// SPDX-License-Identifier: GPL-2.0 /* Copyright 2011-2014 Autronica Fire and Security AS * * Author(s): * 2011-2014 Arvid Brodin, arvid.brodin@alten.se * * Frame router for HSR and PRP. */ #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; /* 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 && hsr_sup_tag->HSR_TLV_type != PRP_TLV_LIFE_CHECK_DD && hsr_sup_tag->HSR_TLV_type != PRP_TLV_LIFE_CHECK_DA) 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_hsr(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; } struct sk_buff *hsr_get_untagged_frame(struct hsr_frame_info *frame, struct hsr_port *port) { if (!frame->skb_std) { if (frame->skb_hsr) { frame->skb_std = create_stripped_skb_hsr(frame->skb_hsr, frame); } else { /* Unexpected */ WARN_ONCE(1, "%s:%d: Unexpected frame received (port_src %s)\n", __FILE__, __LINE__, port->dev->name); return NULL; } } return skb_clone(frame->skb_std, GFP_ATOMIC); } struct sk_buff *prp_get_untagged_frame(struct hsr_frame_info *frame, struct hsr_port *port) { if (!frame->skb_std) { if (frame->skb_prp) { /* trim the skb by len - HSR_HLEN to exclude RCT */ skb_trim(frame->skb_prp, frame->skb_prp->len - HSR_HLEN); frame->skb_std = __pskb_copy(frame->skb_prp, skb_headroom(frame->skb_prp), GFP_ATOMIC); } else { /* Unexpected */ WARN_ONCE(1, "%s:%d: Unexpected frame received (port_src %s)\n", __FILE__, __LINE__, port->dev->name); return NULL; } } return skb_clone(frame->skb_std, GFP_ATOMIC); } static void prp_set_lan_id(struct prp_rct *trailer, struct hsr_port *port) { int lane_id; if (port->type == HSR_PT_SLAVE_A) lane_id = 0; else lane_id = 1; /* Add net_id in the upper 3 bits of lane_id */ lane_id |= port->hsr->net_id; set_prp_lan_id(trailer, lane_id); } /* Tailroom for PRP rct should have been created before calling this */ static struct sk_buff *prp_fill_rct(struct sk_buff *skb, struct hsr_frame_info *frame, struct hsr_port *port) { struct prp_rct *trailer; int min_size = ETH_ZLEN; int lsdu_size; if (!skb) return skb; if (frame->is_vlan) min_size = VLAN_ETH_ZLEN; if (skb_put_padto(skb, min_size)) return NULL; trailer = (struct prp_rct *)skb_put(skb, HSR_HLEN); lsdu_size = skb->len - 14; if (frame->is_vlan) lsdu_size -= 4; prp_set_lan_id(trailer, port); set_prp_LSDU_size(trailer, lsdu_size); trailer->sequence_nr = htons(frame->sequence_nr); trailer->PRP_suffix = htons(ETH_P_PRP); return skb; } static void hsr_set_path_id(struct hsr_ethhdr *hsr_ethhdr, struct hsr_port *port) { int path_id; if (port->type == HSR_PT_SLAVE_A) path_id = 0; else path_id = 1; set_hsr_tag_path(&hsr_ethhdr->hsr_tag, path_id); } static struct sk_buff *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 lsdu_size; /* pad to minimum packet size which is 60 + 6 (HSR tag) */ if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN)) return NULL; lsdu_size = skb->len - 14; if (frame->is_vlan) lsdu_size -= 4; hsr_ethhdr = (struct hsr_ethhdr *)skb_mac_header(skb); hsr_set_path_id(hsr_ethhdr, port); 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); 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'. */ struct sk_buff *hsr_create_tagged_frame(struct hsr_frame_info *frame, struct hsr_port *port) { unsigned char *dst, *src; struct sk_buff *skb; int movelen; if (frame->skb_hsr) { struct hsr_ethhdr *hsr_ethhdr = (struct hsr_ethhdr *)skb_mac_header(frame->skb_hsr); /* set the lane id properly */ hsr_set_path_id(hsr_ethhdr, port); return skb_clone(frame->skb_hsr, GFP_ATOMIC); } /* Create the new skb with enough headroom to fit the HSR tag */ skb = __pskb_copy(frame->skb_std, skb_headroom(frame->skb_std) + 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); /* skb_put_padto free skb on error and hsr_fill_tag returns NULL in * that case */ return hsr_fill_tag(skb, frame, port, port->hsr->prot_version); } struct sk_buff *prp_create_tagged_frame(struct hsr_frame_info *frame, struct hsr_port *port) { struct sk_buff *skb; if (frame->skb_prp) { struct prp_rct *trailer = skb_get_PRP_rct(frame->skb_prp); if (trailer) { prp_set_lan_id(trailer, port); } else { WARN_ONCE(!trailer, "errored PRP skb"); return NULL; } return skb_clone(frame->skb_prp, GFP_ATOMIC); } skb = skb_copy_expand(frame->skb_std, 0, skb_tailroom(frame->skb_std) + HSR_HLEN, GFP_ATOMIC); prp_fill_rct(skb, frame, port); return skb; } 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); } bool prp_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port) { return ((frame->port_rcv->type == HSR_PT_SLAVE_A && port->type == HSR_PT_SLAVE_B) || (frame->port_rcv->type == HSR_PT_SLAVE_B && port->type == HSR_PT_SLAVE_A)); } /* 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 * - if it's a PRP frame: through another PRP slave device (no bridge) * - 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) { struct hsr_priv *hsr = port->hsr; /* 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. * Also fro SAN, this shouldn't be done. */ if (!frame->is_from_san && 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); continue; } /* Check if frame is to be dropped. Eg. for PRP no forward * between ports. */ if (hsr->proto_ops->drop_frame && hsr->proto_ops->drop_frame(frame, port)) continue; if (port->type != HSR_PT_MASTER) skb = hsr->proto_ops->create_tagged_frame(frame, port); else skb = hsr->proto_ops->get_untagged_frame(frame, port); if (!skb) { frame->port_rcv->dev->stats.rx_dropped++; 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 void handle_std_frame(struct sk_buff *skb, struct hsr_frame_info *frame) { struct hsr_port *port = frame->port_rcv; struct hsr_priv *hsr = port->hsr; unsigned long irqflags; frame->skb_hsr = NULL; frame->skb_prp = NULL; frame->skb_std = skb; if (port->type != HSR_PT_MASTER) { frame->is_from_san = true; } else { /* Sequence nr for the master node */ spin_lock_irqsave(&hsr->seqnr_lock, irqflags); frame->sequence_nr = hsr->sequence_nr; hsr->sequence_nr++; spin_unlock_irqrestore(&hsr->seqnr_lock, irqflags); } } void hsr_fill_frame_info(__be16 proto, struct sk_buff *skb, struct hsr_frame_info *frame) { if (proto == htons(ETH_P_PRP) || proto == htons(ETH_P_HSR)) { /* HSR tagged frame :- Data or Supervision */ frame->skb_std = NULL; frame->skb_prp = NULL; frame->skb_hsr = skb; frame->sequence_nr = hsr_get_skb_sequence_nr(skb); return; } /* Standard frame or PRP from master port */ handle_std_frame(skb, frame); } void prp_fill_frame_info(__be16 proto, struct sk_buff *skb, struct hsr_frame_info *frame) { /* Supervision frame */ struct prp_rct *rct = skb_get_PRP_rct(skb); if (rct && prp_check_lsdu_size(skb, rct, frame->is_supervision)) { frame->skb_hsr = NULL; frame->skb_std = NULL; frame->skb_prp = skb; frame->sequence_nr = prp_get_skb_sequence_nr(rct); return; } handle_std_frame(skb, frame); } static int fill_frame_info(struct hsr_frame_info *frame, struct sk_buff *skb, struct hsr_port *port) { struct hsr_priv *hsr = port->hsr; struct hsr_vlan_ethhdr *vlan_hdr; struct ethhdr *ethhdr; __be16 proto; memset(frame, 0, sizeof(*frame)); frame->is_supervision = is_supervision_frame(port->hsr, skb); frame->node_src = hsr_get_node(port, &hsr->node_db, skb, frame->is_supervision, port->type); 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; proto = ethhdr->h_proto; if (proto == htons(ETH_P_8021Q)) frame->is_vlan = true; if (frame->is_vlan) { vlan_hdr = (struct hsr_vlan_ethhdr *)ethhdr; proto = vlan_hdr->vlanhdr.h_vlan_encapsulated_proto; /* FIXME: */ netdev_warn_once(skb->dev, "VLAN not yet supported"); } frame->is_from_san = false; frame->port_rcv = port; hsr->proto_ops->fill_frame_info(proto, skb, frame); 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 (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; } kfree_skb(frame.skb_hsr); kfree_skb(frame.skb_prp); kfree_skb(frame.skb_std); return; out_drop: port->dev->stats.tx_dropped++; kfree_skb(skb); }