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6b4e306a EB |
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> | |
6b4e306a EB |
12 | #include <linux/ipc_namespace.h> |
13 | #include <linux/pid_namespace.h> | |
14 | #include "internal.h" | |
15 | ||
16 | ||
17 | static const struct proc_ns_operations *ns_entries[] = { | |
13b6f576 EB |
18 | #ifdef CONFIG_NET_NS |
19 | &netns_operations, | |
20 | #endif | |
34482e89 EB |
21 | #ifdef CONFIG_UTS_NS |
22 | &utsns_operations, | |
23 | #endif | |
a00eaf11 EB |
24 | #ifdef CONFIG_IPC_NS |
25 | &ipcns_operations, | |
26 | #endif | |
6b4e306a EB |
27 | }; |
28 | ||
29 | static const struct file_operations ns_file_operations = { | |
30 | .llseek = no_llseek, | |
31 | }; | |
32 | ||
33 | static 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); | |
79392533 | 40 | void *ns; |
6b4e306a EB |
41 | |
42 | inode = proc_pid_make_inode(dir->i_sb, task); | |
43 | if (!inode) | |
44 | goto out; | |
45 | ||
79392533 EB |
46 | ns = ns_ops->get(task); |
47 | if (!ns) | |
48 | goto out_iput; | |
49 | ||
6b4e306a EB |
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; | |
79392533 | 54 | ei->ns = ns; |
6b4e306a | 55 | |
1b26c9b3 | 56 | d_set_d_op(dentry, &pid_dentry_operations); |
6b4e306a EB |
57 | d_add(dentry, inode); |
58 | /* Close the race of the process dying before we return the dentry */ | |
0b728e19 | 59 | if (pid_revalidate(dentry, 0)) |
6b4e306a EB |
60 | error = NULL; |
61 | out: | |
62 | return error; | |
63 | out_iput: | |
64 | iput(inode); | |
65 | goto out; | |
66 | } | |
67 | ||
68 | static 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 | ||
77 | static 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; | |
131 | out: | |
132 | put_task_struct(task); | |
133 | out_no_task: | |
134 | return ret; | |
135 | } | |
136 | ||
137 | const struct file_operations proc_ns_dir_operations = { | |
138 | .read = generic_read_dir, | |
139 | .readdir = proc_ns_dir_readdir, | |
140 | }; | |
141 | ||
142 | static struct dentry *proc_ns_dir_lookup(struct inode *dir, | |
00cd8dd3 | 143 | struct dentry *dentry, unsigned int flags) |
6b4e306a EB |
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 | ||
4c619aa0 AM |
159 | last = &ns_entries[ARRAY_SIZE(ns_entries)]; |
160 | for (entry = ns_entries; entry < last; entry++) { | |
6b4e306a EB |
161 | if (strlen((*entry)->name) != len) |
162 | continue; | |
163 | if (!memcmp(dentry->d_name.name, (*entry)->name, len)) | |
164 | break; | |
165 | } | |
62ca24ba | 166 | error = ERR_PTR(-ENOENT); |
4c619aa0 | 167 | if (entry == last) |
6b4e306a EB |
168 | goto out; |
169 | ||
170 | error = proc_ns_instantiate(dir, dentry, task, *entry); | |
171 | out: | |
172 | put_task_struct(task); | |
173 | out_no_task: | |
174 | return error; | |
175 | } | |
176 | ||
177 | const struct inode_operations proc_ns_dir_inode_operations = { | |
178 | .lookup = proc_ns_dir_lookup, | |
179 | .getattr = pid_getattr, | |
180 | .setattr = proc_setattr, | |
181 | }; | |
182 | ||
183 | struct 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 | ||
196 | out_invalid: | |
197 | fput(file); | |
198 | return ERR_PTR(-EINVAL); | |
199 | } | |
200 |