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/slab.h> 18 #include <linux/init.h> 19 #include <linux/sched.h> 20 #include <linux/module.h> 21 #include <linux/bitops.h> 22 #include <linux/mount.h> 23 #include <linux/nsproxy.h> 24 #include <net/net_namespace.h> 25 #include <linux/seq_file.h> 26 27 #include "internal.h" 28 29 30 static struct net *get_proc_net(const struct inode *inode) 31 { 32 return maybe_get_net(PDE_NET(PDE(inode))); 33 } 34 35 int seq_open_net(struct inode *ino, struct file *f, 36 const struct seq_operations *ops, int size) 37 { 38 struct net *net; 39 struct seq_net_private *p; 40 41 BUG_ON(size < sizeof(*p)); 42 43 net = get_proc_net(ino); 44 if (net == NULL) 45 return -ENXIO; 46 47 p = __seq_open_private(f, ops, size); 48 if (p == NULL) { 49 put_net(net); 50 return -ENOMEM; 51 } 52 #ifdef CONFIG_NET_NS 53 p->net = net; 54 #endif 55 return 0; 56 } 57 EXPORT_SYMBOL_GPL(seq_open_net); 58 59 int single_open_net(struct inode *inode, struct file *file, 60 int (*show)(struct seq_file *, void *)) 61 { 62 int err; 63 struct net *net; 64 65 err = -ENXIO; 66 net = get_proc_net(inode); 67 if (net == NULL) 68 goto err_net; 69 70 err = single_open(file, show, net); 71 if (err < 0) 72 goto err_open; 73 74 return 0; 75 76 err_open: 77 put_net(net); 78 err_net: 79 return err; 80 } 81 EXPORT_SYMBOL_GPL(single_open_net); 82 83 int seq_release_net(struct inode *ino, struct file *f) 84 { 85 struct seq_file *seq; 86 87 seq = f->private_data; 88 89 put_net(seq_file_net(seq)); 90 seq_release_private(ino, f); 91 return 0; 92 } 93 EXPORT_SYMBOL_GPL(seq_release_net); 94 95 int single_release_net(struct inode *ino, struct file *f) 96 { 97 struct seq_file *seq = f->private_data; 98 put_net(seq->private); 99 return single_release(ino, f); 100 } 101 EXPORT_SYMBOL_GPL(single_release_net); 102 103 static struct net *get_proc_task_net(struct inode *dir) 104 { 105 struct task_struct *task; 106 struct nsproxy *ns; 107 struct net *net = NULL; 108 109 rcu_read_lock(); 110 task = pid_task(proc_pid(dir), PIDTYPE_PID); 111 if (task != NULL) { 112 ns = task_nsproxy(task); 113 if (ns != NULL) 114 net = get_net(ns->net_ns); 115 } 116 rcu_read_unlock(); 117 118 return net; 119 } 120 121 static struct dentry *proc_tgid_net_lookup(struct inode *dir, 122 struct dentry *dentry, struct nameidata *nd) 123 { 124 struct dentry *de; 125 struct net *net; 126 127 de = ERR_PTR(-ENOENT); 128 net = get_proc_task_net(dir); 129 if (net != NULL) { 130 de = proc_lookup_de(net->proc_net, dir, dentry); 131 put_net(net); 132 } 133 return de; 134 } 135 136 static int proc_tgid_net_getattr(struct vfsmount *mnt, struct dentry *dentry, 137 struct kstat *stat) 138 { 139 struct inode *inode = dentry->d_inode; 140 struct net *net; 141 142 net = get_proc_task_net(inode); 143 144 generic_fillattr(inode, stat); 145 146 if (net != NULL) { 147 stat->nlink = net->proc_net->nlink; 148 put_net(net); 149 } 150 151 return 0; 152 } 153 154 const struct inode_operations proc_net_inode_operations = { 155 .lookup = proc_tgid_net_lookup, 156 .getattr = proc_tgid_net_getattr, 157 }; 158 159 static int proc_tgid_net_readdir(struct file *filp, void *dirent, 160 filldir_t filldir) 161 { 162 int ret; 163 struct net *net; 164 165 ret = -EINVAL; 166 net = get_proc_task_net(filp->f_path.dentry->d_inode); 167 if (net != NULL) { 168 ret = proc_readdir_de(net->proc_net, filp, dirent, filldir); 169 put_net(net); 170 } 171 return ret; 172 } 173 174 const struct file_operations proc_net_operations = { 175 .llseek = generic_file_llseek, 176 .read = generic_read_dir, 177 .readdir = proc_tgid_net_readdir, 178 }; 179 180 181 struct proc_dir_entry *proc_net_fops_create(struct net *net, 182 const char *name, mode_t mode, const struct file_operations *fops) 183 { 184 return proc_create(name, mode, net->proc_net, fops); 185 } 186 EXPORT_SYMBOL_GPL(proc_net_fops_create); 187 188 void proc_net_remove(struct net *net, const char *name) 189 { 190 remove_proc_entry(name, net->proc_net); 191 } 192 EXPORT_SYMBOL_GPL(proc_net_remove); 193 194 static __net_init int proc_net_ns_init(struct net *net) 195 { 196 struct proc_dir_entry *netd, *net_statd; 197 int err; 198 199 err = -ENOMEM; 200 netd = kzalloc(sizeof(*netd) + 4, GFP_KERNEL); 201 if (!netd) 202 goto out; 203 204 netd->data = net; 205 netd->nlink = 2; 206 netd->namelen = 3; 207 netd->parent = &proc_root; 208 memcpy(netd->name, "net", 4); 209 210 err = -EEXIST; 211 net_statd = proc_net_mkdir(net, "stat", netd); 212 if (!net_statd) 213 goto free_net; 214 215 net->proc_net = netd; 216 net->proc_net_stat = net_statd; 217 return 0; 218 219 free_net: 220 kfree(netd); 221 out: 222 return err; 223 } 224 225 static __net_exit void proc_net_ns_exit(struct net *net) 226 { 227 remove_proc_entry("stat", net->proc_net); 228 kfree(net->proc_net); 229 } 230 231 static struct pernet_operations __net_initdata proc_net_ns_ops = { 232 .init = proc_net_ns_init, 233 .exit = proc_net_ns_exit, 234 }; 235 236 int __init proc_net_init(void) 237 { 238 proc_symlink("net", NULL, "self/net"); 239 240 return register_pernet_subsys(&proc_net_ns_ops); 241 } 242