Add VIS_DQ to escape double quotes. OK deraadt@ semarie@ reyk@

3 files changed, 17 insertions, 13 deletions

diff --git a/lib/libc/gen/unvis.c b/lib/libc/gen/unvis.c
index 8982ca50647..25db9ad8f4d 100644
--- a/lib/libc/gen/unvis.c
+++ b/lib/libc/gen/unvis.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: unvis.c,v 1.15 2011/03/13 22:21:32 guenther Exp $ */
+/*	$OpenBSD: unvis.c,v 1.16 2015/07/20 01:52:28 millert Exp $ */
 /*-
  * Copyright (c) 1989, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -78,6 +78,7 @@ unvis(char *cp, char c, int *astate, int flag)
 			*astate = S_GROUND;
 			return (0);
 		case '\\':
+		case '"':
 			*cp = c;
 			*astate = S_GROUND;
 			return (UNVIS_VALID);
diff --git a/lib/libc/gen/vis.3 b/lib/libc/gen/vis.3
index 6808d398dc5..08ee3b519b5 100644
--- a/lib/libc/gen/vis.3
+++ b/lib/libc/gen/vis.3
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: vis.3,v 1.34 2015/02/07 08:44:49 doug Exp $
+.\"	$OpenBSD: vis.3,v 1.35 2015/07/20 01:52:28 millert Exp $
 .\"
 .\" Copyright (c) 1989, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -27,7 +27,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: February 7 2015 $
+.Dd $Mdocdate: July 20 2015 $
 .Dt VIS 3
 .Os
 .Sh NAME
@@ -161,6 +161,9 @@ alter this:
 .Bl -tag -width VIS_WHITEX
 .It Dv VIS_ALL
 Encode all characters, whether visible or not.
+.It Dv VIS_DQ
+Also encode double quote characters
+.Pf ( Ql \&" ) .
 .It Dv VIS_GLOB
 Also encode magic characters recognized by
 .Xr glob 3
diff --git a/lib/libc/gen/vis.c b/lib/libc/gen/vis.c
index 579fa81822e..799f8fd6f21 100644
--- a/lib/libc/gen/vis.c
+++ b/lib/libc/gen/vis.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vis.c,v 1.23 2014/11/17 19:48:27 millert Exp $ */
+/*	$OpenBSD: vis.c,v 1.24 2015/07/20 01:52:28 millert Exp $ */
 /*-
  * Copyright (c) 1989, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -56,9 +56,10 @@ char *
 vis(char *dst, int c, int flag, int nextc)
 {
 	if (isvisible(c, flag)) {
-		*dst++ = c;
-		if (c == '\\' && (flag & VIS_NOSLASH) == 0)
+		if ((c == '"' && (flag & VIS_DQ) != 0) ||
+		    (c == '\\' && (flag & VIS_NOSLASH) == 0))
 			*dst++ = '\\';
+		*dst++ = c;
 		*dst = '\0';
 		return (dst);
 	}
@@ -171,18 +172,17 @@ strnvis(char *dst, const char *src, size_t siz, int flag)
 	i = 0;
 	for (start = dst, end = start + siz - 1; (c = *src) && dst < end; ) {
 		if (isvisible(c, flag)) {
-			i = 1;
-			*dst++ = c;
-			if (c == '\\' && (flag & VIS_NOSLASH) == 0) {
+			if ((c == '"' && (flag & VIS_DQ) != 0) ||
+			    (c == '\\' && (flag & VIS_NOSLASH) == 0)) {
 				/* need space for the extra '\\' */
-				if (dst < end)
-					*dst++ = '\\';
-				else {
-					dst--;
+				if (dst + 1 >= end) {
 					i = 2;
 					break;
 				}
+				*dst++ = '\\';
 			}
+			i = 1;
+			*dst++ = c;
 			src++;
 		} else {
 			i = vis(tbuf, c, flag, *++src) - tbuf;