sys/netgraph7/ng_sppp.c

   1 /*
   2  * ng_sppp.c Netgraph to Sppp module.
   3  */
   4
   5 /*-
   6  * Copyright (C) 2002-2004 Cronyx Engineering.
   7  * Copyright (C) 2002-2004 Roman Kurakin <rik@cronyx.ru>
   8  *
   9  * This software is distributed with NO WARRANTIES, not even the implied
  10  * warranties for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11  *
  12  * Authors grant any other persons or organisations a permission to use,
  13  * modify and redistribute this software in source and binary forms,
  14  * as long as this message is kept with the software, all derivative
  15  * works or modified versions.
  16  *
  17  * Cronyx Id: ng_sppp.c,v 1.1.2.10 2004/03/01 15:17:21 rik Exp $
  18  *
  19  * $FreeBSD: src/sys/netgraph/ng_sppp.c,v 1.11 2006/12/29 13:59:50 jhb Exp $
  20  * $DragonFly: src/sys/netgraph7/ng_sppp.c,v 1.2 2008/06/26 23:05:35 dillon Exp $
  21  */
  22
  23 #include <sys/param.h>
  24 #include <sys/systm.h>
  25 #include <sys/errno.h>
  26 #include <sys/kernel.h>
  27 #include <sys/malloc.h>
  28 #include <sys/mbuf.h>
  29 #include <sys/errno.h>
  30 #include <sys/sockio.h>
  31 #include <sys/socket.h>
  32 #include <sys/syslog.h>
  33 #include <sys/libkern.h>
  34
  35 #include <net/if.h>
  36 #include <net/if_types.h>
  37 #include <net/bpf.h>
  38 #include <net/if_sppp.h>
  39
  40 #include <netinet/in.h>
  41
  42 #include "ng_message.h"
  43 #include "netgraph.h"
  44 #include "ng_parse.h"
  45 #include "ng_sppp.h"
  46
  47 #ifdef NG_SEPARATE_MALLOC
  48 MALLOC_DEFINE(M_NETGRAPH_SPPP, "netgraph_sppp", "netgraph sppp node ");
  49 #else
  50 #define M_NETGRAPH_SPPP M_NETGRAPH
  51 #endif
  52
  53 /* Node private data */
  54 struct ng_sppp_private {
  55         struct  ifnet *ifp;             /* Our interface */
  56         int     unit;                   /* Interface unit number */
  57         node_p  node;                   /* Our netgraph node */
  58         hook_p  hook;                   /* Hook */
  59 };
  60 typedef struct ng_sppp_private *priv_p;
  61
  62 /* Interface methods */
  63 static void     ng_sppp_start (struct ifnet *ifp);
  64 static int      ng_sppp_ioctl (struct ifnet *ifp, u_long cmd, caddr_t data);
  65
  66 /* Netgraph methods */
  67 static ng_constructor_t ng_sppp_constructor;
  68 static ng_rcvmsg_t      ng_sppp_rcvmsg;
  69 static ng_shutdown_t    ng_sppp_shutdown;
  70 static ng_newhook_t     ng_sppp_newhook;
  71 static ng_rcvdata_t     ng_sppp_rcvdata;
  72 static ng_disconnect_t  ng_sppp_disconnect;
  73
  74 /* List of commands and how to convert arguments to/from ASCII */
  75 static const struct ng_cmdlist ng_sppp_cmds[] = {
  76         {
  77           NGM_SPPP_COOKIE,
  78           NGM_SPPP_GET_IFNAME,
  79           "getifname",
  80           NULL,
  81           &ng_parse_string_type
  82         },
  83         { 0 }
  84 };
  85
  86 /* Node type descriptor */
  87 static struct ng_type typestruct = {
  88         .version =      NG_ABI_VERSION,
  89         .name =         NG_SPPP_NODE_TYPE,
  90         .constructor =  ng_sppp_constructor,
  91         .rcvmsg =       ng_sppp_rcvmsg,
  92         .shutdown =     ng_sppp_shutdown,
  93         .newhook =      ng_sppp_newhook,
  94         .rcvdata =      ng_sppp_rcvdata,
  95         .disconnect =   ng_sppp_disconnect,
  96         .cmdlist =      ng_sppp_cmds,
  97 };
  98 NETGRAPH_INIT(sppp, &typestruct);
  99
 100 MODULE_DEPEND (ng_sppp, sppp, 1, 1, 1);
 101
 102 /* We keep a bitmap indicating which unit numbers are free.
