUPP) | |
278 | msg.rep = tipc_get_err_tlv(TIPC_CFG_NOT_SUPPORTED); | |
279 | else if (err == -EINVAL) | |
280 | msg.rep = tipc_get_err_tlv(TIPC_CFG_TLV_ERROR); | |
281 | send: | |
282 | if (!msg.rep) | |
283 | return err; | |
284 | ||
285 | len = nlmsg_total_size(GENL_HDRLEN + TIPC_GENL_HDRLEN); | |
286 | skb_push(msg.rep, len); | |
287 | rep_nlh = nlmsg_hdr(msg.rep); | |
288 | memcpy(rep_nlh, info->nlhdr, len); | |
289 | rep_nlh->nlmsg_len = msg.rep->len; | |
290 | genlmsg_unicast(net, msg.rep, NETLINK_CB(skb).portid); | |
291 | ||
292 | return err; | |
293 | } | |
294 | ||
bfb3e5dd RA |
295 | static int handle_cmd(struct sk_buff *skb, struct genl_info *info) |
296 | { | |
297 | struct net *net = genl_info_net(info); | |
298 | struct sk_buff *rep_buf; | |
299 | struct nlmsghdr *rep_nlh; | |
300 | struct nlmsghdr *req_nlh = info->nlhdr; | |
301 | struct tipc_genlmsghdr *req_userhdr = info->userhdr; | |
302 | int hdr_space = nlmsg_total_size(GENL_HDRLEN + TIPC_GENL_HDRLEN); | |
303 | u16 cmd; | |
304 | ||
305 | if ((req_userhdr->cmd & 0xC000) && | |
306 | (!netlink_net_capable(skb, CAP_NET_ADMIN))) | |
307 | cmd = TIPC_CMD_NOT_NET_ADMIN; | |
308 | else | |
309 | cmd = req_userhdr->cmd; | |
310 | ||
311 | rep_buf = tipc_cfg_do_cmd(net, req_userhdr->dest, cmd, | |
312 | nlmsg_data(req_nlh) + GENL_HDRLEN + | |
313 | TIPC_GENL_HDRLEN, | |
314 | nlmsg_attrlen(req_nlh, GENL_HDRLEN + | |
315 | TIPC_GENL_HDRLEN), hdr_space); | |
316 | ||
317 | if (rep_buf) { | |
318 | skb_push(rep_buf, hdr_space); | |
319 | rep_nlh = nlmsg_hdr(rep_buf); | |
320 | memcpy(rep_nlh, req_nlh, hdr_space); | |
321 | rep_nlh->nlmsg_len = rep_buf->len; | |
322 | genlmsg_unicast(net, rep_buf, NETLINK_CB(skb).portid); | |
323 | } | |
324 | ||
325 | return 0; | |
326 | } | |
327 | ||
d0796d1e RA |
328 | /* Temporary function to keep functionality throughout the patchset |
329 | * without having to mess with the global variables and other trickery | |
330 | * of the old API. | |
331 | */ | |
332 | static int tipc_nl_compat_tmp_wrap(struct sk_buff *skb, struct genl_info *info) | |
333 | { | |
334 | struct tipc_genlmsghdr *req = info->userhdr; | |
335 | ||
336 | switch (req->cmd) { | |
337 | case TIPC_CMD_GET_BEARER_NAMES: | |
338 | return tipc_nl_compat_recv(skb, info); | |
339 | } | |
340 | ||
341 | return handle_cmd(skb, info); | |
342 | } | |
343 | ||
bfb3e5dd RA |
344 | static struct genl_family tipc_genl_compat_family = { |
345 | .id = GENL_ID_GENERATE, | |
346 | .name = TIPC_GENL_NAME, | |
347 | .version = TIPC_GENL_VERSION, | |
348 | .hdrsize = TIPC_GENL_HDRLEN, | |
349 | .maxattr = 0, | |
350 | .netnsok = true, | |
351 | }; | |
352 | ||
353 | static struct genl_ops tipc_genl_compat_ops[] = { | |
354 | { | |
355 | .cmd = TIPC_GENL_CMD, | |
d0796d1e | 356 | .doit = tipc_nl_compat_tmp_wrap, |
bfb3e5dd RA |
357 | }, |
358 | }; | |
359 | ||
360 | int tipc_netlink_compat_start(void) | |
361 | { | |
362 | int res; | |
363 | ||
364 | res = genl_register_family_with_ops(&tipc_genl_compat_family, | |
365 | tipc_genl_compat_ops); | |
366 | if (res) { | |
367 | pr_err("Failed to register legacy compat interface\n"); | |
368 | return res; | |
369 | } | |
370 | ||
371 | return 0; | |
372 | } | |
373 | ||
374 | void tipc_netlink_compat_stop(void) | |
375 | { | |
376 | genl_unregister_family(&tipc_genl_compat_family); | |
377 | } |