net/hsr/hsr_slave.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright 2011-2014 Autronica Fire and Security AS
   3  *
   4  * Author(s):
   5  *      2011-2014 Arvid Brodin, arvid.brodin@alten.se
   6  */
   7
   8 #include "hsr_slave.h"
   9 #include <linux/etherdevice.h>
  10 #include <linux/if_arp.h>
  11 #include <linux/if_vlan.h>
  12 #include "hsr_main.h"
  13 #include "hsr_device.h"
  14 #include "hsr_forward.h"
  15 #include "hsr_framereg.h"
  16
  17 static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
  18 {
  19         struct sk_buff *skb = *pskb;
  20         struct hsr_port *port;
  21         u16 protocol;
  22
  23         if (!skb_mac_header_was_set(skb)) {
  24                 WARN_ONCE(1, "%s: skb invalid", __func__);
  25                 return RX_HANDLER_PASS;
  26         }
  27
  28         rcu_read_lock(); /* hsr->node_db, hsr->ports */
  29         port = hsr_port_get_rcu(skb->dev);
  30         if (!port)
  31                 goto finish_pass;
  32
  33         if (hsr_addr_is_self(port->hsr, eth_hdr(skb)->h_source)) {
  34                 /* Directly kill frames sent by ourselves */
  35                 kfree_skb(skb);
  36                 goto finish_consume;
  37         }
  38
  39         protocol = eth_hdr(skb)->h_proto;
  40         if (protocol != htons(ETH_P_PRP) && protocol != htons(ETH_P_HSR))
  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 static int hsr_check_dev_ok(struct net_device *dev)
  62 {
  63         /* Don't allow HSR on non-ethernet like devices */
  64         if ((dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
  65             dev->addr_len != ETH_ALEN) {
  66                 netdev_info(dev, "Cannot use loopback or non-ethernet device as HSR slave.\n");
  67                 return -EINVAL;
  68         }
  69
  70         /* Don't allow enslaving hsr devices */
  71         if (is_hsr_master(dev)) {
  72                 netdev_info(dev, "Cannot create trees of HSR devices.\n");
  73                 return -EINVAL;
  74         }
  75
  76         if (hsr_port_exists(dev)) {
  77                 netdev_info(dev, "This device is already a HSR slave.\n");
  78                 return -EINVAL;
  79         }
  80
  81         if (is_vlan_dev(dev)) {
  82                 netdev_info(dev, "HSR on top of VLAN is not yet supported in this driver.\n");
  83                 return -EINVAL;
  84         }
  85
  86         if (dev->priv_flags & IFF_DONT_BRIDGE) {
  87                 netdev_info(dev, "This device does not support bridging.\n");
  88                 return -EOPNOTSUPP;
  89         }
  90
  91         /* HSR over bonded devices has not been tested, but I'm not sure it
  92          * won't work...
  93          */
  94
  95         return 0;
  96 }
  97
  98 /* Setup device to be added to the HSR bridge. */
  99 static int hsr_portdev_setup(struct net_device *dev, struct hsr_port *port)
 100 {
 101         int res;
 102
 103         dev_hold(dev);
 104         res = dev_set_promiscuity(dev, 1);
 105         if (res)
 106                 goto fail_promiscuity;
 107
 108         /* FIXME:
 109          * What does net device "adjacency" mean? Should we do
 110          * res = netdev_master_upper_dev_link(port->dev, port->hsr->dev); ?
 111          */
 112
 113         res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
 114         if (res)
 115                 goto fail_rx_handler;
 116         dev_disable_lro(dev);
 117
 118         return 0;
 119
 120 fail_rx_handler:
 121         dev_set_promiscuity(dev, -1);
 122 fail_promiscuity:
 123         dev_put(dev);
 124
 125         return res;
 126 }
 127
 128 int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
 129                  enum hsr_port_type type)
 130 {
 131         struct hsr_port *port, *master;
 132         int res;
 133
 134         if (type != HSR_PT_MASTER) {
 135                 res = hsr_check_dev_ok(dev);
 136                 if (res)
 137                         return res;
 138         }
 139
 140         port = hsr_port_get_hsr(hsr, type);
 141         if (port)
 142                 return -EBUSY;  /* This port already exists */
 143
 144         port = kzalloc(sizeof(*port), GFP_KERNEL);
 145         if (!port)
 146                 return -ENOMEM;
 147
 148         port->hsr = hsr;
 149         port->dev = dev;
 150         port->type = type;
 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         list_add_tail_rcu(&port->port_list, &hsr->ports);
 159         synchronize_rcu();
 160
 161         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 162         netdev_update_features(master->dev);
 163         dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
 164
 165         return 0;
 166
 167 fail_dev_setup:
 168         kfree(port);
 169         return res;
 170 }
 171
 172 void hsr_del_port(struct hsr_port *port)
 173 {
 174         struct hsr_priv *hsr;
 175         struct hsr_port *master;
 176
 177         hsr = port->hsr;
 178         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 179         list_del_rcu(&port->port_list);
 180
 181         if (port != master) {
 182                 if (master) {
 183                         netdev_update_features(master->dev);
 184                         dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
 185                 }
 186                 netdev_rx_handler_unregister(port->dev);
 187                 dev_set_promiscuity(port->dev, -1);
 188         }
 189
 190         /* FIXME?
 191          * netdev_upper_dev_unlink(port->dev, port->hsr->dev);
 192          */
 193
 194         synchronize_rcu();
 195
 196         if (port != master)
 197                 dev_put(port->dev);
 198         kfree(port);
 199 }