diff options
| author | Ziyang Xuan <william.xuanziyang@huawei.com> | 2023-01-13 17:24:51 +0800 |
|---|---|---|
| committer | Martin KaFai Lau <martin.lau@kernel.org> | 2023-01-15 12:56:17 -0800 |
| commit | d219df60a70ed0739aa5dd34b477763311fc5a7b (patch) | |
| tree | d8f5455628830a487861b88051f3811e01e405a9 /net/core/filter.c | |
| parent | 1c48391bc6739f5e3306919d4b887b92c35d5490 (diff) | |
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@google.com>
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/b268ec7f0ff9431f4f43b1b40ab856ebb28cb4e1.1673574419.git.william.xuanziyang@huawei.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Diffstat (limited to 'net/core/filter.c')
| -rw-r--r-- | net/core/filter.c | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index d9befa6ba04e..b4547a2c02f4 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); @@ -3608,6 +3621,22 @@ BPF_CALL_4(bpf_skb_adjust_room, struct sk_buff *, skb, s32, len_diff, return -ENOTSUPP; } + if (flags & BPF_F_ADJ_ROOM_DECAP_L3_MASK) { + if (!shrink) + return -EINVAL; + + switch (flags & BPF_F_ADJ_ROOM_DECAP_L3_MASK) { + case BPF_F_ADJ_ROOM_DECAP_L3_IPV4: + len_min = sizeof(struct iphdr); + break; + case BPF_F_ADJ_ROOM_DECAP_L3_IPV6: + len_min = sizeof(struct ipv6hdr); + break; + default: + return -EINVAL; + } + } + len_cur = skb->len - skb_network_offset(skb); if ((shrink && (len_diff_abs >= len_cur || len_cur - len_diff_abs < len_min)) || |