diff options
| -rw-r--r-- | include/linux/bpf.h | 1 | ||||
| -rw-r--r-- | include/uapi/linux/bpf.h | 1 | ||||
| -rw-r--r-- | kernel/bpf/verifier.c | 2 | ||||
| -rw-r--r-- | net/core/filter.c | 71 |
4 files changed, 73 insertions, 2 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 280a315..d5cda06 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -59,6 +59,7 @@ enum bpf_arg_type { ARG_PTR_TO_STACK, /* any pointer to eBPF program stack */ ARG_CONST_STACK_SIZE, /* number of bytes accessed from stack */ + ARG_PTR_TO_CTX, /* pointer to context */ ARG_ANYTHING, /* any (initialized) argument is ok */ }; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 27dc4ec..74aab6e 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -168,6 +168,7 @@ enum bpf_func_id { BPF_FUNC_map_delete_elem, /* int map_delete_elem(&map, &key) */ BPF_FUNC_get_prandom_u32, /* u32 prandom_u32(void) */ BPF_FUNC_get_smp_processor_id, /* u32 raw_smp_processor_id(void) */ + BPF_FUNC_skb_store_bytes, /* int skb_store_bytes(skb, offset, from, len) */ __BPF_FUNC_MAX_ID, }; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 0e714f7..630a7ba 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -773,6 +773,8 @@ static int check_func_arg(struct verifier_env *env, u32 regno, expected_type = CONST_IMM; } else if (arg_type == ARG_CONST_MAP_PTR) { expected_type = CONST_PTR_TO_MAP; + } else if (arg_type == ARG_PTR_TO_CTX) { + expected_type = PTR_TO_CTX; } else { verbose("unsupported arg_type %d\n", arg_type); return -EFAULT; diff --git a/net/core/filter.c b/net/core/filter.c index 32f43c5..444a07e 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1175,6 +1175,56 @@ 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) +{ + struct sk_buff *skb = (struct sk_buff *) (long) r1; + unsigned int offset = (unsigned int) r2; + void *from = (void *) (long) r3; + unsigned int len = (unsigned int) r4; + char buf[16]; + void *ptr; + + /* bpf verifier guarantees that: + * 'from' pointer points to bpf program stack + * 'len' bytes of it were initialized + * 'len' > 0 + * 'skb' is a valid pointer to 'struct sk_buff' + * + * so check for invalid 'offset' and too large 'len' + */ + if (offset > 0xffff || len > sizeof(buf)) + return -EFAULT; + + if (skb_cloned(skb) && !skb_clone_writable(skb, offset + len)) + return -EFAULT; + + ptr = skb_header_pointer(skb, offset, len, buf); + if (unlikely(!ptr)) + return -EFAULT; + + skb_postpull_rcsum(skb, ptr, len); + + memcpy(ptr, from, len); + + if (ptr == buf) + /* skb_store_bits cannot return -EFAULT here */ + skb_store_bits(skb, offset, ptr, len); + + if (skb->ip_summed == CHECKSUM_COMPLETE) + skb->csum = csum_add(skb->csum, csum_partial(ptr, len, 0)); + return 0; +} + +const struct bpf_func_proto bpf_skb_store_bytes_proto = { + .func = bpf_skb_store_bytes, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_PTR_TO_STACK, + .arg4_type = ARG_CONST_STACK_SIZE, +}; + static const struct bpf_func_proto * sk_filter_func_proto(enum bpf_func_id func_id) { @@ -1194,6 +1244,17 @@ sk_filter_func_proto(enum bpf_func_id func_id) } } +static const struct bpf_func_proto * +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; + default: + return sk_filter_func_proto(func_id); + } +} + static bool sk_filter_is_valid_access(int off, int size, enum bpf_access_type type) { @@ -1270,18 +1331,24 @@ static const struct bpf_verifier_ops sk_filter_ops = { .convert_ctx_access = sk_filter_convert_ctx_access, }; +static const struct bpf_verifier_ops tc_cls_act_ops = { + .get_func_proto = tc_cls_act_func_proto, + .is_valid_access = sk_filter_is_valid_access, + .convert_ctx_access = sk_filter_convert_ctx_access, +}; + static struct bpf_prog_type_list sk_filter_type __read_mostly = { .ops = &sk_filter_ops, .type = BPF_PROG_TYPE_SOCKET_FILTER, }; static struct bpf_prog_type_list sched_cls_type __read_mostly = { - .ops = &sk_filter_ops, + .ops = &tc_cls_act_ops, .type = BPF_PROG_TYPE_SCHED_CLS, }; static struct bpf_prog_type_list sched_act_type __read_mostly = { - .ops = &sk_filter_ops, + .ops = &tc_cls_act_ops, .type = BPF_PROG_TYPE_SCHED_ACT, }; |
