diff options
Diffstat (limited to 'contrib/ipfilter/ip_irc_pxy.c')
-rw-r--r-- | contrib/ipfilter/ip_irc_pxy.c | 435 |
1 files changed, 435 insertions, 0 deletions
diff --git a/contrib/ipfilter/ip_irc_pxy.c b/contrib/ipfilter/ip_irc_pxy.c new file mode 100644 index 0000000..45a120f --- /dev/null +++ b/contrib/ipfilter/ip_irc_pxy.c @@ -0,0 +1,435 @@ +/* $NetBSD$ */ + +/* + * Copyright (C) 2000-2003 Darren Reed + * + * See the IPFILTER.LICENCE file for details on licencing. + * + * Id: ip_irc_pxy.c,v 2.39.2.4 2005/02/04 10:22:55 darrenr Exp + */ + +#define IPF_IRC_PROXY + +#define IPF_IRCBUFSZ 96 /* This *MUST* be >= 64! */ + + +int ippr_irc_init __P((void)); +void ippr_irc_fini __P((void)); +int ippr_irc_new __P((fr_info_t *, ap_session_t *, nat_t *)); +int ippr_irc_out __P((fr_info_t *, ap_session_t *, nat_t *)); +int ippr_irc_send __P((fr_info_t *, nat_t *)); +int ippr_irc_complete __P((ircinfo_t *, char *, size_t)); +u_short ipf_irc_atoi __P((char **)); + +static frentry_t ircnatfr; + +int irc_proxy_init = 0; + + +/* + * Initialize local structures. + */ +int ippr_irc_init() +{ + bzero((char *)&ircnatfr, sizeof(ircnatfr)); + ircnatfr.fr_ref = 1; + ircnatfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE; + MUTEX_INIT(&ircnatfr.fr_lock, "IRC proxy rule lock"); + irc_proxy_init = 1; + + return 0; +} + + +void ippr_irc_fini() +{ + if (irc_proxy_init == 1) { + MUTEX_DESTROY(&ircnatfr.fr_lock); + irc_proxy_init = 0; + } +} + + +char *ippr_irc_dcctypes[] = { + "CHAT ", /* CHAT chat ipnumber portnumber */ + "SEND ", /* SEND filename ipnumber portnumber */ + "MOVE ", + "TSEND ", + "SCHAT ", + NULL, +}; + + +/* + * :A PRIVMSG B :^ADCC CHAT chat 0 0^A\r\n + * PRIVMSG B ^ADCC CHAT chat 0 0^A\r\n + */ + + +int ippr_irc_complete(ircp, buf, len) +ircinfo_t *ircp; +char *buf; +size_t len; +{ + register char *s, c; + register size_t i; + u_32_t l; + int j, k; + + ircp->irc_ipnum = 0; + ircp->irc_port = 0; + + if (len < 31) + return 0; + s = buf; + c = *s++; + i = len - 1; + + if ((c != ':') && (c != 'P')) + return 0; + + if (c == ':') { + /* + * Loosely check that the source is a nickname of some sort + */ + s++; + c = *s; + ircp->irc_snick = s; + if (!ISALPHA(c)) + return 0; + i--; + for (c = *s; !ISSPACE(c) && (i > 0); i--) + c = *s++; + if (i < 31) + return 0; + if (c != 'P') + return 0; + } else + ircp->irc_snick = NULL; + + /* + * Check command string + */ + if (strncmp(s, "PRIVMSG ", 8)) + return 0; + i -= 8; + s += 8; + c = *s; + ircp->irc_dnick = s; + + /* + * Loosely check that the destination is a nickname of some sort + */ + if (!ISALPHA(c)) + return 0; + for (; !ISSPACE(c) && (i > 0); i--) + c = *s++; + if (i < 20) + return 0; + s++, + i--; + + /* + * Look for a ^A to start the DCC + */ + c = *s; + if (c == ':') { + s++; + c = *s; + } + + if (strncmp(s, "\001DCC ", 4)) + return 0; + + i -= 4; + s += 4; + + /* + * Check for a recognised DCC command + */ + for (j = 0, k = 0; ippr_irc_dcctypes[j]; j++) { + k = MIN(strlen(ippr_irc_dcctypes[j]), i); + if (!strncmp(ippr_irc_dcctypes[j], s, k)) + break; + } + if (!ippr_irc_dcctypes[j]) + return 0; + + ircp->irc_type = s; + i -= k; + s += k; + + if (i < 11) + return 0; + + /* + * Check for the arg + */ + c = *s; + if (ISSPACE(c)) + return 0; + ircp->irc_arg = s; + for (; (c != ' ') && (c != '\001') && (i > 0); i--) + c = *s++; + + if (c == '\001') /* In reality a ^A can quote another ^A...*/ + return 0; + + if (i < 5) + return 0; + + s++; + i--; + c = *s; + if (!ISDIGIT(c)) + return 0; + ircp->irc_addr = s; + /* + * Get the IP# + */ + for (l = 0; ISDIGIT(c) && (i > 0); i--) { + l *= 10; + l += c - '0'; + c = *s++; + } + + if (i < 4) + return 0; + + if (c != ' ') + return 0; + + ircp->irc_ipnum = l; + s++; + i--; + c = *s; + if (!ISDIGIT(c)) + return 0; + /* + * Get the port# + */ + for (l = 0; ISDIGIT(c) && (i > 0); i--) { + l *= 10; + l += c - '0'; + c = *s++; + } + if (i < 3) + return 0; + if (strncmp(s, "\001\r\n", 3)) + return 0; + s += 3; + ircp->irc_len = s - buf; + ircp->irc_port = l; + return 1; +} + + +int ippr_irc_new(fin, aps, nat) +fr_info_t *fin; +ap_session_t *aps; +nat_t *nat; +{ + ircinfo_t *irc; + + KMALLOC(irc, ircinfo_t *); + if (irc == NULL) + return -1; + + fin = fin; /* LINT */ + nat = nat; /* LINT */ + + aps->aps_data = irc; + aps->aps_psiz = sizeof(ircinfo_t); + + bzero((char *)irc, sizeof(*irc)); + return 0; +} + + +int ippr_irc_send(fin, nat) +fr_info_t *fin; +nat_t *nat; +{ + char ctcpbuf[IPF_IRCBUFSZ], newbuf[IPF_IRCBUFSZ]; + tcphdr_t *tcp, tcph, *tcp2 = &tcph; + int off, inc = 0, i, dlen; + size_t nlen = 0, olen; + struct in_addr swip; + u_short a5, sp; + ircinfo_t *irc; + fr_info_t fi; + nat_t *nat2; + u_int a1; + ip_t *ip; + mb_t *m; +#ifdef MENTAT + mb_t *m1; +#endif + + m = fin->fin_m; + ip = fin->fin_ip; + tcp = (tcphdr_t *)fin->fin_dp; + bzero(ctcpbuf, sizeof(ctcpbuf)); + off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff; + +#ifdef __sgi + dlen = fin->fin_plen - off; +#else + dlen = MSGDSIZE(m) - off; +#endif + if (dlen <= 0) + return 0; + COPYDATA(m, off, MIN(sizeof(ctcpbuf), dlen), ctcpbuf); + + if (dlen <= 0) + return 0; + ctcpbuf[sizeof(ctcpbuf) - 1] = '\0'; + *newbuf = '\0'; + + irc = nat->nat_aps->aps_data; + if (ippr_irc_complete(irc, ctcpbuf, dlen) == 0) + return 0; + + /* + * check that IP address in the PORT/PASV reply is the same as the + * sender of the command - prevents using PORT for port scanning. + */ + if (irc->irc_ipnum != ntohl(nat->nat_inip.s_addr)) + return 0; + + a5 = irc->irc_port; + + /* + * Calculate new address parts for the DCC command + */ + a1 = ntohl(ip->ip_src.s_addr); + olen = irc->irc_len; + i = irc->irc_addr - ctcpbuf; + i++; + (void) strncpy(newbuf, ctcpbuf, i); + /* DO NOT change these! */ +#if defined(SNPRINTF) && defined(KERNEL) + SNPRINTF(newbuf, sizeof(newbuf) - i, "%u %u\001\r\n", a1, a5); +#else + (void) sprintf(newbuf, "%u %u\001\r\n", a1, a5); +#endif + + nlen = strlen(newbuf); + inc = nlen - olen; + + if ((inc + ip->ip_len) > 65535) + return 0; + +#ifdef MENTAT + for (m1 = m; m1->b_cont; m1 = m1->b_cont) + ; + if ((inc > 0) && (m1->b_datap->db_lim - m1->b_wptr < inc)) { + mblk_t *nm; + + /* alloc enough to keep same trailer space for lower driver */ + nm = allocb(nlen, BPRI_MED); + PANIC((!nm),("ippr_irc_out: allocb failed")); + + nm->b_band = m1->b_band; + nm->b_wptr += nlen; + + m1->b_wptr -= olen; + PANIC((m1->b_wptr < m1->b_rptr), + ("ippr_irc_out: cannot handle fragmented data block")); + + linkb(m1, nm); + } else { +# if SOLARIS && defined(ICK_VALID) + if (m1->b_datap->db_struiolim == m1->b_wptr) + m1->b_datap->db_struiolim += inc; + m1->b_datap->db_struioflag &= ~STRUIO_IP; +# endif + m1->b_wptr += inc; + } +#else + if (inc < 0) + m_adj(m, inc); + /* the mbuf chain will be extended if necessary by m_copyback() */ +#endif + COPYBACK(m, off, nlen, newbuf); + + if (inc != 0) { +#if defined(MENTAT) || defined(__sgi) + register u_32_t sum1, sum2; + + sum1 = ip->ip_len; + sum2 = ip->ip_len + inc; + + /* Because ~1 == -2, We really need ~1 == -1 */ + if (sum1 > sum2) + sum2--; + sum2 -= sum1; + sum2 = (sum2 & 0xffff) + (sum2 >> 16); + + fix_outcksum(fin, &ip->ip_sum, sum2); +#endif + ip->ip_len += inc; + } + + /* + * Add skeleton NAT entry for connection which will come back the + * other way. + */ + sp = htons(a5); + /* + * Don't allow the PORT command to specify a port < 1024 due to + * security crap. + */ + if (ntohs(sp) < 1024) + return 0; + + /* + * The server may not make the connection back from port 20, but + * it is the most likely so use it here to check for a conflicting + * mapping. + */ + bcopy((caddr_t)fin, (caddr_t)&fi, sizeof(fi)); + fi.fin_data[0] = sp; + fi.fin_data[1] = fin->fin_data[1]; + nat2 = nat_outlookup(fin, IPN_TCP, nat->nat_p, nat->nat_inip, + ip->ip_dst); + if (nat2 == NULL) { + bcopy((caddr_t)fin, (caddr_t)&fi, sizeof(fi)); + bzero((char *)tcp2, sizeof(*tcp2)); + tcp2->th_win = htons(8192); + tcp2->th_sport = sp; + tcp2->th_dport = 0; /* XXX - don't specify remote port */ + fi.fin_state = NULL; + fi.fin_nat = NULL; + fi.fin_data[0] = ntohs(sp); + fi.fin_data[1] = 0; + fi.fin_dp = (char *)tcp2; + fi.fin_fr = &ircnatfr; + fi.fin_dlen = sizeof(*tcp2); + fi.fin_plen = fi.fin_hlen + sizeof(*tcp2); + swip = ip->ip_src; + ip->ip_src = nat->nat_inip; + nat2 = nat_new(&fi, nat->nat_ptr, NULL, + NAT_SLAVE|IPN_TCP|SI_W_DPORT, NAT_OUTBOUND); + if (nat2 != NULL) { + (void) nat_proto(&fi, nat2, 0); + nat_update(&fi, nat2, nat2->nat_ptr); + + (void) fr_addstate(&fi, NULL, SI_W_DPORT); + if (fi.fin_state != NULL) + fr_statederef(&fi, (ipstate_t **)&fi.fin_state); + } + ip->ip_src = swip; + } + return inc; +} + + +int ippr_irc_out(fin, aps, nat) +fr_info_t *fin; +ap_session_t *aps; +nat_t *nat; +{ + aps = aps; /* LINT */ + return ippr_irc_send(fin, nat); +} |