/*      $OpenBSD: interface.c,v 1.17 2024/08/21 14:58:14 florian Exp $ */

/*
 * Copyright (c) 2006 Michele Marchetto <mydecay@openbeer.it>
 * Copyright (c) 2005 Claudio Jeker <claudio@openbsd.org>
 * Copyright (c) 2004, 2005 Esben Norby <norby@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 <sys/types.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <net/if_types.h>
#include <ctype.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <event.h>

#include "ripd.h"
#include "log.h"
#include "rip.h"
#include "rde.h"
#include "ripe.h"

extern struct ripd_conf *conf;

int      if_act_start(struct iface *);
int      if_act_reset(struct iface *);

struct {
        int                     state;
        enum iface_event        event;
        enum iface_action       action;
        int                     new_state;
} iface_fsm[] = {
    /* current state    event that happened     action to take  resulting state */
    {IF_STA_DOWN,       IF_EVT_UP,              IF_ACT_STRT,    0},
    {IF_STA_ANY,        IF_EVT_DOWN,            IF_ACT_RST,     IF_STA_DOWN},
    {-1,                IF_EVT_NOTHING,         IF_ACT_NOTHING, 0},
};

const char * const if_action_names[] = {
        "NOTHING",
        "START",
        "RESET"
};

static const char * const if_event_names[] = {
        "NOTHING",
        "UP",
        "DOWN",
};

void
if_init(struct ripd_conf *xconf, struct iface *iface)
{
        struct ifreq    ifr;
        u_int           rdomain;

        /* XXX as in ospfd I would like to kill that. This is a design error */
        iface->fd = xconf->rip_socket;

        strlcpy(ifr.ifr_name, iface->name, sizeof(ifr.ifr_name));
        if (ioctl(iface->fd, SIOCGIFRDOMAIN, (caddr_t)&ifr) == -1)
                rdomain = 0;
        else {
                rdomain = ifr.ifr_rdomainid;
                if (setsockopt(iface->fd, SOL_SOCKET, SO_RTABLE, &rdomain,
                    sizeof(rdomain)) == -1)
                        fatal("failed to set rdomain");
        }
        if (rdomain != xconf->rdomain)
                fatalx("interface rdomain mismatch");

        ripe_demote_iface(iface, 0);
}

int
if_fsm(struct iface *iface, enum iface_event event)
{
        int      old_state;
        int      new_state = 0;
        int      i, ret = 0;

        old_state = iface->state;

        for (i = 0; iface_fsm[i].state != -1; i++)
                if ((iface_fsm[i].state & old_state) &&
                    (iface_fsm[i].event == event)) {
                        new_state = iface_fsm[i].new_state;
                        break;
                }

        if (iface_fsm[i].state == -1) {
                /* event outside of the defined fsm, ignore it. */
                log_debug("if_fsm: interface %s, "
                    "event '%s' not expected in state '%s'", iface->name,
                    if_event_name(event), if_state_name(old_state));
                return (0);
        }

        switch (iface_fsm[i].action) {
        case IF_ACT_STRT:
                ret = if_act_start(iface);
                break;
        case IF_ACT_RST:
                ret = if_act_reset(iface);
                break;
        case IF_ACT_NOTHING:
                /* do nothing */
                break;
        }

        if (ret) {
                log_debug("if_fsm: error changing state for interface %s, "
                    "event '%s', state '%s'", iface->name, if_event_name(event),
                    if_state_name(old_state));
                return (0);
        }

        if (new_state != 0)
                iface->state = new_state;

        if (old_state == IF_STA_ACTIVE && iface->state == IF_STA_DOWN)
                ripe_demote_iface(iface, 0);
        if (old_state & IF_STA_DOWN && iface->state == IF_STA_ACTIVE)
                ripe_demote_iface(iface, 1);

        log_debug("if_fsm: event '%s' resulted in action '%s' and changing "
            "state for interface %s from '%s' to '%s'",
            if_event_name(event), if_action_name(iface_fsm[i].action),
            iface->name, if_state_name(old_state), if_state_name(iface->state));

        return (ret);
}

struct iface *
if_find_index(u_short ifindex)
{
        struct iface     *iface;

