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passt: Relicense to GPL 2.0, or any later version 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>
2023-04-05 18:11:44 +00:00
.\" SPDX-License-Identifier: GPL-2.0-or-later
man page: Update REPORTING BUGS section Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-02-19 03:39:47 +00:00
.\" Copyright (c) 2020-2022 Red Hat GmbH
LICENSES: Add license text files, add missing notices, fix SPDX tags 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>
2021-10-19 10:43:28 +00:00
.\" Author: Stefano Brivio <sbrivio@redhat.com>
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TH passt 1
.SH NAME
.B passt
\- Unprivileged user-mode network connectivity for virtual machines
.br
.B pasta
\- Unprivileged user-mode network connectivity for network namespaces
.SH SYNOPSIS
.B passt
[\fIOPTION\fR]...
.br
.B pasta
Allow pasta to take a command to execute When not given an existing PID or network namspace to attach to, pasta spawns a shell. Most commands which can spawn a shell in an altered environment can also run other commands in that same environment, which can be useful in automation. Allow pasta to do the same thing; it can be given an arbitrary command to run in the network and user namespace which pasta creates. If neither a command nor an existing PID or netns to attach to is given, continue to spawn a default shell, as before. Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-08-26 04:58:39 +00:00
[\fIOPTION\fR]... [\fICOMMAND\fR [\fIARG\fR]...]
.br
.B pasta
[\fIOPTION\fR]... \fIPID\fR
Use explicit --netns option rather than multiplexing with PID When attaching to an existing namespace, pasta can take a PID or the name or path of a network namespace as a non-option parameter. We disambiguate based on what the parameter looks like. Make this more explicit by using a --netns option for explicitly giving the path or name, and treating a non-option argument always as a PID. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> [sbrivio: Fix typo in man page] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-08-26 04:58:38 +00:00
.br
.B pasta
[\fIOPTION\fR]... \fB--netns\fR [\fIPATH\fR|\fINAME\fR]
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.SH DESCRIPTION
.SS passt
.B passt
(\fIP\fRlug \fIA\fR \fIS\fRimple \fIS\fRocket \fIT\fRransport) provides full,
quasi-native network connectivity to virtual machines in user-mode without
requiring any capabilities or privileges.
The data plane implements a translation layer between a Layer-2 virtual network
interface and native Layer-4 (TCP, UDP, ping) sockets on the host, giving the
illusion that application processes residing on the guest are running on the
local host, from a networking perspective.
Built-in ARP, DHCP, NDP, and DHCPv6 implementations are designed to provide the
guest with a network configuration that tightly resembles the host native
configuration. With the default options, guest and host share IP addresses,
routes, and port bindings.
Port forwarding and translation allow networking services running in the guest
to be reachable from both local and remote hosts.
Unlike \fBslirp4netns\fR(1), \fBpasst\fR doesn't implement a full TCP stack: the
TCP translation layer has no stateful data buffering and operates by reflecting
one peer's observed parameters (congestion window size, acknowledged data, etc.)
to the corresponding peer.
Currently, the only supported hypervisor is \fBqemu\fR(1), connecting to
passt, qrap, README: Update notes and documentation for AF_UNIX support in qemu We can't get rid of qrap quite yet, but at least we should start telling users it's not going to be needed anymore starting from qemu 7.2. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-11-04 01:38:31 +00:00
\fBpasst\fR by means of a UNIX domain socket. This is supported starting from
qemu 7.2. For older qemu versions, see the \fBqrap\fR(1) wrapper.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.SS pasta
.B pasta
(\fIP\fRack \fIA\fR \fIS\fRubtle \fIT\fRap \fIA\fRbstraction) provides
equivalent functionality to network namespaces, as the one offered by
\fBpasst\fR for virtual machines.
Allow pasta to take a command to execute When not given an existing PID or network namspace to attach to, pasta spawns a shell. Most commands which can spawn a shell in an altered environment can also run other commands in that same environment, which can be useful in automation. Allow pasta to do the same thing; it can be given an arbitrary command to run in the network and user namespace which pasta creates. If neither a command nor an existing PID or netns to attach to is given, continue to spawn a default shell, as before. Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-08-26 04:58:39 +00:00
If PID or --netns are given, \fBpasta\fR associates to an existing
user and network namespace. Otherwise, \fBpasta\fR creates a new user
and network namespace, and spawns the given command or a default shell
within this context. A \fItap\fR device within the network namespace
is created to provide network connectivity.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
For local TCP and UDP traffic only, \fBpasta\fR also implements a bypass path
directly mapping Layer-4 sockets between \fIinit\fR and target namespaces,
for performance reasons.
.SH OPTIONS
.TP
.BR \-d ", " \-\-debug
conf, passt.1: Don't imply --foreground with --debug Having -f implied by -d (and --trace) usually saves some typing, but debug mode in background (with a log file) is quite useful if pasta is started by Podman, and is probably going to be handy for passt with libvirt later, too. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2022-10-26 14:48:42 +00:00
Be verbose, don't log to the system logger.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
conf, util, tap: Implement --trace option for extra verbose logging --debug can be a bit too noisy, especially as single packets or socket messages are logged: implement a new option, --trace, implying --debug, that enables all debug messages. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-03-14 23:59:09 +00:00
.TP
.BR \-\-trace
conf, passt.1: Don't imply --foreground with --debug Having -f implied by -d (and --trace) usually saves some typing, but debug mode in background (with a log file) is quite useful if pasta is started by Podman, and is probably going to be handy for passt with libvirt later, too. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2022-10-26 14:48:42 +00:00
Be extra verbose, show single packets. Implies \fB--debug\fR.
conf, util, tap: Implement --trace option for extra verbose logging --debug can be a bit too noisy, especially as single packets or socket messages are logged: implement a new option, --trace, implying --debug, that enables all debug messages. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-03-14 23:59:09 +00:00
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
.BR \-q ", " \-\-quiet
Don't print informational messages.
.TP
.BR \-f ", " \-\-foreground
passt, pasta: Namespace-based sandboxing, defer seccomp policy application 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>
2022-02-07 20:11:37 +00:00
Don't run in background. This implies that the process is not moved to a
detached PID namespace after starting, because the PID itself cannot change.
passt: Fork into background also if not running from a terminal This is actually annoying: there's no way to make it fork into background when running from a script. However, it's always possible to keep it in foreground with -f. Make it simpler, and always fork into background if -f is not given. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-10-21 18:13:18 +00:00
Default is to fork into background.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
.BR \-e ", " \-\-stderr
Log to standard error too.
log, conf: Add support for logging to file In some environments, such as KubeVirt pods, we might not have a system logger available. We could choose to run in foreground, but this takes away the convenient synchronisation mechanism derived from forking to background when interfaces are ready. Add optional logging to file with -l/--log-file and --log-size. Unfortunately, this means we need to duplicate features that are more appropriately implemented by a system logger, such as rotation. Keep that reasonably simple, by using fallocate() with range collapsing where supported (Linux kernel >= 3.15, extent-based ext4 and XFS) and falling back to an unsophisticated block-by-block moving of entries toward the beginning of the file once we reach the (mandatory) size limit. While at it, clarify the role of LOG_EMERG in passt.c. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2022-10-06 12:51:04 +00:00
Default is to log to the system logger only, if started from an interactive
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
terminal, and to both system logger and standard error otherwise.
log, conf: Add support for logging to file In some environments, such as KubeVirt pods, we might not have a system logger available. We could choose to run in foreground, but this takes away the convenient synchronisation mechanism derived from forking to background when interfaces are ready. Add optional logging to file with -l/--log-file and --log-size. Unfortunately, this means we need to duplicate features that are more appropriately implemented by a system logger, such as rotation. Keep that reasonably simple, by using fallocate() with range collapsing where supported (Linux kernel >= 3.15, extent-based ext4 and XFS) and falling back to an unsophisticated block-by-block moving of entries toward the beginning of the file once we reach the (mandatory) size limit. While at it, clarify the role of LOG_EMERG in passt.c. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2022-10-06 12:51:04 +00:00
.TP
.BR \-l ", " \-\-log-file " " \fIPATH\fR
Log to file \fIPATH\fR, not to standard error, and not to the system logger.
.TP
.BR \-\-log-size " " \fISIZE\fR
Limit log file size to \fISIZE\fR bytes. When the log file is full, make room
for new entries by removing old ones at the beginning. This limit is mandatory.
Default is 1048576 (1 MiB).
conf: Add --runas option, changing to given UID and GID if started as root On some systems, user and group "nobody" might not be available. The new --runas option allows to override the default "nobody" choice if started as root. Now that we allow this, drop the initgroups() call that was used to add any additional groups for the given user, as that might now grant unnecessarily broad permissions. For instance, several distributions have a "kvm" group to allow regular user access to /dev/kvm, and we don't need that in passt or pasta. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-05-18 17:10:45 +00:00
.TP
.BR \-\-runas " " \fIUID\fR|\fIUID:GID\fR|\fILOGIN\fR|\fILOGIN:GROUP\fR
Split checking for root from dropping root privilege check_root() both checks to see if we are root (in the init namespace), and if we are drops to an unprivileged user. To make future cleanups simpler, split the checking for root (now in check_root()) from the actual dropping of privilege (now in drop_root()). Note that this does slightly alter semantics. Previously we would only setuid() if we were originally root (in the init namespace). Now we will always setuid() and setgid(), though it won't actually change anything if we weren't privileged to begin with. This also means that we will now always attempt to switch to the user specified with --runas, even if we aren't (init namespace) root to begin with. Obviously this will fail with an error if we weren't privileged to start with. --help and the man page are updated accordingly. Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-12 12:24:00 +00:00
Attempt to change to given UID and corresponding group if UID is given,
conf: Add --runas option, changing to given UID and GID if started as root On some systems, user and group "nobody" might not be available. The new --runas option allows to override the default "nobody" choice if started as root. Now that we allow this, drop the initgroups() call that was used to add any additional groups for the given user, as that might now grant unnecessarily broad permissions. For instance, several distributions have a "kvm" group to allow regular user access to /dev/kvm, and we don't need that in passt or pasta. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-05-18 17:10:45 +00:00
or to given UID and given GID if both are given. Alternatively, login name, or
Split checking for root from dropping root privilege check_root() both checks to see if we are root (in the init namespace), and if we are drops to an unprivileged user. To make future cleanups simpler, split the checking for root (now in check_root()) from the actual dropping of privilege (now in drop_root()). Note that this does slightly alter semantics. Previously we would only setuid() if we were originally root (in the init namespace). Now we will always setuid() and setgid(), though it won't actually change anything if we weren't privileged to begin with. This also means that we will now always attempt to switch to the user specified with --runas, even if we aren't (init namespace) root to begin with. Obviously this will fail with an error if we weren't privileged to start with. --help and the man page are updated accordingly. Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-12 12:24:00 +00:00
login name and group name can be passed. This requires privileges (either
initial effective UID 0 or CAP_SETUID capability) to work.
