Add kernel IPv6 RA and forwarding detection on Linux.

diff --git a/platform-linux.c b/platform-linux.c
index 923c9746dc46a766a8da2655c66461fb1ab429b6..e2d2844b8c722a7af20ed64cf16ac22b229b0ac8 100644 (file)
--- a/platform-linux.c
+++ b/platform-linux.c
@@ -27,7 +27,9 @@
 
 #include <errno.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
+#include <syslog.h>
 
 #include "common.h"
 #include "platform.h"
@@ -103,10 +105,35 @@ hardware_platform(void)
        return p;
 }
 
+static int
+check_proc_int(const char *path)
+{
+       FILE *fp;
+       char *buf;
+
+       fp = fopen(path, "r");
+       if (fp == NULL)
+               return -1;
+       buf = get_line(fp);
+       fclose(fp);
+       if (buf == NULL)
+               return -1;
+       return atoi(buf);
+}
+
 int
 check_ipv6(void)
 {
-    
-    // FIXME: Add IPv6 detection here
-    return 1;
+
+       if (check_proc_int("/proc/sys/net/ipv6/conf/all/accept_ra") != 1) {
+               syslog(LOG_WARNING,
+                   "Kernel is not configured to accept IPv6 RAs");
+               return 0;
+       }
+       if (check_proc_int("/proc/sys/net/ipv6/conf/all/forwarding") != 0) {
+               syslog(LOG_WARNING,
+                   "Kernel is configured as a router, not a host");
+               return 0;
+       }
+       return 1;
 }