[bpf-next,v2,3/6] selftests/bpf: move open_tuntap to network helpers

Commit Message

Marcus Wichelmann Feb. 17, 2025, 5:23 p.m. UTC

To test the XDP metadata functionality of the tun driver, it's necessary
to create a new tap device first. A helper function for this already
exists in lwt_helpers.h. Move it to the common network helpers header,
so it can be reused in other tests.

Signed-off-by: Marcus Wichelmann <[e-mail]>
---
 tools/testing/selftests/bpf/network_helpers.c | 28 ++++++++++++++++++
 tools/testing/selftests/bpf/network_helpers.h |  3 ++
 .../selftests/bpf/prog_tests/lwt_helpers.h    | 29 -------------------
 3 files changed, 31 insertions(+), 29 deletions(-)

Comments

Willem de Bruijn Feb. 18, 2025, 1:50 a.m. UTC | #1

Marcus Wichelmann wrote:
> To test the XDP metadata functionality of the tun driver, it's necessary
> to create a new tap device first. A helper function for this already
> exists in lwt_helpers.h. Move it to the common network helpers header,
> so it can be reused in other tests.
> 
> Signed-off-by: Marcus Wichelmann <[e-mail]>

Reviewed-by: Willem de Bruijn <[e-mail]>

Both tests that include lwt_helpers.h also include network_helpers.h,
so the linking with network_helpers.o is already addressed. This was
not entirely obvious from just reading the code.

Patch

diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
index 737a952dcf80..e1cfa1b37754 100644
--- a/tools/testing/selftests/bpf/network_helpers.c
+++ b/tools/testing/selftests/bpf/network_helpers.c
@@ -565,6 +565,34 @@  void close_netns(struct nstoken *token)
 	free(token);
 }
 
+int open_tuntap(const char *dev_name, bool need_mac)
+{
+	int err = 0;
+	struct ifreq ifr;
+	int fd = open("/dev/net/tun", O_RDWR);
+
+	if (!ASSERT_GT(fd, 0, "open(/dev/net/tun)"))
+		return -1;
+
+	ifr.ifr_flags = IFF_NO_PI | (need_mac ? IFF_TAP : IFF_TUN);
+	strncpy(ifr.ifr_name, dev_name, IFNAMSIZ - 1);
+	ifr.ifr_name[IFNAMSIZ - 1] = '\0';
+
+	err = ioctl(fd, TUNSETIFF, &ifr);
+	if (!ASSERT_OK(err, "ioctl(TUNSETIFF)")) {
+		close(fd);
+		return -1;
+	}
+
+	err = fcntl(fd, F_SETFL, O_NONBLOCK);
+	if (!ASSERT_OK(err, "fcntl(O_NONBLOCK)")) {
+		close(fd);
+		return -1;
+	}
+
+	return fd;
+}
+
 int get_socket_local_port(int sock_fd)
 {
 	struct sockaddr_storage addr;
diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h
index 9f6e05d886c5..99d1417c1d8b 100644
--- a/tools/testing/selftests/bpf/network_helpers.h
+++ b/tools/testing/selftests/bpf/network_helpers.h
@@ -8,6 +8,7 @@ 
 typedef __u16 __sum16;
 #include <linux/if_ether.h>
 #include <linux/if_packet.h>
+#include <linux/if_tun.h>
 #include <linux/ip.h>
 #include <linux/ipv6.h>
 #include <linux/ethtool.h>
@@ -98,6 +99,8 @@  int send_recv_data(int lfd, int fd, uint32_t total_bytes);
 int make_netns(const char *name);
 int remove_netns(const char *name);
 
+int open_tuntap(const char *dev_name, bool need_mac);
+
 /**
  * append_tid() - Append thread ID to the given string.
  *
diff --git a/tools/testing/selftests/bpf/prog_tests/lwt_helpers.h b/tools/testing/selftests/bpf/prog_tests/lwt_helpers.h
index fb1eb8c67361..ccec0fcdabc1 100644
--- a/tools/testing/selftests/bpf/prog_tests/lwt_helpers.h
+++ b/tools/testing/selftests/bpf/prog_tests/lwt_helpers.h
@@ -5,7 +5,6 @@ 
 
 #include <time.h>
 #include <net/if.h>
-#include <linux/if_tun.h>
 #include <linux/icmp.h>
 
 #include "test_progs.h"
@@ -37,34 +36,6 @@  static inline int netns_delete(void)
 	return system("ip netns del " NETNS ">/dev/null 2>&1");
 }
 
-static int open_tuntap(const char *dev_name, bool need_mac)
-{
-	int err = 0;
-	struct ifreq ifr;
-	int fd = open("/dev/net/tun", O_RDWR);
-
-	if (!ASSERT_GT(fd, 0, "open(/dev/net/tun)"))
-		return -1;
-
-	ifr.ifr_flags = IFF_NO_PI | (need_mac ? IFF_TAP : IFF_TUN);
-	strncpy(ifr.ifr_name, dev_name, IFNAMSIZ - 1);
-	ifr.ifr_name[IFNAMSIZ - 1] = '\0';
-
-	err = ioctl(fd, TUNSETIFF, &ifr);
-	if (!ASSERT_OK(err, "ioctl(TUNSETIFF)")) {
-		close(fd);
-		return -1;
-	}
-
-	err = fcntl(fd, F_SETFL, O_NONBLOCK);
-	if (!ASSERT_OK(err, "fcntl(O_NONBLOCK)")) {
-		close(fd);
-		return -1;
-	}
-
-	return fd;
-}
-
 #define ICMP_PAYLOAD_SIZE     100
 
 /* Match an ICMP packet with payload len ICMP_PAYLOAD_SIZE */