net/rds/bind.c

   1 /*
   2  * Copyright (c) 2006, 2019 Oracle and/or its affiliates. All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  *
  32  */
  33 #include <linux/kernel.h>
  34 #include <net/sock.h>
  35 #include <linux/in.h>
  36 #include <linux/ipv6.h>
  37 #include <linux/if_arp.h>
  38 #include <linux/jhash.h>
  39 #include <linux/ratelimit.h>
  40 #include "rds.h"
  41
  42 static struct rhashtable bind_hash_table;
  43
  44 static const struct rhashtable_params ht_parms = {
  45         .nelem_hint = 768,
  46         .key_len = RDS_BOUND_KEY_LEN,
  47         .key_offset = offsetof(struct rds_sock, rs_bound_key),
  48         .head_offset = offsetof(struct rds_sock, rs_bound_node),
  49         .max_size = 16384,
  50         .min_size = 1024,
  51 };
  52
  53 /* Create a key for the bind hash table manipulation.  Port is in network byte
  54  * order.
  55  */
  56 static inline void __rds_create_bind_key(u8 *key, const struct in6_addr *addr,
  57                                          __be16 port, __u32 scope_id)
  58 {
  59         memcpy(key, addr, sizeof(*addr));
  60         key += sizeof(*addr);
  61         memcpy(key, &port, sizeof(port));
  62         key += sizeof(port);
  63         memcpy(key, &scope_id, sizeof(scope_id));
  64 }
  65
  66 /*
  67  * Return the rds_sock bound at the given local address.
  68  *
  69  * The rx path can race with rds_release.  We notice if rds_release() has
  70  * marked this socket and don't return a rs ref to the rx path.
  71  */
  72 struct rds_sock *rds_find_bound(const struct in6_addr *addr, __be16 port,
  73                                 __u32 scope_id)
  74 {
  75         u8 key[RDS_BOUND_KEY_LEN];
  76         struct rds_sock *rs;
  77
  78         __rds_create_bind_key(key, addr, port, scope_id);
  79         rcu_read_lock();
  80         rs = rhashtable_lookup(&bind_hash_table, key, ht_parms);
  81         if (rs && (sock_flag(rds_rs_to_sk(rs), SOCK_DEAD) ||
  82                    !refcount_inc_not_zero(&rds_rs_to_sk(rs)->sk_refcnt)))
  83                 rs = NULL;
  84
  85         rcu_read_unlock();
  86
  87         rdsdebug("returning rs %p for %pI6c:%u\n", rs, addr,
  88                  ntohs(port));
  89
  90         return rs;
  91 }
  92
  93 /* returns -ve errno or +ve port */
  94 static int rds_add_bound(struct rds_sock *rs, const struct in6_addr *addr,
  95                          __be16 *port, __u32 scope_id)
  96 {
  97         int ret = -EADDRINUSE;
  98         u16 rover, last;
  99         u8 key[RDS_BOUND_KEY_LEN];
 100
 101         if (*port != 0) {
 102                 rover = be16_to_cpu(*port);
 103                 if (rover == RDS_FLAG_PROBE_PORT)
 104                         return -EINVAL;
 105                 last = rover;
 106         } else {
 107                 rover = max_t(u16, prandom_u32(), 2);
 108                 last = rover - 1;
 109         }
 110
 111         do {
 112                 if (rover == 0)
 113                         rover++;
 114
 115                 if (rover == RDS_FLAG_PROBE_PORT)
 116                         continue;
 117                 __rds_create_bind_key(key, addr, cpu_to_be16(rover),
 118                                       scope_id);
 119                 if (rhashtable_lookup_fast(&bind_hash_table, key, ht_parms))
 120                         continue;
 121
 122                 memcpy(rs->rs_bound_key, key, sizeof(rs->rs_bound_key));
 123                 rs->rs_bound_addr = *addr;
 124                 net_get_random_once(&rs->rs_hash_initval,
 125                                     sizeof(rs->rs_hash_initval));
 126                 rs->rs_bound_port = cpu_to_be16(rover);
 127                 rs->rs_bound_node.next = NULL;
 128                 rds_sock_addref(rs);
 129                 if (!rhashtable_insert_fast(&bind_hash_table,
 130                                             &rs->rs_bound_node, ht_parms)) {
 131                         *port = rs->rs_bound_port;
 132                         rs->rs_bound_scope_id = scope_id;
 133                         ret = 0;
 134                         rdsdebug("rs %p binding to %pI6c:%d\n",
 135                                  rs, addr, (int)ntohs(*port));
 136                         break;
 137                 } else {
 138                         rs->rs_bound_addr = in6addr_any;
 139                         rds_sock_put(rs);
 140                         ret = -ENOMEM;
 141                         break;
 142                 }
 143         } while (rover++ != last);
 144
 145         return ret;
 146 }
 147
 148 void rds_remove_bound(struct rds_sock *rs)
 149 {
 150
 151         if (ipv6_addr_any(&rs->rs_bound_addr))
 152                 return;
 153
 154         rdsdebug("rs %p unbinding from %pI6c:%d\n",
 155                  rs, &rs->rs_bound_addr,
 156                  ntohs(rs->rs_bound_port));
 157
 158         rhashtable_remove_fast(&bind_hash_table, &rs->rs_bound_node, ht_parms);
 159         rds_sock_put(rs);
 160         rs->rs_bound_addr = in6addr_any;
 161 }
 162
 163 int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 164 {
 165         struct sock *sk = sock->sk;
 166         struct rds_sock *rs = rds_sk_to_rs(sk);
 167         struct in6_addr v6addr, *binding_addr;
 168         struct rds_transport *trans;
 169         __u32 scope_id = 0;
 170         int ret = 0;
 171         __be16 port;
 172
 173         /* We allow an RDS socket to be bound to either IPv4 or IPv6
 174          * address.
