tstamp_type is now set based on actual clockid_t compressed into 2 bits. To make the design scalable for future needs this commit bring in the change to extend the tstamp_type:1 to tstamp_type:2 to support other clockid_t timestamp. We now support CLOCK_TAI as part of tstamp_type as part of this commit with exisiting support CLOCK_MONOTONIC and CLOCK_REALTIME. Link: https://lore.kernel.org/netdev/bc037db4-58bb-4861-ac31-a361a93841d3@xxxxxxxxx/ Signed-off-by: Abhishek Chauhan <quic_abchauha@xxxxxxxxxxx> --- Changes since v6 - bpf_skb_set_tstamp now order cases by their enum value, starting with realtime. - custom socket now initialize the sk_clockid in files tcp_ipv4.c and tcp_ipv6.c Changes since v5 - Took care of documentation comments of tstamp_type in skbuff.h as mentioned by Willem. - Use of complete words instead of abbrevation in macro definitions as mentioned by Willem. - Fixed indentation problems - Removed BPF_SKB_TSTAMP_UNSPEC and marked it Deprecated as documentation, and introduced BPF_SKB_CLOCK_REALTIME instead. - BUILD_BUG_ON for additional enums introduced. - __ip_make_skb and ip6_make_skb now has tcp checks to mark tcp packet as mono tstamp base. - separated the selftests/bpf changes into another patch. - Made changes as per Martin in selftest bpf code and tool/include/uapi/linux/bpf.h Changes since v4 - Made changes to BPF code in filter.c as per Martin's comments - Minor fixes on comments given on documentation from Willem in skbuff.h (removed obvious ones) - Made changes to ctx_rewrite.c and test_tc_dtime.c - test_tc_dtime.c i am not really sure if i took care of all the changes as i am not too familiar with the framework. - Introduce common mask SKB_TSTAMP_TYPE_MASK instead of multiple SKB mask. - Optimisation on BPF code as suggested by Martin. - Set default case to SKB_CLOCK_REALTME. Changes since v3 - Carefully reviewed BPF APIs and made changes in BPF code as well. - Re-used actual clockid_t values since skbuff.h indirectly includes uapi/linux/time.h - Added CLOCK_TAI as part of the skb_set_delivery_time handling instead of CLOCK_USER - Added default in switch for unsupported and invalid timestamp with an WARN_ONCE - All of the above comments were given by Willem - Made changes in filter.c as per Martin's comments to handle invalid cases in bpf code with addition of SKB_TAI_DELIVERY_TIME_MASK Changes since v2 - Minor changes to commit subject Changes since v1 - identified additional changes in BPF framework. - Bit shift in SKB_MONO_DELIVERY_TIME_MASK and TC_AT_INGRESS_MASK. - Made changes in skb_set_delivery_time to keep changes similar to previous code for mono_delivery_time and just setting tstamp_type bit 1 for userspace timestamp. include/linux/skbuff.h | 18 ++++++++++------ include/uapi/linux/bpf.h | 15 ++++++++----- net/core/filter.c | 46 +++++++++++++++++++++++----------------- net/ipv4/ip_output.c | 5 ++++- net/ipv4/raw.c | 2 +- net/ipv4/tcp_ipv4.c | 2 ++ net/ipv6/ip6_output.c | 5 ++++- net/ipv6/raw.c | 2 +- net/ipv6/tcp_ipv6.c | 10 +++++++-- net/packet/af_packet.c | 7 +++--- 10 files changed, 71 insertions(+), 41 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 05aec712d16d..fe7d8dbef77e 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -709,6 +709,8 @@ typedef unsigned char *sk_buff_data_t; enum skb_tstamp_type { SKB_CLOCK_REALTIME, SKB_CLOCK_MONOTONIC, + SKB_CLOCK_TAI, + __SKB_CLOCK_MAX = SKB_CLOCK_TAI, }; /** @@ -957,7 +959,7 @@ struct sk_buff { /* private: */ __u8 __mono_tc_offset[0]; /* public: */ - __u8 tstamp_type:1; /* See skb_tstamp_type */ + __u8 tstamp_type:2; /* See skb_tstamp_type */ #ifdef CONFIG_NET_XGRESS __u8 tc_at_ingress:1; /* See TC_AT_INGRESS_MASK */ __u8 tc_skip_classify:1; @@ -1087,15 +1089,16 @@ struct sk_buff { #endif #define PKT_TYPE_OFFSET offsetof(struct sk_buff, __pkt_type_offset) -/* if you move tc_at_ingress or mono_delivery_time +/* if you move tc_at_ingress or tstamp_type * around, you also must adapt these constants. */ #ifdef __BIG_ENDIAN_BITFIELD -#define SKB_MONO_DELIVERY_TIME_MASK (1 << 7) -#define TC_AT_INGRESS_MASK (1 << 6) +#define SKB_TSTAMP_TYPE_MASK (3 << 6) +#define SKB_TSTAMP_TYPE_RSHIFT (6) +#define TC_AT_INGRESS_MASK (1 << 5) #else -#define SKB_MONO_DELIVERY_TIME_MASK (1 << 0) -#define TC_AT_INGRESS_MASK (1 << 1) +#define SKB_TSTAMP_TYPE_MASK (3) +#define TC_AT_INGRESS_MASK (1 << 2) #endif #define SKB_BF_MONO_TC_OFFSET offsetof(struct sk_buff, __mono_tc_offset) @@ -4212,6 +4215,9 @@ static inline void skb_set_delivery_type_by_clockid(struct sk_buff *skb, case CLOCK_MONOTONIC: tstamp_type = SKB_CLOCK_MONOTONIC; break; + case CLOCK_TAI: + tstamp_type = SKB_CLOCK_TAI; + break; default: WARN_ON_ONCE(1); kt = 0; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 90706a47f6ff..25ea393cf084 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -6207,12 +6207,17 @@ union { \ __u64 :64; \ } __attribute__((aligned(8))) +/* The enum used in skb->tstamp_type. It specifies the clock type + * of the time stored in the skb->tstamp. + */ enum { - BPF_SKB_TSTAMP_UNSPEC, - BPF_SKB_TSTAMP_DELIVERY_MONO, /* tstamp has mono delivery time */ - /* For any BPF_SKB_TSTAMP_* that the bpf prog cannot handle, - * the bpf prog should handle it like BPF_SKB_TSTAMP_UNSPEC - * and try to deduce it by ingress, egress or skb->sk->sk_clockid. + BPF_SKB_TSTAMP_UNSPEC = 0, /* DEPRECATED */ + BPF_SKB_TSTAMP_DELIVERY_MONO = 1, /* DEPRECATED */ + BPF_SKB_CLOCK_REALTIME = 0, + BPF_SKB_CLOCK_MONOTONIC = 1, + BPF_SKB_CLOCK_TAI = 2, + /* For any future BPF_SKB_CLOCK_* that the bpf prog cannot handle, + * the bpf prog can try to deduce it by ingress/egress/skb->sk->sk_clockid. */ }; diff --git a/net/core/filter.c b/net/core/filter.c index a3781a796da4..c6edfe9f41bc 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -7726,17 +7726,21 @@ BPF_CALL_3(bpf_skb_set_tstamp, struct sk_buff *, skb, return -EOPNOTSUPP; switch (tstamp_type) { - case BPF_SKB_TSTAMP_DELIVERY_MONO: + case BPF_SKB_CLOCK_REALTIME: + skb->tstamp = tstamp; + skb->tstamp_type = SKB_CLOCK_REALTIME; + break; + case BPF_SKB_CLOCK_MONOTONIC: if (!tstamp) return -EINVAL; skb->tstamp = tstamp; skb->tstamp_type = SKB_CLOCK_MONOTONIC; break; - case BPF_SKB_TSTAMP_UNSPEC: - if (tstamp) + case BPF_SKB_CLOCK_TAI: + if (!tstamp) return -EINVAL; - skb->tstamp = 0; - skb->tstamp_type = SKB_CLOCK_REALTIME; + skb->tstamp = tstamp; + skb->tstamp_type = SKB_CLOCK_TAI; break; default: return -EINVAL; @@ -9387,16 +9391,17 @@ static struct bpf_insn *bpf_convert_tstamp_type_read(const