/*      $OpenBSD: if_mpw.c,v 1.71 2026/02/05 03:26:00 dlg Exp $ */

/*
 * Copyright (c) 2015 Rafael Zalamena <rzalamena@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "bpfilter.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/errno.h>

#include <net/if.h>
#include <net/if_dl.h>
#include <net/route.h>

#include <netinet/in.h>

#include <netinet/if_ether.h>
#include <netmpls/mpls.h>

#if NBPFILTER > 0
#include <net/bpf.h>
#endif /* NBPFILTER */

struct mpw_neighbor {
        struct shim_hdr         n_rshim;
        struct sockaddr_storage n_nexthop;
};

struct mpw_softc {
        struct arpcom           sc_ac;
#define sc_if                   sc_ac.ac_if
        caddr_t                 sc_bpf;

        int                     sc_txhprio;
        int                     sc_rxhprio;
        unsigned int            sc_rdomain;
        struct ifaddr           sc_ifa;
        struct sockaddr_mpls    sc_smpls; /* Local label */

        unsigned int            sc_cword;
        unsigned int            sc_fword;
        uint32_t                sc_flow;
        uint32_t                sc_type;
        struct mpw_neighbor     *sc_neighbor;

        unsigned int            sc_dead;
};

void    mpwattach(int);
int     mpw_clone_create(struct if_clone *, int);
int     mpw_clone_destroy(struct ifnet *);
int     mpw_ioctl(struct ifnet *, u_long, caddr_t);
void    mpw_start(struct ifnet *);
void    mpw_input(struct ifnet *, struct mbuf *, struct netstack *);

struct if_clone mpw_cloner =
    IF_CLONE_INITIALIZER("mpw", mpw_clone_create, mpw_clone_destroy);

void
mpwattach(int n)
{
        if_clone_attach(&mpw_cloner);
}

int
mpw_clone_create(struct if_clone *ifc, int unit)
{
        struct mpw_softc *sc;
        struct ifnet *ifp;

        sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK|M_CANFAIL|M_ZERO);
        if (sc == NULL)
                return (ENOMEM);

        ifp = &sc->sc_if;

        sc->sc_flow = arc4random();
        sc->sc_neighbor = NULL;

        sc->sc_txhprio = 0;
        sc->sc_rxhprio = IF_HDRPRIO_PACKET;
        sc->sc_rdomain = 0;
        refcnt_init_trace(&sc->sc_ifa.ifa_refcnt, DT_REFCNT_IDX_IFADDR);
        sc->sc_ifa.ifa_ifp = ifp;
        sc->sc_ifa.ifa_addr = sdltosa(ifp->if_sadl);
        sc->sc_smpls.smpls_len = sizeof(sc->sc_smpls);
        sc->sc_smpls.smpls_family = AF_MPLS;

        snprintf(ifp->if_xname, sizeof(ifp->if_xname), "%s%d",
            ifc->ifc_name, unit);
        ifp->if_softc = sc;
        ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
        ifp->if_xflags = IFXF_CLONED;
        ifp->if_ioctl = mpw_ioctl;
        ifp->if_start = mpw_start;
        ifp->if_hardmtu = ETHER_MAX_HARDMTU_LEN;
        ether_fakeaddr(ifp);

        sc->sc_dead = 0;

        ether_ifattach(ifp);
        ifp->if_input = mpw_input;

#if NBPFILTER > 0
        bpfdetach(ifp); /* undo bpfattach in ether_ifattach */
        bpfattach(&sc->sc_bpf, ifp, DLT_EN10MB, ETHER_HDR_LEN);
        bpfattach(&ifp->if_bpf, ifp, DLT_MPLS, 0);
#endif

        if_counters_alloc(ifp);
        if_attach(ifp);

        return (0);
}

int
mpw_clone_destroy(struct ifnet *ifp)
{
        struct mpw_softc *sc = ifp->if_softc;

