From 6810c771d3165e6320f991220f0c92519e6bace7 Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Wed, 19 Feb 2025 16:13:31 +0800 Subject: [PATCH 01/19] bpf: Support TCP_RTO_MAX_MS for bpf_setsockopt Some applications don't want to wait for too long because the time of retransmission increases exponentially and can reach more than 10 seconds, for example. Eric implements the core logic on supporting rto max feature in the stack previously. Based on that, we can support it for BPF use. This patch reuses the same logic of TCP_RTO_MAX_MS in do_tcp_setsockopt() and do_tcp_getsockopt(). BPF program can call bpf_{set/get}sockopt() to set/get the maximum value of RTO. Signed-off-by: Jason Xing Signed-off-by: Martin KaFai Lau Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250219081333.56378-2-kerneljasonxing@gmail.com --- net/core/filter.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/core/filter.c b/net/core/filter.c index 2ec162dd83c4..ffec7b4357f9 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5382,6 +5382,7 @@ static int sol_tcp_sockopt(struct sock *sk, int optname, case TCP_USER_TIMEOUT: case TCP_NOTSENT_LOWAT: case TCP_SAVE_SYN: + case TCP_RTO_MAX_MS: if (*optlen != sizeof(int)) return -EINVAL; break; From 7a93ba804847c3257a2f116b7a0c978835813333 Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Wed, 19 Feb 2025 16:13:32 +0800 Subject: [PATCH 02/19] selftests/bpf: Add rto max for bpf_setsockopt test Test the TCP_RTO_MAX_MS optname in the existing setget_sockopt test. Signed-off-by: Jason Xing Signed-off-by: Martin KaFai Lau Link: https://patch.msgid.link/20250219081333.56378-3-kerneljasonxing@gmail.com --- tools/testing/selftests/bpf/progs/bpf_tracing_net.h | 1 + tools/testing/selftests/bpf/progs/setget_sockopt.c | 1 + 2 files changed, 2 insertions(+) diff --git a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h index 59843b430f76..eb6ed1b7b2ef 100644 --- a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h +++ b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h @@ -49,6 +49,7 @@ #define TCP_SAVED_SYN 28 #define TCP_CA_NAME_MAX 16 #define TCP_NAGLE_OFF 1 +#define TCP_RTO_MAX_MS 44 #define TCP_ECN_OK 1 #define TCP_ECN_QUEUE_CWR 2 diff --git a/tools/testing/selftests/bpf/progs/setget_sockopt.c b/tools/testing/selftests/bpf/progs/setget_sockopt.c index 6dd4318debbf..106fe430f41b 100644 --- a/tools/testing/selftests/bpf/progs/setget_sockopt.c +++ b/tools/testing/selftests/bpf/progs/setget_sockopt.c @@ -61,6 +61,7 @@ static const struct sockopt_test sol_tcp_tests[] = { { .opt = TCP_NOTSENT_LOWAT, .new = 1314, .expected = 1314, }, { .opt = TCP_BPF_SOCK_OPS_CB_FLAGS, .new = BPF_SOCK_OPS_ALL_CB_FLAGS, .expected = BPF_SOCK_OPS_ALL_CB_FLAGS, }, + { .opt = TCP_RTO_MAX_MS, .new = 2000, .expected = 2000, }, { .opt = 0, }, }; From 24e82b7c045ba5afde5bd81f691b7a72283de35e Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Thu, 20 Feb 2025 15:29:29 +0800 Subject: [PATCH 03/19] bpf: Add networking timestamping support to bpf_get/setsockopt() The new SK_BPF_CB_FLAGS and new SK_BPF_CB_TX_TIMESTAMPING are added to bpf_get/setsockopt. The later patches will implement the BPF networking timestamping. The BPF program will use bpf_setsockopt(SK_BPF_CB_FLAGS, SK_BPF_CB_TX_TIMESTAMPING) to enable the BPF networking timestamping on a socket. Signed-off-by: Jason Xing Signed-off-by: Martin KaFai Lau Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20250220072940.99994-2-kerneljasonxing@gmail.com --- include/net/sock.h | 3 +++ include/uapi/linux/bpf.h | 7 +++++++ net/core/filter.c | 23 +++++++++++++++++++++++ tools/include/uapi/linux/bpf.h | 7 +++++++ 4 files changed, 40 insertions(+) diff --git a/include/net/sock.h b/include/net/sock.h index 60ebf3c7b229..a95eedacae76 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -303,6 +303,7 @@ struct sk_filter; * @sk_stamp: time stamp of last packet received * @sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only * @sk_tsflags: SO_TIMESTAMPING flags + * @sk_bpf_cb_flags: used in bpf_setsockopt() * @sk_use_task_frag: allow sk_page_frag() to use current->task_frag. * Sockets that can be used under memory reclaim should * set this to false. @@ -525,6 +526,8 @@ struct sock { u8 sk_txtime_deadline_mode : 1, sk_txtime_report_errors : 1, sk_txtime_unused : 6; +#define SK_BPF_CB_FLAG_TEST(SK, FLAG) ((SK)->sk_bpf_cb_flags & (FLAG)) + u8 sk_bpf_cb_flags; void *sk_user_data; #ifdef CONFIG_SECURITY diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 2acf9b336371..4e0632848440 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -6913,6 +6913,12 @@ enum { BPF_SOCK_OPS_ALL_CB_FLAGS = 0x7F, }; +enum { + SK_BPF_CB_TX_TIMESTAMPING = 1<<0, + SK_BPF_CB_MASK = (SK_BPF_CB_TX_TIMESTAMPING - 1) | + SK_BPF_CB_TX_TIMESTAMPING +}; + /* List of known BPF sock_ops operators. * New entries can only be added at the end */ @@ -7091,6 +7097,7 @@ enum { TCP_BPF_SYN_IP = 1006, /* Copy the IP[46] and TCP header */ TCP_BPF_SYN_MAC = 1007, /* Copy the MAC, IP[46], and TCP header */ TCP_BPF_SOCK_OPS_CB_FLAGS = 1008, /* Get or Set TCP sock ops flags */ + SK_BPF_CB_FLAGS = 1009, /* Get or set sock ops flags in socket */ }; enum { diff --git a/net/core/filter.c b/net/core/filter.c index ffec7b4357f9..5b7e44dfc037 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5222,6 +5222,25 @@ static const struct bpf_func_proto bpf_get_socket_uid_proto = { .arg1_type = ARG_PTR_TO_CTX, }; +static int sk_bpf_set_get_cb_flags(struct sock *sk, char *optval, bool getopt) +{ + u32 sk_bpf_cb_flags; + + if (getopt) { + *(u32 *)optval = sk->sk_bpf_cb_flags; + return 0; + } + + sk_bpf_cb_flags = *(u32 *)optval; + + if (sk_bpf_cb_flags & ~SK_BPF_CB_MASK) + return -EINVAL; + + sk->sk_bpf_cb_flags = sk_bpf_cb_flags; + + return 0; +} + static int sol_socket_sockopt(struct sock *sk, int optname, char *optval, int *optlen, bool getopt) @@ -5238,6 +5257,7 @@ static int sol_socket_sockopt(struct sock *sk, int optname, case SO_MAX_PACING_RATE: case SO_BINDTOIFINDEX: case SO_TXREHASH: + case SK_BPF_CB_FLAGS: if (*optlen != sizeof(int)) return -EINVAL; break; @@ -5247,6 +5267,9 @@ static int sol_socket_sockopt(struct sock *sk, int optname, return -EINVAL; } + if (optname == SK_BPF_CB_FLAGS) + return sk_bpf_set_get_cb_flags(sk, optval, getopt); + if (getopt) { if (optname == SO_BINDTODEVICE) return -EINVAL; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 2acf9b336371..4e0632848440 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -6913,6 +6913,12 @@ enum { BPF_SOCK_OPS_ALL_CB_FLAGS = 0x7F, }; +enum { + SK_BPF_CB_TX_TIMESTAMPING = 1<<0, + SK_BPF_CB_MASK = (SK_BPF_CB_TX_TIMESTAMPING - 1) | + SK_BPF_CB_TX_TIMESTAMPING +}; + /* List of known BPF sock_ops operators. * New entries can only be added at the end */ @@ -7091,6 +7097,7 @@ enum { TCP_BPF_SYN_IP = 1006, /* Copy the IP[46] and TCP header */ TCP_BPF_SYN_MAC = 1007, /* Copy the MAC, IP[46], and TCP header */ TCP_BPF_SOCK_OPS_CB_FLAGS = 1008, /* Get or Set TCP sock ops flags */ + SK_BPF_CB_FLAGS = 1009, /* Get or set sock ops flags in socket */ }; enum { From df600f3b1d7963e2203ebf0987f564946a2647f1 Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Thu, 20 Feb 2025 15:29:30 +0800 Subject: [PATCH 04/19] bpf: Prepare the sock_ops ctx and call bpf prog for TX timestamping This patch introduces a new bpf_skops_tx_timestamping() function that prepares the "struct bpf_sock_ops" ctx and then executes the sockops BPF program. The subsequent patch will utilize bpf_skops_tx_timestamping() at the existing TX timestamping kernel callbacks (__sk_tstamp_tx specifically) to call the sockops BPF program. Later, four callback points to report information to user space based on this patch will be introduced. Signed-off-by: Jason Xing Signed-off-by: Martin KaFai Lau Link: https://patch.msgid.link/20250220072940.99994-3-kerneljasonxing@gmail.com --- include/net/sock.h | 7 +++++++ net/core/sock.c | 14 ++++++++++++++ 2 files changed, 21 insertions(+) diff --git a/include/net/sock.h b/include/net/sock.h index a95eedacae76..2f6b55c59c16 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2924,6 +2924,13 @@ int sock_set_timestamping(struct sock *sk, int optname, struct so_timestamping timestamping); void sock_enable_timestamps(struct sock *sk); +#if defined(CONFIG_CGROUP_BPF) +void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op); +#else +static inline void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op) +{ +} +#endif void sock_no_linger(struct sock *sk); void sock_set_keepalive(struct sock *sk); void sock_set_priority(struct sock *sk, u32 priority); diff --git a/net/core/sock.c b/net/core/sock.c index a197f0a0b878..ba653c6a1229 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -949,6 +949,20 @@ int sock_set_timestamping(struct sock *sk, int optname, return 0; } +#if defined(CONFIG_CGROUP_BPF) +void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op) +{ + struct bpf_sock_ops_kern sock_ops; + + memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp)); + sock_ops.op = op; + sock_ops.is_fullsock = 1; + sock_ops.sk = sk; + bpf_skops_init_skb(&sock_ops, skb, 0); + __cgroup_bpf_run_filter_sock_ops(sk, &sock_ops, CGROUP_SOCK_OPS); +} +#endif + void sock_set_keepalive(struct sock *sk) { lock_sock(sk); From fd93eaffb3f977b23bc0a48d4c8616e654fcf133 Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Thu, 20 Feb 2025 15:29:31 +0800 Subject: [PATCH 05/19] bpf: Prevent unsafe access to the sock fields in the BPF timestamping callback The subsequent patch will implement BPF TX timestamping. It will call the sockops BPF program without holding the sock lock. This breaks the current assumption that all sock ops programs will hold the sock lock. The sock's fields of the uapi's bpf_sock_ops requires this assumption. To address this, a new "u8 is_locked_tcp_sock;" field is added. This patch sets it in the current sock_ops callbacks. The "is_fullsock" test is then replaced by the "is_locked_tcp_sock" test during sock_ops_convert_ctx_access(). The new TX timestamping callbacks added in the subsequent patch will not have this set. This will prevent unsafe access from the new timestamping callbacks. Potentially, we could allow read-only access. However, this would require identifying which callback is read-safe-only and also requires additional BPF instruction rewrites in the covert_ctx. Since the BPF program can always read everything from a socket (e.g., by using bpf_core_cast), this patch keeps it simple and disables all read and write access to any socket fields through the bpf_sock_ops UAPI from the new TX timestamping callback. Moreover, note that some of the fields in bpf_sock_ops are specific to tcp_sock, and sock_ops currently only supports tcp_sock. In the future, UDP timestamping will be added, which will also break this assumption. The same idea used in this patch will be reused. Considering that the current sock_ops only supports tcp_sock, the variable is named is_locked_"tcp"_sock. Signed-off-by: Jason Xing Signed-off-by: Martin KaFai Lau Link: https://patch.msgid.link/20250220072940.99994-4-kerneljasonxing@gmail.com --- include/linux/filter.h | 1 + include/net/tcp.h | 1 + net/core/filter.c | 8 ++++---- net/ipv4/tcp_input.c | 2 ++ net/ipv4/tcp_output.c | 2 ++ 5 files changed, 10 insertions(+), 4 deletions(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index a3ea46281595..d36d5d5180b1 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -1508,6 +1508,7 @@ struct bpf_sock_ops_kern { void *skb_data_end; u8 op; u8 