Commit graph

1372 commits

Author SHA1 Message Date
David Gibson
4779dfe12f icmp: Use 'flowside' epoll references for ping sockets
Currently ping sockets use a custom epoll reference type which includes
the ICMP id.  However, now that we have entries in the flow table for
ping flows, finding that is sufficient to get everything else we want,
including the id.  Therefore remove the icmp_epoll_ref type and use the
general 'flowside' field for ping sockets.

Having done this we no longer need separate EPOLL_TYPE_ICMP and
EPOLL_TYPE_ICMPV6 reference types, because we can easily determine
which case we have from the flow type. Merge both types into
EPOLL_TYPE_PING.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-03-12 01:49:05 +01:00
David Gibson
02cbdb0b86 icmp: Flow based error reporting
Use flow_dbg() and flow_err() helpers to generate flow-linked error
messages in most places.  Make a few small improvements to the messages
while we're at it.  This allows us to avoid the awkward 'pname' variables
since whether we're dealing with ICMP or ICMPv6 is already built into the
flow type which these helpers include.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
[sbrivio: Coding style fix in icmp_tap_handler()]
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-03-12 01:36:04 +01:00
David Gibson
3af5e9fdba icmp: Store ping socket information in flow table
Currently icmp_id_map[][] stores information about ping sockets in a
bespoke structure.  Move the same information into new types of flow
in the flow table.  To match that change, replace the existing ICMP
timer with a flow-based timer for expiring ping sockets.  This has the
advantage that we only need to scan the active flows, not all possible
ids.

We convert icmp_id_map[][] to point to the flow table entries, rather
than containing its own information.  We do still use that array for
locating the right ping flows, rather than using a "flow native" form
of lookup for the time being.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
[sbrivio: Update id_sock description in comment to icmp_ping_new()]
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-03-12 01:34:45 +01:00
Stefano Brivio
383a6f67e5 ip: Use regular htons() for non-constant protocol number in L2_BUF_IP4_PSUM
instead of htons_constant(), which is for... constants.

Fixes: 5bf200ae8a ("tcp, udp: Don't include destination address in partially precomputed csums")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2024-03-08 10:31:14 +01:00
David Gibson
137ce01789 iov: Improve documentation of iov_skip_bytes()
As pointed out in review, the documentation comments for iov_skip_bytes()
are more confusing than they should be.  Reword them, including updating
parameter names, to make it clearer.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-03-07 23:09:15 +01:00
Laurent Vivier
bb11d15495 tcp: Introduce tcp_fill_headers4()/tcp_fill_headers6()
Replace the macro SET_TCP_HEADER_COMMON_V4_V6() by a new function
tcp_fill_header().

Move IPv4 and IPv6 code from tcp_l2_buf_fill_headers() to
tcp_fill_headers4() and tcp_fill_headers6()

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-ID: <20240303135114.1023026-10-lvivier@redhat.com>
[dwg: Correct commit message with new function names]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-03-06 08:03:52 +01:00
Laurent Vivier
6b22e10a26 tap: make tap_update_mac() generic
Use ethhdr rather than tap_hdr.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-ID: <20240303135114.1023026-9-lvivier@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-03-06 08:03:49 +01:00
Laurent Vivier
7df624e79a checksum: introduce functions to compute the header part checksum for TCP/UDP
The TCP and UDP checksums are computed using the data in the TCP/UDP
payload but also some informations in the IP header (protocol,
length, source and destination addresses).

We add two functions, proto_ipv4_header_psum() and
proto_ipv6_header_psum(), to compute the checksum of the IP
header part.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-ID: <20240303135114.1023026-8-lvivier@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-03-06 08:03:47 +01:00
Laurent Vivier
feb4900c25 checksum: use csum_ip4_header() in udp.c and tcp.c
We can find the same function to compute the IPv4 header
checksum in tcp.c, udp.c and tap.c

Use the function defined for tap.c, csum_ip4_header(), but
with the code used in tcp.c and udp.c as it doesn't need a fully
initialiazed IPv4 header, only protocol, tot_len, saddr and daddr.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-ID: <20240303135114.1023026-7-lvivier@redhat.com>
[dwg: Fix weird cppcheck regression; it appears to be a problem
 in pre-existing code, but somehow this patch is exposing it]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-03-06 08:03:44 +01:00
Laurent Vivier
e82b4fe5fc udp: little cleanup in udp_update_hdrX() to prepare future changes
in udp_update_hdr4():

