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 int ns_delete_dentry(const struct dentry *dentry)
47 /* Don't cache namespace inodes when not in use */
51 static char *ns_dname(struct dentry *dentry, char *buffer, int buflen)
53 struct inode *inode = dentry->d_inode;
54 const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns.ns_ops;
56 return dynamic_dname(dentry, buffer, buflen, "%s:[%lu]",
57 ns_ops->name, inode->i_ino);
60 const struct dentry_operations ns_dentry_operations =
62 .d_delete = ns_delete_dentry,
66 static struct dentry *proc_ns_get_dentry(struct super_block *sb,
67 struct task_struct *task, const struct proc_ns_operations *ns_ops)
69 struct dentry *dentry, *result;
71 struct proc_inode *ei;
72 struct qstr qname = { .name = "", };
75 ns = ns_ops->get(task);
77 return ERR_PTR(-ENOENT);
79 dentry = d_alloc_pseudo(sb, &qname);
82 return ERR_PTR(-ENOMEM);
85 inode = iget_locked(sb, ns_ops->inum(ns));
89 return ERR_PTR(-ENOMEM);
93 if (inode->i_state & I_NEW) {
94 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
95 inode->i_op = &ns_inode_operations;
96 inode->i_mode = S_IFREG | S_IRUGO;
97 inode->i_fop = &ns_file_operations;
98 ei->ns.ns_ops = ns_ops;
100 unlock_new_inode(inode);
105 d_set_d_op(dentry, &ns_dentry_operations);
106 result = d_instantiate_unique(dentry, inode);
115 static void *proc_ns_follow_link(struct dentry *dentry, struct nameidata *nd)
117 struct inode *inode = dentry->d_inode;
118 struct super_block *sb = inode->i_sb;
119 struct proc_inode *ei = PROC_I(inode);
120 struct task_struct *task;
122 void *error = ERR_PTR(-EACCES);
124 task = get_proc_task(inode);
128 if (!ptrace_may_access(task, PTRACE_MODE_READ))
131 ns_path.dentry = proc_ns_get_dentry(sb, task, ei->ns.ns_ops);
132 if (IS_ERR(ns_path.dentry)) {
133 error = ERR_CAST(ns_path.dentry);
137 ns_path.mnt = mntget(nd->path.mnt);
138 nd_jump_link(nd, &ns_path);
142 put_task_struct(task);
147 static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int buflen)
149 struct inode *inode = dentry->d_inode;
150 struct proc_inode *ei = PROC_I(inode);
151 const struct proc_ns_operations *ns_ops = ei->ns.ns_ops;
152 struct task_struct *task;
157 task = get_proc_task(inode);
161 if (!ptrace_may_access(task, PTRACE_MODE_READ))
165 ns = ns_ops->get(task);
169 snprintf(name, sizeof(name), "%s:[%u]", ns_ops->name, ns_ops->inum(ns));
174 if (copy_to_user(buffer, name, len))
179 put_task_struct(task);
184 static const struct inode_operations proc_ns_link_inode_operations = {
185 .readlink = proc_ns_readlink,
186 .follow_link = proc_ns_follow_link,
187 .setattr = proc_setattr,
190 static int proc_ns_instantiate(struct inode *dir,
191 struct dentry *dentry, struct task_struct *task, const void *ptr)
193 const struct proc_ns_operations *ns_ops = ptr;
195 struct proc_inode *ei;
197 inode = proc_pid_make_inode(dir->i_sb, task);
202 inode->i_mode = S_IFLNK|S_IRWXUGO;
203 inode->i_op = &proc_ns_link_inode_operations;
204 ei->ns.ns_ops = ns_ops;
206 d_set_d_op(dentry, &pid_dentry_operations);
207 d_add(dentry, inode);
208 /* Close the race of the process dying before we return the dentry */
209 if (pid_revalidate(dentry, 0))
215 static int proc_ns_dir_readdir(struct file *file, struct dir_context *ctx)
217 struct task_struct *task = get_proc_task(file_inode(file));
218 const struct proc_ns_operations **entry, **last;
223 if (!dir_emit_dots(file, ctx))
225 if (ctx->pos >= 2 + ARRAY_SIZE(ns_entries))
227 entry = ns_entries + (ctx->pos - 2);
228 last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
229 while (entry <= last) {
230 const struct proc_ns_operations *ops = *entry;
231 if (!proc_fill_cache(file, ctx, ops->name, strlen(ops->name),
232 proc_ns_instantiate, task, ops))
238 put_task_struct(task);
242 const struct file_operations proc_ns_dir_operations = {
243 .read = generic_read_dir,
244 .iterate = proc_ns_dir_readdir,
247 static struct dentry *proc_ns_dir_lookup(struct inode *dir,
248 struct dentry *dentry, unsigned int flags)
251 struct task_struct *task = get_proc_task(dir);
252 const struct proc_ns_operations **entry, **last;
253 unsigned int len = dentry->d_name.len;
260 last = &ns_entries[ARRAY_SIZE(ns_entries)];
261 for (entry = ns_entries; entry < last; entry++) {
262 if (strlen((*entry)->name) != len)
264 if (!memcmp(dentry->d_name.name, (*entry)->name, len))
270 error = proc_ns_instantiate(dir, dentry, task, *entry);
272 put_task_struct(task);
274 return ERR_PTR(error);
277 const struct inode_operations proc_ns_dir_inode_operations = {
278 .lookup = proc_ns_dir_lookup,
279 .getattr = pid_getattr,
280 .setattr = proc_setattr,
283 struct file *proc_ns_fget(int fd)
289 return ERR_PTR(-EBADF);
291 if (file->f_op != &ns_file_operations)
298 return ERR_PTR(-EINVAL);
301 struct proc_ns *get_proc_ns(struct inode *inode)
303 return &PROC_I(inode)->ns;
306 bool proc_ns_inode(struct inode *inode)
308 return inode->i_fop == &ns_file_operations;