Report to the user ifindex and namespace information of offloaded
programs. If device has disappeared return -ENODEV. Specify the
namespace using dev/inode combination.
CC: Eric W. Biederman <ebied...@xmission.com>
Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
Reviewed-by: Quentin Monnet <quentin.mon...@netronome.com>
---
v2:
- take RTNL lock to grab a coherent snapshot of device state
(ifindex vs name space) and avoid races with name space
moves (based on Eric's comment on Kirill's patch to
peernet2id_alloc()).
---
fs/nsfs.c | 2 +-
include/linux/bpf.h | 2 ++
include/linux/proc_ns.h | 1 +
include/uapi/linux/bpf.h | 3 +++
kernel/bpf/offload.c | 44 ++++++++++++++++++++++++++++++++++++++++++
kernel/bpf/syscall.c | 6 ++++++
tools/include/uapi/linux/bpf.h | 3 +++
7 files changed, 60 insertions(+), 1 deletion(-)
diff --git a/fs/nsfs.c b/fs/nsfs.c
index 7c6f76d29f56..e50628675935 100644
--- a/fs/nsfs.c
+++ b/fs/nsfs.c
@@ -51,7 +51,7 @@ static void nsfs_evict(struct inode *inode)
ns->ops->put(ns);
}
-static void *__ns_get_path(struct path *path, struct ns_common *ns)
+void *__ns_get_path(struct path *path, struct ns_common *ns)
{
struct vfsmount *mnt = nsfs_mnt;
struct dentry *dentry;
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 9a916ab34299..7810ae57b357 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -531,6 +531,8 @@ static inline struct bpf_prog *bpf_prog_get_type(u32 ufd,
int bpf_prog_offload_compile(struct bpf_prog *prog);
void bpf_prog_offload_destroy(struct bpf_prog *prog);
+int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
+ struct bpf_prog *prog);
#if defined(CONFIG_NET) && defined(CONFIG_BPF_SYSCALL)
int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr);
diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h
index 2ff18c9840a7..1733359cf713 100644
--- a/include/linux/proc_ns.h
+++ b/include/linux/proc_ns.h
@@ -76,6 +76,7 @@ static inline int ns_alloc_inum(struct ns_common *ns)
extern struct file *proc_ns_fget(int fd);
#define get_proc_ns(inode) ((struct ns_common *)(inode)->i_private)
+extern void *__ns_get_path(struct path *path, struct ns_common *ns);
extern void *ns_get_path(struct path *path, struct task_struct *task,
const struct proc_ns_operations *ns_ops);
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index d01f1cb3cfc0..72b37fc3bc0c 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -921,6 +921,9 @@ struct bpf_prog_info {
__u32 nr_map_ids;
__aligned_u64 map_ids;
char name[BPF_OBJ_NAME_LEN];
+ __u32 ifindex;
+ __u64 netns_dev;
+ __u64 netns_ino;
} __attribute__((aligned(8)));
struct bpf_map_info {
diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
index 1e6064ea3609..4d50000bd1e3 100644
--- a/kernel/bpf/offload.c
+++ b/kernel/bpf/offload.c
@@ -16,9 +16,11 @@
#include <linux/bpf.h>
#include <linux/bpf_verifier.h>
#include <linux/bug.h>
+#include <linux/kdev_t.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/printk.h>
+#include <linux/proc_ns.h>
#include <linux/rtnetlink.h>
#include <linux/rwsem.h>
@@ -181,6 +183,48 @@ int bpf_prog_offload_compile(struct bpf_prog *prog)
return bpf_prog_offload_translate(prog);
}
+int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
+ struct bpf_prog *prog)
+{
+ struct bpf_dev_offload *offload;
+ struct inode *ns_inode;
+ struct path ns_path;
+ int ifindex, err;
+ struct net *net;
+
+again:
+ rtnl_lock();
+ down_read(&bpf_devs_lock);
+
+ offload = prog->aux->offload;
+ if (!offload) {
+ up_read(&bpf_devs_lock);
+ rtnl_unlock();
+ return -ENODEV;
+ }
+
+ ifindex = offload->netdev->ifindex;
+ net = dev_net(offload->netdev);
+ get_net(net); /* __ns_get_path() drops the reference */
+
+ up_read(&bpf_devs_lock);
+ rtnl_unlock();
+
+ err = PTR_ERR_OR_ZERO(__ns_get_path(&ns_path, &net->ns));
+ if (err) {
+ if (err == -EAGAIN)
+ goto again;
+ return err;
+ }
+ ns_inode = ns_path.dentry->d_inode;
+
+ info->ifindex = ifindex;
+ info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
+ info->netns_ino = ns_inode->i_ino;
+
+ return 0;
+}
+
const struct bpf_prog_ops bpf_offload_prog_ops = {
};
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 7d9f5b0f0e49..20444fd678d0 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1624,6 +1624,12 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
return -EFAULT;
}
+ if (bpf_prog_is_dev_bound(prog->aux)) {
+ err = bpf_prog_offload_info_fill(&info, prog);
+ if (err)
+ return err;
+ }
+
done:
if (copy_to_user(uinfo, &info, info_len) ||
put_user(info_len, &uattr->info.info_len))
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index db1b0923a308..4e8c60acfa32 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -921,6 +921,9 @@ struct bpf_prog_info {
__u32 nr_map_ids;
__aligned_u64 map_ids;
char name[BPF_OBJ_NAME_LEN];
+ __u32 ifindex;
+ __u64 netns_dev;
+ __u64 netns_ino;
} __attribute__((aligned(8)));
struct bpf_map_info {
--
2.15.1