        NET_LOCK();
        ifp->if_flags &= ~IFF_RUNNING;
        sc->sc_dead = 1;

        if (sc->sc_smpls.smpls_label) {
                rt_ifa_del(&sc->sc_ifa, RTF_MPLS|RTF_LOCAL,
                    smplstosa(&sc->sc_smpls), sc->sc_rdomain);
        }
        NET_UNLOCK();

        ifq_barrier(&ifp->if_snd);

        ether_ifdetach(ifp);
        if_detach(ifp);
        if (refcnt_rele(&sc->sc_ifa.ifa_refcnt) == 0) {
                panic("%s: ifa refcnt has %u refs", __func__,
                    sc->sc_ifa.ifa_refcnt.r_refs);
        }
        free(sc->sc_neighbor, M_DEVBUF, sizeof(*sc->sc_neighbor));
        free(sc, M_DEVBUF, sizeof(*sc));

        return (0);
}

int
mpw_set_route(struct mpw_softc *sc, uint32_t label, unsigned int rdomain)
{
        int error;

        if (sc->sc_dead)
                return (ENXIO);

        if (sc->sc_smpls.smpls_label) {
                rt_ifa_del(&sc->sc_ifa, RTF_MPLS|RTF_LOCAL,
                    smplstosa(&sc->sc_smpls), sc->sc_rdomain);
        }

        sc->sc_smpls.smpls_label = label;
        sc->sc_rdomain = rdomain;

        /* only install with a label or mpw_clone_destroy() will ignore it */
        if (sc->sc_smpls.smpls_label == MPLS_LABEL2SHIM(0))
                return 0;

        error = rt_ifa_add(&sc->sc_ifa, RTF_MPLS|RTF_LOCAL,
            smplstosa(&sc->sc_smpls), sc->sc_rdomain);
        if (error != 0)
                sc->sc_smpls.smpls_label = 0;

        return (error);
}

static int
mpw_set_neighbor(struct mpw_softc *sc, const struct if_laddrreq *req)
{
        struct mpw_neighbor *n, *o;
        const struct sockaddr_storage *ss;
        const struct sockaddr_mpls *smpls;
        uint32_t label;

        smpls = (const struct sockaddr_mpls *)&req->dstaddr;

        if (smpls->smpls_family != AF_MPLS)
                return (EINVAL);
        label = smpls->smpls_label;
        if (label > MPLS_LABEL_MAX || label <= MPLS_LABEL_RESERVED_MAX)
                return (EINVAL);

        ss = &req->addr;
        switch (ss->ss_family) {
        case AF_INET: {
                const struct sockaddr_in *sin =
                    (const struct sockaddr_in *)ss;

                if (in_nullhost(sin->sin_addr) ||
                    IN_MULTICAST(sin->sin_addr.s_addr))
                        return (EINVAL);

                break;
        }
#ifdef INET6
        case AF_INET6: {
                const struct sockaddr_in6 *sin6 =
                    (const struct sockaddr_in6 *)ss;

                if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr) ||
                    IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
                        return (EINVAL);

                /* check scope */

                break;
        }
#endif
        default:
                return (EAFNOSUPPORT);
        }

        if (sc->sc_dead)
                return (ENXIO);

        n = malloc(sizeof(*n), M_DEVBUF, M_WAITOK|M_CANFAIL|M_ZERO);
        if (n == NULL)
                return (ENOMEM);

        n->n_rshim.shim_label = MPLS_LABEL2SHIM(label);
        n->n_nexthop = *ss;

        o = sc->sc_neighbor;
        sc->sc_neighbor = n;

