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 "hsr_main.h"
  16 #include "hsr_device.h"
  17 #include "hsr_forward.h"
  18 #include "hsr_framereg.h"
  19
  20
  21 static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
  22 {
  23         struct sk_buff *skb = *pskb;
  24         struct hsr_port *port;
  25
  26         if (!skb_mac_header_was_set(skb)) {
  27                 WARN_ONCE(1, "%s: skb invalid", __func__);
  28                 return RX_HANDLER_PASS;
  29         }
  30
  31         rcu_read_lock(); /* hsr->node_db, hsr->ports */
  32         port = hsr_port_get_rcu(skb->dev);
  33         if (!port)
  34                 goto finish_pass;
  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         if (eth_hdr(skb)->h_proto != htons(ETH_P_PRP))
  43                 goto finish_pass;
  44
  45         skb_push(skb, ETH_HLEN);
  46
  47         hsr_forward_skb(skb, port);
  48
  49 finish_consume:
  50         rcu_read_unlock(); /* hsr->node_db, hsr->ports */
  51         return RX_HANDLER_CONSUMED;
  52
  53 finish_pass:
  54         rcu_read_unlock(); /* hsr->node_db, hsr->ports */
  55         return RX_HANDLER_PASS;
  56 }
  57
  58 bool hsr_port_exists(const struct net_device *dev)
  59 {
  60         return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
  61 }
  62
  63
  64 static int hsr_check_dev_ok(struct net_device *dev)
  65 {
  66         /* Don't allow HSR on non-ethernet like devices */
  67         if ((dev->flags & IFF_LOOPBACK) || (dev->type != ARPHRD_ETHER) ||
  68             (dev->addr_len != ETH_ALEN)) {
  69                 netdev_info(dev, "Cannot use loopback or non-ethernet device as HSR slave.\n");
  70                 return -EINVAL;
  71         }
  72
  73         /* Don't allow enslaving hsr devices */
  74         if (is_hsr_master(dev)) {
  75                 netdev_info(dev, "Cannot create trees of HSR devices.\n");
  76                 return -EINVAL;
  77         }
  78
  79         if (hsr_port_exists(dev)) {
  80                 netdev_info(dev, "This device is already a HSR slave.\n");
  81                 return -EINVAL;
  82         }
  83
  84         if (dev->priv_flags & IFF_802_1Q_VLAN) {
  85                 netdev_info(dev, "HSR on top of VLAN is not yet supported in this driver.\n");
  86                 return -EINVAL;
  87         }
  88
  89         if (dev->priv_flags & IFF_DONT_BRIDGE) {
  90                 netdev_info(dev, "This device does not support bridging.\n");
  91                 return -EOPNOTSUPP;
  92         }
  93
  94         /* HSR over bonded devices has not been tested, but I'm not sure it
  95          * won't work...
  96          */
  97
  98         return 0;
  99 }
 100
 101
 102 /* Setup device to be added to the HSR bridge. */
 103 static int hsr_portdev_setup(struct net_device *dev, struct hsr_port *port)
 104 {
 105         int res;
 106
 107         dev_hold(dev);
 108         res = dev_set_promiscuity(dev, 1);
 109         if (res)
 110                 goto fail_promiscuity;
 111
 112         /* FIXME:
 113          * What does net device "adjacency" mean? Should we do
 114          * res = netdev_master_upper_dev_link(port->dev, port->hsr->dev); ?
 115          */
 116
 117         res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
 118         if (res)
 119                 goto fail_rx_handler;
 120         dev_disable_lro(dev);
 121
 122         return 0;
 123
 124 fail_rx_handler:
 125         dev_set_promiscuity(dev, -1);
 126 fail_promiscuity:
 127         dev_put(dev);
 128
 129         return res;
 130 }
 131
 132 int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
 133                  enum hsr_port_type type)
 134 {
 135         struct hsr_port *port, *master;
 136         int res;
 137
 138         if (type != HSR_PT_MASTER) {
 139                 res = hsr_check_dev_ok(dev);
 140                 if (res)
 141                         return res;
 142         }
 143
 144         port = hsr_port_get_hsr(hsr, type);
 145         if (port != NULL)
 146                 return -EBUSY;  /* This port already exists */
 147
 148         port = kzalloc(sizeof(*port), GFP_KERNEL);
 149         if (port == NULL)
 150                 return -ENOMEM;
 151
 152         if (type != HSR_PT_MASTER) {
 153                 res = hsr_portdev_setup(dev, port);
 154                 if (res)
 155                         goto fail_dev_setup;
 156         }
 157
 158         port->hsr = hsr;
 159         port->dev = dev;
 160         port->type = type;
 161
 162         list_add_tail_rcu(&port->port_list, &hsr->ports);
 163         synchronize_rcu();
 164
 165         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 166         netdev_update_features(master->dev);
 167         dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
 168
 169         return 0;
 170
 171 fail_dev_setup:
 172         kfree(port);
 173         return res;
 174 }
 175
 176 void hsr_del_port(struct hsr_port *port)
 177 {
 178         struct hsr_priv *hsr;
 179         struct hsr_port *master;
 180
 181         hsr = port->hsr;
 182         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 183         list_del_rcu(&port->port_list);
 184
 185         if (port != master) {
 186                 if (master != NULL) {
 187                         netdev_update_features(master->dev);
 188                         dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
 189                 }
 190                 netdev_rx_handler_unregister(port->dev);
 191                 dev_set_promiscuity(port->dev, -1);
 192         }
 193
 194         /* FIXME?
 195          * netdev_upper_dev_unlink(port->dev, port->hsr->dev);
 196          */
 197
 198         synchronize_rcu();
 199
 200         if (port != master)
 201                 dev_put(port->dev);
 202 }