The sock_l4() function is very convenient for creating sockets bound to
a given address, but its interface has some problems.
Most importantly, the address and port alone aren't enough in some cases.
For link-local addresses (at least) we also need the pif in order to
properly construct a socket adddress. This case doesn't yet arise, but
it might cause us trouble in future.
Additionally, sock_l4() can take AF_UNSPEC with the special meaning that it
should attempt to create a "dual stack" socket which will respond to both
IPv4 and IPv6 traffic. This only makes sense if there is no specific
address given. We verify this at runtime, but it would be nicer if we
could enforce it structurally.
For sockets associated specifically with a single flow we already replaced
sock_l4() with flowside_sock_l4() which avoids those problems. Now,
replace all the remaining users with a new pif_sock_l4() which also takes
an explicit pif.
The new function takes the address as an inany *, with NULL indicating the
dual stack case. This does add some complexity in some of the callers,
however future planned cleanups should make this go away again.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Require the address and port information for the target (non
initiating) side to be populated when a flow enters TGT state.
Implement that for TCP and ICMP. For now this leaves some information
redundantly recorded in both generic and type specific fields. We'll
fix that in later patches.
For TCP we now use the information from the flow to construct the
destination socket address in both tcp_conn_from_tap() and
tcp_splice_connect().
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Currently we have no generic information flows apart from the type and
state, everything else is specific to the flow type. Start introducing
generic flow information by recording the pifs which the flow connects.
To keep track of what information is valid, introduce new flow states:
INI for when the initiating side information is complete, and TGT for
when both sides information is complete, but we haven't chosen the
flow type yet. For now, these states don't do an awful lot, but
they'll become more important as we add more generic information.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
pif_name() has no current callers, although we expect some as we expand the
flow table support. I'm not sure why this didn't get caught by one of
our static checkers earlier, but it's now causing cppcheck failures for me.
Add a cppcheck suppression.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Future debugging will want to identify a specific passt interface. We make
a distinction in these helpers between the name of the *type* of pif, and
name of the pif itself. For the time being these are always the same
thing, since we have at most instance of each type of pif. However, that
might change in future.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
We have several possible ways of communicating with other entities. We use
sockets to communicate with the host and other network sites, but also in
a different context to communicate "spliced" channels to a namespace. We
also use a tuntap device or a qemu socket to communicate with the namespace
or guest.
For the time being these are just defined implicitly by how we structure
things. However, there are other communication channels we want to use in
future (e.g. virtio-user), and we want to allow more flexible forwarding
between those. To accomplish that we're going to want a specific way of
referring to those channels.
Introduce the concept of a "passt/pasta interface" or "pif" representing a
specific channel to communicate network data. Each pif is assumed to be
associated with a specific network namespace in the broad sense (that is
as a place where IP addresses have a consistent meaning - not the Linux
specific sense). But there could be multiple pifs communicating with the
same namespace (e.g. the spliced and tap interfaces in pasta).
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
