]>
git.proxmox.com Git - mirror_lxc.git/blob - src/lxc/namespace.c
2 * lxc: linux Container library
4 * (C) Copyright IBM Corp. 2007, 2009
7 * Daniel Lezcano <daniel.lezcano at free.fr>
9 * This library is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
14 * This library is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with this library; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
29 #include <sys/param.h>
31 #include <sys/types.h>
34 #include "namespace.h"
37 lxc_log_define(lxc_namespace
, lxc
);
44 static int do_clone(void *arg
)
46 struct clone_arg
*clone_arg
= arg
;
47 return clone_arg
->fn(clone_arg
->arg
);
50 pid_t
lxc_clone(int (*fn
)(void *), void *arg
, int flags
)
52 struct clone_arg clone_arg
= {
57 size_t stack_size
= lxc_getpagesize();
58 void *stack
= alloca(stack_size
);
62 ret
= __clone2(do_clone
, stack
,
63 stack_size
, flags
| SIGCHLD
, &clone_arg
);
65 ret
= clone(do_clone
, stack
+ stack_size
, flags
| SIGCHLD
, &clone_arg
);
68 ERROR("Failed to clone (%#x): %s.", flags
, strerror(errno
));
73 /* Leave the user namespace at the first position in the array of structs so
74 * that we always attach to it first when iterating over the struct and using
75 * setns() to switch namespaces. This especially affects lxc_attach(): Suppose
76 * you cloned a new user namespace and mount namespace as an unprivileged user
77 * on the host and want to setns() to the mount namespace. This requires you to
78 * attach to the user namespace first otherwise the kernel will fail this check:
80 * if (!ns_capable(mnt_ns->user_ns, CAP_SYS_ADMIN) ||
81 * !ns_capable(current_user_ns(), CAP_SYS_CHROOT) ||
82 * !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
87 * linux/fs/namespace.c:mntns_install().
89 const struct ns_info ns_info
[LXC_NS_MAX
] = {
90 [LXC_NS_USER
] = { "user", CLONE_NEWUSER
, "CLONE_NEWUSER", "LXC_USER_NS" },
91 [LXC_NS_MNT
] = { "mnt", CLONE_NEWNS
, "CLONE_NEWNS", "LXC_MNT_NS" },
92 [LXC_NS_PID
] = { "pid", CLONE_NEWPID
, "CLONE_NEWPID", "LXC_PID_NS" },
93 [LXC_NS_UTS
] = { "uts", CLONE_NEWUTS
, "CLONE_NEWUTS", "LXC_UTS_NS" },
94 [LXC_NS_IPC
] = { "ipc", CLONE_NEWIPC
, "CLONE_NEWIPC", "LXC_IPC_NS" },
95 [LXC_NS_NET
] = { "net", CLONE_NEWNET
, "CLONE_NEWNET", "LXC_NET_NS" },
96 [LXC_NS_CGROUP
] = { "cgroup", CLONE_NEWCGROUP
, "CLONE_NEWCGROUP", "LXC_CGROUP_NS" }
99 int lxc_namespace_2_cloneflag(const char *namespace)
102 for (i
= 0; i
< LXC_NS_MAX
; i
++)
103 if (!strcasecmp(ns_info
[i
].proc_name
, namespace))
104 return ns_info
[i
].clone_flag
;
106 ERROR("Invalid namespace name \"%s\"", namespace);
110 int lxc_namespace_2_ns_idx(const char *namespace)
113 for (i
= 0; i
< LXC_NS_MAX
; i
++)
114 if (!strcmp(ns_info
[i
].proc_name
, namespace))
117 ERROR("Invalid namespace name \"%s\"", namespace);
121 int lxc_fill_namespace_flags(char *flaglist
, int *flags
)
123 char *token
, *saveptr
= NULL
;
127 ERROR("At least one namespace is needed.");
131 token
= strtok_r(flaglist
, "|", &saveptr
);
134 aflag
= lxc_namespace_2_cloneflag(token
);
140 token
= strtok_r(NULL
, "|", &saveptr
);