+++ /dev/null
-/*
- * nsplitd.c
- * ---------
- *
- * $Id: nsplitd.c,v 2.6 1998/09/17 14:28:37 sde1000 Exp $
- *
- * Copyright (c) 1995, University of Cambridge Computer Laboratory,
- * Copyright (c) 1995, Richard Black, All Rights Reserved.
- *
- *
- * A complete re-implementation of DME's nsplitd for use from inetd
- *
- */
-
-/* The basic stream comes in (via inetd) and we then conenct to
- * somewhere else providing a loop-through service, except we offer
- * two other ports for connection - one of which gets a second channel
- * using the top bit to distinguish, and the other is a master control
- * port (normally used for gdb) which gets complete exclusive access
- * for its duration.
- *
- * Originally designed for multiplexing a xwcons/telnet with a gdb
- * post-mortem debugging session.
- *
- * Here is a picture:
- *
- * port0 (from inetd)
- * 8-bit connection /
- * made by us <----> nsplitd <-----gdbport (default port0+2)
- * to host:port/tcp |\
- * | port1 (default port0+1)
- * \
- * control (default port0+3)
- *
- * If port1 is explicitly disabled (through a command-line option) then
- * port0 becomes 8-bit clean.
- */
-
-/*
- * N.B.: We do NOT support 8 bit stdin/stdout usage on a
- * /dev/... because to do that right involves much messing with ioctl
- * and TIOC... etc. If you want to do that sort of thing then the
- * right way to do it is to chain this onto wconsd (which does know
- * about and understand all the ioctl and TIOC grief).
- */
-
-#include <sys/types.h>
-#include <stdarg.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <assert.h>
-#include <errno.h>
-#include <unistd.h>
-#include <ctype.h>
-#include <netdb.h>
-#include <string.h>
-
-#include <sys/time.h>
-#include <sys/signal.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <netinet/tcp.h>
-#include <arpa/inet.h>
-#include <sys/ioctl.h>
-#include <syslog.h>
-
-#ifndef FALSE
-#define FALSE 0
-#endif
-#ifndef TRUE
-#define TRUE 1
-#endif
-
-#ifndef LOG_DAEMON
-#define LOG_DAEMON 0
-#endif
-
-#define DB(x) /* ((x), fflush(stderr)) */
-
-extern char *optarg;
-
-extern int optind, opterr, optopt;
-
-static char *prog_name;
-
-static void usage(void)
-{
- fprintf(stderr, "This program (%s) should be run via inetd (tcp)\n\n",
- prog_name);
- fprintf(stderr, "usage: %s [-h<highport>][-g<gdbport>]"
- "[-c<ctlport>][-8] host:service\n",
- prog_name);
- exit(1);
-}
-
-static void fault(char *format, ...)
-{
- va_list ap;
- char logbuf[1024];
-
- va_start(ap, format);
- fprintf(stderr, "%s: ", prog_name);
- vfprintf(stderr, format, ap);
- fflush(stderr);
- va_end(ap);
-
- /* XXX This is a bit dubious, but there is no vsyslog */
- va_start(ap, format);
- vsprintf(logbuf, format, ap);
- syslog(LOG_ERR, logbuf);
- va_end(ap);
- exit(1);
-}
-
-static int getservice(char *name, unsigned short *port)
-{
- struct servent *se;
-
- if (!name) return -1;
-
- if (isdigit(name[0]))
- *port = atoi(name);
- else
- {
- if (!(se = getservbyname(name, "tcp")))
- return -1;
- *port = ntohs(se->s_port);
- }
- return 0;
-}
-
-/*
- * connect_host: connect to ("name", "port")
- */
-static int connect_host (char *name, unsigned int port)
-{
- int fd;
- struct hostent *hostent;
- struct sockaddr_in sin;
- int on;
-
- if ((fd = socket (AF_INET, SOCK_STREAM, 0)) < 0)
