diff options
Diffstat (limited to 'sys/netgraph/ng_ether.c')
| -rw-r--r-- | sys/netgraph/ng_ether.c | 633 |
1 files changed, 633 insertions, 0 deletions
diff --git a/sys/netgraph/ng_ether.c b/sys/netgraph/ng_ether.c new file mode 100644 index 0000000..1df202d --- /dev/null +++ b/sys/netgraph/ng_ether.c @@ -0,0 +1,633 @@ + +/* + * 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 <archie@freebsd.org> + * Julian Elischer <julian@freebsd.org> + * + * $FreeBSD$ + */ + +/* + * ng_ether(4) netgraph node type + */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/kernel.h> +#include <sys/malloc.h> +#include <sys/mbuf.h> +#include <sys/errno.h> +#include <sys/syslog.h> +#include <sys/socket.h> + +#include <net/if.h> +#include <net/if_types.h> +#include <net/if_arp.h> +#include <net/if_var.h> +#include <net/ethernet.h> + +#include <netgraph/ng_message.h> +#include <netgraph/netgraph.h> +#include <netgraph/ng_parse.h> +#include <netgraph/ng_ether.h> + +#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 */ + NG_SEND_DATAQ(error, priv->lower, *mp, meta); + + /* Any reflected packet must come later due to queuing */ + *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 */ + 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; + + /* 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); + } + + /* 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); +} + |