        NET_UNLOCK();
        ifq_barrier(&sc->sc_if.if_snd);
        NET_LOCK();

        free(o, M_DEVBUF, sizeof(*o));

        return (0);
}

static int
mpw_get_neighbor(struct mpw_softc *sc, struct if_laddrreq *req)
{
        struct sockaddr_mpls *smpls = (struct sockaddr_mpls *)&req->dstaddr;
        struct mpw_neighbor *n = sc->sc_neighbor;

        if (n == NULL)
                return (EADDRNOTAVAIL);

        smpls->smpls_len = sizeof(*smpls);
        smpls->smpls_family = AF_MPLS;
        smpls->smpls_label = MPLS_SHIM2LABEL(n->n_rshim.shim_label);

        req->addr = n->n_nexthop;

        return (0);
}

static int
mpw_del_neighbor(struct mpw_softc *sc)
{
        struct mpw_neighbor *o;

        if (sc->sc_dead)
                return (ENXIO);

        o = sc->sc_neighbor;
        sc->sc_neighbor = NULL;

        NET_UNLOCK();
        ifq_barrier(&sc->sc_if.if_snd);
        NET_LOCK();

        free(o, M_DEVBUF, sizeof(*o));

        return (0);
}

static int
mpw_set_label(struct mpw_softc *sc, const struct shim_hdr *label)
{
        uint32_t shim;

        if (label->shim_label > MPLS_LABEL_MAX ||
            label->shim_label <= MPLS_LABEL_RESERVED_MAX)
                return (EINVAL);

        shim = MPLS_LABEL2SHIM(label->shim_label);
        if (sc->sc_smpls.smpls_label == shim)
                return (0);

        return (mpw_set_route(sc, shim, sc->sc_rdomain));
}

static int
mpw_get_label(struct mpw_softc *sc, struct ifreq *ifr)
{
        struct shim_hdr label;

        label.shim_label = MPLS_SHIM2LABEL(sc->sc_smpls.smpls_label);

        if (label.shim_label == 0)
                return (EADDRNOTAVAIL);

        return (copyout(&label, ifr->ifr_data, sizeof(label)));
}

static int
mpw_del_label(struct mpw_softc *sc)
{
        if (sc->sc_dead)
                return (ENXIO);

        if (sc->sc_smpls.smpls_label != MPLS_LABEL2SHIM(0)) {
                rt_ifa_del(&sc->sc_ifa, RTF_MPLS | RTF_LOCAL,
                    smplstosa(&sc->sc_smpls), sc->sc_rdomain);
        }

        sc->sc_smpls.smpls_label = MPLS_LABEL2SHIM(0);

        return (0);
}

static int
mpw_set_config(struct mpw_softc *sc, const struct ifreq *ifr)
{
        struct ifmpwreq imr;
        struct if_laddrreq req;
        struct sockaddr_mpls *smpls;
        struct sockaddr_in *sin;
        int error;

        error = copyin(ifr->ifr_data, &imr, sizeof(imr));
        if (error != 0)
                return (error);

        /* Teardown all configuration if got no nexthop */
        sin = (struct sockaddr_in *)&imr.imr_nexthop;
        if (sin->sin_addr.s_addr == 0) {
                mpw_del_label(sc);
                mpw_del_neighbor(sc);
                sc->sc_cword = 0;
                sc->sc_type = 0;
                return (0);
        }

        error = mpw_set_label(sc, &imr.imr_lshim);
        if (error != 0)
                return (error);

        smpls = (struct sockaddr_mpls *)&req.dstaddr;
        smpls->smpls_family = AF_MPLS;
        smpls->smpls_label = imr.imr_rshim.shim_label;
        req.addr = imr.imr_nexthop;

        error = mpw_set_neighbor(sc, &req);
        if (error != 0)
                return (error);

        sc->sc_cword = ISSET(imr.imr_flags, IMR_FLAG_CONTROLWORD);
        sc->sc_type = imr.imr_type;

        return (0);
}

static int
mpw_get_config(struct mpw_softc *sc, const struct ifreq *ifr)
{
        struct ifmpwreq imr;

        memset(&imr, 0, sizeof(imr));
        imr.imr_flags = sc->sc_cword ? IMR_FLAG_CONTROLWORD : 0;
        imr.imr_type = sc->sc_type;

