bpf, testing: Add get{peer, sock}name selftests to test_progs

Extend the existing connect_force_port test to assert get{peer,sock}name programs
as well. The workflow for e.g. IPv4 is as follows: i) server binds to concrete
port, ii) client calls getsockname() on server fd which exposes 1.2.3.4:60000 to
client, iii) client connects to service address 1.2.3.4:60000 binds to concrete
local address (127.0.0.1:22222) and remaps service address to a concrete backend
address (127.0.0.1:60123), iv) client then calls getsockname() on its own fd to
verify local address (127.0.0.1:22222) and getpeername() on its own fd which then
publishes service address (1.2.3.4:60000) instead of actual backend. Same workflow
is done for IPv6 just with different address/port tuples.

  # ./test_progs -t connect_force_port
  #14 connect_force_port:OK
  Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Link: https://lore.kernel.org/bpf/3343da6ad08df81af715a95d61a84fb4a960f2bf.1589841594.git.daniel@iogearbox.net

1 files changed, 10 insertions, 1 deletions

diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
index 999a775484c1..e36dd1a1780d 100644
--- a/tools/testing/selftests/bpf/network_helpers.c
+++ b/tools/testing/selftests/bpf/network_helpers.c
@@ -5,6 +5,8 @@
 #include <string.h>
 #include <unistd.h>
 
+#include <arpa/inet.h>
+
 #include <sys/epoll.h>
 
 #include <linux/err.h>
@@ -35,7 +37,7 @@ struct ipv6_packet pkt_v6 = {
 	.tcp.doff = 5,
 };
 
-int start_server(int family, int type)
+int start_server_with_port(int family, int type, __u16 port)
 {
 	struct sockaddr_storage addr = {};
 	socklen_t len;
@@ -45,11 +47,13 @@ int start_server(int family, int type)
 		struct sockaddr_in *sin = (void *)&addr;
 
 		sin->sin_family = AF_INET;
+		sin->sin_port = htons(port);
 		len = sizeof(*sin);
 	} else {
 		struct sockaddr_in6 *sin6 = (void *)&addr;
 
 		sin6->sin6_family = AF_INET6;
+		sin6->sin6_port = htons(port);
 		len = sizeof(*sin6);
 	}
 
@@ -76,6 +80,11 @@ int start_server(int family, int type)
 	return fd;
 }
 
+int start_server(int family, int type)
+{
+	return start_server_with_port(family, type, 0);
+}
+
 static const struct timeval timeo_sec = { .tv_sec = 3 };
 static const size_t timeo_optlen = sizeof(timeo_sec);