diff options
author | Julius Volz <juliusv@google.com> | 2008-09-19 12:32:57 +0200 |
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committer | Simon Horman <horms@verge.net.au> | 2008-10-07 08:38:24 +1100 |
commit | cb7f6a7b716e801097b564dec3ccb58d330aef56 (patch) | |
tree | 92fa8fa5381e04576c43eab88874ab54ea670767 /net/netfilter/ipvs/ip_vs_ftp.c | |
parent | 8d5803bf6fbe5264000afc8c34bff08e8ecc023b (diff) | |
download | op-kernel-dev-cb7f6a7b716e801097b564dec3ccb58d330aef56.zip op-kernel-dev-cb7f6a7b716e801097b564dec3ccb58d330aef56.tar.gz |
IPVS: Move IPVS to net/netfilter/ipvs
Since IPVS now has partial IPv6 support, this patch moves IPVS from
net/ipv4/ipvs to net/netfilter/ipvs. It's a result of:
$ git mv net/ipv4/ipvs net/netfilter
and adapting the relevant Kconfigs/Makefiles to the new path.
Signed-off-by: Julius Volz <juliusv@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Diffstat (limited to 'net/netfilter/ipvs/ip_vs_ftp.c')
-rw-r--r-- | net/netfilter/ipvs/ip_vs_ftp.c | 410 |
1 files changed, 410 insertions, 0 deletions
diff --git a/net/netfilter/ipvs/ip_vs_ftp.c b/net/netfilter/ipvs/ip_vs_ftp.c new file mode 100644 index 0000000..2e7dbd8 --- /dev/null +++ b/net/netfilter/ipvs/ip_vs_ftp.c @@ -0,0 +1,410 @@ +/* + * ip_vs_ftp.c: IPVS ftp application module + * + * Authors: Wensong Zhang <wensong@linuxvirtualserver.org> + * + * Changes: + * + * + * 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. + * + * Most code here is taken from ip_masq_ftp.c in kernel 2.2. The difference + * is that ip_vs_ftp module handles the reverse direction to ip_masq_ftp. + * + * IP_MASQ_FTP ftp masquerading module + * + * Version: @(#)ip_masq_ftp.c 0.04 02/05/96 + * + * Author: Wouter Gadeyne + * + */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/kernel.h> +#include <linux/skbuff.h> +#include <linux/in.h> +#include <linux/ip.h> +#include <linux/netfilter.h> +#include <net/protocol.h> +#include <net/tcp.h> +#include <asm/unaligned.h> + +#include <net/ip_vs.h> + + +#define SERVER_STRING "227 Entering Passive Mode (" +#define CLIENT_STRING "PORT " + + +/* + * List of ports (up to IP_VS_APP_MAX_PORTS) to be handled by helper + * First port is set to the default port. + */ +static unsigned short ports[IP_VS_APP_MAX_PORTS] = {21, 0}; +module_param_array(ports, ushort, NULL, 0); +MODULE_PARM_DESC(ports, "Ports to monitor for FTP control commands"); + + +/* Dummy variable */ +static int ip_vs_ftp_pasv; + + +static int +ip_vs_ftp_init_conn(struct ip_vs_app *app, struct ip_vs_conn *cp) +{ + return 0; +} + + +static int +ip_vs_ftp_done_conn(struct ip_vs_app *app, struct ip_vs_conn *cp) +{ + return 0; +} + + +/* + * Get <addr,port> from the string "xxx.xxx.xxx.xxx,ppp,ppp", started + * with the "pattern" and terminated with the "term" character. + * <addr,port> is in network order. + */ +static int ip_vs_ftp_get_addrport(char *data, char *data_limit, + const char *pattern, size_t plen, char term, + __be32 *addr, __be16 *port, + char **start, char **end) +{ + unsigned char p[6]; + int i = 0; + + if (data_limit - data < plen) { + /* check if there is partial match */ + if (strnicmp(data, pattern, data_limit - data) == 0) + return -1; + else + return 0; + } + + if (strnicmp(data, pattern, plen) != 0) { + return 0; + } + *start = data + plen; + + for (data = *start; *data != term; data++) { + if (data == data_limit) + return -1; + } + *end = data; + + memset(p, 0, sizeof(p)); + for (data = *start; data != *end; data++) { + if (*data >= '0' && *data <= '9') { + p[i] = p[i]*10 + *data - '0'; + } else if (*data == ',' && i < 5) { + i++; + } else { + /* unexpected character */ + return -1; + } + } + + if (i != 5) + return -1; + + *addr = get_unaligned((__be32 *)p); + *port = get_unaligned((__be16 *)(p + 4)); + return 1; +} + + +/* + * Look at outgoing ftp packets to catch the response to a PASV command + * from the server (inside-to-outside). + * When we see one, we build a connection entry with the client address, + * client port 0 (unknown at the moment), the server address and the + * server port. Mark the current connection entry as a control channel + * of the new entry. All this work is just to make the data connection + * can be scheduled to the right server later. + * + * The outgoing packet should be something like + * "227 Entering Passive Mode (xxx,xxx,xxx,xxx,ppp,ppp)". + * xxx,xxx,xxx,xxx is the server address, ppp,ppp is the server port number. + */ +static int ip_vs_ftp_out(struct ip_vs_app *app, struct ip_vs_conn *cp, + struct sk_buff *skb, int *diff) +{ + struct iphdr *iph; + struct tcphdr *th; + char *data, *data_limit; + char *start, *end; + union nf_inet_addr from; + __be16 port; + struct ip_vs_conn *n_cp; + char buf[24]; /* xxx.xxx.xxx.xxx,ppp,ppp\000 */ + unsigned buf_len; + int ret; + +#ifdef CONFIG_IP_VS_IPV6 + /* This application helper doesn't work with IPv6 yet, + * so turn this into a no-op for IPv6 packets + */ + if (cp->af == AF_INET6) + return 1; +#endif + + *diff = 0; + + /* Only useful for established sessions */ + if (cp->state != IP_VS_TCP_S_ESTABLISHED) + return 1; + + /* Linear packets are much easier to deal with. */ + if (!skb_make_writable(skb, skb->len)) + return 0; + + if (cp->app_data == &ip_vs_ftp_pasv) { + iph = ip_hdr(skb); + th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]); + data = (char *)th + (th->doff << 2); + data_limit = skb_tail_pointer(skb); + + if (ip_vs_ftp_get_addrport(data, data_limit, + SERVER_STRING, + sizeof(SERVER_STRING)-1, ')', + &from.ip, &port, + &start, &end) != 1) + return 1; + + IP_VS_DBG(7, "PASV response (%u.%u.%u.%u:%d) -> " + "%u.%u.%u.%u:%d detected\n", + NIPQUAD(from.ip), ntohs(port), + NIPQUAD(cp->caddr.ip), 0); + + /* + * Now update or create an connection entry for it + */ + n_cp = ip_vs_conn_out_get(AF_INET, iph->protocol, &from, port, + &cp->caddr, 0); + if (!n_cp) { + n_cp = ip_vs_conn_new(AF_INET, IPPROTO_TCP, + &cp->caddr, 0, + &cp->vaddr, port, + &from, port, + IP_VS_CONN_F_NO_CPORT, + cp->dest); + if (!n_cp) + return 0; + + /* add its controller */ + ip_vs_control_add(n_cp, cp); + } + + /* + * Replace the old passive address with the new one + */ + from.ip = n_cp->vaddr.ip; + port = n_cp->vport; + sprintf(buf, "%d,%d,%d,%d,%d,%d", NIPQUAD(from.ip), + (ntohs(port)>>8)&255, ntohs(port)&255); + buf_len = strlen(buf); + + /* + * Calculate required delta-offset to keep TCP happy + */ + *diff = buf_len - (end-start); + + if (*diff == 0) { + /* simply replace it with new passive address */ + memcpy(start, buf, buf_len); + ret = 1; + } else { + ret = !ip_vs_skb_replace(skb, GFP_ATOMIC, start, + end-start, buf, buf_len); + } + + cp->app_data = NULL; + ip_vs_tcp_conn_listen(n_cp); + ip_vs_conn_put(n_cp); + return ret; + } + return 1; +} + + +/* + * Look at incoming ftp packets to catch the PASV/PORT command + * (outside-to-inside). + * + * The incoming packet having the PORT command should be something like + * "PORT xxx,xxx,xxx,xxx,ppp,ppp\n". + * xxx,xxx,xxx,xxx is the client address, ppp,ppp is the client port number. + * In this case, we create a connection entry using the client address and + * port, so that the active ftp data connection from the server can reach + * the client. + */ +static int ip_vs_ftp_in(struct ip_vs_app *app, struct ip_vs_conn *cp, + struct