392 lines
9.4 KiB
C
392 lines
9.4 KiB
C
/* Serial port emulation using sockets.
|
||
Copyright (C) 1998, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
|
||
Contributed by Cygnus Solutions.
|
||
|
||
This program is free software; you can redistribute it and/or modify
|
||
it under the terms of the GNU General Public License as published by
|
||
the Free Software Foundation; either version 3 of the License, or
|
||
(at your option) any later version.
|
||
|
||
This program is distributed in the hope that it will be useful,
|
||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
GNU General Public License for more details.
|
||
|
||
You should have received a copy of the GNU General Public License
|
||
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
||
|
||
/* FIXME: will obviously need to evolve.
|
||
- connectionless sockets might be more appropriate. */
|
||
|
||
#include "sim-main.h"
|
||
|
||
#ifdef HAVE_STRING_H
|
||
#include <string.h>
|
||
#else
|
||
#ifdef HAVE_STRINGS_H
|
||
#include <strings.h>
|
||
#endif
|
||
#endif
|
||
#include <signal.h>
|
||
#ifdef HAVE_STDLIB_H
|
||
#include <stdlib.h>
|
||
#endif
|
||
#ifdef HAVE_FCNTL_H
|
||
#include <fcntl.h>
|
||
#endif
|
||
#ifdef HAVE_UNISTD_H
|
||
#include <unistd.h>
|
||
#endif
|
||
|
||
#include <errno.h>
|
||
#include <sys/types.h>
|
||
#include <sys/time.h>
|
||
#include <netinet/in.h>
|
||
#include <arpa/inet.h>
|
||
#include <netdb.h>
|
||
#include <sys/socket.h>
|
||
|
||
#ifndef __CYGWIN32__
|
||
#include <netinet/tcp.h>
|
||
#endif
|
||
|
||
#include "sim-assert.h"
|
||
#include "sim-options.h"
|
||
|
||
#include "dv-sockser.h"
|
||
|
||
#ifndef HAVE_SOCKLEN_T
|
||
typedef int socklen_t;
|
||
#endif
|
||
|
||
/* Get definitions for both O_NONBLOCK and O_NDELAY. */
|
||
|
||
#ifndef O_NDELAY
|
||
#ifdef FNDELAY
|
||
#define O_NDELAY FNDELAY
|
||
#else /* ! defined (FNDELAY) */
|
||
#define O_NDELAY 0
|
||
#endif /* ! defined (FNDELAY) */
|
||
#endif /* ! defined (O_NDELAY) */
|
||
|
||
#ifndef O_NONBLOCK
|
||
#ifdef FNBLOCK
|
||
#define O_NONBLOCK FNBLOCK
|
||
#else /* ! defined (FNBLOCK) */
|
||
#define O_NONBLOCK 0
|
||
#endif /* ! defined (FNBLOCK) */
|
||
#endif /* ! defined (O_NONBLOCK) */
|
||
|
||
|
||
/* Compromise between eating cpu and properly busy-waiting.
|
||
One could have an option to set this but for now that seems
|
||
like featuritis. */
|
||
#define DEFAULT_TIMEOUT 1000 /* microseconds */
|
||
|
||
/* FIXME: These should allocated at run time and kept with other simulator
|
||
state (duh...). Later. */
|
||
const char * sockser_addr = NULL;
|
||
/* Timeout in microseconds during status flag computation.
|
||
Setting this to zero achieves proper busy wait semantics but eats cpu. */
|
||
static unsigned int sockser_timeout = DEFAULT_TIMEOUT;
|
||
static int sockser_listen_fd = -1;
|
||
static int sockser_fd = -1;
|
||
|
||
/* FIXME: use tree properties when they're ready. */
|
||
|
||
typedef enum {
|
||
OPTION_ADDR = OPTION_START
|
||
} SOCKSER_OPTIONS;
|
||
|
||
static DECLARE_OPTION_HANDLER (sockser_option_handler);
|
||
|
||
static const OPTION sockser_options[] =
|
||
{
|
||
{ { "sockser-addr", required_argument, NULL, OPTION_ADDR },
|
||
'\0', "SOCKET ADDRESS", "Set serial emulation socket address",
|
||
sockser_option_handler },
|
||
{ { NULL, no_argument, NULL, 0 }, '\0', NULL, NULL, NULL }
|
||
};
|
||
|
||
static SIM_RC
|
||
sockser_option_handler (SIM_DESC sd, sim_cpu *cpu, int opt,
|
||
char *arg, int is_command)
|
||
{
|
||
switch (opt)
|
||
{
|
||
case OPTION_ADDR :
|
||
