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         __be16 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         port = hsr_port_get_rcu(skb->dev);
  29         if (!port)
  30                 goto finish_pass;
  31
  32         if (hsr_addr_is_self(port->hsr, eth_hdr(skb)->h_source)) {
  33                 /* Directly kill frames sent by ourselves */
  34                 kfree_skb(skb);
  35                 goto finish_consume;
  36         }
  37
  38         protocol = eth_hdr(skb)->h_proto;
  39         if (protocol != htons(ETH_P_PRP) && protocol != htons(ETH_P_HSR))
  40                 goto finish_pass;
  41
  42         skb_push(skb, ETH_HLEN);
  43
  44         hsr_forward_skb(skb, port);
  45
  46 finish_consume:
  47         return RX_HANDLER_CONSUMED;
  48
  49 finish_pass:
  50         return RX_HANDLER_PASS;
  51 }
  52
  53 bool hsr_port_exists(const struct net_device *dev)
  54 {
  55         return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
  56 }
  57
  58 static int hsr_check_dev_ok(struct net_device *dev,
  59                             struct netlink_ext_ack *extack)
  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                 NL_SET_ERR_MSG_MOD(extack, "Cannot use loopback or non-ethernet device as HSR slave.");
  65                 return -EINVAL;
  66         }
  67
  68         /* Don't allow enslaving hsr devices */
  69         if (is_hsr_master(dev)) {
  70                 NL_SET_ERR_MSG_MOD(extack,
  71                                    "Cannot create trees of HSR devices.");
  72                 return -EINVAL;
  73         }
  74
  75         if (hsr_port_exists(dev)) {
  76                 NL_SET_ERR_MSG_MOD(extack,
  77                                    "This device is already a HSR slave.");
  78                 return -EINVAL;
  79         }
  80
  81         if (is_vlan_dev(dev)) {
  82                 NL_SET_ERR_MSG_MOD(extack, "HSR on top of VLAN is not yet supported in this driver.");
  83                 return -EINVAL;
  84         }
  85
  86         if (dev->priv_flags & IFF_DONT_BRIDGE) {
  87                 NL_SET_ERR_MSG_MOD(extack,
  88                                    "This device does not support bridging.");
  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 /* Setup device to be added to the HSR bridge. */
 100 static int hsr_portdev_setup(struct hsr_priv *hsr, struct net_device *dev,
 101                              struct hsr_port *port,
 102                              struct netlink_ext_ack *extack)
 103
 104 {
 105         struct net_device *hsr_dev;
 106         struct hsr_port *master;
 107         int res;
 108
 109         res = dev_set_promiscuity(dev, 1);
 110         if (res)
 111                 return res;
 112
 113         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 114         hsr_dev = master->dev;
 115
 116         res = netdev_upper_dev_link(dev, hsr_dev, extack);
 117         if (res)
 118                 goto fail_upper_dev_link;
 119
 120         res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
 121         if (res)
 122                 goto fail_rx_handler;
 123         dev_disable_lro(dev);
 124
 125         return 0;
 126
 127 fail_rx_handler:
 128         netdev_upper_dev_unlink(dev, hsr_dev);
 129 fail_upper_dev_link:
 130         dev_set_promiscuity(dev, -1);
 131         return res;
 132 }
 133
 134 int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
 135                  enum hsr_port_type type, struct netlink_ext_ack *extack)
 136 {
 137         struct hsr_port *port, *master;
 138         int res;
 139
 140         if (type != HSR_PT_MASTER) {
 141                 res = hsr_check_dev_ok(dev, extack);
 142                 if (res)
 143                         return res;
 144         }
 145
 146         port = hsr_port_get_hsr(hsr, type);
 147         if (port)
 148                 return -EBUSY;  /* This port already exists */
 149
 150         port = kzalloc(sizeof(*port), GFP_KERNEL);
 151         if (!port)
 152                 return -ENOMEM;
 153
 154         port->hsr = hsr;
 155         port->dev = dev;
 156         port->type = type;
 157
 158         if (type != HSR_PT_MASTER) {
 159                 res = hsr_portdev_setup(hsr, dev, port, extack);
 160                 if (res)
 161                         goto fail_dev_setup;
 162         }
 163
 164         list_add_tail_rcu(&port->port_list, &hsr->ports);
 165         synchronize_rcu();
 166
 167         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 168         netdev_update_features(master->dev);
 169         dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
 170
 171         return 0;
 172
 173 fail_dev_setup:
 174         kfree(port);
 175         return res;
 176 }
 177
 178 void hsr_del_port(struct hsr_port *port)
 179 {
 180         struct hsr_priv *hsr;
 181         struct hsr_port *master;
 182
 183         hsr = port->hsr;
 184         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 185         list_del_rcu(&port->port_list);
 186
 187         if (port != master) {
 188                 netdev_update_features(master->dev);
 189                 dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
 190                 netdev_rx_handler_unregister(port->dev);
 191                 dev_set_promiscuity(port->dev, -1);
 192                 netdev_upper_dev_unlink(port->dev, master->dev);
 193         }
 194
 195         synchronize_rcu();
 196
 197         kfree(port);
 198 }