diff options
Diffstat (limited to 'net/dsa/tag_sja1105.c')
| -rw-r--r-- | net/dsa/tag_sja1105.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/net/dsa/tag_sja1105.c b/net/dsa/tag_sja1105.c new file mode 100644 index 000000000000..969402c7dbf1 --- /dev/null +++ b/net/dsa/tag_sja1105.c @@ -0,0 +1,131 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2019, Vladimir Oltean <olteanv@gmail.com> + */ +#include <linux/if_vlan.h> +#include <linux/dsa/sja1105.h> +#include <linux/dsa/8021q.h> +#include <linux/packing.h> +#include "dsa_priv.h" + +/* Similar to is_link_local_ether_addr(hdr->h_dest) but also covers PTP */ +static inline bool sja1105_is_link_local(const struct sk_buff *skb) +{ + const struct ethhdr *hdr = eth_hdr(skb); + u64 dmac = ether_addr_to_u64(hdr->h_dest); + + if ((dmac & SJA1105_LINKLOCAL_FILTER_A_MASK) == + SJA1105_LINKLOCAL_FILTER_A) + return true; + if ((dmac & SJA1105_LINKLOCAL_FILTER_B_MASK) == + SJA1105_LINKLOCAL_FILTER_B) + return true; + return false; +} + +/* This is the first time the tagger sees the frame on RX. + * Figure out if we can decode it, and if we can, annotate skb->cb with how we + * plan to do that, so we don't need to check again in the rcv function. + */ +static bool sja1105_filter(const struct sk_buff *skb, struct net_device *dev) +{ + if (sja1105_is_link_local(skb)) { + SJA1105_SKB_CB(skb)->type = SJA1105_FRAME_TYPE_LINK_LOCAL; + return true; + } + if (!dsa_port_is_vlan_filtering(dev->dsa_ptr)) { + SJA1105_SKB_CB(skb)->type = SJA1105_FRAME_TYPE_NORMAL; + return true; + } + return false; +} + +static struct sk_buff *sja1105_xmit(struct sk_buff *skb, + struct net_device *netdev) +{ + struct dsa_port *dp = dsa_slave_to_port(netdev); + struct dsa_switch *ds = dp->ds; + u16 tx_vid = dsa_8021q_tx_vid(ds, dp->index); + u8 pcp = skb->priority; + + /* Transmitting management traffic does not rely upon switch tagging, + * but instead SPI-installed management routes. Part 2 of this + * is the .port_deferred_xmit driver callback. + */ + if (unlikely(sja1105_is_link_local(skb))) + return dsa_defer_xmit(skb, netdev); + + /* If we are under a vlan_filtering bridge, IP termination on + * switch ports based on 802.1Q tags is simply too brittle to + * be passable. So just defer to the dsa_slave_notag_xmit + * implementation. + */ + if (dsa_port_is_vlan_filtering(dp)) + return skb; + + return dsa_8021q_xmit(skb, netdev, ETH_P_SJA1105, + ((pcp << VLAN_PRIO_SHIFT) | tx_vid)); +} + +static struct sk_buff *sja1105_rcv(struct sk_buff *skb, + struct net_device *netdev, + struct packet_type *pt) +{ + struct ethhdr *hdr = eth_hdr(skb); + u64 source_port, switch_id; + struct sk_buff *nskb; + u16 tpid, vid, tci; + bool is_tagged; + + nskb = dsa_8021q_rcv(skb, netdev, pt, &tpid, &tci); + is_tagged = (nskb && tpid == ETH_P_SJA1105); + + skb->priority = (tci & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT; + vid = tci & VLAN_VID_MASK; + + skb->offload_fwd_mark = 1; + + if (SJA1105_SKB_CB(skb)->type == SJA1105_FRAME_TYPE_LINK_LOCAL) { + /* Management traffic path. Switch embeds the switch ID and + * port ID into bytes of the destination MAC, courtesy of + * the incl_srcpt options. + */ + source_port = hdr->h_dest[3]; + switch_id = hdr->h_dest[4]; + /* Clear the DMAC bytes that were mangled by the switch */ + hdr->h_dest[3] = 0; + hdr->h_dest[4] = 0; + } else { + /* Normal traffic path. */ + source_port = dsa_8021q_rx_source_port(vid); + switch_id = dsa_8021q_rx_switch_id(vid); + } + + skb->dev = dsa_master_find_slave(netdev, switch_id, source_port); + if (!skb->dev) { + netdev_warn(netdev, "Couldn't decode source port\n"); + return NULL; + } + + /* Delete/overwrite fake VLAN header, DSA expects to not find + * it there, see dsa_switch_rcv: skb_push(skb, ETH_HLEN). + */ + if (is_tagged) + memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - VLAN_HLEN, + ETH_HLEN - VLAN_HLEN); + + return skb; +} + +static struct dsa_device_ops sja1105_netdev_ops = { + .name = "sja1105", + .proto = DSA_TAG_PROTO_SJA1105, + .xmit = sja1105_xmit, + .rcv = sja1105_rcv, + .filter = sja1105_filter, + .overhead = VLAN_HLEN, +}; + +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_SJA1105); + +module_dsa_tag_driver(sja1105_netdev_ops); |