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1#include <linux/proc_fs.h>
2#include <linux/nsproxy.h>
3#include <linux/sched.h>
4#include <linux/ptrace.h>
5#include <linux/fs_struct.h>
6#include <linux/mount.h>
7#include <linux/path.h>
8#include <linux/namei.h>
9#include <linux/file.h>
10#include <linux/utsname.h>
11#include <net/net_namespace.h>
12#include <linux/ipc_namespace.h>
13#include <linux/pid_namespace.h>
14#include "internal.h"
15
16
17static const struct proc_ns_operations *ns_entries[] = {
18#ifdef CONFIG_NET_NS
19 &netns_operations,
20#endif
21#ifdef CONFIG_UTS_NS
22 &utsns_operations,
23#endif
24#ifdef CONFIG_IPC_NS
25 &ipcns_operations,
26#endif
27};
28
29static const struct file_operations ns_file_operations = {
30 .llseek = no_llseek,
31};
32
33static struct dentry *proc_ns_instantiate(struct inode *dir,
34 struct dentry *dentry, struct task_struct *task, const void *ptr)
35{
36 const struct proc_ns_operations *ns_ops = ptr;
37 struct inode *inode;
38 struct proc_inode *ei;
39 struct dentry *error = ERR_PTR(-ENOENT);
40 void *ns;
41
42 inode = proc_pid_make_inode(dir->i_sb, task);
43 if (!inode)
44 goto out;
45
46 ns = ns_ops->get(task);
47 if (!ns)
48 goto out_iput;
49
50 ei = PROC_I(inode);
51 inode->i_mode = S_IFREG|S_IRUSR;
52 inode->i_fop = &ns_file_operations;
53 ei->ns_ops = ns_ops;
54 ei->ns = ns;
55
56 d_set_d_op(dentry, &pid_dentry_operations);
57 d_add(dentry, inode);
58 /* Close the race of the process dying before we return the dentry */
59 if (pid_revalidate(dentry, NULL))
60 error = NULL;
61out:
62 return error;
63out_iput:
64 iput(inode);
65 goto out;
66}
67
68static int proc_ns_fill_cache(struct file *filp, void *dirent,
69 filldir_t filldir, struct task_struct *task,
70 const struct proc_ns_operations *ops)
71{
72 return proc_fill_cache(filp, dirent, filldir,
73 ops->name, strlen(ops->name),
74 proc_ns_instantiate, task, ops);
75}
76
77static int proc_ns_dir_readdir(struct file *filp, void *dirent,
78 filldir_t filldir)
79{
80 int i;
81 struct dentry *dentry = filp->f_path.dentry;
82 struct inode *inode = dentry->d_inode;
83 struct task_struct *task = get_proc_task(inode);
84 const struct proc_ns_operations **entry, **last;
85 ino_t ino;
86 int ret;
87
88 ret = -ENOENT;
89 if (!task)
90 goto out_no_task;
91
92 ret = -EPERM;
93 if (!ptrace_may_access(task, PTRACE_MODE_READ))
94 goto out;
95
96 ret = 0;
97 i = filp->f_pos;
98 switch (i) {
99 case 0:
100 ino = inode->i_ino;
101 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
102 goto out;
103 i++;
104 filp->f_pos++;
105 /* fall through */
106 case 1:
107 ino = parent_ino(dentry);
108 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
109 goto out;
110 i++;
111 filp->f_pos++;
112 /* fall through */
113 default:
114 i -= 2;
115 if (i >= ARRAY_SIZE(ns_entries)) {
116 ret = 1;
117 goto out;
118 }
119 entry = ns_entries + i;
120 last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
121 while (entry <= last) {
122 if (proc_ns_fill_cache(filp, dirent, filldir,
123 task, *entry) < 0)
124 goto out;
125 filp->f_pos++;
126 entry++;
127 }
128 }
129
130 ret = 1;
131out:
132 put_task_struct(task);
133out_no_task:
134 return ret;
135}
136
137const struct file_operations proc_ns_dir_operations = {
138 .read = generic_read_dir,
139 .readdir = proc_ns_dir_readdir,
140};
141
142static struct dentry *proc_ns_dir_lookup(struct inode *dir,
143 struct dentry *dentry, struct nameidata *nd)
144{
145 struct dentry *error;
146 struct task_struct *task = get_proc_task(dir);
147 const struct proc_ns_operations **entry, **last;
148 unsigned int len = dentry->d_name.len;
149
150 error = ERR_PTR(-ENOENT);
151
152 if (!task)
153 goto out_no_task;
154
155 error = ERR_PTR(-EPERM);
156 if (!ptrace_may_access(task, PTRACE_MODE_READ))
157 goto out;
158
159 last = &ns_entries[ARRAY_SIZE(ns_entries)];
160 for (entry = ns_entries; entry < last; entry++) {
161 if (strlen((*entry)->name) != len)
162 continue;
163 if (!memcmp(dentry->d_name.name, (*entry)->name, len))
164 break;
165 }
166 error = ERR_PTR(-ENOENT);
167 if (entry == last)
168 goto out;
169
170 error = proc_ns_instantiate(dir, dentry, task, *entry);
171out:
172 put_task_struct(task);
173out_no_task:
174 return error;
175}
176
177const struct inode_operations proc_ns_dir_inode_operations = {
178 .lookup = proc_ns_dir_lookup,
179 .getattr = pid_getattr,
180 .setattr = proc_setattr,
181};
182
183struct file *proc_ns_fget(int fd)
184{
185 struct file *file;
186
187 file = fget(fd);
