Add two support functions:

o  gctl_delete_param() -- intended for parameters that are consumed
   by geom(8) itself and which should not be passed to the kernel.
o  gctl_has_param() -- intended to check if optional parameters are
   present.

Both are needed by gpart(8) to process the optional parameter for
writing bootcode to a partition (as part of the bootcode verb).
However, the kernel is itself not involved in this matter and the
parameter needs to be removed from the request destined for the
kernel.

2 files changed, 47 insertions, 0 deletions

diff --git a/sbin/geom/misc/subr.c b/sbin/geom/misc/subr.c
index 745d919..64df7c6 100644
--- a/sbin/geom/misc/subr.c
+++ b/sbin/geom/misc/subr.c
@@ -414,3 +414,47 @@ gctl_change_param(struct gctl_req *req, const char *name, int len,
 	}
 	return (ENOENT);
 }
+
+int
+gctl_delete_param(struct gctl_req *req, const char *name)
+{
+	struct gctl_req_arg *ap;
+	unsigned int i;
+
+	if (req == NULL || req->error != NULL)
+		return (EDOOFUS);
+
+	i = 0;
+	while (i < req->narg) {
+		ap = &req->arg[i];
+		if (strcmp(ap->name, name) == 0)
+			break;
+		i++;
+	}
+	if (i == req->narg)
+		return (ENOENT);
+
+	req->narg--;
+	while (i < req->narg) {
+		req->arg[i] = req->arg[i + 1];
+		i++;
+	}
+	return (0);
+}
+
+int
+gctl_has_param(struct gctl_req *req, const char *name)
+{
+	struct gctl_req_arg *ap;
+	unsigned int i;
+
+	if (req == NULL || req->error != NULL)
+		return (0);
+
+	for (i = 0; i < req->narg; i++) {
+		ap = &req->arg[i];
+		if (strcmp(ap->name, name) == 0)
+			return (1);
+	}
+	return (0);
+}
diff --git a/sbin/geom/misc/subr.h b/sbin/geom/misc/subr.h
index 4c54142..c3242a3 100644
--- a/sbin/geom/misc/subr.h
+++ b/sbin/geom/misc/subr.h
@@ -47,4 +47,7 @@ intmax_t gctl_get_intmax(struct gctl_req *req, const char *pfmt, ...) __printfli
 const char *gctl_get_ascii(struct gctl_req *req, const char *pfmt, ...) __printflike(2, 3);
 int gctl_change_param(struct gctl_req *req, const char *name, int len,
     const void *value);
+int gctl_delete_param(struct gctl_req *req, const char *name);
+int gctl_has_param(struct gctl_req *req, const char *name);
+
 #endif	/* !_SUBR_H_ */