net/sctp/primitive.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* SCTP kernel implementation
   3  * Copyright (c) 1999-2000 Cisco, Inc.
   4  * Copyright (c) 1999-2001 Motorola, Inc.
   5  *
   6  * This file is part of the SCTP kernel implementation
   7  *
   8  * These functions implement the SCTP primitive functions from Section 10.
   9  *
  10  * Note that the descriptions from the specification are USER level
  11  * functions--this file is the functions which populate the struct proto
  12  * for SCTP which is the BOTTOM of the sockets interface.
  13  *
  14  * Please send any bug reports or fixes you make to the
  15  * email address(es):
  16  *    lksctp developers <linux-sctp@vger.kernel.org>
  17  *
  18  * Written or modified by:
  19  *    La Monte H.P. Yarroll <piggy@acm.org>
  20  *    Narasimha Budihal     <narasimha@refcode.org>
  21  *    Karl Knutson          <karl@athena.chicago.il.us>
  22  *    Ardelle Fan           <ardelle.fan@intel.com>
  23  *    Kevin Gao             <kevin.gao@intel.com>
  24  */
  25
  26 #include <linux/types.h>
  27 #include <linux/list.h> /* For struct list_head */
  28 #include <linux/socket.h>
  29 #include <linux/ip.h>
  30 #include <linux/time.h> /* For struct timeval */
  31 #include <linux/gfp.h>
  32 #include <net/sock.h>
  33 #include <net/sctp/sctp.h>
  34 #include <net/sctp/sm.h>
  35
  36 #define DECLARE_PRIMITIVE(name) \
  37 /* This is called in the code as sctp_primitive_ ## name.  */ \
  38 int sctp_primitive_ ## name(struct net *net, struct sctp_association *asoc, \
  39                             void *arg) { \
  40         int error = 0; \
  41         enum sctp_event_type event_type; union sctp_subtype subtype; \
  42         enum sctp_state state; \
  43         struct sctp_endpoint *ep; \
  44         \
  45         event_type = SCTP_EVENT_T_PRIMITIVE; \
  46         subtype = SCTP_ST_PRIMITIVE(SCTP_PRIMITIVE_ ## name); \
  47         state = asoc ? asoc->state : SCTP_STATE_CLOSED; \
  48         ep = asoc ? asoc->ep : NULL; \
  49         \
  50         error = sctp_do_sm(net, event_type, subtype, state, ep, asoc,   \
  51                            arg, GFP_KERNEL); \
  52         return error; \
  53 }
  54
  55 /* 10.1 ULP-to-SCTP
  56  * B) Associate
  57  *
  58  * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
  59  *         outbound stream count)
  60  * -> association id [,destination transport addr list] [,outbound stream
  61  *    count]
  62  *
  63  * This primitive allows the upper layer to initiate an association to a
  64  * specific peer endpoint.
  65  *
  66  * This version assumes that asoc is fully populated with the initial
  67  * parameters.  We then return a traditional kernel indicator of
  68  * success or failure.
  69  */
  70
  71 /* This is called in the code as sctp_primitive_ASSOCIATE.  */
  72
  73 DECLARE_PRIMITIVE(ASSOCIATE)
  74
  75 /* 10.1 ULP-to-SCTP
  76  * C) Shutdown
  77  *
  78  * Format: SHUTDOWN(association id)
  79  * -> result
  80  *
  81  * Gracefully closes an association. Any locally queued user data
  82  * will be delivered to the peer. The association will be terminated only
  83  * after the peer acknowledges all the SCTP packets sent.  A success code
  84  * will be returned on successful termination of the association. If
  85  * attempting to terminate the association results in a failure, an error
  86  * code shall be returned.
  87  */
  88
  89 DECLARE_PRIMITIVE(SHUTDOWN);
  90
  91 /* 10.1 ULP-to-SCTP
  92  * C) Abort
  93  *
  94  * Format: Abort(association id [, cause code])
  95  * -> result
  96  *
  97  * Ungracefully closes an association. Any locally queued user data
  98  * will be discarded and an ABORT chunk is sent to the peer. A success
  99  * code will be returned on successful abortion of the association. If
 100  * attempting to abort the association results in a failure, an error
 101  * code shall be returned.
