blob: c9eac4563fa8ab497dfbc492d4d63f2c6105df9b [file] [log] [blame]
Eric W. Biederman6b4e3062010-03-07 16:41:34 -08001#include <linux/proc_fs.h>
2#include <linux/nsproxy.h>
Eric W. Biederman6b4e3062010-03-07 16:41:34 -08003#include <linux/ptrace.h>
Eric W. Biederman6b4e3062010-03-07 16:41:34 -08004#include <linux/namei.h>
5#include <linux/file.h>
6#include <linux/utsname.h>
7#include <net/net_namespace.h>
Eric W. Biederman6b4e3062010-03-07 16:41:34 -08008#include <linux/ipc_namespace.h>
9#include <linux/pid_namespace.h>
Eric W. Biedermancde19752012-07-26 06:24:06 -070010#include <linux/user_namespace.h>
Eric W. Biederman6b4e3062010-03-07 16:41:34 -080011#include "internal.h"
12
13
14static const struct proc_ns_operations *ns_entries[] = {
Eric W. Biederman13b6f572010-03-07 18:14:23 -080015#ifdef CONFIG_NET_NS
16 &netns_operations,
17#endif
Eric W. Biederman34482e82010-03-07 18:43:27 -080018#ifdef CONFIG_UTS_NS
19 &utsns_operations,
20#endif
Eric W. Biedermana00eaf12010-03-07 18:48:39 -080021#ifdef CONFIG_IPC_NS
22 &ipcns_operations,
23#endif
Eric W. Biederman57e83912010-03-07 18:17:03 -080024#ifdef CONFIG_PID_NS
25 &pidns_operations,
26#endif
Eric W. Biedermancde19752012-07-26 06:24:06 -070027#ifdef CONFIG_USER_NS
28 &userns_operations,
29#endif
Eric W. Biederman8823c072010-03-07 18:49:36 -080030 &mntns_operations,
Eric W. Biederman6b4e3062010-03-07 16:41:34 -080031};
32
Eric W. Biedermanbf056bf2011-06-18 17:48:18 -070033static void *proc_ns_follow_link(struct dentry *dentry, struct nameidata *nd)
34{
35 struct inode *inode = dentry->d_inode;
Al Viro3d3d35b2014-11-01 11:10:28 -040036 const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
Eric W. Biedermanbf056bf2011-06-18 17:48:18 -070037 struct task_struct *task;
Eric W. Biedermandb04dc62013-03-09 00:14:45 -080038 struct path ns_path;
Eric W. Biedermanbf056bf2011-06-18 17:48:18 -070039 void *error = ERR_PTR(-EACCES);
40
41 task = get_proc_task(inode);
42 if (!task)
Al Viroe149ed22014-11-01 10:57:28 -040043 return error;
Eric W. Biedermanbf056bf2011-06-18 17:48:18 -070044
Al Viroe149ed22014-11-01 10:57:28 -040045 if (ptrace_may_access(task, PTRACE_MODE_READ)) {
46 error = ns_get_path(&ns_path, task, ns_ops);
47 if (!error)
48 nd_jump_link(nd, &ns_path);
Eric W. Biedermanbf056bf2011-06-18 17:48:18 -070049 }
Eric W. Biedermanbf056bf2011-06-18 17:48:18 -070050 put_task_struct(task);
Eric W. Biedermanbf056bf2011-06-18 17:48:18 -070051 return error;
52}
53
54static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int buflen)
55{
56 struct inode *inode = dentry->d_inode;
Al Viro3d3d35b2014-11-01 11:10:28 -040057 const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
Eric W. Biedermanbf056bf2011-06-18 17:48:18 -070058 struct task_struct *task;
Eric W. Biedermanbf056bf2011-06-18 17:48:18 -070059 char name[50];
Al Viro5d826c82014-03-14 13:42:45 -040060 int res = -EACCES;
Eric W. Biedermanbf056bf2011-06-18 17:48:18 -070061
62 task = get_proc_task(inode);
63 if (!task)
Al Viroe149ed22014-11-01 10:57:28 -040064 return res;
Eric W. Biedermanbf056bf2011-06-18 17:48:18 -070065
Al Viroe149ed22014-11-01 10:57:28 -040066 if (ptrace_may_access(task, PTRACE_MODE_READ)) {
67 res = ns_get_name(name, sizeof(name), task, ns_ops);
68 if (res >= 0)
69 res = readlink_copy(buffer, buflen, name);
70 }
Eric W. Biedermanbf056bf2011-06-18 17:48:18 -070071 put_task_struct(task);
Al Viro5d826c82014-03-14 13:42:45 -040072 return res;
Eric W. Biedermanbf056bf2011-06-18 17:48:18 -070073}
74
75static const struct inode_operations proc_ns_link_inode_operations = {
76 .readlink = proc_ns_readlink,
77 .follow_link = proc_ns_follow_link,
78 .setattr = proc_setattr,
79};
80
Al Viroc52a47a2013-06-15 11:15:20 +040081static int proc_ns_instantiate(struct inode *dir,
Eric W. Biederman6b4e3062010-03-07 16:41:34 -080082 struct dentry *dentry, struct task_struct *task, const void *ptr)
83{
84 const struct proc_ns_operations *ns_ops = ptr;
85 struct inode *inode;
86 struct proc_inode *ei;
