1 /*
2 * linux/net/sunrpc/gss_rpc_upcall.c
3 *
4 * Copyright (C) 2012 Simo Sorce <simo@redhat.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21 #include <linux/types.h>
22 #include <linux/un.h>
23
24 #include <linux/sunrpc/svcauth.h>
25 #include "gss_rpc_upcall.h"
26
27 #define GSSPROXY_SOCK_PATHNAME "/var/run/gssproxy.sock"
28
29 #define GSSPROXY_PROGRAM (400112u)
30 #define GSSPROXY_VERS_1 (1u)
31
32 /*
33 * Encoding/Decoding functions
34 */
35
36 enum {
37 GSSX_NULL = 0, /* Unused */
38 GSSX_INDICATE_MECHS = 1,
39 GSSX_GET_CALL_CONTEXT = 2,
40 GSSX_IMPORT_AND_CANON_NAME = 3,
41 GSSX_EXPORT_CRED = 4,
42 GSSX_IMPORT_CRED = 5,
43 GSSX_ACQUIRE_CRED = 6,
44 GSSX_STORE_CRED = 7,
45 GSSX_INIT_SEC_CONTEXT = 8,
46 GSSX_ACCEPT_SEC_CONTEXT = 9,
47 GSSX_RELEASE_HANDLE = 10,
48 GSSX_GET_MIC = 11,
49 GSSX_VERIFY = 12,
50 GSSX_WRAP = 13,
51 GSSX_UNWRAP = 14,
52 GSSX_WRAP_SIZE_LIMIT = 15,
53 };
54
55 #define PROC(proc, name) \
56 [GSSX_##proc] = { \
57 .p_proc = GSSX_##proc, \
58 .p_encode = (kxdreproc_t)gssx_enc_##name, \
59 .p_decode = (kxdrdproc_t)gssx_dec_##name, \
60 .p_arglen = GSSX_ARG_##name##_sz, \
61 .p_replen = GSSX_RES_##name##_sz, \
62 .p_statidx = GSSX_##proc, \
63 .p_name = #proc, \
64 }
65
66 static struct rpc_procinfo gssp_procedures[] = {
67 PROC(INDICATE_MECHS, indicate_mechs),
68 PROC(GET_CALL_CONTEXT, get_call_context),
69 PROC(IMPORT_AND_CANON_NAME, import_and_canon_name),
70 PROC(EXPORT_CRED, export_cred),
71 PROC(IMPORT_CRED, import_cred),
72 PROC(ACQUIRE_CRED, acquire_cred),
73 PROC(STORE_CRED, store_cred),
74 PROC(INIT_SEC_CONTEXT, init_sec_context),
75 PROC(ACCEPT_SEC_CONTEXT, accept_sec_context),
76 PROC(RELEASE_HANDLE, release_handle),
77 PROC(GET_MIC, get_mic),
78 PROC(VERIFY, verify),
79 PROC(WRAP, wrap),
80 PROC(UNWRAP, unwrap),
81 PROC(WRAP_SIZE_LIMIT, wrap_size_limit),
82 };
83
84
85
86 /*
87 * Common transport functions
88 */
89
90 static const struct rpc_program gssp_program;
91
gssp_rpc_create(struct net * net,struct rpc_clnt ** _clnt)92 static int gssp_rpc_create(struct net *net, struct rpc_clnt **_clnt)
93 {
94 static const struct sockaddr_un gssp_localaddr = {
95 .sun_family = AF_LOCAL,
96 .sun_path = GSSPROXY_SOCK_PATHNAME,
97 };
98 struct rpc_create_args args = {
99 .net = net,
100 .protocol = XPRT_TRANSPORT_LOCAL,
101 .address = (struct sockaddr *)&gssp_localaddr,
102 .addrsize = sizeof(gssp_localaddr),
103 .servername = "localhost",
104 .program = &gssp_program,
105 .version = GSSPROXY_VERS_1,
106 .authflavor = RPC_AUTH_NULL,
107 /*
108 * Note we want connection to be done in the caller's
109 * filesystem namespace. We therefore turn off the idle
110 * timeout, which would result in reconnections being
111 * done without the correct namespace:
112 */
113 .flags = RPC_CLNT_CREATE_NOPING |
114 RPC_CLNT_CREATE_NO_IDLE_TIMEOUT
115 };
116 struct rpc_clnt *clnt;
117 int result = 0;
118
119 clnt = rpc_create(&args);
120 if (IS_ERR(clnt)) {
