--On Tuesday, February 08, 2011 06:06:47 PM +0100 Hartmut Reuter
<[email protected]> wrote:
Derrick Brashear wrote:
On Tue, Feb 8, 2011 at 11:09 AM, Hartmut Reuter<[email protected]>
wrote:
Simon Wilkinson wrote:
On 8 Feb 2011, at 15:20, Derrick Brashear wrote:
struct {
int addrtype;
int addrlen;
int addr<>
} rx_addr;
# define RX_ADDRTYPE_IPV4 1
# define RX_ADDRTYPE_IPV6 2
Why not just use an opaque? That way you don't get into any of the
ordering issues that ints bring with them.
struct {
int addrtype;
opaque addr<>;
} rx_addr;
opaque requires xdr_alloc and later xdr_free of the data and in the
case of IPv4 the address typically is used as an integer which then
would have been first converted from the opaque (including changing
host byte order).
Therefore I had proposed in my change I8aa46a29:
src/fsint/fs_rxosd_common.xg
for both address types to use afs_uint32s:
union ipadd switch(afs_int32 vsn) {
case 4:
afs_uint32 ipv4;
case 6:
afs_uint32 ipv6[4];
};
I also think instead of inventing new constants it's better to use the
version numbers 4 and 6 directly.
In the case of IPv6 the application easily can fill the contents into
the host's struct in6_addr using the u6_addr32 fields while for IPv4
the address can be used directly.
the only problem is we're back to a union with fixed discrimination
that doesn't allow us to add things later.
But only in the memory, not on the wire.
False. On the wire, it breaks things permanently, because receipt of such
a union with an unknown discriminator will cause decoding to fail, which
means the call gets aborted. If VL_GetAddrsNewAndShiny returns a list of
all of a server's addresses, then we must allow for the case where some of
those addresses will be types not known to the client. In fact, we may
want a fileserver calling VL_RegisterAddrsNewAndShiny to be able to
register addresses of types not known to the vlserver.
-- Jeff
_______________________________________________
AFS3-standardization mailing list
[email protected]
http://lists.openafs.org/mailman/listinfo/afs3-standardization
