tests: added a regression test to demonstrate that sftp_packet_read could run

into an infinite loop

Signed-off-by: Liu Husong <huliu@janestreet.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Eshan Kelkar <eshankelkar@galorithm.com>

tests/client/torture_sftp_packet_read.c

@@ -0,0 +1,102 @@
+/*
+ * This is a regression test to make sure that sftp_read_packet times out
+ * properly in blocking mode
+ */
+
+#define LIBSSH_STATIC
+
+#include "config.h"
+
+#include "torture.h"
+#include "sftp.c"
+
+#include <libssh/socket.h>
+#include <sys/types.h>
+#include <pwd.h>
+#include <errno.h>
+
+static int sshd_setup(void **state)
+{
+    torture_setup_sshd_server(state, false);
+
+    return 0;
+}
+
+static int sshd_teardown(void **state) {
+    torture_teardown_sshd_server(state);
+
+    return 0;
+}
+
+static int session_setup(void **state)
+{
+    struct torture_state *s = *state;
+    struct passwd *pwd;
+    int rc;
+
+    pwd = getpwnam("bob");
+    assert_non_null(pwd);
+
+    rc = setuid(pwd->pw_uid);
+    assert_return_code(rc, errno);
+
+    s->ssh.session = torture_ssh_session(s,
+                                         TORTURE_SSH_SERVER,
+                                         NULL,
+                                         TORTURE_SSH_USER_ALICE,
+                                         NULL);
+    assert_non_null(s->ssh.session);
+
+    s->ssh.tsftp = torture_sftp_session(s->ssh.session);
+    assert_non_null(s->ssh.tsftp);
+
+    return 0;
+}
+
+static int session_teardown(void **state)
+{
+    struct torture_state *s = *state;
+
+    torture_rmdirs(s->ssh.tsftp->testdir);
+    torture_sftp_close(s->ssh.tsftp);
+    ssh_disconnect(s->ssh.session);
+    ssh_free(s->ssh.session);
+
+    return 0;
+}
+
+static void torture_sftp_packet_read(void **state) {
+    struct torture_state *s = *state;
+    struct torture_sftp *t = s->ssh.tsftp;
+
+    int fds[2];
+    int rc;
+
+    // creating blocking fd is the default pipe behaviour
+    rc = pipe(fds);
+    assert_true(rc == 0);
+
+    ssh_socket_set_fd(t->ssh->socket, fds[0]);
+
+    rc = sftp_packet_read(t->sftp);
+    assert_true(rc == SSH_AGAIN);
+
+    close(fds[0]);
+    close(fds[1]);
+}
+
+int torture_run_tests(void) {
+    int rc;
+    struct CMUnitTest tests[] = {
+      cmocka_unit_test_setup_teardown(torture_sftp_packet_read, session_setup,
+                                      session_teardown),
+    };
+
+    ssh_init();
+
+    torture_filter_tests(tests);
+    rc = cmocka_run_group_tests(tests, sshd_setup, sshd_teardown);
+    ssh_finalize();
+
+    return rc;
+}