summaryrefslogtreecommitdiff
path: root/libexec/spamd/sdl.c
blob: bfac803ee6e3bdbe6194891663fe8072ebfc5268 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
/*	$OpenBSD: sdl.c,v 1.13 2005/08/04 09:48:27 otto Exp $ */

/*
 * Copyright (c) 2003 Bob Beck.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * sdl.c - Implement spamd source lists
 *
 * This consists of everything we need to do to determine which lists
 * someone is on. Spamd gets the connecting address, and looks it up
 * against all lists to determine what deferral messages to feed back
 * to the connecting machine. - The redirection to spamd will happen
 * from pf in the kernel, first macth will rdr to us. Spamd (along with
 * setup) must keep track of *all* matches, so as to tell someone all the
 * lists that they are on.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "sdl.h"

static void sdl_free(struct sdlist *);
static void sdl_clear(struct sdlist *);
int match_addr(struct sdaddr *a, struct sdaddr *m, struct sdaddr *b,
    sa_family_t af);

extern int debug;
struct sdlist *blacklists = NULL;
int blc = 0, blu = 0;

int
sdl_add(char *sdname, char *sdstring, char ** addrs, int addrc)
{
	int i, index = -1;
	char astring[40];
	unsigned int maskbits;
	struct sdaddr *m, *n;

	/*
	 * if a blacklist of same tag name is already there, replace it,
	 * otherwise append.
	 */
	for (i = 0; i < blu; i++) {
		if (strcmp(blacklists[i].tag, sdname) == 0) {
			index = i;
			break;
		}
	}
	if (index != -1) {
		if (debug > 0)
			printf("replacing list %s; %d new entries\n",
			    blacklists[index].tag, addrc);
		sdl_free(&blacklists[index]);
	} else {
		if (debug > 0)
			printf("adding list %s; %d entries\n", sdname, addrc);
		index = blu;
	}
	if (index == blu && blu == blc) {
		struct sdlist *tmp;

		tmp = realloc(blacklists, (blc + 128) *
		    sizeof(struct sdlist));
		if (tmp == NULL)
			return (-1);
		blacklists = tmp;
		blc += 128;
		sdl_clear(&blacklists[index]);
	}

	if ((blacklists[index].tag = strdup(sdname)) == NULL)
		goto misc_error;
	if ((blacklists[index].string = strdup(sdstring)) == NULL)
		goto misc_error;

	blacklists[index].naddrs = addrc;

	/*
	 * Cycle through addrs, converting. We assume they are correctly
	 * formatted v4 and v6 addrs, if they don't all convert correctly, the
	 * add fails. Each address should be address/maskbits
	 */
	blacklists[index].addrs = malloc(addrc * sizeof(struct sdentry));
	if (blacklists[index].addrs == NULL)
		goto misc_error;

	for(i = 0; i < addrc; i++) {
		int j, k, af;

		n = &blacklists[index].addrs[i].sda;
		m = &blacklists[index].addrs[i].sdm;

		j = sscanf(addrs[i], "%39[^/]/%u", astring, &maskbits);
		if (j != 2)
			goto parse_error;
		if (maskbits > 128)
			goto parse_error;
		/*
		 * sanity check! we don't allow a 0 mask -
		 * don't blacklist the entire net.
		 */
		if (maskbits == 0)
			goto parse_error;
		if (strchr(astring, ':') != NULL)
			af = AF_INET6;
		else
			af = AF_INET;
		if (af == AF_INET && maskbits > 32)
			goto parse_error;
		j = inet_pton(af, astring, n);
		if (j != 1)
			goto parse_error;
		if (debug > 0)
			printf("added %s/%u\n", astring, maskbits);

		/* set mask, borrowed from pf */
		k = 0;
		for (j = 0; j < 4; j++)
			m->addr32[j] = 0;
		while (maskbits >= 32) {
			m->addr32[k++] = 0xffffffff;
			maskbits -= 32;
		}
		for (j = 31; j > 31 - maskbits; --j)
			m->addr32[k] |= (1 << j);
		if (maskbits)
			m->addr32[k] = htonl(m->addr32[k]);

		/* mask off address bits that won't ever be used */
		for (j = 0; j < 4; j++)
			n->addr32[j] = n->addr32[j] & m->addr32[j];
	}
	if (index == blu) {
		blu++;
		blacklists[blu].tag = NULL;
	}
	return (0);
 parse_error:
	if (debug > 0)
		printf("sdl_add: parse error, \"%s\"\n", addrs[i]);
 misc_error:
	sdl_free(&blacklists[index]);
	return (-1);
}


/*
 * Return 1 if the addresses a (with mask m) matches address b
 * otherwise return 0. It is assumed that address a has been
 * pre-masked out, we only need to mask b.
 */
int
match_addr(struct sdaddr *a, struct sdaddr *m, struct sdaddr *b,
    sa_family_t af)
{
	int	match = 0;

	switch (af) {
	case AF_INET:
		if ((a->addr32[0]) ==
		    (b->addr32[0] & m->addr32[0]))
			match++;
		break;
	case AF_INET6:
		if (((a->addr32[0]) ==
		    (b->addr32[0] & m->addr32[0])) &&
		    ((a->addr32[1]) ==
		    (b->addr32[1] & m->addr32[1])) &&
		    ((a->addr32[2]) ==
		    (b->addr32[2] & m->addr32[2])) &&
		    ((a->addr32[3]) ==
		    (b->addr32[3] & m->addr32[3])))
			match++;
		break;
	}
	return (match);
}


/*
 * Given an address and address family
 * return list of pointers to matching nodes. or NULL if none.
 */
struct sdlist **
sdl_lookup(struct sdlist *head, int af, void * src)
{
	int i, matches = 0;
	struct sdlist *sdl;
	struct sdentry *sda;
	struct sdaddr *source = (struct sdaddr *) src;
	int sdnewlen = 0;
	struct sdlist **sdnew = NULL;

	if (head == NULL)
		return (NULL);
	else
		sdl = head;
	while (sdl->tag != NULL) {
		for (i = 0; i < sdl->naddrs; i++) {
			sda = sdl->addrs + i;
			if (match_addr(&sda->sda, &sda->sdm, source, af)) {
				if (matches == sdnewlen) {
					struct sdlist **tmp;

					tmp = realloc(sdnew,
					    (sdnewlen + 128) *
					    sizeof(struct sdlist *));
					if (tmp == NULL)
						/*
						 * XXX out of memory -
						 * return what we have
						 */
						return (sdnew);
					sdnew = tmp;
					sdnewlen += 128;
				}
				sdnew[matches]= sdl;
				matches++;
				sdnew[matches]=NULL;
				break;
			}
		}
		sdl++;
	}
	return (sdnew);
}

static void
sdl_free(struct sdlist *sdl)
{
	free(sdl->tag);
	free(sdl->string);
	free(sdl->addrs);
	sdl_clear(sdl);
}

static void
sdl_clear(struct sdlist *sdl)
{
	sdl->tag = NULL;
	sdl->string = NULL;
	sdl->addrs = NULL;
	sdl->naddrs = 0;
}