can: gw: use struct canfd_frame as internal data structure

To prepare the CAN FD support this patch implements the first adaptions in
data structures for CAN FD without changing the current functionality.

Additionally some code at the end of this patch is moved or indented to
simplify the review of the next implementation step.

Signed-off-by: Oliver Hartkopp <[e-mail]>
Signed-off-by: Marc Kleine-Budde <[e-mail]>

include/uapi/linux/can/gw.h

···
 
 /* CAN frame elements that are affected by curr. 3 CAN frame modifications */
 #define CGW_MOD_ID	0x01
-#define CGW_MOD_DLC	0x02
+#define CGW_MOD_DLC	0x02		/* contains the data length in bytes */
+#define CGW_MOD_LEN	CGW_MOD_DLC	/* CAN FD length representation */
 #define CGW_MOD_DATA	0x04
 
-#define CGW_FRAME_MODS 3 /* ID DLC DATA */
+#define CGW_FRAME_MODS 3 /* ID DLC/LEN DATA */
 
 #define MAX_MODFUNCTIONS (CGW_MOD_FUNCS * CGW_FRAME_MODS)
 

net/can/gw.c

···
 /* structure that contains the (on-the-fly) CAN frame modifications */
 struct cf_mod {
 	struct {
-		struct can_frame and;
-		struct can_frame or;
-		struct can_frame xor;
-		struct can_frame set;
+		struct canfd_frame and;
+		struct canfd_frame or;
+		struct canfd_frame xor;
+		struct canfd_frame set;
 	} modframe;
 	struct {
 		u8 and;
···
 		u8 xor;
 		u8 set;
 	} modtype;
-	void (*modfunc[MAX_MODFUNCTIONS])(struct can_frame *cf,
+	void (*modfunc[MAX_MODFUNCTIONS])(struct canfd_frame *cf,
 					  struct cf_mod *mod);
 
 	/* CAN frame checksum calculation after CAN frame modifications */
···
 		struct cgw_csum_crc8 crc8;
 	} csum;
 	struct {
-		void (*xor)(struct can_frame *cf, struct cgw_csum_xor *xor);
-		void (*crc8)(struct can_frame *cf, struct cgw_csum_crc8 *crc8);
+		void (*xor)(struct canfd_frame *cf,
+			    struct cgw_csum_xor *xor);
+		void (*crc8)(struct canfd_frame *cf,
+			     struct cgw_csum_crc8 *crc8);
 	} csumfunc;
 	u32 uid;
 };
···
 
 /* modification functions that are invoked in the hot path in can_can_gw_rcv */
 
-#define MODFUNC(func, op) static void func(struct can_frame *cf, \
+#define MODFUNC(func, op) static void func(struct canfd_frame *cf, \
 					   struct cf_mod *mod) { op ; }
 
 MODFUNC(mod_and_id, cf->can_id &= mod->modframe.and.can_id)
-MODFUNC(mod_and_dlc, cf->can_dlc &= mod->modframe.and.can_dlc)
+MODFUNC(mod_and_len, cf->len &= mod->modframe.and.len)
 MODFUNC(mod_and_data, *(u64 *)cf->data &= *(u64 *)mod->modframe.and.data)
 MODFUNC(mod_or_id, cf->can_id |= mod->modframe.or.can_id)
-MODFUNC(mod_or_dlc, cf->can_dlc |= mod->modframe.or.can_dlc)
+MODFUNC(mod_or_len, cf->len |= mod->modframe.or.len)
 MODFUNC(mod_or_data, *(u64 *)cf->data |= *(u64 *)mod->modframe.or.data)
 MODFUNC(mod_xor_id, cf->can_id ^= mod->modframe.xor.can_id)
-MODFUNC(mod_xor_dlc, cf->can_dlc ^= mod->modframe.xor.can_dlc)
+MODFUNC(mod_xor_len, cf->len ^= mod->modframe.xor.len)
 MODFUNC(mod_xor_data, *(u64 *)cf->data ^= *(u64 *)mod->modframe.xor.data)
 MODFUNC(mod_set_id, cf->can_id = mod->modframe.set.can_id)
-MODFUNC(mod_set_dlc, cf->can_dlc = mod->modframe.set.can_dlc)
+MODFUNC(mod_set_len, cf->len = mod->modframe.set.len)
 MODFUNC(mod_set_data, *(u64 *)cf->data = *(u64 *)mod->modframe.set.data)
 
