2 * Copyright (C) 2012 by Darren Reed.
4 * See the IPFILTER.LICENCE file for details on licencing.
11 #define IPF_IRCBUFSZ 96 /* This *MUST* be >= 64! */
14 void ipf_p_irc_main_load(void);
15 void ipf_p_irc_main_unload(void);
16 int ipf_p_irc_new(void *, fr_info_t *, ap_session_t *, nat_t *);
17 int ipf_p_irc_out(void *, fr_info_t *, ap_session_t *, nat_t *);
18 int ipf_p_irc_send(fr_info_t *, nat_t *);
19 int ipf_p_irc_complete(ircinfo_t *, char *, size_t);
20 u_short ipf_irc_atoi(char **);
22 static frentry_t ircnatfr;
24 int irc_proxy_init = 0;
28 * Initialize local structures.
31 ipf_p_irc_main_load(void)
33 bzero((char *)&ircnatfr, sizeof(ircnatfr));
35 ircnatfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
36 MUTEX_INIT(&ircnatfr.fr_lock, "IRC proxy rule lock");
42 ipf_p_irc_main_unload(void)
44 if (irc_proxy_init == 1) {
45 MUTEX_DESTROY(&ircnatfr.fr_lock);
51 const char *ipf_p_irc_dcctypes[] = {
52 "CHAT ", /* CHAT chat ipnumber portnumber */
53 "SEND ", /* SEND filename ipnumber portnumber */
62 * :A PRIVMSG B :^ADCC CHAT chat 0 0^A\r\n
63 * PRIVMSG B ^ADCC CHAT chat 0 0^A\r\n
68 ipf_p_irc_complete(ircinfo_t *ircp, char *buf, size_t len)
84 if ((c != ':') && (c != 'P'))
89 * Loosely check that the source is a nickname of some sort
97 for (c = *s; !ISSPACE(c) && (i > 0); i--)
104 ircp->irc_snick = NULL;
107 * Check command string
109 if (strncmp(s, "PRIVMSG ", 8))
117 * Loosely check that the destination is a nickname of some sort
121 for (; !ISSPACE(c) && (i > 0); i--)
129 * Look for a ^A to start the DCC
137 if (strncmp(s, "\001DCC ", 4))
144 * Check for a recognised DCC command
146 for (j = 0, k = 0; ipf_p_irc_dcctypes[j]; j++) {
147 k = MIN(strlen(ipf_p_irc_dcctypes[j]), i);
148 if (!strncmp(ipf_p_irc_dcctypes[j], s, k))
151 if (!ipf_p_irc_dcctypes[j])
168 for (; (c != ' ') && (c != '\001') && (i > 0); i--)
171 if (c == '\001') /* In reality a ^A can quote another ^A...*/
186 for (l = 0; ISDIGIT(c) && (i > 0); i--) {
207 for (l = 0; ISDIGIT(c) && (i > 0); i--) {
214 if (strncmp(s, "\001\r\n", 3))
217 ircp->irc_len = s - buf;
224 ipf_p_irc_new(void *arg, fr_info_t *fin, ap_session_t *aps, nat_t *nat)
231 KMALLOC(irc, ircinfo_t *);
235 nat = nat; /* LINT */
238 aps->aps_psiz = sizeof(ircinfo_t);
240 bzero((char *)irc, sizeof(*irc));
246 ipf_p_irc_send(fr_info_t *fin, nat_t *nat)
248 char ctcpbuf[IPF_IRCBUFSZ], newbuf[IPF_IRCBUFSZ];
249 tcphdr_t *tcp, tcph, *tcp2 = &tcph;
250 int off, inc = 0, i, dlen;
251 ipf_main_softc_t *softc;
252 size_t nlen = 0, olen;
264 softc = fin->fin_main_soft;
268 tcp = (tcphdr_t *)fin->fin_dp;
269 bzero(ctcpbuf, sizeof(ctcpbuf));
270 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
272 dlen = MSGDSIZE(m) - off;
275 COPYDATA(m, off, MIN(sizeof(ctcpbuf), dlen), ctcpbuf);
279 ctcpbuf[sizeof(ctcpbuf) - 1] = '\0';
282 irc = nat->nat_aps->aps_data;
283 if (ipf_p_irc_complete(irc, ctcpbuf, dlen) == 0)
287 * check that IP address in the DCC reply is the same as the
288 * sender of the command - prevents use for port scanning.
