/*************************************************************************
 * (C) 2011 AITNET - Sofia/Bulgaria - <office@aitbg.com>
 *  by Michael Pounov <misho@aitbg.com>
 *
 * $Author: misho $
 * $Id: sux.c,v 1.7 2015/06/18 23:03:53 misho Exp $
 *
 *************************************************************************
The ELWIX and AITNET software is distributed under the following
terms:

All of the documentation and software included in the ELWIX and AITNET
Releases is copyrighted by ELWIX - Sofia/Bulgaria <info@elwix.org>

Copyright 2004 - 2015
	by Michael Pounov <misho@elwix.org>.  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.
3. All advertising materials mentioning features or use of this software
   must display the following acknowledgement:
This product includes software developed by Michael Pounov <misho@elwix.org>
ELWIX - Embedded LightWeight unIX and its contributors.
4. Neither the name of AITNET 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 AITNET 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.
*/
#include "global.h"


cfg_root_t cfg;
int Verbose;
struct tagProc proc;
FILE *lf;


static inline void
Log(int lvl, const char *fmt, ...)
{
	va_list lst, cp;

	EVERBS(lvl) {
		va_start(lst, fmt);
		va_copy(cp, lst);
		vfprintf(lf, fmt, lst);
		va_end(lst);
		fprintf(lf, "\n");
		vsyslog(LOG_INFO, fmt, cp);
		va_end(cp);
	}
}

static inline void
Err(const char *fmt, ...)
{
	va_list lst, cp;

	va_start(lst, fmt);
	va_copy(cp, lst);
	vfprintf(lf, fmt, lst);
	va_end(lst);
	fprintf(lf, "\n");
	vsyslog(LOG_ERR, fmt, cp);
	va_end(cp);
}

static inline void
DumpProc(const char *txt)
{
	Log(1, "%s:: uid:gid=%d:%d UID:GID=%d:%d Prio=%d Class=%s Name=%s Dir=%s Cmd=%s "
			"Script=%s From=%s:%s Get=%s", txt ? txt : __func__, 
			geteuid(), getegid(), AIT_GET_I16(&proc.proc_uid), 
			AIT_GET_I16(&proc.proc_gid), AIT_GET_I32(&proc.proc_prio), 
			AIT_GET_STR(&proc.proc_class), AIT_GET_STR(&proc.proc_name), 
			AIT_GET_STR(&proc.proc_dir), AIT_GET_STR(&proc.proc_cmd), 
			getenv("PATH_TRANSLATED"), getenv("REMOTE_ADDR"), 
			getenv("REMOTE_PORT"), getenv("REQUEST_URI"));
}

static int
initProg()
{
	AIT_SET_I16(&proc.proc_uid, getuid());
	AIT_SET_I16(&proc.proc_gid, getgid());
	AIT_SET_I32(&proc.proc_prio, getpriority(PRIO_PROCESS, 0));
	AIT_INIT_VAL2(&proc.proc_class, string);
	AIT_INIT_VAL2(&proc.proc_dir, string);
	AIT_INIT_VAL2(&proc.proc_name, string);
	AIT_INIT_VAL2(&proc.proc_cmd, string);

#if 0
	lf = fopen(DEFAULT_LOG, "a");
	if (!lf)
#endif
		lf = stdout;

	openlog(PACKAGE_NAME, LOG_CONS | LOG_PID | LOG_NDELAY, LOG_USER);
	return 0;
}

static void
endProg()
{
	AIT_FREE_VAL(&proc.proc_uid);
	AIT_FREE_VAL(&proc.proc_gid);
	AIT_FREE_VAL(&proc.proc_prio);
	AIT_FREE_VAL(&proc.proc_class);
	AIT_FREE_VAL(&proc.proc_dir);
	AIT_FREE_VAL(&proc.proc_name);
	AIT_FREE_VAL(&proc.proc_cmd);
}

static void
Usage()
{
	printf(	" -= suX =- suExecutor designed for web based applicaions\n"
		"(C)`11 AITNET ltd - Sofia/Bulgaria - <office@aitnet.org>\n\n"
		" Syntax: %s [options] <program|-> [arguments]\n"
		"\t-u <user>\t\t\tUser for suID\n"
		"\t-g <group>\t\t\tGroup for suID\n"
		"\t-p <priority (-20..20)>\t\tExecute with priority\n"
		"\t-d <directory>\t\t\tDirectory for suID\n"
		"\t-C <directory>\t\t\tChroot to directory\n"
		"\t-c <cfgfile>\t\t\tConfig file\n"
		"\t-l <logfile>\t\t\tLog file path (default:/var/log/suX.log)\n"
		"\t-o\t\t\t\tForce set UID,GID and Priority for program\n"
		"\t-v\t\t\t\tVerbose, (more -v, more verbosity)\n"
		"\t-h\t\t\t\tThis help screen!\n\n", PACKAGE_NAME);
}

