// SPDX-License-Identifier: GPL-2.0-or-later

/*

 * PIM for Quagga

 * Copyright (C) 2008  Everton da Silva Marques

 */

#include <zebra.h>

#include "log.h"

#include "prefix.h"

#include "zclient.h"

#include "stream.h"

#include "network.h"

#include "frrevent.h"

#include "prefix.h"

#include "vty.h"

#include "lib_errors.h"

#include "pimd.h"

#include "pim_instance.h"

#include "pim_iface.h"

#include "pim_neighbor.h"

#include "pim_pim.h"

#include "pim_str.h"

#include "pim_oil.h"

#include "pim_zlookup.h"

#include "pim_addr.h"

static struct zclient *zlookup = NULL;

struct event *zlookup_read;

static void zclient_lookup_sched(struct zclient *zlookup, int delay);

static void zclient_lookup_read_pipe(struct event *thread);

/* Connect to zebra for nexthop lookup. */

static void zclient_lookup_connect(struct event *t)

{

  struct zclient *zlookup;

  zlookup = EVENT_ARG(t);

  if (zlookup->sock >= 0) {

    return;

  }

  if (zclient_socket_connect(zlookup) < 0) {

    ++zlookup->fail;

    zlog_warn("%s: failure connecting zclient socket: failures=%d",

        __func__, zlookup->fail);

  } else {

    zlookup->fail = 0; /* reset counter on connection */

  }

  if (zclient_send_hello(zlookup) == ZCLIENT_SEND_FAILURE) {

    if (close(zlookup->sock)) {

      zlog_warn("%s: closing fd=%d: errno=%d %s", __func__,

          zlookup->sock, errno, safe_strerror(errno));

    }

    zlookup->sock = -1;

  }

  if (zlookup->sock < 0) {

    /* Since last connect failed, retry within 10 secs */

    zclient_lookup_sched(zlookup, 10);

    return;

  }

  event_add_timer(router->master, zclient_lookup_read_pipe, zlookup, 60,

      &zlookup_read);

}

/* Schedule connection with delay. */

static void zclient_lookup_sched(struct zclient *zlookup, int delay)

{

  event_add_timer(router->master, zclient_lookup_connect, zlookup, delay,

      &zlookup->t_connect);

  zlog_notice("%s: zclient lookup connection scheduled for %d seconds",

        __func__, delay);

}

/* Schedule connection for now. */

static void zclient_lookup_sched_now(struct zclient *zlookup)

{

  event_add_event(router->master, zclient_lookup_connect, zlookup, 0,

      &zlookup->t_connect);

  zlog_notice("%s: zclient lookup immediate connection scheduled",

        __func__);

}

/* Schedule reconnection, if needed. */

static void zclient_lookup_reconnect(struct zclient *zlookup)

{

  if (zlookup->t_connect) {

    return;

  }

  zclient_lookup_sched_now(zlookup);

}

static void zclient_lookup_failed(struct zclient *zlookup)

{

  if (zlookup->sock >= 0) {

    if (close(zlookup->sock)) {

      zlog_warn("%s: closing fd=%d: errno=%d %s", __func__,

          zlookup->sock, errno, safe_strerror(errno));

    }

    zlookup->sock = -1;

  }

  zclient_lookup_reconnect(zlookup);

}

void zclient_lookup_free(void)

{

  EVENT_OFF(zlookup_read);

  zclient_stop(zlookup);

  zclient_free(zlookup);

  zlookup = NULL;

}

void zclient_lookup_new(void)

{

  struct zclient_options options = zclient_options_default;

  options.synchronous = true;

  zlookup = zclient_new(router->master, &options, NULL, 0);

  if (!zlookup) {

    flog_err(EC_LIB_ZAPI_SOCKET, "%s: zclient_new() failure",

       __func__);

    return;

  }

  zlookup->sock = -1;

  zlookup->t_connect = NULL;

  zlookup->privs = &pimd_privs;

  zclient_lookup_sched_now(zlookup);

  zlog_notice("%s: zclient lookup socket initialized", __func__);

}

static int zclient_read_nexthop(struct pim_instance *pim,

        struct zclient *zlookup,

        struct pim_zlookup_nexthop nexthop_tab[],

        const int tab_size, pim_addr addr)

{

  int num_ifindex = 0;

  struct stream *s;

  uint16_t length;

  uint8_t marker;

  uint8_t version;

  vrf_id_t vrf_id;

  uint16_t command = 0;

  struct ipaddr raddr;

  uint8_t distance;

  uint32_t metric;

  int nexthop_num;

  int i, err;

  if (PIM_DEBUG_PIM_NHT_DETAIL)

    zlog_debug("%s: addr=%pPAs(%s)", __func__, &addr,

         pim->vrf->name);

  s = zlookup->ibuf;

  while (command != ZEBRA_NEXTHOP_LOOKUP_MRIB) {

    stream_reset(s);

    err = zclient_read_header(s, zlookup->sock, &length, &marker,

            &version, &vrf_id, &command);

    if (err < 0) {

      flog_err(EC_LIB_ZAPI_MISSMATCH,

         "%s: zclient_read_header() failed", __func__);

      zclient_lookup_failed(zlookup);

      return -1;

