Allow setextattr(8) to take attribute values from stdin

Add the -i option to setextattr. This option allow extended attribute data
to be provided via stdin. Add a -qq option to getextattr, which omits the
trailing newline. Together these options can be used to work with extended
attributes whose values are large and/or binary.

usr.sbin/extattr/Makefile:
	Link against libsbuf which is used for processing stdin data.

usr.sbin/extattr/rmextattr.8:
	Document setextattr's -i option, getextattr's -qq option, and remove
	the BUG about setextattr only being useful for strings.

usr.sbin/extattr/rmextattr.c:
	For setextattr operations, buffer attribute data in an sbuf. If -i
	is specified, pull the data from stdin, otherwise from the
	appropriate argurment.

	Update usage text and argument validation code for setextattr's -i
	option.

usr.sbin/extattr/tests/extattr_test.sh
	Add tests for -q and -i.

Reviewed by:	wblock (manpage)
MFC after:	4 weeks
Sponsored by:	Spectra Logic Corp
Differential Revision:	https://reviews.freebsd.org/D6090

usr.sbin/extattr/Makefile

@@ -3,6 +3,8 @@
 PROG=	rmextattr
 MAN=	rmextattr.8
 
+LIBADD=	sbuf
+
 LINKS+=	${BINDIR}/rmextattr ${BINDIR}/getextattr
 LINKS+=	${BINDIR}/rmextattr ${BINDIR}/setextattr
 LINKS+=	${BINDIR}/rmextattr ${BINDIR}/lsextattr

usr.sbin/extattr/rmextattr.8

@@ -31,7 +31,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd August 30, 2000
+.Dd April 27, 2016
 .Dt RMEXTATTR 8
 .Os
 .Sh NAME
@@ -61,6 +61,12 @@
 .Ar attrname
 .Ar attrvalue
 .Ar filename ...
+.Nm setextattr
+.Fl i
+.Op Fl fhnq
+.Ar attrnamespace
+.Ar attrname
+.Ar filename ...
 .Sh DESCRIPTION
 These
 utilities
@@ -91,6 +97,9 @@ the remaining arguments.
 (No follow.)
 If the file is a symbolic link, perform the operation on the
 link itself rather than the file that the link points to.
+.It Fl i
+(From stdin.)
+Read attribute data from stdin instead of as an argument.
 .It Fl n
 .Dv ( NUL Ns
 -terminate.)
@@ -99,6 +108,7 @@ link itself rather than the file that the link points to.
 .It Fl q
 (Quiet.)
 Do not print out the pathname and suppress error messages.
+When given twice, do not print a trailing newline.
 .It Fl s
 (Stringify.)
 Escape nonprinting characters and put quotes around the output.
@@ -109,6 +119,7 @@ Print the output in hexadecimal.
 .Sh EXAMPLES
 .Bd -literal
 setextattr system md5 `md5 -q /boot/kernel/kernel` /boot/kernel/kernel
+md5 -q /boot/kernel/kernel | setextattr -i system md5 /boot/kernel/kernel
 getextattr system md5 /boot/kernel/kernel
 lsextattr system /boot/kernel/kernel
 rmextattr system md5 /boot/kernel/kernel
@@ -129,7 +140,3 @@ to be associated with each file or directory.
 .Sh AUTHORS
 .An Robert N M Watson
 .An Poul-Henning Kamp
-.Sh BUGS
-The
-.Nm setextattr
-utility can only be used to set attributes to strings.

usr.sbin/extattr/rmextattr.c

@@ -37,6 +37,7 @@
  */
 
 #include <sys/types.h>
+#include <sys/sbuf.h>
 #include <sys/uio.h>
 #include <sys/extattr.h>
 
