[PATCH v3 28/36] selftest/net: Add TCP-AO ICMPs accept test

Reverse to icmps-discard test: the server accepts ICMPs, using
TCP_AO_CMDF_ACCEPT_ICMP and it is expected to fail under ICMP
flood from client. Test that the default pre-TCP-AO behaviour functions
when TCP_AO_CMDF_ACCEPT_ICMP is set.

Expected output for ipv4 version (in case it receives ICMP_PROT_UNREACH):

# ./icmps-accept_ipv4
1..3
# 3209[lib/setup.c:166] rand seed 1642623870
TAP version 13
# 3209[lib/proc.c:207]    Snmp6             Ip6InReceives: 0 => 1
# 3209[lib/proc.c:207]    Snmp6             Ip6InNoRoutes: 0 => 1
# 3209[lib/proc.c:207]    Snmp6               Ip6InOctets: 0 => 76
# 3209[lib/proc.c:207]    Snmp6            Ip6InNoECTPkts: 0 => 1
# 3209[lib/proc.c:207]      Tcp                    InSegs: 3 => 23
# 3209[lib/proc.c:207]      Tcp                   OutSegs: 2 => 22
# 3209[lib/proc.c:207]  IcmpMsg                   InType3: 0 => 4
# 3209[lib/proc.c:207]     Icmp                    InMsgs: 0 => 4
# 3209[lib/proc.c:207]     Icmp            InDestUnreachs: 0 => 4
# 3209[lib/proc.c:207]       Ip                InReceives: 3 => 27
# 3209[lib/proc.c:207]       Ip                InDelivers: 3 => 27
# 3209[lib/proc.c:207]       Ip               OutRequests: 2 => 22
# 3209[lib/proc.c:207]    IpExt                  InOctets: 288 => 3420
# 3209[lib/proc.c:207]    IpExt                 OutOctets: 124 => 3244
# 3209[lib/proc.c:207]    IpExt               InNoECTPkts: 3 => 25
# 3209[lib/proc.c:207]   TcpExt               TCPPureAcks: 1 => 2
# 3209[lib/proc.c:207]   TcpExt           TCPOrigDataSent: 0 => 20
# 3209[lib/proc.c:207]   TcpExt              TCPDelivered: 0 => 19
# 3209[lib/proc.c:207]   TcpExt                 TCPAOGood: 3 => 23
ok 1 InDestUnreachs delivered 4
ok 2 server failed with -92: Protocol not available
ok 3 TCPAODroppedIcmps counter didn't change: 0 >= 0
# Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0

Expected output for ipv6 version (in case it receives ADM_PROHIBITED):

# ./icmps-accept_ipv6
1..3
# 3277[lib/setup.c:166] rand seed 1642624035
TAP version 13
# 3277[lib/proc.c:207]    Snmp6             Ip6InReceives: 6 => 31
# 3277[lib/proc.c:207]    Snmp6             Ip6InDelivers: 4 => 29
# 3277[lib/proc.c:207]    Snmp6            Ip6OutRequests: 4 => 24
# 3277[lib/proc.c:207]    Snmp6               Ip6InOctets: 592 => 4492
# 3277[lib/proc.c:207]    Snmp6              Ip6OutOctets: 332 => 3852
# 3277[lib/proc.c:207]    Snmp6            Ip6InNoECTPkts: 6 => 31
# 3277[lib/proc.c:207]    Snmp6               Icmp6InMsgs: 1 => 6
# 3277[lib/proc.c:207]    Snmp6       Icmp6InDestUnreachs: 0 => 5
# 3277[lib/proc.c:207]    Snmp6              Icmp6InType1: 0 => 5
# 3277[lib/proc.c:207]      Tcp                    InSegs: 3 => 23
# 3277[lib/proc.c:207]      Tcp                   OutSegs: 2 => 22
# 3277[lib/proc.c:207]   TcpExt               TCPPureAcks: 1 => 2
# 3277[lib/proc.c:207]   TcpExt           TCPOrigDataSent: 0 => 20
# 3277[lib/proc.c:207]   TcpExt              TCPDelivered: 0 => 19
# 3277[lib/proc.c:207]   TcpExt                 TCPAOGood: 3 => 23
ok 1 Icmp6InDestUnreachs delivered 5
ok 2 server failed with -13: Permission denied
ok 3 TCPAODroppedIcmps counter didn't change: 0 >= 0
# Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0

With some luck the server may fail with ECONNREFUSED (depending on what
icmp packet was delivered firstly).
For the kernel error handlers see: tab_unreach[] and icmp_err_convert[].