 103    Zero means the unit number is free, one means it's taken. */
 104 static unsigned char    *ng_sppp_units = NULL;
 105 static unsigned char    ng_sppp_units_len = 0;
 106 static unsigned char    ng_units_in_use = 0;
 107
 108 /*
 109  * Find the first free unit number for a new interface.
 110  * Increase the size of the unit bitmap as necessary.
 111  */
 112 static __inline int
 113 ng_sppp_get_unit (int *unit)
 114 {
 115         int index, bit;
 116         unsigned char mask;
 117
 118         for (index = 0; index < ng_sppp_units_len
 119             && ng_sppp_units[index] == 0xFF; index++);
 120         if (index == ng_sppp_units_len) {               /* extend array */
 121                 unsigned char *newarray;
 122                 int newlen;
 123
 124                 newlen = (2 * ng_sppp_units_len) + sizeof (*ng_sppp_units);
 125                 MALLOC (newarray, unsigned char *,
 126                     newlen * sizeof (*ng_sppp_units), M_NETGRAPH_SPPP, M_WAITOK | M_NULLOK);
 127                 if (newarray == NULL)
 128                         return (ENOMEM);
 129                 bcopy (ng_sppp_units, newarray,
 130                     ng_sppp_units_len * sizeof (*ng_sppp_units));
 131                 bzero (newarray + ng_sppp_units_len,
 132                     newlen - ng_sppp_units_len);
 133                 if (ng_sppp_units != NULL)
 134                         FREE (ng_sppp_units, M_NETGRAPH_SPPP);
 135                 ng_sppp_units = newarray;
 136                 ng_sppp_units_len = newlen;
 137         }
 138         mask = ng_sppp_units[index];
 139         for (bit = 0; (mask & 1) != 0; bit++)
 140                 mask >>= 1;
 141         KASSERT ((bit >= 0 && bit < NBBY),
 142             ("%s: word=%d bit=%d", __func__, ng_sppp_units[index], bit));
 143         ng_sppp_units[index] |= (1 << bit);
 144         *unit = (index * NBBY) + bit;
 145         ng_units_in_use++;
 146         return (0);
 147 }
 148
 149 /*
 150  * Free a no longer needed unit number.
 151  */
 152 static __inline void
 153 ng_sppp_free_unit (int unit)
 154 {
 155         int index, bit;
 156
 157         index = unit / NBBY;
 158         bit = unit % NBBY;
 159         KASSERT (index < ng_sppp_units_len,
 160             ("%s: unit=%d len=%d", __func__, unit, ng_sppp_units_len));
 161         KASSERT ((ng_sppp_units[index] & (1 << bit)) != 0,
 162             ("%s: unit=%d is free", __func__, unit));
 163         ng_sppp_units[index] &= ~(1 << bit);
 164
 165         ng_units_in_use--;
 166         if (ng_units_in_use == 0) {
 167                 FREE (ng_sppp_units, M_NETGRAPH_SPPP);
 168                 ng_sppp_units_len = 0;
 169                 ng_sppp_units = NULL;
 170         }
 171 }
 172
 173 /************************************************************************
 174                         INTERFACE STUFF
 175  ************************************************************************/
 176
 177 /*
 178  * Process an ioctl for the interface
 179  */
 180 static int
 181 ng_sppp_ioctl (struct ifnet *ifp, u_long command, caddr_t data)
 182 {
 183         int error = 0;
 184
 185         error = sppp_ioctl (ifp, command, data);
 186         if (error)
 187                 return error;
 188
 189         return error;
 190 }
 191
 192 /*
 193  * This routine should never be called
 194  */
 195
 196 static void
 197 ng_sppp_start (struct ifnet *ifp)
 198 {
 199         struct mbuf *m;
 200         int len, error = 0;
 201         priv_p priv = ifp->if_softc;
 202
 203         /* Check interface flags */
 204         /*
 205          * This has side effects. It is not good idea to stop sending if we
 206          * are not UP. If we are not running we still want to send LCP term
 207          * packets.