        imr.imr_lshim.shim_label = MPLS_SHIM2LABEL(sc->sc_smpls.smpls_label);
        if (sc->sc_neighbor) {
                imr.imr_rshim.shim_label =
                    MPLS_SHIM2LABEL(sc->sc_neighbor->n_rshim.shim_label);
                imr.imr_nexthop = sc->sc_neighbor->n_nexthop;
        }

        return (copyout(&imr, ifr->ifr_data, sizeof(imr)));
}

int
mpw_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
        struct ifreq *ifr = (struct ifreq *) data;
        struct mpw_softc *sc = ifp->if_softc;
        struct shim_hdr shim;
        int error = 0;

        switch (cmd) {
        case SIOCSIFFLAGS:
                if ((ifp->if_flags & IFF_UP))
                        ifp->if_flags |= IFF_RUNNING;
                else
                        ifp->if_flags &= ~IFF_RUNNING;
                break;

        case SIOCGPWE3:
                ifr->ifr_pwe3 = IF_PWE3_ETHERNET;
                break;
        case SIOCSPWE3CTRLWORD:
                sc->sc_cword = ifr->ifr_pwe3 ? 1 : 0;
                break;
        case SIOCGPWE3CTRLWORD:
                ifr->ifr_pwe3 = sc->sc_cword;
                break;
        case SIOCSPWE3FAT:
                sc->sc_fword = ifr->ifr_pwe3 ? 1 : 0;
                break;
        case SIOCGPWE3FAT:
                ifr->ifr_pwe3 = sc->sc_fword;
                break;

        case SIOCSPWE3NEIGHBOR:
                error = mpw_set_neighbor(sc, (struct if_laddrreq *)data);
                break;
        case SIOCGPWE3NEIGHBOR:
                error = mpw_get_neighbor(sc, (struct if_laddrreq *)data);
                break;
        case SIOCDPWE3NEIGHBOR:
                error = mpw_del_neighbor(sc);
                break;

        case SIOCGETLABEL:
                error = mpw_get_label(sc, ifr);
                break;
        case SIOCSETLABEL:
                error = copyin(ifr->ifr_data, &shim, sizeof(shim));
                if (error != 0)
                        break;
                error = mpw_set_label(sc, &shim);
                break;
        case SIOCDELLABEL:
                error = mpw_del_label(sc);
                break;

        case SIOCSETMPWCFG:
                error = mpw_set_config(sc, ifr);
                break;

        case SIOCGETMPWCFG:
                error = mpw_get_config(sc, ifr);
                break;

        case SIOCSLIFPHYRTABLE:
                if (ifr->ifr_rdomainid < 0 ||
                    ifr->ifr_rdomainid > RT_TABLEID_MAX ||
                    !rtable_exists(ifr->ifr_rdomainid) ||
                    ifr->ifr_rdomainid != rtable_l2(ifr->ifr_rdomainid)) {
                        error = EINVAL;
                        break;
                }
                if (sc->sc_rdomain != ifr->ifr_rdomainid) {
                        error = mpw_set_route(sc, sc->sc_smpls.smpls_label,
                            ifr->ifr_rdomainid);
                }
                break;
        case SIOCGLIFPHYRTABLE:
                ifr->ifr_rdomainid = sc->sc_rdomain;
                break;

        case SIOCSTXHPRIO:
                error = if_txhprio_l2_check(ifr->ifr_hdrprio);
                if (error != 0)
                        break;

                sc->sc_txhprio = ifr->ifr_hdrprio;
                break;
        case SIOCGTXHPRIO:
                ifr->ifr_hdrprio = sc->sc_txhprio;
                break;

        case SIOCSRXHPRIO:
                error = if_rxhprio_l2_check(ifr->ifr_hdrprio);
                if (error != 0)
                        break;

                sc->sc_rxhprio = ifr->ifr_hdrprio;
                break;
        case SIOCGRXHPRIO:
                ifr->ifr_hdrprio = sc->sc_rxhprio;
                break;

