libertas: tweak association debug output
[linux/fpc-iii.git] / net / ipv4 / ipvs / ip_vs_ftp.c
blob59aa166b7678b1e7bd256051b70f243ef3df84d8
1 /*
2 * ip_vs_ftp.c: IPVS ftp application module
4 * Version: $Id: ip_vs_ftp.c,v 1.13 2002/09/15 08:14:08 wensong Exp $
6 * Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
8 * Changes:
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
16 * Most code here is taken from ip_masq_ftp.c in kernel 2.2. The difference
17 * is that ip_vs_ftp module handles the reverse direction to ip_masq_ftp.
19 * IP_MASQ_FTP ftp masquerading module
21 * Version: @(#)ip_masq_ftp.c 0.04 02/05/96
23 * Author: Wouter Gadeyne
27 #include <linux/module.h>
28 #include <linux/moduleparam.h>
29 #include <linux/kernel.h>
30 #include <linux/skbuff.h>
31 #include <linux/in.h>
32 #include <linux/ip.h>
33 #include <linux/netfilter.h>
34 #include <net/protocol.h>
35 #include <net/tcp.h>
36 #include <asm/unaligned.h>
38 #include <net/ip_vs.h>
41 #define SERVER_STRING "227 Entering Passive Mode ("
42 #define CLIENT_STRING "PORT "
46 * List of ports (up to IP_VS_APP_MAX_PORTS) to be handled by helper
47 * First port is set to the default port.
49 static unsigned short ports[IP_VS_APP_MAX_PORTS] = {21, 0};
50 module_param_array(ports, ushort, NULL, 0);
51 MODULE_PARM_DESC(ports, "Ports to monitor for FTP control commands");
54 /* Dummy variable */
55 static int ip_vs_ftp_pasv;
58 static int
59 ip_vs_ftp_init_conn(struct ip_vs_app *app, struct ip_vs_conn *cp)
61 return 0;
65 static int
66 ip_vs_ftp_done_conn(struct ip_vs_app *app, struct ip_vs_conn *cp)
68 return 0;
73 * Get <addr,port> from the string "xxx.xxx.xxx.xxx,ppp,ppp", started
74 * with the "pattern" and terminated with the "term" character.
75 * <addr,port> is in network order.
77 static int ip_vs_ftp_get_addrport(char *data, char *data_limit,
78 const char *pattern, size_t plen, char term,
79 __be32 *addr, __be16 *port,
80 char **start, char **end)
82 unsigned char p[6];
83 int i = 0;
85 if (data_limit - data < plen) {
86 /* check if there is partial match */
87 if (strnicmp(data, pattern, data_limit - data) == 0)
88 return -1;
89 else
90 return 0;
93 if (strnicmp(data, pattern, plen) != 0) {
94 return 0;
96 *start = data + plen;
98 for (data = *start; *data != term; data++) {
99 if (data == data_limit)
100 return -1;
102 *end = data;
104 memset(p, 0, sizeof(p));
105 for (data = *start; data != *end; data++) {
106 if (*data >= '0' && *data <= '9') {
107 p[i] = p[i]*10 + *data - '0';
108 } else if (*data == ',' && i < 5) {
109 i++;
110 } else {
111 /* unexpected character */
112 return -1;
116 if (i != 5)
117 return -1;
119 *addr = get_unaligned((__be32 *)p);
120 *port = get_unaligned((__be16 *)(p + 4));
121 return 1;
126 * Look at outgoing ftp packets to catch the response to a PASV command
127 * from the server (inside-to-outside).
128 * When we see one, we build a connection entry with the client address,
129 * client port 0 (unknown at the moment), the server address and the
130 * server port. Mark the current connection entry as a control channel
131 * of the new entry. All this work is just to make the data connection
132 * can be scheduled to the right server later.
134 * The outgoing packet should be something like
135 * "227 Entering Passive Mode (xxx,xxx,xxx,xxx,ppp,ppp)".
136 * xxx,xxx,xxx,xxx is the server address, ppp,ppp is the server port number.