conf: Add --runas option, changing to given UID and GID if started as root On some systems, user and group "nobody" might not be available. The new --runas option allows to override the default "nobody" choice if started as root. Now that we allow this, drop the initgroups() call that was used to add any additional groups for the given user, as that might now grant unnecessarily broad permissions. For instance, several distributions have a "kvm" group to allow regular user access to /dev/kvm, and we don't need that in passt or pasta. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-05-18 17:10:45 +00:00
Default is to change to user \fInobody\fR if started as root.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
.BR \-h ", " \-\-help
Display a help message and exit.
conf, log, Makefile: Add versioning information Add a --version option displaying that, and also include this information in the log files. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-10-10 08:35:47 +00:00
.TP
.BR \-\-version
Show version and exit.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
.BR \-p ", " \-\-pcap " " \fIfile
Capture tap-facing (that is, guest-side or namespace-side) network packets to
\fIfile\fR in \fBpcap\fR format.
conf: Add -P, --pid, to specify a file where own PID is written to Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-10-14 10:17:47 +00:00
.TP
.BR \-P ", " \-\-pid " " \fIfile
Write own PID to \fIfile\fR once initialisation is done, before forking to
background (if configured to do so).
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
.BR \-m ", " \-\-mtu " " \fImtu
passt.1: Fix description of --mtu option By default, 65520 bytes are advertised, and zero disables DHCP and NDP options. Fixes: ec2b58ea4dc4 ("conf, dhcp, ndp: Fix message about default MTU, make NDP consistent") Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-03-15 09:06:50 +00:00
Assign \fImtu\fR via DHCP (option 26) and NDP (option type 5). A zero value
disables assignment.
By default, the advertised MTU is 65520 bytes, that is, the maximum 802.3 MTU
minus the length of a 802.3 header, rounded to 32 bits (IPv4 words).
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
.BR \-a ", " \-\-address " " \fIaddr
Assign IPv4 \fIaddr\fR via DHCP (\fByiaddr\fR), or \fIaddr\fR via DHCPv6 (option
5) and an \fIaddr\fR-based prefix via NDP Router Advertisement (option type 3)
for an IPv6 \fIaddr\fR.
This option can be specified zero (for defaults) to two times (once for IPv4,
once for IPv6).
passt.1: Default host interfaces are now selected based on IP version Reflect the changes from commit 4b2e018d70f3 ("Allow different external interfaces for IPv4 and IPv6 connectivity") into the manual. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-07-30 20:17:07 +00:00
By default, assigned IPv4 and IPv6 addresses are taken from the host interfaces
with the first default route for the corresponding IP version.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
.BR \-n ", " \-\-netmask " " \fImask
Assign IPv4 netmask \fImask\fR, expressed as dot-decimal or number of bits, via
DHCP (option 1).
By default, the netmask associated to the host address matching the assigned one
is used. If there's no matching address on the host, the netmask is determined
according to the CIDR block of the assigned address (RFC 4632).
.TP
.BR \-M ", " \-\-mac-addr " " \fIaddr
Use source MAC address \fIaddr\fR when communicating to the guest or to the
target namespace.
passt.1: Default host interfaces are now selected based on IP version Reflect the changes from commit 4b2e018d70f3 ("Allow different external interfaces for IPv4 and IPv6 connectivity") into the manual. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-07-30 20:17:07 +00:00
Default is to use the MAC address of the interface with the first IPv4 default
route on the host.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
.BR \-g ", " \-\-gateway " " \fIaddr
Assign IPv4 \fIaddr\fR as default gateway via DHCP (option 3), or IPv6
\fIaddr\fR as source for NDP Router Advertisement and DHCPv6 messages.
This option can be specified zero (for defaults) to two times (once for IPv4,
once for IPv6).
By default, IPv4 and IPv6 addresses are taken from the host interface with the
passt.1: Default host interfaces are now selected based on IP version Reflect the changes from commit 4b2e018d70f3 ("Allow different external interfaces for IPv4 and IPv6 connectivity") into the manual. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-07-30 20:17:07 +00:00
first default route for the corresponding IP version.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
Note: these addresses are also used as source address for packets directed to
the guest or to the target namespace having a loopback or local source address,
to allow mapping of local traffic to guest and target namespace. See the
\fBNOTES\fR below for more details about this mechanism.
.TP
.BR \-i ", " \-\-interface " " \fIname
Use host interface \fIname\fR to derive addresses and routes.
conf, icmp, tcp, udp: Add options to bind to outbound address and interface I didn't notice earlier: libslirp (and slirp4netns) supports binding outbound sockets to specific IPv4 and IPv6 addresses, to force the source addresse selection. If we want to claim feature parity, we should implement that as well. Further, Podman supports specifying outbound interfaces as well, but this is simply done by resolving the primary address for an interface when the network back-end is started. However, since kernel version 5.7, commit c427bfec18f2 ("net: core: enable SO_BINDTODEVICE for non-root users"), we can actually bind to a specific interface name, which doesn't need to be validated in advance. Implement -o / --outbound ADDR to bind to IPv4 and IPv6 addresses, and --outbound-if4 and --outbound-if6 to bind IPv4 and IPv6 sockets to given interfaces. Given that it probably makes little sense to select addresses and routes from interfaces different than the ones given for outbound sockets, also assign those as "template" interfaces, by default, unless explicitly overridden by '-i'. For ICMP and UDP, we call sock_l4() to open outbound sockets, as we already needed to bind to given ports or echo identifiers, and we can bind() a socket only once: there, pass address (if any) and interface (if any) for the existing bind() and setsockopt() calls. For TCP, in general, we wouldn't otherwise bind sockets. Add a specific helper to do that. For UDP outbound sockets, we need to know if the final destination of the socket is a loopback address, before we decide whether it makes sense to bind the socket at all: move the block mangling the address destination before the creation of the socket in the IPv4 path. This was already the case for the IPv6 path. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2023-03-08 02:29:51 +00:00
Default is to use the interfaces specified by \fB--outbound-if4\fR and
\fB--outbound-if6\fR, for IPv4 and IPv6 addresses and routes, respectively. If
no interfaces are given, the interface with the first default routes for each IP
version is selected.
.TP
.BR \-o ", " \-\-outbound " " \fIaddr
Use an IPv4 \fIaddr\fR as source address for IPv4 outbound TCP connections, UDP
flows, ICMP requests, or an IPv6 \fIaddr\fR for IPv6 ones, by binding outbound
sockets to it.
This option can be specified zero (for defaults) to two times (once for IPv4,
once for IPv6).
By default, the source address is selected by the routing tables.
.TP
.BR \-\-outbound-if4 " " \fIname
Bind IPv4 outbound sockets to host interface \fIname\fR, and, unless another
interface is specified via \fB-i\fR, \fB--interface\fR, use this interface to
derive IPv4 addresses and routes.
By default, the interface given by the default route is selected.
.TP
.BR \-\-outbound-if6 " " \fIname
Bind IPv6 outbound sockets to host interface \fIname\fR, and, unless another
interface is specified via \fB-i\fR, \fB--interface\fR, use this interface to
derive IPv6 addresses and routes.
By default, the interface given by the default route is selected.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
.BR \-D ", " \-\-dns " " \fIaddr
conf, udp: Introduce basic DNS forwarding For compatibility with libslirp/slirp4netns users: introduce a mechanism to map, in the UDP routines, an address facing guest or namespace to the first IPv4 or IPv6 address resulting from configuration as resolver. This can be enabled with the new --dns-forward option. This implies that sourcing and using DNS addresses and search lists, passed via command line or read from /etc/resolv.conf, is not bound anymore to DHCP/DHCPv6/NDP usage: for example, pasta users might just want to use addresses from /etc/resolv.conf as mapping target, while not passing DNS options via DHCP. Reflect this in all the involved code paths by differentiating DHCP/DHCPv6/NDP usage from DNS configuration per se, and in the new options --dhcp-dns, --dhcp-search for pasta, and --no-dhcp-dns, --no-dhcp-search for passt. This should be the last bit to enable substantial compatibility between slirp4netns.sh and slirp4netns(1): pass the --dns-forward option from the script too. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-02-18 03:03:53 +00:00
Use \fIaddr\fR (IPv4 or IPv6) for DHCP, DHCPv6, NDP or DNS forwarding, as
configured (see options \fB--no-dhcp-dns\fR, \fB--dhcp-dns\fR,
\fB--dns-forward\fR) instead of reading addresses from \fI/etc/resolv.conf\fR.
conf: Use "-D none" and "-S none" instead of missing empty option arguments Both the -D (--dns) and -S (--search) options take an optional argument. If the argument is omitted the option is disabled entirely. However, handling the optional argument requires some ugly special case handling if it's the last option on the command line, and has potential ambiguity with non-option arguments used with pasta. It can also make it more confusing to read command lines. Simplify the logic here by replacing the non-argument versions with an explicit "-D none" or "-S none". Signed-off-by: David Gibson <david@gibson.dropbear.id.au> [sbrivio: Reworked logic to exclude redundant/conflicting options] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-08-26 04:58:33 +00:00
This option can be specified multiple times. Specifying \fB-D none\fR disables
conf, udp: Introduce basic DNS forwarding For compatibility with libslirp/slirp4netns users: introduce a mechanism to map, in the UDP routines, an address facing guest or namespace to the first IPv4 or IPv6 address resulting from configuration as resolver. This can be enabled with the new --dns-forward option. This implies that sourcing and using DNS addresses and search lists, passed via command line or read from /etc/resolv.conf, is not bound anymore to DHCP/DHCPv6/NDP usage: for example, pasta users might just want to use addresses from /etc/resolv.conf as mapping target, while not passing DNS options via DHCP. Reflect this in all the involved code paths by differentiating DHCP/DHCPv6/NDP usage from DNS configuration per se, and in the new options --dhcp-dns, --dhcp-search for pasta, and --no-dhcp-dns, --no-dhcp-search for passt. This should be the last bit to enable substantial compatibility between slirp4netns.sh and slirp4netns(1): pass the --dns-forward option from the script too. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-02-18 03:03:53 +00:00
usage of DNS addresses altogether.
