net/sunrpc/auth_gss/gss_mech_switch.c

   1 /*
   2  *  linux/net/sunrpc/gss_mech_switch.c
   3  *
   4  *  Copyright (c) 2001 The Regents of the University of Michigan.
   5  *  All rights reserved.
   6  *
   7  *  J. Bruce Fields   <bfields@umich.edu>
   8  *
   9  *  Redistribution and use in source and binary forms, with or without
  10  *  modification, are permitted provided that the following conditions
  11  *  are met:
  12  *
  13  *  1. Redistributions of source code must retain the above copyright
  14  *     notice, this list of conditions and the following disclaimer.
  15  *  2. Redistributions in binary form must reproduce the above copyright
  16  *     notice, this list of conditions and the following disclaimer in the
  17  *     documentation and/or other materials provided with the distribution.
  18  *  3. Neither the name of the University nor the names of its
  19  *     contributors may be used to endorse or promote products derived
  20  *     from this software without specific prior written permission.
  21  *
  22  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  23  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  24  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  25  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  29  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  30  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  31  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  32  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  *
  34  */
  35
  36 #include <linux/types.h>
  37 #include <linux/slab.h>
  38 #include <linux/module.h>
  39 #include <linux/sunrpc/msg_prot.h>
  40 #include <linux/sunrpc/gss_asn1.h>
  41 #include <linux/sunrpc/auth_gss.h>
  42 #include <linux/sunrpc/svcauth_gss.h>
  43 #include <linux/sunrpc/gss_err.h>
  44 #include <linux/sunrpc/sched.h>
  45 #include <linux/sunrpc/gss_api.h>
  46 #include <linux/sunrpc/clnt.h>
  47
  48 #ifdef RPC_DEBUG
  49 # define RPCDBG_FACILITY        RPCDBG_AUTH
  50 #endif
  51
  52 static LIST_HEAD(registered_mechs);
  53 static DEFINE_SPINLOCK(registered_mechs_lock);
  54
  55 static void
  56 gss_mech_free(struct gss_api_mech *gm)
  57 {
  58         struct pf_desc *pf;
  59         int i;
  60
  61         for (i = 0; i < gm->gm_pf_num; i++) {
  62                 pf = &gm->gm_pfs[i];
  63                 kfree(pf->auth_domain_name);
  64                 pf->auth_domain_name = NULL;
  65         }
  66 }
  67
  68 static inline char *
  69 make_auth_domain_name(char *name)
  70 {
  71         static char     *prefix = "gss/";
  72         char            *new;
  73
  74         new = kmalloc(strlen(name) + strlen(prefix) + 1, GFP_KERNEL);
  75         if (new) {
  76                 strcpy(new, prefix);
  77                 strcat(new, name);
  78         }
  79         return new;
  80 }
  81
  82 static int
  83 gss_mech_svc_setup(struct gss_api_mech *gm)
  84 {
  85         struct pf_desc *pf;
  86         int i, status;
  87
  88         for (i = 0; i < gm->gm_pf_num; i++) {
  89                 pf = &gm->gm_pfs[i];
  90                 pf->auth_domain_name = make_auth_domain_name(pf->name);
  91                 status = -ENOMEM;
  92                 if (pf->auth_domain_name == NULL)
  93                         goto out;
  94                 status = svcauth_gss_register_pseudoflavor(pf->pseudoflavor,
  95                                                         pf->auth_domain_name);
  96                 if (status)
  97                         goto out;
  98         }
  99         return 0;
 100 out:
 101         gss_mech_free(gm);
 102         return status;
 103 }
 104
 105 int
 106 gss_mech_register(struct gss_api_mech *gm)
 107 {
 108         int status;
 109
 110         status = gss_mech_svc_setup(gm);
 111         if (status)
 112                 return status;
 113         spin_lock(&registered_mechs_lock);
 114         list_add(&gm->gm_list, &registered_mechs);
 115         spin_unlock(&registered_mechs_lock);
 116         dprintk("RPC:       registered gss mechanism %s\n", gm->gm_name);
 117         return 0;
 118 }
 119
 120 EXPORT_SYMBOL_GPL(gss_mech_register);
 121
 122 void
