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 50 #include <netgraph/ng_message.h> 51 #include <netgraph/netgraph.h> 52 #include "ng_UI.h" 53 54 /* 55 * DEFINITIONS 56 */ 57 58 /* Everything, starting with sdlc on has defined UI as 0x03 */ 59 #define HDLC_UI 0x03 60 61 /* Node private data */ 62 struct ng_UI_private { 63 hook_p downlink; 64 hook_p uplink; 65 }; 66 typedef struct ng_UI_private *priv_p; 67 68 /* Netgraph node methods */ 69 static ng_constructor_t ng_UI_constructor; 70 static ng_rcvmsg_t ng_UI_rcvmsg; 71 static ng_shutdown_t ng_UI_rmnode; 72 static ng_newhook_t ng_UI_newhook; 73 static ng_rcvdata_t ng_UI_rcvdata; 74 static ng_disconnect_t ng_UI_disconnect; 75 76 /* Node type descriptor */ 77 static struct ng_type typestruct = { 78 NG_VERSION, 79 NG_UI_NODE_TYPE, 80 NULL, 81 ng_UI_constructor, 82 ng_UI_rcvmsg, 83 ng_UI_rmnode, 84 ng_UI_newhook, 85 NULL, 86 NULL, 87 ng_UI_rcvdata, 88 ng_UI_rcvdata, 89 ng_UI_disconnect, 90 NULL 91 }; 92 NETGRAPH_INIT(UI, &typestruct); 93 94 /************************************************************************ 95 NETGRAPH NODE STUFF 96 ************************************************************************/ 97 98 /* 99 * Create a newborn node. We start with an implicit reference. 100 */ 101 102 static int 103 ng_UI_constructor(node_p *nodep) 104 { 105 priv_p priv; 106 int error; 107 108 /* Allocate private structure */ 109 priv = kmalloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO); 110 if (priv == NULL) 111 return (ENOMEM); 112 113 /* Call generic node constructor */ 114 if ((error = ng_make_node_common(&typestruct, nodep))) { 115 kfree(priv, M_NETGRAPH); 116 return (error); 117 } 118 (*nodep)->private = priv; 119 120 /* Done */ 121 return (0); 122 } 123 124 /* 125 * Give our ok for a hook to be added 126 */ 127 static int 128 ng_UI_newhook(node_p node, hook_p hook, const char *name) 129 { 130 const priv_p priv = node->private; 131 132 if (!strcmp(name, NG_UI_HOOK_DOWNSTREAM)) { 133 if (priv->downlink) 134 return (EISCONN); 135 priv->downlink = hook; 136 } else if (!strcmp(name, NG_UI_HOOK_UPSTREAM)) { 137 if (priv->uplink) 138 return (EISCONN); 139 priv->uplink = hook; 140 } else 141 return (EINVAL); 142 return (0); 143 } 144 145 /* 146 * Receive a control message 147 */ 148 static int 149 ng_UI_rcvmsg(node_p node, struct ng_mesg *msg, 150 const char *raddr, struct ng_mesg **rp) 151 { 152 kfree(msg, M_NETGRAPH); 153 return (EINVAL); 154 } 155 156 #define MAX_ENCAPS_HDR 1 157 #define ERROUT(x) do { error = (x); goto done; } while (0) 158 159 /* 160 * Receive a data frame 161 */ 162 static int 163 ng_UI_rcvdata(hook_p hook, struct mbuf *m, meta_p meta) 164 { 165 const node_p node = hook->node; 166 const priv_p priv = node->private; 167 int error = 0; 168 169 if (hook == priv->downlink) { 170 u_char *start, *ptr; 171 172 if (!m || (m->m_len < MAX_ENCAPS_HDR 173 && !(m = m_pullup(m, MAX_ENCAPS_HDR)))) 174 ERROUT(ENOBUFS); 175 ptr = start = mtod(m, u_char *); 176 177 /* Must be UI frame */ 178 if (*ptr++ != HDLC_UI) 179 ERROUT(0); 180 181 m_adj(m, ptr - start); 182 NG_SEND_DATA(error, priv->uplink, m, meta); /* m -> NULL */ 183 } else if (hook == priv->uplink) { 184 M_PREPEND(m, 1, M_NOWAIT); /* Prepend IP NLPID */ 185 if (!m) 186 ERROUT(ENOBUFS); 187 mtod(m, u_char *)[0] = HDLC_UI; 188 NG_SEND_DATA(error, priv->downlink, m, meta); /* m -> NULL */ 189 } else 190 panic(__func__); 191 192 done: 193 NG_FREE_DATA(m, meta); /* does nothing if m == NULL */ 194 return (error); 195 } 196 197 /* 198 * Shutdown node 199 */ 200 static int 201 ng_UI_rmnode(node_p node) 202 { 203 const priv_p priv = node->private; 204 205 /* Take down netgraph node */ 206 node->flags |= NG_INVALID; 207 ng_cutlinks(node); 208 ng_unname(node); 209 bzero(priv, sizeof(*priv)); 210 kfree(priv, M_NETGRAPH); 211 node->private = NULL; 212 ng_unref(node); 213 return (0); 214 } 215 216 /* 217 * Hook disconnection 218 */ 219 static int 220 ng_UI_disconnect(hook_p hook) 221 { 222 const priv_p priv = hook->node->private; 223 224 if (hook->node->numhooks == 0) 225 ng_rmnode(hook->node); 226 else if (hook == priv->downlink) 227 priv->downlink = NULL; 228 else if (hook == priv->uplink) 229 priv->uplink = NULL; 230 else 231 panic(__func__); 232 return (0); 233 } 234 235