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* udp, udp_flow: Add instrumentation, handle EPOLLERR without queued errorspodman23686Stefano Brivio2024-09-043-14/+68
| | | | | Link: https://github.com/containers/podman/issues/23686#issuecomment-2324945010 Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* additional debugDavid Gibson2024-09-041-0/+6
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* tcp: Attempt to mitigate EPOLLRDHUP storms with half-closed connectionsDavid Gibson2024-09-041-4/+8
| | | | Link: https://github.com/containers/podman/issues/23686
* log: Don't prefix log file messages with time and severity if they're ↵Stefano Brivio2024-09-041-5/+9
| | | | | | | | | | | | | | | continuations In fecb1b65b1ac ("log: Don't prefix message with timestamp on --debug if it's a continuation"), I fixed this for --debug on standard error, but not for log files: if messages are continuations, they shouldn't be prefixed by timestamp and severity. Otherwise, we'll print stuff like this: 0.0028: ERROR: Receive error on guest connection, reset0.0028: ERROR: : Bad file descriptor Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* Makefile: Enable _FORTIFY_SOURCE iff neededMichal Privoznik2024-08-291-1/+8
| | | | | | | | | | | | | | | | | On some systems source fortification is enabled whenever code optimization is enabled (e.g. with -O2). Since code fortification is explicitly enabled too (with possibly different value than the system wants, there are three levels [1]), distros are required to patch our Makefile, e.g. [2]. Detect whether fortification is not already enabled and enable it explicitly only if really needed. 1: https://www.gnu.org/software/libc/manual/html_node/Source-Fortification.html 2: https://github.com/gentoo/gentoo/commit/edfeb8763ac56112c59248c62c9cda13e5d01c97 Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* fwd, conf: Probe host's ephemeral portsDavid Gibson2024-08-293-2/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | When we forward "all" ports (-t all or -u all), or use an exclude-only range, we don't actually forward *all* ports - that wouln't leave local ports to use for outgoing connections. Rather we forward all non-ephemeral ports - those that won't be used for outgoing connections or datagrams. Currently we assume the range of ephemeral ports is that recommended by RFC 6335, 49152-65535. However, that's not the range used by default on Linux, 32768-60999 but configurable with the net.ipv4.ip_local_port_range sysctl. We can't really know what range the guest will consider ephemeral, but if it differs too much from the host it's likely to cause problems we can't avoid anyway. So, using the host's ephemeral range is a better guess than using the RFC 6335 range. Therefore, add logic to probe the host's ephemeral range, falling back to the RFC 6335 range if that fails. This has the bonus advantage of reducing the number of ports bound by -t all -u all on most Linux machines thereby reducing kernel memory usage. Specifically this reduces kernel memory usage with -t all -u all from ~380MiB to ~289MiB. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* conf, fwd: Don't attempt to forward port 0David Gibson2024-08-291-2/+8
| | | | | | | | | | | | | | When using -t all, -u all or exclude-only ranges, we'll attempt to forward all non-ephemeral port numbers, including port 0. However, this won't work as intended: bind() treats a zero port not as literal port 0, but as "pick a port for me". Because of the special meaning of port 0, we mostly outright exclude it in our handling. Do the same for setting up forwards, not attempting to forward for port 0. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* conf, fwd: Make ephemeral port logic more flexibleDavid Gibson2024-08-294-7/+27
| | | | | | | | | | | | | | | | | | | | | | | | "Ephemeral" ports are those which the kernel may allocate as local port numbers for outgoing connections or datagrams. Because of that, they're generally not good choices for listening servers to bind to. Thefore when using -t all, -u all or exclude-only ranges, we map only non-ephemeral ports. Our logic for this is a bit rigid though: we assume the ephemeral ports are always a fixed range at the top of the port number space. We also assume PORT_EPHEMERAL_MIN is a multiple of 8, or we won't set the forward bitmap correctly. Make the logic in conf.c more flexible, using a helper moved into fwd.[ch], although we don't change which ports we consider ephemeral (yet). The new handling is undoubtedly more computationally expensive, but since it's a once-off operation at start off, I don't think it really matters. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* seccomp.sh: Try to account for terminal width while formatting list of ↵Stefano Brivio2024-08-271-1/+4
| | | | | | | | | | system calls Avoid excess lines on wide terminals, but make sure we don't fail if we can't fetch the number of columns for any reason, as it's not a fundamental feature and we don't want to break anything with it. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Use dual stack sockets for port forwarding when possibleDavid Gibson2024-08-271-0/+19
