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/socket.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/gss_err.h>
  43 #include <linux/sunrpc/sched.h>
  44 #include <linux/sunrpc/gss_api.h>
  45 #include <linux/sunrpc/clnt.h>
  46
  47 #ifdef RPC_DEBUG
  48 # define RPCDBG_FACILITY        RPCDBG_AUTH
  49 #endif
  50
  51 static LIST_HEAD(registered_mechs);
  52 static spinlock_t registered_mechs_lock = SPIN_LOCK_UNLOCKED;
  53
  54 /* Reference counting: The reference count includes the reference in the
  55  * global registered_mechs list.  That reference will never diseappear
  56  * (so the reference count will never go below 1) until after the mech
  57  * is removed from the list.  Nothing can be removed from the list without
  58  * first getting the registered_mechs_lock, so a gss_api_mech won't diseappear
  59  * from underneath us while we hold the registered_mech_lock.  */
  60
  61 int
  62 gss_mech_register(struct xdr_netobj * mech_type, struct gss_api_ops * ops)
  63 {
  64         struct gss_api_mech *gm;
  65
  66         if (!(gm = kmalloc(sizeof(*gm), GFP_KERNEL))) {
  67                 printk("Failed to allocate memory in gss_mech_register");
  68                 return -1;
  69         }
  70         gm->gm_oid.len = mech_type->len;
  71         if (!(gm->gm_oid.data = kmalloc(mech_type->len, GFP_KERNEL))) {
  72                 kfree(gm);
  73                 printk("Failed to allocate memory in gss_mech_register");
  74                 return -1;
  75         }
  76         memcpy(gm->gm_oid.data, mech_type->data, mech_type->len);
  77         /* We're counting the reference in the registered_mechs list: */
  78         atomic_set(&gm->gm_count, 1);
  79         gm->gm_ops = ops;
  80
  81         spin_lock(&registered_mechs_lock);
  82         list_add(&gm->gm_list, &registered_mechs);
  83         spin_unlock(&registered_mechs_lock);
  84         dprintk("RPC: gss_mech_register: registered mechanism with oid:\n");
  85         print_hexl((u32 *)mech_type->data, mech_type->len, 0);
  86         return 0;
  87 }
  88
  89 /* The following must be called with spinlock held: */
  90 int
  91 do_gss_mech_unregister(struct gss_api_mech *gm)
  92 {
  93
  94         list_del(&gm->gm_list);
  95
  96         dprintk("RPC: unregistered mechanism with oid:\n");
  97         print_hexl((u32 *)gm->gm_oid.data, gm->gm_oid.len, 0);
  98         if (!gss_mech_put(gm)) {
  99                 dprintk("RPC: We just unregistered a gss_mechanism which"
 100                                 " someone is still using.\n");
 101                 return -1;
 102         } else {
 103                 return 0;
 104         }
 105 }
 106
 107 int
 108 gss_mech_unregister(struct gss_api_mech *gm)
 109 {
 110         int status;
 111
 112         spin_lock(&registered_mechs_lock);
 113         status = do_gss_mech_unregister(gm);
 114         spin_unlock(&registered_mechs_lock);
 115         return status;
 116 }
 117
 118 int
 119 gss_mech_unregister_all(void)
 120 {
 121         struct list_head        *pos;
 122         struct gss_api_mech     *gm;
 123         int                     status = 0;
 124
 125         spin_lock(&registered_mechs_lock);
 126         while (!list_empty(&registered_mechs)) {
 127                 pos = registered_mechs.next;
 128                 gm = list_entry(pos, struct gss_api_mech, gm_list);
 129                 if (do_gss_mech_unregister(gm))
 130                         status = -1;
 131         }
 132         spin_unlock(&registered_mechs_lock);
 133         return status;
 134 }
 135
 136 struct gss_api_mech *
 137 gss_mech_get(struct gss_api_mech *gm)
 138 {
 139         atomic_inc(&gm->gm_count);
 140         return gm;
 141 }
 142
 143 struct gss_api_mech *
 144 gss_mech_get_by_OID(struct xdr_netobj *mech_type)
 145 {
 146         struct gss_api_mech     *pos, *gm = NULL;
 147
 148         dprintk("RPC: gss_mech_get_by_OID searching for mechanism with OID:\n");
 149         print_hexl((u32 *)mech_type->data, mech_type->len, 0);
 150         spin_lock(&registered_mechs_lock);
 151         list_for_each_entry(pos, &registered_mechs, gm_list) {
