xref: /freebsd/sys/kgssapi/gss_impl.c (revision 9978553d0199e7ec0bdd1c44fc7f6c7b0c11e43b)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2008 Isilon Inc http://www.isilon.com/
5  * Authors: Doug Rabson <dfr@rabson.org>
6  * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/param.h>
31 #include <sys/jail.h>
32 #include <sys/kernel.h>
33 #include <sys/kobj.h>
34 #include <sys/lock.h>
35 #include <sys/malloc.h>
36 #include <sys/module.h>
37 #include <sys/mutex.h>
38 #include <sys/priv.h>
39 #include <sys/proc.h>
40 
41 #include <kgssapi/gssapi.h>
42 #include <kgssapi/gssapi_impl.h>
43 #include <rpc/rpc.h>
44 #include <rpc/rpc_com.h>
45 #include <rpc/rpcsec_gss.h>
46 
47 #include "gssd.h"
48 #include "kgss_if.h"
49 
50 MALLOC_DEFINE(M_GSSAPI, "GSS-API", "GSS-API");
51 
52 struct kgss_mech_list kgss_mechs;
53 struct mtx kgss_gssd_lock;
54 
55 KGSS_VNET_DEFINE(CLIENT *, kgss_gssd_handle) = NULL;
56 
57 static int
58 kgss_load(void)
59 {
60 	CLIENT *cl;
61 
62 	LIST_INIT(&kgss_mechs);
63 
64 	cl = client_nl_create("kgss", GSSD, GSSDVERS);
65 	KASSERT(cl, ("%s: netlink client already exist", __func__));
66 
67 	/*
68 	 * The transport default is no retries at all, since there could
69 	 * be no userland listener to our messages.  We will retry for 5
70 	 * minutes with 10 second interval.  This will potentially cure hosts
71 	 * with misconfigured startup, where kernel starts sending GSS queries
72 	 * before userland had started up the gssd(8) daemon.
73 	 */
74 	clnt_control(cl, CLSET_RETRIES, &(int){30});
75 	clnt_control(cl, CLSET_TIMEOUT, &(struct timeval){.tv_sec = 300});
76 
77 	/*
78 	 * We literally wait on gssd(8), let's see that in top(1).
79 	 */
80 	clnt_control(cl, CLSET_WAITCHAN, "gssd");
81 
82 	KGSS_CURVNET_SET_QUIET(KGSS_TD_TO_VNET(curthread));
83 	mtx_lock(&kgss_gssd_lock);
84 	KGSS_VNET(kgss_gssd_handle) = cl;
85 	mtx_unlock(&kgss_gssd_lock);
86 	KGSS_CURVNET_RESTORE();
87 
88 	return (0);
89 }
90 
91 #if 0
92 static void
93 kgss_unload(void)
94 {
95 
96 	KGSS_CURVNET_SET_QUIET(KGSS_TD_TO_VNET(curthread));
97 	clnt_destroy(KGSS_VNET(kgss_gssd_handle));
98 	KGSS_CURVNET_RESTORE();
99 }
100 #endif
101 
102 int
103 kgss_oid_equal(const gss_OID oid1, const gss_OID oid2)
104 {
105 
106 	if (oid1 == oid2)
107 		return (1);
108 	if (!oid1 || !oid2)
109 		return (0);
110 	if (oid1->length != oid2->length)
111 		return (0);
112 	if (memcmp(oid1->elements, oid2->elements, oid1->length))
113 		return (0);
114 	return (1);
115 }
116 
117 void
118 kgss_install_mech(gss_OID mech_type, const char *name, struct kobj_class *cls)
119 {
120 	struct kgss_mech *km;
121 
122 	km = malloc(sizeof(struct kgss_mech), M_GSSAPI, M_WAITOK);
123 	km->km_mech_type = mech_type;
124 	km->km_mech_name = name;
125 	km->km_class = cls;
126 	LIST_INSERT_HEAD(&kgss_mechs, km, km_link);
