From 92b2eb8d0331abcf7afbddeca80ebdcf136d8b3d Mon Sep 17 00:00:00 2001
From: Rich Felker <dalias@aerifal.cx>
Date: Tue, 5 Apr 2011 13:20:08 -0400
Subject: [PATCH] implement if_indextoname and if_nametoindex functions

---
 src/network/if_indextoname.c | 18 ++++++++++++++++++
 src/network/if_nametoindex.c | 18 ++++++++++++++++++
 2 files changed, 36 insertions(+)
 create mode 100644 src/network/if_indextoname.c
 create mode 100644 src/network/if_nametoindex.c

diff --git a/src/network/if_indextoname.c b/src/network/if_indextoname.c
new file mode 100644
index 00000000..f18f17a6
--- /dev/null
+++ b/src/network/if_indextoname.c
@@ -0,0 +1,18 @@
+#define _GNU_SOURCE
+#include <net/if.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <string.h>
+#include "syscall.h"
+
+char *if_indextoname(unsigned index, char *name)
+{
+	struct ifreq ifr;
+	int fd, r;
+
+	if ((fd = socket(AF_UNIX, SOCK_DGRAM, 0)) < 0) return 0;
+	ifr.ifr_ifindex = index;
+	r = ioctl(fd, SIOCGIFNAME, &ifr);
+	__syscall(SYS_close, fd);
+	return r < 0 ? 0 : strncpy(name, ifr.ifr_name, IF_NAMESIZE);
+}
diff --git a/src/network/if_nametoindex.c b/src/network/if_nametoindex.c
new file mode 100644
index 00000000..419931f9
--- /dev/null
+++ b/src/network/if_nametoindex.c
@@ -0,0 +1,18 @@
+#define _GNU_SOURCE
+#include <net/if.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <string.h>
+#include "syscall.h"
+
+unsigned if_nametoindex(const char *name)
+{
+	struct ifreq ifr;
+	int fd, r;
+
+	if ((fd = socket(AF_UNIX, SOCK_DGRAM, 0)) < 0) return -1;
+	strncpy(ifr.ifr_name, name, sizeof ifr.ifr_name);
+	r = ioctl(fd, SIOCGIFINDEX, &ifr);
+	__syscall(SYS_close, fd);
+	return r < 0 ? r : ifr.ifr_ifindex;
+}
-- 
2.20.1