 175          */
 176         if (addr_len < offsetofend(struct sockaddr, sa_family))
 177                 return -EINVAL;
 178         if (uaddr->sa_family == AF_INET) {
 179                 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
 180
 181                 if (addr_len < sizeof(struct sockaddr_in) ||
 182                     sin->sin_addr.s_addr == htonl(INADDR_ANY) ||
 183                     sin->sin_addr.s_addr == htonl(INADDR_BROADCAST) ||
 184                     ipv4_is_multicast(sin->sin_addr.s_addr))
 185                         return -EINVAL;
 186                 ipv6_addr_set_v4mapped(sin->sin_addr.s_addr, &v6addr);
 187                 binding_addr = &v6addr;
 188                 port = sin->sin_port;
 189 #if IS_ENABLED(CONFIG_IPV6)
 190         } else if (uaddr->sa_family == AF_INET6) {
 191                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)uaddr;
 192                 int addr_type;
 193
 194                 if (addr_len < sizeof(struct sockaddr_in6))
 195                         return -EINVAL;
 196                 addr_type = ipv6_addr_type(&sin6->sin6_addr);
 197                 if (!(addr_type & IPV6_ADDR_UNICAST)) {
 198                         __be32 addr4;
 199
 200                         if (!(addr_type & IPV6_ADDR_MAPPED))
 201                                 return -EINVAL;
 202
 203                         /* It is a mapped address.  Need to do some sanity
 204                          * checks.
 205                          */
 206                         addr4 = sin6->sin6_addr.s6_addr32[3];
 207                         if (addr4 == htonl(INADDR_ANY) ||
 208                             addr4 == htonl(INADDR_BROADCAST) ||
 209                             ipv4_is_multicast(addr4))
 210                                 return -EINVAL;
 211                 }
 212                 /* The scope ID must be specified for link local address. */
 213                 if (addr_type & IPV6_ADDR_LINKLOCAL) {
 214                         if (sin6->sin6_scope_id == 0)
 215                                 return -EINVAL;
 216                         scope_id = sin6->sin6_scope_id;
 217                 }
 218                 binding_addr = &sin6->sin6_addr;
 219                 port = sin6->sin6_port;
 220 #endif
 221         } else {
 222                 return -EINVAL;
 223         }
 224         lock_sock(sk);
 225
 226         /* RDS socket does not allow re-binding. */
 227         if (!ipv6_addr_any(&rs->rs_bound_addr)) {
 228                 ret = -EINVAL;
 229                 goto out;
 230         }
 231         /* Socket is connected.  The binding address should have the same
 232          * scope ID as the connected address, except the case when one is
 233          * non-link local address (scope_id is 0).
 234          */
 235         if (!ipv6_addr_any(&rs->rs_conn_addr) && scope_id &&
 236             rs->rs_bound_scope_id &&
 237             scope_id != rs->rs_bound_scope_id) {
 238                 ret = -EINVAL;
 239                 goto out;
 240         }
 241
 242         /* The transport can be set using SO_RDS_TRANSPORT option before the
 243          * socket is bound.
 244          */
 245         if (rs->rs_transport) {
 246                 trans = rs->rs_transport;
 247                 if (!trans->laddr_check ||
 248                     trans->laddr_check(sock_net(sock->sk),
 249                                        binding_addr, scope_id) != 0) {
 250                         ret = -ENOPROTOOPT;
 251                         goto out;
 252                 }
 253         } else {
 254                 trans = rds_trans_get_preferred(sock_net(sock->sk),
 255                                                 binding_addr, scope_id);
 256                 if (!trans) {
 257                         ret = -EADDRNOTAVAIL;
 258                         pr_info_ratelimited("RDS: %s could not find a transport for %pI6c, load rds_tcp or rds_rdma?\n",
 259                                             __func__, binding_addr);
 260                         goto out;
 261                 }
 262                 rs->rs_transport = trans;
 263         }
 264
 265         sock_set_flag(sk, SOCK_RCU_FREE);
 266         ret = rds_add_bound(rs, binding_addr, &port, scope_id);
 267         if (ret)
 268                 rs->rs_transport = NULL;
 269
 270 out:
 271         release_sock(sk);
 272         return ret;
 273 }
 274
 275 void rds_bind_lock_destroy(void)
 276 {
 277         rhashtable_destroy(&bind_hash_table);
 278 }
 279
 280 int rds_bind_lock_init(void)
 281 {
 282         return rhashtable_init(&bind_hash_table, &ht_parms);
 283 }