290 if (irc->irc_ipnum != ntohl(nat->nat_osrcaddr))
296 * Calculate new address parts for the DCC command
298 a1 = ntohl(ip->ip_src.s_addr);
300 i = irc->irc_addr - ctcpbuf;
302 (void) strncpy(newbuf, ctcpbuf, i);
303 /* DO NOT change these! */
304 (void) snprintf(newbuf, sizeof(newbuf), "%u %u\001\r\n", a1, a5);
306 nlen = strlen(newbuf);
309 if ((inc + fin->fin_plen) > 65535)
313 for (m1 = m; m1->b_cont; m1 = m1->b_cont)
315 if ((inc > 0) && (m1->b_datap->db_lim - m1->b_wptr < inc)) {
318 /* alloc enough to keep same trailer space for lower driver */
319 nm = allocb(nlen, BPRI_MED);
320 PANIC((!nm),("ipf_p_irc_out: allocb failed"));
322 nm->b_band = m1->b_band;
326 PANIC((m1->b_wptr < m1->b_rptr),
327 ("ipf_p_irc_out: cannot handle fragmented data block"));
331 # if SOLARIS && defined(ICK_VALID)
332 if (m1->b_datap->db_struiolim == m1->b_wptr)
333 m1->b_datap->db_struiolim += inc;
334 m1->b_datap->db_struioflag &= ~STRUIO_IP;
341 /* the mbuf chain will be extended if necessary by m_copyback() */
343 COPYBACK(m, off, nlen, newbuf);
344 fin->fin_flx |= FI_DOCKSUM;
348 register u_32_t sum1, sum2;
350 sum1 = fin->fin_plen;
351 sum2 = fin->fin_plen + inc;
353 /* Because ~1 == -2, We really need ~1 == -1 */
357 sum2 = (sum2 & 0xffff) + (sum2 >> 16);
359 ipf_fix_outcksum(0, &ip->ip_sum, sum2, 0);
361 fin->fin_plen += inc;
362 ip->ip_len = htons(fin->fin_plen);
363 fin->fin_dlen += inc;
367 * Add skeleton NAT entry for connection which will come back the
372 * Don't allow the PORT command to specify a port < 1024 due to
375 if (ntohs(sp) < 1024)
379 * The server may not make the connection back from port 20, but
380 * it is the most likely so use it here to check for a conflicting
383 bcopy((caddr_t)fin, (caddr_t)&fi, sizeof(fi));
385 fi.fin_data[1] = fin->fin_data[1];
386 nat2 = ipf_nat_outlookup(fin, IPN_TCP, nat->nat_pr[1], nat->nat_nsrcip,
390 ipf_nat_softc_t *softn = softc->ipf_nat_soft;
393 bcopy((caddr_t)fin, (caddr_t)&fi, sizeof(fi));
394 bzero((char *)tcp2, sizeof(*tcp2));
395 tcp2->th_win = htons(8192);
397 tcp2->th_dport = 0; /* XXX - don't specify remote port */
398 fi.fin_data[0] = ntohs(sp);
400 fi.fin_dp = (char *)tcp2;
401 fi.fin_fr = &ircnatfr;
402 fi.fin_dlen = sizeof(*tcp2);
403 fi.fin_plen = fi.fin_hlen + sizeof(*tcp2);
405 ip->ip_src = nat->nat_nsrcip;
406 MUTEX_ENTER(&softn->ipf_nat_new);
407 nat2 = ipf_nat_add(&fi, nat->nat_ptr, NULL,
408 NAT_SLAVE|IPN_TCP|SI_W_DPORT, NAT_OUTBOUND);
409 MUTEX_EXIT(&softn->ipf_nat_new);
411 (void) ipf_nat_proto(&fi, nat2, 0);
412 MUTEX_ENTER(&nat2->nat_lock);
413 ipf_nat_update(&fi, nat2);
414 MUTEX_EXIT(&nat2->nat_lock);
416 (void) ipf_state_add(softc, &fi, NULL, SI_W_DPORT);
425 ipf_p_irc_out(void *arg, fr_info_t *fin, ap_session_t *aps, nat_t *nat)
427 aps = aps; /* LINT */
428 return (ipf_p_irc_send(fin, nat));