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authorDaniel Borkmann <daniel@iogearbox.net>2016-09-09 02:45:29 +0200
committerDavid S. Miller <davem@davemloft.net>2016-09-09 19:36:04 -0700
commitf035a51536af9802f55d8c79bd87f184ebffb093 (patch)
treeb10ca650031a03f3752a1ea9f7178282e8eb0a75 /net/core
parent6088b5823b4cb132a838878747384cbfb5ce6646 (diff)
bpf: add BPF_SIZEOF and BPF_FIELD_SIZEOF macros
Add BPF_SIZEOF() and BPF_FIELD_SIZEOF() macros to improve the code a bit which otherwise often result in overly long bytes_to_bpf_size(sizeof()) and bytes_to_bpf_size(FIELD_SIZEOF()) lines. So place them into a macro helper instead. Moreover, we currently have a BUILD_BUG_ON(BPF_FIELD_SIZEOF()) check in convert_bpf_extensions(), but we should rather make that generic as well and add a BUILD_BUG_ON() test in all BPF_SIZEOF()/BPF_FIELD_SIZEOF() users to detect any rewriter size issues at compile time. Note, there are currently none, but we want to assert that it stays this way. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/filter.c15
1 files changed, 7 insertions, 8 deletions
diff --git a/net/core/filter.c b/net/core/filter.c
index 628ed8c7d38d..120c813ef030 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -233,9 +233,8 @@ static bool convert_bpf_extensions(struct sock_filter *fp,
case SKF_AD_OFF + SKF_AD_HATYPE:
BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4);
BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2);
- BUILD_BUG_ON(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, dev)) < 0);
- *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, dev)),
+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, dev),
BPF_REG_TMP, BPF_REG_CTX,
offsetof(struct sk_buff, dev));
/* if (tmp != 0) goto pc + 1 */
@@ -2685,7 +2684,7 @@ static u32 bpf_net_convert_ctx_access(enum bpf_access_type type, int dst_reg,
case offsetof(struct __sk_buff, ifindex):
BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4);
- *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, dev)),
+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, dev),
dst_reg, src_reg,
offsetof(struct sk_buff, dev));
*insn++ = BPF_JMP_IMM(BPF_JEQ, dst_reg, 0, 1);
@@ -2750,7 +2749,7 @@ static u32 bpf_net_convert_ctx_access(enum bpf_access_type type, int dst_reg,
break;
case offsetof(struct __sk_buff, data):
- *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, data)),
+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, data),
dst_reg, src_reg,
offsetof(struct sk_buff, data));
break;
@@ -2759,8 +2758,8 @@ static u32 bpf_net_convert_ctx_access(enum bpf_access_type type, int dst_reg,
ctx_off -= offsetof(struct __sk_buff, data_end);
ctx_off += offsetof(struct sk_buff, cb);
ctx_off += offsetof(struct bpf_skb_data_end, data_end);
- *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(sizeof(void *)),
- dst_reg, src_reg, ctx_off);
+ *insn++ = BPF_LDX_MEM(BPF_SIZEOF(void *), dst_reg, src_reg,
+ ctx_off);
break;
case offsetof(struct __sk_buff, tc_index):
@@ -2795,12 +2794,12 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type, int dst_reg,
switch (ctx_off) {
case offsetof(struct xdp_md, data):
- *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct xdp_buff, data)),
+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_buff, data),
dst_reg, src_reg,
offsetof(struct xdp_buff, data));
break;
case offsetof(struct xdp_md, data_end):
- *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct xdp_buff, data_end)),
+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_buff, data_end),
dst_reg, src_reg,
offsetof(struct xdp_buff, data_end));
break;