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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 12:50:00 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 12:50:00 +0000 |
commit | 333f7ecfa3e040191c66b2b92f6c117ca2cbac1d (patch) | |
tree | 178a8f140927896970f47930dae9213161268f10 /man/man5/subuid.5 | |
parent | Initial commit. (diff) | |
download | shadow-333f7ecfa3e040191c66b2b92f6c117ca2cbac1d.tar.xz shadow-333f7ecfa3e040191c66b2b92f6c117ca2cbac1d.zip |
Adding upstream version 1:4.8.1.upstream/1%4.8.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | man/man5/subuid.5 | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/man/man5/subuid.5 b/man/man5/subuid.5 new file mode 100644 index 0000000..0876ecb --- /dev/null +++ b/man/man5/subuid.5 @@ -0,0 +1,100 @@ +'\" t +.\" Title: subuid +.\" Author: Eric Biederman +.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/> +.\" Date: 01/23/2020 +.\" Manual: File Formats and Conversions +.\" Source: shadow-utils 4.8.1 +.\" Language: English +.\" +.TH "SUBUID" "5" "01/23/2020" "shadow\-utils 4\&.8\&.1" "File Formats and Conversions" +.\" ----------------------------------------------------------------- +.\" * Define some portability stuff +.\" ----------------------------------------------------------------- +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.\" http://bugs.debian.org/507673 +.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.ie \n(.g .ds Aq \(aq +.el .ds Aq ' +.\" ----------------------------------------------------------------- +.\" * set default formatting +.\" ----------------------------------------------------------------- +.\" disable hyphenation +.nh +.\" disable justification (adjust text to left margin only) +.ad l +.\" ----------------------------------------------------------------- +.\" * MAIN CONTENT STARTS HERE * +.\" ----------------------------------------------------------------- +.SH "NAME" +subuid \- the subordinate uid file +.SH "DESCRIPTION" +.PP +Each line in +/etc/subuid +contains a user name and a range of subordinate user ids that user is allowed to use\&. This is specified with three fields delimited by colons (\(lq:\(rq)\&. These fields are: +.sp +.RS 4 +.ie n \{\ +\h'-04'\(bu\h'+03'\c +.\} +.el \{\ +.sp -1 +.IP \(bu 2.3 +.\} +login name or UID +.RE +.sp +.RS 4 +.ie n \{\ +\h'-04'\(bu\h'+03'\c +.\} +.el \{\ +.sp -1 +.IP \(bu 2.3 +.\} +numerical subordinate user ID +.RE +.sp +.RS 4 +.ie n \{\ +\h'-04'\(bu\h'+03'\c +.\} +.el \{\ +.sp -1 +.IP \(bu 2.3 +.\} +numerical subordinate user ID count +.RE +.PP +This file specifies the user IDs that ordinary users can use, with the +\fBnewuidmap\fR +command, to configure uid mapping in a user namespace\&. +.PP +Multiple ranges may be specified per user\&. +.PP +When large number of entries (10000\-100000 or more) are defined in +/etc/subuid, parsing performance penalty will become noticeable\&. In this case it is recommended to use UIDs instead of login names\&. Benchmarks have shown speed\-ups up to 20x\&. +.SH "FILES" +.PP +/etc/subuid +.RS 4 +Per user subordinate user IDs\&. +.RE +.PP +/etc/subuid\- +.RS 4 +Backup file for /etc/subuid\&. +.RE +.SH "SEE ALSO" +.PP +\fBlogin.defs\fR(5), +\fBnewgidmap\fR(1), +\fBnewuidmap\fR(1), +\fBnewusers\fR(1), +\fBsubgid\fR(5), +\fBuseradd\fR(8), +\fBuserdel\fR(8), +\fBusermod\fR(8), +\fBuser_namespaces\fR(7)\&. |