OpenBSD-4.6/libexec/spamd/sync.c
/* $OpenBSD: sync.c,v 1.8 2009/04/20 17:42:21 beck Exp $ */
/*
* Copyright (c) 2006, 2007 Reyk Floeter <reyk@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/param.h>
#include <sys/stdint.h>
#include <sys/file.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <sys/resource.h>
#include <sys/uio.h>
#include <sys/ioctl.h>
#include <sys/queue.h>
#include <net/if.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <err.h>
#include <errno.h>
#include <getopt.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sha1.h>
#include <syslog.h>
#include <netdb.h>
#include <openssl/hmac.h>
#include "sdl.h"
#include "grey.h"
#include "sync.h"
extern struct syslog_data sdata;
extern int debug;
extern FILE *grey;
extern int greylist;
u_int32_t sync_counter;
int syncfd;
int sendmcast;
struct sockaddr_in sync_in;
struct sockaddr_in sync_out;
static char *sync_key;
struct sync_host {
LIST_ENTRY(sync_host) h_entry;
char *h_name;
struct sockaddr_in sh_addr;
};
LIST_HEAD(synchosts, sync_host) sync_hosts = LIST_HEAD_INITIALIZER(sync_hosts);
void sync_send(struct iovec *, int);
void sync_addr(time_t, time_t, char *, u_int16_t);
int
sync_addhost(const char *name, u_short port)
{
struct addrinfo hints, *res, *res0;
struct sync_host *shost;
struct sockaddr_in *addr = NULL;
bzero(&hints, sizeof(hints));
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
if (getaddrinfo(name, NULL, &hints, &res0) != 0)
return (EINVAL);
for (res = res0; res != NULL; res = res->ai_next) {
if (addr == NULL && res->ai_family == AF_INET) {
addr = (struct sockaddr_in *)res->ai_addr;
break;
}
}
if (addr == NULL) {
freeaddrinfo(res0);
return (EINVAL);
}
if ((shost = (struct sync_host *)
calloc(1, sizeof(struct sync_host))) == NULL) {
freeaddrinfo(res0);
return (ENOMEM);
}
if ((shost->h_name = strdup(name)) == NULL) {
free(shost);
freeaddrinfo(res0);
return (ENOMEM);
}
shost->sh_addr.sin_family = AF_INET;
shost->sh_addr.sin_port = htons(port);
shost->sh_addr.sin_addr.s_addr = addr->sin_addr.s_addr;
freeaddrinfo(res0);
LIST_INSERT_HEAD(&sync_hosts, shost, h_entry);
if (debug)
fprintf(stderr, "added spam sync host %s "
"(address %s, port %d)\n", shost->h_name,
inet_ntoa(shost->sh_addr.sin_addr), port);
return (0);
}
int
sync_init(const char *iface, const char *baddr, u_short port)
{
int one = 1;
u_int8_t ttl;
struct ifreq ifr;
struct ip_mreq mreq;
struct sockaddr_in *addr;
char ifnam[IFNAMSIZ], *ttlstr;
const char *errstr;
struct in_addr ina;
if (iface != NULL)
sendmcast++;
bzero(&ina, sizeof(ina));
if (baddr != NULL) {
if (inet_pton(AF_INET, baddr, &ina) != 1) {
ina.s_addr = htonl(INADDR_ANY);
if (iface == NULL)
iface = baddr;
else if (iface != NULL && strcmp(baddr, iface) != 0) {
fprintf(stderr, "multicast interface does "
"not match");
return (-1);
}
}
}
sync_key = SHA1File(SPAM_SYNC_KEY, NULL);
if (sync_key == NULL) {
if (errno != ENOENT) {
fprintf(stderr, "failed to open sync key: %s\n",
strerror(errno));
return (-1);
}
/* Use empty key by default */
sync_key = "";
}
syncfd = socket(AF_INET, SOCK_DGRAM, 0);
if (syncfd == -1)
return (-1);
if (setsockopt(syncfd, SOL_SOCKET, SO_REUSEADDR, &one,
sizeof(one)) == -1)
goto fail;
bzero(&sync_out, sizeof(sync_out));
