/* * ng_ether.c * * Copyright (c) 1996-2000 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. * * Authors: Archie Cobbs * Julian Elischer * * $FreeBSD$ */ /* * ng_ether(4) netgraph node type */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define IFP2AC(IFP) ((struct arpcom *)IFP) #define IFP2NG(ifp) ((struct ng_node *)((struct arpcom *)(ifp))->ac_netgraph) /* Per-node private data */ struct private { struct ifnet *ifp; /* associated interface */ hook_p upper; /* upper hook connection */ hook_p lower; /* lower OR orphan hook connection */ u_char lowerOrphan; /* whether lower is lower or orphan */ }; typedef struct private *priv_p; /* Functional hooks called from if_ethersubr.c */ static void ng_ether_input(struct ifnet *ifp, struct mbuf **mp, struct ether_header *eh); static void ng_ether_input_orphan(struct ifnet *ifp, struct mbuf *m, struct ether_header *eh); static int ng_ether_output(struct ifnet *ifp, struct mbuf **mp); static void ng_ether_attach(struct ifnet *ifp); static void ng_ether_detach(struct ifnet *ifp); /* Other functions */ static void ng_ether_input2(node_p node, struct mbuf **mp, struct ether_header *eh); static int ng_ether_glueback_header(struct mbuf **mp, struct ether_header *eh); static int ng_ether_rcv_lower(node_p node, struct mbuf *m, meta_p meta); static int ng_ether_rcv_upper(node_p node, struct mbuf *m, meta_p meta); /* Netgraph node methods */ static ng_constructor_t ng_ether_constructor; static ng_rcvmsg_t ng_ether_rcvmsg; static ng_shutdown_t ng_ether_rmnode; static ng_newhook_t ng_ether_newhook; static ng_rcvdata_t ng_ether_rcvdata; static ng_disconnect_t ng_ether_disconnect; static int ng_ether_mod_event(module_t mod, int event, void *data); /* List of commands and how to convert arguments to/from ASCII */ static const struct ng_cmdlist ng_ether_cmdlist[] = { { NGM_ETHER_COOKIE, NGM_ETHER_GET_IFNAME, "getifname", NULL, &ng_parse_string_type }, { NGM_ETHER_COOKIE, NGM_ETHER_GET_IFINDEX, "getifindex", NULL, &ng_parse_int32_type }, { 0 } }; static struct ng_type ng_ether_typestruct = { NG_VERSION, NG_ETHER_NODE_TYPE, ng_ether_mod_event, ng_ether_constructor, ng_ether_rcvmsg, ng_ether_rmnode, ng_ether_newhook, NULL, NULL, ng_ether_rcvdata, ng_ether_rcvdata, ng_ether_disconnect, ng_ether_cmdlist, }; NETGRAPH_INIT(ether, &ng_ether_typestruct); /****************************************************************** ETHERNET FUNCTION HOOKS ******************************************************************/ /* * Handle a packet that has come in on an interface. We get to * look at it here before any upper layer protocols do. * * NOTE: this function will get called at splimp() */ static void ng_ether_input(struct ifnet *ifp, struct mbuf **mp, struct ether_header *eh) { const node_p node = IFP2NG(ifp); const priv_p priv = node->private; /* If "lower" hook not connected, let packet continue */ if (priv->lower == NULL || priv->lowerOrphan) return; ng_ether_input2(node, mp, eh); } /* * Handle a packet that has come in on an interface, and which * does not match any of our known protocols (an ``orphan''). * * NOTE: this function will get called at splimp() */ static void ng_ether_input_orphan(struct ifnet *ifp, struct mbuf *m, struct ether_header *eh) { const node_p node = IFP2NG(ifp); const priv_p priv = node->private; /* If "orphan" hook not connected, let packet continue */ if (priv->lower == NULL || !priv->lowerOrphan) { m_freem(m); return; } ng_ether_input2(node, &m, eh); if (m != NULL) m_freem(m); } /* * Handle a packet that has come in on an interface. * The Ethernet header has already been detached from the mbuf, * so we have to put it back. * * NOTE: this function will get called at splimp() */ static void ng_ether_input2(node_p node, struct mbuf **mp, struct ether_header *eh) { const priv_p priv = node->private; meta_p meta = NULL; int error; /* Glue Ethernet header back on */ if ((error = ng_ether_glueback_header(mp, eh)) != 0) return; /* Send out lower/orphan hook */ (void)ng_queue_data(priv->lower, *mp, meta); *mp = NULL; } /* * Handle a packet that is going out on an interface. * The Ethernet header is already attached to the mbuf. */ static int ng_ether_output(struct ifnet *ifp, struct mbuf **mp) { const node_p node = IFP2NG(ifp); const priv_p priv = node->private; meta_p meta = NULL; int error = 0; /* If "upper" hook not connected, let packet continue */ if (priv->upper == NULL) return (0); /* Send it out "upper" hook */ NG_SEND_DATA_RET(error, priv->upper, *mp, meta); /* If we got a reflected packet back, handle it */ if (error == 0 && *mp != NULL) { error = ng_ether_rcv_upper(node, *mp, meta); *mp = NULL; } return (error); } /* * A new Ethernet interface has been attached. * Create a new node for it, etc. */ static void ng_ether_attach(struct ifnet *ifp) { char name[IFNAMSIZ + 1]; priv_p priv; node_p node; /* Create node */ KASSERT(!IFP2NG(ifp), ("%s: node already exists?", __FUNCTION__)); snprintf(name, sizeof(name), "%s%d", ifp->if_name, ifp->if_unit); if (ng_make_node_common(&ng_ether_typestruct, &node) != 0) { log(LOG_ERR, "%s: can't %s for %s\n", __FUNCTION__, "create node", name); return; } /* Allocate private data */ MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT); if (priv == NULL) { log(LOG_ERR, "%s: can't %s for %s\n", __FUNCTION__, "allocate memory", name); ng_unref(node); return; } bzero(priv, sizeof(*priv)); node->private = priv; priv->ifp = ifp; IFP2NG(ifp) = node; /* Try to give the node the same name as the interface */ if (ng_name_node(node, name) != 0) { log(LOG_WARNING, "%s: can't name node %s\n", __FUNCTION__, name); } } /* * An Ethernet interface is being detached. * Destroy its node. */ static void ng_ether_detach(struct ifnet *ifp) { const node_p node = IFP2NG(ifp); priv_p priv; if (node == NULL) /* no node (why not?), ignore */ return; ng_rmnode(node); /* break all links to other nodes */ node->flags |= NG_INVALID; ng_unname(node); /* free name (and its reference) */ IFP2NG(ifp) = NULL; /* detach node from interface */ priv = node->private; /* free node private info */ bzero(priv, sizeof(*priv)); FREE(priv, M_NETGRAPH); node->private = NULL; ng_unref(node); /* free node itself */ } /* * Optimization for gluing the Ethernet header back onto * the front of an incoming packet. */ static int ng_ether_glueback_header(struct mbuf **mp, struct ether_header *eh) { struct mbuf *m = *mp; uintfptr_t room; int error = 0; /* * Possibly the header is already on the front. * If this is the case so just move the markers back * to re-include it. We lucked out. * This allows us to avoid a yucky m_pullup * in later nodes if it works. */ if (eh == mtod(m, struct ether_header *) - 1) { m->m_len += sizeof(*eh); m->m_data -= sizeof(*eh); m->m_pkthdr.len += sizeof(*eh); goto done; } /* * Alternatively there may be room even though * it is stored somewhere else. If so, copy it in. * This only safe because we KNOW that this packet has * just been generated by an ethernet card, so there are * no aliases to the buffer (not so for outgoing packets). * Nearly all ethernet cards will end up producing mbufs * that fall into these cases. So we are not optimizing * contorted cases. */ if ((m->m_flags & M_EXT) != 0) { room = mtod(m, caddr_t) - m->m_ext.ext_buf; if (room > m->m_ext.ext_size) /* garbage, fail immediately */ room = 0; } else room = mtod(m, caddr_t) - m->m_pktdat; /* * If we have room, just copy it and adjust */ if (room >= sizeof(*eh)) { m->m_len += sizeof(*eh); m->m_data -= sizeof(*eh); m->m_pkthdr.len += sizeof(*eh); goto copy; } /* * Doing anything more is likely to get more * expensive than it's worth.. * it's probable that everything else is in one * big lump. The next node will do an m_pullup() * for exactly the amount of data it needs and * hopefully everything after that will not * need one. So let's just use M_PREPEND. */ M_PREPEND(m, sizeof (*eh), M_DONTWAIT); if (m == NULL) { error = ENOBUFS; goto done; } copy: /* Copy header and return (possibly new) mbuf */ bcopy((caddr_t)eh, mtod(m, struct ether_header *), sizeof(*eh)); done: *mp = m; return error; } /****************************************************************** NETGRAPH NODE METHODS ******************************************************************/ /* * It is not possible or allowable to create a node of this type. * Nodes get created when the interface is attached (or, when * this node type's KLD is loaded). */ static int ng_ether_constructor(node_p *nodep) { return (EINVAL); } /* * Check for attaching a new hook. */ static int ng_ether_newhook(node_p node, hook_p hook, const char *name) { const priv_p priv = node->private; u_char orphan = priv->lowerOrphan; hook_p *hookptr; /* Divert hook is an alias for lower */ if (strcmp(name, NG_ETHER_HOOK_DIVERT) == 0) name = NG_ETHER_HOOK_LOWER; /* Which hook? */ if (strcmp(name, NG_ETHER_HOOK_UPPER) == 0) hookptr = &priv->upper; else if (strcmp(name, NG_ETHER_HOOK_LOWER) == 0) { hookptr = &priv->lower; orphan = 0; } else if (strcmp(name, NG_ETHER_HOOK_ORPHAN) == 0) { hookptr = &priv->lower; orphan = 1; } else return (EINVAL); /* Check if already connected (shouldn't be, but doesn't