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Diffstat (limited to 'passt-repair.1')
| -rw-r--r-- | passt-repair.1 | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/passt-repair.1 b/passt-repair.1 new file mode 100644 index 0000000..8d07c97 --- /dev/null +++ b/passt-repair.1 @@ -0,0 +1,70 @@ +.\" SPDX-License-Identifier: GPL-2.0-or-later +.\" Copyright (c) 2025 Red Hat GmbH +.\" Author: Stefano Brivio <sbrivio@redhat.com> +.TH passt-repair 1 + +.SH NAME +.B passt-repair +\- Helper setting TCP_REPAIR socket options for \fBpasst\fR(1) + +.SH SYNOPSIS +.B passt-repair +\fIPATH\fR + +.SH DESCRIPTION + +.B passt-repair +is a privileged helper setting and clearing repair mode on TCP sockets on behalf +of \fBpasst\fR(1), as instructed via single-byte commands over a UNIX domain +socket, specified by \fIPATH\fR. + +It can be used to migrate TCP connections between guests without granting +additional capabilities to \fBpasst\fR(1) itself: to migrate TCP connections, +\fBpasst\fR(1) leverages repair mode, which needs the \fBCAP_NET_ADMIN\fR +capability (see \fBcapabilities\fR(7)) to be set or cleared. + +.SH PROTOCOL + +\fBpasst-repair\fR(1) connects to \fBpasst\fR(1) using the socket specified via +\fI--repair-path\fR option in \fBpasst\fR(1) itself. By default, the name is the +same as the UNIX domain socket used for guest communication, suffixed by +\fI.repair\fR. + +The messages consist of one 8-bit signed integer that can be \fITCP_REPAIR_ON\fR +(1), \fITCP_REPAIR_OFF\fR (2), or \fITCP_REPAIR_OFF_WP\fR (-1), as defined by +the Linux kernel user API, and one to SCM_MAX_FD (253) sockets as SCM_RIGHTS +(see \fBunix\fR(7)) ancillary message, sent by the server, \fBpasst\fR(1). + +The client, \fBpasst-repair\fR(1), replies with the same byte (and no ancillary +message) to indicate success, and closes the connection on failure. + +The server closes the connection on error or completion. + +.SH NOTES + +\fBpasst-repair\fR(1) can be granted the \fBCAP_NET_ADMIN\fR capability +(preferred, as it limits privileges to the strictly necessary ones), or it can +be run as root. + +.SH AUTHOR + +Stefano Brivio <sbrivio@redhat.com>. + +.SH REPORTING BUGS + +Please report issues on the bug tracker at https://bugs.passt.top/, or +send a message to the passt-user@passt.top mailing list, see +https://lists.passt.top/. + +.SH COPYRIGHT + +Copyright (c) 2025 Red Hat GmbH. + +\fBpasst-repair\fR is free software: you can redistribute them and/or modify +them under the terms of the GNU General Public License as published by the Free +Software Foundation, either version 2 of the License, or (at your option) any +later version. + +.SH SEE ALSO + +\fBpasst\fR(1), \fBqemu\fR(1), \fBcapabilities\fR(7), \fBunix\fR(7). |