is_fullsock; + u8 is_locked_tcp_sock; u8 remaining_opt_len; u64 temp; /* temp and everything after is not * initialized to 0 before calling diff --git a/include/net/tcp.h b/include/net/tcp.h index 7fd2d7fa4532..94ea09faedf4 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -2657,6 +2657,7 @@ static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp)); if (sk_fullsock(sk)) { sock_ops.is_fullsock = 1; + sock_ops.is_locked_tcp_sock = 1; sock_owned_by_me(sk); } diff --git a/net/core/filter.c b/net/core/filter.c index 5b7e44dfc037..7a20ddae7667 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -10382,10 +10382,10 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, } \ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF( \ struct bpf_sock_ops_kern, \ - is_fullsock), \ + is_locked_tcp_sock), \ fullsock_reg, si->src_reg, \ offsetof(struct bpf_sock_ops_kern, \ - is_fullsock)); \ + is_locked_tcp_sock)); \ *insn++ = BPF_JMP_IMM(BPF_JEQ, fullsock_reg, 0, jmp); \ if (si->dst_reg == si->src_reg) \ *insn++ = BPF_LDX_MEM(BPF_DW, reg, si->src_reg, \ @@ -10470,10 +10470,10 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, temp)); \ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF( \ struct bpf_sock_ops_kern, \ - is_fullsock), \ + is_locked_tcp_sock), \ reg, si->dst_reg, \ offsetof(struct bpf_sock_ops_kern, \ - is_fullsock)); \ + is_locked_tcp_sock)); \ *insn++ = BPF_JMP_IMM(BPF_JEQ, reg, 0, 2); \ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF( \ struct bpf_sock_ops_kern, sk),\ diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 4686783b70de..4a9e70e23ef8 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -169,6 +169,7 @@ static void bpf_skops_parse_hdr(struct sock *sk, struct sk_buff *skb) memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp)); sock_ops.op = BPF_SOCK_OPS_PARSE_HDR_OPT_CB; sock_ops.is_fullsock = 1; + sock_ops.is_locked_tcp_sock = 1; sock_ops.sk = sk; bpf_skops_init_skb(&sock_ops, skb, tcp_hdrlen(skb)); @@ -185,6 +186,7 @@ static void bpf_skops_established(struct sock *sk, int bpf_op, memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp)); sock_ops.op = bpf_op; sock_ops.is_fullsock = 1; + sock_ops.is_locked_tcp_sock = 1; sock_ops.sk = sk; /* sk with TCP_REPAIR_ON does not have skb in tcp_finish_connect */ if (skb) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 464232a0d637..a796cf451e55 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -525,6 +525,7 @@ static void bpf_skops_hdr_opt_len(struct sock *sk, struct sk_buff *skb, sock_owned_by_me(sk); sock_ops.is_fullsock = 1; + sock_ops.is_locked_tcp_sock = 1; sock_ops.sk = sk; } @@ -570,6 +571,7 @@ static void bpf_skops_write_hdr_opt(struct sock *sk, struct sk_buff *skb, sock_owned_by_me(sk); sock_ops.is_fullsock = 1; + sock_ops.is_locked_tcp_sock = 1; sock_ops.sk = sk; } From 2958624b25305142e24203165ff65409ba9dd9d7 Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Thu, 20 Feb 2025 15:29:32 +0800 Subject: [PATCH 06/19] bpf: Disable unsafe helpers in TX timestamping callbacks New TX timestamping sock_ops callbacks will be added in the subsequent patch. Some of the existing BPF helpers will not be safe to be used in the TX timestamping callbacks. The bpf_sock_ops_setsockopt, bpf_sock_ops_getsockopt, and bpf_sock_ops_cb_flags_set require owning the sock lock. TX timestamping callbacks will not own the lock. The bpf_sock_ops_load_hdr_opt needs the skb->data pointing to the TCP header. This will not be true in the TX timestamping callbacks. At the beginning of these helpers, this patch checks the bpf_sock->op to ensure these helpers are used by the existing sock_ops callbacks only. Signed-off-by: Jason Xing Signed-off-by: Martin KaFai Lau Link: https://patch.msgid.link/20250220072940.99994-5-kerneljasonxing@gmail.com --- net/core/filter.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/net/core/filter.c b/net/core/filter.c index 7a20ddae7667..90a8fbc2e096 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5524,6 +5524,11 @@ static int __bpf_setsockopt(struct sock *sk, int level, int optname, return -EINVAL; } +static bool is_locked_tcp_sock_ops(struct bpf_sock_ops_kern *bpf_sock) +{ + return bpf_sock->op <= BPF_SOCK_OPS_WRITE_HDR_OPT_CB; +} + static int _bpf_setsockopt(struct sock *sk, int level, int optname, char *optval, int optlen) { @@ -5674,6 +5679,9 @@ static const struct bpf_func_proto bpf_sock_addr_getsockopt_proto = { BPF_CALL_5(bpf_sock_ops_setsockopt, struct bpf_sock_ops_kern *, bpf_sock, int, level, int, optname, char *, optval, int, optlen) { + if (!is_locked_tcp_sock_ops(bpf_sock)) + return -EOPNOTSUPP; + return _bpf_setsockopt(bpf_sock->sk, level, optname, optval, optlen); } @@ -5759,6 +5767,9 @@ static int bpf_sock_ops_get_syn(struct bpf_sock_ops_kern *bpf_sock, BPF_CALL_5(bpf_sock_ops_getsockopt, struct bpf_sock_ops_kern *, bpf_sock, int, level, int, optname, char *, optval, int, optlen) { + if (!is_locked_tcp_sock_ops(bpf_sock)) + return -EOPNOTSUPP; + if (IS_ENABLED(CONFIG_INET) && level == SOL_TCP && optname >= TCP_BPF_SYN && optname <= TCP_BPF_SYN_MAC) { int ret, copy_len = 0; @@ -5801,6 +5812,9 @@ BPF_CALL_2(bpf_sock_ops_cb_flags_set, struct bpf_sock_ops_kern *, bpf_sock, struct sock *sk = bpf_sock->sk; int val = argval & BPF_SOCK_OPS_ALL_CB_FLAGS; + if (!is_locked_tcp_sock_ops(bpf_sock)) + return -EOPNOTSUPP; + if (!IS_ENABLED(CONFIG_INET) || !sk_fullsock(sk)) return -EINVAL; @@ -7610,6 +7624,9 @@ BPF_CALL_4(bpf_sock_ops_load_hdr_opt, struct bpf_sock_ops_kern *, bpf_sock, u8 search_kind, search_len, copy_len, magic_len; int ret; + if (!is_locked_tcp_sock_ops(bpf_sock)) + return -EOPNOTSUPP; + /* 2 byte is the minimal option len except TCPOPT_NOP and * TCPOPT_EOL which are useless for the bpf prog to learn * and this helper disallow loading them also. From aa290f93a4af662b8d2d9e9df65798f9f24cecf3 Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Thu, 20 Feb 2025 15:29:33 +0800 Subject: [PATCH 07/19] net-timestamp: Prepare for isolating two modes of SO_TIMESTAMPING No functional changes here. Only add test to see if the orig_skb matches the usage of application SO_TIMESTAMPING. In this series, bpf timestamping and previous socket timestamping are implemented in the same function __skb_tstamp_tx(). To test the socket enables socket timestamping feature, this function skb_tstamp_tx_report_so_timestamping() is added. In the next patch, another check for bpf timestamping feature will be introduced just like the above report function, namely, skb_tstamp_tx_report_bpf_timestamping(). Then users will be able to know the socket enables either or both of features. Signed-off-by: Jason Xing Signed-off-by: Martin KaFai Lau Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20250220072940.99994-6-kerneljasonxing@gmail.com --- net/core/skbuff.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index a441613a1e6c..341a3290e898 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -5539,6 +5539,23 @@ void skb_complete_tx_timestamp(struct sk_buff *skb, } EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp); +static bool skb_tstamp_tx_report_so_timestamping(struct sk_buff *skb, + struct skb_shared_hwtstamps *hwtstamps, + int tstype) +{ + switch (tstype) { + case SCM_TSTAMP_SCHED: + return skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP; + case SCM_TSTAMP_SND: + return skb_shinfo(skb)->tx_flags & (hwtstamps ? SKBTX_HW_TSTAMP : + SKBTX_SW_TSTAMP); + case SCM_TSTAMP_ACK: + return TCP_SKB_CB(skb)->txstamp_ack; + } + + return false; +} + void __skb_tstamp_tx(struct sk_buff *orig_skb, const struct sk_buff *ack_skb, struct skb_shared_hwtstamps *hwtstamps, @@ -5551,6 +5568,9 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb, if (!sk) return; + if (!skb_tstamp_tx_report_so_timestamping(orig_skb, hwtstamps, tstype)) + return; + tsflags = READ_ONCE(sk->sk_tsflags); if (!hwtstamps && !(tsflags & SOF_TIMESTAMPING_OPT_TX_SWHW) && skb_shinfo(orig_skb)->tx_flags & SKBTX_IN_PROGRESS) From 6b98ec7e882af1c3088a88757e2226d06c8514f9 Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Thu, 20 Feb 2025 15:29:34 +0800 Subject: [PATCH 08/19] bpf: Add BPF_SOCK_OPS_TSTAMP_SCHED_CB callback Support SCM_TSTAMP_SCHED case for bpf timestamping. Add a new sock_ops callback, BPF_SOCK_OPS_TSTAMP_SCHED_CB. This callback will occur at the same timestamping point as the user space's SCM_TSTAMP_SCHED. The BPF program can use it to get the same SCM_TSTAMP_SCHED timestamp without modifying the user-space application. A new SKBTX_BPF flag is added to mark skb_shinfo(skb)->tx_flags, ensuring that the new BPF timestamping and the current user space's SO_TIMESTAMPING do not interfere with each other. Signed-off-by: Jason Xing Signed-off-by: Martin KaFai Lau Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20250220072940.99994-7-kerneljasonxing@gmail.com --- include/linux/skbuff.h | 6 +++++- include/uapi/linux/bpf.h | 5 +++++ net/core/dev.c | 3 ++- net/core/skbuff.c | 20 ++++++++++++++++++++ tools/include/uapi/linux/bpf.h | 5 +++++ 5 files changed, 37 insertions(+), 2 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index bb2b751d274a..52f6e033e704 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -489,10 +489,14 @@ enum { /* generate software time stamp when entering packet scheduling */ SKBTX_SCHED_TSTAMP = 1 << 6, + + /* used for bpf extension when a bpf program is loaded */ + SKBTX_BPF = 1 << 7, }; #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \ - SKBTX_SCHED_TSTAMP) + SKBTX_SCHED_TSTAMP | \ + SKBTX_BPF) #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | \ SKBTX_HW_TSTAMP_USE_CYCLES | \ SKBTX_ANY_SW_TSTAMP) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 4e0632848440..bb62fe25b2d0 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -7031,6 +7031,11 @@ enum { * by the kernel or the * earlier bpf-progs. */ + BPF_SOCK_OPS_TSTAMP_SCHED_CB, /* Called when skb is passing + * through dev layer when + * SK_BPF_CB_TX_TIMESTAMPING + * feature is on. + */ }; /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect diff --git a/net/core/dev.c b/net/core/dev.c index d5ab9a4b318e..436f2bdfb2d5 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4501,7 +4501,8 @@ int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev) skb_reset_mac_header(skb); skb_assert_len(skb); - if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP)) + if (unlikely(skb_shinfo(skb)->tx_flags & + (SKBTX_SCHED_TSTAMP | SKBTX_BPF))) __skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SCHED); /* Disable soft irqs for various locks below. Also diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 341a3290e898..3206f7708974 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -5556,6 +5556,23 @@ static bool skb_tstamp_tx_report_so_timestamping(struct sk_buff *skb, return false; } +static void skb_tstamp_tx_report_bpf_timestamping(struct sk_buff *skb, + struct sock *sk, + int tstype) +{ + int op; + + switch (tstype) { + case SCM_TSTAMP_SCHED: + op = BPF_SOCK_OPS_TSTAMP_SCHED_CB; + break; + default: + return; + } + + bpf_skops_tx_timestamping(sk, skb, op); +} + void __skb_tstamp_tx(struct sk_buff *orig_skb, const struct sk_buff *ack_skb, struct skb_shared_hwtstamps *hwtstamps, @@ -5568,6 +5585,9 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb, if (!sk) return; + if (skb_shinfo(orig_skb)->tx_flags & SKBTX_BPF) + skb_tstamp_tx_report_bpf_timestamping(orig_skb, sk, tstype); + if (!skb_tstamp_tx_report_so_timestamping(orig_skb, hwtstamps, tstype)) return; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 