Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * ip_vs_ftp.c: IPVS ftp application module |
| 3 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | * Authors: Wensong Zhang <wensong@linuxvirtualserver.org> |
| 5 | * |
| 6 | * Changes: |
| 7 | * |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or |
| 10 | * modify it under the terms of the GNU General Public License |
| 11 | * as published by the Free Software Foundation; either version |
| 12 | * 2 of the License, or (at your option) any later version. |
| 13 | * |
| 14 | * Most code here is taken from ip_masq_ftp.c in kernel 2.2. The difference |
| 15 | * is that ip_vs_ftp module handles the reverse direction to ip_masq_ftp. |
| 16 | * |
| 17 | * IP_MASQ_FTP ftp masquerading module |
| 18 | * |
| 19 | * Version: @(#)ip_masq_ftp.c 0.04 02/05/96 |
| 20 | * |
| 21 | * Author: Wouter Gadeyne |
| 22 | * |
| 23 | */ |
| 24 | |
Hannes Eder | 9aada7a | 2009-07-30 14:29:44 -0700 | [diff] [blame] | 25 | #define KMSG_COMPONENT "IPVS" |
| 26 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt |
| 27 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | #include <linux/module.h> |
| 29 | #include <linux/moduleparam.h> |
| 30 | #include <linux/kernel.h> |
| 31 | #include <linux/skbuff.h> |
| 32 | #include <linux/in.h> |
| 33 | #include <linux/ip.h> |
Herbert Xu | af1e1cf | 2007-10-14 00:39:33 -0700 | [diff] [blame] | 34 | #include <linux/netfilter.h> |
Hannes Eder | 7f1c407 | 2010-07-23 12:48:52 +0200 | [diff] [blame] | 35 | #include <net/netfilter/nf_conntrack.h> |
| 36 | #include <net/netfilter/nf_conntrack_expect.h> |
Julian Anastasov | 7bcbf81 | 2010-09-01 23:07:10 +0000 | [diff] [blame] | 37 | #include <net/netfilter/nf_nat.h> |
Hannes Eder | 7f1c407 | 2010-07-23 12:48:52 +0200 | [diff] [blame] | 38 | #include <net/netfilter/nf_nat_helper.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 39 | #include <linux/gfp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | #include <net/protocol.h> |
| 41 | #include <net/tcp.h> |
Al Viro | 96d2ca4 | 2006-09-28 14:31:49 -0700 | [diff] [blame] | 42 | #include <asm/unaligned.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | |
| 44 | #include <net/ip_vs.h> |
| 45 | |
| 46 | |
Julian Anastasov | c3aa1bd | 2011-05-30 00:02:23 +0300 | [diff] [blame] | 47 | #define SERVER_STRING "227 " |
| 48 | #define CLIENT_STRING "PORT" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | |
| 50 | |
| 51 | /* |
| 52 | * List of ports (up to IP_VS_APP_MAX_PORTS) to be handled by helper |
| 53 | * First port is set to the default port. |
| 54 | */ |
Krzysztof Wilczynski | 52669df | 2011-09-12 10:15:15 +0100 | [diff] [blame] | 55 | static unsigned int ports_count = 1; |
Simon Horman | 28b06c3 | 2006-09-27 22:53:24 -0700 | [diff] [blame] | 56 | static unsigned short ports[IP_VS_APP_MAX_PORTS] = {21, 0}; |
Krzysztof Wilczynski | 52669df | 2011-09-12 10:15:15 +0100 | [diff] [blame] | 57 | module_param_array(ports, ushort, &ports_count, 0444); |
Simon Horman | 70e76b7 | 2006-09-13 19:57:54 -0700 | [diff] [blame] | 58 | MODULE_PARM_DESC(ports, "Ports to monitor for FTP control commands"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | |
| 61 | /* Dummy variable */ |
| 62 | static int ip_vs_ftp_pasv; |
| 63 | |
| 64 | |