 123 gss_mech_unregister(struct gss_api_mech *gm)
 124 {
 125         spin_lock(&registered_mechs_lock);
 126         list_del(&gm->gm_list);
 127         spin_unlock(&registered_mechs_lock);
 128         dprintk("RPC:       unregistered gss mechanism %s\n", gm->gm_name);
 129         gss_mech_free(gm);
 130 }
 131
 132 EXPORT_SYMBOL_GPL(gss_mech_unregister);
 133
 134 struct gss_api_mech *
 135 gss_mech_get(struct gss_api_mech *gm)
 136 {
 137         __module_get(gm->gm_owner);
 138         return gm;
 139 }
 140
 141 EXPORT_SYMBOL_GPL(gss_mech_get);
 142
 143 static struct gss_api_mech *
 144 _gss_mech_get_by_name(const char *name)
 145 {
 146         struct gss_api_mech     *pos, *gm = NULL;
 147
 148         spin_lock(&registered_mechs_lock);
 149         list_for_each_entry(pos, &registered_mechs, gm_list) {
 150                 if (0 == strcmp(name, pos->gm_name)) {
 151                         if (try_module_get(pos->gm_owner))
 152                                 gm = pos;
 153                         break;
 154                 }
 155         }
 156         spin_unlock(&registered_mechs_lock);
 157         return gm;
 158
 159 }
 160
 161 struct gss_api_mech * gss_mech_get_by_name(const char *name)
 162 {
 163         struct gss_api_mech *gm = NULL;
 164
 165         gm = _gss_mech_get_by_name(name);
 166         if (!gm) {
 167                 request_module("rpc-auth-gss-%s", name);
 168                 gm = _gss_mech_get_by_name(name);
 169         }
 170         return gm;
 171 }
 172 EXPORT_SYMBOL_GPL(gss_mech_get_by_name);
 173
 174 struct gss_api_mech *
 175 gss_mech_get_by_OID(struct xdr_netobj *obj)
 176 {
 177         struct gss_api_mech     *pos, *gm = NULL;
 178
 179         spin_lock(&registered_mechs_lock);
 180         list_for_each_entry(pos, &registered_mechs, gm_list) {
 181                 if (obj->len == pos->gm_oid.len) {
 182                         if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
 183                                 if (try_module_get(pos->gm_owner))
 184                                         gm = pos;
 185                                 break;
 186                         }
 187                 }
 188         }
 189         spin_unlock(&registered_mechs_lock);
 190         return gm;
 191
 192 }
 193
 194 EXPORT_SYMBOL_GPL(gss_mech_get_by_OID);
 195
 196 static inline int
 197 mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
 198 {
 199         int i;
 200
 201         for (i = 0; i < gm->gm_pf_num; i++) {
 202                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
 203                         return 1;
 204         }
 205         return 0;
 206 }
 207
 208 static struct gss_api_mech *_gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
 209 {
 210         struct gss_api_mech *gm = NULL, *pos;
 211
 212         spin_lock(&registered_mechs_lock);
 213         list_for_each_entry(pos, &registered_mechs, gm_list) {
 214                 if (!mech_supports_pseudoflavor(pos, pseudoflavor)) {
 215                         module_put(pos->gm_owner);
 216                         continue;
 217                 }
 218                 if (try_module_get(pos->gm_owner))
 219                         gm = pos;
 220                 break;
 221         }
 222         spin_unlock(&registered_mechs_lock);
 223         return gm;
 224 }
 225
 226 struct gss_api_mech *
 227 gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
 228 {
 229         struct gss_api_mech *gm;
 230
 231         gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
 232
 233         if (!gm) {
 234                 request_module("rpc-auth-gss-%u", pseudoflavor);
 235                 gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
 236         }
 237         return gm;
 238 }
 239
 240 EXPORT_SYMBOL_GPL(gss_mech_get_by_pseudoflavor);
 241
 242 /**
 243  * gss_mech_list_pseudoflavors - Discover registered GSS pseudoflavors
 244  * @array: array to fill in
 245  * @size: size of "array"
 246  *
 247  * Returns the number of array items filled in, or a negative errno.
 248  *
 249  * The returned array is not sorted by any policy.  Callers should not
 250  * rely on the order of the items in the returned array.
