| // 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); |
| } |