IRIX 6.2 Applications 1996 May/SGI IRIX 6.2 Applications 1996 May.iso/dist/impr_dev.idb/usr/impressario/src/libspool/SLUtil.c.z/SLUtil.c

C/C++ Source or Header | 1996-05-06 | 20KB | 744 lines

/**************************************************************************
 *                                      *
 *           Copyright (c)    1991 Silicon Graphics, Inc.          *
 *            All Rights Reserved                    *
 *                                      *
 *       THIS    IS UNPUBLISHED PROPRIETARY SOURCE CODE OF SGI          *
 *                                      *
 * The copyright notice above does not evidence any actual of intended      *
 * publication of such source code, and is an unpublished work by Silicon *
 * Graphics, Inc. This material contains CONFIDENTIAL INFORMATION that is *
 * the property of Silicon Graphics, Inc. Any use, duplication or      *
 * disclosure not specifically authorized by Silicon Graphics is strictly *
 * prohibited.                                  *
 *                                      *
 * RESTRICTED RIGHTS LEGEND:                          *
 *                                      *
 * Use, duplication or disclosure by the Government is subject to      *
 * restrictions as set forth in subdivision (c)(1)(ii) of the Rights in      *
 * Technical Data and Computer Software clause at DFARS 52.227-7013,      *
 * and/or in similar or successor clauses in the FAR, DOD or NASA FAR      *
 * Supplement. Unpublished - rights reserved under the Copyright Laws of  *
 * the United States. Contractor is SILICON GRAPHICS, INC., 2011 N.      *
 * Shoreline Blvd., Mountain View, CA 94039-7311              *
 **************************************************************************
 *
 * File: SLUtil.c
 *
 * Description: This file contains misc. utility functions grlobally
 *    available to internal SL routines.
 *
 **************************************************************************/


#ident "$Revision: 1.11 $"


#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <errno.h>
#ifdef sgi
#include <bstring.h>
#endif
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <signal.h>
#include <ctype.h>
#include "spoolI.h"


/* SLExec spooler output buffer globals */

char **_SLspooler_out_buf;            /* Output buffer text */
int _SLspooler_nout;                /* # lines in output buffer */
int _SLspooler_exit;                /* Spooler exit status */


/* External functions needing declarations */

extern int select(int, fd_set*, fd_set*, fd_set*, struct timeval*);


/* Local functions */

static void spooler_buf_init(void);
static void spooler_buf_add(char*);
static int read_ready(int, int);


/**************************************************************************
 *
 * Function: _SLIsEmpty
 *
 * Description: Determines if a string is empty or filled only with
 *      whitespace.
 *
 * Parameters:
 *      str (I) - string to test
 *
 * Return: 0 not empty. 1 if string is empty.
 *
 **************************************************************************/

int _SLIsEmpty(register const char *str)
{
    if (str == NULL)
        return 1;
    for (; *str; str++)
        if (!isspace((int)*str))
            return 0;
    return 1;
}


/**************************************************************************
 *
 * Function: _SLSkipSpace
 *
 * Description: Skips whitespace and returns a pointer to the first
 *    non-whitespace character or NULL if there is only whitespace
 *    on the line.
 *
 * Parameters:
 *    sbuf (I) - string buffer to parse for whitespace.
 *
 * Return: Pointer to first non-whitespace character or NULL if the
 *    line consists only of whitespace characters;
 *
 **************************************************************************/

char *_SLSkipSpace(char *sbuf)
{
    char *sptr = NULL;

    while (*sbuf) {
    if (!isspace(*sbuf)) {
        sptr = sbuf;
        break;
    }
    sbuf++;
    }

    return sptr;
}


/**************************************************************************
 *
 * Function: _SLInitPlist
 *
 * Description: Initializes a printer list.
 *
 * Parameters:
 *    plistp (O) - pointer to printer list.
 *    nump (O) - pointer to number of printers on list.
 *
 * Return: none
 *
 **************************************************************************/

void _SLInitPlist(SLPrinterStruct **plistp, int *nump)
{
    register int i;
    register SLPrinterStruct *ptr;

    if (*plistp) {
    /*
     * Free the storage for each printer. If this becomes a
     * performance problem we can go to free-lists.
     */
    for (i = 0, ptr = *plistp; i < *nump; i++, ptr++)
        _SLInitPentry(ptr);