127 }
128 
129 void
130 kgss_uninstall_mech(gss_OID mech_type)
131 {
132 	struct kgss_mech *km;
133 
134 	LIST_FOREACH(km, &kgss_mechs, km_link) {
135 		if (kgss_oid_equal(km->km_mech_type, mech_type)) {
136 			LIST_REMOVE(km, km_link);
137 			free(km, M_GSSAPI);
138 			return;
139 		}
140 	}
141 }
142 
143 gss_OID
144 kgss_find_mech_by_name(const char *name)
145 {
146 	struct kgss_mech *km;
147 
148 	LIST_FOREACH(km, &kgss_mechs, km_link) {
149 		if (!strcmp(km->km_mech_name, name)) {
150 			return (km->km_mech_type);
151 		}
152 	}
153 	return (GSS_C_NO_OID);
154 }
155 
156 const char *
157 kgss_find_mech_by_oid(const gss_OID oid)
158 {
159 	struct kgss_mech *km;
160 
161 	LIST_FOREACH(km, &kgss_mechs, km_link) {
162 		if (kgss_oid_equal(km->km_mech_type, oid)) {
163 			return (km->km_mech_name);
164 		}
165 	}
166 	return (NULL);
167 }
168 
169 gss_ctx_id_t
170 kgss_create_context(gss_OID mech_type)
171 {
172 	struct kgss_mech *km;
173 	gss_ctx_id_t ctx;
174 
175 	LIST_FOREACH(km, &kgss_mechs, km_link) {
176 		if (kgss_oid_equal(km->km_mech_type, mech_type))
177 			break;
178 	}
179 	if (!km)
180 		return (NULL);
181 
182 	ctx = (gss_ctx_id_t) kobj_create(km->km_class, M_GSSAPI, M_WAITOK);
183 	KGSS_INIT(ctx);
184 
185 	return (ctx);
186 }
187 
188 void
189 kgss_delete_context(gss_ctx_id_t ctx, gss_buffer_t output_token)
190 {
191 
192 	KGSS_DELETE(ctx, output_token);
193 	kobj_delete((kobj_t) ctx, M_GSSAPI);
194 }
195 
196 OM_uint32
197 kgss_transfer_context(gss_ctx_id_t ctx, void *lctx)
198 {
199 	struct export_sec_context_res res;
200 	struct export_sec_context_args args;
201 	enum clnt_stat stat;
202 	OM_uint32 maj_stat;
203 
204 	if (lctx != NULL) {
205 		maj_stat = KGSS_IMPORT(ctx, MIT_V1, lctx);
206 		ctx->handle = 0;
207 		return (maj_stat);
208 	}
209 
210 	KGSS_CURVNET_SET_QUIET(KGSS_TD_TO_VNET(curthread));
211 	if (!KGSS_VNET(kgss_gssd_handle)) {
212 		KGSS_CURVNET_RESTORE();
213 		return (GSS_S_FAILURE);
214 	}
215 
216 	args.ctx = ctx->handle;
217 	bzero(&res, sizeof(res));
218 	stat = gssd_export_sec_context_1(&args, &res, KGSS_VNET(kgss_gssd_handle));
219 	KGSS_CURVNET_RESTORE();
220 	if (stat != RPC_SUCCESS) {
221 		return (GSS_S_FAILURE);
222 	}
223 
224 	maj_stat = KGSS_IMPORT(ctx, res.format, &res.interprocess_token);
225 	ctx->handle = 0;
226 
227 	xdr_free((xdrproc_t) xdr_export_sec_context_res, &res);
228 
229 	return (maj_stat);
230 }
231 
232 void
233 kgss_copy_buffer(const gss_buffer_t from, gss_buffer_t to)
234 {
235 	to->length = from->length;
236 	if (from->length) {
237 		to->value = malloc(from->length, M_GSSAPI, M_WAITOK);
238 		bcopy(from->value, to->value, from->length);
239 	} else {
240 		to->value = NULL;
241 	}
242 }
243 
244 /*
245  * Acquire the kgss_gssd_handle and return it with a reference count,
246  * if it is available.
