xref: /freebsd/usr.sbin/ppp/iplist.c (revision eda14cbc264d6969b02f2b1994cef11148e914f1)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 1997 Brian Somers <brian@Awfulhak.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 #include <sys/types.h>
32 #include <netinet/in.h>
33 #include <arpa/inet.h>
34 
35 #include <stdlib.h>
36 #include <string.h>
37 #include <termios.h>
38 
39 #include "log.h"
40 #include "defs.h"
41 #include "iplist.h"
42 
43 static int
44 do_inet_aton(const char *start, const char *end, struct in_addr *ip)
45 {
46   char ipstr[16];
47 
48   if (end - start > 15) {
49     log_Printf(LogWARN, "%.*s: Invalid IP address\n", (int)(end-start), start);
50     return 0;
51   }
52   strncpy(ipstr, start, end-start);
53   ipstr[end-start] = '\0';
54   return inet_aton(ipstr, ip);
55 }
56 
57 static void
58 iplist_first(struct iplist *list)
59 {
60   list->cur.pos = -1;
61 }
62 
63 static int
64 iplist_setrange(struct iplist *list, char *range)
65 {
66   char *ptr, *to;
67 
68   if ((ptr = strpbrk(range, ",-")) == NULL) {
69     if (!inet_aton(range, &list->cur.ip))
70       return 0;
71     list->cur.lstart = ntohl(list->cur.ip.s_addr);
72     list->cur.nItems = 1;
73   } else {
74     if (!do_inet_aton(range, ptr, &list->cur.ip))
75       return 0;
76     if (*ptr == ',') {
77       list->cur.lstart = ntohl(list->cur.ip.s_addr);
78       list->cur.nItems = 1;
79     } else {
80       struct in_addr endip;
81 
82       to = ptr+1;
83       if ((ptr = strpbrk(to, ",-")) == NULL)
84         ptr = to + strlen(to);
85       if (*to == '-')
86         return 0;
87       if (!do_inet_aton(to, ptr, &endip))
88         return 0;
89       list->cur.lstart = ntohl(list->cur.ip.s_addr);
90       list->cur.nItems = ntohl(endip.s_addr) - list->cur.lstart + 1;
91       if (list->cur.nItems < 1)
92         return 0;
93     }
94   }
95   list->cur.srcitem = 0;
96   list->cur.srcptr = range;
97   return 1;
98 }
99 
100 static int
101 iplist_nextrange(struct iplist *list)
102 {
103   char *ptr, *to, *end;
104 
105   ptr = list->cur.srcptr;
106   if (ptr != NULL && (ptr = strchr(ptr, ',')) != NULL)
107     ptr++;
108   else
109     ptr = list->src;
110 
111   while (*ptr != '\0' && !iplist_setrange(list, ptr)) {
112     if ((end = strchr(ptr, ',')) == NULL)
113       end = ptr + strlen(ptr);
114     if (end == ptr)
115       return 0;
116     log_Printf(LogWARN, "%.*s: Invalid IP range (skipping)\n",
117                (int)(end - ptr), ptr);
118     to = ptr;
119     do
120       *to = *end++;
121     while (*to++ != '\0');
122     if (*ptr == '\0')
123       ptr = list->src;
124   }
125 
126   return 1;
127 }
128 
129 struct in_addr
130 iplist_next(struct iplist *list)
131 {
132   if (list->cur.pos == -1) {
133     list->cur.srcptr = NULL;
134     if (!iplist_nextrange(list)) {
135       list->cur.ip.s_addr = INADDR_ANY;
136       return list->cur.ip;
137     }
138   } else if (++list->cur.srcitem == list->cur.nItems) {
139     if (!iplist_nextrange(list)) {
140       list->cur.ip.s_addr = INADDR_ANY;
141       list->cur.pos = -1;
142       return list->cur.ip;
143     }
144   } else
145     list->cur.ip.s_addr = htonl(list->cur.lstart + list->cur.srcitem);
146   list->cur.pos++;
147 
148   return list->cur.ip;
149 }
150 
151 int
152 iplist_setsrc(struct iplist *list, const char *src)
153 {
154   strncpy(list->src, src, sizeof list->src - 1);
155   list->src[sizeof list->src - 1] = '\0';
156   list->cur.srcptr = list->src;
157   do {
158     if (iplist_nextrange(list))
159       list->nItems += list->cur.nItems;
160     else
161       return 0;
162   } while (list->cur.srcptr != list->src);
163   return 1;
164 }
165 
166 void
167 iplist_reset(struct iplist *list)
168 {
169   list->src[0] = '\0';
170   list->nItems = 0;
171   list->cur.pos = -1;
172 }
173 
174 struct in_addr
175 iplist_setcurpos(struct iplist *list, long pos)
176 {
177   if (pos < 0 || (unsigned)pos >= list->nItems) {
178     list->cur.pos = -1;
179     list->cur.ip.s_addr = INADDR_ANY;
180     return list->cur.ip;
181   }
182 
183   list->cur.srcptr = NULL;
184   list->cur.pos = 0;
185   while (1) {
186     iplist_nextrange(list);
187     if (pos < (int)list->cur.nItems) {
188       if (pos) {
189         list->cur.srcitem = pos;
190         list->cur.pos += pos;
191         list->cur.ip.s_addr = htonl(list->cur.lstart + list->cur.srcitem);
192       }
193       break;
194     }
195     pos -= list->cur.nItems;
196     list->cur.pos += list->cur.nItems;
197   }
198 
199   return list->cur.ip;
200 }
201 
202 struct in_addr
203 iplist_setrandpos(struct iplist *list)
204 {
205   randinit();
206   return iplist_setcurpos(list, random() % list->nItems);
207 }
208 
209 int
210 iplist_ip2pos(struct iplist *list, struct in_addr ip)
211 {
212   struct iplist_cur cur;
213   u_long f;
214   int result;
215 
216   result = -1;
217   memcpy(&cur, &list->cur, sizeof cur);
218 
219   for (iplist_first(list), f = 0; f < list->nItems; f++)
220     if (iplist_next(list).s_addr == ip.s_addr) {
221       result = list->cur.pos;
222       break;
223     }
224 
225   memcpy(&list->cur, &cur, sizeof list->cur);
226   return result;
227 }
228