xref: /freebsd/sys/kgssapi/gss_impl.c (revision 3416500aef140042c64bc149cb1ec6620483bc44)
1 /*-
2  * Copyright (c) 2008 Isilon Inc http://www.isilon.com/
3  * Authors: Doug Rabson <dfr@rabson.org>
4  * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.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/syscall.h>
40 #include <sys/sysent.h>
41 #include <sys/sysproto.h>
42 
43 #include <kgssapi/gssapi.h>
44 #include <kgssapi/gssapi_impl.h>
45 #include <rpc/rpc.h>
46 #include <rpc/rpc_com.h>
47 #include <rpc/rpcsec_gss.h>
48 
49 #include "gssd.h"
50 #include "kgss_if.h"
51 
52 MALLOC_DEFINE(M_GSSAPI, "GSS-API", "GSS-API");
53 
54 /*
55  * Syscall hooks
56  */
57 static int gssd_syscall_offset = SYS_gssd_syscall;
58 static struct sysent gssd_syscall_prev_sysent;
59 MAKE_SYSENT(gssd_syscall);
60 static bool_t gssd_syscall_registered = FALSE;
61 
62 struct kgss_mech_list kgss_mechs;
63 CLIENT *kgss_gssd_handle;
64 struct mtx kgss_gssd_lock;
65 
66 static void
67 kgss_init(void *dummy)
68 {
69 	int error;
70 
71 	LIST_INIT(&kgss_mechs);
72 	error = syscall_register(&gssd_syscall_offset, &gssd_syscall_sysent,
73 	    &gssd_syscall_prev_sysent, SY_THR_STATIC_KLD);
74 	if (error)
75 		printf("Can't register GSSD syscall\n");
76 	else
77 		gssd_syscall_registered = TRUE;
78 }
79 SYSINIT(kgss_init, SI_SUB_LOCK, SI_ORDER_FIRST, kgss_init, NULL);
80 
81 static void
82 kgss_uninit(void *dummy)
83 {
84 
85 	if (gssd_syscall_registered)
86 		syscall_deregister(&gssd_syscall_offset,
87 		    &gssd_syscall_prev_sysent);
88 }
89 SYSUNINIT(kgss_uninit, SI_SUB_LOCK, SI_ORDER_FIRST, kgss_uninit, NULL);
90 
91 int
92 sys_gssd_syscall(struct thread *td, struct gssd_syscall_args *uap)
93 {
94         struct sockaddr_un sun;
95         struct netconfig *nconf;
96 	char path[MAXPATHLEN];
97 	int error;
98 	CLIENT *cl, *oldcl;
99 
100 	error = priv_check(td, PRIV_NFS_DAEMON);
101 	if (error)
102 		return (error);
103 
104 	error = copyinstr(uap->path, path, sizeof(path), NULL);
105 	if (error)
106 		return (error);
107 	if (strlen(path) + 1 > sizeof(sun.sun_path))
108 		return (EINVAL);
109 
110 	if (path[0] != '\0') {
111 		sun.sun_family = AF_LOCAL;
112 		strlcpy(sun.sun_path, path, sizeof(sun.sun_path));
113 		sun.sun_len = SUN_LEN(&sun);
114 
115 		nconf = getnetconfigent("local");
116 		cl = clnt_reconnect_create(nconf,
117 		    (struct sockaddr *) &sun, GSSD, GSSDVERS,
118 		    RPC_MAXDATASIZE, RPC_MAXDATASIZE);
119 	} else
120 		cl = NULL;
121 
122 	mtx_lock(&kgss_gssd_lock);
123 	oldcl = kgss_gssd_handle;
124 	kgss_gssd_handle = cl;
125 	mtx_unlock(&kgss_gssd_lock);
126 
127 	if (oldcl != NULL) {
128 		CLNT_CLOSE(oldcl);
129 		CLNT_RELEASE(oldcl);
130 	}
131 
132 	return (0);
133 }
134 
135 int
136 kgss_oid_equal(const gss_OID oid1, const gss_OID oid2)
137 {
138 
139 	if (oid1 == oid2)
140 		return (1);
141 	if (!oid1 || !oid2)
142 		return (0);
143 	if (oid1->length != oid2->length)
144 		return (0);
