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3c12afe7 DM |
1 | /* |
2 | * linux/fs/proc/net.c | |
3 | * | |
4 | * Copyright (C) 2007 | |
5 | * | |
6 | * Author: Eric Biederman <ebiederm@xmission.com> | |
7 | * | |
8 | * proc net directory handling functions | |
9 | */ | |
10 | ||
11 | #include <asm/uaccess.h> | |
12 | ||
13 | #include <linux/errno.h> | |
14 | #include <linux/time.h> | |
15 | #include <linux/proc_fs.h> | |
16 | #include <linux/stat.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/sched.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/bitops.h> | |
21 | #include <linux/smp_lock.h> | |
22 | #include <linux/mount.h> | |
23 | #include <linux/nsproxy.h> | |
24 | #include <net/net_namespace.h> | |
25 | ||
26 | #include "internal.h" | |
27 | ||
28 | ||
29 | struct proc_dir_entry *proc_net_create(struct net *net, | |
30 | const char *name, mode_t mode, get_info_t *get_info) | |
31 | { | |
32 | return create_proc_info_entry(name,mode, net->proc_net, get_info); | |
33 | } | |
34 | ||
35 | struct proc_dir_entry *proc_net_fops_create(struct net *net, | |
36 | const char *name, mode_t mode, const struct file_operations *fops) | |
37 | { | |
38 | struct proc_dir_entry *res; | |
39 | ||
40 | res = create_proc_entry(name, mode, net->proc_net); | |
41 | if (res) | |
42 | res->proc_fops = fops; | |
43 | return res; | |
44 | } | |
45 | ||
46 | void proc_net_remove(struct net *net, const char *name) | |
47 | { | |
48 | remove_proc_entry(name, net->proc_net); | |
49 | } | |
50 | ||
51 | ||
52 | static struct proc_dir_entry *proc_net_shadow; | |
53 | ||
54 | static struct dentry *proc_net_shadow_dentry(struct dentry *parent, | |
55 | struct proc_dir_entry *de) | |
56 | { | |
57 | struct dentry *shadow = NULL; | |
58 | struct inode *inode; | |
59 | if (!de) | |
60 | goto out; | |
61 | de_get(de); | |
62 | inode = proc_get_inode(parent->d_inode->i_sb, de->low_ino, de); | |
63 | if (!inode) | |
64 | goto out_de_put; | |
65 | shadow = d_alloc_name(parent, de->name); | |
66 | if (!shadow) | |
67 | goto out_iput; | |
68 | shadow->d_op = parent->d_op; /* proc_dentry_operations */ | |
69 | d_instantiate(shadow, inode); | |
70 | out: | |
71 | return shadow; | |
72 | out_iput: | |
73 | iput(inode); | |
74 | out_de_put: | |
75 | de_put(de); | |
76 | goto out; | |
77 | } | |
78 | ||
79 | static void *proc_net_follow_link(struct dentry *parent, struct nameidata *nd) | |
80 | { | |
81 | struct net *net = current->nsproxy->net_ns; | |
82 | struct dentry *shadow; | |
83 | shadow = proc_net_shadow_dentry(parent, net->proc_net); | |
84 | if (!shadow) | |
85 | return ERR_PTR(-ENOENT); | |
86 | ||
87 | dput(nd->dentry); | |
88 | /* My dentry count is 1 and that should be enough as the | |
89 | * shadow dentry is thrown away immediately. | |
90 | */ | |
91 | nd->dentry = shadow; | |
92 | return NULL; | |
93 | } | |
94 | ||
95 | static struct dentry *proc_net_lookup(struct inode *dir, struct dentry *dentry, | |
96 | struct nameidata *nd) | |
97 | { | |
98 | struct net *net = current->nsproxy->net_ns; | |
99 | struct dentry *shadow; | |
100 | ||
101 | shadow = proc_net_shadow_dentry(nd->dentry, net->proc_net); | |
102 | if (!shadow) | |
103 | return ERR_PTR(-ENOENT); | |
104 | ||
105 | dput(nd->dentry); | |
106 | nd->dentry = shadow; | |
107 | ||
108 | return shadow->d_inode->i_op->lookup(shadow->d_inode, dentry, nd); | |
109 | } | |
110 | ||
111 | static int proc_net_setattr(struct dentry *dentry, struct iattr *iattr) | |
112 | { | |
113 | struct net *net = current->nsproxy->net_ns; | |
114 | struct dentry *shadow; | |
115 | int ret; | |
116 | ||
117 | shadow = proc_net_shadow_dentry(dentry->d_parent, net->proc_net); | |
118 | if (!shadow) | |
119 | return -ENOENT; | |
120 | ret = shadow->d_inode->i_op->setattr(shadow, iattr); | |
121 | dput(shadow); | |
122 | return ret; | |
123 | } | |
124 | ||
125 | static const struct file_operations proc_net_dir_operations = { | |
126 | .read = generic_read_dir, | |
127 | }; | |
128 | ||
129 | static struct inode_operations proc_net_dir_inode_operations = { | |
130 | .follow_link = proc_net_follow_link, | |
131 | .lookup = proc_net_lookup, | |
132 | .setattr = proc_net_setattr, | |
133 | }; | |
134 | ||
135 | static int proc_net_ns_init(struct net *net) | |
136 | { | |
137 | struct proc_dir_entry *root, *netd, *net_statd; | |
138 | int err; | |
139 | ||
140 | err = -ENOMEM; | |
141 | root = kzalloc(sizeof(*root), GFP_KERNEL); | |
142 | if (!root) | |
143 | goto out; | |
144 | ||
145 | err = -EEXIST; | |
146 | netd = proc_mkdir("net", root); | |
147 | if (!netd) | |
148 | goto free_root; | |
149 | ||
150 | err = -EEXIST; | |
151 | net_statd = proc_mkdir("stat", netd); | |
152 | if (!net_statd) | |
153 | goto free_net; | |
154 | ||
155 | root->data = net; | |
156 | netd->data = net; | |
157 | net_statd->data = net; | |
158 | ||
159 | net->proc_net_root = root; | |
160 | net->proc_net = netd; | |
161 | net->proc_net_stat = net_statd; | |
162 | err = 0; | |
163 | ||
164 | out: | |
165 | return err; | |
166 | free_net: | |
167 | remove_proc_entry("net", root); | |
168 | free_root: | |
169 | kfree(root); | |
170 | goto out; | |
171 | } | |
172 | ||
173 | static void proc_net_ns_exit(struct net *net) | |
174 | { | |
175 | remove_proc_entry("stat", net->proc_net); | |
176 | remove_proc_entry("net", net->proc_net_root); | |
177 | kfree(net->proc_net_root); | |
178 | } | |
179 | ||
180 | struct pernet_operations proc_net_ns_ops = { | |
181 | .init = proc_net_ns_init, | |
182 | .exit = proc_net_ns_exit, | |
183 | }; | |
184 | ||
185 | int proc_net_init(void) | |
186 | { | |
187 | proc_net_shadow = proc_mkdir("net", NULL); | |
188 | proc_net_shadow->proc_iops = &proc_net_dir_inode_operations; | |
189 | proc_net_shadow->proc_fops = &proc_net_dir_operations; | |
190 | ||
191 | return register_pernet_subsys(&proc_net_ns_ops); | |
192 | } |