cosmopolitan/libc/sock/sockatmark.c
Justine Tunney 1d4eb08fa1
Support non-blocking i/o across platforms
This change introduces new tests for `O_NONBLOCK` and `SOCK_NONBLOCK` to
confirm that non-blocking i/o is now working on all supported platforms,
including Windows. For example, you can now say on Windows, MacOS, etc.:

    socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP);

To create a non-blocking IPv4 TCP socket. Or you can enable non-blocking
i/o on an existing socket / pipe / etc. file descriptor by calling fcntl

    fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK);

This functionality is polyfilled on older Linux kernels too, e.g. RHEL5.
Now that fcntl() support is much better the FIOCLEX / FIONCLEX polyfills
for ioctl() have been removed since they're ugly non-POSIX diameond APIs

This change fixes a weakness in kprintf() that was causing Windows trace
tools to frequently crash.
2023-07-23 02:56:47 -07:00

66 lines
3.1 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/internal.h"
#include "libc/calls/struct/fd.internal.h"
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/dce.h"
#include "libc/intrin/strace.internal.h"
#include "libc/nt/winsock.h"
#include "libc/sock/internal.h"
#include "libc/sock/sock.h"
#include "libc/sysv/errfuns.h"
static textwindows int sockatmark_nt(int fd, unsigned long magnum) {
bool32 res;
int64_t hand;
uint32_t bytes;
if (fd >= g_fds.n) return ebadf();
if (g_fds.p[fd].kind != kFdSocket) return einval();
hand = g_fds.p[fd].handle;
if (WSAIoctl(hand, magnum, 0, 0, &res, sizeof(res), &bytes, 0, 0) == -1) {
return __winsockerr();
}
return !res;
}
/**
* Returns true if out of band data is available on socket for reading.
*
* @return 1 if OOB'd, 0 if not, or -1 w/ errno
* @raise EBADF if `fd` isn't an open file descriptor
* @raise EINVAL if `fd` isn't an appropriate file descriptor
*/
int sockatmark(int fd) {
int rc;
unsigned long magnum;
if (IsLinux()) {
magnum = 0x8905; // SIOCATMARK (Linux only)
} else { //
magnum = 0x40047307; // SIOCATMARK (BSD, Windows)
}
if (!IsWindows()) {
if (sys_ioctl(fd, magnum, &rc) == -1) {
rc = -1;
}
} else {
rc = sockatmark_nt(fd, magnum);
}
STRACE("sockatmark(%d) → %d% m", fd, rc);
return rc;
}