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 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 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 int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr)
 243 {
 244         struct gss_api_mech *pos = NULL;
 245         int j, i = 0;
 246
 247         spin_lock(&registered_mechs_lock);
 248         list_for_each_entry(pos, &registered_mechs, gm_list) {
 249                 for (j=0; j < pos->gm_pf_num; j++) {
 250                         array_ptr[i++] = pos->gm_pfs[j].pseudoflavor;
 251                 }
 252         }
 253         spin_unlock(&registered_mechs_lock);
 254         return i;
 255 }
 256
 257 EXPORT_SYMBOL_GPL(gss_mech_list_pseudoflavors);
 258
 259 u32
 260 gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 service)
 261 {
 262         int i;
 263
 264         for (i = 0; i < gm->gm_pf_num; i++) {
 265                 if (gm->gm_pfs[i].service == service) {
 266                         return gm->gm_pfs[i].pseudoflavor;
 267                 }
 268         }
 269         return RPC_AUTH_MAXFLAVOR; /* illegal value */
 270 }
 271 EXPORT_SYMBOL_GPL(gss_svc_to_pseudoflavor);
 272
 273 u32
 274 gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
 275 {
 276         int i;
 277
 278         for (i = 0; i < gm->gm_pf_num; i++) {
 279                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
 280                         return gm->gm_pfs[i].service;
 281         }
 282         return 0;
 283 }
 284
 285 EXPORT_SYMBOL_GPL(gss_pseudoflavor_to_service);
 286
 287 char *
 288 gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
 289 {
 290         int i;
 291
 292         for (i = 0; i < gm->gm_pf_num; i++) {
 293                 if (gm->gm_pfs[i].service == service)
 294                         return gm->gm_pfs[i].auth_domain_name;
 295         }
 296         return NULL;
 297 }
 298
 299 EXPORT_SYMBOL_GPL(gss_service_to_auth_domain_name);
 300
 301 void
 302 gss_mech_put(struct gss_api_mech * gm)
 303 {
 304         if (gm)
 305                 module_put(gm->gm_owner);
 306 }
 307
 308 EXPORT_SYMBOL_GPL(gss_mech_put);
 309
 310 /* The mech could probably be determined from the token instead, but it's just
 311  * as easy for now to pass it in. */
 312 int
 313 gss_import_sec_context(const void *input_token, size_t bufsize,
 314                        struct gss_api_mech      *mech,
 315                        struct gss_ctx           **ctx_id,
 316                        gfp_t gfp_mask)
 317 {
 318         if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
 319                 return -ENOMEM;
 320         (*ctx_id)->mech_type = gss_mech_get(mech);
 321
 322         return mech->gm_ops
 323                 ->gss_import_sec_context(input_token, bufsize, *ctx_id, gfp_mask);
 324 }
 325
 326 /* gss_get_mic: compute a mic over message and return mic_token. */
 327
 328 u32
 329 gss_get_mic(struct gss_ctx      *context_handle,
 330             struct xdr_buf      *message,
 331             struct xdr_netobj   *mic_token)
 332 {
 333          return context_handle->mech_type->gm_ops
 334                 ->gss_get_mic(context_handle,
 335                               message,
 336                               mic_token);
 337 }
 338
 339 /* gss_verify_mic: check whether the provided mic_token verifies message. */
 340
 341 u32
 342 gss_verify_mic(struct gss_ctx           *context_handle,
 343                struct xdr_buf           *message,
 344                struct xdr_netobj        *mic_token)
 345 {
 346         return context_handle->mech_type->gm_ops
 347                 ->gss_verify_mic(context_handle,
 348                                  message,
 349                                  mic_token);
 350 }
 351
 352 /*
 353  * This function is called from both the client and server code.
 354  * Each makes guarantees about how much "slack" space is available
 355  * for the underlying function in "buf"'s head and tail while
 356  * performing the wrap.
 357  *
 358  * The client and server code allocate RPC_MAX_AUTH_SIZE extra
 359  * space in both the head and tail which is available for use by
 360  * the wrap function.
 361  *
 362  * Underlying functions should verify they do not use more than
 363  * RPC_MAX_AUTH_SIZE of extra space in either the head or tail
 364  * when performing the wrap.
 365  */
 366 u32
 367 gss_wrap(struct gss_ctx *ctx_id,
 368          int            offset,
 369          struct xdr_buf *buf,
 370          struct page    **inpages)
 371 {
 372         return ctx_id->mech_type->gm_ops
 373                 ->gss_wrap(ctx_id, offset, buf, inpages);
 374 }
 375
 376 u32
 377 gss_unwrap(struct gss_ctx       *ctx_id,
 378            int                  offset,
 379            struct xdr_buf       *buf)
 380 {
 381         return ctx_id->mech_type->gm_ops
 382                 ->gss_unwrap(ctx_id, offset, buf);
 383 }
 384
 385
 386 /* gss_delete_sec_context: free all resources associated with context_handle.
 387  * Note this differs from the RFC 2744-specified prototype in that we don't
 388  * bother returning an output token, since it would never be used anyway. */
 389
 390 u32
 391 gss_delete_sec_context(struct gss_ctx   **context_handle)
 392 {
 393         dprintk("RPC:       gss_delete_sec_context deleting %p\n",
 394                         *context_handle);
 395
 396         if (!*context_handle)
 397                 return GSS_S_NO_CONTEXT;
 398         if ((*context_handle)->internal_ctx_id)
 399                 (*context_handle)->mech_type->gm_ops
 400                         ->gss_delete_sec_context((*context_handle)
 401                                                         ->internal_ctx_id);
 402         gss_mech_put((*context_handle)->mech_type);
 403         kfree(*context_handle);
 404         *context_handle=NULL;
 405         return GSS_S_COMPLETE;
 406 }