Eric W. Biederman6b4e3062010-03-07 16:41:34 -080087
88 inode = proc_pid_make_inode(dir->i_sb, task);
89 if (!inode)
90 goto out;
91
92 ei = PROC_I(inode);
Eric W. Biedermanbf056bf2011-06-18 17:48:18 -070093 inode->i_mode = S_IFLNK|S_IRWXUGO;
94 inode->i_op = &proc_ns_link_inode_operations;
Al Viro3d3d35b2014-11-01 11:10:28 -040095 ei->ns_ops = ns_ops;
Eric W. Biederman6b4e3062010-03-07 16:41:34 -080096
Pravin B Shelar1b26c9b2012-03-23 15:02:55 -070097 d_set_d_op(dentry, &pid_dentry_operations);
Eric W. Biederman6b4e3062010-03-07 16:41:34 -080098 d_add(dentry, inode);
99 /* Close the race of the process dying before we return the dentry */
Al Viro0b728e12012-06-10 16:03:43 -0400100 if (pid_revalidate(dentry, 0))
Al Viroc52a47a2013-06-15 11:15:20 +0400101 return 0;
Eric W. Biederman6b4e3062010-03-07 16:41:34 -0800102out:
Al Viroc52a47a2013-06-15 11:15:20 +0400103 return -ENOENT;
Eric W. Biederman6b4e3062010-03-07 16:41:34 -0800104}
105
Al Virof0c3b502013-05-16 12:07:31 -0400106static int proc_ns_dir_readdir(struct file *file, struct dir_context *ctx)
Eric W. Biederman6b4e3062010-03-07 16:41:34 -0800107{
Al Virof0c3b502013-05-16 12:07:31 -0400108 struct task_struct *task = get_proc_task(file_inode(file));
Eric W. Biederman6b4e3062010-03-07 16:41:34 -0800109 const struct proc_ns_operations **entry, **last;
Eric W. Biederman6b4e3062010-03-07 16:41:34 -0800110
Eric W. Biederman6b4e3062010-03-07 16:41:34 -0800111 if (!task)
Al Virof0c3b502013-05-16 12:07:31 -0400112 return -ENOENT;
Eric W. Biederman6b4e3062010-03-07 16:41:34 -0800113
Al Virof0c3b502013-05-16 12:07:31 -0400114 if (!dir_emit_dots(file, ctx))
115 goto out;
116 if (ctx->pos >= 2 + ARRAY_SIZE(ns_entries))
117 goto out;
118 entry = ns_entries + (ctx->pos - 2);
119 last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
120 while (entry <= last) {
121 const struct proc_ns_operations *ops = *entry;
122 if (!proc_fill_cache(file, ctx, ops->name, strlen(ops->name),
123 proc_ns_instantiate, task, ops))
124 break;
125 ctx->pos++;
126 entry++;
Eric W. Biederman6b4e3062010-03-07 16:41:34 -0800127 }
Eric W. Biederman6b4e3062010-03-07 16:41:34 -0800128out:
129 put_task_struct(task);
Al Virof0c3b502013-05-16 12:07:31 -0400130 return 0;
Eric W. Biederman6b4e3062010-03-07 16:41:34 -0800131}
132
133const struct file_operations proc_ns_dir_operations = {
134 .read = generic_read_dir,
Al Virof0c3b502013-05-16 12:07:31 -0400135 .iterate = proc_ns_dir_readdir,
Eric W. Biederman6b4e3062010-03-07 16:41:34 -0800136};
137
138static struct dentry *proc_ns_dir_lookup(struct inode *dir,
Al Viro00cd8dd2012-06-10 17:13:09 -0400139 struct dentry *dentry, unsigned int flags)
Eric W. Biederman6b4e3062010-03-07 16:41:34 -0800140{
Al Viroc52a47a2013-06-15 11:15:20 +0400141 int error;
Eric W. Biederman6b4e3062010-03-07 16:41:34 -0800142 struct task_struct *task = get_proc_task(dir);
143 const struct proc_ns_operations **entry, **last;
144 unsigned int len = dentry->d_name.len;
145
Al Viroc52a47a2013-06-15 11:15:20 +0400146 error = -ENOENT;
Eric W. Biederman6b4e3062010-03-07 16:41:34 -0800147
148 if (!task)
149 goto out_no_task;
150
Andrew Morton4c619aa2012-03-28 14:42:52 -0700151 last = &ns_entries[ARRAY_SIZE(ns_entries)];
152 for (entry = ns_entries; entry < last; entry++) {
Eric W. Biederman6b4e3062010-03-07 16:41:34 -0800153 if (strlen((*entry)->name) != len)
154 continue;
155 if (!memcmp(dentry->d_name.name, (*entry)->name, len))
156 break;
157 }
Andrew Morton4c619aa2012-03-28 14:42:52 -0700158 if (entry == last)
Eric W. Biederman6b4e3062010-03-07 16:41:34 -0800159 goto out;
160
161 error = proc_ns_instantiate(dir, dentry, task, *entry);
162out:
163 put_task_struct(task);
164out_no_task:
Al Viroc52a47a2013-06-15 11:15:20 +0400165 return ERR_PTR(error);
Eric W. Biederman6b4e3062010-03-07 16:41:34 -0800166}
167
168const struct inode_operations proc_ns_dir_inode_operations = {
169 .lookup = proc_ns_dir_lookup,
170 .getattr = pid_getattr,
171 .setattr = proc_setattr,
172};