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 p->net = net; 48 return 0; 49 } 50 EXPORT_SYMBOL_GPL(seq_open_net); 51 52 int seq_release_net(struct inode *ino, struct file *f) 53 { 54 struct seq_file *seq; 55 struct seq_net_private *p; 56 57 seq = f->private_data; 58 p = seq->private; 59 60 put_net(p->net); 61 seq_release_private(ino, f); 62 return 0; 63 } 64 EXPORT_SYMBOL_GPL(seq_release_net); 65 66 static struct net *get_proc_task_net(struct inode *dir) 67 { 68 struct task_struct *task; 69 struct nsproxy *ns; 70 struct net *net = NULL; 71 72 rcu_read_lock(); 73 task = pid_task(proc_pid(dir), PIDTYPE_PID); 74 if (task != NULL) { 75 ns = task_nsproxy(task); 76 if (ns != NULL) 77 net = get_net(ns->net_ns); 78 } 79 rcu_read_unlock(); 80 81 return net; 82 } 83 84 static struct dentry *proc_tgid_net_lookup(struct inode *dir, 85 struct dentry *dentry, struct nameidata *nd) 86 { 87 struct dentry *de; 88 struct net *net; 89 90 de = ERR_PTR(-ENOENT); 91 net = get_proc_task_net(dir); 92 if (net != NULL) { 93 de = proc_lookup_de(net->proc_net, dir, dentry); 94 put_net(net); 95 } 96 return de; 97 } 98 99 static int proc_tgid_net_getattr(struct vfsmount *mnt, struct dentry *dentry, 100 struct kstat *stat) 101 { 102 struct inode *inode = dentry->d_inode; 103 struct net *net; 104 105 net = get_proc_task_net(inode); 106 107 generic_fillattr(inode, stat); 108 109 if (net != NULL) { 110 stat->nlink = net->proc_net->nlink; 111 put_net(net); 112 } 113 114 return 0; 115 } 116 117 const struct inode_operations proc_net_inode_operations = { 118 .lookup = proc_tgid_net_lookup, 119 .getattr = proc_tgid_net_getattr, 120 }; 121 122 static int proc_tgid_net_readdir(struct file *filp, void *dirent, 123 filldir_t filldir) 124 { 125 int ret; 126 struct net *net; 127 128 ret = -EINVAL; 129 net = get_proc_task_net(filp->f_path.dentry->d_inode); 130 if (net != NULL) { 131 ret = proc_readdir_de(net->proc_net, filp, dirent, filldir); 132 put_net(net); 133 } 134 return ret; 135 } 136 137 const struct file_operations proc_net_operations = { 138 .read = generic_read_dir, 139 .readdir = proc_tgid_net_readdir, 140 }; 141 142 143 struct proc_dir_entry *proc_net_fops_create(struct net *net, 144 const char *name, mode_t mode, const struct file_operations *fops) 145 { 146 return proc_create(name, mode, net->proc_net, fops); 147 } 148 EXPORT_SYMBOL_GPL(proc_net_fops_create); 149 150 void proc_net_remove(struct net *net, const char *name) 151 { 152 remove_proc_entry(name, net->proc_net); 153 } 154 EXPORT_SYMBOL_GPL(proc_net_remove); 155 156 struct net *get_proc_net(const struct inode *inode) 157 { 158 return maybe_get_net(PDE_NET(PDE(inode))); 159 } 160 EXPORT_SYMBOL_GPL(get_proc_net); 161 162 struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name, 163 struct proc_dir_entry *parent) 164 { 165 struct proc_dir_entry *pde; 166 pde = proc_mkdir_mode(name, S_IRUGO | S_IXUGO, parent); 167 if (pde != NULL) 168 pde->data = net; 169 return pde; 170 } 171 EXPORT_SYMBOL_GPL(proc_net_mkdir); 172 173 static __net_init int proc_net_ns_init(struct net *net) 174 { 175 struct proc_dir_entry *netd, *net_statd; 176 int err; 177 178 err = -ENOMEM; 179 netd = kzalloc(sizeof(*netd), GFP_KERNEL); 180 if (!netd) 181 goto out; 182 183 netd->data = net; 184 netd->nlink = 2; 185 netd->name = "net"; 186 netd->namelen = 3; 187 netd->parent = &proc_root; 188 189 err = -EEXIST; 190 net_statd = proc_net_mkdir(net, "stat", netd); 191 if (!net_statd) 192 goto free_net; 193 194 net->proc_net = netd; 195 net->proc_net_stat = net_statd; 196 return 0; 197 198 free_net: 199 kfree(netd); 200 out: 201 return err; 202 } 203 204 static __net_exit void proc_net_ns_exit(struct net *net) 205 { 206 remove_proc_entry("stat", net->proc_net); 207 kfree(net->proc_net); 208 } 209 210 static struct pernet_operations __net_initdata proc_net_ns_ops = { 211 .init = proc_net_ns_init, 212 .exit = proc_net_ns_exit, 213 }; 214 215 int __init proc_net_init(void) 216 { 217 proc_symlink("net", NULL, "self/net"); 218 219 return register_pernet_subsys(&proc_net_ns_ops); 220 } 221