145 	if (memcmp(oid1->elements, oid2->elements, oid1->length))
146 		return (0);
147 	return (1);
148 }
149 
150 void
151 kgss_install_mech(gss_OID mech_type, const char *name, struct kobj_class *cls)
152 {
153 	struct kgss_mech *km;
154 
155 	km = malloc(sizeof(struct kgss_mech), M_GSSAPI, M_WAITOK);
156 	km->km_mech_type = mech_type;
157 	km->km_mech_name = name;
158 	km->km_class = cls;
159 	LIST_INSERT_HEAD(&kgss_mechs, km, km_link);
160 }
161 
162 void
163 kgss_uninstall_mech(gss_OID mech_type)
164 {
165 	struct kgss_mech *km;
166 
167 	LIST_FOREACH(km, &kgss_mechs, km_link) {
168 		if (kgss_oid_equal(km->km_mech_type, mech_type)) {
169 			LIST_REMOVE(km, km_link);
170 			free(km, M_GSSAPI);
171 			return;
172 		}
173 	}
174 }
175 
176 gss_OID
177 kgss_find_mech_by_name(const char *name)
178 {
179 	struct kgss_mech *km;
180 
181 	LIST_FOREACH(km, &kgss_mechs, km_link) {
182 		if (!strcmp(km->km_mech_name, name)) {
183 			return (km->km_mech_type);
184 		}
185 	}
186 	return (GSS_C_NO_OID);
187 }
188 
189 const char *
190 kgss_find_mech_by_oid(const gss_OID oid)
191 {
192 	struct kgss_mech *km;
193 
194 	LIST_FOREACH(km, &kgss_mechs, km_link) {
195 		if (kgss_oid_equal(km->km_mech_type, oid)) {
196 			return (km->km_mech_name);
197 		}
198 	}
199 	return (NULL);
200 }
201 
202 gss_ctx_id_t
203 kgss_create_context(gss_OID mech_type)
204 {
205 	struct kgss_mech *km;
206 	gss_ctx_id_t ctx;
207 
208 	LIST_FOREACH(km, &kgss_mechs, km_link) {
209 		if (kgss_oid_equal(km->km_mech_type, mech_type))
210 			break;
211 	}
212 	if (!km)
213 		return (NULL);
214 
215 	ctx = (gss_ctx_id_t) kobj_create(km->km_class, M_GSSAPI, M_WAITOK);
216 	KGSS_INIT(ctx);
217 
218 	return (ctx);
219 }
220 
221 void
222 kgss_delete_context(gss_ctx_id_t ctx, gss_buffer_t output_token)
223 {
224 
225 	KGSS_DELETE(ctx, output_token);
226 	kobj_delete((kobj_t) ctx, M_GSSAPI);
227 }
228 
229 OM_uint32
230 kgss_transfer_context(gss_ctx_id_t ctx)
231 {
232 	struct export_sec_context_res res;
233 	struct export_sec_context_args args;
234 	enum clnt_stat stat;
235 	OM_uint32 maj_stat;
236 
237 	if (!kgss_gssd_handle)
238 		return (GSS_S_FAILURE);
239 
240 	args.ctx = ctx->handle;
241 	bzero(&res, sizeof(res));
242 	stat = gssd_export_sec_context_1(&args, &res, kgss_gssd_handle);
243 	if (stat != RPC_SUCCESS) {
244 		return (GSS_S_FAILURE);
245 	}
246 
247 	maj_stat = KGSS_IMPORT(ctx, res.format, &res.interprocess_token);
248 	ctx->handle = 0;
249 
250 	xdr_free((xdrproc_t) xdr_export_sec_context_res, &res);
251 
252 	return (maj_stat);
253 }
254 
255 void
256 kgss_copy_buffer(const gss_buffer_t from, gss_buffer_t to)
257 {
258 	to->length = from->length;
259 	if (from->length) {
260 		to->value = malloc(from->length, M_GSSAPI, M_WAITOK);
261 		bcopy(from->value, to->value, from->length);
262 	} else {
263 		to->value = NULL;
264 	}
265 }
266 
267 /*
268  * Acquire the kgss_gssd_handle and return it with a reference count,
269  * if it is available.
