linux_dsm_epyc7002/drivers/net/wan
Xie He 9fb030a704 drivers/net/wan/hdlc: Set skb->protocol before transmitting
This patch sets skb->protocol before transmitting frames on the HDLC
device, so that a user listening on the HDLC device with an AF_PACKET
socket will see outgoing frames' sll_protocol field correctly set and
consistent with that of incoming frames.

1. Control frames in hdlc_cisco and hdlc_ppp

When these drivers send control frames, skb->protocol is not set.

This value should be set to htons(ETH_P_HDLC), because when receiving
control frames, their skb->protocol is set to htons(ETH_P_HDLC).

When receiving, hdlc_type_trans in hdlc.h is called, which then calls
cisco_type_trans or ppp_type_trans. The skb->protocol of control frames
is set to htons(ETH_P_HDLC) so that the control frames can be received
by hdlc_rcv in hdlc.c, which calls cisco_rx or ppp_rx to process the
control frames.

2. hdlc_fr

When this driver sends control frames, skb->protocol is set to internal
values used in this driver.

When this driver sends data frames (from upper stacked PVC devices),
skb->protocol is the same as that of the user data packet being sent on
the upper PVC device (for normal PVC devices), or is htons(ETH_P_802_3)
(for Ethernet-emulating PVC devices).

However, skb->protocol for both control frames and data frames should be
set to htons(ETH_P_HDLC), because when receiving, all frames received on
the HDLC device will have their skb->protocol set to htons(ETH_P_HDLC).

When receiving, hdlc_type_trans in hdlc.h is called, and because this
driver doesn't provide a type_trans function in struct hdlc_proto,
all frames will have their skb->protocol set to htons(ETH_P_HDLC).
The frames are then received by hdlc_rcv in hdlc.c, which calls fr_rx
to process the frames (control frames are consumed and data frames
are re-received on upper PVC devices).

Cc: Krzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-17 16:41:12 -07:00
..
lmc drivers: net: wan: Fix trivial spelling 2020-07-15 18:18:21 -07:00
.gitignore
c101.c WAN: Replace HTTP links with HTTPS ones 2020-07-13 16:58:01 -07:00
cosa.c net: wan: cosa: Replace HTTP links with HTTPS ones 2020-07-13 17:45:22 -07:00
cosa.h
dlci.c net: wan: dlci: Remove set but not used variable 'err' 2020-08-14 20:42:25 -07:00
farsync.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-08-05 20:13:21 -07:00
farsync.h
fsl_ucc_hdlc.c
fsl_ucc_hdlc.h
hd64570.c
hd64570.h
hd64572.c
hd64572.h
hdlc_cisco.c drivers/net/wan/hdlc: Set skb->protocol before transmitting 2020-09-17 16:41:12 -07:00
hdlc_fr.c drivers/net/wan/hdlc: Set skb->protocol before transmitting 2020-09-17 16:41:12 -07:00
hdlc_ppp.c drivers/net/wan/hdlc: Set skb->protocol before transmitting 2020-09-17 16:41:12 -07:00
hdlc_raw_eth.c
hdlc_raw.c
hdlc_x25.c drivers/net/wan/hdlc_x25: Added needed_headroom and a skb->len check 2020-08-14 20:41:08 -07:00
hdlc.c drivers/net/wan/hdlc: Change the default of hard_header_len to 0 2020-09-02 15:42:43 -07:00
hostess_sv11.c
ixp4xx_hss.c
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
lapbether.c drivers/net/wan/lapbether: Make skb->protocol consistent with the header 2020-09-17 16:38:03 -07:00
Makefile
n2.c WAN: Replace HTTP links with HTTPS ones 2020-07-13 16:58:01 -07:00
pc300too.c WAN: Replace HTTP links with HTTPS ones 2020-07-13 16:58:01 -07:00
pci200syn.c WAN: Replace HTTP links with HTTPS ones 2020-07-13 16:58:01 -07:00
sbni.c
sbni.h
sdla.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
sealevel.c
slic_ds26522.c
slic_ds26522.h
wanxl.c wan: wanxl: switch from 'pci_' to 'dma_' API 2020-08-04 16:17:00 -07:00
wanxl.h
wanxlfw.inc_shipped
wanxlfw.S
x25_asy.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
x25_asy.h
z85230.c treewide: Remove uninitialized_var() usage 2020-07-16 12:35:15 -07:00
z85230.h