Signed-off-by: Dmitry Safonov <redacted>
---
 tools/testing/selftests/net/tcp_ao/Makefile     |  4 +++-
 .../testing/selftests/net/tcp_ao/icmps-accept.c |  1 +
 .../selftests/net/tcp_ao/icmps-discard.c        | 17 +++++++++++++++--
 3 files changed, 19 insertions(+), 3 deletions(-)
 create mode 120000 tools/testing/selftests/net/tcp_ao/icmps-accept.c

diff --git a/tools/testing/selftests/net/tcp_ao/Makefile b/tools/testing/selftests/net/tcp_ao/Makefile
index 9acfd782c20f..a178bde0af08 100644
--- a/tools/testing/selftests/net/tcp_ao/Makefile
+++ b/tools/testing/selftests/net/tcp_ao/Makefile

@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
-TEST_BOTH_AF := connect icmps-discard
+TEST_BOTH_AF := connect icmps-discard icmps-accept
 
 TEST_IPV4_PROGS := $(TEST_BOTH_AF:%=%_ipv4)
 TEST_IPV6_PROGS := $(TEST_BOTH_AF:%=%_ipv6)

@@ -43,3 +43,5 @@ $(OUTPUT)/%_ipv4: %.c
 $(OUTPUT)/%_ipv6: %.c
 	$(LINK.c) -DIPV6_TEST $^ $(LDLIBS) -o $@
 
+$(OUTPUT)/icmps-accept_ipv4: CFLAGS+= -DTEST_ICMPS_ACCEPT
+$(OUTPUT)/icmps-accept_ipv6: CFLAGS+= -DTEST_ICMPS_ACCEPT

diff --git a/tools/testing/selftests/net/tcp_ao/icmps-accept.c b/tools/testing/selftests/net/tcp_ao/icmps-accept.c
new file mode 120000
index 000000000000..0a5bb85eb260
--- /dev/null
+++ b/tools/testing/selftests/net/tcp_ao/icmps-accept.c

@@ -0,0 +1 @@
+icmps-discard.c

\ No newline at end of file

diff --git a/tools/testing/selftests/net/tcp_ao/icmps-discard.c b/tools/testing/selftests/net/tcp_ao/icmps-discard.c
index 07eba1308b4e..d90017dfc20d 100644
--- a/tools/testing/selftests/net/tcp_ao/icmps-discard.c
+++ b/tools/testing/selftests/net/tcp_ao/icmps-discard.c

@@ -43,8 +43,17 @@ const int sk_ip_level	= SOL_IP;
 const int sk_recverr	= IP_RECVERR;
 #endif
 
-#define test_icmps_fail test_fail
-#define test_icmps_ok test_ok
+/*
+ * Server is expected to fail with hard error if
+ * TCP_AO_CMDF_ACCEPT_ICMP is set
+ */
+#ifdef TEST_ICMPS_ACCEPT
+# define test_icmps_fail test_ok
+# define test_icmps_ok test_fail
+#else
+# define test_icmps_fail test_fail
+# define test_icmps_ok test_ok
+#endif
 
 static void serve_interfered(int sk)
 {

@@ -98,6 +107,10 @@ static void *server_fn(void *arg)
 
 	lsk = test_listen_socket(this_ip_addr, test_server_port, 1);
 
+#ifdef TEST_ICMPS_ACCEPT
+	flags = TCP_AO_CMDF_ACCEPT_ICMP;
+#endif
+
 	if (test_set_ao(lsk, "password", flags, this_ip_dest, -1, 100, 100))
 		test_error("setsockopt(TCP_AO)");
 	synchronize_threads();

-- 
2.38.1