-static inline void canframecpy(struct can_frame *dst, struct can_frame *src)
+static void canframecpy(struct canfd_frame *dst, struct can_frame *src)
 {
 	/* Copy the struct members separately to ensure that no uninitialized
 	 * data are copied in the 3 bytes hole of the struct. This is needed
···
 	 */
 
 	dst->can_id = src->can_id;
-	dst->can_dlc = src->can_dlc;
+	dst->len = src->can_dlc;
 	*(u64 *)dst->data = *(u64 *)src->data;
 }
 
 static int cgw_chk_csum_parms(s8 fr, s8 to, s8 re)
 {
+	s8 dlen = CAN_MAX_DLEN;
+
 	/* absolute dlc values 0 .. 7 => 0 .. 7, e.g. data [0]
 	 * relative to received dlc -1 .. -8 :
 	 * e.g. for received dlc = 8
···
 	 * -8 => index = 0 (data[0])
 	 */
 
-	if (fr > -9 && fr < 8 &&
-	    to > -9 && to < 8 &&
-	    re > -9 && re < 8)
+	if (fr >= -dlen && fr < dlen &&
+	    to >= -dlen && to < dlen &&
+	    re >= -dlen && re < dlen)
 		return 0;
 	else
 		return -EINVAL;
 }
 
-static inline int calc_idx(int idx, int rx_dlc)
+static inline int calc_idx(int idx, int rx_len)
 {
 	if (idx < 0)
-		return rx_dlc + idx;
+		return rx_len + idx;
 	else
 		return idx;
 }
 
-static void cgw_csum_xor_rel(struct can_frame *cf, struct cgw_csum_xor *xor)
+static void cgw_csum_xor_rel(struct canfd_frame *cf, struct cgw_csum_xor *xor)
 {
-	int from = calc_idx(xor->from_idx, cf->can_dlc);
-	int to = calc_idx(xor->to_idx, cf->can_dlc);
-	int res = calc_idx(xor->result_idx, cf->can_dlc);
+	int from = calc_idx(xor->from_idx, cf->len);
+	int to = calc_idx(xor->to_idx, cf->len);
+	int res = calc_idx(xor->result_idx, cf->len);
 	u8 val = xor->init_xor_val;
 	int i;
 
···
 	cf->data[res] = val;
 }
 
-static void cgw_csum_xor_pos(struct can_frame *cf, struct cgw_csum_xor *xor)
+static void cgw_csum_xor_pos(struct canfd_frame *cf, struct cgw_csum_xor *xor)
 {
 	u8 val = xor->init_xor_val;
 	int i;
···
 	cf->data[xor->result_idx] = val;
 }
 
-static void cgw_csum_xor_neg(struct can_frame *cf, struct cgw_csum_xor *xor)
+static void cgw_csum_xor_neg(struct canfd_frame *cf, struct cgw_csum_xor *xor)
 {
 	u8 val = xor->init_xor_val;
 	int i;
···
 	cf->data[xor->result_idx] = val;
 }
 
-static void cgw_csum_crc8_rel(struct can_frame *cf, struct cgw_csum_crc8 *crc8)
+static void cgw_csum_crc8_rel(struct canfd_frame *cf,
+			      struct cgw_csum_crc8 *crc8)
 {
-	int from = calc_idx(crc8->from_idx, cf->can_dlc);
-	int to = calc_idx(crc8->to_idx, cf->can_dlc);
-	int res = calc_idx(crc8->result_idx, cf->can_dlc);
+	int from = calc_idx(crc8->from_idx, cf->len);
+	int to = calc_idx(crc8->to_idx, cf->len);
+	int res = calc_idx(crc8->result_idx, cf->len);
 	u8 crc = crc8->init_crc_val;
 	int i;
 
···
 	cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
 }
 
-static void cgw_csum_crc8_pos(struct can_frame *cf, struct cgw_csum_crc8 *crc8)
+static void cgw_csum_crc8_pos(struct canfd_frame *cf,
+			      struct cgw_csum_crc8 *crc8)
 {
 	u8 crc = crc8->init_crc_val;
 	int i;
···
 	cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
 }
 
-static void cgw_csum_crc8_neg(struct can_frame *cf, struct cgw_csum_crc8 *crc8)
+static void cgw_csum_crc8_neg(struct canfd_frame *cf,
+			      struct cgw_csum_crc8 *crc8)
 {
 	u8 crc = crc8->init_crc_val;
 	int i;
···
 static void can_can_gw_rcv(struct sk_buff *skb, void *data)
 {
 	struct cgw_job *gwj = (struct cgw_job *)data;
-	struct can_frame *cf;
+	struct canfd_frame *cf;
 	struct sk_buff *nskb;
 	int modidx = 0;
 
