This patchset is the 2nd in the dynptr series. The 1st can be found here [0].
This patchset adds skb and xdp type dynptrs, which have two main benefits for
packet parsing:
* allowing operations on sizes that are not statically known at
compile-time (eg variable-sized accesses).
* more ergonomic and less brittle iteration through data (eg does not need
manual if checking for being within bounds of data_end)
When comparing the differences in runtime for packet parsing without dynptrs
vs. with dynptrs, there is no noticeable difference. Patch 5 contains more
details as well as examples of how to use skb and xdp dynptrs.
[0]
https://lore.kernel.org/bpf/20220523210712.3641569-1-joannelkoong@xxxxxxxxx/
--
Changelog:
v8 = https://lore.kernel.org/bpf/20230126233439.3739120-1-joannelkoong@xxxxxxxxx/
v8 -> v9:
* Fix dynptr_get_type() to check non-stack dynptrs
v7 = https://lore.kernel.org/bpf/20221021011510.1890852-1-joannelkoong@xxxxxxxxx/
v7 -> v8:
* Change helpers to kfuncs
* Add 2 new patches (1/5 and 2/5)
v6 = https://lore.kernel.org/bpf/20220907183129.745846-1-joannelkoong@xxxxxxxxx/
v6 -> v7
* Change bpf_dynptr_data() to return read-only data slices if the skb prog
is read-only (Martin)
* Add test "skb_invalid_write" to test that writes to rd-only data slices
are rejected
v5 = https://lore.kernel.org/bpf/20220831183224.3754305-1-joannelkoong@xxxxxxxxx/
v5 -> v6
* Address kernel test robot errors by static inlining
v4 = https://lore.kernel.org/bpf/20220822235649.2218031-1-joannelkoong@xxxxxxxxx/
v4 -> v5
* Address kernel test robot errors for configs w/out CONFIG_NET set
* For data slices, return PTR_TO_MEM instead of PTR_TO_PACKET (Kumar)
* Split selftests into subtests (Andrii)
* Remove insn patching. Use rdonly and rdwr protos for dynptr skb
construction (Andrii)
* bpf_dynptr_data() returns NULL for rd-only dynptrs. There will be a
separate bpf_dynptr_data_rdonly() added later (Andrii and Kumar)
v3 = https://lore.kernel.org/bpf/20220822193442.657638-1-joannelkoong@xxxxxxxxx/
v3 -> v4
* Forgot to commit --amend the kernel test robot error fixups
v2 = https://lore.kernel.org/bpf/20220811230501.2632393-1-joannelkoong@xxxxxxxxx/
v2 -> v3
* Fix kernel test robot build test errors
v1 = https://lore.kernel.org/bpf/20220726184706.954822-1-joannelkoong@xxxxxxxxx/
v1 -> v2
* Return data slices to rd-only skb dynptrs (Martin)
* bpf_dynptr_write allows writes to frags for skb dynptrs, but always
invalidates associated data slices (Martin)
* Use switch casing instead of ifs (Andrii)
* Use 0xFD for experimental kind number in the selftest (Zvi)
* Put selftest conversions w/ dynptrs into new files (Alexei)
* Add new selftest "test_cls_redirect_dynptr.c"
Joanne Koong (5):
bpf: Allow "sk_buff" and "xdp_buff" as valid kfunc arg types
bpf: Allow initializing dynptrs in kfuncs
bpf: Add skb dynptrs
bpf: Add xdp dynptrs
selftests/bpf: tests for using dynptrs to parse skb and xdp buffers
include/linux/bpf.h | 88 +-
include/linux/bpf_verifier.h | 3 -
include/linux/filter.h | 38 +
include/uapi/linux/bpf.h | 41 +-
kernel/bpf/btf.c | 22 +
kernel/bpf/helpers.c | 107 +-
kernel/bpf/verifier.c | 325 +++---
net/core/filter.c | 104 +-
tools/include/uapi/linux/bpf.h | 41 +-
.../selftests/bpf/prog_tests/cls_redirect.c | 25 +
.../testing/selftests/bpf/prog_tests/dynptr.c | 63 +-
.../selftests/bpf/prog_tests/l4lb_all.c | 2 +
.../bpf/prog_tests/parse_tcp_hdr_opt.c | 93 ++
.../selftests/bpf/prog_tests/xdp_attach.c | 11 +-
.../testing/selftests/bpf/progs/dynptr_fail.c | 124 +++
.../selftests/bpf/progs/dynptr_success.c | 28 +
.../bpf/progs/test_cls_redirect_dynptr.c | 973 ++++++++++++++++++
.../bpf/progs/test_l4lb_noinline_dynptr.c | 474 +++++++++
.../bpf/progs/test_parse_tcp_hdr_opt.c | 119 +++
.../bpf/progs/test_parse_tcp_hdr_opt_dynptr.c | 112 ++
.../selftests/bpf/progs/test_xdp_dynptr.c | 237 +++++
.../selftests/bpf/test_tcp_hdr_options.h | 1 +
22 files changed, 2827 insertions(+), 204 deletions(-)
create mode 100644 tools/testing/selftests/bpf/prog_tests/parse_tcp_hdr_opt.c
create mode 100644 tools/testing/selftests/bpf/progs/test_cls_redirect_dynptr.c
create mode 100644 tools/testing/selftests/bpf/progs/test_l4lb_noinline_dynptr.c
create mode 100644 tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt.c
create mode 100644 tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt_dynptr.c
create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_dynptr.c
--
2.30.2
