/*
 * Copyright (C) 1994-2021 Altair Engineering, Inc.
 * For more information, contact Altair at www.altair.com.
 *
 * This file is part of both the OpenPBS software ("OpenPBS")
 * and the PBS Professional ("PBS Pro") software.
 *
 * Open Source License Information:
 *
 * OpenPBS is free software. You can redistribute it and/or modify it under
 * the terms of the GNU Affero General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 *
 * OpenPBS 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 Affero General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Commercial License Information:
 *
 * PBS Pro is commercially licensed software that shares a common core with
 * the OpenPBS software.  For a copy of the commercial license terms and
 * conditions, go to: (http://www.pbspro.com/agreement.html) or contact the
 * Altair Legal Department.
 *
 * Altair's dual-license business model allows companies, individuals, and
 * organizations to create proprietary derivative works of OpenPBS and
 * distribute them - whether embedded or bundled with other software -
 * under a commercial license agreement.
 *
 * Use of Altair's trademarks, including but not limited to "PBS™",
 * "OpenPBS®", "PBS Professional®", and "PBS Pro™" and Altair's logos is
 * subject to Altair's trademark licensing policies.
 */

#include <pbs_config.h> /* the master config generated by configure */
/**
 * @file prolog.c
 */
#define PBS_MOM 1
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/types.h>

#include <unistd.h>
#include <pwd.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include "libpbs.h"
#include "list_link.h"
#include "server_limits.h"
#include "attribute.h"
#include "job.h"
#include "log.h"
#include "mom_mach.h"
#include "mom_func.h"

#define PBS_PROLOG_TIME 30

unsigned int pe_alarm_time = PBS_PROLOG_TIME;
static pid_t child;
static int run_exit;

extern int pe_input(char *jobid);

/**
 * @brief
 *	convert resources_[list or used] values to a single string that are
 *	comma-separated.
 *
 * @param[in] pattr - the attribute to convert.
 * @param[in][out] buf - the buffer into which to convert.
 * @param[in] buflen - the length of the above buffer.
 *
 * @return pointer to 'buf', and also a modified 'buf'.
 * @retval = string
 * @retval = empty buffer on malloc failure under windows only
 *
 * @note     	This function may not concatenate all resources and their values as one string if buf size is insufficient.
 *		That mean returned buf value may have less resources list compared to actual list.
 *		This effect may occur in both windows and Linux. No indication of this error given.
 *		Also, for windows only, this function returns empty buf if malloc fails.
 *
 */

static char *
resc_to_string(job *pjob, int attr_idx, char *buf, int buflen)
{
	int need;
	svrattrl *patlist;
	pbs_list_head svlist;

	CLEAR_HEAD(svlist);
	*buf = '\0';

	if (encode_resc(get_jattr(pjob, attr_idx), &svlist, "x", NULL, ATR_ENCODE_CLIENT, NULL) <= 0)
		return (buf);

	patlist = (svrattrl *) GET_NEXT(svlist);
	while (patlist) {
		need = strlen(patlist->al_resc) + strlen(patlist->al_value) + 3;
		if (need < buflen) {
			(void) strcat(buf, patlist->al_resc);
			(void) strcat(buf, "=");
			(void) strcat(buf, patlist->al_value);
			buflen -= need;
		}
		patlist = (svrattrl *) GET_NEXT(patlist->al_link);
		if (patlist)
			(void) strcat(buf, ",");
	}
	return (buf);
}

/**
 * @brief
 * 	pelog_err - record error for run_pelog()
 *
 * @param[in] pjob - pointer to job structure
 * @param[in] file - file name
 * @param[in] text - error message
 *
 * @return int
 * @retval error number
 *
 */

static int
pelog_err(pjob, file, n, text)
job *pjob;
char *file;
int n;
char *text;
{
	sprintf(log_buffer, "pro/epilogue failed, file: %s, exit: %d, %s",
		file, n, text);
	log_event(PBSEVENT_ERROR, PBS_EVENTCLASS_JOB, LOG_WARNING,
		  pjob->ji_qs.ji_jobid, log_buffer);
	return (n);
}

/**
 * @brief
 *	pelogalm() - alarm handler for run_pelog()
 *
 * @param[in] sig - signal number
 *
 * @return Void
 *
 */
static void
	pelogalm(sig) int sig;
{
	run_exit = -4;
}

