[apple/xnu.git] / bsd / net / ether_if_module.c

/*
 * Copyright (c) 2000-2013 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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 * Please see the License for the specific language governing rights and
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 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1982, 1989, 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 disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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 DISCLAIMED.  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.
 *
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>

#include <pexpert/pexpert.h>

#define etherbroadcastaddr      fugly
#include <net/if.h>
#include <net/route.h>
#include <net/if_llc.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/if_ether.h>
#include <net/if_gif.h>
#include <netinet/if_ether.h>
#include <netinet/in.h> /* For M_LOOP */
#include <net/kpi_interface.h>
#include <net/kpi_protocol.h>
#undef etherbroadcastaddr

/*
 #if INET
 #include <netinet/in.h>
 #include <netinet/in_var.h>
 *
 #include <netinet/in_systm.h>
 #include <netinet/ip.h>
 #endif
 */
#include <net/ether_if_module.h>
#include <sys/socketvar.h>
#include <net/if_vlan_var.h>
#if BOND
#include <net/if_bond_internal.h>
#endif /* BOND */
#if IF_BRIDGE
#include <net/if_bridgevar.h>
#endif /* IF_BRIDGE */
#if IF_FAKE
#include <net/if_fake_var.h>
#endif /* IF_FAKE */

#include <net/dlil.h>

SYSCTL_DECL(_net_link);
SYSCTL_NODE(_net_link, IFT_ETHER, ether, CTLFLAG_RW | CTLFLAG_LOCKED, 0,
    "Ethernet");

struct en_desc {
        u_int16_t type;                 /* Type of protocol stored in data */
        u_int32_t protocol_family;      /* Protocol family */
        u_int32_t data[2];              /* Protocol data */
};

/* descriptors are allocated in blocks of ETHER_DESC_BLK_SIZE */
#if CONFIG_EMBEDDED
#define ETHER_DESC_BLK_SIZE (2) /* IP, ARP */
#else
#define ETHER_DESC_BLK_SIZE (10)
#endif

/*
 * Header for the demux list, hangs off of IFP at if_family_cookie
 */
struct ether_desc_blk_str {
        u_int32_t  n_max_used;
        u_int32_t       n_count;
        u_int32_t       n_used;
        struct en_desc  block_ptr[1];
};

/* Size of the above struct before the array of struct en_desc */
#define ETHER_DESC_HEADER_SIZE  \
        ((size_t) offsetof(struct ether_desc_blk_str, block_ptr))

__private_extern__ u_char etherbroadcastaddr[ETHER_ADDR_LEN] =
{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };

/*
 * Release all descriptor entries owned by this protocol (there may be several).
 * Setting the type to 0 releases the entry. Eventually we should compact-out
 * the unused entries.
 */
int
ether_del_proto(ifnet_t ifp, protocol_family_t protocol_family)
{
        struct ether_desc_blk_str *desc_blk =
            (struct ether_desc_blk_str *)ifp->if_family_cookie;
        u_int32_t current = 0;
        int found = 0;

        if (desc_blk == NULL) {
                return 0;
        }

        for (current = desc_blk->n_max_used; current > 0; current--) {
                if (desc_blk->block_ptr[current - 1].protocol_family ==
                    protocol_family) {
                        found = 1;
                        desc_blk->block_ptr[current - 1].type = 0;
                        desc_blk->n_used--;
                }
        }

        if (desc_blk->n_used == 0) {
                FREE(ifp->if_family_cookie, M_IFADDR);
                ifp->if_family_cookie = 0;
        } else {
                /* Decrement n_max_used */
                for (; desc_blk->n_max_used > 0 &&
                    desc_blk->block_ptr[desc_blk->n_max_used - 1].type == 0;
                    desc_blk->n_max_used--) {
                        ;
                }
        }

        return 0;
}

static int
ether_add_proto_internal(struct ifnet *ifp, protocol_family_t protocol,
    const struct ifnet_demux_desc *demux)
{
        struct en_desc *ed;
        struct ether_desc_blk_str *desc_blk =
            (struct ether_desc_blk_str *)ifp->if_family_cookie;
        u_int32_t i;