.TP
.BR \-\-dns-forward " " \fIaddr
Map \fIaddr\fR (IPv4 or IPv6) as seen from guest or namespace to the first
configured DNS resolver (with corresponding IP version). Mapping is limited to
UDP traffic directed to port 53, and DNS answers are translated back with a
reverse mapping.
This option can be specified zero to two times (once for IPv4, once for IPv6).
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
.BR \-S ", " \-\-search " " \fIlist
conf, udp: Introduce basic DNS forwarding For compatibility with libslirp/slirp4netns users: introduce a mechanism to map, in the UDP routines, an address facing guest or namespace to the first IPv4 or IPv6 address resulting from configuration as resolver. This can be enabled with the new --dns-forward option. This implies that sourcing and using DNS addresses and search lists, passed via command line or read from /etc/resolv.conf, is not bound anymore to DHCP/DHCPv6/NDP usage: for example, pasta users might just want to use addresses from /etc/resolv.conf as mapping target, while not passing DNS options via DHCP. Reflect this in all the involved code paths by differentiating DHCP/DHCPv6/NDP usage from DNS configuration per se, and in the new options --dhcp-dns, --dhcp-search for pasta, and --no-dhcp-dns, --no-dhcp-search for passt. This should be the last bit to enable substantial compatibility between slirp4netns.sh and slirp4netns(1): pass the --dns-forward option from the script too. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-02-18 03:03:53 +00:00
Use space-separated \fIlist\fR for DHCP, DHCPv6, and NDP purposes, instead of
reading entries from \fI/etc/resolv.conf\fR. See options \fB--no-dhcp-search\fR
conf: Use "-D none" and "-S none" instead of missing empty option arguments Both the -D (--dns) and -S (--search) options take an optional argument. If the argument is omitted the option is disabled entirely. However, handling the optional argument requires some ugly special case handling if it's the last option on the command line, and has potential ambiguity with non-option arguments used with pasta. It can also make it more confusing to read command lines. Simplify the logic here by replacing the non-argument versions with an explicit "-D none" or "-S none". Signed-off-by: David Gibson <david@gibson.dropbear.id.au> [sbrivio: Reworked logic to exclude redundant/conflicting options] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-08-26 04:58:33 +00:00
and \fB--dhcp-search\fR. \fB--search none\fR disables the DNS domain search
list altogether (if you need to search a domain called "none" you can use
\fB--search none.\fR).
conf, udp: Introduce basic DNS forwarding For compatibility with libslirp/slirp4netns users: introduce a mechanism to map, in the UDP routines, an address facing guest or namespace to the first IPv4 or IPv6 address resulting from configuration as resolver. This can be enabled with the new --dns-forward option. This implies that sourcing and using DNS addresses and search lists, passed via command line or read from /etc/resolv.conf, is not bound anymore to DHCP/DHCPv6/NDP usage: for example, pasta users might just want to use addresses from /etc/resolv.conf as mapping target, while not passing DNS options via DHCP. Reflect this in all the involved code paths by differentiating DHCP/DHCPv6/NDP usage from DNS configuration per se, and in the new options --dhcp-dns, --dhcp-search for pasta, and --no-dhcp-dns, --no-dhcp-search for passt. This should be the last bit to enable substantial compatibility between slirp4netns.sh and slirp4netns(1): pass the --dns-forward option from the script too. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-02-18 03:03:53 +00:00
.TP
.BR \-\-no-dhcp-dns " " \fIaddr
In \fIpasst\fR mode, do not assign IPv4 addresses via DHCP (option 23) or IPv6
addresses via NDP Router Advertisement (option type 25) and DHCPv6 (option 23)
as DNS resolvers.
By default, all the configured addresses are passed.
.TP
.BR \-\-dhcp-dns " " \fIaddr
In \fIpasta\fR mode, assign IPv4 addresses via DHCP (option 23) or IPv6
addresses via NDP Router Advertisement (option type 25) and DHCPv6 (option 23)
as DNS resolvers.
By default, configured addresses, if any, are not passed.
.TP
.BR \-\-no-dhcp-search " " \fIaddr
In \fIpasst\fR mode, do not send the DNS domain search list addresses via DHCP
(option 119), via NDP Router Advertisement (option type 31) and DHCPv6 (option
24).
By default, the DNS domain search list resulting from configuration is passed.
.TP
.BR \-\-dhcp-search " " \fIaddr
In \fIpasta\fR mode, send the DNS domain search list addresses via DHCP (option
119), via NDP Router Advertisement (option type 31) and DHCPv6 (option 24).
By default, the DNS domain search list resulting from configuration is not
passed.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
.BR \-\-no-tcp
Disable the TCP protocol handler. No TCP connections will be accepted host-side,
and TCP packets coming from guest or target namespace will be silently dropped.
.TP
.BR \-\-no-udp
Disable the UDP protocol handler. No UDP traffic coming from the host side will
be forwarded, and UDP packets coming from guest or target namespace will be
silently dropped.
.TP
.BR \-\-no-icmp
Disable the ICMP/ICMPv6 echo handler. ICMP and ICMPv6 echo requests coming from
guest or target namespace will be silently dropped.
.TP
.BR \-\-no-dhcp
Disable the DHCP server. DHCP client requests coming from guest or target
conf: Don't exit if sourced default route has no gateway If we use a template interface without a gateway on the default route, we can still offer almost complete functionality, except that, of course, we can't map the gateway address to the outer namespace or host, and that we have no obvious server address or identifier for use in DHCP's siaddr and option 54 (Server identifier, mandatory). Continue, if we have a default route but no default gateway, and imply --no-map-gw and --no-dhcp in that case. NDP responder and DHCPv6 should be able to work as usual because we require a link-local address to be present, and we'll fall back to that. Together with the previous commits implementing an actual copy of routes from the outer namespace, this should finally fix the operation of 'pasta --config-net' for cases where we have a default route on the host, but no default gateway, as it's the case for tap-style routes, including typical Wireguard endpoints. Reported-by: me@yawnt.com Link: https://bugs.passt.top/show_bug.cgi?id=49 Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2023-05-14 14:24:11 +00:00
namespace will be silently dropped. Implied if there is no gateway on the
selected IPv4 default route.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
.BR \-\-no-ndp
Disable NDP responses. NDP messages coming from guest or target namespace will
be ignored.
.TP
.BR \-\-no-dhcpv6
Disable the DHCPv6 server. DHCPv6 client requests coming from guest or target
namespace will be silently dropped.
.TP
.BR \-\-no-ra
Disable Router Advertisements. Router Solicitations coming from guest or target
namespace will be ignored.
conf, tcp, udp: Add --no-map-gw to disable mapping gateway address to host Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-10-14 03:26:37 +00:00
.TP
.BR \-\-no-map-gw
Don't remap TCP connections and untracked UDP traffic, with the gateway address
conf: Don't exit if sourced default route has no gateway If we use a template interface without a gateway on the default route, we can still offer almost complete functionality, except that, of course, we can't map the gateway address to the outer namespace or host, and that we have no obvious server address or identifier for use in DHCP's siaddr and option 54 (Server identifier, mandatory). Continue, if we have a default route but no default gateway, and imply --no-map-gw and --no-dhcp in that case. NDP responder and DHCPv6 should be able to work as usual because we require a link-local address to be present, and we'll fall back to that. Together with the previous commits implementing an actual copy of routes from the outer namespace, this should finally fix the operation of 'pasta --config-net' for cases where we have a default route on the host, but no default gateway, as it's the case for tap-style routes, including typical Wireguard endpoints. Reported-by: me@yawnt.com Link: https://bugs.passt.top/show_bug.cgi?id=49 Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2023-05-14 14:24:11 +00:00
as destination, to the host. Implied if there is no gateway on the selected
default route for any of the enabled address families.
conf, tcp, udp: Add --no-map-gw to disable mapping gateway address to host Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-10-14 03:26:37 +00:00
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
.BR \-4 ", " \-\-ipv4-only
Enable IPv4-only operation. IPv6 traffic will be ignored.
By default, IPv6 operation is enabled as long as at least an IPv6 default route
and an interface address are configured on a given host interface.
.TP
correct -6 option in manpage Signed-off-by: lemmi <lemmi@nerd2nerd.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-05-08 16:05:01 +00:00
.BR \-6 ", " \-\-ipv6-only
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
Enable IPv6-only operation. IPv4 traffic will be ignored.
By default, IPv4 operation is enabled as long as at least an IPv4 default route
and an interface address are configured on a given host interface.
.SS \fBpasst\fR-only options
.TP
.BR \-s ", " \-\-socket " " \fIpath
Path for UNIX domain socket used by \fBqemu\fR(1) or \fBqrap\fR(1) to connect to
\fBpasst\fR.
Default is to probe a free socket, not accepting connections, starting from
\fI/tmp/passt_1.socket\fR to \fI/tmp/passt_64.socket\fR.
passt, tap: Add --fd option This passes a fully connected stream socket to passt. Signed-off-by: Richard W.M. Jones <rjones@redhat.com> [sbrivio: reuse fd_tap instead of adding a new descriptor, imply --one-off on --fd, add to optstring and usage()] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-11-17 18:49:34 +00:00
.TP
.BR \-F ", " \-\-fd " " \fIFD
Pass a pre-opened, connected socket to \fBpasst\fR. Usually the socket is opened
in the parent process and \fBpasst\fR inherits it when run as a child. This
allows the parent process to open sockets using another address family or
requiring special privileges.
This option implies the behaviour described for \-\-one-off, once this socket
is closed.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
conf, tap: Add option to quit once the client closes the connection This is practical to avoid explicit lifecycle management in users, e.g. libvirtd, and is trivial to implement. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2022-10-07 02:01:56 +00:00
.BR \-1 ", " \-\-one-off
Quit after handling a single client connection, that is, once the client closes
the socket, or once we get a socket error.
.TP
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.BR \-t ", " \-\-tcp-ports " " \fIspec
Configure TCP port forwarding to guest. \fIspec\fR can be one of:
.RS
.TP
.BR none
Don't forward any ports
.TP
.BR all
Forward all unbound, non-ephemeral ports, as permitted by current capabilities.
For low (< 1024) ports, see \fBNOTES\fR.