/**
 * @brief
 *	run_pelog() - Run the Prologue/Epilogue script
 * @par
 *	Script is run under uid of root, prologue and the epilogue have:
 *		- argv[1] is the jobid
 *		- argv[2] is the user's name
 *		- argv[3] is the user's group name
 *		- the input file is a architecture dependent file
 *		- the output and error are the job's output and error
 #ifdef NAS localmod 095
 *	The prologue also has:
 *		- argv[4] is the list of resource limits specified
 #endif localmod 095
 *	The epilogue also has:
 *		- argv[4] is the job name
 *		- argv[5] is the session id
 *		- argv[6] is the list of resource limits specified
 *		- argv[7] is the list of resources used
 *		- argv[8] is the queue in which the job resides
 *		- argv[9] is the Account under which the job run
 *		- argv[10] is the job exit code
 *
 * @param[in] which - Script type (PE_PROLOGUE or PE_EPILOGUE)
 * @param[in] pelog - Path to the script file
 * @param[in] pjob - Pointer to the associated job structure
 * @param[in] pe_io_type - Output specifier (PE_IO_TYPE_NULL, PE_IO_TYPE_ASIS, or PE_IO_TYPE_STD)
 *
 * @return - Exit code
 * @retval  -2 - script not found
 * @retval  -1 - permission error
 * @retval   0 - success
 * @retval  >0 - exit status returned from script
 *
 */

int
run_pelog(which, pelog, pjob, pe_io_type)
int which;
char *pelog;
job *pjob;
int pe_io_type;
{
	char *arg[12];
	char exitcode[20];
	char resc_list[2048];
	char resc_used[2048];
	struct stat sbuf;
	char sid[20];
	struct sigaction act;
	int fd_input;
	int waitst;
	char buf[MAXNAMLEN + MAXPATHLEN + 2];

	if (stat(pelog, &sbuf) == -1) {
		if (errno == ENOENT)
			return (0);
		else
			return (pelog_err(pjob, pelog, errno, "cannot stat"));
	} else if ((sbuf.st_uid != 0) ||
		   (!S_ISREG(sbuf.st_mode)) ||
		   ((sbuf.st_mode & (S_IRUSR | S_IXUSR)) !=
		    (S_IRUSR | S_IXUSR)) ||
		   (sbuf.st_mode & (S_IWGRP | S_IWOTH)))
		return (pelog_err(pjob, pelog, -1, "Permission Error"));

	fd_input = pe_input(pjob->ji_qs.ji_jobid);
	if (fd_input < 0) {
		return (pelog_err(pjob, pelog, -2,
				  "no pro/epilogue input file"));
	}

	run_exit = 0;
	child = fork();
	if (child > 0) { /* parent */
		(void) close(fd_input);
		sprintf(log_buffer, "running %s",
			which == PE_PROLOGUE ? "prologue" : "epilogue");
		log_event(PBSEVENT_DEBUG, PBS_EVENTCLASS_JOB, LOG_INFO,
			  pjob->ji_qs.ji_jobid, log_buffer);

		act.sa_handler = pelogalm;
		sigemptyset(&act.sa_mask);
		act.sa_flags = 0;
		sigaction(SIGALRM, &act, 0);
		alarm(pe_alarm_time);
		while (wait(&waitst) < 0) {
			if (errno != EINTR) { /* continue loop on signal */
				run_exit = -3;
				break;
			}
			kill(-child, SIGKILL);
		}
		alarm(0);
		act.sa_handler = SIG_DFL;
		sigaction(SIGALRM, &act, 0);
		kill(-child, SIGKILL);
		if (run_exit == 0) {
			if (WIFEXITED(waitst)) {
				run_exit = WEXITSTATUS(waitst);
			} else if (WIFSIGNALED(waitst)) {
				run_exit = -3;
			}
		} else {
			sprintf(log_buffer, "completed %s, exit=%d",
				which == PE_PROLOGUE ? "prologue" : "epilogue",
				run_exit);
			log_event(PBSEVENT_DEBUG, PBS_EVENTCLASS_JOB, LOG_INFO,
				  pjob->ji_qs.ji_jobid, log_buffer);
		}

	} else { /* child */
		 /*
		 * For sanity sake we make sure the following are defined.
		 * They should have been defined in unistd.h
		 */
#ifndef STDIN_FILENO
#define STDIN_FILENO 0
#endif
#ifndef STDOUT_FILENO
#define STDOUT_FILENO 1
#endif
#ifndef STDERR_FILENO
#define STDERR_FILENO 2
#endif

		/*
		 ** As these fd variabes (fds1(2)) are used in the child
		 ** process, define here only.
		 */
		int fds1 = -1;
		int fds2 = -1;

		if (fd_input != 0) {
			(void) close(STDIN_FILENO);
			if (dup(fd_input) == -1) 
				log_errf(-1, __func__, "dup failed. ERR : %s", strerror(errno));				
			(void) close(fd_input);
		}

		/* unprotect from kernel killers (such as oom) */
		daemon_protect(0, PBS_DAEMON_PROTECT_OFF);

