net/hsr/hsr_slave.c

   1 /* Copyright 2011-2014 Autronica Fire and Security AS
   2  *
   3  * This program is free software; you can redistribute it and/or modify it
   4  * under the terms of the GNU General Public License as published by the Free
   5  * Software Foundation; either version 2 of the License, or (at your option)
   6  * any later version.
   7  *
   8  * Author(s):
   9  *      2011-2014 Arvid Brodin, arvid.brodin@alten.se
  10  */
  11
  12 #include "hsr_slave.h"
  13 #include <linux/etherdevice.h>
  14 #include <linux/if_arp.h>
  15 #include <linux/if_vlan.h>
  16 #include "hsr_main.h"
  17 #include "hsr_device.h"
  18 #include "hsr_forward.h"
  19 #include "hsr_framereg.h"
  20
  21
  22 static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
  23 {
  24         struct sk_buff *skb = *pskb;
  25         struct hsr_port *port;
  26         u16 protocol;
  27
  28         if (!skb_mac_header_was_set(skb)) {
  29                 WARN_ONCE(1, "%s: skb invalid", __func__);
  30                 return RX_HANDLER_PASS;
  31         }
  32
  33         rcu_read_lock(); /* hsr->node_db, hsr->ports */
  34         port = hsr_port_get_rcu(skb->dev);
  35
  36         if (hsr_addr_is_self(port->hsr, eth_hdr(skb)->h_source)) {
  37                 /* Directly kill frames sent by ourselves */
  38                 kfree_skb(skb);
  39                 goto finish_consume;
  40         }
  41
  42         protocol = eth_hdr(skb)->h_proto;
  43         if (protocol != htons(ETH_P_PRP) && protocol != htons(ETH_P_HSR))
  44                 goto finish_pass;
  45
  46         skb_push(skb, ETH_HLEN);
  47
  48         hsr_forward_skb(skb, port);
  49
  50 finish_consume:
  51         rcu_read_unlock(); /* hsr->node_db, hsr->ports */
  52         return RX_HANDLER_CONSUMED;
  53
  54 finish_pass:
  55         rcu_read_unlock(); /* hsr->node_db, hsr->ports */
  56         return RX_HANDLER_PASS;
  57 }
  58
  59 bool hsr_port_exists(const struct net_device *dev)
  60 {
  61         return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
  62 }
  63
  64
  65 static int hsr_check_dev_ok(struct net_device *dev)
  66 {
  67         /* Don't allow HSR on non-ethernet like devices */
  68         if ((dev->flags & IFF_LOOPBACK) || (dev->type != ARPHRD_ETHER) ||
  69             (dev->addr_len != ETH_ALEN)) {
  70                 netdev_info(dev, "Cannot use loopback or non-ethernet device as HSR slave.\n");
  71                 return -EINVAL;
  72         }
  73
  74         /* Don't allow enslaving hsr devices */
  75         if (is_hsr_master(dev)) {
  76                 netdev_info(dev, "Cannot create trees of HSR devices.\n");
  77                 return -EINVAL;
  78         }
  79
  80         if (hsr_port_exists(dev)) {
  81                 netdev_info(dev, "This device is already a HSR slave.\n");
  82                 return -EINVAL;
  83         }
  84
  85         if (is_vlan_dev(dev)) {
  86                 netdev_info(dev, "HSR on top of VLAN is not yet supported in this driver.\n");
  87                 return -EINVAL;
  88         }
  89
  90         if (dev->priv_flags & IFF_DONT_BRIDGE) {
  91                 netdev_info(dev, "This device does not support bridging.\n");
  92                 return -EOPNOTSUPP;
  93         }
  94
  95         /* HSR over bonded devices has not been tested, but I'm not sure it
  96          * won't work...
  97          */
  98
  99         return 0;
 100 }
 101
 102
 103 /* Setup device to be added to the HSR bridge. */
 104 static int hsr_portdev_setup(struct net_device *dev, struct hsr_port *port)
 105 {
 106         int res;
 107
 108         dev_hold(dev);
 109         res = dev_set_promiscuity(dev, 1);
 110         if (res)
 111                 goto fail_promiscuity;
 112
 113         /* FIXME:
 114          * What does net device "adjacency" mean? Should we do
 115          * res = netdev_master_upper_dev_link(port->dev, port->hsr->dev); ?
 116          */
 117
 118         res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
 119         if (res)
 120                 goto fail_rx_handler;
 121         dev_disable_lro(dev);
 122
 123         return 0;
 124
 125 fail_rx_handler:
 126         dev_set_promiscuity(dev, -1);
 127 fail_promiscuity:
 128         dev_put(dev);
 129
 130         return res;
 131 }
 132
 133 int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
 134                  enum hsr_port_type type)
 135 {
 136         struct hsr_port *port, *master;
 137         int res;
 138
 139         if (type != HSR_PT_MASTER) {
 140                 res = hsr_check_dev_ok(dev);
 141                 if (res)
 142                         return res;
 143         }
 144
 145         port = hsr_port_get_hsr(hsr, type);
 146         if (port != NULL)
 147                 return -EBUSY;  /* This port already exists */
 148
 149         port = kzalloc(sizeof(*port), GFP_KERNEL);
 150         if (port == NULL)
 151                 return -ENOMEM;
 152
 153         if (type != HSR_PT_MASTER) {
 154                 res = hsr_portdev_setup(dev, port);
 155                 if (res)
 156                         goto fail_dev_setup;
 157         }
 158
 159         port->hsr = hsr;
 160         port->dev = dev;
 161         port->type = type;
 162
 163         list_add_tail_rcu(&port->port_list, &hsr->ports);
 164         synchronize_rcu();
 165
 166         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 167         netdev_update_features(master->dev);
 168         dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
 169
 170         return 0;
 171
 172 fail_dev_setup:
 173         kfree(port);
 174         return res;
 175 }
 176
 177 void hsr_del_port(struct hsr_port *port)
 178 {
 179         struct hsr_priv *hsr;
 180         struct hsr_port *master;
 181
 182         hsr = port->hsr;
 183         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 184         list_del_rcu(&port->port_list);
 185
 186         if (port != master) {
 187                 if (master != NULL) {
 188                         netdev_update_features(master->dev);
 189                         dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
 190                 }
 191                 netdev_rx_handler_unregister(port->dev);
 192                 dev_set_promiscuity(port->dev, -1);
 193         }
 194
 195         /* FIXME?
 196          * netdev_upper_dev_unlink(port->dev, port->hsr->dev);
 197          */
 198
 199         synchronize_rcu();
 200
 201         if (port != master)
 202                 dev_put(port->dev);
 203 }