From: Karel Zak <kzak@redhat.com>
Date: Mon, 10 Mar 2025 14:32:58 +0000 (+0100)
Subject: libsmartcols: add scols_filter_has_holder()
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8097dd31c24cb7f10d404ec5f756f9f5a7c248a1;p=thirdparty%2Futil-linux.git

libsmartcols: add scols_filter_has_holder()

Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/libsmartcols/docs/libsmartcols-sections.txt b/libsmartcols/docs/libsmartcols-sections.txt
index 94bb9ef05..e7fe4b75d 100644
--- a/libsmartcols/docs/libsmartcols-sections.txt
+++ b/libsmartcols/docs/libsmartcols-sections.txt
@@ -89,6 +89,7 @@ scols_counter_set_param
 scols_dump_filter
 scols_filter_assign_column
 scols_filter_get_errmsg
+scols_filter_has_holder
 scols_filter_new_counter
 scols_filter_next_counter
 scols_filter_next_holder
diff --git a/libsmartcols/src/filter-param.c b/libsmartcols/src/filter-param.c
index 4a67cbfaf..17757f0d9 100644
--- a/libsmartcols/src/filter-param.c
+++ b/libsmartcols/src/filter-param.c
@@ -887,3 +887,30 @@ int scols_filter_next_holder(struct libscols_filter *fltr,
 
 	return rc;
 }
+
+/**
+ * scols_filter_has_holder:
+ * @fltr: filter instance
+ * @name: wanted holder
+ *
+ * Returns: 0 or 1
+ *
+ * Since: 2.42
+ */
+int scols_filter_has_holder(struct libscols_filter *fltr, const char *name)
+{
+	struct libscols_iter itr;
+	const char *n = NULL;
+
+	if (!fltr || !name)
+		return 0;
+
+	scols_reset_iter(&itr, SCOLS_ITER_FORWARD);
+
+	while (scols_filter_next_holder(fltr, &itr, &n, 0) == 0) {
+		if (strcmp(n, name) == 0)
+			return 1;
+	}
+
+	return 0;
+}
diff --git a/libsmartcols/src/libsmartcols.h.in b/libsmartcols/src/libsmartcols.h.in
index 1acff2f0e..abb9cdd6c 100644
--- a/libsmartcols/src/libsmartcols.h.in
+++ b/libsmartcols/src/libsmartcols.h.in
@@ -452,6 +452,8 @@ extern int scols_line_apply_filter(struct libscols_line *ln,
 
 extern int scols_filter_next_holder(struct libscols_filter *fltr,
                         struct libscols_iter *itr, const char **name, int type);
+extern int scols_filter_has_holder(struct libscols_filter *fltr, const char *name);
+
 extern int scols_filter_assign_column(struct libscols_filter *fltr,
 			struct libscols_iter *itr,
                         const char *name, struct libscols_column *col);
diff --git a/libsmartcols/src/libsmartcols.sym b/libsmartcols/src/libsmartcols.sym
index ce77b0df3..6fe8f6187 100644
--- a/libsmartcols/src/libsmartcols.sym
+++ b/libsmartcols/src/libsmartcols.sym
@@ -256,3 +256,8 @@ SMARTCOLS_2.41 {
 	scols_column_set_uri;
 	scols_column_get_uri;
 } SMARTCOLS_2.40;
+
+SMARTCOLS_2.42 {
+	scols_filter_has_holder;
+} SMARTCOLS_2.41;
+
diff --git a/sys-utils/lsns.c b/sys-utils/lsns.c
index a97e7ef3c..b64f70406 100644
--- a/sys-utils/lsns.c
+++ b/sys-utils/lsns.c
@@ -278,24 +278,12 @@ static int column_name_to_id(const char *name, size_t namesz)
 	return -1;
 }
 
-static int is_column_in_filter(int id, struct libscols_filter *filter)
+static inline const char *column_id_to_name(int id)
 {
-	int r = 0;
-	const char *name = NULL;
-	struct libscols_iter *itr = scols_new_iter(SCOLS_ITER_FORWARD);
-
-	if (!itr)
-		err(EXIT_FAILURE, _("failed to allocate iterator"));
-
-	while (scols_filter_next_holder(filter, itr, &name, 0) == 0) {
-		if (strcmp(infos[id].name, name) == 0) {
-			r = 1;
-			break;
-		}
-	}
+	assert(id >= 0);
+	assert(id < (int) ARRAY_SIZE(infos));
 
-	scols_free_iter(itr);
-	return r;
+	return infos[ id ].name;
 }
 
 static int has_column(int id)
@@ -323,6 +311,7 @@ static inline const struct colinfo *get_column_info(unsigned num)
 	return &infos[ get_column_id(num) ];
 }
 
+
 #ifdef USE_NS_GET_API
 /* Get the inode number for the parent namespace of the namespace `fd' specifies.
  * If `pfd' is non-null, the file descriptor opening the parent namespace.*/
@@ -1812,7 +1801,8 @@ int main(int argc, char *argv[])
 
 #ifdef HAVE_LINUX_NET_NAMESPACE_H
 	if (has_column(COL_NETNSID)
-	    || (ls.filter && is_column_in_filter(COL_NETNSID, ls.filter)))
+	    || (ls.filter && scols_filter_has_holder(ls.filter,
+						     column_id_to_name(COL_NETNSID))))
 		netlink_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
 #endif
 	ls.tab = mnt_new_table_from_file(_PATH_PROC_MOUNTINFO);