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)