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 (unless the device offloads
  52          * HSR tag removal), but for PRP there could be non tagged frames as
  53          * well from Single attached nodes (SANs).
  54          */
  55         protocol = eth_hdr(skb)->h_proto;
  56
  57         if (!(port->dev->features & NETIF_F_HW_HSR_TAG_RM) &&
  58             port->type != HSR_PT_INTERLINK &&
  59             hsr->proto_ops->invalid_dan_ingress_frame &&
  60             hsr->proto_ops->invalid_dan_ingress_frame(protocol))
  61                 goto finish_pass;
  62
  63         skb_push(skb, ETH_HLEN);
  64         skb_reset_mac_header(skb);
  65         if ((!hsr->prot_version && protocol == htons(ETH_P_PRP)) ||
  66             protocol == htons(ETH_P_HSR))
  67                 skb_set_network_header(skb, ETH_HLEN + HSR_HLEN);
  68         skb_reset_mac_len(skb);
  69
  70         /* Only the frames received over the interlink port will assign a
  71          * sequence number and require synchronisation vs other sender.
  72          */
  73         if (port->type == HSR_PT_INTERLINK) {
  74                 spin_lock_bh(&hsr->seqnr_lock);
  75                 hsr_forward_skb(skb, port);
  76                 spin_unlock_bh(&hsr->seqnr_lock);
  77         } else {
  78                 hsr_forward_skb(skb, port);
  79         }
  80
  81 finish_consume:
  82         return RX_HANDLER_CONSUMED;
  83
  84 finish_pass:
  85         return RX_HANDLER_PASS;
  86 }
  87
  88 bool hsr_port_exists(const struct net_device *dev)
  89 {
  90         return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
  91 }
  92
  93 static int hsr_check_dev_ok(struct net_device *dev,
  94                             struct netlink_ext_ack *extack)
  95 {
  96         /* Don't allow HSR on non-ethernet like devices */
  97         if ((dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
  98             dev->addr_len != ETH_ALEN) {
  99                 NL_SET_ERR_MSG_MOD(extack, "Cannot use loopback or non-ethernet device as HSR slave.");
 100                 return -EINVAL;
 101         }
 102
 103         /* Don't allow enslaving hsr devices */
 104         if (is_hsr_master(dev)) {
 105                 NL_SET_ERR_MSG_MOD(extack,
 106                                    "Cannot create trees of HSR devices.");
 107                 return -EINVAL;
 108         }
 109
 110         if (hsr_port_exists(dev)) {
 111                 NL_SET_ERR_MSG_MOD(extack,
 112                                    "This device is already a HSR slave.");
 113                 return -EINVAL;
 114         }
 115
 116         if (is_vlan_dev(dev)) {
 117                 NL_SET_ERR_MSG_MOD(extack, "HSR on top of VLAN is not yet supported in this driver.");
 118                 return -EINVAL;
 119         }
 120
 121         if (dev->priv_flags & IFF_DONT_BRIDGE) {
 122                 NL_SET_ERR_MSG_MOD(extack,
 123                                    "This device does not support bridging.");
 124                 return -EOPNOTSUPP;
 125         }
 126
 127         /* HSR over bonded devices has not been tested, but I'm not sure it
 128          * won't work...
 129          */
 130
 131         return 0;
 132 }
 133
 134 /* Setup device to be added to the HSR bridge. */
 135 static int hsr_portdev_setup(struct hsr_priv *hsr, struct net_device *dev,
 136                              struct hsr_port *port,
 137                              struct netlink_ext_ack *extack)
 138
 139 {
 140         struct net_device *hsr_dev;
 141         struct hsr_port *master;
 142         int res;
 143
 144         /* Don't use promiscuous mode for offload since L2 frame forward
 145          * happens at the offloaded hardware.
 146          */
 147         if (!port->hsr->fwd_offloaded) {
 148                 res = dev_set_promiscuity(dev, 1);
 149                 if (res)
 150                         return res;
 151         }
 152
 153         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 154         hsr_dev = master->dev;
 155
 156         res = netdev_upper_dev_link(dev, hsr_dev, extack);
 157         if (res)
 158                 goto fail_upper_dev_link;
 159
 160         res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
 161         if (res)
 162                 goto fail_rx_handler;
 163         dev_disable_lro(dev);
 164
 165         return 0;
 166
 167 fail_rx_handler:
 168         netdev_upper_dev_unlink(dev, hsr_dev);
 169 fail_upper_dev_link:
 170         if (!port->hsr->fwd_offloaded)
 171                 dev_set_promiscuity(dev, -1);
 172
 173         return res;
 174 }
 175
 176 int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
 177                  enum hsr_port_type type, struct netlink_ext_ack *extack)
 178 {
 179         struct hsr_port *port, *master;
 180         int res;
 181
 182         if (type != HSR_PT_MASTER) {
 183                 res = hsr_check_dev_ok(dev, extack);
 184                 if (res)
 185                         return res;
 186         }
 187
 188         port = hsr_port_get_hsr(hsr, type);
 189         if (port)
 190                 return -EBUSY;  /* This port already exists */
 191
 192         port = kzalloc(sizeof(*port), GFP_KERNEL);
 193         if (!port)
 194                 return -ENOMEM;
 195
 196         port->hsr = hsr;
 197         port->dev = dev;
 198         port->type = type;
 199
 200         if (type != HSR_PT_MASTER) {
 201                 res = hsr_portdev_setup(hsr, dev, port, extack);
 202                 if (res)
 203                         goto fail_dev_setup;
 204         }
 205
 206         list_add_tail_rcu(&port->port_list, &hsr->ports);
 207         synchronize_rcu();
 208
 209         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 210         netdev_update_features(master->dev);
 211         dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
 212
 213         return 0;
 214
 215 fail_dev_setup:
 216         kfree(port);
 217         return res;
 218 }
 219
 220 void hsr_del_port(struct hsr_port *port)
 221 {
 222         struct hsr_priv *hsr;
 223         struct hsr_port *master;
 224
 225         hsr = port->hsr;
 226         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 227         list_del_rcu(&port->port_list);
 228
 229         if (port != master) {
 230                 netdev_update_features(master->dev);
 231                 dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
 232                 netdev_rx_handler_unregister(port->dev);
 233                 if (!port->hsr->fwd_offloaded)
 234                         dev_set_promiscuity(port->dev, -1);
 235                 netdev_upper_dev_unlink(port->dev, master->dev);
 236         }
 237
 238         synchronize_rcu();
 239
 240         kfree(port);
 241 }