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