bpf: add selftest for tcpbpf

Added a selftest for tcpbpf (sock_ops) that checks that the appropriate
callbacks occured and that it can access tcp_sock fields and that their
values are correct.

Run with command: ./test_tcpbpf_user
Adding the flag "-d" will show why it did not pass.

Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Lawrence Brakmo
2018-01-25 16:14:16 -08:00
committed by Alexei Starovoitov
parent d44874910a
commit d6d4f60c3a
8 changed files with 480 additions and 6 deletions

View File

@@ -17,7 +17,7 @@
#define BPF_ALU64 0x07 /* alu mode in double word width */
/* ld/ldx fields */
#define BPF_DW 0x18 /* double word */
#define BPF_DW 0x18 /* double word (64-bit) */
#define BPF_XADD 0xc0 /* exclusive add */
/* alu/jmp fields */
@@ -642,6 +642,14 @@ union bpf_attr {
* @optlen: length of optval in bytes
* Return: 0 or negative error
*
* int bpf_sock_ops_cb_flags_set(bpf_sock_ops, flags)
* Set callback flags for sock_ops
* @bpf_sock_ops: pointer to bpf_sock_ops_kern struct
* @flags: flags value
* Return: 0 for no error
* -EINVAL if there is no full tcp socket
* bits in flags that are not supported by current kernel
*
* int bpf_skb_adjust_room(skb, len_diff, mode, flags)
* Grow or shrink room in sk_buff.
* @skb: pointer to skb
@@ -748,7 +756,8 @@ union bpf_attr {
FN(perf_event_read_value), \
FN(perf_prog_read_value), \
FN(getsockopt), \
FN(override_return),
FN(override_return), \
FN(sock_ops_cb_flags_set),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
@@ -952,8 +961,9 @@ struct bpf_map_info {
struct bpf_sock_ops {
__u32 op;
union {
__u32 reply;
__u32 replylong[4];
__u32 args[4]; /* Optionally passed to bpf program */
__u32 reply; /* Returned by bpf program */
__u32 replylong[4]; /* Optionally returned by bpf prog */
};
__u32 family;
__u32 remote_ip4; /* Stored in network byte order */
@@ -968,8 +978,39 @@ struct bpf_sock_ops {
*/
__u32 snd_cwnd;
__u32 srtt_us; /* Averaged RTT << 3 in usecs */
__u32 bpf_sock_ops_cb_flags; /* flags defined in uapi/linux/tcp.h */
__u32 state;
__u32 rtt_min;
__u32 snd_ssthresh;
__u32 rcv_nxt;
__u32 snd_nxt;
__u32 snd_una;
__u32 mss_cache;
__u32 ecn_flags;
__u32 rate_delivered;
__u32 rate_interval_us;
__u32 packets_out;
__u32 retrans_out;
__u32 total_retrans;
__u32 segs_in;
__u32 data_segs_in;
__u32 segs_out;
__u32 data_segs_out;
__u32 lost_out;
__u32 sacked_out;
__u32 sk_txhash;
__u64 bytes_received;
__u64 bytes_acked;
};
/* Definitions for bpf_sock_ops_cb_flags */
#define BPF_SOCK_OPS_RTO_CB_FLAG (1<<0)
#define BPF_SOCK_OPS_RETRANS_CB_FLAG (1<<1)
#define BPF_SOCK_OPS_STATE_CB_FLAG (1<<2)
#define BPF_SOCK_OPS_ALL_CB_FLAGS 0x7 /* Mask of all currently
* supported cb flags
*/
/* List of known BPF sock_ops operators.
* New entries can only be added at the end
*/
@@ -1003,6 +1044,43 @@ enum {
* a congestion threshold. RTTs above
* this indicate congestion
*/
BPF_SOCK_OPS_RTO_CB, /* Called when an RTO has triggered.
* Arg1: value of icsk_retransmits
* Arg2: value of icsk_rto
* Arg3: whether RTO has expired
*/
BPF_SOCK_OPS_RETRANS_CB, /* Called when skb is retransmitted.
* Arg1: sequence number of 1st byte
* Arg2: # segments
* Arg3: return value of
* tcp_transmit_skb (0 => success)
*/
BPF_SOCK_OPS_STATE_CB, /* Called when TCP changes state.
* Arg1: old_state
* Arg2: new_state
*/
};
/* List of TCP states. There is a build check in net/ipv4/tcp.c to detect
* changes between the TCP and BPF versions. Ideally this should never happen.
* If it does, we need to add code to convert them before calling
* the BPF sock_ops function.
*/
enum {
BPF_TCP_ESTABLISHED = 1,
BPF_TCP_SYN_SENT,
BPF_TCP_SYN_RECV,
BPF_TCP_FIN_WAIT1,
BPF_TCP_FIN_WAIT2,
BPF_TCP_TIME_WAIT,
BPF_TCP_CLOSE,
BPF_TCP_CLOSE_WAIT,
BPF_TCP_LAST_ACK,
BPF_TCP_LISTEN,
BPF_TCP_CLOSING, /* Now a valid state */
BPF_TCP_NEW_SYN_RECV,
BPF_TCP_MAX_STATES /* Leave at the end! */
};
#define TCP_BPF_IW 1001 /* Set TCP initial congestion window */