net/rxrpc/ar-security.c

   1 /* RxRPC security handling
   2  *
   3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/net.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/udp.h>
  16 #include <linux/crypto.h>
  17 #include <net/sock.h>
  18 #include <net/af_rxrpc.h>
  19 #include <keys/rxrpc-type.h>
  20 #include "ar-internal.h"
  21
  22 static LIST_HEAD(rxrpc_security_methods);
  23 static DECLARE_RWSEM(rxrpc_security_sem);
  24
  25 static const struct rxrpc_security *rxrpc_security_types[] = {
  26 #ifdef CONFIG_RXKAD
  27         [RXRPC_SECURITY_RXKAD]  = &rxkad,
  28 #endif
  29 };
  30
  31 int __init rxrpc_init_security(void)
  32 {
  33         int i, ret;
  34
  35         for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++) {
  36                 if (rxrpc_security_types[i]) {
  37                         ret = rxrpc_security_types[i]->init();
  38                         if (ret < 0)
  39                                 goto failed;
  40                 }
  41         }
  42
  43         return 0;
  44
  45 failed:
  46         for (i--; i >= 0; i--)
  47                 if (rxrpc_security_types[i])
  48                         rxrpc_security_types[i]->exit();
  49         return ret;
  50 }
  51
  52 void rxrpc_exit_security(void)
  53 {
  54         int i;
  55
  56         for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++)
  57                 if (rxrpc_security_types[i])
  58                         rxrpc_security_types[i]->exit();
  59 }
  60
  61 /*
  62  * look up an rxrpc security module
  63  */
  64 static const struct rxrpc_security *rxrpc_security_lookup(u8 security_index)
  65 {
  66         if (security_index >= ARRAY_SIZE(rxrpc_security_types))
  67                 return NULL;
  68         return rxrpc_security_types[security_index];
  69 }
  70
  71 /*
  72  * initialise the security on a client connection
  73  */
  74 int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
  75 {
  76         const struct rxrpc_security *sec;
  77         struct rxrpc_key_token *token;
  78         struct key *key = conn->key;
  79         int ret;
  80
  81         _enter("{%d},{%x}", conn->debug_id, key_serial(key));
  82
  83         if (!key)
  84                 return 0;
  85
  86         ret = key_validate(key);
  87         if (ret < 0)
  88                 return ret;
  89
  90         token = key->payload.data[0];
  91         if (!token)
  92                 return -EKEYREJECTED;
  93
  94         sec = rxrpc_security_lookup(token->security_index);
  95         if (!sec)
  96                 return -EKEYREJECTED;
  97         conn->security = sec;
  98
  99         ret = conn->security->init_connection_security(conn);
 100         if (ret < 0) {
 101                 conn->security = NULL;
 102                 return ret;
 103         }
 104
 105         _leave(" = 0");
 106         return 0;
 107 }
 108
 109 /*
 110  * initialise the security on a server connection
 111  */
 112 int rxrpc_init_server_conn_security(struct rxrpc_connection *conn)
 113 {
 114         const struct rxrpc_security *sec;
 115         struct rxrpc_local *local = conn->trans->local;
 116         struct rxrpc_sock *rx;
 117         struct key *key;
 118         key_ref_t kref;
 119         char kdesc[5 + 1 + 3 + 1];
 120
 121         _enter("");
 122
 123         sprintf(kdesc, "%u:%u", conn->service_id, conn->security_ix);
 124
 125         sec = rxrpc_security_lookup(conn->security_ix);
 126         if (!sec) {
 127                 _leave(" = -ENOKEY [lookup]");
 128                 return -ENOKEY;
 129         }
 130
 131         /* find the service */
 132         read_lock_bh(&local->services_lock);
 133         list_for_each_entry(rx, &local->services, listen_link) {
 134                 if (rx->srx.srx_service == conn->service_id)
 135                         goto found_service;
 136         }
 137
 138         /* the service appears to have died */
 139         read_unlock_bh(&local->services_lock);
 140         _leave(" = -ENOENT");
 141         return -ENOENT;
 142
 143 found_service:
 144         if (!rx->securities) {
 145                 read_unlock_bh(&local->services_lock);
 146                 _leave(" = -ENOKEY");
 147                 return -ENOKEY;
 148         }
 149
 150         /* look through the service's keyring */
 151         kref = keyring_search(make_key_ref(rx->securities, 1UL),
 152                               &key_type_rxrpc_s, kdesc);
 153         if (IS_ERR(kref)) {
 154                 read_unlock_bh(&local->services_lock);
 155                 _leave(" = %ld [search]", PTR_ERR(kref));
 156                 return PTR_ERR(kref);
 157         }
 158
 159         key = key_ref_to_ptr(kref);
 160         read_unlock_bh(&local->services_lock);
 161
 162         conn->server_key = key;
 163         conn->security = sec;
 164
 165         _leave(" = 0");
 166         return 0;
 167 }
 168
 169 /*
 170  * secure a packet prior to transmission
 171  */
 172 int rxrpc_secure_packet(const struct rxrpc_call *call,
 173                         struct sk_buff *skb,
 174                         size_t data_size,
 175                         void *sechdr)
 176 {
 177         if (call->conn->security)
 178                 return call->conn->security->secure_packet(
 179                         call, skb, data_size, sechdr);
 180         return 0;
 181 }
 182
 183 /*
 184  * secure a packet prior to transmission
 185  */
 186 int rxrpc_verify_packet(const struct rxrpc_call *call, struct sk_buff *skb,
 187                         u32 *_abort_code)
 188 {
 189         if (call->conn->security)
 190                 return call->conn->security->verify_packet(
 191                         call, skb, _abort_code);
 192         return 0;
 193 }
 194
 195 /*
 196  * clear connection security
 197  */
 198 void rxrpc_clear_conn_security(struct rxrpc_connection *conn)
 199 {
 200         _enter("{%d}", conn->debug_id);
 201
 202         if (conn->security)
 203                 conn->security->clear(conn);
 204
 205         key_put(conn->key);
 206         key_put(conn->server_key);
 207 }