linux_dsm_epyc7002/include/linux/inet_diag.h
Martin KaFai Lau 085c20cacf bpf: inet_diag: Dump bpf_sk_storages in inet_diag_dump()
This patch will dump out the bpf_sk_storages of a sk
if the request has the INET_DIAG_REQ_SK_BPF_STORAGES nlattr.

An array of SK_DIAG_BPF_STORAGE_REQ_MAP_FD can be specified in
INET_DIAG_REQ_SK_BPF_STORAGES to select which bpf_sk_storage to dump.
If no map_fd is specified, all bpf_sk_storages of a sk will be dumped.

bpf_sk_storages can be added to the system at runtime.  It is difficult
to find a proper static value for cb->min_dump_alloc.

This patch learns the nlattr size required to dump the bpf_sk_storages
of a sk.  If it happens to be the very first nlmsg of a dump and it
cannot fit the needed bpf_sk_storages,  it will try to expand the
skb by "pskb_expand_head()".

Instead of expanding it in inet_sk_diag_fill(), it is expanded at a
sleepable context in __inet_diag_dump() so __GFP_DIRECT_RECLAIM can
be used.  In __inet_diag_dump(), it will retry as long as the
skb is empty and the cb->min_dump_alloc becomes larger than before.
cb->min_dump_alloc is bounded by KMALLOC_MAX_SIZE.  The min_dump_alloc
is also changed from 'u16' to 'u32' to accommodate a sk that may have
a few large bpf_sk_storages.

The updated cb->min_dump_alloc will also be used to allocate the skb in
the next dump.  This logic already exists in netlink_dump().

Here is the sample output of a locally modified 'ss' and it could be made
more readable by using BTF later:
[root@arch-fb-vm1 ~]# ss --bpf-map-id 14 --bpf-map-id 13 -t6an 'dst [::1]:8989'
State Recv-Q Send-Q Local Address:Port  Peer Address:PortProcess
ESTAB 0      0              [::1]:51072        [::1]:8989
	 bpf_map_id:14 value:[ 3feb ]
	 bpf_map_id:13 value:[ 3f ]
ESTAB 0      0              [::1]:51070        [::1]:8989
	 bpf_map_id:14 value:[ 3feb ]
	 bpf_map_id:13 value:[ 3f ]

[root@arch-fb-vm1 ~]# ~/devshare/github/iproute2/misc/ss --bpf-maps -t6an 'dst [::1]:8989'
State         Recv-Q         Send-Q                   Local Address:Port                    Peer Address:Port         Process
ESTAB         0              0                                [::1]:51072                          [::1]:8989
	 bpf_map_id:14 value:[ 3feb ]
	 bpf_map_id:13 value:[ 3f ]
	 bpf_map_id:12 value:[ 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000... total:65407 ]
ESTAB         0              0                                [::1]:51070                          [::1]:8989
	 bpf_map_id:14 value:[ 3feb ]
	 bpf_map_id:13 value:[ 3f ]
	 bpf_map_id:12 value:[ 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000... total:65407 ]

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200225230427.1976129-1-kafai@fb.com
2020-02-27 18:50:19 -08:00

77 lines
2.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _INET_DIAG_H_
#define _INET_DIAG_H_ 1
#include <uapi/linux/inet_diag.h>
struct net;
struct sock;
struct inet_hashinfo;
struct nlattr;
struct nlmsghdr;
struct sk_buff;
struct netlink_callback;
struct inet_diag_handler {
void (*dump)(struct sk_buff *skb,
struct netlink_callback *cb,
const struct inet_diag_req_v2 *r);
int (*dump_one)(struct netlink_callback *cb,
const struct inet_diag_req_v2 *req);
void (*idiag_get_info)(struct sock *sk,
struct inet_diag_msg *r,
void *info);
int (*idiag_get_aux)(struct sock *sk,
bool net_admin,
struct sk_buff *skb);
size_t (*idiag_get_aux_size)(struct sock *sk,
bool net_admin);
int (*destroy)(struct sk_buff *in_skb,
const struct inet_diag_req_v2 *req);
__u16 idiag_type;
__u16 idiag_info_size;
};
struct bpf_sk_storage_diag;
struct inet_diag_dump_data {
struct nlattr *req_nlas[__INET_DIAG_REQ_MAX];
#define inet_diag_nla_bc req_nlas[INET_DIAG_REQ_BYTECODE]
#define inet_diag_nla_bpf_stgs req_nlas[INET_DIAG_REQ_SK_BPF_STORAGES]
struct bpf_sk_storage_diag *bpf_stg_diag;
};
struct inet_connection_sock;
int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
struct sk_buff *skb, struct netlink_callback *cb,
const struct inet_diag_req_v2 *req,
u16 nlmsg_flags, bool net_admin);
void inet_diag_dump_icsk(struct inet_hashinfo *h, struct sk_buff *skb,
struct netlink_callback *cb,
const struct inet_diag_req_v2 *r);
int inet_diag_dump_one_icsk(struct inet_hashinfo *hashinfo,
struct netlink_callback *cb,
const struct inet_diag_req_v2 *req);
struct sock *inet_diag_find_one_icsk(struct net *net,
struct inet_hashinfo *hashinfo,
const struct inet_diag_req_v2 *req);
int inet_diag_bc_sk(const struct nlattr *_bc, struct sock *sk);
void inet_diag_msg_common_fill(struct inet_diag_msg *r, struct sock *sk);
int inet_diag_msg_attrs_fill(struct sock *sk, struct sk_buff *skb,
struct inet_diag_msg *r, int ext,
struct user_namespace *user_ns, bool net_admin);
extern int inet_diag_register(const struct inet_diag_handler *handler);
extern void inet_diag_unregister(const struct inet_diag_handler *handler);
#endif /* _INET_DIAG_H_ */