From: Xie He <xie.he.0...@gmail.com> Date: Mon, 28 Sep 2020 05:56:43 -0700
> The fr_hard_header function is used to prepend the header to skbs before > transmission. It is used in 3 situations: > 1) When a control packet is generated internally in this driver; > 2) When a user sends an skb on an Ethernet-emulating PVC device; > 3) When a user sends an skb on a normal PVC device. > > These 3 situations need to be handled differently by fr_hard_header. > Different headers should be prepended to the skb in different situations. > > Currently fr_hard_header distinguishes these 3 situations using > skb->protocol. For situation 1 and 2, a special skb->protocol value > will be assigned before calling fr_hard_header, so that it can recognize > these 2 situations. All skb->protocol values other than these special ones > are treated by fr_hard_header as situation 3. > > However, it is possible that in situation 3, the user sends an skb with > one of the special skb->protocol values. In this case, fr_hard_header > would incorrectly treat it as situation 1 or 2. > > This patch tries to solve this issue by using skb->dev instead of > skb->protocol to distinguish between these 3 situations. For situation > 1, skb->dev would be NULL; for situation 2, skb->dev->type would be > ARPHRD_ETHER; and for situation 3, skb->dev->type would be ARPHRD_DLCI. > > This way fr_hard_header would be able to distinguish these 3 situations > correctly regardless what skb->protocol value the user tries to use in > situation 3. > > Cc: Krzysztof Halasa <k...@pm.waw.pl> > Signed-off-by: Xie He <xie.he.0...@gmail.com> Applied, thank you.