| 65 | static int |
| 66 | ip_vs_ftp_init_conn(struct ip_vs_app *app, struct ip_vs_conn *cp) |
| 67 | { |
Julian Anastasov | f4bc17c | 2010-09-21 17:35:41 +0200 | [diff] [blame] | 68 | /* We use connection tracking for the command connection */ |
| 69 | cp->flags |= IP_VS_CONN_F_NFCT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | return 0; |
| 71 | } |
| 72 | |
| 73 | |
| 74 | static int |
| 75 | ip_vs_ftp_done_conn(struct ip_vs_app *app, struct ip_vs_conn *cp) |
| 76 | { |
| 77 | return 0; |
| 78 | } |
| 79 | |
| 80 | |
| 81 | /* |
| 82 | * Get <addr,port> from the string "xxx.xxx.xxx.xxx,ppp,ppp", started |
Julian Anastasov | c3aa1bd | 2011-05-30 00:02:23 +0300 | [diff] [blame] | 83 | * with the "pattern", ignoring before "skip" and terminated with |
| 84 | * the "term" character. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | * <addr,port> is in network order. |
| 86 | */ |
| 87 | static int ip_vs_ftp_get_addrport(char *data, char *data_limit, |
Julian Anastasov | c3aa1bd | 2011-05-30 00:02:23 +0300 | [diff] [blame] | 88 | const char *pattern, size_t plen, |
| 89 | char skip, char term, |
Al Viro | 014d730 | 2006-09-28 14:29:52 -0700 | [diff] [blame] | 90 | __be32 *addr, __be16 *port, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | char **start, char **end) |
| 92 | { |
Julian Anastasov | c3aa1bd | 2011-05-30 00:02:23 +0300 | [diff] [blame] | 93 | char *s, c; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | unsigned char p[6]; |
| 95 | int i = 0; |
| 96 | |
| 97 | if (data_limit - data < plen) { |
| 98 | /* check if there is partial match */ |
Rasmus Villemoes | 1808274 | 2014-10-13 15:54:31 -0700 | [diff] [blame] | 99 | if (strncasecmp(data, pattern, data_limit - data) == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | return -1; |
| 101 | else |
| 102 | return 0; |
| 103 | } |
| 104 | |
Rasmus Villemoes | 1808274 | 2014-10-13 15:54:31 -0700 | [diff] [blame] | 105 | if (strncasecmp(data, pattern, plen) != 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | return 0; |
| 107 | } |
Julian Anastasov | c3aa1bd | 2011-05-30 00:02:23 +0300 | [diff] [blame] | 108 | s = data + plen; |
| 109 | if (skip) { |
| 110 | int found = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | |
Julian Anastasov | c3aa1bd | 2011-05-30 00:02:23 +0300 | [diff] [blame] | 112 | for (;; s++) { |
| 113 | if (s == data_limit) |
| 114 | return -1; |
| 115 | if (!found) { |
| 116 | if (*s == skip) |
| 117 | found = 1; |
| 118 | } else if (*s != skip) { |
| 119 | break; |
| 120 | } |
| 121 | } |
| 122 | } |
| 123 | |
| 124 | for (data = s; ; data++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | if (data == data_limit) |
| 126 | return -1; |
Julian Anastasov | c3aa1bd | 2011-05-30 00:02:23 +0300 | [diff] [blame] | 127 | if (*data == term) |
| 128 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | } |
| 130 | *end = data; |
| 131 | |
| 132 | memset(p, 0, sizeof(p)); |
Julian Anastasov | c3aa1bd | 2011-05-30 00:02:23 +0300 | [diff] [blame] | 133 | for (data = s; ; data++) { |
| 134 | c = *data; |
| 135 | if (c == term) |
| 136 | break; |
| 137 | if (c >= '0' && c <= '9') { |
| 138 | p[i] = p[i]*10 + c - '0'; |
| 139 | } else if (c == ',' && i < 5) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | i++; |
