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Message-Id: <20190322015406.26453-4-lmb@cloudflare.com>
Date: Fri, 22 Mar 2019 09:54:01 +0800
From: Lorenz Bauer <lmb@...udflare.com>
To: ast@...nel.org, daniel@...earbox.net, netdev@...r.kernel.org,
bpf@...r.kernel.org
Cc: kafai@...com, Lorenz Bauer <lmb@...udflare.com>
Subject: [PATCH bpf-next v3 3/8] bpf: add skc_lookup_tcp helper
Allow looking up a sock_common. This gives eBPF programs
access to timewait and request sockets.
Signed-off-by: Lorenz Bauer <lmb@...udflare.com>
---
include/uapi/linux/bpf.h | 20 +++++-
kernel/bpf/verifier.c | 3 +-
net/core/filter.c | 144 +++++++++++++++++++++++++++++++++------
3 files changed, 143 insertions(+), 24 deletions(-)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 929c8e537a14..fab05317f5e7 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -2431,6 +2431,23 @@ union bpf_attr {
* Return
* A **struct bpf_sock** pointer on success, or **NULL** in
* case of failure.
+ *
+ * struct bpf_sock *bpf_skc_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
+ * Description
+ * Look for TCP socket matching *tuple*, optionally in a child
+ * network namespace *netns*. The return value must be checked,
+ * and if non-**NULL**, released via **bpf_sk_release**\ ().
+ *
+ * This function is identical to bpf_sk_lookup_tcp, except that it
+ * also returns timewait or request sockets. Use bpf_sk_fullsock
+ * or bpf_tcp_socket to access the full structure.
+ *
+ * This helper is available only if the kernel was compiled with
+ * **CONFIG_NET** configuration option.
+ * Return
+ * Pointer to **struct bpf_sock**, or **NULL** in case of failure.
+ * For sockets with reuseport option, the **struct bpf_sock**
+ * result is from **reuse->socks**\ [] using the hash of the tuple.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -2531,7 +2548,8 @@ union bpf_attr {
FN(sk_fullsock), \
FN(tcp_sock), \
FN(skb_ecn_set_ce), \
- FN(get_listener_sock),
+ FN(get_listener_sock), \
+ FN(skc_lookup_tcp),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index a476e13201d6..dffeec3706ce 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -369,7 +369,8 @@ static bool is_release_function(enum bpf_func_id func_id)
static bool is_acquire_function(enum bpf_func_id func_id)
{
return func_id == BPF_FUNC_sk_lookup_tcp ||
- func_id == BPF_FUNC_sk_lookup_udp;
+ func_id == BPF_FUNC_sk_lookup_udp ||
+ func_id == BPF_FUNC_skc_lookup_tcp;
}
static bool is_ptr_cast_function(enum bpf_func_id func_id)
diff --git a/net/core/filter.c b/net/core/filter.c
index 647c63a7b25b..b6d83ba97621 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5156,15 +5156,15 @@ static struct sock *sk_lookup(struct net *net, struct bpf_sock_tuple *tuple,
return sk;
}
-/* bpf_sk_lookup performs the core lookup for different types of sockets,
+/* bpf_skc_lookup performs the core lookup for different types of sockets,
* taking a reference on the socket if it doesn't have the flag SOCK_RCU_FREE.
* Returns the socket as an 'unsigned long' to simplify the casting in the
* callers to satisfy BPF_CALL declarations.
