[PATCH bpf v5 09/12] bpf: sockmap, build helper to create connected socket pair

John Fastabend
2023-04-06T01:01:44Z

A common operation for testing is to spin up a pair of sockets that are
connected. Then we can use these to run specific tests that need to
send data, check BPF programs and so on.

The sockmap_listen programs already have this logic lets move it into
the new sockmap_helpers header file for general use.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
.../bpf/prog_tests/sockmap_helpers.h | 125 ++++++++++++++++++
.../selftests/bpf/prog_tests/sockmap_listen.c | 107 +--------------
2 files changed, 130 insertions(+), 102 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_helpers.h b/tools/testing/selftests/bpf/prog_tests/sockmap_helpers.h
index 08b7b76e4c90..eb0959bed893 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockmap_helpers.h
+++ b/tools/testing/selftests/bpf/prog_tests/sockmap_helpers.h
@@ -246,4 +246,129 @@ static inline struct sockaddr *sockaddr(struct sockaddr_storage *ss)
return (struct sockaddr *)ss;
}

+static inline int add_to_sockmap(int sock_mapfd, int fd1, int fd2)
+{
+ u64 value;
+ u32 key;
+ int err;
+
+ key = 0;
+ value = fd1;
+ err = xbpf_map_update_elem(sock_mapfd, &key, &value, BPF_NOEXIST);
+ if (err)
+ return err;
+
+ key = 1;
+ value = fd2;
+ return xbpf_map_update_elem(sock_mapfd, &key, &value, BPF_NOEXIST);
+}
+
+static inline int create_socket_pairs(int s, int family, int sotype,
+ int *c0, int *c1, int *p0, int *p1)
+{
+ struct sockaddr_storage addr;
+ socklen_t len;
+ int err = 0;
+
+ len = sizeof(addr);
+ err = xgetsockname(s, sockaddr(&addr), &len);
+ if (err)
+ return err;
+
+ *c0 = xsocket(family, sotype, 0);
+ if (*c0 < 0)
+ return errno;
+ err = xconnect(*c0, sockaddr(&addr), len);
+ if (err) {
+ err = errno;
+ goto close_cli0;
+ }
+
+ *p0 = xaccept_nonblock(s, NULL, NULL);
+ if (*p0 < 0) {
+ err = errno;
+ goto close_cli0;
+ }
+
+ *c1 = xsocket(family, sotype, 0);
+ if (*c1 < 0) {
+ err = errno;
+ goto close_peer0;
+ }
+ err = xconnect(*c1, sockaddr(&addr), len);
+ if (err) {
+ err = errno;
+ goto close_cli1;
+ }
+
+ *p1 = xaccept_nonblock(s, NULL, NULL);
+ if (*p1 < 0) {
+ err = errno;
+ goto close_peer1;
+ }
+ return err;
+close_peer1:
+ close(*p1);
+close_cli1:
+ close(*c1);
+close_peer0:
+ close(*p0);
+close_cli0:
+ close(*c0);
+ return err;
+}
+
+static inline int enable_reuseport(int s, int progfd)
+{
+ int err, one = 1;
+
+ err = xsetsockopt(s, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one));
+ if (err)
+ return -1;
+ err = xsetsockopt(s, SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF, &progfd,
+ sizeof(progfd));
+ if (err)
+ return -1;
+
+ return 0;
+}
+
+static inline int socket_loopback_reuseport(int family, int sotype, int progfd)
+{
+ struct sockaddr_storage addr;
+ socklen_t len;
+ int err, s;
+
+ init_addr_loopback(family, &addr, &len);
+
+ s = xsocket(family, sotype, 0);
+ if (s == -1)
+ return -1;
+
+ if (progfd >= 0)
+ enable_reuseport(s, progfd);
+
+ err = xbind(s, sockaddr(&addr), len);
+ if (err)
+ goto close;
+
+ if (sotype & SOCK_DGRAM)
+ return s;
+
+ err = xlisten(s, SOMAXCONN);
+ if (err)
+ goto close;
+
+ return s;
+close:
+ xclose(s);
+ return -1;
+}
+
+static inline int socket_loopback(int family, int sotype)
+{
+ return socket_loopback_reuseport(family, sotype, -1);
+}
+
+
#endif // __SOCKMAP_HELPERS__
diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_listen.c b/tools/testing/selftests/bpf/prog_tests/sockmap_listen.c
index 0f0cddd4e15e..f3913ba9e899 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockmap_listen.c
+++ b/tools/testing/selftests/bpf/prog_tests/sockmap_listen.c
@@ -28,58 +28,6 @@

