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 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 | 26 +++++++---- include/uapi/linux/bpf.h | 1 + net/core/filter.c | 46 +++++++++++-------- net/ipv4/ip_output.c | 2 +- net/ipv4/raw.c | 2 +- net/ipv6/ip6_output.c | 6 +-- net/ipv6/raw.c | 2 +- net/packet/af_packet.c | 7 ++- .../selftests/bpf/prog_tests/ctx_rewrite.c | 10 ++-- .../selftests/bpf/progs/test_tc_dtime.c | 24 ++++++++-- 10 files changed, 80 insertions(+), 46 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index e464d0ebc9c1..3ad0de07d261 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -711,6 +711,8 @@ 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, }; /** @@ -831,8 +833,8 @@ enum skb_tstamp_type { * @decrypted: Decrypted SKB * @slow_gro: state present at GRO time, slower prepare step required * @tstamp_type: When set, skb->tstamp has the - * delivery_time in mono clock base Otherwise, the - * timestamp is considered real clock base. + * delivery_time in mono clock base or clock base of skb->tstamp. + * Otherwise, the timestamp is considered real clock base * @napi_id: id of the NAPI struct this skb came from * @sender_cpu: (aka @napi_id) source CPU in XPS * @alloc_cpu: CPU which did the skb allocation. @@ -960,7 +962,7 @@ 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; @@ -1090,15 +1092,17 @@ 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:2 * 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_RSH (6) +#define TC_AT_INGRESS_RSH (5) +#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) @@ -4204,6 +4208,12 @@ static inline void skb_set_tstamp_type_frm_clkid(struct sk_buff *skb, case CLOCK_MONOTONIC: skb->tstamp_type = SKB_CLOCK_MONOTONIC; break; + case CLOCK_TAI: + skb->tstamp_type = SKB_CLOCK_TAI; + break; + default: + WARN_ONCE(true, "clockid %d not supported", clockid); + skb->tstamp_type = SKB_CLOCK_REALTIME; } } diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index cee0a7915c08..1376ed5ece10 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -6209,6 +6209,7 @@ union { \ enum { BPF_SKB_TSTAMP_UNSPEC, BPF_SKB_TSTAMP_DELIVERY_MONO, /* tstamp has mono delivery time */ + BPF_SKB_TSTAMP_DELIVERY_TAI, /* tstamp has tai 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. diff --git a/net/core/filter.c b/net/core/filter.c index 957c2fc724eb..c67622f4fe98 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -7733,6 +7733,12 @@ BPF_CALL_3(bpf_skb_set_tstamp, struct sk_buff *, skb, skb->tstamp = tstamp; skb->tstamp_type = SKB_CLOCK_MONOTONIC; break; + case BPF_SKB_TSTAMP_DELIVERY_TAI: + if (!tstamp) + return -EINVAL; + skb->tstamp = tstamp; + skb->tstamp_type = SKB_CLOCK_TAI; + break; case BPF_SKB_TSTAMP_UNSPEC: if (tstamp) return -EINVAL; @@ -9388,17 +9394,17 @@ 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 != BPF_SKB_TSTAMP_DELIVERY_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_RSH); +#else + BUILD_BUG_ON(!