newlib-cygwin/winsup/cygwin/libc/rexec.cc

/*
 * Copyright (c) 1980, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD$
 */

/* CV 2006-07-04: Tweaked for inclusion into Cygwin. */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)rexec.c	8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */

#ifdef __CYGWIN__
#include "winsup.h"
#include "sigproc.h"
#include "cygtls.h"
#include <wininet.h>
#endif

#include <sys/types.h>
#include <sys/uio.h>
#include <sys/socket.h>
#include <sys/param.h>
#include <sys/stat.h>

#include <netinet/in.h>

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <netdb.h>
#include <errno.h>
#include <ctype.h>
#include <err.h>
#include <stdlib.h>
#include <unistd.h>

extern "C" {
  int cygwin_accept (int, struct sockaddr *, socklen_t *);
  int cygwin_connect (int, const struct sockaddr *, socklen_t);
  int cygwin_gethostname (char *__name, size_t __len);
  int cygwin_getsockname (int, struct sockaddr *, socklen_t *);
  void cygwin_herror (const char *);
  int cygwin_listen (int, int);
  int cygwin_socket (int, int, int);
}

/*
 * Options and other state info.
 */
struct macel {
	char mac_name[9];	/* macro name */
	char *mac_start;	/* start of macro in macbuf */
	char *mac_end;		/* end of macro in macbuf */
};

int macnum;			/* number of defined macros */
struct macel macros[16];
char macbuf[4096];

static	FILE *cfile;

#define	DEFAULT	1
#define	LOGIN	2
#define	PASSWD	3
#define	ACCOUNT 4
#define MACDEF  5
#define	ID	10
#define	MACH	11

static char tokval[100];

static struct toktab {
	const char *tokstr;
	int tval;
} toktab[]= {
	{ "default",	DEFAULT },
	{ "login",	LOGIN },
	{ "password",	PASSWD },
	{ "passwd",	PASSWD },
	{ "account",	ACCOUNT },
	{ "machine",	MACH },
	{ "macdef",	MACDEF },
	{ NULL,		0 }
};

static int
token()
{
	char *cp;
	int c;
	struct toktab *t;

	if (feof(cfile) || ferror(cfile))
		return (0);
	while ((c = getc(cfile)) != EOF &&
	    (c == '\n' || c == '\t' || c == ' ' || c == ','))
		continue;
	if (c == EOF)
		return (0);
	cp = tokval;
	if (c == '"') {
		while ((c = getc(cfile)) != EOF && c != '"') {
			if (c == '\\')
				c = getc(cfile);
			*cp++ = c;
		}
	} else {
		*cp++ = c;
		while ((c = getc(cfile)) != EOF
		    && c != '\n' && c != '\t' && c != ' ' && c != ',') {
			if (c == '\\')
				c = getc(cfile);
			*cp++ = c;
		}
	}
	*cp = 0;
	if (tokval[0] == 0)
		return (0);
	for (t = toktab; t->tokstr; t++)
		if (!strcmp(t->tokstr, tokval))
			return (t->tval);
	return (ID);
}

static int
ruserpass(const char *host, char **aname, char **apass, char **aacct)
{
	const char *hdir;
	char buf[BUFSIZ], *tmp;
	char myname[INTERNET_MAX_HOST_NAME_LENGTH + 1];
	const char *mydomain;
	int t, i, c, usedefault = 0;
	struct stat stb;

	hdir = getenv("HOME");
	if (hdir == NULL)
		hdir = ".";
	if (strlen(hdir) + 8 > sizeof(buf))
		return (0);
	(void) sprintf(buf, "%s/.netrc", hdir);
	cfile = fopen(buf, "r");
	if (cfile == NULL) {
		if (errno != ENOENT)
			warn("%s", buf);
		return (0);
	}
	if (cygwin_gethostname(myname, sizeof(myname)) < 0)
		myname[0] = '\0';
	if ((mydomain = strchr(myname, '.')) == NULL)
		mydomain = "";
next:
	while ((t = token())) switch(t) {

	case DEFAULT:
		usedefault = 1;
		fallthrough;

	case MACH:
		if (!usedefault) {
			if (token() != ID)
				continue;
			/*
			 * Allow match either for user's input host name
			 * or official hostname.  Also allow match of
			 * incompletely-specified host in local domain.
			 */
			if (strcasecmp(host, tokval) == 0)
				goto match;
			if ((tmp = strchr(host, '.')) != NULL &&
			    strcasecmp(tmp, mydomain) == 0 &&
			    strncasecmp(host, tokval, tmp - host) == 0 &&
			    tokval[tmp - host] == '\0')
				goto match;
			continue;
		}
	match:
		while ((t = token()) && t != MACH && t != DEFAULT) switch(t) {

