text: /*
   * Copyright (c) 2014, 2015, 2016, 2017 Nicira, Inc.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at:
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include <config.h>
  
  #include "ovs-router.h"
  
  #include <sys/types.h>
  #include <netinet/in.h>
  #include <arpa/inet.h>
  #include <errno.h>
  #include <inttypes.h>
  #include <sys/socket.h>
  #include <net/if.h>
  #include <stdarg.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  
  #include "classifier.h"
  #include "command-line.h"
  #include "compiler.h"
  #include "dpif.h"
  #include "fatal-signal.h"
  #include "openvswitch/dynamic-string.h"
  #include "netdev.h"
  #include "packets.h"
  #include "seq.h"
  #include "ovs-thread.h"
  #include "route-table.h"
  #include "tnl-ports.h"
  #include "unixctl.h"
  #include "util.h"
  #include "unaligned.h"
  #include "openvswitch/vlog.h"
  
  VLOG_DEFINE_THIS_MODULE(ovs_router);
  
  static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
  
  static struct ovs_mutex mutex = OVS_MUTEX_INITIALIZER;
  static struct classifier cls;
  
  struct ovs_router_entry {
      struct cls_rule cr;
      char output_bridge[IFNAMSIZ];
      struct in6_addr gw;
      struct in6_addr nw_addr;
      struct in6_addr src_addr;
      uint8_t plen;
      uint8_t priority;
      uint32_t mark;
  };
  
  static struct ovs_router_entry *
  ovs_router_entry_cast(const struct cls_rule *cr)
  {
      return cr ? CONTAINER_OF(cr, struct ovs_router_entry, cr) : NULL;
  }
  
  static bool
  ovs_router_lookup_fallback(const struct in6_addr *ip6_dst, char output_bridge[],
                             struct in6_addr *src6, struct in6_addr *gw6)
  {
      ovs_be32 src;
  
      if (!route_table_fallback_lookup(ip6_dst, output_bridge, gw6)) {
          return false;
      }
      if (netdev_get_in4_by_name(output_bridge, (struct in_addr *)&src)) {
          return false;
      }
      if (src6) {
          in6_addr_set_mapped_ipv4(src6, src);
      }
      return true;
  }
  
  bool
  ovs_router_lookup(uint32_t mark, const struct in6_addr *ip6_dst,
                    char output_bridge[],
                    struct in6_addr *src, struct in6_addr *gw)
  {
      const struct cls_rule *cr;
      struct flow flow = {.ipv6_dst = *ip6_dst, .pkt_mark = mark};
  
      cr = classifier_lookup(&cls, OVS_VERSION_MAX, &flow, NULL);
      if (cr) {
          struct ovs_router_entry *p = ovs_router_entry_cast(cr);
  
          ovs_strlcpy(output_bridge, p->output_bridge, IFNAMSIZ);
          *gw = p->gw;
          if (src) {
              *src = p->src_addr;
          }
          return true;
      }
      return ovs_router_lookup_fallback(ip6_dst, output_bridge, src, gw);
  }
  
  static void
  rt_entry_free(struct ovs_router_entry *p)
  {
      cls_rule_destroy(&p->cr);
      free(p);
  }
  
  static void rt_init_match(struct match *match, uint32_t mark,
                            const struct in6_addr *ip6_dst,
                            uint8_t plen)
  {
      struct in6_addr dst;
      struct in6_addr mask;
  
      mask = ipv6_create_mask(plen);
  
      dst = ipv6_addr_bitand(ip6_dst, &mask);
      memset(match, 0, sizeof *match);
      match->flow.ipv6_dst = dst;
      match->wc.masks.ipv6_dst = mask;
      match->wc.masks.pkt_mark = UINT32_MAX;
      match->flow.pkt_mark = mark;
  }
  
  static int
  get_src_addr(const struct in6_addr *ip6_dst,
               const char output_bridge[], struct in6_addr *psrc)
  {
      struct in6_addr *mask, *addr6;
      int err, n_in6, i, max_plen = -1;
      struct netdev *dev;
      bool is_ipv4;
  
      err = netdev_open(output_bridge, NULL, &dev);
      if (err) {
          return err;
      }
  
