xref: /freebsd/usr.sbin/ppp/iplist.c (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 
29 #include <sys/types.h>
30 #include <netinet/in.h>
31 #include <arpa/inet.h>
32 
33 #include <stdlib.h>
34 #include <string.h>
35 #include <termios.h>
36 
37 #include "log.h"
38 #include "defs.h"
39 #include "iplist.h"
40 
41 static int
42 do_inet_aton(const char *start, const char *end, struct in_addr *ip)
43 {
44   char ipstr[16];
45 
46   if (end - start > 15) {
47     log_Printf(LogWARN, "%.*s: Invalid IP address\n", (int)(end-start), start);
48     return 0;
49   }
50   strncpy(ipstr, start, end-start);
51   ipstr[end-start] = '\0';
52   return inet_aton(ipstr, ip);
53 }
54 
55 static void
56 iplist_first(struct iplist *list)
57 {
58   list->cur.pos = -1;
59 }
60 
61 static int
62 iplist_setrange(struct iplist *list, char *range)
63 {
64   char *ptr, *to;
65 
66   if ((ptr = strpbrk(range, ",-")) == NULL) {
67     if (!inet_aton(range, &list->cur.ip))
68       return 0;
69     list->cur.lstart = ntohl(list->cur.ip.s_addr);
70     list->cur.nItems = 1;
71   } else {
72     if (!do_inet_aton(range, ptr, &list->cur.ip))
73       return 0;
74     if (*ptr == ',') {
75       list->cur.lstart = ntohl(list->cur.ip.s_addr);
76       list->cur.nItems = 1;
77     } else {
78       struct in_addr endip;
79 
80       to = ptr+1;
81       if ((ptr = strpbrk(to, ",-")) == NULL)
82         ptr = to + strlen(to);
83       if (*to == '-')
84         return 0;
85       if (!do_inet_aton(to, ptr, &endip))
86         return 0;
87       list->cur.lstart = ntohl(list->cur.ip.s_addr);
88       list->cur.nItems = ntohl(endip.s_addr) - list->cur.lstart + 1;
89       if (list->cur.nItems < 1)
90         return 0;
91     }
92   }
93   list->cur.srcitem = 0;
94   list->cur.srcptr = range;
95   return 1;
96 }
97 
98 static int
99 iplist_nextrange(struct iplist *list)
100 {
101   char *ptr, *to, *end;
102 
103   ptr = list->cur.srcptr;
104   if (ptr != NULL && (ptr = strchr(ptr, ',')) != NULL)
105     ptr++;
106   else
107     ptr = list->src;
108 
109   while (*ptr != '\0' && !iplist_setrange(list, ptr)) {
110     if ((end = strchr(ptr, ',')) == NULL)
111       end = ptr + strlen(ptr);
112     if (end == ptr)
113       return 0;
114     log_Printf(LogWARN, "%.*s: Invalid IP range (skipping)\n",
115                (int)(end - ptr), ptr);
116     to = ptr;
117     do
118       *to = *end++;
119     while (*to++ != '\0');
120     if (*ptr == '\0')
121       ptr = list->src;
122   }
123 
124   return 1;
125 }
126 
127 struct in_addr
128 iplist_next(struct iplist *list)
129 {
130   if (list->cur.pos == -1) {
131     list->cur.srcptr = NULL;
132     if (!iplist_nextrange(list)) {
133       list->cur.ip.s_addr = INADDR_ANY;
134       return list->cur.ip;
135     }
136   } else if (++list->cur.srcitem == list->cur.nItems) {
137     if (!iplist_nextrange(list)) {
138       list->cur.ip.s_addr = INADDR_ANY;
139       list->cur.pos = -1;
140       return list->cur.ip;
141     }
142   } else
143     list->cur.ip.s_addr = htonl(list->cur.lstart + list->cur.srcitem);
144   list->cur.pos++;
145 
146   return list->cur.ip;
147 }
148 
149 int
150 iplist_setsrc(struct iplist *list, const char *src)
151 {
152   strncpy(list->src, src, sizeof list->src - 1);
153   list->src[sizeof list->src - 1] = '\0';
154   list->cur.srcptr = list->src;
155   do {
156     if (iplist_nextrange(list))
157       list->nItems += list->cur.nItems;
158     else
159       return 0;
160   } while (list->cur.srcptr != list->src);
161   return 1;
162 }
163 
164 void
165 iplist_reset(struct iplist *list)
166 {
167   list->src[0] = '\0';
168   list->nItems = 0;
169   list->cur.pos = -1;
170 }
171 
172 struct in_addr
173 iplist_setcurpos(struct iplist *list, long pos)
174 {
175   if (pos < 0 || (unsigned)pos >= list->nItems) {
176     list->cur.pos = -1;
177     list->cur.ip.s_addr = INADDR_ANY;
178     return list->cur.ip;
179   }
180 
181   list->cur.srcptr = NULL;
182   list->cur.pos = 0;
183   while (1) {
184     iplist_nextrange(list);
185     if (pos < (int)list->cur.nItems) {
186       if (pos) {
187         list->cur.srcitem = pos;
188         list->cur.pos += pos;
189         list->cur.ip.s_addr = htonl(list->cur.lstart + list->cur.srcitem);
190       }
191       break;
192     }
193     pos -= list->cur.nItems;
194     list->cur.pos += list->cur.nItems;
195   }
196 
197   return list->cur.ip;
198 }
199 
200 struct in_addr
201 iplist_setrandpos(struct iplist *list)
202 {
203   randinit();
204   return iplist_setcurpos(list, random() % list->nItems);
205 }
206 
207 int
208 iplist_ip2pos(struct iplist *list, struct in_addr ip)
209 {
210   struct iplist_cur cur;
211   u_long f;
212   int result;
213 
214   result = -1;
215   memcpy(&cur, &list->cur, sizeof cur);
216 
217   for (iplist_first(list), f = 0; f < list->nItems; f++)
218     if (iplist_next(list).s_addr == ip.s_addr) {
219       result = list->cur.pos;
220       break;
221     }
222 
223   memcpy(&list->cur, &cur, sizeof list->cur);
224   return result;
225 }
226