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: src/sys/netgraph/ng_UI.c,v 1.6.2.2 2000/10/24 18:36:44 julian Exp $ 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 "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_rmnode; 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_VERSION, 81 NG_UI_NODE_TYPE, 82 NULL, 83 ng_UI_constructor, 84 ng_UI_rcvmsg, 85 ng_UI_rmnode, 86 ng_UI_newhook, 87 NULL, 88 NULL, 89 ng_UI_rcvdata, 90 ng_UI_rcvdata, 91 ng_UI_disconnect, 92 NULL 93 }; 94 NETGRAPH_INIT(UI, &typestruct); 95 96 /************************************************************************ 97 NETGRAPH NODE STUFF 98 ************************************************************************/ 99 100 /* 101 * Create a newborn node. We start with an implicit reference. 102 */ 103 104 static int 105 ng_UI_constructor(node_p *nodep) 106 { 107 priv_p priv; 108 int error; 109 110 /* Allocate private structure */ 111 priv = kmalloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO); 112 if (priv == NULL) 113 return (ENOMEM); 114 115 /* Call generic node constructor */ 116 if ((error = ng_make_node_common(&typestruct, nodep))) { 117 kfree(priv, M_NETGRAPH); 118 return (error); 119 } 120 (*nodep)->private = priv; 121 122 /* Done */ 123 return (0); 124 } 125 126 /* 127 * Give our ok for a hook to be added 128 */ 129 static int 130 ng_UI_newhook(node_p node, hook_p hook, const char *name) 131 { 132 const priv_p priv = node->private; 133 134 if (!strcmp(name, NG_UI_HOOK_DOWNSTREAM)) { 135 if (priv->downlink) 136 return (EISCONN); 137 priv->downlink = hook; 138 } else if (!strcmp(name, NG_UI_HOOK_UPSTREAM)) { 139 if (priv->uplink) 140 return (EISCONN); 141 priv->uplink = hook; 142 } else 143 return (EINVAL); 144 return (0); 145 } 146 147 /* 148 * Receive a control message 149 */ 150 static int 151 ng_UI_rcvmsg(node_p node, struct ng_mesg *msg, 152 const char *raddr, struct ng_mesg **rp) 153 { 154 kfree(msg, M_NETGRAPH); 155 return (EINVAL); 156 } 157 158 #define MAX_ENCAPS_HDR 1 159 #define ERROUT(x) do { error = (x); goto done; } while (0) 160 161 /* 162 * Receive a data frame 163 */ 164 static int 165 ng_UI_rcvdata(hook_p hook, struct mbuf *m, meta_p meta) 166 { 167 const node_p node = hook->node; 168 const priv_p priv = node->private; 169 int error = 0; 170 171 if (hook == priv->downlink) { 172 u_char *start, *ptr; 173 174 if (!m || (m->m_len < MAX_ENCAPS_HDR 175 && !(m = m_pullup(m, MAX_ENCAPS_HDR)))) 176 ERROUT(ENOBUFS); 177 ptr = start = mtod(m, u_char *); 178 179 /* Must be UI frame */ 180 if (*ptr++ != HDLC_UI) 181 ERROUT(0); 182 183 m_adj(m, ptr - start); 184 NG_SEND_DATA(error, priv->uplink, m, meta); /* m -> NULL */ 185 } else if (hook == priv->uplink) { 186 M_PREPEND(m, 1, MB_DONTWAIT); /* Prepend IP NLPID */ 187 if (!m) 188 ERROUT(ENOBUFS); 189 mtod(m, u_char *)[0] = HDLC_UI; 190 NG_SEND_DATA(error, priv->downlink, m, meta); /* m -> NULL */ 191 } else 192 panic(__func__); 193 194 done: 195 NG_FREE_DATA(m, meta); /* does nothing if m == NULL */ 196 return (error); 197 } 198 199 /* 200 * Shutdown node 201 */ 202 static int 203 ng_UI_rmnode(node_p node) 204 { 205 const priv_p priv = node->private; 206 207 /* Take down netgraph node */ 208 node->flags |= NG_INVALID; 209 ng_cutlinks(node); 210 ng_unname(node); 211 bzero(priv, sizeof(*priv)); 212 kfree(priv, M_NETGRAPH); 213 node->private = NULL; 214 ng_unref(node); 215 return (0); 216 } 217 218 /* 219 * Hook disconnection 220 */ 221 static int 222 ng_UI_disconnect(hook_p hook) 223 { 224 const priv_p priv = hook->node->private; 225 226 if (hook->node->numhooks == 0) 227 ng_rmnode(hook->node); 228 else if (hook == priv->downlink) 229 priv->downlink = NULL; 230 else if (hook == priv->uplink) 231 priv->uplink = NULL; 232 else 233 panic(__func__); 234 return (0); 235 } 236 237