| 141 | } else { |
| 142 | /* unexpected character */ |
| 143 | return -1; |
| 144 | } |
| 145 | } |
| 146 | |
| 147 | if (i != 5) |
| 148 | return -1; |
| 149 | |
Julian Anastasov | c3aa1bd | 2011-05-30 00:02:23 +0300 | [diff] [blame] | 150 | *start = s; |
| 151 | *addr = get_unaligned((__be32 *) p); |
| 152 | *port = get_unaligned((__be16 *) (p + 4)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | return 1; |
| 154 | } |
| 155 | |
Hannes Eder | 7f1c407 | 2010-07-23 12:48:52 +0200 | [diff] [blame] | 156 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | * Look at outgoing ftp packets to catch the response to a PASV command |
| 158 | * from the server (inside-to-outside). |
| 159 | * When we see one, we build a connection entry with the client address, |
| 160 | * client port 0 (unknown at the moment), the server address and the |
| 161 | * server port. Mark the current connection entry as a control channel |
| 162 | * of the new entry. All this work is just to make the data connection |
| 163 | * can be scheduled to the right server later. |
| 164 | * |
| 165 | * The outgoing packet should be something like |
| 166 | * "227 Entering Passive Mode (xxx,xxx,xxx,xxx,ppp,ppp)". |
| 167 | * xxx,xxx,xxx,xxx is the server address, ppp,ppp is the server port number. |
| 168 | */ |
| 169 | static int ip_vs_ftp_out(struct ip_vs_app *app, struct ip_vs_conn *cp, |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 170 | struct sk_buff *skb, int *diff) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | { |
| 172 | struct iphdr *iph; |
| 173 | struct tcphdr *th; |
| 174 | char *data, *data_limit; |
| 175 | char *start, *end; |
Julius Volz | 28364a5 | 2008-09-02 15:55:43 +0200 | [diff] [blame] | 176 | union nf_inet_addr from; |
Al Viro | 014d730 | 2006-09-28 14:29:52 -0700 | [diff] [blame] | 177 | __be16 port; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | struct ip_vs_conn *n_cp; |
| 179 | char buf[24]; /* xxx.xxx.xxx.xxx,ppp,ppp\000 */ |
Eric Dumazet | 95c9617 | 2012-04-15 05:58:06 +0000 | [diff] [blame] | 180 | unsigned int buf_len; |
Hannes Eder | 7f1c407 | 2010-07-23 12:48:52 +0200 | [diff] [blame] | 181 | int ret = 0; |
| 182 | enum ip_conntrack_info ctinfo; |
| 183 | struct nf_conn *ct; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | |
Dan Carpenter | 3b05ac3 | 2014-12-06 16:49:24 +0300 | [diff] [blame] | 185 | *diff = 0; |
| 186 | |
Julius Volz | a0eb662 | 2008-09-02 15:55:51 +0200 | [diff] [blame] | 187 | #ifdef CONFIG_IP_VS_IPV6 |
| 188 | /* This application helper doesn't work with IPv6 yet, |
| 189 | * so turn this into a no-op for IPv6 packets |
| 190 | */ |
| 191 | if (cp->af == AF_INET6) |
| 192 | return 1; |
| 193 | #endif |
| 194 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | /* Only useful for established sessions */ |
| 196 | if (cp->state != IP_VS_TCP_S_ESTABLISHED) |
| 197 | return 1; |
| 198 | |
| 199 | /* Linear packets are much easier to deal with. */ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 200 | if (!skb_make_writable(skb, skb->len)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | return 0; |
| 202 | |
| 203 | if (cp->app_data == &ip_vs_ftp_pasv) { |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 204 | iph = ip_hdr(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]); |