sync_out.sin_family = AF_INET;
sync_out.sin_len = sizeof(sync_out);
sync_out.sin_addr.s_addr = ina.s_addr;
if (baddr == NULL && iface == NULL)
sync_out.sin_port = 0;
else
sync_out.sin_port = htons(port);
if (bind(syncfd, (struct sockaddr *)&sync_out, sizeof(sync_out)) == -1)
goto fail;
/* Don't use multicast messages */
if (iface == NULL)
return (syncfd);
strlcpy(ifnam, iface, sizeof(ifnam));
ttl = SPAM_SYNC_MCASTTTL;
if ((ttlstr = strchr(ifnam, ':')) != NULL) {
*ttlstr++ = '\0';
ttl = (u_int8_t)strtonum(ttlstr, 1, UINT8_MAX, &errstr);
if (errstr) {
fprintf(stderr, "invalid multicast ttl %s: %s",
ttlstr, errstr);
goto fail;
}
}
bzero(&ifr, sizeof(ifr));
strlcpy(ifr.ifr_name, ifnam, sizeof(ifr.ifr_name));
if (ioctl(syncfd, SIOCGIFADDR, &ifr) == -1)
goto fail;
bzero(&sync_in, sizeof(sync_in));
addr = (struct sockaddr_in *)&ifr.ifr_addr;
sync_in.sin_family = AF_INET;
sync_in.sin_len = sizeof(sync_in);
sync_in.sin_addr.s_addr = addr->sin_addr.s_addr;
sync_in.sin_port = htons(port);
bzero(&mreq, sizeof(mreq));
sync_out.sin_addr.s_addr = inet_addr(SPAM_SYNC_MCASTADDR);
mreq.imr_multiaddr.s_addr = inet_addr(SPAM_SYNC_MCASTADDR);
mreq.imr_interface.s_addr = sync_in.sin_addr.s_addr;
if (setsockopt(syncfd, IPPROTO_IP,
IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) == -1) {
fprintf(stderr, "failed to add multicast membership to %s: %s",
SPAM_SYNC_MCASTADDR, strerror(errno));
goto fail;
}
if (setsockopt(syncfd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl,
sizeof(ttl)) < 0) {
fprintf(stderr, "failed to set multicast ttl to "
"%u: %s\n", ttl, strerror(errno));
setsockopt(syncfd, IPPROTO_IP,
IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq));
goto fail;
}
if (debug)
printf("using multicast spam sync %smode "
"(ttl %u, group %s, port %d)\n",
sendmcast ? "" : "receive ",
ttl, inet_ntoa(sync_out.sin_addr), port);
return (syncfd);
fail:
close(syncfd);
return (-1);
}
void
sync_recv(void)
{
struct spam_synchdr *hdr;
struct sockaddr_in addr;
struct spam_synctlv_hdr *tlv;
struct spam_synctlv_grey *sg;
struct spam_synctlv_addr *sd;
u_int8_t buf[SPAM_SYNC_MAXSIZE];
u_int8_t hmac[2][SPAM_SYNC_HMAC_LEN];
struct in_addr ip;
char *from, *to, *helo;
u_int8_t *p;
socklen_t addr_len;
ssize_t len;
u_int hmac_len;
time_t expire;
bzero(&addr, sizeof(addr));
bzero(buf, sizeof(buf));
addr_len = sizeof(addr);
if ((len = recvfrom(syncfd, buf, sizeof(buf), 0,
(struct sockaddr *)&addr, &addr_len)) < 1)
return;
if (addr.sin_addr.s_addr != htonl(INADDR_ANY) &&
bcmp(&sync_in.sin_addr, &addr.sin_addr,
sizeof(addr.sin_addr)) == 0)
return;
/* Ignore invalid or truncated packets */
hdr = (struct spam_synchdr *)buf;
if (len < sizeof(struct spam_synchdr) ||
hdr->sh_version != SPAM_SYNC_VERSION ||
hdr->sh_af != AF_INET ||
len < ntohs(hdr->sh_length))
goto trunc;
len = ntohs(hdr->sh_length);
/* Compute and validate HMAC */
bcopy(hdr->sh_hmac, hmac[0], SPAM_SYNC_HMAC_LEN);
bzero(hdr->sh_hmac, SPAM_SYNC_HMAC_LEN);
HMAC(EVP_sha1(), sync_key, strlen(sync_key), buf, len,
hmac[1], &hmac_len);
if (bcmp(hmac[0], hmac[1], SPAM_SYNC_HMAC_LEN) != 0)
goto trunc;
if (debug)
fprintf(stderr,
"%s(sync): received packet of %d bytes\n",
inet_ntoa(addr.sin_addr), (int)len);
p = (u_int8_t *)(hdr + 1);
while (len) {
