From 3024d95a4c521c278a7504ee9e80c57c3a9750e0 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Wed, 17 Aug 2022 23:32:09 +0200 Subject: bpf: Partially revert flexible-array member replacement Partially revert 94dfc73e7cf4 ("treewide: uapi: Replace zero-length arrays with flexible-array members") given it breaks BPF UAPI. For example, BPF CI run reveals build breakage under LLVM: [...] CLNG-BPF [test_maps] map_ptr_kern.o CLNG-BPF [test_maps] btf__core_reloc_arrays___diff_arr_val_sz.o CLNG-BPF [test_maps] test_bpf_cookie.o progs/map_ptr_kern.c:314:26: error: field 'trie_key' with variable sized type 'struct bpf_lpm_trie_key' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] struct bpf_lpm_trie_key trie_key; ^ CLNG-BPF [test_maps] btf__core_reloc_type_based___diff.o 1 error generated. make: *** [Makefile:521: /tmp/runner/work/bpf/bpf/tools/testing/selftests/bpf/map_ptr_kern.o] Error 1 make: *** Waiting for unfinished jobs.... [...] Typical usage of the bpf_lpm_trie_key is that the struct gets embedded into a user defined key for the LPM BPF map, from the selftest example: struct bpf_lpm_trie_key { <-- UAPI exported struct __u32 prefixlen; __u8 data[]; }; struct lpm_key { <-- BPF program defined struct struct bpf_lpm_trie_key trie_key; __u32 data; }; Undo this for BPF until a different solution can be found. It's the only flexible- array member case in the UAPI header. This was discovered in BPF CI after Dave reported that the include/uapi/linux/bpf.h header was out of sync with tools/include/uapi/linux/bpf.h after 94dfc73e7cf4. And the subsequent sync attempt failed CI. Fixes: 94dfc73e7cf4 ("treewide: uapi: Replace zero-length arrays with flexible-array members") Reported-by: Dave Marchevsky Signed-off-by: Daniel Borkmann Cc: Gustavo A. R. Silva Link: https://lore.kernel.org/bpf/22aebc88-da67-f086-e620-dd4a16e2bc69@iogearbox.net --- include/uapi/linux/bpf.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 7bf9ba1329be..59a217ca2dfd 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -79,7 +79,7 @@ struct bpf_insn { /* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */ struct bpf_lpm_trie_key { __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */ - __u8 data[]; /* Arbitrary size */ + __u8 data[0]; /* Arbitrary size */ }; struct bpf_cgroup_storage_key { -- cgit v1.2.3 From 7ec9fce4b31604f8415136a4c07f7dc8ad431aec Mon Sep 17 00:00:00 2001 From: Eyal Birger Date: Thu, 18 Aug 2022 10:41:18 +0300 Subject: ip_tunnel: Respect tunnel key's "flow_flags" in IP tunnels Commit 451ef36bd229 ("ip_tunnels: Add new flow flags field to ip_tunnel_key") added a "flow_flags" member to struct ip_tunnel_key which was later used by the commit in the fixes tag to avoid dropping packets with sources that aren't locally configured when set in bpf_set_tunnel_key(). VXLAN and GENEVE were made to respect this flag, ip tunnels like IPIP and GRE were not. This commit fixes this omission by making ip_tunnel_init_flow() receive the flow flags from the tunnel key in the relevant collect_md paths. Fixes: b8fff748521c ("bpf: Set flow flag to allow any source IP in bpf_tunnel_key") Signed-off-by: Eyal Birger Signed-off-by: Daniel Borkmann Reviewed-by: Paul Chaignon Link: https://lore.kernel.org/bpf/20220818074118.726639-1-eyal.birger@gmail.com --- include/net/ip_tunnels.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h index 63fac94f9ace..ced80e2f8b58 100644 --- a/include/net/ip_tunnels.h +++ b/include/net/ip_tunnels.h @@ -246,7 +246,8 @@ static inline void ip_tunnel_init_flow(struct flowi4 *fl4, __be32 daddr, __be32 saddr, __be32 key, __u8 tos, struct net *net, int oif, - __u32 mark, __u32 tun_inner_hash) + __u32 mark, __u32 tun_inner_hash, + __u8 flow_flags) { memset(fl4, 0, sizeof(*fl4)); @@ -263,6 +264,7 @@ static inline void ip_tunnel_init_flow(struct flowi4 *fl4, fl4->fl4_gre_key = key; fl4->flowi4_mark = mark; fl4->flowi4_multipath_hash = tun_inner_hash; + fl4->flowi4_flags = flow_flags; } int ip_tunnel_init(struct net_device *dev); -- cgit v1.2.3