/*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1982, 1986, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following edsclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following edsclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE EDSCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON 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 ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * Discard interface driver for protocol testing and timing. * Mimics an Ethernet device so that VLANs can be attached to it etc. */ #include <sys/param.h> /* types, important constants */ #include <sys/kernel.h> /* SYSINIT for load-time initializations */ #include <sys/malloc.h> /* malloc(9) */ #include <sys/module.h> /* module(9) */ #include <sys/mbuf.h> /* mbuf(9) */ #include <sys/socket.h> /* struct ifreq */ #include <sys/sockio.h> /* socket ioctl's */ /* #include <sys/systm.h> if you need printf(9) or other all-purpose globals */ #include <net/bpf.h> /* bpf(9) */ #include <net/ethernet.h> /* Ethernet related constants and types */ #include <net/if.h> #include <net/if_var.h> /* basic part of ifnet(9) */ #include <net/if_private.h> #include <net/if_clone.h> /* network interface cloning */ #include <net/if_types.h> /* IFT_ETHER and friends */ #include <net/vnet.h> static const char edscname[] = "edsc"; /* * Software configuration of an interface specific to this device type. */ struct edsc_softc { struct ifnet *sc_ifp; /* ptr to generic interface configuration */ /* * A non-null driver can keep various things here, for instance, * the hardware revision, cached values of write-only registers, etc. */ }; /* * Attach to the interface cloning framework. */ VNET_DEFINE_STATIC(struct if_clone *, edsc_cloner); #define V_edsc_cloner VNET(edsc_cloner) static int edsc_clone_create(struct if_clone *, int, caddr_t); static void edsc_clone_destroy(struct ifnet *); /* * Interface driver methods. */ static void edsc_init(void *dummy); /* static void edsc_input(struct ifnet *ifp, struct mbuf *m); would be here */ static int edsc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data); static void edsc_start(struct ifnet *ifp); /* * We'll allocate softc instances from this. */ static MALLOC_DEFINE(M_EDSC, edscname, "Ethernet discard interface"); /* * Create an interface instance. */ static int edsc_clone_create(struct if_clone *ifc, int unit, caddr_t params) { struct edsc_softc *sc; struct ifnet *ifp; struct ether_addr eaddr; /* * Allocate soft and ifnet structures. Link each to the other. */ sc = malloc(sizeof(struct edsc_softc), M_EDSC, M_WAITOK | M_ZERO); ifp = sc->sc_ifp = if_alloc(IFT_ETHER); ifp->if_softc = sc; /* * Get a name for this particular interface in its ifnet structure. */ if_initname(ifp, edscname, unit); /* * Typical Ethernet interface flags: we can do broadcast and * multicast but can't hear our own broadcasts or multicasts. */ ifp->if_flags = IFF_BROADCAST | IFF_MULTICAST | IFF_SIMPLEX; /* * We can pretent we have the whole set of hardware features * because we just discard all packets we get from the upper layer. * However, the features are disabled initially. They can be * enabled via edsc_ioctl() when needed. */ ifp->if_capabilities = IFCAP_VLAN_MTU | IFCAP_VLAN_HWTAGGING | IFCAP_VLAN_HWCSUM | IFCAP_HWCSUM | IFCAP_TSO | IFCAP_JUMBO_MTU; ifp->if_capenable = 0; /* * Set the interface driver methods. */ ifp->if_init = edsc_init; /* ifp->if_input = edsc_input; */ ifp->if_ioctl = edsc_ioctl; ifp->if_start = edsc_start; /* * Set the maximum output queue length from the global parameter. */ ifp->if_snd.ifq_maxlen = ifqmaxlen; /* * Generate an arbitrary MAC address for the cloned interface. */ ether_gen_addr(ifp, &eaddr); /* * Do ifnet initializations common to all Ethernet drivers * and attach to the network interface framework. */ ether_ifattach(ifp, eaddr.octet); /* * Now we can mark the interface as running, i.e., ready * for operation. */ ifp->if_drv_flags |= IFF_DRV_RUNNING; return (0); } /* * Destroy an interface instance. */ static void edsc_clone_destroy(struct ifnet *ifp) { struct edsc_softc *sc = ifp->if_softc; /* * Detach from the network interface framework. */ ether_ifdetach(ifp); /* * Free