        switch (demux->type) {
        /* These types are supported */
        /* Top three are preferred */
        case DLIL_DESC_ETYPE2:
                if (demux->datalen != 2) {
                        return EINVAL;
                }
                break;

        case DLIL_DESC_SAP:
                if (demux->datalen != 3) {
                        return EINVAL;
                }
                break;

        case DLIL_DESC_SNAP:
                if (demux->datalen != 5) {
                        return EINVAL;
                }
                break;

        default:
                return ENOTSUP;
        }

        /* Verify a matching descriptor does not exist */
        if (desc_blk != NULL) {
                switch (demux->type) {
                case DLIL_DESC_ETYPE2:
                        for (i = 0; i < desc_blk->n_max_used; i++) {
                                if (desc_blk->block_ptr[i].type ==
                                    DLIL_DESC_ETYPE2 &&
                                    desc_blk->block_ptr[i].data[0] ==
                                    *(u_int16_t*)demux->data) {
                                        return EADDRINUSE;
                                }
                        }
                        break;
                case DLIL_DESC_SAP:
                case DLIL_DESC_SNAP:
                        for (i = 0; i < desc_blk->n_max_used; i++) {
                                if (desc_blk->block_ptr[i].type ==
                                    demux->type &&
                                    bcmp(desc_blk->block_ptr[i].data,
                                    demux->data, demux->datalen) == 0) {
                                        return EADDRINUSE;
                                }
                        }
                        break;
                }
        }

        /* Check for case where all of the descriptor blocks are in use */
        if (desc_blk == NULL || desc_blk->n_used == desc_blk->n_count) {
                struct ether_desc_blk_str *tmp;
                u_int32_t new_count = ETHER_DESC_BLK_SIZE;
                u_int32_t new_size;
                u_int32_t old_size = 0;

                i = 0;

                if (desc_blk) {
                        new_count += desc_blk->n_count;
                        old_size = desc_blk->n_count * sizeof(struct en_desc) +
                            ETHER_DESC_HEADER_SIZE;
                        i = desc_blk->n_used;
                }

                new_size = new_count * sizeof(struct en_desc) +
                    ETHER_DESC_HEADER_SIZE;

                tmp = _MALLOC(new_size, M_IFADDR, M_WAITOK);
                if (tmp == NULL) {
                        /*
                         * Remove any previous descriptors set in the call.
                         */
                        return ENOMEM;
                }

                bzero(((char *)tmp) + old_size, new_size - old_size);
                if (desc_blk) {
                        bcopy(desc_blk, tmp, old_size);
                        FREE(desc_blk, M_IFADDR);
                }
                desc_blk = tmp;
                ifp->if_family_cookie = (uintptr_t)desc_blk;
                desc_blk->n_count = new_count;
        } else {
                /* Find a free entry */
                for (i = 0; i < desc_blk->n_count; i++) {
                        if (desc_blk->block_ptr[i].type == 0) {
                                break;
                        }
                }
        }

        /* Bump n_max_used if appropriate */
        if (i + 1 > desc_blk->n_max_used) {
                desc_blk->n_max_used = i + 1;
        }

        ed = &desc_blk->block_ptr[i];
        ed->protocol_family = protocol;
        ed->data[0] = 0;
        ed->data[1] = 0;

        switch (demux->type) {
        case DLIL_DESC_ETYPE2:
                /* 2 byte ethernet raw protocol type is at native_type */
                /* prtocol must be in network byte order */
                ed->type = DLIL_DESC_ETYPE2;
                ed->data[0] = *(u_int16_t*)demux->data;
                break;

        case DLIL_DESC_SAP:
                ed->type = DLIL_DESC_SAP;
                bcopy(demux->data, &ed->data[0], 3);
                break;

        case DLIL_DESC_SNAP: {
                u_int8_t*       pDest = ((u_int8_t*)&ed->data[0]) + 3;
                ed->type = DLIL_DESC_SNAP;
                bcopy(demux->data, pDest, 5);
                break;
        }
        }

