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
  34         if (hsr_addr_is_self(port->hsr, eth_hdr(skb)->h_source)) {
  35                 /* Directly kill frames sent by ourselves */
  36                 kfree_skb(skb);
  37                 goto finish_consume;
  38         }
  39
  40         if (eth_hdr(skb)->h_proto != htons(ETH_P_PRP))
  41                 goto finish_pass;
  42
  43         skb_push(skb, ETH_HLEN);
  44
  45         hsr_forward_skb(skb, port);
  46
  47 finish_consume:
  48         rcu_read_unlock(); /* hsr->node_db, hsr->ports */
  49         return RX_HANDLER_CONSUMED;
  50
  51 finish_pass:
  52         rcu_read_unlock(); /* hsr->node_db, hsr->ports */
  53         return RX_HANDLER_PASS;
  54 }
  55
  56 bool hsr_port_exists(const struct net_device *dev)
  57 {
  58         return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
  59 }
  60
  61
  62 static int hsr_check_dev_ok(struct net_device *dev)
  63 {
  64         /* Don't allow HSR on non-ethernet like devices */
  65         if ((dev->flags & IFF_LOOPBACK) || (dev->type != ARPHRD_ETHER) ||
  66             (dev->addr_len != ETH_ALEN)) {
  67                 netdev_info(dev, "Cannot use loopback or non-ethernet device as HSR slave.\n");
  68                 return -EINVAL;
  69         }
  70
  71         /* Don't allow enslaving hsr devices */
  72         if (is_hsr_master(dev)) {
  73                 netdev_info(dev, "Cannot create trees of HSR devices.\n");
  74                 return -EINVAL;
  75         }
  76
  77         if (hsr_port_exists(dev)) {
  78                 netdev_info(dev, "This device is already a HSR slave.\n");
  79                 return -EINVAL;
  80         }
  81
  82         if (dev->priv_flags & IFF_802_1Q_VLAN) {
  83                 netdev_info(dev, "HSR on top of VLAN is not yet supported in this driver.\n");
  84                 return -EINVAL;
  85         }
  86
  87         if (dev->priv_flags & IFF_DONT_BRIDGE) {
  88                 netdev_info(dev, "This device does not support bridging.\n");
  89                 return -EOPNOTSUPP;
  90         }
  91
  92         /* HSR over bonded devices has not been tested, but I'm not sure it
  93          * won't work...
  94          */
  95
  96         return 0;
  97 }
  98
  99
 100 /* Setup device to be added to the HSR bridge. */
 101 static int hsr_portdev_setup(struct net_device *dev, struct hsr_port *port)
 102 {
 103         int res;
 104
 105         dev_hold(dev);
 106         res = dev_set_promiscuity(dev, 1);
 107         if (res)
 108                 goto fail_promiscuity;
 109
 110         /* FIXME:
 111          * What does net device "adjacency" mean? Should we do
 112          * res = netdev_master_upper_dev_link(port->dev, port->hsr->dev); ?
 113          */
 114
 115         res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
 116         if (res)
 117                 goto fail_rx_handler;
 118         dev_disable_lro(dev);
 119
 120         return 0;
 121
 122 fail_rx_handler:
 123         dev_set_promiscuity(dev, -1);
 124 fail_promiscuity:
 125         dev_put(dev);
 126
 127         return res;
 128 }
 129
 130 int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
 131                  enum hsr_port_type type)
 132 {
 133         struct hsr_port *port, *master;
 134         int res;
 135
 136         if (type != HSR_PT_MASTER) {
 137                 res = hsr_check_dev_ok(dev);
 138                 if (res)
 139                         return res;
 140         }
 141
 142         port = hsr_port_get_hsr(hsr, type);
 143         if (port != NULL)
 144                 return -EBUSY;  /* This port already exists */
 145
 146         port = kzalloc(sizeof(*port), GFP_KERNEL);
 147         if (port == NULL)
 148                 return -ENOMEM;
 149
 150         if (type != HSR_PT_MASTER) {
 151                 res = hsr_portdev_setup(dev, port);
 152                 if (res)
 153                         goto fail_dev_setup;
 154         }
 155
 156         port->hsr = hsr;
 157         port->dev = dev;
 158         port->type = type;
 159
 160         list_add_tail_rcu(&port->port_list, &hsr->ports);
 161         synchronize_rcu();
 162
 163         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 164         netdev_update_features(master->dev);
 165         dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
 166
 167         return 0;
 168
 169 fail_dev_setup:
 170         kfree(port);
 171         return res;
 172 }
 173
 174 void hsr_del_port(struct hsr_port *port)
 175 {
 176         struct hsr_priv *hsr;
 177         struct hsr_port *master;
 178
 179         hsr = port->hsr;
 180         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 181         list_del_rcu(&port->port_list);
 182
 183         if (port != master) {
 184                 if (master != NULL) {
 185                         netdev_update_features(master->dev);
 186                         dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
 187                 }
 188                 netdev_rx_handler_unregister(port->dev);
 189                 dev_set_promiscuity(port->dev, -1);
 190         }
 191
 192         /* FIXME?
 193          * netdev_upper_dev_unlink(port->dev, port->hsr->dev);
 194          */
 195
 196         synchronize_rcu();
 197
 198         if (port != master)
 199                 dev_put(port->dev);
 200 }