The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/netgraph/ng_sample.c

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    1 /*
    2  * ng_sample.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: releng/11.0/sys/netgraph/ng_sample.c 298813 2016-04-29 21:25:05Z pfg $
   41  * $Whistle: ng_sample.c,v 1.13 1999/11/01 09:24:52 julian Exp $
   42  */
   43 
   44 #include <sys/param.h>
   45 #include <sys/systm.h>
   46 #include <sys/kernel.h>
   47 #include <sys/mbuf.h>
   48 #include <sys/malloc.h>
   49 #include <sys/ctype.h>
   50 #include <sys/errno.h>
   51 #include <sys/syslog.h>
   52 
   53 #include <netgraph/ng_message.h>
   54 #include <netgraph/ng_parse.h>
   55 #include <netgraph/ng_sample.h>
   56 #include <netgraph/netgraph.h>
   57 
   58 /* If you do complicated mallocs you may want to do this */
   59 /* and use it for your mallocs */
   60 #ifdef NG_SEPARATE_MALLOC
   61 static MALLOC_DEFINE(M_NETGRAPH_XXX, "netgraph_xxx", "netgraph xxx node");
   62 #else
   63 #define M_NETGRAPH_XXX M_NETGRAPH
   64 #endif
   65 
   66 /*
   67  * This section contains the netgraph method declarations for the
   68  * sample node. These methods define the netgraph 'type'.
   69  */
   70 
   71 static ng_constructor_t ng_xxx_constructor;
   72 static ng_rcvmsg_t      ng_xxx_rcvmsg;
   73 static ng_shutdown_t    ng_xxx_shutdown;
   74 static ng_newhook_t     ng_xxx_newhook;
   75 static ng_connect_t     ng_xxx_connect;
   76 static ng_rcvdata_t     ng_xxx_rcvdata;
   77 static ng_disconnect_t  ng_xxx_disconnect;
   78 
   79 /* Parse type for struct ngxxxstat */
   80 static const struct ng_parse_struct_field ng_xxx_stat_type_fields[]
   81         = NG_XXX_STATS_TYPE_INFO;
   82 static const struct ng_parse_type ng_xxx_stat_type = {
   83         &ng_parse_struct_type,
   84         &ng_xxx_stat_type_fields
   85 };
   86 
   87 /* List of commands and how to convert arguments to/from ASCII */
   88 static const struct ng_cmdlist ng_xxx_cmdlist[] = {
   89         {
   90           NGM_XXX_COOKIE,
   91           NGM_XXX_GET_STATUS,
   92           "getstatus",
   93           NULL,
   94           &ng_xxx_stat_type,
   95         },
   96         {
   97           NGM_XXX_COOKIE,
   98           NGM_XXX_SET_FLAG,
   99           "setflag",
  100           &ng_parse_int32_type,
  101           NULL
  102         },
  103         { 0 }
  104 };
  105 
  106 /* Netgraph node type descriptor */
  107 static struct ng_type typestruct = {
  108         .version =      NG_ABI_VERSION,
  109         .name =         NG_XXX_NODE_TYPE,
  110         .constructor =  ng_xxx_constructor,
  111         .rcvmsg =       ng_xxx_rcvmsg,
  112         .shutdown =     ng_xxx_shutdown,
  113         .newhook =      ng_xxx_newhook,
  114 /*      .findhook =     ng_xxx_findhook,        */
  115         .connect =      ng_xxx_connect,
  116         .rcvdata =      ng_xxx_rcvdata,
  117         .disconnect =   ng_xxx_disconnect,
  118         .cmdlist =      ng_xxx_cmdlist,
  119 };
  120 NETGRAPH_INIT(xxx, &typestruct);
  121 
  122 /* Information we store for each hook on each node */
  123 struct XXX_hookinfo {
  124         int     dlci;           /* The DLCI it represents, -1 == downstream */
  125         int     channel;        /* The channel representing this DLCI */
  126         hook_p  hook;
  127 };
  128 
  129 /* Information we store for each node */
  130 struct XXX {
  131         struct XXX_hookinfo channel[XXX_NUM_DLCIS];
  132         struct XXX_hookinfo downstream_hook;
  133         node_p          node;           /* back pointer to node */
  134         hook_p          debughook;
  135         u_int           packets_in;     /* packets in from downstream */
  136         u_int           packets_out;    /* packets out towards downstream */
  137         u_int32_t       flags;
  138 };
  139 typedef struct XXX *xxx_p;
  140 
  141 /*
  142  * Allocate the private data structure. The generic node has already
  143  * been created. Link them together. We arrive with a reference to the node
  144  * i.e. the reference count is incremented for us already.
