sys/netgraph/UI/ng_UI.c

   1
   2 /*
   3  * ng_UI.c
   4  *
   5  * Copyright (c) 1996-1999 Whistle Communications, Inc.
   6  * All rights reserved.
   7  *
   8  * Subject to the following obligations and disclaimer of warranty, use and
   9  * redistribution of this software, in source or object code forms, with or
  10  * without modifications are expressly permitted by Whistle Communications;
  11  * provided, however, that:
  12  * 1. Any and all reproductions of the source or object code must include the
  13  *    copyright notice above and the following disclaimer of warranties; and
  14  * 2. No rights are granted, in any manner or form, to use Whistle
  15  *    Communications, Inc. trademarks, including the mark "WHISTLE
  16  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
  17  *    such appears in the above copyright notice or in the software.
  18  *
  19  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
  20  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
  21  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
  22  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
  23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
  24  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
  25  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
  26  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
  27  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
  28  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
  29  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
  30  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
  31  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
  32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  34  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
  35  * OF SUCH DAMAGE.
  36  *
  37  * Author: Julian Elischer <julian@freebsd.org>
  38  *
  39  * $FreeBSD: src/sys/netgraph/ng_UI.c,v 1.6.2.2 2000/10/24 18:36:44 julian Exp $
  40  * $DragonFly: src/sys/netgraph/UI/ng_UI.c,v 1.5 2005/02/17 13:59:59 joerg Exp $
  41  * $Whistle: ng_UI.c,v 1.14 1999/11/01 09:24:51 julian Exp $
  42  */
  43
  44 #include <sys/param.h>
  45 #include <sys/systm.h>
  46 #include <sys/errno.h>
  47 #include <sys/kernel.h>
  48 #include <sys/malloc.h>
  49 #include <sys/mbuf.h>
  50 #include <sys/errno.h>
  51
  52
  53 #include <netgraph/ng_message.h>
  54 #include <netgraph/netgraph.h>
  55 #include "ng_UI.h"
  56
  57 /*
  58  * DEFINITIONS
  59  */
  60
  61 /* Everything, starting with sdlc on has defined UI as 0x03 */
  62 #define HDLC_UI 0x03
  63
  64 /* Node private data */
  65 struct ng_UI_private {
  66         hook_p  downlink;
  67         hook_p  uplink;
  68 };
  69 typedef struct ng_UI_private *priv_p;
  70
  71 /* Netgraph node methods */
  72 static ng_constructor_t ng_UI_constructor;
  73 static ng_rcvmsg_t      ng_UI_rcvmsg;
  74 static ng_shutdown_t    ng_UI_rmnode;
  75 static ng_newhook_t     ng_UI_newhook;
  76 static ng_rcvdata_t     ng_UI_rcvdata;
  77 static ng_disconnect_t  ng_UI_disconnect;
  78
  79 /* Node type descriptor */
  80 static struct ng_type typestruct = {
  81         NG_VERSION,
  82         NG_UI_NODE_TYPE,
  83         NULL,
  84         ng_UI_constructor,
  85         ng_UI_rcvmsg,
  86         ng_UI_rmnode,
  87         ng_UI_newhook,
  88         NULL,
  89         NULL,
  90         ng_UI_rcvdata,
  91         ng_UI_rcvdata,
  92         ng_UI_disconnect,
  93         NULL
  94 };
  95 NETGRAPH_INIT(UI, &typestruct);
  96
  97 /************************************************************************
  98                         NETGRAPH NODE STUFF
  99  ************************************************************************/
 100
 101 /*
 102  * Create a newborn node. We start with an implicit reference.
