1 /*
   2  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
   3  */
   4 
   5 /*
   6  * This file contains code imported from the OFED rds source file loop.c
   7  * Oracle elects to have and use the contents of loop.c under and governed
   8  * by the OpenIB.org BSD license (see below for full license text). However,
   9  * the following notice accompanied the original version of this file:
  10  */
  11 
  12 /*
  13  * Copyright (c) 2006 Oracle.  All rights reserved.
  14  *
  15  * This software is available to you under a choice of one of two
  16  * licenses.  You may choose to be licensed under the terms of the GNU
  17  * General Public License (GPL) Version 2, available from the file
  18  * COPYING in the main directory of this source tree, or the
  19  * OpenIB.org BSD license below:
  20  *
  21  *     Redistribution and use in source and binary forms, with or
  22  *     without modification, are permitted provided that the following
  23  *     conditions are met:
  24  *
  25  *      - Redistributions of source code must retain the above
  26  *        copyright notice, this list of conditions and the following
  27  *        disclaimer.
  28  *
  29  *      - Redistributions in binary form must reproduce the above
  30  *        copyright notice, this list of conditions and the following
  31  *        disclaimer in the documentation and/or other materials
  32  *        provided with the distribution.
  33  *
  34  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  35  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  36  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  37  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  38  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  39  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  40  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  41  * SOFTWARE.
  42  *
  43  */
  44 #include <sys/rds.h>
  45 
  46 #include <sys/ib/clients/rdsv3/rdsv3.h>
  47 #include <sys/ib/clients/rdsv3/loop.h>
  48 #include <sys/ib/clients/rdsv3/rdsv3_debug.h>
  49 
  50 kmutex_t loop_conns_lock;
  51 list_t loop_conns;
  52 
  53 /*
  54  * This 'loopback' transport is a special case for flows that originate
  55  * and terminate on the same machine.
  56  *
  57  * Connection build-up notices if the destination address is thought of
  58  * as a local address by a transport.  At that time it decides to use the
  59  * loopback transport instead of the bound transport of the sending socket.
  60  *
  61  * The loopback transport's sending path just hands the sent rds_message
  62  * straight to the receiving path via an embedded rds_incoming.
  63  */
  64 
  65 /*
  66  * Usually a message transits both the sender and receiver's conns as it
  67  * flows to the receiver.  In the loopback case, though, the receive path
  68  * is handed the sending conn so the sense of the addresses is reversed.
  69  */
  70 static int
  71 rdsv3_loop_xmit(struct rdsv3_connection *conn, struct rdsv3_message *rm,
  72     unsigned int hdr_off, unsigned int sg,
  73     unsigned int off)
  74 {
  75         /* Do not send cong updates to loopback */
  76         if (rm->m_inc.i_hdr.h_flags & RDSV3_FLAG_CONG_BITMAP) {
  77                 rdsv3_cong_map_updated(conn->c_fcong, ~(uint64_t)0);
  78                 return (sizeof (struct rdsv3_header) + RDSV3_CONG_MAP_BYTES);
  79         }
  80         ASSERT(!(hdr_off || sg || off));
  81 
  82         RDSV3_DPRINTF4("rdsv3_loop_xmit", "Enter(conn: %p, rm: %p)", conn, rm);
  83 
  84         rdsv3_inc_init(&rm->m_inc, conn, conn->c_laddr);
  85         /* For the embedded inc. Matching put is in loop_inc_free() */
  86         rdsv3_message_addref(rm);
  87 
  88         rdsv3_recv_incoming(conn, conn->c_laddr, conn->c_faddr, &rm->m_inc,
  89             KM_NOSLEEP);
  90 
  91         rdsv3_send_drop_acked(conn, ntohll(rm->m_inc.i_hdr.h_sequence),
  92             NULL);
  93 
  94         rdsv3_inc_put(&rm->m_inc);
  95 
  96         RDSV3_DPRINTF4("rdsv3_loop_xmit", "Return(conn: %p, rm: %p)", conn, rm);
  97 
  98         return (sizeof (struct rdsv3_header) +
  99             ntohl(rm->m_inc.i_hdr.h_len));
 100 }
 101 
 102 /*
 103  * See rds_loop_xmit(). Since our inc is embedded in the rm, we
 104  * make sure the rm lives at least until the inc is done.
