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-rw-r--r--include/linux/bpf.h1
-rw-r--r--include/net/net_namespace.h10
-rw-r--r--include/uapi/linux/bpf.h16
-rw-r--r--kernel/bpf/verifier.c16
-rw-r--r--net/core/filter.c37
-rw-r--r--net/core/net_namespace.c15
-rw-r--r--tools/include/uapi/linux/bpf.h16
7 files changed, 103 insertions, 8 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index bdb981c204fa..78046c570596 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -233,6 +233,7 @@ enum bpf_arg_type {
ARG_CONST_SIZE_OR_ZERO, /* number of bytes accessed from memory or 0 */
ARG_PTR_TO_CTX, /* pointer to context */
+ ARG_PTR_TO_CTX_OR_NULL, /* pointer to context or NULL */
ARG_ANYTHING, /* any (initialized) argument is ok */
ARG_PTR_TO_SPIN_LOCK, /* pointer to bpf_spin_lock */
ARG_PTR_TO_SOCK_COMMON, /* pointer to sock_common */
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 854d39ef1ca3..1c6edfdb9a2c 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -168,6 +168,9 @@ struct net {
#ifdef CONFIG_XFRM
struct netns_xfrm xfrm;
#endif
+
+ atomic64_t net_cookie; /* written once */
+
#if IS_ENABLED(CONFIG_IP_VS)
struct netns_ipvs *ipvs;
#endif
@@ -273,6 +276,8 @@ static inline int check_net(const struct net *net)
void net_drop_ns(void *);
+u64 net_gen_cookie(struct net *net);
+
#else
static inline struct net *get_net(struct net *net)
@@ -300,6 +305,11 @@ static inline int check_net(const struct net *net)
return 1;
}
+static inline u64 net_gen_cookie(struct net *net)
+{
+ return 0;
+}
+
#define net_drop_ns NULL
#endif
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 5d01c5c7e598..bd81c4555206 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -2950,6 +2950,19 @@ union bpf_attr {
* restricted to raw_tracepoint bpf programs.
* Return
* 0 on success, or a negative error in case of failure.
+ *
+ * u64 bpf_get_netns_cookie(void *ctx)
+ * Description
+ * Retrieve the cookie (generated by the kernel) of the network
+ * namespace the input *ctx* is associated with. The network
+ * namespace cookie remains stable for its lifetime and provides
+ * a global identifier that can be assumed unique. If *ctx* is
+ * NULL, then the helper returns the cookie for the initial
+ * network namespace. The cookie itself is very similar to that
+ * of bpf_get_socket_cookie() helper, but for network namespaces
+ * instead of sockets.
+ * Return
+ * A 8-byte long opaque number.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -3073,7 +3086,8 @@ union bpf_attr {
FN(jiffies64), \
FN(read_branch_records), \
FN(get_ns_current_pid_tgid), \
- FN(xdp_output),
+ FN(xdp_output), \
+ FN(get_netns_cookie),
/* 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 2ea2a868324e..46ba86c540e2 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3461,13 +3461,17 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
expected_type = CONST_PTR_TO_MAP;
if (type != expected_type)
goto err_type;
- } else if (arg_type == ARG_PTR_TO_CTX) {
+ } else if (arg_type == ARG_PTR_TO_CTX ||
+ arg_type == ARG_PTR_TO_CTX_OR_NULL) {
expected_type = PTR_TO_CTX;
- if (type != expected_type)
- goto err_type;
- err = check_ctx_reg(env, reg, regno);
- if (err < 0)
- return err;
+ if (!(register_is_null(reg) &&
+ arg_type == ARG_PTR_TO_CTX_OR_NULL)) {
+ if (type != expected_type)
+ goto err_type;
+ err = check_ctx_reg(env, reg, regno);
+ if (err < 0)
+ return err;
+ }
} else if (arg_type == ARG_PTR_TO_SOCK_COMMON) {
expected_type = PTR_TO_SOCK_COMMON;
/* Any sk pointer can be ARG_PTR_TO_SOCK_COMMON */
diff --git a/net/core/filter.c b/net/core/filter.c
index 6cb7e0e24473..e249a499cbe5 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4141,6 +4141,39 @@ static const struct bpf_func_proto bpf_get_socket_cookie_sock_ops_proto = {