hurt) */ if (*hookptr != NULL) return (EISCONN); /* OK */ *hookptr = hook; priv->lowerOrphan = orphan; return (0); } /* * Receive an incoming control message. */ static int ng_ether_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr, struct ng_mesg **rptr, hook_p lasthook) { const priv_p priv = node->private; struct ng_mesg *resp = NULL; int error = 0; switch (msg->header.typecookie) { case NGM_ETHER_COOKIE: switch (msg->header.cmd) { case NGM_ETHER_GET_IFNAME: NG_MKRESPONSE(resp, msg, IFNAMSIZ + 1, M_NOWAIT); if (resp == NULL) { error = ENOMEM; break; } snprintf(resp->data, IFNAMSIZ + 1, "%s%d", priv->ifp->if_name, priv->ifp->if_unit); break; case NGM_ETHER_GET_IFINDEX: NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT); if (resp == NULL) { error = ENOMEM; break; } *((u_int32_t *)resp->data) = priv->ifp->if_index; break; default: error = EINVAL; break; } break; default: error = EINVAL; break; } if (rptr) *rptr = resp; else if (resp != NULL) FREE(resp, M_NETGRAPH); FREE(msg, M_NETGRAPH); return (error); } /* * Receive data on a hook. */ static int ng_ether_rcvdata(hook_p hook, struct mbuf *m, meta_p meta, struct mbuf **ret_m, meta_p *ret_meta) { const node_p node = hook->node; const priv_p priv = node->private; if (hook == priv->lower) return ng_ether_rcv_lower(node, m, meta); if (hook == priv->upper) return ng_ether_rcv_upper(node, m, meta); panic("%s: weird hook", __FUNCTION__); } /* * Handle an mbuf received on the "lower" hook. */ static int ng_ether_rcv_lower(node_p node, struct mbuf *m, meta_p meta) { const priv_p priv = node->private; struct ether_header *eh; /* Make sure header is fully pulled up */ if (m->m_pkthdr.len < sizeof(struct ether_header)) { NG_FREE_DATA(m, meta); return (EINVAL); } if (m->m_len < sizeof(struct ether_header) && (m = m_pullup(m, sizeof(struct ether_header))) == NULL) { NG_FREE_META(meta); return (ENOBUFS); } /* drop in the MAC address */ eh = mtod(m, struct ether_header *); bcopy((IFP2AC(priv->ifp))->ac_enaddr, eh->ether_shost, 6); /* Send it on its way */ NG_FREE_META(meta); return ether_output_frame(priv->ifp, m); } /* * Handle an mbuf received on the "upper" hook. */ static int ng_ether_rcv_upper(node_p node, struct mbuf *m, meta_p meta) { const priv_p priv = node->private; struct ether_header *eh; /* Check length and pull off header */ if (m->m_pkthdr.len < sizeof(*eh)) { NG_FREE_DATA(m, meta); return (EINVAL); } if (m->m_len < sizeof(*eh) && (m = m_pullup(m, sizeof(*eh))) == NULL) { NG_FREE_META(meta); return (ENOBUFS); } eh = mtod(m, struct ether_header *); m->m_data += sizeof(*eh); m->m_len -= sizeof(*eh); m->m_pkthdr.len -= sizeof(*eh); /* Route packet back in */ NG_FREE_META(meta); ether_demux(priv->ifp, eh, m); return (0); } /* * Shutdown node. This resets the node but does not remove it. */ static int ng_ether_rmnode(node_p node) { ng_cutlinks(node); node->flags &= ~NG_INVALID; /* bounce back to life */ return (0); } /* * Hook disconnection. */ static int ng_ether_disconnect(hook_p hook) { const priv_p priv = hook->node->private; if (hook == priv->upper) priv->upper = NULL; else if (hook == priv->lower) { priv->lower = NULL; priv->lowerOrphan = 0; } else panic("%s: weird hook", __FUNCTION__); return (0); } /****************************************************************** INITIALIZATION ******************************************************************/ /* * Handle loading and unloading for this node type. */ static int ng_ether_mod_event(module_t mod, int event, void *data) { struct ifnet *ifp; int error = 0; int s; s = splnet(); switch (event) { case MOD_LOAD: /* Register function hooks */ if (ng_ether_attach_p != NULL) { error = EEXIST; break; } ng_ether_attach_p = ng_ether_attach; ng_ether_detach_p = ng_ether_detach; ng_ether_output_p = ng_ether_output; ng_ether_input_p = ng_ether_input; ng_ether_input_orphan_p = ng_ether_input_orphan; /* Create nodes for any already-existing Ethernet interfaces */ TAILQ_FOREACH(ifp, &ifnet, if_link) { if (ifp->if_type == IFT_ETHER) ng_ether_attach(ifp); } break; case MOD_UNLOAD: /* * Note that the base code won't try to unload us until * all nodes have been removed, and that can't happen * until all Ethernet interfaces are removed. In any * case, we know there are no nodes left if the action * is MOD_UNLOAD, so there's no need to detach any nodes. */ /* Unregister function hooks */ ng_ether_attach_p = NULL; ng_ether_detach_p = NULL; ng_ether_output_p = NULL; ng_ether_input_p = NULL; ng_ether_input_orphan_p = NULL; break; default: error = EOPNOTSUPP; break; } splx(s); return (error); }