*/
-static unsigned long
-__bpf_sk_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len,
- struct net *caller_net, u32 ifindex, u8 proto, u64 netns_id,
- u64 flags)
+static struct sock *
+__bpf_skc_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len,
+ struct net *caller_net, u32 ifindex, u8 proto, u64 netns_id,
+ u64 flags)
{
struct sock *sk = NULL;
u8 family = AF_UNSPEC;
@@ -5192,15 +5192,27 @@ __bpf_sk_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len,
put_net(net);
}
+out:
+ return sk;
+}
+
+static struct sock *
+__bpf_sk_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len,
+ struct net *caller_net, u32 ifindex, u8 proto, u64 netns_id,
+ u64 flags)
+{
+ struct sock *sk = __bpf_skc_lookup(skb, tuple, len, caller_net,
+ ifindex, proto, netns_id, flags);
+
if (sk)
sk = sk_to_full_sk(sk);
-out:
- return (unsigned long) sk;
+
+ return sk;
}
-static unsigned long
-bpf_sk_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len,
- u8 proto, u64 netns_id, u64 flags)
+static struct sock *
+bpf_skc_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len,
+ u8 proto, u64 netns_id, u64 flags)
{
struct net *caller_net;
int ifindex;
@@ -5213,14 +5225,47 @@ bpf_sk_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len,
ifindex = 0;
}
- return __bpf_sk_lookup(skb, tuple, len, caller_net, ifindex,
- proto, netns_id, flags);
+ return __bpf_skc_lookup(skb, tuple, len, caller_net, ifindex, proto,
+ netns_id, flags);
}
+static struct sock *
+bpf_sk_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len,
+ u8 proto, u64 netns_id, u64 flags)
+{
+ struct sock *sk = bpf_skc_lookup(skb, tuple, len, proto, netns_id,
+ flags);
+
+ if (sk)
+ sk = sk_to_full_sk(sk);
+
+ return sk;
+}
+
+BPF_CALL_5(bpf_skc_lookup_tcp, struct sk_buff *, skb,
+ struct bpf_sock_tuple *, tuple, u32, len, u64, netns_id, u64, flags)
+{
+ return (unsigned long)bpf_skc_lookup(skb, tuple, len, IPPROTO_TCP,
+ netns_id, flags);
+}
+
+static const struct bpf_func_proto bpf_skc_lookup_tcp_proto = {
+ .func = bpf_skc_lookup_tcp,
+ .gpl_only = false,
+ .pkt_access = true,
+ .ret_type = RET_PTR_TO_SOCK_COMMON_OR_NULL,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_PTR_TO_MEM,
+ .arg3_type = ARG_CONST_SIZE,
+ .arg4_type = ARG_ANYTHING,
+ .arg5_type = ARG_ANYTHING,
+};
+
BPF_CALL_5(bpf_sk_lookup_tcp, struct sk_buff *, skb,
struct bpf_sock_tuple *, tuple, u32, len, u64, netns_id, u64, flags)
{
- return bpf_sk_lookup(skb, tuple, len, IPPROTO_TCP, netns_id, flags);
+ return (unsigned long)bpf_sk_lookup(skb, tuple, len, IPPROTO_TCP,
+ netns_id, flags);
}
static const struct bpf_func_proto bpf_sk_lookup_tcp_proto = {
@@ -5238,7 +5283,8 @@ static const struct bpf_func_proto bpf_sk_lookup_tcp_proto = {
BPF_CALL_5(bpf_sk_lookup_udp, struct sk_buff *, skb,
struct bpf_sock_tuple *, tuple, u32, len, u64, netns_id, u64, flags)
{
- return bpf_sk_lookup(skb, tuple, len, IPPROTO_UDP, netns_id, flags);
+ return (unsigned long)bpf_sk_lookup(skb, tuple, len, IPPROTO_UDP,
+ netns_id, flags);
}
static const struct bpf_func_proto bpf_sk_lookup_udp_proto = {
@@ -5273,8 +5319,9 @@ BPF_CALL_5(bpf_xdp_sk_lookup_udp, struct xdp_buff *, ctx,
struct net *caller_net = dev_net(ctx->rxq->dev);
int ifindex = ctx->rxq->dev->ifindex;
- return __bpf_sk_lookup(NULL, tuple, len, caller_net, ifindex,
- IPPROTO_UDP, netns_id, flags);
+ return (unsigned long)__bpf_sk_lookup(NULL, tuple, len, caller_net,
+ ifindex, IPPROTO_UDP, netns_id,
+ flags);
}
static const struct bpf_func_proto bpf_xdp_sk_lookup_udp_proto = {
@@ -5289,14 +5336,38 @@ static const struct bpf_func_proto bpf_xdp_sk_lookup_udp_proto = {
.arg5_type = ARG_ANYTHING,
};
+BPF_CALL_5(bpf_xdp_skc_lookup_tcp, struct xdp_buff *, ctx,
+ struct bpf_sock_tuple *, tuple, u32, len, u32, netns_id, u64, flags)
+{
+ struct net *caller_net = dev_net(ctx->rxq->dev);
+ int ifindex = ctx->rxq->dev->ifindex;
+
