// SPDX-License-Identifier: GPL-2.0 /* Copyright 2011-2014 Autronica Fire and Security AS * * Author(s): * 2011-2014 Arvid Brodin, arvid.brodin@alten.se */ #include "hsr_forward.h" #include <linux/types.h> #include <linux/skbuff.h> #include <linux/etherdevice.h> #include <linux/if_vlan.h> #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 ethhdr *eth_hdr; struct hsr_sup_tag *hsr_sup_tag; struct hsrv1_ethhdr_sp *hsr_V1_hdr; WARN_ON_ONCE(!skb_mac_header_was_set(skb)); eth_hdr = (struct ethhdr *)skb_mac_header(skb); /* Correct addr? */ if (!ether_addr_equal(eth_hdr->h_dest, hsr->sup_multicast_addr)) return false; /* Correct ether type?. */ if (!(eth_hdr->h_proto == htons(ETH_P_PRP) || eth_hdr->h_proto == htons(ETH_P_HSR))) return false; /* Get the supervision header from correct location. */ if (eth_hdr->h_proto == htons(ETH_P_HSR)) { /* Okay HSRv1. */ hsr_V1_hdr = (struct hsrv1_ethhdr_sp *)skb_mac_header(skb); if (hsr_V1_hdr->hsr.encap_proto != htons(ETH_P_PRP)) return false; hsr_sup_tag = &hsr_V1_hdr->hsr_sup; } else { hsr_sup_tag = &((struct hsrv0_ethhdr_sp *)skb_mac_header(skb))->hsr_sup; } if (hsr_sup_tag->HSR_TLV_type != HSR_TLV_ANNOUNCE && hsr_sup_tag->HSR_TLV_type != HSR_TLV_LIFE_CHECK) return false; if (hsr_sup_tag->HSR_TLV_length != 12 && hsr_sup_tag->HSR_TLV_length != sizeof(struct hsr_sup_payload)) 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) 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, u8 proto_version) { 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(proto_version ? ETH_P_HSR : 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) 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, port->hsr->prot_version); 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) { /* 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) { 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, skb, frame->is_supervision); if (!frame->node_src) 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) || ethhdr->h_proto == htons(ETH_P_HSR)) { 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); /* Gets called for ingress frames as well as egress from master port. * So check and increment stats for master port only here. */ if (port->type == HSR_PT_MASTER) { port->dev->stats.tx_packets++; port->dev->stats.tx_bytes += skb->len; } if (frame.skb_hsr) kfree_skb(frame.skb_hsr); if (frame.skb_std) kfree_skb(frame.skb_std); return; out_drop: port->dev->stats.tx_dropped++; kfree_skb(skb); }