    /*
     * Free the list storage
     */
    free((char*)*plistp);
    *plistp = NULL;
    }
    *nump = 0;
}


/**************************************************************************
 *
 * Function: _SLInitPentry
 *
 * Description: Initializes a printer info entry. All storage alocated int
 *    the SLPrinterStruct is freed.
 *
 * Parameters:
 *    pentry (O) - pointer to printer info structure.
 *
 * Return: none
 *
 **************************************************************************/

void _SLInitPentry(SLPrinterStruct *pentry)
{
    if (pentry) {
        if (pentry->local_name) {
        free((char*)pentry->local_name);
        pentry->local_name = NULL;
    }
    if (pentry->formal_name) {
        free((char*)pentry->formal_name);
        pentry->formal_name = NULL;
    }
    if (pentry->type) {
        free((char*)pentry->type);
        pentry->type = NULL;
    }
    if (pentry->dev) {
        free((char*)pentry->dev);
        pentry->dev = NULL;
    }
    if (pentry->remote_host) {
        free((char*)pentry->remote_host);
        pentry->remote_host = NULL;
    }
    if (pentry->remote_name) {
        free((char*)pentry->remote_name);
        pentry->remote_name = NULL;
    }
    if (pentry->network_type) {
        free(pentry->network_type);
        pentry->network_type = NULL;
    }
    }
}


/**************************************************************************
 *
 * Function: _SLAddPrinter
 *
 * Description: Adds a printer to the specified printer list
 *
 * Parameters:
 *    pinfo (I) - pointer to the printer info struct to add to the list
 *    plistp (O) - pointer to printer list.
 *    nump (O) - pointer to number of printers on list.
 *
 * Return: None
 *
 **************************************************************************/

void _SLAddPrinter(const SLPrinterStruct *pinfo, SLPrinterStruct **plistp,
                int *nump)
{
    (*nump)++;
    if (*plistp)
    /*
     * We realloc for each printer we add. Can realloc in chunks
     * if this is a performance problem.
    */
    *plistp = (SLPrinterStruct*)realloc(*plistp,
                (*nump) * sizeof(SLPrinterStruct));
    else
    *plistp = (SLPrinterStruct*)malloc((*nump) * sizeof(SLPrinterStruct));
    (*plistp)[*nump - 1] = *pinfo;
}


/**************************************************************************
 *
 * Function: _SLInitQueue
 *
 * Description: Initializes a printer queue.
 *
 * Parameters:
 *    queuep (O) - pointer to queue.
 *    nump (O) - pointer to number of jobs in queue.
 *
 * Return: none
 *
 **************************************************************************/

void _SLInitQueue(SLQueueStruct **queuep, int *nump)
{
    int i;
    SLQueueStruct *qptr;

    if (*queuep) {
    /*
     * Free the storage for each job. If this becomes a
     * performance problem we can go to free-lists.
     */
    for (i = 0, qptr = *queuep; i < *nump; i++, qptr++)
        _SLFreeQueueEntry(qptr);

    /*
     * Free the list storage
     */
    free((char*)*queuep);
    *queuep = NULL;
    }
    *nump = 0;
}


/**************************************************************************
 *
 * Function: _SLFreeQueueEntry
 *
 * Description: Frees the storage for a single queue entry
 *
 * Parameters:
 *    entry (I) - pointer to the entry whose storage is to be freed
 *
 * Return: none
 *
 **************************************************************************/

void _SLFreeQueueEntry(SLQueueStruct *entry)
{
    if (entry->job_id)
    free((char*)entry->job_id);
    if (entry->username)
    free((char*)entry->username);
    if (entry->title)
    free(entry->title);
}


/**************************************************************************
 *
 * Function: _SLAddQueue
 *
 * Description: Adds a job to the specified queue
 *
 * Parameters:
 *    queuep (O) - pointer to queue
 *    nump (O) - pointer to number of jobs in queue.
 *
 * Return: Pointer to newly added queue structure.
 *
 **************************************************************************/

SLQueueStruct* _SLAddQueue(SLQueueStruct **queuep, int *nump)
{
    (*nump)++;
    if (*queuep)
    /*
     * We realloc for each job we add. Can realloc in chunks
     * if this is a performance problem.
    */
    *queuep = (SLQueueStruct*)realloc(*queuep,
                (*nump) * sizeof(SLQueueStruct));
    else
    *queuep = (SLQueueStruct*)malloc((*nump) * sizeof(SLQueueStruct));
    return &(*queuep)[*nump - 1];
}


