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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 1.6 by root, Sat Sep 3 23:47:02 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
… …
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 35
36Example: unshare the network namespace and prove that by calling ifconfig, 36Example: unshare the network namespace and prove that by calling ifconfig,
37showing only an unconfigured lo interface. 37showing only the unconfigured lo interface.
38 38
39 Linux::Clone::unshare Linux::Clone::NEWNET 39 Linux::Clone::unshare Linux::Clone::NEWNET
40 and "unshare: $!"; 40 and "unshare: $!";
41 Linux::Clone::configure_loopback;
41 system "ifconfig -a"; 42 system "ifconfig";
42 43
43Example: unshare the network namespace, initialise the loopback interface, 44Example: unshare the network namespace, initialise the loopback interface,
44create a veth interface pair, put one interface into the parent processes 45create a veth interface pair, put one interface into the parent processes
45namespace (use ifconfig -a from another shell), configure the other 46namespace (use ifconfig -a from another shell), configure the other
46interface with 192.168.99.2 -> 192.168.99.1 and start a shell. 47interface with 192.168.99.2 -> 192.168.99.1 and start a shell.
… …
49 50
50 # unshare our network namespace 51 # unshare our network namespace
51 Linux::Clone::unshare Linux::Clone::NEWNET 52 Linux::Clone::unshare Linux::Clone::NEWNET
52 and "unshare: $!"; 53 and "unshare: $!";
53 54
55 Linux::Clone::configure_loopback;
56
54 my $ppid = getppid; 57 my $ppid = getppid;
55 58
56 system " 59 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 60 # create veth pair
62 ip link add name veth_master type veth peer name veth_slave 61 ip link add name veth_master type veth peer name veth_slave
63 62
64 # move veth_master to our parent process' namespace 63 # move veth_master to our parent process' namespace
65 ip link set veth_master netns $ppid 64 ip link set veth_master netns $ppid
… …
88 use Linux::Clone; 87 use Linux::Clone;
89 88
90 Linux::Clone::unshare Linux::Clone::NEWNS 89 Linux::Clone::unshare Linux::Clone::NEWNS
91 and die "unshare: $!"; 90 and die "unshare: $!";
92 91
93 # now bind-mount /lib over /etc and ls -l /etc - scary 92 # now bind-mount /lib over /etc and ls -l /etc - looks scary
94 system "mount -n --bind /lib /etc"; 93 system "mount -n --bind /lib /etc";
95 system "ls -l /etc"; 94 system "ls -l /etc";
96 95
97=item $retval = Linux::Clone::clone $coderef, $stacksize, $flags[, $ptid, $tls, $ctid] 96=item $retval = Linux::Clone::clone $coderef, $stacksize, $flags[, $ptid, $tls, $ctid]
98 97
… …
123 Linux::Clone::VFORK 122 Linux::Clone::VFORK
124 Linux::Clone::SETTLS (not yet implemented) 123 Linux::Clone::SETTLS (not yet implemented)
125 Linux::Clone::PARENT_SETTID (not yet implemented) 124 Linux::Clone::PARENT_SETTID (not yet implemented)
126 Linux::Clone::CHILD_SETTID (not yet implemented) 125 Linux::Clone::CHILD_SETTID (not yet implemented)
127 Linux::Clone::CHILD_CLEARTID (not yet implemented) 126 Linux::Clone::CHILD_CLEARTID (not yet implemented)
127 Linux::Clone::PIDFD (not yet implemented)
128 Linux::Clone::DETACHED 128 Linux::Clone::DETACHED
129 Linux::Clone::UNTRACED 129 Linux::Clone::UNTRACED
130 Linux::Clone::IO 130 Linux::Clone::IO
131 Linux::Clone::CSIGNAL exit signal mask
131 132
132Note that for practical reasons you basically must not use 133Note that for practical reasons you basically must not use
133C<Linux::Clone::VM> or C<Linux::Clone::VFORK>, as perl is unlikely to cope 134C<Linux::Clone::VM> or C<Linux::Clone::VFORK>, as perl is unlikely to cope
134with that. 135with that.
135 136
… …
162 163
163C<Linux::Clone::KCMP_FILE>, C<Linux::Clone::KCMP_VM>, C<Linux::Clone::KCMP_FILES>, 164C<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 165C<Linux::Clone::KCMP_FS>, C<Linux::Clone::KCMP_SIGHAND>, C<Linux::Clone::KCMP_IO> and
165C<Linux::Clone::KCMP_SYSVSEM>. 166C<Linux::Clone::KCMP_SYSVSEM>.
166 167
168=item Linux::Clone::configure_loopback
169
170Configures a working loopback interface (basically, does the equivalent of
171"ifconfig lo up" which automatically adds ipv4/ipv6 addresses and routes),
172which can be useful to get a network namespace going.
173
174Dies on error and returns nothing.
167 175
168=back 176=back
169 177
170=cut 178=cut
171 179
172package Linux::Clone; 180package Linux::Clone;
173 181
174# use common::sense; 182# use common::sense;
175 183
176BEGIN { 184BEGIN {
177 our $VERSION = '1.2'; 185 our $VERSION = '1.3';
178 186
179 require XSLoader; 187 require XSLoader;
180 XSLoader::load (__PACKAGE__, $VERSION); 188 XSLoader::load (__PACKAGE__, $VERSION);
181} 189}
182 190
191sub configure_loopback() {
192 siocsifflags "lo"
193 and die "Linux::Clone::configure_looopback: unable to bring up loopback interface: $!\n";
194}
195
1831; 1961;
184 197
185=head1 AUTHOR 198=head1 AUTHOR
186 199
187 Marc Lehmann <schmorp@schmorp.de> 200 Marc Lehmann <schmorp@schmorp.de>

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