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[bpf-next,v8,1/4] bpf: add function for XDP meta data length check

Message ID 20210707221657.3985075-2-zeffron@riotgames.com (mailing list archive)
State Accepted
Delegated to: BPF
Headers show
Series bpf: support input xdp_md context in BPF_PROG_TEST_RUN | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for bpf-next
netdev/subject_prefix success Link
netdev/cc_maintainers success CCed 13 of 13 maintainers
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 4897 this patch: 4897
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 27 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 4956 this patch: 4956
netdev/header_inline success Link

Commit Message

Zvi Effron July 7, 2021, 10:16 p.m. UTC 
This commit prepares to use the XDP meta data length check in multiple
places by making it into a static inline function instead of a literal.

Co-developed-by: Cody Haas <chaas@riotgames.com>
Signed-off-by: Cody Haas <chaas@riotgames.com>
Co-developed-by: Lisa Watanabe <lwatanabe@riotgames.com>
Signed-off-by: Lisa Watanabe <lwatanabe@riotgames.com>
Signed-off-by: Zvi Effron <zeffron@riotgames.com>
Acked-by: Yonghong Song <yhs@fb.com>
---
 include/net/xdp.h | 5 +++++
 net/core/filter.c | 4 ++--
 2 files changed, 7 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/include/net/xdp.h b/include/net/xdp.h
index 5533f0ab2afc..ad5b02dcb6f4 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -276,6 +276,11 @@  xdp_data_meta_unsupported(const struct xdp_buff *xdp)
 	return unlikely(xdp->data_meta > xdp->data);
 }
 
+static inline bool xdp_metalen_invalid(unsigned long metalen)
+{
+	return (metalen & (sizeof(__u32) - 1)) || (metalen > 32);
+}
+
 struct xdp_attachment_info {
 	struct bpf_prog *prog;
 	u32 flags;
diff --git a/net/core/filter.c b/net/core/filter.c
index d70187ce851b..f2c15b2a057a 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -77,6 +77,7 @@ 
 #include <net/transp_v6.h>
 #include <linux/btf_ids.h>
 #include <net/tls.h>
+#include <net/xdp.h>
 
 static const struct bpf_func_proto *
 bpf_sk_base_func_proto(enum bpf_func_id func_id);
@@ -3880,8 +3881,7 @@  BPF_CALL_2(bpf_xdp_adjust_meta, struct xdp_buff *, xdp, int, offset)
 	if (unlikely(meta < xdp_frame_end ||
 		     meta > xdp->data))
 		return -EINVAL;
-	if (unlikely((metalen & (sizeof(__u32) - 1)) ||
-		     (metalen > 32)))
+	if (unlikely(xdp_metalen_invalid(metalen)))
 		return -EACCES;
 
 	xdp->data_meta = meta;