/**************************************************************************
 *
 * Function: _SLExec
 *
 * Description: Executes the specified command and returns the exit
 *    status. The command output and the number of lines of output
 *    are stored in globals for use in error reporting and ID
 *    parsing.
 *
 * Parameters:
 *    job_source (I) - specifies the source of a print job. This is
 *        specified for print job submittal. Otherwise it may be
 *        set to NULL.
 *    cmd (I) - command to execute
 *    timeout_flag (I) - TRUE == use select with a timeout; FALSE ==
 *               do not use select (i.e. no timeouts).
 *    timeout_resp (O) - Timeout result. TRUE if timed out, FALSE if
 *               did not timeout. Pointer can be NULL if
 *               timeout_flag is not TRUE.
 *
 * Return: Exit status of the specified command.
 *
 **************************************************************************/

int _SLExec(SLJobSourceUnion *job_source, char *cmd, int timeout_flag,
                int *timeout_resp)
{
    char buf[SL_BUFSIZ];
    FILE *pptr;
    int status;
    int ret, ready_ret, pid, read_pipe[2];
    int write_pipe[2];
    int infd;
    struct sigaction sact, orig_sact;
    sigset_t sig_mask;

    /*
     * First free the old output buffer if any
     */
    spooler_buf_init();

    /*
     * Initialize the write pipe
     */
    write_pipe[0] = write_pipe[1] = 0;

    /*
     * Initialize the input file descriptor.  If this is non-zero in
     * the child process, we'll dup it to standard input.
     */
    infd = 0;

    /*
     * If appropriate specify a file descriptor for the command to read
     * from on its standard input.
     *
     * If a file descriptor is specified simply tell the command to read
     * from that descriptor.
     *
     * If a buffer has been specified we will open a pipe and specify
     * the pipe's read end as the file descriptor for the command to
     * read as its stdin. We will write the buffer to the write end of
     * the pipe.
     */
    (void)strcpy(buf, cmd);
    if (job_source) {
        switch(job_source->type) {
        case SL_JOB_FILENAME:
            if (SLdebug)
            (void)fprintf(stderr,
                gettxt(_SGI_LIBSPOOL_DEBUG_FILENAME_JOB,
                "libspool Debug: _SLExec filename job\n"));
        break;
        case SL_JOB_FD:
            if (SLdebug)
           (void)fprintf(stderr,
                gettxt(_SGI_LIBSPOOL_DEBUG_FD_JOB,
                "libspool Debug: _SLExec fd job\n"));
        infd = job_source->fd_job.file_desc;
        break;
        case SL_JOB_BUF:
            if (SLdebug)
            (void)fprintf(stderr,
                gettxt(_SGI_LIBSPOOL_DEBUG_BUF_JOB,
                "libspool Debug: _SLExec buffer job\n"));
        if (pipe(write_pipe) < 0) {
            (void)fprintf(stderr, gettxt(_SGI_LIBSPOOL_PIPE_FAILED,
          "libspool INTERNAL ERROR: _SLExec pipe failed (errno=%d)\n"),
            errno);
            return SL_ERROR;
        }
        infd = write_pipe[0];
        break;
        default:
        break;
    }
    }

    /*
     * Print some debug info if requested
     */
    if (SLdebug)
    (void)fprintf(stderr, gettxt(_SGI_LIBSPOOL_DEBUG_EXECCMD,
            "libspool Debug: _SLExec command \"%s\"\n"), cmd);

    /*
     * Before we execute the command we need to default SIGCLD so that
     * when the command terminates we don not call a user's SIGCLD
     * handler. Do not worry about losing SIGCLD for the user because
     * if we get one during our ignore period, the user's child will
     * zombie and sigaction will raise a new SIGCLD if it detects a
     * zombie when we reinstall the original handler.
     */
    sigemptyset(&sig_mask);
    sact.sa_handler = SIG_DFL;
    sact.sa_mask = sig_mask;
    sact.sa_flags = 0;
    (void)sigaction(SIGCLD, &sact, &orig_sact);