| 206 | data = (char *)th + (th->doff << 2); |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 207 | data_limit = skb_tail_pointer(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 208 | |
| 209 | if (ip_vs_ftp_get_addrport(data, data_limit, |
| 210 | SERVER_STRING, |
Julian Anastasov | c3aa1bd | 2011-05-30 00:02:23 +0300 | [diff] [blame] | 211 | sizeof(SERVER_STRING)-1, |
| 212 | '(', ')', |
Julius Volz | 28364a5 | 2008-09-02 15:55:43 +0200 | [diff] [blame] | 213 | &from.ip, &port, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | &start, &end) != 1) |
| 215 | return 1; |
| 216 | |
Harvey Harrison | 14d5e83 | 2008-10-31 00:54:29 -0700 | [diff] [blame] | 217 | IP_VS_DBG(7, "PASV response (%pI4:%d) -> %pI4:%d detected\n", |
| 218 | &from.ip, ntohs(port), &cp->caddr.ip, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 219 | |
| 220 | /* |
| 221 | * Now update or create an connection entry for it |
| 222 | */ |
Simon Horman | f11017e | 2010-08-22 21:37:52 +0900 | [diff] [blame] | 223 | { |
| 224 | struct ip_vs_conn_param p; |
Eric W. Biederman | 19913de | 2015-09-21 13:01:43 -0500 | [diff] [blame] | 225 | ip_vs_conn_fill_param(cp->ipvs, AF_INET, |
Hans Schillstrom | 6e67e58 | 2011-01-03 14:44:57 +0100 | [diff] [blame] | 226 | iph->protocol, &from, port, |
| 227 | &cp->caddr, 0, &p); |
Simon Horman | f11017e | 2010-08-22 21:37:52 +0900 | [diff] [blame] | 228 | n_cp = ip_vs_conn_out_get(&p); |
| 229 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | if (!n_cp) { |
Simon Horman | f11017e | 2010-08-22 21:37:52 +0900 | [diff] [blame] | 231 | struct ip_vs_conn_param p; |
Eric W. Biederman | 19913de | 2015-09-21 13:01:43 -0500 | [diff] [blame] | 232 | ip_vs_conn_fill_param(cp->ipvs, |
Hans Schillstrom | 6e67e58 | 2011-01-03 14:44:57 +0100 | [diff] [blame] | 233 | AF_INET, IPPROTO_TCP, &cp->caddr, |
Simon Horman | f11017e | 2010-08-22 21:37:52 +0900 | [diff] [blame] | 234 | 0, &cp->vaddr, port, &p); |
Alex Gartrell | ba38528 | 2014-09-09 16:40:23 -0700 | [diff] [blame] | 235 | /* As above, this is ipv4 only */ |
| 236 | n_cp = ip_vs_conn_new(&p, AF_INET, &from, port, |
Julian Anastasov | f4bc17c | 2010-09-21 17:35:41 +0200 | [diff] [blame] | 237 | IP_VS_CONN_F_NO_CPORT | |
| 238 | IP_VS_CONN_F_NFCT, |
Hans Schillstrom | 0e051e6 | 2010-11-19 14:25:07 +0100 | [diff] [blame] | 239 | cp->dest, skb->mark); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | if (!n_cp) |
| 241 | return 0; |
| 242 | |
| 243 | /* add its controller */ |
| 244 | ip_vs_control_add(n_cp, cp); |
| 245 | } |
| 246 | |
| 247 | /* |
| 248 | * Replace the old passive address with the new one |
| 249 | */ |
Julius Volz | 28364a5 | 2008-09-02 15:55:43 +0200 | [diff] [blame] | 250 | from.ip = n_cp->vaddr.ip; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | port = n_cp->vport; |
Joe Perches | 1da05f5 | 2010-03-15 18:03:05 +0100 | [diff] [blame] | 252 | snprintf(buf, sizeof(buf), "%u,%u,%u,%u,%u,%u", |
| 253 | ((unsigned char *)&from.ip)[0], |
| 254 | ((unsigned char *)&from.ip)[1], |
| 255 | ((unsigned char *)&from.ip)[2], |
| 256 | ((unsigned char *)&from.ip)[3], |
| 257 | ntohs(port) >> 8, |
| 258 | ntohs(port) & 0xFF); |
| 259 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | buf_len = strlen(buf); |