| | | | | | | | | | | | | | | | | | | Platforms like Linux allow IPv6 sockets to listen for IPv4 connections as well as native IPv6 connections. By doing this we halve the number of listening sockets we need (assuming passt/pasta is listening on the same ports for IPv4 and IPv6). When forwarding many ports (e.g. -u all) this can significantly reduce the amount of kernel memory that passt consumes. We've used such dual stack sockets for TCP since 8e914238b "tcp: Use dual stack sockets for port forwarding when possible". Add similar support for UDP "listening" sockets. Since UDP sockets don't use as much kernel memory as TCP sockets this isn't as big a saving, but it's still significant. When forwarding all TCP and UDP ports for both IPv4 & IPv6 (-t all -u all), this reduces kernel memory usage from ~522 MiB to ~380MiB (kernel version 6.10.6 on Fedora 40, x86_64). Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Remove unnnecessary local from udp_sock_init()David Gibson2024-08-271-15/+15
| | | | | | | | The 's' variable is always redundant with either 'r4' or 'r6', so remove it. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Merge udp[46]_mh_recv arraysDavid Gibson2024-08-272-39/+17
| | | | | | | | | | | | | | | | | | | | | | We've already gotten rid of most of the IPv4/IPv6 specific data structures in udp.c by merging them with each other. One significant one remains: udp[46]_mh_recv. This was a bit awkward to remove because of a subtle interaction. We initialise the msg_namelen fields to represent the total size we have for a socket address, but when we receive into the arrays those are modified to the actual length of the sockaddr we received. That meant that naively merging the arrays meant that if we received IPv4 datagrams, then IPv6 datagrams, the addresses for the latter would be truncated. In this patch address that by resetting the received msg_namelen as soon as we've found a flow for the datagram. Finding the flow is the only thing that might use the actual sockaddr length, although we in fact don't need it for the time being. This also removes the last use of the 'v6' field from udp_listen_epoll_ref, so remove that as well. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* test: Look for possible sshd-session paths (if it's there at all) in mbuto's ↵Stefano Brivio2024-08-271-2/+9
| | | | | | | | | | | | | | | | | | | | | profile Some distributions already have OpenSSH 9.8, which introduces split sshd/sshd-session binaries, and there we need to copy the binary from the host, which can be /usr/libexec/openssh/sshd-session (Fedora Rawhide), /usr/lib/ssh/sshd-session (Arch Linux), /usr/lib/openssh/sshd-session (Debian), and possibly other paths. Add at least those three, and, if we don't find sshd-session, assume we don't need it: it could very well be an older version of OpenSSH, as reported by David for Fedora 40, or perhaps another daemon (would Dropbear even work? I'm not sure). Reported-by: David Gibson <david@gibson.dropbear.id.au> Fixes: d6817b3930be ("test/passt.mbuto: Install sshd-session OpenSSH's split process") Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Tested-by: David Gibson <david@gibson.dropbear.id.au>
* README: pasta is indeed a supported back-end for rootless Docker2024_08_21.1d6142fStefano Brivio2024-08-211-1/+3
| | | | | | | ...https://github.com/moby/moby/issues/48257 just reminded me. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* util: Don't stop on unrelated values when looking for --fd in close_open_files()Stefano Brivio2024-08-212-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Seen with krun: we get a file descriptor via --fd, but we close it and happily use the same number for TCP files. The issue is that if we also get other options before --fd, with arguments, getopt_long() stops parsing them because it sees them as non-option values. Use the - modifier at the beginning of optstring (before :, which is needed to avoid printing errors) instead of +, which means we'll continue parsing after finding unrelated option values, but getopt_long() won't reorder them anyway: they'll be passed with option value '1', which we can ignore. By the way, we also need to add : after F in the optstring, so that we're able to parse the option when given as short name as well. Now that we change the parsing mode between close_open_files() and conf(), we need to reset optind to 0, not to 1, whenever we call getopt_long() again in conf(), so that the internal initialisation of getopt_long() evaluating GNU extensions is re-triggered. Link: https://github.com/slp/krun/issues/17#issuecomment-2294943828 Fixes: baccfb95ce0e ("conf: Stop parsing options at first non-option argument") Fixes: 09603cab28f9 ("passt, util: Close any open file that the parent might have leaked") Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* test: Update list of dependencies in README.mdStefano Brivio2024-08-211-4/+5
| | | | | | | Mostly packages we now need to run Podman-based tests. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* tcp, udp: Allow timerfd_gettime64() and recvmmsg_time64() on arm (armhf)Stefano Brivio2024-08-212-2/+2