    /*
     * Execute the command (adapted from popen)
     *
     * We fork a shell that executes the speicified command. The standard
     * out of the command has been connected to the write end of a pipe
     * that our parent process reads. For convenience we fdopen a stream
     * based on the read end of the pipe.
     */
    if (pipe(read_pipe) < 0) {
        (void)sigaction(SIGCLD, &orig_sact, NULL);
    (void)fprintf(stderr, gettxt(_SGI_LIBSPOOL_PIPE_FAILED,
        "libspool INTERNAL ERROR: _SLExec pipe failed (errno=%d)\n"),
        errno);
    return SL_ERROR;
    }
    if ((pid = fork()) == 0) {
    /*
     * Make child a process group leader so that if we timeout
     * we can kill the child's pgroup and have all its children killed.
     * This is especially important when dealing with rsh since it is
     * flakey.
     */
    (void)setpgrp();

    /*
     * Set up the pipes that the child will use to communicate with
     * the parent.
     */
    if (infd) {
        (void)dup2(infd, 0);
        (void)close(infd);
    }
    if (write_pipe[1])            /* If writing to command */
        (void)close(write_pipe[1]);        /*    close child write end */
    (void)close(read_pipe[0]);        /* Close child read end */
    if (read_pipe[1] != 1) {        /* If pipe not already stdout */
        (void)close(1);            /* Close child stdout */
        (void)fcntl(read_pipe[1], F_DUPFD, 1);    /* Make pipe chld out */
        (void)close(read_pipe[1]);        /* Close our pipe write */
    }

    /*
     * Set up the environment so that we get output in the
     * language we can parse and in the error message format
     * we require.
     */
    putenv(SL_LANG);
    putenv(SL_MSGFORMAT);

    /*
     * Execute the child command
     */
    (void)execl(SL_CMD_SH, SL_CMD_SH_NAME, SL_CMD_SH_FLAG, buf, NULL);
    exit(1);
    }
    if (pid == -1) {
        (void)sigaction(SIGCLD, &orig_sact, NULL);
    (void)fprintf(stderr, gettxt(_SGI_LIBSPOOL_FORK_FAILED,
        "libspool INTERNAL ERROR: _SLExec fork failed (errno=%d)\n"),
        errno);
    return SL_ERROR;
    }

    /*
     * Set up the pipes that will be used to communicate with
     * the child
     */
    if (write_pipe[0])            /* If writing to command */
    (void)close(write_pipe[0]);    /*    close parent read end */
    (void)close(read_pipe[1]);        /* Close parent write end */
                    /* Create a stream for the pipe */
    if ((pptr = fdopen(read_pipe[0], "r")) == NULL) {
    (void)fprintf(stderr, gettxt(_SGI_LIBSPOOL_FDOPEN_FAILED,
            "libspool INTERNAL ERROR: fdopen failed\n"));
    return SL_ERROR;
    }

    /*
     * If the command is to be fed from a buffer, feed it
     */
    if (write_pipe[1]) {
    (void)write(write_pipe[1], job_source->buf_job.buffer,
                    job_source->buf_job.amount);
    (void)close(write_pipe[1]);
    }

    /*
     * Read the output from the command and build the output buffer
     */
    while ((ready_ret = read_ready(read_pipe[0], timeout_flag)) != 0) {
        if (fgets(buf, SL_SML_BUFSIZ, pptr) == NULL)
        break;
    buf[strlen(buf)-1] = '\0';
    spooler_buf_add(buf);
    }

    /*
     * Close our end of the pipe to the child
     */
    (void)fclose(pptr);

    /*
     * If the we have a timeout condition, explicitly kill the
     * child's process group and set the timeout response
     * (if not NULL pointer). The child is a process group leader
     * and killing its group kills any children that may have been
     * forked.
     */
    if (ready_ret == 0) {
        if (SLdebug)
        (void)fprintf(stderr, gettxt(_SGI_LIBSPOOL_DEBUG_TIMEOUT,
        "libspool Debug: _SLExec timeout - killing pid %d\n"), pid);
        (void)kill(-pid, SIGKILL);
    }
    if (timeout_resp)
        *timeout_resp = (ready_ret) ? SL_FALSE: SL_TRUE;

    /*
     * Wait for the child process executing the command to finish
     * and save the command exit status. This is adapted from pclose.
     */
#ifdef sgi
    while (((ret = waitpid(pid, &status, 0)) < 0) && oserror() == EINTR)
    ;
#else
    while (((ret = waitpid(pid, &status, 0)) < 0) && errno == EINTR)
    ;
#endif
    _SLspooler_exit = ((ret < 0) || (ready_ret == 0)) ?
    SL_ERROR : WEXITSTATUS(status);

