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 /**
 134  *      l3mdev_get_saddr - get source address for a flow based on an interface
 135  *                         enslaved to an L3 master device
 136  *      @net: network namespace for device index lookup
 137  *      @ifindex: Interface index
 138  *      @fl4: IPv4 flow struct
 139  */
 140
 141 int l3mdev_get_saddr(struct net *net, int ifindex, struct flowi4 *fl4)
 142 {
 143         struct net_device *dev;
 144         int rc = 0;
 145
 146         if (ifindex) {
 147                 rcu_read_lock();
 148
 149                 dev = dev_get_by_index_rcu(net, ifindex);
 150                 if (dev && netif_is_l3_slave(dev))
 151                         dev = netdev_master_upper_dev_get_rcu(dev);
 152
 153                 if (dev && netif_is_l3_master(dev) &&
 154                     dev->l3mdev_ops->l3mdev_get_saddr)
 155                         rc = dev->l3mdev_ops->l3mdev_get_saddr(dev, fl4);
 156
 157                 rcu_read_unlock();
 158         }
 159
 160         return rc;
 161 }
 162 EXPORT_SYMBOL_GPL(l3mdev_get_saddr);
 163
 164 int l3mdev_get_saddr6(struct net *net, const struct sock *sk,
 165                       struct flowi6 *fl6)
 166 {
 167         struct net_device *dev;
 168         int rc = 0;
 169
 170         if (fl6->flowi6_oif) {
 171                 rcu_read_lock();
 172
 173                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 174                 if (dev && netif_is_l3_slave(dev))
 175                         dev = netdev_master_upper_dev_get_rcu(dev);
 176
 177                 if (dev && netif_is_l3_master(dev) &&
 178                     dev->l3mdev_ops->l3mdev_get_saddr6)
 179                         rc = dev->l3mdev_ops->l3mdev_get_saddr6(dev, sk, fl6);
 180
 181                 rcu_read_unlock();
 182         }
 183
 184         return rc;
 185 }
 186 EXPORT_SYMBOL_GPL(l3mdev_get_saddr6);
 187
 188 /**
 189  *      l3mdev_fib_rule_match - Determine if flowi references an
 190  *                              L3 master device
 191  *      @net: network namespace for device index lookup
 192  *      @fl:  flow struct
 193  */
 194
 195 int l3mdev_fib_rule_match(struct net *net, struct flowi *fl,
 196                           struct fib_lookup_arg *arg)
 197 {
 198         struct net_device *dev;
 199         int rc = 0;
 200
 201         rcu_read_lock();
 202
 203         dev = dev_get_by_index_rcu(net, fl->flowi_oif);
 204         if (dev && netif_is_l3_master(dev) &&
 205             dev->l3mdev_ops->l3mdev_fib_table) {
 206                 arg->table = dev->l3mdev_ops->l3mdev_fib_table(dev);
 207                 rc = 1;
 208                 goto out;
 209         }
 210
 211         dev = dev_get_by_index_rcu(net, fl->flowi_iif);
 212         if (dev && netif_is_l3_master(dev) &&
 213             dev->l3mdev_ops->l3mdev_fib_table) {
 214                 arg->table = dev->l3mdev_ops->l3mdev_fib_table(dev);
 215                 rc = 1;
 216                 goto out;
 217         }
 218
 219 out:
 220         rcu_read_unlock();
 221
 222         return rc;
 223 }
 224
 225 void l3mdev_update_flow(struct net *net, struct flowi *fl)
 226 {
 227         struct net_device *dev;
 228         int ifindex;
 229
 230         rcu_read_lock();
 231
 232         if (fl->flowi_oif) {
 233                 dev = dev_get_by_index_rcu(net, fl->flowi_oif);
 234                 if (dev) {
 235                         ifindex = l3mdev_master_ifindex_rcu(dev);
 236                         if (ifindex) {
 237                                 fl->flowi_oif = ifindex;
 238                                 fl->flowi_flags |= FLOWI_FLAG_SKIP_NH_OIF;
 239                                 goto out;
 240                         }
 241                 }
 242         }
 243
 244         if (fl->flowi_iif) {
 245                 dev = dev_get_by_index_rcu(net, fl->flowi_iif);
 246                 if (dev) {
 247                         ifindex = l3mdev_master_ifindex_rcu(dev);
 248                         if (ifindex) {
 249                                 fl->flowi_iif = ifindex;
 250                                 fl->flowi_flags |= FLOWI_FLAG_SKIP_NH_OIF;
 251                         }
 252                 }
 253         }
 254
 255 out:
 256         rcu_read_unlock();
 257 }
 258 EXPORT_SYMBOL_GPL(l3mdev_update_flow);