Payload expression works on byte-boundaries, leverage this with suitable
prefix lengths.
Signed-off-by: Phil Sutter <phil@xxxxxx>
---
Changes since v1:
- Fix prefix printing in arptables, it uses add_addr() as well.
---
iptables/nft-arp.c | 11 ++++++++---
iptables/nft-ipv4.c | 6 ++++--
iptables/nft-ipv6.c | 6 ++++--
iptables/nft-shared.c | 14 ++++++++++----
iptables/nft-shared.h | 4 ++++
5 files changed, 30 insertions(+), 11 deletions(-)
diff --git a/iptables/nft-arp.c b/iptables/nft-arp.c
index 67f4529d93652..952f0c6916e59 100644
--- a/iptables/nft-arp.c
+++ b/iptables/nft-arp.c
@@ -303,7 +303,8 @@ static bool nft_arp_parse_devaddr(struct nft_xt_ctx *ctx,
memcpy(info->mask, ctx->bitwise.mask, ETH_ALEN);
ctx->flags &= ~NFT_XT_CTX_BITWISE;
} else {
- memset(info->mask, 0xff, ETH_ALEN);
+ memset(info->mask, 0xff,
+ min(ctx->payload.len, ETH_ALEN));
}
return inv;
@@ -360,7 +361,9 @@ static void nft_arp_parse_payload(struct nft_xt_ctx *ctx,
parse_mask_ipv4(ctx, &fw->arp.smsk);
ctx->flags &= ~NFT_XT_CTX_BITWISE;
} else {
- fw->arp.smsk.s_addr = 0xffffffff;
+ memset(&fw->arp.smsk, 0xff,
+ min(ctx->payload.len,
+ sizeof(struct in_addr)));
}
if (inv)
@@ -380,7 +383,9 @@ static void nft_arp_parse_payload(struct nft_xt_ctx *ctx,
parse_mask_ipv4(ctx, &fw->arp.tmsk);
ctx->flags &= ~NFT_XT_CTX_BITWISE;
} else {
- fw->arp.tmsk.s_addr = 0xffffffff;
+ memset(&fw->arp.tmsk, 0xff,
+ min(ctx->payload.len,
+ sizeof(struct in_addr)));
}
if (inv)
diff --git a/iptables/nft-ipv4.c b/iptables/nft-ipv4.c
index afdecf9711e64..ce702041af0f4 100644
--- a/iptables/nft-ipv4.c
+++ b/iptables/nft-ipv4.c
@@ -199,7 +199,8 @@ static void nft_ipv4_parse_payload(struct nft_xt_ctx *ctx,
parse_mask_ipv4(ctx, &cs->fw.ip.smsk);
ctx->flags &= ~NFT_XT_CTX_BITWISE;
} else {
- cs->fw.ip.smsk.s_addr = 0xffffffff;
+ memset(&cs->fw.ip.smsk, 0xff,
+ min(ctx->payload.len, sizeof(struct in_addr)));
}
if (inv)
@@ -212,7 +213,8 @@ static void nft_ipv4_parse_payload(struct nft_xt_ctx *ctx,
parse_mask_ipv4(ctx, &cs->fw.ip.dmsk);
ctx->flags &= ~NFT_XT_CTX_BITWISE;
} else {
- cs->fw.ip.dmsk.s_addr = 0xffffffff;
+ memset(&cs->fw.ip.dmsk, 0xff,
+ min(ctx->payload.len, sizeof(struct in_addr)));
}
if (inv)
diff --git a/iptables/nft-ipv6.c b/iptables/nft-ipv6.c
index 4008b7eab4f2a..c877ec6d10887 100644
--- a/iptables/nft-ipv6.c
+++ b/iptables/nft-ipv6.c
@@ -146,7 +146,8 @@ static void nft_ipv6_parse_payload(struct nft_xt_ctx *ctx,
parse_mask_ipv6(ctx, &cs->fw6.ipv6.smsk);
ctx->flags &= ~NFT_XT_CTX_BITWISE;
} else {
- memset(&cs->fw6.ipv6.smsk, 0xff, sizeof(struct in6_addr));
+ memset(&cs->fw6.ipv6.smsk, 0xff,
+ min(ctx->payload.len, sizeof(struct in6_addr)));
}
if (inv)
@@ -159,7 +160,8 @@ static void nft_ipv6_parse_payload(struct nft_xt_ctx *ctx,
parse_mask_ipv6(ctx, &cs->fw6.ipv6.dmsk);
ctx->flags &= ~NFT_XT_CTX_BITWISE;
} else {
- memset(&cs->fw6.ipv6.dmsk, 0xff, sizeof(struct in6_addr));
+ memset(&cs->fw6.ipv6.dmsk, 0xff,
+ min(ctx->payload.len, sizeof(struct in6_addr)));
}
if (inv)
diff --git a/iptables/nft-shared.c b/iptables/nft-shared.c
index 7741d23befc5a..545e9c60fa015 100644
--- a/iptables/nft-shared.c
+++ b/iptables/nft-shared.c
@@ -166,16 +166,22 @@ void add_addr(struct nftnl_rule *r, int offset,
void *data, void *mask, size_t len, uint32_t op)
{
const unsigned char *m = mask;
+ bool bitwise = false;
int i;
- add_payload(r, offset, len, NFT_PAYLOAD_NETWORK_HEADER);
-
for (i = 0; i < len; i++) {
- if (m[i] != 0xff)
+ if (m[i] != 0xff) {
+ bitwise = m[i] != 0;
break;
+ }
}
- if (i != len)
+ if (!bitwise)
+ len = i;
+
+ add_payload(r, offset, len, NFT_PAYLOAD_NETWORK_HEADER);
+
+ if (bitwise)
add_bitwise(r, mask, len);
add_cmp_ptr(r, op, data, len);
diff --git a/iptables/nft-shared.h b/iptables/nft-shared.h
index 4440fd17bfeac..a52463342b30a 100644
--- a/iptables/nft-shared.h
+++ b/iptables/nft-shared.h
@@ -247,4 +247,8 @@ void xtables_restore_parse(struct nft_handle *h,
const struct nft_xt_restore_parse *p);
void nft_check_xt_legacy(int family, bool is_ipt_save);
+
+#define min(x, y) ((x) < (y) ? (x) : (y))
+#define max(x, y) ((x) > (y) ? (x) : (y))
+
#endif
--
2.28.0
