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 EXPORT_SYMBOL_GPL(gss_mech_get_by_name);
 162
 163 struct gss_api_mech *
 164 gss_mech_get_by_OID(struct xdr_netobj *obj)
 165 {
 166         struct gss_api_mech     *pos, *gm = NULL;
 167
 168         spin_lock(&registered_mechs_lock);
 169         list_for_each_entry(pos, &registered_mechs, gm_list) {
 170                 if (obj->len == pos->gm_oid.len) {
 171                         if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
 172                                 if (try_module_get(pos->gm_owner))
 173                                         gm = pos;
 174                                 break;
 175                         }
 176                 }
 177         }
 178         spin_unlock(&registered_mechs_lock);
 179         return gm;
 180
 181 }
 182
 183 EXPORT_SYMBOL_GPL(gss_mech_get_by_OID);
 184
 185 static inline int
 186 mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
 187 {
 188         int i;
 189
 190         for (i = 0; i < gm->gm_pf_num; i++) {
 191                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
 192                         return 1;
 193         }
 194         return 0;
 195 }
 196
 197 struct gss_api_mech *
 198 gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
 199 {
 200         struct gss_api_mech *pos, *gm = NULL;
 201
 202         spin_lock(&registered_mechs_lock);
 203         list_for_each_entry(pos, &registered_mechs, gm_list) {
 204                 if (!mech_supports_pseudoflavor(pos, pseudoflavor)) {
 205                         module_put(pos->gm_owner);
 206                         continue;
 207                 }
 208                 if (try_module_get(pos->gm_owner))
 209                         gm = pos;
 210                 break;
 211         }
 212         spin_unlock(&registered_mechs_lock);
 213         return gm;
 214 }
 215
 216 EXPORT_SYMBOL_GPL(gss_mech_get_by_pseudoflavor);
 217
 218 u32
 219 gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 service)
 220 {
 221         int i;
 222
 223         for (i = 0; i < gm->gm_pf_num; i++) {
 224                 if (gm->gm_pfs[i].service == service) {
 225                         return gm->gm_pfs[i].pseudoflavor;
 226                 }
 227         }
 228         return RPC_AUTH_MAXFLAVOR; /* illegal value */
 229 }
 230 EXPORT_SYMBOL_GPL(gss_svc_to_pseudoflavor);
 231
 232 u32
 233 gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
 234 {
 235         int i;
 236
 237         for (i = 0; i < gm->gm_pf_num; i++) {
 238                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
 239                         return gm->gm_pfs[i].service;
 240         }
 241         return 0;
 242 }
 243
 244 EXPORT_SYMBOL_GPL(gss_pseudoflavor_to_service);
 245
 246 char *
 247 gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
 248 {
 249         int i;
 250
 251         for (i = 0; i < gm->gm_pf_num; i++) {
 252                 if (gm->gm_pfs[i].service == service)
 253                         return gm->gm_pfs[i].auth_domain_name;
 254         }
 255         return NULL;
 256 }
 257
 258 EXPORT_SYMBOL_GPL(gss_service_to_auth_domain_name);
 259
 260 void
 261 gss_mech_put(struct gss_api_mech * gm)
 262 {
 263         if (gm)
 264                 module_put(gm->gm_owner);
 265 }
 266
 267 EXPORT_SYMBOL_GPL(gss_mech_put);
 268
 269 /* The mech could probably be determined from the token instead, but it's just
 270  * as easy for now to pass it in. */
 271 int
 272 gss_import_sec_context(const void *input_token, size_t bufsize,
 273                        struct gss_api_mech      *mech,
 274                        struct gss_ctx           **ctx_id,
 275                        gfp_t gfp_mask)
 276 {
 277         if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
 278                 return -ENOMEM;
 279         (*ctx_id)->mech_type = gss_mech_get(mech);
 280
 281         return mech->gm_ops
 282                 ->gss_import_sec_context(input_token, bufsize, *ctx_id, gfp_mask);
 283 }
 284
 285 /* gss_get_mic: compute a mic over message and return mic_token. */
 286
 287 u32
 288 gss_get_mic(struct gss_ctx      *context_handle,
 289             struct xdr_buf      *message,
 290             struct xdr_netobj   *mic_token)
 291 {
 292          return context_handle->mech_type->gm_ops
 293                 ->gss_get_mic(context_handle,
 294                               message,
 295                               mic_token);
 296 }
 297
 298 /* gss_verify_mic: check whether the provided mic_token verifies message. */
 299
 300 u32
 301 gss_verify_mic(struct gss_ctx           *context_handle,
 302                struct xdr_buf           *message,
 303                struct xdr_netobj        *mic_token)
 304 {
 305         return context_handle->mech_type->gm_ops
 306                 ->gss_verify_mic(context_handle,
 307                                  message,
 308                                  mic_token);
 309 }
 310
 311 /*
 312  * This function is called from both the client and server code.
 313  * Each makes guarantees about how much "slack" space is available
 314  * for the underlying function in "buf"'s head and tail while
 315  * performing the wrap.
 316  *
 317  * The client and server code allocate RPC_MAX_AUTH_SIZE extra
 318  * space in both the head and tail which is available for use by
 319  * the wrap function.
 320  *
 321  * Underlying functions should verify they do not use more than
 322  * RPC_MAX_AUTH_SIZE of extra space in either the head or tail
 323  * when performing the wrap.
 324  */
 325 u32
 326 gss_wrap(struct gss_ctx *ctx_id,
 327          int            offset,
 328          struct xdr_buf *buf,
 329          struct page    **inpages)
 330 {
 331         return ctx_id->mech_type->gm_ops
 332                 ->gss_wrap(ctx_id, offset, buf, inpages);
 333 }
 334
 335 u32
 336 gss_unwrap(struct gss_ctx       *ctx_id,
 337            int                  offset,
 338            struct xdr_buf       *buf)
 339 {
 340         return ctx_id->mech_type->gm_ops
 341                 ->gss_unwrap(ctx_id, offset, buf);
 342 }
 343
 344
 345 /* gss_delete_sec_context: free all resources associated with context_handle.
 346  * Note this differs from the RFC 2744-specified prototype in that we don't
 347  * bother returning an output token, since it would never be used anyway. */
 348
 349 u32
 350 gss_delete_sec_context(struct gss_ctx   **context_handle)
 351 {
 352         dprintk("RPC:       gss_delete_sec_context deleting %p\n",
 353                         *context_handle);
 354
 355         if (!*context_handle)
 356                 return GSS_S_NO_CONTEXT;
 357         if ((*context_handle)->internal_ctx_id)
 358                 (*context_handle)->mech_type->gm_ops
 359                         ->gss_delete_sec_context((*context_handle)
 360                                                         ->internal_ctx_id);
 361         gss_mech_put((*context_handle)->mech_type);
 362         kfree(*context_handle);
 363         *context_handle=NULL;
 364         return GSS_S_COMPLETE;
 365 }