sk_buff *skb, int *diff) +{ + struct iphdr *iph; + struct tcphdr *th; + char *data, *data_start, *data_limit; + char *start, *end; + union nf_inet_addr to; + __be16 port; + struct ip_vs_conn *n_cp; + +#ifdef CONFIG_IP_VS_IPV6 + /* This application helper doesn't work with IPv6 yet, + * so turn this into a no-op for IPv6 packets + */ + if (cp->af == AF_INET6) + return 1; +#endif + + /* no diff required for incoming packets */ + *diff = 0; + + /* Only useful for established sessions */ + if (cp->state != IP_VS_TCP_S_ESTABLISHED) + return 1; + + /* Linear packets are much easier to deal with. */ + if (!skb_make_writable(skb, skb->len)) + return 0; + + /* + * Detecting whether it is passive + */ + iph = ip_hdr(skb); + th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]); + + /* Since there may be OPTIONS in the TCP packet and the HLEN is + the length of the header in 32-bit multiples, it is accurate + to calculate data address by th+HLEN*4 */ + data = data_start = (char *)th + (th->doff << 2); + data_limit = skb_tail_pointer(skb); + + while (data <= data_limit - 6) { + if (strnicmp(data, "PASV\r\n", 6) == 0) { + /* Passive mode on */ + IP_VS_DBG(7, "got PASV at %td of %td\n", + data - data_start, + data_limit - data_start); + cp->app_data = &ip_vs_ftp_pasv; + return 1; + } + data++; + } + + /* + * To support virtual FTP server, the scenerio is as follows: + * FTP client ----> Load Balancer ----> FTP server + * First detect the port number in the application data, + * then create a new connection entry for the coming data + * connection. + */ + if (ip_vs_ftp_get_addrport(data_start, data_limit, + CLIENT_STRING, sizeof(CLIENT_STRING)-1, + '\r', &to.ip, &port, + &start, &end) != 1) + return 1; + + IP_VS_DBG(7, "PORT %u.%u.%u.%u:%d detected\n", + NIPQUAD(to.ip), ntohs(port)); + + /* Passive mode off */ + cp->app_data = NULL; + + /* + * Now update or create a connection entry for it + */ + IP_VS_DBG(7, "protocol %s %u.%u.%u.%u:%d %u.%u.%u.%u:%d\n", + ip_vs_proto_name(iph->protocol), + NIPQUAD(to.ip), ntohs(port), NIPQUAD(cp->vaddr.ip), 0); + + n_cp = ip_vs_conn_in_get(AF_INET, iph->protocol, + &to, port, + &cp->vaddr, htons(ntohs(cp->vport)-1)); + if (!n_cp) { + n_cp = ip_vs_conn_new(AF_INET, IPPROTO_TCP, + &to, port, + &cp->vaddr, htons(ntohs(cp->vport)-1), + &cp->daddr, htons(ntohs(cp->dport)-1), + 0, + cp->dest); + if (!n_cp) + return 0; + + /* add its controller */ + ip_vs_control_add(n_cp, cp); + } + + /* + * Move tunnel to listen state + */ + ip_vs_tcp_conn_listen(n_cp); + ip_vs_conn_put(n_cp); + + return 1; +} + + +static struct ip_vs_app ip_vs_ftp = { + .name = "ftp", + .type = IP_VS_APP_TYPE_FTP, + .protocol = IPPROTO_TCP, + .module = THIS_MODULE, + .incs_list = LIST_HEAD_INIT(ip_vs_ftp.incs_list), + .init_conn = ip_vs_ftp_init_conn, + .done_conn = ip_vs_ftp_done_conn, + .bind_conn = NULL, + .unbind_conn = NULL, + .pkt_out = ip_vs_ftp_out, + .pkt_in = ip_vs_ftp_in, +}; + + +/* + * ip_vs_ftp initialization + */ +static int __init ip_vs_ftp_init(void) +{ + int i, ret; + struct ip_vs_app *app = &ip_vs_ftp; + + ret = register_ip_vs_app(app); + if (ret) + return ret; + + for (i=0; i<IP_VS_APP_MAX_PORTS; i++) { + if (!ports[i]) + continue; + ret = register_ip_vs_app_inc(app, app->protocol, ports[i]); + if (ret) + break; + IP_VS_INFO("%s: loaded support on port[%d] = %d\n", + app->name, i, ports[i]); + } + + if (ret) + unregister_ip_vs_app(app); + + return ret; +} + + +/* + * ip_vs_ftp finish. + */ +static void __exit ip_vs_ftp_exit(void) +{ + unregister_ip_vs_app(&ip_vs_ftp); +} + + +module_init(ip_vs_ftp_init); +module_exit(ip_vs_ftp_exit); +MODULE_LICENSE("GPL"); |