[snip]
Wait a minute there please. The MAC address should be unique in the system so user should be using just one IP address per one MAC address. Since MAC address should be unique in the system then the IP address assigned to this MAC address should be just one, shouldn't it ? You can easily add multiple IP address to an interface (and therefore to the same MAC address)
ip addr add 192.168.0.17 dev eth0 ip addr add 192.168.0.42 dev eth0
In this case, yes. Like I said, I didn't consider that option nor it didn't come to my mind at all since I'm not familiar with networking too much for the cases I never used.
Nevertheless I think you know more about networking options than I do so Well, I know that there is no strict 1:1 mapping between MAC and IP addresses and I want that this fact is consider in the discussion here and we don't add a new API that turns out to be too simple/restricted in the end. Whether we really want/need to cover this case is a different question.
I can see the point and I think it's always good to discuss the possibilities that arise in the process.
when I consider the scenario you wrote me about I don't like the idea of leaving the parsing to the caller and for the scenario of multiple IP addresses in the return value I recommend a new prototype:
char **virDomainGetIPAddress(virDomainPtr domain, char *devmac, unsigned int *count, unsigned int flags);
where count will be the output parameter with the number of elements in the return value. It should be used like:
virDomainPtr domain = ...; char *macaddr = "11:22:33:44:55:66"; char **ips = NULL; int count = -1;
ips = virDomainGetIPAddress(domain, macaddr, &count, 0);
for (i = 0; i < count; i++) { ... ips[i] ... ... free(ips[i]) ... }
The return value allocation should be done by the function itself and the called should free the result (ips in this case). That's a possible way to deal with this, yes.
And now lets spin this a bit further and consider IPv6 addresses.
ipv4s = virDomainGetIPAddress(domain, macaddr, &count, VIR_DOMAIN_ADDRESS_IPV4); ipv6s = virDomainGetIPAddress(domain, macaddr, &count, VIR_DOMAIN_ADDRESS_IPV6);
This are the simple cases where the caller explicitly requests only one version and knows the version of the returned IP addresses. But what about this
ips = virDomainGetIPAddress(domain, macaddr, &count, VIR_DOMAIN_ADDRESS_IPV4 | VIR_DOMAIN_ADDRESS_IPV6);
For this the virSocketAddr representation would be better, right. However my scenario didn't count with the option of definiting VIR_DOMAIN_ADDRESS_IPV4 | VIR_DOMAIN_ADDRESS_IPV6 together. Michal -- Michal Novotny <minovotn@redhat.com>, RHCE, Red Hat Virtualization | libvirt-php bindings | php-virt-control.org