 208          */
 209 /*      if (!((ifp->if_flags & IFF_UP) && */
 210 /*          (ifp->if_drv_flags & IFF_DRV_RUNNING))) { */
 211 /*              return;*/
 212 /*      }*/
 213
 214         if (ifp->if_drv_flags & IFF_DRV_OACTIVE)
 215                 return;
 216
 217         if (!priv->hook)
 218                 return;
 219
 220         ifp->if_drv_flags |= IFF_DRV_OACTIVE;
 221
 222         while ((m = sppp_dequeue (ifp)) != NULL) {
 223                 BPF_MTAP (ifp, m);
 224                 len = m->m_pkthdr.len;
 225
 226                 NG_SEND_DATA_ONLY (error, priv->hook, m);
 227
 228                 if (error) {
 229                         ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
 230                         return;
 231                 }
 232         }
 233         ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
 234 }
 235
 236 /************************************************************************
 237                         NETGRAPH NODE STUFF
 238  ************************************************************************/
 239
 240 /*
 241  * Constructor for a node
 242  */
 243 static int
 244 ng_sppp_constructor (node_p node)
 245 {
 246         struct sppp *pp;
 247         struct ifnet *ifp;
 248         priv_p priv;
 249         int error = 0;
 250
 251         /* Allocate node and interface private structures */
 252         MALLOC (priv, priv_p, sizeof(*priv), M_NETGRAPH_SPPP, M_WAITOK | M_NULLOK | M_ZERO);
 253         if (priv == NULL)
 254                 return (ENOMEM);
 255
 256         ifp = if_alloc(IFT_PPP);
 257         if (ifp == NULL) {
 258                 FREE (priv, M_NETGRAPH_SPPP);
 259                 return (ENOSPC);
 260         }
 261         pp = IFP2SP(ifp);
 262
 263         /* Link them together */
 264         ifp->if_softc = priv;
 265         priv->ifp = ifp;
 266
 267         /* Get an interface unit number */
 268         if ((error = ng_sppp_get_unit(&priv->unit)) != 0) {
 269                 FREE (pp, M_NETGRAPH_SPPP);
 270                 FREE (priv, M_NETGRAPH_SPPP);
 271                 return (error);
 272         }
 273
 274
 275         /* Link together node and private info */
 276         NG_NODE_SET_PRIVATE (node, priv);
 277         priv->node = node;
 278
 279         /* Initialize interface structure */
 280         if_initname (SP2IFP(pp), NG_SPPP_IFACE_NAME, priv->unit);
 281         ifp->if_start = ng_sppp_start;
 282         ifp->if_ioctl = ng_sppp_ioctl;
 283         ifp->if_watchdog = NULL;
 284         ifp->if_flags = (IFF_POINTOPOINT|IFF_MULTICAST);
 285
 286         /* Give this node the same name as the interface (if possible) */
 287         if (ng_name_node(node, SP2IFP(pp)->if_xname) != 0)
 288                 log (LOG_WARNING, "%s: can't acquire netgraph name\n",
 289                     SP2IFP(pp)->if_xname);
 290
 291         /* Attach the interface */
 292         sppp_attach (ifp);
 293         if_attach (ifp);
 294         bpfattach (ifp, DLT_NULL, sizeof(u_int32_t));
 295
 296         /* Done */
 297         return (0);
 298 }
 299
 300 /*
 301  * Give our ok for a hook to be added
 302  */
 303 static int
 304 ng_sppp_newhook (node_p node, hook_p hook, const char *name)
 305 {
 306         priv_p priv = NG_NODE_PRIVATE (node);
 307
 308         if (strcmp (name, NG_SPPP_HOOK_DOWNSTREAM) != 0)
 309                 return (EINVAL);
 310
 311         if (priv->hook)