188 if (!file)
189 return ERR_PTR(-EBADF);
190
191 if (file->f_op != &ns_file_operations)
192 goto out_invalid;
193
194 return file;
195
196out_invalid:
197 fput(file);
198 return ERR_PTR(-EINVAL);
199}
200
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>
12#include "internal.h"
13
14
15static const struct proc_ns_operations *ns_entries[] = {
16#ifdef CONFIG_NET_NS
17 &netns_operations,
18#endif
19#ifdef CONFIG_UTS_NS
20 &utsns_operations,
21#endif
22#ifdef CONFIG_IPC_NS
23 &ipcns_operations,
24#endif
25#ifdef CONFIG_PID_NS
26 &pidns_operations,
27 &pidns_for_children_operations,
28#endif
29#ifdef CONFIG_USER_NS
30 &userns_operations,
31#endif
32 &mntns_operations,
33#ifdef CONFIG_CGROUPS
34 &cgroupns_operations,
35#endif
36};
37
38static const char *proc_ns_get_link(struct dentry *dentry,
39 struct inode *inode,
40 struct delayed_call *done)
41{
42 const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
43 struct task_struct *task;
44 struct path ns_path;
45 void *error = ERR_PTR(-EACCES);
46
47 if (!dentry)
48 return ERR_PTR(-ECHILD);
49
50 task = get_proc_task(inode);
51 if (!task)
52 return error;
53
54 if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
55 error = ns_get_path(&ns_path, task, ns_ops);
56 if (!error)
57 nd_jump_link(&ns_path);
58 }
59 put_task_struct(task);
60 return error;
61}
62
63static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int buflen)
64{
65 struct inode *inode = d_inode(dentry);
66 const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
67 struct task_struct *task;
68 char name[50];
69 int res = -EACCES;
70
71 task = get_proc_task(inode);
72 if (!task)
73 return res;
74
75 if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
76 res = ns_get_name(name, sizeof(name), task, ns_ops);
77 if (res >= 0)
78 res = readlink_copy(buffer, buflen, name);
79 }
80 put_task_struct(task);
81 return res;
82}
83
84static const struct inode_operations proc_ns_link_inode_operations = {
85 .readlink = proc_ns_readlink,
86 .get_link = proc_ns_get_link,
87 .setattr = proc_setattr,
88};
89
90static struct dentry *proc_ns_instantiate(struct dentry *dentry,
91 struct task_struct *task, const void *ptr)
92{
93 const struct proc_ns_operations *ns_ops = ptr;
94 struct inode *inode;
95 struct proc_inode *ei;
96
97 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK | S_IRWXUGO);
98 if (!inode)
99 return ERR_PTR(-ENOENT);
100
101 ei = PROC_I(inode);
102 inode->i_op = &proc_ns_link_inode_operations;
103 ei->ns_ops = ns_ops;
104 pid_update_inode(task, inode);
105
106 d_set_d_op(dentry, &pid_dentry_operations);
107 return d_splice_alias(inode, dentry);
108}
109
110static int proc_ns_dir_readdir(struct file *file, struct dir_context *ctx)
111{
112 struct task_struct *task = get_proc_task(file_inode(file));
113 const struct proc_ns_operations **entry, **last;
114
115 if (!task)
116 return -ENOENT;
117
118 if (!dir_emit_dots(file, ctx))
119 goto out;
120 if (ctx->pos >= 2 + ARRAY_SIZE(ns_entries))
121 goto out;
122 entry = ns_entries + (ctx->pos - 2);
123 last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
124 while (entry <= last) {
125 const struct proc_ns_operations *ops = *entry;
126 if (!proc_fill_cache(file, ctx, ops->name, strlen(ops->name),
127 proc_ns_instantiate, task, ops))
128 break;
129 ctx->pos++;
130 entry++;
131 }
132out:
133 put_task_struct(task);
134 return 0;
135}
136
137const struct file_operations proc_ns_dir_operations = {
138 .read = generic_read_dir,
139 .iterate_shared = proc_ns_dir_readdir,
140 .llseek = generic_file_llseek,
141};
142
143static struct dentry *proc_ns_dir_lookup(struct inode *dir,
144 struct dentry *dentry, unsigned int flags)
145{
146 struct task_struct *task = get_proc_task(dir);
147 const struct proc_ns_operations **entry, **last;
148 unsigned int len = dentry->d_name.len;
149 struct dentry *res = ERR_PTR(-ENOENT);
150
151 if (!task)
152 goto out_no_task;
153
154 last = &ns_entries[ARRAY_SIZE(ns_entries)];
155 for (entry = ns_entries; entry < last; entry++) {
156 if (strlen((*entry)->name) != len)
157 continue;
158 if (!memcmp(dentry->d_name.name, (*entry)->name, len))
159 break;
160 }
161 if (entry == last)
162 goto out;
163
164 res = proc_ns_instantiate(dentry, task, *entry);
165out:
166 put_task_struct(task);
167out_no_task:
168 return res;
169}
170
171const struct inode_operations proc_ns_dir_inode_operations = {
172 .lookup = proc_ns_dir_lookup,
173 .getattr = pid_getattr,
174 .setattr = proc_setattr,
175};