        case SIOCADDMULTI:
        case SIOCDELMULTI:
                break;

        default:
                error = ether_ioctl(ifp, &sc->sc_ac, cmd, data);
                break;
        }

        return (error);
}

void
mpw_input(struct ifnet *ifp, struct mbuf *m, struct netstack *ns)
{
        struct mpw_softc *sc = ifp->if_softc;
        struct shim_hdr *shim;
        struct mbuf *n;
        uint32_t exp;
        int rxprio;
        int off;
#if NBPFILTER > 0
        caddr_t if_bpf;
#endif

        if (!ISSET(ifp->if_flags, IFF_RUNNING))
                goto drop;

        shim = mtod(m, struct shim_hdr *);
        exp = ntohl(shim->shim_label & MPLS_EXP_MASK) >> MPLS_EXP_OFFSET;
        if (sc->sc_fword) {
                uint32_t flow;

                if (MPLS_BOS_ISSET(shim->shim_label))
                        goto drop;
                m_adj(m, sizeof(*shim));

                if (m->m_len < sizeof(*shim)) {
                        m = m_pullup(m, sizeof(*shim));
                        if (m == NULL)
                                return;
                }
                shim = mtod(m, struct shim_hdr *);

                if (!MPLS_BOS_ISSET(shim->shim_label))
                        goto drop;

                flow = MPLS_SHIM2LABEL(shim->shim_label);
                flow ^= sc->sc_flow;
                SET(m->m_pkthdr.csum_flags, M_FLOWID);
                m->m_pkthdr.ph_flowid = flow;
        } else {
                if (!MPLS_BOS_ISSET(shim->shim_label))
                        goto drop;
        }
        m_adj(m, sizeof(*shim));

        if (sc->sc_cword) {
                if (m->m_len < sizeof(*shim)) {
                        m = m_pullup(m, sizeof(*shim));
                        if (m == NULL)
                                return;
                }
                shim = mtod(m, struct shim_hdr *);

                /*
                 * The first 4 bits identifies that this packet is a
                 * control word. If the control word is configured and
                 * we received an IP datagram we shall drop it.
                 */
                if (shim->shim_label & CW_ZERO_MASK) {
                        ifp->if_ierrors++;
                        goto drop;
                }

                /* We don't support fragmentation just yet. */
                if (shim->shim_label & CW_FRAG_MASK) {
                        ifp->if_ierrors++;
                        goto drop;
                }

                m_adj(m, MPLS_HDRLEN);
        }

        if (m->m_len < sizeof(struct ether_header)) {
                m = m_pullup(m, sizeof(struct ether_header));
                if (m == NULL)
                        return;
        }

        n = m_getptr(m, sizeof(struct ether_header), &off);
        if (n == NULL) {
                ifp->if_ierrors++;
                goto drop;
        }
        if (!ALIGNED_POINTER(mtod(n, caddr_t) + off, uint32_t)) {
                n = m_dup_pkt(m, ETHER_ALIGN, M_NOWAIT);
                /* Dispose of the original mbuf chain */
                m_freem(m);
                if (n == NULL)
                        return;
                m = n;
        }

        rxprio = sc->sc_rxhprio;
        switch (rxprio) {
        case IF_HDRPRIO_PACKET:
                /* nop */
                break;
        case IF_HDRPRIO_OUTER:
                m->m_pkthdr.pf.prio = exp;
                break;
        default:
                m->m_pkthdr.pf.prio = rxprio;
                break;
        }

        m->m_pkthdr.ph_ifidx = ifp->if_index;
        m->m_pkthdr.ph_rtableid = ifp->if_rdomain;

        /* packet has not been processed by PF yet. */
        KASSERT(m->m_pkthdr.pf.statekey == NULL);

