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* doc: Trivial fix for reuseaddr-priorityDavid Gibson2024-07-151-1/+1
| | | | | | | | | | | | | This test program checks for particular behaviour regardless of order of operations. So, we step through the test with all possible orders for a number of different of parts. Or at least, we're supposed to, a copy pasta error led to using the same order for two things which should be independent. Fixes: 299c40750137 ("doc: Add program to document and test assumptions about SO_REUSEADDR") Reported-by: David Taylor <davidt@yadt.co.uk> Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* doc: Test behaviour of zero length datagram recv()sDavid Gibson2024-07-053-3/+78
| | | | | | | | Add a test program verifying that we're able to discard datagrams from a socket without needing a big discard buffer, by using a zero length recv(). Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* doc: Add program to document and test assumptions about SO_REUSEADDRDavid Gibson2024-07-056-0/+417
| | | | | | | | | | | | | | For the approach we intend to use for handling UDP flows, we have some pretty specific requirements about how SO_REUSEADDR works with UDP sockets. Specifically SO_REUSEADDR allows multiple sockets with overlapping bind()s, and therefore there can be multiple sockets which are eligible to receive the same datagram. Which one will actually receive it is important to us. Add a test program which verifies things work the way we expect, which documents what those expectations are in the process. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* passt: Relicense to GPL 2.0, or any later versionStefano Brivio2023-04-063-3/+3
| | | | | | | | | | | | | | | | | | | In practical terms, passt doesn't benefit from the additional protection offered by the AGPL over the GPL, because it's not suitable to be executed over a computer network. Further, restricting the distribution under the version 3 of the GPL wouldn't provide any practical advantage either, as long as the passt codebase is concerned, and might cause unnecessary compatibility dilemmas. Change licensing terms to the GNU General Public License Version 2, or any later version, with written permission from all current and past contributors, namely: myself, David Gibson, Laine Stump, Andrea Bolognani, Paul Holzinger, Richard W.M. Jones, Chris Kuhn, Florian Weimer, Giuseppe Scrivano, Stefan Hajnoczi, and Vasiliy Ulyanov. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* doc/demo: Fix and suppress ShellCheck warningsStefano Brivio2023-02-271-1/+3
| | | | | | | | | | | | ShellCheck reports (SC2034) that __qemu_arch is not used. Use it, and silence the resulting SC2086 warning as we want word splitting on options we pass with it. While at it, silence SC2317 warnings for commands in cleanup() that appear to be unreachable: cleanup() is only called as trap. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* doc/demo: Clone and use mbuto in init namespaceStefano Brivio2022-09-221-5/+17
| | | | | | | | ...and not in pasta's namespace: the fakeroot(1) version shipping with (at least) Fedora 36 assumes "nested" operation as it sees that the UID is 0, and claims it's not supported. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* doc/demo: Drop /sbin from dhclient command, pass script file explicitlyStefano Brivio2022-09-221-4/+4
| | | | | | | | | | | dhclient might be in /usr/sbin on recent versions of Fedora, and mbuto just adds it to the same location as it was on the host: just call dhclient instead of /sbin/dhclient. This also applies for dhclient-script: given that we create the file on boot, pass its explicit location with -sf. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* doc: Rewrite demo scriptStefano Brivio2022-08-181-109/+231
| | | | | | | | | | | | | | | The original demo script was written when pasta wasn't a thing yet, so it needed to run as root, set up a veth pair, and configure addresses and routes by itself. Now pasta can do all that for us, and become part of the demo as well. Further, extend it to start qemu, optionally preparing a basic demo image with mbuto (https://mbuto.sh), and execute one logical step at a time, for clarity. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* Don't abbreviate ip(8) arguments in examples and testsDavid Gibson2022-06-151-4/+4
| | | | | | | | ip(8)'s ability to take abbreviated arguments (e.g. "li sh" instead of "link show") is very handy when using it interactively, but it doesn't make for very readable scripts and examples when shown that way. Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
* README: Make it somewhat readable on mobile devicesStefano Brivio2022-03-044-0/+76
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* LICENSES: Add license text files, add missing notices, fix SPDX tagsStefano Brivio2021-10-202-0/+4
| | | | | | | | | | SPDX tags don't replace license files. Some notices were missing and some tags were not according to the SPDX specification, too. Now reuse --lint from the REUSE tool (https://reuse.software/) passes. Reported-by: Martin Hauke <mardnh@gmx.de> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* doc: Add source Excalidraw scene files for diagramsStefano Brivio2021-09-272-0/+7984
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* doc/demo: Also forward all UDP ports from namespaceStefano Brivio2021-09-011-1/+1
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* doc/demo: Explicitly run in foreground, drop pipe to catStefano Brivio2021-09-011-1/+1
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* doc/demo.sh: Pick IPv6 interface only if it has a nexthop routeStefano Brivio2021-08-041-1/+1
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* doc/demo.sh: Increase tcp_rmem and tcp_wmem before running passtStefano Brivio2021-07-261-0/+2
