1145516Sdarrenr/* 2145516Sdarrenr * Copyright (C) 2000-2003 Darren Reed 3145516Sdarrenr * 4145516Sdarrenr * See the IPFILTER.LICENCE file for details on licencing. 5145516Sdarrenr * 6170263Sdarrenr * $Id: ip_irc_pxy.c,v 2.39.2.6 2006/07/14 06:12:14 darrenr Exp $ 7145516Sdarrenr */ 8145516Sdarrenr 9145516Sdarrenr#define IPF_IRC_PROXY 10145516Sdarrenr 11145516Sdarrenr#define IPF_IRCBUFSZ 96 /* This *MUST* be >= 64! */ 12145516Sdarrenr 13145516Sdarrenr 14145516Sdarrenrint ippr_irc_init __P((void)); 15145516Sdarrenrvoid ippr_irc_fini __P((void)); 16145516Sdarrenrint ippr_irc_new __P((fr_info_t *, ap_session_t *, nat_t *)); 17145516Sdarrenrint ippr_irc_out __P((fr_info_t *, ap_session_t *, nat_t *)); 18145516Sdarrenrint ippr_irc_send __P((fr_info_t *, nat_t *)); 19145516Sdarrenrint ippr_irc_complete __P((ircinfo_t *, char *, size_t)); 20145516Sdarrenru_short ipf_irc_atoi __P((char **)); 21145516Sdarrenr 22145516Sdarrenrstatic frentry_t ircnatfr; 23145516Sdarrenr 24145516Sdarrenrint irc_proxy_init = 0; 25145516Sdarrenr 26145516Sdarrenr 27145516Sdarrenr/* 28145516Sdarrenr * Initialize local structures. 29145516Sdarrenr */ 30145516Sdarrenrint ippr_irc_init() 31145516Sdarrenr{ 32145516Sdarrenr bzero((char *)&ircnatfr, sizeof(ircnatfr)); 33145516Sdarrenr ircnatfr.fr_ref = 1; 34145516Sdarrenr ircnatfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE; 35145516Sdarrenr MUTEX_INIT(&ircnatfr.fr_lock, "IRC proxy rule lock"); 36145516Sdarrenr irc_proxy_init = 1; 37145516Sdarrenr 38145516Sdarrenr return 0; 39145516Sdarrenr} 40145516Sdarrenr 41145516Sdarrenr 42145516Sdarrenrvoid ippr_irc_fini() 43145516Sdarrenr{ 44145516Sdarrenr if (irc_proxy_init == 1) { 45145516Sdarrenr MUTEX_DESTROY(&ircnatfr.fr_lock); 46145516Sdarrenr irc_proxy_init = 0; 47145516Sdarrenr } 48145516Sdarrenr} 49145516Sdarrenr 50145516Sdarrenr 51153872Sguidoconst char *ippr_irc_dcctypes[] = { 52145516Sdarrenr "CHAT ", /* CHAT chat ipnumber portnumber */ 53145516Sdarrenr "SEND ", /* SEND filename ipnumber portnumber */ 54145516Sdarrenr "MOVE ", 55145516Sdarrenr "TSEND ", 56145516Sdarrenr "SCHAT ", 57145516Sdarrenr NULL, 58145516Sdarrenr}; 59145516Sdarrenr 60145516Sdarrenr 61145516Sdarrenr/* 62145516Sdarrenr * :A PRIVMSG B :^ADCC CHAT chat 0 0^A\r\n 63145516Sdarrenr * PRIVMSG B ^ADCC CHAT chat 0 0^A\r\n 64145516Sdarrenr */ 65145516Sdarrenr 66145516Sdarrenr 67145516Sdarrenrint ippr_irc_complete(ircp, buf, len) 68145516Sdarrenrircinfo_t *ircp; 69145516Sdarrenrchar *buf; 70145516Sdarrenrsize_t len; 71145516Sdarrenr{ 72145516Sdarrenr register char *s, c; 73145516Sdarrenr register size_t i; 74145516Sdarrenr u_32_t l; 75145516Sdarrenr int j, k; 76145516Sdarrenr 77145516Sdarrenr ircp->irc_ipnum = 0; 78145516Sdarrenr ircp->irc_port = 0; 79145516Sdarrenr 80145516Sdarrenr if (len < 31) 81145516Sdarrenr return 0; 82145516Sdarrenr s = buf; 83145516Sdarrenr c = *s++; 84145516Sdarrenr i = len - 1; 85145516Sdarrenr 86145516Sdarrenr if ((c != ':') && (c != 'P')) 87145516Sdarrenr return 0; 88145516Sdarrenr 89145516Sdarrenr if (c == ':') { 90145516Sdarrenr /* 91145516Sdarrenr * Loosely check that the source is a nickname of some sort 92145516Sdarrenr */ 93145516Sdarrenr s++; 94145516Sdarrenr c = *s; 95145516Sdarrenr ircp->irc_snick = s; 96145516Sdarrenr if (!ISALPHA(c)) 97145516Sdarrenr return 0; 98145516Sdarrenr i--; 99145516Sdarrenr for (c = *s; !ISSPACE(c) && (i > 0); i--) 100145516Sdarrenr c = *s++; 101145516Sdarrenr if (i < 31) 102145516Sdarrenr return 0; 103145516Sdarrenr if (c != 'P') 104145516Sdarrenr return 0; 105145516Sdarrenr } else 106145516Sdarrenr ircp->irc_snick = NULL; 107145516Sdarrenr 108145516Sdarrenr /* 109145516Sdarrenr * Check command string 110145516Sdarrenr */ 111145516Sdarrenr if (strncmp(s, "PRIVMSG ", 8)) 112145516Sdarrenr return 0; 113145516Sdarrenr i -= 8; 114145516Sdarrenr s += 8; 115145516Sdarrenr c = *s; 116145516Sdarrenr ircp->irc_dnick = s; 117145516Sdarrenr 118145516Sdarrenr /* 119145516Sdarrenr * Loosely check that the destination is a nickname of some sort 120145516Sdarrenr */ 121145516Sdarrenr if (!ISALPHA(c)) 122145516Sdarrenr return 0; 123145516Sdarrenr for (; !ISSPACE(c) && (i > 0); i--) 124145516Sdarrenr c = *s++; 125145516Sdarrenr if (i < 20) 126145516Sdarrenr return 0; 127145516Sdarrenr s++, 128145516Sdarrenr i--; 129145516Sdarrenr 130145516Sdarrenr /* 131145516Sdarrenr * Look for a ^A to start the DCC 132145516Sdarrenr */ 133145516Sdarrenr c = *s; 134145516Sdarrenr if (c == ':') { 135145516Sdarrenr s++; 136145516Sdarrenr c = *s; 137145516Sdarrenr } 138145516Sdarrenr 139145516Sdarrenr if (strncmp(s, "\001DCC ", 4)) 140145516Sdarrenr return 0; 141145516Sdarrenr 142145516Sdarrenr i -= 4; 143145516Sdarrenr s += 4; 144145516Sdarrenr 145145516Sdarrenr /* 146145516Sdarrenr * Check for a recognised DCC command 147145516Sdarrenr */ 148145516Sdarrenr for (j = 0, k = 0; ippr_irc_dcctypes[j]; j++) { 149145516Sdarrenr k = MIN(strlen(ippr_irc_dcctypes[j]), i); 150145516Sdarrenr if (!strncmp(ippr_irc_dcctypes[j], s, k)) 151145516Sdarrenr break; 152145516Sdarrenr } 153145516Sdarrenr if (!ippr_irc_dcctypes[j]) 154145516Sdarrenr return 0; 155145516Sdarrenr 156145516Sdarrenr ircp->irc_type = s; 157145516Sdarrenr i -= k; 158145516Sdarrenr s += k; 159145516Sdarrenr 160145516Sdarrenr if (i < 11) 161145516Sdarrenr return 0; 162145516Sdarrenr 163145516Sdarrenr /* 164145516Sdarrenr * Check for the arg 165145516Sdarrenr */ 166145516Sdarrenr c = *s; 167145516Sdarrenr if (ISSPACE(c)) 168145516Sdarrenr return 0; 169145516Sdarrenr ircp->irc_arg = s; 170145516Sdarrenr for (; (c != ' ') && (c != '\001') && (i > 0); i--) 171145516Sdarrenr c = *s++; 172145516Sdarrenr 173145516Sdarrenr if (c == '\001') /* In reality a ^A can quote another ^A...