#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
+#include <linux/ctype.h>
+#include <linux/inet.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/netfilter.h>
#include <net/ip_vs.h>
-#define SERVER_STRING "227 "
-#define CLIENT_STRING "PORT"
+#define SERVER_STRING_PASV "227 "
+#define CLIENT_STRING_PORT "PORT"
+#define SERVER_STRING_EPSV "229 "
+#define CLIENT_STRING_EPRT "EPRT"
+enum {
+ IP_VS_FTP_ACTIVE = 0,
+ IP_VS_FTP_PORT = 0,
+ IP_VS_FTP_PASV,
+ IP_VS_FTP_EPRT,
+ IP_VS_FTP_EPSV,
+};
/*
* List of ports (up to IP_VS_APP_MAX_PORTS) to be handled by helper
MODULE_PARM_DESC(ports, "Ports to monitor for FTP control commands");
-/* Dummy variable */
-static int ip_vs_ftp_pasv;
+static char *ip_vs_ftp_data_ptr(struct sk_buff *skb, struct ip_vs_iphdr *ipvsh)
+{
+ struct tcphdr *th = (struct tcphdr *)((char *)skb->data + ipvsh->len);
+
+ if ((th->doff << 2) < sizeof(struct tcphdr))
+ return NULL;
+ return (char *)th + (th->doff << 2);
+}
static int
ip_vs_ftp_init_conn(struct ip_vs_app *app, struct ip_vs_conn *cp)
}
-/*
- * Get <addr,port> from the string "xxx.xxx.xxx.xxx,ppp,ppp", started
- * with the "pattern", ignoring before "skip" and terminated with
- * the "term" character.
- * <addr,port> is in network order.
+/* Get <addr,port> from the string "xxx.xxx.xxx.xxx,ppp,ppp", started
+ * with the "pattern". <addr,port> is in network order.
+ * Parse extended format depending on ext. In this case addr can be pre-set.
*/
static int ip_vs_ftp_get_addrport(char *data, char *data_limit,
const char *pattern, size_t plen,
- char skip, char term,
- __be32 *addr, __be16 *port,
- char **start, char **end)
+ char skip, bool ext, int mode,
+ union nf_inet_addr *addr, __be16 *port,
+ __u16 af, char **start, char **end)
{
char *s, c;
unsigned char p[6];
+ char edelim;
+ __u16 hport;
int i = 0;
if (data_limit - data < plen) {
if (s == data_limit)
return -1;
if (!found) {
+ /* "(" is optional for non-extended format,
+ * so catch the start of IPv4 address
+ */
+ if (!ext && isdigit(*s))
+ break;
if (*s == skip)
found = 1;
} else if (*s != skip) {
}
}
}
+ /* Old IPv4-only format? */
+ if (!ext) {
+ p[0] = 0;
+ for (data = s; ; data++) {
+ if (data == data_limit)
+ return -1;
+ c = *data;
+ if (isdigit(c)) {
+ p[i] = p[i]*10 + c - '0';
+ } else if (c == ',' && i < 5) {
+ i++;
+ p[i] = 0;
+ } else {
+ /* unexpected character or terminator */
+ break;
+ }
+ }
- for (data = s; ; data++) {
- if (data == data_limit)
+ if (i != 5)
return -1;
- if (*data == term)
- break;
+
+ *start = s;
+ *end = data;
+ addr->ip = get_unaligned((__be32 *) p);
+ *port = get_unaligned((__be16 *) (p + 4));
+ return 1;
}
- *end = data;
+ if (s == data_limit)
+ return -1;
+ *start = s;
+ edelim = *s++;
+ if (edelim < 33 || edelim > 126)
+ return -1;
+ if (s == data_limit)
+ return -1;
+ if (*s == edelim) {
+ /* Address family is usually missing for EPSV response */
+ if (mode != IP_VS_FTP_EPSV)
+ return -1;
+ s++;
+ if (s == data_limit)
+ return -1;
+ /* Then address should be missing too */
+ if (*s != edelim)
+ return -1;
