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bpf: Remove BPF_SKB_DELIVERY_TIME_NONE and rename s/delivery_time_/tstamp_/
This patch is to simplify the uapi bpf.h regarding to the tstamp type and use a similar way as the kernel to describe the value stored in __sk_buff->tstamp. My earlier thought was to avoid describing the semantic and clock base for the rcv timestamp until there is more clarity on the use case, so the __sk_buff->delivery_time_type naming instead of __sk_buff->tstamp_type. With some thoughts, it can reuse the UNSPEC naming. This patch first removes BPF_SKB_DELIVERY_TIME_NONE and also rename BPF_SKB_DELIVERY_TIME_UNSPEC to BPF_SKB_TSTAMP_UNSPEC and BPF_SKB_DELIVERY_TIME_MONO to BPF_SKB_TSTAMP_DELIVERY_MONO. The semantic of BPF_SKB_TSTAMP_DELIVERY_MONO is the same: __sk_buff->tstamp has delivery time in mono clock base. BPF_SKB_TSTAMP_UNSPEC means __sk_buff->tstamp has the (rcv) tstamp at ingress and the delivery time at egress. At egress, the clock base could be found from skb->sk->sk_clockid. __sk_buff->tstamp == 0 naturally means NONE, so NONE is not needed. With BPF_SKB_TSTAMP_UNSPEC for the rcv tstamp at ingress, the __sk_buff->delivery_time_type is also renamed to __sk_buff->tstamp_type which was also suggested in the earlier discussion: https://lore.kernel.org/bpf/b181acbe-caf8-502d-4b7b-7d96b9fc5d55@iogearbox.net/ The above will then make __sk_buff->tstamp and __sk_buff->tstamp_type the same as its kernel skb->tstamp and skb->mono_delivery_time counter part. The internal kernel function bpf_skb_convert_dtime_type_read() is then renamed to bpf_skb_convert_tstamp_type_read() and it can be simplified with the BPF_SKB_DELIVERY_TIME_NONE gone. A BPF_ALU32_IMM(BPF_AND) insn is also saved by using BPF_JMP32_IMM(BPF_JSET). The bpf helper bpf_skb_set_delivery_time() is also renamed to bpf_skb_set_tstamp(). The arg name is changed from dtime to tstamp also. It only allows setting tstamp 0 for BPF_SKB_TSTAMP_UNSPEC and it could be relaxed later if there is use case to change mono delivery time to non mono. prog->delivery_time_access is also renamed to prog->tstamp_type_access. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220309090509.3712315-1-kafai@fb.com
This commit is contained in:
Martin KaFai Lau
Daniel Borkmann
parent
9d90db97e4
commit
9bb984f28d
@ -573,7 +573,7 @@ struct bpf_prog {
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enforce_expected_attach_type:1, /* Enforce expected_attach_type checking at attach time */
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call_get_stack:1, /* Do we call bpf_get_stack() or bpf_get_stackid() */
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call_get_func_ip:1, /* Do we call get_func_ip() */
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delivery_time_access:1; /* Accessed __sk_buff->delivery_time_type */
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tstamp_type_access:1; /* Accessed __sk_buff->tstamp_type */
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enum bpf_prog_type type; /* Type of BPF program */
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enum bpf_attach_type expected_attach_type; /* For some prog types */
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u32 len; /* Number of filter blocks */
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@ -5090,23 +5090,22 @@ union bpf_attr {
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* 0 on success, or a negative error in case of failure. On error
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* *dst* buffer is zeroed out.
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*
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* long bpf_skb_set_delivery_time(struct sk_buff *skb, u64 dtime, u32 dtime_type)
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* long bpf_skb_set_tstamp(struct sk_buff *skb, u64 tstamp, u32 tstamp_type)
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* Description
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* Set a *dtime* (delivery time) to the __sk_buff->tstamp and also
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* change the __sk_buff->delivery_time_type to *dtime_type*.
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* Change the __sk_buff->tstamp_type to *tstamp_type*
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* and set *tstamp* to the __sk_buff->tstamp together.
