[PATCH bpf-next v2 1/4] bpf: enable bpf_{g,s}etsockopt in BPF_CGROUP_UDP{4,6}_SENDMSG
From: Stanislav Fomichev <hidden>
Date: 2021-01-27 23:31:06
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [networking] (tcx & tc bpf, sock_addr), bpf [selftests] (test runners & infrastructure), kernel selftest framework, networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Shuah Khan, Shuah Khan, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <redacted> --- 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