[PATCH net-next v03 2/3] selftests: net/psock_fanout: socket joins fanout when link is down

[Gur Stavi]

Modify test_control_group to have toggle parameter.
When toggle is non-zero, loopback device will be set down for the
initialization of fd[1] which is still expected to successfully join
the fanout.

Signed-off-by: Gur Stavi <gur.st...@huawei.com>
---
 tools/testing/selftests/net/psock_fanout.c | 42 ++++++++++++++++++++--
 1 file changed, 39 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/net/psock_fanout.c 
b/tools/testing/selftests/net/psock_fanout.c
index 4f31e92ebd96..acdfae8f8a9a 100644
--- a/tools/testing/selftests/net/psock_fanout.c
+++ b/tools/testing/selftests/net/psock_fanout.c
@@ -48,6 +48,7 @@
 #include <string.h>
 #include <sys/mman.h>
 #include <sys/socket.h>
+#include <sys/ioctl.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ -59,6 +60,33 @@
 
 static uint32_t cfg_max_num_members;
 
+static void loopback_set_up_down(int state_up)
+{
+       struct ifreq ifreq = {};
+       int fd, err;
+
+       fd = socket(AF_PACKET, SOCK_RAW, 0);
+       if (fd < 0) {
+               perror("socket loopback");
+               exit(1);
+       }
+       strcpy(ifreq.ifr_name, "lo");
+       err = ioctl(fd, SIOCGIFFLAGS, &ifreq);
+       if (err) {
+               perror("SIOCGIFFLAGS");
+               exit(1);
+       }
+       if (state_up != !!(ifreq.ifr_flags & IFF_UP)) {
+               ifreq.ifr_flags ^= IFF_UP;
+               err = ioctl(fd, SIOCSIFFLAGS, &ifreq);
+               if (err) {
+                       perror("SIOCSIFFLAGS");
+                       exit(1);
+               }
+       }
+       close(fd);
+}
+
 /* Open a socket in a given fanout mode.
  * @return -1 if mode is bad, a valid socket otherwise */
 static int sock_fanout_open(uint16_t typeflags, uint16_t group_id)
@@ -264,17 +292,22 @@ static void test_control_single(void)
 }
 
 /* Test illegal group with different modes or flags */
-static void test_control_group(void)
+static void test_control_group(int toggle)
 {
        int fds[2];
 
-       fprintf(stderr, "test: control multiple sockets\n");
+       if (toggle)
+               fprintf(stderr, "test: control multiple sockets with link down 
toggle\n");
+       else
+               fprintf(stderr, "test: control multiple sockets\n");
 
        fds[0] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
        if (fds[0] == -1) {
                fprintf(stderr, "ERROR: failed to open HASH socket\n");
                exit(1);
        }
+       if (toggle)
+               loopback_set_up_down(0);
        if (sock_fanout_open(PACKET_FANOUT_HASH |
                               PACKET_FANOUT_FLAG_DEFRAG, 0) != -1) {
                fprintf(stderr, "ERROR: joined group with wrong flag defrag\n");
@@ -294,6 +327,8 @@ static void test_control_group(void)
                fprintf(stderr, "ERROR: failed to join group\n");
                exit(1);
        }
+       if (toggle)
+               loopback_set_up_down(1);
        if (close(fds[1]) || close(fds[0])) {
                fprintf(stderr, "ERROR: closing sockets\n");
                exit(1);
@@ -489,7 +524,8 @@ int main(int argc, char **argv)
        int port_off = 2, tries = 20, ret;
 
        test_control_single();
-       test_control_group();
+       test_control_group(0);
+       test_control_group(1);
        test_control_group_max_num_members();
        test_unique_fanout_group_ids();
 
-- 
2.45.2