@@ -64,6 +65,8 @@ usage(void)
 	case EASET:
 		fprintf(stderr, "usage: setextattr [-fhnq] attrnamespace");
 		fprintf(stderr, " attrname attrvalue filename ...\n");
+		fprintf(stderr, "   or  setextattr -i [-fhnq] attrnamespace");
+		fprintf(stderr, " attrname filename ...\n");
 		exit(-1);
 	case EARM:
 		fprintf(stderr, "usage: rmextattr [-fhq] attrnamespace");
@@ -99,24 +102,28 @@ mkbuf(char **buf, int *oldlen, int newlen)
 int
 main(int argc, char *argv[])
 {
-	char	*buf, *visbuf, *p;
+#define STDIN_BUF_SZ 1024
+	char	 stdin_data[STDIN_BUF_SZ];
+	char	*p;
 
 	const char *options, *attrname;
 	size_t	len;
 	ssize_t	ret;
-	int	 buflen, visbuflen, ch, error, i, arg_counter, attrnamespace,
-		 minargc;
+	int	 ch, error, i, arg_counter, attrnamespace, minargc;
 
+	char   *visbuf = NULL;
+	int	visbuflen = 0;
+	char   *buf = NULL;
+	int	buflen = 0;
+	struct	sbuf *attrvalue = NULL;
 	int	flag_force = 0;
 	int	flag_nofollow = 0;
 	int	flag_null = 0;
-	int	flag_quiet = 0;
+	int	count_quiet = 0;
+	int	flag_from_stdin = 0;
 	int	flag_string = 0;
 	int	flag_hex = 0;
 
-	visbuflen = buflen = 0;
-	visbuf = buf = NULL;
-
 	p = basename(argv[0]);
 	if (p == NULL)
 		p = argv[0];
@@ -126,8 +133,8 @@ main(int argc, char *argv[])
 		minargc = 3;
 	} else if (!strcmp(p, "setextattr")) {
 		what = EASET;
-		options = "fhnq";
-		minargc = 4;
+		options = "fhinq";
+		minargc = 3;
 	} else if (!strcmp(p, "rmextattr")) {
 		what = EARM;
 		options = "fhq";
@@ -148,11 +155,14 @@ main(int argc, char *argv[])
 		case 'h':
 			flag_nofollow = 1;
 			break;
+		case 'i':
+			flag_from_stdin = 1;
+			break;
 		case 'n':
 			flag_null = 1;
 			break;
 		case 'q':
-			flag_quiet = 1;
+			count_quiet += 1;
 			break;
 		case 's':
 			flag_string = 1;
@@ -169,6 +179,9 @@ main(int argc, char *argv[])
 	argc -= optind;
 	argv += optind;
 
+	if (what == EASET && flag_from_stdin == 0)
+		minargc++;
+
 	if (argc < minargc)
 		usage();
 
@@ -184,9 +197,15 @@ main(int argc, char *argv[])
 		attrname = NULL;
 
 	if (what == EASET) {
-		mkbuf(&buf, &buflen, strlen(argv[0]) + 1);
-		strcpy(buf, argv[0]);
-		argc--; argv++;
+		attrvalue = sbuf_new_auto();
+		if (flag_from_stdin) {
+			while ((error = read(0, stdin_data, STDIN_BUF_SZ)) > 0)
+				sbuf_bcat(attrvalue, stdin_data, error);
+		} else {
+			sbuf_cpy(attrvalue, argv[0]);
+			argc--; argv++;
+		}
+		sbuf_finish(attrvalue);
 	}
 
