LXR linux/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
  42static struct rhashtable bind_hash_table;
  43
  44static 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 */
  56static 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 */
  72struct 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 */
  94static 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
 148void 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
 163int 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
 270out:
 271        release_sock(sk);
 272        return ret;
 273}
 274
 275void rds_bind_lock_destroy(void)
 276{
 277        rhashtable_destroy(&bind_hash_table);
 278}
 279
 280int rds_bind_lock_init(void)
 281{
 282        return rhashtable_init(&bind_hash_table, &ht_parms);
 283}
 284