1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/proc_fs.h>
3 #include <linux/nsproxy.h>
4 #include <linux/ptrace.h>
5 #include <linux/namei.h>
6 #include <linux/file.h>
7 #include <linux/utsname.h>
8 #include <net/net_namespace.h>
9 #include <linux/ipc_namespace.h>
10 #include <linux/pid_namespace.h>
11 #include <linux/user_namespace.h>
15 static const struct proc_ns_operations
*ns_entries
[] = {
27 &pidns_for_children_operations
,
38 &timens_for_children_operations
,
42 static const char *proc_ns_get_link(struct dentry
*dentry
,
44 struct delayed_call
*done
)
46 const struct proc_ns_operations
*ns_ops
= PROC_I(inode
)->ns_ops
;
47 struct task_struct
*task
;
52 return ERR_PTR(-ECHILD
);
54 task
= get_proc_task(inode
);
56 return ERR_PTR(-EACCES
);
58 if (!ptrace_may_access(task
, PTRACE_MODE_READ_FSCREDS
))
61 error
= ns_get_path(&ns_path
, task
, ns_ops
);
65 error
= nd_jump_link(&ns_path
);
67 put_task_struct(task
);
68 return ERR_PTR(error
);
71 static int proc_ns_readlink(struct dentry
*dentry
, char __user
*buffer
, int buflen
)
73 struct inode
*inode
= d_inode(dentry
);
74 const struct proc_ns_operations
*ns_ops
= PROC_I(inode
)->ns_ops
;
75 struct task_struct
*task
;
79 task
= get_proc_task(inode
);
83 if (ptrace_may_access(task
, PTRACE_MODE_READ_FSCREDS
)) {
84 res
= ns_get_name(name
, sizeof(name
), task
, ns_ops
);
86 res
= readlink_copy(buffer
, buflen
, name
);
88 put_task_struct(task
);
92 static const struct inode_operations proc_ns_link_inode_operations
= {
93 .readlink
= proc_ns_readlink
,
94 .get_link
= proc_ns_get_link
,
95 .setattr
= proc_setattr
,
98 static struct dentry
*proc_ns_instantiate(struct dentry
*dentry
,
99 struct task_struct
*task
, const void *ptr
)
101 const struct proc_ns_operations
*ns_ops
= ptr
;
103 struct proc_inode
*ei
;
105 inode
= proc_pid_make_inode(dentry
->d_sb
, task
, S_IFLNK
| S_IRWXUGO
);
107 return ERR_PTR(-ENOENT
);
110 inode
->i_op
= &proc_ns_link_inode_operations
;
112 pid_update_inode(task
, inode
);
114 d_set_d_op(dentry
, &pid_dentry_operations
);
115 return d_splice_alias(inode
, dentry
);
118 static int proc_ns_dir_readdir(struct file
*file
, struct dir_context
*ctx
)
120 struct task_struct
*task
= get_proc_task(file_inode(file
));
121 const struct proc_ns_operations
**entry
, **last
;
126 if (!dir_emit_dots(file
, ctx
))
128 if (ctx
->pos
>= 2 + ARRAY_SIZE(ns_entries
))
130 entry
= ns_entries
+ (ctx
->pos
- 2);
131 last
= &ns_entries
[ARRAY_SIZE(ns_entries
) - 1];
132 while (entry
<= last
) {
133 const struct proc_ns_operations
*ops
= *entry
;
134 if (!proc_fill_cache(file
, ctx
, ops
->name
, strlen(ops
->name
),
135 proc_ns_instantiate
, task
, ops
))
141 put_task_struct(task
);
145 const struct file_operations proc_ns_dir_operations
= {
146 .read
= generic_read_dir
,
147 .iterate_shared
= proc_ns_dir_readdir
,
148 .llseek
= generic_file_llseek
,
151 static struct dentry
*proc_ns_dir_lookup(struct inode
*dir
,
152 struct dentry
*dentry
, unsigned int flags
)
154 struct task_struct
*task
= get_proc_task(dir
);
155 const struct proc_ns_operations
**entry
, **last
;
156 unsigned int len
= dentry
->d_name
.len
;
157 struct dentry
*res
= ERR_PTR(-ENOENT
);
162 last
= &ns_entries
[ARRAY_SIZE(ns_entries
)];
163 for (entry
= ns_entries
; entry
< last
; entry
++) {
164 if (strlen((*entry
)->name
) != len
)
166 if (!memcmp(dentry
->d_name
.name
, (*entry
)->name
, len
))
172 res
= proc_ns_instantiate(dentry
, task
, *entry
);
174 put_task_struct(task
);
179 const struct inode_operations proc_ns_dir_inode_operations
= {
180 .lookup
= proc_ns_dir_lookup
,
181 .getattr
= pid_getattr
,
182 .setattr
= proc_setattr
,