···
 	nskb->dev = gwj->dst.dev;
 
 	/* pointer to modifiable CAN frame */
-	cf = (struct can_frame *)nskb->data;
+	cf = (struct canfd_frame *)nskb->data;
 
 	/* perform preprocessed modification functions if there are any */
 	while (modidx < MAX_MODFUNCTIONS && gwj->mod.modfunc[modidx])
···
 	/* Has the CAN frame been modified? */
 	if (modidx) {
 		/* get available space for the processed CAN frame type */
-		int max_len = nskb->len - offsetof(struct can_frame, data);
+		int max_len = nskb->len - offsetof(struct canfd_frame, data);
 
 		/* dlc may have changed, make sure it fits to the CAN frame */
-		if (cf->can_dlc > max_len)
+		if (cf->len > max_len)
 			goto out_delete;
 
 		/* check for checksum updates in classic CAN length only */
 		if (gwj->mod.csumfunc.crc8) {
-			if (cf->can_dlc > 8)
+			if (cf->len > 8)
 				goto out_delete;
 
 			(*gwj->mod.csumfunc.crc8)(cf, &gwj->mod.csum.crc8);
 		}
 
 		if (gwj->mod.csumfunc.xor) {
-			if (cf->can_dlc > 8)
+			if (cf->len > 8)
 				goto out_delete;
 
 			(*gwj->mod.csumfunc.xor)(cf, &gwj->mod.csum.xor);
···
 static int cgw_put_job(struct sk_buff *skb, struct cgw_job *gwj, int type,
 		       u32 pid, u32 seq, int flags)
 {
-	struct cgw_frame_mod mb;
 	struct rtcanmsg *rtcan;
 	struct nlmsghdr *nlh;
 
···
 			goto cancel;
 	}
 
-	if (gwj->mod.modtype.and) {
-		memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf));
-		mb.modtype = gwj->mod.modtype.and;
-		if (nla_put(skb, CGW_MOD_AND, sizeof(mb), &mb) < 0)
-			goto cancel;
-	}
+	if (1) {
+		struct cgw_frame_mod mb;
 
-	if (gwj->mod.modtype.or) {
-		memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf));
-		mb.modtype = gwj->mod.modtype.or;
-		if (nla_put(skb, CGW_MOD_OR, sizeof(mb), &mb) < 0)
-			goto cancel;
-	}
+		if (gwj->mod.modtype.and) {
+			memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf));
+			mb.modtype = gwj->mod.modtype.and;
+			if (nla_put(skb, CGW_MOD_AND, sizeof(mb), &mb) < 0)
+				goto cancel;
+		}
 
-	if (gwj->mod.modtype.xor) {
-		memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf));
-		mb.modtype = gwj->mod.modtype.xor;
-		if (nla_put(skb, CGW_MOD_XOR, sizeof(mb), &mb) < 0)
-			goto cancel;
-	}
+		if (gwj->mod.modtype.or) {
+			memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf));
+			mb.modtype = gwj->mod.modtype.or;
+			if (nla_put(skb, CGW_MOD_OR, sizeof(mb), &mb) < 0)
+				goto cancel;
+		}
 
-	if (gwj->mod.modtype.set) {
-		memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf));
-		mb.modtype = gwj->mod.modtype.set;
-		if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0)
-			goto cancel;
+		if (gwj->mod.modtype.xor) {
+			memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf));
+			mb.modtype = gwj->mod.modtype.xor;
+			if (nla_put(skb, CGW_MOD_XOR, sizeof(mb), &mb) < 0)
+				goto cancel;
+		}
+
+		if (gwj->mod.modtype.set) {
+			memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf));
+			mb.modtype = gwj->mod.modtype.set;
+			if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0)
+				goto cancel;
+		}
 	}
 
 	if (gwj->mod.uid) {
···
 			  u8 gwtype, void *gwtypeattr, u8 *limhops)
 {
 	struct nlattr *tb[CGW_MAX + 1];
-	struct cgw_frame_mod mb;
 	int modidx = 0;
 	int err = 0;
 
···
 	}
 
 	/* check for AND/OR/XOR/SET modifications */
+	if (1) {
+		struct cgw_frame_mod mb;
 
-	if (tb[CGW_MOD_AND]) {
-		nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN);
+		if (tb[CGW_MOD_AND]) {
+			nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN);
 
