/* Test of select() substitute. Copyright (C) 2008-2023 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ /* Written by Paolo Bonzini, 2008. */ #include #include #include #include #include #include #include #include #include #include #include "macros.h" #if defined _WIN32 && ! defined __CYGWIN__ # define WINDOWS_NATIVE #endif #ifdef HAVE_SYS_WAIT_H # include #endif typedef int (*select_fn) (int, fd_set *, fd_set *, fd_set *, struct timeval *); /* Minimal testing infrastructure. */ static int failures; static void failed (const char *reason) { if (++failures > 1) printf (" "); printf ("failed (%s)\n", reason); } static int test (void (*fn) (select_fn), select_fn my_select, const char *msg) { failures = 0; printf ("%s... ", msg); fflush (stdout); fn (my_select); if (!failures) printf ("passed\n"); return failures; } /* Funny socket code. */ static int open_server_socket (void) { int s, x; struct sockaddr_in ia; s = socket (AF_INET, SOCK_STREAM, 0); x = 1; setsockopt (s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof (x)); memset (&ia, 0, sizeof (ia)); ia.sin_family = AF_INET; inet_pton (AF_INET, "127.0.0.1", &ia.sin_addr); ia.sin_port = htons (TEST_PORT); if (bind (s, (struct sockaddr *) &ia, sizeof (ia)) < 0) { perror ("bind"); exit (77); } if (listen (s, 1) < 0) { perror ("listen"); exit (77); } return s; } static int connect_to_socket (bool blocking) { int s; struct sockaddr_in ia; s = socket (AF_INET, SOCK_STREAM, 0); memset (&ia, 0, sizeof (ia)); ia.sin_family = AF_INET; inet_pton (AF_INET, "127.0.0.1", &ia.sin_addr); ia.sin_port = htons (TEST_PORT); if (!blocking) { #ifdef WINDOWS_NATIVE unsigned long iMode = 1; ioctl (s, FIONBIO, (char *) &iMode); #elif defined F_GETFL int oldflags = fcntl (s, F_GETFL, NULL); if (!(oldflags & O_NONBLOCK)) fcntl (s, F_SETFL, oldflags | O_NONBLOCK); #endif } if (connect (s, (struct sockaddr *) &ia, sizeof (ia)) < 0 && (blocking || errno != EINPROGRESS)) { perror ("connect"); exit (77); } return s; } /* A slightly more convenient interface to select(2). Waits until a specific event occurs on a file descriptor FD. EV is a bit mask of events to look for: SEL_IN - input can be polled without blocking, SEL_OUT - output can be provided without blocking, SEL_EXC - an exception occurred, A maximum wait time is specified by TIMEOUT. *TIMEOUT = { 0, 0 } means to return immediately, TIMEOUT = NULL means to wait indefinitely. */ enum { SEL_IN = 1, SEL_OUT = 2, SEL_EXC = 4 }; static int do_select (int fd, int ev, struct timeval *timeout, select_fn my_select) { fd_set rfds, wfds, xfds; int r, rev; FD_ZERO (&rfds); FD_ZERO (&wfds); FD_ZERO (&xfds); if (ev & SEL_IN) FD_SET (fd, &rfds); if (ev & SEL_OUT) FD_SET (fd, &wfds); if (ev & SEL_EXC) FD_SET (fd, &xfds); r = my_select (fd + 1, &rfds, &wfds, &xfds, timeout); if (r < 0) return r; rev = 0; if (FD_ISSET (fd, &rfds)) rev |= SEL_IN; if (FD_ISSET (fd, &wfds)) rev |= SEL_OUT; if (FD_ISSET (fd, &xfds)) rev |= SEL_EXC; if (rev && r == 0) failed ("select returned 0"); if (rev & ~ev) failed ("select returned unrequested events"); return rev; } static int do_select_nowait (int fd, int ev, select_fn my_select) { struct timeval tv0; tv0.tv_sec = 0; tv0.tv_usec = 0; return do_select (fd, ev, &tv0, my_select); } static int do_select_wait (int fd, int ev, select_fn