| 261 | |
Hannes Eder | 7f1c407 | 2010-07-23 12:48:52 +0200 | [diff] [blame] | 262 | ct = nf_ct_get(skb, &ctinfo); |
Julian Anastasov | 7bcbf81 | 2010-09-01 23:07:10 +0000 | [diff] [blame] | 263 | if (ct && !nf_ct_is_untracked(ct) && nfct_nat(ct)) { |
Hannes Eder | 7f1c407 | 2010-07-23 12:48:52 +0200 | [diff] [blame] | 264 | /* If mangling fails this function will return 0 |
| 265 | * which will cause the packet to be dropped. |
| 266 | * Mangling can only fail under memory pressure, |
| 267 | * hopefully it will succeed on the retransmitted |
| 268 | * packet. |
| 269 | */ |
Julian Anastasov | ac69269 | 2013-03-22 11:46:54 +0200 | [diff] [blame] | 270 | rcu_read_lock(); |
Hannes Eder | 7f1c407 | 2010-07-23 12:48:52 +0200 | [diff] [blame] | 271 | ret = nf_nat_mangle_tcp_packet(skb, ct, ctinfo, |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 272 | iph->ihl * 4, |
Hannes Eder | 7f1c407 | 2010-07-23 12:48:52 +0200 | [diff] [blame] | 273 | start-data, end-start, |
| 274 | buf, buf_len); |
Julian Anastasov | ac69269 | 2013-03-22 11:46:54 +0200 | [diff] [blame] | 275 | rcu_read_unlock(); |
Julian Anastasov | 8b27b10 | 2010-10-17 16:17:20 +0300 | [diff] [blame] | 276 | if (ret) { |
Julian Anastasov | f4bc17c | 2010-09-21 17:35:41 +0200 | [diff] [blame] | 277 | ip_vs_nfct_expect_related(skb, ct, n_cp, |
| 278 | IPPROTO_TCP, 0, 0); |
Julian Anastasov | 8b27b10 | 2010-10-17 16:17:20 +0300 | [diff] [blame] | 279 | if (skb->ip_summed == CHECKSUM_COMPLETE) |
| 280 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
| 281 | /* csum is updated */ |
| 282 | ret = 1; |
| 283 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | } |
| 285 | |
Hannes Eder | 7f1c407 | 2010-07-23 12:48:52 +0200 | [diff] [blame] | 286 | /* |
| 287 | * Not setting 'diff' is intentional, otherwise the sequence |
| 288 | * would be adjusted twice. |
| 289 | */ |
| 290 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | cp->app_data = NULL; |
Eric W. Biederman | 69f3909 | 2015-09-21 13:02:57 -0500 | [diff] [blame] | 292 | ip_vs_tcp_conn_listen(n_cp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 293 | ip_vs_conn_put(n_cp); |
| 294 | return ret; |
| 295 | } |
| 296 | return 1; |
| 297 | } |
| 298 | |
| 299 | |
| 300 | /* |
| 301 | * Look at incoming ftp packets to catch the PASV/PORT command |
| 302 | * (outside-to-inside). |
| 303 | * |
| 304 | * The incoming packet having the PORT command should be something like |
| 305 | * "PORT xxx,xxx,xxx,xxx,ppp,ppp\n". |
| 306 | * xxx,xxx,xxx,xxx is the client address, ppp,ppp is the client port number. |
| 307 | * In this case, we create a connection entry using the client address and |
| 308 | * port, so that the active ftp data connection from the server can reach |
| 309 | * the client. |
| 310 | */ |
| 311 | static int ip_vs_ftp_in(struct ip_vs_app *app, struct ip_vs_conn *cp, |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 312 | struct sk_buff *skb, int *diff) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 313 | { |
| 314 | struct iphdr *iph; |
| 315 | struct tcphdr *th; |
| 316 | char *data, *data_start, *data_limit; |
| 317 | char *start, *end; |
Julius Volz | 28364a5 | 2008-09-02 15:55:43 +0200 | [diff] [blame] | 318 | union nf_inet_addr to; |
