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/*
* Copyright (C) 2003-2009 FAUmachine Team <info@faumachine.org>.
* This program is free software. You can redistribute it and/or modify it
* under the terms of the GNU General Public License, either version 2 of
* the License, or (at your option) any later version. See COPYING.
*/
#ifdef INCLUDE
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <assert.h>
#include <fcntl.h>
#include <stdio.h>
#include <signal.h>
#include <unistd.h>
#include "glue-io.h"
#endif /* INCLUDE */
#ifdef STATE
struct {
int slirp_fd;
pid_t slirp_pid;
pid_t grep_pid;
} NAME;
#endif /* STATE */
#ifdef BEHAVIOR
#define END 0300
#define ESC 0333
#define ESC_END 0334
#define ESC_ESC 0335
/** send an ip packet to the slip line
*
* packet will be encoded and written to the line
* must already be a bare ip packet, without eth frame
* called by ip_recv
*/
static int
NAME_(send)(struct cpssp *cpssp, const unsigned char *ip_buf, int ip_len)
{
unsigned char buf[ETHERMTU*2];
int i;
int len;
int ret;
/* escape some characters */
len = 0;
for (i = 0; i < ip_len; i++) {
switch (ip_buf[i]) {
case END:
buf[len++] = ESC;
buf[len++] = ESC_END;
break;
case ESC:
buf[len++] = ESC;
buf[len++] = ESC_ESC;
break;
default:
buf[len++] = ip_buf[i];
break;
}
}
/* send packet to slirp */
buf[len++] = END;
ret = write(cpssp->NAME.slirp_fd, buf, len);
assert(ret == len); /* FIXME */
return 0;
}
/** receive ip packet from slip line
*
* passes the decoded packet(s) to ip_send
*/
static void
NAME_(interrupt2)(struct cpssp *cpssp, unsigned char *buf, int len)
{
/* space is reserved for whole packet, including header+crc */
static unsigned char packet[0x10000 + 2];
static unsigned int packet_len = 0;
static int esc = 0;
int i;
/* parse them to form an ip packet */
for (i = 0; i < len; i++) {
switch (buf[i]) {
case END:
if (sizeof(struct ip) < packet_len
&& packet_len <= 0x10000) {
/* We have a complete packet now. */
NAME_(recv)(cpssp, packet, packet_len);
}
packet_len = 0;
break;
case ESC:
esc = 1;
break;
case ESC_END:
packet[packet_len++] = esc ? END : ESC_END;
esc = 0;
break;
case ESC_ESC:
packet[packet_len++] = esc ? ESC : ESC_ESC;
esc = 0;
break;
default:
packet[packet_len++] = buf[i];
break;
}
if (0x10000 < packet_len) {
packet_len = 0x10000 + 1;
}
}
}
/** receive data from slip line
*
* called whenever data is ready.
* passes data to slip_recv
*/
static void
NAME_(interrupt)(int fd, void *_cpssp)
{
struct cpssp *cpssp = _cpssp;
unsigned char buf[4096];
int len;
for (;;) {
do {
len = read(cpssp->NAME.slirp_fd, buf, sizeof(buf));
} while (len < 0 && errno == EINTR);
if (len < 0 && errno == EAGAIN) {
break;
}
if (len < 0) {
perror("read");
} else if (len == 0) {
fprintf(stderr, "read: len = 0\n");
}
assert(0 < len);
NAME_(interrupt2)(cpssp, buf, len);
}
}
static void
NAME_(create)(struct cpssp *cpssp)
{
int errpipe[2];
int iopipe[2];
int ret;
pid_t child_pid;
ret = pipe(errpipe);
assert(0 <= ret);
/* fork grep only output real error messages */
switch (child_pid = fork()) {
case -1:
assert(0); /* Mustn't happen. */
/*NOTREACHED*/
case 0:
ret = dup2(errpipe[0], 0); /* read from pipe */
assert(0 <= ret);
ret = dup2(2, 1); /* output goes to stderr */
assert(0 <= ret);
ret = close(errpipe[0]);
assert(0 <= ret);
ret = close(errpipe[1]);
assert(0 <= ret);
execlp("grep", "grep", "Error", (char *) 0);
perror("exec");
_exit(1);
default:
cpssp->NAME.grep_pid = child_pid;
break;
}
ret = socketpair(PF_UNIX, SOCK_STREAM, 0, iopipe);
assert(0 <= ret);
switch (child_pid = fork()) {
case -1:
assert(0); /* Shouldn't happen. */
/*NOTREACHED*/
case 0: /* child, executing slirp */
ret = dup2(iopipe[0], 0);
assert(0 <= ret);
ret = close(1);
assert(0 <= ret);
ret = open("/dev/null", O_WRONLY);
assert(ret == 1);
ret = dup2(errpipe[1], 2); /* stderr goes to above pipe */
assert(0 <= ret);
ret = close(iopipe[0]);
assert(0 <= ret);
ret = close(iopipe[1]);
assert(0 <= ret);
ret = close(errpipe[0]);
assert(0 <= ret);
ret = close(errpipe[1]);
assert(0 <= ret);
execlp("slirp", "slirp", "mtu 1486", (char *) 0);
/* mtu = 1500 - sizeof(ethhdr) */
fprintf(stderr, "Error: slirp: %s.", strerror(errno));
_exit(1);
default:
cpssp->NAME.slirp_pid = child_pid;
break;
}
ret = close(iopipe[0]);
assert(0 <= ret);
ret = close(errpipe[0]);
assert(0 <= ret);
ret = close(errpipe[1]);
assert(0 <= ret);
cpssp->NAME.slirp_fd = iopipe[1];
io_register(cpssp->NAME.slirp_fd, cpssp, NAME_(interrupt));
}
static void
NAME_(destroy)(struct cpssp *cpssp)
{
int ret;
io_unregister(cpssp->NAME.slirp_fd);
ret = close(cpssp->NAME.slirp_fd);
assert(0 <= ret);
ret = kill(cpssp->NAME.slirp_pid, 15);
assert(0 <= ret);
ret = waitpid(cpssp->NAME.slirp_pid, NULL, 0);
assert(ret == cpssp->NAME.slirp_pid);
ret = kill(cpssp->NAME.grep_pid, 15);
assert(0 <= ret);
ret = waitpid(cpssp->NAME.grep_pid, NULL, 0);
assert(ret == cpssp->NAME.grep_pid);
}
#endif /* BEHAVIOR */
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