4e0632848440..bb62fe25b2d0 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -7031,6 +7031,11 @@ enum { * by the kernel or the * earlier bpf-progs. */ + BPF_SOCK_OPS_TSTAMP_SCHED_CB, /* Called when skb is passing + * through dev layer when + * SK_BPF_CB_TX_TIMESTAMPING + * feature is on. + */ }; /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect From ecebb17ad818bc043e558c278a6c56d5bbaebacc Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Thu, 20 Feb 2025 15:29:35 +0800 Subject: [PATCH 09/19] bpf: Add BPF_SOCK_OPS_TSTAMP_SND_SW_CB callback Support sw SCM_TSTAMP_SND case for bpf timestamping. Add a new sock_ops callback, BPF_SOCK_OPS_TSTAMP_SND_SW_CB. This callback will occur at the same timestamping point as the user space's software SCM_TSTAMP_SND. The BPF program can use it to get the same SCM_TSTAMP_SND timestamp without modifying the user-space application. Based on this patch, BPF program will get the software timestamp when the driver is ready to send the skb. In the sebsequent patch, the hardware timestamp will be supported. Signed-off-by: Jason Xing Signed-off-by: Martin KaFai Lau Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20250220072940.99994-8-kerneljasonxing@gmail.com --- include/linux/skbuff.h | 2 +- include/uapi/linux/bpf.h | 4 ++++ net/core/skbuff.c | 9 ++++++++- tools/include/uapi/linux/bpf.h | 4 ++++ 4 files changed, 17 insertions(+), 2 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 52f6e033e704..76582500c5ea 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -4568,7 +4568,7 @@ void skb_tstamp_tx(struct sk_buff *orig_skb, static inline void skb_tx_timestamp(struct sk_buff *skb) { skb_clone_tx_timestamp(skb); - if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP) + if (skb_shinfo(skb)->tx_flags & (SKBTX_SW_TSTAMP | SKBTX_BPF)) skb_tstamp_tx(skb, NULL); } diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index bb62fe25b2d0..abe8d6c30dae 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -7036,6 +7036,10 @@ enum { * SK_BPF_CB_TX_TIMESTAMPING * feature is on. */ + BPF_SOCK_OPS_TSTAMP_SND_SW_CB, /* Called when skb is about to send + * to the nic when SK_BPF_CB_TX_TIMESTAMPING + * feature is on. + */ }; /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 3206f7708974..308db7dae1ab 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -5557,6 +5557,7 @@ static bool skb_tstamp_tx_report_so_timestamping(struct sk_buff *skb, } static void skb_tstamp_tx_report_bpf_timestamping(struct sk_buff *skb, + struct skb_shared_hwtstamps *hwtstamps, struct sock *sk, int tstype) { @@ -5566,6 +5567,11 @@ static void skb_tstamp_tx_report_bpf_timestamping(struct sk_buff *skb, case SCM_TSTAMP_SCHED: op = BPF_SOCK_OPS_TSTAMP_SCHED_CB; break; + case SCM_TSTAMP_SND: + if (hwtstamps) + return; + op = BPF_SOCK_OPS_TSTAMP_SND_SW_CB; + break; default: return; } @@ -5586,7 +5592,8 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb, return; if (skb_shinfo(orig_skb)->tx_flags & SKBTX_BPF) - skb_tstamp_tx_report_bpf_timestamping(orig_skb, sk, tstype); + skb_tstamp_tx_report_bpf_timestamping(orig_skb, hwtstamps, + sk, tstype); if (!skb_tstamp_tx_report_so_timestamping(orig_skb, hwtstamps, tstype)) return; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index bb62fe25b2d0..abe8d6c30dae 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -7036,6 +7036,10 @@ enum { * SK_BPF_CB_TX_TIMESTAMPING * feature is on. */ + BPF_SOCK_OPS_TSTAMP_SND_SW_CB, /* Called when skb is about to send + * to the nic when SK_BPF_CB_TX_TIMESTAMPING + * feature is on. + */ }; /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect From 2deaf7f42b8c551e84da20483ca2d4a65c3623b3 Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Thu, 20 Feb 2025 15:29:36 +0800 Subject: [PATCH 10/19] bpf: Add BPF_SOCK_OPS_TSTAMP_SND_HW_CB callback Support hw SCM_TSTAMP_SND case for bpf timestamping. Add a new sock_ops callback, BPF_SOCK_OPS_TSTAMP_SND_HW_CB. This callback will occur at the same timestamping point as the user space's hardware SCM_TSTAMP_SND. The BPF program can use it to get the same SCM_TSTAMP_SND timestamp without modifying the user-space application. To avoid increasing the code complexity, replace SKBTX_HW_TSTAMP with SKBTX_HW_TSTAMP_NOBPF instead of changing numerous callers from driver side using SKBTX_HW_TSTAMP. The new definition of SKBTX_HW_TSTAMP means the combination tests of socket timestamping and bpf timestamping. After this patch, drivers can work under the bpf timestamping. Considering some drivers don't assign the skb with hardware timestamp, this patch does the assignment and then BPF program can acquire the hwstamp from skb directly. Signed-off-by: Jason Xing Signed-off-by: Martin KaFai Lau Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20250220072940.99994-9-kerneljasonxing@gmail.com --- include/linux/skbuff.h | 4 +++- include/uapi/linux/bpf.h | 4 ++++ net/core/skbuff.c | 11 +++++++---- net/dsa/user.c | 2 +- net/socket.c | 2 +- tools/include/uapi/linux/bpf.h | 4 ++++ 6 files changed, 20 insertions(+), 7 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 76582500c5ea..0b4f1889500d 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -470,7 +470,7 @@ struct skb_shared_hwtstamps { /* Definitions for tx_flags in struct skb_shared_info */ enum { /* generate hardware time stamp */ - SKBTX_HW_TSTAMP = 1 << 0, + SKBTX_HW_TSTAMP_NOBPF = 1 << 0, /* generate software time stamp when queueing packet to NIC */ SKBTX_SW_TSTAMP = 1 << 1, @@ -494,6 +494,8 @@ enum { SKBTX_BPF = 1 << 7, }; +#define SKBTX_HW_TSTAMP (SKBTX_HW_TSTAMP_NOBPF | SKBTX_BPF) + #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \ SKBTX_SCHED_TSTAMP | \ SKBTX_BPF) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index abe8d6c30dae..72045c242396 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -7040,6 +7040,10 @@ enum { * to the nic when SK_BPF_CB_TX_TIMESTAMPING * feature is on. */ + BPF_SOCK_OPS_TSTAMP_SND_HW_CB, /* Called in hardware phase when + * SK_BPF_CB_TX_TIMESTAMPING feature + * is on. + */ }; /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 308db7dae1ab..77b8866f94c5 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -5547,7 +5547,7 @@ static bool skb_tstamp_tx_report_so_timestamping(struct sk_buff *skb, case SCM_TSTAMP_SCHED: return skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP; case SCM_TSTAMP_SND: - return skb_shinfo(skb)->tx_flags & (hwtstamps ? SKBTX_HW_TSTAMP : + return skb_shinfo(skb)->tx_flags & (hwtstamps ? SKBTX_HW_TSTAMP_NOBPF : SKBTX_SW_TSTAMP); case SCM_TSTAMP_ACK: return TCP_SKB_CB(skb)->txstamp_ack; @@ -5568,9 +5568,12 @@ static void skb_tstamp_tx_report_bpf_timestamping(struct sk_buff *skb, op = BPF_SOCK_OPS_TSTAMP_SCHED_CB; break; case SCM_TSTAMP_SND: - if (hwtstamps) - return; - op = BPF_SOCK_OPS_TSTAMP_SND_SW_CB; + if (hwtstamps) { + op = BPF_SOCK_OPS_TSTAMP_SND_HW_CB; + *skb_hwtstamps(skb) = *hwtstamps; + } else { + op = BPF_SOCK_OPS_TSTAMP_SND_SW_CB; + } break; default: return; diff --git a/net/dsa/user.c b/net/dsa/user.c index 2296a4ead020..804dc7dac4f2 100644 --- a/net/dsa/user.c +++ b/net/dsa/user.c @@ -897,7 +897,7 @@ static void dsa_skb_tx_timestamp(struct dsa_user_priv *p, { struct dsa_switch *ds = p->dp->ds; - if (!(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)) + if (!(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP_NOBPF)) return; if (!ds->ops->port_txtstamp) diff --git a/net/socket.c b/net/socket.c index 28bae5a94234..0545e9ea7058 100644 --- a/net/socket.c +++ b/net/socket.c @@ -681,7 +681,7 @@ void __sock_tx_timestamp(__u32 tsflags, __u8 *tx_flags) u8 flags = *tx_flags; if (tsflags & SOF_TIMESTAMPING_TX_HARDWARE) { - flags |= SKBTX_HW_TSTAMP; + flags |= SKBTX_HW_TSTAMP_NOBPF; /* PTP hardware clocks can provide a free running cycle counter * as a time base for virtual clocks. Tell driver to use the diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index abe8d6c30dae..72045c242396 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -7040,6 +7040,10 @@ enum { * to the nic when SK_BPF_CB_TX_TIMESTAMPING * feature is on. */ + BPF_SOCK_OPS_TSTAMP_SND_HW_CB, /* Called in hardware phase when + * SK_BPF_CB_TX_TIMESTAMPING feature + * is on. + */ }; /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect From b3b81e6b009dd8f85cd3b9c65eb492249c2649a8 Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Thu, 20 Feb 2025 15:29:37 +0800 Subject: [PATCH 11/19] bpf: Add BPF_SOCK_OPS_TSTAMP_ACK_CB callback Support the ACK case for bpf timestamping. Add a new sock_ops callback, BPF_SOCK_OPS_TSTAMP_ACK_CB. This callback will occur at the same timestamping point as the user space's SCM_TSTAMP_ACK. The BPF program can use it to get the same SCM_TSTAMP_ACK timestamp without modifying the user-space application. This patch extends txstamp_ack to two bits: 1 stands for SO_TIMESTAMPING mode, 2 bpf extension. Signed-off-by: Jason Xing Signed-off-by: Martin KaFai Lau Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20250220072940.99994-10-kerneljasonxing@gmail.com --- include/net/tcp.h | 6 ++++-- include/uapi/linux/bpf.h | 5 +++++ net/core/skbuff.c | 5 ++++- net/ipv4/tcp.c | 2 +- tools/include/uapi/linux/bpf.h | 5 +++++ 5 files changed, 19 insertions(+), 4 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 94ea09faedf4..ae6c95b01012 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -964,10 +964,12 @@ struct tcp_skb_cb { __u8 sacked; /* State flags for SACK. */ __u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */ - __u8 txstamp_ack:1, /* Record TX timestamp for ack? */ +#define TSTAMP_ACK_SK 0x1 +#define TSTAMP_ACK_BPF 0x2 + __u8 txstamp_ack:2, /* Record TX timestamp for ack? */ eor:1, /* Is skb MSG_EOR marked? */ has_rxtstamp:1, /* SKB has a RX timestamp */ - unused:5; + unused:4; __u32 ack_seq; /* Sequence number ACK'd */ union { struct { diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 72045c242396..cc10104f34a0 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -7044,6 +7044,11 @@ enum { * SK_BPF_CB_TX_TIMESTAMPING feature * is on. */ + BPF_SOCK_OPS_TSTAMP_ACK_CB, /* Called when all the skbs in the + * same sendmsg call are acked + * when SK_BPF_CB_TX_TIMESTAMPING + * feature is on. + */ }; /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 77b8866f94c5..dd33c12f00ca 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -5550,7 +5550,7 @@ static bool skb_tstamp_tx_report_so_timestamping(struct sk_buff *skb, return skb_shinfo(skb)->tx_flags & (hwtstamps ? SKBTX_HW_TSTAMP_NOBPF : SKBTX_SW_TSTAMP); case SCM_TSTAMP_ACK: - return TCP_SKB_CB(skb)->txstamp_ack; + return TCP_SKB_CB(skb)->txstamp_ack & TSTAMP_ACK_SK; } return false; @@ -5575,6 +5575,9 @@ static void skb_tstamp_tx_report_bpf_timestamping(struct sk_buff *skb, op = BPF_SOCK_OPS_TSTAMP_SND_SW_CB; } break; + case SCM_TSTAMP_ACK: + op = BPF_SOCK_OPS_TSTAMP_ACK_CB; + break; default: return; } diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 992d5c9b2487..2171e2f045bb 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -492,7 +492,7 @@ static void tcp_tx_timestamp(struct sock *sk, struct sockcm_cookie *sockc) sock_tx_timestamp(sk, sockc, &shinfo->tx_flags); if (tsflags & SOF_TIMESTAMPING_TX_ACK) - tcb->txstamp_ack = 1; + tcb->txstamp_ack |= TSTAMP_ACK_SK; if (tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK) shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1; } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 72045c242396..cc10104f34a0 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -7044,6 +7044,11 @@ enum { * SK_BPF_CB_TX_TIMESTAMPING feature * is on. */ + BPF_SOCK_OPS_TSTAMP_ACK_CB, /* Called when all the skbs in the + * same sendmsg call are acked + * when SK_BPF_CB_TX_TIMESTAMPING + * feature is on. + */ }; /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect From c9525d240c8117de35171ae705058ddf9667be27 Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Thu, 20 Feb 2025 15:29:38 +0800 Subject: [PATCH 12/19] bpf: Add BPF_SOCK_OPS_TSTAMP_SENDMSG_CB callback This patch introduces a new callback in tcp_tx_timestamp() to correlate tcp_sendmsg timestamp with timestamps from other tx timestamping callbacks (e.g., SND/SW/ACK). Without this patch, BPF program wouldn't know which timestamps belong to which flow because of no socket lock protection. This new callback is inserted in tcp_tx_timestamp() to address this issue because tcp_tx_timestamp() still owns the same socket lock with tcp_sendmsg_locked() in the meanwhile tcp_tx_timestamp() initializes the timestamping related fields for the skb, especially tskey. The tskey is the bridge to do the correlation. For TCP, BPF program hooks the beginning of tcp_sendmsg_locked() and then stores the sendmsg timestamp at the bpf_sk_storage, correlating this timestamp with its tskey that are later used in other sending timestamping callbacks. Signed-off-by: Jason Xing Signed-off-by: Martin KaFai Lau Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20250220072940.99994-11-kerneljasonxing@gmail.com --- include/uapi/linux/bpf.h | 5 +++++ net/ipv4/tcp.c | 4 ++++ tools/include/uapi/linux/bpf.h | 5 +++++ 3 files changed, 14 insertions(+) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index cc10104f34a0..defa5bb881f4 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -7049,6 +7049,11 @@ enum { * when SK_BPF_CB_TX_TIMESTAMPING * feature is on. */ + BPF_SOCK_OPS_TSTAMP_SENDMSG_CB, /* Called when every sendmsg syscall + * is triggered. It's used to correlate + * sendmsg timestamp with corresponding + * tskey. + */ }; /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 2171e2f045bb..298d1da05bee 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -496,6 +496,10 @@ static void tcp_tx_timestamp(struct sock *sk, struct sockcm_cookie *sockc) if (tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK) shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1; } + + if (cgroup_bpf_enabled(CGROUP_SOCK_OPS) && + SK_BPF_CB_FLAG_TEST(sk, SK_BPF_CB_TX_TIMESTAMPING) && skb) + bpf_skops_tx_timestamping(sk, skb, BPF_SOCK_OPS_TSTAMP_SENDMSG_CB); } static bool tcp_stream_is_readable(struct sock *sk, int target) diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index cc10104f34a0..defa5bb881f4 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -7049,6 +7049,11 @@ enum { * when SK_BPF_CB_TX_TIMESTAMPING * feature is on. */ + BPF_SOCK_OPS_TSTAMP_SENDMSG_CB, /* Called when every sendmsg syscall + * is triggered. It's used to correlate + * sendmsg timestamp with corresponding + * tskey. + */ }; /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect From 59422464266f8baa091edcb3779f0955a21abf00 Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Thu, 20 Feb 2025 15:29:39 +0800 Subject: [PATCH 13/19] bpf: Support selective sampling for bpf timestamping Add the bpf_sock_ops_enable_tx_tstamp kfunc to allow BPF programs to selectively enable TX timestamping on a skb during tcp_sendmsg(). For example, BPF program will limit tracking X numbers of packets and then will stop there instead of tracing all the sendmsgs of matched flow all along. It would be helpful for users who cannot afford to calculate latencies from every sendmsg call probably due to the performance or storage space consideration. Signed-off-by: Jason Xing Signed-off-by: Martin KaFai Lau Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20250220072940.99994-12-kerneljasonxing@gmail.com --- kernel/bpf/btf.c | 1 + net/core/filter.c | 31 ++++++++++++++++++++++++++++++- 2 files changed, 31 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 9de6acddd479..551eedb87d58 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -8524,6 +8524,7 @@ static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: case BPF_PROG_TYPE_CGROUP_SOCKOPT: case BPF_PROG_TYPE_CGROUP_SYSCTL: + case BPF_PROG_TYPE_SOCK_OPS: return BTF_KFUNC_HOOK_CGROUP; case BPF_PROG_TYPE_SCHED_ACT: return BTF_KFUNC_HOOK_SCHED_ACT; diff --git a/net/core/filter.c b/net/core/filter.c index 90a8fbc2e096..a0867c5b32b3 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -12103,6 +12103,25 @@ __bpf_kfunc int bpf_sk_assign_tcp_reqsk(struct __sk_buff *s, struct sock *sk, #endif } +__bpf_kfunc int bpf_sock_ops_enable_tx_tstamp(struct bpf_sock_ops_kern *skops, + u64 flags) +{ + struct sk_buff *skb; + + if (skops->op != BPF_SOCK_OPS_TSTAMP_SENDMSG_CB) + return -EOPNOTSUPP; + + if (flags) + return -EINVAL; + + skb = skops->skb; + skb_shinfo(skb)->tx_flags |= SKBTX_BPF; + TCP_SKB_CB(skb)->txstamp_ack |= TSTAMP_ACK_BPF; + skb_shinfo(skb)->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1; + + return 0; +} + __bpf_kfunc_end_defs(); int bpf_dynptr_from_skb_rdonly(struct __sk_buff *skb, u64 flags, @@ -12136,6 +12155,10 @@ BTF_KFUNCS_START(bpf_kfunc_check_set_tcp_reqsk) BTF_ID_FLAGS(func, bpf_sk_assign_tcp_reqsk, KF_TRUSTED_ARGS) BTF_KFUNCS_END(bpf_kfunc_check_set_tcp_reqsk) +BTF_KFUNCS_START(bpf_kfunc_check_set_sock_ops) +BTF_ID_FLAGS(func, bpf_sock_ops_enable_tx_tstamp, KF_TRUSTED_ARGS) +BTF_KFUNCS_END(bpf_kfunc_check_set_sock_ops) + static const struct btf_kfunc_id_set bpf_kfunc_set_skb = { .owner = THIS_MODULE, .set = &bpf_kfunc_check_set_skb, @@ -12156,6 +12179,11 @@ static const struct btf_kfunc_id_set bpf_kfunc_set_tcp_reqsk = { .set = &bpf_kfunc_check_set_tcp_reqsk, }; +static const struct btf_kfunc_id_set bpf_kfunc_set_sock_ops = { + .owner = THIS_MODULE, + .set = &bpf_kfunc_check_set_sock_ops, +}; + static int __init bpf_kfunc_init(void) { int ret; @@ -12174,7 +12202,8 @@ static int __init bpf_kfunc_init(void) ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &bpf_kfunc_set_xdp); ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_CGROUP_SOCK_ADDR, &bpf_kfunc_set_sock_addr); - return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &bpf_kfunc_set_tcp_reqsk); + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &bpf_kfunc_set_tcp_reqsk); + return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SOCK_OPS, &bpf_kfunc_set_sock_ops); } late_initcall(bpf_kfunc_init); From f4924aec58dd9e14779f4bc11a6bf3a830a42a6c Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Thu, 20 Feb 2025 15:29:40 +0800 Subject: [PATCH 14/19] selftests/bpf: Add simple bpf tests in the tx path for timestamping feature BPF program calculates a couple of latency deltas between each tx timestamping callbacks. It can be used in the real world to diagnose the kernel behaviour in the tx path. Check the safety issues by accessing a few bpf calls in bpf_test_access_bpf_calls() which are implemented in the patch 3 and 4. Check if the bpf timestamping can co-exist with socket timestamping. There remains a few realistic things[1][2] to highlight: 1. in general a packet may pass through multiple qdiscs. For instance with bonding or tunnel virtual devices in the egress path. 2. packets may be resent, in which case an ACK might precede a repeat SCHED and SND. 3. erroneous or malicious peers may also just never send an ACK. [1]: https://lore.kernel.org/all/67a389af981b0_14e0832949d@willemb.c.googlers.com.notmuch/ [2]: https://lore.kernel.org/all/c329a0c1-239b-4ca1-91f2-cb30b8dd2f6a@linux.dev/ Signed-off-by: Jason Xing Signed-off-by: Martin KaFai Lau Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20250220072940.99994-13-kerneljasonxing@gmail.com --- .../bpf/prog_tests/net_timestamping.c | 239 +++++++++++++++++ .../selftests/bpf/progs/net_timestamping.c | 248 ++++++++++++++++++ 2 files changed, 487 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/net_timestamping.c create mode 100644 tools/testing/selftests/bpf/progs/net_timestamping.c diff --git a/tools/testing/selftests/bpf/prog_tests/net_timestamping.c b/tools/testing/selftests/bpf/prog_tests/net_timestamping.c new file mode 100644 index 000000000000..dbfd87499b6b --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/net_timestamping.c @@ -0,0 +1,239 @@ +#include +#include +#include +#include "test_progs.h" +#include "network_helpers.h" +#include "net_timestamping.skel.h" + +#define CG_NAME "/net-timestamping-test" +#define NSEC_PER_SEC 1000000000LL + +static const char addr4_str[] = "127.0.0.1"; +static const char addr6_str[] = "::1"; +static struct net_timestamping *skel; +static const int cfg_payload_len = 30; +static struct timespec usr_ts; +static u64 delay_tolerance_nsec = 10000000000; /* 10 seconds */ +int SK_TS_SCHED; +int SK_TS_TXSW; +int SK_TS_ACK; + +static int64_t timespec_to_ns64(struct timespec *ts) +{ + return ts->tv_sec * NSEC_PER_SEC + ts->tv_nsec; +} + +static void validate_key(int tskey, int tstype) +{ + static int expected_tskey = -1; + + if (tstype == SCM_TSTAMP_SCHED) + expected_tskey = cfg_payload_len - 1; + + ASSERT_EQ(expected_tskey, tskey, "tskey mismatch"); + + expected_tskey = tskey; +} + +static void validate_timestamp(struct timespec *cur, struct timespec *prev) +{ + int64_t cur_ns, prev_ns; + + cur_ns = timespec_to_ns64(cur); + prev_ns = timespec_to_ns64(prev); + + ASSERT_LT(cur_ns - prev_ns, delay_tolerance_nsec, "latency"); +} + +static void test_socket_timestamp(struct scm_timestamping *tss, int tstype, + int tskey) +{ + static struct timespec prev_ts; + + validate_key(tskey, tstype); + + switch (tstype) { + case SCM_TSTAMP_SCHED: + validate_timestamp(&tss->ts[0], &usr_ts); + SK_TS_SCHED += 1; + break; + case SCM_TSTAMP_SND: + validate_timestamp(&tss->ts[0], &prev_ts); + SK_TS_TXSW += 1; + break; + case SCM_TSTAMP_ACK: + validate_timestamp(&tss->ts[0], &prev_ts); + SK_TS_ACK += 1; + break; + } + + prev_ts = tss->ts[0]; +} + +static void test_recv_errmsg_cmsg(struct msghdr *msg) +{ + struct sock_extended_err *serr = NULL; + struct scm_timestamping *tss = NULL; + struct cmsghdr *cm; + + for (cm = CMSG_FIRSTHDR(msg); + cm && cm->cmsg_len; + cm = CMSG_NXTHDR(msg, cm)) { + if (cm->cmsg_level == SOL_SOCKET && + cm->cmsg_type == SCM_TIMESTAMPING) { + tss = (void *)CMSG_DATA(cm); + } else if ((cm->cmsg_level == SOL_IP && + cm->cmsg_type == IP_RECVERR) || + (cm->cmsg_level == SOL_IPV6 && + cm->cmsg_type == IPV6_RECVERR) || + (cm->cmsg_level == SOL_PACKET && + cm->cmsg_type == PACKET_TX_TIMESTAMP)) { + serr = (void *)CMSG_DATA(cm); + ASSERT_EQ(serr->ee_origin, SO_EE_ORIGIN_TIMESTAMPING, + "cmsg type"); + } + + if (serr && tss) + test_socket_timestamp(tss, serr->ee_info, + serr->ee_data); + } +} + +static bool socket_recv_errmsg(int fd) +{ + static char ctrl[1024 /* overprovision*/]; + char data[cfg_payload_len]; + static struct msghdr msg; + struct iovec entry; + int n = 0; + + memset(&msg, 0, sizeof(msg)); + memset(&entry, 0, sizeof(entry)); + memset(ctrl, 0, sizeof(ctrl)); + + entry.iov_base = data; + entry.iov_len = cfg_payload_len; + msg.msg_iov = &entry; + msg.msg_iovlen = 1; + msg.msg_name = NULL; + msg.msg_namelen = 0; + msg.msg_control = ctrl; + msg.msg_controllen = sizeof(ctrl); + + n = recvmsg(fd, &msg, MSG_ERRQUEUE); + if (n == -1) + ASSERT_EQ(errno, EAGAIN, "recvmsg MSG_ERRQUEUE"); + + if (n >= 0) + test_recv_errmsg_cmsg(&msg); + + return n == -1; +} + +static void test_socket_timestamping(int fd) +{ + while (!socket_recv_errmsg(fd)); + + ASSERT_EQ(SK_TS_SCHED, 1, "SCM_TSTAMP_SCHED"); + ASSERT_EQ(SK_TS_TXSW, 1, "SCM_TSTAMP_SND"); + ASSERT_EQ(SK_TS_ACK, 1, "SCM_TSTAMP_ACK"); + + SK_TS_SCHED = 0; + SK_TS_TXSW = 0; + SK_TS_ACK = 0; +} + +static void test_tcp(int family, bool enable_socket_timestamping) +{ + struct net_timestamping__bss *bss; + char buf[cfg_payload_len]; + int sfd = -1, cfd = -1; + unsigned int sock_opt; + struct netns_obj *ns; + int cg_fd; + int ret; + + cg_fd = test__join_cgroup(CG_NAME); + if (!ASSERT_OK_FD(cg_fd, "join cgroup")) + return; + + ns = netns_new("net_timestamping_ns", true); + if (!ASSERT_OK_PTR(ns, "create ns")) + goto out; + + skel = net_timestamping__open_and_load(); + if (!ASSERT_OK_PTR(skel, "open and load skel")) + goto out; + + if (!ASSERT_OK(net_timestamping__attach(skel), "attach skel")) + goto out; + + skel->links.skops_sockopt = + bpf_program__attach_cgroup(skel->progs.skops_sockopt, cg_fd); + if (!ASSERT_OK_PTR(skel->links.skops_sockopt, "attach cgroup")) + goto out; + + bss = skel->bss; + memset(bss, 0, sizeof(*bss)); + + skel->bss->monitored_pid = getpid(); + + sfd = start_server(family, SOCK_STREAM, + family == AF_INET6 ? addr6_str : addr4_str, 0, 0); + if (!ASSERT_OK_FD(sfd, "start_server")) + goto out; + + cfd = connect_to_fd(sfd, 0); + if (!ASSERT_OK_FD(cfd, "connect_to_fd_server")) + goto out; + + if (enable_socket_timestamping) { + sock_opt = SOF_TIMESTAMPING_SOFTWARE | + SOF_TIMESTAMPING_OPT_ID | + SOF_TIMESTAMPING_TX_SCHED | + SOF_TIMESTAMPING_TX_SOFTWARE | + SOF_TIMESTAMPING_TX_ACK; + ret = setsockopt(cfd, SOL_SOCKET, SO_TIMESTAMPING, + (char *) &sock_opt, sizeof(sock_opt)); + if (!ASSERT_OK(ret, "setsockopt SO_TIMESTAMPING")) + goto out; + + ret = clock_gettime(CLOCK_REALTIME, &usr_ts); + if (!ASSERT_OK(ret, "get user time")) + goto out; + } + + ret = write(cfd, buf, sizeof(buf)); + if (!ASSERT_EQ(ret, sizeof(buf), "send to server")) + goto out; + + if (enable_socket_timestamping) + test_socket_timestamping(cfd); + + ASSERT_EQ(bss->nr_active, 1, "nr_active"); + ASSERT_EQ(bss->nr_snd, 2, "nr_snd"); + ASSERT_EQ(bss->nr_sched, 1, "nr_sched"); + ASSERT_EQ(bss->nr_txsw, 1, "nr_txsw"); + ASSERT_EQ(bss->nr_ack, 1, "nr_ack"); + +out: + if (sfd >= 0) + close(sfd); + if (cfd >= 0) + close(cfd); + net_timestamping__destroy(skel); + netns_free(ns); + close(cg_fd); +} + +void test_net_timestamping(void) +{ + if (test__start_subtest("INET4: bpf timestamping")) + test_tcp(AF_INET, false); + if (test__start_subtest("INET4: bpf and socket timestamping")) + test_tcp(AF_INET, true); + if (test__start_subtest("INET6: bpf timestamping")) + test_tcp(AF_INET6, false); + if (test__start_subtest("INET6: bpf and socket timestamping")) + test_tcp(AF_INET6, true); +} diff --git a/tools/testing/selftests/bpf/progs/net_timestamping.c b/tools/testing/selftests/bpf/progs/net_timestamping.c new file mode 100644 index 000000000000..b4c2f0f2be11 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/net_timestamping.c @@ -0,0 +1,248 @@ +#include "vmlinux.h" +#include "bpf_tracing_net.h" +#include +#include +#include "bpf_misc.h" +#include "bpf_kfuncs.h" +#include + +__u32 monitored_pid = 0; + +int nr_active; +int nr_snd; +int nr_passive; +int nr_sched; +int nr_txsw; +int nr_ack; + +struct sk_stg { + __u64 sendmsg_ns; /* record ts when sendmsg is called */ +}; + +struct sk_tskey { + u64 cookie; + u32 tskey; +}; + +struct delay_info { + u64 sendmsg_ns; /* record ts when sendmsg is called */ + u32 sched_delay; /* SCHED_CB - sendmsg_ns */ + u32 snd_sw_delay; /* SND_SW_CB - SCHED_CB */ + u32 ack_delay; /* ACK_CB - SND_SW_CB */ +}; + +struct { + __uint(type, BPF_MAP_TYPE_SK_STORAGE); + __uint(map_flags, BPF_F_NO_PREALLOC); + __type(key, int); + __type(value, struct sk_stg); +} sk_stg_map SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __type(key, struct sk_tskey); + __type(value, struct delay_info); + __uint(max_entries, 1024); +} time_map SEC(".maps"); + +static u64 delay_tolerance_nsec = 10000000000; /* 10 second as an example */ + +extern int bpf_sock_ops_enable_tx_tstamp(struct bpf_sock_ops_kern *skops, u64 flags) __ksym; + +static int bpf_test_sockopt(void *ctx, const struct sock *sk, int expected) +{ + int tmp, new = SK_BPF_CB_TX_TIMESTAMPING; + int opt = SK_BPF_CB_FLAGS; + int level = SOL_SOCKET; + + if (bpf_setsockopt(ctx, level, opt, &new, sizeof(new)) != expected) + return 1; + + if (bpf_getsockopt(ctx, level, opt, &tmp, sizeof(tmp)) != expected || + (!expected && tmp != new)) + return 1; + + return 0; +} + +static bool bpf_test_access_sockopt(void *ctx, const struct sock *sk) +{ + if (bpf_test_sockopt(ctx, sk, -EOPNOTSUPP)) + return true; + return false; +} + +static bool bpf_test_access_load_hdr_opt(struct bpf_sock_ops *skops) +{ + u8 opt[3] = {0}; + int load_flags = 0; + int ret; + + ret = bpf_load_hdr_opt(skops, opt, sizeof(opt), load_flags); + if (ret != -EOPNOTSUPP) + return true; + + return false; +} + +static bool bpf_test_access_cb_flags_set(struct bpf_sock_ops *skops) +{ + int ret; + + ret = bpf_sock_ops_cb_flags_set(skops, 0); + if (ret != -EOPNOTSUPP) + return true; + + return false; +} + +/* In the timestamping callbacks, we're not allowed to call the following + * BPF CALLs for the safety concern. Return false if expected. + */ +static bool bpf_test_access_bpf_calls(struct bpf_sock_ops *skops, + const struct sock *sk) +{ + if (bpf_test_access_sockopt(skops, sk)) + return true; + + if (bpf_test_access_load_hdr_opt(skops)) + return true; + + if (bpf_test_access_cb_flags_set(skops)) + return true; + + return false; +} + +static bool bpf_test_delay(struct bpf_sock_ops *skops, const struct sock *sk) +{ + struct bpf_sock_ops_kern *skops_kern; + u64 timestamp = bpf_ktime_get_ns(); + struct skb_shared_info *shinfo; + struct delay_info dinfo = {0}; + struct sk_tskey key = {0}; + struct delay_info *val; + struct sk_buff *skb; + struct sk_stg *stg; + u64 prior_ts, delay; + + if (bpf_test_access_bpf_calls(skops, sk)) + return false; + + skops_kern = bpf_cast_to_kern_ctx(skops); + skb = skops_kern->skb; + shinfo = bpf_core_cast(skb->head + skb->end, struct skb_shared_info); + + key.cookie = bpf_get_socket_cookie(skops); + if (!key.cookie) + return false; + + if (skops->op == BPF_SOCK_OPS_TSTAMP_SENDMSG_CB) { + stg = bpf_sk_storage_get(&sk_stg_map, (void *)sk, 0, 0); + if (!stg) + return false; + dinfo.sendmsg_ns = stg->sendmsg_ns; + bpf_sock_ops_enable_tx_tstamp(skops_kern, 0); + key.tskey = shinfo->tskey; + if (!key.tskey) + return false; + bpf_map_update_elem(&time_map, &key, &dinfo, BPF_ANY); + return true; + } + + key.tskey = shinfo->tskey; + if (!key.tskey) + return false; + + val = bpf_map_lookup_elem(&time_map, &key); + if (!val) + return false; + + switch (skops->op) { + case BPF_SOCK_OPS_TSTAMP_SCHED_CB: + val->sched_delay = timestamp - val->sendmsg_ns; + delay = val->sched_delay; + break; + case BPF_SOCK_OPS_TSTAMP_SND_SW_CB: + prior_ts = val->sched_delay + val->sendmsg_ns; + val->snd_sw_delay = timestamp - prior_ts; + delay = val->snd_sw_delay; + break; + case BPF_SOCK_OPS_TSTAMP_ACK_CB: + prior_ts = val->snd_sw_delay + val->sched_delay + val->sendmsg_ns; + val->ack_delay = timestamp - prior_ts; + delay = val->ack_delay; + break; + } + + if (delay >= delay_tolerance_nsec) + return false; + + /* Since it's the last one, remove from the map after latency check */ + if (skops->op == BPF_SOCK_OPS_TSTAMP_ACK_CB) + bpf_map_delete_elem(&time_map, &key); + + return true; +} + +SEC("fentry/tcp_sendmsg_locked") +int BPF_PROG(trace_tcp_sendmsg_locked, struct sock *sk, struct msghdr *msg, + size_t size) +{ + __u32 pid = bpf_get_current_pid_tgid() >> 32; + u64 timestamp = bpf_ktime_get_ns(); + u32 flag = sk->sk_bpf_cb_flags; + struct sk_stg *stg; + + if (pid != monitored_pid || !flag) + return 0; + + stg = bpf_sk_storage_get(&sk_stg_map, sk, 0, + BPF_SK_STORAGE_GET_F_CREATE); + if (!stg) + return 0; + + stg->sendmsg_ns = timestamp; + nr_snd += 1; + return 0; +} + +SEC("sockops") +int skops_sockopt(struct bpf_sock_ops *skops) +{ + struct bpf_sock *bpf_sk = skops->sk; + const struct sock *sk; + + if (!bpf_sk) + return 1; + + sk = (struct sock *)bpf_skc_to_tcp_sock(bpf_sk); + if (!sk) + return 1; + + switch (skops->op) { + case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB: + nr_active += !bpf_test_sockopt(skops, sk, 0); + break; + case BPF_SOCK_OPS_TSTAMP_SENDMSG_CB: + if (bpf_test_delay(skops, sk)) + nr_snd += 1; + break; + case BPF_SOCK_OPS_TSTAMP_SCHED_CB: + if (bpf_test_delay(skops, sk)) + nr_sched += 1; + break; + case BPF_SOCK_OPS_TSTAMP_SND_SW_CB: + if (bpf_test_delay(skops, sk)) + nr_txsw += 1; + break; + case BPF_SOCK_OPS_TSTAMP_ACK_CB: + if (bpf_test_delay(skops, sk)) + nr_ack += 1; + break; + } + + return 1; +} + +char _license[] SEC("license") = "GPL"; From ca4419f15abd19ba8be1e109661b60f9f5b6c9f0 Mon Sep 17 00:00:00 2001 From: Song Yoong Siang Date: Sun, 16 Feb 2025 17:34:26 +0800 Subject: [PATCH 15/19] xsk: Add launch time hardware offload support to XDP Tx metadata Extend the XDP Tx metadata framework so that user can requests launch time hardware offload, where the Ethernet device will schedule the packet for transmission at a pre-determined time called launch time. The value of launch time is communicated from user space to Ethernet driver via launch_time field of struct xsk_tx_metadata. Suggested-by: Stanislav Fomichev Signed-off-by: Song Yoong Siang Signed-off-by: Martin KaFai Lau Acked-by: Stanislav Fomichev Acked-by: Jakub Kicinski Link: https://patch.msgid.link/20250216093430.957880-2-yoong.siang.song@intel.com --- Documentation/netlink/specs/netdev.yaml | 4 ++ Documentation/networking/xsk-tx-metadata.rst | 62 ++++++++++++++++++++ include/net/xdp_sock.h | 10 ++++ include/net/xdp_sock_drv.h | 1 + include/uapi/linux/if_xdp.h | 10 ++++ include/uapi/linux/netdev.h | 3 + net/core/netdev-genl.c | 2 + net/xdp/xsk.c | 3 + tools/include/uapi/linux/if_xdp.h | 10 ++++ tools/include/uapi/linux/netdev.h | 3 + 10 files changed, 108 insertions(+) diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml index 288923e965ae..5f6f84630b16 100644 --- a/Documentation/netlink/specs/netdev.yaml +++ b/Documentation/netlink/specs/netdev.yaml @@ -70,6 +70,10 @@ definitions: name: tx-checksum doc: L3 checksum HW offload is supported by the driver. + - + name: tx-launch-time-fifo + doc: + Launch time HW offload is supported by the driver. - name: queue-type type: enum diff --git a/Documentation/networking/xsk-tx-metadata.rst b/Documentation/networking/xsk-tx-metadata.rst index e76b0cfc32f7..df53a10ccac3 100644 --- a/Documentation/networking/xsk-tx-metadata.rst +++ b/Documentation/networking/xsk-tx-metadata.rst @@ -50,6 +50,10 @@ The flags field enables the particular offload: checksum. ``csum_start`` specifies byte offset of where the checksumming should start and ``csum_offset`` specifies byte offset where the device should store the computed checksum. +- ``XDP_TXMD_FLAGS_LAUNCH_TIME``: requests the device to schedule the + packet for transmission at a pre-determined time called launch time. The + value of launch time is indicated by ``launch_time`` field of + ``union xsk_tx_metadata``. Besides the flags above, in order to trigger the offloads, the first packet's ``struct xdp_desc`` descriptor should set ``XDP_TX_METADATA`` @@ -65,6 +69,63 @@ In this case, when running in ``XDK_COPY`` mode, the TX checksum is calculated on the CPU. Do not enable this option in production because it will negatively affect performance. +Launch Time +=========== + +The value of the requested launch time should be based on the device's PTP +Hardware Clock (PHC) to ensure accuracy. AF_XDP takes a different data path +compared to the ETF queuing discipline, which organizes packets and delays +their transmission. Instead, AF_XDP immediately hands off the packets to +the device driver without rearranging their order or holding them prior to +transmission. Since the driver maintains FIFO behavior and does not perform +packet reordering, a packet with a launch time request will block other +packets in the same Tx Queue until it is sent. Therefore, it is recommended +to allocate separate queue for scheduling traffic that is intended for +future transmission. + +In scenarios where the launch time offload feature is disabled, the device +driver is expected to disregard the launch time request. For correct +interpretation and meaningful operation, the launch time should never be +set to a value larger than the farthest programmable time in the future +(the horizon). Different devices have different hardware limitations on the +launch time offload feature. + +stmmac driver +------------- + +For stmmac, TSO and launch time (TBS) features are mutually exclusive for +each individual Tx Queue. By default, the driver configures Tx Queue 0 to +support TSO and the rest of the Tx Queues to support TBS. The launch time +hardware offload feature can be enabled or disabled by using the tc-etf +command to call the driver's ndo_setup_tc() callback. + +The value of the launch time that is programmed in the Enhanced Normal +Transmit Descriptors is a 32-bit value, where the most significant 8 bits +represent the time in seconds and the remaining 24 bits represent the time +in 256 ns increments. The programmed launch time is compared against the +PTP time (bits[39:8]) and rolls over after 256 seconds. Therefore, the +horizon of the launch time for dwmac4 and dwxlgmac2 is 128 seconds in the +future. + +igc driver +---------- + +For igc, all four Tx Queues support the launch time feature. The launch +time hardware offload feature can be enabled or disabled by using the +tc-etf command to call the driver's ndo_setup_tc() callback. When entering +TSN mode, the igc driver will reset the device and create a default Qbv +schedule with a 1-second cycle time, with all Tx Queues open at all times. + +The value of the launch time that is programmed in the Advanced Transmit +Context Descriptor is a relative offset to the starting time of the Qbv +transmission window of the queue. The Frst flag of the descriptor can be +set to schedule the packet for the next Qbv cycle. Therefore, the horizon +of the launch time for i225 and i226 is the ending time of the next cycle +of the Qbv transmission window of the queue. For example, when the Qbv +cycle time is set to 1 second, the horizon of the launch time ranges +from 1 second to 2 seconds, depending on where the Qbv cycle is currently +running. + Querying Device Capabilities ============================ @@ -74,6 +135,7 @@ Refer to ``xsk-flags`` features bitmask in - ``tx-timestamp``: device supports ``XDP_TXMD_FLAGS_TIMESTAMP`` - ``tx-checksum``: device supports ``XDP_TXMD_FLAGS_CHECKSUM`` +- ``tx-launch-time-fifo``: device supports ``XDP_TXMD_FLAGS_LAUNCH_TIME`` See ``tools/net/ynl/samples/netdev.c`` on how to query this information. diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h index bfe625b55d55..a58ae7589d12 100644 --- a/include/net/xdp_sock.h +++ b/include/net/xdp_sock.h @@ -110,11 +110,16 @@ struct xdp_sock { * indicates position where checksumming should start. * csum_offset indicates position where checksum should be stored. * + * void (*tmo_request_launch_time)(u64 launch_time, void *priv) + * Called when AF_XDP frame requested launch time HW offload support. + * launch_time indicates the PTP time at which the device can schedule the + * packet for transmission. */ struct xsk_tx_metadata_ops { void (*tmo_request_timestamp)(void *priv); u64 (*tmo_fill_timestamp)(void *priv); void (*tmo_request_checksum)(u16 csum_start, u16 csum_offset, void *priv); + void (*tmo_request_launch_time)(u64 launch_time, void *priv); }; #ifdef CONFIG_XDP_SOCKETS @@ -162,6 +167,11 @@ static inline void xsk_tx_metadata_request(const struct xsk_tx_metadata *meta, if (!meta) return; + if (ops->tmo_request_launch_time) + if (meta->flags & XDP_TXMD_FLAGS_LAUNCH_TIME) + ops->tmo_request_launch_time(meta->request.launch_time, + priv); + if (ops->tmo_request_timestamp) if (meta->flags & XDP_TXMD_FLAGS_TIMESTAMP) ops->tmo_request_timestamp(priv); diff --git a/include/net/xdp_sock_drv.h b/include/net/xdp_sock_drv.h index 15086dcf51d8..513c8e9704f6 100644 --- a/include/net/xdp_sock_drv.h +++ b/include/net/xdp_sock_drv.h @@ -216,6 +216,7 @@ xsk_buff_raw_get_ctx(const struct xsk_buff_pool *pool, u64 addr) #define XDP_TXMD_FLAGS_VALID ( \ XDP_TXMD_FLAGS_TIMESTAMP | \ XDP_TXMD_FLAGS_CHECKSUM | \ + XDP_TXMD_FLAGS_LAUNCH_TIME | \ 0) static inline bool diff --git a/include/uapi/linux/if_xdp.h b/include/uapi/linux/if_xdp.h index 42ec5ddaab8d..42869770776e 100644 --- a/include/uapi/linux/if_xdp.h +++ b/include/uapi/linux/if_xdp.h @@ -127,6 +127,12 @@ struct xdp_options { */ #define XDP_TXMD_FLAGS_CHECKSUM (1 << 1) +/* Request launch time hardware offload. The device will schedule the packet for + * transmission at a pre-determined time called launch time. The value of + * launch time is communicated via launch_time field of struct xsk_tx_metadata. + */ +#define XDP_TXMD_FLAGS_LAUNCH_TIME (1 << 2) + /* AF_XDP offloads request. 'request' union member is consumed by the driver * when the packet is being transmitted. 'completion' union member is * filled by the driver when the transmit completion arrives. @@ -142,6 +148,10 @@ struct xsk_tx_metadata { __u16 csum_start; /* Offset from csum_start where checksum should be stored. */ __u16 csum_offset; + + /* XDP_TXMD_FLAGS_LAUNCH_TIME */ + /* Launch time in nanosecond against the PTP HW Clock */ + __u64 launch_time; } request; struct { diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h index 6c6ee183802d..b97ff8bbb0c6 100644 --- a/include/uapi/linux/netdev.h +++ b/include/uapi/linux/netdev.h @@ -59,10 +59,13 @@ enum netdev_xdp_rx_metadata { * by the driver. * @NETDEV_XSK_FLAGS_TX_CHECKSUM: L3 checksum HW offload is supported by the * driver. + * @NETDEV_XSK_FLAGS_TX_LAUNCH_TIME_FIFO: Launch time HW offload is supported + * by the driver. */ enum netdev_xsk_flags { NETDEV_XSK_FLAGS_TX_TIMESTAMP = 1, NETDEV_XSK_FLAGS_TX_CHECKSUM = 2, + NETDEV_XSK_FLAGS_TX_LAUNCH_TIME_FIFO = 4, }; enum netdev_queue_type { diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c index c18bb53d13fd..55bb58d623ac 100644 --- a/net/core/netdev-genl.c +++ b/net/core/netdev-genl.c @@ -53,6 +53,8 @@ XDP_METADATA_KFUNC_xxx xsk_features |= NETDEV_XSK_FLAGS_TX_TIMESTAMP; if (netdev->xsk_tx_metadata_ops->tmo_request_checksum) xsk_features |= NETDEV_XSK_FLAGS_TX_CHECKSUM; + if (netdev->xsk_tx_metadata_ops->tmo_request_launch_time) + xsk_features |= NETDEV_XSK_FLAGS_TX_LAUNCH_TIME_FIFO; } if (nla_put_u32(rsp, NETDEV_A_DEV_IFINDEX, netdev->ifindex) || diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 89d2bef96469..41093ea63700 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -742,6 +742,9 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, goto free_err; } } + + if (meta->flags & XDP_TXMD_FLAGS_LAUNCH_TIME) + skb->skb_mstamp_ns = meta->request.launch_time; } } diff --git a/tools/include/uapi/linux/if_xdp.h b/tools/include/uapi/linux/if_xdp.h index 42ec5ddaab8d..42869770776e 100644 --- a/tools/include/uapi/linux/if_xdp.h +++ b/tools/include/uapi/linux/if_xdp.h @@ -127,6 +127,12 @@ struct xdp_options { */ #define XDP_TXMD_FLAGS_CHECKSUM (1 << 1) +/* Request launch time hardware offload. The device will schedule the packet for + * transmission at a pre-determined time called launch time. The value of + * launch time is communicated via launch_time field of struct xsk_tx_metadata. + */ +#define XDP_TXMD_FLAGS_LAUNCH_TIME (1 << 2) + /* AF_XDP offloads request. 'request' union member is consumed by the driver * when the packet is being transmitted. 'completion' union member is * filled by the driver when the transmit completion arrives. @@ -142,6 +148,10 @@ struct xsk_tx_metadata { __u16 csum_start; /* Offset from csum_start where checksum should be stored. */ __u16 csum_offset; + + /* XDP_TXMD_FLAGS_LAUNCH_TIME */ + /* Launch time in nanosecond against the PTP HW Clock */ + __u64 launch_time; } request; struct { diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h index 6c6ee183802d..b97ff8bbb0c6 100644 --- a/tools/include/uapi/linux/netdev.h +++ b/tools/include/uapi/linux/netdev.h @@ -59,10 +59,13 @@ enum netdev_xdp_rx_metadata { * by the driver. * @NETDEV_XSK_FLAGS_TX_CHECKSUM: L3 checksum HW offload is supported by the * driver. + * @NETDEV_XSK_FLAGS_TX_LAUNCH_TIME_FIFO: Launch time HW offload is supported + * by the driver. */ enum netdev_xsk_flags { NETDEV_XSK_FLAGS_TX_TIMESTAMP = 1, NETDEV_XSK_FLAGS_TX_CHECKSUM = 2, + NETDEV_XSK_FLAGS_TX_LAUNCH_TIME_FIFO = 4, }; enum netdev_queue_type { From 6164847e5403dd56ec06c36e22526747bce61b13 Mon Sep 17 00:00:00 2001 From: Song Yoong Siang Date: Sun, 16 Feb 2025 17:34:27 +0800 Subject: [PATCH 16/19] selftests/bpf: Add launch time request to xdp_hw_metadata Add launch time hardware offload request to xdp_hw_metadata. Users can configure the delta of launch time relative to HW RX-time using the "-l" argument. By default, the delta is set to 0 ns, which means the launch time is disabled. By setting the delta to a non-zero value, the launch time hardware offload feature will be enabled and requested. Additionally, users can configure the Tx Queue to be enabled with the launch time hardware offload using the "-L" argument. By default, Tx Queue 0 will be used. Signed-off-by: Song Yoong Siang Signed-off-by: Martin KaFai Lau Acked-by: Stanislav Fomichev Link: https://patch.msgid.link/20250216093430.957880-3-yoong.siang.song@intel.com --- tools/testing/selftests/bpf/xdp_hw_metadata.c | 168 +++++++++++++++++- 1 file changed, 163 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/bpf/xdp_hw_metadata.c b/tools/testing/selftests/bpf/xdp_hw_metadata.c index 6f7b15d6c6ed..3d8de0d4c96a 100644 --- a/tools/testing/selftests/bpf/xdp_hw_metadata.c +++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c @@ -13,6 +13,7 @@ * - UDP 9091 packets trigger TX reply * - TX HW timestamp is requested and reported back upon completion * - TX checksum is requested + * - TX launch time HW offload is requested for transmission */ #include @@ -37,6 +38,15 @@ #include #include #include +#include +#include +#include +#include +#include +#include +#include +#include +#include #include "xdp_metadata.h" @@ -64,6 +74,18 @@ int rxq; bool skip_tx; __u64 last_hw_rx_timestamp; __u64 last_xdp_rx_timestamp; +__u64 last_launch_time; +__u64 launch_time_delta_to_hw_rx_timestamp; +int launch_time_queue; + +#define run_command(cmd, ...) \ +({ \ + char command[1024]; \ + memset(command, 0, sizeof(command)); \ + snprintf(command, sizeof(command), cmd, ##__VA_ARGS__); \ + fprintf(stderr, "Running: %s\n", command); \ + system(command); \ +}) void test__fail(void) { /* for network_helpers.c */ } @@ -298,6 +320,12 @@ static bool complete_tx(struct xsk *xsk, clockid_t clock_id) if (meta->completion.tx_timestamp) { __u64 ref_tstamp = gettime(clock_id); + if (launch_time_delta_to_hw_rx_timestamp) { + print_tstamp_delta("HW