		case LOGIN:
			if (token()) {
				if (*aname == 0) {
					*aname = (char *) malloc((unsigned) strlen(tokval) + 1);
					(void) strcpy(*aname, tokval);
				} else {
					if (strcmp(*aname, tokval))
						goto next;
				}
			}
			break;
		case PASSWD:
			if ((*aname == 0 || strcmp(*aname, "anonymous")) &&
			    fstat64(fileno(cfile), &stb) >= 0 &&
			    (stb.st_mode & 077) != 0) {
	warnx("Error: .netrc file is readable by others.");
	warnx("Remove password or make file unreadable by others.");
				goto bad;
			}
			if (token() && *apass == 0) {
				*apass = (char *) malloc((unsigned) strlen(tokval) + 1);
				(void) strcpy(*apass, tokval);
			}
			break;
		case ACCOUNT:
			if (fstat64(fileno(cfile), &stb) >= 0
			    && (stb.st_mode & 077) != 0) {
	warnx("Error: .netrc file is readable by others.");
	warnx("Remove account or make file unreadable by others.");
				goto bad;
			}
			if (token() && aacct && *aacct == 0) {
				*aacct = (char *) malloc((unsigned) strlen(tokval) + 1);
				(void) strcpy(*aacct, tokval);
			}
			break;
		case MACDEF:
			while ((c=getc(cfile)) != EOF &&
						(c == ' ' || c == '\t'))
				;
			if (c == EOF || c == '\n') {
				printf("Missing macdef name argument.\n");
				goto bad;
			}
			if (macnum == 16) {
				printf("Limit of 16 macros have already been defined\n");
				goto bad;
			}
			tmp = macros[macnum].mac_name;
			*tmp++ = c;
			for (i=0; i < 8 && (c=getc(cfile)) != EOF &&
			    !isspace(c); ++i) {
				*tmp++ = c;
			}
			if (c == EOF) {
				printf("Macro definition missing null line terminator.\n");
				goto bad;
			}
			*tmp = '\0';
			if (c != '\n') {
				while ((c=getc(cfile)) != EOF && c != '\n');
			}
			if (c == EOF) {
				printf("Macro definition missing null line terminator.\n");
				goto bad;
			}
			if (macnum == 0) {
				macros[macnum].mac_start = macbuf;
			}
			else {
				macros[macnum].mac_start = macros[macnum-1].mac_end + 1;
			}
			tmp = macros[macnum].mac_start;
			while (tmp != macbuf + 4096) {
				if ((c=getc(cfile)) == EOF) {
				printf("Macro definition missing null line terminator.\n");
					goto bad;
				}
				*tmp = c;
				if (*tmp == '\n') {
					if (*(tmp-1) == '\0') {
					   macros[macnum++].mac_end = tmp - 1;
					   break;
					}
					*tmp = '\0';
				}
				tmp++;
			}
			if (tmp == macbuf + 4096) {
				printf("4K macro buffer exceeded\n");
				goto bad;
			}
			break;
		default:
			warnx("Unknown .netrc keyword %s", tokval);
			break;
		}
		goto done;
	}
done:
	(void) fclose(cfile);
	return (0);
bad:
	(void) fclose(cfile);
	return (-1);
}

extern "C" int
cygwin_rexec (char **ahost, unsigned short rport, char *name, char *pass,
	      char *cmd, int *fd2p)
{
  struct sockaddr_in sin, sin2, from;
  struct hostent *hp;
  uint16_t port = 0;
  int s, timo = 1, s3;
  char c;
  static char ahostbuf[INTERNET_MAX_HOST_NAME_LENGTH + 1];

  __try
    {
      hp = cygwin_gethostbyname(*ahost);
      if (hp == 0) {
	      cygwin_herror(*ahost);
	      return (-1);
      }
      *ahost = strcpy (ahostbuf, hp->h_name);
      ruserpass(hp->h_name, &name, &pass, NULL);
      if (!name)
	      name = getlogin ();
      if (!pass)
	      pass = almost_null;
retry:
      s = cygwin_socket(AF_INET, SOCK_STREAM, 0);
      if (s < 0) {
	      perror("rexec: socket");
	      return (-1);
      }
      sin.sin_family = hp->h_addrtype;
      sin.sin_port = rport;
      bcopy(hp->h_addr, (caddr_t)&sin.sin_addr, hp->h_length);
      if (cygwin_connect(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
	      if (errno == ECONNREFUSED && timo <= 16) {
		      (void) close(s);
		      sleep(timo);
		      timo *= 2;
		      goto retry;
	      }
	      perror(hp->h_name);
	      return (-1);
      }
      if (fd2p == 0) {
	      (void) write(s, "", 1);
      } else {
	      char num[8];
	      int s2, sin2len;

	      s2 = cygwin_socket(AF_INET, SOCK_STREAM, 0);
	      if (s2 < 0) {
		      (void) close(s);
		      return (-1);
	      }
	      cygwin_listen(s2, 1);
	      sin2len = sizeof (sin2);
	      if (cygwin_getsockname(s2, (struct sockaddr *)&sin2, &sin2len) < 0 ||
		sin2len != sizeof (sin2)) {
		      perror("getsockname");
		      (void) close(s2);
		      goto bad;
	      }
	      port = ntohs((uint16_t)sin2.sin_port);
	      (void) sprintf(num, "%u", port);
	      (void) write(s, num, strlen(num)+1);
	      { int len = sizeof (from);
		s3 = cygwin_accept(s2, (struct sockaddr *)&from, &len);
		close(s2);
		if (s3 < 0) {
		      perror("accept");
		      port = 0;
		      goto bad;
		}
	      }
	      *fd2p = s3;
      }
      (void) write(s, name, strlen(name) + 1);
      /* should public key encypt the password here */
      (void) write(s, pass, strlen(pass) + 1);
      (void) write(s, cmd, strlen(cmd) + 1);
      if (read(s, &c, 1) != 1) {
	      perror(*ahost);
	      goto bad;
      }
      if (c != 0) {
	      while (read(s, &c, 1) == 1) {
		      (void) write(2, &c, 1);
		      if (c == '\n')
			      break;
	      }
	      goto bad;
      }
      return (s);
bad:
      if (port)
	      (void) close(*fd2p);
      (void) close(s);
    }
  __except (EFAULT) {}
  __endtry
  return (-1);
}