Al Viro | 014d730 | 2006-09-28 14:29:52 -0700 | [diff] [blame] | 319 | __be16 port; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | struct ip_vs_conn *n_cp; |
| 321 | |
Dan Carpenter | 3b05ac3 | 2014-12-06 16:49:24 +0300 | [diff] [blame] | 322 | /* no diff required for incoming packets */ |
| 323 | *diff = 0; |
| 324 | |
Julius Volz | a0eb662 | 2008-09-02 15:55:51 +0200 | [diff] [blame] | 325 | #ifdef CONFIG_IP_VS_IPV6 |
| 326 | /* This application helper doesn't work with IPv6 yet, |
| 327 | * so turn this into a no-op for IPv6 packets |
| 328 | */ |
| 329 | if (cp->af == AF_INET6) |
| 330 | return 1; |
| 331 | #endif |
| 332 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | /* Only useful for established sessions */ |
| 334 | if (cp->state != IP_VS_TCP_S_ESTABLISHED) |
| 335 | return 1; |
| 336 | |
| 337 | /* Linear packets are much easier to deal with. */ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 338 | if (!skb_make_writable(skb, skb->len)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | return 0; |
| 340 | |
| 341 | /* |
| 342 | * Detecting whether it is passive |
| 343 | */ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 344 | iph = ip_hdr(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]); |
| 346 | |
| 347 | /* Since there may be OPTIONS in the TCP packet and the HLEN is |
| 348 | the length of the header in 32-bit multiples, it is accurate |
| 349 | to calculate data address by th+HLEN*4 */ |
| 350 | data = data_start = (char *)th + (th->doff << 2); |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 351 | data_limit = skb_tail_pointer(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 352 | |
| 353 | while (data <= data_limit - 6) { |
Rasmus Villemoes | 1808274 | 2014-10-13 15:54:31 -0700 | [diff] [blame] | 354 | if (strncasecmp(data, "PASV\r\n", 6) == 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 355 | /* Passive mode on */ |
Al Viro | 5e7ddac | 2006-10-10 22:49:07 +0100 | [diff] [blame] | 356 | IP_VS_DBG(7, "got PASV at %td of %td\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 357 | data - data_start, |
| 358 | data_limit - data_start); |
| 359 | cp->app_data = &ip_vs_ftp_pasv; |
| 360 | return 1; |
| 361 | } |
| 362 | data++; |
| 363 | } |
| 364 | |
| 365 | /* |
| 366 | * To support virtual FTP server, the scenerio is as follows: |
| 367 | * FTP client ----> Load Balancer ----> FTP server |
| 368 | * First detect the port number in the application data, |
| 369 | * then create a new connection entry for the coming data |
| 370 | * connection. |
| 371 | */ |
| 372 | if (ip_vs_ftp_get_addrport(data_start, data_limit, |
| 373 | CLIENT_STRING, sizeof(CLIENT_STRING)-1, |
Julian Anastasov | c3aa1bd | 2011-05-30 00:02:23 +0300 | [diff] [blame] | 374 | ' ', '\r', &to.ip, &port, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | &start, &end) != 1) |
| 376 | return 1; |
| 377 | |
Harvey Harrison | 14d5e83 | 2008-10-31 00:54:29 -0700 | [diff] [blame] | 378 | IP_VS_DBG(7, "PORT %pI4:%d detected\n", &to.ip, ntohs(port)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | |
| 380 | /* Passive mode off */ |
| 381 | cp->app_data = NULL; |
| 382 | |
| 383 | /* |
| 384 | * Now update or create a connection entry for it |
| 385 | */ |
