readconf.c

这是一个关于linux下上外网的drcom1.4.4

/*
	libdrcom - Library for communicating with DrCOM 2133 Broadband Access Server
	Copyright (C) 2005 William Poetra Yoga Hadisoeseno <[e-mail]>

	This program 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; either version 2 of the License, or
	(at your option) any later version.

	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 <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include "drcomd.h"
#include "daemon_server.h"
#include "daemon_kernel.h"

#include "utils.h"

#define __OPTLEN 256

#define __istidy(x) \
	((x >= 'a' && x <= 'z') \
	|| (x >= 'A' && x <= 'Z') \
	|| (x >= '0' && x <= '9') \
	|| (x == '_' || x == '=' || x == '.' || x == ',' || x == ':' || x == '/'))

/*
	Some kind of checklist:
	+ 0 means option was never encountered in the config file
	+ 1 means option found, value specified and valid
	+ 2 means option found, value specified and invalid
	+ 3 means option found, but no value specified
	+ 4 means option found more than once
*/
struct _opt_checklist
{
	u_int8_t username;
	u_int8_t password;
	u_int8_t dev;
	u_int8_t mac;
	u_int8_t mac0;
	u_int8_t nic[4];
	u_int8_t dnsp;
	u_int8_t dnss;
	u_int8_t dhcp;
	u_int8_t hostip;
	u_int8_t servip;
	u_int8_t hostport;
	u_int8_t servport;
	u_int8_t hostname;
	u_int8_t winver;
	u_int8_t winbuild;
	u_int8_t servicepack;
};

int __stripcomments(char *);
int __tidyup(char *);
int __optname(char *, char *);
int __optval(char *, char *);
int __parseopt(struct drcom_conf *, char *, struct _opt_checklist *opts);
int __fillopts(struct drcom_conf *, struct drcom_info *, struct drcom_host *, struct _opt_checklist *);

void init_conf(struct drcom_conf *conf);
int get_except(struct drcom_conf *conf, char *buf);

/* _readconf
	A routine for parsing the config file.
*/

int _readconf(struct drcom_conf *conf, struct drcom_info *info, struct drcom_host *host)
{
	FILE *dotconf;
	char buf[__OPTLEN], *s;
	struct _opt_checklist opts;
	int lineno = 0, r = 0;

	memset(&opts, 0, sizeof(opts));

	init_conf(conf);

	dotconf = fopen(DRCOM_CONF, "r");
	if (!dotconf)
		return -1;

	while (1)
	{
		s = fgets(buf, __OPTLEN, dotconf);
		if (s == NULL)
			break;

		r = __parseopt(conf, buf, &opts);

		++lineno;

		if (r < 0 || r > 1) {
			fprintf(stderr, "Error processing config file at line %d.\n", lineno);
			break;
		}
	}

	/* Even if there was an error, we should close the file first */
	fclose(dotconf);

	if (r < 0 || r > 1)
		return -1;

	r = __fillopts(conf, info, host, &opts);
	if (r) {fprintf(stderr, "fillopts failed\n");goto out;}
	r = add_except(conf, conf->dnsp, 0xffffffff);
	if (r) goto out;
	r = add_except(conf, conf->dnss, 0xffffffff);

out:
	if (r)
	{
		fprintf(stderr, "Error digesting configuration!\n");
		return -1;
	}

	return 0;
}

int __stripcomments(char *buf)
{
	char *c;

	c = strchr(buf, '#');
	if (c != NULL)
		*c = '\0';

	return (c - buf + 1);
}

int __tidyup(char *buf)
{
	int i, len, tidylen, inquote;

	len = strlen(buf);
	tidylen = 0;
	inquote = 0;
	for (i = 0; i < len; ++i)
	{
		if (__istidy(buf[i]) || (inquote && (buf[i] != '"')))
		{
			buf[tidylen] = buf[i];
			++tidylen;
		}
		else if (buf[i] == '"')
		{
			inquote = (inquote) ? 0 : 1;
		}
	}
	buf[tidylen] = '\0';

	return tidylen;
}

int __optname(char *buf, char *optname)
{
	char *t;
	int len;

	memset(optname, 0, 256);