| | | | | | ...this is convenient for performance testing. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* doc/demo.sh: Set MTU to 65535 for both veth interfacesStefano Brivio2021-07-211-0/+2
| | | | | | There's no reason to limit the MTU here to any lower value. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* doc/demo.sh: Support IPv4-only environments tooStefano Brivio2021-07-171-12/+15
| | | | | | | If no IPv6 global addresses are available, proceed with just IPv4 addresses and routes. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* passt: Also log to stderr, don't fork to background if not interactiveStefano Brivio2021-05-211-1/+1
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* passt: Add support for multiple instances in different network namespacesStefano Brivio2021-05-211-27/+57
| | | | | | | | | | | | | ...sharing the same filesystem. Instead of a fixed path for the UNIX domain socket, passt now uses a path with a counter, probing for existing instances, and picking the first free one. The demo script is updated accordingly -- it can now be started several times to create multiple namespaces with an instance of passt each, with addressing reflecting separate subnets, and NDP proxying between them. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* doc/demo: Set send and receive buffers to 16MiBStefano Brivio2021-04-231-0/+6
| | | | | | | Otherwise, buffers for UNIX domain sockets are limited to about 200KB. This makes performance testing a bit more consistent. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* doc/demo: Bring up loopback interface in network namespaceStefano Brivio2021-04-221-0/+1
| | | | | | | Otherwise, connections to the local host (which becomes the guest, actually) will fail. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* doc/demo: Explicitly add route to guestStefano Brivio2021-04-221-0/+1
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* passt: Set soft limit for number of open files to hard limitStefano Brivio2021-03-181-1/+0
| | | | | | | | Default value for /proc/sys/fs/nr_open is 2^20, which is more than enough: set this hard limit as current (soft) limit on start, and drop the 'ulimit -n' from the demo script. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* passt: Introduce ICMP echo proxyStefano Brivio2021-03-181-0/+1
| | | | | | | | It's nice to be able to confirm connectivity using ICMP or ICMPv6 echo requests, and "ping" sockets on Linux (IPPROTO_ICMP datagram) allow us to do that without any special capability. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* passt: Assorted fixes from "fresh eyes" reviewStefano Brivio2021-02-211-1/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A bunch of fixes not worth single commits at this stage, notably: - make buffer, length parameter ordering consistent in ARP, DHCP, NDP handlers - strict checking of buffer, message and option length in DHCP handler (a malicious client could have easily crashed it) - set up forwarding for IPv4 and IPv6, and masquerading with nft for IPv4, from demo script - get rid of separate slow and fast timers, we don't save any overhead that way - stricter checking of buffer lengths as passed to tap handlers - proper dequeuing from qemu socket back-end: I accidentally trashed messages that were bundled up together in a single tap read operation -- the length header tells us what's the size of the next frame, but there's no apparent limit to the number of messages we get with one single receive - rework some bits of the TCP state machine, now passive and active connection closes appear to be robust -- introduce a new FIN_WAIT_1_SOCK_FIN state indicating a FIN_WAIT_1 with a FIN flag from socket - streamline TCP option parsing routine - track TCP state changes to stderr (this is temporary, proper debugging and syslogging support pending) - observe that multiplying a number by four might very well change its value, and this happens to be the case for the data offset from the TCP header as we check if it's the same as the total length to find out if it's a duplicated ACK segment - recent estimates suggest that the duration of a millisecond is closer to a million nanoseconds than a thousand of them, this trend is now reflected into the timespec_diff_ms() convenience routine Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* passt: New design and implementation with native Layer 4 socketsStefano Brivio2021-02-161-0/+69
This is a reimplementation, partially building on the earlier draft, that uses L4 sockets (SOCK_DGRAM, SOCK_STREAM) instead of SOCK_RAW, providing L4-L2 translation functionality without requiring any security capability. Conceptually, this follows the design presented at: https://gitlab.com/abologna/kubevirt-and-kvm/-/blob/master/Networking.md The most significant novelty here comes from TCP and UDP translation layers. In particular, the TCP state and translation logic follows the intent of being minimalistic, without reimplementing a full TCP stack in either direction, and synchronising as much as possible the TCP dynamic and flows between guest and host kernel. Another important introduction concerns addressing, port translation and forwarding. The Layer 4 implementations now attempt to bind on all unbound ports, in order to forward connections in a transparent way. While at it: - the qemu 'tap' back-end can't be used as-is by qrap anymore, because of explicit checks now introduced in qemu to ensure that the corresponding file descriptor is actually a tap device. For this reason, qrap now operates on a 'socket' back-end type, accounting for and building the additional header reporting frame length - provide a demo script that sets up namespaces, addresses and routes, and starts the daemon. A virtual machine started in the network namespace, wrapped by qrap, will now directly interface with passt and communicate using Layer 4 sockets provided by the host kernel. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>