Harvey Harrison | 14d5e83 | 2008-10-31 00:54:29 -0700 | [diff] [blame] | 386 | IP_VS_DBG(7, "protocol %s %pI4:%d %pI4:%d\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | ip_vs_proto_name(iph->protocol), |
Harvey Harrison | 14d5e83 | 2008-10-31 00:54:29 -0700 | [diff] [blame] | 388 | &to.ip, ntohs(port), &cp->vaddr.ip, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 389 | |
Simon Horman | f11017e | 2010-08-22 21:37:52 +0900 | [diff] [blame] | 390 | { |
| 391 | struct ip_vs_conn_param p; |
Eric W. Biederman | 19913de | 2015-09-21 13:01:43 -0500 | [diff] [blame] | 392 | ip_vs_conn_fill_param(cp->ipvs, AF_INET, |
Hans Schillstrom | 6e67e58 | 2011-01-03 14:44:57 +0100 | [diff] [blame] | 393 | iph->protocol, &to, port, &cp->vaddr, |
| 394 | htons(ntohs(cp->vport)-1), &p); |
Simon Horman | f11017e | 2010-08-22 21:37:52 +0900 | [diff] [blame] | 395 | n_cp = ip_vs_conn_in_get(&p); |
| 396 | if (!n_cp) { |
Alex Gartrell | ba38528 | 2014-09-09 16:40:23 -0700 | [diff] [blame] | 397 | /* This is ipv4 only */ |
| 398 | n_cp = ip_vs_conn_new(&p, AF_INET, &cp->daddr, |
Simon Horman | f11017e | 2010-08-22 21:37:52 +0900 | [diff] [blame] | 399 | htons(ntohs(cp->dport)-1), |
Hans Schillstrom | 0e051e6 | 2010-11-19 14:25:07 +0100 | [diff] [blame] | 400 | IP_VS_CONN_F_NFCT, cp->dest, |
| 401 | skb->mark); |
Simon Horman | f11017e | 2010-08-22 21:37:52 +0900 | [diff] [blame] | 402 | if (!n_cp) |
| 403 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 404 | |
Simon Horman | f11017e | 2010-08-22 21:37:52 +0900 | [diff] [blame] | 405 | /* add its controller */ |
| 406 | ip_vs_control_add(n_cp, cp); |
| 407 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | } |
| 409 | |
| 410 | /* |
| 411 | * Move tunnel to listen state |
| 412 | */ |
Eric W. Biederman | 69f3909 | 2015-09-21 13:02:57 -0500 | [diff] [blame] | 413 | ip_vs_tcp_conn_listen(n_cp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 414 | ip_vs_conn_put(n_cp); |
| 415 | |
| 416 | return 1; |
| 417 | } |
| 418 | |
| 419 | |
| 420 | static struct ip_vs_app ip_vs_ftp = { |
| 421 | .name = "ftp", |
| 422 | .type = IP_VS_APP_TYPE_FTP, |
| 423 | .protocol = IPPROTO_TCP, |
| 424 | .module = THIS_MODULE, |
| 425 | .incs_list = LIST_HEAD_INIT(ip_vs_ftp.incs_list), |
| 426 | .init_conn = ip_vs_ftp_init_conn, |
| 427 | .done_conn = ip_vs_ftp_done_conn, |
| 428 | .bind_conn = NULL, |
| 429 | .unbind_conn = NULL, |
| 430 | .pkt_out = ip_vs_ftp_out, |
| 431 | .pkt_in = ip_vs_ftp_in, |
| 432 | }; |
| 433 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | /* |
Hans Schillstrom | 61b1ab4 | 2011-01-03 14:44:42 +0100 | [diff] [blame] | 435 | * per netns ip_vs_ftp initialization |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | */ |
Hans Schillstrom | 61b1ab4 | 2011-01-03 14:44:42 +0100 | [diff] [blame] | 437 | static int __net_init __ip_vs_ftp_init(struct net *net) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 438 | { |
| 439 | int i, ret; |
Hans Schillstrom | c74c0bf | 2011-05-24 14:11:05 +0200 | [diff] [blame] | 440 | struct ip_vs_app *app; |
| 441 | struct netns_ipvs *ipvs = net_ipvs(net); |
| 442 | |
Julian Anastasov | 8d08d71 | 2012-04-25 00:29:59 +0300 | [diff] [blame] | 443 | if (!ipvs) |
| 444 | return -ENOENT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 445 | |