Launch-time", + "HW TX-complete-time", + last_launch_time, + meta->completion.tx_timestamp); + } print_tstamp_delta("HW TX-complete-time", "User TX-complete-time", meta->completion.tx_timestamp, ref_tstamp); print_tstamp_delta("XDP RX-time", "User TX-complete-time", @@ -395,6 +423,17 @@ static void ping_pong(struct xsk *xsk, void *rx_packet, clockid_t clock_id) xsk, ntohs(udph->check), ntohs(want_csum), meta->request.csum_start, meta->request.csum_offset); + /* Set the value of launch time */ + if (launch_time_delta_to_hw_rx_timestamp) { + meta->flags |= XDP_TXMD_FLAGS_LAUNCH_TIME; + meta->request.launch_time = last_hw_rx_timestamp + + launch_time_delta_to_hw_rx_timestamp; + last_launch_time = meta->request.launch_time; + print_tstamp_delta("HW RX-time", "HW Launch-time", + last_hw_rx_timestamp, + meta->request.launch_time); + } + memcpy(data, rx_packet, len); /* don't share umem chunk for simplicity */ tx_desc->options |= XDP_TX_METADATA; tx_desc->len = len; @@ -407,6 +446,7 @@ static int verify_metadata(struct xsk *rx_xsk, int rxq, int server_fd, clockid_t const struct xdp_desc *rx_desc; struct pollfd fds[rxq + 1]; __u64 comp_addr; + __u64 deadline; __u64 addr; __u32 idx = 0; int ret; @@ -477,9 +517,15 @@ static int verify_metadata(struct xsk *rx_xsk, int rxq, int server_fd, clockid_t if (ret) printf("kick_tx ret=%d\n", ret); - for (int j = 0; j < 500; j++) { + /* wait 1 second + cover launch time */ + deadline = gettime(clock_id) + + NANOSEC_PER_SEC + + launch_time_delta_to_hw_rx_timestamp; + while (true) { if (complete_tx(xsk, clock_id)) break; + if (gettime(clock_id) >= deadline) + break; usleep(10); } } @@ -608,6 +654,10 @@ static void print_usage(void) " -h Display this help and exit\n\n" " -m Enable multi-buffer XDP for larger MTU\n" " -r Don't generate AF_XDP reply (rx metadata only)\n" + " -l Delta of launch time relative to HW RX-time in ns\n" + " default: 0 ns (launch time request is disabled)\n" + " -L Tx Queue to be enabled with launch time offload\n" + " default: 0 (Tx Queue 0)\n" "Generate test packets on the other machine with:\n" " echo -n xdp | nc -u -q1 9091\n"; @@ -618,7 +668,7 @@ static void read_args(int argc, char *argv[]) { int opt; - while ((opt = getopt(argc, argv, "chmr")) != -1) { + while ((opt = getopt(argc, argv, "chmrl:L:")) != -1) { switch (opt) { case 'c': bind_flags &= ~XDP_USE_NEED_WAKEUP; @@ -634,6 +684,12 @@ static void read_args(int argc, char *argv[]) case 'r': skip_tx = true; break; + case 'l': + launch_time_delta_to_hw_rx_timestamp = atoll(optarg); + break; + case 'L': + launch_time_queue = atoll(optarg); + break; case '?': if (isprint(optopt)) fprintf(stderr, "Unknown option: -%c\n", optopt); @@ -657,23 +713,118 @@ static void read_args(int argc, char *argv[]) error(-1, errno, "Invalid interface name"); } +void clean_existing_configurations(void) +{ + /* Check and delete root qdisc if exists */ + if (run_command("sudo tc qdisc show dev %s | grep -q 'qdisc mqprio 8001:'", ifname) == 0) + run_command("sudo tc qdisc del dev %s root", ifname); + + /* Check and delete ingress qdisc if exists */ + if (run_command("sudo tc qdisc show dev %s | grep -q 'qdisc ingress ffff:'", ifname) == 0) + run_command("sudo tc qdisc del dev %s ingress", ifname); + + /* Check and delete ethtool filters if any exist */ + if (run_command("sudo ethtool -n %s | grep -q 'Filter:'", ifname) == 0) { + run_command("sudo ethtool -n %s | grep 'Filter:' | awk '{print $2}' | xargs -n1 sudo ethtool -N %s delete >&2", + ifname, ifname); + } +} + +#define MAX_TC 16 + int main(int argc, char *argv[]) { clockid_t clock_id = CLOCK_TAI; + struct bpf_program *prog; int server_fd = -1; + size_t map_len = 0; + size_t que_len = 0; + char *buf = NULL; + char *map = NULL; + char *que = NULL; + char *tmp = NULL; + int tc = 0; int ret; int i; - struct bpf_program *prog; - read_args(argc, argv); rxq = rxq_num(ifname); - printf("rxq: %d\n", rxq); + if (launch_time_queue >= rxq || launch_time_queue < 0) + error(1, 0, "Invalid launch_time_queue."); + + clean_existing_configurations(); + sleep(1); + + /* Enable tx and rx hardware timestamping */ hwtstamp_enable(ifname); + /* Prepare priority to traffic class map for tc-mqprio */ + for (i = 0; i < MAX_TC; i++) { + if (i < rxq) + tc = i; + + if (asprintf(&buf, "%d ", tc) == -1) { + printf("Failed to malloc buf for tc map.\n"); + goto free_mem; + } + + map_len += strlen(buf); + tmp = realloc(map, map_len + 1); + if (!tmp) { + printf("Failed to realloc tc map.\n"); + goto free_mem; + } + map = tmp; + strcat(map, buf); + free(buf); + buf = NULL; + } + + /* Prepare traffic class to hardware queue map for tc-mqprio */ + for (i = 0; i <= tc; i++) { + if (asprintf(&buf, "1@%d ", i) == -1) { + printf("Failed to malloc buf for tc queues.\n"); + goto free_mem; + } + + que_len += strlen(buf); + tmp = realloc(que, que_len + 1); + if (!tmp) { + printf("Failed to realloc tc queues.\n"); + goto free_mem; + } + que = tmp; + strcat(que, buf); + free(buf); + buf = NULL; + } + + /* Add mqprio qdisc */ + run_command("sudo tc qdisc add dev %s handle 8001: parent root mqprio num_tc %d map %squeues %shw 0", + ifname, tc + 1, map, que); + + /* To test launch time, send UDP packet with VLAN priority 1 to port 9091 */ + if (launch_time_delta_to_hw_rx_timestamp) { + /* Enable launch time hardware offload on launch_time_queue */ + run_command("sudo tc qdisc replace dev %s parent 8001:%d etf offload clockid CLOCK_TAI delta 500000", + ifname, launch_time_queue + 1); + sleep(1); + + /* Route incoming packet with VLAN priority 1 into launch_time_queue */ + if (run_command("sudo ethtool -N %s flow-type ether vlan 0x2000 vlan-mask 0x1FFF action %d", + ifname, launch_time_queue)) { + run_command("sudo tc qdisc add dev %s ingress", ifname); + run_command("sudo tc filter add dev %s parent ffff: protocol 802.1Q flower vlan_prio 1 hw_tc %d", + ifname, launch_time_queue); + } + + /* Enable VLAN tag stripping offload */ + run_command("sudo ethtool -K %s rxvlan on", ifname); + } + rx_xsk = malloc(sizeof(struct xsk) * rxq); if (!rx_xsk) error(1, ENOMEM, "malloc"); @@ -733,4 +884,11 @@ int main(int argc, char *argv[]) cleanup(); if (ret) error(1, -ret, "verify_metadata"); + + clean_existing_configurations(); + +free_mem: + free(buf); + free(map); + free(que); } From 04f64dea13640fb456422c171c0a68462665d638 Mon Sep 17 00:00:00 2001 From: Song Yoong Siang Date: Sun, 16 Feb 2025 17:34:28 +0800 Subject: [PATCH 17/19] net: stmmac: Add launch time support to XDP ZC Enable launch time (Time-Based Scheduling) support for XDP zero copy via the XDP Tx metadata framework. This patch has been tested with tools/testing/selftests/bpf/xdp_hw_metadata on Intel Tiger Lake platform. Below are the test steps and result. Test 1: Send a single packet with the launch time set to 1 s in the future. Test steps: 1. On the DUT, start the xdp_hw_metadata selftest application: $ sudo ./xdp_hw_metadata enp0s30f4 -l 1000000000 -L 1 2. On the Link Partner, send a UDP packet with VLAN priority 1 to port 9091 of the DUT. Result: When the launch time is set to 1 s in the future, the delta between the launch time and the transmit hardware timestamp is 16.963 us, as shown in printout of the xdp_hw_metadata application below. 0x55b5864717a8: rx_desc[4]->addr=88100 addr=88100 comp_addr=88100 EoP No rx_hash, err=-95 HW RX-time: 1734579065767717328 (sec:1734579065.7677) delta to User RX-time sec:0.0004 (375.624 usec) XDP RX-time: 1734579065768004454 (sec:1734579065.7680) delta to User RX-time sec:0.0001 (88.498 usec) No rx_vlan_tci or rx_vlan_proto, err=-95 0x55b5864717a8: ping-pong with csum=5619 (want 0000) csum_start=34 csum_offset=6 HW RX-time: 1734579065767717328 (sec:1734579065.7677) delta to HW Launch-time sec:1.0000 (1000000.000 usec) 0x55b5864717a8: complete tx idx=4 addr=4018 HW Launch-time: 1734579066767717328 (sec:1734579066.7677) delta to HW TX-complete-time sec:0.0000 (16.963 usec) HW TX-complete-time: 1734579066767734291 (sec:1734579066.7677) delta to User TX-complete-time sec:0.0001 (130.408 usec) XDP RX-time: 1734579065768004454 (sec:1734579065.7680) delta to User TX-complete-time sec:0.9999 (999860.245 usec) HW RX-time: 1734579065767717328 (sec:1734579065.7677) delta to HW TX-complete-time sec:1.0000 (1000016.963 usec) 0x55b5864717a8: complete rx idx=132 addr=88100 Test 2: Send 1000 packets with a 10 ms interval and the launch time set to 500 us in the future. Test steps: 1. On the DUT, start the xdp_hw_metadata selftest application: $ sudo chrt -f 99 ./xdp_hw_metadata enp0s30f4 -l 500000 -L 1 > \ /dev/shm/result.log 2. On the Link Partner, send 1000 UDP packets with a 10 ms interval and VLAN priority 1 to port 9091 of the DUT. Result: When the launch time is set to 500 us in the future, the average delta between the launch time and the transmit hardware timestamp is 13.854 us, as shown in the analysis of /dev/shm/result.log below. The XDP launch time works correctly in sending 1000 packets continuously. Min delta: 08.410 us Avr delta: 13.854 us Max delta: 17.076 us Total packets forwarded: 1000 Signed-off-by: Song Yoong Siang Signed-off-by: Martin KaFai Lau Reviewed-by: Choong Yong Liang Link: https://patch.msgid.link/20250216093430.957880-4-yoong.siang.song@intel.com --- drivers/net/ethernet/stmicro/stmmac/stmmac.h | 2 ++ drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 13 +++++++++++++ 2 files changed, 15 insertions(+) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h index f05cae103d83..925d8b97a42b 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h @@ -106,6 +106,8 @@ struct stmmac_metadata_request { struct stmmac_priv *priv; struct dma_desc *tx_desc; bool *set_ic; + struct dma_edesc *edesc; + int tbs; }; struct stmmac_xsk_tx_complete { diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index d99ff4146512..61ff545b74e3 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -2491,9 +2491,20 @@ static u64 stmmac_xsk_fill_timestamp(void *_priv) return 0; } +static void stmmac_xsk_request_launch_time(u64 launch_time, void *_priv) +{ + struct timespec64 ts = ns_to_timespec64(launch_time); + struct stmmac_metadata_request *meta_req = _priv; + + if (meta_req->tbs & STMMAC_TBS_EN) + stmmac_set_desc_tbs(meta_req->priv, meta_req->edesc, ts.tv_sec, + ts.tv_nsec); +} + static const struct xsk_tx_metadata_ops stmmac_xsk_tx_metadata_ops = { .tmo_request_timestamp = stmmac_xsk_request_timestamp, .tmo_fill_timestamp = stmmac_xsk_fill_timestamp, + .tmo_request_launch_time = stmmac_xsk_request_launch_time, }; static bool stmmac_xdp_xmit_zc(struct stmmac_priv *priv, u32 queue, u32 budget) @@ -2577,6 +2588,8 @@ static bool stmmac_xdp_xmit_zc(struct stmmac_priv *priv, u32 queue, u32 budget) meta_req.priv = priv; meta_req.tx_desc = tx_desc; meta_req.set_ic = &set_ic; + meta_req.tbs = tx_q->tbs; + meta_req.edesc = &tx_q->dma_entx[entry]; xsk_tx_metadata_request(meta, &stmmac_xsk_tx_metadata_ops, &meta_req); if (set_ic) { From f9b53bb13923f0a6ed2e784a35301cfb4c28f4f4 Mon Sep 17 00:00:00 2001 From: Song Yoong Siang Date: Sun, 16 Feb 2025 17:34:29 +0800 Subject: [PATCH 18/19] igc: Refactor empty frame insertion for launch time support Refactor the code for inserting an empty frame into a new function igc_insert_empty_frame(). This change extracts the logic for inserting an empty packet from igc_xmit_frame_ring() into a separate function, allowing it to be reused in future implementations, such as the XDP zero copy transmit function. Remove the igc_desc_unused() checking in