net/rds/bind.c

   1 /*
   2  * Copyright (c) 2006 Oracle.  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/if_arp.h>
  37 #include <linux/jhash.h>
  38 #include <linux/ratelimit.h>
  39 #include "rds.h"
  40
  41 static struct rhashtable bind_hash_table;
  42
  43 static struct rhashtable_params ht_parms = {
  44         .nelem_hint = 768,
  45         .key_len = sizeof(u64),
  46         .key_offset = offsetof(struct rds_sock, rs_bound_key),
  47         .head_offset = offsetof(struct rds_sock, rs_bound_node),
  48         .max_size = 16384,
  49         .min_size = 1024,
  50 };
  51
  52 /*
  53  * Return the rds_sock bound at the given local address.
  54  *
  55  * The rx path can race with rds_release.  We notice if rds_release() has
  56  * marked this socket and don't return a rs ref to the rx path.
  57  */
  58 struct rds_sock *rds_find_bound(__be32 addr, __be16 port)
  59 {
  60         u64 key = ((u64)addr << 32) | port;
  61         struct rds_sock *rs;
  62
  63         rs = rhashtable_lookup_fast(&bind_hash_table, &key, ht_parms);
  64         if (rs && !sock_flag(rds_rs_to_sk(rs), SOCK_DEAD))
  65                 rds_sock_addref(rs);
  66         else
  67                 rs = NULL;
  68
  69         rdsdebug("returning rs %p for %pI4:%u\n", rs, &addr,
  70                 ntohs(port));
  71
  72         return rs;
  73 }
  74
  75 /* returns -ve errno or +ve port */
  76 static int rds_add_bound(struct rds_sock *rs, __be32 addr, __be16 *port)
  77 {
  78         int ret = -EADDRINUSE;
  79         u16 rover, last;
  80         u64 key;
  81
  82         if (*port != 0) {
  83                 rover = be16_to_cpu(*port);
  84                 last = rover;
  85         } else {
  86                 rover = max_t(u16, prandom_u32(), 2);
  87                 last = rover - 1;
  88         }
  89
  90         do {
  91                 if (rover == 0)
  92                         rover++;
  93
  94                 key = ((u64)addr << 32) | cpu_to_be16(rover);
  95                 if (rhashtable_lookup_fast(&bind_hash_table, &key, ht_parms))
  96                         continue;
  97
  98                 rs->rs_bound_key = key;
  99                 rs->rs_bound_addr = addr;
 100                 rs->rs_bound_port = cpu_to_be16(rover);
 101                 rs->rs_bound_node.next = NULL;
 102                 rds_sock_addref(rs);
 103                 if (!rhashtable_insert_fast(&bind_hash_table,
 104                                             &rs->rs_bound_node, ht_parms)) {
 105                         *port = rs->rs_bound_port;
 106                         ret = 0;
 107                         rdsdebug("rs %p binding to %pI4:%d\n",
 108                           rs, &addr, (int)ntohs(*port));
 109                         break;
 110                 } else {
 111                         rs->rs_bound_addr = 0;
 112                         rds_sock_put(rs);
 113                         ret = -ENOMEM;
 114                         break;
 115                 }
 116         } while (rover++ != last);
 117
 118         return ret;
 119 }
 120
 121 void rds_remove_bound(struct rds_sock *rs)
 122 {
 123
 124         if (!rs->rs_bound_addr)
 125                 return;
 126
 127         rdsdebug("rs %p unbinding from %pI4:%d\n",
 128                  rs, &rs->rs_bound_addr,
 129                  ntohs(rs->rs_bound_port));
 130
 131         rhashtable_remove_fast(&bind_hash_table, &rs->rs_bound_node, ht_parms);
 132         rds_sock_put(rs);
 133         rs->rs_bound_addr = 0;
 134 }
 135
 136 int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 137 {
 138         struct sock *sk = sock->sk;
 139         struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
 140         struct rds_sock *rs = rds_sk_to_rs(sk);
 141         struct rds_transport *trans;
 142         int ret = 0;
 143
 144         lock_sock(sk);
 145
 146         if (addr_len != sizeof(struct sockaddr_in) ||
 147             sin->sin_family != AF_INET ||
 148             rs->rs_bound_addr ||
 149             sin->sin_addr.s_addr == htonl(INADDR_ANY)) {
 150                 ret = -EINVAL;
 151                 goto out;
 152         }
 153
 154         ret = rds_add_bound(rs, sin->sin_addr.s_addr, &sin->sin_port);
 155         if (ret)
 156                 goto out;
 157
 158         if (rs->rs_transport) { /* previously bound */
 159                 trans = rs->rs_transport;
 160                 if (trans->laddr_check(sock_net(sock->sk),
 161                                        sin->sin_addr.s_addr) != 0) {
 162                         ret = -ENOPROTOOPT;
 163                         rds_remove_bound(rs);
 164                 } else {
 165                         ret = 0;
 166                 }
 167                 goto out;
 168         }
 169         trans = rds_trans_get_preferred(sock_net(sock->sk),
 170                                         sin->sin_addr.s_addr);
 171         if (!trans) {
 172                 ret = -EADDRNOTAVAIL;
 173                 rds_remove_bound(rs);
 174                 printk_ratelimited(KERN_INFO "RDS: rds_bind() could not find a transport, "
 175                                 "load rds_tcp or rds_rdma?\n");
 176                 goto out;
 177         }
 178
 179         rs->rs_transport = trans;
 180         ret = 0;
 181
 182 out:
 183         release_sock(sk);
 184         return ret;
 185 }
 186
 187 void rds_bind_lock_destroy(void)
 188 {
 189         rhashtable_destroy(&bind_hash_table);
 190 }
 191
 192 int rds_bind_lock_init(void)
 193 {
 194         return rhashtable_init(&bind_hash_table, &ht_parms);
 195 }