+ /* Caller can pre-set addr, if needed */
+ s++;
+ } else {
+ const char *ep;
- memset(p, 0, sizeof(p));
- for (data = s; ; data++) {
- c = *data;
- if (c == term)
- break;
- if (c >= '0' && c <= '9') {
- p[i] = p[i]*10 + c - '0';
- } else if (c == ',' && i < 5) {
- i++;
- } else {
- /* unexpected character */
+ /* We allow address only from same family */
+ if (af == AF_INET6 && *s != '2')
return -1;
+ if (af == AF_INET && *s != '1')
+ return -1;
+ s++;
+ if (s == data_limit)
+ return -1;
+ if (*s != edelim)
+ return -1;
+ s++;
+ if (s == data_limit)
+ return -1;
+ if (af == AF_INET6) {
+ if (in6_pton(s, data_limit - s, (u8 *)addr, edelim,
+ &ep) <= 0)
+ return -1;
+ } else {
+ if (in4_pton(s, data_limit - s, (u8 *)addr, edelim,
+ &ep) <= 0)
+ return -1;
}
+ s = (char *) ep;
+ if (s == data_limit)
+ return -1;
+ if (*s != edelim)
+ return -1;
+ s++;
}
-
- if (i != 5)
+ for (hport = 0; ; s++)
+ {
+ if (s == data_limit)
+ return -1;
+ if (!isdigit(*s))
+ break;
+ hport = hport * 10 + *s - '0';
+ }
+ if (s == data_limit || !hport || *s != edelim)
return -1;
-
- *start = s;
- *addr = get_unaligned((__be32 *) p);
- *port = get_unaligned((__be16 *) (p + 4));
+ s++;
+ *end = s;
+ *port = htons(hport);
return 1;
}
-/*
- * Look at outgoing ftp packets to catch the response to a PASV command
+/* Look at outgoing ftp packets to catch the response to a PASV/EPSV 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
* 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.
+ * The extended format for EPSV response provides usually only port:
+ * "229 Entering Extended Passive Mode (|||ppp|)"
*/
static int ip_vs_ftp_out(struct ip_vs_app *app, struct ip_vs_conn *cp,
- struct sk_buff *skb, int *diff)
+ struct sk_buff *skb, int *diff,
+ struct ip_vs_iphdr *ipvsh)
{
- struct iphdr *iph;
- struct tcphdr *th;
char *data, *data_limit;
char *start, *end;
union nf_inet_addr from;
*diff = 0;
-#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
-
/* Only useful for established sessions */
if (cp->state != IP_VS_TCP_S_ESTABLISHED)
return 1;
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);
+ if (cp->app_data == (void *) IP_VS_FTP_PASV) {
+ data = ip_vs_ftp_data_ptr(skb, ipvsh);
data_limit = skb_tail_pointer(skb);
+ if (!data || data >= data_limit)
+ return 1;
+
if (ip_vs_ftp_get_addrport(data, data_limit,
- SERVER_STRING,
- sizeof(SERVER_STRING)-1,
- '(', ')',
- &from.ip, &port,
+ SERVER_STRING_PASV,
+ sizeof(SERVER_STRING_PASV)-1,
+ '(', false, IP_VS_FTP_PASV,
+ &from, &port, cp->af,
&start, &end) != 1)
return 1;
- IP_VS_DBG(7, "PASV response (%pI4:%d) -> %pI4:%d detected\n",
+ IP_VS_DBG(7, "PASV response (%pI4:%u) -> %pI4:%u detected\n",
&from.ip, ntohs(port), &cp->caddr.ip, 0);
+ } else if (cp->app_data == (void *) IP_VS_FTP_EPSV) {
+ data = ip_vs_ftp_data_ptr(skb, ipvsh);
+ data_limit = skb_tail_pointer(skb);
- /*
- * Now update or create an connection entry for it
+ if (!data || data >= data_limit)
+ return 1;
+
+ /* Usually, data address is not specified but
+ * we support different address, so pre-set it.