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*
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* When setting a delivery time (non zero *dtime*) to
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* __sk_buff->tstamp, only BPF_SKB_DELIVERY_TIME_MONO *dtime_type*
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* is supported. It is the only delivery_time_type that will be
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* kept after bpf_redirect_*().
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*
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* If there is no need to change the __sk_buff->delivery_time_type,
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* the delivery time can be directly written to __sk_buff->tstamp
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* If there is no need to change the __sk_buff->tstamp_type,
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* the tstamp value can be directly written to __sk_buff->tstamp
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* instead.
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*
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* *dtime* 0 and *dtime_type* BPF_SKB_DELIVERY_TIME_NONE
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* can be used to clear any delivery time stored in
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* __sk_buff->tstamp.
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* BPF_SKB_TSTAMP_DELIVERY_MONO is the only tstamp that
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* will be kept during bpf_redirect_*(). A non zero
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* *tstamp* must be used with the BPF_SKB_TSTAMP_DELIVERY_MONO
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* *tstamp_type*.
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*
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* A BPF_SKB_TSTAMP_UNSPEC *tstamp_type* can only be used
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* with a zero *tstamp*.
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*
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* Only IPv4 and IPv6 skb->protocol are supported.
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*
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@ -5119,7 +5118,7 @@ union bpf_attr {
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* Return
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* 0 on success.
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* **-EINVAL** for invalid input
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* **-EOPNOTSUPP** for unsupported delivery_time_type and protocol
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* **-EOPNOTSUPP** for unsupported protocol
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*/
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#define __BPF_FUNC_MAPPER(FN) \
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FN(unspec), \
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@ -5314,7 +5313,7 @@ union bpf_attr {
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FN(xdp_load_bytes), \
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FN(xdp_store_bytes), \
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FN(copy_from_user_task), \
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FN(skb_set_delivery_time), \
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FN(skb_set_tstamp), \
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/* */
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/* integer value in 'imm' field of BPF_CALL instruction selects which helper
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@ -5505,9 +5504,12 @@ union { \
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} __attribute__((aligned(8)))
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enum {
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BPF_SKB_DELIVERY_TIME_NONE,
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BPF_SKB_DELIVERY_TIME_UNSPEC,
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BPF_SKB_DELIVERY_TIME_MONO,
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BPF_SKB_TSTAMP_UNSPEC,
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BPF_SKB_TSTAMP_DELIVERY_MONO, /* tstamp has mono delivery time */
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/* For any BPF_SKB_TSTAMP_* that the bpf prog cannot handle,
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* the bpf prog should handle it like BPF_SKB_TSTAMP_UNSPEC
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* and try to deduce it by ingress, egress or skb->sk->sk_clockid.
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*/
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};
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/* user accessible mirror of in-kernel sk_buff.
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@ -5550,7 +5552,7 @@ struct __sk_buff {
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__u32 gso_segs;
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__bpf_md_ptr(struct bpf_sock *, sk);
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__u32 gso_size;
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__u8 delivery_time_type;
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__u8 tstamp_type;
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__u32 :24; /* Padding, future use. */
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__u64 hwtstamp;
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};
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@ -7388,36 +7388,36 @@ static const struct bpf_func_proto bpf_sock_ops_reserve_hdr_opt_proto = {
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.arg3_type = ARG_ANYTHING,
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};
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BPF_CALL_3(bpf_skb_set_delivery_time, struct sk_buff *, skb,
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u64, dtime, u32, dtime_type)
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BPF_CALL_3(bpf_skb_set_tstamp, struct sk_buff *, skb,
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u64, tstamp, u32, tstamp_type)
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{
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/* skb_clear_delivery_time() is done for inet protocol */