    }

    if (command == ZEBRA_ERROR) {

      enum zebra_error_types error;

      zapi_error_decode(s, &error);

      /* Do nothing with it for now */

      return -1;

    }

  }

  stream_get_ipaddr(s, &raddr);

  if (raddr.ipa_type != PIM_IPADDR ||

      pim_addr_cmp(raddr.ipaddr_pim, addr)) {

    zlog_warn("%s: address mismatch: addr=%pPA(%s) raddr=%pIA",

        __func__, &addr, pim->vrf->name, &raddr);

    /* warning only */

  }

  distance = stream_getc(s);

  metric = stream_getl(s);

  nexthop_num = stream_getc(s);

  if (nexthop_num < 1 || nexthop_num > router->multipath) {

    if (PIM_DEBUG_PIM_NHT_DETAIL)

      zlog_debug("%s: socket %d bad nexthop_num=%d", __func__,

           zlookup->sock, nexthop_num);

    return -6;

  }

  for (i = 0; i < nexthop_num; ++i) {

    vrf_id_t nexthop_vrf_id;

    enum nexthop_types_t nexthop_type;

    struct in_addr nh_ip4;

    struct in6_addr nh_ip6;

    ifindex_t nh_ifi;

    nexthop_vrf_id = stream_getl(s);

    nexthop_type = stream_getc(s);

    if (num_ifindex >= tab_size) {

      zlog_warn(

        "%s: found too many nexthop ifindexes (%d > %d) for address %pPAs(%s)",

        __func__, (num_ifindex + 1), tab_size, &addr,

        pim->vrf->name);

      return num_ifindex;

    }

    nexthop_tab[num_ifindex].protocol_distance = distance;

    nexthop_tab[num_ifindex].route_metric = metric;

    nexthop_tab[num_ifindex].vrf_id = nexthop_vrf_id;

    switch (nexthop_type) {

    case NEXTHOP_TYPE_IFINDEX:

      nexthop_tab[num_ifindex].ifindex = stream_getl(s);

      /*

       * Connected route (i.e. no nexthop), use

       * address passed in as PIM nexthop.  This will

       * allow us to work in cases where we are

       * trying to find a route for this box.

       */

      nexthop_tab[num_ifindex].nexthop_addr = addr;

      ++num_ifindex;

      break;

    case NEXTHOP_TYPE_IPV4_IFINDEX:

    case NEXTHOP_TYPE_IPV4:

      nh_ip4.s_addr = stream_get_ipv4(s);

      nh_ifi = stream_getl(s);

#if PIM_IPV == 4

      nexthop_tab[num_ifindex].nexthop_addr = nh_ip4;

      nexthop_tab[num_ifindex].ifindex = nh_ifi;

      ++num_ifindex;

#else

      zlog_warn(

        "cannot use IPv4 nexthop %pI4(%d) for IPv6 %pPA",

        &nh_ip4, nh_ifi, &addr);

#endif

      break;

    case NEXTHOP_TYPE_IPV6:

    case NEXTHOP_TYPE_IPV6_IFINDEX:

      stream_get(&nh_ip6, s, sizeof(nh_ip6));

      nh_ifi = stream_getl(s);

#if PIM_IPV == 6

      nexthop_tab[num_ifindex].nexthop_addr = nh_ip6;

      nexthop_tab[num_ifindex].ifindex = nh_ifi;

      ++num_ifindex;

#else

      /* RFC 5549 v4-over-v6 nexthop handling */

      /*

       * If we are sending v6 secondary assume we receive v6

       * secondary

       */

      struct interface *ifp = if_lookup_by_index(

        nh_ifi,

        nexthop_vrf_id);

      if (!ifp)

        break;

      struct pim_neighbor *nbr;

      if (pim->send_v6_secondary) {

        struct prefix p;

        p.family = AF_INET6;

        p.prefixlen = IPV6_MAX_BITLEN;

        p.u.prefix6 = nh_ip6;

        nbr = pim_neighbor_find_by_secondary(ifp, &p);

      } else

        nbr = pim_neighbor_find_if(ifp);

      if (!nbr)

        break;

      nexthop_tab[num_ifindex].nexthop_addr =

        nbr->source_addr;

      nexthop_tab[num_ifindex].ifindex = nh_ifi;

      ++num_ifindex;

#endif

      break;

    case NEXTHOP_TYPE_BLACKHOLE:

