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/* rblcheck.c
dnsbl (rbl) checker application
Copyright (C) 2005 Michael Tokarev <mjt@corpit.ru>
This file is part of UDNS library, an async DNS stub resolver.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library, in file named COPYING.LGPL; if not,
write to the Free Software Foundation, Inc., 59 Temple Place,
Suite 330, Boston, MA 02111-1307 USA
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef __MINGW32__
# include <winsock2.h>
#else
# include <unistd.h>
# include <sys/types.h>
# include <sys/socket.h>
# include <netinet/in.h>
#endif
#include <time.h>
#include <errno.h>
#include <stdarg.h>
#include "udns.h"
#ifndef HAVE_GETOPT
# include "getopt.c"
#endif
static const char *version = "udns-rblcheck 0.4";
static char *progname;
static void error(int die, const char *fmt, ...) {
va_list ap;
fprintf(stderr, "%s: ", progname);
va_start(ap, fmt); vfprintf(stderr, fmt, ap); va_end(ap);
putc('\n', stderr);
fflush(stderr);
if (die)
exit(1);
}
struct rblookup {
struct ipcheck *parent;
struct in_addr key;
const char *zone;
struct dns_rr_a4 *addr;
struct dns_rr_txt *txt;
};
struct ipcheck {
const char *name;
int naddr;
int listed;
struct rblookup *lookup;
};
#define notlisted ((void*)1)
static int nzones, nzalloc;
static const char **zones;
static int do_txt;
static int stopfirst;
static int verbose = 1;
/* verbosity level:
* <0 - only bare As/TXTs
* 0 - what RBL result
* 1(default) - what is listed by RBL: result
* 2 - what is[not ]listed by RBL: result, name lookups
*/
static int listed;
static int failures;
static void *ecalloc(int size, int cnt) {
void *t = calloc(size, cnt);
if (!t)
error(1, "out of memory");
return t;
}
static void addzone(const char *zone) {
if (nzones >= nzalloc) {
const char **zs = (const char**)ecalloc(sizeof(char*), (nzalloc += 16));
if (zones) {
memcpy(zs, zones, nzones * sizeof(char*));
free(zones);
}
zones = zs;
}
zones[nzones++] = zone;
}
static int addzonefile(const char *fname) {
FILE *f = fopen(fname, "r");
char linebuf[2048];
if (!f)
return 0;
while(fgets(linebuf, sizeof(linebuf), f)) {
char *p = linebuf, *e;
while(*p == ' ' || *p == '\t') ++p;
if (*p == '#' || *p == '\n') continue;
e = p;
while(*e && *e != ' ' && *e != '\t' && *e != '\n')
++e;
*e++ = '\0';
p = memcpy(ecalloc(e - p, 1), p, e - p); // strdup
addzone(p);
}
fclose(f);
return 1;
}
static void dnserror(struct rblookup *ipl, const char *what) {
char buf[4*4];
error(0, "unable to %s for %s (%s): %s",
what, dns_ntop(AF_INET, &ipl->key, buf, sizeof(buf)),
ipl->zone, dns_strerror(dns_status(0)));
++failures;
}
static void display_result(struct ipcheck *ipc) {
int j;
struct rblookup *l, *le;
char buf[4*4];
if (!ipc->naddr) return;
for (l = ipc->lookup, le = l + nzones * ipc->naddr; l < le; ++l) {
if (!l->addr) continue;
if (verbose < 2 && l->addr == notlisted) continue;
if (verbose >= 0) {
dns_ntop(AF_INET, &l->key, buf, sizeof(buf));
if (ipc->name) printf("%s[%s]", ipc->name, buf);
else printf("%s", buf);
}
if (l->addr == notlisted) {
printf(" is NOT listed by %s\n", l->zone);
continue;
}
else if (verbose >= 1)
printf(" is listed by %s: ", l->zone);
else if (verbose >= 0)
printf(" %s ", l->zone);
if (verbose >= 1 || !do_txt)
for (j = 0; j < l->addr->dnsa4_nrr; ++j)
printf("%s%s", j ? " " : "",
dns_ntop(AF_INET, &l->addr->dnsa4_addr[j], buf, sizeof(buf)));
if (!do_txt) ;
else if (l->txt) {
for(j = 0; j < l->txt->dnstxt_nrr; ++j) {
unsigned char *t = l->txt->dnstxt_txt[j].txt;
unsigned char *e = t + l->txt->dnstxt_txt[j].len;
printf("%s\"", verbose > 0 ? "\n\t" : j ? " " : "");
while(t < e) {
if (*t < ' ' || *t >= 127) printf("\\x%02x", *t);
else if (*t == '\\' || *t == '"') printf("\\%c", *t);
else putchar(*t);
++t;
}
putchar('"');
}
free(l->txt);
}
else
printf("%s<no text available>", verbose > 0 ? "\n\t" : "");
free(l->addr);
putchar('\n');
}
free(ipc->lookup);
}
static void txtcb(struct dns_ctx *ctx, struct dns_rr_txt *r, void *data) {
struct rblookup *ipl = data;
if (r) {
ipl->txt = r;
++ipl->parent->listed;
}
else if (dns_status(ctx) != DNS_E_NXDOMAIN)
dnserror(ipl, "lookup DNSBL TXT record");
}
static void a4cb(struct dns_ctx *ctx, struct dns_rr_a4 *r, void *data) {
struct rblookup *ipl = data;
if (r) {
ipl->addr = r;
++listed;
if (do_txt) {
