Add ibuf_get_string() to the ibuf API (used by bgpd and xlockmore)

OK tb@

4 files changed, 51 insertions, 17 deletions

diff --git a/lib/libutil/Symbols.map b/lib/libutil/Symbols.map
index c1bac13aa21..9b6ddfe712d 100644
--- a/lib/libutil/Symbols.map
+++ b/lib/libutil/Symbols.map
@@ -46,6 +46,7 @@
 		ibuf_get_n32;
 		ibuf_get_n64;
 		ibuf_get_n8;
+		ibuf_get_string;
 		ibuf_left;
 		ibuf_open;
 		ibuf_reserve;
diff --git a/lib/libutil/ibuf_add.3 b/lib/libutil/ibuf_add.3
index fa3e2dace5e..e8486aa7324 100644
--- a/lib/libutil/ibuf_add.3
+++ b/lib/libutil/ibuf_add.3
@@ -1,4 +1,4 @@
-.\" $OpenBSD: ibuf_add.3,v 1.1 2023/12/12 15:49:21 claudio Exp $
+.\" $OpenBSD: ibuf_add.3,v 1.2 2024/11/21 12:42:14 claudio Exp $
 .\"
 .\" Copyright (c) 2023 Claudio Jeker <claudio@openbsd.org>
 .\" Copyright (c) 2010 Nicholas Marriott <nicm@openbsd.org>
@@ -15,7 +15,7 @@
 .\" IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 .\" OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: December 12 2023 $
+.Dd $Mdocdate: November 21 2024 $
 .Dt IBUF_ADD 3
 .Os
 .Sh NAME
@@ -47,6 +47,7 @@
 .Nm ibuf_get_n32 ,
 .Nm ibuf_get_n64 ,
 .Nm ibuf_get_n8 ,
+.Nm ibuf_get_string ,
 .Nm ibuf_left ,
 .Nm ibuf_open ,
 .Nm ibuf_reserve ,
@@ -128,6 +129,8 @@
 .Fn ibuf_get_n64 "struct ibuf *buf" "uint64_t *value"
 .Ft int
 .Fn ibuf_get_n8 "struct ibuf *buf" "uint8_t *value"
+.Ft "char *"
+.Fn ibuf_get_string "struct ibuf *buf" "size_t len"
 .Ft size_t
 .Fn ibuf_left "const struct ibuf *buf"
 .Ft "struct ibuf *"
@@ -355,6 +358,18 @@ from
 converting the value from network to host byte order.
 0 is returned on success and \-1 on failure.
 .Pp
+.Fn ibuf_get_string
+consumes
+.Fa len
+bytes from the buffer
+.Fa buf
+and returns the result of passing the bytes and len to
+.Xr strndup(3) .
+The returned pointer should be passed to
+.Xr free 3
+when it is no longer needed.
+On error NULL is returned.
+.Pp
 The
 .Fn ibuf_open
 function allocates a fixed-length buffer.
diff --git a/lib/libutil/imsg-buffer.c b/lib/libutil/imsg-buffer.c
index d45802d8d04..4a3a352e92c 100644
--- a/lib/libutil/imsg-buffer.c
+++ b/lib/libutil/imsg-buffer.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: imsg-buffer.c,v 1.19 2024/08/26 13:57:34 claudio Exp $	*/
+/*	$OpenBSD: imsg-buffer.c,v 1.20 2024/11/21 12:42:14 claudio Exp $	*/
 
 /*
  * Copyright (c) 2023 Claudio Jeker <claudio@openbsd.org>
@@ -429,6 +429,24 @@ ibuf_get_ibuf(struct ibuf *buf, size_t len, struct ibuf *new)
 }
 
 int
+ibuf_get_h16(struct ibuf *buf, uint16_t *value)
+{
+	return ibuf_get(buf, value, sizeof(*value));
+}
+
+int
+ibuf_get_h32(struct ibuf *buf, uint32_t *value)
+{
+	return ibuf_get(buf, value, sizeof(*value));
+}
+
+int
+ibuf_get_h64(struct ibuf *buf, uint64_t *value)
+{
+	return ibuf_get(buf, value, sizeof(*value));
+}
+
+int
 ibuf_get_n8(struct ibuf *buf, uint8_t *value)
 {
 	return ibuf_get(buf, value, sizeof(*value));
@@ -464,22 +482,21 @@ ibuf_get_n64(struct ibuf *buf, uint64_t *value)
 	return (rv);
 }
 
-int
-ibuf_get_h16(struct ibuf *buf, uint16_t *value)
+char *
+ibuf_get_string(struct ibuf *buf, size_t len)
 {
-	return ibuf_get(buf, value, sizeof(*value));
-}
+	char *str;
 
-int
-ibuf_get_h32(struct ibuf *buf, uint32_t *value)
-{
-	return ibuf_get(buf, value, sizeof(*value));
-}
+	if (ibuf_size(buf) < len) {
+		errno = EBADMSG;
+		return (NULL);
+	}
 
-int
-ibuf_get_h64(struct ibuf *buf, uint64_t *value)
-{
-	return ibuf_get(buf, value, sizeof(*value));
+	str = strndup(ibuf_data(buf), len);
+	if (str == NULL)
+		return (NULL);
+	buf->rpos += len;
+	return (str);
 }
 
 int
diff --git a/lib/libutil/imsg.h b/lib/libutil/imsg.h
index dd47b1889da..e105de71573 100644
--- a/lib/libutil/imsg.h
+++ b/lib/libutil/imsg.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: imsg.h,v 1.8 2023/12/12 15:47:41 claudio Exp $	*/
+/*	$OpenBSD: imsg.h,v 1.9 2024/11/21 12:42:14 claudio Exp $	*/
 
 /*
  * Copyright (c) 2023 Claudio Jeker <claudio@openbsd.org>
@@ -119,6 +119,7 @@ int		 ibuf_get_n64(struct ibuf *, uint64_t *);
 int		 ibuf_get_h16(struct ibuf *, uint16_t *);
 int		 ibuf_get_h32(struct ibuf *, uint32_t *);
 int		 ibuf_get_h64(struct ibuf *, uint64_t *);
+char		*ibuf_get_string(struct ibuf *, size_t);
 int		 ibuf_skip(struct ibuf *, size_t);
 void		 ibuf_free(struct ibuf *);
 int		 ibuf_fd_avail(struct ibuf *);