138 static int ip_vs_ftp_out(struct ip_vs_app *app, struct ip_vs_conn *cp,
139 struct sk_buff *skb, int *diff)
141 struct iphdr *iph;
142 struct tcphdr *th;
143 char *data, *data_limit;
144 char *start, *end;
145 __be32 from;
146 __be16 port;
147 struct ip_vs_conn *n_cp;
148 char buf[24]; /* xxx.xxx.xxx.xxx,ppp,ppp\000 */
149 unsigned buf_len;
150 int ret;
152 *diff = 0;
154 /* Only useful for established sessions */
155 if (cp->state != IP_VS_TCP_S_ESTABLISHED)
156 return 1;
158 /* Linear packets are much easier to deal with. */
159 if (!skb_make_writable(skb, skb->len))
160 return 0;
162 if (cp->app_data == &ip_vs_ftp_pasv) {
163 iph = ip_hdr(skb);
164 th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]);
165 data = (char *)th + (th->doff << 2);
166 data_limit = skb_tail_pointer(skb);
168 if (ip_vs_ftp_get_addrport(data, data_limit,
169 SERVER_STRING,
170 sizeof(SERVER_STRING)-1, ')',
171 &from, &port,
172 &start, &end) != 1)
173 return 1;
175 IP_VS_DBG(7, "PASV response (%u.%u.%u.%u:%d) -> "
176 "%u.%u.%u.%u:%d detected\n",
177 NIPQUAD(from), ntohs(port), NIPQUAD(cp->caddr), 0);
180 * Now update or create an connection entry for it
182 n_cp = ip_vs_conn_out_get(iph->protocol, from, port,
183 cp->caddr, 0);
184 if (!n_cp) {
185 n_cp = ip_vs_conn_new(IPPROTO_TCP,
186 cp->caddr, 0,
187 cp->vaddr, port,
188 from, port,
189 IP_VS_CONN_F_NO_CPORT,
190 cp->dest);
191 if (!n_cp)
192 return 0;
194 /* add its controller */
195 ip_vs_control_add(n_cp, cp);
199 * Replace the old passive address with the new one
201 from = n_cp->vaddr;
202 port = n_cp->vport;
203 sprintf(buf,"%d,%d,%d,%d,%d,%d", NIPQUAD(from),
204 (ntohs(port)>>8)&255, ntohs(port)&255);
205 buf_len = strlen(buf);
208 * Calculate required delta-offset to keep TCP happy
210 *diff = buf_len - (end-start);
212 if (*diff == 0) {
213 /* simply replace it with new passive address */
214 memcpy(start, buf, buf_len);
215 ret = 1;
216 } else {
217 ret = !ip_vs_skb_replace(skb, GFP_ATOMIC, start,
218 end-start, buf, buf_len);
221 cp->app_data = NULL;
222 ip_vs_tcp_conn_listen(n_cp);
223 ip_vs_conn_put(n_cp);
224 return ret;
226 return 1;
231 * Look at incoming ftp packets to catch the PASV/PORT command
232 * (outside-to-inside).
234 * The incoming packet having the PORT command should be something like
235 * "PORT xxx,xxx,xxx,xxx,ppp,ppp\n".
236 * xxx,xxx,xxx,xxx is the client address, ppp,ppp is the client port number.
237 * In this case, we create a connection entry using the client address and
238 * port, so that the active ftp data connection from the server can reach
239 * the client.