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if (skb->protocol != htons(ETH_P_IP) &&
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skb->protocol != htons(ETH_P_IPV6))
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return -EOPNOTSUPP;
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switch (dtime_type) {
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case BPF_SKB_DELIVERY_TIME_MONO:
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if (!dtime)
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switch (tstamp_type) {
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case BPF_SKB_TSTAMP_DELIVERY_MONO:
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if (!tstamp)
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return -EINVAL;
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skb->tstamp = dtime;
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skb->tstamp = tstamp;
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skb->mono_delivery_time = 1;
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break;
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case BPF_SKB_DELIVERY_TIME_NONE:
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if (dtime)
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case BPF_SKB_TSTAMP_UNSPEC:
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if (tstamp)
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return -EINVAL;
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skb->tstamp = 0;
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skb->mono_delivery_time = 0;
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break;
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default:
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return -EOPNOTSUPP;
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return -EINVAL;
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}
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return 0;
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}
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static const struct bpf_func_proto bpf_skb_set_delivery_time_proto = {
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.func = bpf_skb_set_delivery_time,
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static const struct bpf_func_proto bpf_skb_set_tstamp_proto = {
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.func = bpf_skb_set_tstamp,
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.gpl_only = false,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_CTX,
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@ -7786,8 +7786,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
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return &bpf_tcp_gen_syncookie_proto;
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case BPF_FUNC_sk_assign:
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return &bpf_sk_assign_proto;
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case BPF_FUNC_skb_set_delivery_time:
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return &bpf_skb_set_delivery_time_proto;
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case BPF_FUNC_skb_set_tstamp:
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return &bpf_skb_set_tstamp_proto;
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#endif
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default:
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return bpf_sk_base_func_proto(func_id);
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@ -8127,9 +8127,9 @@ static bool bpf_skb_is_valid_access(int off, int size, enum bpf_access_type type
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return false;
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info->reg_type = PTR_TO_SOCK_COMMON_OR_NULL;
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break;
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case offsetof(struct __sk_buff, delivery_time_type):
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case offsetof(struct __sk_buff, tstamp_type):
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return false;
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case offsetofend(struct __sk_buff, delivery_time_type) ... offsetof(struct __sk_buff, hwtstamp) - 1:
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case offsetofend(struct __sk_buff, tstamp_type) ... offsetof(struct __sk_buff, hwtstamp) - 1:
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/* Explicitly prohibit access to padding in __sk_buff. */
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return false;
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default:
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@ -8484,14 +8484,14 @@ static bool tc_cls_act_is_valid_access(int off, int size,
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break;
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case bpf_ctx_range_till(struct __sk_buff, family, local_port):
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return false;
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case offsetof(struct __sk_buff, delivery_time_type):
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case offsetof(struct __sk_buff, tstamp_type):
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/* The convert_ctx_access() on reading and writing
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* __sk_buff->tstamp depends on whether the bpf prog
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* has used __sk_buff->delivery_time_type or not.
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* Thus, we need to set prog->delivery_time_access
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* has used __sk_buff->tstamp_type or not.
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* Thus, we need to set prog->tstamp_type_access
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* earlier during is_valid_access() here.
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*/
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((struct bpf_prog *)prog)->delivery_time_access = 1;
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((struct bpf_prog *)prog)->tstamp_type_access = 1;
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return size == sizeof(__u8);
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}