struct bpf_insn *si, { __u8 value_reg = si->dst_reg; __u8 skb_reg = si->src_reg; - /* AX is needed because src_reg and dst_reg could be the same */ - __u8 tmp_reg = BPF_REG_AX; - - *insn++ = BPF_LDX_MEM(BPF_B, tmp_reg, skb_reg, - SKB_BF_MONO_TC_OFFSET); - *insn++ = BPF_JMP32_IMM(BPF_JSET, tmp_reg, - SKB_MONO_DELIVERY_TIME_MASK, 2); - *insn++ = BPF_MOV32_IMM(value_reg, BPF_SKB_TSTAMP_UNSPEC); - *insn++ = BPF_JMP_A(1); - *insn++ = BPF_MOV32_IMM(value_reg, BPF_SKB_TSTAMP_DELIVERY_MONO); + BUILD_BUG_ON(__SKB_CLOCK_MAX != (int)BPF_SKB_CLOCK_TAI); + BUILD_BUG_ON(SKB_CLOCK_REALTIME != (int)BPF_SKB_CLOCK_REALTIME); + BUILD_BUG_ON(SKB_CLOCK_MONOTONIC != (int)BPF_SKB_CLOCK_MONOTONIC); + BUILD_BUG_ON(SKB_CLOCK_TAI != (int)BPF_SKB_CLOCK_TAI); + *insn++ = BPF_LDX_MEM(BPF_B, value_reg, skb_reg, SKB_BF_MONO_TC_OFFSET); + *insn++ = BPF_ALU32_IMM(BPF_AND, value_reg, SKB_TSTAMP_TYPE_MASK); +#ifdef __BIG_ENDIAN_BITFIELD + *insn++ = BPF_ALU32_IMM(BPF_RSH, value_reg, SKB_TSTAMP_TYPE_RSHIFT); +#else + BUILD_BUG_ON(!(SKB_TSTAMP_TYPE_MASK & 0x1)); +#endif return insn; } @@ -9439,10 +9444,11 @@ static struct bpf_insn *bpf_convert_tstamp_read(const struct bpf_prog *prog, __u8 tmp_reg = BPF_REG_AX; *insn++ = BPF_LDX_MEM(BPF_B, tmp_reg, skb_reg, SKB_BF_MONO_TC_OFFSET); - *insn++ = BPF_ALU32_IMM(BPF_AND, tmp_reg, - TC_AT_INGRESS_MASK | SKB_MONO_DELIVERY_TIME_MASK); - *insn++ = BPF_JMP32_IMM(BPF_JNE, tmp_reg, - TC_AT_INGRESS_MASK | SKB_MONO_DELIVERY_TIME_MASK, 2); + /* check if ingress mask bits is set */ + *insn++ = BPF_JMP32_IMM(BPF_JSET, tmp_reg, TC_AT_INGRESS_MASK, 1); + *insn++ = BPF_JMP_A(4); + *insn++ = BPF_JMP32_IMM(BPF_JSET, tmp_reg, SKB_TSTAMP_TYPE_MASK, 1); + *insn++ = BPF_JMP_A(2); /* skb->tc_at_ingress && skb->tstamp_type, * read 0 as the (rcv) timestamp. */ @@ -9479,7 +9485,7 @@ static struct bpf_insn *bpf_convert_tstamp_write(const struct bpf_prog *prog, /* goto <store> */ *insn++ = BPF_JMP_A(2); /* <clear>: skb->tstamp_type */ - *insn++ = BPF_ALU32_IMM(BPF_AND, tmp_reg, ~SKB_MONO_DELIVERY_TIME_MASK); + *insn++ = BPF_ALU32_IMM(BPF_AND, tmp_reg, ~SKB_TSTAMP_TYPE_MASK); *insn++ = BPF_STX_MEM(BPF_B, skb_reg, tmp_reg, SKB_BF_MONO_TC_OFFSET); } #endif diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index fe86cadfa85b..b90d0f78ac80 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -1457,7 +1457,10 @@ struct sk_buff *__ip_make_skb(struct sock *sk, skb->priority = (cork->tos != -1) ? cork->priority: READ_ONCE(sk->sk_priority); skb->mark = cork->mark; - skb->tstamp = cork->transmit_time; + if (sk_is_tcp(sk)) + skb_set_delivery_time(skb, cork->transmit_time, SKB_CLOCK_MONOTONIC); + else + skb_set_delivery_type_by_clockid(skb, cork->transmit_time, sk->sk_clockid); /* * Steal rt from cork.dst to avoid a pair of atomic_inc/atomic_dec * on dst refcount diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c index 4cb43401e0e0..1a0953650356 100644 --- a/net/ipv4/raw.c +++ b/net/ipv4/raw.c @@ -360,7 +360,7 @@ static int raw_send_hdrinc(struct sock *sk, struct flowi4 *fl4, skb->protocol = htons(ETH_P_IP); skb->priority = READ_ONCE(sk->sk_priority); skb->mark = sockc->mark; - skb->tstamp = sockc->transmit_time; + skb_set_delivery_type_by_clockid(skb, sockc->transmit_time, sk->sk_clockid); skb_dst_set(skb, &rt->dst); *rtp = NULL; diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 95e3d28b83b8..46a8f1c11a91 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -3626,6 +3626,8 @@ void __init tcp_v4_init(void) */ inet_sk(sk)->pmtudisc = IP_PMTUDISC_DO; + sk->sk_clockid = CLOCK_MONOTONIC; + per_cpu(ipv4_tcp_sk, cpu) = sk; } if (register_pernet_subsys(&tcp_sk_ops)) diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 05067bd44775..6f198b928974 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1924,7 +1924,10 @@ struct sk_buff *__ip6_make_skb(struct sock *sk, skb->priority = READ_ONCE(sk->sk_priority); skb->mark = cork->base.mark; - skb->tstamp = cork->base.transmit_time; + if (sk_is_tcp(sk)) + skb_set_delivery_time(skb, cork->base.transmit_time, SKB_CLOCK_MONOTONIC); + else + skb_set_delivery_type_by_clockid(skb, cork->base.transmit_time, sk->sk_clockid); ip6_cork_steal_dst(skb, cork); IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTREQUESTS); diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c index 2eedf255600b..f838366e8256 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -621,7 +621,7 @@ static int rawv6_send_hdrinc(struct sock *sk, struct msghdr *msg, int length, skb->protocol = htons(ETH_P_IPV6); skb->priority = READ_ONCE(sk->sk_priority); skb->mark = sockc->mark; - skb->tstamp = sockc->transmit_time; + skb_set_delivery_type_by_clockid(skb, sockc->transmit_time, sk->sk_clockid); skb_put(skb, length); skb_reset_network_header(skb); diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 16c545f0d064..fa3f8e43c7e6 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -2388,8 +2388,14 @@ static struct inet_protosw tcpv6_protosw = { static int __net_init tcpv6_net_init(struct net *net) { - return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6, - SOCK_RAW, IPPROTO_TCP, net); + int res; + + res = inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6, + SOCK_RAW, IPPROTO_TCP, net); + if (!res) + net->ipv6.tcp_sk->sk_clockid = CLOCK_MONOTONIC; + + return res; } static void __net_exit tcpv6_net_exit(struct net *net) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 8c6d3fbb4ed8..89b54021d196 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2056,8 +2056,7 @@ static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, skb->dev = dev; skb->priority = READ_ONCE(sk->sk_priority); skb->mark = READ_ONCE(sk->sk_mark); - skb->tstamp = sockc.transmit_time; - + skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid); skb_setup_tx_timestamp(skb, sockc.tsflags); if (unlikely(extra_len == 4)) @@ -2585,7 +2584,7 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, skb->dev = dev; skb->priority = READ_ONCE(po->sk.sk_priority); skb->mark = READ_ONCE(po->sk.sk_mark); - skb->tstamp = sockc->transmit_time; + skb_set_delivery_type_by_clockid(skb, sockc->transmit_time, po->sk.sk_clockid); skb_setup_tx_timestamp(skb, sockc->tsflags); skb_zcopy_set_nouarg(skb, ph.raw); @@ -3063,7 +3062,7 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) skb->dev = dev; skb->priority = READ_ONCE(sk->sk_priority); skb->mark = sockc.mark; - skb->tstamp = sockc.transmit_time; + skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid); if (unlikely(extra_len == 4)) skb->no_fcs = 1; -- 2.25.1