 105  */
 106 static void
 107 rdsv3_loop_inc_free(struct rdsv3_incoming *inc)
 108 {
 109         struct rdsv3_message *rm = container_of(inc, struct rdsv3_message,
 110             m_inc);
 111         rdsv3_message_put(rm);
 112 }
 113 
 114 static int
 115 rdsv3_loop_xmit_cong_map(struct rdsv3_connection *conn,
 116     struct rdsv3_cong_map *map,
 117     unsigned long offset)
 118 {
 119         RDSV3_DPRINTF4("rdsv3_loop_xmit_cong_map", "Enter(conn: %p)", conn);
 120 
 121         ASSERT(!offset);
 122         ASSERT(map == conn->c_lcong);
 123 
 124         rdsv3_cong_map_updated(conn->c_fcong, ~(uint64_t)0);
 125 
 126         RDSV3_DPRINTF4("rdsv3_loop_xmit_cong_map", "Return(conn: %p)", conn);
 127 
 128         return (sizeof (struct rdsv3_header) + RDSV3_CONG_MAP_BYTES);
 129 }
 130 
 131 /* we need to at least give the thread something to succeed */
 132 /* ARGSUSED */
 133 static int
 134 rdsv3_loop_recv(struct rdsv3_connection *conn)
 135 {
 136         return (0);
 137 }
 138 
 139 struct rdsv3_loop_connection {
 140         struct list_node loop_node;
 141         struct rdsv3_connection *conn;
 142 };
 143 
 144 /*
 145  * Even the loopback transport needs to keep track of its connections,
 146  * so it can call rdsv3_conn_destroy() on them on exit. N.B. there are
 147  * 1+ loopback addresses (127.*.*.*) so it's not a bug to have
 148  * multiple loopback conns allocated, although rather useless.
 149  */
 150 /* ARGSUSED */
 151 static int
 152 rdsv3_loop_conn_alloc(struct rdsv3_connection *conn, int gfp)
 153 {
 154         struct rdsv3_loop_connection *lc;
 155 
 156         RDSV3_DPRINTF4("rdsv3_loop_conn_alloc", "Enter(conn: %p)", conn);
 157 
 158         lc = kmem_zalloc(sizeof (struct rdsv3_loop_connection), KM_NOSLEEP);
 159         if (!lc)
 160                 return (-ENOMEM);
 161 
 162         list_link_init(&lc->loop_node);
 163         lc->conn = conn;
 164         conn->c_transport_data = lc;
 165 
 166         mutex_enter(&loop_conns_lock);
 167         list_insert_tail(&loop_conns, lc);
 168         mutex_exit(&loop_conns_lock);
 169 
 170         RDSV3_DPRINTF4("rdsv3_loop_conn_alloc", "Return(conn: %p)", conn);
 171 
 172         return (0);
 173 }
 174 
 175 static void
 176 rdsv3_loop_conn_free(void *arg)
 177 {
 178         struct rdsv3_loop_connection *lc = arg;
 179         RDSV3_DPRINTF5("rdsv3_loop_conn_free", "lc %p\n", lc);
 180         list_remove_node(&lc->loop_node);
 181         kmem_free(lc, sizeof (struct rdsv3_loop_connection));
 182 }
 183 
 184 static int
 185 rdsv3_loop_conn_connect(struct rdsv3_connection *conn)
 186 {
 187         rdsv3_connect_complete(conn);
 188         return (0);
 189 }
 190 
 191 /* ARGSUSED */
 192 static void
 193 rdsv3_loop_conn_shutdown(struct rdsv3_connection *conn)
 194 {
 195 }
 196 
 197 void
 198 rdsv3_loop_exit(void)
 199 {
 200         struct rdsv3_loop_connection *lc, *_lc;
 201         list_t tmp_list;
 202 
 203         RDSV3_DPRINTF4("rdsv3_loop_exit", "Enter");
 204 
 205         list_create(&tmp_list, sizeof (struct rdsv3_loop_connection),
 206             offsetof(struct rdsv3_loop_connection, loop_node));
 207 
 208         /* avoid calling conn_destroy with irqs off */
 209         mutex_enter(&loop_conns_lock);
 210         list_splice(&loop_conns, &tmp_list);
 211         mutex_exit(&loop_conns_lock);
 212 
 213         RDSV3_FOR_EACH_LIST_NODE_SAFE(lc, _lc, &tmp_list, loop_node) {
 214                 ASSERT(!lc->conn->c_passive);
 215                 rdsv3_conn_destroy(lc->conn);
 216         }
 217 
 218         list_destroy(&loop_conns);
 219         mutex_destroy(&loop_conns_lock);
 220 
 221         RDSV3_DPRINTF4("rdsv3_loop_exit", "Return");
 222 }
 223 
 224 /*
 225  * This is missing .xmit_* because loop doesn't go through generic
 226  * rdsv3_send_xmit() and doesn't call rdsv3_recv_incoming().  .listen_stop and
 227  * .laddr_check are missing because transport.c doesn't iterate over
 228  * rdsv3_loop_transport.
 229  */
 230 struct rdsv3_transport rdsv3_loop_transport = {
 231         .xmit                   = rdsv3_loop_xmit,
 232         .xmit_cong_map          = rdsv3_loop_xmit_cong_map,
 233         .recv                   = rdsv3_loop_recv,
 234         .conn_alloc             = rdsv3_loop_conn_alloc,
 235         .conn_free              = rdsv3_loop_conn_free,
 236         .conn_connect           = rdsv3_loop_conn_connect,
 237         .conn_shutdown          = rdsv3_loop_conn_shutdown,
 238         .inc_copy_to_user       = rdsv3_message_inc_copy_to_user,
 239         .inc_free               = rdsv3_loop_inc_free,
 240         .t_name                 = "loopback",
 241 };