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 * $FreeBSD$ 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 */ 64 struct ng_UI_private { 65 hook_p downlink; 66 hook_p uplink; 67 }; 68 typedef struct ng_UI_private *priv_p; 69 70 /* Netgraph node methods */ 71 static ng_constructor_t ng_UI_constructor; 72 static ng_rcvmsg_t ng_UI_rcvmsg; 73 static ng_shutdown_t ng_UI_shutdown; 74 static ng_newhook_t ng_UI_newhook; 75 static ng_rcvdata_t ng_UI_rcvdata; 76 static ng_disconnect_t ng_UI_disconnect; 77 78 /* Node type descriptor */ 79 static 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 }; 93 NETGRAPH_INIT(UI, &typestruct); 94 95 /************************************************************************ 96 NETGRAPH NODE STUFF 97 ************************************************************************/ 98 99 /* 100 * Create a newborn node. We start with an implicit reference. 101 */ 102 103 static int 104 ng_UI_constructor(node_p nodep) 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 nodep->private = priv; 114 return (0); 115 } 116 117 /* 118 * Give our ok for a hook to be added 119 */ 120 static int 121 ng_UI_newhook(node_p node, hook_p hook, const char *name) 122 { 123 const priv_p priv = node->private; 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 */ 141 static int 142 ng_UI_rcvmsg(node_p node, item_p item, hook_p lasthook) 143 { 144 int error; 145 const priv_p priv = node->private; 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_MSG_HOOK(error, node, item, 153 priv->uplink, 0); 154 return (error); 155 } 156 } else { 157 if (priv->downlink) { 158 NG_FWD_MSG_HOOK(error, node, item, 159 priv->downlink, 0); 160 return (error); 161 } 162 } 163 } 164 165 NG_FREE_MSG(msg); 166 return (EINVAL); 167 } 168 169 #define MAX_ENCAPS_HDR 1 170 #define ERROUT(x) do { error = (x); goto done; } while (0) 171 172 /* 173 * Receive a data frame 174 */ 175 static int 176 ng_UI_rcvdata(hook_p hook, item_p item) 177 { 178 const node_p node = hook->node; 179 const priv_p priv = node->private; 180 struct mbuf *m; 181 int error = 0; 182 183 NGI_GET_M(item, m); 184 if (hook == priv->downlink) { 185 u_char *start, *ptr; 186 187 if (!m || (m->m_len < MAX_ENCAPS_HDR 188 && !(m = m_pullup(m, MAX_ENCAPS_HDR)))) 189 ERROUT(ENOBUFS); 190 ptr = start = mtod(m, u_char *); 191 192 /* Must be UI frame */ 193 if (*ptr++ != HDLC_UI) 194 ERROUT(0); 195 196 m_adj(m, ptr - start); 197 NG_FWD_NEW_DATA(error, item, priv->uplink, m); /* m -> NULL */ 198 } else if (hook == priv->uplink) { 199 M_PREPEND(m, 1, M_DONTWAIT); /* Prepend IP NLPID */ 200 if (!m) 201 ERROUT(ENOBUFS); 202 mtod(m, u_char *)[0] = HDLC_UI; 203 NG_FWD_NEW_DATA(error, item, priv->downlink, m); /* m -> NULL */ 204 } else 205 panic(__FUNCTION__); 206 207 done: 208 NG_FREE_M(m); /* does nothing if m == NULL */ 209 if (item) 210 NG_FREE_ITEM(item); 211 return (error); 212 } 213 214 /* 215 * Shutdown node 216 */ 217 static int 218 ng_UI_shutdown(node_p node) 219 { 220 const priv_p priv = node->private; 221 222 /* Take down netgraph node */ 223 FREE(priv, M_NETGRAPH); 224 node->private = NULL; 225 ng_unref(node); 226 return (0); 227 } 228 229 /* 230 * Hook disconnection 231 */ 232 static int 233 ng_UI_disconnect(hook_p hook) 234 { 235 const priv_p priv = hook->node->private; 236 237 if (hook == priv->downlink) 238 priv->downlink = NULL; 239 else if (hook == priv->uplink) 240 priv->uplink = NULL; 241 else 242 panic(__FUNCTION__); 243 /* 244 * If we are not already shutting down, 245 * and we have no more hooks, then DO shut down. 246 */ 247 if ((hook->node->numhooks == 0) 248 && ((hook->node->flags & NG_INVALID) == 0)) { 249 ng_rmnode_self(hook->node); 250 } 251 return (0); 252 } 253 254