sockser_addr = arg;
|
||
break;
|
||
}
|
||
|
||
return SIM_RC_OK;
|
||
}
|
||
|
||
static SIM_RC
|
||
dv_sockser_init (SIM_DESC sd)
|
||
{
|
||
struct hostent *hostent;
|
||
struct sockaddr_in sockaddr;
|
||
char hostname[100];
|
||
const char *port_str;
|
||
int tmp,port;
|
||
|
||
if (STATE_ENVIRONMENT (sd) != OPERATING_ENVIRONMENT
|
||
|| sockser_addr == NULL)
|
||
return SIM_RC_OK;
|
||
|
||
if (*sockser_addr == '/')
|
||
{
|
||
/* support for these can come later */
|
||
sim_io_eprintf (sd, "sockser init: unix domain sockets not supported: `%s'\n",
|
||
sockser_addr);
|
||
return SIM_RC_FAIL;
|
||
}
|
||
|
||
port_str = strchr (sockser_addr, ':');
|
||
if (!port_str)
|
||
{
|
||
sim_io_eprintf (sd, "sockser init: missing port number: `%s'\n",
|
||
sockser_addr);
|
||
return SIM_RC_FAIL;
|
||
}
|
||
tmp = port_str - sockser_addr;
|
||
if (tmp >= sizeof hostname)
|
||
tmp = sizeof (hostname) - 1;
|
||
strncpy (hostname, sockser_addr, tmp);
|
||
hostname[tmp] = '\000';
|
||
port = atoi (port_str + 1);
|
||
|
||
hostent = gethostbyname (hostname);
|
||
if (! hostent)
|
||
{
|
||
sim_io_eprintf (sd, "sockser init: unknown host: %s\n",
|
||
hostname);
|
||
return SIM_RC_FAIL;
|
||
}
|
||
|
||
sockser_listen_fd = socket (PF_INET, SOCK_STREAM, 0);
|
||
if (sockser_listen_fd < 0)
|
||
{
|
||
sim_io_eprintf (sd, "sockser init: unable to get socket: %s\n",
|
||
strerror (errno));
|
||
return SIM_RC_FAIL;
|
||
}
|
||
|
||
sockaddr.sin_family = PF_INET;
|
||
sockaddr.sin_port = htons(port);
|
||
memcpy (&sockaddr.sin_addr.s_addr, hostent->h_addr,
|
||
sizeof (struct in_addr));
|
||
|
||
tmp = 1;
|
||
if (setsockopt (sockser_listen_fd, SOL_SOCKET, SO_REUSEADDR, (void*)& tmp, sizeof(tmp)) < 0)
|
||
{
|
||
sim_io_eprintf (sd, "sockser init: unable to set SO_REUSEADDR: %s\n",
|
||
strerror (errno));
|
||
}
|
||
if (bind (sockser_listen_fd, (struct sockaddr *) &sockaddr, sizeof (sockaddr)) < 0)
|
||
{
|
||
sim_io_eprintf (sd, "sockser init: unable to bind socket address: %s\n",
|
||
strerror (errno));
|
||
close (sockser_listen_fd);
|
||
sockser_listen_fd = -1;
|
||
return SIM_RC_FAIL;
|
||
}
|
||
if (listen (sockser_listen_fd, 1) < 0)
|
||
{
|
||
sim_io_eprintf (sd, "sockser init: unable to set up listener: %s\n",
|
||
strerror (errno));
|
||
close (sockser_listen_fd);
|
||
sockser_listen_fd = -1;
|
||
return SIM_RC_OK;
|
||
}
|
||
|
||
/* Handle writes to missing client -> SIGPIPE.
|
||
??? Need a central signal management module. */
|
||
{
|
||
RETSIGTYPE (*orig) ();
|
||
orig = signal (SIGPIPE, SIG_IGN);
|
||
/* If a handler is already set up, don't mess with it. */
|
||
if (orig != SIG_DFL && orig != SIG_IGN)
|
||
signal (SIGPIPE, orig);
|
||
}
|
||
|
||
return SIM_RC_OK;
|
||
}
|
||
|
||
static void
|
||
dv_sockser_uninstall (SIM_DESC sd)
|
||
{
|
||
if (sockser_listen_fd != -1)
|
||
{
|
||
close (sockser_listen_fd);
|
||
sockser_listen_fd = -1;
|
||
}
|
||
if (sockser_fd != -1)
|
||
{
|
||
close (sockser_fd);
|
||
sockser_fd = -1;
|
||
}
|
||
}
|
||
|
||
SIM_RC
|
||
dv_sockser_install (SIM_DESC sd)
|
||
{
|
||
SIM_ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);
|
||
if (sim_add_option_table (sd, NULL, sockser_options) != SIM_RC_OK)
|
||
return SIM_RC_FAIL;
|
||
sim_module_add_init_fn (sd, dv_sockser_init);
|
||
sim_module_add_uninstall_fn (sd, dv_sockser_uninstall);
|
||
return SIM_RC_OK;
|
||
}
|
||
|
||
static int
|
||
connected_p (SIM_DESC sd)
|
||
{
|
||
int numfds,flags;
|
||
struct timeval tv;
|
||
fd_set readfds;
|
||
struct sockaddr sockaddr;
|
||
socklen_t addrlen;
|
||
|
||
