As soon as we bring up the interface, the Linux kernel will set up a link-local address for it, so we can fetch it and start using right away, if we need a link-local address to communicate to the container before we see any traffic coming from it. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
It makes no sense for a container or a guest to try and perform duplicate address detection for their link-local address, as we'll anyway not relay neighbour solicitations with an unspecified source address. While they perform duplicate address detection, the link-local address is not usable, which prevents us from bringing up especially containers and communicate with them right away via IPv6. This is not enough to prevent DAD and reach the container right away: we'll need a couple more patches. As we send NLM_F_REPLACE requests right away, while we still have to read out other addresses on the same socket, we can't use nl_do(): keep track of the last sequence we sent (last address we changed), and deal with the answers to those NLM_F_REPLACE requests in a separate loop, later. Link: https://github.com/containers/podman/pull/23561#discussion_r1711639663 Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
In the next patches, we'll reuse it to set flags other than IFF_UP. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
As we'll use nl_link_up() for more than just bringing up devices, it will become awkward to carry empty MTU values around whenever we call it. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Newer versions of cppcheck (as of 2.12.0, at least) added a warning for pointers which could be declared to point at const data, but aren't. Based on that, make many pointers throughout the codebase const. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
We now detect errors on netlink "set" operations while configuring the pasta namespace with --config-net. However in many cases rather than a simple "set" we use a more complex "dup" function to copy configuration from the host to the namespace. We're not yet properly detecting and reporting netlink errors for that case. Change the "dup" operations to propagate netlink errors to their caller, pasta_ns_conf() and report them there. Link: https://bugs.passt.top/show_bug.cgi?id=60 Signed-off-by: David Gibson <david@gibson.dropbear.id.au> [sbrivio: Minor formatting changes in pasta_ns_conf()] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Currently if we receive any netlink errors while discovering network configuration from the host, we'll just ignore it and carry on. This might lead to cryptic error messages later on, or even silent misconfiguration. We now have the mechanisms to detect errors from get/dump netlink operations. Propgate these errors up to the callers and report them usefully. Link: https://bugs.passt.top/show_bug.cgi?id=60 Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Currently if anything goes wrong while we're configuring the namespace network with --config-net, we'll just ignore it and carry on. This might lead to a silently unconfigured or misconfigured namespace environment. For simple "set" operations based on nl_do() we can now detect failures reported via netlink. Propagate those errors up to pasta_ns_conf() and report them usefully. Link: https://bugs.passt.top/show_bug.cgi?id=60 Signed-off-by: David Gibson <david@gibson.dropbear.id.au> [sbrivio: Minor formatting changes in pasta_ns_conf()] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
All the netlink operations currently implicitly use one of the two global netlink sockets, sometimes depending on an 'ns' parameter. Change them all to explicitly take the socket to use (or two sockets to use in the case of the *_dup() functions). As well as making these functions strictly more general, it makes the callers easier to follow because we're passing a socket variable with a name rather than an unexplained '0' or '1' for the ns parameter. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> [sbrivio: Minor formatting changes in pasta_ns_conf()] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
nl_route() can perform 3 quite different operations based on the 'op' parameter. Split this into separate functions for each one. This requires more lines of code, but makes the internal logic of each operation much easier to follow. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>