From d1e91173cd29ba13c5953d1820a7543140feec93 Mon Sep 17 00:00:00 2001 From: Maryam Tahhan Date: Tue, 15 Nov 2022 09:49:21 -0500 Subject: bpf, docs: DEVMAPs and XDP_REDIRECT MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add documentation for BPF_MAP_TYPE_DEVMAP and BPF_MAP_TYPE_DEVMAP_HASH including kernel version introduced, usage and examples. Add documentation that describes XDP_REDIRECT. Signed-off-by: Maryam Tahhan Signed-off-by: Daniel Borkmann Reviewed-by: Toke Høiland-Jørgensen Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20221115144921.165483-1-mtahhan@redhat.com --- net/core/filter.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'net/core') diff --git a/net/core/filter.c b/net/core/filter.c index 754dd01354d8..2a105fb1ceb2 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4108,7 +4108,10 @@ static const struct bpf_func_proto bpf_xdp_adjust_meta_proto = { .arg2_type = ARG_ANYTHING, }; -/* XDP_REDIRECT works by a three-step process, implemented in the functions +/** + * DOC: xdp redirect + * + * XDP_REDIRECT works by a three-step process, implemented in the functions * below: * * 1. The bpf_redirect() and bpf_redirect_map() helpers will lookup the target @@ -4123,7 +4126,8 @@ static const struct bpf_func_proto bpf_xdp_adjust_meta_proto = { * 3. Before exiting its NAPI poll loop, the driver will call xdp_do_flush(), * which will flush all the different bulk queues, thus completing the * redirect. - * + */ +/* * Pointers to the map entries will be kept around for this whole sequence of * steps, protected by RCU. However, there is no top-level rcu_read_lock() in * the core code; instead, the RCU protection relies on everything happening -- cgit v1.2.3