| | | | | | | | | | | | | These system calls are needed after the conversion of time_t to 64-bit types on 32-bit architectures. Tested by running some transfer tests with passt and pasta on Debian Bookworm (glibc 2.36) and Trixie (glibc 2.39), running on armv6l. Suggested-by: Faidon Liambotis <paravoid@debian.org> Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1078981 Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* util: Provide own version of close_range(), and no-op fallbackStefano Brivio2024-08-211-0/+22
| | | | | | | | | | | | | | | musl, as of 1.2.5, and glibc < 2.34 don't ship a (trivial) close_range() implementation. This will probably be added to musl soon, by the way: https://www.openwall.com/lists/musl/2024/08/01/9 Add a weakly-aliased implementation, if it's supported by the kernel. If it's not supported (< 5.9), use a no-op fallback. Looping over 2^31 file descriptors calling close() on them is probably not a good idea. Reported-by: lemmi <lemmi@nerd2nerd.org> Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* udp_flow: Add missing unistd.h include for close()Stefano Brivio2024-08-211-0/+1
| | | | | | | | For some reason, this is reported only with musl, and older glibc versions (2.31, at least). Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* test: Duplicate existing recvfrom() valgrind suppression for recv()Stefano Brivio2024-08-211-0/+9
| | | | | | | | | Some architectures, including i686, actually have a recv() system call, not just a recvfrom(), and we need to cover the recv() with MSG_TRUNC into a NULL buffer for them as well. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* test/passt.mbuto: Install sshd-session OpenSSH's split processStefano Brivio2024-08-211-1/+2
| | | | | | | | | | OpenSSH now ships a per-session binary, sshd-session, with sshd acting as mere listener. It's typically not found in $PATH, so specify the whole path at which it's commonly installed in $PROGS. Link: https://www.openssh.com/releasenotes.html#9.8p1 Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* test/passt.mbuto: Run sshd from vsock proxy with absolute pathStefano Brivio2024-08-211-1/+1
| | | | | | | | | | | ...OpenSSH >= 9.8 otherwise complains that: sshd requires execution with an absolute path Link: https://bugs.gentoo.org/936041 Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1078429 Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* test/lib/setup: Transform i686 kernel architecture name into QEMU name (i386)Stefano Brivio2024-08-211-4/+6
| | | | | | | | It's qemu-system-i386, but uname -m reports i686. I didn't test i486 and i586. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* treewide: Allow additional system calls for i386/i686Stefano Brivio2024-08-218-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I haven't tested i386 for a long time (after playing with some openSUSE i586 image a couple of years ago). It turns out that a number of system calls we actually need were denied by the seccomp filter, and not even basic functionality works. Add some system calls that glibc started using with the 64-bit time ("t64") transition, see also: https://wiki.debian.org/ReleaseGoals/64bit-time that is: clock_gettime64, timerfd_gettime64, fcntl64, and recvmmsg_time64. Add further system calls that are needed regardless of time_t width, that is, mmap2 (valgrind profile only), _llseek and sigreturn (common outside x86_64), and socketcall (same as s390x). I validated this against an almost full run of the test suite, with just a few selected tests skipped. Fixes needed to run most tests on i386/i686, and other assorted fixes for tests, are included in upcoming patches. Reported-by: Uroš Knupleš <uros@knuples.net> Analysed-by: Faidon Liambotis <paravoid@debian.org> Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1078981 Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* fwd, conf: Allow NAT of the guest's assigned addressDavid Gibson2024-08-214-17/+60
| | | | | | | | | | | | | | | | | | | The guest is usually assigned one of the host's IP addresses. That means it can't access the host itself via its usual address. The --map-host-loopback option (enabled by default with the gateway address) allows the guest to contact the host. However, connections forwarded this way appear on the host to have originated from the loopback interface, which isn't always desirable. Add a new --map-guest-addr option, which acts similarly but forwarded connections will go to the host's external address, instead of loopback. If '-a' is used, so the guest's address is not the same as the host's, this will instead forward to whatever host-visible site is shadowed by the guest's assigned address. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* fwd: Distinguish translatable from untranslatable addresses on inboundDavid Gibson2024-08-211-1/+8
