kernel/linux.git/net/nfc/digital_dep.c, branch linux-4.16.y

NFC: digital: NFC-DEP Target WT(nfcdep,max) is now 14

2017-06-22T22:19:59+00:00

Version 1.1 of the NFC Forum's NFC Digital Protocol Technical Specification dated 2014-07-14 specifies that the NFC-DEP Protocol's Target WT(nfcdep,max) value is 14. In version 1.0 it was 8 so change the value in the Linux NFC-DEP Protocol code accordingly. Signed-off-by: Mark Greer Signed-off-by: Samuel Ortiz

networking: add and use skb_put_u8()

2017-06-16T15:48:40+00:00

Joe and Bjørn suggested that it'd be nicer to not have the cast in the fairly common case of doing *(u8 *)skb_put(skb, 1) = c; Add skb_put_u8() for this case, and use it across the code, using the following spatch: @@ expression SKB, C, S; typedef u8; identifier fn = {skb_put}; fresh identifier fn2 = fn ## "_u8"; @@ - *(u8 *)fn(SKB, S) = C; + fn2(SKB, C); Note that due to the "S", the spatch isn't perfect, it should have checked that S is 1, but there's also places that use a sizeof expression like sizeof(var) or sizeof(u8) etc. Turns out that nobody ever did something like *(u8 *)skb_put(skb, 2) = c; which would be wrong anyway since the second byte wouldn't be initialized. Suggested-by: Joe Perches Suggested-by: Bjørn Mork Signed-off-by: Johannes Berg Signed-off-by: David S. Miller

networking: make skb_push & __skb_push return void pointers

2017-06-16T15:48:40+00:00

It seems like a historic accident that these return unsigned char *, and in many places that means casts are required, more often than not. Make these functions return void * and remove all the casts across the tree, adding a (u8 *) cast only where the unsigned char pointer was used directly, all done with the following spatch: @@ expression SKB, LEN; typedef u8; identifier fn = { skb_push, __skb_push, skb_push_rcsum }; @@ - *(fn(SKB, LEN)) + *(u8 *)fn(SKB, LEN) @@ expression E, SKB, LEN; identifier fn = { skb_push, __skb_push, skb_push_rcsum }; type T; @@ - E = ((T *)(fn(SKB, LEN))) + E = fn(SKB, LEN) @@ expression SKB, LEN; identifier fn = { skb_push, __skb_push, skb_push_rcsum }; @@ - fn(SKB, LEN)[0] + *(u8 *)fn(SKB, LEN) Note that the last part there converts from push(...)[0] to the more idiomatic *(u8 *)push(...). Signed-off-by: Johannes Berg Signed-off-by: David S. Miller

networking: make skb_put & friends return void pointers

2017-06-16T15:48:39+00:00

It seems like a historic accident that these return unsigned char *, and in many places that means casts are required, more often than not. Make these functions (skb_put, __skb_put and pskb_put) return void * and remove all the casts across the tree, adding a (u8 *) cast only where the unsigned char pointer was used directly, all done with the following spatch: @@ expression SKB, LEN; typedef u8; identifier fn = { skb_put, __skb_put }; @@ - *(fn(SKB, LEN)) + *(u8 *)fn(SKB, LEN) @@ expression E, SKB, LEN; identifier fn = { skb_put, __skb_put }; type T; @@ - E = ((T *)(fn(SKB, LEN))) + E = fn(SKB, LEN) which actually doesn't cover pskb_put since there are only three users overall. A handful of stragglers were converted manually, notably a macro in drivers/isdn/i4l/isdn_bsdcomp.c and, oddly enough, one of the many instances in net/bluetooth/hci_sock.c. In the former file, I also had to fix one whitespace problem spatch introduced. Signed-off-by: Johannes Berg Signed-off-by: David S. Miller

networking: introduce and use skb_put_data()