.TP
.BR ports
A comma-separated list of ports, optionally ranged with \fI-\fR, and,
conf, tcp, udp: Allow address specification for forwarded ports This feature is available in slirp4netns but was missing in passt and pasta. Given that we don't do dynamic memory allocation, we need to bind sockets while parsing port configuration. This means we need to process all other options first, as they might affect addressing and IP version support. It also implies a minor rework of how TCP and UDP implementations bind sockets. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-05-01 04:36:34 +00:00
optionally, with target ports after \fI:\fR, if they differ. Specific addresses
conf, tcp, udp: Allow specification of interface to bind to Since kernel version 5.7, commit c427bfec18f2 ("net: core: enable SO_BINDTODEVICE for non-root users"), we can bind sockets to interfaces, if they haven't been bound yet (as in bind()). Introduce an optional interface specification for forwarded ports, prefixed by %, that can be passed together with an address. Reported use case: running local services that use ports we want to have externally forwarded: https://github.com/containers/podman/issues/14425 Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2022-10-07 02:53:40 +00:00
can be bound as well, separated by \fI/\fR, and also, since Linux 5.7, limited
to specific interfaces, prefixed by \fI%\fR. Within given ranges, selected ports
conf: Allow to specify ranges and ports excluded from given ranges This is useful in environments where we want to forward a large number of ports, or all non-ephemeral ones, and some other service running on the host needs a few selected ports. I'm using ~ as prefix for the specification of excluded ranges and ports to avoid the need for explicit command line quoting. Ranges and ports can be excluded from given ranges by adding them in the comma-separated list, prefixed by ~. Some quick examples: -t 5000-6000,~5555: forward ports 5000 to 6000, but not 5555 -t ~20000-20010: forward all non-ephemeral, allowed ports, except for ports 20000 to 20010 ...more details in usage message and man page. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-07-13 06:05:01 +00:00
and ranges can be excluded by an additional specification prefixed by \fI~\fR.
Specifying excluded ranges only implies that all other ports are forwarded.
Examples:
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.RS
.TP
-t 22
passt.1: Fix typo, improve wording in examples of port forwarding specifiers Based on a patch from Laine, and reports from Laine and Yalan: fix the "22-80:32-90" example, and improve wording for the other ones: instead of using "to" to denote the end of a range, use "between ... and", so that it's clear we're *not* referring to target ports. Reported-by: Laine Stump <laine@redhat.com> Reported-by: Yalan Zhang <yalzhang@redhat.com> Fixes: da20f57f19dc ("passt, qrap: Add man pages") Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-02-16 01:00:47 +00:00
Forward local port 22 to port 22 on the guest
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
-t 22:23
Forward local port 22 to port 23 on the guest
.TP
-t 22,25
Forward local ports 22 and 25 to ports 22 and 25 on the guest
.TP
-t 22-80
passt.1: Fix typo, improve wording in examples of port forwarding specifiers Based on a patch from Laine, and reports from Laine and Yalan: fix the "22-80:32-90" example, and improve wording for the other ones: instead of using "to" to denote the end of a range, use "between ... and", so that it's clear we're *not* referring to target ports. Reported-by: Laine Stump <laine@redhat.com> Reported-by: Yalan Zhang <yalzhang@redhat.com> Fixes: da20f57f19dc ("passt, qrap: Add man pages") Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-02-16 01:00:47 +00:00
Forward local ports between 22 and 80 to corresponding ports on the guest
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
passt.1: Fix typo, improve wording in examples of port forwarding specifiers Based on a patch from Laine, and reports from Laine and Yalan: fix the "22-80:32-90" example, and improve wording for the other ones: instead of using "to" to denote the end of a range, use "between ... and", so that it's clear we're *not* referring to target ports. Reported-by: Laine Stump <laine@redhat.com> Reported-by: Yalan Zhang <yalzhang@redhat.com> Fixes: da20f57f19dc ("passt, qrap: Add man pages") Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-02-16 01:00:47 +00:00
-t 22-80:32-90
Forward local ports between 22 and 80 to ports between 32 and 90 on the guest
conf, tcp, udp: Allow address specification for forwarded ports This feature is available in slirp4netns but was missing in passt and pasta. Given that we don't do dynamic memory allocation, we need to bind sockets while parsing port configuration. This means we need to process all other options first, as they might affect addressing and IP version support. It also implies a minor rework of how TCP and UDP implementations bind sockets. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-05-01 04:36:34 +00:00
.TP
-t 192.0.2.1/22
Forward local port 22, bound to 192.0.2.1, to port 22 on the guest
conf: Allow to specify ranges and ports excluded from given ranges This is useful in environments where we want to forward a large number of ports, or all non-ephemeral ones, and some other service running on the host needs a few selected ports. I'm using ~ as prefix for the specification of excluded ranges and ports to avoid the need for explicit command line quoting. Ranges and ports can be excluded from given ranges by adding them in the comma-separated list, prefixed by ~. Some quick examples: -t 5000-6000,~5555: forward ports 5000 to 6000, but not 5555 -t ~20000-20010: forward all non-ephemeral, allowed ports, except for ports 20000 to 20010 ...more details in usage message and man page. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-07-13 06:05:01 +00:00
.TP
conf, tcp, udp: Allow specification of interface to bind to Since kernel version 5.7, commit c427bfec18f2 ("net: core: enable SO_BINDTODEVICE for non-root users"), we can bind sockets to interfaces, if they haven't been bound yet (as in bind()). Introduce an optional interface specification for forwarded ports, prefixed by %, that can be passed together with an address. Reported use case: running local services that use ports we want to have externally forwarded: https://github.com/containers/podman/issues/14425 Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2022-10-07 02:53:40 +00:00
-t 192.0.2.1%eth0/22
Forward local port 22, bound to 192.0.2.1 and interface eth0, to port 22
.TP
conf: Allow binding to ports on an interface without a specific address Somebody might want to bind listening sockets to a specific interface, but not a specific address, and there isn't really a reason to prevent that. For example: -t %eth0/2022 Alternatively, we support options such as -t 0.0.0.0%eth0/2022 and -t ::%eth0/2022, but not together, for the same port. Enable this kind of syntax and add examples to the man page. Reported-by: Paul Holzinger <pholzing@redhat.com> Link: https://github.com/containers/podman/issues/14425#issuecomment-1485192195 Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-03-27 17:35:26 +00:00
-t %eth0/22
Forward local port 22, bound to any address on interface eth0, to port 22
.TP
conf: Allow to specify ranges and ports excluded from given ranges This is useful in environments where we want to forward a large number of ports, or all non-ephemeral ones, and some other service running on the host needs a few selected ports. I'm using ~ as prefix for the specification of excluded ranges and ports to avoid the need for explicit command line quoting. Ranges and ports can be excluded from given ranges by adding them in the comma-separated list, prefixed by ~. Some quick examples: -t 5000-6000,~5555: forward ports 5000 to 6000, but not 5555 -t ~20000-20010: forward all non-ephemeral, allowed ports, except for ports 20000 to 20010 ...more details in usage message and man page. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-07-13 06:05:01 +00:00
-t 2000-5000,~3000-3010
passt.1: Fix typo, improve wording in examples of port forwarding specifiers Based on a patch from Laine, and reports from Laine and Yalan: fix the "22-80:32-90" example, and improve wording for the other ones: instead of using "to" to denote the end of a range, use "between ... and", so that it's clear we're *not* referring to target ports. Reported-by: Laine Stump <laine@redhat.com> Reported-by: Yalan Zhang <yalzhang@redhat.com> Fixes: da20f57f19dc ("passt, qrap: Add man pages") Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-02-16 01:00:47 +00:00
Forward local ports between 2000 and 5000, except for those between 3000 and
3010
conf: Allow to specify ranges and ports excluded from given ranges This is useful in environments where we want to forward a large number of ports, or all non-ephemeral ones, and some other service running on the host needs a few selected ports. I'm using ~ as prefix for the specification of excluded ranges and ports to avoid the need for explicit command line quoting. Ranges and ports can be excluded from given ranges by adding them in the comma-separated list, prefixed by ~. Some quick examples: -t 5000-6000,~5555: forward ports 5000 to 6000, but not 5555 -t ~20000-20010: forward all non-ephemeral, allowed ports, except for ports 20000 to 20010 ...more details in usage message and man page. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-07-13 06:05:01 +00:00
.TP
-t 192.0.2.1/20-30,~25
passt.1: Fix typo, improve wording in examples of port forwarding specifiers Based on a patch from Laine, and reports from Laine and Yalan: fix the "22-80:32-90" example, and improve wording for the other ones: instead of using "to" to denote the end of a range, use "between ... and", so that it's clear we're *not* referring to target ports. Reported-by: Laine Stump <laine@redhat.com> Reported-by: Yalan Zhang <yalzhang@redhat.com> Fixes: da20f57f19dc ("passt, qrap: Add man pages") Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-02-16 01:00:47 +00:00
For the local address 192.0.2.1, forward ports between 20 and 24 and between 26
and 30
conf: Allow to specify ranges and ports excluded from given ranges This is useful in environments where we want to forward a large number of ports, or all non-ephemeral ones, and some other service running on the host needs a few selected ports. I'm using ~ as prefix for the specification of excluded ranges and ports to avoid the need for explicit command line quoting. Ranges and ports can be excluded from given ranges by adding them in the comma-separated list, prefixed by ~. Some quick examples: -t 5000-6000,~5555: forward ports 5000 to 6000, but not 5555 -t ~20000-20010: forward all non-ephemeral, allowed ports, except for ports 20000 to 20010 ...more details in usage message and man page. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-07-13 06:05:01 +00:00
.TP
-t ~20000-20010
Forward all ports to the guest, except for the range from 20000 to 20010
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.RE
Default is \fBnone\fR.
.RE
.TP
.BR \-u ", " \-\-udp-ports " " \fIspec
Configure UDP port forwarding to guest. \fIspec\fR is as described for TCP
above.
Note: unless overridden, UDP ports with numbers corresponding to forwarded TCP
port numbers are forwarded too, without, however, any port translation. IPv6
bound ports are also forwarded for IPv4.
Default is \fBnone\fR.
.SS \fBpasta\fR-only options
.TP
.BR \-I ", " \-\-ns-ifname " " \fIname
Name of tap interface to be created in target namespace.
By default, the same interface name as the external, routable interface is used.
