SGI Developer Toolbox 6.1/SGI Developer Toolbox 6.1 - Disc 4.iso/public/fax/src/faxd/Getty.c++

C/C++ Source or Header | 1994-08-01 | 5KB | 195 lines

/*    $Header: /usr/people/sam/fax/faxd/RCS/Getty.c++,v 1.24 1994/02/28 14:15:22 sam Rel $ */
/*
 * Copyright (c) 1990, 1991, 1992, 1993, 1994 Sam Leffler
 * Copyright (c) 1991, 1992, 1993, 1994 Silicon Graphics, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software and
 * its documentation for any purpose is hereby granted without fee, provided
 * that (i) the above copyright notices and this permission notice appear in
 * all copies of the software and related documentation, and (ii) the names of
 * Sam Leffler and Silicon Graphics may not be used in any advertising or
 * publicity relating to the software without the specific, prior written
 * permission of Sam Leffler and Silicon Graphics.
 *
 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
 *
 * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 */
#include "Getty.h"
#include "UUCPLock.h"

#include <stdarg.h>
#include <termios.h>
#include <osfcn.h>
#include <signal.h>
#include <syslog.h>
#include <paths.h>
#include <sys/param.h>
#include <sys/stat.h>

/*
 * FAX Server Getty Support Base Class.
 */

const fxStr Getty::getty = _PATH_GETTY;

Getty::Getty(const fxStr& l, const fxStr& s, u_int t)
    : line(l)
    , speed(s)
{
    pid = 0;
    timeout = t;
}

Getty::~Getty()
{
}

void Getty::setTimeout(u_int t)        { timeout = t; }

static void
sigHUP(int)
{
    (void) close(0);
    (void) close(1);
    (void) close(2);
    sleep(5);
    _exit(1);
}

/*
 * Parse the getty argument string and
 * substitute runtime parameters:
 *
 *    %l    tty device name
 *    %s    current baud rate
 *
 * The resultant argv array is used to
 * exec getty below.
 */
void
Getty::setupArgv(const char* args)
{
    argbuf = args;
    u_int l;
    /*
     * Substitute escape sequences.
     */
    for (l = 0; l < argbuf.length();) {
    l = argbuf.next(l, '%');
    if (l >= argbuf.length()-1)
        break;
    switch (argbuf[l+1]) {
    case 'l':            // %l = tty device name
        argbuf.remove(l,2);
        argbuf.insert(line, l);
        l += line.length();        // avoid loops
        break;
    case 's':            // %s = tty speed
        argbuf.remove(l,2);
        argbuf.insert(speed, l);
        l += speed.length();    // avoid loops
        break;
    case '%':            // %% = %
        argbuf.remove(l,1);
        break;
    }
    }
    /*
     * Crack argument string and setup argv.
     */
    argv[0] = &getty[getty.nextR(getty.length(), '/')];
    u_int nargs = 1;
    for (l = 0; l < argbuf.length() && nargs < GETTY_MAXARGS-1;) {
    l = argbuf.skip(l, " \t");
    u_int token = l;
    l = argbuf.next(l, " \t");
    if (l > token) {
        if (l < argbuf.length())
        argbuf[l++] = '\0';        // null terminate argument
        argv[nargs++] = &argbuf[token];
    }
    }
    argv[nargs] = NULL;
}

/*
 * Run a getty session and if successful exec the
 * getty program.  Note that this is always run in
 * the child.  We actually fork again here so that
 * we immediately reap the real getty and cleanup
 * state.  It also simplifies matters of uid management
 * since the fax server runs as effective uid other
 * than root, but we're started up with real&effective
 * uid root.
 */
void
Getty::run(int fd, const char* args)
{
    pid = fork();
    if (pid == -1)
    fatal("getty: can not fork reaper process");
    closelog();
    openlog("FaxGetty", LOG_PID, LOG_AUTH);
    if (chdir("/dev") < 0)
    fatal("chdir: %m");
    if (pid == 0) {            // child, exec getty
    signal(SIGHUP, fxSIGHANDLER(sigHUP));
    setupArgv(args);
    /*
     * After the session is properly setup, the
     * stdio streams will be hooked to the tty
     * and we can discard the file descriptor.
     */
    setupSession(fd);

    char* envp[1];
    envp[0] = NULL;
    execve((char*) getty, argv, envp);
    _exit(127);
    } else {                // parent, wait for getty/login
    close(fd);            // close so HUPCL works correctly
    int status;
    wait(status, TRUE);        // wait for getty/login work to complete
    hangup();
    _exit(status);            // pass exit status upward
    }
}

void
Getty::hangup()
{
    chown(getLine(), UUCPLock::getUUCPUid(), UUCPLock::getUUCPGid());
    chmod(getLine(), 0600);        // reset protection
}

void
Getty::error(const char* va_alist, ...)
#define    fmt va_alist
{
    va_list ap;
    va_start(ap, fmt);
    vsyslog(LOG_ERR, fmt, ap);
    va_end(ap);
}
#undef fmt

void
Getty::fatal(const char* va_alist, ...)
#define    fmt va_alist
{
    va_list ap;
    va_start(ap, fmt);
    vsyslog(LOG_ERR, fmt, ap);
    va_end(ap);
    hangup();
}
#undef fmt