*/
- {
- struct ip_vs_conn_param p;
- ip_vs_conn_fill_param(cp->ipvs, AF_INET,
- iph->protocol, &from, port,
- &cp->caddr, 0, &p);
- n_cp = ip_vs_conn_out_get(&p);
- }
- if (!n_cp) {
- struct ip_vs_conn_param p;
- ip_vs_conn_fill_param(cp->ipvs,
- AF_INET, IPPROTO_TCP, &cp->caddr,
- 0, &cp->vaddr, port, &p);
- /* As above, this is ipv4 only */
- n_cp = ip_vs_conn_new(&p, AF_INET, &from, port,
- IP_VS_CONN_F_NO_CPORT |
- IP_VS_CONN_F_NFCT,
- cp->dest, skb->mark);
- if (!n_cp)
- return 0;
+ from = cp->daddr;
+ if (ip_vs_ftp_get_addrport(data, data_limit,
+ SERVER_STRING_EPSV,
+ sizeof(SERVER_STRING_EPSV)-1,
+ '(', true, IP_VS_FTP_EPSV,
+ &from, &port, cp->af,
+ &start, &end) != 1)
+ return 1;
- /* add its controller */
- ip_vs_control_add(n_cp, cp);
- }
+ IP_VS_DBG_BUF(7, "EPSV response (%s:%u) -> %s:%u detected\n",
+ IP_VS_DBG_ADDR(cp->af, &from), ntohs(port),
+ IP_VS_DBG_ADDR(cp->af, &cp->caddr), 0);
+ } else {
+ return 1;
+ }
- /*
- * Replace the old passive address with the new one
- */
+ /* Now update or create a connection entry for it */
+ {
+ struct ip_vs_conn_param p;
+
+ ip_vs_conn_fill_param(cp->ipvs, cp->af,
+ ipvsh->protocol, &from, port,
+ &cp->caddr, 0, &p);
+ n_cp = ip_vs_conn_out_get(&p);
+ }
+ if (!n_cp) {
+ struct ip_vs_conn_param p;
+
+ ip_vs_conn_fill_param(cp->ipvs,
+ cp->af, ipvsh->protocol, &cp->caddr,
+ 0, &cp->vaddr, port, &p);
+ n_cp = ip_vs_conn_new(&p, cp->af, &from, port,
+ IP_VS_CONN_F_NO_CPORT |
+ IP_VS_CONN_F_NFCT,
+ cp->dest, skb->mark);
+ if (!n_cp)
+ return 0;
+
+ /* add its controller */
+ ip_vs_control_add(n_cp, cp);
+ }
+
+ /* Replace the old passive address with the new one */
+ if (cp->app_data == (void *) IP_VS_FTP_PASV) {
from.ip = n_cp->vaddr.ip;
port = n_cp->vport;
snprintf(buf, sizeof(buf), "%u,%u,%u,%u,%u,%u",
((unsigned char *)&from.ip)[3],
ntohs(port) >> 8,
ntohs(port) & 0xFF);
+ } else if (cp->app_data == (void *) IP_VS_FTP_EPSV) {
+ from = n_cp->vaddr;
+ port = n_cp->vport;
+ /* Only port, client will use VIP for the data connection */
+ snprintf(buf, sizeof(buf), "|||%u|",
+ ntohs(port));
+ } else {
+ *buf = 0;
+ }
+ buf_len = strlen(buf);
- buf_len = strlen(buf);
-
- ct = nf_ct_get(skb, &ctinfo);
- if (ct) {
- bool mangled;
-
- /* If mangling fails this function will return 0
- * which will cause the packet to be dropped.