| | | | | | | | | | | | fwd_nat_from_host() needs to adjust the source address for new flows coming from an address which is not accessible to the guest. Currently we always use our_tap_addr or our_tap_ll. However in cases where the address is accessible to the guest via translation (i.e. via --map-host-loopback) then it makes more sense to use that translation, rather than the fallback mapping of our_tap_*. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* conf: Allow address remapped to host to be configuredDavid Gibson2024-08-2111-95/+237
| | | | | | | | | | | | | | | | | | | | | Because the host and guest share the same IP address with passt/pasta, it's not possible for the guest to directly address the host. Therefore we allow packets from the guest going to a special "NAT to host" address to be redirected to the host, appearing there as though they have both source and destination address of loopback. Currently that special address is always the address of the default gateway (or none). That can be a problem if we want that gateway to be addressable by the guest. Therefore, allow the special "NAT to host" address to be overridden on the command line with a new --map-host-loopback option. In order to exercise and test it, update the passt_in_ns and perf tests to use this option and give different mapping addresses for the two layers of the environment. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* test: Reconfigure IPv6 address after changing MTUDavid Gibson2024-08-211-0/+4
| | | | | | | | | | | | | | | | | | | | In the TCP throughput tests, we adjust the guest's MTU in order to test various packet sizes. Some of those are below 1280 which causes IPv6 to be deconfigured on the guest interface. When we increase it above 1280 again, IPv6 is re-enabled and we get an address in the right prefix with NDP, but we don't get exactly the expected address back - that's only communicated with --config-net or DHCPv6. With changes to how we handle NAT this can cause some of the IPv6 tests to fail, because they don't use the address that passt/pasta expects, and the guest doesn't initiate any traffic which allows us to learn what the new address is. Work around this by re-invoking dhclient -6 between adjusting the MTU and running IPv6 test cases. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* conf, fwd: Split notion of gateway/router from guest-visible host addressDavid Gibson2024-08-215-42/+55
| | | | | | | | | | | | | | | | | | | | | | | The @gw fields in the ip4_ctx and ip6_ctx give the (host's) default gateway. We use this for two quite distinct things: advertising the gateway that the guest should use (via DHCP, NDP and/or --config-net) and for a limited form of NAT. So that the guest can access services on the host, we map the gateway address within the guest to the loopback address on the host. Using the gateway address for this isn't necessarily the best choice for this purpose, certainly not for all circumstances. So, start off by splitting the notion of these into two different values: @guest_gw which is the gateway address the guest should use and @nat_host_loopback, which is the guest visible address to remap to the host's loopback. Usually nat_host_loopback will have the same value as guest_gw. However when --no-map-gw is specified we leave them unspecified instead. This means when we use nat_host_loopback, we don't need to separately check c->no_map_gw to see if it's relevant. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* Don't take "our" MAC address from the hostDavid Gibson2024-08-213-35/+13
| | | | | | | | | | | | | | | | | | | | | | When sending frames to the guest over the tap link, we need a source MAC address. Currently we take that from the MAC address of the main interface on the host, but that doesn't actually make much sense: * We can't preserve the real MAC address of packets from anywhere external so there's no transparency case here * In fact, it's confusingly different from how we handle IP addresses: whereas we give the guest the same IP as the host, we're making the host's MAC the one MAC that the guest *can't* use for itself. * We already need a fallback case if the host doesn't have an Ethernet like MAC (e.g. if it's connected via a point to point interface, such as a wireguard VPN). Change to just just use an arbitrary fixed MAC address - I've picked 9a:55:9a:55:9a:55. It's simpler and has the small advantage of making the fact that passt/pasta is in use typically obvious from guest side packet dumps. This can still, of course, be overridden with the -M option. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* fwd: Split notion of "our tap address" from gateway for IPv4David Gibson2024-08-213-7/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ip4.gw conflates 3 conceptually different things, which (for now) have the same value: 1. The router/gateway address as seen by the guest 2. An address to NAT to the host with --no-map-gw isn't specified 3. An address to use as source when nothing else makes sense Case 3 occurs in two situations: a) for our DHCP responses - since they come from passt internally there's no naturally meaningful address for them to come from b) for forwarded connections coming from an address that isn't guest accessible (localhost or the guest's own address). (b) occurs even with --no-map-gw, and the expected behaviour of forwarding local connections requires it. For IPv6 role (3) is now taken by ip6.our_tap_ll (which usually has the same value as ip6.gw). For future flexibility we may want to make this "address of last resort" different from the gateway address, so split them logically for IPv4 as well. Specifically, add a new ip4.our_tap_addr field for the address with this role, and initialise it to ip4.gw for now. Unlike IPv6 where we can always get a link-local address, we might not be able to get a (non 0.0.0.0) address here (e.g. if the host is disconnected or only has a point to point link with no gateway address). In that case we have to disable forwarding of inbound connections with guest-inaccessible source addresses. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* fwd: Helpers to clarify what host addresses aren't guest accessibleDavid Gibson2024-08-211-11/+87
| | | | | | | | | | | | | | | | | | | We usually avoid NAT, but in a few cases we need to apply address translations. For inbound connections that happens for addresses which make sense to the host but are either inaccessible, or mean a different location from the guest's point of view. Add some helper functions to determine such addresses, and use them in fwd_nat_from_host(). In doing so clarify some of the reasons for the logic. We'll also have further use for these helpers in future. While we're there fix one unneccessary inconsistency between IPv4 and IPv6. We always translated the guest's observed address, but for IPv4 we didn't translate the guest's assigned address, whereas for IPv6 we did. Change this to translate both in all cases for consistency. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* Initialise our_tap_ll to ip6.gw when suitableDavid Gibson2024-08-214-12/+6
| | | | | | | | | In every place we use our_tap_ll, we only use it as a fallback if the IPv6 gateway address is not link-local. We can avoid that conditional at use time by doing it at initialisation of our_tap_ll instead. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* Clarify which addresses in ip[46]_ctx are meaningful whereDavid Gibson2024-08-211-4/+10
| | | | | | | | | Some are guest visible addresses and may not be valid on the host, others are host visible addresses and may not be valid on the guest. Rearrange and comment the ip[46]_ctx definitions to make it clearer which is which. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* treewide: Change misleading 'addr_ll' nameDavid Gibson2024-08-215-8/+9
| | | | | | | | | c->ip6.addr_ll is not like c->ip6.addr. The latter is an address for the guest, but the former is an address for our use on the tap link. Rename it accordingly, to 'our_tap_ll'. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* util: Correct sock_l4() binding for link local addressesDavid Gibson2024-08-211-2/+1
| | | | | | | | | | | | | | | | | When binding an IPv6 socket in sock_l4() we need to supply a scope id if the address is link-local. We check for this by comparing the given address to c->ip6.addr_ll. This is correct only by accident: while c->ip6.addr_ll is typically set to the host interface's link local address, the actual purpose of it is to provide a link local address for passt's private use on the tap interface. Instead set the scope id for any link-local address we're binding to. We're going to need something and this is what makes sense for sockets on the host. It doesn't make sense for PIF_SPLICE sockets, but those should always have loopback, not link-local addresses. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* conf: Remove incorrect initialisation of addr_ll_seenDavid Gibson2024-08-211-1/+0
| | | | | | | | | | | | Despite the names, addr_ll_seen does not relate to addr_ll the same way addr_seen relates to addr. addr_ll_seen is an observed address from the guest, whereas addr_ll is *our* link-local address for use on the tap link when we can't use an external endpoint address. It's used both for passt provided services (DHCPv6, NDP) and in some cases for connections from addresses the guest can't access. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* conf: Treat --dns addresses as guest visible addressesDavid Gibson2024-08-212-50/+52
| | | | | | | | | | | | | | | | | | | | Although it's not 100% explicit in the man page, addresses given to the --dns option are intended to be addresses as seen by the guest. This differs from addresses taken from the host's /etc/resolv.conf, which must be translated to guest accessible versions in some cases. Our implementation is currently inconsistent on this: when using --dns-forward, you must usually also give --dns with the matching address, which is meaningful only in the guest's address view. However if you give --dns with a loopback addres, it will be translated like a host view address. Move the remapping logic for DNS addresses out of add_dns4() and add_dns6() into add_dns_resolv() so that it is only applied for host nameserver addresses, not for nameservers given explicitly with --dns. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* conf: Correct setting of dns_match address in add_dns6()David Gibson2024-08-211-1/+1