121 dprintk("RPC: failed to create AF_LOCAL gssproxy "
122 "client (errno %ld).\n", PTR_ERR(clnt));
123 result = PTR_ERR(clnt);
124 *_clnt = NULL;
125 goto out;
126 }
127
128 dprintk("RPC: created new gssp local client (gssp_local_clnt: "
129 "%p)\n", clnt);
130 *_clnt = clnt;
131
132 out:
133 return result;
134 }
135
init_gssp_clnt(struct sunrpc_net * sn)136 void init_gssp_clnt(struct sunrpc_net *sn)
137 {
138 mutex_init(&sn->gssp_lock);
139 sn->gssp_clnt = NULL;
140 }
141
set_gssp_clnt(struct net * net)142 int set_gssp_clnt(struct net *net)
143 {
144 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
145 struct rpc_clnt *clnt;
146 int ret;
147
148 mutex_lock(&sn->gssp_lock);
149 ret = gssp_rpc_create(net, &clnt);
150 if (!ret) {
151 if (sn->gssp_clnt)
152 rpc_shutdown_client(sn->gssp_clnt);
153 sn->gssp_clnt = clnt;
154 }
155 mutex_unlock(&sn->gssp_lock);
156 return ret;
157 }
158
clear_gssp_clnt(struct sunrpc_net * sn)159 void clear_gssp_clnt(struct sunrpc_net *sn)
160 {
161 mutex_lock(&sn->gssp_lock);
162 if (sn->gssp_clnt) {
163 rpc_shutdown_client(sn->gssp_clnt);
164 sn->gssp_clnt = NULL;
165 }
166 mutex_unlock(&sn->gssp_lock);
167 }
168
get_gssp_clnt(struct sunrpc_net * sn)169 static struct rpc_clnt *get_gssp_clnt(struct sunrpc_net *sn)
170 {
171 struct rpc_clnt *clnt;
172
173 mutex_lock(&sn->gssp_lock);
174 clnt = sn->gssp_clnt;
175 if (clnt)
176 atomic_inc(&clnt->cl_count);
177 mutex_unlock(&sn->gssp_lock);
178 return clnt;
179 }
180
gssp_call(struct net * net,struct rpc_message * msg)181 static int gssp_call(struct net *net, struct rpc_message *msg)
182 {
183 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
184 struct rpc_clnt *clnt;
185 int status;
186
187 clnt = get_gssp_clnt(sn);
188 if (!clnt)
189 return -EIO;
190 status = rpc_call_sync(clnt, msg, 0);
191 if (status < 0) {
192 dprintk("gssp: rpc_call returned error %d\n", -status);
193 switch (status) {
194 case -EPROTONOSUPPORT:
195 status = -EINVAL;
196 break;
197 case -ECONNREFUSED:
198 case -ETIMEDOUT:
199 case -ENOTCONN:
200 status = -EAGAIN;
201 break;
202 case -ERESTARTSYS:
203 if (signalled ())
204 status = -EINTR;
205 break;
206 default:
207 break;
208 }
209 }
210 rpc_release_client(clnt);
211 return status;
212 }
213
gssp_free_receive_pages(struct gssx_arg_accept_sec_context * arg)214 static void gssp_free_receive_pages(struct gssx_arg_accept_sec_context *arg)
215 {
216 int i;
217
218 for (i = 0; i < arg->npages && arg->pages[i]; i++)
219 __free_page(arg->pages[i]);
220
221 kfree(arg->pages);
222 }
223
gssp_alloc_receive_pages(struct gssx_arg_accept_sec_context * arg)224 static int gssp_alloc_receive_pages(struct gssx_arg_accept_sec_context *arg)
225 {
226 arg->npages = DIV_ROUND_UP(NGROUPS_MAX * 4, PAGE_SIZE);
227 arg->pages = kzalloc(arg->npages * sizeof(struct page *), GFP_KERNEL);
228 /*
229 * XXX: actual pages are allocated by xdr layer in
230 * xdr_partial_copy_from_skb.
