[PATCH net-next v2 1/4] net: hsr: generate supervision frame without HSR/PRP tag

George McCollister
2021-02-04T22:00:59Z

For a switch to offload insertion of HSR/PRP tags, frames must not be
sent to the CPU facing switch port with a tag. Generate supervision frames
(eth type ETH_P_PRP) without HSR v1 (ETH_P_HSR)/PRP tag and rely on
create_tagged_frame which inserts it later. This will allow skipping the
tag insertion for all outgoing frames in the future which is required for
HSR v1/PRP tag insertions to be offloaded.

HSR v0 supervision frames always contain tag information so insertion of
the tag can't be offloaded. IEC 62439-3 Ed.2.0 (HSR v1) specifically
notes that this was changed since v0 to allow offloading.

Signed-off-by: George McCollister <george.mccollister@gmail.com>
---
net/hsr/hsr_device.c | 32 ++++----------------------------
net/hsr/hsr_forward.c | 6 +++++-
2 files changed, 9 insertions(+), 29 deletions(-)

diff --git a/net/hsr/hsr_device.c b/net/hsr/hsr_device.c
index ab953a1a0d6c..161b8da6a21d 100644
--- a/net/hsr/hsr_device.c
+++ b/net/hsr/hsr_device.c
@@ -242,8 +242,7 @@ static struct sk_buff *hsr_init_skb(struct hsr_port *master, u16 proto)
* being, for PRP it is a trailer and for HSR it is a
* header
*/
- skb = dev_alloc_skb(sizeof(struct hsr_tag) +
- sizeof(struct hsr_sup_tag) +
+ skb = dev_alloc_skb(sizeof(struct hsr_sup_tag) +
sizeof(struct hsr_sup_payload) + hlen + tlen);

if (!skb)
@@ -275,12 +274,10 @@ static void send_hsr_supervision_frame(struct hsr_port *master,
{
struct hsr_priv *hsr = master->hsr;
__u8 type = HSR_TLV_LIFE_CHECK;
- struct hsr_tag *hsr_tag = NULL;
struct hsr_sup_payload *hsr_sp;
struct hsr_sup_tag *hsr_stag;
unsigned long irqflags;
struct sk_buff *skb;
- u16 proto;

*interval = msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
if (hsr->announce_count < 3 && hsr->prot_version == 0) {
@@ -289,23 +286,12 @@ static void send_hsr_supervision_frame(struct hsr_port *master,
hsr->announce_count++;
}

- if (!hsr->prot_version)
- proto = ETH_P_PRP;
- else
- proto = ETH_P_HSR;
-
- skb = hsr_init_skb(master, proto);
+ skb = hsr_init_skb(master, ETH_P_PRP);
if (!skb) {
WARN_ONCE(1, "HSR: Could not send supervision frame\n");
return;
}

- if (hsr->prot_version > 0) {
- hsr_tag = skb_put(skb, sizeof(struct hsr_tag));
- hsr_tag->encap_proto = htons(ETH_P_PRP);
- set_hsr_tag_LSDU_size(hsr_tag, HSR_V1_SUP_LSDUSIZE);
- }
-
hsr_stag = skb_put(skb, sizeof(struct hsr_sup_tag));
set_hsr_stag_path(hsr_stag, (hsr->prot_version ? 0x0 : 0xf));
set_hsr_stag_HSR_ver(hsr_stag, hsr->prot_version);
@@ -315,8 +301,6 @@ static void send_hsr_supervision_frame(struct hsr_port *master,
if (hsr->prot_version > 0) {
hsr_stag->sequence_nr = htons(hsr->sup_sequence_nr);
hsr->sup_sequence_nr++;
- hsr_tag->sequence_nr = htons(hsr->sequence_nr);
- hsr->sequence_nr++;
} else {
hsr_stag->sequence_nr = htons(hsr->sequence_nr);
hsr->sequence_nr++;
@@ -332,7 +316,7 @@ static void send_hsr_supervision_frame(struct hsr_port *master,
hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
ether_addr_copy(hsr_sp->macaddress_A, master->dev->dev_addr);

- if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
+ if (skb_put_padto(skb, ETH_ZLEN))
return;

hsr_forward_skb(skb, master);
@@ -348,8 +332,6 @@ static void send_prp_supervision_frame(struct hsr_port *master,
struct hsr_sup_tag *hsr_stag;
unsigned long irqflags;
struct sk_buff *skb;
- struct prp_rct *rct;
- u8 *tail;

skb = hsr_init_skb(master, ETH_P_PRP);
if (!skb) {
@@ -373,17 +355,11 @@ static void send_prp_supervision_frame(struct hsr_port *master,
hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
ether_addr_copy(hsr_sp->macaddress_A, master->dev->dev_addr);

- if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN)) {
+ if (skb_put_padto(skb, ETH_ZLEN)) {
spin_unlock_irqrestore(&master->hsr->seqnr_lock, irqflags);
return;
}

- tail = skb_tail_pointer(skb) - HSR_HLEN;
- rct = (struct prp_rct *)tail;
- rct->PRP_suffix = htons(ETH_P_PRP);
- set_prp_LSDU_size(rct, HSR_V1_SUP_LSDUSIZE);
- rct->sequence_nr = htons(hsr->sequence_nr);
- hsr->sequence_nr++;
spin_unlock_irqrestore(&master->hsr->seqnr_lock, irqflags);

hsr_forward_skb(skb, master);
diff --git a/net/hsr/hsr_forward.c b/net/hsr/hsr_forward.c
index cadfccd7876e..c11be87daa8f 100644
--- a/net/hsr/hsr_forward.c
+++ b/net/hsr/hsr_forward.c
@@ -454,7 +454,11 @@ static void handle_std_frame(struct sk_buff *skb,
void hsr_fill_frame_info(__be16 proto, struct sk_buff *skb,
struct hsr_frame_info *frame)
{
- if (proto == htons(ETH_P_PRP) ||
+ struct hsr_port *port = frame->port_rcv;
+ struct hsr_priv *hsr = port->hsr;
+
+ /* HSRv0 supervisory frames double as a tag so treat them as tagged. */
+ if ((!hsr->prot_version && proto == htons(ETH_P_PRP)) ||
proto == htons(ETH_P_HSR)) {
/* HSR tagged frame :- Data or Supervision */
frame->skb_std = NULL;
--
2.11.0