| Message ID | 20210219154330.93615-3-lmb@cloudflare.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF |
| Headers | show |
| Series | Expose network namespace cookies to user space | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for bpf-next |
| netdev/subject_prefix | success | Link |
| netdev/cc_maintainers | warning | 7 maintainers not CCed: yhs@fb.com linux-fsdevel@vger.kernel.org viro@zeniv.linux.org.uk john.fastabend@gmail.com kpsingh@kernel.org songliubraving@fb.com kafai@fb.com |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 3 this patch: 3 |
| netdev/kdoc | success | Errors and warnings before: 2 this patch: 2 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 32 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 3 this patch: 3 |
| netdev/header_inline | success | Link |
| netdev/stable | success | Stable not CCed |
diff --git a/fs/nsfs.c b/fs/nsfs.c index 800c1d0eb0d0..48198a1b1685 100644 --- a/fs/nsfs.c +++ b/fs/nsfs.c @@ -11,6 +11,7 @@ #include <linux/user_namespace.h> #include <linux/nsfs.h> #include <linux/uaccess.h> +#include <net/net_namespace.h> #include "internal.h" @@ -191,6 +192,7 @@ static long ns_ioctl(struct file *filp, unsigned int ioctl, struct user_namespace *user_ns; struct ns_common *ns = get_proc_ns(file_inode(filp)); uid_t __user *argp; + struct net *net_ns; uid_t uid; switch (ioctl) { @@ -209,6 +211,11 @@ static long ns_ioctl(struct file *filp, unsigned int ioctl, argp = (uid_t __user *) arg; uid = from_kuid_munged(current_user_ns(), user_ns->owner); return put_user(uid, argp); + case NS_GET_COOKIE: + if (ns->ops->type != CLONE_NEWNET) + return -EINVAL; + net_ns = container_of(ns, struct net, ns); + return put_user(net_ns->net_cookie, (u64 __user *)arg); default: return -ENOTTY; } diff --git a/include/uapi/linux/nsfs.h b/include/uapi/linux/nsfs.h index a0c8552b64ee..86611c2cf908 100644 --- a/include/uapi/linux/nsfs.h +++ b/include/uapi/linux/nsfs.h @@ -15,5 +15,7 @@ #define NS_GET_NSTYPE _IO(NSIO, 0x3) /* Get owner UID (in the caller's user namespace) for a user namespace */ #define NS_GET_OWNER_UID _IO(NSIO, 0x4) +/* Returns a unique non-zero identifier for a network namespace */ +#define NS_GET_COOKIE _IO(NSIO, 0x5) #endif /* __LINUX_NSFS_H */
Network namespaces have a globally unique non-zero identifier aka a cookie, in line with socket cookies. Add an ioctl to retrieve the cookie from user space without going via BPF. Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> --- fs/nsfs.c | 7 +++++++ include/uapi/linux/nsfs.h | 2 ++ 2 files changed, 9 insertions(+)