net/sctp/command.c

   1 /* SCTP kernel reference Implementation Copyright (C) 1999-2001
   2  * Cisco, Motorola, and IBM
   3  * Copyright 2001 La Monte H.P. Yarroll
   4  *
   5  * This file is part of the SCTP kernel reference Implementation
   6  *
   7  * These functions manipulate sctp command sequences.
   8  *
   9  * The SCTP reference implementation is free software;
  10  * you can redistribute it and/or modify it under the terms of
  11  * the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2, or (at your option)
  13  * any later version.
  14  *
  15  * The SCTP reference implementation is distributed in the hope that it
  16  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  17  *                 ************************
  18  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  19  * See the GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with GNU CC; see the file COPYING.  If not, write to
  23  * the Free Software Foundation, 59 Temple Place - Suite 330,
  24  * Boston, MA 02111-1307, USA.
  25  *
  26  * Please send any bug reports or fixes you make to the
  27  * email address(es):
  28  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  29  *
  30  * Or submit a bug report through the following website:
  31  *    http://www.sf.net/projects/lksctp
  32  *
  33  * Written or modified by:
  34  *    La Monte H.P. Yarroll <piggy@acm.org>
  35  *    Karl Knutson <karl@athena.chicago.il.us>
  36  *
  37  * Any bugs reported given to us we will try to fix... any fixes shared will
  38  * be incorporated into the next SCTP release.
  39  */
  40
  41 #include <linux/types.h>
  42 #include <net/sctp/sctp.h>
  43 #include <net/sctp/sm.h>
  44
  45 /* Create a new sctp_command_sequence.  */
  46 sctp_cmd_seq_t *sctp_new_cmd_seq(int gfp)
  47 {
  48         sctp_cmd_seq_t *retval = t_new(sctp_cmd_seq_t, gfp);
  49
  50         if (retval)
  51                 sctp_init_cmd_seq(retval);
  52
  53         return retval;
  54 }
  55
  56 /* Initialize a block of memory as a command sequence. */
  57 int sctp_init_cmd_seq(sctp_cmd_seq_t *seq)
  58 {
  59         memset(seq, 0, sizeof(sctp_cmd_seq_t));
  60         return 1;               /* We always succeed.  */
  61 }
  62
  63 /* Add a command to a sctp_cmd_seq_t.
  64  * Return 0 if the command sequence is full.
  65  */
  66 int sctp_add_cmd(sctp_cmd_seq_t *seq, sctp_verb_t verb, sctp_arg_t obj)
  67 {
  68         if (seq->next_free_slot >= SCTP_MAX_NUM_COMMANDS)
  69                 goto fail;
  70
  71         seq->cmds[seq->next_free_slot].verb = verb;
  72         seq->cmds[seq->next_free_slot++].obj = obj;
  73
  74         return 1;
  75
  76 fail:
  77         return 0;
  78 }
  79
  80 /* Rewind an sctp_cmd_seq_t to iterate from the start.  */
  81 int sctp_rewind_sequence(sctp_cmd_seq_t *seq)
  82 {
  83         seq->next_cmd = 0;
  84         return 1;               /* We always succeed. */
  85 }
  86
  87 /* Return the next command structure in a sctp_cmd_seq.
  88  * Returns NULL at the end of the sequence.
  89  */
  90 sctp_cmd_t *sctp_next_cmd(sctp_cmd_seq_t *seq)
  91 {
  92         sctp_cmd_t *retval = NULL;
  93
  94         if (seq->next_cmd < seq->next_free_slot)
  95                 retval = &seq->cmds[seq->next_cmd++];
  96
  97         return retval;
  98 }
  99
 100 /* Dispose of a command sequence.  */
 101 void sctp_free_cmd_seq(sctp_cmd_seq_t *seq)
 102 {
 103         kfree(seq);
 104 }