diff options
Diffstat (limited to 'net/core/filter.c')
| -rw-r--r-- | net/core/filter.c | 108 |
1 files changed, 104 insertions, 4 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 955a7d77decd..b669e75d2b36 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1175,7 +1175,9 @@ int sk_attach_bpf(u32 ufd, struct sock *sk) return 0; } -static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) +#define BPF_RECOMPUTE_CSUM(flags) ((flags) & 1) + +static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags) { struct sk_buff *skb = (struct sk_buff *) (long) r1; unsigned int offset = (unsigned int) r2; @@ -1192,7 +1194,7 @@ static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) * * so check for invalid 'offset' and too large 'len' */ - if (offset > 0xffff || len > sizeof(buf)) + if (unlikely(offset > 0xffff || len > sizeof(buf))) return -EFAULT; if (skb_cloned(skb) && !skb_clone_writable(skb, offset + len)) @@ -1202,7 +1204,8 @@ static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) if (unlikely(!ptr)) return -EFAULT; - skb_postpull_rcsum(skb, ptr, len); + if (BPF_RECOMPUTE_CSUM(flags)) + skb_postpull_rcsum(skb, ptr, len); memcpy(ptr, from, len); @@ -1210,7 +1213,7 @@ static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) /* skb_store_bits cannot return -EFAULT here */ skb_store_bits(skb, offset, ptr, len); - if (skb->ip_summed == CHECKSUM_COMPLETE) + if (BPF_RECOMPUTE_CSUM(flags) && skb->ip_summed == CHECKSUM_COMPLETE) skb->csum = csum_add(skb->csum, csum_partial(ptr, len, 0)); return 0; } @@ -1223,6 +1226,99 @@ const struct bpf_func_proto bpf_skb_store_bytes_proto = { .arg2_type = ARG_ANYTHING, .arg3_type = ARG_PTR_TO_STACK, .arg4_type = ARG_CONST_STACK_SIZE, + .arg5_type = ARG_ANYTHING, +}; + +#define BPF_HEADER_FIELD_SIZE(flags) ((flags) & 0x0f) +#define BPF_IS_PSEUDO_HEADER(flags) ((flags) & 0x10) + +static u64 bpf_l3_csum_replace(u64 r1, u64 offset, u64 from, u64 to, u64 flags) +{ + struct sk_buff *skb = (struct sk_buff *) (long) r1; + __sum16 sum, *ptr; + + if (unlikely(offset > 0xffff)) + return -EFAULT; + + if (skb_cloned(skb) && !skb_clone_writable(skb, offset + sizeof(sum))) + return -EFAULT; + + ptr = skb_header_pointer(skb, offset, sizeof(sum), &sum); + if (unlikely(!ptr)) + return -EFAULT; + + switch (BPF_HEADER_FIELD_SIZE(flags)) { + case 2: + csum_replace2(ptr, from, to); + break; + case 4: + csum_replace4(ptr, from, to); + break; + default: + return -EINVAL; + } + + if (ptr == &sum) + /* skb_store_bits guaranteed to not return -EFAULT here */ + skb_store_bits(skb, offset, ptr, sizeof(sum)); + + return 0; +} + +const struct bpf_func_proto bpf_l3_csum_replace_proto = { + .func = bpf_l3_csum_replace, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_ANYTHING, + .arg5_type = ARG_ANYTHING, +}; + +static u64 bpf_l4_csum_replace(u64 r1, u64 offset, u64 from, u64 to, u64 flags) +{ + struct sk_buff *skb = (struct sk_buff *) (long) r1; + u32 is_pseudo = BPF_IS_PSEUDO_HEADER(flags); + __sum16 sum, *ptr; + + if (unlikely(offset > 0xffff)) + return -EFAULT; + + if (skb_cloned(skb) && !skb_clone_writable(skb, offset + sizeof(sum))) + return -EFAULT; + + ptr = skb_header_pointer(skb, offset, sizeof(sum), &sum); + if (unlikely(!ptr)) + return -EFAULT; + + switch (BPF_HEADER_FIELD_SIZE(flags)) { + case 2: + inet_proto_csum_replace2(ptr, skb, from, to, is_pseudo); + break; + case 4: + inet_proto_csum_replace4(ptr, skb, from, to, is_pseudo); + break; + default: + return -EINVAL; + } + + if (ptr == &sum) + /* skb_store_bits guaranteed to not return -EFAULT here */ + skb_store_bits(skb, offset, ptr, sizeof(sum)); + + return 0; +} + +const struct bpf_func_proto bpf_l4_csum_replace_proto = { + .func = bpf_l4_csum_replace, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_ANYTHING, + .arg5_type = ARG_ANYTHING, }; static const struct bpf_func_proto * @@ -1250,6 +1346,10 @@ tc_cls_act_func_proto(enum bpf_func_id func_id) switch (func_id) { case BPF_FUNC_skb_store_bytes: return &bpf_skb_store_bytes_proto; + case BPF_FUNC_l3_csum_replace: + return &bpf_l3_csum_replace_proto; + case BPF_FUNC_l4_csum_replace: + return &bpf_l4_csum_replace_proto; default: return sk_filter_func_proto(func_id); } |