net/l3mdev/l3mdev.c

   1 /*
   2  * net/l3mdev/l3mdev.c - L3 master device implementation
   3  * Copyright (c) 2015 Cumulus Networks
   4  * Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <linux/netdevice.h>
  13 #include <net/fib_rules.h>
  14 #include <net/l3mdev.h>
  15
  16 /**
  17  *      l3mdev_master_ifindex - get index of L3 master device
  18  *      @dev: targeted interface
  19  */
  20
  21 int l3mdev_master_ifindex_rcu(const struct net_device *dev)
  22 {
  23         int ifindex = 0;
  24
  25         if (!dev)
  26                 return 0;
  27
  28         if (netif_is_l3_master(dev)) {
  29                 ifindex = dev->ifindex;
  30         } else if (netif_is_l3_slave(dev)) {
  31                 struct net_device *master;
  32                 struct net_device *_dev = (struct net_device *)dev;
  33
  34                 /* netdev_master_upper_dev_get_rcu calls
  35                  * list_first_or_null_rcu to walk the upper dev list.
  36                  * list_first_or_null_rcu does not handle a const arg. We aren't
  37                  * making changes, just want the master device from that list so
  38                  * typecast to remove the const
  39                  */
  40                 master = netdev_master_upper_dev_get_rcu(_dev);
  41                 if (master)
  42                         ifindex = master->ifindex;
  43         }
  44
  45         return ifindex;
  46 }
  47 EXPORT_SYMBOL_GPL(l3mdev_master_ifindex_rcu);
  48
  49 /**
  50  *      l3mdev_fib_table - get FIB table id associated with an L3
  51  *                             master interface
  52  *      @dev: targeted interface
  53  */
  54
  55 u32 l3mdev_fib_table_rcu(const struct net_device *dev)
  56 {
  57         u32 tb_id = 0;
  58
  59         if (!dev)
  60                 return 0;
  61
  62         if (netif_is_l3_master(dev)) {
  63                 if (dev->l3mdev_ops->l3mdev_fib_table)
  64                         tb_id = dev->l3mdev_ops->l3mdev_fib_table(dev);
  65         } else if (netif_is_l3_slave(dev)) {
  66                 /* Users of netdev_master_upper_dev_get_rcu need non-const,
  67                  * but current inet_*type functions take a const
  68                  */
  69                 struct net_device *_dev = (struct net_device *) dev;
  70                 const struct net_device *master;
  71
  72                 master = netdev_master_upper_dev_get_rcu(_dev);
  73                 if (master &&
  74                     master->l3mdev_ops->l3mdev_fib_table)
  75                         tb_id = master->l3mdev_ops->l3mdev_fib_table(master);
  76         }
  77
  78         return tb_id;
  79 }
  80 EXPORT_SYMBOL_GPL(l3mdev_fib_table_rcu);
  81
  82 u32 l3mdev_fib_table_by_index(struct net *net, int ifindex)
  83 {
  84         struct net_device *dev;
  85         u32 tb_id = 0;
  86
  87         if (!ifindex)
  88                 return 0;
  89
  90         rcu_read_lock();
  91
  92         dev = dev_get_by_index_rcu(net, ifindex);
  93         if (dev)
  94                 tb_id = l3mdev_fib_table_rcu(dev);
  95
  96         rcu_read_unlock();
  97
  98         return tb_id;
  99 }
 100 EXPORT_SYMBOL_GPL(l3mdev_fib_table_by_index);
 101
 102 /**
 103  *      l3mdev_link_scope_lookup - IPv6 route lookup based on flow for link
 104  *                           local and multicast addresses
 105  *      @net: network namespace for device index lookup
 106  *      @fl6: IPv6 flow struct for lookup
 107  */
 108
 109 struct dst_entry *l3mdev_link_scope_lookup(struct net *net,
 110                                            struct flowi6 *fl6)
 111 {
 112         struct dst_entry *dst = NULL;
 113         struct net_device *dev;
 114
 115         if (fl6->flowi6_oif) {
 116                 rcu_read_lock();
 117
