[RFC PATCH 09/16] bpf/crib: Add CRIB kfuncs for getting socket source/destination addresses

[Juntong Deng]

This patch adds CRIB kfuncs for getting socket source/destination
addresses, which are wrappers for inet_getname() and inet6_getname().

Signed-off-by: Juntong Deng <juntong.deng@xxxxxxxxxxx>
---
 kernel/bpf/crib/bpf_checkpoint.c | 50 ++++++++++++++++++++++++++++++++
 kernel/bpf/crib/bpf_crib.c       |  5 ++++
 2 files changed, 55 insertions(+)

diff --git a/kernel/bpf/crib/bpf_checkpoint.c b/kernel/bpf/crib/bpf_checkpoint.c
index 28ad26986053..4d48f08324ef 100644
--- a/kernel/bpf/crib/bpf_checkpoint.c
+++ b/kernel/bpf/crib/bpf_checkpoint.c
@@ -8,6 +8,8 @@
 
 #include <linux/bpf_crib.h>
 #include <linux/fdtable.h>
+#include <net/inet_common.h>
+#include <net/ipv6.h>
 
 extern void bpf_file_release(struct file *file);
 
@@ -98,4 +100,52 @@ __bpf_kfunc void bpf_iter_task_file_destroy(struct bpf_iter_task_file *it)
 		bpf_file_release(kit->file);
 }
 
+/**
+ * bpf_inet_src_addr_from_socket() - Wrap inet_getname to get the source
+ * IPv4 address and source port of the specified socket
+ *
+ * @sock: specified socket
+ * @addr: buffer
+ */
+__bpf_kfunc int bpf_inet_src_addr_from_socket(struct socket *sock, struct sockaddr_in *addr)
+{
+	return inet_getname(sock, (struct sockaddr *)addr, 0);
+}
+
+/**
+ * bpf_inet_dst_addr_from_socket() - Wrap inet_getname to get the destination
+ * IPv4 address and destination port of the specified socket
+ *
+ * @sock: specified socket
+ * @addr: buffer
+ */
+__bpf_kfunc int bpf_inet_dst_addr_from_socket(struct socket *sock, struct sockaddr_in *addr)
+{
+	return inet_getname(sock, (struct sockaddr *)addr, 1);
+}
+
+/**
+ * bpf_inet6_src_addr_from_socket() - Wrap inet6_getname to get the source
+ * IPv6 address and source port of the specified socket
+ *
+ * @sock: specified socket
+ * @addr: buffer
+ */
+__bpf_kfunc int bpf_inet6_src_addr_from_socket(struct socket *sock, struct sockaddr_in6 *addr)
+{
+	return inet6_getname(sock, (struct sockaddr *)addr, 0);
+}
+
+/**
+ * bpf_inet6_dst_addr_from_socket() - Wrap inet6_getname to get the destination
+ * IPv6 address and destination port of the specified socket
+ *
+ * @sock: specified socket
+ * @addr: buffer
+ */
+__bpf_kfunc int bpf_inet6_dst_addr_from_socket(struct socket *sock, struct sockaddr_in6 *addr)
+{
+	return inet6_getname(sock, (struct sockaddr *)addr, 1);
+}
+
 __bpf_kfunc_end_defs();
diff --git a/kernel/bpf/crib/bpf_crib.c b/kernel/bpf/crib/bpf_crib.c
index da545f55b4eb..e33fa37f8f72 100644
--- a/kernel/bpf/crib/bpf_crib.c
+++ b/kernel/bpf/crib/bpf_crib.c
@@ -234,6 +234,11 @@ BTF_ID_FLAGS(func, bpf_receive_queue_from_sock, KF_OBTAIN)
 BTF_ID_FLAGS(func, bpf_write_queue_from_sock, KF_OBTAIN)
 BTF_ID_FLAGS(func, bpf_reader_queue_from_udp_sock, KF_OBTAIN)
 
+BTF_ID_FLAGS(func, bpf_inet_src_addr_from_socket, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_inet_dst_addr_from_socket, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_inet6_src_addr_from_socket, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_inet6_dst_addr_from_socket, KF_TRUSTED_ARGS)
+
 BTF_KFUNCS_END(bpf_crib_kfuncs)
 
 static int bpf_prog_run_crib(struct bpf_prog *prog,
-- 
2.39.2