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/* Copyright (c) 2002-2018 Dovecot authors, see the included COPYING file */
/* kludge a bit to remove _FILE_OFFSET_BITS definition from config.h.
It's required to be able to include sys/sendfile.h with Linux. */
#include "config.h"
#undef HAVE_CONFIG_H
#ifdef HAVE_LINUX_SENDFILE
# undef _FILE_OFFSET_BITS
#endif
#include "lib.h"
#include "sendfile-util.h"
#ifdef HAVE_LINUX_SENDFILE
#include <sys/sendfile.h>
ssize_t safe_sendfile(int out_fd, int in_fd, uoff_t *offset, size_t count)
{
/* REMEMBER: uoff_t and off_t may not be of same size. */
off_t safe_offset;
ssize_t ret;
i_assert(count > 0);
/* make sure given offset fits into off_t */
if (sizeof(off_t) * CHAR_BIT == 32) {
/* 32bit off_t */
if (*offset >= 2147483647L) {
errno = EINVAL;
return -1;
}
if (count > 2147483647L - *offset)
count = 2147483647L - *offset;
} else {
/* they're most likely the same size. if not, fix this
code later */
i_assert(sizeof(off_t) == sizeof(uoff_t));
if (*offset >= OFF_T_MAX) {
errno = EINVAL;
return -1;
}
if (count > OFF_T_MAX - *offset)
count = OFF_T_MAX - *offset;
}
safe_offset = (off_t)*offset;
ret = sendfile(out_fd, in_fd, &safe_offset, count);
/* ret=0 : trying to read past EOF */
*offset = (uoff_t)safe_offset;
return ret;
}
#elif defined(HAVE_FREEBSD_SENDFILE)
#include <sys/socket.h>
#include <sys/uio.h>
ssize_t safe_sendfile(int out_fd, int in_fd, uoff_t *offset, size_t count)
{
struct sf_hdtr hdtr;
off_t sbytes;
int ret;
/* if count=0 is passed to sendfile(), it sends everything
from in_fd until EOF. We don't want that. */
i_assert(count > 0);
i_assert(count <= SSIZE_T_MAX);
i_zero(&hdtr);
ret = sendfile(in_fd, out_fd, *offset, count, &hdtr, &sbytes, 0);
*offset += sbytes;
if (ret == 0 || (ret < 0 && errno == EAGAIN && sbytes > 0))
return (ssize_t)sbytes;
else {
if (errno == ENOTSOCK) {
/* out_fd wasn't a socket. behave as if sendfile()
wasn't supported at all. */
errno = EINVAL;
}
return -1;
}
}
#elif defined (HAVE_SOLARIS_SENDFILE)
#include <sys/sendfile.h>
#include "net.h"
ssize_t safe_sendfile(int out_fd, int in_fd, uoff_t *offset, size_t count)
{
ssize_t ret;
off_t s_offset;
i_assert(count > 0);
i_assert(count <= SSIZE_T_MAX);
/* NOTE: if outfd is not a socket, some Solaris versions will
kernel panic */
s_offset = (off_t)*offset;
ret = sendfile(out_fd, in_fd, &s_offset, count);
if (ret < 0) {
/* if remote is gone, EPIPE is returned */
if (errno == EINVAL) {
/* most likely trying to read past EOF */
ret = 0;
} else if (errno == EAFNOSUPPORT || errno == EOPNOTSUPP) {
/* not supported, return Linux-like EINVAL so caller
sees only consistent errnos. */
errno = EINVAL;
} else if (s_offset != (off_t)*offset) {
/* some data was sent, return it */
i_assert(s_offset > (off_t)*offset);
ret = s_offset - (off_t)*offset;
}
}
*offset = (uoff_t)s_offset;
i_assert(ret < 0 || (size_t)ret <= count);
return ret;
}
#else
ssize_t safe_sendfile(int out_fd ATTR_UNUSED, int in_fd ATTR_UNUSED,
uoff_t *offset ATTR_UNUSED,
size_t count ATTR_UNUSED)
{
errno = EINVAL;
return -1;
}
#endif
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