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/* Copyright (c) 2007-2018 Dovecot authors, see the included COPYING file */
#include "lib.h"
#include "array.h"
#include "dup2-array.h"
#include <unistd.h>
void dup2_append(ARRAY_TYPE(dup2) *dups, int fd_src, int fd_dest)
{
struct dup2 d;
i_assert(fd_src >= 0);
i_assert(fd_dest >= 0);
d.fd_src = fd_src;
d.fd_dest = fd_dest;
array_push_back(dups, &d);
}
int dup2_array(ARRAY_TYPE(dup2) *dups_arr)
{
struct dup2 *dups;
bool *moved, moves;
unsigned int i, j, count, conflict;
int fd;
dups = array_get_modifiable(dups_arr, &count);
moved = t_new(bool, count);
for (;;) {
conflict = count;
moves = FALSE;
for (i = 0; i < count; i++) {
if (moved[i])
continue;
for (j = 0; j < count; j++) {
if (dups[j].fd_src == dups[i].fd_dest &&
!moved[j]) {
conflict = j;
break;
}
}
if (j == count) {
/* no conflicts, move it */
moved[i] = TRUE;
moves = TRUE;
if (dup2(dups[i].fd_src, dups[i].fd_dest) < 0) {
i_error("dup2(%d, %d) failed: %m",
dups[i].fd_src,
dups[i].fd_dest);
return -1;
}
}
}
if (conflict == count)
break;
if (moves) {
/* it's possible that the conflicting fd was
moved already. try again. */
continue;
}
/* ok, we have to dup() */
fd = dup(dups[conflict].fd_src);
if (fd == -1) {
i_error("dup(%d) failed: %m", dups[conflict].fd_src);
return -1;
}
fd_close_on_exec(fd, TRUE);
dups[conflict].fd_src = fd;
}
return 0;
}
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