.TP
.BR \-t ", " \-\-tcp-ports " " \fIspec
Configure TCP port forwarding to namespace. \fIspec\fR can be one of:
.RS
.TP
.BR none
Don't forward any ports
.TP
.BR auto
conf, tcp: Periodic detection of bound ports for pasta port forwarding Detecting bound ports at start-up time isn't terribly useful: do this periodically instead, if configured. This is only implemented for TCP at the moment, UDP is somewhat more complicated: leave a TODO there. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-09-27 03:24:30 +00:00
Dynamically forward ports bound in the namespace. The list of ports is
periodically derived (every second) from listening sockets reported by
\fI/proc/net/tcp\fR and \fI/proc/net/tcp6\fR, see \fBproc\fR(5).
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
.BR ports
A comma-separated list of ports, optionally ranged with \fI-\fR, and,
conf, tcp, udp: Allow address specification for forwarded ports This feature is available in slirp4netns but was missing in passt and pasta. Given that we don't do dynamic memory allocation, we need to bind sockets while parsing port configuration. This means we need to process all other options first, as they might affect addressing and IP version support. It also implies a minor rework of how TCP and UDP implementations bind sockets. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-05-01 04:36:34 +00:00
optionally, with target ports after \fI:\fR, if they differ. Specific addresses
conf, tcp, udp: Allow specification of interface to bind to Since kernel version 5.7, commit c427bfec18f2 ("net: core: enable SO_BINDTODEVICE for non-root users"), we can bind sockets to interfaces, if they haven't been bound yet (as in bind()). Introduce an optional interface specification for forwarded ports, prefixed by %, that can be passed together with an address. Reported use case: running local services that use ports we want to have externally forwarded: https://github.com/containers/podman/issues/14425 Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2022-10-07 02:53:40 +00:00
can be bound as well, separated by \fI/\fR, and also, since Linux 5.7, limited
to specific interfaces, prefixed by \fI%\fR. Within given ranges, selected ports
conf: Allow to specify ranges and ports excluded from given ranges This is useful in environments where we want to forward a large number of ports, or all non-ephemeral ones, and some other service running on the host needs a few selected ports. I'm using ~ as prefix for the specification of excluded ranges and ports to avoid the need for explicit command line quoting. Ranges and ports can be excluded from given ranges by adding them in the comma-separated list, prefixed by ~. Some quick examples: -t 5000-6000,~5555: forward ports 5000 to 6000, but not 5555 -t ~20000-20010: forward all non-ephemeral, allowed ports, except for ports 20000 to 20010 ...more details in usage message and man page. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-07-13 06:05:01 +00:00
and ranges can be excluded by an additional specification prefixed by \fI~\fR.
Specifying excluded ranges only implies that all other ports are forwarded.
Examples:
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.RS
.TP
-t 22
Forward local port 22 to 22 in the target namespace
.TP
-t 22:23
Forward local port 22 to port 23 in the target namespace
.TP
-t 22,25
Forward local ports 22 and 25 to ports 22 and 25 in the target namespace
.TP
-t 22-80
passt.1: Fix typo, improve wording in examples of port forwarding specifiers Based on a patch from Laine, and reports from Laine and Yalan: fix the "22-80:32-90" example, and improve wording for the other ones: instead of using "to" to denote the end of a range, use "between ... and", so that it's clear we're *not* referring to target ports. Reported-by: Laine Stump <laine@redhat.com> Reported-by: Yalan Zhang <yalzhang@redhat.com> Fixes: da20f57f19dc ("passt, qrap: Add man pages") Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-02-16 01:00:47 +00:00
Forward local ports between 22 and 80 to corresponding ports in the target
namespace
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.TP
passt.1: Fix typo, improve wording in examples of port forwarding specifiers Based on a patch from Laine, and reports from Laine and Yalan: fix the "22-80:32-90" example, and improve wording for the other ones: instead of using "to" to denote the end of a range, use "between ... and", so that it's clear we're *not* referring to target ports. Reported-by: Laine Stump <laine@redhat.com> Reported-by: Yalan Zhang <yalzhang@redhat.com> Fixes: da20f57f19dc ("passt, qrap: Add man pages") Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-02-16 01:00:47 +00:00
-t 22-80:32-90
Forward local ports between 22 and 80 to ports between 32 and 90 in the target
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
namespace
conf, tcp, udp: Allow address specification for forwarded ports This feature is available in slirp4netns but was missing in passt and pasta. Given that we don't do dynamic memory allocation, we need to bind sockets while parsing port configuration. This means we need to process all other options first, as they might affect addressing and IP version support. It also implies a minor rework of how TCP and UDP implementations bind sockets. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-05-01 04:36:34 +00:00
.TP
-t 192.0.2.1/22
Forward local port 22, bound to 192.0.2.1, to port 22 in the target namespace
conf: Allow to specify ranges and ports excluded from given ranges This is useful in environments where we want to forward a large number of ports, or all non-ephemeral ones, and some other service running on the host needs a few selected ports. I'm using ~ as prefix for the specification of excluded ranges and ports to avoid the need for explicit command line quoting. Ranges and ports can be excluded from given ranges by adding them in the comma-separated list, prefixed by ~. Some quick examples: -t 5000-6000,~5555: forward ports 5000 to 6000, but not 5555 -t ~20000-20010: forward all non-ephemeral, allowed ports, except for ports 20000 to 20010 ...more details in usage message and man page. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-07-13 06:05:01 +00:00
.TP
conf, tcp, udp: Allow specification of interface to bind to Since kernel version 5.7, commit c427bfec18f2 ("net: core: enable SO_BINDTODEVICE for non-root users"), we can bind sockets to interfaces, if they haven't been bound yet (as in bind()). Introduce an optional interface specification for forwarded ports, prefixed by %, that can be passed together with an address. Reported use case: running local services that use ports we want to have externally forwarded: https://github.com/containers/podman/issues/14425 Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2022-10-07 02:53:40 +00:00
-t 192.0.2.1%eth0/22
Forward local port 22, bound to 192.0.2.1 and interface eth0, to port 22
.TP
conf: Allow binding to ports on an interface without a specific address Somebody might want to bind listening sockets to a specific interface, but not a specific address, and there isn't really a reason to prevent that. For example: -t %eth0/2022 Alternatively, we support options such as -t 0.0.0.0%eth0/2022 and -t ::%eth0/2022, but not together, for the same port. Enable this kind of syntax and add examples to the man page. Reported-by: Paul Holzinger <pholzing@redhat.com> Link: https://github.com/containers/podman/issues/14425#issuecomment-1485192195 Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-03-27 17:35:26 +00:00
-t %eth0/22
Forward local port 22, bound to any address on interface eth0, to port 22
.TP
conf: Allow to specify ranges and ports excluded from given ranges This is useful in environments where we want to forward a large number of ports, or all non-ephemeral ones, and some other service running on the host needs a few selected ports. I'm using ~ as prefix for the specification of excluded ranges and ports to avoid the need for explicit command line quoting. Ranges and ports can be excluded from given ranges by adding them in the comma-separated list, prefixed by ~. Some quick examples: -t 5000-6000,~5555: forward ports 5000 to 6000, but not 5555 -t ~20000-20010: forward all non-ephemeral, allowed ports, except for ports 20000 to 20010 ...more details in usage message and man page. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-07-13 06:05:01 +00:00
-t 2000-5000,~3000-3010
passt.1: Fix typo, improve wording in examples of port forwarding specifiers Based on a patch from Laine, and reports from Laine and Yalan: fix the "22-80:32-90" example, and improve wording for the other ones: instead of using "to" to denote the end of a range, use "between ... and", so that it's clear we're *not* referring to target ports. Reported-by: Laine Stump <laine@redhat.com> Reported-by: Yalan Zhang <yalzhang@redhat.com> Fixes: da20f57f19dc ("passt, qrap: Add man pages") Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-02-16 01:00:47 +00:00
Forward local ports between 2000 and 5000, except for those between 3000 and
3010
conf: Allow to specify ranges and ports excluded from given ranges This is useful in environments where we want to forward a large number of ports, or all non-ephemeral ones, and some other service running on the host needs a few selected ports. I'm using ~ as prefix for the specification of excluded ranges and ports to avoid the need for explicit command line quoting. Ranges and ports can be excluded from given ranges by adding them in the comma-separated list, prefixed by ~. Some quick examples: -t 5000-6000,~5555: forward ports 5000 to 6000, but not 5555 -t ~20000-20010: forward all non-ephemeral, allowed ports, except for ports 20000 to 20010 ...more details in usage message and man page. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-07-13 06:05:01 +00:00
.TP
-t 192.0.2.1/20-30,~25
passt.1: Fix typo, improve wording in examples of port forwarding specifiers Based on a patch from Laine, and reports from Laine and Yalan: fix the "22-80:32-90" example, and improve wording for the other ones: instead of using "to" to denote the end of a range, use "between ... and", so that it's clear we're *not* referring to target ports. Reported-by: Laine Stump <laine@redhat.com> Reported-by: Yalan Zhang <yalzhang@redhat.com> Fixes: da20f57f19dc ("passt, qrap: Add man pages") Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-02-16 01:00:47 +00:00
For the local address 192.0.2.1, forward ports between 20 and 24 and between 26
and 30
conf: Allow to specify ranges and ports excluded from given ranges This is useful in environments where we want to forward a large number of ports, or all non-ephemeral ones, and some other service running on the host needs a few selected ports. I'm using ~ as prefix for the specification of excluded ranges and ports to avoid the need for explicit command line quoting. Ranges and ports can be excluded from given ranges by adding them in the comma-separated list, prefixed by ~. Some quick examples: -t 5000-6000,~5555: forward ports 5000 to 6000, but not 5555 -t ~20000-20010: forward all non-ephemeral, allowed ports, except for ports 20000 to 20010 ...more details in usage message and man page. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-07-13 06:05:01 +00:00
.TP
-t ~20000-20010
passt.1: Fix typo, improve wording in examples of port forwarding specifiers Based on a patch from Laine, and reports from Laine and Yalan: fix the "22-80:32-90" example, and improve wording for the other ones: instead of using "to" to denote the end of a range, use "between ... and", so that it's clear we're *not* referring to target ports. Reported-by: Laine Stump <laine@redhat.com> Reported-by: Yalan Zhang <yalzhang@redhat.com> Fixes: da20f57f19dc ("passt, qrap: Add man pages") Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-02-16 01:00:47 +00:00
Forward all ports to the namespace, except for those between 20000 and 20010
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.RE
IPv6 bound ports are also forwarded for IPv4.
Default is \fBauto\fR.