    /*
     * Restore the original SIGCLD handler. If there are zombies
     * out there a SIGCLD will be raised and the user's desired action
     * will be performed.
     */
    (void)sigaction(SIGCLD, &orig_sact, NULL);

    /*
     * If the command exit code was not 0 but we do not have any
     * spooler error message, put some generic message in the output
     * buffer so that apps get some sort of error text.
     */
    if (_SLspooler_exit != 0 && _SLspooler_nout == 0) {
    spooler_buf_add(gettxt(_SGI_LIBSPOOL_SPOOLER_CMD_ERR_1,
                "Spooler command execution error."));
    spooler_buf_add(gettxt(_SGI_LIBSPOOL_SPOOLER_CMD_ERR_2,
                "Filenames or other input data may"));
    spooler_buf_add(gettxt(_SGI_LIBSPOOL_SPOOLER_CMD_ERR_3,
                "be improperly specified."));
    }

    return _SLspooler_exit;
}


/*
 ========================================================================
            LOCAL FUNCTIONS
 ========================================================================
*/


/**************************************************************************
 *
 * Function: spooler_buf_init
 *
 * Description: Initializes the spooler output message buffer global
 *    variables.
 *
 * Parameters: none
 *
 * Return: none
 *
 **************************************************************************/

static void spooler_buf_init(void)
{
    register int i;

    if (_SLspooler_nout) {
    for (i = 0; i < _SLspooler_nout; i++)
        free((char*)_SLspooler_out_buf[i]);
    free((char*)_SLspooler_out_buf);
    _SLspooler_out_buf = NULL;
    _SLspooler_nout = 0;
    }

}


/**************************************************************************
 *
 * Function: spooler_buf_add
 *
 * Description: Adds the specified text line to the spooler output message
 *    buffer.
 *
 * Parameters:
 *    str (I) - line of text to add to buffer
 *
 * Return: none
 *
 **************************************************************************/

static void spooler_buf_add(char *str)
{
    _SLspooler_nout++;
    if (_SLspooler_out_buf)
        _SLspooler_out_buf = (char**)realloc((char*)_SLspooler_out_buf,
                    _SLspooler_nout * sizeof(char*));
    else
    _SLspooler_out_buf = (char**)malloc(sizeof(char*));
    _SLspooler_out_buf[_SLspooler_nout-1] = strdup(str);
}


/**************************************************************************
 *
 * Function: read_ready
 *
 * Description: Does a select on the read end of the child process output
 *    pipe. The select will timeout if there is some problem (e.g.
 *    rsh hanging) or will return normally indicating we have output
 *    ready to read.
 *
 * Parameters:
 *    read_fd (I) - fd to select on for read
 *    do_select (I) - TRUE == do the timed select. FALSE == simply
 *            return a ready indication.
 *
 * Return: 1 is returned if we are ready to read. 0 is returned if select
 *    has timed out.
 *
 **************************************************************************/

static int read_ready(int read_fd, int do_select)
{
    fd_set fdset;
    struct timeval timeout;
    int ret, rv = 0, again = 1;

    /*
     * Return immediately with a ready if select not requested
     */
    if (do_select == SL_FALSE)
    return 1;

    /*
     * Run select in a loop in case the call is interrupted by a
     * signal (EINTR). This way we can reissue the select.
     */
    while (again) {
    /*
     * Clear the descriptor array and set our descriptor
     * for select
     */
        FD_ZERO(&fdset);
        FD_SET(read_fd, &fdset);

    /*
     * Set a timeout. Note that we do this in the loop per
     * select man page recommendation (see BUGS section in
     * man page).
     */
        timeout.tv_sec = SLnet_timeout;
        timeout.tv_usec = 0;

    /*
     * Issue the select and handle the response. If a timeout
     * occurs return with 0. If select returns normally, return
     * a 1. If select is interrupted, don't return but do
     * another select. If select returns with any other error
     * call it a draw and return 0.
     */
        ret = select(read_fd + 1, &fdset, (fd_set*)NULL,
                        (fd_set*)NULL, &timeout);
    again = 0;
    if (ret < 0 && errno == EINTR)
        again = 1;
    else if (ret > 0)
        rv = 1;
    }

    return rv;
}