On Wed, Oct 14, 2009 at 12:51:32PM +0200, Daniel Veillard wrote:
On Wed, Oct 14, 2009 at 10:49:20AM +0100, Daniel P. Berrange wrote:
On Tue, Oct 13, 2009 at 04:12:47PM +0200, Daniel Veillard wrote:
* src/util/util.h src/util/util.c: two new functions virParseIPv4 and virParseIPv6
I think this should just be a thin wrapper around getaddrinfo() which already knows how to parse all possible address types.
Are we allowing all possible address types in the XML ?
Well at this time we only allow IPv4 addreses in this, so we would want to pass the AF_INET flag to restrict it. Other areas of libvirt which could uses this code would be more flexible. We've got an open RFE for IPv6 support https://bugzilla.redhat.com/show_bug.cgi?id=514749
I based that parsing routing in a large part as a syntactic check on the allowed set of addresses. For example I didn't allow
::ffff:12.34.56.78
kind of IPv6 syntax.
Why shouldn't we allow that - its valid IPv6 address syntax }
If we avoid a custom typedef, and just use 'struct sockaddr_storage' this in turn makes it easy for callers to pass the result straight into any socket API calls they might use. eg this could all be done with a couple of lines of code
That would automatically cope with both IPv4 / 6 addresses. If we want to restrict it we could add a 3rd argument, 'int family' and use that to set hints.ai_family field - the caller would just pass AF_INET or AF_INET6 to specify a particular type, or leave it at 0 to allow any type.
Dunno, I find the getaddrinfo interface and the hints stuff fairly incomprehensible. When I see the OpenGroup definition of struct sockaddr_storage
struct sockaddr_storage { sa_family_t ss_family; /* Address family. */ /* * Following fields are implementation-defined. */ char _ss_pad1[_SS_PAD1SIZE]; /* 6-byte pad; this is to make implementation-defined pad up to alignment field that follows explicit in the data structure. */ int64_t _ss_align; /* Field to force desired structure storage alignment. */ char _ss_pad2[_SS_PAD2SIZE]; /* 112-byte pad to achieve desired size, _SS_MAXSIZE value minus size of ss_family __ss_pad1, __ss_align fields is 112. */ };
NB it is not intended to use the internals of the sockaddr_storage struct, with the exception of the ss_family field. It is provided as a struct that is guarenteed large enough to store any type of address. To use the data, you'd cast to the appropriate struct based on ss_family. eg, if ss_family == AF_INET, then you can cast to struct sockaddr_in which has a 'struct in_addr sin_addr' field available to get the raw address - in this case 'in_addr' is just an int32 For AF_INET6, you would cast to sockaddr_in6, which has a 'struct in6_addr sin6_addr' which gives you easy acess to the 16 byte array of the address.
I'm not too enthusiastic about using this for internal APIs. And I don't see how I would check ranges for the IP addresses based on this. Actually I don't find it helps to calculate a range, and I prefer my good old arrays of well defined ints for that purpose.
The sockaddr_in/in6 structs both give you an array of bytes in exactly the same manner Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|