xref: /freebsd/sys/kgssapi/gss_impl.c (revision 137a344c6341d1469432e9deb3a25593f96672ad)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/kernel.h>
35 #include <sys/kobj.h>
36 #include <sys/lock.h>
37 #include <sys/malloc.h>
38 #include <sys/module.h>
39 #include <sys/mutex.h>
40 #include <sys/priv.h>
41 #include <sys/syscall.h>
42 #include <sys/sysent.h>
43 #include <sys/sysproto.h>
44 
45 #include <kgssapi/gssapi.h>
46 #include <kgssapi/gssapi_impl.h>
47 #include <rpc/rpc.h>
48 #include <rpc/rpc_com.h>
49 #include <rpc/rpcsec_gss.h>
50 
51 #include "gssd.h"
52 #include "kgss_if.h"
53 
54 MALLOC_DEFINE(M_GSSAPI, "GSS-API", "GSS-API");
55 
56 /*
57  * Syscall hooks
58  */
59 static int gssd_syscall_offset = SYS_gssd_syscall;
60 static struct sysent gssd_syscall_prev_sysent;
61 MAKE_SYSENT(gssd_syscall);
62 static bool_t gssd_syscall_registered = FALSE;
63 
64 struct kgss_mech_list kgss_mechs;
65 CLIENT *kgss_gssd_handle;
66 struct mtx kgss_gssd_lock;
67 
68 static void
69 kgss_init(void *dummy)
70 {
71 	int error;
72 
73 	LIST_INIT(&kgss_mechs);
74 	error = syscall_register(&gssd_syscall_offset, &gssd_syscall_sysent,
75 	    &gssd_syscall_prev_sysent, SY_THR_STATIC_KLD);
76 	if (error)
77 		printf("Can't register GSSD syscall\n");
78 	else
79 		gssd_syscall_registered = TRUE;
80 }
81 SYSINIT(kgss_init, SI_SUB_LOCK, SI_ORDER_FIRST, kgss_init, NULL);
82 
83 static void
84 kgss_uninit(void *dummy)
85 {
86 
87 	if (gssd_syscall_registered)
88 		syscall_deregister(&gssd_syscall_offset,
89 		    &gssd_syscall_prev_sysent);
90 }
91 SYSUNINIT(kgss_uninit, SI_SUB_LOCK, SI_ORDER_FIRST, kgss_uninit, NULL);
92 
93 int
94 sys_gssd_syscall(struct thread *td, struct gssd_syscall_args *uap)
95 {
96         struct sockaddr_un sun;
97         struct netconfig *nconf;
98 	char path[MAXPATHLEN];
99 	int error;
100 	CLIENT *cl, *oldcl;
101 
102 	error = priv_check(td, PRIV_NFS_DAEMON);
103 	if (error)
104 		return (error);
105 
106 	error = copyinstr(uap->path, path, sizeof(path), NULL);
107 	if (error)
108 		return (error);
109 	if (strlen(path) + 1 > sizeof(sun.sun_path))
110 		return (EINVAL);
111 
112 	if (path[0] != '\0') {
113 		sun.sun_family = AF_LOCAL;
114 		strlcpy(sun.sun_path, path, sizeof(sun.sun_path));
115 		sun.sun_len = SUN_LEN(&sun);
116 
117 		nconf = getnetconfigent("local");
118 		cl = clnt_reconnect_create(nconf,
119 		    (struct sockaddr *) &sun, GSSD, GSSDVERS,
120 		    RPC_MAXDATASIZE, RPC_MAXDATASIZE);
121 	} else
122 		cl = NULL;
123 
124 	mtx_lock(&kgss_gssd_lock);
125 	oldcl = kgss_gssd_handle;
126 	kgss_gssd_handle = cl;
127 	mtx_unlock(&kgss_gssd_lock);
128 
129 	if (oldcl != NULL) {
130 		CLNT_CLOSE(oldcl);
131 		CLNT_RELEASE(oldcl);
132 	}
133 
134 	return (0);
135 }
136 
137 int
138 kgss_oid_equal(const gss_OID oid1, const gss_OID oid2)
139 {
140 
141 	if (oid1 == oid2)
142 		return (1);
143 	if (!oid1 || !oid2)
144 		return (0);
145 	if (oid1->length != oid2->length)
146 		return (0);