Eric W. Biederman | 9f8128a | 2015-09-21 13:02:32 -0500 | [diff] [blame] | 446 | app = register_ip_vs_app(ipvs, &ip_vs_ftp); |
Julian Anastasov | be97fdb | 2012-07-12 23:06:20 +0300 | [diff] [blame] | 447 | if (IS_ERR(app)) |
| 448 | return PTR_ERR(app); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | |
Krzysztof Wilczynski | 52669df | 2011-09-12 10:15:15 +0100 | [diff] [blame] | 450 | for (i = 0; i < ports_count; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 451 | if (!ports[i]) |
| 452 | continue; |
Eric W. Biederman | 3250dc9 | 2015-09-21 13:02:31 -0500 | [diff] [blame] | 453 | ret = register_ip_vs_app_inc(ipvs, app, app->protocol, ports[i]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | if (ret) |
Hans Schillstrom | c74c0bf | 2011-05-24 14:11:05 +0200 | [diff] [blame] | 455 | goto err_unreg; |
Hannes Eder | 1e3e238 | 2009-08-02 11:05:41 +0000 | [diff] [blame] | 456 | pr_info("%s: loaded support on port[%d] = %d\n", |
| 457 | app->name, i, ports[i]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | } |
Hans Schillstrom | c74c0bf | 2011-05-24 14:11:05 +0200 | [diff] [blame] | 459 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 460 | |
Hans Schillstrom | c74c0bf | 2011-05-24 14:11:05 +0200 | [diff] [blame] | 461 | err_unreg: |
Eric W. Biederman | 9f8128a | 2015-09-21 13:02:32 -0500 | [diff] [blame] | 462 | unregister_ip_vs_app(ipvs, &ip_vs_ftp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | return ret; |
| 464 | } |
Hans Schillstrom | 61b1ab4 | 2011-01-03 14:44:42 +0100 | [diff] [blame] | 465 | /* |
| 466 | * netns exit |
| 467 | */ |
| 468 | static void __ip_vs_ftp_exit(struct net *net) |
| 469 | { |
Eric W. Biederman | 9f8128a | 2015-09-21 13:02:32 -0500 | [diff] [blame] | 470 | struct netns_ipvs *ipvs = net_ipvs(net); |
| 471 | |
| 472 | if (!ipvs) |
| 473 | return; |
| 474 | |
| 475 | unregister_ip_vs_app(ipvs, &ip_vs_ftp); |
Hans Schillstrom | 61b1ab4 | 2011-01-03 14:44:42 +0100 | [diff] [blame] | 476 | } |
| 477 | |
| 478 | static struct pernet_operations ip_vs_ftp_ops = { |
| 479 | .init = __ip_vs_ftp_init, |
| 480 | .exit = __ip_vs_ftp_exit, |
| 481 | }; |
| 482 | |
H Hartley Sweeten | d5cce20 | 2012-04-26 11:17:28 -0700 | [diff] [blame] | 483 | static int __init ip_vs_ftp_init(void) |
Hans Schillstrom | 61b1ab4 | 2011-01-03 14:44:42 +0100 | [diff] [blame] | 484 | { |
| 485 | int rv; |
| 486 | |
| 487 | rv = register_pernet_subsys(&ip_vs_ftp_ops); |
Julian Anastasov | 363c97d | 2013-03-21 11:58:07 +0200 | [diff] [blame] | 488 | /* rcu_barrier() is called by netns on error */ |
Hans Schillstrom | 61b1ab4 | 2011-01-03 14:44:42 +0100 | [diff] [blame] | 489 | return rv; |
| 490 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 491 | |
| 492 | /* |
| 493 | * ip_vs_ftp finish. |
| 494 | */ |
| 495 | static void __exit ip_vs_ftp_exit(void) |
| 496 | { |
Hans Schillstrom | 61b1ab4 | 2011-01-03 14:44:42 +0100 | [diff] [blame] | 497 | unregister_pernet_subsys(&ip_vs_ftp_ops); |
Julian Anastasov | 363c97d | 2013-03-21 11:58:07 +0200 | [diff] [blame] | 498 | /* rcu_barrier() is called by netns */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | } |
| 500 | |
| 501 | |
| 502 | module_init(ip_vs_ftp_init); |
| 503 | module_exit(ip_vs_ftp_exit); |
| 504 | MODULE_LICENSE("GPL"); |