(SKB_TSTAMP_TYPE_MASK & 0x1)); +#endif + *insn++ = BPF_JMP32_IMM(BPF_JNE, value_reg, SKB_TSTAMP_TYPE_MASK, 1); + /* Both the bits set then mark it BPF_SKB_TSTAMP_UNSPEC */ + *insn++ = BPF_MOV64_IMM(value_reg, BPF_SKB_TSTAMP_UNSPEC); return insn; } @@ -9430,6 +9436,7 @@ static struct bpf_insn *bpf_convert_tstamp_read(const struct bpf_prog *prog, __u8 value_reg = si->dst_reg; __u8 skb_reg = si->src_reg; +BUILD_BUG_ON(__SKB_CLOCK_MAX != BPF_SKB_TSTAMP_DELIVERY_TAI); #ifdef CONFIG_NET_XGRESS /* If the tstamp_type is read, * the bpf prog is aware the tstamp could have delivery time. @@ -9440,11 +9447,12 @@ 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); - /* skb->tc_at_ingress && skb->tstamp_type:1, + /* 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:2, * read 0 as the (rcv) timestamp. */ *insn++ = BPF_MOV64_IMM(value_reg, 0); @@ -9469,7 +9477,7 @@ static struct bpf_insn *bpf_convert_tstamp_write(const struct bpf_prog *prog, * the bpf prog is aware the tstamp could have delivery time. * Thus, write skb->tstamp as is if tstamp_type_access is true. * Otherwise, writing at ingress will have to clear the - * mono_delivery_time (skb->tstamp_type:1)bit also. + * mono_delivery_time (skb->tstamp_type:2)bit also. */ if (!prog->tstamp_type_access) { __u8 tmp_reg = BPF_REG_AX; @@ -9479,8 +9487,8 @@ static struct bpf_insn *bpf_convert_tstamp_write(const struct bpf_prog *prog, *insn++ = BPF_JMP32_IMM(BPF_JSET, tmp_reg, TC_AT_INGRESS_MASK, 1); /* goto <store> */ *insn++ = BPF_JMP_A(2); - /* <clear>: mono_delivery_time or (skb->tstamp_type:1) */ - *insn++ = BPF_ALU32_IMM(BPF_AND, tmp_reg, ~SKB_MONO_DELIVERY_TIME_MASK); + /* <clear>: skb->tstamp_type:2 */ + *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 591226dcde26..f195b31d6e75 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -1457,7 +1457,7 @@ 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; + skb_set_tstamp_type_frm_clkid(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 dcb11f22cbf2..8b370369cdd8 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_tstamp_type_frm_clkid(skb, sockc->transmit_time, sk->sk_clockid); skb_dst_set(skb, &rt->dst); *rtp = NULL; diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index a9e819115622..63e4cc30d18d 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -955,7 +955,7 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, if (iter.frag) ip6_fraglist_prepare(skb, &iter); - skb_set_delivery_time(skb, tstamp, tstamp_type); + skb_set_tstamp_type_frm_clkid(skb, tstamp, tstamp_type); err = output(net, sk, skb); if (!err) IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), @@ -1016,7 +1016,7 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, /* * Put this fragment into the sending queue. */ - skb_set_delivery_time(frag, tstamp, tstamp_type); + skb_set_tstamp_type_frm_clkid(frag, tstamp, tstamp_type); err = output(net, sk, frag); if (err) goto fail; @@ -1924,7 +1924,7 @@ 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; + skb_set_tstamp_type_frm_clkid(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 0d896ca7b589..5649362577ab 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_tstamp_type_frm_clkid(skb, sockc->transmit_time, sk->sk_clockid); skb_put(skb, length); skb_reset_network_header(skb); diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 8c6d3fbb4ed8..6a4a86c26d2a 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_tstamp_type_frm_clkid(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_tstamp_type_frm_clkid(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_tstamp_type_frm_clkid(skb, sockc.transmit_time, sk->sk_clockid); if (unlikely(extra_len == 4)) skb->no_fcs = 1; diff --git a/tools/testing/selftests/bpf/prog_tests/ctx_rewrite.c b/tools/testing/selftests/bpf/prog_tests/ctx_rewrite.c index 3b7c57fe55a5..71940f4ef0fb 