147 	if (memcmp(oid1->elements, oid2->elements, oid1->length))
148 		return (0);
149 	return (1);
150 }
151 
152 void
153 kgss_install_mech(gss_OID mech_type, const char *name, struct kobj_class *cls)
154 {
155 	struct kgss_mech *km;
156 
157 	km = malloc(sizeof(struct kgss_mech), M_GSSAPI, M_WAITOK);
158 	km->km_mech_type = mech_type;
159 	km->km_mech_name = name;
160 	km->km_class = cls;
161 	LIST_INSERT_HEAD(&kgss_mechs, km, km_link);
162 }
163 
164 void
165 kgss_uninstall_mech(gss_OID mech_type)
166 {
167 	struct kgss_mech *km;
168 
169 	LIST_FOREACH(km, &kgss_mechs, km_link) {
170 		if (kgss_oid_equal(km->km_mech_type, mech_type)) {
171 			LIST_REMOVE(km, km_link);
172 			free(km, M_GSSAPI);
173 			return;
174 		}
175 	}
176 }
177 
178 gss_OID
179 kgss_find_mech_by_name(const char *name)
180 {
181 	struct kgss_mech *km;
182 
183 	LIST_FOREACH(km, &kgss_mechs, km_link) {
184 		if (!strcmp(km->km_mech_name, name)) {
185 			return (km->km_mech_type);
186 		}
187 	}
188 	return (GSS_C_NO_OID);
189 }
190 
191 const char *
192 kgss_find_mech_by_oid(const gss_OID oid)
193 {
194 	struct kgss_mech *km;
195 
196 	LIST_FOREACH(km, &kgss_mechs, km_link) {
197 		if (kgss_oid_equal(km->km_mech_type, oid)) {
198 			return (km->km_mech_name);
199 		}
200 	}
201 	return (NULL);
202 }
203 
204 gss_ctx_id_t
205 kgss_create_context(gss_OID mech_type)
206 {
207 	struct kgss_mech *km;
208 	gss_ctx_id_t ctx;
209 
210 	LIST_FOREACH(km, &kgss_mechs, km_link) {
211 		if (kgss_oid_equal(km->km_mech_type, mech_type))
212 			break;
213 	}
214 	if (!km)
215 		return (NULL);
216 
217 	ctx = (gss_ctx_id_t) kobj_create(km->km_class, M_GSSAPI, M_WAITOK);
218 	KGSS_INIT(ctx);
219 
220 	return (ctx);
221 }
222 
223 void
224 kgss_delete_context(gss_ctx_id_t ctx, gss_buffer_t output_token)
225 {
226 
227 	KGSS_DELETE(ctx, output_token);
228 	kobj_delete((kobj_t) ctx, M_GSSAPI);
229 }
230 
231 OM_uint32
232 kgss_transfer_context(gss_ctx_id_t ctx)
233 {
234 	struct export_sec_context_res res;
235 	struct export_sec_context_args args;
236 	enum clnt_stat stat;
237 	OM_uint32 maj_stat;
238 
239 	if (!kgss_gssd_handle)
240 		return (GSS_S_FAILURE);
241 
242 	args.ctx = ctx->handle;
243 	bzero(&res, sizeof(res));
244 	stat = gssd_export_sec_context_1(&args, &res, kgss_gssd_handle);
245 	if (stat != RPC_SUCCESS) {
246 		return (GSS_S_FAILURE);
247 	}
248 
249 	maj_stat = KGSS_IMPORT(ctx, res.format, &res.interprocess_token);
250 	ctx->handle = 0;
251 
252 	xdr_free((xdrproc_t) xdr_export_sec_context_res, &res);
253 
254 	return (maj_stat);
255 }
256 
257 void
258 kgss_copy_buffer(const gss_buffer_t from, gss_buffer_t to)
259 {
260 	to->length = from->length;
261 	if (from->length) {
262 		to->value = malloc(from->length, M_GSSAPI, M_WAITOK);
263 		bcopy(from->value, to->value, from->length);
264 	} else {
265 		to->value = NULL;
266 	}
267 }
268 
269 /*
270  * Acquire the kgss_gssd_handle and return it with a reference count,
271  * if it is available.
