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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#ifdef CONFIG_TIME_NS
37 &timens_operations,
38 &timens_for_children_operations,
39#endif
40};
41
42static const char *proc_ns_get_link(struct dentry *dentry,
43 struct inode *inode,
44 struct delayed_call *done)
45{
46 const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
47 struct task_struct *task;
48 struct path ns_path;
49 int error = -EACCES;
50
51 if (!dentry)
52 return ERR_PTR(-ECHILD);
53
54 task = get_proc_task(inode);
55 if (!task)
56 return ERR_PTR(-EACCES);
57
58 if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
59 goto out;
60
61 error = ns_get_path(&ns_path, task, ns_ops);
62 if (error)
63 goto out;
64
65 error = nd_jump_link(&ns_path);
66out:
67 put_task_struct(task);
68 return ERR_PTR(error);
69}
70
71static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int buflen)
72{
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;
76 char name[50];
77 int res = -EACCES;
78
79 task = get_proc_task(inode);
80 if (!task)
81 return res;
82
83 if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
84 res = ns_get_name(name, sizeof(name), task, ns_ops);
85 if (res >= 0)
86 res = readlink_copy(buffer, buflen, name);
87 }
88 put_task_struct(task);
89 return res;
90}
91
92static 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,
96};
97
98static struct dentry *proc_ns_instantiate(struct dentry *dentry,
99 struct task_struct *task, const void *ptr)
100{
101 const struct proc_ns_operations *ns_ops = ptr;
102 struct inode *inode;
103 struct proc_inode *ei;
104
105 inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK | S_IRWXUGO);
106 if (!inode)
107 return ERR_PTR(-ENOENT);
108
109 ei = PROC_I(inode);
110 inode->i_op = &proc_ns_link_inode_operations;
111 ei->ns_ops = ns_ops;
112 pid_update_inode(task, inode);
113
114 d_set_d_op(dentry, &pid_dentry_operations);
115 return d_splice_alias(inode, dentry);
116}
117
118static int proc_ns_dir_readdir(struct file *file, struct dir_context *ctx)
119{
120 struct task_struct *task = get_proc_task(file_inode(file));
121 const struct proc_ns_operations **entry, **last;
122
123 if (!task)
124 return -ENOENT;
125
126 if (!dir_emit_dots(file, ctx))
127 goto out;
128 if (ctx->pos >= 2 + ARRAY_SIZE(ns_entries))
129 goto out;
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))
136 break;
137 ctx->pos++;
138 entry++;
139 }
140out:
141 put_task_struct(task);
142 return 0;
143}
144
145const struct file_operations proc_ns_dir_operations = {
146 .read = generic_read_dir,
147 .iterate_shared = proc_ns_dir_readdir,
148 .llseek = generic_file_llseek,
149};
150
151static struct dentry *proc_ns_dir_lookup(struct inode *dir,
152 struct dentry *dentry, unsigned int flags)
153{
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);
158
159 if (!task)
160 goto out_no_task;
161
162 last = &ns_entries[ARRAY_SIZE(ns_entries)];
163 for (entry = ns_entries; entry < last; entry++) {
164 if (strlen((*entry)->name) != len)
165 continue;
166 if (!memcmp(dentry->d_name.name, (*entry)->name, len))
167 break;
168 }
169 if (entry == last)
170 goto out;
171
172 res = proc_ns_instantiate(dentry, task, *entry);
173out:
174 put_task_struct(task);
175out_no_task:
176 return res;
177}
178
179const struct inode_operations proc_ns_dir_inode_operations = {
180 .lookup = proc_ns_dir_lookup,
181 .getattr = pid_getattr,
182 .setattr = proc_setattr,
183};