1 files changed, 305 insertions, 162 deletions

diff --git a/net/netfilter/ipvs/ip_vs_ftp.c b/net/netfilter/ipvs/ip_vs_ftp.c
index 58d5d05aec24..4398a72edec5 100644
--- a/net/netfilter/ipvs/ip_vs_ftp.c
+++ b/net/netfilter/ipvs/ip_vs_ftp.c
@@ -29,6 +29,8 @@
 #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>
@@ -44,9 +46,18 @@
 #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
@@ -58,9 +69,15 @@ module_param_array(ports, ushort, &ports_count, 0444);
 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)
@@ -78,20 +95,20 @@ ip_vs_ftp_done_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) {
@@ -113,6 +130,11 @@ static int ip_vs_ftp_get_addrport(char *data, char *data_limit,
 			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) {
@@ -120,41 +142,102 @@ static int ip_vs_ftp_get_addrport(char *data, char *data_limit,
 			}
 		}
 	}
+	/* 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
@@ -165,12 +248,13 @@ static int ip_vs_ftp_get_addrport(char *data, char *data_limit,
  * 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;
@@ -184,14 +268,6 @@ static int ip_vs_ftp_out(struct ip_vs_app *app, struct ip_vs_conn *cp,
 
 	*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;
@@ -200,53 +276,77 @@ static int ip_vs_ftp_out(struct ip_vs_app *app, struct ip_vs_conn *cp,
 	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",
@@ -256,50 +356,54 @@ static int ip_vs_ftp_out(struct ip_vs_app *app, struct ip_vs_conn *cp,
 			 ((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
@@ -308,12 +412,19 @@ static int ip_vs_ftp_out(struct ip_vs_app *app, struct ip_vs_conn *cp,
  * 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;
@@ -323,14 +434,6 @@ static int ip_vs_ftp_in(struct ip_vs_app *app, struct ip_vs_conn *cp,
 	/* 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;
@@ -339,27 +442,48 @@ static int ip_vs_ftp_in(struct ip_vs_app *app, struct ip_vs_conn *cp,
 	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++;
 	}
 
@@ -370,33 +494,52 @@ static int ip_vs_ftp_in(struct ip_vs_app *app, struct ip_vs_conn *cp,
 	 * 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);
@@ -454,7 +597,7 @@ static int __net_init __ip_vs_ftp_init(struct net *net)
 		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;