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authorPatrick McHardy <kaber@trash.net>2013-03-31 18:10:34 +0200
committerPatrick McHardy <kaber@trash.net>2013-03-31 18:10:34 +0200
commit70711d223510ba1773cfe1d7770a56141c815ff8 (patch)
tree4a71f38a3a554ddecaa31b7d8c6bc49b7d1705b4 /fs/proc/namespaces.c
parentd53b4ed072d9779cdf53582c46436dec06d0961f (diff)
parent19f949f52599ba7c3f67a5897ac6be14bfcb1200 (diff)
Merge tag 'v3.8' of /home/kaber/src/repos/linux
Linux 3.8 Signed-off-by: Patrick McHardy <kaber@trash.net> Conflicts: include/linux/Kbuild include/linux/netlink.h
Diffstat (limited to 'fs/proc/namespaces.c')
-rw-r--r--fs/proc/namespaces.c189
1 files changed, 166 insertions, 23 deletions
diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index 0d9e23a39e4..b7a47196c8c 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -11,6 +11,7 @@
#include <net/net_namespace.h>
#include <linux/ipc_namespace.h>
#include <linux/pid_namespace.h>
+#include <linux/user_namespace.h>
#include "internal.h"
@@ -24,12 +25,168 @@ static const struct proc_ns_operations *ns_entries[] = {
#ifdef CONFIG_IPC_NS
&ipcns_operations,
#endif
+#ifdef CONFIG_PID_NS
+ &pidns_operations,
+#endif
+#ifdef CONFIG_USER_NS
+ &userns_operations,
+#endif
+ &mntns_operations,
};
static const struct file_operations ns_file_operations = {
.llseek = no_llseek,
};
+static const struct inode_operations ns_inode_operations = {
+ .setattr = proc_setattr,
+};
+
+static int ns_delete_dentry(const struct dentry *dentry)
+{
+ /* Don't cache namespace inodes when not in use */
+ return 1;
+}
+
+static char *ns_dname(struct dentry *dentry, char *buffer, int buflen)
+{
+ struct inode *inode = dentry->d_inode;
+ const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
+
+ return dynamic_dname(dentry, buffer, buflen, "%s:[%lu]",
+ ns_ops->name, inode->i_ino);
+}
+
+const struct dentry_operations ns_dentry_operations =
+{
+ .d_delete = ns_delete_dentry,
+ .d_dname = ns_dname,
+};
+
+static struct dentry *proc_ns_get_dentry(struct super_block *sb,
+ struct task_struct *task, const struct proc_ns_operations *ns_ops)
+{
+ struct dentry *dentry, *result;
+ struct inode *inode;
+ struct proc_inode *ei;
+ struct qstr qname = { .name = "", };
+ void *ns;
+
+ ns = ns_ops->get(task);
+ if (!ns)
+ return ERR_PTR(-ENOENT);
+
+ dentry = d_alloc_pseudo(sb, &qname);
+ if (!dentry) {
+ ns_ops->put(ns);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ inode = iget_locked(sb, ns_ops->inum(ns));
+ if (!inode) {
+ dput(dentry);
+ ns_ops->put(ns);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ ei = PROC_I(inode);
+ if (inode->i_state & I_NEW) {
+ inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+ inode->i_op = &ns_inode_operations;
+ inode->i_mode = S_IFREG | S_IRUGO;
+ inode->i_fop = &ns_file_operations;
+ ei->ns_ops = ns_ops;
+ ei->ns = ns;
+ unlock_new_inode(inode);
+ } else {
+ ns_ops->put(ns);
+ }
+
+ d_set_d_op(dentry, &ns_dentry_operations);
+ result = d_instantiate_unique(dentry, inode);
+ if (result) {
+ dput(dentry);
+ dentry = result;
+ }
+
+ return dentry;
+}
+
+static void *proc_ns_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+ struct inode *inode = dentry->d_inode;
+ struct super_block *sb = inode->i_sb;
+ struct proc_inode *ei = PROC_I(inode);
+ struct task_struct *task;
+ struct dentry *ns_dentry;
+ void *error = ERR_PTR(-EACCES);
+
+ task = get_proc_task(inode);
+ if (!task)
+ goto out;
+
+ if (!ptrace_may_access(task, PTRACE_MODE_READ))