 118                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 119                 if (dev && netif_is_l3_slave(dev))
 120                         dev = netdev_master_upper_dev_get_rcu(dev);
 121
 122                 if (dev && netif_is_l3_master(dev) &&
 123                     dev->l3mdev_ops->l3mdev_link_scope_lookup)
 124                         dst = dev->l3mdev_ops->l3mdev_link_scope_lookup(dev, fl6);
 125
 126                 rcu_read_unlock();
 127         }
 128
 129         return dst;
 130 }
 131 EXPORT_SYMBOL_GPL(l3mdev_link_scope_lookup);
 132
 133 int l3mdev_get_saddr6(struct net *net, const struct sock *sk,
 134                       struct flowi6 *fl6)
 135 {
 136         struct net_device *dev;
 137         int rc = 0;
 138
 139         if (fl6->flowi6_oif) {
 140                 rcu_read_lock();
 141
 142                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 143                 if (dev && netif_is_l3_slave(dev))
 144                         dev = netdev_master_upper_dev_get_rcu(dev);
 145
 146                 if (dev && netif_is_l3_master(dev) &&
 147                     dev->l3mdev_ops->l3mdev_get_saddr6)
 148                         rc = dev->l3mdev_ops->l3mdev_get_saddr6(dev, sk, fl6);
 149
 150                 rcu_read_unlock();
 151         }
 152
 153         return rc;
 154 }
 155 EXPORT_SYMBOL_GPL(l3mdev_get_saddr6);
 156
 157 /**
 158  *      l3mdev_fib_rule_match - Determine if flowi references an
 159  *                              L3 master device
 160  *      @net: network namespace for device index lookup
 161  *      @fl:  flow struct
 162  */
 163
 164 int l3mdev_fib_rule_match(struct net *net, struct flowi *fl,
 165                           struct fib_lookup_arg *arg)
 166 {
 167         struct net_device *dev;
 168         int rc = 0;
 169
 170         rcu_read_lock();
 171
 172         dev = dev_get_by_index_rcu(net, fl->flowi_oif);
 173         if (dev && netif_is_l3_master(dev) &&
 174             dev->l3mdev_ops->l3mdev_fib_table) {
 175                 arg->table = dev->l3mdev_ops->l3mdev_fib_table(dev);
 176                 rc = 1;
 177                 goto out;
 178         }
 179
 180         dev = dev_get_by_index_rcu(net, fl->flowi_iif);
 181         if (dev && netif_is_l3_master(dev) &&
 182             dev->l3mdev_ops->l3mdev_fib_table) {
 183                 arg->table = dev->l3mdev_ops->l3mdev_fib_table(dev);
 184                 rc = 1;
 185                 goto out;
 186         }
 187
 188 out:
 189         rcu_read_unlock();
 190
 191         return rc;
 192 }
 193
 194 void l3mdev_update_flow(struct net *net, struct flowi *fl)
 195 {
 196         struct net_device *dev;
 197         int ifindex;
 198
 199         rcu_read_lock();
 200
 201         if (fl->flowi_oif) {
 202                 dev = dev_get_by_index_rcu(net, fl->flowi_oif);
 203                 if (dev) {
 204                         ifindex = l3mdev_master_ifindex_rcu(dev);
 205                         if (ifindex) {
 206                                 fl->flowi_oif = ifindex;
 207                                 fl->flowi_flags |= FLOWI_FLAG_SKIP_NH_OIF;
 208                                 goto out;
 209                         }
 210                 }
 211         }
 212
 213         if (fl->flowi_iif) {
 214                 dev = dev_get_by_index_rcu(net, fl->flowi_iif);
 215                 if (dev) {
 216                         ifindex = l3mdev_master_ifindex_rcu(dev);
 217                         if (ifindex) {
 218                                 fl->flowi_iif = ifindex;
 219                                 fl->flowi_flags |= FLOWI_FLAG_SKIP_NH_OIF;
 220                         }
 221                 }
 222         }
 223
 224 out:
 225         rcu_read_unlock();
 226 }
 227 EXPORT_SYMBOL_GPL(l3mdev_update_flow);