 251  */
 252 int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr, int size)
 253 {
 254         struct gss_api_mech *pos = NULL;
 255         int j, i = 0;
 256
 257         spin_lock(&registered_mechs_lock);
 258         list_for_each_entry(pos, &registered_mechs, gm_list) {
 259                 for (j = 0; j < pos->gm_pf_num; j++) {
 260                         if (i >= size) {
 261                                 spin_unlock(&registered_mechs_lock);
 262                                 return -ENOMEM;
 263                         }
 264                         array_ptr[i++] = pos->gm_pfs[j].pseudoflavor;
 265                 }
 266         }
 267         spin_unlock(&registered_mechs_lock);
 268         return i;
 269 }
 270
 271 u32
 272 gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 service)
 273 {
 274         int i;
 275
 276         for (i = 0; i < gm->gm_pf_num; i++) {
 277                 if (gm->gm_pfs[i].service == service) {
 278                         return gm->gm_pfs[i].pseudoflavor;
 279                 }
 280         }
 281         return RPC_AUTH_MAXFLAVOR; /* illegal value */
 282 }
 283 EXPORT_SYMBOL_GPL(gss_svc_to_pseudoflavor);
 284
 285 u32
 286 gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
 287 {
 288         int i;
 289
 290         for (i = 0; i < gm->gm_pf_num; i++) {
 291                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
 292                         return gm->gm_pfs[i].service;
 293         }
 294         return 0;
 295 }
 296
 297 EXPORT_SYMBOL_GPL(gss_pseudoflavor_to_service);
 298
 299 char *
 300 gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
 301 {
 302         int i;
 303
 304         for (i = 0; i < gm->gm_pf_num; i++) {
 305                 if (gm->gm_pfs[i].service == service)
 306                         return gm->gm_pfs[i].auth_domain_name;
 307         }
 308         return NULL;
 309 }
 310
 311 EXPORT_SYMBOL_GPL(gss_service_to_auth_domain_name);
 312
 313 void
 314 gss_mech_put(struct gss_api_mech * gm)
 315 {
 316         if (gm)
 317                 module_put(gm->gm_owner);
 318 }
 319
 320 EXPORT_SYMBOL_GPL(gss_mech_put);
 321
 322 /* The mech could probably be determined from the token instead, but it's just
 323  * as easy for now to pass it in. */
 324 int
 325 gss_import_sec_context(const void *input_token, size_t bufsize,
 326                        struct gss_api_mech      *mech,
 327                        struct gss_ctx           **ctx_id,
 328                        gfp_t gfp_mask)
 329 {
 330         if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
 331                 return -ENOMEM;
 332         (*ctx_id)->mech_type = gss_mech_get(mech);
 333
 334         return mech->gm_ops
 335                 ->gss_import_sec_context(input_token, bufsize, *ctx_id, gfp_mask);
 336 }
 337
 338 /* gss_get_mic: compute a mic over message and return mic_token. */
 339
 340 u32
 341 gss_get_mic(struct gss_ctx      *context_handle,
 342             struct xdr_buf      *message,
 343             struct xdr_netobj   *mic_token)
 344 {
 345          return context_handle->mech_type->gm_ops
 346                 ->gss_get_mic(context_handle,
 347                               message,
 348                               mic_token);
 349 }
 350
 351 /* gss_verify_mic: check whether the provided mic_token verifies message. */
 352
 353 u32
 354 gss_verify_mic(struct gss_ctx           *context_handle,
 355                struct xdr_buf           *message,
 356                struct xdr_netobj        *mic_token)
 357 {
 358         return context_handle->mech_type->gm_ops
 359                 ->gss_verify_mic(context_handle,
 360                                  message,
 361                                  mic_token);
 362 }
 363
 364 /*
 365  * This function is called from both the client and server code.
 366  * Each makes guarantees about how much "slack" space is available
 367  * for the underlying function in "buf"'s head and tail while
 368  * performing the wrap.
 369  *
 370  * The client and server code allocate RPC_MAX_AUTH_SIZE extra
 371  * space in both the head and tail which is available for use by
 372  * the wrap function.
 373  *
 374  * Underlying functions should verify they do not use more than
 375  * RPC_MAX_AUTH_SIZE of extra space in either the head or tail
 376  * when performing the wrap.
 377  */
 378 u32
 379 gss_wrap(struct gss_ctx *ctx_id,
 380          int            offset,
 381          struct xdr_buf *buf,
 382          struct page    **inpages)
 383 {
 384         return ctx_id->mech_type->gm_ops
 385                 ->gss_wrap(ctx_id, offset, buf, inpages);
 386 }
 387
 388 u32
 389 gss_unwrap(struct gss_ctx       *ctx_id,
 390            int                  offset,
 391            struct xdr_buf       *buf)
 392 {
 393         return ctx_id->mech_type->gm_ops
 394                 ->gss_unwrap(ctx_id, offset, buf);
 395 }
 396
 397
 398 /* gss_delete_sec_context: free all resources associated with context_handle.
 399  * Note this differs from the RFC 2744-specified prototype in that we don't
 400  * bother returning an output token, since it would never be used anyway. */
 401
 402 u32
 403 gss_delete_sec_context(struct gss_ctx   **context_handle)
 404 {
 405         dprintk("RPC:       gss_delete_sec_context deleting %p\n",
 406                         *context_handle);
 407
 408         if (!*context_handle)
 409                 return GSS_S_NO_CONTEXT;
 410         if ((*context_handle)->internal_ctx_id)
 411                 (*context_handle)->mech_type->gm_ops
 412                         ->gss_delete_sec_context((*context_handle)
 413                                                         ->internal_ctx_id);
 414         gss_mech_put((*context_handle)->mech_type);
 415         kfree(*context_handle);
 416         *context_handle=NULL;
 417         return GSS_S_COMPLETE;
 418 }