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@ -8888,42 +8888,22 @@ static u32 flow_dissector_convert_ctx_access(enum bpf_access_type type,
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return insn - insn_buf;
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}
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static struct bpf_insn *bpf_convert_dtime_type_read(const struct bpf_insn *si,
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struct bpf_insn *insn)
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static struct bpf_insn *bpf_convert_tstamp_type_read(const struct bpf_insn *si,
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struct bpf_insn *insn)
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{
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__u8 value_reg = si->dst_reg;
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__u8 skb_reg = si->src_reg;
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/* AX is needed because src_reg and dst_reg could be the same */
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__u8 tmp_reg = BPF_REG_AX;
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*insn++ = BPF_LDX_MEM(BPF_B, tmp_reg, skb_reg,
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PKT_VLAN_PRESENT_OFFSET);
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*insn++ = BPF_ALU32_IMM(BPF_AND, tmp_reg,
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SKB_MONO_DELIVERY_TIME_MASK);
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*insn++ = BPF_JMP32_IMM(BPF_JEQ, tmp_reg, 0, 2);
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/* value_reg = BPF_SKB_DELIVERY_TIME_MONO */
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*insn++ = BPF_MOV32_IMM(value_reg, BPF_SKB_DELIVERY_TIME_MONO);
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*insn++ = BPF_JMP_A(IS_ENABLED(CONFIG_NET_CLS_ACT) ? 10 : 5);
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*insn++ = BPF_LDX_MEM(BPF_DW, tmp_reg, skb_reg,
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offsetof(struct sk_buff, tstamp));
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*insn++ = BPF_JMP_IMM(BPF_JNE, tmp_reg, 0, 2);
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/* value_reg = BPF_SKB_DELIVERY_TIME_NONE */
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*insn++ = BPF_MOV32_IMM(value_reg, BPF_SKB_DELIVERY_TIME_NONE);
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*insn++ = BPF_JMP_A(IS_ENABLED(CONFIG_NET_CLS_ACT) ? 6 : 1);
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#ifdef CONFIG_NET_CLS_ACT
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*insn++ = BPF_LDX_MEM(BPF_B, tmp_reg, skb_reg, PKT_VLAN_PRESENT_OFFSET);
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*insn++ = BPF_ALU32_IMM(BPF_AND, tmp_reg, TC_AT_INGRESS_MASK);
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*insn++ = BPF_JMP32_IMM(BPF_JEQ, tmp_reg, 0, 2);
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/* At ingress, value_reg = 0 */
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*insn++ = BPF_MOV32_IMM(value_reg, 0);
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*insn++ = BPF_JMP32_IMM(BPF_JSET, tmp_reg,
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SKB_MONO_DELIVERY_TIME_MASK, 2);
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*insn++ = BPF_MOV32_IMM(value_reg, BPF_SKB_TSTAMP_UNSPEC);
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*insn++ = BPF_JMP_A(1);
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#endif
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*insn++ = BPF_MOV32_IMM(value_reg, BPF_SKB_TSTAMP_DELIVERY_MONO);
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/* value_reg = BPF_SKB_DELIVERYT_TIME_UNSPEC */
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*insn++ = BPF_MOV32_IMM(value_reg, BPF_SKB_DELIVERY_TIME_UNSPEC);
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/* 15 insns with CONFIG_NET_CLS_ACT */
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return insn;
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}
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@ -8956,11 +8936,11 @@ static struct bpf_insn *bpf_convert_tstamp_read(const struct bpf_prog *prog,
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__u8 skb_reg = si->src_reg;
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#ifdef CONFIG_NET_CLS_ACT
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/* If the delivery_time_type is read,
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/* If the tstamp_type is read,
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* the bpf prog is aware the tstamp could have delivery time.
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* Thus, read skb->tstamp as is if delivery_time_access is true.
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* Thus, read skb->tstamp as is if tstamp_type_access is true.
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*/
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if (!prog->delivery_time_access) {
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if (!prog->tstamp_type_access) {
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/* AX is needed because src_reg and dst_reg could be the same */
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__u8 tmp_reg = BPF_REG_AX;
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@ -8990,13 +8970,13 @@ static struct bpf_insn *bpf_convert_tstamp_write(const struct bpf_prog *prog,
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__u8 skb_reg = si->dst_reg;
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#ifdef CONFIG_NET_CLS_ACT
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/* If the delivery_time_type is read,
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/* If the tstamp_type is read,
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* the bpf prog is aware the tstamp could have delivery time.
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* Thus, write skb->tstamp as is if delivery_time_access is true.
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* Thus, write skb->tstamp as is if tstamp_type_access is true.
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* Otherwise, writing at ingress will have to clear the
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* mono_delivery_time bit also.
