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Comparing Linux-Clone/Clone.pm (file contents):
Revision 1.5 by root, Mon Jul 25 10:59:29 2022 UTC vs.
Revision 1.10 by root, Tue Sep 6 10:57:01 2022 UTC

… …
6 6
7 use Linux::Clone; 7 use Linux::Clone;
8 8
9=head1 DESCRIPTION 9=head1 DESCRIPTION
10 10
11This module exposes the linux clone(2), unshare(2) and related syscalls to 11This module exposes the linux clone(2), unshare(2) and some related
12Perl. 12syscalls to Perl.
13 13
14=over 4 14=over 4
15 15
16=item $retval = unshare $flags 16=item $retval = unshare $flags
17 17
… …
30 Linux::Clone::NEWPID 30 Linux::Clone::NEWPID
31 Linux::Clone::NEWUTS 31 Linux::Clone::NEWUTS
32 Linux::Clone::NEWIPC 32 Linux::Clone::NEWIPC
33 Linux::Clone::NEWNET 33 Linux::Clone::NEWNET
34 Linux::Clone::NEWCGROUP 34 Linux::Clone::NEWCGROUP
35 Linux::Clone::NEWTIME
35 36
36Example: unshare the network namespace and prove that by calling ifconfig, 37Example: unshare the network namespace and prove that by calling ifconfig,
37showing only an unconfigured lo interface. 38showing only the unconfigured lo interface.
38 39
39 Linux::Clone::unshare Linux::Clone::NEWNET 40 Linux::Clone::unshare Linux::Clone::NEWNET
40 and "unshare: $!"; 41 and "unshare: $!";
42 Linux::Clone::configure_loopback;
41 system "ifconfig -a"; 43 system "ifconfig";
42 44
43Example: unshare the network namespace, initialise the loopback interface, 45Example: unshare the network namespace, initialise the loopback interface,
44create a veth interface pair, put one interface into the parent processes 46create a veth interface pair, put one interface into the parent processes
45namespace (use ifconfig -a from another shell), configure the other 47namespace (use ifconfig -a from another shell), configure the other
46interface with 192.168.99.2 -> 192.168.99.1 and start a shell. 48interface with 192.168.99.2 -> 192.168.99.1 and start a shell.
… …
49 51
50 # unshare our network namespace 52 # unshare our network namespace
51 Linux::Clone::unshare Linux::Clone::NEWNET 53 Linux::Clone::unshare Linux::Clone::NEWNET
52 and "unshare: $!"; 54 and "unshare: $!";
53 55
56 Linux::Clone::configure_loopback;
57
54 my $ppid = getppid; 58 my $ppid = getppid;
55 59
56 system " 60 system "
57 # configure loopback interface
58 ip link set lo up
59 ip route add 127.0.0.0/8 dev lo
60
61 # create veth pair 61 # create veth pair
62 ip link add name veth_master type veth peer name veth_slave 62 ip link add name veth_master type veth peer name veth_slave
63 63
64 # move veth_master to our parent process' namespace 64 # move veth_master to our parent process' namespace
65 ip link set veth_master netns $ppid 65 ip link set veth_master netns $ppid
… …
88 use Linux::Clone; 88 use Linux::Clone;
89 89
90 Linux::Clone::unshare Linux::Clone::NEWNS 90 Linux::Clone::unshare Linux::Clone::NEWNS
91 and die "unshare: $!"; 91 and die "unshare: $!";
92 92
93 # now bind-mount /lib over /etc and ls -l /etc - scary 93 # now bind-mount /lib over /etc and ls -l /etc - looks scary
94 system "mount -n --bind /lib /etc"; 94 system "mount -n --bind /lib /etc";
95 system "ls -l /etc"; 95 system "ls -l /etc";
96 96
97=item $retval = Linux::Clone::clone $coderef, $stacksize, $flags[, $ptid, $tls, $ctid] 97=item $retval = Linux::Clone::clone $coderef, $stacksize, $flags[, $ptid, $tls, $ctid]
98 98
… …
123 Linux::Clone::VFORK 123 Linux::Clone::VFORK
124 Linux::Clone::SETTLS (not yet implemented) 124 Linux::Clone::SETTLS (not yet implemented)
125 Linux::Clone::PARENT_SETTID (not yet implemented) 125 Linux::Clone::PARENT_SETTID (not yet implemented)
126 Linux::Clone::CHILD_SETTID (not yet implemented) 126 Linux::Clone::CHILD_SETTID (not yet implemented)
127 Linux::Clone::CHILD_CLEARTID (not yet implemented) 127 Linux::Clone::CHILD_CLEARTID (not yet implemented)
128 Linux::Clone::PIDFD (not yet implemented)
128 Linux::Clone::DETACHED 129 Linux::Clone::DETACHED
129 Linux::Clone::UNTRACED 130 Linux::Clone::UNTRACED
130 Linux::Clone::IO 131 Linux::Clone::IO
132 Linux::Clone::CSIGNAL exit signal mask
131 133
132Note that for practical reasons you basically must not use 134Note that for practical reasons you basically must not use
133C<Linux::Clone::VM> or C<Linux::Clone::VFORK>, as perl is unlikely to cope 135C<Linux::Clone::VM> or C<Linux::Clone::VFORK>, as perl is unlikely to cope
134with that. 136with that.
