From 4abab5ad6c8465a7528ccdd5f49367da05f78bbd Mon Sep 17 00:00:00 2001
From: Vladimir Azarov <avm@intermediate-node.net>
Date: Tue, 1 Oct 2024 15:47:05 +0200
Subject: Initial version

---
 src/network/if_indextoname.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 src/network/if_indextoname.c

(limited to 'src/network/if_indextoname.c')

diff --git a/src/network/if_indextoname.c b/src/network/if_indextoname.c
new file mode 100644
index 0000000..3b368bf
--- /dev/null
+++ b/src/network/if_indextoname.c
@@ -0,0 +1,23 @@
+#define _GNU_SOURCE
+#include <net/if.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <string.h>
+#include <errno.h>
+#include "syscall.h"
+
+char *if_indextoname(unsigned index, char *name)
+{
+	struct ifreq ifr;
+	int fd, r;
+
+	if ((fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) return 0;
+	ifr.ifr_ifindex = index;
+	r = ioctl(fd, SIOCGIFNAME, &ifr);
+	__syscall(SYS_close, fd);
+	if (r < 0) {
+		if (errno == ENODEV) errno = ENXIO;
+		return 0;
+	}
+	return strncpy(name, ifr.ifr_name, IF_NAMESIZE);
+}
-- 
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