Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-01-26

We've added 107 non-merge commits during the last 4 day(s) which contain
a total of 101 files changed, 6009 insertions(+), 1260 deletions(-).

The main changes are:

1) Add BPF token support to delegate a subset of BPF subsystem
   functionality from privileged system-wide daemons such as systemd
   through special mount options for userns-bound BPF fs to a trusted
   & unprivileged application. With addressed changes from Christian
   and Linus' reviews, from Andrii Nakryiko.

2) Support registration of struct_ops types from modules which helps
   projects like fuse-bpf that seeks to implement a new struct_ops type,
   from Kui-Feng Lee.

3) Add support for retrieval of cookies for perf/kprobe multi links,
   from Jiri Olsa.

4) Bigger batch of prep-work for the BPF verifier to eventually support
   preserving boundaries and tracking scalars on narrowing fills,
   from Maxim Mikityanskiy.

5) Extend the tc BPF flavor to support arbitrary TCP SYN cookies to help
   with the scenario of SYN floods, from Kuniyuki Iwashima.

6) Add code generation to inline the bpf_kptr_xchg() helper which
   improves performance when stashing/popping the allocated BPF objects,
   from Hou Tao.

7) Extend BPF verifier to track aligned ST stores as imprecise spilled
   registers, from Yonghong Song.

8) Several fixes to BPF selftests around inline asm constraints and
   unsupported VLA code generation, from Jose E. Marchesi.

9) Various updates to the BPF IETF instruction set draft document such
   as the introduction of conformance groups for instructions,
   from Dave Thaler.

10) Fix BPF verifier to make infinite loop detection in is_state_visited()
    exact to catch some too lax spill/fill corner cases,
    from Eduard Zingerman.

11) Refactor the BPF verifier pointer ALU check to allow ALU explicitly
    instead of implicitly for various register types, from Hao Sun.

12) Fix the flaky tc_redirect_dtime BPF selftest due to slowness
    in neighbor advertisement at setup time, from Martin KaFai Lau.

13) Change BPF selftests to skip callback tests for the case when the
    JIT is disabled, from Tiezhu Yang.

14) Add a small extension to libbpf which allows to auto create
    a map-in-map's inner map, from Andrey Grafin.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (107 commits)
  selftests/bpf: Add missing line break in test_verifier
  bpf, docs: Clarify definitions of various instructions
  bpf: Fix error checks against bpf_get_btf_vmlinux().
  bpf: One more maintainer for libbpf and BPF selftests
  selftests/bpf: Incorporate LSM policy to token-based tests
  selftests/bpf: Add tests for LIBBPF_BPF_TOKEN_PATH envvar
  libbpf: Support BPF token path setting through LIBBPF_BPF_TOKEN_PATH envvar
  selftests/bpf: Add tests for BPF object load with implicit token
  selftests/bpf: Add BPF object loading tests with explicit token passing
  libbpf: Wire up BPF token support at BPF object level
  libbpf: Wire up token_fd into feature probing logic
  libbpf: Move feature detection code into its own file
  libbpf: Further decouple feature checking logic from bpf_object
  libbpf: Split feature detectors definitions from cached results
  selftests/bpf: Utilize string values for delegate_xxx mount options
  bpf: Support symbolic BPF FS delegation mount options
  bpf: Fail BPF_TOKEN_CREATE if no delegation option was set on BPF FS
  bpf,selinux: Allocate bpf_security_struct per BPF token
  selftests/bpf: Add BPF token-enabled tests
  libbpf: Add BPF token support to bpf_prog_load() API
  ...
====================

Link: https://lore.kernel.org/r/20240126215710.19855-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 20 insertions, 1 deletions

diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 6cd9c501624f..5723cbbfcc41 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -177,10 +177,29 @@ struct bpf_object_open_opts {
 	 * logs through its print callback.
 	 */
 	__u32 kernel_log_level;
+	/* Path to BPF FS mount point to derive BPF token from.
+	 *
+	 * Created BPF token will be used for all bpf() syscall operations
+	 * that accept BPF token (e.g., map creation, BTF and program loads,
+	 * etc) automatically within instantiated BPF object.
+	 *
+	 * If bpf_token_path is not specified, libbpf will consult
+	 * LIBBPF_BPF_TOKEN_PATH environment variable. If set, it will be
+	 * taken as a value of bpf_token_path option and will force libbpf to
+	 * either create BPF token from provided custom BPF FS path, or will
+	 * disable implicit BPF token creation, if envvar value is an empty
+	 * string. bpf_token_path overrides LIBBPF_BPF_TOKEN_PATH, if both are
+	 * set at the same time.
+	 *
+	 * Setting bpf_token_path option to empty string disables libbpf's
+	 * automatic attempt to create BPF token from default BPF FS mount
+	 * point (/sys/fs/bpf), in case this default behavior is undesirable.
+	 */
+	const char *bpf_token_path;
 
 	size_t :0;
 };
-#define bpf_object_open_opts__last_field kernel_log_level
+#define bpf_object_open_opts__last_field bpf_token_path
 
 /**
  * @brief **bpf_object__open()** creates a bpf_object by opening