241 static int ip_vs_ftp_in(struct ip_vs_app *app, struct ip_vs_conn *cp,
242 struct sk_buff *skb, int *diff)
244 struct iphdr *iph;
245 struct tcphdr *th;
246 char *data, *data_start, *data_limit;
247 char *start, *end;
248 __be32 to;
249 __be16 port;
250 struct ip_vs_conn *n_cp;
252 /* no diff required for incoming packets */
253 *diff = 0;
255 /* Only useful for established sessions */
256 if (cp->state != IP_VS_TCP_S_ESTABLISHED)
257 return 1;
259 /* Linear packets are much easier to deal with. */
260 if (!skb_make_writable(skb, skb->len))
261 return 0;
264 * Detecting whether it is passive
266 iph = ip_hdr(skb);
267 th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]);
269 /* Since there may be OPTIONS in the TCP packet and the HLEN is
270 the length of the header in 32-bit multiples, it is accurate
271 to calculate data address by th+HLEN*4 */
272 data = data_start = (char *)th + (th->doff << 2);
273 data_limit = skb_tail_pointer(skb);
275 while (data <= data_limit - 6) {
276 if (strnicmp(data, "PASV\r\n", 6) == 0) {
277 /* Passive mode on */
278 IP_VS_DBG(7, "got PASV at %td of %td\n",
279 data - data_start,
280 data_limit - data_start);
281 cp->app_data = &ip_vs_ftp_pasv;
282 return 1;
284 data++;
288 * To support virtual FTP server, the scenerio is as follows:
289 * FTP client ----> Load Balancer ----> FTP server
290 * First detect the port number in the application data,
291 * then create a new connection entry for the coming data
292 * connection.
294 if (ip_vs_ftp_get_addrport(data_start, data_limit,
295 CLIENT_STRING, sizeof(CLIENT_STRING)-1,
296 '\r', &to, &port,
297 &start, &end) != 1)
298 return 1;
300 IP_VS_DBG(7, "PORT %u.%u.%u.%u:%d detected\n",
301 NIPQUAD(to), ntohs(port));
303 /* Passive mode off */
304 cp->app_data = NULL;
307 * Now update or create a connection entry for it
309 IP_VS_DBG(7, "protocol %s %u.%u.%u.%u:%d %u.%u.%u.%u:%d\n",
310 ip_vs_proto_name(iph->protocol),
311 NIPQUAD(to), ntohs(port), NIPQUAD(cp->vaddr), 0);
313 n_cp = ip_vs_conn_in_get(iph->protocol,
314 to, port,
315 cp->vaddr, htons(ntohs(cp->vport)-1));
316 if (!n_cp) {
317 n_cp = ip_vs_conn_new(IPPROTO_TCP,
318 to, port,
319 cp->vaddr, htons(ntohs(cp->vport)-1),
320 cp->daddr, htons(ntohs(cp->dport)-1),
322 cp->dest);
323 if (!n_cp)
324 return 0;
326 /* add its controller */
327 ip_vs_control_add(n_cp, cp);
331 * Move tunnel to listen state
333 ip_vs_tcp_conn_listen(n_cp);
334 ip_vs_conn_put(n_cp);
336 return 1;
340 static struct ip_vs_app ip_vs_ftp = {
341 .name = "ftp",
342 .type = IP_VS_APP_TYPE_FTP,
343 .protocol = IPPROTO_TCP,
344 .module = THIS_MODULE,
345 .incs_list = LIST_HEAD_INIT(ip_vs_ftp.incs_list),
346 .init_conn = ip_vs_ftp_init_conn,
347 .done_conn = ip_vs_ftp_done_conn,
348 .bind_conn = NULL,
349 .unbind_conn = NULL,
350 .pkt_out = ip_vs_ftp_out,
351 .pkt_in = ip_vs_ftp_in,
356 * ip_vs_ftp initialization
358 static int __init ip_vs_ftp_init(void)
360 int i, ret;
361 struct ip_vs_app *app = &ip_vs_ftp;
363 ret = register_ip_vs_app(app);
364 if (ret)
365 return ret;
367 for (i=0; i<IP_VS_APP_MAX_PORTS; i++) {
368 if (!ports[i])
369 continue;
370 ret = register_ip_vs_app_inc(app, app->protocol, ports[i]);
371 if (ret)
372 break;
373 IP_VS_INFO("%s: loaded support on port[%d] = %d\n",
374 app->name, i, ports[i]);
377 if (ret)
378 unregister_ip_vs_app(app);
380 return ret;
385 * ip_vs_ftp finish.
387 static void __exit ip_vs_ftp_exit(void)
389 unregister_ip_vs_app(&ip_vs_ftp);
393 module_init(ip_vs_ftp_init);
394 module_exit(ip_vs_ftp_exit);
395 MODULE_LICENSE("GPL");