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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 |
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.. | ||
preload | ||
arraymap.c | ||
bpf_inode_storage.c | ||
bpf_iter.c | ||
bpf_local_storage.c | ||
bpf_lru_list.c | ||
bpf_lru_list.h | ||
bpf_lsm.c | ||
bpf_struct_ops_types.h | ||
bpf_struct_ops.c | ||
bpf_task_storage.c | ||
btf.c | ||
cgroup.c | ||
core.c | ||
cpumap.c | ||
devmap.c | ||
disasm.c | ||
disasm.h | ||
dispatcher.c | ||
hashtab.c | ||
helpers.c | ||
inode.c | ||
local_storage.c | ||
lpm_trie.c | ||
Makefile | ||
map_in_map.c | ||
map_in_map.h | ||
map_iter.c | ||
net_namespace.c | ||
offload.c | ||
percpu_freelist.c | ||
percpu_freelist.h | ||
prog_iter.c | ||
queue_stack_maps.c | ||
reuseport_array.c | ||
ringbuf.c | ||
stackmap.c | ||
syscall.c | ||
sysfs_btf.c | ||
task_iter.c | ||
tnum.c | ||
trampoline.c | ||
verifier.c |