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*/
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if (!prog->delivery_time_access) {
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if (!prog->tstamp_type_access) {
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__u8 tmp_reg = BPF_REG_AX;
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*insn++ = BPF_LDX_MEM(BPF_B, tmp_reg, skb_reg, PKT_VLAN_PRESENT_OFFSET);
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@ -9329,8 +9309,8 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type,
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insn = bpf_convert_tstamp_read(prog, si, insn);
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break;
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case offsetof(struct __sk_buff, delivery_time_type):
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insn = bpf_convert_dtime_type_read(si, insn);
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case offsetof(struct __sk_buff, tstamp_type):
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insn = bpf_convert_tstamp_type_read(si, insn);
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break;
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case offsetof(struct __sk_buff, gso_segs):
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@ -5090,23 +5090,22 @@ union bpf_attr {
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* 0 on success, or a negative error in case of failure. On error
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* *dst* buffer is zeroed out.
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*
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* long bpf_skb_set_delivery_time(struct sk_buff *skb, u64 dtime, u32 dtime_type)
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* long bpf_skb_set_tstamp(struct sk_buff *skb, u64 tstamp, u32 tstamp_type)
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* Description
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* Set a *dtime* (delivery time) to the __sk_buff->tstamp and also
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* change the __sk_buff->delivery_time_type to *dtime_type*.
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* Change the __sk_buff->tstamp_type to *tstamp_type*
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* and set *tstamp* to the __sk_buff->tstamp together.
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*
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* When setting a delivery time (non zero *dtime*) to
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* __sk_buff->tstamp, only BPF_SKB_DELIVERY_TIME_MONO *dtime_type*
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* is supported. It is the only delivery_time_type that will be
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* kept after bpf_redirect_*().
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*
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* If there is no need to change the __sk_buff->delivery_time_type,
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* the delivery time can be directly written to __sk_buff->tstamp
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* If there is no need to change the __sk_buff->tstamp_type,
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* the tstamp value can be directly written to __sk_buff->tstamp
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* instead.
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*
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* *dtime* 0 and *dtime_type* BPF_SKB_DELIVERY_TIME_NONE
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* can be used to clear any delivery time stored in
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* __sk_buff->tstamp.
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* BPF_SKB_TSTAMP_DELIVERY_MONO is the only tstamp that
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* will be kept during bpf_redirect_*(). A non zero
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* *tstamp* must be used with the BPF_SKB_TSTAMP_DELIVERY_MONO
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* *tstamp_type*.
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*
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* A BPF_SKB_TSTAMP_UNSPEC *tstamp_type* can only be used
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* with a zero *tstamp*.
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*
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* Only IPv4 and IPv6 skb->protocol are supported.
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*
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@ -5119,7 +5118,7 @@ union bpf_attr {
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* Return
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* 0 on success.
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* **-EINVAL** for invalid input
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* **-EOPNOTSUPP** for unsupported delivery_time_type and protocol
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* **-EOPNOTSUPP** for unsupported protocol
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*/
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#define __BPF_FUNC_MAPPER(FN) \
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FN(unspec), \
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@ -5314,7 +5313,7 @@ union bpf_attr {
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FN(xdp_load_bytes), \
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FN(xdp_store_bytes), \
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FN(copy_from_user_task), \
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FN(skb_set_delivery_time), \
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FN(skb_set_tstamp), \
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/* */
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/* integer value in 'imm' field of BPF_CALL instruction selects which helper
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@ -5505,9 +5504,12 @@ union { \
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} __attribute__((aligned(8)))
|
||||
|
||||
enum {
|
||||
BPF_SKB_DELIVERY_TIME_NONE,
|
||||
BPF_SKB_DELIVERY_TIME_UNSPEC,
|
||||
BPF_SKB_DELIVERY_TIME_MONO,
|
||||
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.
|
||||
*/
|
||||
};
|
||||
|
||||
/* user accessible mirror of in-kernel sk_buff.
|
||||
@ -5550,7 +5552,7 @@ struct __sk_buff {
|
||||
__u32 gso_segs;
|
||||
__bpf_md_ptr(struct bpf_sock *, sk);
|
||||
__u32 gso_size;
|
||||
__u8 delivery_time_type;
|
||||
__u8 tstamp_type;
|
||||
__u32 :24; /* Padding, future use. */
|
||||
__u64 hwtstamp;
|
||||
};
|
||||
|
||||
Loading…
Reference in New Issue
Block a user