Implement the rest of the missing include/net/if.h interfaces

 -Erik

libc/inet/if_nametoindex.c

@@ -1,40 +1,167 @@
-/*
+/* Copyright (C) 1997,98,99,2000,02 Free Software Foundation, Inc.
+ * This file is part of the GNU C Library.
+ * 
+ * The GNU C Library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.  
  *
- * Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>,
- *                     The Silver Hammer Group, Ltd.
+ * The GNU C Library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.  
  *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Library General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with the GNU C Library; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ * 02111-1307 USA.  
  *
+ * Reworked Dec 2002 by Erik Andersen <andersen@codepoet.org>
  */
+
 #define __FORCE_GLIBC
 #include <features.h>
+#include <string.h>
+#include <errno.h>
 #include <net/if.h>
 #include <sys/ioctl.h>
 #include <unistd.h>
+#include <stdlib.h>
 
-unsigned int if_nametoindex(const char* blub) {
-	struct ifreq ifr;
-	int fd;
-	char *tmp;
-	int len=sizeof(ifr.ifr_name);
-
+static int __opensock(void)
+{
+    int fd;
 #ifdef __UCLIBC_HAS_IPV6__
-	fd=socket(AF_INET6,SOCK_DGRAM,0);
-	if (fd<0)
+    fd=socket(AF_INET6,SOCK_DGRAM,0);
+    if (fd<0)
 #endif /* __UCLIBC_HAS_IPV6__ */
-		fd=socket(AF_INET,SOCK_DGRAM,0);
+	fd=socket(AF_INET,SOCK_DGRAM,0);
+    return(fd);
+}
+
+unsigned int if_nametoindex(const char* ifname) 
+{
+#ifndef SIOCGIFINDEX
+    __set_errno (ENOSYS);
+    return 0;
+#else
+    int fd;
+    struct ifreq ifr;
 
-	for (tmp=ifr.ifr_name; len>0; --len) {
-		if ((*tmp++ = *blub++)==0) break;
+    fd = __opensock();
+    if (fd < 0)
+	return 0;
+    strncpy (ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
+    if (ioctl(fd,SIOCGIFINDEX,&ifr) < 0) {
+	int saved_errno = errno;
+	close(fd);
+	if (saved_errno == EINVAL)
+	    __set_errno(ENOSYS);
+	return 0;
+    }
+    close(fd);
+    return ifr.ifr_ifindex;
+
+#endif /* SIOCGIFINDEX */
+}
+
+void if_freenameindex (struct if_nameindex *ifn)
+{
+    struct if_nameindex *ptr = ifn;
+    while (ptr->if_name || ptr->if_index) {
+	if (ptr->if_name) {
+	    free (ptr->if_name);
 	}
+	++ptr;
+    }
+    free (ifn);
+}
+
+struct if_nameindex * if_nameindex (void)
+{
+#ifndef SIOCGIFINDEX
+    __set_errno (ENOSYS);
+    return NULL;
+#else
+    int fd;
+    struct ifconf ifc;
+    unsigned int nifs, i;
+    int rq_len;
+    struct if_nameindex *idx = NULL;
+# define RQ_IFS	4
+
+    fd = __opensock();
+    if (fd < 0)
+	return 0;
+
+    ifc.ifc_buf = NULL;
 
-	if (ioctl(fd,SIOCGIFINDEX,&ifr)==0) {
-		close(fd);
-		return ifr.ifr_ifindex;
+    /* Guess on the correct buffer size... */
+    rq_len = RQ_IFS * sizeof (struct ifreq);
+
+    /* Read all the interfaces out of the kernel.  */
+    do {
+	ifc.ifc_buf = realloc(ifc.ifc_buf, ifc.ifc_len = rq_len);
+	if (ifc.ifc_buf == NULL || ioctl(fd, SIOCGIFCONF, &ifc) < 0) {
+	    close(fd);
+	    return NULL;
 	}
+	rq_len *= 2;
+    } while (ifc.ifc_len == rq_len);
+
+    nifs = ifc.ifc_len / sizeof(struct ifreq);
+
+    idx = malloc ((nifs + 1) * sizeof(struct if_nameindex));
+    if (idx == NULL) {
 	close(fd);
-	return 0;
+	__set_errno(ENOBUFS);
+	return NULL;
+    }
+
+    for (i = 0; i < nifs; ++i) {
+	struct ifreq *ifr = &ifc.ifc_req[i];
+	idx[i].if_name = strdup (ifr->ifr_name);
+	if (idx[i].if_name == NULL || ioctl(fd,SIOCGIFINDEX,ifr) < 0) {
+	    int saved_errno = errno;
+	    unsigned int j;
+	    for (j =  0; j < i; ++j)
+		free (idx[j].if_name);
+	    free(idx);
+	    close(fd);
+	    if (saved_errno == EINVAL)
+		saved_errno = ENOSYS;
+	    else if (saved_errno == ENOMEM)
+		saved_errno = ENOBUFS;
+	    __set_errno (saved_errno);
+	    return NULL;
+	}
+	idx[i].if_index = ifr->ifr_ifindex;
+    }
+
+    idx[i].if_index = 0;
+    idx[i].if_name = NULL;
+
+    close(fd);
+    return idx;
+#endif
 }
+
+char * if_indextoname (unsigned int ifindex, char *ifname)
+{
+    struct if_nameindex *idx;
+    struct if_nameindex *p;
+    char *result = NULL;
+
+    idx = if_nameindex();
+    if (idx != NULL) {
+	for (p = idx; p->if_index || p->if_name; ++p) {
+	    if (p->if_index == ifindex) {
+		result = strncpy (ifname, p->if_name, IFNAMSIZ);
+		break;
+	    }
+	}
+	if_freenameindex (idx);
+    }
+    return result;
+}
+