        desc_blk->n_used++;

        return 0;
}

int
ether_add_proto(ifnet_t  ifp, protocol_family_t protocol,
    const struct ifnet_demux_desc *demux_list, u_int32_t demux_count)
{
        int error = 0;
        u_int32_t i;

        for (i = 0; i < demux_count; i++) {
                error = ether_add_proto_internal(ifp, protocol, &demux_list[i]);
                if (error) {
                        ether_del_proto(ifp, protocol);
                        break;
                }
        }

        return error;
}

int
ether_demux(ifnet_t ifp, mbuf_t m, char *frame_header,
    protocol_family_t *protocol_family)
{
        struct ether_header *eh = (struct ether_header *)(void *)frame_header;
        u_short  ether_type = eh->ether_type;
        u_int16_t type;
        u_int8_t *data;
        u_int32_t i = 0;
        struct ether_desc_blk_str *desc_blk =
            (struct ether_desc_blk_str *)ifp->if_family_cookie;
        u_int32_t maxd = desc_blk ? desc_blk->n_max_used : 0;
        struct en_desc  *ed = desc_blk ? desc_blk->block_ptr : NULL;
        u_int32_t extProto1 = 0;
        u_int32_t extProto2 = 0;

        if (eh->ether_dhost[0] & 1) {
                /* Check for broadcast */
                if (_ether_cmp(etherbroadcastaddr, eh->ether_dhost) == 0) {
                        m->m_flags |= M_BCAST;
                } else {
                        m->m_flags |= M_MCAST;
                }
        }

        if (m->m_flags & M_HASFCS) {
                /*
                 * If the M_HASFCS is set by the driver we want to make sure
                 * that we strip off the trailing FCS data before handing it
                 * up the stack.
                 */
                m_adj(m, -ETHER_CRC_LEN);
                m->m_flags &= ~M_HASFCS;
        }

        if (ifp->if_eflags & IFEF_BOND) {
                /* if we're bonded, bond "protocol" gets all the packets */
                *protocol_family = PF_BOND;
                return 0;
        }

        if ((eh->ether_dhost[0] & 1) == 0) {
                /*
                 * When the driver is put into promiscuous mode we may receive
                 * unicast frames that are not intended for our interfaces.
                 * They are marked here as being promiscuous so the caller may
                 * dispose of them after passing the packets to any interface
                 * filters.
                 */
                if (_ether_cmp(eh->ether_dhost, IF_LLADDR(ifp))) {
                        m->m_flags |= M_PROMISC;
                }
        }

        /* check for VLAN */
        if ((m->m_pkthdr.csum_flags & CSUM_VLAN_TAG_VALID) != 0) {
                if (EVL_VLANOFTAG(m->m_pkthdr.vlan_tag) != 0) {
                        *protocol_family = PF_VLAN;
                        return 0;
                }
                /* the packet is just priority-tagged, clear the bit */
                m->m_pkthdr.csum_flags &= ~CSUM_VLAN_TAG_VALID;
        } else if (ether_type == htons(ETHERTYPE_VLAN)) {
                struct ether_vlan_header *      evl;

                evl = (struct ether_vlan_header *)(void *)frame_header;
                if (m->m_len < ETHER_VLAN_ENCAP_LEN ||
                    ntohs(evl->evl_proto) == ETHERTYPE_VLAN ||
                    EVL_VLANOFTAG(ntohs(evl->evl_tag)) != 0) {
                        *protocol_family = PF_VLAN;
                        return 0;
                }
                /* the packet is just priority-tagged */

                /* make the encapsulated ethertype the actual ethertype */
                ether_type = evl->evl_encap_proto = evl->evl_proto;

