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Diffstat (limited to 'atomicio.c')
| -rw-r--r-- | atomicio.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/atomicio.c b/atomicio.c new file mode 100644 index 0000000..f854a06 --- /dev/null +++ b/atomicio.c @@ -0,0 +1,170 @@ +/* $OpenBSD: atomicio.c,v 1.28 2016/07/27 23:18:12 djm Exp $ */ +/* + * Copyright (c) 2006 Damien Miller. All rights reserved. + * Copyright (c) 2005 Anil Madhavapeddy. All rights reserved. + * Copyright (c) 1995,1999 Theo de Raadt. All rights reserved. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" + +#include <sys/param.h> +#include <sys/uio.h> + +#include <errno.h> +#ifdef HAVE_POLL_H +#include <poll.h> +#else +# ifdef HAVE_SYS_POLL_H +# include <sys/poll.h> +# endif +#endif +#include <string.h> +#include <unistd.h> +#include <limits.h> + +#include "atomicio.h" + +/* + * ensure all of data on socket comes through. f==read || f==vwrite + */ +size_t +atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n, + int (*cb)(void *, size_t), void *cb_arg) +{ + char *s = _s; + size_t pos = 0; + ssize_t res; + struct pollfd pfd; + +#ifndef BROKEN_READ_COMPARISON + pfd.fd = fd; + pfd.events = f == read ? POLLIN : POLLOUT; +#endif + while (n > pos) { + res = (f) (fd, s + pos, n - pos); + switch (res) { + case -1: + if (errno == EINTR) + continue; + if (errno == EAGAIN || errno == EWOULDBLOCK) { +#ifndef BROKEN_READ_COMPARISON + (void)poll(&pfd, 1, -1); +#endif + continue; + } + return 0; + case 0: + errno = EPIPE; + return pos; + default: + pos += (size_t)res; + if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { + errno = EINTR; + return pos; + } + } + } + return pos; +} + +size_t +atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n) +{ + return atomicio6(f, fd, _s, n, NULL, NULL); +} + +/* + * ensure all of data on socket comes through. f==readv || f==writev + */ +size_t +atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd, + const struct iovec *_iov, int iovcnt, + int (*cb)(void *, size_t), void *cb_arg) +{ + size_t pos = 0, rem; + ssize_t res; + struct iovec iov_array[IOV_MAX], *iov = iov_array; + struct pollfd pfd; + + if (iovcnt < 0 || iovcnt > IOV_MAX) { + errno = EINVAL; + return 0; + } + /* Make a copy of the iov array because we may modify it below */ + memcpy(iov, _iov, (size_t)iovcnt * sizeof(*_iov)); + +#ifndef BROKEN_READV_COMPARISON + pfd.fd = fd; + pfd.events = f == readv ? POLLIN : POLLOUT; +#endif + for (; iovcnt > 0 && iov[0].iov_len > 0;) { + res = (f) (fd, iov, iovcnt); + switch (res) { + case -1: + if (errno == EINTR) + continue; + if (errno == EAGAIN || errno == EWOULDBLOCK) { +#ifndef BROKEN_READV_COMPARISON + (void)poll(&pfd, 1, -1); +#endif + continue; + } + return 0; + case 0: + errno = EPIPE; + return pos; + default: + rem = (size_t)res; + pos += rem; + /* skip completed iov entries */ + while (iovcnt > 0 && rem >= iov[0].iov_len) { + rem -= iov[0].iov_len; + iov++; + iovcnt--; + } + /* This shouldn't happen... */ + if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) { + errno = EFAULT; + return 0; + } + if (iovcnt == 0) + break; + /* update pointer in partially complete iov */ + iov[0].iov_base = ((char *)iov[0].iov_base) + rem; + iov[0].iov_len -= rem; + } + if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { + errno = EINTR; + return pos; + } + } + return pos; +} + +size_t +atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd, + const struct iovec *_iov, int iovcnt) +{ + return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL); +} |