Commit 608cd71a authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by David S. Miller

tc: bpf: generalize pedit action

existing TC action 'pedit' can munge any bits of the packet.
Generalize it for use in bpf programs attached as cls_bpf and act_bpf via
bpf_skb_store_bytes() helper function.
Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
Reviewed-by: default avatarJiri Pirko <jiri@resnulli.us>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7836b16c
......@@ -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 */
};
......
......@@ -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,
};
......
......@@ -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;
......
......@@ -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,
};
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment