ng_UI.c revision 87599
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 87599 2001-12-10 08:09:49Z obrien $ 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 NG_ABI_VERSION, 81 NG_UI_NODE_TYPE, 82 NULL, 83 ng_UI_constructor, 84 ng_UI_rcvmsg, 85 ng_UI_shutdown, 86 ng_UI_newhook, 87 NULL, 88 NULL, 89 ng_UI_rcvdata, 90 ng_UI_disconnect, 91 NULL 92}; 93NETGRAPH_INIT(UI, &typestruct); 94 95/************************************************************************ 96 NETGRAPH NODE STUFF 97 ************************************************************************/ 98 99/* 100 * Create a newborn node. We start with an implicit reference. 101 */ 102 103static int 104ng_UI_constructor(node_p node) 105{ 106 priv_p priv; 107 108 /* Allocate private structure */ 109 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO); 110 if (priv == NULL) { 111 return (ENOMEM); 112 } 113 NG_NODE_SET_PRIVATE(node, priv); 114 return (0); 115} 116 117/* 118 * Give our ok for a hook to be added 119 */ 120static int 121ng_UI_newhook(node_p node, hook_p hook, const char *name) 122{ 123 const priv_p priv = NG_NODE_PRIVATE(node); 124 125 if (!strcmp(name, NG_UI_HOOK_DOWNSTREAM)) { 126 if (priv->downlink) 127 return (EISCONN); 128 priv->downlink = hook; 129 } else if (!strcmp(name, NG_UI_HOOK_UPSTREAM)) { 130 if (priv->uplink) 131 return (EISCONN); 132 priv->uplink = hook; 133 } else 134 return (EINVAL); 135 return (0); 136} 137 138/* 139 * Receive a control message 140 */ 141static int 142ng_UI_rcvmsg(node_p node, item_p item, hook_p lasthook) 143{ 144 int error; 145 const priv_p priv = NG_NODE_PRIVATE(node); 146 struct ng_mesg *msg; 147 148 msg = NGI_MSG(item); /* only peeking */ 149 if ((msg->header.typecookie == NGM_FLOW_COOKIE) && lasthook) { 150 if (lasthook == priv->downlink) { 151 if (priv->uplink) { 152 NG_FWD_ITEM_HOOK(error, item, priv->uplink); 153 return (error); 154 } 155 } else { 156 if (priv->downlink) { 157 NG_FWD_ITEM_HOOK(error, item, priv->downlink); 158 return (error); 159 } 160 } 161 } 162 163 NG_FREE_ITEM(item); 164 return (EINVAL); 165} 166 167#define MAX_ENCAPS_HDR 1 168#define ERROUT(x) do { error = (x); goto done; } while (0) 169 170/* 171 * Receive a data frame 172 */ 173static int 174ng_UI_rcvdata(hook_p hook, item_p item) 175{ 176 const node_p node = NG_HOOK_NODE(hook); 177 const priv_p priv = NG_NODE_PRIVATE(node); 178 struct mbuf *m; 179 int error = 0; 180 181 NGI_GET_M(item, m); 182 if (hook == priv->downlink) { 183 u_char *start, *ptr; 184 185 if (!m || (m->m_len < MAX_ENCAPS_HDR 186 && !(m = m_pullup(m, MAX_ENCAPS_HDR)))) 187 ERROUT(ENOBUFS); 188 ptr = start = mtod(m, u_char *); 189 190 /* Must be UI frame */ 191 if (*ptr++ != HDLC_UI) 192 ERROUT(0); 193 194 m_adj(m, ptr - start); 195 NG_FWD_NEW_DATA(error, item, priv->uplink, m); /* m -> NULL */ 196 } else if (hook == priv->uplink) { 197 M_PREPEND(m, 1, M_DONTWAIT); /* Prepend IP NLPID */ 198 if (!m) 199 ERROUT(ENOBUFS); 200 mtod(m, u_char *)[0] = HDLC_UI; 201 NG_FWD_NEW_DATA(error, item, priv->downlink, m); /* m -> NULL */ 202 } else 203 panic(__func__); 204 205done: 206 NG_FREE_M(m); /* does nothing if m == NULL */ 207 if (item) 208 NG_FREE_ITEM(item); 209 return (error); 210} 211 212/* 213 * Shutdown node 214 */ 215static int 216ng_UI_shutdown(node_p node) 217{ 218 const priv_p priv = NG_NODE_PRIVATE(node); 219 220 /* Take down netgraph node */ 221 FREE(priv, M_NETGRAPH); 222 NG_NODE_SET_PRIVATE(node, NULL); 223 NG_NODE_UNREF(node); 224 return (0); 225} 226 227/* 228 * Hook disconnection 229 */ 230static int 231ng_UI_disconnect(hook_p hook) 232{ 233 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 234 235 if (hook == priv->downlink) 236 priv->downlink = NULL; 237 else if (hook == priv->uplink) 238 priv->uplink = NULL; 239 else 240 panic(__func__); 241 /* 242 * If we are not already shutting down, 243 * and we have no more hooks, then DO shut down. 244 */ 245 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 246 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) { 247 ng_rmnode_self(NG_HOOK_NODE(hook)); 248 } 249 return (0); 250} 251 252