linux/kernel/bpf
Björn Töpel ee75aef23a bpf, xdp: Restructure redirect actions
The XDP_REDIRECT implementations for maps and non-maps are fairly
similar, but obviously need to take different code paths depending on
if the target is using a map or not. Today, the redirect targets for
XDP either uses a map, or is based on ifindex.

Here, the map type and id are added to bpf_redirect_info, instead of
the actual map. Map type, map item/ifindex, and the map_id (if any) is
passed to xdp_do_redirect().

For ifindex-based redirect, used by the bpf_redirect() XDP BFP helper,
a special map type/id are used. Map type of UNSPEC together with map id
equal to INT_MAX has the special meaning of an ifindex based
redirect. Note that valid map ids are 1 inclusive, INT_MAX exclusive
([1,INT_MAX[).

In addition to making the code easier to follow, using explicit type
and id in bpf_redirect_info has a slight positive performance impact
by avoiding a pointer indirection for the map type lookup, and instead
use the cacheline for bpf_redirect_info.

Since the actual map is not passed via bpf_redirect_info anymore, the
map lookup is only done in the BPF helper. This means that the
bpf_clear_redirect_map() function can be removed. The actual map item
is RCU protected.

The bpf_redirect_info flags member is not used by XDP, and not
read/written any more. The map member is only written to when
required/used, and not unconditionally.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210308112907.559576-3-bjorn.topel@gmail.com
2021-03-10 01:06:34 +01:00
..
preload Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-02-02 14:21:31 -08:00
arraymap.c bpf: Add arraymap support for bpf_for_each_map_elem() helper 2021-02-26 13:23:52 -08:00
bpf_inode_storage.c bpf: Prevent deadlock from recursive bpf_task_storage_[get|delete] 2021-02-26 11:51:48 -08:00
bpf_iter.c bpf: Add bpf_for_each_map_elem() helper 2021-02-26 13:23:52 -08:00
bpf_local_storage.c bpf: Prevent deadlock from recursive bpf_task_storage_[get|delete] 2021-02-26 11:51:48 -08:00
bpf_lru_list.c bpf_lru_list: Read double-checked variable once without lock 2021-02-10 15:54:26 -08:00
bpf_lru_list.h bpf: Fix a typo "inacitve" -> "inactive" 2020-04-06 21:54:10 +02:00
bpf_lsm.c bpf: Enable task local storage for tracing programs 2021-02-26 11:51:47 -08:00
bpf_struct_ops_types.h bpf: tcp: Support tcp_congestion_ops in bpf 2020-01-09 08:46:18 -08:00
bpf_struct_ops.c bpf: Eliminate rlimit-based memory accounting for bpf_struct_ops maps 2020-12-02 18:32:46 -08:00
bpf_task_storage.c bpf: Prevent deadlock from recursive bpf_task_storage_[get|delete] 2021-02-26 11:51:48 -08:00
btf.c bpf: Add BTF_KIND_FLOAT support 2021-03-04 17:58:16 -08:00
cgroup.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-02-16 13:14:06 -08:00
core.c bpf: Clear per_cpu pointers during bpf_prog_realloc 2021-02-11 19:35:00 -08:00
cpumap.c bpf, xdp: Restructure redirect actions 2021-03-10 01:06:34 +01:00
devmap.c bpf, xdp: Restructure redirect actions 2021-03-10 01:06:34 +01:00
disasm.c bpf: Change 'BPF_ADD' to 'BPF_AND' in print_bpf_insn() 2021-01-27 22:23:46 +01:00
disasm.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 295 2019-06-05 17:36:38 +02:00
dispatcher.c bpf: Remove bpf_image tree 2020-03-13 12:49:52 -07:00
hashtab.c bpf: Add hashtab support for bpf_for_each_map_elem() helper 2021-02-26 13:23:52 -08:00
helpers.c bpf: Add bpf_for_each_map_elem() helper 2021-02-26 13:23:52 -08:00
inode.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-09-22 16:45:34 -07:00
local_storage.c bpf: Eliminate rlimit-based memory accounting for cgroup storage maps 2020-12-02 18:32:46 -08:00
lpm_trie.c bpf: Eliminate rlimit-based memory accounting for lpm_trie maps 2020-12-02 18:32:46 -08:00
Makefile bpf: Enable task local storage for tracing programs 2021-02-26 11:51:47 -08:00
map_in_map.c bpf: Relax max_entries check for most of the inner map types 2020-08-28 15:41:30 +02:00
map_in_map.h bpf: Add map_meta_equal map ops 2020-08-28 15:41:30 +02:00
map_iter.c bpf: Implement link_query callbacks in map element iterators 2020-08-21 14:01:39 -07:00
net_namespace.c bpf: Add support for forced LINK_DETACH command 2020-08-01 20:38:28 -07:00
offload.c bpf, offload: Replace bitwise AND by logical AND in bpf_prog_offload_info_fill 2020-02-17 16:53:49 +01:00
percpu_freelist.c bpf: Use raw_spin_trylock() for pcpu_freelist_push/pop in NMI 2020-10-06 00:04:11 +02:00
percpu_freelist.h bpf: Use raw_spin_trylock() for pcpu_freelist_push/pop in NMI 2020-10-06 00:04:11 +02:00
prog_iter.c bpf: Refactor bpf_iter_reg to have separate seq_info member 2020-07-25 20:16:32 -07:00
queue_stack_maps.c bpf: Eliminate rlimit-based memory accounting for queue_stack_maps maps 2020-12-02 18:32:46 -08:00
reuseport_array.c bpf: Eliminate rlimit-based memory accounting for reuseport_array maps 2020-12-02 18:32:47 -08:00
ringbuf.c bpf: Eliminate rlimit-based memory accounting for bpf ringbuffer 2020-12-02 18:32:47 -08:00
stackmap.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-02-10 13:30:12 -08:00
syscall.c bpf: Count the number of times recursion was prevented 2021-02-11 16:19:20 +01:00
sysfs_btf.c bpf: Load and verify kernel module BTFs 2020-11-10 15:25:53 -08:00
task_iter.c bpf: Introduce task_vma bpf_iter 2021-02-12 12:56:53 -08:00
tnum.c bpf: Verifier, do explicit ALU32 bounds tracking 2020-03-30 14:59:53 -07:00
trampoline.c bpf: Count the number of times recursion was prevented 2021-02-11 16:19:20 +01:00
verifier.c bpf, xdp: Make bpf_redirect_map() a map operation 2021-03-10 01:06:34 +01:00