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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/mnt_namespace.h>
13#include <linux/ipc_namespace.h>
14#include <linux/pid_namespace.h>
15#include "internal.h"
16
17
18static const struct proc_ns_operations *ns_entries[] = {
19#ifdef CONFIG_NET_NS
20 &netns_operations,
21#endif
22#ifdef CONFIG_UTS_NS
23 &utsns_operations,
24#endif
25#ifdef CONFIG_IPC_NS
26 &ipcns_operations,
27#endif
28};
29
30static const struct file_operations ns_file_operations = {
31 .llseek = no_llseek,
32};
33
34static struct dentry *proc_ns_instantiate(struct inode *dir,
35 struct dentry *dentry, struct task_struct *task, const void *ptr)
36{
37 const struct proc_ns_operations *ns_ops = ptr;
38 struct inode *inode;
39 struct proc_inode *ei;
40 struct dentry *error = ERR_PTR(-ENOENT);
41 void *ns;
42
43 inode = proc_pid_make_inode(dir->i_sb, task);
44 if (!inode)
45 goto out;
46
47 ns = ns_ops->get(task);
48 if (!ns)
49 goto out_iput;
50
51 ei = PROC_I(inode);
52 inode->i_mode = S_IFREG|S_IRUSR;
53 inode->i_fop = &ns_file_operations;
54 ei->ns_ops = ns_ops;
55 ei->ns = ns;
56
57 dentry->d_op = &pid_dentry_operations;
58 d_add(dentry, inode);
59 /* Close the race of the process dying before we return the dentry */
60 if (pid_revalidate(dentry, NULL))
61 error = NULL;
62out:
63 return error;
64out_iput:
65 iput(inode);
66 goto out;
67}
68
69static int proc_ns_fill_cache(struct file *filp, void *dirent,
70 filldir_t filldir, struct task_struct *task,
71 const struct proc_ns_operations *ops)
72{
73 return proc_fill_cache(filp, dirent, filldir,
74 ops->name, strlen(ops->name),
75 proc_ns_instantiate, task, ops);
76}
77
78static int proc_ns_dir_readdir(struct file *filp, void *dirent,
79 filldir_t filldir)
80{
81 int i;
82 struct dentry *dentry = filp->f_path.dentry;
83 struct inode *inode = dentry->d_inode;
84 struct task_struct *task = get_proc_task(inode);
85 const struct proc_ns_operations **entry, **last;
86 ino_t ino;
87 int ret;
88
89 ret = -ENOENT;
90 if (!task)
91 goto out_no_task;
92
93 ret = -EPERM;
94 if (!ptrace_may_access(task, PTRACE_MODE_READ))
95 goto out;
96
97 ret = 0;
98 i = filp->f_pos;
99 switch (i) {
100 case 0:
101 ino = inode->i_ino;
102 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
103 goto out;
104 i++;
105 filp->f_pos++;
106 /* fall through */
107 case 1:
108 ino = parent_ino(dentry);
109 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
110 goto out;
111 i++;
112 filp->f_pos++;
113 /* fall through */
114 default:
115 i -= 2;
116 if (i >= ARRAY_SIZE(ns_entries)) {
117 ret = 1;
118 goto out;
119 }
120 entry = ns_entries + i;
121 last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
122 while (entry <= last) {
123 if (proc_ns_fill_cache(filp, dirent, filldir,
124 task, *entry) < 0)
125 goto out;
126 filp->f_pos++;
127 entry++;
128 }
129 }
130
131 ret = 1;
132out:
133 put_task_struct(task);
134out_no_task:
135 return ret;
136}
137
138const struct file_operations proc_ns_dir_operations = {
139 .read = generic_read_dir,
140 .readdir = proc_ns_dir_readdir,
141};
142
143static struct dentry *proc_ns_dir_lookup(struct inode *dir,
144 struct dentry *dentry, struct nameidata *nd)
145{
146 struct dentry *error;
147 struct task_struct *task = get_proc_task(dir);
148 const struct proc_ns_operations **entry, **last;
149 unsigned int len = dentry->d_name.len;
150
151 error = ERR_PTR(-ENOENT);
152
153 if (!task)
154 goto out_no_task;
155
156 error = ERR_PTR(-EPERM);
157 if (!ptrace_may_access(task, PTRACE_MODE_READ))
158 goto out;
159
160 last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
161 for (entry = ns_entries; entry <= last; entry++) {
162 if (strlen((*entry)->name) != len)
163 continue;
164 if (!memcmp(dentry->d_name.name, (*entry)->name, len))
165 break;
166 }
167 error = ERR_PTR(-ENOENT);
168 if (entry > last)
169 goto out;
170
171 error = proc_ns_instantiate(dir, dentry, task, *entry);
172out:
173 put_task_struct(task);
174out_no_task:
175 return error;
176}
177
178const struct inode_operations proc_ns_dir_inode_operations = {
179 .lookup = proc_ns_dir_lookup,
180 .getattr = pid_getattr,
181 .setattr = proc_setattr,
182};
183
184struct file *proc_ns_fget(int fd)
185{
186 struct file *file;
187
188 file = fget(fd);
189 if (!file)
190 return ERR_PTR(-EBADF);
191
192 if (file->f_op != &ns_file_operations)
193 goto out_invalid;
194
195 return file;
196
197out_invalid:
198 fput(file);
199 return ERR_PTR(-EINVAL);
200}
201
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};