        LIST_FOREACH(iface, &conf->iface_list, entry) {
                if (iface->ifindex == ifindex)
                        return (iface);
        }

        return (NULL);
}


/* actions */
int
if_act_start(struct iface *iface)
{
        struct in_addr   addr;
        struct timeval   now;

        if (iface->passive) {
                log_debug("if_act_start: cannot start passive interface %s",
                    iface->name);
                return (0);
        }

        if (!((iface->flags & IFF_UP) &&
            LINK_STATE_IS_UP(iface->linkstate))) {
                log_debug("if_act_start: interface %s link down",
                    iface->name);
                return (0);
        }

        gettimeofday(&now, NULL);
        iface->uptime = now.tv_sec;

        switch (iface->type) {
        case IF_TYPE_POINTOPOINT:
        case IF_TYPE_BROADCAST:
                inet_pton(AF_INET, ALL_RIP_ROUTERS, &addr);
                if (if_join_group(iface, &addr)) {
                        log_warn("if_act_start: error joining group %s, "
                            "interface %s", inet_ntoa(addr), iface->name);
                        return (-1);
                }

                iface->state = IF_STA_ACTIVE;
                break;
        default:
                fatalx("if_act_start: unknown interface type");
        }

        return (0);
}

int
if_act_reset(struct iface *iface)
{
        struct nbr              *nbr = NULL;
        struct in_addr           addr;

        if (iface->passive)
                return (0);

        switch (iface->type) {
        case IF_TYPE_POINTOPOINT:
        case IF_TYPE_BROADCAST:
                inet_pton(AF_INET, ALL_RIP_ROUTERS, &addr);
                if (if_leave_group(iface, &addr)) {
                log_warn("if_act_reset: error leaving group %s, "
                    "interface %s", inet_ntoa(addr), iface->name);
                }
                break;
        default:
                fatalx("if_act_reset: unknown interface type");
        }

        LIST_FOREACH(nbr, &iface->nbr_list, entry) {
                if (nbr_fsm(nbr, NBR_EVT_KILL_NBR)) {
                        log_debug("if_act_reset: error killing neighbor %s",
                            inet_ntoa(nbr->id));
                }
        }

        return (0);
}

const char *
if_event_name(int event)
{
        return (if_event_names[event]);
}

const char *
if_action_name(int action)
{
        return (if_action_names[action]);
}

/* misc */
int
if_set_mcast_ttl(int fd, u_int8_t ttl)
{
        if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL,
            (char *)&ttl, sizeof(ttl)) == -1) {
                log_warn("if_set_mcast_ttl: error setting "
                    "IP_MULTICAST_TTL to %d", ttl);
                return (-1);
        }

        return (0);
}

int
if_set_opt(int fd)
{
        int      yes = 1;

        if (setsockopt(fd, IPPROTO_IP, IP_RECVIF, &yes,
            sizeof(int)) == -1) {
                log_warn("if_set_opt: error setting IP_RECVIF");
                return (-1);
        }

        return (0);
}

int
if_set_tos(int fd, int tos)
{
        if (setsockopt(fd, IPPROTO_IP, IP_TOS,
            (int *)&tos, sizeof(tos)) == -1) {
                log_warn("if_set_tos: error setting IP_TOS to 0x%x", tos);
                return (-1);
        }

        return (0);
}

int
if_set_mcast(struct iface *iface)
{
        switch (iface->type) {
        case IF_TYPE_POINTOPOINT:
        case IF_TYPE_BROADCAST:
                if (setsockopt(iface->fd, IPPROTO_IP, IP_MULTICAST_IF,
                    &iface->addr.s_addr, sizeof(iface->addr.s_addr)) == -1) {
                        log_debug("if_set_mcast: error setting "
                                "IP_MULTICAST_IF, interface %s", iface->name);
                        return (-1);
                }
                break;
        default:
                fatalx("if_set_mcast: unknown interface type");
        }

        return (0);
}

int
if_set_mcast_loop(int fd)
{
        u_int8_t         loop = 0;

        if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,
            (char *)&loop, sizeof(loop)) == -1) {
                log_warn("if_set_mcast_loop: error setting IP_MULTICAST_LOOP");
                return (-1);
        }

        return (0);
}

void
if_set_recvbuf(int fd)
{
        int      bsize;

        bsize = 65535;
        while (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &bsize,
            sizeof(bsize)) == -1)
                bsize /= 2;
}

int
if_join_group(struct iface *iface, struct in_addr *addr)
{
        struct ip_mreq   mreq;

        switch (iface->type) {
        case IF_TYPE_POINTOPOINT:
        case IF_TYPE_BROADCAST:
                mreq.imr_multiaddr.s_addr = addr->s_addr;
                mreq.imr_interface.s_addr = iface->addr.s_addr;

                if (setsockopt(iface->fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
                    (void *)&mreq, sizeof(mreq)) == -1)
                        return (-1);
                break;
        default:
                fatalx("if_join_group: unknown interface type");
        }

