diff options
Diffstat (limited to 'net/hsr/hsr_device.c')
| -rw-r--r-- | net/hsr/hsr_device.c | 596 |
1 files changed, 596 insertions, 0 deletions
diff --git a/net/hsr/hsr_device.c b/net/hsr/hsr_device.c new file mode 100644 index 00000000000..e5302b7f7ca --- /dev/null +++ b/net/hsr/hsr_device.c @@ -0,0 +1,596 @@ +/* Copyright 2011-2013 Autronica Fire and Security AS + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + * Author(s): + * 2011-2013 Arvid Brodin, arvid.brodin@xdin.com + * + * This file contains device methods for creating, using and destroying + * virtual HSR devices. + */ + +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <linux/etherdevice.h> +#include <linux/if_arp.h> +#include <linux/rtnetlink.h> +#include <linux/pkt_sched.h> +#include "hsr_device.h" +#include "hsr_framereg.h" +#include "hsr_main.h" + + +static bool is_admin_up(struct net_device *dev) +{ + return dev && (dev->flags & IFF_UP); +} + +static bool is_slave_up(struct net_device *dev) +{ + return dev && is_admin_up(dev) && netif_oper_up(dev); +} + +static void __hsr_set_operstate(struct net_device *dev, int transition) +{ + write_lock_bh(&dev_base_lock); + if (dev->operstate != transition) { + dev->operstate = transition; + write_unlock_bh(&dev_base_lock); + netdev_state_change(dev); + } else { + write_unlock_bh(&dev_base_lock); + } +} + +void hsr_set_operstate(struct net_device *hsr_dev, struct net_device *slave1, + struct net_device *slave2) +{ + if (!is_admin_up(hsr_dev)) { + __hsr_set_operstate(hsr_dev, IF_OPER_DOWN); + return; + } + + if (is_slave_up(slave1) || is_slave_up(slave2)) + __hsr_set_operstate(hsr_dev, IF_OPER_UP); + else + __hsr_set_operstate(hsr_dev, IF_OPER_LOWERLAYERDOWN); +} + +void hsr_set_carrier(struct net_device *hsr_dev, struct net_device *slave1, + struct net_device *slave2) +{ + if (is_slave_up(slave1) || is_slave_up(slave2)) + netif_carrier_on(hsr_dev); + else + netif_carrier_off(hsr_dev); +} + + +void hsr_check_announce(struct net_device *hsr_dev, int old_operstate) +{ + struct hsr_priv *hsr_priv; + + hsr_priv = netdev_priv(hsr_dev); + + if ((hsr_dev->operstate == IF_OPER_UP) && (old_operstate != IF_OPER_UP)) { + /* Went up */ + hsr_priv->announce_count = 0; + hsr_priv->announce_timer.expires = jiffies + + msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL); + add_timer(&hsr_priv->announce_timer); + } + + if ((hsr_dev->operstate != IF_OPER_UP) && (old_operstate == IF_OPER_UP)) + /* Went down */ + del_timer(&hsr_priv->announce_timer); +} + + +int hsr_get_max_mtu(struct hsr_priv *hsr_priv) +{ + int mtu_max; + + if (hsr_priv->slave[0] && hsr_priv->slave[1]) + mtu_max = min(hsr_priv->slave[0]->mtu, hsr_priv->slave[1]->mtu); + else if (hsr_priv->slave[0]) + mtu_max = hsr_priv->slave[0]->mtu; + else if (hsr_priv->slave[1]) + mtu_max = hsr_priv->slave[1]->mtu; + else + mtu_max = HSR_TAGLEN; + + return mtu_max - HSR_TAGLEN; +} + +static int hsr_dev_change_mtu(struct net_device *dev, int new_mtu) +{ + struct hsr_priv *hsr_priv; + + hsr_priv = netdev_priv(dev); + + if (new_mtu > hsr_get_max_mtu(hsr_priv)) { + netdev_info(hsr_priv->dev, "A HSR master's MTU cannot be greater than the smallest MTU of its slaves minus the HSR Tag length (%d octets).