Restore handling of the third argument (id) of hid_start_parse(), same as

it is done in NetBSD/OpenBSD, and as it was here before r205728.

I personally think this API or its implementation is incorrect, as it is not
correct to filter collections based on report ID, as they are orthogonal
in general case, but I see no harm from supporting this feature.

PR:		usb/171810
Submitted by:	Vitaly Magerya <vmagerya@gmail.com>
MFC after:	1 month

3 files changed, 23 insertions, 9 deletions

diff --git a/lib/libusbhid/descr.c b/lib/libusbhid/descr.c
index def90da..0c66342 100644
--- a/lib/libusbhid/descr.c
+++ b/lib/libusbhid/descr.c
@@ -68,7 +68,7 @@ hid_get_report_id(int fd)
 	if ((rep = hid_get_report_desc(fd)) == NULL)
 		goto use_ioctl;
 	kindset = 1 << hid_input | 1 << hid_output | 1 << hid_feature;
-	for (d = hid_start_parse(rep, kindset, 0); hid_get_item(d, &h); ) {
+	for (d = hid_start_parse(rep, kindset, -1); hid_get_item(d, &h); ) {
 		/* Return the first report ID we met. */
 		if (h.report_ID != 0) {
 			temp = h.report_ID;
diff --git a/lib/libusbhid/parse.c b/lib/libusbhid/parse.c
index 041e289..7a2b3f4 100644
--- a/lib/libusbhid/parse.c
+++ b/lib/libusbhid/parse.c
@@ -70,6 +70,7 @@ struct hid_data {
 	uint8_t	iusage;		/* current "usages_min/max" index */
 	uint8_t ousage;		/* current "usages_min/max" offset */
 	uint8_t	susage;		/* usage set flags */
+	int32_t	reportid;	/* requested report ID */
 };
 
 /*------------------------------------------------------------------------*
@@ -149,7 +150,7 @@ hid_switch_rid(struct hid_data *s, struct hid_item *c, int32_t next_rID)
  *	hid_start_parse
  *------------------------------------------------------------------------*/
 hid_data_t
-hid_start_parse(report_desc_t d, int kindset, int id __unused)
+hid_start_parse(report_desc_t d, int kindset, int id)
 {
 	struct hid_data *s;
 
@@ -158,6 +159,7 @@ hid_start_parse(report_desc_t d, int kindset, int id __unused)
 	s->start = s->p = d->data;
 	s->end = d->data + d->size;
 	s->kindset = kindset;
+	s->reportid = id;
 	return (s);
 }
 
@@ -207,8 +209,8 @@ hid_get_byte(struct hid_data *s, const uint16_t wSize)
 /*------------------------------------------------------------------------*
  *	hid_get_item
  *------------------------------------------------------------------------*/
-int
-hid_get_item(hid_data_t s, hid_item_t *h)
+static int
+hid_get_item_raw(hid_data_t s, hid_item_t *h)
 {
 	hid_item_t *c;
 	unsigned int bTag, bType, bSize;
@@ -509,6 +511,19 @@ hid_get_item(hid_data_t s, hid_item_t *h)
 }
 
 int
+hid_get_item(hid_data_t s, hid_item_t *h)
+{
+	int r;
+
+	for (;;) {
+		r = hid_get_item_raw(s, h);
+		if (r <= 0 || s->reportid == -1 || h->report_ID == s->reportid)
+			break;
+	}
+	return (r);
+}
+
+int
 hid_report_size(report_desc_t r, enum hid_kind k, int id)
 {
 	struct hid_data *d;
@@ -523,7 +538,7 @@ hid_report_size(report_desc_t r, enum hid_kind k, int id)
 
 	memset(&h, 0, sizeof h);
 	for (d = hid_start_parse(r, 1 << k, id); hid_get_item(d, &h); ) {
-		if ((h.report_ID == id || id < 0) && h.kind == k) {
+		if (h.kind == k) {
 			/* compute minimum */
 			if (lpos > h.pos)
 				lpos = h.pos;
diff --git a/lib/libusbhid/usbhid.3 b/lib/libusbhid/usbhid.3
index c34a109..98fcdf5 100644
--- a/lib/libusbhid/usbhid.3
+++ b/lib/libusbhid/usbhid.3
@@ -144,16 +144,15 @@ fails it will return
 .Ss Descriptor Parsing Functions
 To parse the report descriptor the
 .Fn hid_start_parse
-function should be called with a report descriptor and a set that
-describes which items that are interesting.
+function should be called with a report descriptor, a set that
+describes which items that are interesting, and the desired report
+ID (or -1 to obtain items of all report IDs).
 The set is obtained by OR-ing together values
 .Fa "(1 << k)"
 where
 .Fa k
 is an item of type
 .Vt hid_kind_t .
-The report ID (if present) is given by
-.Fa id .
 The function returns
 .Dv NULL
 if the initialization fails, otherwise an opaque value to be used