4 * Copyright (C) 2012 by Darren Reed.
6 * See the IPFILTER.LICENCE file for details on licencing.
8 * $Id: ip_raudio_pxy.c,v 1.40.2.4 2006/07/14 06:12:17 darrenr Exp $
11 #define IPF_RAUDIO_PROXY
14 void ipf_p_raudio_main_load __P((void));
15 void ipf_p_raudio_main_unload __P((void));
16 int ipf_p_raudio_new __P((void *, fr_info_t *, ap_session_t *, nat_t *));
17 int ipf_p_raudio_in __P((void *, fr_info_t *, ap_session_t *, nat_t *));
18 int ipf_p_raudio_out __P((void *, fr_info_t *, ap_session_t *, nat_t *));
20 static frentry_t raudiofr;
22 int raudio_proxy_init = 0;
26 * Real Audio application proxy initialization.
29 ipf_p_raudio_main_load()
31 bzero((char *)&raudiofr, sizeof(raudiofr));
33 raudiofr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
34 MUTEX_INIT(&raudiofr.fr_lock, "Real Audio proxy rule lock");
35 raudio_proxy_init = 1;
40 ipf_p_raudio_main_unload()
42 if (raudio_proxy_init == 1) {
43 MUTEX_DESTROY(&raudiofr.fr_lock);
44 raudio_proxy_init = 0;
50 * Setup for a new proxy to handle Real Audio.
53 ipf_p_raudio_new(arg, fin, aps, nat)
66 KMALLOCS(aps->aps_data, void *, sizeof(raudio_t));
67 if (aps->aps_data == NULL)
70 bzero(aps->aps_data, sizeof(raudio_t));
72 aps->aps_psiz = sizeof(raudio_t);
73 rap->rap_mode = RAP_M_TCP; /* default is for TCP */
80 ipf_p_raudio_out(arg, fin, aps, nat)
86 raudio_t *rap = aps->aps_data;
87 unsigned char membuf[512 + 1], *s;
97 * If we've already processed the start messages, then nothing left
98 * for the proxy to do.
100 if (rap->rap_eos == 1)
104 tcp = (tcphdr_t *)fin->fin_dp;
105 off = (char *)tcp - (char *)fin->fin_ip;
106 off += (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
108 dlen = MSGDSIZE(m) - off;
112 if (dlen > sizeof(membuf))
113 dlen = sizeof(membuf);
115 bzero((char *)membuf, sizeof(membuf));
116 COPYDATA(m, off, dlen, (char *)membuf);
118 * In all the startup parsing, ensure that we don't go outside
119 * the packet buffer boundary.
122 * Look for the start of connection "PNA" string if not seen yet.
124 if (rap->rap_seenpna == 0) {
125 s = (u_char *)memstr("PNA", (char *)membuf, 3, dlen);
129 rap->rap_seenpna = 1;
134 * Directly after the PNA will be the version number of this
137 if (rap->rap_seenpna == 1 && rap->rap_seenver == 0) {
138 if ((s + 1) - membuf < dlen) {
139 rap->rap_version = (*s << 8) | *(s + 1);
141 rap->rap_seenver = 1;
147 * Now that we've been past the PNA and version number, we're into the
148 * startup messages block. This ends when a message with an ID of 0.
150 while ((rap->rap_eos == 0) && ((s + 1) - membuf < dlen)) {
151 if (rap->rap_gotid == 0) {
152 id = (*s << 8) | *(s + 1);
155 if (id == RA_ID_END) {
159 } else if (rap->rap_gotlen == 0) {
160 len = (*s << 8) | *(s + 1);
165 if (rap->rap_gotid == 1 && rap->rap_gotlen == 1) {
166 if (id == RA_ID_UDP) {
167 rap->rap_mode &= ~RAP_M_TCP;
168 rap->rap_mode |= RAP_M_UDP;
169 rap->rap_plport = (*s << 8) | *(s + 1);
170 } else if (id == RA_ID_ROBUST) {
171 rap->rap_mode |= RAP_M_ROBUST;
172 rap->rap_prport = (*s << 8) | *(s + 1);
184 ipf_p_raudio_in(arg, fin, aps, nat)
190 unsigned char membuf[IPF_MAXPORTLEN + 1], *s;
191 tcphdr_t *tcp, tcph, *tcp2 = &tcph;
192 raudio_t *rap = aps->aps_data;
193 ipf_main_softc_t *softc;
194 ipf_nat_softc_t *softn;
195 struct in_addr swa, swb;
206 softc = fin->fin_main_soft;
207 softn = softc->ipf_nat_soft;
209 * Wait until we've seen the end of the start messages and even then
210 * only proceed further if we're using UDP. If they want to use TCP
211 * then data is sent back on the same channel that is already open.
