diff options
Diffstat (limited to 'pfinet/linux-src/net/ipv4/ip_masq_irc.c')
| -rw-r--r-- | pfinet/linux-src/net/ipv4/ip_masq_irc.c | 345 |
1 files changed, 345 insertions, 0 deletions
diff --git a/pfinet/linux-src/net/ipv4/ip_masq_irc.c b/pfinet/linux-src/net/ipv4/ip_masq_irc.c new file mode 100644 index 00000000..e52a5720 --- /dev/null +++ b/pfinet/linux-src/net/ipv4/ip_masq_irc.c @@ -0,0 +1,345 @@ +/* + * IP_MASQ_IRC irc masquerading module + * + * + * Version: @(#)ip_masq_irc.c 0.04 99/06/19 + * + * Author: Juan Jose Ciarlante + * + * Additions: + * - recognize a few non-irc-II DCC requests (Oliver Wagner) + * DCC MOVE (AmIRC/DCC.MOVE; SEND with resuming) + * DCC SCHAT (AmIRC IDEA encrypted CHAT) + * DCC TSEND (AmIRC/PIRCH SEND without ACKs) + * Fixes: + * Juan Jose Ciarlante : set NO_DADDR flag in ip_masq_new() + * Nigel Metheringham : Added multiple port support + * Juan Jose Ciarlante : litl bits for 2.1 + * Oliver Wagner : more IRC cmds processing + * <winmute@lucifer.gv.kotnet.org> + * Juan Jose Ciarlante : put new ms entry to listen() + * Scottie Shore : added support for clients that add extra args + * <sshore@escape.ca> + * + * FIXME: + * - detect also previous "PRIVMSG" string ?. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * Multiple Port Support + * The helper can be made to handle up to MAX_MASQ_APP_PORTS (normally 12) + * with the port numbers being defined at module load time. The module + * uses the symbol "ports" to define a list of monitored ports, which can + * be specified on the insmod command line as + * ports=x1,x2,x3... + * where x[n] are integer port numbers. This option can be put into + * /etc/conf.modules (or /etc/modules.conf depending on your config) + * where modload will pick it up should you use modload to load your + * modules. + * + */ + +#include <linux/config.h> +#include <linux/module.h> + +#include <linux/types.h> +#include <linux/kernel.h> +#include <asm/system.h> +#include <linux/skbuff.h> +#include <linux/in.h> +#include <linux/ip.h> +#include <linux/init.h> +#include <net/protocol.h> +#include <net/tcp.h> +#include <net/ip_masq.h> + + +/* + * List of ports (up to MAX_MASQ_APP_PORTS) to be handled by helper + * First port is set to the default port. + */ +int ports[MAX_MASQ_APP_PORTS] = {6667}; /* I rely on the trailing items being set to zero */ +struct ip_masq_app *masq_incarnations[MAX_MASQ_APP_PORTS]; +/* + * Debug level + */ +#ifdef CONFIG_IP_MASQ_DEBUG +static int debug=0; +MODULE_PARM(debug, "i"); +#endif + +MODULE_PARM(ports, "1-" __MODULE_STRING(MAX_MASQ_APP_PORTS) "i"); + + +/* + * List of supported DCC protocols + */ + +#define NUM_DCCPROTO 5 + +struct dccproto +{ + char *match; + int matchlen; +}; + +struct dccproto dccprotos[NUM_DCCPROTO] = { + { "SEND ", 5 }, + { "CHAT ", 5 }, + { "MOVE ", 5 }, + { "TSEND ", 6 }, + { "SCHAT ", 6 } +}; +#define MAXMATCHLEN 6 + +static int +masq_irc_init_1 (struct ip_masq_app *mapp, struct ip_masq *ms) +{ + MOD_INC_USE_COUNT; + return 0; +} + +static int +masq_irc_done_1 (struct ip_masq_app *mapp, struct ip_masq *ms) +{ + MOD_DEC_USE_COUNT; + return 0; +} + +int +masq_irc_out (struct ip_masq_app *mapp, struct ip_masq *ms, struct sk_buff **skb_p, __u32 maddr) +{ + struct sk_buff *skb; + struct iphdr *iph; + struct tcphdr *th; + char *data, *data_limit; + __u32 s_addr; + __u16 s_port; + struct ip_masq *n_ms; + char buf[20]; /* "m_addr m_port" (dec base)*/ + unsigned buf_len; + int diff; + char *dcc_p, *addr_beg_p, *addr_end_p; + + skb = *skb_p; + iph = skb->nh.iph; + th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]); + data = (char *)&th[1]; + + /* + * Hunt irc DCC string, the _shortest_: + * + * strlen("\1DCC CHAT chat AAAAAAAA P\1\n")=27 + * strlen("\1DCC SCHAT chat AAAAAAAA P\1\n")=28 + * strlen("\1DCC SEND F AAAAAAAA P S\1\n")=26 + * strlen("\1DCC MOVE F AAAAAAAA P S\1\n")=26 + * strlen("\1DCC