.RE
.TP
.BR \-u ", " \-\-udp-ports " " \fIspec
conf, tcp: Periodic detection of bound ports for pasta port forwarding Detecting bound ports at start-up time isn't terribly useful: do this periodically instead, if configured. This is only implemented for TCP at the moment, UDP is somewhat more complicated: leave a TODO there. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-09-27 03:24:30 +00:00
Configure UDP port forwarding to namespace. \fIspec\fR is as described for TCP
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
above, and the list of ports is derived from listening sockets reported by
udp,pasta: Periodically scan for ports to automatically forward pasta supports automatic port forwarding, where we look for listening sockets in /proc/net (in both namespace and outside) and establish port forwarding to match. For TCP we do this scan both at initial startup, then periodically thereafter. For UDP however, we currently only scan at start. So unlike TCP we won't update forwarding to handle services that start after pasta has begun. There's no particular reason for that, other than that we didn't implement it. So, remove that difference, by scanning for new UDP forwards periodically too. The logic is basically identical to that for TCP, but it needs some changes to handle the mildly different data structures in the UDP case. Link: https://bugs.passt.top/show_bug.cgi?id=45 Link: https://github.com/rootless-containers/rootlesskit/issues/383 Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-11-15 05:25:34 +00:00
\fI/proc/net/udp\fR and \fI/proc/net/udp6\fR, see \fBproc\fR(5).
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
Note: unless overridden, UDP ports with numbers corresponding to forwarded TCP
port numbers are forwarded too, without, however, any port translation.
IPv6 bound ports are also forwarded for IPv4.
Default is \fBauto\fR.
.TP
.BR \-T ", " \-\-tcp-ns " " \fIspec
Configure TCP port forwarding from target namespace to init namespace.
conf, tcp: Periodic detection of bound ports for pasta port forwarding Detecting bound ports at start-up time isn't terribly useful: do this periodically instead, if configured. This is only implemented for TCP at the moment, UDP is somewhat more complicated: leave a TODO there. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-09-27 03:24:30 +00:00
\fIspec\fR is as described above for TCP.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
Default is \fBauto\fR.
.TP
.BR \-U ", " \-\-udp-ns " " \fIspec
Configure UDP port forwarding from target namespace to init namespace.
conf, tcp: Periodic detection of bound ports for pasta port forwarding Detecting bound ports at start-up time isn't terribly useful: do this periodically instead, if configured. This is only implemented for TCP at the moment, UDP is somewhat more complicated: leave a TODO there. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-09-27 03:24:30 +00:00
\fIspec\fR is as described above for UDP.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
Default is \fBauto\fR.
pasta: Allow specifying paths and names of namespaces Based on a patch from Giuseppe Scrivano, this adds the ability to: - specify paths and names of target namespaces to join, instead of a PID, also for user namespaces, with --userns - request to join or create a network namespace only, without entering or creating a user namespace, with --netns-only - specify the base directory for netns mountpoints, with --nsrun-dir Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com> [sbrivio: reworked logic to actually join the given namespaces when they're not created, implemented --netns-only and --nsrun-dir, updated pasta demo script and man page] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-09-29 14:11:06 +00:00
.TP
.BR \-\-userns " " \fIspec
Correct manpage for --userns The man page states that the --userns option can be given either as a path or as a name relative to --nsrun-dir. This is not correct: as the name suggests --nsrun-dir is (correctly) used only for *netns* resolution, not *userns* resolution. Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-08-26 04:58:34 +00:00
Target user namespace to join, as a path. If PID is given, without this option,
the user namespace will be the one of the corresponding process.
pasta: Allow specifying paths and names of namespaces Based on a patch from Giuseppe Scrivano, this adds the ability to: - specify paths and names of target namespaces to join, instead of a PID, also for user namespaces, with --userns - request to join or create a network namespace only, without entering or creating a user namespace, with --netns-only - specify the base directory for netns mountpoints, with --nsrun-dir Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com> [sbrivio: reworked logic to actually join the given namespaces when they're not created, implemented --netns-only and --nsrun-dir, updated pasta demo script and man page] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-09-29 14:11:06 +00:00
Use explicit --netns option rather than multiplexing with PID When attaching to an existing namespace, pasta can take a PID or the name or path of a network namespace as a non-option parameter. We disambiguate based on what the parameter looks like. Make this more explicit by using a --netns option for explicitly giving the path or name, and treating a non-option argument always as a PID. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> [sbrivio: Fix typo in man page] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-08-26 04:58:38 +00:00
.TP
.BR \-\-netns " " \fIspec
Target network namespace to join, as a path or a name. A name is treated as
with \fBip-netns(8)\fR as equivalent to a path in \fI/run/netns\fR.
This option can't be specified with a PID.
pasta: Allow specifying paths and names of namespaces Based on a patch from Giuseppe Scrivano, this adds the ability to: - specify paths and names of target namespaces to join, instead of a PID, also for user namespaces, with --userns - request to join or create a network namespace only, without entering or creating a user namespace, with --netns-only - specify the base directory for netns mountpoints, with --nsrun-dir Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com> [sbrivio: reworked logic to actually join the given namespaces when they're not created, implemented --netns-only and --nsrun-dir, updated pasta demo script and man page] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-09-29 14:11:06 +00:00
.TP
.BR \-\-netns-only
passt, pasta: Namespace-based sandboxing, defer seccomp policy application 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>
2022-02-07 20:11:37 +00:00
Join only a target network namespace, not a user namespace, and don't create one
for sandboxing purposes either. This is implied if PATH or NAME are given
without \-\-userns.
pasta: Allow specifying paths and names of namespaces Based on a patch from Giuseppe Scrivano, this adds the ability to: - specify paths and names of target namespaces to join, instead of a PID, also for user namespaces, with --userns - request to join or create a network namespace only, without entering or creating a user namespace, with --netns-only - specify the base directory for netns mountpoints, with --nsrun-dir Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com> [sbrivio: reworked logic to actually join the given namespaces when they're not created, implemented --netns-only and --nsrun-dir, updated pasta demo script and man page] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-09-29 14:11:06 +00:00
pasta: By default, quit if filesystem-bound net namespace goes away This should be convenient for users managing filesystem-bound network namespaces: monitor the base directory of the namespace and exit if the namespace given as PATH or NAME target is deleted. We can't add an inotify watch directly on the namespace directory, that won't work with nsfs. Add an option to disable this behaviour, --no-netns-quit. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-02-18 15:12:11 +00:00
.TP
.BR \-\-no-netns-quit
If the target network namespace is bound to the filesystem (that is, if PATH or
NAME are given as target), do not exit once the network namespace is deleted.
conf, tap: Split netlink and pasta functions, allow interface configuration Move netlink routines to their own file, and use netlink to configure or fetch all the information we need, except for the TUNSETIFF ioctl. Move pasta-specific functions to their own file as well, add parameters and calls to configure the tap interface in the namespace. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-10-11 10:01:31 +00:00
.TP
.BR \-\-config-net
Configure networking in the namespace: set up addresses and routes as configured
passt.1: Drop duplicate --dns section Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-02-23 12:22:08 +00:00
or sourced from the host, and bring up the tap interface.
conf, tap: Split netlink and pasta functions, allow interface configuration Move netlink routines to their own file, and use netlink to configure or fetch all the information we need, except for the TUNSETIFF ioctl. Move pasta-specific functions to their own file as well, add parameters and calls to configure the tap interface in the namespace. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-10-11 10:01:31 +00:00
conf, pasta: With --config-net, copy all routes by default Use the newly-introduced NL_DUP mode for nl_route() to copy all the routes associated to the template interface in the outer namespace, unless --no-copy-routes (also implied by -g) is given. This option is introduced as deprecated right away: it's not expected to be of any use, but it's helpful to keep it around for a while to debug any suspected issue with this change. Otherwise, we can't use default gateways which are not, address-wise, on the same subnet as the container, as reported by Callum. Reported-by: Callum Parsey <callum@neoninteger.au> Link: https://github.com/containers/podman/issues/18539 Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2023-05-14 13:04:38 +00:00
.TP
.BR \-\-no-copy-routes " " (DEPRECATED)
With \-\-config-net, do not copy all the routes associated to the interface we
derive addresses and routes from: set up only the default gateway. Implied by
-g, \-\-gateway.
Default is to copy all the routing entries from the interface in the outer
namespace to the target namespace, translating the output interface attribute to
the outbound interface in the namespace.
Note that this configuration option is \fBdeprecated\fR and will be removed in a
future version. It is not expected to be of any use, and it simply reflects a
legacy behaviour. If you have any use for this, refer to \fBREPORTING BUGS\fR
below.
conf, pasta: With --config-net, copy all addresses by default Use the newly-introduced NL_DUP mode for nl_addr() to copy all the addresses associated to the template interface in the outer namespace, unless --no-copy-addrs (also implied by -a) is given. This option is introduced as deprecated right away: it's not expected to be of any use, but it's helpful to keep it around for a while to debug any suspected issue with this change. This is done mostly for consistency with routes. It might partially cover the issue at: https://bugs.passt.top/show_bug.cgi?id=47 Support multiple addresses per address family for some use cases, but not the originally intended one: we'll still use a single outbound address (unless the routing table specifies different preferred source addresses depending on the destination), regardless of the address used in the target namespace. Link: https://bugs.passt.top/show_bug.cgi?id=47 Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2023-05-14 17:12:09 +00:00
.TP
.BR \-\-no-copy-addrs " " (DEPRECATED)
With \-\-config-net, do not copy all the addresses associated to the interface
we derive addresses and routes from: set up a single one. Implied by \-a,
\-\-address.
Default is to copy all the addresses, except for link-local ones, from the
interface from the outer namespace to the target namespace.
Note that this configuration option is \fBdeprecated\fR and will be removed in a
future version. It is not expected to be of any use, and it simply reflects a
legacy behaviour. If you have any use for this, refer to \fBREPORTING BUGS\fR
below.
conf, tap: Split netlink and pasta functions, allow interface configuration Move netlink routines to their own file, and use netlink to configure or fetch all the information we need, except for the TUNSETIFF ioctl. Move pasta-specific functions to their own file as well, add parameters and calls to configure the tap interface in the namespace. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-10-11 10:01:31 +00:00
.TP
.BR \-\-ns-mac-addr " " \fIaddr
Configure MAC address \fIaddr\fR on the tap interface in the namespace.