*/ 174145516Sdarrenr return 0; 175145516Sdarrenr 176145516Sdarrenr if (i < 5) 177145516Sdarrenr return 0; 178145516Sdarrenr 179145516Sdarrenr s++; 180145516Sdarrenr i--; 181145516Sdarrenr c = *s; 182145516Sdarrenr if (!ISDIGIT(c)) 183145516Sdarrenr return 0; 184145516Sdarrenr ircp->irc_addr = s; 185145516Sdarrenr /* 186145516Sdarrenr * Get the IP# 187145516Sdarrenr */ 188145516Sdarrenr for (l = 0; ISDIGIT(c) && (i > 0); i--) { 189145516Sdarrenr l *= 10; 190145516Sdarrenr l += c - '0'; 191145516Sdarrenr c = *s++; 192145516Sdarrenr } 193145516Sdarrenr 194145516Sdarrenr if (i < 4) 195145516Sdarrenr return 0; 196145516Sdarrenr 197145516Sdarrenr if (c != ' ') 198145516Sdarrenr return 0; 199145516Sdarrenr 200145516Sdarrenr ircp->irc_ipnum = l; 201145516Sdarrenr s++; 202145516Sdarrenr i--; 203145516Sdarrenr c = *s; 204145516Sdarrenr if (!ISDIGIT(c)) 205145516Sdarrenr return 0; 206145516Sdarrenr /* 207145516Sdarrenr * Get the port# 208145516Sdarrenr */ 209145516Sdarrenr for (l = 0; ISDIGIT(c) && (i > 0); i--) { 210145516Sdarrenr l *= 10; 211145516Sdarrenr l += c - '0'; 212145516Sdarrenr c = *s++; 213145516Sdarrenr } 214145516Sdarrenr if (i < 3) 215145516Sdarrenr return 0; 216145516Sdarrenr if (strncmp(s, "\001\r\n", 3)) 217145516Sdarrenr return 0; 218145516Sdarrenr s += 3; 219145516Sdarrenr ircp->irc_len = s - buf; 220145516Sdarrenr ircp->irc_port = l; 221145516Sdarrenr return 1; 222145516Sdarrenr} 223145516Sdarrenr 224145516Sdarrenr 225145516Sdarrenrint ippr_irc_new(fin, aps, nat) 226145516Sdarrenrfr_info_t *fin; 227145516Sdarrenrap_session_t *aps; 228145516Sdarrenrnat_t *nat; 229145516Sdarrenr{ 230145516Sdarrenr ircinfo_t *irc; 231145516Sdarrenr 232145516Sdarrenr KMALLOC(irc, ircinfo_t *); 233145516Sdarrenr if (irc == NULL) 234145516Sdarrenr return -1; 235145516Sdarrenr 236145516Sdarrenr fin = fin; /* LINT */ 237145516Sdarrenr nat = nat; /* LINT */ 238145516Sdarrenr 239145516Sdarrenr aps->aps_data = irc; 240145516Sdarrenr aps->aps_psiz = sizeof(ircinfo_t); 241145516Sdarrenr 242145516Sdarrenr bzero((char *)irc, sizeof(*irc)); 243145516Sdarrenr return 0; 244145516Sdarrenr} 245145516Sdarrenr 246145516Sdarrenr 247145516Sdarrenrint ippr_irc_send(fin, nat) 248145516Sdarrenrfr_info_t *fin; 249145516Sdarrenrnat_t *nat; 250145516Sdarrenr{ 251145516Sdarrenr char ctcpbuf[IPF_IRCBUFSZ], newbuf[IPF_IRCBUFSZ]; 252145516Sdarrenr tcphdr_t *tcp, tcph, *tcp2 = &tcph; 253145516Sdarrenr int off, inc = 0, i, dlen; 254145516Sdarrenr size_t nlen = 0, olen; 255145516Sdarrenr struct in_addr swip; 256145516Sdarrenr u_short a5, sp; 257145516Sdarrenr ircinfo_t *irc; 258145516Sdarrenr fr_info_t fi; 259145516Sdarrenr nat_t *nat2; 260145516Sdarrenr u_int a1; 261145516Sdarrenr ip_t *ip; 262145516Sdarrenr mb_t *m; 263145516Sdarrenr#ifdef MENTAT 264145516Sdarrenr mb_t *m1; 265145516Sdarrenr#endif 266145516Sdarrenr 267145516Sdarrenr m = fin->fin_m; 268145516Sdarrenr ip = fin->fin_ip; 269145516Sdarrenr tcp = (tcphdr_t *)fin->fin_dp; 270145516Sdarrenr bzero(ctcpbuf, sizeof(ctcpbuf)); 271145516Sdarrenr off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff; 272145516Sdarrenr 273145516Sdarrenr#ifdef __sgi 274145516Sdarrenr dlen = fin->fin_plen - off; 275145516Sdarrenr#else 276145516Sdarrenr dlen = MSGDSIZE(m) - off; 277145516Sdarrenr#endif 278145516Sdarrenr if (dlen <= 0) 279145516Sdarrenr return 0; 280145516Sdarrenr COPYDATA(m, off, MIN(sizeof(ctcpbuf), dlen), ctcpbuf); 281145516Sdarrenr 282145516Sdarrenr if (dlen <= 