if (sockser_listen_fd == -1)
|
||
return 0;
|
||
|
||
if (sockser_fd >= 0)
|
||
{
|
||
/* FIXME: has client gone away? */
|
||
return 1;
|
||
}
|
||
|
||
/* Not connected. Connect with a client if there is one. */
|
||
|
||
FD_ZERO (&readfds);
|
||
FD_SET (sockser_listen_fd, &readfds);
|
||
|
||
/* ??? One can certainly argue this should be done differently,
|
||
but for now this is sufficient. */
|
||
tv.tv_sec = 0;
|
||
tv.tv_usec = sockser_timeout;
|
||
|
||
numfds = select (sockser_listen_fd + 1, &readfds, 0, 0, &tv);
|
||
if (numfds <= 0)
|
||
return 0;
|
||
|
||
addrlen = sizeof (sockaddr);
|
||
sockser_fd = accept (sockser_listen_fd, &sockaddr, &addrlen);
|
||
if (sockser_fd < 0)
|
||
return 0;
|
||
|
||
/* Set non-blocking i/o. */
|
||
flags = fcntl (sockser_fd, F_GETFL);
|
||
flags |= O_NONBLOCK | O_NDELAY;
|
||
if (fcntl (sockser_fd, F_SETFL, flags) == -1)
|
||
{
|
||
sim_io_eprintf (sd, "unable to set nonblocking i/o");
|
||
close (sockser_fd);
|
||
sockser_fd = -1;
|
||
return 0;
|
||
}
|
||
return 1;
|
||
}
|
||
|
||
int
|
||
dv_sockser_status (SIM_DESC sd)
|
||
{
|
||
int numrfds,numwfds,status;
|
||
struct timeval tv;
|
||
fd_set readfds,writefds;
|
||
|
||
/* status to return if the socket isn't set up, or select fails */
|
||
status = DV_SOCKSER_INPUT_EMPTY | DV_SOCKSER_OUTPUT_EMPTY;
|
||
|
||
if (! connected_p (sd))
|
||
return status;
|
||
|
||
FD_ZERO (&readfds);
|
||
FD_ZERO (&writefds);
|
||
FD_SET (sockser_fd, &readfds);
|
||
FD_SET (sockser_fd, &writefds);
|
||
|
||
/* ??? One can certainly argue this should be done differently,
|
||
but for now this is sufficient. The read is done separately
|
||
from the write to enforce the delay which we heuristically set to
|
||
once every SOCKSER_TIMEOUT_FREQ tries.
|
||
No, this isn't great for SMP situations, blah blah blah. */
|
||
|
||
{
|
||
static int n;
|
||
#define SOCKSER_TIMEOUT_FREQ 42
|
||
if (++n == SOCKSER_TIMEOUT_FREQ)
|
||
n = 0;
|
||
if (n == 0)
|
||
{
|
||
tv.tv_sec = 0;
|
||
tv.tv_usec = sockser_timeout;
|
||
numrfds = select (sockser_fd + 1, &readfds, 0, 0, &tv);
|
||
tv.tv_sec = 0;
|
||
tv.tv_usec = 0;
|
||
numwfds = select (sockser_fd + 1, 0, &writefds, 0, &tv);
|
||
}
|
||
else /* do both selects at once */
|
||
{
|
||
tv.tv_sec = 0;
|
||
tv.tv_usec = 0;
|
||
numrfds = numwfds = select (sockser_fd + 1, &readfds, &writefds, 0, &tv);
|
||
}
|
||
}
|
||
|
||
status = 0;
|
||
if (numrfds <= 0 || ! FD_ISSET (sockser_fd, &readfds))
|
||
status |= DV_SOCKSER_INPUT_EMPTY;
|
||
if (numwfds <= 0 || FD_ISSET (sockser_fd, &writefds))
|
||
status |= DV_SOCKSER_OUTPUT_EMPTY;
|
||
return status;
|
||
}
|
||
|
||
int
|
||
dv_sockser_write (SIM_DESC sd, unsigned char c)
|
||
{
|
||
int n;
|
||
|
||
if (! connected_p (sd))
|
||
return -1;
|
||
n = write (sockser_fd, &c, 1);
|
||
if (n == -1)
|
||
{
|
||
if (errno == EPIPE)
|
||
{
|
||
close (sockser_fd);
|
||
sockser_fd = -1;
|
||
}
|
||
return -1;
|
||
}
|
||
if (n != 1)
|
||
return -1;
|
||
return 1;
|
||
}
|
||
|
||
int
|
||
dv_sockser_read (SIM_DESC sd)
|
||
{
|
||
unsigned char c;
|
||
int n;
|
||
|
||
if (! connected_p (sd))
|
||
return -1;
|
||
n = read (sockser_fd, &c, 1);
|
||
/* ??? We're assuming semantics that may not be correct for all hosts.
|
||
In particular (from cvssrc/src/server.c), this assumes that we are using
|
||
BSD or POSIX nonblocking I/O. System V nonblocking I/O returns zero if
|
||
there is nothing to read. */
|
||
if (n == 0)
|
||
{
|
||
close (sockser_fd);
|
||
sockser_fd = -1;
|
||
return -1;
|
||
}
|
||
if (n != 1)
|
||
return -1;
|
||
return c;
|
||
}
|