/* * ng_sample.c * * Copyright (c) 1996-1999 Whistle Communications, Inc. * All rights reserved. * * Subject to the following obligations and disclaimer of warranty, use and * redistribution of this software, in source or object code forms, with or * without modifications are expressly permitted by Whistle Communications; * provided, however, that: * 1. Any and all reproductions of the source or object code must include the * copyright notice above and the following disclaimer of warranties; and * 2. No rights are granted, in any manner or form, to use Whistle * Communications, Inc. trademarks, including the mark "WHISTLE * COMMUNICATIONS" on advertising, endorsements, or otherwise except as * such appears in the above copyright notice or in the software. * * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY * OF SUCH DAMAGE. * * Author: Julian Elischer <julian@freebsd.org> * * $FreeBSD: src/sys/netgraph/ng_sample.c,v 1.7.2.3 2002/07/02 23:44:03 archie Exp $ * $Whistle: ng_sample.c,v 1.13 1999/11/01 09:24:52 julian Exp $ */ #include <sys/param.h> #include <sys/systm.h> #include <sys/kernel.h> #include <sys/mbuf.h> #include <sys/malloc.h> #include <sys/ctype.h> #include <sys/errno.h> #include <sys/syslog.h> #include <netgraph/ng_message.h> #include <netgraph/ng_parse.h> #include <netgraph/ng_sample.h> #include <netgraph/netgraph.h> /* * This section contains the netgraph method declarations for the * sample node. These methods define the netgraph 'type'. */ static ng_constructor_t ng_xxx_constructor; static ng_rcvmsg_t ng_xxx_rcvmsg; static ng_shutdown_t ng_xxx_rmnode; static ng_newhook_t ng_xxx_newhook; static ng_connect_t ng_xxx_connect; static ng_rcvdata_t ng_xxx_rcvdata; /* note these are both ng_rcvdata_t */ static ng_rcvdata_t ng_xxx_rcvdataq; /* note these are both ng_rcvdata_t */ static ng_disconnect_t ng_xxx_disconnect; /* Parse type for struct ngxxxstat */ static const struct ng_parse_struct_field ng_xxx_stat_type_fields[] = NG_XXX_STATS_TYPE_INFO; static const struct ng_parse_type ng_xxx_stat_type = { &ng_parse_struct_type, &ng_xxx_stat_type_fields }; /* List of commands and how to convert arguments to/from ASCII */ static const struct ng_cmdlist ng_xxx_cmdlist[] = { { NGM_XXX_COOKIE, NGM_XXX_GET_STATUS, "getstatus", NULL, &ng_xxx_stat_type, }, { NGM_XXX_COOKIE, NGM_XXX_SET_FLAG, "setflag", &ng_parse_int32_type, NULL }, { 0 } }; /* Netgraph node type descriptor */ static struct ng_type typestruct = { NG_VERSION, NG_XXX_NODE_TYPE, NULL, ng_xxx_constructor, ng_xxx_rcvmsg, ng_xxx_rmnode, ng_xxx_newhook, NULL, ng_xxx_connect, ng_xxx_rcvdata, ng_xxx_rcvdataq, ng_xxx_disconnect, ng_xxx_cmdlist }; NETGRAPH_INIT(xxx, &typestruct); /* Information we store for each hook on each node */ struct XXX_hookinfo { int dlci; /* The DLCI it represents, -1 == downstream */ int channel; /* The channel representing this DLCI */ hook_p hook; }; /* Information we store for each node */ struct XXX { struct XXX_hookinfo channel[XXX_NUM_DLCIS]; struct XXX_hookinfo downstream_hook; node_p node; /* back pointer to node */ hook_p debughook; u_int packets_in; /* packets in from downstream */ u_int packets_out; /* packets out towards downstream */ u_int32_t flags; }; typedef struct XXX *xxx_p; /* * Allocate the private data structure and the generic node * and link them together. * * ng_make_node_common() returns with a generic node struct * with a single reference for us.. we transfer it to the * private structure.. when we free the private struct we must * unref the node so it gets freed too. * * If this were a device node than this work would be done in the attach() * routine and the constructor would return EINVAL as you should not be able * to creatednodes that depend on hardware (unless you can add the hardware :) */ static int ng_xxx_constructor(node_p *nodep) { xxx_p privdata; int i, error; /* Initialize private descriptor */ privdata = kmalloc(sizeof(*privdata), M_NETGRAPH, M_NOWAIT | M_ZERO); if (privdata == NULL) return (ENOMEM); for (i = 0; i < XXX_NUM_DLCIS; i++) { privdata->channel[i].dlci = -2; privdata->channel[i].channel = i; } /* Call