2017-06-16T15:48:37+00:00

A common pattern with skb_put() is to just want to memcpy() some data into the new space, introduce skb_put_data() for this. An spatch similar to the one for skb_put_zero() converts many of the places using it: @@ identifier p, p2; expression len, skb, data; type t, t2; @@ ( -p = skb_put(skb, len); +p = skb_put_data(skb, data, len); | -p = (t)skb_put(skb, len); +p = skb_put_data(skb, data, len); ) ( p2 = (t2)p; -memcpy(p2, data, len); | -memcpy(p, data, len); ) @@ type t, t2; identifier p, p2; expression skb, data; @@ t *p; ... ( -p = skb_put(skb, sizeof(t)); +p = skb_put_data(skb, data, sizeof(t)); | -p = (t *)skb_put(skb, sizeof(t)); +p = skb_put_data(skb, data, sizeof(t)); ) ( p2 = (t2)p; -memcpy(p2, data, sizeof(*p)); | -memcpy(p, data, sizeof(*p)); ) @@ expression skb, len, data; @@ -memcpy(skb_put(skb, len), data, len); +skb_put_data(skb, data, len); (again, manually post-processed to retain some comments) Reviewed-by: Stephen Hemminger Signed-off-by: Johannes Berg Signed-off-by: David S. Miller

NFC: digital: Fix RTOX supervisor PDU handling

2016-07-11T00:02:03+00:00

When the target needs more time to process the received PDU, it sends Response Timeout Extension (RTOX) PDU. When the initiator receives a RTOX PDU, it must reply with a RTOX PDU and extends the current rwt value with the formula: rwt_int = rwt * rtox This patch takes care of the rtox value passed by the target in the RTOX PDU and extends the timeout for the next response accordingly. Signed-off-by: Thierry Escande Signed-off-by: Samuel Ortiz

NFC: digital: Add support for NFC DEP Response Waiting Time

2016-07-11T00:01:14+00:00

When sending an ATR_REQ, the initiator must wait for the ATR_RES at least 'RWT(nfcdep,activation) + dRWT(nfcdep)' and no more than 'RWT(nfcdep,activation) + dRWT(nfcdep) + dT(nfcdep,initiator)'. This gives a timeout value between 1237 ms and 1337 ms. This patch defines DIGITAL_ATR_RES_RWT to 1337 used for the timeout value of ATR_REQ command. For other DEP PDUs, the initiator must wait between 'RWT + dRWT(nfcdep)' and 'RWT + dRWT(nfcdep) + dT(nfcdep,initiator)' where RWT is given by the following formula: '(256 * 16 / f(c)) * 2^wt' where wt is the value of the TO field in the ATR_RES response and is in the range between 0 and 14. This patch declares a mapping table for wt values and gives RWT max values between 100 ms and 5049 ms. This patch also defines DIGITAL_ATR_RES_TO_WT, the maximum wt value in target mode, to 8. Signed-off-by: Thierry Escande Signed-off-by: Samuel Ortiz

NFC: digital: Free supervisor PDUs

2016-07-11T00:00:26+00:00

This patch frees the RTOX resp sk_buff in initiator mode. It also makes use of the free_resp exit point for ATN supervisor PDUs in both initiator and target mode. Signed-off-by: Thierry Escande Signed-off-by: Samuel Ortiz

NFC: digital: Rework ACK PDU handling in initiator mode

2016-07-10T23:59:37+00:00

With this patch, ACK PDU sk_buffs are now freed and code has been refactored for better errors handling. Signed-off-by: Thierry Escande Signed-off-by: Samuel Ortiz

NFC: digital: Fix ACK & NACK PDUs handling in target mode

2016-07-10T23:58:46+00:00

When the target receives a NACK PDU, it re-sends the last sent PDU. ACK PDUs are received by the target as a reply from the initiator to chained I-PDUs. There are 3 cases to handle: - If the target has previously received 1 or more ATN PDUs and the PNI in the ACK PDU is equal to the target PNI - 1, then it means that the initiator did not received the last issued PDU from the target. In this case it re-sends this PDU. - If the target has received 1 or more ATN PDUs but the ACK PNI is not the target PNI - 1, then this means that this ACK is the reply of the previous chained I-PDU sent by the target. The target did not received it on the first attempt and it is being re-sent by the initiator. The process continues as usual. - No ATN PDU received before this ACK PDU. This is the reply of a chained I-PDU. The target keeps on processing its chained I-PDU. The code has been refactored to avoid too many indentation levels. Also, ACK and NACK PDUs were not freed. This is now fixed. Signed-off-by: Thierry Escande Signed-off-by: Samuel Ortiz