ng_UI.c revision 131112
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: head/sys/netgraph/ng_UI.c 131112 2004-06-25 21:11:14Z julian $ 40 * $Whistle: ng_UI.c,v 1.14 1999/11/01 09:24:51 julian Exp $ 41 */ 42 43#include <sys/param.h> 44#include <sys/systm.h> 45#include <sys/errno.h> 46#include <sys/kernel.h> 47#include <sys/malloc.h> 48#include <sys/mbuf.h> 49#include <sys/errno.h> 50 51 52#include <netgraph/ng_message.h> 53#include <netgraph/netgraph.h> 54#include <netgraph/ng_UI.h> 55 56/* 57 * DEFINITIONS 58 */ 59 60/* Everything, starting with sdlc on has defined UI as 0x03 */ 61#define HDLC_UI 0x03 62 63/* Node private data */ 64struct ng_UI_private { 65 hook_p downlink; 66 hook_p uplink; 67}; 68typedef struct ng_UI_private *priv_p; 69 70/* Netgraph node methods */ 71static ng_constructor_t ng_UI_constructor; 72static ng_rcvmsg_t ng_UI_rcvmsg; 73static ng_shutdown_t ng_UI_shutdown; 74static ng_newhook_t ng_UI_newhook; 75static ng_rcvdata_t ng_UI_rcvdata; 76static ng_disconnect_t ng_UI_disconnect; 77 78/* Node type descriptor */ 79static struct ng_type typestruct = { 80 .version = NG_ABI_VERSION, 81 .name = NG_UI_NODE_TYPE, 82 .constructor = ng_UI_constructor, 83 .rcvmsg = ng_UI_rcvmsg, 84 .shutdown = ng_UI_shutdown, 85 .newhook = ng_UI_newhook, 86 .rcvdata = ng_UI_rcvdata, 87 .disconnect = ng_UI_disconnect, 88}; 89NETGRAPH_INIT(UI, &typestruct); 90 91/************************************************************************ 92 NETGRAPH NODE STUFF 93 ************************************************************************/ 94 95/* 96 * Create a newborn node. We start with an implicit reference. 97 */ 98 99static int 100ng_UI_constructor(node_p node) 101{ 102 priv_p priv; 103 104 /* Allocate private structure */ 105 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO); 106 if (priv == NULL) { 107 return (ENOMEM); 108 } 109 NG_NODE_SET_PRIVATE(node, priv); 110 return (0); 111} 112 113/* 114 * Give our ok for a hook to be added 115 */ 116static int 117ng_UI_newhook(node_p node, hook_p hook, const char *name) 118{ 119 const priv_p priv = NG_NODE_PRIVATE(node); 120 121 if (!strcmp(name, NG_UI_HOOK_DOWNSTREAM)) { 122 if (priv->downlink) 123 return (EISCONN); 124 priv->downlink = hook; 125 } else if (!strcmp(name, NG_UI_HOOK_UPSTREAM)) { 126 if (priv->uplink) 127 return (EISCONN); 128 priv->uplink = hook; 129 } else 130 return (EINVAL); 131 return (0); 132} 133 134/* 135 * Receive a control message 136 */ 137static int 138ng_UI_rcvmsg(node_p node, item_p item, hook_p lasthook) 139{ 140 int error; 141 const priv_p priv = NG_NODE_PRIVATE(node); 142 struct ng_mesg *msg; 143 144 msg = NGI_MSG(item); /* only peeking */ 145 if ((msg->header.typecookie == NGM_FLOW_COOKIE) && lasthook) { 146 if (lasthook == priv->downlink) { 147 if (priv->uplink) { 148 NG_FWD_ITEM_HOOK(error, item, priv->uplink); 149 return (error); 150 } 151 } else { 152 if (priv->downlink) { 153 NG_FWD_ITEM_HOOK(error, item, priv->downlink); 154 return (error); 155 } 156 } 157 } 158 159 NG_FREE_ITEM(item); 160 return (EINVAL); 161} 162 163#define MAX_ENCAPS_HDR 1 164#define ERROUT(x) do { error = (x); goto done; } while (0) 165 166/* 167 * Receive a data frame 168 */ 169static int 170ng_UI_rcvdata(hook_p hook, item_p item) 171{ 172 const node_p node = NG_HOOK_NODE(hook); 173 const priv_p priv = NG_NODE_PRIVATE(node); 174 struct mbuf *m; 175 int error = 0; 176 177 NGI_GET_M(item, m); 178 if (hook == priv->downlink) { 179 u_char *start, *ptr; 180 181 if (m->m_len < MAX_ENCAPS_HDR 182 && !(m = m_pullup(m, MAX_ENCAPS_HDR))) 183 ERROUT(ENOBUFS); 184 ptr = start = mtod(m, u_char *); 185 186 /* Must be UI frame */ 187 if (*ptr++ != HDLC_UI) 188 ERROUT(0); 189 190 m_adj(m, ptr - start); 191 NG_FWD_NEW_DATA(error, item, priv->uplink, m); /* m -> NULL */ 192 } else if (hook == priv->uplink) { 193 M_PREPEND(m, 1, M_DONTWAIT); /* Prepend IP NLPID */ 194 if (!m) 195 ERROUT(ENOBUFS); 196 mtod(m, u_char *)[0] = HDLC_UI; 197 NG_FWD_NEW_DATA(error, item, priv->downlink, m); /* m -> NULL */ 198 } else 199 panic(__func__); 200 201done: 202 NG_FREE_M(m); /* does nothing if m == NULL */ 203 if (item) 204 NG_FREE_ITEM(item); 205 return (error); 206} 207 208/* 209 * Shutdown node 210 */ 211static int 212ng_UI_shutdown(node_p node) 213{ 214 const priv_p priv = NG_NODE_PRIVATE(node); 215 216 /* Take down netgraph node */ 217 FREE(priv, M_NETGRAPH); 218 NG_NODE_SET_PRIVATE(node, NULL); 219 NG_NODE_UNREF(node); 220 return (0); 221} 222 223/* 224 * Hook disconnection 225 */ 226static int 227ng_UI_disconnect(hook_p hook) 228{ 229 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 230 231 if (hook == priv->downlink) 232 priv->downlink = NULL; 233 else if (hook == priv->uplink) 234 priv->uplink = NULL; 235 else 236 panic(__func__); 237 /* 238 * If we are not already shutting down, 239 * and we have no more hooks, then DO shut down. 240 */ 241 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 242 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) { 243 ng_rmnode_self(NG_HOOK_NODE(hook)); 244 } 245 return (0); 246} 247 248