iproute2: support dotted-quad netmask notation.

On tor, 2007-12-06 at 11:53 -0800, Stephen Hemminger wrote:
> On Tue, 4 Dec 2007 14:58:18 +0100
> Andreas Henriksson <andreas@fatal.se> wrote:
>
> > Suggested patch for allowing netmask to be specified in dotted quad format.
> > See http://bugs.debian.org/357172
> >
> > (Known problem: this will not prevent some invalid syntaxes,
> > ie. "255.0.255.0" will be treated as "255.255.255.0")
> >
> > Comments? Suggestions? Improvements?
>
> Fix the bug you mentioned?
>
> [... snip example code ...]

Updated patch, added your netmask validation code but without the check
that made 0.0.0.0 (default) and 255.255.255.255 (one address) invalid
netmasks as they are permitted in CIDR format.

Signed-off-by: Andreas Henriksson <andreas@fatal.se>
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>

diff --git a/lib/utils.c b/lib/utils.c
index ffef6fed91481bbeca0995e7d9904d6f2d517e2d..eb8e312c87345e8e127384c7aa944aeb302ae005 100644 (file)
--- a/lib/utils.c
+++ b/lib/utils.c
@@ -47,6 +47,41 @@ int get_integer(int *val, const char *arg, int base)
        return 0;
 }
 
+/* a valid netmask must be 2^n - 1 (n = 1..31) */
+static int is_valid_netmask(const inet_prefix *addr)
+{
+        uint32_t host;
+
+        if (addr->family != AF_INET)
+                return 0;
+
+        host = ~ntohl(addr->data[0]);
+
+        return (host & (host + 1)) == 0;
+}
+
+static int get_netmask(unsigned *val, const char *arg, int base)
+{
+       inet_prefix addr;
+
+       if (!get_unsigned(val, arg, base))
+               return 0;
+
+       /* try coverting dotted quad to CIDR */
+       if (!get_addr_1(&addr, arg, AF_INET)) {
+               u_int32_t mask;
+
+               *val=0;
+               for (mask = addr.data[0]; mask; mask >>= 1)
+                       (*val)++;
+
+               if (is_valid_netmask(&addr))
+                       return 0;
+       }
+
+       return -1;
+}
+
 int get_unsigned(unsigned *val, const char *arg, int base)
 {
        unsigned long res;
@@ -304,7 +339,8 @@ int get_prefix_1(inet_prefix *dst, char *arg, int family)
                                dst->bitlen = 32;
                }
                if (slash) {
-                       if (get_unsigned(&plen, slash+1, 0) || plen > dst->bitlen) {
+                       if (get_netmask(&plen, slash+1, 0)
+                                       || plen > dst->bitlen) {
                                err = -1;
                                goto done;
                        }