.arg1_type = ARG_PTR_TO_CTX,
};
+static u64 __bpf_get_netns_cookie(struct sock *sk)
+{
+#ifdef CONFIG_NET_NS
+ return net_gen_cookie(sk ? sk->sk_net.net : &init_net);
+#else
+ return 0;
+#endif
+}
+
+BPF_CALL_1(bpf_get_netns_cookie_sock, struct sock *, ctx)
+{
+ return __bpf_get_netns_cookie(ctx);
+}
+
+static const struct bpf_func_proto bpf_get_netns_cookie_sock_proto = {
+ .func = bpf_get_netns_cookie_sock,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX_OR_NULL,
+};
+
+BPF_CALL_1(bpf_get_netns_cookie_sock_addr, struct bpf_sock_addr_kern *, ctx)
+{
+ return __bpf_get_netns_cookie(ctx ? ctx->sk : NULL);
+}
+
+static const struct bpf_func_proto bpf_get_netns_cookie_sock_addr_proto = {
+ .func = bpf_get_netns_cookie_sock_addr,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX_OR_NULL,
+};
+
BPF_CALL_1(bpf_get_socket_uid, struct sk_buff *, skb)
{
struct sock *sk = sk_to_full_sk(skb->sk);
@@ -5968,6 +6001,8 @@ sock_filter_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_get_local_storage_proto;
case BPF_FUNC_get_socket_cookie:
return &bpf_get_socket_cookie_sock_proto;
+ case BPF_FUNC_get_netns_cookie:
+ return &bpf_get_netns_cookie_sock_proto;
case BPF_FUNC_perf_event_output:
return &bpf_event_output_data_proto;
default:
@@ -5994,6 +6029,8 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
}
case BPF_FUNC_get_socket_cookie:
return &bpf_get_socket_cookie_sock_addr_proto;
+ case BPF_FUNC_get_netns_cookie:
+ return &bpf_get_netns_cookie_sock_addr_proto;
case BPF_FUNC_get_local_storage:
return &bpf_get_local_storage_proto;
case BPF_FUNC_perf_event_output:
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 757cc1d084e7..190ca66a383b 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -69,6 +69,20 @@ EXPORT_SYMBOL_GPL(pernet_ops_rwsem);
static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
+static atomic64_t cookie_gen;
+
+u64 net_gen_cookie(struct net *net)
+{
+ while (1) {
+ u64 res = atomic64_read(&net->net_cookie);
+
+ if (res)
+ return res;
+ res = atomic64_inc_return(&cookie_gen);
+ atomic64_cmpxchg(&net->net_cookie, 0, res);
+ }
+}
+
static struct net_generic *net_alloc_generic(void)
{
struct net_generic *ng;
@@ -1087,6 +1101,7 @@ static int __init net_ns_init(void)
panic("Could not allocate generic netns");
rcu_assign_pointer(init_net.gen, ng);
+ net_gen_cookie(&init_net);
down_write(&pernet_ops_rwsem);
if (setup_net(&init_net, &init_user_ns))
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 5d01c5c7e598..bd81c4555206 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -2950,6 +2950,19 @@ union bpf_attr {
* restricted to raw_tracepoint bpf programs.
* Return
* 0 on success, or a negative error in case of failure.
+ *
+ * u64 bpf_get_netns_cookie(void *ctx)
+ * Description
+ * Retrieve the cookie (generated by the kernel) of the network
+ * namespace the input *ctx* is associated with. The network
+ * namespace cookie remains stable for its lifetime and provides
+ * a global identifier that can be assumed unique. If *ctx* is
+ * NULL, then the helper returns the cookie for the initial
+ * network namespace. The cookie itself is very similar to that
+ * of bpf_get_socket_cookie() helper, but for network namespaces
+ * instead of sockets.
+ * Return
+ * A 8-byte long opaque number.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -3073,7 +3086,8 @@ union bpf_attr {
FN(jiffies64), \
FN(read_branch_records), \
FN(get_ns_current_pid_tgid), \
- FN(xdp_output),
+ FN(xdp_output), \
+ FN(get_netns_cookie),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
generated by cgit (git 2.34.1) at 2024-05-29 05:12:27 +0000