selftests/bpf: Test [::] -> [::1] rewrite in sys_sendmsg in test_sock_addr

Test that sys_sendmsg BPF hook doesn't break sys_sendmsg behaviour to
rewrite destination IPv6 = [::] with [::1] (BSD'ism).

Two test cases are added:

1) User passes dst IPv6 = [::] and BPF_CGROUP_UDP6_SENDMSG program
   doesn't touch it.

2) User passes dst IPv6 != [::], but BPF_CGROUP_UDP6_SENDMSG program
   rewrites it with [::].

In both cases [::1] is used by sys_sendmsg code eventually and datagram
is sent successfully for unconnected UDP socket.

Example of relevant output:
  Test case: sendmsg6: set dst IP = [::] (BSD'ism) .. [PASS]
  Test case: sendmsg6: preserve dst IP = [::] (BSD'ism) .. [PASS]

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Andrey Ignatov 2019-01-04 01:07:08 -08:00 committed by Alexei Starovoitov
parent e8e3698408
commit 976b4f3a46

View File

@ -44,6 +44,7 @@
#define SERV6_V4MAPPED_IP "::ffff:192.168.0.4"
#define SRC6_IP "::1"
#define SRC6_REWRITE_IP "::6"
#define WILDCARD6_IP "::"
#define SERV6_PORT 6060
#define SERV6_REWRITE_PORT 6666
@ -85,12 +86,14 @@ static int bind4_prog_load(const struct sock_addr_test *test);
static int bind6_prog_load(const struct sock_addr_test *test);
static int connect4_prog_load(const struct sock_addr_test *test);
static int connect6_prog_load(const struct sock_addr_test *test);
static int sendmsg_allow_prog_load(const struct sock_addr_test *test);
static int sendmsg_deny_prog_load(const struct sock_addr_test *test);
static int sendmsg4_rw_asm_prog_load(const struct sock_addr_test *test);
static int sendmsg4_rw_c_prog_load(const struct sock_addr_test *test);
static int sendmsg6_rw_asm_prog_load(const struct sock_addr_test *test);
static int sendmsg6_rw_c_prog_load(const struct sock_addr_test *test);
static int sendmsg6_rw_v4mapped_prog_load(const struct sock_addr_test *test);
static int sendmsg6_rw_wildcard_prog_load(const struct sock_addr_test *test);
static struct sock_addr_test tests[] = {
/* bind */
@ -462,6 +465,34 @@ static struct sock_addr_test tests[] = {
SRC6_REWRITE_IP,
SYSCALL_ENOTSUPP,
},
{
"sendmsg6: set dst IP = [::] (BSD'ism)",
sendmsg6_rw_wildcard_prog_load,
BPF_CGROUP_UDP6_SENDMSG,
BPF_CGROUP_UDP6_SENDMSG,
AF_INET6,
SOCK_DGRAM,
SERV6_IP,
SERV6_PORT,
SERV6_REWRITE_IP,
SERV6_REWRITE_PORT,
SRC6_REWRITE_IP,
SUCCESS,
},
{
"sendmsg6: preserve dst IP = [::] (BSD'ism)",
sendmsg_allow_prog_load,
BPF_CGROUP_UDP6_SENDMSG,
BPF_CGROUP_UDP6_SENDMSG,
AF_INET6,
SOCK_DGRAM,
WILDCARD6_IP,
SERV6_PORT,
SERV6_REWRITE_IP,
SERV6_PORT,
SRC6_IP,
SUCCESS,
},
{
"sendmsg6: deny call",
sendmsg_deny_prog_load,
@ -734,16 +765,27 @@ static int connect6_prog_load(const struct sock_addr_test *test)
return load_path(test, CONNECT6_PROG_PATH);
}
static int sendmsg_deny_prog_load(const struct sock_addr_test *test)
static int sendmsg_ret_only_prog_load(const struct sock_addr_test *test,
int32_t rc)
{
struct bpf_insn insns[] = {
/* return 0 */
BPF_MOV64_IMM(BPF_REG_0, 0),
/* return rc */
BPF_MOV64_IMM(BPF_REG_0, rc),
BPF_EXIT_INSN(),
};
return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn));
}
static int sendmsg_allow_prog_load(const struct sock_addr_test *test)
{
return sendmsg_ret_only_prog_load(test, /*rc*/ 1);
}
static int sendmsg_deny_prog_load(const struct sock_addr_test *test)
{
return sendmsg_ret_only_prog_load(test, /*rc*/ 0);
}
static int sendmsg4_rw_asm_prog_load(const struct sock_addr_test *test)
{
struct sockaddr_in dst4_rw_addr;
@ -864,6 +906,11 @@ static int sendmsg6_rw_v4mapped_prog_load(const struct sock_addr_test *test)
return sendmsg6_rw_dst_asm_prog_load(test, SERV6_V4MAPPED_IP);
}
static int sendmsg6_rw_wildcard_prog_load(const struct sock_addr_test *test)
{
return sendmsg6_rw_dst_asm_prog_load(test, WILDCARD6_IP);
}
static int sendmsg6_rw_c_prog_load(const struct sock_addr_test *test)
{
return load_path(test, SENDMSG6_PROG_PATH);