- fault("socket");
-
- if (!(hostent = gethostbyname(name)))
- fault("gethostbyname: %s: %s\n", name, strerror(errno));
-
- memset(&sin, 0, sizeof(sin));
- sin.sin_family = AF_INET;
- sin.sin_port = htons (port);
- memcpy(&sin.sin_addr.s_addr, hostent->h_addr, sizeof(struct in_addr));
-
- if (connect(fd, (struct sockaddr *) &sin, sizeof (sin)) < 0)
- fault("connect: %s:%u: %s\n", name, port, strerror(errno));
-
- on = 1;
- if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &on, sizeof (on)) < 0)
- syslog(LOG_WARNING, "setsockopt (TCP_NODELAY): %m");
-
- on = 1;
- if (setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof (on)) < 0)
- syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
-
- return fd;
-}
-
-/*
- * open a tcp socket and start listening for connections on it
- */
-static int startlistening(unsigned short port)
-{
- int fd, on;
- struct sockaddr_in sin;
-
- if ((fd = socket (AF_INET, SOCK_STREAM, 0)) < 0)
- fault("socket");
-
- on = 1;
- if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof (on)) < 0)
- syslog(LOG_WARNING, "setsockopt (SO_REUSEADDR): %m");
-
- memset(&sin, 0, sizeof(sin));
- sin.sin_family = AF_INET;
- sin.sin_port = htons (port);
- sin.sin_addr.s_addr = INADDR_ANY;
- if (bind(fd, &sin, sizeof(sin)) < 0)
- fault("bind: %u: %s\n", port, strerror(errno));
-
- if (listen(fd, 1) < 0)
- fault("listen: %s\n", strerror(errno));
-
- return fd;
-}
-
-static void noblock(int fd)
-{
- int on=1;
-
- if (ioctl(fd, FIONBIO, &on) < 0)
- fault("ioctl: FIONBIO: %s\n", strerror(errno));
-}
-
-
-/* You might not believe this, but fd_sets don't have to be a 32-bit
- * integer. In particular, in glibc2 it is an array of unsigned
- * longs. Hence, this hacked up FD_SET_rjb() that works out if it
- * would have been a nop. */
-#define FD_SET_rjb(fd, setp) \
-do { \
- if ((fd) != 32) \
- FD_SET((fd), (setp)); \
-} while(0)
-
-#define FD_ISSET_rjb(fd, setp) (((fd) != 32)? FD_ISSET((fd), (setp)) : 0)
-
-#define MAXSIZE 256
-
-/* -----------------------------------------------------------------
- * The main bit of the algorithm. Note we use 32 to mean not connected
- * because this gives us 1<<32 == 0. We could have done this one
- * character at a time, but that would have been very inefficient and
- * not the unix way. */
-static int debug;
-
-static void doit(int actl, int acto, int lish, int lisg, int lisc)
-{
- int acth, actg, actc;
- int gdbmode = FALSE;
- char gibuf[MAXSIZE], oibuf[MAXSIZE];
- char libuf[MAXSIZE], lobuf[MAXSIZE];
- char hibuf[MAXSIZE], hobuf[MAXSIZE];
- char ctlbuf[MAXSIZE];
- fd_set rdfs, wrfs, exfs;
- int gicc, oicc, licc, locc, hicc, hocc, ctlcc;
- char *giptr, *oiptr, *liptr, *loptr, *hiptr, *hoptr;
- int rc, fromlen;
- struct sockaddr_in from;
-
- gicc = oicc = licc = locc = hicc = hocc = ctlcc = 0;
- acth = actg = actc = 32; /* XXX yummy */
-
- noblock(actl);
- noblock(acto);
-
- for(;;)
- {
- FD_ZERO(&rdfs);
- FD_ZERO(&wrfs);
- FD_ZERO(&exfs);
-
- /* always take input from the control port (if it's connected) */
- FD_SET_rjb(actc, &rdfs);
-
- if (gdbmode)
- {
- if (oicc)
- FD_SET_rjb(actg, &wrfs);
- else
- FD_SET_rjb(acto, &rdfs);
-
- if (gicc)
- FD_SET_rjb(acto, &wrfs);
- else
- FD_SET_rjb(actg, &rdfs);
- }
- else
- {
- /* There is no such thing as oibuf because its been split into