                /* remove the encapsulation header */
                m->m_len -= ETHER_VLAN_ENCAP_LEN;
                m->m_data += ETHER_VLAN_ENCAP_LEN;
                m->m_pkthdr.len -= ETHER_VLAN_ENCAP_LEN;
                m->m_pkthdr.csum_flags = 0; /* can't trust hardware checksum */
        } else if (ether_type == htons(ETHERTYPE_ARP)) {
                m->m_pkthdr.pkt_flags |= PKTF_INET_RESOLVE; /* ARP packet */
        }
        data = mtod(m, u_int8_t*);

        /*
         * Determine the packet's protocol type and stuff the protocol into
         * longs for quick compares.
         */
        if (ntohs(ether_type) <= 1500) {
                bcopy(data, &extProto1, sizeof(u_int32_t));

                /* SAP or SNAP */
                if ((extProto1 & htonl(0xFFFFFF00)) == htonl(0xAAAA0300)) {
                        /* SNAP */
                        type = DLIL_DESC_SNAP;
                        bcopy(data + sizeof(u_int32_t), &extProto2,
                            sizeof(u_int32_t));
                        extProto1 &= htonl(0x000000FF);
                } else {
                        type = DLIL_DESC_SAP;
                        extProto1 &= htonl(0xFFFFFF00);
                }
        } else {
                type = DLIL_DESC_ETYPE2;
        }

        /*
         * Search through the connected protocols for a match.
         */
        switch (type) {
        case DLIL_DESC_ETYPE2:
                for (i = 0; i < maxd; i++) {
                        if ((ed[i].type == type) &&
                            (ed[i].data[0] == ether_type)) {
                                *protocol_family = ed[i].protocol_family;
                                return 0;
                        }
                }
                break;

        case DLIL_DESC_SAP:
                for (i = 0; i < maxd; i++) {
                        if ((ed[i].type == type) &&
                            (ed[i].data[0] == extProto1)) {
                                *protocol_family = ed[i].protocol_family;
                                return 0;
                        }
                }
                break;

        case DLIL_DESC_SNAP:
                for (i = 0; i < maxd; i++) {
                        if ((ed[i].type == type) &&
                            (ed[i].data[0] == extProto1) &&
                            (ed[i].data[1] == extProto2)) {
                                *protocol_family = ed[i].protocol_family;
                                return 0;
                        }
                }
                break;
        }

        return ENOENT;
}

/*
 * On embedded, ether_frameout is practicaly ether_frameout_extended.
 * On non-embedded, ether_frameout has long been exposed as a public KPI,
 * and therefore its signature must remain the same (without the pre- and
 * postpend length parameters.)
 */
#if KPI_INTERFACE_EMBEDDED
int
ether_frameout(struct ifnet *ifp, struct mbuf **m,
    const struct sockaddr *ndest, const char *edst,
    const char *ether_type, u_int32_t *prepend_len, u_int32_t *postpend_len)
#else /* !KPI_INTERFACE_EMBEDDED */
int
ether_frameout(struct ifnet *ifp, struct mbuf **m,
    const struct sockaddr *ndest, const char *edst,
    const char *ether_type)
#endif /* KPI_INTERFACE_EMBEDDED */
{
#if KPI_INTERFACE_EMBEDDED
        return ether_frameout_extended(ifp, m, ndest, edst, ether_type,
                   prepend_len, postpend_len);
#else /* !KPI_INTERFACE_EMBEDDED */
        return ether_frameout_extended(ifp, m, ndest, edst, ether_type,
                   NULL, NULL);
#endif /* !KPI_INTERFACE_EMBEDDED */
}

/*
 * Ethernet output routine.
 * Encapsulate a packet of type family for the local net.
 * Use trailer local net encapsulation if enough data in first
 * packet leaves a multiple of 512 bytes of data in remainder.
 */
int
ether_frameout_extended(struct ifnet *ifp, struct mbuf **m,
    const struct sockaddr *ndest, const char *edst,
    const char *ether_type, u_int32_t *prepend_len, u_int32_t *postpend_len)
{
        struct ether_header *eh;
        int hlen;       /* link layer header length */

        hlen = ETHER_HDR_LEN;