    Assign the source address to src, either b->s_in.sin_addr,
    c->ip4.dns_match or c->ip4.gw and then set b->iph.saddr to src->s_addr.

in udp_update_hdr6():

   Assign the source address to src, either b->s_in6.sin6_addr,
   c->ip6.dns_match, c->ip6.gw or c->ip6.addr_ll.
   Assign the destination to dst, either c->ip6.addr_seen or
   &c->ip6.addr_ll_seen.
   Then set dst to b->ip6h.daddr and src to b->ip6h.saddr.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-ID: <20240303135114.1023026-6-lvivier@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-03-06 08:03:41 +01:00
Laurent Vivier
324bd46782 util: move IP stuff from util.[ch] to ip.[ch]
Introduce ip.[ch] file to encapsulate IP protocol handling functions and
structures.  Modify various files to include the new header ip.h when
it's needed.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-ID: <20240303135114.1023026-5-lvivier@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-03-06 08:03:38 +01:00
Laurent Vivier
e289d287c6 checksum: add csum_iov()
Introduce the function csum_unfolded() that computes the unfolded
32-bit checksum of a data buffer, and call it from csum() that returns
the folded value.

Introduce csum_iov() that computes the checksum using csum_folded() on
all vectors of the iovec array and returns the folded result.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-ID: <20240303135114.1023026-4-lvivier@redhat.com>
[dwg: Fixed trivial cppcheck & clang-tidy regressions]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-03-06 08:03:36 +01:00
Laurent Vivier
907621eaae checksum: align buffers
If buffer is not aligned use sum_16b() only on the not aligned
part, and then use csum_avx2() on the remaining part

Remove unneeded now function csum_unaligned().

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-ID: <20240303135114.1023026-3-lvivier@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-03-06 08:03:32 +01:00
Laurent Vivier
94502fa15e pcap: add pcap_iov()
Introduce a new function pcap_iov() to capture packet desribed by an IO
vector.

Update pcap_frame() to manage iovcnt > 1.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-ID: <20240303135114.1023026-2-lvivier@redhat.com>
[dwg: Fixed trivial cppcheck regressions]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-03-06 08:03:30 +01:00
David Gibson
3b9098aa49 fwd: Rename port_fwd.[ch] and their contents
Currently port_fwd.[ch] contains helpers related to port forwarding,
particular automatic port forwarding.  We're planning to allow much more
flexible sorts of forwarding, including both port translation and NAT based
on the flow table.  This will subsume the existing port forwarding logic,
so rename port_fwd.[ch] to fwd.[ch] with matching updates to all the names
within.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:48:27 +01:00
David Gibson
10376e7a2f port_fwd: Fix copypasta error in port_fwd_scan_udp() comments
port_fwd_scan_udp() handles UDP, as the name suggests, but its
function comment has the wrong function name and references TCP, due
to a bad copy-paste from port_fwd_scan_tcp().

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:48:24 +01:00
David Gibson
f15be719b3 tap: Disallow loopback addresses on tap interface
The "tap" interface, whether it's actually a tuntap device or a qemu
socket, presents a virtual external link between different network hosts.
Hence, loopback addresses make no sense there.  However, nothing prevents
the guest from putting bogus packets with loopback addresses onto the
interface and it's not entirely clear what effect that will have on passt.

Explicitly test for such packets and drop them.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:48:21 +01:00
David Gibson
3b59b9748a tcp: Validate TCP endpoint addresses
TCP connections should typically not have wildcard addresses (0.0.0.0
or ::) nor a zero port number for either endpoint.  It's not entirely
clear (at least to me) if it's strictly against the RFCs to do so, but
at any rate the socket interfaces often treat those values
specially[1], so it's not really possible to manipulate such
connections.  Likewise they should not have broadcast or multicast
addresses for either endpoint.

