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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 | /* * IP_MASQ_QUAKE quake masquerading module * * * Version: @(#)ip_masq_quake.c 1.00 22/02/97 * * Author: Harald Hoyer mailto:HarryH@Royal.Net * * * Fixes: * Harald Hoyer : Unofficial Quake Specs found at * http://www.gamers.org/dEngine/quake/spec/ * Harald Hoyer : Check for QUAKE-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. * * */ #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 <net/protocol.h> #include <net/udp.h> #include <net/ip_masq.h> #ifndef DEBUG_CONFIG_IP_MASQ_QUAKE #define DEBUG_CONFIG_IP_MASQ_QUAKE 0 #endif /* * List of ports (up to MAX_MASQ_APP_PORTS) to be handled by helper * First ports are set to the default port. */ int ports[MAX_MASQ_APP_PORTS] = { 26000, /* I rely on the trailing items */ 27000 }; /* being set to zero */ struct ip_masq_app *masq_incarnations[MAX_MASQ_APP_PORTS]; typedef struct { __u16 type; /* (Little Endian) Type of message. */ __u16 length; /* (Little Endian) Length of message, header included. */ char message[0]; /* The contents of the message. */ } QUAKEHEADER; struct quake_priv_data { /* Have we seen a client connect message */ char cl_connect; }; static int masq_quake_init_1 (struct ip_masq_app *mapp, struct ip_masq *ms) { MOD_INC_USE_COUNT; if ((ms->app_data = kmalloc(sizeof(struct quake_priv_data), GFP_ATOMIC)) == NULL) printk(KERN_INFO "Quake: No memory for application data\n"); else { struct quake_priv_data *priv = (struct quake_priv_data *)ms->app_data; priv->cl_connect = 0; } return 0; } static int masq_quake_done_1 (struct ip_masq_app *mapp, struct ip_masq *ms) { MOD_DEC_USE_COUNT; if (ms->app_data) kfree_s(ms->app_data, sizeof(struct quake_priv_data)); return 0; } int masq_quake_in (struct ip_masq_app *mapp, struct ip_masq *ms, struct sk_buff **skb_p, struct device *dev) { struct sk_buff *skb; struct iphdr *iph; struct udphdr *uh; QUAKEHEADER *qh; __u16 udp_port; char *data; unsigned char code; struct quake_priv_data *priv = (struct quake_priv_data *)ms->app_data; if(priv->cl_connect == -1) return 0; skb = *skb_p; iph = skb->h.iph; /* iph = skb->nh.iph; */ uh = (struct udphdr *)&(((char *)iph)[iph->ihl*4]); /* Check for lenght */ if(ntohs(uh->len) < 5) return 0; qh = (QUAKEHEADER *)&uh[1]; if(qh->type != 0x0080) return 0; code = qh->message[0]; #if DEBUG_CONFIG_IP_MASQ_QUAKE printk("Quake_in: code = %d \n", (int)code); #endif switch(code) { case 0x01: /* Connection Request */ if(ntohs(qh->length) < 0x0c) { #if DEBUG_CONFIG_IP_MASQ_QUAKE printk("Quake_in: length < 0xc \n"); #endif return 0; } data = &qh->message[1]; /* Check for stomping string */ if(memcmp(data,"QUAKE\0\3",7)) { #if DEBUG_CONFIG_IP_MASQ_QUAKE printk("Quake_out: memcmp failed \n"); #endif return 0; } else { priv->cl_connect = 1; #if DEBUG_CONFIG_IP_MASQ_QUAKE printk("Quake_out: memcmp ok \n"); #endif } break; case 0x81: /* Accept Connection */ if((ntohs(qh->length) < 0x09) || (priv->cl_connect == 0)) return 0; data = &qh->message[1]; memcpy(&udp_port, data, 2); ms->dport = htons(udp_port); #if