 152                 if ((pos->gm_oid.len == mech_type->len)
 153                         && !memcmp(pos->gm_oid.data, mech_type->data,
 154                                                         mech_type->len)) {
 155                         gm = gss_mech_get(pos);
 156                         break;
 157                 }
 158         }
 159         spin_unlock(&registered_mechs_lock);
 160         dprintk("RPC: gss_mech_get_by_OID %s it\n", gm ? "found" : "didn't find");
 161         return gm;
 162 }
 163
 164 struct gss_api_mech *
 165 gss_mech_get_by_name(char *name)
 166 {
 167         struct gss_api_mech     *pos, *gm = NULL;
 168
 169         spin_lock(&registered_mechs_lock);
 170         list_for_each_entry(pos, &registered_mechs, gm_list) {
 171                 if (0 == strcmp(name, pos->gm_ops->name)) {
 172                         gm = gss_mech_get(pos);
 173                         break;
 174                 }
 175         }
 176         spin_unlock(&registered_mechs_lock);
 177         return gm;
 178
 179 }
 180
 181 int
 182 gss_mech_put(struct gss_api_mech * gm)
 183 {
 184         if (atomic_dec_and_test(&gm->gm_count)) {
 185                 if (gm->gm_oid.len >0)
 186                         kfree(gm->gm_oid.data);
 187                 kfree(gm);
 188                 return 1;
 189         } else {
 190                 return 0;
 191         }
 192 }
 193
 194 /* The mech could probably be determined from the token instead, but it's just
 195  * as easy for now to pass it in. */
 196 u32
 197 gss_import_sec_context(struct xdr_netobj        *input_token,
 198                        struct gss_api_mech      *mech,
 199                        struct gss_ctx           **ctx_id)
 200 {
 201         if (!(*ctx_id = kmalloc(sizeof(**ctx_id), GFP_KERNEL)))
 202                 return GSS_S_FAILURE;
 203         memset(*ctx_id, 0, sizeof(**ctx_id));
 204         (*ctx_id)->mech_type = gss_mech_get(mech);
 205
 206         return mech->gm_ops
 207                 ->gss_import_sec_context(input_token, *ctx_id);
 208 }
 209
 210 /* gss_get_mic: compute a mic over message and return mic_token. */
 211
 212 u32
 213 gss_get_mic(struct gss_ctx      *context_handle,
 214             u32                 qop,
 215             struct xdr_buf      *message,
 216             struct xdr_netobj   *mic_token)
 217 {
 218          return context_handle->mech_type->gm_ops
 219                 ->gss_get_mic(context_handle,
 220                               qop,
 221                               message,
 222                               mic_token);
 223 }
 224
 225 /* gss_verify_mic: check whether the provided mic_token verifies message. */
 226
 227 u32
 228 gss_verify_mic(struct gss_ctx           *context_handle,
 229                struct xdr_buf           *message,
 230                struct xdr_netobj        *mic_token,
 231                u32                      *qstate)
 232 {
 233         return context_handle->mech_type->gm_ops
 234                 ->gss_verify_mic(context_handle,
 235                                  message,
 236                                  mic_token,
 237                                  qstate);
 238 }
 239
 240 /* gss_delete_sec_context: free all resources associated with context_handle.
 241  * Note this differs from the RFC 2744-specified prototype in that we don't
 242  * bother returning an output token, since it would never be used anyway. */
 243
 244 u32
 245 gss_delete_sec_context(struct gss_ctx   **context_handle)
 246 {
 247         dprintk("gss_delete_sec_context deleting %p\n",*context_handle);
 248
 249         if (!*context_handle)
 250                 return(GSS_S_NO_CONTEXT);
 251         if ((*context_handle)->internal_ctx_id != 0)
 252                 (*context_handle)->mech_type->gm_ops
 253                         ->gss_delete_sec_context((*context_handle)
 254                                                         ->internal_ctx_id);
 255         if ((*context_handle)->mech_type)
 256                 gss_mech_put((*context_handle)->mech_type);
 257         kfree(*context_handle);
 258         *context_handle=NULL;
 259         return GSS_S_COMPLETE;
 260 }