However, nothing prevents a guest from creating a SYN packet with such
values, and it's not entirely clear what the effect on passt would be.
To ensure sane behaviour, explicitly check for this case and drop such
packets, logging a debug warning (we don't want a higher level,
because that would allow a guest to spam the logs).

We never expect such an address on an accept()ed socket either, but
just in case, check for it as well.

[1] Depending on context as "unknown", "match any" or "kernel, pick
    something for me"

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:48:17 +01:00
David Gibson
dc9a5d71e9 tcp, tcp_splice: Parse listening socket epoll ref in tcp_listen_handler()
tcp_listen_handler() uses the epoll reference for the listening socket
it handles, and also passes on one variant of it to
tcp_tap_conn_from_sock() and tcp_splice_conn_from_sock().  The latter
two functions only need a couple of specific fields from the
reference.

Pass those specific values instead of the whole reference, which
localises the handling of the listening (as opposed to accepted)
socket and its reference entirely within tcp_listen_handler().

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:48:15 +01:00
David Gibson
ee677e0a42 tcp_splice: Improve logic deciding when to splice
This makes several tweaks to improve the logic which decides whether
we're able to use the splice method for a new connection.

 * Rather than only calling tcp_splice_conn_from_sock() in pasta mode, we
   check for pasta mode within it, better localising the checks.
 * Previously if we got a connection from a non-loopback address we'd
   always fall back to the "tap" path, even if the  connection was on a
   socket in the namespace.  If we did get a non-loopback address on a
   namespace socket, something has gone wrong and the "tap" path certainly
   won't be able to handle it.  Report the error and close, rather than
   passing it along to tap.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:48:13 +01:00
David Gibson
4c2d923b12 tcp_splice: Improve error reporting on connect path
This makes a number of changes to improve error reporting while
connecting a new spliced socket:
* We use flow_err() and similar functions so all messages include info
   on which specific flow was affected
 * We use strerror() to interpret raw error values
 * We now report errors on connection (at "trace" level, since this would
   allow spamming the logs)
 * We also look up and report some details on EPOLLERR events, which can
   include connection errors, since we use a non-blocking connect().  Again
   we use "trace" level since this can spam the logs.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:48:11 +01:00
David Gibson
f0e2a6b8c9 tcp_splice: Make tcp_splice_connect() create its own sockets
Currently creating the connected socket for a splice is split between
tcp_splice_conn_from_sock(), which opens the socket, and
tcp_splice_connect() which connects it.  Alter tcp_splice_connect() to
open its own socket based on an address family and pif we pass it.

This does require a second conditional on pif, but makes for a more
logical split of functionality: tcp_splice_conn_from_sock() picks the
target, tcp_splice_connect() creates the connection.  While we're
there improve reporting of errors

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:48:09 +01:00
David Gibson
f4e5d73684 tcp_splice: Merge tcp_splice_new() into its caller
The only caller of tcp_splice_new() is tcp_splice_conn_from_sock().
Both are quite short, and the division of responsibilities between the
two isn't particularly obvious.  Simplify by merging the former into
the latter.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:48:06 +01:00
David Gibson
04d3d02603 tcp_splice: More specific variable names in new splice path
In tcp_splice_conn_from_sock(), the 'port' variable stores the source
port of the connection on the originating side.  In tcp_splice_new(),
called directly from it, the 'port' parameter gives the _destination_
port of the originating connection and is then updated to the
destination port of the connection on the other side.

Similarly, in tcp_splice_conn_from_sock(), 's' is the fd of the
accetped socket (on side 0), whereas in tcp_splice_new(), 's' is the
fd of the connecting socket (side 1).

I, for one, find having the same variable name with different meanings
in such close proximity in the flow of control pretty confusing.
Alter the names for greater specificity and clarity.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:48:03 +01:00
David Gibson
0f938c3b9a flow: Clarify flow entry life cycle, introduce uniform logging
Our allocation scheme for flow entries means there are some
non-obvious constraints on when what things can be done with an entry.
Add a big doc comment explaining the life cycle.

In addition, make a FLOW_START() macro to mark one of the important
transitions.  This encourages correct usage, by making it natural to
only access the flow type specific structure after calling it.  It
also logs that a new flow has been created, which is useful for
debugging.