- * lobuf and hobuf
- */
- if (locc || hocc)
- {
- if (locc)
- FD_SET_rjb(actl, &wrfs);
- if (hocc)
- FD_SET_rjb(acth, &wrfs);
- }
- else
- FD_SET_rjb(acto, &rdfs);
-
- if (licc)
- FD_SET_rjb(acto, &wrfs);
- else
- FD_SET_rjb(actl, &rdfs);
-
- if (hicc)
- FD_SET_rjb(acto, &wrfs);
- else
- FD_SET_rjb(acth, &rdfs);
- }
-
- if (acth == 32 && lish>=0) FD_SET_rjb(lish, &rdfs);
- if (actg == 32) FD_SET_rjb(lisg, &rdfs);
- if (actc == 32) FD_SET_rjb(lisc, &rdfs);
-
- /* now make exfs the union of the read and write fd sets, plus
- * "actl" */
- {
- int i;
- exfs = rdfs;
- for(i=0; i<32; i++) /* XXX we only copy fd numbers up to 31 */
- if (FD_ISSET(i, &wrfs))
- FD_SET_rjb(i, &exfs);
- FD_SET_rjb(actl, &exfs);
- }
-
- /* XXX AND: can't print something of type fd_set as %x - it
- * might be an array */
- DB(fprintf(stderr, "%s: before select: %08x %08x %08x\n",
- prog_name, rdfs, wrfs, exfs));
-
- if (select(32, &rdfs, &wrfs, &exfs, NULL) < 0)
- fault("select: %s\n", strerror(errno));
-
- DB(fprintf(stderr, "%s: after select: %08x %08x %08x\n",
- prog_name, rdfs, wrfs, exfs));
-
- /* XXX it appears that a non-blocking socket may not show up
- * correctly in exfs but instead goes readable with no data in
- * it. Thus we check for zero and goto the appropriate close
- * method. */
-
- /* Deal with exceptions */
- if (FD_ISSET_rjb(actg, &exfs))
- {
- exfs_actg:
- close(actg);
- gdbmode = FALSE;
- oicc = 0;
- oiptr = oibuf;
- actg = 32;
- continue; /* because assumptions changed */
- }
- if (FD_ISSET_rjb(acth, &exfs))
- {
- exfs_acth:
- close(acth);
- hicc = hocc = 0;
- hiptr = hibuf;
- hoptr = hibuf;
- acth = 32;
- continue; /* because assumptions changed */
- }
- if (FD_ISSET_rjb(actl, &exfs) ||
- FD_ISSET_rjb(acto, &exfs))
- {
- exfs_actl:
- exfs_acto:
- /* Thats all folks ... */
- break;
- }
- if (FD_ISSET_rjb(actc, &exfs))
- {
- exfs_ctl:
- close(actc);
- actc = 32;
- ctlcc = 0;
- continue;
- }
-
- /* Deal with reading */
- if (FD_ISSET_rjb(acto, &rdfs))
- {
- if ((oicc = read(acto, oiptr = oibuf, MAXSIZE)) < 0)
- fault("read acto: %d: %s\n", oicc, strerror(errno));
- if (!oicc) goto exfs_acto;
-
- if (!gdbmode)
- {
- int t;
-
- assert((locc == 0) && (hocc == 0));
- loptr = lobuf;
- hoptr = hobuf;
-
- if (lish>=0) {
- for(t=0; t<oicc; t++)
- if (oibuf[t] & 0x80)
- hobuf[hocc++] = oibuf[t] & 0x7f;
- else
- lobuf[locc++] = oibuf[t];
- } else {
- for (t=0; t<oicc; t++)
- lobuf[locc++] = oibuf[t];
- }
- /* If no high connection scratch that */
- if (acth == 32)
- hocc=0;
- }
- }
- if (FD_ISSET_rjb(actl, &rdfs))
- {
- if ((licc = read(actl, liptr = libuf, MAXSIZE)) < 0)
- fault("read actl: %d: %s\n", licc, strerror(errno));
- if (!licc) goto exfs_actl;
- }
- if (FD_ISSET_rjb(acth, &rdfs))
- {
- int t;
-
- if ((hicc = read(acth, hiptr = hibuf, MAXSIZE)) < 0)
- fault("read acth: %d: %s\n", hicc, strerror(errno));
- if (!hicc) goto exfs_acth;
- for(t=0; t<hicc; t++)
- hibuf[t] |= 0x80;
- }
- if (FD_ISSET_rjb(actg, &rdfs))
- {
- if ((gicc = read(actg, giptr = gibuf, MAXSIZE)) < 0)
- fault("read actg: %d: %s\n", gicc, strerror(errno));
- if (debug) write(1, giptr, gicc); /* XXX */
- if (!gicc) goto exfs_actg;
- }
- if (FD_ISSET_rjb(actc, &rdfs))
- {
- if ((ctlcc = read(actc, ctlbuf, MAXSIZE)) < 0)
- fault("read actc: %d: %s\n", ctlcc, strerror(errno));
