1 /* 2 * ng_UI.c 3 */ 4 5 /*- 6 * Copyright (c) 1996-1999 Whistle Communications, Inc. 7 * All rights reserved. 8 * 9 * Subject to the following obligations and disclaimer of warranty, use and 10 * redistribution of this software, in source or object code forms, with or 11 * without modifications are expressly permitted by Whistle Communications; 12 * provided, however, that: 13 * 1. Any and all reproductions of the source or object code must include the 14 * copyright notice above and the following disclaimer of warranties; and 15 * 2. No rights are granted, in any manner or form, to use Whistle 16 * Communications, Inc. trademarks, including the mark "WHISTLE 17 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as 18 * such appears in the above copyright notice or in the software. 19 * 20 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND 21 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO 22 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, 23 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF 24 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. 25 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY 26 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS 27 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. 28 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES 29 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING 30 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 31 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR 32 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY 36 * OF SUCH DAMAGE. 37 * 38 * Author: Julian Elischer <julian@freebsd.org> 39 * 40 * $FreeBSD$ 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 <netgraph/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_shutdown; 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 .version = NG_ABI_VERSION, 82 .name = NG_UI_NODE_TYPE, 83 .constructor = ng_UI_constructor, 84 .rcvmsg = ng_UI_rcvmsg, 85 .shutdown = ng_UI_shutdown, 86 .newhook = ng_UI_newhook, 87 .rcvdata = ng_UI_rcvdata, 88 .disconnect = ng_UI_disconnect, 89 }; 90 NETGRAPH_INIT(UI, &typestruct); 91 92 /************************************************************************ 93 NETGRAPH NODE STUFF 94 ************************************************************************/ 95 96 /* 97 * Create a newborn node. We start with an implicit reference. 98 */ 99 100 static int 101 ng_UI_constructor(node_p node) 102 { 103 priv_p priv; 104 105 /* Allocate private structure */ 106 priv = malloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO); 107 if (priv == NULL) { 108 return (ENOMEM); 109 } 110 NG_NODE_SET_PRIVATE(node, priv); 111 return (0); 112 } 113 114 /* 115 * Give our ok for a hook to be added 116 */ 117 static int 118 ng_UI_newhook(node_p node, hook_p hook, const char *name) 119 { 120 const priv_p priv = NG_NODE_PRIVATE(node); 121 122 if (!strcmp(name, NG_UI_HOOK_DOWNSTREAM)) { 123 if (priv->downlink) 124 return (EISCONN); 125 priv->downlink = hook; 126 } else if (!strcmp(name, NG_UI_HOOK_UPSTREAM)) { 127 if (priv->uplink) 128 return (EISCONN); 129 priv->uplink = hook; 130 } else 131 return (EINVAL); 132 return (0); 133 } 134 135 /* 136 * Receive a control message 137 */ 138 static int 139 ng_UI_rcvmsg(node_p node, item_p item, hook_p lasthook) 140 { 141 int error; 142 const priv_p priv = NG_NODE_PRIVATE(node); 143 struct ng_mesg *msg; 144 145 msg = NGI_MSG(item); /* only peeking */ 146 if ((msg->header.typecookie == NGM_FLOW_COOKIE) && lasthook) { 147 if (lasthook == priv->downlink) { 148 if (priv->uplink) { 149 NG_FWD_ITEM_HOOK(error, item, priv->uplink); 150 return (error); 151 } 152 } else { 153 if (priv->downlink) { 154 NG_FWD_ITEM_HOOK(error, item, priv->downlink); 155 return (error); 156 } 157 } 158 } 159 160 NG_FREE_ITEM(item); 161 return (EINVAL); 162 } 163 164 #define MAX_ENCAPS_HDR 1 165 #define ERROUT(x) do { error = (x); goto done; } while (0) 166 167 /* 168 * Receive a data frame 169 */ 170 static int 171 ng_UI_rcvdata(hook_p hook, item_p item) 172 { 173 const node_p node = NG_HOOK_NODE(hook); 174 const priv_p priv = NG_NODE_PRIVATE(node); 175 struct mbuf *m; 176 int error = 0; 177 178 NGI_GET_M(item, m); 179 if (hook == priv->downlink) { 180 u_char *start, *ptr; 181 182 if (m->m_len < MAX_ENCAPS_HDR 183 && !(m = m_pullup(m, MAX_ENCAPS_HDR))) 184 ERROUT(ENOBUFS); 185 ptr = start = mtod(m, u_char *); 186 187 /* Must be UI frame */ 188 if (*ptr++ != HDLC_UI) 189 ERROUT(0); 190 191 m_adj(m, ptr - start); 192 NG_FWD_NEW_DATA(error, item, priv->uplink, m); /* m -> NULL */ 193 } else if (hook == priv->uplink) { 194 M_PREPEND(m, 1, M_DONTWAIT); /* Prepend IP NLPID */ 195 if (!m) 196 ERROUT(ENOBUFS); 197 mtod(m, u_char *)[0] = HDLC_UI; 198 NG_FWD_NEW_DATA(error, item, priv->downlink, m); /* m -> NULL */ 199 } else 200 panic(__func__); 201 202 done: 203 NG_FREE_M(m); /* does nothing if m == NULL */ 204 if (item) 205 NG_FREE_ITEM(item); 206 return (error); 207 } 208 209 /* 210 * Shutdown node 211 */ 212 static int 213 ng_UI_shutdown(node_p node) 214 { 215 const priv_p priv = NG_NODE_PRIVATE(node); 216 217 /* Take down netgraph node */ 218 free(priv, M_NETGRAPH); 219 NG_NODE_SET_PRIVATE(node, NULL); 220 NG_NODE_UNREF(node); 221 return (0); 222 } 223 224 /* 225 * Hook disconnection 226 */ 227 static int 228 ng_UI_disconnect(hook_p hook) 229 { 230 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 231 232 if (hook == priv->downlink) 233 priv->downlink = NULL; 234 else if (hook == priv->uplink) 235 priv->uplink = NULL; 236 else 237 panic(__func__); 238 /* 239 * If we are not already shutting down, 240 * and we have no more hooks, then DO shut down. 241 */ 242 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 243 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) { 244 ng_rmnode_self(NG_HOOK_NODE(hook)); 245 } 246 return (0); 247 } 248 249