diff options
| -rw-r--r-- | doc/helper/conntrackd.conf | 8 | ||||
| -rw-r--r-- | doc/manual/conntrack-tools.tmpl | 1 | ||||
| -rw-r--r-- | src/helpers/Makefile.am | 7 | ||||
| -rw-r--r-- | src/helpers/ssdp.c | 134 |
4 files changed, 149 insertions, 1 deletions
diff --git a/doc/helper/conntrackd.conf b/doc/helper/conntrackd.conf index 358ad10..d2d94a9 100644 --- a/doc/helper/conntrackd.conf +++ b/doc/helper/conntrackd.conf @@ -70,6 +70,14 @@ Helper { ExpectTimeout 300 } } + Type ssdp inet udp { + QueueNum 5 + QueueLen 10240 + Policy ssdp { + ExpectMax 1 + ExpectTimeout 300 + } + } } # diff --git a/doc/manual/conntrack-tools.tmpl b/doc/manual/conntrack-tools.tmpl index f21a4ff..d23dec5 100644 --- a/doc/manual/conntrack-tools.tmpl +++ b/doc/manual/conntrack-tools.tmpl @@ -890,6 +890,7 @@ maintainance.</para></listitem> <listitem><para>Oracle*TNS, to support its special <emphasis>Redirect</emphasis> message.</para></listitem> <listitem><para>NFSv3, mind that version 4 does not require this helper.</para></listitem> <listitem><para>FTP (this helper is also available in kernel-space).</para></listitem> +<listitem><para>SSDP.</para></listitem> </itemizedlist> <para>The following steps describe how to enable the RPC portmapper helper for NFSv3 (this is similar for other helpers):</para> diff --git a/src/helpers/Makefile.am b/src/helpers/Makefile.am index fe28e83..78ef7aa 100644 --- a/src/helpers/Makefile.am +++ b/src/helpers/Makefile.am @@ -6,7 +6,8 @@ pkglib_LTLIBRARIES = ct_helper_amanda.la \ ct_helper_rpc.la \ ct_helper_tftp.la \ ct_helper_tns.la \ - ct_helper_sane.la + ct_helper_sane.la \ + ct_helper_ssdp.la ct_helper_amanda_la_SOURCES = amanda.c ct_helper_amanda_la_LDFLAGS = -avoid-version -module $(LIBNETFILTER_CONNTRACK_LIBS) @@ -35,3 +36,7 @@ ct_helper_tns_la_CFLAGS = $(AM_CFLAGS) $(LIBNETFILTER_CONNTRACK_CFLAGS) ct_helper_sane_la_SOURCES = sane.c ct_helper_sane_la_LDFLAGS = -avoid-version -module $(LIBNETFILTER_CONNTRACK_LIBS) ct_helper_sane_la_CFLAGS = $(AM_CFLAGS) $(LIBNETFILTER_CONNTRACK_CFLAGS) + +ct_helper_ssdp_la_SOURCES = ssdp.c +ct_helper_ssdp_la_LDFLAGS = -avoid-version -module $(LIBNETFILTER_CONNTRACK_LIBS) +ct_helper_ssdp_la_CFLAGS = $(AM_CFLAGS) $(LIBNETFILTER_CONNTRACK_CFLAGS) diff --git a/src/helpers/ssdp.c b/src/helpers/ssdp.c new file mode 100644 index 0000000..2713f23 --- /dev/null +++ b/src/helpers/ssdp.c @@ -0,0 +1,134 @@ +/* + * SSDP connection tracking helper + * (SSDP = Simple Service Discovery Protocol) + * For documentation about SSDP see + * http://en.wikipedia.org/wiki/Simple_Service_Discovery_Protocol + * + * Copyright (C) 2014 Ashley Hughes <ashley.hughes@blueyonder.co.uk> + * Based on the SSDP conntrack helper (nf_conntrack_ssdp.c), + * :http://marc.info/?t=132945775100001&r=1&w=2 + * (C) 2012 Ian Pilcher <arequipeno@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "conntrackd.h" +#include "helper.h" +#include "myct.h" +#include "log.h" +#include <errno.h> +#include <arpa/inet.h> +#include <netinet/ip.h> +#include <netinet/udp.h> +#include <libmnl/libmnl.h> +#include <libnetfilter_conntrack/libnetfilter_conntrack.h> +#include <libnetfilter_queue/libnetfilter_queue.h> +#include <libnetfilter_queue/libnetfilter_queue_tcp.h> +#include <libnetfilter_queue/pktbuff.h> +#include <linux/netfilter.h> + +#define SSDP_MCAST_ADDR "239.255.255.250" +#define UPNP_MCAST_LL_ADDR "FF02::C" /* link-local */ +#define UPNP_MCAST_SL_ADDR "FF05::C" /* site-local */ + +#define SSDP_M_SEARCH "M-SEARCH" +#define SSDP_M_SEARCH_SIZE (sizeof SSDP_M_SEARCH - 1) + +static int ssdp_helper_cb(struct pkt_buff *pkt, uint32_t protoff, + struct myct *myct, uint32_t ctinfo) +{ + int ret = NF_ACCEPT; + union nfct_attr_grp_addr daddr, saddr, taddr; + struct iphdr *net_hdr = (struct iphdr *)pktb_network_header(pkt); + int good_packet = 0; + struct nf_expect *exp; + u_int16_t port; + unsigned int dataoff; + void *sb_ptr; + + cthelper_get_addr_dst(myct->ct, MYCT_DIR_ORIG, &daddr); + switch (nfct_get_attr_u8(myct->ct, ATTR_L3PROTO)) { + case AF_INET: + inet_pton(AF_INET, SSDP_MCAST_ADDR, &(taddr.ip)); + if (daddr.ip == taddr.ip) + good_packet = 1; + break; + case AF_INET6: + inet_pton(AF_INET6, UPNP_MCAST_LL_ADDR, &(taddr.ip6)); + if (daddr.ip6[0] == taddr.ip6[0] && + daddr.ip6[1] == taddr.ip6[1] && + daddr.ip6[2] == taddr.ip6[2] && + daddr.ip6[3] == taddr.ip6[3]) { + good_packet = 1; + break; + } + inet_pton(AF_INET6, UPNP_MCAST_SL_ADDR, &(taddr.ip6)); + if (daddr.ip6[0] == taddr.ip6[0] && + daddr.ip6[1] == taddr.ip6[1] && + daddr.ip6[2] == taddr.ip6[2] && + daddr.ip6[3] == taddr.ip6[3]) { + good_packet = 1; + break; + } + break; + default: + break; + } + + if (!good_packet) { + pr_debug("ssdp_help: destination address not multicast; ignoring\n"); + return NF_ACCEPT; + } + + /* No data? Ignore */ + dataoff = net_hdr->ihl*4 + sizeof(struct udphdr); + if (dataoff >= pktb_len(pkt)) { + pr_debug("ssdp_help: UDP payload too small for M-SEARCH; ignoring\n"); + return NF_ACCEPT; + } + + sb_ptr = pktb_network_header(pkt) + dataoff; + + if (memcmp(sb_ptr, SSDP_M_SEARCH, SSDP_M_SEARCH_SIZE) != 0) { + pr_debug("ssdp_help: UDP payload does not begin with 'M-SEARCH'; ignoring\n"); + return NF_ACCEPT; + } + + cthelper_get_addr_src(myct->ct, MYCT_DIR_ORIG, &saddr); + cthelper_get_port_src(myct->ct, MYCT_DIR_ORIG, &port); + + exp = nfexp_new(); + if (exp == NULL) + return NF_DROP; + + if (cthelper_expect_init(exp, myct->ct, 0, NULL, &saddr, + IPPROTO_UDP, NULL, &port, + NF_CT_EXPECT_PERMANENT)) { + nfexp_destroy(exp); + return NF_DROP; + } + myct->exp = exp; + + return ret; +} + +static struct ctd_helper ssdp_helper = { + .name = "ssdp", + .l4proto = IPPROTO_UDP, + .priv_data_len = 0, + .cb = ssdp_helper_cb, + .policy = { + [0] = { + .name = "ssdp", + .expect_max = 1, + .expect_timeout = 5 * 60, + }, + }, +}; + +static void __attribute__ ((constructor)) ssdp_init(void) +{ + helper_register(&ssdp_helper); +} |