Default is to let the tap driver build a pseudorandom hardware address.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.SH EXAMPLES
.SS \fBpasta
.BR "Create and use a new, connected, user and network namespace"
.RS
.nf
$ iperf3 -s -D
$ ./pasta
Outbound interface: eth0, namespace interface: eth0
ARP:
address: 28:16:ad:39:a9:ea
DHCP:
assign: 192.168.1.118
mask: 255.255.255.0
router: 192.168.1.1
NDP/DHCPv6:
assign: 2a02:6d40:3ca5:2001:b81d:fa4a:8cdd:cf17
router: fe80::62e3:27ff:fe33:2b01
#
Use dhclient instead of udhcpc For some reason, the passt/pasta tests and examples use dhclient for DHCPv6, but in most cases use udhcpc for DHCPv4. Change it to use dhclient for both DHCPv4 and DHCPv6. This means one less tool we need for testing, plus dhclient is easily available on Fedora whereas udhcpc is not. Note that the passt tests still rely on udhcpc indirectly because mbuto wants to put it into the guest images it generates. Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-06-10 02:32:44 +00:00
# dhclient -4 --no-pid
Tweak dhclient arguments for readability A number of tests and examples use dhclient in both IPv4 and IPv6 modes. We use "dhclient -6" for IPv6, but usually just "dhclient" for IPv4. Add an explicit "-4" argument to make it more clear and explicit. In addition, when dhclient is run from within pasta it usually won't be "real" root, and so will not have access to write the default global pid file. This results in a mostly harmless but irritating error: Can't create /var/run/dhclient.pid: Permission denied We can avoid that by using the --no-pid flag to dhclient. Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-06-10 02:32:43 +00:00
# dhclient -6 --no-pid
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
# ip address show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 65520 qdisc pfifo_fast state UNKNOWN group default qlen 1000
link/ether 5e:90:02:eb:b0:2a brd ff:ff:ff:ff:ff:ff
inet 192.168.1.118/24 brd 192.168.1.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 2a02:6d40:3ca5:2001:b81d:fa4a:8cdd:cf17/128 scope global
valid_lft forever preferred_lft forever
inet6 2a02:6d40:3ca5:2001:5c90:2ff:feeb:b02a/64 scope global dynamic mngtmpaddr
valid_lft 3591sec preferred_lft 3591sec
inet6 fe80::5c90:2ff:feeb:b02a/64 scope link
valid_lft forever preferred_lft forever
# ip route show
default via 192.168.1.1 dev eth0
192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.118
# ip -6 route show
2a02:6d40:3ca5:2001:b81d:fa4a:8cdd:cf17 dev eth0 proto kernel metric 256 pref medium
2a02:6d40:3ca5:2001::/64 dev eth0 proto kernel metric 256 expires 3584sec pref medium
fe80::/64 dev eth0 proto kernel metric 256 pref medium
default via fe80::62e3:27ff:fe33:2b01 dev eth0 proto ra metric 1024 expires 3584sec pref medium
# iperf3 -c 127.0.0.1 -t1
Connecting to host 127.0.0.1, port 5201
[ 5] local 127.0.0.1 port 51938 connected to 127.0.0.1 port 5201
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-1.00 sec 4.46 GBytes 38.3 Gbits/sec 0 3.93 MBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-1.00 sec 4.46 GBytes 38.3 Gbits/sec 0 sender
[ 5] 0.00-1.41 sec 4.45 GBytes 27.1 Gbits/sec receiver
iperf Done.
# iperf3 -c ::1 -t1
Connecting to host ::1, port 5201
[ 5] local ::1 port 50108 connected to ::1 port 5201
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-1.00 sec 4.35 GBytes 37.4 Gbits/sec 0 4.99 MBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-1.00 sec 4.35 GBytes 37.4 Gbits/sec 0 sender
[ 5] 0.00-1.41 sec 4.35 GBytes 26.4 Gbits/sec receiver
iperf Done.
# ping -c1 -4 spaghetti.pizza
PING spaghetti.pizza (172.67.192.217) 56(84) bytes of data.
64 bytes from 172.67.192.217: icmp_seq=1 ttl=255 time=37.3 ms
--- spaghetti.pizza ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
# ping -c1 -6 spaghetti.pizza
PING spaghetti.pizza(2606:4700:3034::6815:147a (2606:4700:3034::6815:147a)) 56 data bytes
64 bytes from 2606:4700:3034::6815:147a: icmp_seq=1 ttl=255 time=35.6 ms
--- spaghetti.pizza ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 35.605/35.605/35.605/0.000 ms
# logout
$
.RE
.fi
.BR "Connect an existing user and network namespace"
.RS
.nf
$ unshare -rUn
# echo $$
2446678
.fi
.BR " [From another terminal]"
.nf
$ ./pasta 2446678
Outbound interface: eth0, namespace interface: eth0
ARP:
address: 28:16:ad:39:a9:ea
DHCP:
assign: 192.168.1.118
mask: 255.255.255.0
router: 192.168.1.1
NDP/DHCPv6:
assign: 2a02:6d40:3ca5:2001:b81d:fa4a:8cdd:cf17
router: fe80::62e3:27ff:fe33:2b01
.fi
.BR " [Back to the original terminal]"
.nf
Use dhclient instead of udhcpc For some reason, the passt/pasta tests and examples use dhclient for DHCPv6, but in most cases use udhcpc for DHCPv4. Change it to use dhclient for both DHCPv4 and DHCPv6. This means one less tool we need for testing, plus dhclient is easily available on Fedora whereas udhcpc is not. Note that the passt tests still rely on udhcpc indirectly because mbuto wants to put it into the guest images it generates. Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-06-10 02:32:44 +00:00
# dhclient -4 --no-pid
Tweak dhclient arguments for readability A number of tests and examples use dhclient in both IPv4 and IPv6 modes. We use "dhclient -6" for IPv6, but usually just "dhclient" for IPv4. Add an explicit "-4" argument to make it more clear and explicit. In addition, when dhclient is run from within pasta it usually won't be "real" root, and so will not have access to write the default global pid file. This results in a mostly harmless but irritating error: Can't create /var/run/dhclient.pid: Permission denied We can avoid that by using the --no-pid flag to dhclient. Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-06-10 02:32:43 +00:00
# dhclient -6 --no-pid
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
# ip address show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 65520 qdisc pfifo_fast state UNKNOWN group default qlen 1000
link/ether fa:c1:2a:27:92:a9 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.118/24 brd 192.168.1.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 2a02:6d40:3ca5:2001:b81d:fa4a:8cdd:cf17/128 scope global
valid_lft forever preferred_lft forever
inet6 2a02:6d40:3ca5:2001:f8c1:2aff:fe27:92a9/64 scope global dynamic mngtmpaddr
valid_lft 3594sec preferred_lft 3594sec
inet6 fe80::f8c1:2aff:fe27:92a9/64 scope link
valid_lft forever preferred_lft forever
.fi
.RE
.SS \fBpasst
.BR "Start and connect a guest with basic port forwarding"
.RS
.nf
$ ./passt -f -t 2222:22
Outbound interface: eth0
ARP:
address: 28:16:ad:39:a9:ea
DHCP:
assign: 192.168.1.118
mask: 255.255.255.0
router: 192.168.1.1
search:
redhat.com
NDP/DHCPv6:
assign: 2a02:6d40:3ca5:2001:b81d:fa4a:8cdd:cf17
router: fe80::62e3:27ff:fe33:2b01
search:
redhat.com
UNIX domain socket bound at /tmp/passt_1.socket
You can now start qrap:
Invoke specific qemu-system-* binaries A lot of tests and examples invoke qemu with the command "kvm". However, as far as I can tell, "kvm" being aliased to the appropriate qemu system binary is Debian specific. The binary names from qemu upstream - qemu-system-$ARCH - also aren't universal, but they are more common (they should be good for both Debian and Fedora at least). In order to still get KVM acceleration when available, we use the option "-M accel=kvm:tcg" to tell qemu to try using either KVM or TCG in that order A number of the places we invoked "kvm" are expecting specifically an x86 guest, and so it's also safer to explicitly invoke qemu-system-x86_64. Some others appear to be independent of the target arch (just wanting the same arch as the host to allow KVM acceleration). Although I suspect there may be more subtle x86 specific options in the qemu command lines, attempt to preserve arch independence by using $(uname -m). Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-07-06 07:28:58 +00:00
./qrap 5 qemu-system-x86_64 ... -net socket,fd=5 -net nic,model=virtio
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
or directly qemu, patched with:
qemu/0001-net-Allow-also-UNIX-domain-sockets-to-be-used-as-net.patch
as follows:
Invoke specific qemu-system-* binaries A lot of tests and examples invoke qemu with the command "kvm". However, as far as I can tell, "kvm" being aliased to the appropriate qemu system binary is Debian specific. The binary names from qemu upstream - qemu-system-$ARCH - also aren't universal, but they are more common (they should be good for both Debian and Fedora at least). In order to still get KVM acceleration when available, we use the option "-M accel=kvm:tcg" to tell qemu to try using either KVM or TCG in that order A number of the places we invoked "kvm" are expecting specifically an x86 guest, and so it's also safer to explicitly invoke qemu-system-x86_64. Some others appear to be independent of the target arch (just wanting the same arch as the host to allow KVM acceleration). Although I suspect there may be more subtle x86 specific options in the qemu command lines, attempt to preserve arch independence by using $(uname -m). Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-07-06 07:28:58 +00:00
qemu-system-x86_64 ... -net socket,connect=/tmp/passt_1.socket -net nic,model=virtio
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.fi
.BR " [From another terminal]"
.nf
Invoke specific qemu-system-* binaries A lot of tests and examples invoke qemu with the command "kvm". However, as far as I can tell, "kvm" being aliased to the appropriate qemu system binary is Debian specific. The binary names from qemu upstream - qemu-system-$ARCH - also aren't universal, but they are more common (they should be good for both Debian and Fedora at least). In order to still get KVM acceleration when available, we use the option "-M accel=kvm:tcg" to tell qemu to try using either KVM or TCG in that order A number of the places we invoked "kvm" are expecting specifically an x86 guest, and so it's also safer to explicitly invoke qemu-system-x86_64. Some others appear to be independent of the target arch (just wanting the same arch as the host to allow KVM acceleration). Although I suspect there may be more subtle x86 specific options in the qemu command lines, attempt to preserve arch independence by using $(uname -m). Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-07-06 07:28:58 +00:00
$ ./qrap 5 qemu-system-x86_64 test.qcow2 -m 1024 -display none -nodefaults -nographic -net socket,fd=5 -net nic,model=virtio
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
Connected to /tmp/passt_1.socket
.fi
.BR " [Back to the original terminal]"
.nf
passt: DHCP: ack to request
passt: from 52:54:00:12:34:56
passt: NDP: received NS, sending NA
passt: NDP: received RS, sending RA
passt: DHCPv6: received SOLICIT, sending ADVERTISE
passt: NDP: received NS, sending NA
passt: DHCPv6: received REQUEST/RENEW/CONFIRM, sending REPLY
passt: NDP: received NS, sending NA
.fi
.BR " [From yet another terminal]"
.nf
$ ssh -p 2222 root@localhost
root@localhost's password:
.fi
.BR " [...]"
