1 files changed, 140 insertions, 0 deletions

diff --git a/src/lib/libc/net/if_nameindex.c b/src/lib/libc/net/if_nameindex.c
new file mode 100644
index 0000000000..3675a2a450
--- /dev/null
+++ b/src/lib/libc/net/if_nameindex.c
@@ -0,0 +1,140 @@
+/*      $OpenBSD: if_nameindex.c,v 1.9 2002/03/07 22:40:23 millert Exp $        */
+/*      $KAME: if_nameindex.c,v 1.7 2000/11/24 08:17:20 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_nameindex.c,v 2.3 2000/04/17 22:38:05 dab Exp
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <net/if_dl.h>
+#include <net/if.h>
+#include <ifaddrs.h>
+#include <stdlib.h>
+#include <string.h>
+
+/*
+ * From RFC 2553:
+ *
+ * 4.3 Return All Interface Names and Indexes
+ *
+ *    The if_nameindex structure holds the information about a single
+ *    interface and is defined as a result of including the <net/if.h>
+ *    header.
+ *
+ *       struct if_nameindex {
+ *         unsigned int   if_index;
+ *         char          *if_name;
+ *       };
+ *
+ *    The final function returns an array of if_nameindex structures, one
+ *    structure per interface.
+ *
+ *       struct if_nameindex  *if_nameindex(void);
+ *
+ *    The end of the array of structures is indicated by a structure with
+ *    an if_index of 0 and an if_name of NULL.  The function returns a NULL
+ *    pointer upon an error, and would set errno to the appropriate value.
+ *
+ *    The memory used for this array of structures along with the interface
+ *    names pointed to by the if_name members is obtained dynamically.
+ *    This memory is freed by the next function.
+ *
+ * 4.4.  Free Memory
+ *
+ *    The following function frees the dynamic memory that was allocated by
+ *    if_nameindex().
+ *
+ *        #include <net/if.h>
+ *
+ *        void  if_freenameindex(struct if_nameindex *ptr);
+ *
+ *    The argument to this function must be a pointer that was returned by
+ *    if_nameindex().
+ */
+
+struct if_nameindex *
+if_nameindex(void)
+{
+        struct ifaddrs *ifaddrs, *ifa;
+        unsigned int ni;
+        size_t nbytes;
+        struct if_nameindex *ifni, *ifni2;
+        char *cp;
+
+        if (getifaddrs(&ifaddrs) < 0)
+                return(NULL);
+
+        /*
+         * First, find out how many interfaces there are, and how
+         * much space we need for the string names.
+         */
+        ni = 0;
+        nbytes = 0;
+        for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
+                if (ifa->ifa_addr &&
+                    ifa->ifa_addr->sa_family == AF_LINK) {
+                        nbytes += strlen(ifa->ifa_name) + 1;
+                        ni++;
+                }
+        }
+
+        /*
+         * Next, allocate a chunk of memory, use the first part
+         * for the array of structures, and the last part for
+         * the strings.
+         */
+        cp = malloc((ni + 1) * sizeof(struct if_nameindex) + nbytes);
+        ifni = (struct if_nameindex *)cp;
+        if (ifni == NULL)
+                goto out;
+        cp += (ni + 1) * sizeof(struct if_nameindex);
+
+        /*
+         * Now just loop through the list of interfaces again,
+         * filling in the if_nameindex array and making copies
+         * of all the strings.
+         */
+        ifni2 = ifni;
+        for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
+                if (ifa->ifa_addr &&
+                    ifa->ifa_addr->sa_family == AF_LINK) {
+                        ifni2->if_index =
+                            ((struct sockaddr_dl*)ifa->ifa_addr)->sdl_index;
+                        ifni2->if_name = cp;
+                        nbytes = strlen(ifa->ifa_name) + 1;
+                        memcpy(cp, ifa->ifa_name, nbytes);
+                        ifni2++;
+                        cp += nbytes;
+                }
+        }
+        /*
+         * Finally, don't forget to terminate the array.
+         */
+        ifni2->if_index = 0;
+        ifni2->if_name = NULL;
+out:
+        freeifaddrs(ifaddrs);
+        return(ifni);
+}