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/* Copyright (c) 2006-2018 Dovecot authors, see the included COPYING file */
#include "lib.h"
#include "istream.h"
#include "ostream.h"
#include "file-copy.h"
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
static int file_copy_to_tmp(const char *srcpath, const char *tmppath,
bool try_hardlink)
{
struct istream *input;
struct ostream *output;
struct stat st;
mode_t old_umask;
int fd_in, fd_out;
int ret = -1;
if (try_hardlink) {
/* see if hardlinking works */
if (link(srcpath, tmppath) == 0)
return 1;
if (errno == EEXIST) {
if (i_unlink_if_exists(tmppath) < 0)
return -1;
if (link(srcpath, tmppath) == 0)
return 1;
}
if (errno == ENOENT)
return 0;
if (!ECANTLINK(errno)) {
i_error("link(%s, %s) failed: %m", srcpath, tmppath);
return -1;
}
/* fallback to manual copying */
}
fd_in = open(srcpath, O_RDONLY);
if (fd_in == -1) {
if (errno == ENOENT)
return 0;
i_error("open(%s) failed: %m", srcpath);
return -1;
}
if (fstat(fd_in, &st) < 0) {
i_error("fstat(%s) failed: %m", srcpath);
i_close_fd(&fd_in);
return -1;
}
old_umask = umask(0);
fd_out = open(tmppath, O_WRONLY | O_CREAT | O_TRUNC, st.st_mode);
umask(old_umask);
if (fd_out == -1) {
i_error("open(%s, O_CREAT) failed: %m", tmppath);
i_close_fd(&fd_in);
return -1;
}
/* try to change the group, don't really care if it fails */
if (fchown(fd_out, (uid_t)-1, st.st_gid) < 0 && errno != EPERM)
i_error("fchown(%s) failed: %m", tmppath);
input = i_stream_create_fd(fd_in, IO_BLOCK_SIZE);
output = o_stream_create_fd_file(fd_out, 0, FALSE);
switch (o_stream_send_istream(output, input)) {
case OSTREAM_SEND_ISTREAM_RESULT_FINISHED:
ret = 0;
break;
case OSTREAM_SEND_ISTREAM_RESULT_WAIT_INPUT:
case OSTREAM_SEND_ISTREAM_RESULT_WAIT_OUTPUT:
i_unreached();
case OSTREAM_SEND_ISTREAM_RESULT_ERROR_INPUT:
i_error("read(%s) failed: %s", srcpath,
i_stream_get_error(input));
break;
case OSTREAM_SEND_ISTREAM_RESULT_ERROR_OUTPUT:
i_error("write(%s) failed: %s", tmppath,
o_stream_get_error(output));
break;
}
i_stream_destroy(&input);
o_stream_destroy(&output);
if (close(fd_in) < 0) {
i_error("close(%s) failed: %m", srcpath);
ret = -1;
}
if (close(fd_out) < 0) {
i_error("close(%s) failed: %m", tmppath);
ret = -1;
}
return ret < 0 ? -1 : 1;
}
int file_copy(const char *srcpath, const char *destpath, bool try_hardlink)
{
int ret;
T_BEGIN {
const char *tmppath;
tmppath = t_strconcat(destpath, ".tmp", NULL);
ret = file_copy_to_tmp(srcpath, tmppath, try_hardlink);
if (ret > 0) {
if (rename(tmppath, destpath) < 0) {
i_error("rename(%s, %s) failed: %m",
tmppath, destpath);
ret = -1;
}
}
if (ret < 0)
i_unlink(tmppath);
} T_END;
return ret;
}
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