bpf: Sync bpf headers in tooling infrastucture

Synchronize tools/include/uapi/linux/bpf.h which was missing changes
from various commits:

  - f3c45326ee71 ("bpf: Document PROG_TEST_RUN limitations")
  - e5e35e754c28 ("bpf: BPF-helper for MTU checking add length input")

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 6990260..e1ee1be 100644 (file)
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -312,6 +312,27 @@ union bpf_iter_link_info {
  *             *ctx_out*, *data_out* (for example, packet data), result of the
  *             execution *retval*, and *duration* of the test run.
  *
+ *             The sizes of the buffers provided as input and output
+ *             parameters *ctx_in*, *ctx_out*, *data_in*, and *data_out* must
+ *             be provided in the corresponding variables *ctx_size_in*,
+ *             *ctx_size_out*, *data_size_in*, and/or *data_size_out*. If any
+ *             of these parameters are not provided (ie set to NULL), the
+ *             corresponding size field must be zero.
+ *
+ *             Some program types have particular requirements:
+ *
+ *             **BPF_PROG_TYPE_SK_LOOKUP**
+ *                     *data_in* and *data_out* must be NULL.
+ *
+ *             **BPF_PROG_TYPE_XDP**
+ *                     *ctx_in* and *ctx_out* must be NULL.
+ *
+ *             **BPF_PROG_TYPE_RAW_TRACEPOINT**,
+ *             **BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE**
+ *
+ *                     *ctx_out*, *data_in* and *data_out* must be NULL.
+ *                     *repeat* must be zero.
+ *
  *     Return
  *             Returns zero on success. On error, -1 is returned and *errno*
  *             is set appropriately.
@@ -4578,7 +4599,7 @@ union bpf_attr {
  *
  * long bpf_check_mtu(void *ctx, u32 ifindex, u32 *mtu_len, s32 len_diff, u64 flags)
  *     Description
- *             Check ctx packet size against exceeding MTU of net device (based
+ *             Check packet size against exceeding MTU of net device (based
  *             on *ifindex*).  This helper will likely be used in combination
  *             with helpers that adjust/change the packet size.
  *
@@ -4595,6 +4616,14 @@ union bpf_attr {
  *             against the current net device.  This is practical if this isn't
  *             used prior to redirect.
  *
+ *             On input *mtu_len* must be a valid pointer, else verifier will
+ *             reject BPF program.  If the value *mtu_len* is initialized to
+ *             zero then the ctx packet size is use.  When value *mtu_len* is
+ *             provided as input this specify the L3 length that the MTU check
+ *             is done against. Remember XDP and TC length operate at L2, but
+ *             this value is L3 as this correlate to MTU and IP-header tot_len
+ *             values which are L3 (similar behavior as bpf_fib_lookup).
+ *
  *             The Linux kernel route table can configure MTUs on a more
  *             specific per route level, which is not provided by this helper.
  *             For route level MTU checks use the **bpf_fib_lookup**\ ()
@@ -4619,11 +4648,9 @@ union bpf_attr {
  *
  *             On return *mtu_len* pointer contains the MTU value of the net
  *             device.  Remember the net device configured MTU is the L3 size,
- *             which is returned here and XDP and TX length operate at L2.
+ *             which is returned here and XDP and TC length operate at L2.
  *             Helper take this into account for you, but remember when using
- *             MTU value in your BPF-code.  On input *mtu_len* must be a valid
- *             pointer and be initialized (to zero), else verifier will reject
- *             BPF program.
+ *             MTU value in your BPF-code.
  *
  *     Return
  *             * 0 on success, and populate MTU value in *mtu_len* pointer.