 102  */
 103
 104 DECLARE_PRIMITIVE(ABORT);
 105
 106 /* 10.1 ULP-to-SCTP
 107  * E) Send
 108  *
 109  * Format: SEND(association id, buffer address, byte count [,context]
 110  *         [,stream id] [,life time] [,destination transport address]
 111  *         [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
 112  * -> result
 113  *
 114  * This is the main method to send user data via SCTP.
 115  *
 116  * Mandatory attributes:
 117  *
 118  *  o association id - local handle to the SCTP association
 119  *
 120  *  o buffer address - the location where the user message to be
 121  *    transmitted is stored;
 122  *
 123  *  o byte count - The size of the user data in number of bytes;
 124  *
 125  * Optional attributes:
 126  *
 127  *  o context - an optional 32 bit integer that will be carried in the
 128  *    sending failure notification to the ULP if the transportation of
 129  *    this User Message fails.
 130  *
 131  *  o stream id - to indicate which stream to send the data on. If not
 132  *    specified, stream 0 will be used.
 133  *
 134  *  o life time - specifies the life time of the user data. The user data
 135  *    will not be sent by SCTP after the life time expires. This
 136  *    parameter can be used to avoid efforts to transmit stale
 137  *    user messages. SCTP notifies the ULP if the data cannot be
 138  *    initiated to transport (i.e. sent to the destination via SCTP's
 139  *    send primitive) within the life time variable. However, the
 140  *    user data will be transmitted if SCTP has attempted to transmit a
 141  *    chunk before the life time expired.
 142  *
 143  *  o destination transport address - specified as one of the destination
 144  *    transport addresses of the peer endpoint to which this packet
 145  *    should be sent. Whenever possible, SCTP should use this destination
 146  *    transport address for sending the packets, instead of the current
 147  *    primary path.
 148  *
 149  *  o unorder flag - this flag, if present, indicates that the user
 150  *    would like the data delivered in an unordered fashion to the peer
 151  *    (i.e., the U flag is set to 1 on all DATA chunks carrying this
 152  *    message).
 153  *
 154  *  o no-bundle flag - instructs SCTP not to bundle this user data with
 155  *    other outbound DATA chunks. SCTP MAY still bundle even when
 156  *    this flag is present, when faced with network congestion.
 157  *
 158  *  o payload protocol-id - A 32 bit unsigned integer that is to be
 159  *    passed to the peer indicating the type of payload protocol data
 160  *    being transmitted. This value is passed as opaque data by SCTP.
 161  */
 162
 163 DECLARE_PRIMITIVE(SEND);
 164
 165 /* 10.1 ULP-to-SCTP
 166  * J) Request Heartbeat
 167  *
 168  * Format: REQUESTHEARTBEAT(association id, destination transport address)
 169  *
 170  * -> result
 171  *
 172  * Instructs the local endpoint to perform a HeartBeat on the specified
 173  * destination transport address of the given association. The returned
 174  * result should indicate whether the transmission of the HEARTBEAT
 175  * chunk to the destination address is successful.
 176  *
 177  * Mandatory attributes:
 178  *
 179  * o association id - local handle to the SCTP association
 180  *
 181  * o destination transport address - the transport address of the
 182  *   association on which a heartbeat should be issued.
 183  */
 184
 185 DECLARE_PRIMITIVE(REQUESTHEARTBEAT);
 186
 187 /* ADDIP
 188 * 3.1.1 Address Configuration Change Chunk (ASCONF)
 189 *
 190 * This chunk is used to communicate to the remote endpoint one of the
 191 * configuration change requests that MUST be acknowledged.  The
 192 * information carried in the ASCONF Chunk uses the form of a
 193 * Type-Length-Value (TLV), as described in "3.2.1 Optional/
 194 * Variable-length Parameter Format" in RFC2960 [5], forall variable
 195 * parameters.
 196 */
 197
 198 DECLARE_PRIMITIVE(ASCONF);
 199
 200 /* RE-CONFIG 5.1 */
 201 DECLARE_PRIMITIVE(RECONF);