1 /*  ethers.c
2  *
3  * Copyright (c) 2010 SeaD <sead at deep.perm.ru>
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  *  $Id: ethers.c,v 1.14 2010/07/12 03:46:36 sead Exp $
27  *
28  */
29 
30 #include "ipguard.h"
31 
32 #define STR_SIZE        128
33 #define ADDR_LEN        64
34 
ethers_init(void)35 void ethers_init(void) {
36     FILE *eth_fp;
37     char str[STR_SIZE];
38     char mac[ADDR_LEN], ip[ADDR_LEN];
39     register int n, m;
40 
41     if (!(eth_fp = fopen(ethers_name, "r"))) {
42         snprintf(s, 128, "fopen(%s):", ethers_name);
43         log_str(WARNING, s, strerror(errno));
44         return;
45     }
46 
47     while (fgets(str, STR_SIZE, eth_fp)) {
48         if (debug > 2) fprintf(stderr, "ETHERS: %s", str);
49         for (n = 0; n < STR_SIZE; n++)
50             if ((str[n] == '\n') || (str[n] == '\r') || (str[n] == '#')) {
51                 str[n] = '\0'; break;
52             }
53         for (mac[0] = ip[0] = '\0', n = 0; n < STR_SIZE; n++)
54             if ((str[n] != ' ') && (str[n] != '\t')) break;
55         if ((str[n] == '+') || (str[n] == '\0')) continue;
56         for (m = 0; (m < ADDR_LEN) && (n < STR_SIZE); m++, n++) {
57             if ((str[n] == ' ') || (str[n] == '\t') || (str[n] == '\0')) {
58                 mac[m] = '\0'; break;
59             }
60             mac[m] = str[n];
61         }
62         for (; n < STR_SIZE; n++) if ((str[n] != ' ') && (str[n] != '\t')) break;
63         for (m = 0; (m < ADDR_LEN) && (n < STR_SIZE); m++, n++) {
64             if ((str[n] == ' ') || (str[n] == '\t') || (str[n] == '\0')) {
65                 ip[m] = '\0'; break;
66             }
67             ip[m] = str[n];
68         }
69 
70         if (ip[0] == '\0') { if (verbose) log_str(NOTICE, "Incorrect MAC-IP pair:", str); continue; }
71         if (strchr(mac, '.')) { strncpy(str, mac, ADDR_LEN); strncpy(mac, ip, ADDR_LEN); strncpy(ip, str, ADDR_LEN); }
72         if (!strchr(mac, ':')) { if (verbose) log_str(NOTICE, "Wrong MAC address", ip); continue; }
73         if (!strchr(ip, '.')) { if (verbose) log_str(NOTICE, "Wrong IP address", ip); continue; }
74 
75         pair_add(mac, ip);
76     }
77 
78     if (fclose(eth_fp)) {
79         snprintf(s, 128, "fclose(%s):", ethers_name);
80         log_str(ERROR, s, strerror(errno));
81         exit_ipguard(EXIT_FAILURE);
82     }
83 }
84 
ethers_reinit(void)85 void ethers_reinit(void) {
86     pair_destroy(); pair_init(); ethers_init();
87     log_str(NOTICE, "MAC-IP file rescanned:", ethers_name);
88 }
89