        return (0);
}

int
if_leave_group(struct iface *iface, struct in_addr *addr)
{
        struct ip_mreq   mreq;

        switch (iface->type) {
        case IF_TYPE_POINTOPOINT:
        case IF_TYPE_BROADCAST:
                mreq.imr_multiaddr.s_addr = addr->s_addr;
                mreq.imr_interface.s_addr = iface->addr.s_addr;

                if (setsockopt(iface->fd, IPPROTO_IP, IP_DROP_MEMBERSHIP,
                    (void *)&mreq, sizeof(mreq)) == -1)
                        return (-1);
                break;
        default:
                fatalx("if_leave_group: unknown interface type");
        }

        return (0);
}

struct iface *
if_new(struct kif *kif)
{
        struct sockaddr_in      *sain;
        struct iface            *iface;
        struct ifreq            *ifr;
        int                     s;

        if ((iface = calloc(1, sizeof(*iface))) == NULL)
                err(1, "if_new: calloc");

        iface->state = IF_STA_DOWN;

        LIST_INIT(&iface->nbr_list);
        TAILQ_INIT(&iface->rp_list);
        TAILQ_INIT(&iface->rq_list);

        strlcpy(iface->name, kif->ifname, sizeof(iface->name));

        if ((ifr = calloc(1, sizeof(*ifr))) == NULL)
                err(1, "if_new: calloc");

        /* set up ifreq */
        strlcpy(ifr->ifr_name, kif->ifname, sizeof(ifr->ifr_name));
        if ((s = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
            0)) == -1)
                err(1, "if_new: socket");

        /* get type */
        if (kif->flags & IFF_POINTOPOINT)
                iface->type = IF_TYPE_POINTOPOINT;
        if (kif->flags & IFF_BROADCAST &&
            kif->flags & IFF_MULTICAST)
                iface->type = IF_TYPE_BROADCAST;
        if (kif->flags & IFF_LOOPBACK) {
                iface->type = IF_TYPE_POINTOPOINT;
                /* XXX protect loopback from sending packets over lo? */
        }

        /* get mtu, index and flags */
        iface->mtu = kif->mtu;
        iface->ifindex = kif->ifindex;
        iface->flags = kif->flags;
        iface->linkstate = kif->link_state;
        iface->if_type = kif->if_type;
        iface->baudrate = kif->baudrate;

        /* get address */
        if (ioctl(s, SIOCGIFADDR, ifr) == -1)
                err(1, "if_new: cannot get address");
        sain = (struct sockaddr_in *)&ifr->ifr_addr;
        iface->addr = sain->sin_addr;

        /* get mask */
        if (ioctl(s, SIOCGIFNETMASK, ifr) == -1)
                err(1, "if_new: cannot get mask");
        sain = (struct sockaddr_in *)&ifr->ifr_addr;
        iface->mask = sain->sin_addr;

        /* get p2p dst address */
        if (kif->flags & IFF_POINTOPOINT) {
                if (ioctl(s, SIOCGIFDSTADDR, ifr) == -1)
                        err(1, "if_new: cannot get dst addr");
                sain = (struct sockaddr_in *)&ifr->ifr_addr;
                iface->dst = sain->sin_addr;
        }

        free(ifr);
        close(s);

        return (iface);
}

void
if_del(struct iface *iface)
{
        struct nbr      *nbr;

        log_debug("if_del: interface %s", iface->name);

        /* clear lists etc */
        while ((nbr = LIST_FIRST(&iface->nbr_list)) != NULL)
                nbr_del(nbr);

        /* XXX rq_list, rp_list */

        free(iface);
}

struct ctl_iface *
if_to_ctl(struct iface *iface)
{
        static struct ctl_iface  ictl;
        struct timeval           now;

        memcpy(ictl.name, iface->name, sizeof(ictl.name));
        memcpy(&ictl.addr, &iface->addr, sizeof(ictl.addr));
        memcpy(&ictl.mask, &iface->mask, sizeof(ictl.mask));

        ictl.ifindex = iface->ifindex;
        ictl.state = iface->state;
        ictl.mtu = iface->mtu;

        ictl.baudrate = iface->baudrate;
        ictl.flags = iface->flags;
        ictl.metric = iface->cost;
        ictl.type = iface->type;
        ictl.linkstate = iface->linkstate;
        ictl.passive = iface->passive;
        ictl.if_type = iface->if_type;

        gettimeofday(&now, NULL);

        if (iface->state != IF_STA_DOWN) {
                ictl.uptime = now.tv_sec - iface->uptime;
        } else
                ictl.uptime = 0;

        return (&ictl);
}