[iproute2-next,v2,1/7] lib: rt_names: Add rtnl_dsfield_get_name()

Commit Message

Petr Machata Jan. 2, 2021, 12:03 a.m. UTC

For formatting DSCP (not full dsfield), it would be handy to be able to
just get the name from the name table, and not get any of the remaining
cruft related to formatting. Add a new entry point to just fetch the
name table string uninterpreted. Use it from rtnl_dsfield_n2a().

Signed-off-by: Petr Machata <[e-mail]>
---
 include/rt_names.h |  1 +
 lib/rt_names.c     | 20 ++++++++++++++++----
 2 files changed, 17 insertions(+), 4 deletions(-)

Patch

diff --git a/include/rt_names.h b/include/rt_names.h
index 990ed7f22e69..1835f3be2bed 100644
--- a/include/rt_names.h
+++ b/include/rt_names.h
@@ -9,6 +9,7 @@  const char *rtnl_rtscope_n2a(int id, char *buf, int len);
 const char *rtnl_rttable_n2a(__u32 id, char *buf, int len);
 const char *rtnl_rtrealm_n2a(int id, char *buf, int len);
 const char *rtnl_dsfield_n2a(int id, char *buf, int len);
+const char *rtnl_dsfield_get_name(int id);
 const char *rtnl_group_n2a(int id, char *buf, int len);
 
 int rtnl_rtprot_a2n(__u32 *id, const char *arg);
diff --git a/lib/rt_names.c b/lib/rt_names.c
index ca0680a12150..b976471d7979 100644
--- a/lib/rt_names.c
+++ b/lib/rt_names.c
@@ -479,18 +479,30 @@  static void rtnl_rtdsfield_initialize(void)
 
 const char *rtnl_dsfield_n2a(int id, char *buf, int len)
 {
+	const char *name;
+
 	if (id < 0 || id >= 256) {
 		snprintf(buf, len, "%d", id);
 		return buf;
 	}
+	if (!numeric) {
+		name = rtnl_dsfield_get_name(id);
+		if (name != NULL)
+			return name;
+	}
+	snprintf(buf, len, "0x%02x", id);
+	return buf;
+}
+
+const char *rtnl_dsfield_get_name(int id)
+{
+	if (id < 0 || id >= 256)
+		return NULL;
 	if (!rtnl_rtdsfield_tab[id]) {
 		if (!rtnl_rtdsfield_init)
 			rtnl_rtdsfield_initialize();
 	}
-	if (!numeric && rtnl_rtdsfield_tab[id])
-		return rtnl_rtdsfield_tab[id];
-	snprintf(buf, len, "0x%02x", id);
-	return buf;
+	return rtnl_rtdsfield_tab[id];
 }