      /* do nothing */

      zlog_warn(

        "%s: found non-ifindex nexthop type=%d for address %pPAs(%s)",

        __func__, nexthop_type, &addr, pim->vrf->name);

      break;

    }

  }

  return num_ifindex;

}

static int zclient_lookup_nexthop_once(struct pim_instance *pim,

               struct pim_zlookup_nexthop nexthop_tab[],

               const int tab_size, pim_addr addr)

{

  struct stream *s;

  int ret;

  struct ipaddr ipaddr;

  if (PIM_DEBUG_PIM_NHT_DETAIL)

    zlog_debug("%s: addr=%pPAs(%s)", __func__, &addr,

         pim->vrf->name);

  /* Check socket. */

  if (zlookup->sock < 0) {

    flog_err(EC_LIB_ZAPI_SOCKET,

       "%s: zclient lookup socket is not connected",

       __func__);

    zclient_lookup_failed(zlookup);

    return -1;

  }

  if (pim->vrf->vrf_id == VRF_UNKNOWN) {

    zlog_notice(

      "%s: VRF: %s does not fully exist yet, delaying lookup",

      __func__, pim->vrf->name);

    return -1;

  }

  ipaddr.ipa_type = PIM_IPADDR;

  ipaddr.ipaddr_pim = addr;

  s = zlookup->obuf;

  stream_reset(s);

  zclient_create_header(s, ZEBRA_NEXTHOP_LOOKUP_MRIB, pim->vrf->vrf_id);

  stream_put_ipaddr(s, &ipaddr);

  stream_putw_at(s, 0, stream_get_endp(s));

  ret = writen(zlookup->sock, s->data, stream_get_endp(s));

  if (ret < 0) {

    flog_err(

      EC_LIB_SOCKET,

      "%s: writen() failure: %d writing to zclient lookup socket",

      __func__, errno);

    zclient_lookup_failed(zlookup);

    return -2;

  }

  if (ret == 0) {

    flog_err_sys(EC_LIB_SOCKET,

           "%s: connection closed on zclient lookup socket",

           __func__);

    zclient_lookup_failed(zlookup);

    return -3;

  }

  return zclient_read_nexthop(pim, zlookup, nexthop_tab, tab_size, addr);

}

void zclient_lookup_read_pipe(struct event *thread)

{

  struct zclient *zlookup = EVENT_ARG(thread);

  struct pim_instance *pim = pim_get_pim_instance(VRF_DEFAULT);

  struct pim_zlookup_nexthop nexthop_tab[10];

  pim_addr l = PIMADDR_ANY;

  if (!pim) {

    if (PIM_DEBUG_PIM_NHT_DETAIL)

      zlog_debug("%s: Unable to find pim instance", __func__);

    return;

  }

  zclient_lookup_nexthop_once(pim, nexthop_tab, 10, l);

  event_add_timer(router->master, zclient_lookup_read_pipe, zlookup, 60,

      &zlookup_read);

}

int zclient_lookup_nexthop(struct pim_instance *pim,

         struct pim_zlookup_nexthop nexthop_tab[],

         const int tab_size, pim_addr addr,

         int max_lookup)

{

  int lookup;

  uint32_t route_metric = 0xFFFFFFFF;

  uint8_t protocol_distance = 0xFF;

  pim->nexthop_lookups++;

  for (lookup = 0; lookup < max_lookup; ++lookup) {

    int num_ifindex;

    int first_ifindex;

    pim_addr nexthop_addr;

    num_ifindex = zclient_lookup_nexthop_once(pim, nexthop_tab,

                tab_size, addr);

    if (num_ifindex < 1) {

      if (PIM_DEBUG_PIM_NHT_DETAIL)

        zlog_debug(

          "%s: lookup=%d/%d: could not find nexthop ifindex for address %pPA(%s)",

          __func__, lookup, max_lookup, &addr,

          pim->vrf->name);

      return -1;

    }

    if (lookup < 1) {

      /* this is the non-recursive lookup - save original

       * metric/distance */

      route_metric = nexthop_tab[0].route_metric;

      protocol_distance = nexthop_tab[0].protocol_distance;

    }

    /*

     * FIXME: Non-recursive nexthop ensured only for first ifindex.

     * However, recursive route lookup should really be fixed in

     * zebra daemon.

     * See also TODO T24.

     *

     * So Zebra for NEXTHOP_TYPE_IPV4 returns the ifindex now since

     * it was being stored.  This Doesn't solve all cases of

     * recursive lookup but for the most common types it does.

