mirror of https://gitee.com/openkylin/linux.git
9fb030a704
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> |
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| .. | ||
| lmc | ||
| .gitignore | ||
| Kconfig | ||
| Makefile | ||
| c101.c | ||
| cosa.c | ||
| cosa.h | ||
| dlci.c | ||
| farsync.c | ||
| farsync.h | ||
| fsl_ucc_hdlc.c | ||
| fsl_ucc_hdlc.h | ||
| hd64570.c | ||
| hd64570.h | ||
| hd64572.c | ||
| hd64572.h | ||
| hdlc.c | ||
| hdlc_cisco.c | ||
| hdlc_fr.c | ||
| hdlc_ppp.c | ||
| hdlc_raw.c | ||
| hdlc_raw_eth.c | ||
| hdlc_x25.c | ||
| hostess_sv11.c | ||
| ixp4xx_hss.c | ||
| lapbether.c | ||
| n2.c | ||
| pc300too.c | ||
| pci200syn.c | ||
| sbni.c | ||
| sbni.h | ||
| sdla.c | ||
| sealevel.c | ||
| slic_ds26522.c | ||
| slic_ds26522.h | ||
| wanxl.c | ||
| wanxl.h | ||
| wanxlfw.S | ||
| wanxlfw.inc_shipped | ||
| x25_asy.c | ||
| x25_asy.h | ||
| z85230.c | ||
| z85230.h | ||