.nf
# ip address show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 65520 qdisc pfifo_fast state UP group default qlen 1000
link/ether 52:54:00:12:34:56 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.118/24 brd 192.168.1.255 scope global noprefixroute ens2
valid_lft forever preferred_lft forever
inet6 2a02:6d40:3ca5:2001:b81d:fa4a:8cdd:cf17/128 scope global noprefixroute
valid_lft forever preferred_lft forever
inet6 2a02:6d40:3ca5:2001:b019:9ae2:a2fe:e6b4/64 scope global dynamic noprefixroute
valid_lft 3588sec preferred_lft 3588sec
inet6 fe80::1f98:d09f:9309:9e77/64 scope link noprefixroute
valid_lft forever preferred_lft forever
.fi
.RE
.SH NOTES
passt.1: Fix typo: "addressses", reported by Lintian Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-10-27 12:28:00 +00:00
.SS Handling of traffic with local destination and source addresses
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
Both \fBpasst\fR and \fBpasta\fR can bind on ports with a local address,
depending on the configuration. Local destination or source addresses need to be
changed before packets are delivered to the guest or target namespace: most
operating systems would drop packets received from non-loopback interfaces with
local addresses, and it would also be impossible for guest or target namespace
to route answers back.
For convenience, and somewhat arbitrarily, the source address on these packets
is translated to the address of the default IPv4 or IPv6 gateway -- this is
known to be an existing, valid address on the same subnet.
Loopback destination addresses are instead translated to the observed external
address of the guest or target namespace. For IPv6 packets, if usage of a
link-local address by guest or namespace has ever been observed, and the
original destination address is also a link-local address, the observed
link-local address is used. Otherwise, the observed global address is used. For
both IPv4 and IPv6, if no addresses have been seen yet, the configured addresses
will be used instead.
For example, if \fBpasst\fR or \fBpasta\fR receive a connection from 127.0.0.1,
with destination 127.0.0.10, and the default IPv4 gateway is 192.0.2.1, while
the last observed source address from guest or namespace is 192.0.2.2, this will
be translated to a connection from 192.0.2.1 to 192.0.2.2.
Similarly, for traffic coming from guest or namespace, packets with destination
address corresponding to the default gateway will have their destination address
translated to a loopback address, if and only if a packet, in the opposite
direction, with a loopback destination or source address, port-wise matching for
UDP, or connection-wise for TCP, has been recently forwarded to guest or
conf, tcp, udp: Add --no-map-gw to disable mapping gateway address to host Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-10-14 03:26:37 +00:00
namespace. This behaviour can be disabled with \-\-no\-map\-gw.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.SS Handling of local traffic in pasta
Depending on the configuration, \fBpasta\fR can bind to local ports in the init
namespace, in the target namespace, or both, and forward connections and packets
to corresponding ports in the other namespace.
To avoid unnecessary overhead, these connections and packets are not forwarded
through the tap device connecting the namespaces: \fBpasta\fR creates a socket
in the destination namespace, with matching Layer-4 protocol, and uses it to
forward local data. For TCP, data is forwarded between the originating socket
and the new socket using the \fBsplice\fR(2) system call, and for UDP, a pair
of \fBrecvmmsg\fR(2) and \fBsendmmsg\fR(2) system calls deals with packet
transfers.
This bypass only applies to local connections and traffic, because it's not
possible to bind sockets to foreign addresses.
.SS Binding to low numbered ports (well-known or system ports, up to 1023)
conf: Bind inbound ports with CAP_NET_BIND_SERVICE before isolate_user() Even if CAP_NET_BIND_SERVICE is granted, we'll lose the capability in the target user namespace as we isolate the process, which means we're unable to bind to low ports at that point. Bind inbound ports, and only those, before isolate_user(). Keep the handling of outbound ports (for pasta mode only) after the setup of the namespace, because that's where we'll bind them. To this end, initialise the netlink socket for the init namespace before isolate_user() as well, as we actually need to know the addresses of the upstream interface before binding ports, in case they're not explicitly passed by the user. As we now call nl_sock_init() twice, checking its return code from conf() twice looks a bit heavy: make it exit(), instead, as we can't do much if we don't have netlink sockets. While at it: - move the v4_only && v6_only options check just after the first option processing loop, as this is more strictly related to option parsing proper - update the man page, explaining that CAP_NET_BIND_SERVICE is *not* the preferred way to bind ports, because passt and pasta can be abused to allow other processes to make effective usage of it. Add a note about the recommended sysctl instead - simplify nl_sock_init_do() now that it's called once for each case Reported-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-10-13 16:21:27 +00:00
If the port forwarding configuration requires binding to ports with numbers
lower than 1024, \fBpasst\fR and \fBpasta\fR will try to bind to them, but will
fail, unless, either:
.IP \(bu 2
the \fIsys.net.ipv4.ip_unprivileged_port_start\fR sysctl is set to the number
of the lowest port \fBpasst\fR and \fBpasta\fR need. For example, as root:
.nf
sysctl -w net.ipv4.ip_unprivileged_port_start=443
.fi
\fBNote\fR: this is the recommended way of enabling \fBpasst\fR and \fBpasta\fR
to bind to ports with numbers below 1024.
.IP \(bu
or the \fICAP_NET_BIND_SERVICE\fR Linux capability is granted, see
\fBservices\fR(5) and \fBcapabilities\fR(7).
This is, in general, \fBnot the recommended way\fR, because \fBpasst\fR and
\fBpasta\fR might be used as vector to effectively use this capability from
another process.
However, if your environment is sufficiently controlled by an LSM (Linux
Security Module) such as \fIAppArmor\fR, \fISELinux\fR, \fISmack\fR or
\fITOMOYO\fR, and no other processes can interact in such a way in virtue of
this, granting this capability to \fBpasst\fR and \fBpasta\fR only can
effectively prevent other processes from utilising it.
Note that this will not work for automatic detection and forwarding of ports
with \fBpasta\fR, because \fBpasta\fR will relinquish this capability at
runtime.
To grant this capability, you can issue, as root:
.nf
for p in $(which passt passt.avx2); do
setcap 'cap_net_bind_service=+ep' "${p}"
done
.fi
doc: Add to man page tip to grant passt the CAP_NET_BIND_SERVICE capability Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-10-12 21:03:01 +00:00
.RE
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.SS ICMP/ICMPv6 Echo sockets
ICMP and ICMPv6 Echo requests coming from guest or target namespace are handled
using so-called "ping" sockets, introduced in Linux 2.6.30. To preserve the
original identifier (see RFC 792, page 14, for ICMP, and RFC 4443, section 4.1,
for ICMPv6), \fBpasst\fR and \fBpasta\fR try to bind these sockets using the
observed source identifier as "port" -- that corresponds to Echo identifiers
for "ping" sockets.
As \fBbind\fR(2) failures were seen with particularly restrictive SELinux
policies, a fall-back mechanism maps different identifiers to different sockets,
and identifiers in replies will be mapped back to the original identifier of the
request. However, if \fBbind\fR(2) fails and the fall-back mechanism is used,
echo requests will be forwarded with different, albeit unique, identifiers.
For ICMP and ICMPv6 Echo requests to work, the \fIping_group_range\fR parameter
needs to include the PID of \fBpasst\fR or \fBpasta\fR, see \fBicmp\fR(7).
.SS pasta and loopback interface
As \fBpasta\fR connects to an existing namespace, or once it creates a new
namespace, it will also ensure that the loopback interface, \fIlo\fR, is brought
up. This is needed to bind ports using the loopback address in the namespace.
.SS TCP sending window and \fITCP_INFO\fB before Linux 5.3
To synchronise the TCP sending window from host Layer-4 sockets to the TCP
parameters announced in TCP segments sent over the Layer-2 interface,
\fBpasst\fR and \fBpasta\fR routinely query the size of the sending window seen
by the kernel on the corresponding socket using the \fITCP_INFO\fR socket
option, see \fBtcp\fR(7). Before Linux 5.3, i.e. before Linux kernel commit
8f7baad7f035 ("tcp: Add snd_wnd to TCP_INFO"), the sending window
(\fIsnd_wnd\fR field) is not available.
doc: Fix up note about missing tcpi_snd_wnd in man page The behaviour without tcpi_snd_wnd changed: the only difference now is the advertised window, which corresponds to the queried sending buffer size. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-10-12 20:56:36 +00:00
If the sending window cannot be queried, it will always be announced as the
current sending buffer size to guest or target namespace. This might affect
throughput of TCP connections.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.SH LIMITATIONS
Currently, IGMP/MLD proxying (RFC 4605) and support for SCTP (RFC 4960) are not
implemented.
TCP Selective Acknowledgment (RFC 2018), as well as Protection Against Wrapped
Sequences (PAWS) and Round-Trip Time Measurement (RTTM), both described by RFC
7232, are currently not implemented.
passt.1: Add David to AUTHORS I just realised while reading the man page. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2022-10-13 19:58:13 +00:00
.SH AUTHORS
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
passt.1: Add David to AUTHORS I just realised while reading the man page. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2022-10-13 19:58:13 +00:00
Stefano Brivio <sbrivio@redhat.com>, David Gibson <david@gibson.dropbear.id.au>.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.SH REPORTING BUGS
man page: Update REPORTING BUGS section Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-02-19 03:39:47 +00:00
Please report issues on the bug tracker at https://passt.top/passt/bugs, or
send a message to the passt-user@passt.top mailing list, see
https://passt.top/passt/lists.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
.SH COPYRIGHT
man page: Update REPORTING BUGS section Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-02-19 03:39:47 +00:00
Copyright (c) 2020-2022 Red Hat GmbH.
passt, qrap: Add man pages Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-08-19 18:22:40 +00:00
\fBpasst\fR and \fBpasta\fR are free software: you can redistribute them and/or
modify them under the terms of the GNU Affero General Public License as
published by the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
.SH SEE ALSO
\fBnamespaces\fR(7), \fBqemu\fR(1), \fBqrap\fR(1), \fBslirp4netns\fR(1).
High-level documentation is available at https://passt.top/passt/about/.
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