From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- net/hsr/hsr_forward.c | 368 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 368 insertions(+) create mode 100644 net/hsr/hsr_forward.c (limited to 'net/hsr/hsr_forward.c') diff --git a/net/hsr/hsr_forward.c b/net/hsr/hsr_forward.c new file mode 100644 index 000000000..7871ed6d3 --- /dev/null +++ b/net/hsr/hsr_forward.c @@ -0,0 +1,368 @@ +/* Copyright 2011-2014 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): + * 2011-2014 Arvid Brodin, arvid.brodin@alten.se + */ + +#include "hsr_forward.h" +#include +#include +#include +#include +#include "hsr_main.h" +#include "hsr_framereg.h" + + +struct hsr_node; + +struct hsr_frame_info { + struct sk_buff *skb_std; + struct sk_buff *skb_hsr; + struct hsr_port *port_rcv; + struct hsr_node *node_src; + u16 sequence_nr; + bool is_supervision; + bool is_vlan; + bool is_local_dest; + bool is_local_exclusive; +}; + + +/* The uses I can see for these HSR supervision frames are: + * 1) Use the frames that are sent after node initialization ("HSR_TLV.Type = + * 22") to reset any sequence_nr counters belonging to that node. Useful if + * the other node's counter has been reset for some reason. + * -- + * Or not - resetting the counter and bridging the frame would create a + * loop, unfortunately. + * + * 2) Use the LifeCheck frames to detect ring breaks. I.e. if no LifeCheck + * frame is received from a particular node, we know something is wrong. + * We just register these (as with normal frames) and throw them away. + * + * 3) Allow different MAC addresses for the two slave interfaces, using the + * MacAddressA field. + */ +static bool is_supervision_frame(struct hsr_priv *hsr, struct sk_buff *skb) +{ + struct hsr_ethhdr_sp *hdr; + + WARN_ON_ONCE(!skb_mac_header_was_set(skb)); + hdr = (struct hsr_ethhdr_sp *) skb_mac_header(skb); + + if (!ether_addr_equal(hdr->ethhdr.h_dest, + hsr->sup_multicast_addr)) + return false; + + if (get_hsr_stag_path(&hdr->hsr_sup) != 0x0f) + return false; + if ((hdr->hsr_sup.HSR_TLV_Type != HSR_TLV_ANNOUNCE) && + (hdr->hsr_sup.HSR_TLV_Type != HSR_TLV_LIFE_CHECK)) + return false; + if (hdr->hsr_sup.HSR_TLV_Length != 12) + return false; + + return true; +} + + +static struct sk_buff *create_stripped_skb(struct sk_buff *skb_in, + struct hsr_frame_info *frame) +{ + struct sk_buff *skb; + int copylen; + unsigned char *dst, *src; + + skb_pull(skb_in, HSR_HLEN); + skb = __pskb_copy(skb_in, skb_headroom(skb_in) - HSR_HLEN, GFP_ATOMIC); + skb_push(skb_in, HSR_HLEN); + if (skb == NULL) + return NULL; + + skb_reset_mac_header(skb); + + if (skb->ip_summed == CHECKSUM_PARTIAL) + skb->csum_start -= HSR_HLEN; + + copylen = 2*ETH_ALEN; + if (frame->is_vlan) + copylen += VLAN_HLEN; + src = skb_mac_header(skb_in); + dst = skb_mac_header(skb); + memcpy(dst, src, copylen); + + skb->protocol = eth_hdr(skb)->h_proto; + return skb; +} + +static struct sk_buff *frame_get_stripped_skb(struct hsr_frame_info *frame, + struct hsr_port *port) +{ + if (!frame->skb_std) + frame->skb_std = create_stripped_skb(frame->skb_hsr, frame); + return skb_clone(frame->skb_std, GFP_ATOMIC); +} + + +static void hsr_fill_tag(struct sk_buff *skb, struct hsr_frame_info *frame, + struct hsr_port *port) +{ + struct hsr_ethhdr *hsr_ethhdr; + int lane_id; + int lsdu_size; + + if (port->type == HSR_PT_SLAVE_A) + lane_id = 0; + else + lane_id = 1; + + lsdu_size = skb->len - 14; + if (frame->is_vlan) + lsdu_size -= 4; + + hsr_ethhdr = (struct hsr_ethhdr *) skb_mac_header(skb); + + set_hsr_tag_path(&hsr_ethhdr->hsr_tag, lane_id); + set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, lsdu_size); + hsr_ethhdr->hsr_tag.sequence_nr = htons(frame->sequence_nr); + hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto; + hsr_ethhdr->ethhdr.h_proto = htons(ETH_P_PRP); +} + +static struct sk_buff *create_tagged_skb(struct sk_buff *skb_o, + struct hsr_frame_info *frame, + struct hsr_port *port) +{ + int movelen; + unsigned char *dst, *src; + struct sk_buff *skb; + + /* Create the new skb with enough headroom to fit the HSR tag */ + skb = __pskb_copy(skb_o, skb_headroom(skb_o) + HSR_HLEN, GFP_ATOMIC); + if (skb == NULL) + return NULL; + skb_reset_mac_header(skb); + + if (skb->ip_summed == CHECKSUM_PARTIAL) + skb->csum_start += HSR_HLEN; + + movelen = ETH_HLEN; + if (frame->is_vlan) + movelen += VLAN_HLEN; + + src = skb_mac_header(skb); + dst = skb_push(skb, HSR_HLEN); + memmove(dst, src, movelen); + skb_reset_mac_header(skb); + + hsr_fill_tag(skb, frame, port); + + return skb; +} + +/* If the original frame was an HSR tagged frame, just clone it to be sent + * unchanged. Otherwise, create a private frame especially tagged for 'port'. + */ +static struct sk_buff *frame_get_tagged_skb(struct hsr_frame_info *frame, + struct hsr_port *port) +{ + if (frame->skb_hsr) + return skb_clone(frame->skb_hsr, GFP_ATOMIC); + + if ((port->type != HSR_PT_SLAVE_A) && (port->type != HSR_PT_SLAVE_B)) { + WARN_ONCE(1, "HSR: Bug: trying to create a tagged frame for a non-ring port"); + return NULL; + } + + return create_tagged_skb(frame->skb_std, frame, port); +} + + +static void hsr_deliver_master(struct sk_buff *skb, struct net_device *dev, + struct hsr_node *node_src) +{ + bool was_multicast_frame; + int res; + + was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST); + hsr_addr_subst_source(node_src, skb); + skb_pull(skb, ETH_HLEN); + res = netif_rx(skb); + if (res == NET_RX_DROP) { + dev->stats.rx_dropped++; + } else { + dev->stats.rx_packets++; + dev->stats.rx_bytes += skb->len; + if (was_multicast_frame) + dev->stats.multicast++; + } +} + +static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port, + struct hsr_frame_info *frame) +{ + if (frame->port_rcv->type == HSR_PT_MASTER) { + hsr_addr_subst_dest(frame->node_src, skb, port); + + /* Address substitution (IEC62439-3 pp 26, 50): replace mac + * address of outgoing frame with that of the outgoing slave's. + */ + ether_addr_copy(eth_hdr(skb)->h_source, port->dev->dev_addr); + } + return dev_queue_xmit(skb); +} + + +/* Forward the frame through all devices except: + * - Back through the receiving device + * - If it's a HSR frame: through a device where it has passed before + * - To the local HSR master only if the frame is directly addressed to it, or + * a non-supervision multicast or broadcast frame. + * + * HSR slave devices should insert a HSR tag into the frame, or forward the + * frame unchanged if it's already tagged. Interlink devices should strip HSR + * tags if they're of the non-HSR type (but only after duplicate discard). The + * master device always strips HSR tags. + */ +static void hsr_forward_do(struct hsr_frame_info *frame) +{ + struct hsr_port *port; + struct sk_buff *skb; + + hsr_for_each_port(frame->port_rcv->hsr, port) { + /* Don't send frame back the way it came */ + if (port == frame->port_rcv) + continue; + + /* Don't deliver locally unless we should */ + if ((port->type == HSR_PT_MASTER) && !frame->is_local_dest) + continue; + + /* Deliver frames directly addressed to us to master only */ + if ((port->type != HSR_PT_MASTER) && frame->is_local_exclusive) + continue; + + /* Don't send frame over port where it has been sent before */ + if (hsr_register_frame_out(port, frame->node_src, + frame->sequence_nr)) + continue; + + if (frame->is_supervision && (port->type == HSR_PT_MASTER)) { + hsr_handle_sup_frame(frame->skb_hsr, + frame->node_src, + frame->port_rcv); + continue; + } + + if (port->type != HSR_PT_MASTER) + skb = frame_get_tagged_skb(frame, port); + else + skb = frame_get_stripped_skb(frame, port); + if (skb == NULL) { + /* FIXME: Record the dropped frame? */ + continue; + } + + skb->dev = port->dev; + if (port->type == HSR_PT_MASTER) + hsr_deliver_master(skb, port->dev, frame->node_src); + else + hsr_xmit(skb, port, frame); + } +} + + +static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb, + struct hsr_frame_info *frame) +{ + struct net_device *master_dev; + + master_dev = hsr_port_get_hsr(hsr, HSR_PT_MASTER)->dev; + + if (hsr_addr_is_self(hsr, eth_hdr(skb)->h_dest)) { + frame->is_local_exclusive = true; + skb->pkt_type = PACKET_HOST; + } else { + frame->is_local_exclusive = false; + } + + if ((skb->pkt_type == PACKET_HOST) || + (skb->pkt_type == PACKET_MULTICAST) || + (skb->pkt_type == PACKET_BROADCAST)) { + frame->is_local_dest = true; + } else { + frame->is_local_dest = false; + } +} + + +static int hsr_fill_frame_info(struct hsr_frame_info *frame, + struct sk_buff *skb, struct hsr_port *port) +{ + struct ethhdr *ethhdr; + unsigned long irqflags; + + frame->is_supervision = is_supervision_frame(port->hsr, skb); + frame->node_src = hsr_get_node(&port->hsr->node_db, skb, + frame->is_supervision); + if (frame->node_src == NULL) + return -1; /* Unknown node and !is_supervision, or no mem */ + + ethhdr = (struct ethhdr *) skb_mac_header(skb); + frame->is_vlan = false; + if (ethhdr->h_proto == htons(ETH_P_8021Q)) { + frame->is_vlan = true; + /* FIXME: */ + WARN_ONCE(1, "HSR: VLAN not yet supported"); + } + if (ethhdr->h_proto == htons(ETH_P_PRP)) { + frame->skb_std = NULL; + frame->skb_hsr = skb; + frame->sequence_nr = hsr_get_skb_sequence_nr(skb); + } else { + frame->skb_std = skb; + frame->skb_hsr = NULL; + /* Sequence nr for the master node */ + spin_lock_irqsave(&port->hsr->seqnr_lock, irqflags); + frame->sequence_nr = port->hsr->sequence_nr; + port->hsr->sequence_nr++; + spin_unlock_irqrestore(&port->hsr->seqnr_lock, irqflags); + } + + frame->port_rcv = port; + check_local_dest(port->hsr, skb, frame); + + return 0; +} + +/* Must be called holding rcu read lock (because of the port parameter) */ +void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port) +{ + struct hsr_frame_info frame; + + if (skb_mac_header(skb) != skb->data) { + WARN_ONCE(1, "%s:%d: Malformed frame (port_src %s)\n", + __FILE__, __LINE__, port->dev->name); + goto out_drop; + } + + if (hsr_fill_frame_info(&frame, skb, port) < 0) + goto out_drop; + hsr_register_frame_in(frame.node_src, port, frame.sequence_nr); + hsr_forward_do(&frame); + + if (frame.skb_hsr != NULL) + kfree_skb(frame.skb_hsr); + if (frame.skb_std != NULL) + kfree_skb(frame.skb_std); + return; + +out_drop: + port->dev->stats.tx_dropped++; + kfree_skb(skb); +} -- cgit v1.2.3-54-g00ecf