272  */
273 CLIENT *
274 kgss_gssd_client(void)
275 {
276 	CLIENT *cl;
277 
278 	mtx_lock(&kgss_gssd_lock);
279 	cl = kgss_gssd_handle;
280 	if (cl != NULL)
281 		CLNT_ACQUIRE(cl);
282 	mtx_unlock(&kgss_gssd_lock);
283 	return (cl);
284 }
285 
286 /*
287  * Kernel module glue
288  */
289 static int
290 kgssapi_modevent(module_t mod, int type, void *data)
291 {
292 	int error = 0;
293 
294 	switch (type) {
295 	case MOD_LOAD:
296 		rpc_gss_entries.rpc_gss_refresh_auth = rpc_gss_refresh_auth;
297 		rpc_gss_entries.rpc_gss_secfind = rpc_gss_secfind;
298 		rpc_gss_entries.rpc_gss_secpurge = rpc_gss_secpurge;
299 		rpc_gss_entries.rpc_gss_seccreate = rpc_gss_seccreate;
300 		rpc_gss_entries.rpc_gss_set_defaults = rpc_gss_set_defaults;
301 		rpc_gss_entries.rpc_gss_max_data_length =
302 		    rpc_gss_max_data_length;
303 		rpc_gss_entries.rpc_gss_get_error = rpc_gss_get_error;
304 		rpc_gss_entries.rpc_gss_mech_to_oid = rpc_gss_mech_to_oid;
305 		rpc_gss_entries.rpc_gss_oid_to_mech = rpc_gss_oid_to_mech;
306 		rpc_gss_entries.rpc_gss_qop_to_num = rpc_gss_qop_to_num;
307 		rpc_gss_entries.rpc_gss_get_mechanisms = rpc_gss_get_mechanisms;
308 		rpc_gss_entries.rpc_gss_get_versions = rpc_gss_get_versions;
309 		rpc_gss_entries.rpc_gss_is_installed = rpc_gss_is_installed;
310 		rpc_gss_entries.rpc_gss_set_svc_name = rpc_gss_set_svc_name;
311 		rpc_gss_entries.rpc_gss_clear_svc_name = rpc_gss_clear_svc_name;
312 		rpc_gss_entries.rpc_gss_getcred = rpc_gss_getcred;
313 		rpc_gss_entries.rpc_gss_set_callback = rpc_gss_set_callback;
314 		rpc_gss_entries.rpc_gss_clear_callback = rpc_gss_clear_callback;
315 		rpc_gss_entries.rpc_gss_get_principal_name =
316 		    rpc_gss_get_principal_name;
317 		rpc_gss_entries.rpc_gss_svc_max_data_length =
318 		    rpc_gss_svc_max_data_length;
319 		mtx_init(&kgss_gssd_lock, "kgss_gssd_lock", NULL, MTX_DEF);
320 		break;
321 	case MOD_UNLOAD:
322 		/*
323 		 * Unloading of the kgssapi module is not currently supported.
324 		 * If somebody wants this, we would need to keep track of
325 		 * currently executing threads and make sure the count is 0.
326 		 */
327 		/* FALLTHROUGH */
328 	default:
329 		error = EOPNOTSUPP;
330 	}
331 	return (error);
332 }
333 static moduledata_t kgssapi_mod = {
334 	"kgssapi",
335 	kgssapi_modevent,
336 	NULL,
337 };
338 DECLARE_MODULE(kgssapi, kgssapi_mod, SI_SUB_VFS, SI_ORDER_ANY);
339 MODULE_DEPEND(kgssapi, krpc, 1, 1, 1);
340 MODULE_VERSION(kgssapi, 1);
341