Can be used to query/modify socket state for unconnected UDP sendmsg.
Those hooks run as BPF_CGROUP_RUN_SA_PROG_LOCK and operate on
a locked socket.
Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
---
net/core/filter.c | 4 ++++
.../selftests/bpf/bpf_sockopt_helpers.h | 21 +++++++++++++++++++
.../selftests/bpf/progs/sendmsg4_prog.c | 7 +++++++
.../selftests/bpf/progs/sendmsg6_prog.c | 5 +++++
4 files changed, 37 insertions(+)
create mode 100644 tools/testing/selftests/bpf/bpf_sockopt_helpers.h
diff --git a/net/core/filter.c b/net/core/filter.c
index 9ab94e90d660..3d7f78a19565 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -7023,6 +7023,8 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
case BPF_CGROUP_INET6_BIND:
case BPF_CGROUP_INET4_CONNECT:
case BPF_CGROUP_INET6_CONNECT:
+ case BPF_CGROUP_UDP4_SENDMSG:
+ case BPF_CGROUP_UDP6_SENDMSG:
return &bpf_sock_addr_setsockopt_proto;
default:
return NULL;
@@ -7033,6 +7035,8 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
case BPF_CGROUP_INET6_BIND:
case BPF_CGROUP_INET4_CONNECT:
case BPF_CGROUP_INET6_CONNECT:
+ case BPF_CGROUP_UDP4_SENDMSG:
+ case BPF_CGROUP_UDP6_SENDMSG:
return &bpf_sock_addr_getsockopt_proto;
default:
return NULL;
diff --git a/tools/testing/selftests/bpf/bpf_sockopt_helpers.h b/tools/testing/selftests/bpf/bpf_sockopt_helpers.h
new file mode 100644
index 000000000000..11f3a0976174
--- /dev/null
+++ b/tools/testing/selftests/bpf/bpf_sockopt_helpers.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <sys/socket.h>
+#include <bpf/bpf_helpers.h>
+
+int get_set_sk_priority(void *ctx)
+{
+ int prio;
+
+ /* Verify that context allows calling bpf_getsockopt and
+ * bpf_setsockopt by reading and writing back socket
+ * priority.
+ */
+
+ if (bpf_getsockopt(ctx, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio)))
+ return 0;
+ if (bpf_setsockopt(ctx, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio)))
+ return 0;
+
+ return 1;
+}
diff --git a/tools/testing/selftests/bpf/progs/sendmsg4_prog.c b/tools/testing/selftests/bpf/progs/sendmsg4_prog.c
index 092d9da536f3..ac5abc34cde8 100644
--- a/tools/testing/selftests/bpf/progs/sendmsg4_prog.c
+++ b/tools/testing/selftests/bpf/progs/sendmsg4_prog.c
@@ -8,6 +8,8 @@
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
+#include <bpf_sockopt_helpers.h>
+
#define SRC1_IP4 0xAC100001U /* 172.16.0.1 */
#define SRC2_IP4 0x00000000U
#define SRC_REWRITE_IP4 0x7f000004U
@@ -21,9 +23,14 @@ int _version SEC("version") = 1;
SEC("cgroup/sendmsg4")
int sendmsg_v4_prog(struct bpf_sock_addr *ctx)
{
+ int prio;
+
if (ctx->type != SOCK_DGRAM)
return 0;
+ if (!get_set_sk_priority(ctx))
+ return 0;
+
/* Rewrite source. */
if (ctx->msg_src_ip4 == bpf_htonl(SRC1_IP4) ||
ctx->msg_src_ip4 == bpf_htonl(SRC2_IP4)) {
diff --git a/tools/testing/selftests/bpf/progs/sendmsg6_prog.c b/tools/testing/selftests/bpf/progs/sendmsg6_prog.c
index 255a432bc163..24694b1a8d82 100644
--- a/tools/testing/selftests/bpf/progs/sendmsg6_prog.c
+++ b/tools/testing/selftests/bpf/progs/sendmsg6_prog.c
@@ -8,6 +8,8 @@
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
+#include <bpf_sockopt_helpers.h>
+
#define SRC_REWRITE_IP6_0 0
#define SRC_REWRITE_IP6_1 0
#define SRC_REWRITE_IP6_2 0
@@ -28,6 +30,9 @@ int sendmsg_v6_prog(struct bpf_sock_addr *ctx)
if (ctx->type != SOCK_DGRAM)
return 0;
+ if (!get_set_sk_priority(ctx))
+ return 0;
+
/* Rewrite source. */
if (ctx->msg_src_ip6[3] == bpf_htonl(1) ||
ctx->msg_src_ip6[3] == bpf_htonl(0)) {
--
2.30.0.280.ga3ce27912f-goog