tlv = (struct spam_synctlv_hdr *)p;
if (len < sizeof(struct spam_synctlv_hdr) ||
len < ntohs(tlv->st_length))
goto trunc;
switch (ntohs(tlv->st_type)) {
case SPAM_SYNC_GREY:
sg = (struct spam_synctlv_grey *)tlv;
if ((sizeof(*sg) +
ntohs(sg->sg_from_length) +
ntohs(sg->sg_to_length) +
ntohs(sg->sg_helo_length)) >
ntohs(tlv->st_length))
goto trunc;
ip.s_addr = sg->sg_ip;
from = (char *)(sg + 1);
to = from + ntohs(sg->sg_from_length);
helo = to + ntohs(sg->sg_to_length);
if (debug) {
fprintf(stderr, "%s(sync): "
"received grey entry ",
inet_ntoa(addr.sin_addr));
fprintf(stderr, "helo %s ip %s "
"from %s to %s\n",
helo, inet_ntoa(ip), from, to);
}
if (greylist) {
/* send this info to the greylister */
fprintf(grey,
"SYNC\nHE:%s\nIP:%s\nFR:%s\nTO:%s\n",
helo, inet_ntoa(ip), from, to);
fflush(grey);
}
break;
case SPAM_SYNC_WHITE:
sd = (struct spam_synctlv_addr *)tlv;
if (sizeof(*sd) != ntohs(tlv->st_length))
goto trunc;
ip.s_addr = sd->sd_ip;
expire = ntohl(sd->sd_expire);
if (debug) {
fprintf(stderr, "%s(sync): "
"received white entry ",
inet_ntoa(addr.sin_addr));
fprintf(stderr, "ip %s ", inet_ntoa(ip));
}
if (greylist) {
/* send this info to the greylister */
fprintf(grey, "WHITE:%s:", inet_ntoa(ip));
fprintf(grey, "%s:%u\n",
inet_ntoa(addr.sin_addr), expire);
fflush(grey);
}
break;
case SPAM_SYNC_TRAPPED:
sd = (struct spam_synctlv_addr *)tlv;
if (sizeof(*sd) != ntohs(tlv->st_length))
goto trunc;
ip.s_addr = sd->sd_ip;
expire = ntohl(sd->sd_expire);
if (debug) {
fprintf(stderr, "%s(sync): "
"received trapped entry ",
inet_ntoa(addr.sin_addr));
fprintf(stderr, "ip %s ", inet_ntoa(ip));
}
if (greylist) {
/* send this info to the greylister */
fprintf(grey, "TRAP:%s:", inet_ntoa(ip));
fprintf(grey, "%s:%u\n",
inet_ntoa(addr.sin_addr), expire);
fflush(grey);
}
break;
case SPAM_SYNC_END:
goto done;
default:
printf("invalid type: %d\n", ntohs(tlv->st_type));
goto trunc;
}
len -= ntohs(tlv->st_length);
p = ((u_int8_t *)tlv) + ntohs(tlv->st_length);
}
done:
return;
trunc:
if (debug)
fprintf(stderr, "%s(sync): truncated or invalid packet\n",
inet_ntoa(addr.sin_addr));
}
void
sync_send(struct iovec *iov, int iovlen)
{
struct sync_host *shost;
struct msghdr msg;
/* setup buffer */
bzero(&msg, sizeof(msg));
msg.msg_iov = iov;
msg.msg_iovlen = iovlen;
if (sendmcast) {
if (debug)
fprintf(stderr, "sending multicast sync message\n");
msg.msg_name = &sync_out;
msg.msg_namelen = sizeof(sync_out);
sendmsg(syncfd, &msg, 0);
}
LIST_FOREACH(shost, &sync_hosts, h_entry) {
if (debug)
fprintf(stderr, "sending sync message to %s (%s)\n",
shost->h_name, inet_ntoa(shost->sh_addr.sin_addr));
msg.msg_name = &shost->sh_addr;
msg.msg_namelen = sizeof(shost->sh_addr);
sendmsg(syncfd, &msg, 0);
}
}
void
sync_update(time_t now, char *helo, char *ip, char *from, char *to)
{
struct iovec iov[7];
struct spam_synchdr hdr;
struct spam_synctlv_grey sg;
struct spam_synctlv_hdr end;
u_int16_t sglen, fromlen, tolen, helolen, padlen;
char pad[SPAM_ALIGNBYTES];
int i = 0;
HMAC_CTX ctx;
u_int hmac_len;
if (debug)
fprintf(stderr,
"sync grey update helo %s ip %s from %s to %s\n",
helo, ip, from, to);
bzero(&hdr, sizeof(hdr));
bzero(&sg, sizeof(sg));
bzero(&pad, sizeof(pad));
fromlen = strlen(from) + 1;
tolen = strlen(to) + 1;
