2 * Copyright (C) 2004 IBM Corporation
4 * Author: Serge Hallyn <serue@us.ibm.com>
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation, version 2 of the
12 #include <linux/export.h>
13 #include <linux/uts.h>
14 #include <linux/utsname.h>
15 #include <linux/err.h>
16 #include <linux/slab.h>
17 #include <linux/user_namespace.h>
18 #include <linux/proc_ns.h>
20 static struct uts_namespace *create_uts_ns(void)
22 struct uts_namespace *uts_ns;
24 uts_ns = kmalloc(sizeof(struct uts_namespace), GFP_KERNEL);
26 kref_init(&uts_ns->kref);
31 * Clone a new ns copying an original utsname, setting refcount to 1
32 * @old_ns: namespace to clone
33 * Return ERR_PTR(-ENOMEM) on error (failure to kmalloc), new ns otherwise
35 static struct uts_namespace *clone_uts_ns(struct user_namespace *user_ns,
36 struct uts_namespace *old_ns)
38 struct uts_namespace *ns;
43 return ERR_PTR(-ENOMEM);
45 err = proc_alloc_inum(&ns->proc_inum);
52 memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
53 ns->user_ns = get_user_ns(user_ns);
59 * Copy task tsk's utsname namespace, or clone it if flags
60 * specifies CLONE_NEWUTS. In latter case, changes to the
61 * utsname of this process won't be seen by parent, and vice
64 struct uts_namespace *copy_utsname(unsigned long flags,
65 struct user_namespace *user_ns, struct uts_namespace *old_ns)
67 struct uts_namespace *new_ns;
72 if (!(flags & CLONE_NEWUTS))
75 new_ns = clone_uts_ns(user_ns, old_ns);
81 void free_uts_ns(struct kref *kref)
83 struct uts_namespace *ns;
85 ns = container_of(kref, struct uts_namespace, kref);
86 put_user_ns(ns->user_ns);
87 proc_free_inum(ns->proc_inum);
91 static void *utsns_get(struct task_struct *task)
93 struct uts_namespace *ns = NULL;
94 struct nsproxy *nsproxy;
97 nsproxy = task_nsproxy(task);
107 static void utsns_put(void *ns)
112 static int utsns_install(struct nsproxy *nsproxy, void *new)
114 struct uts_namespace *ns = new;
116 if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) ||
117 !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
121 put_uts_ns(nsproxy->uts_ns);
122 nsproxy->uts_ns = ns;
126 static unsigned int utsns_inum(void *vp)
128 struct uts_namespace *ns = vp;
130 return ns->proc_inum;
133 const struct proc_ns_operations utsns_operations = {
135 .type = CLONE_NEWUTS,
138 .install = utsns_install,