memory occupied by ifnet and softc. */ if_free(ifp); free(sc, M_EDSC); } /* * This method is invoked from ether_ioctl() when it's time * to bring up the hardware. */ static void edsc_init(void *dummy) { #if 0 /* what a hardware driver would do here... */ struct edsc_soft *sc = (struct edsc_softc *)dummy; struct ifnet *ifp = sc->sc_ifp; /* blah-blah-blah */ #endif } /* * Network interfaces are controlled via the ioctl(2) syscall. */ static int edsc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) { struct ifreq *ifr = (struct ifreq *)data; switch (cmd) { case SIOCSIFCAP: #if 1 /* * Just turn on any capabilities requested. * The generic ifioctl() function has already made sure * that they are supported, i.e., set in if_capabilities. */ ifp->if_capenable = ifr->ifr_reqcap; #else /* * A h/w driver would need to analyze the requested * bits and program the hardware, e.g.: */ mask = ifp->if_capenable ^ ifr->ifr_reqcap; if (mask & IFCAP_VLAN_HWTAGGING) { ifp->if_capenable ^= IFCAP_VLAN_HWTAGGING; if (ifp->if_capenable & IFCAP_VLAN_HWTAGGING) /* blah-blah-blah */ else /* etc-etc-etc */ } #endif break; default: /* * Offload the rest onto the common Ethernet handler. */ return (ether_ioctl(ifp, cmd, data)); } return (0); } /* * Process the output queue. */ static void edsc_start(struct ifnet *ifp) { struct mbuf *m; /* * A hardware interface driver can set IFF_DRV_OACTIVE * in ifp->if_drv_flags: * * ifp->if_drv_flags |= IFF_DRV_OACTIVE; * * to prevent if_start from being invoked again while the * transmission is under way. The flag is to protect the * device's transmitter, not the method itself. The output * queue is locked and several threads can process it in * parallel safely, so the driver can use other means to * serialize access to the transmitter. * * If using IFF_DRV_OACTIVE, the driver should clear the flag * not earlier than the current transmission is complete, e.g., * upon an interrupt from the device, not just before returning * from if_start. This method merely starts the transmission, * which may proceed asynchronously. */ /* * We loop getting packets from the queue until it's empty. * A h/w driver would loop until the device can accept more * data into its buffer, or while there are free transmit * descriptors, or whatever. */ for (;;) { /* * Try to dequeue one packet. Stop if the queue is empty. * Use IF_DEQUEUE() here if ALTQ(9) support is unneeded. */ IFQ_DEQUEUE(&ifp->if_snd, m); if (m == NULL) break; /* * Let bpf(9) at the packet. */ BPF_MTAP(ifp, m); /* * Update the interface counters. */ if_inc_counter(ifp, IFCOUNTER_OBYTES, m->m_pkthdr.len); if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); /* * Finally, just drop the packet. * TODO: Reply to ARP requests unless IFF_NOARP is set. */ m_freem(m); } /* * ifp->if_drv_flags &= ~IFF_DRV_OACTIVE; * would be here only if the transmission were synchronous. */ } static void vnet_edsc_init(const void *unused __unused) { /* * Connect to the network interface cloning framework. * The last argument is the number of units to be created * from the outset. It's also the minimum number of units * allowed. We don't want any units created as soon as the * driver is loaded. */ V_edsc_cloner = if_clone_simple(edscname, edsc_clone_create, edsc_clone_destroy, 0); } VNET_SYSINIT(vnet_edsc_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, vnet_edsc_init, NULL); static void vnet_edsc_uninit(const void *unused __unused) { /* * Disconnect from the cloning framework. * Existing interfaces will be disposed of properly. */ if_clone_detach(V_edsc_cloner); } VNET_SYSUNINIT(vnet_edsc_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY, vnet_edsc_uninit, NULL); /* * This function provides handlers for module events, namely load and unload. */ static int edsc_modevent(module_t mod, int type, void *data) { switch (type) { case MOD_LOAD: case MOD_UNLOAD: break; default: /* * There are other event types, but we don't handle them. * See module(9). */ return (EOPNOTSUPP); } return (0); } static moduledata_t edsc_mod = { "if_edsc", /* name */ edsc_modevent, /* event handler */ NULL /* additional data */ }; DECLARE_MODULE(if_edsc, edsc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