igc_init_tx_empty_descriptor() because the number of descriptors needed is guaranteed. Ensure that skb allocation and DMA mapping work for the empty frame, before proceeding to fill in igc_tx_buffer info, context descriptor, and data descriptor. Rate limit the error messages for skb allocation and DMA mapping failures. Update the comment to indicate that the 2 descriptors needed by the empty frame are already taken into consideration in igc_xmit_frame_ring(). Handle the case where the insertion of an empty frame fails and explain the reason behind this handling. Signed-off-by: Song Yoong Siang Signed-off-by: Martin KaFai Lau Reviewed-by: Faizal Rahim Reviewed-by: Maciej Fijalkowski Link: https://patch.msgid.link/20250216093430.957880-5-yoong.siang.song@intel.com --- drivers/net/ethernet/intel/igc/igc_main.c | 82 ++++++++++++++--------- 1 file changed, 50 insertions(+), 32 deletions(-) diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index 84307bb7313e..1bfa71545e37 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -1092,7 +1092,8 @@ static int igc_init_empty_frame(struct igc_ring *ring, dma = dma_map_single(ring->dev, skb->data, size, DMA_TO_DEVICE); if (dma_mapping_error(ring->dev, dma)) { - netdev_err_once(ring->netdev, "Failed to map DMA for TX\n"); + net_err_ratelimited("%s: DMA mapping error for empty frame\n", + netdev_name(ring->netdev)); return -ENOMEM; } @@ -1108,20 +1109,12 @@ static int igc_init_empty_frame(struct igc_ring *ring, return 0; } -static int igc_init_tx_empty_descriptor(struct igc_ring *ring, - struct sk_buff *skb, - struct igc_tx_buffer *first) +static void igc_init_tx_empty_descriptor(struct igc_ring *ring, + struct sk_buff *skb, + struct igc_tx_buffer *first) { union igc_adv_tx_desc *desc; u32 cmd_type, olinfo_status; - int err; - - if (!igc_desc_unused(ring)) - return -EBUSY; - - err = igc_init_empty_frame(ring, first, skb); - if (err) - return err; cmd_type = IGC_ADVTXD_DTYP_DATA | IGC_ADVTXD_DCMD_DEXT | IGC_ADVTXD_DCMD_IFCS | IGC_TXD_DCMD | @@ -1140,8 +1133,6 @@ static int igc_init_tx_empty_descriptor(struct igc_ring *ring, ring->next_to_use++; if (ring->next_to_use == ring->count) ring->next_to_use = 0; - - return 0; } #define IGC_EMPTY_FRAME_SIZE 60 @@ -1567,6 +1558,40 @@ static bool igc_request_tx_tstamp(struct igc_adapter *adapter, struct sk_buff *s return false; } +static int igc_insert_empty_frame(struct igc_ring *tx_ring) +{ + struct igc_tx_buffer *empty_info; + struct sk_buff *empty_skb; + void *data; + int ret; + + empty_info = &tx_ring->tx_buffer_info[tx_ring->next_to_use]; + empty_skb = alloc_skb(IGC_EMPTY_FRAME_SIZE, GFP_ATOMIC); + if (unlikely(!empty_skb)) { + net_err_ratelimited("%s: skb alloc error for empty frame\n", + netdev_name(tx_ring->netdev)); + return -ENOMEM; + } + + data = skb_put(empty_skb, IGC_EMPTY_FRAME_SIZE); + memset(data, 0, IGC_EMPTY_FRAME_SIZE); + + /* Prepare DMA mapping and Tx buffer information */ + ret = igc_init_empty_frame(tx_ring, empty_info, empty_skb); + if (unlikely(ret)) { + dev_kfree_skb_any(empty_skb); + return ret; + } + + /* Prepare advanced context descriptor for empty packet */ + igc_tx_ctxtdesc(tx_ring, 0, false, 0, 0, 0); + + /* Prepare advanced data descriptor for empty packet */ + igc_init_tx_empty_descriptor(tx_ring, empty_skb, empty_info); + + return 0; +} + static netdev_tx_t igc_xmit_frame_ring(struct sk_buff *skb, struct igc_ring *tx_ring) { @@ -1586,6 +1611,7 @@ static netdev_tx_t igc_xmit_frame_ring(struct sk_buff *skb, * + 1 desc for skb_headlen/IGC_MAX_DATA_PER_TXD, * + 2 desc gap to keep tail from touching head, * + 1 desc for context descriptor, + * + 2 desc for inserting an empty packet for launch time, * otherwise try next time */ for (f = 0; f < skb_shinfo(skb)->nr_frags; f++) @@ -1605,24 +1631,16 @@ static netdev_tx_t igc_xmit_frame_ring(struct sk_buff *skb, launch_time = igc_tx_launchtime(tx_ring, txtime, &first_flag, &insert_empty); if (insert_empty) { - struct igc_tx_buffer *empty_info; - struct sk_buff *empty; - void *data; - - empty_info = &tx_ring->tx_buffer_info[tx_ring->next_to_use]; - empty = alloc_skb(IGC_EMPTY_FRAME_SIZE, GFP_ATOMIC); - if (!empty) - goto done; - - data = skb_put(empty, IGC_EMPTY_FRAME_SIZE); - memset(data, 0, IGC_EMPTY_FRAME_SIZE); - - igc_tx_ctxtdesc(tx_ring, 0, false, 0, 0, 0); - - if (igc_init_tx_empty_descriptor(tx_ring, - empty, - empty_info) < 0) - dev_kfree_skb_any(empty); + /* Reset the launch time if the required empty frame fails to + * be inserted. However, this packet is not dropped, so it + * "dirties" the current Qbv cycle. This ensures that the + * upcoming packet, which is scheduled in the next Qbv cycle, + * does not require an empty frame. This way, the launch time + * continues to function correctly despite the current failure + * to insert the empty frame. + */ + if (igc_insert_empty_frame(tx_ring)) + launch_time = 0; } done: From d7c3a7ff75028bea9e4879bd3dcd04a6dc3e33c8 Mon Sep 17 00:00:00 2001 From: Song Yoong Siang Date: Sun, 16 Feb 2025 17:34:30 +0800 Subject: [PATCH 19/19] igc: Add launch time support to XDP ZC Enable Launch Time Control (LTC) support for XDP zero copy via XDP Tx metadata framework. This patch has been tested with tools/testing/selftests/bpf/xdp_hw_metadata on Intel I225-LM Ethernet controller. Below are the test steps and result. Test 1: Send a single packet with the launch time set to 1 s in the future. Test steps: 1. On the DUT, start the xdp_hw_metadata selftest application: $ sudo ./xdp_hw_metadata enp2s0 -l 1000000000 -L 1 2. On the Link Partner, send a UDP packet with VLAN priority 1 to port 9091 of the DUT. Result: When the launch time is set to 1 s in the future, the delta between the launch time and the transmit hardware timestamp is 0.016 us, as shown in printout of the xdp_hw_metadata application below. 0x562ff5dc8880: rx_desc[4]->addr=84110 addr=84110 comp_addr=84110 EoP rx_hash: 0xE343384 with RSS type:0x1 HW RX-time: 1734578015467548904 (sec:1734578015.4675) delta to User RX-time sec:0.0002 (183.103 usec) XDP RX-time: 1734578015467651698 (sec:1734578015.4677) delta to User RX-time sec:0.0001 (80.309 usec) No rx_vlan_tci or rx_vlan_proto, err=-95 0x562ff5dc8880: ping-pong with csum=561c (want c7dd) csum_start=34 csum_offset=6 HW RX-time: 1734578015467548904 (sec:1734578015.4675) delta to HW Launch-time sec:1.0000 (1000000.000 usec) 0x562ff5dc8880: complete tx idx=4 addr=4018 HW Launch-time: 1734578016467548904 (sec:1734578016.4675) delta to HW TX-complete-time sec:0.0000 (0.016 usec) HW TX-complete-time: 1734578016467548920 (sec:1734578016.4675) delta to User TX-complete-time sec:0.0000 (32.546 usec) XDP RX-time: 1734578015467651698 (sec:1734578015.4677) delta to User TX-complete-time sec:0.9999 (999929.768 usec) HW RX-time: 1734578015467548904 (sec:1734578015.4675) delta to HW TX-complete-time sec:1.0000 (1000000.016 usec) 0x562ff5dc8880: complete rx idx=132 addr=84110 Test 2: Send 1000 packets with a 10 ms interval and the launch time set to 500 us in the future. Test steps: 1. On the DUT, start the xdp_hw_metadata selftest application: $ sudo chrt -f 99 ./xdp_hw_metadata enp2s0 -l 500000 -L 1 > \ /dev/shm/result.log 2. On the Link Partner, send 1000 UDP packets with a 10 ms interval and VLAN priority 1 to port 9091 of the DUT. Result: When the launch time is set to 500 us in the future, the average delta between the launch time and the transmit hardware timestamp is 0.016 us, as shown in the analysis of /dev/shm/result.log below. The XDP launch time works correctly in sending 1000 packets continuously. Min delta: 0.005 us Avr delta: 0.016 us Max delta: 0.031 us Total packets forwarded: 1000 Signed-off-by: Song Yoong Siang Signed-off-by: Martin KaFai Lau Reviewed-by: Faizal Rahim Reviewed-by: Maciej Fijalkowski Link: https://patch.msgid.link/20250216093430.957880-6-yoong.siang.song@intel.com --- drivers/net/ethernet/intel/igc/igc.h | 1 + drivers/net/ethernet/intel/igc/igc_main.c | 61 ++++++++++++++++++++++- 2 files changed, 60 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h index b8111ad9a9a8..cd1d7b6c1782 100644 --- a/drivers/net/ethernet/intel/igc/igc.h +++ b/drivers/net/ethernet/intel/igc/igc.h @@ -579,6 +579,7 @@ struct igc_metadata_request { struct xsk_tx_metadata *meta; struct igc_ring *tx_ring; u32 cmd_type; + u16 used_desc; }; struct igc_q_vector { diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index 1bfa71545e37..3044392e8ded 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -2971,9 +2971,48 @@ static u64 igc_xsk_fill_timestamp(void *_priv) return *(u64 *)_priv; } +static void igc_xsk_request_launch_time(u64 launch_time, void *_priv) +{ + struct igc_metadata_request *meta_req = _priv; + struct igc_ring *tx_ring = meta_req->tx_ring; + __le32 launch_time_offset; + bool insert_empty = false; + bool first_flag = false; + u16 used_desc = 0; + + if (!tx_ring->launchtime_enable) + return; + + launch_time_offset = igc_tx_launchtime(tx_ring, + ns_to_ktime(launch_time), + &first_flag, &insert_empty); + if (insert_empty) { + /* Disregard the launch time request if the required empty frame + * fails to be inserted. + */ + if (igc_insert_empty_frame(tx_ring)) + return; + + meta_req->tx_buffer = + &tx_ring->tx_buffer_info[tx_ring->next_to_use]; + /* Inserting an empty packet requires two descriptors: + * one data descriptor and one context descriptor. + */ + used_desc += 2; + } + + /* Use one context descriptor to specify launch time and first flag. */ + igc_tx_ctxtdesc(tx_ring, launch_time_offset, first_flag, 0, 0, 0); + used_desc += 1; + + /* Update the number of used descriptors in this request */ + meta_req->used_desc += used_desc; +} + const struct xsk_tx_metadata_ops igc_xsk_tx_metadata_ops = { .tmo_request_timestamp = igc_xsk_request_timestamp, .tmo_fill_timestamp = igc_xsk_fill_timestamp, + .tmo_request_launch_time = igc_xsk_request_launch_time, }; static void igc_xdp_xmit_zc(struct igc_ring *ring) @@ -2996,7 +3035,13 @@ static void igc_xdp_xmit_zc(struct igc_ring *ring) ntu = ring->next_to_use; budget = igc_desc_unused(ring); - while (xsk_tx_peek_desc(pool, &xdp_desc) && budget--) { + /* Packets with launch time require one data descriptor and one context + * descriptor. When the launch time falls into the next Qbv cycle, we + * may need to insert an empty packet, which requires two more + * descriptors. Therefore, to be safe, we always ensure we have at least + * 4 descriptors available. + */ + while (xsk_tx_peek_desc(pool, &xdp_desc) && budget >= 4) { struct igc_metadata_request meta_req; struct xsk_tx_metadata *meta = NULL; struct igc_tx_buffer *bi; @@ -3017,9 +3062,19 @@ static void igc_xdp_xmit_zc(struct igc_ring *ring) meta_req.tx_ring = ring; meta_req.tx_buffer = bi; meta_req.meta = meta; + meta_req.used_desc = 0; xsk_tx_metadata_request(meta, &igc_xsk_tx_metadata_ops, &meta_req); + /* xsk_tx_metadata_request() may have updated next_to_use */ + ntu = ring->next_to_use; + + /* xsk_tx_metadata_request() may have updated Tx buffer info */ + bi = meta_req.tx_buffer; + + /* xsk_tx_metadata_request() may use a few descriptors */ + budget -= meta_req.used_desc; + tx_desc = IGC_TX_DESC(ring, ntu); tx_desc->read.cmd_type_len = cpu_to_le32(meta_req.cmd_type); tx_desc->read.olinfo_status = cpu_to_le32(olinfo_status); @@ -3037,9 +3092,11 @@ static void igc_xdp_xmit_zc(struct igc_ring *ring) ntu++; if (ntu == ring->count) ntu = 0; + + ring->next_to_use = ntu; + budget--; } - ring->next_to_use = ntu; if (tx_desc) { igc_flush_tx_descriptors(ring); xsk_tx_release(pool);