if (dns_submit_a4dnsbl_txt(0, &ipl->key, ipl->zone, txtcb, ipl))
return;
dnserror(ipl, "submit DNSBL TXT record");
}
++ipl->parent->listed;
}
else if (dns_status(ctx) != DNS_E_NXDOMAIN)
dnserror(ipl, "lookup DNSBL A record");
else
ipl->addr = notlisted;
}
static int
submit_a_queries(struct ipcheck *ipc,
int naddr, const struct in_addr *addr) {
int z, a;
struct rblookup *rl = ecalloc(sizeof(*rl), nzones * naddr);
ipc->lookup = rl;
ipc->naddr = naddr;
for(a = 0; a < naddr; ++a) {
for(z = 0; z < nzones; ++z) {
rl->key = addr[a];
rl->zone = zones[z];
rl->parent = ipc;
if (!dns_submit_a4dnsbl(0, &rl->key, rl->zone, a4cb, rl))
dnserror(rl, "submit DNSBL A query");
++rl;
}
}
return 0;
}
static void namecb(struct dns_ctx *ctx, struct dns_rr_a4 *rr, void *data) {
struct ipcheck *ipc = data;
if (rr) {
submit_a_queries(ipc, rr->dnsa4_nrr, rr->dnsa4_addr);
free(rr);
}
else {
error(0, "unable to lookup `%s': %s",
ipc->name, dns_strerror(dns_status(ctx)));
++failures;
}
}
static int submit(struct ipcheck *ipc) {
struct in_addr addr;
if (dns_pton(AF_INET, ipc->name, &addr) > 0) {
submit_a_queries(ipc, 1, &addr);
ipc->name = NULL;
}
else if (!dns_submit_a4(0, ipc->name, 0, namecb, ipc)) {
error(0, "unable to submit name query for %s: %s\n",
ipc->name, dns_strerror(dns_status(0)));
++failures;
}
return 0;
}
static void waitdns(struct ipcheck *ipc) {
struct timeval tv;
fd_set fds;
int c;
int fd = dns_sock(NULL);
time_t now = 0;
FD_ZERO(&fds);
while((c = dns_timeouts(NULL, -1, now)) > 0) {
FD_SET(fd, &fds);
tv.tv_sec = c;
tv.tv_usec = 0;
c = select(fd+1, &fds, NULL, NULL, &tv);
now = time(NULL);
if (c > 0)
dns_ioevent(NULL, now);
if (stopfirst && ipc->listed)
break;
}
}
int main(int argc, char **argv) {
int c;
struct ipcheck ipc;
char *nameserver = NULL;
int zgiven = 0;
if (!(progname = strrchr(argv[0], '/'))) progname = argv[0];
else argv[0] = ++progname;
while((c = getopt(argc, argv, "hqtvms:S:cn:")) != EOF) switch(c) {
case 's': ++zgiven; addzone(optarg); break;
case 'S':
++zgiven;
if (addzonefile(optarg)) break;
error(1, "unable to read zonefile `%s'", optarg);
case 'c': ++zgiven; nzones = 0; break;
case 'q': --verbose; break;
case 'v': ++verbose; break;
case 't': do_txt = 1; break;
case 'n': nameserver = optarg; break;
case 'm': ++stopfirst; break;
case 'h':
printf("%s: %s (udns library version %s).\n",
progname, version, dns_version());
printf("Usage is: %s [options] address..\n", progname);
printf(
"Where options are:\n"
" -h - print this help and exit\n"
" -s service - add the service (DNSBL zone) to the serice list\n"
" -S service-file - add the DNSBL zone(s) read from the given file\n"
" -c - clear service list\n"
" -v - increase verbosity level (more -vs => more verbose)\n"
" -q - decrease verbosity level (opposite of -v)\n"
" -t - obtain and print TXT records if any\n"
" -m - stop checking after first address match in any list\n"
" -n ipaddr - use the given nameserver instead of the default\n"
"(if no -s or -S option is given, use $RBLCHECK_ZONES, ~/.rblcheckrc\n"
"or /etc/rblcheckrc in that order)\n"
);
return 0;
default:
error(1, "use `%s -h' for help", progname);
}
if (!zgiven) {
char *s = getenv("RBLCHECK_ZONES");
if (s) {
char *k;
s = strdup(s);
for(k = strtok(s, " \t"); k; k = strtok(NULL, " \t"))
addzone(k);
free(s);
}
else { /* probably worthless on windows? */
char *path;
char *home = getenv("HOME");
if (!home) home = ".";
path = malloc(strlen(home) + 1 + sizeof(".rblcheckrc"));
sprintf(path, "%s/.rblcheckrc", home);
if (!addzonefile(path))
addzonefile("/etc/rblcheckrc");
free(path);
}
}
if (!nzones)
error(1, "no service (zone) list specified (-s or -S option)");
argv += optind;
argc -= optind;
if (!argc)
return 0;
if (dns_init(NULL, 0) < 0)
error(1, "unable to initialize DNS library: %s", strerror(errno));
if (nameserver) {
dns_add_serv(NULL, NULL);
if (dns_add_serv(NULL, nameserver) < 0)
error(1, "wrong IP address for a nameserver: `%s'", nameserver);
}
if (dns_open(NULL) < 0)
error(1, "unable to initialize DNS library: %s", strerror(errno));
for (c = 0; c < argc; ++c) {
if (c && (verbose > 1 || (verbose == 1 && do_txt))) putchar('\n');
memset(&ipc, 0, sizeof(ipc));
ipc.name = argv[c];
submit(&ipc);
waitdns(&ipc);
display_result(&ipc);
if (stopfirst > 1 && listed) break;
}
return listed ? 100 : failures ? 2 : 0;
}