      err = netdev_get_addr_list(dev, &addr6, &mask, &n_in6);
      if (err) {
          goto out;
      }
  
      is_ipv4 = IN6_IS_ADDR_V4MAPPED(ip6_dst);
  
      for (i = 0; i < n_in6; i++) {
          struct in6_addr a1, a2;
          int mask_bits;
  
          if (is_ipv4 && !IN6_IS_ADDR_V4MAPPED(&addr6[i])) {
              continue;
          }
  
          a1 = ipv6_addr_bitand(ip6_dst, &mask[i]);
          a2 = ipv6_addr_bitand(&addr6[i], &mask[i]);
          mask_bits = bitmap_count1(ALIGNED_CAST(const unsigned long *, &mask[i]), 128);
  
          if (!memcmp(&a1, &a2, sizeof (a1)) && mask_bits > max_plen) {
              *psrc = addr6[i];
              max_plen = mask_bits;
          }
      }
      if (max_plen == -1) {
          err = ENOENT;
      }
  out:
      free(addr6);
      free(mask);
      netdev_close(dev);
      return err;
  }
  
  static int
  ovs_router_insert__(uint32_t mark, uint8_t priority,
                      const struct in6_addr *ip6_dst,
                      uint8_t plen, const char output_bridge[],
                      const struct in6_addr *gw)
  {
      const struct cls_rule *cr;
      struct ovs_router_entry *p;
      struct match match;
      int err;
  
      rt_init_match(&match, mark, ip6_dst, plen);
  
      p = xzalloc(sizeof *p);
      ovs_strlcpy(p->output_bridge, output_bridge, sizeof p->output_bridge);
      if (ipv6_addr_is_set(gw)) {
          p->gw = *gw;
      }
      p->mark = mark;
      p->nw_addr = match.flow.ipv6_dst;
      p->plen = plen;
      p->priority = priority;
      err = get_src_addr(ip6_dst, output_bridge, &p->src_addr);
      if (err && ipv6_addr_is_set(gw)) {
          err = get_src_addr(gw, output_bridge, &p->src_addr);
      }
      if (err) {
          struct ds ds = DS_EMPTY_INITIALIZER;
  
          ipv6_format_mapped(ip6_dst, &ds);
          VLOG_DBG_RL(&rl, "src addr not available for route %s", ds_cstr(&ds));
          free(p);
          ds_destroy(&ds);
          return err;
      }
      /* Longest prefix matches first. */
      cls_rule_init(&p->cr, &match, priority);
  
      ovs_mutex_lock(&mutex);
      cr = classifier_replace(&cls, &p->cr, OVS_VERSION_MIN, NULL, 0);
      ovs_mutex_unlock(&mutex);
  
      if (cr) {
          /* An old rule with the same match was displaced. */
          ovsrcu_postpone(rt_entry_free, ovs_router_entry_cast(cr));
      }
      tnl_port_map_insert_ipdev(output_bridge);
      seq_change(tnl_conf_seq);
      return 0;
  }
  
  void
  ovs_router_insert(uint32_t mark, const struct in6_addr *ip_dst, uint8_t plen,
                    const char output_bridge[], const struct in6_addr *gw)
  {
      ovs_router_insert__(mark, plen, ip_dst, plen, output_bridge, gw);
  }
  
  static void
  rt_entry_delete__(const struct cls_rule *cr)
  {
      struct ovs_router_entry *p = ovs_router_entry_cast(cr);
  
      tnl_port_map_delete_ipdev(p->output_bridge);
      classifier_remove_assert(&cls, cr);
      ovsrcu_postpone(rt_entry_free, ovs_router_entry_cast(cr));
  }
  
  static bool
  rt_entry_delete(uint32_t mark, uint8_t priority,
                  const struct in6_addr *ip6_dst, uint8_t plen)
  {
      const struct cls_rule *cr;
      struct cls_rule rule;
      struct match match;
      bool res = false;
  
      rt_init_match(&match, mark, ip6_dst, plen);
  
      cls_rule_init(&rule, &match, priority);
  