#include "sockmap_helpers.h"

-static int enable_reuseport(int s, int progfd)
-{
- int err, one = 1;
-
- err = xsetsockopt(s, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one));
- if (err)
- return -1;
- err = xsetsockopt(s, SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF, &progfd,
- sizeof(progfd));
- if (err)
- return -1;
-
- return 0;
-}
-
-static int socket_loopback_reuseport(int family, int sotype, int progfd)
-{
- struct sockaddr_storage addr;
- socklen_t len;
- int err, s;
-
- init_addr_loopback(family, &addr, &len);
-
- s = xsocket(family, sotype, 0);
- if (s == -1)
- return -1;
-
- if (progfd >= 0)
- enable_reuseport(s, progfd);
-
- err = xbind(s, sockaddr(&addr), len);
- if (err)
- goto close;
-
- if (sotype & SOCK_DGRAM)
- return s;
-
- err = xlisten(s, SOMAXCONN);
- if (err)
- goto close;
-
- return s;
-close:
- xclose(s);
- return -1;
-}
-
-static int socket_loopback(int family, int sotype)
-{
- return socket_loopback_reuseport(family, sotype, -1);
-}
-
static void test_insert_invalid(struct test_sockmap_listen *skel __always_unused,
int family, int sotype, int mapfd)
{
@@ -722,31 +670,12 @@ static const char *redir_mode_str(enum redir_mode mode)
}
}

-static int add_to_sockmap(int sock_mapfd, int fd1, int fd2)
-{
- u64 value;
- u32 key;
- int err;
-
- key = 0;
- value = fd1;
- err = xbpf_map_update_elem(sock_mapfd, &key, &value, BPF_NOEXIST);
- if (err)
- return err;
-
- key = 1;
- value = fd2;
- return xbpf_map_update_elem(sock_mapfd, &key, &value, BPF_NOEXIST);
-}
-
static void redir_to_connected(int family, int sotype, int sock_mapfd,
int verd_mapfd, enum redir_mode mode)
{
const char *log_prefix = redir_mode_str(mode);
- struct sockaddr_storage addr;
int s, c0, c1, p0, p1;
unsigned int pass;
- socklen_t len;
int err, n;
u32 key;
char b;
@@ -757,36 +686,13 @@ static void redir_to_connected(int family, int sotype, int sock_mapfd,
if (s < 0)
return;

- len = sizeof(addr);
- err = xgetsockname(s, sockaddr(&addr), &len);
+ err = create_socket_pairs(s, family, sotype, &c0, &c1, &p0, &p1);
if (err)
goto close_srv;

- c0 = xsocket(family, sotype, 0);
- if (c0 < 0)
- goto close_srv;
- err = xconnect(c0, sockaddr(&addr), len);
- if (err)
- goto close_cli0;
-
- p0 = xaccept_nonblock(s, NULL, NULL);
- if (p0 < 0)
- goto close_cli0;
-
- c1 = xsocket(family, sotype, 0);
- if (c1 < 0)
- goto close_peer0;
- err = xconnect(c1, sockaddr(&addr), len);
- if (err)
- goto close_cli1;
-
- p1 = xaccept_nonblock(s, NULL, NULL);
- if (p1 < 0)
- goto close_cli1;
-
err = add_to_sockmap(sock_mapfd, p0, p1);
if (err)
- goto close_peer1;
+ goto close;

n = write(mode == REDIR_INGRESS ? c1 : p1, "a", 1);
if (n < 0)
@@ -794,12 +700,12 @@ static void redir_to_connected(int family, int sotype, int sock_mapfd,
if (n == 0)
FAIL("%s: incomplete write", log_prefix);
if (n < 1)
- goto close_peer1;
+ goto close;

key = SK_PASS;
err = xbpf_map_lookup_elem(verd_mapfd, &key, &pass);
if (err)
- goto close_peer1;
+ goto close;
if (pass != 1)
FAIL("%s: want pass count 1, have %d", log_prefix, pass);
n = recv_timeout(c0, &b, 1, 0, IO_TIMEOUT_SEC);
@@ -808,13 +714,10 @@ static void redir_to_connected(int family, int sotype, int sock_mapfd,
if (n == 0)
FAIL("%s: incomplete recv", log_prefix);

-close_peer1:
+close:
xclose(p1);
-close_cli1:
xclose(c1);
-close_peer0:
xclose(p0);
-close_cli0:
xclose(c0);
close_srv:
xclose(s);
--
2.33.0