We also add logging when a flow's lifecycle ends.  This doesn't need a
new helper, because it can only happen either from flow_alloc_cancel()
or from the flow deferred handler.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:48:01 +01:00
David Gibson
d0550f97cd tcp_splice: Don't use flow_trace() before setting flow type
In tcp_splice_conn_from_sock() we can call flow_trace() if there's an
error setting TCP_QUICKACK.  However, we do so before we've set the
flow type in the flow entry.  That means that flow_trace() will print
nonsense when it tries to print the flow type.

There's no reason the setsockopt() has to happen before initialising
the flow entry, so just move it after.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:47:58 +01:00
David Gibson
80f9b61b50 tcp_splice: Simplify clean up logic
Currently tcp_splice_flow_defer() contains specific logic to determine
if we're far enough initialised that we need to close pipes and/or
sockets.  This is potentially fragile if we change something about the
order in which we do things.  We can simplify this by initialising the
pipe and socket fields to -1 very early, then close()ing them if and
only if they're non-negative.

This lets us remove a special case cleanup if our connect() fails.
This will already trigger a CLOSING event, and the socket fd in
question is populated in the connection structure.  Thus we can let
the new cleanup logic handle it rather than requiring an explicit
close().

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:47:48 +01:00
David Gibson
76c7e1dca3 flow: Add helper to determine a flow's protocol
Each flow already has a type field.  This implies the protocol the
flow represents, but also has more information: we have two ways to
represent TCP flows, "tap" and "spliced".  In order to generalise some
of the flow mechanics, we'll need to determine a flow's protocol in
terms of the IP (L4) protocol number.

Introduce a constant table and helper macro to derive this from the flow
type.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:47:45 +01:00
David Gibson
bb9bf0bb8f tcp, udp: Don't precompute port remappings in epoll references
The epoll references for both TCP listening sockets and UDP sockets
includes a port number.  This gives the destination port that traffic
to that socket will be sent to on the other side.  That will usually
be the same as the socket's bound port, but might not if the -t, -u,
-T or -U options are given with different original and forwarded port
numbers.

As we move towards a more flexible forwarding model for passt, it's
going to become possible for that destination port to vary depending
on more things (for example the source or destination address).  So,
it will no longer make sense to have a fixed value for a listening
socket.

Change to simpler semantics where this field in the reference gives
the bound port of the socket.  We apply the translations to the
correct destination port later on, when we're actually forwarding.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:47:40 +01:00
David Gibson
e196eada6f util: Allow IN4_IS_* macros to operate on untyped addresses
The IN4_IS_*() macros expect a pointer to a struct in_addr.  That
makes sense, but sometimes we have an IPv4 address as a void * pointer
or union type which makes these less convenient.  Additionally, this
doesn't match the behaviour of the standard library's IN6_IS_*()
macros on which they're modelled, nor our own IN4_ARE_ADDR_EQUAL().

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:47:35 +01:00
David Gibson
f6e6e8ad40 inany: Introduce union sockaddr_inany
There are a number of places where we want to handle either a
sockaddr_in or a sockaddr_in6.  In some of those we use a void *,
which works ok and matches some standard library interfaces, but
doesn't give a signature level hint that we're dealing with only
sockaddr_in or sockaddr_in6, not (say) sockaddr_un or another type of
socket address.  Other places we use a sockaddr_storage, which also
works, but has the same problem in addition to allocating more on the
stack than we need to.

Introduce union sockaddr_inany to explictly handle this case: it has
variants for sockaddr_in and sockaddr_in6.  Use it in a number of
places where it's easy to do so.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:47:31 +01:00
David Gibson
0cf6b2d89d inany: Provide more conveniently typed constants for special addresses
Our inany_addr type is used in some places to represent either IPv4 or
IPv6 addresses, and we plan to use it more widely.  We don't yet
provide constants of this type for special addresses (loopback and
"any").  Add some of these, both the IPv4 and IPv6 variants of those
addresses, but typed as union inany_addr.

To avoid actually adding more things to .data we can use some macros and
casting to overlay the IPv6 versions of these with the standard library's
in6addr_loopback and in6addr_any.  For the IPv4 versions we need to create
new constant globals.

