From e9720acd728a46cb40daa52c99a979f7c4ff195c Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Fri, 7 Mar 2008 11:08:40 -0800 Subject: [NET]: Make /proc/net a symlink on /proc/self/net (v3) Current /proc/net is done with so called "shadows", but current implementation is broken and has little chances to get fixed. The problem is that dentries subtree of /proc/net directory has fancy revalidation rules to make processes living in different net namespaces see different entries in /proc/net subtree, but currently, tasks see in the /proc/net subdir the contents of any other namespace, depending on who opened the file first. The proposed fix is to turn /proc/net into a symlink, which points to /proc/self/net, which in turn shows what previously was in /proc/net - the network-related info, from the net namespace the appropriate task lives in. # ls -l /proc/net lrwxrwxrwx 1 root root 8 Mar 5 15:17 /proc/net -> self/net In other words - this behaves like /proc/mounts, but unlike "mounts", "net" is not a file, but a directory. Changes from v2: * Fixed discrepancy of /proc/net nlink count and selinux labeling screwup pointed out by Stephen. To get the correct nlink count the ->getattr callback for /proc/net is overridden to read one from the net->proc_net entry. To make selinux still work the net->proc_net entry is initialized properly, i.e. with the "net" name and the proc_net parent. Selinux fixes are Acked-by: Stephen Smalley Changes from v1: * Fixed a task_struct leak in get_proc_task_net, pointed out by Paul. Signed-off-by: Pavel Emelyanov Acked-by: "Eric W. Biederman" Signed-off-by: David S. Miller --- fs/proc/internal.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'fs/proc/internal.h') diff --git a/fs/proc/internal.h b/fs/proc/internal.h index 1c81c8f1aee..bc72f5c8c47 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -64,6 +64,8 @@ extern const struct file_operations proc_numa_maps_operations; extern const struct file_operations proc_smaps_operations; extern const struct file_operations proc_clear_refs_operations; extern const struct file_operations proc_pagemap_operations; +extern const struct file_operations proc_net_operations; +extern const struct inode_operations proc_net_inode_operations; void free_proc_entry(struct proc_dir_entry *de); @@ -83,3 +85,8 @@ static inline int proc_fd(struct inode *inode) { return PROC_I(inode)->fd; } + +struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *ino, + struct dentry *dentry); +int proc_readdir_de(struct proc_dir_entry *de, struct file *filp, void *dirent, + filldir_t filldir); -- cgit v1.2.3