1 files changed, 81 insertions, 0 deletions

diff --git a/src/lib/libc/net/if_nametoindex.c b/src/lib/libc/net/if_nametoindex.c
new file mode 100644
index 0000000000..8bd792b949
--- /dev/null
+++ b/src/lib/libc/net/if_nametoindex.c
@@ -0,0 +1,81 @@
+/*      $OpenBSD: if_nametoindex.c,v 1.8 2002/03/07 22:40:23 millert Exp $      */
+/*      $KAME: if_nametoindex.c,v 1.5 2000/11/24 08:04:40 itojun Exp $  */
+
+/*-
+ * Copyright (c) 1997, 2000
+ *      Berkeley Software Design, Inc.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *      BSDI Id: if_nametoindex.c,v 2.3 2000/04/17 22:38:05 dab Exp
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <net/if.h>
+#include <net/if_dl.h>
+#include <ifaddrs.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+/*
+ * From RFC 2553:
+ *
+ * 4.1 Name-to-Index
+ *
+ *
+ *    The first function maps an interface name into its corresponding
+ *    index.
+ *
+ *       #include <net/if.h>
+ *
+ *       unsigned int  if_nametoindex(const char *ifname);
+ *
+ *    If the specified interface name does not exist, the return value is
+ *    0, and errno is set to ENXIO.  If there was a system error (such as
+ *    running out of memory), the return value is 0 and errno is set to the
+ *    proper value (e.g., ENOMEM).
+ */
+
+unsigned int
+if_nametoindex(const char *ifname)
+{
+        struct ifaddrs *ifaddrs, *ifa;
+        unsigned int ni;
+
+        if (getifaddrs(&ifaddrs) < 0)
+                return(0);
+
+        ni = 0;
+
+        for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
+                if (ifa->ifa_addr &&
+                    ifa->ifa_addr->sa_family == AF_LINK &&
+                    strcmp(ifa->ifa_name, ifname) == 0) {
+                        ni = ((struct sockaddr_dl*)ifa->ifa_addr)->sdl_index;
+                        break;
+                }
+        }
+
+        freeifaddrs(ifaddrs);
+        if (!ni)
+                errno = ENXIO;
+        return(ni);
+}