  145  *
  146  * If this were a device node than this work would be done in the attach()
  147  * routine and the constructor would return EINVAL as you should not be able
  148  * to creatednodes that depend on hardware (unless you can add the hardware :)
  149  */
  150 static int
  151 ng_xxx_constructor(node_p node)
  152 {
  153         xxx_p privdata;
  154         int i;
  155 
  156         /* Initialize private descriptor */
  157         privdata = malloc(sizeof(*privdata), M_NETGRAPH, M_WAITOK | M_ZERO);
  158         for (i = 0; i < XXX_NUM_DLCIS; i++) {
  159                 privdata->channel[i].dlci = -2;
  160                 privdata->channel[i].channel = i;
  161         }
  162 
  163         /* Link structs together; this counts as our one reference to *nodep */
  164         NG_NODE_SET_PRIVATE(node, privdata);
  165         privdata->node = node;
  166         return (0);
  167 }
  168 
  169 /*
  170  * Give our ok for a hook to be added...
  171  * If we are not running this might kick a device into life.
  172  * Possibly decode information out of the hook name.
  173  * Add the hook's private info to the hook structure.
  174  * (if we had some). In this example, we assume that there is a
  175  * an array of structs, called 'channel' in the private info,
  176  * one for each active channel. The private
  177  * pointer of each hook points to the appropriate XXX_hookinfo struct
  178  * so that the source of an input packet is easily identified.
  179  * (a dlci is a frame relay channel)
  180  */
  181 static int
  182 ng_xxx_newhook(node_p node, hook_p hook, const char *name)
  183 {
  184         const xxx_p xxxp = NG_NODE_PRIVATE(node);
  185         const char *cp;
  186         int dlci = 0;
  187         int chan;
  188 
  189 #if 0
  190         /* Possibly start up the device if it's not already going */
  191         if ((xxxp->flags & SCF_RUNNING) == 0) {
  192                 ng_xxx_start_hardware(xxxp);
  193         }
  194 #endif
  195 
  196         /* Example of how one might use hooks with embedded numbers: All
  197          * hooks start with 'dlci' and have a decimal trailing channel
  198          * number up to 4 digits Use the leadin defined int he associated .h
  199          * file. */
  200         if (strncmp(name,
  201             NG_XXX_HOOK_DLCI_LEADIN, strlen(NG_XXX_HOOK_DLCI_LEADIN)) == 0) {
  202                 char *eptr;
  203 
  204                 cp = name + strlen(NG_XXX_HOOK_DLCI_LEADIN);
  205                 if (!isdigit(*cp) || (cp[0] == '' && cp[1] != '\0'))
  206                         return (EINVAL);
  207                 dlci = (int)strtoul(cp, &eptr, 10);
  208                 if (*eptr != '\0' || dlci < 0 || dlci > 1023)
  209                         return (EINVAL);
  210 
  211                 /* We have a dlci, now either find it, or allocate it */
  212                 for (chan = 0; chan < XXX_NUM_DLCIS; chan++)
  213                         if (xxxp->channel[chan].dlci == dlci)
  214                                 break;
  215                 if (chan == XXX_NUM_DLCIS) {
  216                         for (chan = 0; chan < XXX_NUM_DLCIS; chan++)
  217                                 if (xxxp->channel[chan].dlci == -2)
  218                                         break;
  219                         if (chan == XXX_NUM_DLCIS)
  220                                 return (ENOBUFS);
  221                         xxxp->channel[chan].dlci = dlci;
  222                 }
  223                 if (xxxp->channel[chan].hook != NULL)
  224                         return (EADDRINUSE);
  225                 NG_HOOK_SET_PRIVATE(hook, xxxp->channel + chan);
  226                 xxxp->channel[chan].hook = hook;
  227                 return (0);
  228         } else if (strcmp(name, NG_XXX_HOOK_DOWNSTREAM) == 0) {
  229                 /* Example of simple predefined hooks. */
  230                 /* do something specific to the downstream connection */
  231                 xxxp->downstream_hook.hook = hook;
  232                 NG_HOOK_SET_PRIVATE(hook, &xxxp->downstream_hook);
  233         } else if (strcmp(name, NG_XXX_HOOK_DEBUG) == 0) {
  234                 /* do something specific to a debug connection */
  235                 xxxp->debughook = hook;
  236                 NG_HOOK_SET_PRIVATE(hook, NULL);
  237         } else
  238                 return (EINVAL);        /* not a hook we know about */
  239         return(0);
  240 }
  241 
  242 /*
  243  * Get a netgraph control message.
  244  * We actually receive a queue item that has a pointer to the message.
  245  * If we free the item, the message will be freed too, unless we remove
  246  * it from the item using NGI_GET_MSG();
  247  * The return address is also stored in the item, as an ng_ID_t,
  248  * accessible as NGI_RETADDR(item);
  249  * Check it is one we understand. If needed, send a response.
  250  * We could save the address for an async action later, but don't here.
  251  * Always free the message.