      /* Find the exact rule. */
      cr = classifier_find_rule_exactly(&cls, &rule, OVS_VERSION_MAX);
      if (cr) {
          ovs_mutex_lock(&mutex);
          rt_entry_delete__(cr);
          ovs_mutex_unlock(&mutex);
  
          res = true;
      }
  
      cls_rule_destroy(&rule);
      return res;
  }
  
  static bool
  scan_ipv6_route(const char *s, struct in6_addr *addr, unsigned int *plen)
  {
      char *error = ipv6_parse_cidr(s, addr, plen);
      if (error) {
          free(error);
          return false;
      }
      return true;
  }
  
  static bool
  scan_ipv4_route(const char *s, ovs_be32 *addr, unsigned int *plen)
  {
      char *error = ip_parse_cidr(s, addr, plen);
      if (error) {
          free(error);
          return false;
      }
      return true;
  }
  
  static void
  ovs_router_add(struct unixctl_conn *conn, int argc,
                const char *argv[], void *aux OVS_UNUSED)
  {
      struct in6_addr gw6 = in6addr_any;
      struct in6_addr ip6;
      uint32_t mark = 0;
      unsigned int plen;
      ovs_be32 ip;
      int err;
  
      if (scan_ipv4_route(argv[1], &ip, &plen)) {
          ovs_be32 gw = 0;
  
          if (argc > 3) {
              if (!ovs_scan(argv[3], "pkt_mark=%"SCNi32, &mark) &&
                  !ip_parse(argv[3], &gw)) {
                  unixctl_command_reply_error(conn, "Invalid pkt_mark or gateway");
                  return;
              }
          }
          in6_addr_set_mapped_ipv4(&ip6, ip);
          if (gw) {
              in6_addr_set_mapped_ipv4(&gw6, gw);
          }
          plen += 96;
      } else if (scan_ipv6_route(argv[1], &ip6, &plen)) {
          if (argc > 3) {
              if (!ovs_scan(argv[3], "pkt_mark=%"SCNi32, &mark) &&
                  !ipv6_parse(argv[3], &gw6)) {
                  unixctl_command_reply_error(conn, "Invalid pkt_mark or IPv6 gateway");
                  return;
              }
          }
      } else {
          unixctl_command_reply_error(conn, "Invalid parameters");
          return;
      }
      if (argc > 4) {
          if (!ovs_scan(argv[4], "pkt_mark=%"SCNi32, &mark)) {
              unixctl_command_reply_error(conn, "Invalid pkt_mark");
              return;
          }
      }
  
      err = ovs_router_insert__(mark, plen + 32, &ip6, plen, argv[2], &gw6);
      if (err) {
          unixctl_command_reply_error(conn, "Error while inserting route.");
      } else {
          unixctl_command_reply(conn, "OK");
      }
  }
  
  static void
  ovs_router_del(struct unixctl_conn *conn, int argc OVS_UNUSED,
                const char *argv[], void *aux OVS_UNUSED)
  {
      struct in6_addr ip6;
      uint32_t mark = 0;
      unsigned int plen;
      ovs_be32 ip;
  
      if (scan_ipv4_route(argv[1], &ip, &plen)) {
          in6_addr_set_mapped_ipv4(&ip6, ip);
          plen += 96;
      } else if (!scan_ipv6_route(argv[1], &ip6, &plen)) {
          unixctl_command_reply_error(conn, "Invalid parameters");
          return;
      }
      if (argc > 2) {
          if (!ovs_scan(argv[2], "pkt_mark=%"SCNi32, &mark)) {
              unixctl_command_reply_error(conn, "Invalid pkt_mark");
              return;
          }
      }
  
      if (rt_entry_delete(mark, plen + 32, &ip6, plen)) {
          unixctl_command_reply(conn, "OK");
          seq_change(tnl_conf_seq);
      } else {
          unixctl_command_reply_error(conn, "Not found");
      }
  }
  
  static void
  ovs_router_show(struct unixctl_conn *conn, int argc OVS_UNUSED,
                 const char *argv[] OVS_UNUSED, void *aux OVS_UNUSED)
  {
      struct ovs_router_entry *rt;
      struct ds ds = DS_EMPTY_INITIALIZER;
  
