lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <b231c7d0acacd702284158cd44734e72ef661a01.1673423199.git.william.xuanziyang@huawei.com>
Date:   Wed, 11 Jan 2023 16:01:33 +0800
From:   Ziyang Xuan <william.xuanziyang@...wei.com>
To:     <ast@...nel.org>, <daniel@...earbox.net>, <andrii@...nel.org>,
        <davem@...emloft.net>, <edumazet@...gle.com>, <kuba@...nel.org>,
        <pabeni@...hat.com>, <willemb@...gle.com>, <bpf@...r.kernel.org>,
        <netdev@...r.kernel.org>, <martin.lau@...ux.dev>,
        <song@...nel.org>, <yhs@...com>, <john.fastabend@...il.com>,
        <kpsingh@...nel.org>, <sdf@...gle.com>, <haoluo@...gle.com>,
        <jolsa@...nel.org>
Subject: [PATCH bpf-next v2 1/2] bpf: Add ipip6 and ip6ip decap support for bpf_skb_adjust_room()

Add ipip6 and ip6ip decap support for bpf_skb_adjust_room().
Main use case is for using cls_bpf on ingress hook to decapsulate
IPv4 over IPv6 and IPv6 over IPv4 tunnel packets.

Add two new flags BPF_F_ADJ_ROOM_DECAP_L3_IPV{4,6} to indicate the
new IP header version after decapsulating the outer IP header.

Suggested-by: Willem de Bruijn <willemb@...gle.com>
Signed-off-by: Ziyang Xuan <william.xuanziyang@...wei.com>
---
 include/uapi/linux/bpf.h       |  8 ++++++++
 net/core/filter.c              | 26 +++++++++++++++++++++++++-
 tools/include/uapi/linux/bpf.h |  8 ++++++++
 3 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 464ca3f01fe7..dde1c2ea1c84 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -2644,6 +2644,12 @@ union bpf_attr {
  *		  Use with BPF_F_ADJ_ROOM_ENCAP_L2 flag to further specify the
  *		  L2 type as Ethernet.
  *
+ *              * **BPF_F_ADJ_ROOM_DECAP_L3_IPV4**,
+ *                **BPF_F_ADJ_ROOM_DECAP_L3_IPV6**:
+ *                Indicate the new IP header version after decapsulating the
+ *                outer IP header. Mainly used in scenarios that the inner and
+ *                outer IP versions are different.
+ *
  * 		A call to this helper is susceptible to change the underlying
  * 		packet buffer. Therefore, at load time, all checks on pointers
  * 		previously done by the verifier are invalidated and must be
@@ -5803,6 +5809,8 @@ enum {
 	BPF_F_ADJ_ROOM_ENCAP_L4_UDP	= (1ULL << 4),
 	BPF_F_ADJ_ROOM_NO_CSUM_RESET	= (1ULL << 5),
 	BPF_F_ADJ_ROOM_ENCAP_L2_ETH	= (1ULL << 6),
+	BPF_F_ADJ_ROOM_DECAP_L3_IPV4	= (1ULL << 7),
+	BPF_F_ADJ_ROOM_DECAP_L3_IPV6	= (1ULL << 8),
 };
 
 enum {
diff --git a/net/core/filter.c b/net/core/filter.c
index 43cc1fe58a2c..5fb113953f80 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3381,13 +3381,17 @@ static u32 bpf_skb_net_base_len(const struct sk_buff *skb)
 #define BPF_F_ADJ_ROOM_ENCAP_L3_MASK	(BPF_F_ADJ_ROOM_ENCAP_L3_IPV4 | \
 					 BPF_F_ADJ_ROOM_ENCAP_L3_IPV6)
 
+#define BPF_F_ADJ_ROOM_DECAP_L3_MASK	(BPF_F_ADJ_ROOM_DECAP_L3_IPV4 | \
+					 BPF_F_ADJ_ROOM_DECAP_L3_IPV6)
+
 #define BPF_F_ADJ_ROOM_MASK		(BPF_F_ADJ_ROOM_FIXED_GSO | \
 					 BPF_F_ADJ_ROOM_ENCAP_L3_MASK | \
 					 BPF_F_ADJ_ROOM_ENCAP_L4_GRE | \
 					 BPF_F_ADJ_ROOM_ENCAP_L4_UDP | \
 					 BPF_F_ADJ_ROOM_ENCAP_L2_ETH | \
 					 BPF_F_ADJ_ROOM_ENCAP_L2( \
-					  BPF_ADJ_ROOM_ENCAP_L2_MASK))
+					  BPF_ADJ_ROOM_ENCAP_L2_MASK) | \
+					 BPF_F_ADJ_ROOM_DECAP_L3_MASK)
 
