On 12/3/20 10:33 PM, Florent Revest wrote:
This creates a new helper proto because the existing
bpf_get_socket_cookie_sock_proto has a ARG_PTR_TO_CTX argument and only
works for BPF programs where the context is a sock.
This helper could also be useful to other BPF program types such as LSM.
Signed-off-by: Florent Revest <[email protected]>
---
include/uapi/linux/bpf.h | 7 +++++++
kernel/trace/bpf_trace.c | 4 ++++
net/core/filter.c | 7 +++++++
tools/include/uapi/linux/bpf.h | 7 +++++++
4 files changed, 25 insertions(+)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index c3458ec1f30a..3e0e33c43998 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1662,6 +1662,13 @@ union bpf_attr {
* Return
* A 8-byte long non-decreasing number.
*
+ * u64 bpf_get_socket_cookie(void *sk)
+ * Description
+ * Equivalent to **bpf_get_socket_cookie**\ () helper that accepts
+ * *sk*, but gets socket from a BTF **struct sock**.
+ * Return
+ * A 8-byte long non-decreasing number.
I would not mention this here since it's not fully correct and we should avoid
users
taking non-decreasing granted in their progs. The only assumption you can make
is
that it can be considered a unique number. See also [0] with reverse counter..
[0]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=92acdc58ab11af66fcaef485433fde61b5e32fac
+ *
* u32 bpf_get_socket_uid(struct sk_buff *skb)
* Return
* The owner UID of the socket associated to *skb*. If the socket
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index d255bc9b2bfa..14ad96579813 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1725,6 +1725,8 @@ raw_tp_prog_func_proto(enum bpf_func_id func_id, const
struct bpf_prog *prog)
}
}
+extern const struct bpf_func_proto bpf_get_socket_cookie_sock_tracing_proto;
+
const struct bpf_func_proto *
tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
@@ -1748,6 +1750,8 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const
struct bpf_prog *prog)
return &bpf_sk_storage_get_tracing_proto;
case BPF_FUNC_sk_storage_delete:
return &bpf_sk_storage_delete_tracing_proto;
+ case BPF_FUNC_get_socket_cookie:
+ return &bpf_get_socket_cookie_sock_tracing_proto;
#endif
case BPF_FUNC_seq_printf:
return prog->expected_attach_type == BPF_TRACE_ITER ?
diff --git a/net/core/filter.c b/net/core/filter.c
index 2ca5eecebacf..177c4e5e529d 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4631,6 +4631,13 @@ static const struct bpf_func_proto
bpf_get_socket_cookie_sock_proto = {
.arg1_type = ARG_PTR_TO_CTX,
};
+const struct bpf_func_proto bpf_get_socket_cookie_sock_tracing_proto = {
+ .func = bpf_get_socket_cookie_sock,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON,
+};
+