\n", + HSR_TAGLEN); + return -EINVAL; + } + + dev->mtu = new_mtu; + + return 0; +} + +static int hsr_dev_open(struct net_device *dev) +{ + struct hsr_priv *hsr_priv; + int i; + char *slave_name; + + hsr_priv = netdev_priv(dev); + + for (i = 0; i < HSR_MAX_SLAVE; i++) { + if (hsr_priv->slave[i]) + slave_name = hsr_priv->slave[i]->name; + else + slave_name = "null"; + + if (!is_slave_up(hsr_priv->slave[i])) + netdev_warn(dev, "Slave %c (%s) is not up; please bring it up to get a working HSR network\n", + 'A' + i, slave_name); + } + + return 0; +} + +static int hsr_dev_close(struct net_device *dev) +{ + /* Nothing to do here. We could try to restore the state of the slaves + * to what they were before being changed by the hsr master dev's state, + * but they might have been changed manually in the mean time too, so + * taking them up or down here might be confusing and is probably not a + * good idea. + */ + return 0; +} + + +static void hsr_fill_tag(struct hsr_ethhdr *hsr_ethhdr, struct hsr_priv *hsr_priv) +{ + unsigned long irqflags; + + /* IEC 62439-1:2010, p 48, says the 4-bit "path" field can take values + * between 0001-1001 ("ring identifier", for regular HSR frames), + * or 1111 ("HSR management", supervision frames). Unfortunately, the + * spec writers forgot to explain what a "ring identifier" is, or + * how it is used. So we just set this to 0001 for regular frames, + * and 1111 for supervision frames. + */ + set_hsr_tag_path(&hsr_ethhdr->hsr_tag, 0x1); + + /* IEC 62439-1:2010, p 12: "The link service data unit in an Ethernet + * frame is the content of the frame located between the Length/Type + * field and the Frame Check Sequence." + * + * IEC 62439-3, p 48, specifies the "original LPDU" to include the + * original "LT" field (what "LT" means is not explained anywhere as + * far as I can see - perhaps "Length/Type"?). So LSDU_size might + * equal original length + 2. + * Also, the fact that this field is not used anywhere (might be used + * by a RedBox connecting HSR and PRP nets?) means I cannot test its + * correctness. Instead of guessing, I set this to 0 here, to make any + * problems immediately apparent. Anyone using this driver with PRP/HSR + * RedBoxes might need to fix this... + */ + set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, 0); + + spin_lock_irqsave(&hsr_priv->seqnr_lock, irqflags); + hsr_ethhdr->hsr_tag.sequence_nr = htons(hsr_priv->sequence_nr); + hsr_priv->sequence_nr++; + spin_unlock_irqrestore(&hsr_priv->seqnr_lock, irqflags); + + hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto; + + hsr_ethhdr->ethhdr.h_proto = htons(ETH_P_PRP); +} + +static int slave_xmit(struct sk_buff *skb, struct hsr_priv *hsr_priv, + enum hsr_dev_idx dev_idx) +{ + struct hsr_ethhdr *hsr_ethhdr; + + hsr_ethhdr = (struct hsr_ethhdr *) skb->data; + + skb->dev = hsr_priv->slave[dev_idx]; + + hsr_addr_subst_dest(hsr_priv, &hsr_ethhdr->ethhdr, dev_idx); + + /* Address substitution (IEC62439-3 pp 26, 50): replace mac + * address of outgoing frame with that of the outgoing slave's. + */ + ether_addr_copy(hsr_ethhdr->ethhdr.h_source, skb->dev->dev_addr); + + return dev_queue_xmit(skb); +} + + +static int hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct hsr_priv *hsr_priv; + struct hsr_ethhdr *hsr_ethhdr; + struct sk_buff *skb2; + int res1, res2; + + hsr_priv = netdev_priv(dev); + hsr_ethhdr = (struct hsr_ethhdr *) skb->data; + + if ((skb->protocol != htons(ETH_P_PRP)) || + (hsr_ethhdr->ethhdr.h_proto != htons(ETH_P_PRP))) { + hsr_fill_tag(hsr_ethhdr, hsr_priv); + skb->protocol = htons(ETH_P_PRP); + } + + skb2 = pskb_copy(skb, GFP_ATOMIC); + + res1 = NET_XMIT_DROP; + if (likely(hsr_priv->slave[HSR_DEV_SLAVE_A])) + res1 = slave_xmit(skb, hsr_priv, HSR_DEV_SLAVE_A); + + res2 = NET_XMIT_DROP; + if (likely(skb2 && hsr_priv->slave[HSR_DEV_SLAVE_B])) + res2 = slave_xmit(skb2, hsr_priv, HSR_DEV_SLAVE_B); + + if (likely(res1 == NET_XMIT_SUCCESS || res1 == NET_XMIT_CN || + res2 == NET_XMIT_SUCCESS || res2 == NET_XMIT_CN)) { + hsr_priv->dev->stats.tx_packets++; + hsr_priv->dev->stats.tx_bytes += skb->len; + } else { + hsr_priv->dev->stats.tx_dropped++; + } + + return NETDEV_TX_OK; +} + + +static int hsr_header_create(struct sk_buff *skb, struct net_device *dev, + unsigned short type, const void *daddr, + const void *saddr, unsigned int len) +{ + int res; + + /* Make room for the HSR tag now. We will fill it in later (in + * hsr_dev_xmit) + */ + if (skb_headroom(skb) < HSR_TAGLEN + ETH_HLEN) + return -ENOBUFS; + skb_push(skb, HSR_TAGLEN); + + /* To allow VLAN/HSR combos we should probably use + * res = dev_hard_header(skb, dev, type, daddr, saddr, len + HSR_TAGLEN); + * here instead. It would require other changes too, though - e.g. + * separate headers for each slave etc... + */ + res = eth_header(skb, dev, type, daddr, saddr, len + HSR_TAGLEN); + if (res <= 0) + return res; + skb_reset_mac_header(skb); + + return res + HSR_TAGLEN; +} + + +static const struct header_ops hsr_header_ops = { + .create = hsr_header_create, + .parse = eth_header_parse, +}; + + +/* HSR:2010 supervision frames should be padded so that the whole frame, + * including headers and FCS, is 64 bytes (without VLAN). + */ +static int hsr_pad(int size) +{ + const int min_size = ETH_ZLEN - HSR_TAGLEN - ETH_HLEN; + + if (size >= min_size) + return size; + return min_size; +} + +static void send_hsr_supervision_frame(struct net_device *hsr_dev, u8 type) +{ + struct hsr_priv *hsr_priv; + struct sk_buff *skb; + int hlen, tlen; + struct hsr_sup_tag *hsr_stag; + struct hsr_sup_payload *hsr_sp; + unsigned long irqflags; + + hlen = LL_RESERVED_SPACE(hsr_dev); + tlen = hsr_dev->needed_tailroom; + skb = alloc_skb(hsr_pad(sizeof(struct hsr_sup_payload)) + hlen + tlen, + GFP_ATOMIC); + + if (skb == NULL) + return; + + hsr_priv = netdev_priv(hsr_dev); + + skb_reserve(skb, hlen); + + skb->dev = hsr_dev; + skb->protocol = htons(ETH_P_PRP); + skb->priority = TC_PRIO_CONTROL; + + if (dev_hard_header(skb, skb->dev, ETH_P_PRP, + hsr_priv->sup_multicast_addr, + skb->dev->dev_addr, skb->len) < 0) + goto out; + + skb_pull(skb, sizeof(struct ethhdr)); + hsr_stag = (typeof(hsr_stag)) skb->data; + + set_hsr_stag_path(hsr_stag, 0xf); + set_hsr_stag_HSR_Ver(hsr_stag, 0); + + spin_lock_irqsave(&hsr_priv->seqnr_lock, irqflags); + hsr_stag->sequence_nr = htons(hsr_priv->sequence_nr); + hsr_priv->sequence_nr++; + spin_unlock_irqrestore(&hsr_priv->seqnr_lock, irqflags); + + hsr_stag->HSR_TLV_Type = type; + hsr_stag->HSR_TLV_Length = 12; + + skb_push(skb, sizeof(struct ethhdr)); + + /* Payload: MacAddressA */ + hsr_sp = (typeof(hsr_sp)) skb_put(skb, sizeof(*hsr_sp)); + ether_addr_copy(hsr_sp->MacAddressA, hsr_dev->dev_addr); + + dev_queue_xmit(skb); + return; + +out: + kfree_skb(skb); +} + + +/* Announce (supervision frame) timer function + */ +static void hsr_announce(unsigned long data) +{ + struct hsr_priv *hsr_priv; + + hsr_priv = (struct hsr_priv *) data; + + if (hsr_priv->announce_count < 3) { + send_hsr_supervision_frame(hsr_priv->dev, HSR_TLV_ANNOUNCE); + hsr_priv->announce_count++; + } else { + send_hsr_supervision_frame(hsr_priv->dev, HSR_TLV_LIFE_CHECK); + } + + if (hsr_priv->announce_count < 3) + hsr_priv->announce_timer.expires = jiffies + + msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL); + else + hsr_priv->announce_timer.expires = jiffies + + msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL); + + if (is_admin_up(hsr_priv->dev)) + add_timer(&hsr_priv->announce_timer); +} + + +static void restore_slaves(struct net_device *hsr_dev) +{ + struct hsr_priv *hsr_priv; + int i; + int res; + + hsr_priv = netdev_priv(hsr_dev); + + rtnl_lock(); + + /* Restore promiscuity */ + for (i = 0; i < HSR_MAX_SLAVE; i++) { + if (!hsr_priv->slave[i]) + continue; + res = dev_set_promiscuity(hsr_priv->slave[i], -1); + if (res) + netdev_info(hsr_dev, + "Cannot restore slave promiscuity (%s, %d)\n", + hsr_priv->slave[i]->name, res); + } + + rtnl_unlock(); +} + +static void reclaim_hsr_dev(struct rcu_head *rh) +{ + struct hsr_priv *hsr_priv; + + hsr_priv = container_of(rh, struct hsr_priv, rcu_head); + free_netdev(hsr_priv->dev); +} + + +/* According to comments in the declaration of struct net_device, this function + * is "Called from unregister, can be used to call free_netdev". Ok then... + */ +static void hsr_dev_destroy(struct net_device *hsr_dev) +{ + struct hsr_priv *hsr_priv; + + hsr_priv = netdev_priv(hsr_dev); + + del_timer(&hsr_priv->announce_timer); + unregister_hsr_master(hsr_priv); /* calls list_del_rcu on hsr_priv */ + restore_slaves(hsr_dev); + call_rcu(&hsr_priv->rcu_head, reclaim_hsr_dev); /* reclaim hsr_priv */ +} + +static const struct net_device_ops hsr_device_ops = { + .ndo_change_mtu = hsr_dev_change_mtu, + .ndo_open = hsr_dev_open, + .ndo_stop = hsr_dev_close, + .ndo_start_xmit = hsr_dev_xmit, +}; + + +void hsr_dev_setup(struct net_device *dev) +{ + random_ether_addr(dev->dev_addr); + + ether_setup(dev); + dev->header_ops = &hsr_header_ops; + dev->netdev_ops = &hsr_device_ops; + dev->tx_queue_len = 0; + + dev->destructor = hsr_dev_destroy; +} + + +/* Return true if dev is a HSR master; return false otherwise. + */ +bool is_hsr_master(struct net_device *dev) +{ + return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit); +} + +static int check_slave_ok(struct net_device *dev) +{ + /* Don't allow HSR on non-ethernet like devices */ + if ((dev->flags & IFF_LOOPBACK) || (dev->type != ARPHRD_ETHER) || + (dev->addr_len != ETH_ALEN)) { + netdev_info(dev, "Cannot use loopback or non-ethernet device as HSR slave.\n"); + return -EINVAL; + } + + /* Don't allow enslaving hsr devices */ + if (is_hsr_master(dev)) { + netdev_info(dev, "Cannot create trees of HSR devices.\n"); + return -EINVAL; + } + + if (is_hsr_slave(dev)) { + netdev_info(dev, "This device is already a HSR slave.\n"); + return -EINVAL; + } + + if (dev->priv_flags & IFF_802_1Q_VLAN) { + netdev_info(dev, "HSR on top of VLAN is not yet supported in this driver.\n"); + return -EINVAL; + } + + /* HSR over bonded devices has not been tested, but I'm not sure it + * won't work... + */ + + return 0; +} + + +/* Default multicast address for HSR Supervision frames */ +static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = { + 0x01, 0x15, 0x4e, 0x00, 0x01, 0x00 +}; + +int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2], + unsigned char multicast_spec) +{ + struct hsr_priv *hsr_priv; + int i; + int res; + + hsr_priv = netdev_priv(hsr_dev); + hsr_priv->dev = hsr_dev; + INIT_LIST_HEAD(&hsr_priv->node_db); + INIT_LIST_HEAD(&hsr_priv->self_node_db); + for (i = 0; i < HSR_MAX_SLAVE; i++) + hsr_priv->slave[i] = slave[i]; + + spin_lock_init(&hsr_priv->seqnr_lock); + /* Overflow soon to find bugs easier: */ + hsr_priv->sequence_nr = USHRT_MAX - 1024; + + init_timer(&hsr_priv->announce_timer); + hsr_priv->announce_timer.function = hsr_announce; + hsr_priv->announce_timer.data = (unsigned long) hsr_priv; + + ether_addr_copy(hsr_priv->sup_multicast_addr, def_multicast_addr); + hsr_priv->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec; + +/* FIXME: should I modify the value of these? + * + * - hsr_dev->flags - i.e. + * IFF_MASTER/SLAVE? + * - hsr_dev->priv_flags - i.e. + * IFF_EBRIDGE? + * IFF_TX_SKB_SHARING? + * IFF_HSR_MASTER/SLAVE? + */ + + for (i = 0; i < HSR_MAX_SLAVE; i++) { + res = check_slave_ok(slave[i]); + if (res) + return res; + } + + hsr_dev->features = slave[0]->features & slave[1]->features; + /* Prevent recursive tx locking */ + hsr_dev->features |= NETIF_F_LLTX; + /* VLAN on top of HSR needs testing and probably some work on + * hsr_header_create() etc. + */ + hsr_dev->features |= NETIF_F_VLAN_CHALLENGED; + + /* Set hsr_dev's MAC address to that of mac_slave1 */ + ether_addr_copy(hsr_dev->dev_addr, hsr_priv->slave[0]->dev_addr); + + /* Set required header length */ + for (i = 0; i < HSR_MAX_SLAVE; i++) { + if (slave[i]->hard_header_len + HSR_TAGLEN > + hsr_dev->hard_header_len) + hsr_dev->hard_header_len = + slave[i]->hard_header_len + HSR_TAGLEN; + } + + /* MTU */ + for (i = 0; i < HSR_MAX_SLAVE; i++) + if (slave[i]->mtu - HSR_TAGLEN < hsr_dev->mtu) + hsr_dev->mtu = slave[i]->mtu - HSR_TAGLEN; + + /* Make sure the 1st call to netif_carrier_on() gets through */ + netif_carrier_off(hsr_dev); + + /* Promiscuity */ + for (i = 0; i < HSR_MAX_SLAVE; i++) { + res = dev_set_promiscuity(slave[i], 1); + if (res) { + netdev_info(hsr_dev, "Cannot set slave promiscuity (%s, %d)\n", + slave[i]->name, res); + goto fail; + } + } + + /* Make sure we recognize frames from ourselves in hsr_rcv() */ + res = hsr_create_self_node(&hsr_priv->self_node_db, + hsr_dev->dev_addr, + hsr_priv->slave[1]->dev_addr); + if (res < 0) + goto fail; + + res = register_netdevice(hsr_dev); + if (res) + goto fail; + + register_hsr_master(hsr_priv); + + return 0; + +fail: + restore_slaves(hsr_dev); + return res; +} |