 	for (arg_counter = 0; arg_counter < argc; arg_counter++) {
@@ -202,15 +221,17 @@ main(int argc, char *argv[])
 				continue;
 			break;
 		case EASET:
-			len = strlen(buf) + flag_null;
+			len = sbuf_len(attrvalue) + flag_null;
 			if (flag_nofollow)
 				ret = extattr_set_link(argv[arg_counter],
-				    attrnamespace, attrname, buf, len);
+				    attrnamespace, attrname,
+				    sbuf_data(attrvalue), len);
 			else
 				ret = extattr_set_file(argv[arg_counter],
-				    attrnamespace, attrname, buf, len);
+				    attrnamespace, attrname,
+				    sbuf_data(attrvalue), len);
 			if (ret >= 0) {
-				if ((size_t)ret != len && !flag_quiet) {
+				if ((size_t)ret != len && !count_quiet) {
 					warnx("Set %zd bytes of %zu for %s",
 					    ret, len, attrname);
 				}
@@ -235,7 +256,7 @@ main(int argc, char *argv[])
 				    attrnamespace, buf, buflen);
 			if (ret < 0)
 				break;
-			if (!flag_quiet)
+			if (!count_quiet)
 				printf("%s\t", argv[arg_counter]);
 			for (i = 0; i < ret; i += ch + 1) {
 			    /* The attribute name length is unsigned. */
@@ -243,7 +264,7 @@ main(int argc, char *argv[])
 			    printf("%s%*.*s", i ? "\t" : "",
 				ch, ch, buf + i + 1);
 			}
-			if (!flag_quiet || ret > 0)
+			if (!count_quiet || ret > 0)
 				printf("\n");
 			continue;
 		case EAGET:
@@ -264,29 +285,26 @@ main(int argc, char *argv[])
 				    attrnamespace, attrname, buf, buflen);
 			if (ret < 0)
 				break;
-			if (!flag_quiet)
+			if (!count_quiet)
 				printf("%s\t", argv[arg_counter]);
 			if (flag_string) {
 				mkbuf(&visbuf, &visbuflen, ret * 4 + 1);
 				strvisx(visbuf, buf, ret,
 				    VIS_SAFE | VIS_WHITE);
-				printf("\"%s\"\n", visbuf);
-				continue;
+				printf("\"%s\"", visbuf);
 			} else if (flag_hex) {
 				for (i = 0; i < ret; i++)
-					printf("%s%02x", i ? " " : "",
-					    buf[i]);
-				printf("\n");
-				continue;
+					printf("%s%02x", i ? " " : "", buf[i]);
 			} else {
 				fwrite(buf, ret, 1, stdout);
-				printf("\n");
-				continue;
 			}
+			if (count_quiet < 2)
+				printf("\n");
+			continue;
 		default:
 			break;
 		}
-		if (!flag_quiet) 
+		if (!count_quiet) 
 			warn("%s: failed", argv[arg_counter]);
 		if (flag_force)
 			continue;

usr.sbin/extattr/tests/extattr_test.sh

@@ -66,6 +66,23 @@ long_name_body() {
 	atf_check -s exit:0 -o empty lsextattr -q user foo
 }	
 
+atf_test_case loud
+loud_head() {
+	atf_set "descr" "Loud (non -q) output for each command"
+}
+loud_body() {
+	touch foo
+	# setextattr(8) and friends print hard tabs.  Use printf to convert
+	# them to spaces before checking the output.
+	atf_check -s exit:0 -o empty setextattr user myattr myvalue foo
+	atf_check -s exit:0 -o inline:"foo myattr" \
+		printf "%s %s" $(lsextattr user foo)
+	atf_check -s exit:0 -o inline:"foo myvalue" \
+		printf "%s %s" $(getextattr user myattr foo)
+	atf_check -s exit:0 -o empty rmextattr user myattr foo
+	atf_check -s exit:0 -o inline:"foo" printf %s $(lsextattr user foo)
+}	
+
 atf_test_case noattrs
 noattrs_head() {
 	atf_set "descr" "A file with no extended attributes"
@@ -127,6 +144,19 @@ one_system_attr_body() {
 	atf_check -s exit:0 -o empty lsextattr -q system foo
 }	
 
+atf_test_case stdin
+stdin_head() {
+	atf_set "descr" "Set attribute value from stdin"
+}
+stdin_body() {
+	dd if=/dev/random of=infile bs=1k count=8
+	touch foo
+	setextattr -i user myattr foo < infile || atf_fail "setextattr failed"
+	atf_check -s exit:0 -o inline:"myattr\n" lsextattr -q user foo
+	getextattr -qq user myattr foo > outfile || atf_fail "getextattr failed"
+	atf_check -s exit:0 cmp -s infile outfile
+}	
+
 atf_test_case stringify
 stringify_head() {
 	atf_set "descr" "Stringify the output of getextattr"
@@ -273,12 +303,14 @@ atf_init_test_cases() {
 	atf_add_test_case bad_namespace
 	atf_add_test_case hex
 	atf_add_test_case long_name
+	atf_add_test_case loud
 	atf_add_test_case noattrs
 	atf_add_test_case nonexistent_file
 	atf_add_test_case null
 	atf_add_test_case symlink_nofollow
 	atf_add_test_case one_user_attr
 	atf_add_test_case one_system_attr
+	atf_add_test_case stdin
 	atf_add_test_case stringify
 	atf_add_test_case symlink
 	atf_add_test_case symlink_nofollow