Last year big HID parser modification introduced a regression reported by Benjamin Baier [0]. He confirmed that the diff below fixes it for his use case.
I'm looking for more tests to know if this does not break anything else. [0] http://marc.info/?l=openbsd-bugs&m=142153086729320&w=2 Index: parse.c =================================================================== RCS file: /cvs/src/lib/libusbhid/parse.c,v retrieving revision 1.10 diff -u -p -r1.10 parse.c --- parse.c 18 Jan 2015 17:16:06 -0000 1.10 +++ parse.c 31 Jan 2015 11:34:55 -0000 @@ -67,6 +67,8 @@ struct hid_data { uint8_t ousage; /* current "usages_min/max" offset */ uint8_t susage; /* usage set flags */ int32_t reportid; /* requested report ID */ + struct hid_item savedcoll; /* save coll until we know the ID */ + uint8_t hassavedcoll; }; static void @@ -151,6 +153,7 @@ hid_start_parse(report_desc_t d, int kin s->end = d->data + d->size; s->kindset = kindset; s->reportid = id; + s->hassavedcoll = 0; return (s); } @@ -191,10 +194,20 @@ hid_get_byte(struct hid_data *s, const u return (retval); } +#define REPORT_SAVED_COLL \ + do { \ + if (s->hassavedcoll) { \ + *h = s->savedcoll; \ + h->report_ID = c->report_ID; \ + s->hassavedcoll = 0; \ + return (1); \ + } \ + } while(0) + static int hid_get_item_raw(hid_data_t s, hid_item_t *h) { - hid_item_t *c; + hid_item_t nc, *c; unsigned int bTag, bType, bSize; int32_t mask; int32_t dval; @@ -207,6 +220,7 @@ hid_get_item_raw(hid_data_t s, hid_item_ top: /* check if there is an array of items */ if (s->icount < s->ncount) { + REPORT_SAVED_COLL; /* get current usage */ if (s->iusage < s->nusage) { dval = s->usages_min[s->iusage] + s->ousage; @@ -328,13 +342,23 @@ hid_get_item_raw(hid_data_t s, hid_item_ c->collection = dval; c->collevel++; c->usage = s->usage_last; - *h = *c; - return (1); + nc = *c; + if (s->hassavedcoll) { + *h = s->savedcoll; + h->report_ID = nc.report_ID; + s->savedcoll = nc; + return (1); + } else { + s->hassavedcoll = 1; + s->savedcoll = nc; + } + goto top; case 11: /* Feature */ c->kind = hid_feature; c->flags = dval; goto ret; case 12: /* End collection */ + REPORT_SAVED_COLL; c->kind = hid_endcollection; if (c->collevel == 0) { /* Invalid end collection. */