my_select) { return do_select (fd, ev, NULL, my_select); } /* Test select(2) for TTYs. */ #ifdef INTERACTIVE static void test_tty (select_fn my_select) { if (do_select_nowait (0, SEL_IN, my_select) != 0) failed ("can read"); if (do_select_nowait (0, SEL_OUT, my_select) == 0) failed ("cannot write"); if (do_select_wait (0, SEL_IN, my_select) == 0) failed ("return with infinite timeout"); getchar (); if (do_select_nowait (0, SEL_IN, my_select) != 0) failed ("can read after getc"); } #endif static int do_select_bad_nfd_nowait (int nfd, select_fn my_select) { struct timeval tv0; tv0.tv_sec = 0; tv0.tv_usec = 0; errno = 0; return my_select (nfd, NULL, NULL, NULL, &tv0); } static void test_bad_nfd (select_fn my_select) { if (do_select_bad_nfd_nowait (-1, my_select) != -1 || errno != EINVAL) failed ("invalid errno after negative nfds"); /* Can't test FD_SETSIZE + 1 for EINVAL, since some systems allow dynamically larger set size by redefining FD_SETSIZE anywhere up to the actual maximum fd. */ #if 0 if (do_select_bad_nfd_nowait (FD_SETSIZE + 1, my_select) != -1 || errno != EINVAL) failed ("invalid errno after bogus nfds"); #endif } /* Test select(2) on invalid file descriptors. */ static int do_select_bad_fd (int fd, int ev, struct timeval *timeout, select_fn my_select) { fd_set rfds, wfds, xfds; FD_ZERO (&rfds); FD_ZERO (&wfds); FD_ZERO (&xfds); if (ev & SEL_IN) FD_SET (fd, &rfds); if (ev & SEL_OUT) FD_SET (fd, &wfds); if (ev & SEL_EXC) FD_SET (fd, &xfds); errno = 0; return my_select (fd + 1, &rfds, &wfds, &xfds, timeout); /* In this case, when fd is invalid, on some platforms, the bit for fd is left alone in the fd_set, whereas on other platforms it is cleared. So, don't check the bit for fd here. */ } static int do_select_bad_fd_nowait (int fd, int ev, select_fn my_select) { struct timeval tv0; tv0.tv_sec = 0; tv0.tv_usec = 0; return do_select_bad_fd (fd, ev, &tv0, my_select); } static void test_bad_fd (select_fn my_select) { /* This tests fails on OSF/1 and native Windows, even with fd = 16. */ #if !(defined __osf__ || defined WINDOWS_NATIVE) int fd; /* On Linux, Mac OS X, *BSD, values of fd like 99 or 399 are discarded by the kernel early and therefore do *not* lead to EBADF, as required by POSIX. */ # if defined __linux__ || (defined __APPLE__ && defined __MACH__) || (defined __FreeBSD__ || defined __DragonFly__) || defined __OpenBSD__ || defined __NetBSD__ fd = 14; # else fd = 99; # endif /* Even on the best POSIX compliant platforms, values of fd >= FD_SETSIZE require an nfds argument that is > FD_SETSIZE and thus may lead to EINVAL, not EBADF. */ if (fd >= FD_SETSIZE) fd = FD_SETSIZE - 1; close (fd); if (do_select_bad_fd_nowait (fd, SEL_IN, my_select) == 0 || errno != EBADF) failed ("invalid fd among rfds"); if (do_select_bad_fd_nowait (fd, SEL_OUT, my_select) == 0 || errno != EBADF) failed ("invalid fd among wfds"); if (do_select_bad_fd_nowait (fd, SEL_EXC, my_select) == 0 || errno != EBADF) failed ("invalid fd among xfds"); #endif } /* Test select(2) for unconnected nonblocking sockets. */ static void test_connect_first (select_fn my_select) { int s = open_server_socket (); struct sockaddr_in ia; socklen_t addrlen; int c1, c2; if (do_select_nowait (s, SEL_IN | SEL_EXC, my_select) != 0) failed ("can read, socket not connected"); c1 = connect_to_socket (false); if (do_select_wait (s, SEL_IN | SEL_EXC, my_select) != SEL_IN) failed ("expecting readability on passive socket"); if (do_select_nowait (s, SEL_IN | SEL_EXC, my_select) != SEL_IN) failed ("expecting readability on passive socket"); addrlen = sizeof (ia); c2 = accept (s, (struct sockaddr *) &ia, &addrlen); ASSERT (close (s) == 0); ASSERT (close (c1) == 0); ASSERT (close (c2) == 0); } /* Test select(2) for unconnected blocking sockets. */ static void test_accept_first (select_fn my_select) { #ifndef WINDOWS_NATIVE int s = open_server_socket (); struct sockaddr_in ia; socklen_t addrlen; char buf[3]; int c, pid; pid = fork (); if (pid < 0) return; if (pid == 0) { addrlen = sizeof (ia); c = accept (s, (struct sockaddr *) &ia, &addrlen); ASSERT (close (s) == 0); ASSERT (write (c, "foo", 3) == 3); ASSERT (read (c, buf, 3) == 3); shutdown (c, SHUT_RD); ASSERT (close (c) == 0); exit (0); } else { ASSERT (close (s) == 0); c = connect_to_socket (true); if (do_select_nowait (c, SEL_OUT, my_select) != SEL_OUT) failed ("cannot write after blocking connect"); ASSERT (write (c, "foo", 3) == 3); wait (&pid); if (do_select_wait (c, SEL_IN, my_select) != SEL_IN) failed ("cannot read data left in the socket by closed process"); ASSERT (read (c, buf, 3) == 3); ASSERT (write (c, "foo", 3) == 3); (void) close (c); /* may fail with errno = ECONNRESET */ } #endif } /* Common code for pipes and connected sockets. */ static void test_pair (int rd, int wd, select_fn my_select) { char buf[3]; if (do_select_wait (wd, SEL_IN | SEL_OUT | SEL_EXC, my_select) != SEL_OUT) failed ("expecting writability before writing"); if (do_select_nowait (wd, SEL_IN | SEL_OUT | SEL_EXC, my_select) != SEL_OUT) failed ("expecting writability before writing"); ASSERT (write (wd, "foo", 3) == 3); if (do_select_wait (rd, SEL_IN, my_select) != SEL_IN) failed ("expecting readability after writing"); if (do_select_nowait (rd, SEL_IN, my_select) != SEL_IN) failed ("expecting readability after writing"); ASSERT (read (rd, buf, 3) == 3); } /* Test select(2) on connected sockets. */ static void test_socket_pair (select_fn my_select) { struct sockaddr_in ia; socklen_t addrlen = sizeof (ia); int s = open_server_socket (); int c1 = connect_to_socket (false); int c2 = accept (s, (struct sockaddr *) &ia, &addrlen); ASSERT (close (s) == 0); test_pair (c1, c2, my_select); ASSERT (close (c1) == 0); ASSERT (write (c2, "foo", 3) == 3); (void) close (c2); /* may fail with errno = ECONNRESET */ } /* Test select(2) on pipes. */ static void test_pipe (select_fn my_select) { int fd[2]; ASSERT (pipe (fd) == 0); test_pair (fd[0], fd[1], my_select); ASSERT (close (fd[0]) == 0); ASSERT (close (fd[1]) == 0); } /* Do them all. */ static int test_function (select_fn my_select) { int result = 0; #ifdef INTERACTIVE printf ("Please press Enter\n"); test (test_tty, "TTY", my_select); #endif result += test (test_bad_nfd, my_select, "Invalid nfd test"); result += test (test_bad_fd, my_select, "Invalid fd test"); result += test (test_connect_first, my_select, "Unconnected socket test"); result += test (test_socket_pair, my_select, "Connected sockets test"); result += test (test_accept_first, my_select, "General socket test with fork"); result += test (test_pipe, my_select, "Pipe test"); return result; }