+ return (unsigned long)__bpf_skc_lookup(NULL, tuple, len, caller_net,
+ ifindex, IPPROTO_TCP, netns_id,
+ flags);
+}
+
+static const struct bpf_func_proto bpf_xdp_skc_lookup_tcp_proto = {
+ .func = bpf_xdp_skc_lookup_tcp,
+ .gpl_only = false,
+ .pkt_access = true,
+ .ret_type = RET_PTR_TO_SOCK_COMMON_OR_NULL,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_PTR_TO_MEM,
+ .arg3_type = ARG_CONST_SIZE,
+ .arg4_type = ARG_ANYTHING,
+ .arg5_type = ARG_ANYTHING,
+};
+
BPF_CALL_5(bpf_xdp_sk_lookup_tcp, struct xdp_buff *, ctx,
struct bpf_sock_tuple *, tuple, u32, len, u32, netns_id, u64, flags)
{
struct net *caller_net = dev_net(ctx->rxq->dev);
int ifindex = ctx->rxq->dev->ifindex;
- return __bpf_sk_lookup(NULL, tuple, len, caller_net, ifindex,
- IPPROTO_TCP, netns_id, flags);
+ return (unsigned long)__bpf_sk_lookup(NULL, tuple, len, caller_net,
+ ifindex, IPPROTO_TCP, netns_id,
+ flags);
}
static const struct bpf_func_proto bpf_xdp_sk_lookup_tcp_proto = {
@@ -5311,11 +5382,31 @@ static const struct bpf_func_proto bpf_xdp_sk_lookup_tcp_proto = {
.arg5_type = ARG_ANYTHING,
};
+BPF_CALL_5(bpf_sock_addr_skc_lookup_tcp, struct bpf_sock_addr_kern *, ctx,
+ struct bpf_sock_tuple *, tuple, u32, len, u64, netns_id, u64, flags)
+{
+ return (unsigned long)__bpf_skc_lookup(NULL, tuple, len,
+ sock_net(ctx->sk), 0,
+ IPPROTO_TCP, netns_id, flags);
+}
+
+static const struct bpf_func_proto bpf_sock_addr_skc_lookup_tcp_proto = {
+ .func = bpf_sock_addr_skc_lookup_tcp,
+ .gpl_only = false,
+ .ret_type = RET_PTR_TO_SOCK_COMMON_OR_NULL,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_PTR_TO_MEM,
+ .arg3_type = ARG_CONST_SIZE,
+ .arg4_type = ARG_ANYTHING,
+ .arg5_type = ARG_ANYTHING,
+};
+
BPF_CALL_5(bpf_sock_addr_sk_lookup_tcp, struct bpf_sock_addr_kern *, ctx,
struct bpf_sock_tuple *, tuple, u32, len, u64, netns_id, u64, flags)
{
- return __bpf_sk_lookup(NULL, tuple, len, sock_net(ctx->sk), 0,
- IPPROTO_TCP, netns_id, flags);
+ return (unsigned long)__bpf_sk_lookup(NULL, tuple, len,
+ sock_net(ctx->sk), 0, IPPROTO_TCP,
+ netns_id, flags);
}
static const struct bpf_func_proto bpf_sock_addr_sk_lookup_tcp_proto = {
@@ -5332,8 +5423,9 @@ static const struct bpf_func_proto bpf_sock_addr_sk_lookup_tcp_proto = {
BPF_CALL_5(bpf_sock_addr_sk_lookup_udp, struct bpf_sock_addr_kern *, ctx,
struct bpf_sock_tuple *, tuple, u32, len, u64, netns_id, u64, flags)
{
- return __bpf_sk_lookup(NULL, tuple, len, sock_net(ctx->sk), 0,
- IPPROTO_UDP, netns_id, flags);
+ return (unsigned long)__bpf_sk_lookup(NULL, tuple, len,
+ sock_net(ctx->sk), 0, IPPROTO_UDP,
+ netns_id, flags);
}
static const struct bpf_func_proto bpf_sock_addr_sk_lookup_udp_proto = {
@@ -5586,6 +5678,8 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_sock_addr_sk_lookup_udp_proto;
case BPF_FUNC_sk_release:
return &bpf_sk_release_proto;
+ case BPF_FUNC_skc_lookup_tcp:
+ return &bpf_sock_addr_skc_lookup_tcp_proto;
#endif /* CONFIG_INET */
default:
return bpf_base_func_proto(func_id);
@@ -5719,6 +5813,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_tcp_sock_proto;
case BPF_FUNC_get_listener_sock:
return &bpf_get_listener_sock_proto;
+ case BPF_FUNC_skc_lookup_tcp:
+ return &bpf_skc_lookup_tcp_proto;
#endif
default:
return bpf_base_func_proto(func_id);
@@ -5754,6 +5850,8 @@ xdp_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_xdp_sk_lookup_tcp_proto;
case BPF_FUNC_sk_release:
return &bpf_sk_release_proto;
+ case BPF_FUNC_skc_lookup_tcp:
+ return &bpf_xdp_skc_lookup_tcp_proto;
#endif
default:
return bpf_base_func_proto(func_id);
@@ -5846,6 +5944,8 @@ sk_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_sk_lookup_udp_proto;
case BPF_FUNC_sk_release:
return &bpf_sk_release_proto;
+ case BPF_FUNC_skc_lookup_tcp:
+ return &bpf_skc_lookup_tcp_proto;
#endif
default:
return bpf_base_func_proto(func_id);
--
2.19.1
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