the 'generic' (ie, superclass) node constructor */ if ((error = ng_make_node_common(&typestruct, nodep))) { kfree(privdata, M_NETGRAPH); return (error); } /* Link structs together; this counts as our one reference to *nodep */ (*nodep)->private = privdata; privdata->node = *nodep; return (0); } /* * Give our ok for a hook to be added... * If we are not running this might kick a device into life. * Possibly decode information out of the hook name. * Add the hook's private info to the hook structure. * (if we had some). In this example, we assume that there is a * an array of structs, called 'channel' in the private info, * one for each active channel. The private * pointer of each hook points to the appropriate XXX_hookinfo struct * so that the source of an input packet is easily identified. * (a dlci is a frame relay channel) */ static int ng_xxx_newhook(node_p node, hook_p hook, const char *name) { const xxx_p xxxp = node->private; const char *cp; int dlci = 0; int chan; #if 0 /* Possibly start up the device if it's not already going */ if ((xxxp->flags & SCF_RUNNING) == 0) { ng_xxx_start_hardware(xxxp); } #endif /* Example of how one might use hooks with embedded numbers: All * hooks start with 'dlci' and have a decimal trailing channel * number up to 4 digits Use the leadin defined int he associated .h * file. */ if (strncmp(name, NG_XXX_HOOK_DLCI_LEADIN, strlen(NG_XXX_HOOK_DLCI_LEADIN)) == 0) { char *eptr; cp = name + sizeof(NG_XXX_HOOK_DLCI_LEADIN); if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0')) return (EINVAL); dlci = (int)strtoul(cp, &eptr, 10); if (*eptr != '\0' || dlci < 0 || dlci > 1023) return (EINVAL); /* We have a dlci, now either find it, or allocate it */ for (chan = 0; chan < XXX_NUM_DLCIS; chan++) if (xxxp->channel[chan].dlci == dlci) break; if (chan == XXX_NUM_DLCIS) { for (chan = 0; chan < XXX_NUM_DLCIS; chan++) if (xxxp->channel[chan].dlci != -2) continue; if (chan == XXX_NUM_DLCIS) return (ENOBUFS); } if (xxxp->channel[chan].hook != NULL) return (EADDRINUSE); hook->private = xxxp->channel + chan; xxxp->channel[chan].hook = hook; return (0); } else if (strcmp(name, NG_XXX_HOOK_DOWNSTREAM) == 0) { /* Example of simple predefined hooks. */ /* do something specific to the downstream connection */ xxxp->downstream_hook.hook = hook; hook->private = &xxxp->downstream_hook; } else if (strcmp(name, NG_XXX_HOOK_DEBUG) == 0) { /* do something specific to a debug connection */ xxxp->debughook = hook; hook->private = NULL; } else return (EINVAL); /* not a hook we know about */ return(0); } /* * Get a netgraph control message. * Check it is one we understand. If needed, send a response. * We could save the address for an async action later, but don't here. * Always free the message. * The response should be in a malloc'd region that the caller can 'free'. * A response is not required. * Theoretically you could respond defferently to old message types if * the cookie in the header didn't match what we consider to be current * (so that old userland programs could continue to work). */ static int ng_xxx_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr, struct ng_mesg **rptr) { const xxx_p xxxp = node->private; struct ng_mesg *resp = NULL; int error = 0; /* Deal with message according to cookie and command */ switch (msg->header.typecookie) { case NGM_XXX_COOKIE: switch (msg->header.cmd) { case NGM_XXX_GET_STATUS: { struct ngxxxstat *stats; NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT); if (!resp) { error = ENOMEM; break; } stats = (struct ngxxxstat *) resp->data; stats->packets_in = xxxp->packets_in; stats->packets_out = xxxp->packets_out; break; } case NGM_XXX_SET_FLAG: if (msg->header.arglen != sizeof(u_int32_t)) { error = EINVAL; break; } xxxp->flags = *((u_int32_t *) msg->data); break; default: error = EINVAL; /* unknown command */ break; } break; default: error = EINVAL; /* unknown cookie type */ break; } /* Take care of synchronous response, if any */ if (rptr) *rptr = resp; else if (resp) kfree(resp, M_NETGRAPH); /* Free the message and return */ kfree(msg, M_NETGRAPH); return(error); } /* * Receive data, and do something with it. * Possibly send it out on another link after processing. * Possibly do something different if it comes from different * hooks. the caller will never free m or meta, so * if we use up this data or abort we must free BOTH of these. * * If we want, we may decide to force this data to be queued and reprocessed * at the netgraph NETISR time. (at which time it will be entered using ng_xxx_rcvdataq(). */ static int ng_xxx_rcvdata(hook_p hook, struct mbuf *m, meta_p meta) { int dlci = -2; if (hook->private) { /* * If it's dlci 1023, requeue it so that it's handled * at a lower priority. This is how a node decides to * defer a data message. */ dlci = ((struct XXX_hookinfo *) hook->private)->dlci; if (dlci == 1023) { return(ng_queue_data(hook->peer, m, meta)); } } return(ng_xxx_rcvdataq(hook, m, meta)); } /* * Always accept the data. This version of rcvdata is called from the dequeueing routine. */ static int ng_xxx_rcvdataq(hook_p hook, struct mbuf *m, meta_p meta) { const xxx_p xxxp = hook->node->private; int chan = -2; int dlci = -2; int error; if (hook->private) { dlci = ((struct XXX_hookinfo *) hook->private)->dlci; chan = ((struct XXX_hookinfo *) hook->private)->channel; if (dlci != -1) { /* If received on a DLCI hook process for this * channel and pass it to the downstream module. * Normally one would add a multiplexing header at * the front here */ /* M_PREPEND(....) ; */ /* mtod(m, xxxxxx)->dlci = dlci; */ error = ng_send_data(xxxp->downstream_hook.hook, m, meta); xxxp->packets_out++; } else { /* data came from the multiplexed link */ dlci = 1; /* get dlci from header */ /* madjust(....) *//* chop off header */ for (chan = 0; chan < XXX_NUM_DLCIS; chan++) if (xxxp->channel[chan].dlci == dlci) break; if (chan == XXX_NUM_DLCIS) { NG_FREE_DATA(m, meta); return (ENETUNREACH); } /* If we were called at splnet, use the following: * NG_SEND_DATA(error, otherhook, m, meta); if this * node is running at some SPL other than SPLNET * then you should use instead: error = * ng_queueit(otherhook, m, meta); m = NULL: meta = * NULL; this queues the data using the standard * NETISR system and schedules the data to be picked * up again once the system has moved to SPLNET and * the processing of the data can continue. after * these are run 'm' and 'meta' should be considered * as invalid and NG_SEND_DATA actually zaps them. */ NG_SEND_DATA(error, xxxp->channel[chan].hook, m, meta); xxxp->packets_in++; } } else { /* It's the debug hook, throw it away.. */ if (hook == xxxp->downstream_hook.hook) NG_FREE_DATA(m, meta); } return 0; } #if 0 /* * If this were a device node, the data may have been received in response * to some interrupt. * in which case it would probably look as follows: */ void devintr(void) { meta_p meta = NULL; /* whatever metadata we might imagine goes * here */ /* get packet from device and send on */ m = MGET(blah blah) error = ng_queueit(upstream, m, meta); /* see note above in * xxx_rcvdata() */ } #endif /* 0 */ /* * Do local shutdown processing.. * If we are a persistant device, we might refuse to go away, and * we'd only remove our links and reset ourself. */ static int ng_xxx_rmnode(node_p node) { const xxx_p privdata = node->private; node->flags |= NG_INVALID; ng_cutlinks(node); #ifndef PERSISTANT_NODE ng_unname(node); node->private = NULL; ng_unref(privdata->node); kfree(privdata, M_NETGRAPH); #else privdata->packets_in = 0; /* reset stats */ privdata->packets_out = 0; node->flags &= ~NG_INVALID; /* reset invalid flag */ #endif /* PERSISTANT_NODE */ return (0); } /* * This is called once we've already connected a new hook to the other node. * It gives us a chance to balk at the last minute. */ static int ng_xxx_connect(hook_p hook) { /* be really amiable and just say "YUP that's OK by me! " */ return (0); } /* * Dook disconnection * * For this type, removal of the last link destroys the node */ static int ng_xxx_disconnect(hook_p hook) { if (hook->private) ((struct XXX_hookinfo *) (hook->private))->hook = NULL; if (hook->node->numhooks == 0) ng_rmnode(hook->node); return (0); }
