V1F: Read end-of-chunk as part of the chunk

Until now, we read the (CR)?LF at the end of a chunk as part of the
next chunk header (see: /* Skip leading whitespace */).

For a follow up commit, we are going to want to know if the next chunk
header is available for read, so we now consume the chunk end as part
of the chunk itself.

This also fixes a corner case: We previously accepted chunks with a
missing end-of-chunk (see fix of r01729.vtc).

Ref: https://datatracker.ietf.org/doc/html/rfc7230#section-4.1

bin/varnishd/http1/cache_http1_vfp.c

@@ -89,6 +89,24 @@ v1f_read(const struct vfp_ctx *vc, struct http_conn *htc, void *d, ssize_t len)
 }
 
 
+/*--------------------------------------------------------------------
+ * read (CR)?LF at the end of a chunk
+ */
+static enum vfp_status
+v1f_chunk_end(struct vfp_ctx *vc, struct http_conn *htc)
+{
+	char c;
+
+	if (v1f_read(vc, htc, &c, 1) <= 0)
+		return (VFP_Error(vc, "chunked read err"));
+	if (c == '\r' && v1f_read(vc, htc, &c, 1) <= 0)
+		return (VFP_Error(vc, "chunked read err"));
+	if (c != '\n')
+		return (VFP_Error(vc, "chunked tail no NL"));
+	return (VFP_OK);
+}
+
+
 /*--------------------------------------------------------------------
  * Read a chunked HTTP object.
  *
@@ -99,6 +117,7 @@ static enum vfp_status v_matchproto_(vfp_pull_f)
 v1f_chunked_pull(struct vfp_ctx *vc, struct vfp_entry *vfe, void *ptr,
     ssize_t *lp)
 {
+	static enum vfp_status vfps;
 	struct http_conn *htc;
 	char buf[20];		/* XXX: 20 is arbitrary */
 	char *q;
@@ -169,18 +188,15 @@ v1f_chunked_pull(struct vfp_ctx *vc, struct vfp_entry *vfe, void *ptr,
 			return (VFP_Error(vc, "chunked insufficient bytes"));
 		*lp = lr;
 		vfe->priv2 -= lr;
-		if (vfe->priv2 == 0)
-			vfe->priv2 = -1;
-		return (VFP_OK);
+		if (vfe->priv2 != 0)
+			return (VFP_OK);
+
+		vfe->priv2 = -1;
+		return (v1f_chunk_end(vc, htc));
 	}
 	AZ(vfe->priv2);
-	if (v1f_read(vc, htc, buf, 1) <= 0)
-		return (VFP_Error(vc, "chunked read err"));
-	if (buf[0] == '\r' && v1f_read(vc, htc, buf, 1) <= 0)
-		return (VFP_Error(vc, "chunked read err"));
-	if (buf[0] != '\n')
-		return (VFP_Error(vc, "chunked tail no NL"));
-	return (VFP_END);
+	vfps = v1f_chunk_end(vc, htc);
+	return (vfps == VFP_OK ? VFP_END : vfps);
 }
 
 static const struct vfp v1f_chunked = {

bin/varnishtest/tests/r01184.vtc

@@ -62,6 +62,7 @@ server s1 {
 		sendhex " 10 45 f3 a9 83 b8 18 1c  7b c2 30 55 04 17 13 c4"
 		sendhex " 0f 07 5f 7a 38 f4 8e 50  b3 37 d4 3a 32 4a 34 07"
 		sendhex " FF FF FF FF FF FF FF FF  72 ea 06 5f b3 1c fa dd"
+	send "\n"
 	expect_close
 } -start
 
@@ -93,6 +94,7 @@ server s1 {
 		sendhex " 10 45 f3 a9 83 b8 18 1c  7b c2 30 55 04 17 13 c4"
 		sendhex " 0f 07 5f 7a 38 f4 8e 50  b3 37 d4 3a 32 4a 34 07"
 		sendhex " FF FF FF FF FF FF FF FF  72 ea 06 5f b3 1c fa dd"
+	send "\n"
 	expect_close
 } -start
 

bin/varnishtest/tests/r01729.vtc

@@ -11,7 +11,7 @@ server s1 {
 	send "\r\n"
 	send "14\r\n"
 	send "0123456789"
-	send "0123456789"
+	send "0123456789\n"
 	send "0\r\n"
 	send "\r\n"
 
@@ -29,7 +29,7 @@ client c1 {
 	send "\r\n"
 	send "14\r\n"
 	send "0123456789"
-	send "0123456789"
+	send "0123456789\n"
 	send "0\r\n"
 	send "\r\n"
 
@@ -45,7 +45,7 @@ client c1 {
 	send "\r\n"
 	send "14\r\n"
 	send "0123456789"
-	send "0123456789"
+	send "0123456789\n"
 	send "0\r\n"
 	send "\r\n"