static inline int
setUIDGID(char flg, const char *name)
{
	struct stat sb;
	struct passwd *pass;
	short uid, gid;

	if (name) {
		if (stat(name, &sb) == -1) {
			ESYSERR(0);
			return -1;
		}
		uid = sb.st_uid;
		gid = sb.st_gid;
	} else {
		pass = getpwnam(getenv("SUX_USER") ? getenv("SUX_USER") : DEFAULT_SUX_USER);
		if (!pass) {
			Err("Error:: User %s not found", getenv("SUX_USER"));
			endpwent();
			return -1;
		}
		uid = pass->pw_uid;
		gid = pass->pw_gid;
		endpwent();
	}

	if (!(flg & SUX_GET_UID))
		AIT_SET_I16(&proc.proc_uid, uid);
	if (!(flg & SUX_GET_GID))
		AIT_SET_I16(&proc.proc_gid, gid);

	return 0;
}

static inline int
setClassDir()
{
	struct passwd *pass;
	int ret = 0;

	pass = getpwuid(AIT_GET_I16(&proc.proc_uid));
	if (!pass) {
		Err("Error:: User with this UID %d not found", AIT_GET_I16(&proc.proc_uid));
		ret = -1;
	} else {
		AIT_SET_STR(&proc.proc_class, pass->pw_class);
		AIT_SET_STR(&proc.proc_dir, pass->pw_dir);

		if (setusercontext(NULL, pass, AIT_GET_I16(&proc.proc_uid), 
					LOGIN_SETLOGIN | LOGIN_SETGROUP | LOGIN_SETUSER | 
					LOGIN_SETPRIORITY | LOGIN_SETRESOURCES)) {
			Err("Error:: Can't set login class %s", AIT_GET_STR(&proc.proc_class));
			ret = -1;
		}
	}

	endpwent();
	return ret;
}

static int
LoadCfgData(char flg)
{
	const char *str;
	char mode = 0;

	str = cfg_getAttribute(&cfg, "global", "mode");
	if (!str) {
		Err("Error:: Unknown mode ...");
		return -1;
	}
	if (!strcasecmp(str, "SCRIPT")) {
		mode = 1;
		if (setUIDGID(flg, (getenv("SUX_USER") ? NULL : getenv("PATH_TRANSLATED"))) == -1)
			return -1;
	} else if (!strcasecmp(str, "FILE")) {
		mode = 2;
		if (setUIDGID(flg, AIT_GET_STR(&proc.proc_name)) == -1)
			return -1;
	} else if (!strcasecmp(str, "DIR")) {
		mode = 3;
		str = AIT_GET_STR(&proc.proc_dir) ? AIT_GET_STR(&proc.proc_dir) : ".";
		if (setUIDGID(flg, str) == -1)
			return -1;
	} else {
		Err("Error:: Unknown mode %s", str);
		return -1;
	}
	if (!(flg & SUX_GET_PRIO)) {
		str = cfg_getAttribute(&cfg, "global", "priority");
		if (str)
			AIT_SET_I32(&proc.proc_prio, strtol(str, NULL, 10));
	}

	/* find associate extension */
	str = strrchr(AIT_GET_STR(&proc.proc_name), '.');
	if (str) {
		str++;
		str = (*str) ? str : "default";
		switch (cfg_loadAttribute(&cfg, "associate", str, &proc.proc_cmd, NULL)) {
			case -1:
				ELIBERR(cfg);
				return -1;
			case 0:
				cfg_loadAttribute(&cfg, "associate", "default", 
						&proc.proc_cmd, DEFAULT_CMD);
		}
	} else
		AIT_SET_STR(&proc.proc_cmd, DEFAULT_CMD);

	return 0;
}

static int
Run(char **argv, char flg)
{
	char **args, *cmd;
	array_t *acmd, *aarg;
	int n;

	if (!argv)
		return -1;

	n = array_Args(AIT_GET_STR(&proc.proc_cmd), 0, " \t", &acmd);
	if (n < 1)
		return -1;
	if (!(aarg = array_From((const char***) &argv, 0))) {
		array_Destroy(&acmd);
		return -1;
	}
	/* '!' exclude associated wrapper aka direct args execution */
	if (*array(acmd, 0, char*) == '!') {
		if (array_Grow(acmd, 0, 0)) {
			array_Destroy(&aarg);
			array_Destroy(&acmd);
			return -1;
		}
		cmd = array(aarg, 0, char*);
	} else
		cmd = array(acmd, 0, char*);

	if (!(flg & SUX_GET_STDIN) && array_Concat(acmd, aarg) == -1) {
		array_Destroy(&aarg);
		array_Destroy(&acmd);
		return -1;
	}
	array_Destroy(&aarg);
	if (!(args = array_To(acmd))) {
		array_Destroy(&acmd);
		return -1;
	}
	array_Destroy(&acmd);

	if (setClassDir()) {
		if (args)
			e_free(args);
		return -1;
	}

	if (flg & SUX_GET_FORCE) {
		if (setegid(AIT_GET_I16(&proc.proc_gid)) == -1)
			goto err;
		if (seteuid(AIT_GET_I16(&proc.proc_uid)) == -1)
			goto err;
		if (setpriority(PRIO_PROCESS, 0, AIT_GET_I32(&proc.proc_prio)) == -1)
			goto err;
	}