     */

    first_ifindex = nexthop_tab[0].ifindex;

    nexthop_addr = nexthop_tab[0].nexthop_addr;

    if (first_ifindex > 0) {

      /* found: first ifindex is non-recursive nexthop */

      if (lookup > 0) {

        /* Report non-recursive success after first

         * lookup */

        if (PIM_DEBUG_PIM_NHT)

          zlog_debug(

            "%s: lookup=%d/%d: found non-recursive ifindex=%d for address %pPA(%s) dist=%d met=%d",

            __func__, lookup, max_lookup,

            first_ifindex, &addr,

            pim->vrf->name,

            nexthop_tab[0]

              .protocol_distance,

            nexthop_tab[0].route_metric);

        /* use last address as nexthop address */

        nexthop_tab[0].nexthop_addr = addr;

        /* report original route metric/distance */

        nexthop_tab[0].route_metric = route_metric;

        nexthop_tab[0].protocol_distance =

          protocol_distance;

      }

      return num_ifindex;

    }

    if (PIM_DEBUG_PIM_NHT)

      zlog_debug(

        "%s: lookup=%d/%d: zebra returned recursive nexthop %pPAs for address %pPA(%s) dist=%d met=%d",

        __func__, lookup, max_lookup, &nexthop_addr,

        &addr, pim->vrf->name,

        nexthop_tab[0].protocol_distance,

        nexthop_tab[0].route_metric);

    addr = nexthop_addr; /* use nexthop

          addr for recursive lookup */

  } /* for (max_lookup) */

  if (PIM_DEBUG_PIM_NHT)

    zlog_warn(

      "%s: lookup=%d/%d: failure searching recursive nexthop ifindex for address %pPA(%s)",

      __func__, lookup, max_lookup, &addr, pim->vrf->name);

  return -2;

}

void pim_zlookup_show_ip_multicast(struct vty *vty)

{

  vty_out(vty, "Zclient lookup socket: ");

  if (zlookup) {

    vty_out(vty, "%d failures=%d\n", zlookup->sock, zlookup->fail);

  } else {

    vty_out(vty, "<null zclient>\n");

  }

}

int pim_zlookup_sg_statistics(struct channel_oil *c_oil)

{

  struct stream *s = zlookup->obuf;

  uint16_t command = 0;

  unsigned long long lastused;

  pim_sgaddr sg;

  int count = 0;

  int ret;

  pim_sgaddr more = {};

  struct interface *ifp =

    pim_if_find_by_vif_index(c_oil->pim, *oil_parent(c_oil));

  if (PIM_DEBUG_ZEBRA) {

    more.src = *oil_origin(c_oil);

    more.grp = *oil_mcastgrp(c_oil);

    zlog_debug(

      "Sending Request for New Channel Oil Information%pSG VIIF %d(%s)",

      &more, *oil_parent(c_oil), c_oil->pim->vrf->name);

  }

  if (!ifp)

    return -1;

  stream_reset(s);

  zclient_create_header(s, ZEBRA_IPMR_ROUTE_STATS,

            c_oil->pim->vrf->vrf_id);

  stream_putl(s, PIM_AF);

  stream_write(s, oil_origin(c_oil), sizeof(pim_addr));

  stream_write(s, oil_mcastgrp(c_oil), sizeof(pim_addr));

  stream_putl(s, ifp->ifindex);

  stream_putw_at(s, 0, stream_get_endp(s));

  count = stream_get_endp(s);

  ret = writen(zlookup->sock, s->data, count);

  if (ret <= 0) {

    flog_err(

      EC_LIB_SOCKET,

      "%s: writen() failure: %d writing to zclient lookup socket",

      __func__, errno);

    return -1;

  }

  s = zlookup->ibuf;

  while (command != ZEBRA_IPMR_ROUTE_STATS) {

    int err;

    uint16_t length = 0;

    vrf_id_t vrf_id;

    uint8_t marker;

    uint8_t version;

    stream_reset(s);

    err = zclient_read_header(s, zlookup->sock, &length, &marker,

            &version, &vrf_id, &command);

    if (err < 0) {

      flog_err(EC_LIB_ZAPI_MISSMATCH,

         "%s: zclient_read_header() failed", __func__);

      zclient_lookup_failed(zlookup);

      return -1;

    }

  }

  stream_get(&sg.src, s, sizeof(pim_addr));

  stream_get(&sg.grp, s, sizeof(pim_addr));

  more.src = *oil_origin(c_oil);

  more.grp = *oil_mcastgrp(c_oil);

  if (pim_sgaddr_cmp(sg, more)) {

    if (PIM_DEBUG_ZEBRA)

      flog_err(

        EC_LIB_ZAPI_MISSMATCH,

        "%s: Received wrong %pSG(%s) information requested",

        __func__, &more, c_oil->pim->vrf->name);

    zclient_lookup_failed(zlookup);

    return -3;

  }

  stream_get(&lastused, s, sizeof(lastused));

  /* signed success value from netlink_talk; currently unused */

  (void)stream_getl(s);

  c_oil->cc.lastused = lastused;

  return 0;

}