helolen = strlen(helo) + 1;
HMAC_CTX_init(&ctx);
HMAC_Init(&ctx, sync_key, strlen(sync_key), EVP_sha1());
sglen = sizeof(sg) + fromlen + tolen + helolen;
padlen = SPAM_ALIGN(sglen) - sglen;
/* Add SPAM sync packet header */
hdr.sh_version = SPAM_SYNC_VERSION;
hdr.sh_af = AF_INET;
hdr.sh_counter = htonl(sync_counter++);
hdr.sh_length = htons(sizeof(hdr) + sglen + padlen + sizeof(end));
iov[i].iov_base = &hdr;
iov[i].iov_len = sizeof(hdr);
HMAC_Update(&ctx, iov[i].iov_base, iov[i].iov_len);
i++;
/* Add single SPAM sync greylisting entry */
sg.sg_type = htons(SPAM_SYNC_GREY);
sg.sg_length = htons(sglen + padlen);
sg.sg_timestamp = htonl(now);
sg.sg_ip = inet_addr(ip);
sg.sg_from_length = htons(fromlen);
sg.sg_to_length = htons(tolen);
sg.sg_helo_length = htons(helolen);
iov[i].iov_base = &sg;
iov[i].iov_len = sizeof(sg);
HMAC_Update(&ctx, iov[i].iov_base, iov[i].iov_len);
i++;
iov[i].iov_base = from;
iov[i].iov_len = fromlen;
HMAC_Update(&ctx, iov[i].iov_base, iov[i].iov_len);
i++;
iov[i].iov_base = to;
iov[i].iov_len = tolen;
HMAC_Update(&ctx, iov[i].iov_base, iov[i].iov_len);
i++;
iov[i].iov_base = helo;
iov[i].iov_len = helolen;
HMAC_Update(&ctx, iov[i].iov_base, iov[i].iov_len);
i++;
iov[i].iov_base = pad;
iov[i].iov_len = padlen;
HMAC_Update(&ctx, iov[i].iov_base, iov[i].iov_len);
i++;
/* Add end marker */
end.st_type = htons(SPAM_SYNC_END);
end.st_length = htons(sizeof(end));
iov[i].iov_base = &end;
iov[i].iov_len = sizeof(end);
HMAC_Update(&ctx, iov[i].iov_base, iov[i].iov_len);
i++;
HMAC_Final(&ctx, hdr.sh_hmac, &hmac_len);
/* Send message to the target hosts */
sync_send(iov, i);
HMAC_CTX_cleanup(&ctx);
}
void
sync_addr(time_t now, time_t expire, char *ip, u_int16_t type)
{
struct iovec iov[3];
struct spam_synchdr hdr;
struct spam_synctlv_addr sd;
struct spam_synctlv_hdr end;
int i = 0;
HMAC_CTX ctx;
u_int hmac_len;
if (debug)
fprintf(stderr, "sync %s %s\n",
type == SPAM_SYNC_WHITE ? "white" : "trapped", ip);
bzero(&hdr, sizeof(hdr));
bzero(&sd, sizeof(sd));
HMAC_CTX_init(&ctx);
HMAC_Init(&ctx, sync_key, strlen(sync_key), EVP_sha1());
/* Add SPAM sync packet header */
hdr.sh_version = SPAM_SYNC_VERSION;
hdr.sh_af = AF_INET;
hdr.sh_counter = htonl(sync_counter++);
hdr.sh_length = htons(sizeof(hdr) + sizeof(sd) + sizeof(end));
iov[i].iov_base = &hdr;
iov[i].iov_len = sizeof(hdr);
HMAC_Update(&ctx, iov[i].iov_base, iov[i].iov_len);
i++;
/* Add single SPAM sync address entry */
sd.sd_type = htons(type);
sd.sd_length = htons(sizeof(sd));
sd.sd_timestamp = htonl(now);
sd.sd_expire = htonl(expire);
sd.sd_ip = inet_addr(ip);
iov[i].iov_base = &sd;
iov[i].iov_len = sizeof(sd);
HMAC_Update(&ctx, iov[i].iov_base, iov[i].iov_len);
i++;
/* Add end marker */
end.st_type = htons(SPAM_SYNC_END);
end.st_length = htons(sizeof(end));
iov[i].iov_base = &end;
iov[i].iov_len = sizeof(end);
HMAC_Update(&ctx, iov[i].iov_base, iov[i].iov_len);
i++;
HMAC_Final(&ctx, hdr.sh_hmac, &hmac_len);
/* Send message to the target hosts */
sync_send(iov, i);
HMAC_CTX_cleanup(&ctx);
}
void
sync_white(time_t now, time_t expire, char *ip)
{
sync_addr(now, expire, ip, SPAM_SYNC_WHITE);
}
void
sync_trapped(time_t now, time_t expire, char *ip)
{
sync_addr(now, expire, ip, SPAM_SYNC_TRAPPED);
}