  252  * The response should be in a malloc'd region that the caller can 'free'.
  253  * A response is not required.
  254  * Theoretically you could respond defferently to old message types if
  255  * the cookie in the header didn't match what we consider to be current
  256  * (so that old userland programs could continue to work).
  257  */
  258 static int
  259 ng_xxx_rcvmsg(node_p node, item_p item, hook_p lasthook)
  260 {
  261         const xxx_p xxxp = NG_NODE_PRIVATE(node);
  262         struct ng_mesg *resp = NULL;
  263         int error = 0;
  264         struct ng_mesg *msg;
  265 
  266         NGI_GET_MSG(item, msg);
  267         /* Deal with message according to cookie and command */
  268         switch (msg->header.typecookie) {
  269         case NGM_XXX_COOKIE:
  270                 switch (msg->header.cmd) {
  271                 case NGM_XXX_GET_STATUS:
  272                     {
  273                         struct ngxxxstat *stats;
  274 
  275                         NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
  276                         if (!resp) {
  277                                 error = ENOMEM;
  278                                 break;
  279                         }
  280                         stats = (struct ngxxxstat *) resp->data;
  281                         stats->packets_in = xxxp->packets_in;
  282                         stats->packets_out = xxxp->packets_out;
  283                         break;
  284                     }
  285                 case NGM_XXX_SET_FLAG:
  286                         if (msg->header.arglen != sizeof(u_int32_t)) {
  287                                 error = EINVAL;
  288                                 break;
  289                         }
  290                         xxxp->flags = *((u_int32_t *) msg->data);
  291                         break;
  292                 default:
  293                         error = EINVAL;         /* unknown command */
  294                         break;
  295                 }
  296                 break;
  297         default:
  298                 error = EINVAL;                 /* unknown cookie type */
  299                 break;
  300         }
  301 
  302         /* Take care of synchronous response, if any */
  303         NG_RESPOND_MSG(error, node, item, resp);
  304         /* Free the message and return */
  305         NG_FREE_MSG(msg);
  306         return(error);
  307 }
  308 
  309 /*
  310  * Receive data, and do something with it.
  311  * Actually we receive a queue item which holds the data.
  312  * If we free the item it will also free the data unless we have
  313  * previously disassociated it using the NGI_GET_M() macro.
  314  * Possibly send it out on another link after processing.
  315  * Possibly do something different if it comes from different
  316  * hooks. The caller will never free m, so if we use up this data or
  317  * abort we must free it.
  318  *
  319  * If we want, we may decide to force this data to be queued and reprocessed
  320  * at the netgraph NETISR time.
  321  * We would do that by setting the HK_QUEUE flag on our hook. We would do that
  322  * in the connect() method.
  323  */
  324 static int
  325 ng_xxx_rcvdata(hook_p hook, item_p item )
  326 {
  327         const xxx_p xxxp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
  328         int chan = -2;
  329         int dlci = -2;
  330         int error;
  331         struct mbuf *m;
  332 
  333         NGI_GET_M(item, m);
  334         if (NG_HOOK_PRIVATE(hook)) {
  335                 dlci = ((struct XXX_hookinfo *) NG_HOOK_PRIVATE(hook))->dlci;
  336                 chan = ((struct XXX_hookinfo *) NG_HOOK_PRIVATE(hook))->channel;
  337                 if (dlci != -1) {
  338                         /* If received on a DLCI hook process for this
  339                          * channel and pass it to the downstream module.
  340                          * Normally one would add a multiplexing header at
  341                          * the front here */
  342                         /* M_PREPEND(....)      ; */
  343                         /* mtod(m, xxxxxx)->dlci = dlci; */
  344                         NG_FWD_NEW_DATA(error, item,
  345                                 xxxp->downstream_hook.hook, m);
  346                         xxxp->packets_out++;
  347                 } else {
  348                         /* data came from the multiplexed link */
  349                         dlci = 1;       /* get dlci from header */
  350                         /* madjust(....) *//* chop off header */
  351                         for (chan = 0; chan < XXX_NUM_DLCIS; chan++)
  352                                 if (xxxp->channel[chan].dlci == dlci)
  353                                         break;
  354                         if (chan == XXX_NUM_DLCIS) {
  355                                 NG_FREE_ITEM(item);
  356                                 NG_FREE_M(m);
  357                                 return (ENETUNREACH);
  358                         }
  359                         /* If we were called at splnet, use the following:
  360                          * NG_SEND_DATA_ONLY(error, otherhook, m); if this
  361                          * node is running at some SPL other than SPLNET
  362                          * then you should use instead: error =
  363                          * ng_queueit(otherhook, m, NULL); m = NULL;
  364                          * This queues the data using the standard NETISR
  365                          * system and schedules the data to be picked
  366                          * up again once the system has moved to SPLNET and
  367                          * the processing of the data can continue. After
  368                          * these are run 'm' should be considered
  369                          * as invalid and NG_SEND_DATA actually zaps them. */
  370                         NG_FWD_NEW_DATA(error, item,
  371                                 xxxp->channel[chan].hook, m);
  372                         xxxp->packets_in++;
  373                 }
  374         } else {
  375                 /* It's the debug hook, throw it away.. */
  376                 if (hook == xxxp->downstream_hook.hook) {
  377                         NG_FREE_ITEM(item);
  378                         NG_FREE_M(m);
  379                 }
  380         }
  381         return 0;
  382 }
  383 
  384 #if 0
  385 /*
  386  * If this were a device node, the data may have been received in response
  387  * to some interrupt.
