udp_buf_reply_sock_data() can handle forwarding data either from socket
to socket ("splicing") or from socket to tap. It has a test on each
datagram for which case we're in, but that will be the same for everything
in the batch.
Split out the spliced path into a separate udp_sock_to_sock() function.
This leaves udp_{buf,vu}_reply_sock_data() handling only forwards from
socket to tap, so rename and simplify them accordingly.
This makes the code slightly longer for now, but will allow future cleanups
to shrink it back down again.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
[sbrivio: Fix typos in comments to udp_sock_recv() and
udp_vu_listen_sock_data()]
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Both udp_buf_reply_sock_data() and udp_vu_reply_sock_data() internally
decide what the maximum number of datagrams they will forward is. We have
some upcoming reasons to allow the caller to decide that instead, so make
the maximum number of datagrams a parameter for both of them.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Since UDP has no built in knowledge of connections, the only way we
know when we're done with a UDP flow is a timeout with no activity.
To keep track of this struct udp_flow includes a timestamp to record
the last time we saw traffic on the flow.
For data from listening sockets and from tap, this is done implicitly via
udp_flow_from_{sock,tap}() but for reply sockets it's done explicitly.
However, that logic is duplicated between the vhost-user and "buf" paths.
Make it common in udp_reply_sock_handler() instead.
Technically this is a behavioural change: previously if we got an EPOLLIN
event, but there wasn't actually any data we wouldn't update the timestamp,
now we will. This should be harmless: if there's an EPOLLIN we expect
there to be data, and even if there isn't the worst we can do is mildly
delay the cleanup of a stale flow.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Share some additional miscellaneous logic between the vhost-user and "buf"
paths for data on udp reply sockets. The biggest piece is error handling
of cases where we can't forward between the two pifs of the flow. We also
make common some more simple logic locating the correct flow and its
parameters.
This adds some lines of code due to extra comment lines, but nonetheless
reduces logic duplication.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
udp_{listen,reply}_sock_handler() can accept both EPOLLERR and EPOLLIN
events. However, unlike most epoll event handlers we don't check the
event bits right there. EPOLLERR is checked within udp_sock_errs() which
we call unconditionally. Checking EPOLLIN is still more buried: it is
checked within both udp_sock_recv() and udp_vu_sock_recv().
We can simplify the logic and pass less extraneous parameters around by
moving the checking of the event bits to the top level event handlers.
This makes udp_{buf,vu}_{listen,reply}_sock_handler() no longer general
event handlers, but specific to EPOLLIN events, meaning new data. So,
rename those functions to udp_{buf,vu}_{listen,reply}_sock_data() to better
reflect their function.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
add virtio and vhost-user functions to connect with QEMU.
$ ./passt --vhost-user
and
# qemu-system-x86_64 ... -m 4G \
-object memory-backend-memfd,id=memfd0,share=on,size=4G \
-numa node,memdev=memfd0 \
-chardev socket,id=chr0,path=/tmp/passt_1.socket \
-netdev vhost-user,id=netdev0,chardev=chr0 \
-device virtio-net,mac=9a:2b:2c:2d:2e:2f,netdev=netdev0 \
...
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
[sbrivio: as suggested by lvivier, include <netinet/if_ether.h>
before including <linux/if_ether.h> as C libraries such as musl
__UAPI_DEF_ETHHDR in <netinet/if_ether.h> if they already have
a definition of struct ethhdr]
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
