diff options
| author | Jeremy Kerr <jk@codeconstruct.com.au> | 2026-07-24 13:15:29 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-07-30 16:54:59 -0700 |
| commit | d52fc7f09a18d0c2b2c164e0a82136510cfa1798 (patch) | |
| tree | 5408c20fa7e1b6ad183cddf0ee701209e4eeb1d1 /include/linux | |
| parent | f5bf226f3c7aab957d8874f7d437b08017b5c428 (diff) | |
net: mctp: usblib: Implement receive-side packet spanning
Using the existing prepare/complete API, we can persist the rx skb
across receives to implement v1.1 packet spanning.
Alter the packet-extraction loop to allow truncated packets, returning
early with the skb persisted for the next IN urb completion. When we see
we have a complete packet, netif_rx() that. If the packet boundary
aligns with the urb completion, we can netif_rx() the whole thing.
Those intermediate packets are cloned from the original
(large-transfer-data) skb. Unlike existing behaviour, if the clone
fails, we drop just that clone, instead of the existing transfer skb.
This allows us to process the rest of the skb data, and any continuation
of the span into the next transfer.
One subtle change: the mctp_usblib_rx() helper now handles skbs with the
full transport header, so we shift the skb_pull() for the header data to
the helper, before doing the rx_bytes stats update.
We still need to handle non-spanning mode, so error out on
truncated-packet cases there.
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Link: https://patch.msgid.link/20260724-dev-mctp-usb-1-1-v5-8-e66bbba0dbdc@codeconstruct.com.au
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/usb/mctp-usb.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/include/linux/usb/mctp-usb.h b/include/linux/usb/mctp-usb.h index 1a5e795b4ec1..2979ddaa4dab 100644 --- a/include/linux/usb/mctp-usb.h +++ b/include/linux/usb/mctp-usb.h @@ -34,6 +34,8 @@ struct mctp_usb_hdr { #define MCTP_USB_MTU_MIN MCTP_USB_BTU #define MCTP_USB_1_0_PKTLEN_MAX U8_MAX #define MCTP_USB_1_0_MTU_MAX (MCTP_USB_1_0_PKTLEN_MAX - sizeof(struct mctp_usb_hdr)) +#define MCTP_USB_1_1_PKTLEN_MAX GENMASK(12, 0) +#define MCTP_USB_1_1_MTU_MAX (MCTP_USB_1_1_PKTLEN_MAX - sizeof(struct mctp_usb_hdr)) #define MCTP_USB_DMTF_ID 0x1ab4 /* mctp-usblib */ @@ -46,9 +48,11 @@ struct mctp_usb_hdr { */ struct mctp_usblib_rx { struct sk_buff *skb; + u16 ep_pktlen; + bool span; }; -void mctp_usblib_rx_init(struct mctp_usblib_rx *rx); +int mctp_usblib_rx_init(struct mctp_usblib_rx *rx, u16 ep_pktlen, bool span); void mctp_usblib_rx_fini(struct mctp_usblib_rx *rx); int mctp_usblib_rx_prepare(struct net_device *netdev, |