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 <linux/user_namespace.h>
18 static const struct proc_ns_operations *ns_entries[] = {
37 static const struct file_operations ns_file_operations = {
41 static const struct inode_operations ns_inode_operations = {
42 .setattr = proc_setattr,
45 static char *ns_dname(struct dentry *dentry, char *buffer, int buflen)
47 struct inode *inode = dentry->d_inode;
48 const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns.ns_ops;
50 return dynamic_dname(dentry, buffer, buflen, "%s:[%lu]",
51 ns_ops->name, inode->i_ino);
54 const struct dentry_operations ns_dentry_operations =
56 .d_delete = always_delete_dentry,
60 static struct dentry *proc_ns_get_dentry(struct super_block *sb,
61 struct task_struct *task, const struct proc_ns_operations *ns_ops)
63 struct dentry *dentry, *result;
65 struct proc_inode *ei;
66 struct qstr qname = { .name = "", };
69 ns = ns_ops->get(task);
71 return ERR_PTR(-ENOENT);
73 dentry = d_alloc_pseudo(sb, &qname);
76 return ERR_PTR(-ENOMEM);
79 inode = iget_locked(sb, ns_ops->inum(ns));
83 return ERR_PTR(-ENOMEM);
87 if (inode->i_state & I_NEW) {
88 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
89 inode->i_op = &ns_inode_operations;
90 inode->i_mode = S_IFREG | S_IRUGO;
91 inode->i_fop = &ns_file_operations;
92 ei->ns.ns_ops = ns_ops;
94 unlock_new_inode(inode);
99 d_set_d_op(dentry, &ns_dentry_operations);
100 result = d_instantiate_unique(dentry, inode);
109 static void *proc_ns_follow_link(struct dentry *dentry, struct nameidata *nd)
111 struct inode *inode = dentry->d_inode;
112 struct super_block *sb = inode->i_sb;
113 struct proc_inode *ei = PROC_I(inode);
114 struct task_struct *task;
116 void *error = ERR_PTR(-EACCES);
118 task = get_proc_task(inode);
122 if (!ptrace_may_access(task, PTRACE_MODE_READ))
125 ns_path.dentry = proc_ns_get_dentry(sb, task, ei->ns.ns_ops);
126 if (IS_ERR(ns_path.dentry)) {
127 error = ERR_CAST(ns_path.dentry);
131 ns_path.mnt = mntget(nd->path.mnt);
132 nd_jump_link(nd, &ns_path);
136 put_task_struct(task);
141 static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int buflen)
143 struct inode *inode = dentry->d_inode;
144 struct proc_inode *ei = PROC_I(inode);
145 const struct proc_ns_operations *ns_ops = ei->ns.ns_ops;
146 struct task_struct *task;
151 task = get_proc_task(inode);
155 if (!ptrace_may_access(task, PTRACE_MODE_READ))
159 ns = ns_ops->get(task);
163 snprintf(name, sizeof(name), "%s:[%u]", ns_ops->name, ns_ops->inum(ns));
164 res = readlink_copy(buffer, buflen, name);
167 put_task_struct(task);
172 static const struct inode_operations proc_ns_link_inode_operations = {
173 .readlink = proc_ns_readlink,
174 .follow_link = proc_ns_follow_link,
175 .setattr = proc_setattr,
178 static int proc_ns_instantiate(struct inode *dir,
179 struct dentry *dentry, struct task_struct *task, const void *ptr)
181 const struct proc_ns_operations *ns_ops = ptr;
183 struct proc_inode *ei;
185 inode = proc_pid_make_inode(dir->i_sb, task);
190 inode->i_mode = S_IFLNK|S_IRWXUGO;
191 inode->i_op = &proc_ns_link_inode_operations;
192 ei->ns.ns_ops = ns_ops;
194 d_set_d_op(dentry, &pid_dentry_operations);
195 d_add(dentry, inode);
196 /* Close the race of the process dying before we return the dentry */
197 if (pid_revalidate(dentry, 0))
203 static int proc_ns_dir_readdir(struct file *file, struct dir_context *ctx)
205 struct task_struct *task = get_proc_task(file_inode(file));
206 const struct proc_ns_operations **entry, **last;
211 if (!dir_emit_dots(file, ctx))
213 if (ctx->pos >= 2 + ARRAY_SIZE(ns_entries))
215 entry = ns_entries + (ctx->pos - 2);
216 last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
217 while (entry <= last) {
218 const struct proc_ns_operations *ops = *entry;
219 if (!proc_fill_cache(file, ctx, ops->name, strlen(ops->name),
220 proc_ns_instantiate, task, ops))
226 put_task_struct(task);
230 const struct file_operations proc_ns_dir_operations = {
231 .read = generic_read_dir,
232 .iterate = proc_ns_dir_readdir,
235 static struct dentry *proc_ns_dir_lookup(struct inode *dir,
236 struct dentry *dentry, unsigned int flags)
239 struct task_struct *task = get_proc_task(dir);
240 const struct proc_ns_operations **entry, **last;
241 unsigned int len = dentry->d_name.len;
248 last = &ns_entries[ARRAY_SIZE(ns_entries)];
249 for (entry = ns_entries; entry < last; entry++) {
250 if (strlen((*entry)->name) != len)
252 if (!memcmp(dentry->d_name.name, (*entry)->name, len))
258 error = proc_ns_instantiate(dir, dentry, task, *entry);
260 put_task_struct(task);
262 return ERR_PTR(error);
265 const struct inode_operations proc_ns_dir_inode_operations = {
266 .lookup = proc_ns_dir_lookup,
267 .getattr = pid_getattr,
268 .setattr = proc_setattr,
271 struct file *proc_ns_fget(int fd)
277 return ERR_PTR(-EBADF);
279 if (file->f_op != &ns_file_operations)
286 return ERR_PTR(-EINVAL);
289 struct proc_ns *get_proc_ns(struct inode *inode)
291 return &PROC_I(inode)->ns;
294 bool proc_ns_inode(struct inode *inode)
296 return inode->i_fop == &ns_file_operations;