diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 8bed7f1176b8..d94797ce9a5a 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -273,6 +273,22 @@ enum bpf_func_id { __BPF_FUNC_MAX_ID, }; +/* All flags used by eBPF helper functions, placed here. */ + +/* BPF_FUNC_skb_store_bytes flags. */ +#define BPF_F_RECOMPUTE_CSUM (1ULL << 0) + +/* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags. + * First 4 bits are for passing the header field size. + */ +#define BPF_F_HDR_FIELD_MASK 0xfULL + +/* BPF_FUNC_l4_csum_replace flags. */ +#define BPF_F_PSEUDO_HDR (1ULL << 4) + +/* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */ +#define BPF_F_INGRESS (1ULL << 0) + /* user accessible mirror of in-kernel sk_buff. * new fields can only be added to the end of this structure */ diff --git a/net/core/filter.c b/net/core/filter.c index 0db92b5e2cbf..7c55cadc0f38 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1328,8 +1328,7 @@ int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk) return 0; } -#define BPF_RECOMPUTE_CSUM(flags) ((flags) & 1) -#define BPF_LDST_LEN 16U +#define BPF_LDST_LEN 16U static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags) { @@ -1340,6 +1339,9 @@ static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags) char buf[BPF_LDST_LEN]; void *ptr; + if (unlikely(flags & ~(BPF_F_RECOMPUTE_CSUM))) + return -EINVAL; + /* bpf verifier guarantees that: * 'from' pointer points to bpf program stack * 'len' bytes of it were initialized @@ -1359,7 +1361,7 @@ static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags) if (unlikely(!ptr)) return -EFAULT; - if (BPF_RECOMPUTE_CSUM(flags)) + if (flags & BPF_F_RECOMPUTE_CSUM) skb_postpull_rcsum(skb, ptr, len); memcpy(ptr, from, len); @@ -1368,7 +1370,7 @@ static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags) /* skb_store_bits cannot return -EFAULT here */ skb_store_bits(skb, offset, ptr, len); - if (BPF_RECOMPUTE_CSUM(flags)) + if (flags & BPF_F_RECOMPUTE_CSUM) skb_postpush_rcsum(skb, ptr, len); return 0; @@ -1415,15 +1417,14 @@ const struct bpf_func_proto bpf_skb_load_bytes_proto = { .arg4_type = ARG_CONST_STACK_SIZE, }; -#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 r2, u64 from, u64 to, u64 flags) { struct sk_buff *skb = (struct sk_buff *) (long) r1; int offset = (int) r2; __sum16 sum, *ptr; + if (unlikely(flags & ~(BPF_F_HDR_FIELD_MASK))) + return -EINVAL; if (unlikely((u32) offset > 0xffff)) return -EFAULT; @@ -1435,7 +1436,7 @@ static u64 bpf_l3_csum_replace(u64 r1, u64 r2, u64 from, u64 to, u64 flags) if (unlikely(!ptr)) return -EFAULT; - switch (BPF_HEADER_FIELD_SIZE(flags)) { + switch (flags & BPF_F_HDR_FIELD_MASK) { case 2: csum_replace2(ptr, from, to); break; @@ -1467,10 +1468,12 @@ const struct bpf_func_proto bpf_l3_csum_replace_proto = { static u64 bpf_l4_csum_replace(u64 r1, u64 r2, u64 from, u64 to, u64 flags) { struct sk_buff *skb = (struct sk_buff *) (long) r1; - bool is_pseudo = !!BPF_IS_PSEUDO_HEADER(flags); + bool is_pseudo = flags & BPF_F_PSEUDO_HDR; int offset = (int) r2; __sum16 sum, *ptr; + if (unlikely(flags & ~(BPF_F_PSEUDO_HDR | BPF_F_HDR_FIELD_MASK))) + return -EINVAL; if (unlikely((u32) offset > 0xffff)) return -EFAULT; @@ -1482,7 +1485,7 @@ static u64 bpf_l4_csum_replace(u64 r1, u64 r2, u64 from, u64 to, u64 flags) if (unlikely(!ptr)) return -EFAULT; - switch (BPF_HEADER_FIELD_SIZE(flags)) { + switch (flags & BPF_F_HDR_FIELD_MASK) { case 2: inet_proto_csum_replace2(ptr, skb, from, to, is_pseudo); break; @@ -1511,13 +1514,14 @@ const struct bpf_func_proto bpf_l4_csum_replace_proto = { .arg5_type = ARG_ANYTHING, }; -#define BPF_IS_REDIRECT_INGRESS(flags) ((flags) & 1) - static u64 bpf_clone_redirect(u64 r1, u64 ifindex, u64 flags, u64 r4, u64 r5) { struct sk_buff *skb = (struct sk_buff *) (long) r1, *skb2; struct net_device *dev; + if (unlikely(flags & ~(BPF_F_INGRESS))) + return -EINVAL; + dev = dev_get_by_index_rcu(dev_net(skb->dev), ifindex); if (unlikely(!dev)) return -EINVAL; @@ -1526,7 +1530,7 @@ static u64 bpf_clone_redirect(u64 r1, u64 ifindex, u64 flags, u64 r4, u64 r5) if (unlikely(!skb2)) return -ENOMEM; - if (BPF_IS_REDIRECT_INGRESS(flags)) { + if (flags & BPF_F_INGRESS) { if (skb_at_tc_ingress(skb2)) skb_postpush_rcsum(skb2, skb_mac_header(skb2), skb2->mac_len); @@ -1553,12 +1557,17 @@ struct redirect_info { }; static DEFINE_PER_CPU(struct redirect_info, redirect_info); + static u64 bpf_redirect(u64 ifindex, u64 flags, u64 r3, u64 r4, u64 r5) { struct redirect_info *ri = this_cpu_ptr(&redirect_info); + if (unlikely(flags & ~(BPF_F_INGRESS))) + return TC_ACT_SHOT; + ri->ifindex = ifindex; ri->flags = flags; + return TC_ACT_REDIRECT; } @@ -1574,7 +1583,7 @@ int skb_do_redirect(struct sk_buff *skb) return -EINVAL; } - if (BPF_IS_REDIRECT_INGRESS(ri->flags)) { + if (ri->flags & BPF_F_INGRESS) { if (skb_at_tc_ingress(skb)) skb_postpush_rcsum(skb, skb_mac_header(skb), skb->mac_len);