      ds_put_format(&ds, "Route Table:\n");
      CLS_FOR_EACH(rt, cr, &cls) {
          uint8_t plen;
          if (rt->priority == rt->plen) {
              ds_put_format(&ds, "Cached: ");
          } else {
              ds_put_format(&ds, "User: ");
          }
          ipv6_format_mapped(&rt->nw_addr, &ds);
          plen = rt->plen;
          if (IN6_IS_ADDR_V4MAPPED(&rt->nw_addr)) {
              plen -= 96;
          }
          ds_put_format(&ds, "/%"PRIu8, plen);
          if (rt->mark) {
              ds_put_format(&ds, " MARK %"PRIu32, rt->mark);
          }
  
          ds_put_format(&ds, " dev %s", rt->output_bridge);
          if (ipv6_addr_is_set(&rt->gw)) {
              ds_put_format(&ds, " GW ");
              ipv6_format_mapped(&rt->gw, &ds);
          }
          ds_put_format(&ds, " SRC ");
          ipv6_format_mapped(&rt->src_addr, &ds);
          ds_put_format(&ds, "\n");
      }
      unixctl_command_reply(conn, ds_cstr(&ds));
      ds_destroy(&ds);
  }
  
  static void
  ovs_router_lookup_cmd(struct unixctl_conn *conn, int argc,
                        const char *argv[], void *aux OVS_UNUSED)
  {
      struct in6_addr gw, src;
      char iface[IFNAMSIZ];
      struct in6_addr ip6;
      unsigned int plen;
      uint32_t mark = 0;
      ovs_be32 ip;
  
      if (scan_ipv4_route(argv[1], &ip, &plen) && plen == 32) {
          in6_addr_set_mapped_ipv4(&ip6, ip);
      } else if (!(scan_ipv6_route(argv[1], &ip6, &plen) && plen == 128)) {
          unixctl_command_reply_error(conn, "Invalid parameters");
          return;
      }
      if (argc > 2) {
          if (!ovs_scan(argv[2], "pkt_mark=%"SCNi32, &mark)) {
              unixctl_command_reply_error(conn, "Invalid pkt_mark");
              return;
          }
      }
      if (ovs_router_lookup(mark, &ip6, iface, &src, &gw)) {
          struct ds ds = DS_EMPTY_INITIALIZER;
  
          ds_put_format(&ds, "src ");
          ipv6_format_mapped(&src, &ds);
          ds_put_format(&ds, "\ngateway ");
          ipv6_format_mapped(&gw, &ds);
          ds_put_format(&ds, "\ndev %s\n", iface);
          unixctl_command_reply(conn, ds_cstr(&ds));
          ds_destroy(&ds);
      } else {
          unixctl_command_reply_error(conn, "Not found");
      }
  }
  
  void
  ovs_router_flush(void)
  {
      struct ovs_router_entry *rt;
  
      ovs_mutex_lock(&mutex);
      classifier_defer(&cls);
      CLS_FOR_EACH(rt, cr, &cls) {
          if (rt->priority == rt->plen) {
              rt_entry_delete__(&rt->cr);
          }
      }
      classifier_publish(&cls);
      ovs_mutex_unlock(&mutex);
      seq_change(tnl_conf_seq);
  }
  
  static void
  ovs_router_flush_handler(void *aux OVS_UNUSED)
  {
      ovs_router_flush();
  }
  
  void
  ovs_router_init(void)
  {
      static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
  
      if (ovsthread_once_start(&once)) {
          fatal_signal_add_hook(ovs_router_flush_handler, NULL, NULL, true);
          classifier_init(&cls, NULL);
          unixctl_command_register("ovs/route/add",
                                   "ip_addr/prefix_len out_br_name [gw] "
                                   "[pkt_mark=mark]",
                                   2, 4, ovs_router_add, NULL);
          unixctl_command_register("ovs/route/show", "", 0, 0,
                                   ovs_router_show, NULL);
          unixctl_command_register("ovs/route/del", "ip_addr/prefix_len "
                                   "[pkt_mark=mark]", 1, 2, ovs_router_del,
                                   NULL);
          unixctl_command_register("ovs/route/lookup", "ip_addr "
                                   "[pkt_mark=mark]", 1, 2,
                                   ovs_router_lookup_cmd, NULL);
          ovsthread_once_done(&once);
      }
  }
  