135 137
… …
159 161
160The following C<$type> constants are available if the kcmp syscall number 162The following C<$type> constants are available if the kcmp syscall number
161was available during compilation: 163was available during compilation:
162 164
163C<Linux::Clone::KCMP_FILE>, C<Linux::Clone::KCMP_VM>, C<Linux::Clone::KCMP_FILES>, 165C<Linux::Clone::KCMP_FILE>, C<Linux::Clone::KCMP_VM>, C<Linux::Clone::KCMP_FILES>,
164C<Linux::Clone::KCMP_FS>, C<Linux::Clone::KCMP_SIGHAND>, C<Linux::Clone::KCMP_IO> and 166C<Linux::Clone::KCMP_FS>, C<Linux::Clone::KCMP_SIGHAND>, C<Linux::Clone::KCMP_IO>,
165C<Linux::Clone::KCMP_SYSVSEM>. 167C<Linux::Clone::KCMP_SYSVSEM> and C<Linux::Clone::KCMP_EPOLL_TFD>.
166 168
169=item Linux::Clone::configure_loopback
170
171Configures a working loopback interface (basically, does the equivalent of
172"ifconfig lo up" which automatically adds ipv4/ipv6 addresses and routes),
173which can be useful to get a network namespace going.
174
175Dies on error and returns nothing.
176
177=item C<ioctl> symbols
178
179The following ioctl symbols are also provided by this module (see L<ioctl_ns(8)>).
180
181 Linux::Clone::NS_GET_USERNS
182 Linux::Clone::NS_GET_PARENT
183 Linux::Clone::NS_GET_NSTYPE
184 Linux::Clone::NS_OWNER_UID
167 185
168=back 186=back
169 187
170=cut 188=cut
171 189
172package Linux::Clone; 190package Linux::Clone;
173 191
174# use common::sense; 192# use common::sense;
175 193
176BEGIN { 194BEGIN {
177 our $VERSION = '1.2'; 195 our $VERSION = '1.3';
178 196
179 require XSLoader; 197 require XSLoader;
180 XSLoader::load (__PACKAGE__, $VERSION); 198 XSLoader::load (__PACKAGE__, $VERSION);
181} 199}
182 200
201sub configure_loopback() {
202 siocsifflags "lo"
203 and die "Linux::Clone::configure_looopback: unable to bring up loopback interface: $!\n";
204}
205
1831; 2061;
207
208=head1 SEE ALSO
209
210L<IO::AIO> has some related functions, such as C<pidfd_send_signal>, and
211some unrelated functions that might be useful.
212
213L<namspaces(7)>, L<cgroup_namespaces(7)>, L<pid_namespaces(7)>,
214L<user_namespaces(7)>, L<time_namespaces(7)>, L<ip-netns(8)>,
215L<switch_root(8)>, L<ioctl_ns(2)>, L<lsns(8)>Q
184 216
185=head1 AUTHOR 217=head1 AUTHOR
186 218
187 Marc Lehmann <schmorp@schmorp.de> 219 Marc Lehmann <schmorp@schmorp.de>
188 http://home.schmorp.de/ 220 http://home.schmorp.de/

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