- * Mangling can only fail under memory pressure,
- * hopefully it will succeed on the retransmitted
- * packet.
- */
- mangled = nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
- iph->ihl * 4,
- start - data,
- end - start,
- buf, buf_len);
- if (mangled) {
- ip_vs_nfct_expect_related(skb, ct, n_cp,
- IPPROTO_TCP, 0, 0);
- if (skb->ip_summed == CHECKSUM_COMPLETE)
- skb->ip_summed = CHECKSUM_UNNECESSARY;
- /* csum is updated */
- ret = 1;
- }
- }
+ ct = nf_ct_get(skb, &ctinfo);
+ if (ct) {
+ bool mangled;
- /*
- * Not setting 'diff' is intentional, otherwise the sequence
- * would be adjusted twice.
+ /* If mangling fails this function will return 0
+ * which will cause the packet to be dropped.
+ * Mangling can only fail under memory pressure,
+ * hopefully it will succeed on the retransmitted
+ * packet.
*/
-
- cp->app_data = NULL;
- ip_vs_tcp_conn_listen(n_cp);
- ip_vs_conn_put(n_cp);
- return ret;
+ mangled = nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
+ ipvsh->len,
+ start - data,
+ end - start,
+ buf, buf_len);
+ if (mangled) {
+ ip_vs_nfct_expect_related(skb, ct, n_cp,
+ ipvsh->protocol, 0, 0);
+ if (skb->ip_summed == CHECKSUM_COMPLETE)
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ /* csum is updated */
+ ret = 1;
+ }
}
- return 1;
+
+ /* Not setting 'diff' is intentional, otherwise the sequence
+ * would be adjusted twice.
+ */
+
+ cp->app_data = (void *) IP_VS_FTP_ACTIVE;
+ ip_vs_tcp_conn_listen(n_cp);
+ ip_vs_conn_put(n_cp);
+ return ret;
}
-/*
- * Look at incoming ftp packets to catch the PASV/PORT command
+/* Look at incoming ftp packets to catch the PASV/PORT/EPRT/EPSV command
* (outside-to-inside).
*
* The incoming packet having the PORT command should be something like
* 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.
+ * Extended format:
+ * "EPSV\r\n" when client requests server address from same family
+ * "EPSV 1\r\n" when client requests IPv4 server address
+ * "EPSV 2\r\n" when client requests IPv6 server address
+ * "EPSV ALL\r\n" - not supported
+ * EPRT with specified delimiter (ASCII 33..126), "|" by default:
+ * "EPRT |1|IPv4ADDR|PORT|\r\n" when client provides IPv4 addrport
+ * "EPRT |2|IPv6ADDR|PORT|\r\n" when client provides IPv6 addrport
*/
static int ip_vs_ftp_in(struct ip_vs_app *app, struct ip_vs_conn *cp,
- struct sk_buff *skb, int *diff)
+ struct sk_buff *skb, int *diff,
+ struct ip_vs_iphdr *ipvsh)
{
- struct iphdr *iph;
- struct tcphdr *th;
char *data, *data_start, *data_limit;
char *start, *end;
union nf_inet_addr to;
/* no diff required for incoming packets */
*diff = 0;
-#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
-
/* Only useful for established sessions */
if (cp->state != IP_VS_TCP_S_ESTABLISHED)
return 1;
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 = data_start = ip_vs_ftp_data_ptr(skb, ipvsh);
data_limit = skb_tail_pointer(skb);
+ if (!data || data >= data_limit)