- if (debug) write(1, ctlbuf, gicc);
- if (!ctlcc) goto exfs_ctl;
- if (ctlbuf[0] == 'r') /* reset command */
- {
- syslog(LOG_INFO, "reset command read, exiting");
- if (debug) write(1, "reseting\n", sizeof("reseting\n"));
- break;
- }
- }
-
- /* Deal with writing */
- if (FD_ISSET_rjb(actg, &wrfs))
- {
- /* We must be in gdb mode so send oi buffer data */
- assert(gdbmode);
- if (debug) write(2, oiptr, oicc); /* XXX */
- if ((rc = write(actg, oiptr, oicc)) <= 0)
- fault("write actg: %d: %s\n", rc, strerror(errno));
- oiptr += rc;
- oicc -= rc;
- }
- if (FD_ISSET_rjb(actl, &wrfs))
- {
- if ((rc = write(actl, loptr, locc)) <= 0)
- fault("write actl: %d: %s\n", rc, strerror(errno));
- loptr += rc;
- locc -= rc;
- }
- if (FD_ISSET_rjb(acth, &wrfs))
- {
- if ((rc = write(acth, hoptr, hocc)) <= 0)
- fault("write acth: %d: %s\n", rc, strerror(errno));
- hoptr += rc;
- hocc -= rc;
- }
- if (FD_ISSET_rjb(acto, &wrfs))
- {
- /* If in gdb mode send gdb input, otherwise send low data
- preferentially */
- if (gdbmode)
- {
- assert(gicc);
- if ((rc = write(acto, giptr, gicc)) <= 0)
- fault("write acto: %d: %s\n", rc, strerror(errno));
- giptr += rc;
- gicc -= rc;
- }
- else
- {
- if (licc)
- {
- if ((rc = write(acto, liptr, licc)) <= 0)
- fault("write acto: %d: %s\n", rc, strerror(errno));
- liptr += rc;
- licc -= rc;
- }
- else
- {
- assert(hicc);
- if ((rc = write(acto, hiptr, hicc)) <= 0)
- fault("write acto: %d: %s\n", rc, strerror(errno));
- hiptr += rc;
- hicc -= rc;
- }
- }
- }
-
- /* Deals with new connections */
- if ((acth == 32) && lish>=0 && (FD_ISSET_rjb(lish, &rdfs)))
- {
- fromlen = sizeof(from);
- if ((acth = accept(lish, &from, &fromlen)) < 0)
- {
- syslog(LOG_WARNING, "accept: %m");
- acth = 32;
- }
- else
- {
- noblock(acth);
- hicc = hocc = 0;
- syslog(LOG_INFO, "highbit client peer is %s:%u\n",
- inet_ntoa(from.sin_addr), ntohs(from.sin_port));
- }
- }
-
- if ((actg == 32) && (FD_ISSET_rjb(lisg, &rdfs)))
- {
- fromlen = sizeof(from);
- if ((actg = accept(lisg, &from, &fromlen)) < 0)
- {
- syslog(LOG_WARNING, "accept: %m");
- actg = 32;
- }
- else
- {
- noblock(actg);
- gicc = 0;
- gdbmode = TRUE;
- syslog(LOG_INFO, "gdb client peer is %s:%u\n",
- inet_ntoa(from.sin_addr), ntohs(from.sin_port));
- }
- }
-
- if ((actc == 32) && (FD_ISSET_rjb(lisc, &rdfs)))
- {
- fromlen = sizeof(from);
- if ((actc = accept(lisc, &from, &fromlen)) < 0)
- {
- syslog(LOG_WARNING, "accept (ctl): %m");
- actc = 32;
- }
- else
- {
- noblock(actc);
- syslog(LOG_INFO, "ctl client peer is %s:%u\n",
- inet_ntoa(from.sin_addr), ntohs(from.sin_port));
- }
- }
-
- /* Back to top of loop */
- }
-
- /* We are bailing because one of the primary connections has gone
- * away. We close these all explicitly here because that way the
- * timeout on reusing the port numbers is smnaller. */
-
- close(acth);
- close(actg);
- /* XXX AND: why are we closing all these "character counts" ?? */
- close(gicc);
- close(oicc);
- close(licc);
- close(locc);
- close(hicc);
- close(hocc);
-}
-
-/*
- * ------------------------------------------------------------
- */
-int main(int argc, char **argv)
-{
- /* In general, suffix "l" is low channel, "h" is high channel, "g"
- * is gdb channel, "c" is control channel and "o" is output channel.