213 if (rap->rap_sdone != 0)
217 tcp = (tcphdr_t *)fin->fin_dp;
218 off = (char *)tcp - (char *)fin->fin_ip;
219 off += (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
221 dlen = MSGDSIZE(m) - off;
225 if (dlen > sizeof(membuf))
226 dlen = sizeof(membuf);
228 bzero((char *)membuf, sizeof(membuf));
229 COPYDATA(m, off, dlen, (char *)membuf);
231 seq = ntohl(tcp->th_seq);
233 * Check to see if the data in this packet is of interest to us.
234 * We only care for the first 19 bytes coming back from the server.
236 if (rap->rap_sseq == 0) {
237 s = (u_char *)memstr("PNA", (char *)membuf, 3, dlen);
244 a2 = MIN(dlen, sizeof(rap->rap_svr));
245 } else if (seq <= rap->rap_sseq + sizeof(rap->rap_svr)) {
247 * seq # which is the start of data and from that the offset
248 * into the buffer array.
250 a1 = seq - rap->rap_sseq;
251 a2 = MIN(dlen, sizeof(rap->rap_svr));
257 for (a3 = a1, a4 = a2; (a4 > 0) && (a3 < 19) && (a3 >= 0); a4--,a3++) {
258 rap->rap_sbf |= (1 << a3);
259 rap->rap_svr[a3] = *s++;
262 if ((rap->rap_sbf != 0x7ffff) || (!rap->rap_eos)) /* 19 bits */
266 s = (u_char *)rap->rap_svr + 11;
267 if (((*s << 8) | *(s + 1)) == RA_ID_ROBUST) {
269 rap->rap_srport = (*s << 8) | *(s + 1);
277 ip->ip_p = IPPROTO_UDP;
278 ip->ip_src = nat->nat_ndstip;
279 ip->ip_dst = nat->nat_odstip;
281 bcopy((char *)fin, (char *)&fi, sizeof(fi));
282 bzero((char *)tcp2, sizeof(*tcp2));
284 fi.fin_flx |= FI_IGNORE;
285 fi.fin_dp = (char *)tcp2;
286 fi.fin_fr = &raudiofr;
287 fi.fin_dlen = sizeof(*tcp2);
288 fi.fin_plen = fi.fin_hlen + sizeof(*tcp2);
289 tcp2->th_win = htons(8192);
291 ip->ip_len = htons(fin->fin_hlen + sizeof(*tcp));
293 if (((rap->rap_mode & RAP_M_UDP_ROBUST) == RAP_M_UDP_ROBUST) &&
294 (rap->rap_srport != 0)) {
295 dp = rap->rap_srport;
296 sp = rap->rap_prport;
297 tcp2->th_sport = htons(sp);
298 tcp2->th_dport = htons(dp);
302 MUTEX_ENTER(&softn->ipf_nat_new);
303 nat2 = ipf_nat_add(&fi, nat->nat_ptr, NULL,
304 NAT_SLAVE|IPN_UDP | (sp ? 0 : SI_W_SPORT),
306 MUTEX_EXIT(&softn->ipf_nat_new);
308 (void) ipf_nat_proto(&fi, nat2, IPN_UDP);
309 MUTEX_ENTER(&nat2->nat_lock);
310 ipf_nat_update(&fi, nat2);
311 MUTEX_EXIT(&nat2->nat_lock);
313 (void) ipf_state_add(softc, &fi, NULL,
314 (sp ? 0 : SI_W_SPORT));
318 if ((rap->rap_mode & RAP_M_UDP) == RAP_M_UDP) {
319 sp = rap->rap_plport;
320 tcp2->th_sport = htons(sp);
321 tcp2->th_dport = 0; /* XXX - don't specify remote port */
325 MUTEX_ENTER(&softn->ipf_nat_new);
326 nat2 = ipf_nat_add(&fi, nat->nat_ptr, NULL,
327 NAT_SLAVE|IPN_UDP|SI_W_DPORT,
329 MUTEX_EXIT(&softn->ipf_nat_new);
331 (void) ipf_nat_proto(&fi, nat2, IPN_UDP);
332 MUTEX_ENTER(&nat2->nat_lock);
333 ipf_nat_update(&fi, nat2);
334 MUTEX_EXIT(&nat2->nat_lock);
336 (void) ipf_state_add(softc, &fi, NULL, SI_W_DPORT);