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: src/sys/netgraph/ng_UI.c,v 1.20 2005/01/07 01:45:39 imp Exp $ 41 * $DragonFly: src/sys/netgraph7/ng_UI.c,v 1.2 2008/06/26 23:05:35 dillon Exp $ 42 * $Whistle: ng_UI.c,v 1.14 1999/11/01 09:24:51 julian Exp $ 43 */ 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/errno.h> 48 #include <sys/kernel.h> 49 #include <sys/malloc.h> 50 #include <sys/mbuf.h> 51 #include <sys/errno.h> 52 53 54 #include <netgraph7/ng_message.h> 55 #include <netgraph7/netgraph.h> 56 #include "ng_UI.h" 57 58 /* 59 * DEFINITIONS 60 */ 61 62 /* Everything, starting with sdlc on has defined UI as 0x03 */ 63 #define HDLC_UI 0x03 64 65 /* Node private data */ 66 struct ng_UI_private { 67 hook_p downlink; 68 hook_p uplink; 69 }; 70 typedef struct ng_UI_private *priv_p; 71 72 /* Netgraph node methods */ 73 static ng_constructor_t ng_UI_constructor; 74 static ng_rcvmsg_t ng_UI_rcvmsg; 75 static ng_shutdown_t ng_UI_shutdown; 76 static ng_newhook_t ng_UI_newhook; 77 static ng_rcvdata_t ng_UI_rcvdata; 78 static ng_disconnect_t ng_UI_disconnect; 79 80 /* Node type descriptor */ 81 static struct ng_type typestruct = { 82 .version = NG_ABI_VERSION, 83 .name = NG_UI_NODE_TYPE, 84 .constructor = ng_UI_constructor, 85 .rcvmsg = ng_UI_rcvmsg, 86 .shutdown = ng_UI_shutdown, 87 .newhook = ng_UI_newhook, 88 .rcvdata = ng_UI_rcvdata, 89 .disconnect = ng_UI_disconnect, 90 }; 91 NETGRAPH_INIT(UI, &typestruct); 92 93 /************************************************************************ 94 NETGRAPH NODE STUFF 95 ************************************************************************/ 96 97 /* 98 * Create a newborn node. We start with an implicit reference. 99 */ 100 101 static int 102 ng_UI_constructor(node_p node) 103 { 104 priv_p priv; 105 106 /* Allocate private structure */ 107 priv = kmalloc(sizeof(*priv), M_NETGRAPH, 108 M_WAITOK | M_NULLOK | M_ZERO); 109 if (priv == NULL) { 110 return (ENOMEM); 111 } 112 NG_NODE_SET_PRIVATE(node, priv); 113 return (0); 114 } 115 116 /* 117 * Give our ok for a hook to be added 118 */ 119 static int 120 ng_UI_newhook(node_p node, hook_p hook, const char *name) 121 { 122 const priv_p priv = NG_NODE_PRIVATE(node); 123 124 if (!strcmp(name, NG_UI_HOOK_DOWNSTREAM)) { 125 if (priv->downlink) 126 return (EISCONN); 127 priv->downlink = hook; 128 } else if (!strcmp(name, NG_UI_HOOK_UPSTREAM)) { 129 if (priv->uplink) 130 return (EISCONN); 131 priv->uplink = hook; 132 } else 133 return (EINVAL); 134 return (0); 135 } 136 137 /* 138 * Receive a control message 139 */ 140 static int 141 ng_UI_rcvmsg(node_p node, item_p item, hook_p lasthook) 142 { 143 int error; 144 const priv_p priv = NG_NODE_PRIVATE(node); 145 struct ng_mesg *msg; 146 147 msg = NGI_MSG(item); /* only peeking */ 148 if ((msg->header.typecookie == NGM_FLOW_COOKIE) && lasthook) { 149 if (lasthook == priv->downlink) { 150 if (priv->uplink) { 151 NG_FWD_ITEM_HOOK(error, item, priv->uplink); 152 return (error); 153 } 154 } else { 155 if (priv->downlink) { 156 NG_FWD_ITEM_HOOK(error, item, priv->downlink); 157 return (error); 158 } 159 } 160 } 161 162 NG_FREE_ITEM(item); 163 return (EINVAL); 164 } 165 166 #define MAX_ENCAPS_HDR 1 167 #define ERROUT(x) do { error = (x); goto done; } while (0) 168 169 /* 170 * Receive a data frame 171 */ 172 static int 173 ng_UI_rcvdata(hook_p hook, item_p item) 174 { 175 const node_p node = NG_HOOK_NODE(hook); 176 const priv_p priv = NG_NODE_PRIVATE(node); 177 struct mbuf *m; 178 int error = 0; 179 180 NGI_GET_M(item, m); 181 if (hook == priv->downlink) { 182 u_char *start, *ptr; 183 184 if (m->m_len < MAX_ENCAPS_HDR 185 && !(m = m_pullup(m, MAX_ENCAPS_HDR))) 186 ERROUT(ENOBUFS); 187 ptr = start = mtod(m, u_char *); 188 189 /* Must be UI frame */ 190 if (*ptr++ != HDLC_UI) 191 ERROUT(0); 192 193 m_adj(m, ptr - start); 194 NG_FWD_NEW_DATA(error, item, priv->uplink, m); /* m -> NULL */ 195 } else if (hook == priv->uplink) { 196 M_PREPEND(m, 1, MB_DONTWAIT); /* Prepend IP NLPID */ 197 if (!m) 198 ERROUT(ENOBUFS); 199 mtod(m, u_char *)[0] = HDLC_UI; 200 NG_FWD_NEW_DATA(error, item, priv->downlink, m); /* m -> NULL */ 201 } else 202 panic(__func__); 203 204 done: 205 NG_FREE_M(m); /* does nothing if m == NULL */ 206 if (item) 207 NG_FREE_ITEM(item); 208 return (error); 209 } 210 211 /* 212 * Shutdown node 213 */ 214 static int 215 ng_UI_shutdown(node_p node) 216 { 217 const priv_p priv = NG_NODE_PRIVATE(node); 218 219 /* Take down netgraph node */ 220 kfree(priv, M_NETGRAPH); 221 NG_NODE_SET_PRIVATE(node, NULL); 222 NG_NODE_UNREF(node); 223 return (0); 224 } 225 226 /* 227 * Hook disconnection 228 */ 229 static int 230 ng_UI_disconnect(hook_p hook) 231 { 232 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 233 234 if (hook == priv->downlink) 235 priv->downlink = NULL; 236 else if (hook == priv->uplink) 237 priv->uplink = NULL; 238 else 239 panic(__func__); 240 /* 241 * If we are not already shutting down, 242 * and we have no more hooks, then DO shut down. 243 */ 244 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 245 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) { 246 ng_rmnode_self(NG_HOOK_NODE(hook)); 247 } 248 return (0); 249 } 250 251