        /*
         * If a simplex interface, and the packet is being sent to our
         * Ethernet address or a broadcast address, loopback a copy.
         * XXX To make a simplex device behave exactly like a duplex
         * device, we should copy in the case of sending to our own
         * ethernet address (thus letting the original actually appear
         * on the wire). However, we don't do that here for security
         * reasons and compatibility with the original behavior.
         */
        if ((ifp->if_flags & IFF_SIMPLEX) &&
            ((*m)->m_flags & M_LOOP) && lo_ifp != NULL) {
                if ((*m)->m_flags & M_BCAST) {
                        struct mbuf *n = m_copy(*m, 0, (int)M_COPYALL);
                        if (n != NULL) {
                                dlil_output(lo_ifp, ndest->sa_family,
                                    n, NULL, ndest, 0, NULL);
                        }
                } else if (_ether_cmp(edst, IF_LLADDR(ifp)) == 0) {
                        dlil_output(lo_ifp, ndest->sa_family, *m,
                            NULL, ndest, 0, NULL);
                        return EJUSTRETURN;
                }
        }

        /*
         * Add local net header.  If no space in first mbuf,
         * allocate another.
         */
        M_PREPEND(*m, sizeof(struct ether_header), M_DONTWAIT, 0);
        if (*m == NULL) {
                return EJUSTRETURN;
        }

        if (prepend_len != NULL) {
                *prepend_len = sizeof(struct ether_header);
        }
        if (postpend_len != NULL) {
                *postpend_len = 0;
        }

        eh = mtod(*m, struct ether_header *);
        (void) memcpy(&eh->ether_type, ether_type, sizeof(eh->ether_type));
        (void) memcpy(eh->ether_dhost, edst, ETHER_ADDR_LEN);
        ifnet_lladdr_copy_bytes(ifp, eh->ether_shost, ETHER_ADDR_LEN);

        return 0;
}

errno_t
ether_check_multi(ifnet_t ifp, const struct sockaddr *proto_addr)
{
#pragma unused(ifp)
        errno_t result = EAFNOSUPPORT;
        const u_char *e_addr;

        /*
         * AF_SPEC and AF_LINK don't require translation. We do
         * want to verify that they specify a valid multicast.
         */
        switch (proto_addr->sa_family) {
        case AF_UNSPEC:
                e_addr = (const u_char*)&proto_addr->sa_data[0];
                if ((e_addr[0] & 0x01) != 0x01) {
                        result = EADDRNOTAVAIL;
                } else {
                        result = 0;
                }
                break;

        case AF_LINK:
                e_addr = CONST_LLADDR((const struct sockaddr_dl*)
                    (uintptr_t)(size_t)proto_addr);
                if ((e_addr[0] & 0x01) != 0x01) {
                        result = EADDRNOTAVAIL;
                } else {
                        result = 0;
                }
                break;
        }

        return result;
}

int
ether_ioctl(ifnet_t ifp, u_int32_t command, void *data)
{
#pragma unused(ifp, command, data)
        return EOPNOTSUPP;
}

__private_extern__ int
ether_family_init(void)
{
        errno_t error = 0;

        /* Register protocol registration functions */
        if ((error = proto_register_plumber(PF_INET, APPLE_IF_FAM_ETHERNET,
            ether_attach_inet, ether_detach_inet)) != 0) {
                printf("proto_register_plumber failed for PF_INET error=%d\n",
                    error);
                goto done;
        }
#if INET6
        if ((error = proto_register_plumber(PF_INET6, APPLE_IF_FAM_ETHERNET,
            ether_attach_inet6, ether_detach_inet6)) != 0) {
                printf("proto_register_plumber failed for PF_INET6 error=%d\n",
                    error);
                goto done;
        }
#endif /* INET6 */
#if VLAN
        vlan_family_init();
#endif /* VLAN */
#if BOND
        bond_family_init();
#endif /* BOND */
#if IF_BRIDGE
        bridgeattach(0);
#endif /* IF_BRIDGE */
#if IF_FAKE
        if_fake_init();
#endif /* IF_FAKE */

done:

        return error;
}