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/* $OpenBSD: sdl.c,v 1.12 2004/02/26 08:18:56 deraadt 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\n", blacklists[index].tag);
sdl_free(&blacklists[index]);
} else {
if (debug > 0)
printf("adding list %s\n", sdname);
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;
}
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