For complicated historical reasons, the standard library doesn't
provide constants for IPv4 loopback and any addresses as struct
in_addr.  It just has macros of type in_addr_t == uint32_t, which has
some gotchas w.r.t. endianness.  We can use some more macros to
address this lack, using macros to effectively create these IPv4
constants as pieces of the inany constants above.

We use this last to avoid some awkward temporary variables just used
to get an address of an IPv4 loopback address.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:47:28 +01:00
David Gibson
330b5db77d inany: Add inany_ntop() helper
Add this helper to format an inany into either IPv4 or IPv6 text
format as appropriate.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:47:25 +01:00
David Gibson
d31277e292 inany: Helper to test for various address types
Add helpers to determine if an inany is loopback, unspecified or
multicast, regardless of whether it's a "true" IPv6 address or an IPv4
address represented as v4-mapped.

Use the loopback helper to simplify tcp_splice_conn_from_sock() slightly.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 09:47:21 +01:00
David Gibson
9a3fb5eb68 tap: Use write_remainder() in tap_send_frames_passt()
When we determine we have sent a partial frame in tap_send_frames_passt(),
we call tap_send_remainder() to send the remainder of it.  The logic in
that function is very similar to that in the more general write_remainder()
except that it uses send() instead of write()/writev().  But we are dealing
specifically with the qemu socket here, which is a connected stream socket.
In that case write()s do the same thing as send() with the options we were
using, so we can just reuse write_remainder().

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 06:35:03 +01:00
David Gibson
dda7945ca9 pcap: Handle short writes in pcap_frame()
Currently pcap_frame() assumes that if write() doesn't return an error, it
has written everything we want.  That's not necessarily true, because it
could return a short write.  That's not likely to happen on a regular file,
but there's not a lot of reason not to be robust here; it's conceivable we
might want to direct the pcap fd at a named pipe or similar.

So, make pcap_frame() handle short frames by using the write_remainder()
helper.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
[sbrivio: Formatting fix, and avoid gcc warning in pcap_frame()]
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 06:35:01 +01:00
David Gibson
8bdb0883b4 util: Add write_remainder() helper
We have several places where we want to write(2) a buffer or buffers and we
handle short write()s by retrying until everything is successfully written.
Add a helper for this in util.c.

This version has some differences from the typical write_all() function.
First, take an IO vector rather than a single buffer, because that will be
useful for some of our cases.  Second, allow it to take an parameter to
skip the first n bytes of the given buffers.  This will be useful for some
of the cases we want, and also falls out quite naturally from the
implementation.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
[sbrivio: Minor formatting fixes in write_remainder()]
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 06:25:17 +01:00
David Gibson
24410b37a4 pcap: Update pcap_frame() to take an iovec and offset
Update the low-level helper pcap_frame() to take a struct iovec and
offset within it, rather than an explicit pointer and length for the
frame.  This moves the handling of an offset (to skip vnet_len) from
pcap_multiple() to pcap_frame().

This doesn't accomplish a great deal immediately, but will make
subsequent changes easier.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 06:24:10 +01:00
David Gibson
64b63d9e3e iov: Add helper to find skip over first n bytes of an io vector
Several of the IOV functions in iov.c, and also tap_send_frames_passt()
needs to determine which buffer element a byte offset into an IO vector
lies in.  Split this out into a helper function iov_skip_bytes().

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 06:24:07 +01:00
Laurent Vivier
2a6f8bcca7 iov: add some functions to manage iovec
Introduce functions to copy to/from a buffer from/to an iovec array,
to compute data length in in bytes of an iovec and to copy memory from
an iovec to another.

iov_from_buf(), iov_to_buf(), iov_size(), iov_copy().

