conf.c

wdiag-0.10.gz ( Diagnostic source )

/* Westell 6100 multicast data collection utility
 * Copyright: Josh Carroll ([e-mail])
 * 10/13/2004
 *
 * Thanks to LSorensen, mith, rkeene, and bgr on EFNet
 * #Linux for the help with my rusty C skills, and thanks
 * to dmonnier, Yock, no_strings, freerock, hondje, 
 * shenion, and shray on #ATU freenode.
 *
 * Also thanks to aedinius on #c on EFNet for helping clean the code
 *   up.
 *
 * conf.c is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 2.
 * 
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
*/

#include "conf.h"

char *search_path[SEARCH_LEN] = {"/usr/local/etc/wdiag.conf", "/etc/wdiag.conf"};

int read_config(wconf_t *conf) {
	int i;
	char *conf_path = NULL;
	struct stat file;

	/* first path that is found wins, if you want to change the search order
		or put the config file in a non-standard location, edit the above array*/
	for(i = 0; i < SEARCH_LEN; i++) {
		if(stat(search_path[i], &file) == 0) {
			conf_path = malloc(strlen(search_path[i]) + 1);
			strcpy(conf_path, search_path[i]);
			break;
		}
	}
	
	if(conf_path == NULL) {
		/* finally, check home dir */
		/* 13 extra chars for /.wdiag.conf */
		conf_path = malloc(strlen(getenv("HOME")) + 13);
		sprintf(conf_path, "%s/.wdiag.conf", getenv("HOME"));
		if(stat(conf_path, &file) != 0) {
			free(conf_path);
			conf_path = NULL;
		}
	}

	if(conf_path != NULL) {
		if( (strlen(conf_path) + 1) > 80) {
			printf("conf path: %s too long\n", conf_path);
			exit(EXIT_FAILURE);
		}
		strcpy(conf->path, conf_path);
		free(conf_path);
		/* initialize to detect lack of option later */
		conf->model = -1;
		conf->bcast = NULL;
		conf->decimal = 0;
		conf->laddr = NULL;
		if(parse_config(conf)) {
			printf("Failed to parse configuration file\n");
			return 0;
		}
		return 0;
	}

	free(conf_path);
	return 1;
}

int parse_config(wconf_t *conf) {
	FILE *fh;
	char errmsg[80];
	char buffer[READ_BUFF];
	int model, decimal;
	char *bcast, *laddr;

	if( (fh = fopen(conf->path, "r")) == NULL ) {
		sprintf(errmsg, "Could not open config: %s", conf->path);
		perror(errmsg);
		conf = NULL;
		return 1;
	} else {
		while( fgets(buffer, READ_BUFF, fh) != NULL) {
			/* strip \n */
			if(buffer[strlen(buffer)-1] == '\n')
				buffer[strlen(buffer)-1] = '\0';
			if(rematch("^ *#", buffer) || rematch("^ *$", buffer)) {
				/* comment or blank line, skip it */
				continue;
			}

			if((model = model_def(buffer)) != -1) {
				conf->model = model;
				continue;
			}
		
			if((decimal = decimal_def(buffer)) != -1) {
				conf->decimal = decimal;
				continue;
			}
		
			if((bcast = bcast_def(buffer)) != NULL) {
				conf->bcast = malloc(strlen(bcast)+1);
				strncpy(conf->bcast, bcast, strlen(bcast)+1);
				continue;
			}

			if((laddr = laddr_def(buffer)) != NULL) {
				conf->laddr = malloc(strlen(laddr)+1);
				strncpy(conf->laddr, laddr, strlen(laddr)+1);
				continue;
			}
		}
		fclose(fh);
	}

	return 0;
}

int rematch(const char *regexp, const char *string) {
	regex_t reg;
	
	if(regcomp(&reg, regexp, REG_EXTENDED|REG_NOSUB) != 0) {
		perror("regular expression compile failed");
	} else {
		if(regexec(&reg, string, 0, NULL, 0) == 0) {
			regfree(&reg);
			return 1;
		}
	}
	regfree(&reg);
	return 0;
}

int model_def(char *line) {
	char *match_ret;

	match_ret = match_config("^[ \t]*model[ \t]*=[ \t]*([0-9]+)", line);
	if(match_ret == NULL)
		return -1;
	else
		return atoi(match_ret);
}

char *bcast_def(char *line) {
	char *match_ret;

	match_ret = match_config("^[ \t]*broadcast[ \t]*=[ \t]*([0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}) *$", line);
	/* NULL if not found */
	return match_ret;
}

int decimal_def(char *line) {
	char *match_ret;
	int dec;

	match_ret = match_config("^[ \t]*decimal[ \t]*=[ \t]*([0-9]+)", line);

	if(match_ret == NULL)
		return -1;
	else
		dec = atoi(match_ret);
		if(dec == 1)
			return 1;
		else
			return 0;
}

char *match_config(char *regex, char * line) {
	char *match_str;
	regmatch_t match[2];
	int reg_ret;
	regex_t reg;
	
	/* look for model or broadcast configuration */
	if(regcomp(&reg, regex, REG_EXTENDED) != 0) {
		perror("regular expression compile failed");
		return NULL;
	}

	if( (reg_ret = regexec(&reg, line, 2, match, 0)) == 0) {
		/* extract the value */
		match_str = &line[match[1].rm_so];
		return match_str;
	}

	return NULL;
}

char *laddr_def(char *line) {
	char *match_ret;

	match_ret = match_config("^[ \t]*listen[ \t]*=[ \t]*([0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}) *$", line);
	/* NULL if not found */
	return match_ret;
}