+ return 1;
while (data <= data_limit - 6) {
- if (strncasecmp(data, "PASV\r\n", 6) == 0) {
+ if (cp->af == AF_INET &&
+ strncasecmp(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;
+ cp->app_data = (void *) IP_VS_FTP_PASV;
return 1;
}
+
+ /* EPSV or EPSV<space><net-prt> */
+ if (strncasecmp(data, "EPSV", 4) == 0 &&
+ (data[4] == ' ' || data[4] == '\r')) {
+ if (data[4] == ' ') {
+ char proto = data[5];
+
+ if (data > data_limit - 7 || data[6] != '\r')
+ return 1;
+
+#ifdef CONFIG_IP_VS_IPV6
+ if (cp->af == AF_INET6 && proto == '2') {
+ } else
+#endif
+ if (cp->af == AF_INET && proto == '1') {
+ } else {
+ return 1;
+ }
+ }
+ /* Extended Passive mode on */
+ IP_VS_DBG(7, "got EPSV at %td of %td\n",
+ data - data_start,
+ data_limit - data_start);
+ cp->app_data = (void *) IP_VS_FTP_EPSV;
+ return 1;
+ }
+
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)
+ if (cp->af == AF_INET &&
+ ip_vs_ftp_get_addrport(data_start, data_limit,
+ CLIENT_STRING_PORT,
+ sizeof(CLIENT_STRING_PORT)-1,
+ ' ', false, IP_VS_FTP_PORT,
+ &to, &port, cp->af,
+ &start, &end) == 1) {
+
+ IP_VS_DBG(7, "PORT %pI4:%u detected\n", &to.ip, ntohs(port));
+
+ /* Now update or create a connection entry for it */
+ IP_VS_DBG(7, "protocol %s %pI4:%u %pI4:%u\n",
+ ip_vs_proto_name(ipvsh->protocol),
+ &to.ip, ntohs(port), &cp->vaddr.ip,
+ ntohs(cp->vport)-1);
+ } else if (ip_vs_ftp_get_addrport(data_start, data_limit,
+ CLIENT_STRING_EPRT,
+ sizeof(CLIENT_STRING_EPRT)-1,
+ ' ', true, IP_VS_FTP_EPRT,
+ &to, &port, cp->af,
+ &start, &end) == 1) {
+
+ IP_VS_DBG_BUF(7, "EPRT %s:%u detected\n",
+ IP_VS_DBG_ADDR(cp->af, &to), ntohs(port));
+
+ /* Now update or create a connection entry for it */
+ IP_VS_DBG_BUF(7, "protocol %s %s:%u %s:%u\n",
+ ip_vs_proto_name(ipvsh->protocol),
+ IP_VS_DBG_ADDR(cp->af, &to), ntohs(port),
+ IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
+ ntohs(cp->vport)-1);
+ } else {
return 1;
-
- IP_VS_DBG(7, "PORT %pI4:%d detected\n", &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 %pI4:%d %pI4:%d\n",
- ip_vs_proto_name(iph->protocol),
- &to.ip, ntohs(port), &cp->vaddr.ip, 0);
+ cp->app_data = (void *) IP_VS_FTP_ACTIVE;
{
struct ip_vs_conn_param p;
- ip_vs_conn_fill_param(cp->ipvs, AF_INET,
- iph->protocol, &to, port, &cp->vaddr,
+ ip_vs_conn_fill_param(cp->ipvs, cp->af,
+ ipvsh->protocol, &to, port, &cp->vaddr,
htons(ntohs(cp->vport)-1), &p);
n_cp = ip_vs_conn_in_get(&p);
if (!n_cp) {
- /* This is ipv4 only */
- n_cp = ip_vs_conn_new(&p, AF_INET, &cp->daddr,
+ n_cp = ip_vs_conn_new(&p, cp->af, &cp->daddr,
htons(ntohs(cp->dport)-1),
IP_VS_CONN_F_NFCT, cp->dest,
skb->mark);
ret = register_ip_vs_app_inc(ipvs, app, app->protocol, ports[i]);
if (ret)
goto err_unreg;
- pr_info("%s: loaded support on port[%d] = %d\n",
+ pr_info("%s: loaded support on port[%d] = %u\n",
app->name, i, ports[i]);
}
return 0;
projects / linux.git / commitdiff