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 #include <linux/seq_file.h> 26 27 #include "internal.h" 28 29 30 int seq_open_net(struct inode *ino, struct file *f, 31 const struct seq_operations *ops, int size) 32 { 33 struct net *net; 34 struct seq_net_private *p; 35 36 BUG_ON(size < sizeof(*p)); 37 38 net = get_proc_net(ino); 39 if (net == NULL) 40 return -ENXIO; 41 42 p = __seq_open_private(f, ops, size); 43 if (p == NULL) { 44 put_net(net); 45 return -ENOMEM; 46 } 47 #ifdef CONFIG_NET_NS 48 p->net = net; 49 #endif 50 return 0; 51 } 52 EXPORT_SYMBOL_GPL(seq_open_net); 53 54 int single_open_net(struct inode *inode, struct file *file, 55 int (*show)(struct seq_file *, void *)) 56 { 57 int err; 58 struct net *net; 59 60 err = -ENXIO; 61 net = get_proc_net(inode); 62 if (net == NULL) 63 goto err_net; 64 65 err = single_open(file, show, net); 66 if (err < 0) 67 goto err_open; 68 69 return 0; 70 71 err_open: 72 put_net(net); 73 err_net: 74 return err; 75 } 76 EXPORT_SYMBOL_GPL(single_open_net); 77 78 int seq_release_net(struct inode *ino, struct file *f) 79 { 80 struct seq_file *seq; 81 82 seq = f->private_data; 83 84 put_net(seq_file_net(seq)); 85 seq_release_private(ino, f); 86 return 0; 87 } 88 EXPORT_SYMBOL_GPL(seq_release_net); 89 90 int single_release_net(struct inode *ino, struct file *f) 91 { 92 struct seq_file *seq = f->private_data; 93 put_net(seq->private); 94 return single_release(ino, f); 95 } 96 EXPORT_SYMBOL_GPL(single_release_net); 97 98 static struct net *get_proc_task_net(struct inode *dir) 99 { 100 struct task_struct *task; 101 struct nsproxy *ns; 102 struct net *net = NULL; 103 104 rcu_read_lock(); 105 task = pid_task(proc_pid(dir), PIDTYPE_PID); 106 if (task != NULL) { 107 ns = task_nsproxy(task); 108 if (ns != NULL) 109 net = get_net(ns->net_ns); 110 } 111 rcu_read_unlock(); 112 113 return net; 114 } 115 116 static struct dentry *proc_tgid_net_lookup(struct inode *dir, 117 struct dentry *dentry, struct nameidata *nd) 118 { 119 struct dentry *de; 120 struct net *net; 121 122 de = ERR_PTR(-ENOENT); 123 net = get_proc_task_net(dir); 124 if (net != NULL) { 125 de = proc_lookup_de(net->proc_net, dir, dentry); 126 put_net(net); 127 } 128 return de; 129 } 130 131 static int proc_tgid_net_getattr(struct vfsmount *mnt, struct dentry *dentry, 132 struct kstat *stat) 133 { 134 struct inode *inode = dentry->d_inode; 135 struct net *net; 136 137 net = get_proc_task_net(inode); 138 139 generic_fillattr(inode, stat); 140 141 if (net != NULL) { 142 stat->nlink = net->proc_net->nlink; 143 put_net(net); 144 } 145 146 return 0; 147 } 148 149 const struct inode_operations proc_net_inode_operations = { 150 .lookup = proc_tgid_net_lookup, 151 .getattr = proc_tgid_net_getattr, 152 }; 153 154 static int proc_tgid_net_readdir(struct file *filp, void *dirent, 155 filldir_t filldir) 156 { 157 int ret; 158 struct net *net; 159 160 ret = -EINVAL; 161 net = get_proc_task_net(filp->f_path.dentry->d_inode); 162 if (net != NULL) { 163 ret = proc_readdir_de(net->proc_net, filp, dirent, filldir); 164 put_net(net); 165 } 166 return ret; 167 } 168 169 const struct file_operations proc_net_operations = { 170 .read = generic_read_dir, 171 .readdir = proc_tgid_net_readdir, 172 }; 173 174 175 struct proc_dir_entry *proc_net_fops_create(struct net *net, 176 const char *name, mode_t mode, const struct file_operations *fops) 177 { 178 return proc_create(name, mode, net->proc_net, fops); 179 } 180 EXPORT_SYMBOL_GPL(proc_net_fops_create); 181 182 void proc_net_remove(struct net *net, const char *name) 183 { 184 remove_proc_entry(name, net->proc_net); 185 } 186 EXPORT_SYMBOL_GPL(proc_net_remove); 187 188 struct net *get_proc_net(const struct inode *inode) 189 { 190 return maybe_get_net(PDE_NET(PDE(inode))); 191 } 192 EXPORT_SYMBOL_GPL(get_proc_net); 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), GFP_KERNEL); 201 if (!netd) 202 goto out; 203 204 netd->data = net; 205 netd->nlink = 2; 206 netd->name = "net"; 207 netd->namelen = 3; 208 netd->parent = &proc_root; 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