TSEND F AAAAAAAA P S\1\n")=27 + * AAAAAAAAA: bound addr (1.0.0.0==16777216, min 8 digits) + * P: bound port (min 1 d ) + * F: filename (min 1 d ) + * S: size (min 1 d ) + * 0x01, \n: terminators + */ + + data_limit = skb->h.raw + skb->len; + + while (data < (data_limit - ( 22 + MAXMATCHLEN ) ) ) + { + int i; + if (memcmp(data,"\1DCC ",5)) { + data ++; + continue; + } + + dcc_p = data; + data += 5; /* point to DCC cmd */ + + for(i=0; i<NUM_DCCPROTO; i++) + { + /* + * go through the table and hunt a match string + */ + + if( memcmp(data, dccprotos[i].match, dccprotos[i].matchlen ) == 0 ) + { + data += dccprotos[i].matchlen; + + /* + * skip next string. + */ + + while( *data++ != ' ') + + /* + * must still parse, at least, "AAAAAAAA P\1\n", + * 12 bytes left. + */ + if (data > (data_limit-12)) return 0; + + + addr_beg_p = data; + + /* + * client bound address in dec base + */ + + s_addr = simple_strtoul(data,&data,10); + if (*data++ !=' ') + continue; + + /* + * client bound port in dec base + */ + + s_port = simple_strtoul(data,&data,10); + addr_end_p = data; + + /* + * Now create an masquerade entry for it + * must set NO_DPORT and NO_DADDR because + * connection is requested by another client. + */ + + n_ms = ip_masq_new(IPPROTO_TCP, + maddr, 0, + htonl(s_addr),htons(s_port), + 0, 0, + IP_MASQ_F_NO_DPORT|IP_MASQ_F_NO_DADDR); + if (n_ms==NULL) + return 0; + + /* + * Replace the old "address port" with the new one + */ + + buf_len = sprintf(buf,"%lu %u", + ntohl(n_ms->maddr),ntohs(n_ms->mport)); + + /* + * Calculate required delta-offset to keep TCP happy + */ + + diff = buf_len - (addr_end_p-addr_beg_p); + + *addr_beg_p = '\0'; + IP_MASQ_DEBUG(1-debug, "masq_irc_out(): '%s' %X:%X detected (diff=%d)\n", dcc_p, s_addr,s_port, diff); + + /* + * No shift. + */ + + if (diff==0) { + /* + * simple case, just copy. + */ + memcpy(addr_beg_p,buf,buf_len); + } else { + + *skb_p = ip_masq_skb_replace(skb, GFP_ATOMIC, + addr_beg_p, addr_end_p-addr_beg_p, + buf, buf_len); + } + ip_masq_listen(n_ms); + ip_masq_put(n_ms); + return diff; + } + } + } + return 0; + +} + +/* + * Main irc object + * You need 1 object per port in case you need + * to offer also other used irc ports (6665,6666,etc), + * they will share methods but they need own space for + * data. + */ + +struct ip_masq_app ip_masq_irc = { + NULL, /* next */ + "irc", /* name */ + 0, /* type */ + 0, /* n_attach */ + masq_irc_init_1, /* init_1 */ + masq_irc_done_1, /* done_1 */ + masq_irc_out, /* pkt_out */ + NULL /* pkt_in */ +}; + +/* + * ip_masq_irc initialization + */ + +__initfunc(int ip_masq_irc_init(void)) +{ + int i, j; + + for (i=0; (i<MAX_MASQ_APP_PORTS); i++) { + if (ports[i]) { + if ((masq_incarnations[i] = kmalloc(sizeof(struct ip_masq_app), + GFP_KERNEL)) == NULL) + return -ENOMEM; + memcpy(masq_incarnations[i], &ip_masq_irc, sizeof(struct ip_masq_app)); + if ((j = register_ip_masq_app(masq_incarnations[i], + IPPROTO_TCP, + ports[i]))) { + return j; + } + IP_MASQ_DEBUG(1-debug, + "Irc: loaded support on port[%d] = %d\n", + i, ports[i]); + } else { + /* To be safe, force the incarnation table entry to NULL */ + masq_incarnations[i] = NULL; + } + } + return 0; +} + +/* + * ip_masq_irc fin. + */ + +int ip_masq_irc_done(void) +{ + int i, j, k; + + k=0; + for (i=0; (i<MAX_MASQ_APP_PORTS); i++) { + if (masq_incarnations[i]) { + if ((j = unregister_ip_masq_app(masq_incarnations[i]))) { + k = j; + } else { + kfree(masq_incarnations[i]); + masq_incarnations[i] = NULL; + IP_MASQ_DEBUG(1-debug, "Irc: unloaded support on port[%d] = %d\n", + i, ports[i]); + } + } + } + return k; +} + + +#ifdef MODULE +EXPORT_NO_SYMBOLS; + +int init_module(void) +{ + if (ip_masq_irc_init() != 0) + return -EIO; + return 0; +} + +void cleanup_module(void) +{ + if (ip_masq_irc_done() != 0) + printk(KERN_INFO "ip_masq_irc: can't remove module"); +} + +#endif /* MODULE */ |