231 */
232 if (!arg->pages)
233 return -ENOMEM;
234 return 0;
235 }
236
237 /*
238 * Public functions
239 */
240
241 /* numbers somewhat arbitrary but large enough for current needs */
242 #define GSSX_MAX_OUT_HANDLE 128
243 #define GSSX_MAX_SRC_PRINC 256
244 #define GSSX_KMEMBUF (GSSX_max_output_handle_sz + \
245 GSSX_max_oid_sz + \
246 GSSX_max_princ_sz + \
247 sizeof(struct svc_cred))
248
gssp_accept_sec_context_upcall(struct net * net,struct gssp_upcall_data * data)249 int gssp_accept_sec_context_upcall(struct net *net,
250 struct gssp_upcall_data *data)
251 {
252 struct gssx_ctx ctxh = {
253 .state = data->in_handle
254 };
255 struct gssx_arg_accept_sec_context arg = {
256 .input_token = data->in_token,
257 };
258 struct gssx_ctx rctxh = {
259 /*
260 * pass in the max length we expect for each of these
261 * buffers but let the xdr code kmalloc them:
262 */
263 .exported_context_token.len = GSSX_max_output_handle_sz,
264 .mech.len = GSS_OID_MAX_LEN,
265 .src_name.display_name.len = GSSX_max_princ_sz
266 };
267 struct gssx_res_accept_sec_context res = {
268 .context_handle = &rctxh,
269 .output_token = &data->out_token
270 };
271 struct rpc_message msg = {
272 .rpc_proc = &gssp_procedures[GSSX_ACCEPT_SEC_CONTEXT],
273 .rpc_argp = &arg,
274 .rpc_resp = &res,
275 .rpc_cred = NULL, /* FIXME ? */
276 };
277 struct xdr_netobj client_name = { 0 , NULL };
278 int ret;
279
280 if (data->in_handle.len != 0)
281 arg.context_handle = &ctxh;
282 res.output_token->len = GSSX_max_output_token_sz;
283
284 ret = gssp_alloc_receive_pages(&arg);
285 if (ret)
286 return ret;
287
288 /* use nfs/ for targ_name ? */
289
290 ret = gssp_call(net, &msg);
291
292 gssp_free_receive_pages(&arg);
293
294 /* we need to fetch all data even in case of error so
295 * that we can free special strctures is they have been allocated */
296 data->major_status = res.status.major_status;
297 data->minor_status = res.status.minor_status;
298 if (res.context_handle) {
299 data->out_handle = rctxh.exported_context_token;
300 data->mech_oid.len = rctxh.mech.len;
301 if (rctxh.mech.data)
302 memcpy(data->mech_oid.data, rctxh.mech.data,
303 data->mech_oid.len);
304 client_name = rctxh.src_name.display_name;
305 }
306
307 if (res.options.count == 1) {
308 gssx_buffer *value = &res.options.data[0].value;
309 /* Currently we only decode CREDS_VALUE, if we add
310 * anything else we'll have to loop and match on the
311 * option name */
312 if (value->len == 1) {
313 /* steal group info from struct svc_cred */
314 data->creds = *(struct svc_cred *)value->data;
315 data->found_creds = 1;
316 }
317 /* whether we use it or not, free data */
318 kfree(value->data);
319 }
320
321 if (res.options.count != 0) {
322 kfree(res.options.data);
323 }
324
325 /* convert to GSS_NT_HOSTBASED_SERVICE form and set into creds */
326 if (data->found_creds && client_name.data != NULL) {
327 char *c;
328
329 data->creds.cr_raw_principal = kstrndup(client_name.data,
330 client_name.len, GFP_KERNEL);
331
332 data->creds.cr_principal = kstrndup(client_name.data,
333 client_name.len, GFP_KERNEL);
334 if (data->creds.cr_principal) {
335 /* terminate and remove realm part */
336 c = strchr(data->creds.cr_principal, '@');
337 if (c) {
338 *c = '\0';
339
340 /* change service-hostname delimiter */
341 c = strchr(data->creds.cr_principal, '/');
342 if (c) *c = '@';
343 }
344 if (!c) {
345 /* not a service principal */
346 kfree(data->creds.cr_principal);
347 data->creds.cr_principal = NULL;
348 }
349 }
350 }
351 kfree(client_name.data);
352
353 return ret;
354 }
355
gssp_free_upcall_data(struct gssp_upcall_data * data)356 void gssp_free_upcall_data(struct gssp_upcall_data *data)
357 {
358 kfree(data->in_handle.data);
359 kfree(data->out_handle.data);
360 kfree(data->out_token.data);
361 free_svc_cred(&data->creds);
362 }
363
364 /*
365 * Initialization stuff
366 */
367
368 static const struct rpc_version gssp_version1 = {
369 .number = GSSPROXY_VERS_1,
370 .nrprocs = ARRAY_SIZE(gssp_procedures),
371 .procs = gssp_procedures,
372 };
373
374 static const struct rpc_version *gssp_version[] = {
375 NULL,
376 &gssp_version1,
377 };
378
379 static struct rpc_stat gssp_stats;
380
381 static const struct rpc_program gssp_program = {
382 .name = "gssproxy",
383 .number = GSSPROXY_PROGRAM,
384 .nrvers = ARRAY_SIZE(gssp_version),
385 .version = gssp_version,
386 .stats = &gssp_stats,
387 };
388