	EVERBS(3) {
		char **el = args - 1;
		while (*++el)
			Log(3, "args: %s", *el);
	}

	DumpProc(__func__);

	fflush(lf);

	execve(cmd, args, environ);
err:
	ESYSERR(0);
	if (args)
		e_free(args);
	return -1;
}


int
main(int argc, char **argv)
{
	char ch, *str, *wrk, szCfg[MAXPATHLEN], **pp, flg = 0;
	struct passwd *pass;
	struct group *grp;
	FILE *f;

	initProg();
	strlcpy(szCfg, DEFAULT_CONFIG, sizeof szCfg);

	while ((ch = getopt(argc, argv, "hvoC:c:u:g:p:d:l:")) != -1)
		switch (ch) {
			case 'l':
				f = fopen(optarg, "a");
				if (!f) {
					Err("Error:: logfile #%d - %s", errno, strerror(errno));
					return 1;
				} else
					if (fileno(lf) > 2)
						fclose(lf);
				lf = f;
				break;
			case 'd':
				AIT_SET_STR(&proc.proc_dir, optarg);
				flg |= SUX_GET_DIR;
				break;
			case 'p':
				AIT_SET_I32(&proc.proc_prio, strtol(optarg, NULL, 0));
				flg |= SUX_GET_PRIO;
				break;
			case 'g':
				setgrent();
				grp = getgrnam(optarg);
				if (grp) {
					AIT_SET_I16(&proc.proc_gid, grp->gr_gid);
					flg |= SUX_GET_GID;
				} else
					Err("Error:: Group not found!");
				endgrent();
				break;
			case 'u':
				setpwent();
				pass = getpwnam(optarg);
				if (pass) {
					AIT_SET_I16(&proc.proc_uid, pass->pw_uid);
					flg |= SUX_GET_UID;
				} else
					Err("Error:: User not found!");
				endpwent();
				break;
			case 'c':
				strlcpy(szCfg, optarg, sizeof szCfg);
				break;
			case 'C':
				if (chroot(optarg) == -1)
					Err("Error:: chroot to dir");
				if ((str = getenv("PATH_TRANSLATED")))
					if ((wrk = strstr(str, optarg)))
						setenv("PATH_TRANSLATED", str + strlen(optarg), 42);
				break;
			case 'o':
				flg |= SUX_GET_FORCE;
				break;
			case 'v':
				e_incVerbose;
				break;
			case 'h':
			default:
				Usage();
				endProg();
				if (fileno(lf) > 2)
					fclose(lf);
				return 1;
		}
	argc -= optind;
	argv += optind;

	EVERBS(2) {
		for (pp = argv; *pp; pp++)
			Log(2, "Args=%s\n", *pp);
		for (pp = environ; *pp; pp++)
			Log(2, "Envs=%s\n", *pp);
	}

	if (!argc) {
		if (!(str = getenv("PATH_TRANSLATED"))) {
			Usage();
			endProg();
			if (fileno(lf) > 2)
				fclose(lf);
			return 1;
		} else
			AIT_SET_STR(&proc.proc_name, str);
	} else if (strcmp(*argv, "-"))
		AIT_SET_STR(&proc.proc_name, *argv);
	else {
		flg |= SUX_GET_STDIN;
		AIT_SET_STR(&proc.proc_name, "-.stdin");	/* hack for associate to stdin */
	}
	Log(2, "Try to load config %s", szCfg);
	if (cfgLoadConfig(szCfg, &cfg)) {
		ELIBERR(cfg);
		endProg();
		if (fileno(lf) > 2)
			fclose(lf);
		return 2;
	} else
		if (LoadCfgData(flg) == -1) {
			cfgUnloadConfig(&cfg);
			endProg();
			if (fileno(lf) > 2)
				fclose(lf);
			closelog();
			return 3;
		}
	cfgUnloadConfig(&cfg);

	if (Run(argv, flg) == -1) {
		endProg();
		if (fileno(lf) > 2)
			fclose(lf);
		closelog();
		return 4;
	}

	endProg();
	if (fileno(lf) > 2)
		fclose(lf);
	closelog();
	return 0;
}