  388  * in which case it would probably look as follows:
  389  */
  390 devintr()
  391 {
  392         int error;
  393 
  394         /* get packet from device and send on */
  395         m = MGET(blah blah)
  396         
  397         NG_SEND_DATA_ONLY(error, xxxp->upstream_hook.hook, m);
  398                                 /* see note above in xxx_rcvdata() */
  399                                 /* and ng_xxx_connect() */
  400 }
  401 
  402 #endif                          /* 0 */
  403 
  404 /*
  405  * Do local shutdown processing..
  406  * All our links and the name have already been removed.
  407  * If we are a persistent device, we might refuse to go away.
  408  * In the case of a persistent node we signal the framework that we
  409  * are still in business by clearing the NGF_INVALID bit. However
  410  * If we find the NGF_REALLY_DIE bit set, this means that
  411  * we REALLY need to die (e.g. hardware removed).
  412  * This would have been set using the NG_NODE_REALLY_DIE(node)
  413  * macro in some device dependent function (not shown here) before
  414  * calling ng_rmnode_self().
  415  */
  416 static int
  417 ng_xxx_shutdown(node_p node)
  418 {
  419         const xxx_p privdata = NG_NODE_PRIVATE(node);
  420 
  421 #ifndef PERSISTANT_NODE
  422         NG_NODE_SET_PRIVATE(node, NULL);
  423         NG_NODE_UNREF(node);
  424         free(privdata, M_NETGRAPH);
  425 #else
  426         if (node->nd_flags & NGF_REALLY_DIE) {
  427                 /*
  428                  * WE came here because the widget card is being unloaded,
  429                  * so stop being persistent.
  430                  * Actually undo all the things we did on creation.
  431                  */
  432                 NG_NODE_SET_PRIVATE(node, NULL);
  433                 NG_NODE_UNREF(privdata->node);
  434                 free(privdata, M_NETGRAPH);
  435                 return (0);
  436         }
  437         NG_NODE_REVIVE(node);           /* tell ng_rmnode() we will persist */
  438 #endif /* PERSISTANT_NODE */
  439         return (0);
  440 }
  441 
  442 /*
  443  * This is called once we've already connected a new hook to the other node.
  444  * It gives us a chance to balk at the last minute.
  445  */
  446 static int
  447 ng_xxx_connect(hook_p hook)
  448 {
  449 #if 0
  450         /*
  451          * If we were a driver running at other than splnet then
  452          * we should set the QUEUE bit on the edge so that we
  453          * will deliver by queing.
  454          */
  455         if /*it is the upstream hook */
  456         NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook));
  457 #endif
  458 #if 0
  459         /*
  460          * If for some reason we want incoming date to be queued
  461          * by the NETISR system and delivered later we can set the same bit on
  462          * OUR hook. (maybe to allow unwinding of the stack)
  463          */
  464 
  465         if (NG_HOOK_PRIVATE(hook)) {
  466                 int dlci;
  467                 /*
  468                  * If it's dlci 1023, requeue it so that it's handled
  469                  * at a lower priority. This is how a node decides to
  470                  * defer a data message.
  471                  */
  472                 dlci = ((struct XXX_hookinfo *) NG_HOOK_PRIVATE(hook))->dlci;
  473                 if (dlci == 1023) {
  474                         NG_HOOK_FORCE_QUEUE(hook);
  475                 }
  476 #endif
  477         /* otherwise be really amiable and just say "YUP that's OK by me! " */
  478         return (0);
  479 }
  480 
  481 /*
  482  * Hook disconnection
  483  *
  484  * For this type, removal of the last link destroys the node
  485  */
  486 static int
  487 ng_xxx_disconnect(hook_p hook)
  488 {
  489         if (NG_HOOK_PRIVATE(hook))
  490                 ((struct XXX_hookinfo *) (NG_HOOK_PRIVATE(hook)))->hook = NULL;
  491         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
  492         && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) /* already shutting down? */
  493                 ng_rmnode_self(NG_HOOK_NODE(hook));
  494         return (0);
  495 }
  496 

Cache object: c6006c6675cc9c5eac89988c176569a8


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.