1 files changed, 51 insertions, 104 deletions

diff --git a/src/lib/libc/net/if_indextoname.c b/src/lib/libc/net/if_indextoname.c
index 4f3990b4c2..f99e52e387 100644
--- a/src/lib/libc/net/if_indextoname.c
+++ b/src/lib/libc/net/if_indextoname.c
@@ -1,26 +1,20 @@
-/*
- * Copyright (c) 1998-1999, Craig Metz, All rights reserved.
+/*      $OpenBSD: if_indextoname.c,v 1.9 2002/03/07 22:40:23 millert Exp $      */
+/*      $KAME: if_indextoname.c,v 1.6 2000/11/07 22:33:25 jinmei 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.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *      This product includes software developed by Craig Metz and
- *      by other contributors.
- * 4. Neither the name of the author nor the names of contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
  *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * 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 THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * 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)
@@ -28,112 +22,65 @@
  * 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_indextoname.c,v 2.3 2000/04/17 22:38:05 dab Exp
  */
 
 #include <sys/types.h>
-#include <stdlib.h>
 #include <sys/socket.h>
-#include <sys/ioctl.h>
-#include <net/if.h>
 #include <net/if_dl.h>
-#include <errno.h>
-#include <unistd.h>
+#include <net/if.h>
+#include <ifaddrs.h>
+#include <stdlib.h>
 #include <string.h>
+#include <errno.h>
 
-static char __name[IFNAMSIZ];
+/*
+ * From RFC 2533:
+ *
+ * The second function maps an interface index into its corresponding
+ * name.
+ *
+ *    #include <net/if.h>
+ *
+ *    char  *if_indextoname(unsigned int ifindex, char *ifname);
+ *
+ * The ifname argument must point to a buffer of at least IF_NAMESIZE
+ * bytes into which the interface name corresponding to the specified
+ * index is returned.  (IF_NAMESIZE is also defined in <net/if.h> and
+ * its value includes a terminating null byte at the end of the
+ * interface name.) This pointer is also the return value of the
+ * function.  If there is no interface corresponding to the specified
+ * index, NULL is returned, and errno is set to ENXIO, if there was a
+ * system error (such as running out of memory), if_indextoname returns
+ * NULL and errno would be set to the proper value (e.g., ENOMEM).
+ */
 
 char *
-if_indextoname(unsigned int index, char *name)
+if_indextoname(unsigned int ifindex, char *ifname)
 {
-        int     i, fd = -1, extra, len = 0;
-        struct ifconf ifconf;
-        char    lastname[IFNAMSIZ], iname[IFNAMSIZ], *retname = NULL, *inbuf;
-        struct sockaddr *sa;
-        void    *p;
-
-        ifconf.ifc_buf = 0;
-
-        if (!name)
-                name = __name;
+        struct ifaddrs *ifaddrs, *ifa;
+        int error = 0;
 
-        if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
-                goto ret;
+        if (getifaddrs(&ifaddrs) < 0)
+                return(NULL);   /* getifaddrs properly set errno */
 
-        /*
-         * Try ifc_len == 0 hack first, to get the actual length.
-         * If that fails, revert to a loop which grows the ifc_buf
-         * until it is sufficiently large.
-         */
-        extra = sizeof(struct ifreq);
-        while (1) {
-                ifconf.ifc_len = len;
-                if (ioctl(fd, SIOCGIFCONF, (void *) &ifconf) == -1 &&
-                    ifconf.ifc_buf)
-                        goto ret;
-                if (ifconf.ifc_buf &&
-                    ifconf.ifc_len + extra < len)
+        for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
+                if (ifa->ifa_addr &&
+                    ifa->ifa_addr->sa_family == AF_LINK &&
+                    ifindex == ((struct sockaddr_dl*)ifa->ifa_addr)->sdl_index)
                         break;
-                if (ifconf.ifc_buf) {
-                        if (len == 0)
-                                len = 4096;
-                        ifconf.ifc_len = len *= 2;
-                } else {
-                        len = ifconf.ifc_len;
-                        extra = 0;
-                }
-                inbuf = realloc(ifconf.ifc_buf, ifconf.ifc_len);
-                if (inbuf == NULL)
-                        goto ret;
-                ifconf.ifc_buf = inbuf;
         }
 
-        i = 0;
-        p = ifconf.ifc_buf;
-        len = ifconf.ifc_len;
-        lastname[0] = 0;
-        lastname[sizeof(lastname)-1] = 0;
-        iname[0] = 0;
-
-        while (len > 0) {
-                if (len < (IFNAMSIZ + sizeof(struct sockaddr)))
-                        goto ret;
-                if (strncmp(lastname, p, IFNAMSIZ)) {
-                        if (i == index)
-                                memcpy(iname, lastname, sizeof(iname));
-                        strlcpy(lastname, p, sizeof(lastname));
-                        i++;
-                }
-                len -= IFNAMSIZ;
-                p += IFNAMSIZ;
-                sa = p;
-
-                if (sa->sa_family == AF_LINK) {
-                        struct sockaddr_dl *sd = p;
-
-                        if (sd->sdl_index == index) {
-                                strlcpy(name, lastname, IFNAMSIZ);
-                                retname = name;
-                                goto ret;
-                        }
-                }
-
-                if (len < sa->sa_len)
-                        goto ret;
-                len -= sa->sa_len;
-                p += sa->sa_len;
+        if (ifa == NULL) {
+                error = ENXIO;
+                ifname = NULL;
         }
+        else
+                strlcpy(ifname, ifa->ifa_name, IFNAMSIZ);
 
-        if (i == index)
-                strlcpy(iname, lastname, sizeof(iname));
+        freeifaddrs(ifaddrs);
 
-        if (iname[0]) {
-                strlcpy(name, iname, IFNAMSIZ);
-                retname = name;
-        }
-ret:
-        if (fd != -1)
-                close(fd);
-        if (ifconf.ifc_buf)
-                free(ifconf.ifc_buf);
-        return (retname);
+        errno = error;
+        return(ifname);
 }