	t = strchr(buf, '=');
	if (t != NULL)
	{
		len = t - buf;
		strncpy(optname, buf, len);
	}
	else
	{
		len = -1;
		optname[0] = '\0';
	}

	return len;
}

int __optval(char *buf, char *optval)
{
	char *t;
	int len;

	memset(optval, 0, 256);

	t = strchr(buf, '=');
	if (t != NULL)
	{
		len = strlen(buf) - (t - buf + 1);
		strncpy(optval, t + 1, len);
	}
	else
	{
		len = -1;
		optval[0] = '\0';
	}

	return len;
}

void init_conf(struct drcom_conf *conf)
{
	memset(conf, 0, sizeof(struct drcom_conf));
}

int add_except(struct drcom_conf *conf, u_int32_t ip, u_int32_t mask)
{
	static unsigned int bufsize = 0;
	int i;

	if (conf->except == NULL){
		bufsize = 32*sizeof(struct e_address);
		conf->except_count = 0;
		conf->except = (struct e_address *)malloc(bufsize);
		if (conf->except == NULL){
			return -1;
		}
	}

	for(i=0; i<conf->except_count; i++) {
		struct e_address *p = conf->except + i;
		if ((p->addr & p->mask) == (ip & mask))
			return 0;
	}

	if (bufsize == conf->except_count*sizeof(struct e_address)) {
		bufsize *= 2;
		conf->except = (struct e_address *)realloc(conf->except, bufsize);
		if (conf->except == NULL){
			return -1;
		}
	}

	conf->except[conf->except_count].addr = ip;
	conf->except[conf->except_count].mask = mask;
	conf->except_count++;

	return 0;
}

int get_except(struct drcom_conf *conf, char *buf)
{
	struct in_addr ip, mask;
	char *t, *p, *m;

	p = buf;
	while (*p != '\0') {
		t = strchr(p, ',');
		if (t == NULL)
			t = p+strlen(p);
		else {
			*t = '\0';
			t++;
		}
	
		m = strchr(p, '/');
		if (m == NULL)
			return -1;
		*m = '\0';
		m++;
	
		if (!inet_pton(AF_INET, p, &ip) || !inet_pton(AF_INET, m, &mask))
			return -1;
	
		if (add_except(conf, ip.s_addr, mask.s_addr)!=0)
			return -1;
	
		p = t;
	} 

	return 0;
}

int __parseopt(struct drcom_conf *conf, char *buf, struct _opt_checklist *opts)
{
/* define them here because they are __parseopt()-specific */
#define __optprefix(y, n) \
	(strncmp(optname, y, n) == 0)
#define __isopt(y, n) \
	(strncmp(optname, y, n) == 0 && optname_len == n)

	int len, optname_len, optval_len, r;
	long int l;
	unsigned int _mac[6];
	char optname[256], optval[256];
	struct in_addr ip = {0};

	len = strlen(buf);
	if (len > 256)
	{
		len = 256;
		buf[len] = '\0';
	}

	len = __stripcomments(buf);
	if (len == 0)
		goto skip;
	len = __tidyup(buf);
	if (len == 0)
		goto skip;

	optname_len = __optname(buf, optname);
	if (optname_len < 0)
		goto err;
	optval_len = __optval(buf, optval);
	if (optval_len < 0)
		goto err;

	if (optname_len == 0)
	{ goto err; }
	else if (__isopt("username", 8))
	{
		if (opts->username != 0) { opts->username = 4; goto ok; }
		if (optval_len == 0) { opts->username = 3; goto ok; }
		memset(conf->username, 0, 36);
		strncpy(conf->username, optval, 36);
		opts->username = 1; goto ok;
	}
	else if (__isopt("password", 8))
	{
		if (opts->password != 0) { opts->password = 4; goto ok; }
		if (optval_len == 0) { opts->password = 3; goto ok; }
		memset(conf->password, 0, 16);
		strncpy(conf->password, optval, 16);
		opts->password = 1; goto ok;
	}
	else if (__isopt("except", 6)) {
		if (optval_len == 0) goto ok;
		else {
			int r = get_except(conf, optval);
			if (r==0)
				goto ok;
			else{
				fprintf(stderr, "except list error\n");
				goto err;
			}