 static int bpf_skb_net_grow(struct sk_buff *skb, u32 off, u32 len_diff,
 			    u64 flags)
@@ -3501,6 +3505,7 @@ static int bpf_skb_net_shrink(struct sk_buff *skb, u32 off, u32 len_diff,
 	int ret;
 
 	if (unlikely(flags & ~(BPF_F_ADJ_ROOM_FIXED_GSO |
+			       BPF_F_ADJ_ROOM_DECAP_L3_MASK |
 			       BPF_F_ADJ_ROOM_NO_CSUM_RESET)))
 		return -EINVAL;
 
@@ -3519,6 +3524,14 @@ static int bpf_skb_net_shrink(struct sk_buff *skb, u32 off, u32 len_diff,
 	if (unlikely(ret < 0))
 		return ret;
 
+	/* Match skb->protocol to new outer l3 protocol */
+	if (skb->protocol == htons(ETH_P_IP) &&
+	    flags & BPF_F_ADJ_ROOM_DECAP_L3_IPV6)
+		skb->protocol = htons(ETH_P_IPV6);
+	else if (skb->protocol == htons(ETH_P_IPV6) &&
+		 flags & BPF_F_ADJ_ROOM_DECAP_L3_IPV4)
+		skb->protocol = htons(ETH_P_IP);
+
 	if (skb_is_gso(skb)) {
 		struct skb_shared_info *shinfo = skb_shinfo(skb);
 
@@ -3596,6 +3609,10 @@ BPF_CALL_4(bpf_skb_adjust_room, struct sk_buff *, skb, s32, len_diff,
 	if (unlikely(proto != htons(ETH_P_IP) &&
 		     proto != htons(ETH_P_IPV6)))
 		return -ENOTSUPP;
+	if (unlikely((shrink && ((flags & BPF_F_ADJ_ROOM_DECAP_L3_MASK) ==
+		      BPF_F_ADJ_ROOM_DECAP_L3_MASK)) || (!shrink &&
+		      flags & BPF_F_ADJ_ROOM_DECAP_L3_MASK)))
+		return -EINVAL;
 
 	off = skb_mac_header_len(skb);
 	switch (mode) {
@@ -3608,6 +3625,13 @@ BPF_CALL_4(bpf_skb_adjust_room, struct sk_buff *, skb, s32, len_diff,
 		return -ENOTSUPP;
 	}
 
+	if (shrink) {
+		if (flags & BPF_F_ADJ_ROOM_DECAP_L3_IPV6)
+			len_min = sizeof(struct ipv6hdr);
+		else if (flags & BPF_F_ADJ_ROOM_DECAP_L3_IPV4)
+			len_min = sizeof(struct iphdr);
+	}
+
 	len_cur = skb->len - skb_network_offset(skb);
 	if ((shrink && (len_diff_abs >= len_cur ||
 			len_cur - len_diff_abs < len_min)) ||
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 464ca3f01fe7..22672e5c8466 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -2644,6 +2644,12 @@ union bpf_attr {
  *		  Use with BPF_F_ADJ_ROOM_ENCAP_L2 flag to further specify the
  *		  L2 type as Ethernet.
  *
+ *              * **BPF_F_ADJ_ROOM_DECAP_L3_IPV4**,
+ *                **BPF_F_ADJ_ROOM_DECAP_L3_IPV6**:
+ *                Indicate the new IP header version after decapsulating the
+ *                outer IP header. Mainly used in scenarios that the inner and
+ *                outer IP versions are different.
+ *
  * 		A call to this helper is susceptible to change the underlying
  * 		packet buffer. Therefore, at load time, all checks on pointers
  * 		previously done by the verifier are invalidated and must be
@@ -5803,6 +5809,8 @@ enum {
 	BPF_F_ADJ_ROOM_ENCAP_L4_UDP	= (1ULL << 4),
 	BPF_F_ADJ_ROOM_NO_CSUM_RESET	= (1ULL << 5),
 	BPF_F_ADJ_ROOM_ENCAP_L2_ETH	= (1ULL << 6),
+	BPF_F_ADJ_ROOM_DECAP_L3_IPV4    = (1ULL << 7),
+	BPF_F_ADJ_ROOM_DECAP_L3_IPV6    = (1ULL << 8),
 };
 
 enum {
-- 
2.25.1

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