#if NBPFILTER > 0
        if_bpf = sc->sc_bpf;
        if (if_bpf)
                bpf_mtap(if_bpf, m, BPF_DIRECTION_OUT);
#endif

        ether_input(ifp, m, ns);
        return;
drop:
        m_freem(m);
}

void
mpw_start(struct ifnet *ifp)
{
        struct mpw_softc *sc = ifp->if_softc;
        struct rtentry *rt;
        struct ifnet *ifp0;
        struct mbuf *m, *m0;
        struct shim_hdr *shim;
        struct mpw_neighbor *n;
        struct sockaddr_mpls smpls = {
                .smpls_len = sizeof(smpls),
                .smpls_family = AF_MPLS,
        };
        int txprio = sc->sc_txhprio;
        uint8_t prio;
        uint32_t exp, bos;

        n = sc->sc_neighbor;
        if (!ISSET(ifp->if_flags, IFF_RUNNING) ||
            n == NULL) {
                ifq_purge(&ifp->if_snd);
                return;
        }

        rt = rtalloc(sstosa(&n->n_nexthop), RT_RESOLVE, sc->sc_rdomain);
        if (!rtisvalid(rt)) {
                ifq_purge(&ifp->if_snd);
                goto rtfree;
        }

        ifp0 = if_get(rt->rt_ifidx);
        if (ifp0 == NULL) {
                ifq_purge(&ifp->if_snd);
                goto rtfree;
        }

        while ((m = ifq_dequeue(&ifp->if_snd)) != NULL) {
#if NBPFILTER > 0
                caddr_t if_bpf;

                if_bpf = sc->sc_bpf;
                if (if_bpf)
                        bpf_mtap(if_bpf, m, BPF_DIRECTION_OUT);
#endif /* NBPFILTER */

                m0 = m_get(M_DONTWAIT, m->m_type);
                if (m0 == NULL) {
                        m_freem(m);
                        continue;
                }

                M_MOVE_PKTHDR(m0, m);
                m0->m_next = m;
                m_align(m0, 0);
                m0->m_len = 0;

                if (sc->sc_cword) {
                        m0 = m_prepend(m0, sizeof(*shim), M_NOWAIT);
                        if (m0 == NULL)
                                continue;

                        shim = mtod(m0, struct shim_hdr *);
                        memset(shim, 0, sizeof(*shim));
                }

                switch (txprio) {
                case IF_HDRPRIO_PACKET:
                        prio = m->m_pkthdr.pf.prio;
                        break;
                default:
                        prio = txprio;
                        break;
                }
                exp = htonl(prio << MPLS_EXP_OFFSET);

                bos = MPLS_BOS_MASK;
                if (sc->sc_fword) {
                        uint32_t flow = sc->sc_flow;

                        m0 = m_prepend(m0, sizeof(*shim), M_NOWAIT);
                        if (m0 == NULL)
                                continue;

                        if (ISSET(m->m_pkthdr.csum_flags, M_FLOWID))
                                flow ^= m->m_pkthdr.ph_flowid;

                        shim = mtod(m0, struct shim_hdr *);
                        shim->shim_label = htonl(1) & MPLS_TTL_MASK;
                        shim->shim_label |= MPLS_LABEL2SHIM(flow) | exp | bos;

                        bos = 0;
                }

                m0 = m_prepend(m0, sizeof(*shim), M_NOWAIT);
                if (m0 == NULL)
                        continue;

                shim = mtod(m0, struct shim_hdr *);
                shim->shim_label = htonl(mpls_defttl) & MPLS_TTL_MASK;
                shim->shim_label |= n->n_rshim.shim_label | exp | bos;

#if NBPFILTER > 0
                if_bpf = ifp->if_bpf;
                if (if_bpf)
                        bpf_mtap(if_bpf, m, BPF_DIRECTION_OUT);
#endif /* NBPFILTER */

                m0->m_pkthdr.ph_rtableid = sc->sc_rdomain;
                CLR(m0->m_flags, M_BCAST|M_MCAST);

                mpls_output(ifp0, m0, (struct sockaddr *)&smpls, rt);
        }

        if_put(ifp0);
rtfree:
        rtfree(rt);
}