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* README, hooks: Build HTML man page on push, add a linkStefano Brivio2022-02-211-0/+2
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* passt, pasta: Namespace-based sandboxing, defer seccomp policy applicationStefano Brivio2022-02-211-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To reach (at least) a conceptually equivalent security level as implemented by --enable-sandbox in slirp4netns, we need to create a new mount namespace and pivot_root() into a new (empty) mountpoint, so that passt and pasta can't access any filesystem resource after initialisation. While at it, also detach IPC, PID (only for passt, to prevent vulnerabilities based on the knowledge of a target PID), and UTS namespaces. With this approach, if we apply the seccomp filters right after the configuration step, the number of allowed syscalls grows further. To prevent this, defer the application of seccomp policies after the initialisation phase, before the main loop, that's where we expect bad things to happen, potentially. This way, we get back to 22 allowed syscalls for passt and 34 for pasta, on x86_64. While at it, move #syscalls notes to specific code paths wherever it conceptually makes sense. We have to open all the file handles we'll ever need before sandboxing: - the packet capture file can only be opened once, drop instance numbers from the default path and use the (pre-sandbox) PID instead - /proc/net/tcp{,v6} and /proc/net/udp{,v6}, for automatic detection of bound ports in pasta mode, are now opened only once, before sandboxing, and their handles are stored in the execution context - the UNIX domain socket for passt is also bound only once, before sandboxing: to reject clients after the first one, instead of closing the listening socket, keep it open, accept and immediately discard new connection if we already have a valid one Clarify the (unchanged) behaviour for --netns-only in the man page. To actually make passt and pasta processes run in a separate PID namespace, we need to unshare(CLONE_NEWPID) before forking to background (if configured to do so). Introduce a small daemon() implementation, __daemon(), that additionally saves the PID file before forking. While running in foreground, the process itself can't move to a new PID namespace (a process can't change the notion of its own PID): mention that in the man page. For some reason, fork() in a detached PID namespace causes SIGTERM and SIGQUIT to be ignored, even if the handler is still reported as SIG_DFL: add a signal handler that just exits. We can now drop most of the pasta_child_handler() implementation, that took care of terminating all processes running in the same namespace, if pasta started a shell: the shell itself is now the init process in that namespace, and all children will terminate once the init process exits. Issuing 'echo $$' in a detached PID namespace won't return the actual namespace PID as seen from the init namespace: adapt demo and test setup scripts to reflect that. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* test: Add distribution tests for several architectures and kernel versionsStefano Brivio2022-01-281-2/+2
| | | | | | | | | | | | | | | The new tests check build and a simple case with pasta sending a short message in both directions (namespace to init, init to namespace). Tests cover a mix of Debian, Fedora, OpenSUSE and Ubuntu combinations on aarch64, i386, ppc64, ppc64le, s390x, x86_64. Builds tested starting from approximately glibc 2.19, gcc 4.7, and actual functionality approximately from 4.4 kernels, glibc 2.25, gcc 4.8, all the way up to current glibc/gcc/kernel versions. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* README: Fix link to IGMP/MLD proxy ticketStefano Brivio2022-01-281-1/+1
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* README: Fix anchor for Performance sectionStefano Brivio2022-01-271-1/+1
| | | | | | It shouldn't refer to the subsection under "Features". Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* seccomp: Add a number of alternate and per-arch syscallsStefano Brivio2022-01-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Depending on the C library, but not necessarily in all the functions we use, statx() might be used instead of stat(), getdents() instead of getdents64(), readlinkat() instead of readlink(), openat() instead of open(). On aarch64, it's clone() and not fork(), and dup3() instead of dup2() -- just allow the existing alternative instead of dealing with per-arch selections. Since glibc commit 9a7565403758 ("posix: Consolidate fork implementation"), we need to allow set_robust_list() for fork()/clone(), even in a single-threaded context. On some architectures, epoll_pwait() is provided instead of epoll_wait(), but never both. Same with newfstat() and fstat(), sigreturn() and rt_sigreturn(), getdents64() and getdents(), readlink() and readlinkat(), unlink() and unlinkat(), whereas pipe() might not be available, but pipe2() always is, exclusively or not. Seen on Fedora 34: newfstatat() is used on top of fstat(). syslog() is an actual system call on some glibc/arch combinations, instead of a connect()/send() implementation. On ppc64 and ppc64le, _llseek(), recv(), send() and getuid() are used. For ppc64 only: ugetrlimit() for the getrlimit() implementation, plus sigreturn() and fcntl64(). On s390x, additionally, we need to allow socketcall() (on top of socket()), and sigreturn() also for passt (not just for pasta). Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* README: Feature list, links to lists, bugs, chatStefano Brivio2021-10-231-10/+122