100644 --- a/tools/testing/selftests/bpf/prog_tests/ctx_rewrite.c +++ b/tools/testing/selftests/bpf/prog_tests/ctx_rewrite.c @@ -69,15 +69,17 @@ static struct test_case test_cases[] = { { N(SCHED_CLS, struct __sk_buff, tstamp), .read = "r11 = *(u8 *)($ctx + sk_buff::__mono_tc_offset);" - "w11 &= 3;" - "if w11 != 0x3 goto pc+2;" + "if w11 == 0x4 goto pc+1;" + "goto pc+4;" + "if w11 == 0x3 goto pc+1;" + "goto pc+2;" "$dst = 0;" "goto pc+1;" "$dst = *(u64 *)($ctx + sk_buff::tstamp);", .write = "r11 = *(u8 *)($ctx + sk_buff::__mono_tc_offset);" - "if w11 & 0x2 goto pc+1;" + "if w11 & 0x4 goto pc+1;" "goto pc+2;" - "w11 &= -2;" + "w11 &= -3;" "*(u8 *)($ctx + sk_buff::__mono_tc_offset) = r11;" "*(u64 *)($ctx + sk_buff::tstamp) = $src;", }, diff --git a/tools/testing/selftests/bpf/progs/test_tc_dtime.c b/tools/testing/selftests/bpf/progs/test_tc_dtime.c index 74ec09f040b7..19dba6d88265 100644 --- a/tools/testing/selftests/bpf/progs/test_tc_dtime.c +++ b/tools/testing/selftests/bpf/progs/test_tc_dtime.c @@ -227,6 +227,12 @@ int egress_host(struct __sk_buff *skb) inc_dtimes(EGRESS_ENDHOST); else inc_errs(EGRESS_ENDHOST); + } else if (skb_proto(skb_type) == IPPROTO_UDP) { + if (skb->tstamp_type == BPF_SKB_TSTAMP_DELIVERY_TAI && + skb->tstamp) + inc_dtimes(EGRESS_ENDHOST); + else + inc_errs(EGRESS_ENDHOST); } else { if (skb->tstamp_type == BPF_SKB_TSTAMP_UNSPEC && skb->tstamp) @@ -255,6 +261,9 @@ int ingress_host(struct __sk_buff *skb) if (skb->tstamp_type == BPF_SKB_TSTAMP_DELIVERY_MONO && skb->tstamp == EGRESS_FWDNS_MAGIC) inc_dtimes(INGRESS_ENDHOST); + else if (skb->tstamp_type == BPF_SKB_TSTAMP_DELIVERY_TAI && + skb->tstamp == EGRESS_FWDNS_MAGIC) + inc_dtimes(INGRESS_ENDHOST); else inc_errs(INGRESS_ENDHOST); @@ -323,12 +332,14 @@ int ingress_fwdns_prio101(struct __sk_buff *skb) /* Should have handled in prio100 */ return TC_ACT_SHOT; - if (skb_proto(skb_type) == IPPROTO_UDP) + if (skb_proto(skb_type) == IPPROTO_UDP && + skb->tstamp_type != BPF_SKB_TSTAMP_DELIVERY_TAI) expected_dtime = 0; if (skb->tstamp_type) { if (fwdns_clear_dtime() || - skb->tstamp_type != BPF_SKB_TSTAMP_DELIVERY_MONO || + (skb->tstamp_type != BPF_SKB_TSTAMP_DELIVERY_MONO && + skb->tstamp_type != BPF_SKB_TSTAMP_DELIVERY_TAI) || skb->tstamp != expected_dtime) inc_errs(INGRESS_FWDNS_P101); else @@ -338,7 +349,8 @@ int ingress_fwdns_prio101(struct __sk_buff *skb) inc_errs(INGRESS_FWDNS_P101); } - if (skb->tstamp_type == BPF_SKB_TSTAMP_DELIVERY_MONO) { + if (skb->tstamp_type == BPF_SKB_TSTAMP_DELIVERY_MONO || + skb->tstamp_type == BPF_SKB_TSTAMP_DELIVERY_TAI) { skb->tstamp = INGRESS_FWDNS_MAGIC; } else { if (bpf_skb_set_tstamp(skb, INGRESS_FWDNS_MAGIC, @@ -370,7 +382,8 @@ int egress_fwdns_prio101(struct __sk_buff *skb) if (skb->tstamp_type) { if (fwdns_clear_dtime() || - skb->tstamp_type != BPF_SKB_TSTAMP_DELIVERY_MONO || + (skb->tstamp_type != BPF_SKB_TSTAMP_DELIVERY_MONO && + skb->tstamp_type != BPF_SKB_TSTAMP_DELIVERY_TAI) || skb->tstamp != INGRESS_FWDNS_MAGIC) inc_errs(EGRESS_FWDNS_P101); else @@ -380,7 +393,8 @@ int egress_fwdns_prio101(struct __sk_buff *skb) inc_errs(EGRESS_FWDNS_P101); } - if (skb->tstamp_type == BPF_SKB_TSTAMP_DELIVERY_MONO) { + if (skb->tstamp_type == BPF_SKB_TSTAMP_DELIVERY_MONO || + skb->tstamp_type == BPF_SKB_TSTAMP_DELIVERY_TAI) { skb->tstamp = EGRESS_FWDNS_MAGIC; } else { if (bpf_skb_set_tstamp(skb, EGRESS_FWDNS_MAGIC, -- 2.25.1