247  */
248 CLIENT *
249 kgss_gssd_client(void)
250 {
251 	CLIENT *cl;
252 
253 	KGSS_CURVNET_SET_QUIET(KGSS_TD_TO_VNET(curthread));
254 	mtx_lock(&kgss_gssd_lock);
255 	cl = KGSS_VNET(kgss_gssd_handle);
256 	if (cl != NULL)
257 		CLNT_ACQUIRE(cl);
258 	mtx_unlock(&kgss_gssd_lock);
259 	KGSS_CURVNET_RESTORE();
260 	return (cl);
261 }
262 
263 /*
264  * Kernel module glue
265  */
266 static int
267 kgssapi_modevent(module_t mod, int type, void *data)
268 {
269 	int error = 0;
270 
271 	switch (type) {
272 	case MOD_LOAD:
273 		rpc_gss_entries.rpc_gss_refresh_auth = rpc_gss_refresh_auth;
274 		rpc_gss_entries.rpc_gss_secfind = rpc_gss_secfind;
275 		rpc_gss_entries.rpc_gss_secpurge = rpc_gss_secpurge;
276 		rpc_gss_entries.rpc_gss_seccreate = rpc_gss_seccreate;
277 		rpc_gss_entries.rpc_gss_set_defaults = rpc_gss_set_defaults;
278 		rpc_gss_entries.rpc_gss_max_data_length =
279 		    rpc_gss_max_data_length;
280 		rpc_gss_entries.rpc_gss_get_error = rpc_gss_get_error;
281 		rpc_gss_entries.rpc_gss_mech_to_oid = rpc_gss_mech_to_oid;
282 		rpc_gss_entries.rpc_gss_oid_to_mech = rpc_gss_oid_to_mech;
283 		rpc_gss_entries.rpc_gss_qop_to_num = rpc_gss_qop_to_num;
284 		rpc_gss_entries.rpc_gss_get_mechanisms = rpc_gss_get_mechanisms;
285 		rpc_gss_entries.rpc_gss_get_versions = rpc_gss_get_versions;
286 		rpc_gss_entries.rpc_gss_is_installed = rpc_gss_is_installed;
287 		rpc_gss_entries.rpc_gss_set_svc_name = rpc_gss_set_svc_name;
288 		rpc_gss_entries.rpc_gss_clear_svc_name = rpc_gss_clear_svc_name;
289 		rpc_gss_entries.rpc_gss_getcred = rpc_gss_getcred;
290 		rpc_gss_entries.rpc_gss_set_callback = rpc_gss_set_callback;
291 		rpc_gss_entries.rpc_gss_clear_callback = rpc_gss_clear_callback;
292 		rpc_gss_entries.rpc_gss_get_principal_name =
293 		    rpc_gss_get_principal_name;
294 		rpc_gss_entries.rpc_gss_svc_max_data_length =
295 		    rpc_gss_svc_max_data_length;
296 		rpc_gss_entries.rpc_gss_ip_to_srv_principal =
297 		    rpc_gss_ip_to_srv_principal;
298 		mtx_init(&kgss_gssd_lock, "kgss_gssd_lock", NULL, MTX_DEF);
299 		error = kgss_load();
300 		break;
301 	case MOD_UNLOAD:
302 #if 0
303 		kgss_unload();
304 		mtx_destroy(&kgss_gssd_lock);
305 #endif
306 		/*
307 		 * Unloading of the kgssapi module is not currently supported.
308 		 * If somebody wants this, we would need to keep track of
309 		 * currently executing threads and make sure the count is 0.
310 		 */
311 		/* FALLTHROUGH */
312 	default:
313 		error = EOPNOTSUPP;
314 	}
315 	return (error);
316 }
317 static moduledata_t kgssapi_mod = {
318 	"kgssapi",
319 	kgssapi_modevent,
320 	NULL,
321 };
322 DECLARE_MODULE(kgssapi, kgssapi_mod, SI_SUB_VFS, SI_ORDER_SECOND);
323 MODULE_DEPEND(kgssapi, xdr, 1, 1, 1);
324 MODULE_DEPEND(kgssapi, krpc, 1, 1, 1);
325 MODULE_VERSION(kgssapi, 1);
326