copy from intranet.

src/common/interface.c

@@ -0,0 +1,158 @@
+/* $Id: interface.c 2423 2010-03-13 07:09:49Z aturner $ */
+
+/*
+ * Copyright (c) 2007-2010 Aaron Turner.
+ * 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. Neither the names of the copyright owners nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED ``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 AUTHORS OR COPYRIGHT HOLDERS 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.
+ */
+
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+#include "config.h"
+#include "defines.h"
+#include "common.h"
+#include "interface.h"
+
+/**
+ * Method takes a user specified device name and returns
+ * the canonical name for that device.  This allows me to 
+ * create named interface aliases on platforms like Windows
+ * which use horrifically long interface names
+ * 
+ * Returns NULL on error
+ * 
+ * On success, it *may* malloc() memory equal to the length of *alias.
+ */
+char *
+get_interface(interface_list_t *list, const char *alias)
+{
+    interface_list_t *ptr;
+    char *name;
+    
+    assert(alias);
+    
+    if (list != NULL) {        
+        ptr = list;
+    
+        do {
+            /* check both the alias & name fields */
+            if (strcmp(alias, ptr->alias) == 0)
+                return(ptr->name);
+        
+            if (strcmp(alias, ptr->name) == 0)
+                return(ptr->name);
+            
+            ptr = ptr->next;
+        } while (ptr != NULL);
+    } else {
+        name = (char *)safe_malloc(strlen(alias) + 1);
+        strlcpy(name, alias, sizeof(name));
+        return(name);
+    }
+    
+    return(NULL);
+}
+
+/** 
+ * Get all available interfaces as an interface_list *
+ */
+interface_list_t *
+get_interface_list(void)
+{
+    interface_list_t *list_head, *list_ptr;
+    char ebuf[PCAP_ERRBUF_SIZE];
+    pcap_if_t *pcap_if, *pcap_if_ptr;
+    int i = 0;
+    
+#ifndef HAVE_WIN32
+	/* Unix just has a warning about being root */
+	if (geteuid() != 0)
+		warn("May need to run as root to get complete list.");
+#endif
+
+    if (pcap_findalldevs(&pcap_if, ebuf) < 0)
+        errx(-1, "Error: %s", ebuf);
+            
+    pcap_if_ptr = pcap_if;
+    list_head = (interface_list_t *)safe_malloc(sizeof(interface_list_t));
+    list_ptr = list_head;
+    
+    while (pcap_if_ptr != NULL) {
+        if (i > 0) {
+            list_ptr->next = (interface_list_t *)safe_malloc(sizeof(interface_list_t));
+            list_ptr = list_ptr->next;
+        }
+        strlcpy(list_ptr->name, pcap_if_ptr->name, sizeof(list_ptr->name));
+        
+        /* description is usually null under Unix */
+        if (pcap_if_ptr->description != NULL)
+            strlcpy(list_ptr->description, pcap_if_ptr->description, sizeof(list_ptr->description));
+            
+        sprintf(list_ptr->alias, "%%%d", i++);
+        list_ptr->flags = pcap_if_ptr->flags;
+        pcap_if_ptr = pcap_if_ptr->next;
+    }
+    pcap_freealldevs(pcap_if);
+    return(list_head);
+}
+
+/**
+ * Prints all the available interfaces found by get_interface_list()
+ */
+void
+list_interfaces(interface_list_t *list)
+{
+    interface_list_t *ptr;
+
+    if (list == NULL) {
+        printf("No network interfaces available");
+        return;
+    }
+
+    printf("Available network interfaces:\n");
+        
+#ifdef HAVE_WIN32  /* Win32 has alias/name/description */
+	printf("Alias\tName\tDescription\n");
+#endif
+    
+    
+    ptr = list;
+
+    do {
+        if (! ptr->flags & PCAP_IF_LOOPBACK) {
+#ifdef HAVE_WIN32
+            printf("%s\t%s\n\t%s\n", ptr->alias, ptr->name, ptr->description);
+#else
+			printf("%s\n", ptr->name);
+#endif
+        }
+        ptr = ptr->next;
+    } while (ptr != NULL);
+}