DEBUG_CONFIG_IP_MASQ_QUAKE printk("Quake_in: in_rewrote UDP port %d \n", udp_port); #endif priv->cl_connect = -1; break; } return 0; } int masq_quake_out (struct ip_masq_app *mapp, struct ip_masq *ms, struct sk_buff **skb_p, struct device *dev) { struct sk_buff *skb; struct iphdr *iph; struct udphdr *uh; QUAKEHEADER *qh; __u16 udp_port; char *data; unsigned char code; struct ip_masq *n_ms; struct quake_priv_data *priv = (struct quake_priv_data *)ms->app_data; if(priv->cl_connect == -1) return 0; skb = *skb_p; iph = skb->h.iph; /* iph = skb->nh.iph; */ uh = (struct udphdr *)&(((char *)iph)[iph->ihl*4]); /* Check for lenght */ if(ntohs(uh->len) < 5) return 0; qh = (QUAKEHEADER *)&uh[1]; #if DEBUG_CONFIG_IP_MASQ_QUAKE printk("Quake_out: qh->type = %d \n", (int)qh->type); #endif if(qh->type != 0x0080) return 0; code = qh->message[0]; #if DEBUG_CONFIG_IP_MASQ_QUAKE printk("Quake_out: code = %d \n", (int)code); #endif switch(code) { case 0x01: /* Connection Request */ if(ntohs(qh->length) < 0x0c) { #if DEBUG_CONFIG_IP_MASQ_QUAKE printk("Quake_out: length < 0xc \n"); #endif return 0; } data = &qh->message[1]; /* Check for stomping string */ if(memcmp(data,"QUAKE\0\3",7)) { #if DEBUG_CONFIG_IP_MASQ_QUAKE printk("Quake_out: memcmp failed \n"); #endif return 0; } else { priv->cl_connect = 1; #if DEBUG_CONFIG_IP_MASQ_QUAKE printk("Quake_out: memcmp ok \n"); #endif } break; case 0x81: /* Maybe a redirection of a quake-server at the inner side works in the future? */ /* Accept Connection */ if((ntohs(qh->length) < 0x09) || (priv->cl_connect == 0)) return 0; data = &qh->message[1]; memcpy(&udp_port, data, 2); n_ms = ip_masq_new(dev, IPPROTO_UDP, ms->saddr, htons(udp_port), ms->daddr, ms->dport, 0); if (n_ms==NULL) return 0; #if DEBUG_CONFIG_IP_MASQ_QUAKE printk("Quake_out: out_rewrote UDP port %d -> %d\n", udp_port, ntohs(n_ms->mport)); #endif udp_port = ntohs(n_ms->mport); memcpy(data, &udp_port, 2); break; } return 0; } struct ip_masq_app ip_masq_quake = { NULL, /* next */ "Quake", /* name */ 0, /* type */ 0, /* n_attach */ masq_quake_init_1, /* ip_masq_init_1 */ masq_quake_done_1, /* ip_masq_done_1 */ masq_quake_out, /* pkt_out */ masq_quake_in /* pkt_in */ }; /* * ip_masq_quake initialization */ int ip_masq_quake_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_quake, sizeof(struct ip_masq_app)); if ((j = register_ip_masq_app(masq_incarnations[i], IPPROTO_UDP, ports[i]))) { return j; } #if DEBUG_CONFIG_IP_MASQ_QUAKE printk("Quake: loaded support on port[%d] = %d\n", i, ports[i]); #endif } else { /* To be safe, force the incarnation table entry to NULL */ masq_incarnations[i] = NULL; } } return 0; } /* * ip_masq_quake fin. */ int ip_masq_quake_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; #if DEBUG_CONFIG_IP_MASQ_QUAKE printk("Quake: unloaded support on port[%d] = %d\n", i, ports[i]); #endif } } } return k; } #ifdef MODULE int init_module(void) { if (ip_masq_quake_init() != 0) return -EIO; register_symtab(0); return 0; } void cleanup_module(void) { if (ip_masq_quake_done() != 0) printk("ip_masq_quake: can't remove module"); } #endif /* MODULE */ |