NAME

       bpftool-iter - tool to create BPF iterators

SYNOPSIS

       bpftool [OPTIONS] iter COMMAND

       OPTIONS := { { -j | --json } [{ -p | --pretty }] | { -d | --debug } }

       COMMANDS := { pin | help }

ITER COMMANDS

       bpftool iter pin OBJ PATH [map MAP]
       bpftool iter help

       OBJ := /a/file/of/bpf_iter_target.o
       MAP := { id MAP_ID | pinned FILE }

DESCRIPTION

       bpftool iter pin OBJ PATH [map MAP]
              A bpf iterator combines a kernel iterating of particular kernel data (e.g., tasks, bpf_maps, etc.)
              and  a  bpf  program  called for each kernel data object (e.g., one task, one bpf_map, etc.). User
              space can read kernel iterator output through read() syscall.

              The pin command creates a bpf iterator from OBJ, and pin it to PATH.  The PATH should  be  located
              in bpffs mount. It must not contain a dot character ('.'), which is reserved for future extensions
              of bpffs.

              Map  element bpf iterator requires an additional parameter MAP so bpf program can iterate over map
              elements for that map. User can have a bpf program in kernel to run  with  each  map  element,  do
              checking, filtering, aggregation, etc. without copying data to user space.

              User can then cat PATH to see the bpf iterator output.

       bpftool iter help
              Print short help message.

OPTIONS

       -h, --help
              Print short help message (similar to bpftool help).

       -V, --version
              Print  bpftool's  version number (similar to bpftool version), the number of the libbpf version in
              use, and optional features that were included when bpftool was compiled. Optional features include
              linking against LLVM or libbfd to provide the disassembler for JIT-ted programs (bpftool prog dump
              jited) and usage of BPF skeletons (some  features  like  bpftool  prog  profile  or  showing  pids
              associated to BPF objects may rely on it).

       -j, --json
              Generate JSON output. For commands that cannot produce JSON, this option has no effect.

       -p, --pretty
              Generate human-readable JSON output. Implies -j.

       -d, --debug
              Print  all logs available, even debug-level information. This includes logs from libbpf as well as
              from the verifier, when attempting to load programs.

EXAMPLES

       # bpftool iter pin bpf_iter_netlink.o /sys/fs/bpf/my_netlink

          Create a file-based bpf iterator from bpf_iter_netlink.o and pin it
          to /sys/fs/bpf/my_netlink

       # bpftool iter pin bpf_iter_hashmap.o /sys/fs/bpf/my_hashmap map id 20

          Create a file-based bpf iterator from bpf_iter_hashmap.o and map with
          id 20, and pin it to /sys/fs/bpf/my_hashmap

SEE ALSO

       bpf(2),    bpf-helpers(7),    bpftool(8),    bpftool-btf(8),    bpftool-cgroup(8),    bpftool-feature(8),
       bpftool-gen(8),   bpftool-link(8),   bpftool-map(8),  bpftool-net(8),  bpftool-perf(8),  bpftool-prog(8),
       bpftool-struct_ops(8)

                                                                                                 BPFTOOL-ITER(8)