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-ID: <20240217150725.661467-2-lvivier@redhat.com>
[dwg: Small changes to suppress cppcheck warnings]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 06:23:49 +01:00
David Gibson
90f1d3b354 udp: Remove unnecessary test for unspecified addr_out
If the configured output address is unspecified, we don't set the bind
address to it when creating a new socket in udp_tap_handler().  That sounds
sensible, but what we're leaving the bind address as is, exactly, the
unspecified address, so this test makes no difference.  Remove it.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 06:23:47 +01:00
David Gibson
745fa38169 udp: Fix incorrect usage of IPv6 state in IPv4 path
When forwarding IPv4 packets in udp_tap_handler(), we incorrectly use an
IPv6 address test on our IPv4 address (which could cause an out of bounds
access), and possibly set our bind interface to the IPv6 interface based on
it.  Adjust to correctly look at the IPv4 address and IPv4 interface.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 05:41:03 +01:00
David Gibson
deea5a8437 udp: Small streamline to udp_update_hdr4()
Streamline the logic here slightly, by introducing a 'src' temporary for
brevity.  We also transform the logic for setting/clearing PORT_LOOPBACK.
This makes udp_update_hdr4() more closely match the corresponding logic
from udp_update_udp6().

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 05:41:01 +01:00
David Gibson
bc2d0d381c udp: Set pif in epoll reference for ephemeral host sockets
The udp_epoll_ref contains a field for the pif to which the socket belongs.
We fill this in for permanent sockets created with udp_sock_init() and for
spliced sockets, however, we omit it for ephemeral sockets created for
tap originated flows.

This is a bug, although we currently get away with it, because we don't
consult that field for such flows.  Correctly fill it in.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 05:40:59 +01:00
David Gibson
720d777a69 udp: Don't attempt to translate a 0.0.0.0 source address
If an incoming packet has a source address of 0.0.0.0 we translate that to
the gateway address.  This doesn't really make sense, because we have no
way to do a reverse translation for reply packets.

Certain UDP protocols do use an unspecified source address in some
circumstances (e.g. DHCP).  These generally either require no reply, a
multicast reply, or provide a suitable reply address by other means.

In none of those cases does translating it in passt/pasta make sense.  The
best we can really do here is just leave it as is.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-29 05:40:46 +01:00
Stefano Brivio
bee61dd7d0 conf: If no interface with a default route was found, say it
...instead of implying that by stating that there's no routable
interface for a given IP version. There might be interfaces with
non-default routes.

Suggested-by: Paul Holzinger <pholzing@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Paul Holzinger <pholzing@redhat.com>
2024-02-28 18:57:49 +01:00
Stefano Brivio
925af4ef82 Makefile: check for cppcheck's --check-level option in cppcheck target
Don't run cppcheck to find out if the --check-level=exhaustive option
is available, unless we're actually going to run cppcheck later.

To avoid this, move this check under the cppcheck target, and
implement it in shell script instead of using Makefile directives,
because we can't easily implement conditionals in recipes.

Reported-by: Rahil Bhimjiani <me@rahil.website>
Link: https://bugs.gentoo.org/920795
Fixes: 8640d62af7 ("cppcheck: Use "exhaustive" level checking when available")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2024-02-28 18:57:30 +01:00
Paul Holzinger
15001b39ef conf: set the log level much earlier
--quiet is supposed to silence the "No routable interface" message but
it does not work because the log level was set long after conf_ip4/6()
was called which means it uses the default level which logs everything.

To address this move the log level logic directly after the option
parsing in conf().

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-27 14:08:33 +01:00
Paul Holzinger
b08716551a passt: make --quiet set the log level to warning
Based on the man page and help output --quiet hides informational
messages. This means that warnings should still be logged. This was
discussed in[1].

[1] https://archives.passt.top/passt-dev/20240216114304.7234a83f@elisabeth/T/#m42652824644973674e84baf9e0bf1d0e88104450

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-27 14:08:00 +01:00
David Gibson
e5e6f29459 tcp: Don't store errnos in socket pool
If tcp_sock_refill_pool() gets an error opening new sockets, it stores the
negative errno of that error in the socket pool.  This isn't especially
useful:
  * It's inconsistent with the initial state of the pool (all -1)
  * It's inconsistent with the state of an entry that was valid and was
    then consumed (also -1)
  * By the time we did anything with this error code, it's now far removed
    from the situation in which the error occurred, making it difficult to
    report usefully

We now have error reporting closer to when failures happen on the refill
paths, so just leave a pool slot we can't fill as -1.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-02-27 12:53:30 +01:00