 103  */
 104
 105 static int
 106 ng_UI_constructor(node_p *nodep)
 107 {
 108         priv_p  priv;
 109         int     error;
 110
 111         /* Allocate private structure */
 112         MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT);
 113         if (priv == NULL)
 114                 return (ENOMEM);
 115         bzero(priv, sizeof(*priv));
 116
 117         /* Call generic node constructor */
 118         if ((error = ng_make_node_common(&typestruct, nodep))) {
 119                 FREE(priv, M_NETGRAPH);
 120                 return (error);
 121         }
 122         (*nodep)->private = priv;
 123
 124         /* Done */
 125         return (0);
 126 }
 127
 128 /*
 129  * Give our ok for a hook to be added
 130  */
 131 static int
 132 ng_UI_newhook(node_p node, hook_p hook, const char *name)
 133 {
 134         const priv_p priv = node->private;
 135
 136         if (!strcmp(name, NG_UI_HOOK_DOWNSTREAM)) {
 137                 if (priv->downlink)
 138                         return (EISCONN);
 139                 priv->downlink = hook;
 140         } else if (!strcmp(name, NG_UI_HOOK_UPSTREAM)) {
 141                 if (priv->uplink)
 142                         return (EISCONN);
 143                 priv->uplink = hook;
 144         } else
 145                 return (EINVAL);
 146         return (0);
 147 }
 148
 149 /*
 150  * Receive a control message
 151  */
 152 static int
 153 ng_UI_rcvmsg(node_p node, struct ng_mesg *msg,
 154              const char *raddr, struct ng_mesg **rp)
 155 {
 156         FREE(msg, M_NETGRAPH);
 157         return (EINVAL);
 158 }
 159
 160 #define MAX_ENCAPS_HDR  1
 161 #define ERROUT(x)       do { error = (x); goto done; } while (0)
 162
 163 /*
 164  * Receive a data frame
 165  */
 166 static int
 167 ng_UI_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
 168 {
 169         const node_p node = hook->node;
 170         const priv_p priv = node->private;
 171         int error = 0;
 172
 173         if (hook == priv->downlink) {
 174                 u_char *start, *ptr;
 175
 176                 if (!m || (m->m_len < MAX_ENCAPS_HDR
 177                     && !(m = m_pullup(m, MAX_ENCAPS_HDR))))
 178                         ERROUT(ENOBUFS);
 179                 ptr = start = mtod(m, u_char *);
 180
 181                 /* Must be UI frame */
 182                 if (*ptr++ != HDLC_UI)
 183                         ERROUT(0);
 184
 185                 m_adj(m, ptr - start);
 186                 NG_SEND_DATA(error, priv->uplink, m, meta);     /* m -> NULL */
 187         } else if (hook == priv->uplink) {
 188                 M_PREPEND(m, 1, MB_DONTWAIT);   /* Prepend IP NLPID */
 189                 if (!m)
 190                         ERROUT(ENOBUFS);
 191                 mtod(m, u_char *)[0] = HDLC_UI;
 192                 NG_SEND_DATA(error, priv->downlink, m, meta);   /* m -> NULL */
 193         } else
 194                 panic(__func__);
 195
 196 done:
 197         NG_FREE_DATA(m, meta);  /* does nothing if m == NULL */
 198         return (error);
 199 }
 200
 201 /*
 202  * Shutdown node
 203  */
 204 static int
 205 ng_UI_rmnode(node_p node)
 206 {
 207         const priv_p priv = node->private;
 208
 209         /* Take down netgraph node */
 210         node->flags |= NG_INVALID;
 211         ng_cutlinks(node);
 212         ng_unname(node);
 213         bzero(priv, sizeof(*priv));
 214         FREE(priv, M_NETGRAPH);
 215         node->private = NULL;
 216         ng_unref(node);
 217         return (0);
 218 }
 219
 220 /*
 221  * Hook disconnection
 222  */
 223 static int
 224 ng_UI_disconnect(hook_p hook)
 225 {
 226         const priv_p priv = hook->node->private;
 227
 228         if (hook->node->numhooks == 0)
 229                 ng_rmnode(hook->node);
 230         else if (hook == priv->downlink)
 231                 priv->downlink = NULL;
 232         else if (hook == priv->uplink)
 233                 priv->uplink = NULL;
 234         else
 235                 panic(__func__);
 236         return (0);
 237 }
 238