 312                 return (EISCONN);
 313
 314         priv->hook = hook;
 315         NG_HOOK_SET_PRIVATE (hook, priv);
 316
 317         return (0);
 318 }
 319
 320 /*
 321  * Receive a control message
 322  */
 323 static int
 324 ng_sppp_rcvmsg (node_p node, item_p item, hook_p lasthook)
 325 {
 326         const priv_p priv = NG_NODE_PRIVATE (node);
 327         struct ng_mesg *msg = NULL;
 328         struct ng_mesg *resp = NULL;
 329         struct sppp *const pp = IFP2SP(priv->ifp);
 330         int error = 0;
 331
 332         NGI_GET_MSG (item, msg);
 333         switch (msg->header.typecookie) {
 334         case NGM_SPPP_COOKIE:
 335                 switch (msg->header.cmd) {
 336                 case NGM_SPPP_GET_IFNAME:
 337                         NG_MKRESPONSE (resp, msg, IFNAMSIZ, M_WAITOK | M_NULLOK);
 338                         if (!resp) {
 339                                 error = ENOMEM;
 340                                 break;
 341                         }
 342                         strlcpy(resp->data, SP2IFP(pp)->if_xname, IFNAMSIZ);
 343                         break;
 344
 345                 default:
 346                         error = EINVAL;
 347                         break;
 348                 }
 349                 break;
 350         default:
 351                 error = EINVAL;
 352                 break;
 353         }
 354         NG_RESPOND_MSG (error, node, item, resp);
 355         NG_FREE_MSG (msg);
 356         return (error);
 357 }
 358
 359 /*
 360  * Recive data from a hook. Pass the packet to the correct input routine.
 361  */
 362 static int
 363 ng_sppp_rcvdata (hook_p hook, item_p item)
 364 {
 365         struct mbuf *m;
 366         const priv_p priv = NG_NODE_PRIVATE (NG_HOOK_NODE (hook));
 367         struct sppp *const pp = IFP2SP(priv->ifp);
 368
 369         NGI_GET_M (item, m);
 370         NG_FREE_ITEM (item);
 371         /* Sanity checks */
 372         KASSERT (m->m_flags & M_PKTHDR, ("%s: not pkthdr", __func__));
 373         if ((SP2IFP(pp)->if_flags & IFF_UP) == 0) {
 374                 NG_FREE_M (m);
 375                 return (ENETDOWN);
 376         }
 377
 378         /* Update interface stats */
 379         SP2IFP(pp)->if_ipackets++;
 380
 381         /* Note receiving interface */
 382         m->m_pkthdr.rcvif = SP2IFP(pp);
 383
 384         /* Berkeley packet filter */
 385         BPF_MTAP (SP2IFP(pp), m);
 386
 387         /* Send packet */
 388         sppp_input (SP2IFP(pp), m);
 389         return 0;
 390 }
 391
 392 /*
 393  * Shutdown and remove the node and its associated interface.
 394  */
 395 static int
 396 ng_sppp_shutdown (node_p node)
 397 {
 398         const priv_p priv = NG_NODE_PRIVATE(node);
 399         /* Detach from the packet filter list of interfaces. */
 400         bpfdetach (priv->ifp);
 401         sppp_detach (priv->ifp);
 402         if_detach (priv->ifp);
 403         if_free(priv->ifp);
 404         ng_sppp_free_unit (priv->unit);
 405         FREE (priv, M_NETGRAPH_SPPP);
 406         NG_NODE_SET_PRIVATE (node, NULL);
 407         NG_NODE_UNREF (node);
 408         return (0);
 409 }
 410
 411 /*
 412  * Hook disconnection.
 413  */
 414 static int
 415 ng_sppp_disconnect (hook_p hook)
 416 {
 417         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 418
 419         if (priv)
 420                 priv->hook = NULL;
 421
 422         return (0);
 423 }