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