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  * Frame handler other utility functions for HSR and PRP.
   8  */
   9
  10 #include "hsr_slave.h"
  11 #include <linux/etherdevice.h>
  12 #include <linux/if_arp.h>
  13 #include <linux/if_vlan.h>
  14 #include "hsr_main.h"
  15 #include "hsr_device.h"
  16 #include "hsr_forward.h"
  17 #include "hsr_framereg.h"
  18
  19 bool hsr_invalid_dan_ingress_frame(__be16 protocol)
  20 {
  21         return (protocol != htons(ETH_P_PRP) && protocol != htons(ETH_P_HSR));
  22 }
  23
  24 static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
  25 {
  26         struct sk_buff *skb = *pskb;
  27         struct hsr_port *port;
  28         struct hsr_priv *hsr;
  29         __be16 protocol;
  30
  31         /* Packets from dev_loopback_xmit() do not have L2 header, bail out */
  32         if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
  33                 return RX_HANDLER_PASS;
  34
  35         if (!skb_mac_header_was_set(skb)) {
  36                 WARN_ONCE(1, "%s: skb invalid", __func__);
  37                 return RX_HANDLER_PASS;
  38         }
  39
  40         port = hsr_port_get_rcu(skb->dev);
  41         if (!port)
  42                 goto finish_pass;
  43         hsr = port->hsr;
  44
  45         if (hsr_addr_is_self(port->hsr, eth_hdr(skb)->h_source)) {
  46                 /* Directly kill frames sent by ourselves */
  47                 kfree_skb(skb);
  48                 goto finish_consume;
  49         }
  50
  51         /* For HSR, only tagged frames are expected, but for PRP
  52          * there could be non tagged frames as well from Single
  53          * attached nodes (SANs).
  54          */
  55         protocol = eth_hdr(skb)->h_proto;
  56         if (hsr->proto_ops->invalid_dan_ingress_frame &&
  57             hsr->proto_ops->invalid_dan_ingress_frame(protocol))
  58                 goto finish_pass;
  59
  60         skb_push(skb, ETH_HLEN);
  61
  62         if (skb_mac_header(skb) != skb->data) {
  63                 WARN_ONCE(1, "%s:%d: Malformed frame at source port %s)\n",
  64                           __func__, __LINE__, port->dev->name);
  65                 goto finish_consume;
  66         }
  67
  68         hsr_forward_skb(skb, port);
  69
  70 finish_consume:
  71         return RX_HANDLER_CONSUMED;
  72
  73 finish_pass:
  74         return RX_HANDLER_PASS;
  75 }
  76
  77 bool hsr_port_exists(const struct net_device *dev)
  78 {
  79         return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
  80 }
  81
  82 static int hsr_check_dev_ok(struct net_device *dev,
  83                             struct netlink_ext_ack *extack)
  84 {
  85         /* Don't allow HSR on non-ethernet like devices */
  86         if ((dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
  87             dev->addr_len != ETH_ALEN) {
  88                 NL_SET_ERR_MSG_MOD(extack, "Cannot use loopback or non-ethernet device as HSR slave.");
  89                 return -EINVAL;
  90         }
  91
  92         /* Don't allow enslaving hsr devices */
  93         if (is_hsr_master(dev)) {
  94                 NL_SET_ERR_MSG_MOD(extack,
  95                                    "Cannot create trees of HSR devices.");
  96                 return -EINVAL;
  97         }
  98
  99         if (hsr_port_exists(dev)) {
 100                 NL_SET_ERR_MSG_MOD(extack,
 101                                    "This device is already a HSR slave.");
 102                 return -EINVAL;
 103         }
 104
 105         if (is_vlan_dev(dev)) {
 106                 NL_SET_ERR_MSG_MOD(extack, "HSR on top of VLAN is not yet supported in this driver.");
 107                 return -EINVAL;
 108         }
 109
 110         if (dev->priv_flags & IFF_DONT_BRIDGE) {
 111                 NL_SET_ERR_MSG_MOD(extack,
 112                                    "This device does not support bridging.");
 113                 return -EOPNOTSUPP;
 114         }
 115
 116         /* HSR over bonded devices has not been tested, but I'm not sure it
 117          * won't work...
 118          */
 119
 120         return 0;
 121 }
 122
 123 /* Setup device to be added to the HSR bridge. */
 124 static int hsr_portdev_setup(struct hsr_priv *hsr, struct net_device *dev,
 125                              struct hsr_port *port,
 126                              struct netlink_ext_ack *extack)
 127
 128 {
 129         struct net_device *hsr_dev;
 130         struct hsr_port *master;
 131         int res;
 132
 133         res = dev_set_promiscuity(dev, 1);
 134         if (res)
 135                 return res;
 136
 137         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 138         hsr_dev = master->dev;
 139
 140         res = netdev_upper_dev_link(dev, hsr_dev, extack);
 141         if (res)
 142                 goto fail_upper_dev_link;
 143
 144         res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
 145         if (res)
 146                 goto fail_rx_handler;
 147         dev_disable_lro(dev);
 148
 149         return 0;
 150
 151 fail_rx_handler:
 152         netdev_upper_dev_unlink(dev, hsr_dev);
 153 fail_upper_dev_link:
 154         dev_set_promiscuity(dev, -1);
 155         return res;
 156 }
 157
 158 int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
 159                  enum hsr_port_type type, struct netlink_ext_ack *extack)
 160 {
 161         struct hsr_port *port, *master;
 162         int res;
 163
 164         if (type != HSR_PT_MASTER) {
 165                 res = hsr_check_dev_ok(dev, extack);
 166                 if (res)
 167                         return res;
 168         }
 169
 170         port = hsr_port_get_hsr(hsr, type);
 171         if (port)
 172                 return -EBUSY;  /* This port already exists */
 173
 174         port = kzalloc(sizeof(*port), GFP_KERNEL);
 175         if (!port)
 176                 return -ENOMEM;
 177
 178         port->hsr = hsr;
 179         port->dev = dev;
 180         port->type = type;
 181
 182         if (type != HSR_PT_MASTER) {
 183                 res = hsr_portdev_setup(hsr, dev, port, extack);
 184                 if (res)
 185                         goto fail_dev_setup;
 186         }
 187
 188         list_add_tail_rcu(&port->port_list, &hsr->ports);
 189         synchronize_rcu();
 190
 191         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 192         netdev_update_features(master->dev);
 193         dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
 194
 195         return 0;
 196
 197 fail_dev_setup:
 198         kfree(port);
 199         return res;
 200 }
 201
 202 void hsr_del_port(struct hsr_port *port)
 203 {
 204         struct hsr_priv *hsr;
 205         struct hsr_port *master;
 206
 207         hsr = port->hsr;
 208         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 209         list_del_rcu(&port->port_list);
 210
 211         if (port != master) {
 212                 netdev_update_features(master->dev);
 213                 dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
 214                 netdev_rx_handler_unregister(port->dev);
 215                 dev_set_promiscuity(port->dev, -1);
 216                 netdev_upper_dev_unlink(port->dev, master->dev);
 217         }
 218
 219         synchronize_rcu();
 220
 221         kfree(port);
 222 }