- */
- struct sockaddr_in from;
- int infd = 0, outfd;
- unsigned short portl, porth, portg, portc, porto;
- int on = 1, c;
- char *outname, *outservice;
- int fromlen;
- int lish, lisg, lisc;
-#if 0
- FILE *newerr;
-#endif /* 0 */
-
- prog_name = argv[0];
-
- if (isatty(infd))
- usage();
-
- /* Here, then not just a simple idiot. */
-
- signal(SIGPIPE, SIG_IGN);
-
- openlog(prog_name, LOG_PID, LOG_DAEMON);
-
- fromlen = sizeof(from);
- if (getsockname(infd, &from, &fromlen) < 0)
- fault("getsockname: %s", strerror(errno));
- if ((fromlen != sizeof(from)) || (from.sin_family != AF_INET))
- fault("not an inet socket (family=%d)\n", from.sin_family);
-
- portl = ntohs(from.sin_port);
- porth = portl+1;
- portg = porth+1;
- portc = portg+1;
-
- fromlen = sizeof(from);
- if (getpeername(infd, &from, &fromlen) < 0)
- fault("getpeername: %s", strerror(errno));
- if ((fromlen != sizeof(from)) || (from.sin_family != AF_INET))
- fault("not an inet socket (family=%d)\n", from.sin_family);
-
- syslog(LOG_INFO, "on port %u peer is %s:%u\n", portl,
- inet_ntoa(from.sin_addr), ntohs(from.sin_port));
-
- if (setsockopt(infd, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof (on)) < 0)
- syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
-
- /* from here on, we map stderr to output on the connection so we can
- * report errors to the remote user.
- */
-#if 0
- if (!(newerr = fdopen(infd, "w")))
- syslog(LOG_WARNING, "fdopen: %m");
- else
- *stderr = *newerr;
-#endif
-
- while((c = getopt(argc, argv, "d8h:g:c:")) != EOF)
- {
- switch(c)
- {
- case 'd':
- debug++;
- break;
-
- case 'h':
- /* high bit port */
- if (getservice(optarg, &porth) < 0)
- fault("getservice failed (high port '%s')\n", optarg);
- break;
-
- case 'g':
- /* gdb port */
- if (getservice(optarg, &portg) < 0)
- fault("getservice failed (gdb port '%s')\n", optarg);
- break;
-
- case 'c':
- /* control port */
- if (getservice(optarg, &portc) < 0)
- fault("getservice failed (control port '%s')\n", optarg);
- break;
-
- case '8':
- /* 8-bit clean; no high port */
- porth=0;
- break;
-
- default:
- fault("bad argument list!\n");
- }
- }
-
- if (argc != optind + 1)
- fault("unparsed arguments (%d!=%d)\n", argc, optind+1);
-
- outname = argv[optind];
- if (!(outservice = strchr(outname, ':')))
- fault("output arg '%s' doesn't contain ':'\n", outname);
- *outservice++ = 0;
- if (getservice(outservice, &porto) < 0)
- fault("getservice failed (output port '%s')\n", outservice);
-
- /* Time to start the sockets */
-
- if (porth) {
- lish = startlistening(porth);
- } else {
- lish = -1;
- }
- lisg = startlistening(portg);
- lisc = startlistening(portc);
-
- outfd = connect_host(outname, porto);
-
- doit(infd, outfd, lish, lisg, lisc);
-
- syslog(LOG_INFO, "terminating normally\n");
-
- fclose(stderr);
-
- closelog();
- exit(0);
-}
-
-/* End $Id: nsplitd.c,v 2.6 1998/09/17 14:28:37 sde1000 Exp $ */
projects / xen.git / commitdiff