-		canframecpy(&mod->modframe.and, &mb.cf);
-		mod->modtype.and = mb.modtype;
+			canframecpy(&mod->modframe.and, &mb.cf);
+			mod->modtype.and = mb.modtype;
 
-		if (mb.modtype & CGW_MOD_ID)
-			mod->modfunc[modidx++] = mod_and_id;
+			if (mb.modtype & CGW_MOD_ID)
+				mod->modfunc[modidx++] = mod_and_id;
 
-		if (mb.modtype & CGW_MOD_DLC)
-			mod->modfunc[modidx++] = mod_and_dlc;
+			if (mb.modtype & CGW_MOD_LEN)
+				mod->modfunc[modidx++] = mod_and_len;
 
-		if (mb.modtype & CGW_MOD_DATA)
-			mod->modfunc[modidx++] = mod_and_data;
-	}
+			if (mb.modtype & CGW_MOD_DATA)
+				mod->modfunc[modidx++] = mod_and_data;
+		}
 
-	if (tb[CGW_MOD_OR]) {
-		nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN);
+		if (tb[CGW_MOD_OR]) {
+			nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN);
 
-		canframecpy(&mod->modframe.or, &mb.cf);
-		mod->modtype.or = mb.modtype;
+			canframecpy(&mod->modframe.or, &mb.cf);
+			mod->modtype.or = mb.modtype;
 
-		if (mb.modtype & CGW_MOD_ID)
-			mod->modfunc[modidx++] = mod_or_id;
+			if (mb.modtype & CGW_MOD_ID)
+				mod->modfunc[modidx++] = mod_or_id;
 
-		if (mb.modtype & CGW_MOD_DLC)
-			mod->modfunc[modidx++] = mod_or_dlc;
+			if (mb.modtype & CGW_MOD_LEN)
+				mod->modfunc[modidx++] = mod_or_len;
 
-		if (mb.modtype & CGW_MOD_DATA)
-			mod->modfunc[modidx++] = mod_or_data;
-	}
+			if (mb.modtype & CGW_MOD_DATA)
+				mod->modfunc[modidx++] = mod_or_data;
+		}
 
-	if (tb[CGW_MOD_XOR]) {
-		nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN);
+		if (tb[CGW_MOD_XOR]) {
+			nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN);
 
-		canframecpy(&mod->modframe.xor, &mb.cf);
-		mod->modtype.xor = mb.modtype;
+			canframecpy(&mod->modframe.xor, &mb.cf);
+			mod->modtype.xor = mb.modtype;
 
-		if (mb.modtype & CGW_MOD_ID)
-			mod->modfunc[modidx++] = mod_xor_id;
+			if (mb.modtype & CGW_MOD_ID)
+				mod->modfunc[modidx++] = mod_xor_id;
 
-		if (mb.modtype & CGW_MOD_DLC)
-			mod->modfunc[modidx++] = mod_xor_dlc;
+			if (mb.modtype & CGW_MOD_LEN)
+				mod->modfunc[modidx++] = mod_xor_len;
 
-		if (mb.modtype & CGW_MOD_DATA)
-			mod->modfunc[modidx++] = mod_xor_data;
-	}
+			if (mb.modtype & CGW_MOD_DATA)
+				mod->modfunc[modidx++] = mod_xor_data;
+		}
 
-	if (tb[CGW_MOD_SET]) {
-		nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN);
+		if (tb[CGW_MOD_SET]) {
+			nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN);
 
-		canframecpy(&mod->modframe.set, &mb.cf);
-		mod->modtype.set = mb.modtype;
+			canframecpy(&mod->modframe.set, &mb.cf);
+			mod->modtype.set = mb.modtype;
 
-		if (mb.modtype & CGW_MOD_ID)
-			mod->modfunc[modidx++] = mod_set_id;
+			if (mb.modtype & CGW_MOD_ID)
+				mod->modfunc[modidx++] = mod_set_id;
 
-		if (mb.modtype & CGW_MOD_DLC)
-			mod->modfunc[modidx++] = mod_set_dlc;
+			if (mb.modtype & CGW_MOD_LEN)
+				mod->modfunc[modidx++] = mod_set_len;
 
-		if (mb.modtype & CGW_MOD_DATA)
-			mod->modfunc[modidx++] = mod_set_data;
+			if (mb.modtype & CGW_MOD_DATA)
+				mod->modfunc[modidx++] = mod_set_data;
+		}
 	}
 
 	/* check for checksum operations after CAN frame modifications */