| | | | | | | | | | | | | | add_dns6() (but not add_dns4()) has a bug setting dns_match: it sets it to the given address, rather than the gateway address. This is doubly wrong: - We've just established the given address is a host loopback address the guest can't access - We've just set ip6.dns[] to tell the guest to use the gateway address, so it won't use the dns_match address we're setting Correct this to use the gateway address, like IPv4. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* conf: Move adding of a nameserver from resolv.conf into subfunctionDavid Gibson2024-08-211-7/+26
| | | | | | | | | get_dns() is already quite deeply nested, and future changes I have in mind will add more complexity. Prepare for this by splitting out the adding of a single nameserver to the configuration into its own function. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* conf: Move DNS array bounds checks into add_dns[46]David Gibson2024-08-211-8/+10
| | | | | | | | | | | | | Every time we call add_dns[46] we need to first check if there's space in the c->ip[46].dns array for the new entry. We might as well make that check in add_dns[46]() itself. In fact it looks like the calls in get_dns() had an off by one error, not allowing the last entry of the array to be filled. So, that bug is also fixed by the change. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* conf: More accurately count entries added in get_dns()David Gibson2024-08-211-8/+3
| | | | | | | | | | get_dns() counts the number of guest DNS servers it adds, and gives an error if it couldn't add any. However, this count ignores the fact that add_dns[46]() may in some cases *not* add an entry. Use the array indices we're already tracking to get an accurate count. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* conf: Use array indices rather than pointers for DNS array slotsDavid Gibson2024-08-211-32/+41
| | | | | | | | | | | | Currently add_dns[46]() take a somewhat awkward double pointer to the entry in the c->ip[46].dns array to update. It turns out to be easier to work with indices into that array instead. This diff does add some lines, but it's comments, and will allow some future code reductions. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* treewide: Use struct assignment instead of memcpy() for IP addressesDavid Gibson2024-08-212-10/+12
| | | | | | | | | | | We rely on C11 already, so we can use clearer and more type-checkable struct assignment instead of mempcy() for copying IP addresses around. This exposes some "pointer could be const" warnings from cppcheck, so address those too. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* treewide: Rename MAC address fields for clarityDavid Gibson2024-08-218-26/+28
| | | | | | | | | | | c->mac isn't a great name, because it doesn't say whose mac address it is and it's not necessarily obvious in all the contexts we use it. Since this is specifically the address that we (passt/pasta) use on the tap interface, rename it to "our_tap_mac". Rename the "mac_guest" field to "guest_mac" to be grammatically consistent. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* util: Helper for formatting MAC addressesDavid Gibson2024-08-214-7/+27
| | | | | | | | | There are a couple of places where we somewhat messily open code formatting an Ethernet like MAC address for display. Add an eth_ntop() helper for this. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* treewide: Use "our address" instead of "forwarding address"David Gibson2024-08-217-105/+106
| | | | | | | | | | | | The term "forwarding address" to indicate the local-to-passt address was well-intentioned, but ends up being kinda confusing. As discussed on a recent call, let's try "our" instead. (While we're there correct an error in flow_initiate_af()s comments where we referred to parameters by the wrong name). Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Fix typo in function comment for nl_addr_set()Stefano Brivio2024-08-181-1/+1
| | | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* pasta: Disable neighbour solicitations on device up to prevent DADStefano Brivio2024-08-181-1/+10
| | | | | | | | | | | | | | | | | | | As soon as we the kernel notifier for IPv6 address configuration (addrconf_notify()) sees that we bring the target interface up (NETDEV_UP), it will schedule duplicate address detection, so, by itself, setting the nodad flag later is useless, because that won't stop a detection that's already in progress. However, if we disable neighbour solicitations with IFF_NOARP (which is a misnomer for IPv6 interfaces, but there's no possibility of mixing things up), the notifier will not trigger DAD, because it can't be done, of course, without neighbour solicitations. Set IFF_NOARP as we bring up the device, and drop it after we had a chance to set the nodad attribute on the link. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* netlink, pasta: Fetch link-local address from namespace interface once it's upStefano Brivio2024-08-183-0/+55
| | | | | | | | | | 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>