path: root/libexec_pipe_commandsvn.c

/* See LICENSE file for copyright and license details. */
#include "common.h"
#ifndef TEST


static void
remove_last_pluming(struct libexec_command *cmd)
{
	if (!cmd->nplumings || !cmd->plumings)
		abort();
	if (cmd->plumings[--cmd->nplumings].type != LIBEXEC_PLUMING_PIPE)
		abort();
	close(cmd->plumings[cmd->nplumings].target.fd);
	if (!cmd->nplumings) {
		free(cmd->plumings);
		cmd->plumings = NULL;
	}
}


static int
pipe_two_commands(enum libexec_pipe how, struct libexec_command *left, struct libexec_command *right)
{
	int fds[2], r;
	struct libexec_pluming tmp;

	if (!left || !right) {
	einval:
		errno = EINVAL;
		return -1;
	}

	if (how == LIBEXEC_PIPE)
		r = pipe(fds);
	else if (how == LIBEXEC_SOCK_STREAM)
		r = socketpair(PF_UNIX, SOCK_STREAM, 0, fds);
	else if (how == LIBEXEC_SOCK_SEQPACKET)
		r = socketpair(PF_UNIX, SOCK_SEQPACKET, 0, fds);
	else if (how == LIBEXEC_SOCK_DGRAM)
		r = socketpair(PF_UNIX, SOCK_DGRAM, 0, fds);
	else if (how == LIBEXEC_DIRECT_PIPE)
		r = pipe2(fds, O_DIRECT);
	else
		goto einval;
	if (r)
		return -1;

	if (libexec_dup(left, STDOUT_FILENO, fds[1])) {
		close(fds[0]);
		close(fds[1]);
		return -1;
	}
	left->plumings[left->nplumings - 1].type = LIBEXEC_PLUMING_PIPE;

	if (libexec_dup(right, STDIN_FILENO, fds[0])) {
		remove_last_pluming(left);
		close(fds[0]);
		return -1;
	}
	right->plumings[right->nplumings - 1].type = LIBEXEC_PLUMING_PIPE;

	/* TOOD should `fds[0]` be closed from `left`, and `fds[1]` close from `right`
	 *      (isn't this a problem in general with LIBEXEC_PLUMING_PIPE) */

	/* pluming shall be at the front */
	tmp = left->plumings[left->nplumings - 1];
	memcpy(&left->plumings[1], &left->plumings[0], (left->nplumings - 1) * sizeof(*left->plumings));
	left->plumings[0] = tmp;
	tmp = right->plumings[right->nplumings - 1];
	memcpy(&right->plumings[1], &right->plumings[0], (right->nplumings - 1) * sizeof(*right->plumings));
	right->plumings[0] = tmp;

	return 0;
}


int
libexec_pipe_commandsvn(enum libexec_pipe how, struct libexec_command *const *cmds, size_t n)
{
	enum libexec_pipe circular;
	size_t i;

	circular = how;
	circular &= LIBEXEC_PIPE_CIRCULARLY;
	how ^= circular;

	for (i = 1; i < n; i++)
		if (pipe_two_commands(how, cmds[i - 1], cmds[i]))
			goto fail;

	if (circular && n)
		if (pipe_two_commands(how, cmds[n - 1], cmds[0]))
			goto fail;

	return 0;

fail:
	i -= 1;
	while (i) {
		remove_last_pluming(cmds[i--]);
		remove_last_pluming(cmds[i]);
	}
	return -1;
}


#else
LIBEXEC_CONST__ int main(void) {return 0;} /* TODO test */
#endif