- don't include <bio.h> we're not using it.
- be more careful about string descriptors
- use %H and not hexstr().  avoid truncation, malloc, and extra code

Reference: /n/atom/patch/applied/usbuseencodefmt
Date: Sat Apr 19 16:12:21 CES 2014
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/usb/lib/dev.c	Sat Apr 19 16:10:56 2014
+++ /sys/src/cmd/usb/lib/dev.c	Sat Apr 19 16:10:56 2014
@@ -242,13 +242,15 @@
 	if(sid == 0)
 		return estrdup("none");
 	type = Rd2h|Rstd|Rdev;
-	nr = usbcmd(d, type, Rgetdesc, Dstr<<8|sid, 0, buf, sizeof(buf));
-	if(nr < 4)
+	nr = usbcmd(d, type, Rgetdesc, Dstr<<8|sid, 0, buf, 9);
+	if(nr < 4){
 		langid = 0x0409;		/* english */
+		buf[0] = 0;
+		usbcmd(d, type, Rgetdesc, Dstr<<8|sid, langid, buf, 9);
+	}
 	else
 		langid = buf[3]<<8 | buf[2];
-	nr = usbcmd(d, type, Rgetdesc, Dstr<<8|sid, langid, buf, sizeof(buf));
-
+	nr = usbcmd(d, type, Rgetdesc, Dstr<<8|sid, langid, buf, buf[0]);
 	return mkstr(buf, nr);
 }
 
@@ -395,7 +397,7 @@
 	int ndata, n;
 	uchar *wp;
 	uchar buf[8];
-	char *hd, *rs;
+	char *rs;
 
 	assert(d != nil);
 	if(data == nil){
@@ -413,12 +415,10 @@
 	if(data != nil)
 		memmove(wp+8, data, ndata);
 	if(usbdebug>2){
-		hd = hexstr(wp, ndata+8);
 		rs = reqstr(type, req);
-		fprint(2, "%s: %s val %d|%d idx %d cnt %d out[%d] %s\n",
+		fprint(2, "%s: %s val %d|%d idx %d cnt %d out[%d] %.*H\n",
 			d->dir, rs, value>>8, value&0xFF,
-			index, count, ndata+8, hd);
-		free(hd);
+			index, count, ndata+8, ndata+8, wp);
 	}
 	n = write(d->dfd, wp, 8+ndata);
 	if(wp != buf)
--- /sys/src/cmd/usb/lib/dump.c	Sat Apr 19 16:10:56 2014
+++ /sys/src/cmd/usb/lib/dump.c	Sat Apr 19 16:10:56 2014
@@ -1,7 +1,6 @@
 #include <u.h>
 #include <libc.h>
 #include <thread.h>
-#include <bio.h>
 #include "usb.h"
 
 int usbdebug;
@@ -29,24 +28,6 @@
 		snprint(buf, sizeof(buf), "%d", c);
 		return buf;
 	}
-}
-
-char *
-hexstr(void *a, int n)
-{
-	int i;
-	char *dbuff, *s, *e;
-	uchar *b;
-
-	b = a;
-	dbuff = s = emallocz(1024, 0);
-	*s = 0;
-	e = s + 1024;
-	for(i = 0; i < n; i++)
-		s = seprint(s, e, " %.2ux", b[i]);
-	if(s == e)
-		fprint(2, "%s: usb/lib: hexdump: bug: small buffer\n", argv0);
-	return dbuff;
 }
 
 static int
--- /sys/src/cmd/usb/lib/parse.c	Sat Apr 19 16:10:56 2014
+++ /sys/src/cmd/usb/lib/parse.c	Sat Apr 19 16:10:56 2014
@@ -1,24 +1,27 @@
 #include <u.h>
 #include <libc.h>
 #include <thread.h>
-#include <bio.h>
 #include "usb.h"
 
+static int
+min(int a, int b)
+{
+	if(a < b)
+		return a;
+	return b;
+}
+
 int
 parsedev(Dev *xd, uchar *b, int n)
 {
 	Usbdev *d;
 	DDev *dd;
-	char *hd;
 
 	d = xd->usb;
 	assert(d != nil);
 	dd = (DDev*)b;
-	if(usbdebug>1){
-		hd = hexstr(b, Ddevlen);
-		fprint(2, "%s: parsedev %s: %s\n", argv0, xd->dir, hd);
-		free(hd);
-	}
+	if(usbdebug>1)
+		fprint(2, "%s: parsedev %s: %.*H\n", argv0, xd->dir, min(Ddevlen, n), b);
 	if(dd->bLength < Ddevlen){
 		werrstr("short dev descr. (%d < %d)", dd->bLength, Ddevlen);
 		return -1;
@@ -163,7 +166,6 @@
 	Iface	*ip;
 	Ep 	*ep;
 	Altc	*altc;
-	char	*hd;
 
 	assert(d != nil && c != nil);
 	tot = 0;
@@ -176,12 +178,9 @@
 
 	while(n > 2 && b[0] != 0 && b[0] <= n){
 		len = b[0];
-		if(usbdebug>1){
-			hd = hexstr(b, len);
-			fprint(2, "%s:\t\tparsedesc %s %x[%d] %s\n",
-				argv0, dname(b[1]), b[1], b[0], hd);
-			free(hd);
-		}
+		if(usbdebug>1)
+			fprint(2, "%s:\t\tparsedesc %s %x[%d] %.*H\n",
+				argv0, dname(b[1]), b[1], b[0], len, b);
 		switch(b[1]){
 		case Ddev:
 		case Dconf:
@@ -233,15 +232,11 @@
 	DConf* dc;
 	int	l;
 	int	nr;
-	char	*hd;
 
 	assert(d != nil && c != nil);
 	dc = (DConf*)b;
-	if(usbdebug>1){
-		hd = hexstr(b, Dconflen);
-		fprint(2, "%s:\tparseconf  %s\n", argv0, hd);
-		free(hd);
-	}
+	if(usbdebug>1)
+		fprint(2, "%s:\tparseconf  %.*H\n", argv0, min(Dconflen, n), b);
 	if(dc->bLength < Dconflen){
 		werrstr("short configuration descriptor");
 		return -1;
--- /sys/src/cmd/usb/lib/usb.h	Sat Apr 19 16:10:56 2014
+++ /sys/src/cmd/usb/lib/usb.h	Sat Apr 19 16:10:56 2014
@@ -341,7 +341,6 @@
 char*	estrdup(char *s);
 int	matchdevcsp(char *info, void *a);
 int	finddevs(int (*matchf)(char*,void*), void *farg, char** dirs, int ndirs);
-char*	hexstr(void *a, int n);
 int	loaddevconf(Dev *d, int n);
 int	loaddevdesc(Dev *d);
 char*	loaddevstr(Dev *d, int sid);
@@ -354,7 +353,6 @@
 void	startdevs(char *args, char *argv[], int argc, int (*mf)(char*,void*), void*ma, int (*df)(Dev*,int,char**));
 int	unstall(Dev *dev, Dev *ep, int dir);
 int	usbcmd(Dev *d, int type, int req, int value, int index, uchar *data, int count);
-
 
 extern int usbdebug;	/* more messages for bigger values */