mirror of
https://github.com/jart/cosmopolitan.git
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69 lines
3.5 KiB
C
69 lines
3.5 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/calls/calls.h"
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#include "libc/calls/internal.h"
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#include "libc/calls/strace.internal.h"
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#include "libc/calls/struct/iovec.h"
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#include "libc/calls/struct/iovec.internal.h"
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#include "libc/calls/syscall-sysv.internal.h"
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#include "libc/dce.h"
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#include "libc/intrin/asan.internal.h"
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#include "libc/intrin/weaken.h"
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#include "libc/sock/internal.h"
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#include "libc/sock/sock.h"
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#include "libc/sysv/errfuns.h"
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#include "libc/zipos/zipos.internal.h"
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/**
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* Reads data from file descriptor.
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*
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* @param fd is something open()'d earlier
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* @param buf is copied into, cf. copy_file_range(), sendfile(), etc.
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* @param size in range [1..0x7ffff000] is reasonable
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* @return [1..size] bytes on success, 0 on EOF, or -1 w/ errno; with
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* exception of size==0, in which case return zero means no error
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* @see write(), pread(), readv()
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* @asyncsignalsafe
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* @restartable
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*/
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ssize_t read(int fd, void *buf, size_t size) {
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ssize_t rc;
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if (fd >= 0) {
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if (IsAsan() && !__asan_is_valid(buf, size)) {
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rc = efault();
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} else if (fd < g_fds.n && g_fds.p[fd].kind == kFdZip) {
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rc = weaken(__zipos_read)(
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(struct ZiposHandle *)(intptr_t)g_fds.p[fd].handle,
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&(struct iovec){buf, size}, 1, -1);
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} else if (!IsWindows() && !IsMetal()) {
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rc = sys_read(fd, buf, size);
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} else if (fd >= g_fds.n) {
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rc = ebadf();
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} else if (IsMetal()) {
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rc = sys_readv_metal(g_fds.p + fd, &(struct iovec){buf, size}, 1);
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} else {
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rc = sys_readv_nt(g_fds.p + fd, &(struct iovec){buf, size}, 1);
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}
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} else {
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rc = einval();
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}
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DATATRACE("read(%d, [%#.*hhs%s], %'zu) → %'zd% m", fd, MAX(0, MIN(40, rc)),
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buf, rc > 40 ? "..." : "", size, rc);
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return rc;
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}
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