270  */
271 CLIENT *
272 kgss_gssd_client(void)
273 {
274 	CLIENT *cl;
275 
276 	mtx_lock(&kgss_gssd_lock);
277 	cl = kgss_gssd_handle;
278 	if (cl != NULL)
279 		CLNT_ACQUIRE(cl);
280 	mtx_unlock(&kgss_gssd_lock);
281 	return (cl);
282 }
283 
284 /*
285  * Kernel module glue
286  */
287 static int
288 kgssapi_modevent(module_t mod, int type, void *data)
289 {
290 	int error = 0;
291 
292 	switch (type) {
293 	case MOD_LOAD:
294 		rpc_gss_entries.rpc_gss_refresh_auth = rpc_gss_refresh_auth;
295 		rpc_gss_entries.rpc_gss_secfind = rpc_gss_secfind;
296 		rpc_gss_entries.rpc_gss_secpurge = rpc_gss_secpurge;
297 		rpc_gss_entries.rpc_gss_seccreate = rpc_gss_seccreate;
298 		rpc_gss_entries.rpc_gss_set_defaults = rpc_gss_set_defaults;
299 		rpc_gss_entries.rpc_gss_max_data_length =
300 		    rpc_gss_max_data_length;
301 		rpc_gss_entries.rpc_gss_get_error = rpc_gss_get_error;
302 		rpc_gss_entries.rpc_gss_mech_to_oid = rpc_gss_mech_to_oid;
303 		rpc_gss_entries.rpc_gss_oid_to_mech = rpc_gss_oid_to_mech;
304 		rpc_gss_entries.rpc_gss_qop_to_num = rpc_gss_qop_to_num;
305 		rpc_gss_entries.rpc_gss_get_mechanisms = rpc_gss_get_mechanisms;
306 		rpc_gss_entries.rpc_gss_get_versions = rpc_gss_get_versions;
307 		rpc_gss_entries.rpc_gss_is_installed = rpc_gss_is_installed;
308 		rpc_gss_entries.rpc_gss_set_svc_name = rpc_gss_set_svc_name;
309 		rpc_gss_entries.rpc_gss_clear_svc_name = rpc_gss_clear_svc_name;
310 		rpc_gss_entries.rpc_gss_getcred = rpc_gss_getcred;
311 		rpc_gss_entries.rpc_gss_set_callback = rpc_gss_set_callback;
312 		rpc_gss_entries.rpc_gss_clear_callback = rpc_gss_clear_callback;
313 		rpc_gss_entries.rpc_gss_get_principal_name =
314 		    rpc_gss_get_principal_name;
315 		rpc_gss_entries.rpc_gss_svc_max_data_length =
316 		    rpc_gss_svc_max_data_length;
317 		mtx_init(&kgss_gssd_lock, "kgss_gssd_lock", NULL, MTX_DEF);
318 		break;
319 	case MOD_UNLOAD:
320 		/*
321 		 * Unloading of the kgssapi module is not currently supported.
322 		 * If somebody wants this, we would need to keep track of
323 		 * currently executing threads and make sure the count is 0.
324 		 */
325 		/* FALLTHROUGH */
326 	default:
327 		error = EOPNOTSUPP;
328 	}
329 	return (error);
330 }
331 static moduledata_t kgssapi_mod = {
332 	"kgssapi",
333 	kgssapi_modevent,
334 	NULL,
335 };
336 DECLARE_MODULE(kgssapi, kgssapi_mod, SI_SUB_VFS, SI_ORDER_ANY);
337 MODULE_DEPEND(kgssapi, krpc, 1, 1, 1);
338 MODULE_VERSION(kgssapi, 1);
339