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* README, perf_report: Markdown and CSS fixesStefano Brivio2021-10-221-21/+22
| | | | | | Updating md2html on the server needs a few adjustments. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* README: .. doesn't actually work for comments in MarkdownStefano Brivio2021-10-201-3/+5
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* LICENSES: Add license text files, add missing notices, fix SPDX tagsStefano Brivio2021-10-201-0/+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>
* README: Drop domain part in absolute linksStefano Brivio2021-10-071-25/+25
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* README: Fix pasta anchor in Try it sectionStefano Brivio2021-09-281-1/+1
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* README: Add demo sectionStefano Brivio2021-09-271-0/+15
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* README: pasta mode, CI, performance, updated links, etc.Stefano Brivio2021-09-271-66/+185
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* README: Source jsStefano Brivio2021-09-181-0/+8
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* README: Mention the -DDEBUG flagStefano Brivio2021-05-101-0/+5
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Connection tracking for ephemeral, local ports, and related fixesStefano Brivio2021-04-291-4/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As we support UDP forwarding for packets that are sent to local ports, we actually need some kind of connection tracking for UDP. While at it, this commit introduces a number of vaguely related fixes for issues observed while trying this out. In detail: - implement an explicit, albeit minimalistic, connection tracking for UDP, to allow usage of ephemeral ports by the guest and by the host at the same time, by binding them dynamically as needed, and to allow mapping address changes for packets with a loopback address as destination - set the guest MAC address whenever we receive a packet from tap instead of waiting for an ARP request, and set it to broadcast on start, otherwise DHCPv6 might not work if all DHCPv6 requests time out before the guest starts talking IPv4 - split context IPv6 address into address we assign, global or site address seen on tap, and link-local address seen on tap, and make sure we use the addresses we've seen as destination (link-local choice depends on source address). Similarly, for IPv4, split into address we assign and address we observe, and use the address we observe as destination - introduce a clock_gettime() syscall right after epoll_wait() wakes up, so that we can remove all the other ones and pass the current timestamp to tap and socket handlers -- this is additionally needed by UDP to time out bindings to ephemeral ports and mappings between loopback address and a local address - rename sock_l4_add() to sock_l4(), no semantic changes intended - include <arpa/inet.h> in passt.c before kernel headers so that we can use <netinet/in.h> macros to check IPv6 address types, and remove a duplicate <linux/ip.h> inclusion Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* README: Don't let <canvas> steal pointer eventsStefano Brivio2021-04-131-1/+1
| | | | | | ...otherwise some links on the bottom won't be clickable. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* passt: Introduce a DHCPv6 serverStefano Brivio2021-04-131-11/+10
| | | | | | | | | | | | This implementation, similarly to the IPv4 DHCP one, hands out a single address, which is the same as the upstream address for the host. This avoids the need for address translation as long as the client runs a DHCPv6 client. The NDP "Managed" flag is now set in Router Advertisements. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* README: Add image map for overviewStefano Brivio2021-03-251-1/+86
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* passt: Add libvirt patch for qemu UNIX socket domain back-endStefano Brivio2021-03-211-1/+14
| | | | | | | | | | ...and mention it in the README. While at it, remove useless escaping in the README, and fix indentation in the syslog message with the qemu command line example. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* passt: Add the READMEStefano Brivio2021-03-181-0/+177
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>