		/*
		 * If PE_IO_TYPE_ASIS, leave stdout/stderr alone as they
		 * are already open to job. Otherwise, set FDs 1 and 2
		 * appropriately being careful to join them where
		 * necessary.
		 */
		if (pe_io_type == PE_IO_TYPE_NULL) {
			/* Close any existing stdout/stderr. */
			(void) close(STDOUT_FILENO);
			(void) close(STDERR_FILENO);
			/* No output, force to /dev/null */
			fds1 = open("/dev/null", O_WRONLY, 0600);
			fds2 = dup(fds1);
		} else if (pe_io_type == PE_IO_TYPE_STD) {
			int join_method;
			/* Close any existing stdout/stderr. */
			(void) close(STDOUT_FILENO);
			(void) close(STDERR_FILENO);
			/*
			 * Do not open an output file unless it will be used.
			 * Otherwise, it will be left behind in spool.
			 */
			join_method = is_joined(pjob);
			/* Open job stdout/stderr. */
			if (join_method < 0) { /* joined as stderr */
				fds1 = open("/dev/null", O_WRONLY, 0600);
				fds2 = open_std_file(pjob, StdErr, O_WRONLY | O_APPEND,
						     pjob->ji_qs.ji_un.ji_momt.ji_exgid);
				(void) close(fds1);
				fds1 = dup(fds2);
			} else if (join_method > 0) { /* joined as stdout */
				fds1 = open_std_file(pjob, StdOut, O_WRONLY | O_APPEND,
						     pjob->ji_qs.ji_un.ji_momt.ji_exgid);
				fds2 = dup(fds1);
			} else { /* not joined */
				fds1 = open_std_file(pjob, StdOut, O_WRONLY | O_APPEND,
						     pjob->ji_qs.ji_un.ji_momt.ji_exgid);
				fds2 = open_std_file(pjob, StdErr, O_WRONLY | O_APPEND,
						     pjob->ji_qs.ji_un.ji_momt.ji_exgid);
			}
			if (fds1 == -1 || fds2 == -1) {
				log_event(PBSEVENT_ERROR, PBS_EVENTCLASS_JOB, LOG_WARNING,
					  pjob->ji_qs.ji_jobid, "problem opening job output file(s)");
			}
		}

		/* for both prologue and epilogue */

		arg[0] = pelog;
		arg[1] = pjob->ji_qs.ji_jobid;
		arg[2] = get_jattr_str(pjob, JOB_ATR_euser);
		arg[3] = get_jattr_str(pjob, JOB_ATR_egroup);

		/* for epilogue only */

		if (which == PE_EPILOGUE) {
			arg[4] = get_jattr_str(pjob, JOB_ATR_jobname);
			sprintf(sid, "%ld", get_jattr_long(pjob, JOB_ATR_session_id));
			arg[5] = sid;
			arg[6] = resc_to_string(pjob, JOB_ATR_resource, resc_list, 2048);
			arg[7] = resc_to_string(pjob, JOB_ATR_resc_used, resc_used, 2048);
			arg[8] = get_jattr_str(pjob, JOB_ATR_in_queue);
			if ((is_jattr_set(pjob, JOB_ATR_account)) && (strlen(get_jattr_str(pjob, JOB_ATR_account)) > 0))
				arg[9] = get_jattr_str(pjob, JOB_ATR_account);
			else
				arg[9] = "null";
			sprintf(exitcode, "%d", pjob->ji_qs.ji_un.ji_momt.ji_exitstat);
			arg[10] = exitcode;
			arg[11] = 0;

		} else {
#ifdef NAS /* localmod 095 */
			arg[4] = resc_to_string(pjob, JOB_ATR_resource, resc_list, 2048);
			arg[5] = NULL;
#else
			arg[4] = NULL;
#endif /* localmod 095 */
		}

		(void) setsid();

		/* Add PBS_JOBDIR to the current process environement */
		if (pjob->ji_grpcache) {
			if ((is_jattr_set(pjob, JOB_ATR_sandbox)) && (strcasecmp(get_jattr_str(pjob, JOB_ATR_sandbox), "PRIVATE") == 0)) {
				/* set PBS_JOBDIR to the per-job staging and execution directory*/
				sprintf(buf, "PBS_JOBDIR=%s",
					jobdirname(pjob->ji_qs.ji_jobid,
						   pjob->ji_grpcache->gc_homedir));
			} else {
				/* set PBS_JOBDIR to user HOME*/
				sprintf(buf, "PBS_JOBDIR=%s", pjob->ji_grpcache->gc_homedir);
			}
			if (setenv("PBS_JOBDIR", pjob->ji_grpcache->gc_homedir, 1) != 0)
				log_err(-1, "run_pelog", "set environment variable PBS_JOBDIR");
		}

		execv(pelog, arg);

		log_err(errno, "run_pelog", "execle of prologue failed");
		exit(255);
	}

	if (run_exit)
		(void) pelog_err(pjob, pelog, run_exit, "nonzero p/e exit status");

	return (run_exit);
}