0) 283145516Sdarrenr return 0; 284145516Sdarrenr ctcpbuf[sizeof(ctcpbuf) - 1] = '\0'; 285145516Sdarrenr *newbuf = '\0'; 286145516Sdarrenr 287145516Sdarrenr irc = nat->nat_aps->aps_data; 288145516Sdarrenr if (ippr_irc_complete(irc, ctcpbuf, dlen) == 0) 289145516Sdarrenr return 0; 290145516Sdarrenr 291145516Sdarrenr /* 292145516Sdarrenr * check that IP address in the PORT/PASV reply is the same as the 293145516Sdarrenr * sender of the command - prevents using PORT for port scanning. 294145516Sdarrenr */ 295145516Sdarrenr if (irc->irc_ipnum != ntohl(nat->nat_inip.s_addr)) 296145516Sdarrenr return 0; 297145516Sdarrenr 298145516Sdarrenr a5 = irc->irc_port; 299145516Sdarrenr 300145516Sdarrenr /* 301145516Sdarrenr * Calculate new address parts for the DCC command 302145516Sdarrenr */ 303145516Sdarrenr a1 = ntohl(ip->ip_src.s_addr); 304145516Sdarrenr olen = irc->irc_len; 305145516Sdarrenr i = irc->irc_addr - ctcpbuf; 306145516Sdarrenr i++; 307145516Sdarrenr (void) strncpy(newbuf, ctcpbuf, i); 308145516Sdarrenr /* DO NOT change these! */ 309145516Sdarrenr#if defined(SNPRINTF) && defined(KERNEL) 310145516Sdarrenr SNPRINTF(newbuf, sizeof(newbuf) - i, "%u %u\001\r\n", a1, a5); 311145516Sdarrenr#else 312145516Sdarrenr (void) sprintf(newbuf, "%u %u\001\r\n", a1, a5); 313145516Sdarrenr#endif 314145516Sdarrenr 315145516Sdarrenr nlen = strlen(newbuf); 316145516Sdarrenr inc = nlen - olen; 317145516Sdarrenr 318145516Sdarrenr if ((inc + ip->ip_len) > 65535) 319145516Sdarrenr return 0; 320145516Sdarrenr 321145516Sdarrenr#ifdef MENTAT 322145516Sdarrenr for (m1 = m; m1->b_cont; m1 = m1->b_cont) 323145516Sdarrenr ; 324145516Sdarrenr if ((inc > 0) && (m1->b_datap->db_lim - m1->b_wptr < inc)) { 325145516Sdarrenr mblk_t *nm; 326145516Sdarrenr 327145516Sdarrenr /* alloc enough to keep same trailer space for lower driver */ 328145516Sdarrenr nm = allocb(nlen, BPRI_MED); 329145516Sdarrenr PANIC((!nm),("ippr_irc_out: allocb failed")); 330145516Sdarrenr 331145516Sdarrenr nm->b_band = m1->b_band; 332145516Sdarrenr nm->b_wptr += nlen; 333145516Sdarrenr 334145516Sdarrenr m1->b_wptr -= olen; 335145516Sdarrenr PANIC((m1->b_wptr < m1->b_rptr), 336145516Sdarrenr ("ippr_irc_out: cannot handle fragmented data block")); 337145516Sdarrenr 338145516Sdarrenr linkb(m1, nm); 339145516Sdarrenr } else { 340145516Sdarrenr# if SOLARIS && defined(ICK_VALID) 341145516Sdarrenr if (m1->b_datap->db_struiolim == m1->b_wptr) 342145516Sdarrenr m1->b_datap->db_struiolim += inc; 343145516Sdarrenr m1->b_datap->db_struioflag &= ~STRUIO_IP; 344145516Sdarrenr# endif 345145516Sdarrenr m1->b_wptr += inc; 346145516Sdarrenr } 347145516Sdarrenr#else 348145516Sdarrenr if (inc < 0) 349145516Sdarrenr m_adj(m, inc); 350145516Sdarrenr /* the mbuf chain will be extended if necessary by m_copyback() */ 351145516Sdarrenr#endif 352145516Sdarrenr COPYBACK(m, off, nlen, newbuf); 353145516Sdarrenr 354145516Sdarrenr if (inc != 0) { 355145516Sdarrenr#if defined(MENTAT) || defined(__sgi) 356145516Sdarrenr register u_32_t sum1, sum2; 357145516Sdarrenr 358145516Sdarrenr sum1 = ip->ip_len; 359145516Sdarrenr sum2 = ip->ip_len + inc; 360145516Sdarrenr 361145516Sdarrenr /* Because ~1 == -2, We really need ~1 == -1 */ 362145516Sdarrenr if (sum1 > sum2) 363145516Sdarrenr sum2--; 364145516Sdarrenr sum2 -= sum1; 365145516Sdarrenr sum2 = (sum2 & 0xffff) + (sum2 >> 16); 366145516Sdarrenr 367145516Sdarrenr fix_outcksum(fin, &ip->ip_sum, sum2); 368145516Sdarrenr#endif 369145516Sdarrenr ip->ip_len += inc; 370145516Sdarrenr } 371145516Sdarrenr 372145516Sdarrenr /* 373145516Sdarrenr * Add skeleton NAT entry for connection which will come back the 374145516Sdarrenr * other way. 375145516Sdarrenr */ 376145516Sdarrenr sp = htons(a5); 377145516Sdarrenr /* 378145516Sdarrenr * Don't allow the PORT command to specify a port < 1024 due to 379145516Sdarrenr * security crap. 380145516Sdarrenr */ 381145516Sdarrenr if (ntohs(sp) < 1024) 382145516Sdarrenr return 0; 383145516Sdarrenr 384145516Sdarrenr /* 385145516Sdarrenr * The server may not make the connection back from port 20, but 386145516Sdarrenr * it is the most likely so use it here to check for a conflicting 387145516Sdarrenr * mapping. 388145516Sdarrenr */ 389145516Sdarrenr bcopy((caddr_t)fin, (caddr_t)&fi, sizeof(fi)); 390145516Sdarrenr fi.fin_data[0] = sp; 391145516Sdarrenr fi.fin_data[1] = fin->fin_data[1]; 392145516Sdarrenr nat2 = nat_outlookup(fin, IPN_TCP, nat->nat_p, nat->nat_inip, 393145516Sdarrenr ip->ip_dst); 394145516Sdarrenr if (nat2 == NULL) { 395145516Sdarrenr bcopy((caddr_t)fin, (caddr_t)&fi, sizeof(fi)); 396145516Sdarrenr bzero((char *)tcp2, sizeof(*tcp2)); 397145516Sdarrenr tcp2->th_win = htons(8192); 398145516Sdarrenr tcp2->th_sport = sp; 399145516Sdarrenr tcp2->th_dport = 0; /* XXX - don't specify remote port */ 400145516Sdarrenr fi.fin_state = NULL; 401145516Sdarrenr fi.fin_nat = NULL; 402145516Sdarrenr fi.fin_data[0] = ntohs(sp); 403145516Sdarrenr fi.fin_data[1] = 0; 404145516Sdarrenr fi.fin_dp = (char *)tcp2; 405145516Sdarrenr fi.fin_fr = &ircnatfr; 406145516Sdarrenr fi.fin_dlen = sizeof(*tcp2); 407145516Sdarrenr fi.fin_plen = fi.fin_hlen + sizeof(*tcp2); 408145516Sdarrenr swip = ip->ip_src; 409145516Sdarrenr ip->ip_src = nat->nat_inip; 410145516Sdarrenr nat2 = nat_new(&fi, nat->nat_ptr, NULL, 411145516Sdarrenr NAT_SLAVE|IPN_TCP|SI_W_DPORT, NAT_OUTBOUND); 412145516Sdarrenr if (nat2 != NULL) { 413145516Sdarrenr (void) nat_proto(&fi, nat2, 0); 414145516Sdarrenr nat_update(&fi, nat2, nat2->nat_ptr); 415145516Sdarrenr 416145516Sdarrenr (void) fr_addstate(&fi, NULL, SI_W_DPORT); 417145516Sdarrenr if (fi.fin_state != NULL) 418170263Sdarrenr fr_statederef((ipstate_t **)&fi.fin_state); 419145516Sdarrenr } 420145516Sdarrenr ip->ip_src = swip; 421145516Sdarrenr } 422145516Sdarrenr return inc; 423145516Sdarrenr} 424145516Sdarrenr 425145516Sdarrenr 426145516Sdarrenrint ippr_irc_out(fin, aps, nat) 427145516Sdarrenrfr_info_t *fin; 428145516Sdarrenrap_session_t *aps; 429145516Sdarrenrnat_t *nat; 430145516Sdarrenr{ 431145516Sdarrenr aps = aps; /* LINT */ 432145516Sdarrenr return ippr_irc_send(fin, nat); 433145516Sdarrenr} 434