diff options
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/filter.c | 38 |
1 files changed, 27 insertions, 11 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index e7b7720b18e9..d3240a0a0eeb 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2963,12 +2963,19 @@ static u32 bpf_skb_net_base_len(const struct sk_buff *skb) } } -static int bpf_skb_net_grow(struct sk_buff *skb, u32 off, u32 len_diff) +#define BPF_F_ADJ_ROOM_MASK (BPF_F_ADJ_ROOM_FIXED_GSO) + +static int bpf_skb_net_grow(struct sk_buff *skb, u32 off, u32 len_diff, + u64 flags) { int ret; - if (skb_is_gso(skb) && !skb_is_gso_tcp(skb)) - return -ENOTSUPP; + if (skb_is_gso(skb) && !skb_is_gso_tcp(skb)) { + /* udp gso_size delineates datagrams, only allow if fixed */ + if (!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) || + !(flags & BPF_F_ADJ_ROOM_FIXED_GSO)) + return -ENOTSUPP; + } ret = skb_cow_head(skb, len_diff); if (unlikely(ret < 0)) @@ -2982,7 +2989,9 @@ static int bpf_skb_net_grow(struct sk_buff *skb, u32 off, u32 len_diff) struct skb_shared_info *shinfo = skb_shinfo(skb); /* Due to header grow, MSS needs to be downgraded. */ - skb_decrease_gso_size(shinfo, len_diff); + if (!(flags & BPF_F_ADJ_ROOM_FIXED_GSO)) + skb_decrease_gso_size(shinfo, len_diff); + /* Header must be checked, and gso_segs recomputed. */ shinfo->gso_type |= SKB_GSO_DODGY; shinfo->gso_segs = 0; @@ -2991,12 +3000,17 @@ static int bpf_skb_net_grow(struct sk_buff *skb, u32 off, u32 len_diff) return 0; } -static int bpf_skb_net_shrink(struct sk_buff *skb, u32 off, u32 len_diff) +static int bpf_skb_net_shrink(struct sk_buff *skb, u32 off, u32 len_diff, + u64 flags) { int ret; - if (skb_is_gso(skb) && !skb_is_gso_tcp(skb)) - return -ENOTSUPP; + if (skb_is_gso(skb) && !skb_is_gso_tcp(skb)) { + /* udp gso_size delineates datagrams, only allow if fixed */ + if (!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) || + !(flags & BPF_F_ADJ_ROOM_FIXED_GSO)) + return -ENOTSUPP; + } ret = skb_unclone(skb, GFP_ATOMIC); if (unlikely(ret < 0)) @@ -3010,7 +3024,9 @@ static int bpf_skb_net_shrink(struct sk_buff *skb, u32 off, u32 len_diff) struct skb_shared_info *shinfo = skb_shinfo(skb); /* Due to header shrink, MSS can be upgraded. */ - skb_increase_gso_size(shinfo, len_diff); + if (!(flags & BPF_F_ADJ_ROOM_FIXED_GSO)) + skb_increase_gso_size(shinfo, len_diff); + /* Header must be checked, and gso_segs recomputed. */ shinfo->gso_type |= SKB_GSO_DODGY; shinfo->gso_segs = 0; @@ -3037,7 +3053,7 @@ BPF_CALL_4(bpf_skb_adjust_room, struct sk_buff *, skb, s32, len_diff, u32 off; int ret; - if (unlikely(flags)) + if (unlikely(flags & ~BPF_F_ADJ_ROOM_MASK)) return -EINVAL; if (unlikely(len_diff_abs > 0xfffU)) return -EFAULT; @@ -3065,8 +3081,8 @@ BPF_CALL_4(bpf_skb_adjust_room, struct sk_buff *, skb, s32, len_diff, !skb_is_gso(skb)))) return -ENOTSUPP; - ret = shrink ? bpf_skb_net_shrink(skb, off, len_diff_abs) : - bpf_skb_net_grow(skb, off, len_diff_abs); + ret = shrink ? bpf_skb_net_shrink(skb, off, len_diff_abs, flags) : + bpf_skb_net_grow(skb, off, len_diff_abs, flags); bpf_compute_data_pointers(skb); return ret; |