+ goto out_put_task;
+
+ ns_dentry = proc_ns_get_dentry(sb, task, ei->ns_ops);
+ if (IS_ERR(ns_dentry)) {
+ error = ERR_CAST(ns_dentry);
+ goto out_put_task;
+ }
+
+ dput(nd->path.dentry);
+ nd->path.dentry = ns_dentry;
+ error = NULL;
+
+out_put_task:
+ put_task_struct(task);
+out:
+ return error;
+}
+
+static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int buflen)
+{
+ struct inode *inode = dentry->d_inode;
+ struct proc_inode *ei = PROC_I(inode);
+ const struct proc_ns_operations *ns_ops = ei->ns_ops;
+ struct task_struct *task;
+ void *ns;
+ char name[50];
+ int len = -EACCES;
+
+ task = get_proc_task(inode);
+ if (!task)
+ goto out;
+
+ if (!ptrace_may_access(task, PTRACE_MODE_READ))
+ goto out_put_task;
+
+ len = -ENOENT;
+ ns = ns_ops->get(task);
+ if (!ns)
+ goto out_put_task;
+
+ snprintf(name, sizeof(name), "%s:[%u]", ns_ops->name, ns_ops->inum(ns));
+ len = strlen(name);
+
+ if (len > buflen)
+ len = buflen;
+ if (copy_to_user(buffer, name, len))
+ len = -EFAULT;
+
+ ns_ops->put(ns);
+out_put_task:
+ put_task_struct(task);
+out:
+ return len;
+}
+
+static const struct inode_operations proc_ns_link_inode_operations = {
+ .readlink = proc_ns_readlink,
+ .follow_link = proc_ns_follow_link,
+ .setattr = proc_setattr,
+};
+
static struct dentry *proc_ns_instantiate(struct inode *dir,
struct dentry *dentry, struct task_struct *task, const void *ptr)
{
@@ -37,32 +194,23 @@ static struct dentry *proc_ns_instantiate(struct inode *dir,
struct inode *inode;
struct proc_inode *ei;
struct dentry *error = ERR_PTR(-ENOENT);
- void *ns;
inode = proc_pid_make_inode(dir->i_sb, task);
if (!inode)
goto out;
- ns = ns_ops->get(task);
- if (!ns)
- goto out_iput;
-
ei = PROC_I(inode);
- inode->i_mode = S_IFREG|S_IRUSR;
- inode->i_fop = &ns_file_operations;
- ei->ns_ops = ns_ops;
- ei->ns = ns;
+ inode->i_mode = S_IFLNK|S_IRWXUGO;
+ inode->i_op = &proc_ns_link_inode_operations;
+ ei->ns_ops = ns_ops;
d_set_d_op(dentry, &pid_dentry_operations);
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
- if (pid_revalidate(dentry, NULL))
+ if (pid_revalidate(dentry, 0))
error = NULL;
out:
return error;
-out_iput:
- iput(inode);
- goto out;
}
static int proc_ns_fill_cache(struct file *filp, void *dirent,
@@ -89,10 +237,6 @@ static int proc_ns_dir_readdir(struct file *filp, void *dirent,
if (!task)
goto out_no_task;
- ret = -EPERM;
- if (!ptrace_may_access(task, PTRACE_MODE_READ))
- goto out;
-
ret = 0;
i = filp->f_pos;
switch (i) {
@@ -140,7 +284,7 @@ const struct file_operations proc_ns_dir_operations = {
};
static struct dentry *proc_ns_dir_lookup(struct inode *dir,
- struct dentry *dentry, struct nameidata *nd)
+ struct dentry *dentry, unsigned int flags)
{
struct dentry *error;
struct task_struct *task = get_proc_task(dir);
@@ -152,10 +296,6 @@ static struct dentry *proc_ns_dir_lookup(struct inode *dir,
if (!task)
goto out_no_task;
- error = ERR_PTR(-EPERM);
- if (!ptrace_may_access(task, PTRACE_MODE_READ))
- goto out;
-
last = &ns_entries[ARRAY_SIZE(ns_entries)];
for (entry = ns_entries; entry < last; entry++) {
if (strlen((*entry)->name) != len)
@@ -163,7 +303,6 @@ static struct dentry *proc_ns_dir_lookup(struct inode *dir,
if (!memcmp(dentry->d_name.name, (*entry)->name, len))
break;
}
- error = ERR_PTR(-ENOENT);
if (entry == last)
goto out;
@@ -198,3 +337,7 @@ out_invalid:
return ERR_PTR(-EINVAL);
}
+bool proc_ns_inode(struct inode *inode)
+{
+ return inode->i_fop == &ns_file_operations;
+}