[IPVS]: ip_vs_ftp breaks connections using persistence
ip_vs_ftp when loaded can create NAT connections with unknown client
port for passive FTP. For such expectations we lookup with cport=0 on
incoming packet but it matches the format of the persistence templates
causing packets to other persistent virtual servers to be forwarded to
real server without creating connection. Later the reply packets are
treated as foreign and not SNAT-ed.
This patch changes the connection lookup for packets from clients:
* introduce IP_VS_CONN_F_TEMPLATE connection flag to mark the
connection as template
* create new connection lookup function just for templates -
ip_vs_ct_in_get
* make sure ip_vs_conn_in_get hits only connections with
IP_VS_CONN_F_NO_CPORT flag set when s_port is 0. By this way
we avoid returning template when looking for cport=0 (ftp)
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index e426641..06b4235 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -84,6 +84,7 @@
#define IP_VS_CONN_F_IN_SEQ 0x0400 /* must do input seq adjust */
#define IP_VS_CONN_F_SEQ_MASK 0x0600 /* in/out sequence mask */
#define IP_VS_CONN_F_NO_CPORT 0x0800 /* no client port set yet */
+#define IP_VS_CONN_F_TEMPLATE 0x1000 /* template, not connection */
/* Move it to better place one day, for now keep it unique */
#define NFC_IPVS_PROPERTY 0x10000
@@ -739,6 +740,8 @@
extern struct ip_vs_conn *ip_vs_conn_in_get
(int protocol, __u32 s_addr, __u16 s_port, __u32 d_addr, __u16 d_port);
+extern struct ip_vs_conn *ip_vs_ct_in_get
+(int protocol, __u32 s_addr, __u16 s_port, __u32 d_addr, __u16 d_port);
extern struct ip_vs_conn *ip_vs_conn_out_get
(int protocol, __u32 s_addr, __u16 s_port, __u32 d_addr, __u16 d_port);
diff --git a/net/ipv4/ipvs/ip_vs_conn.c b/net/ipv4/ipvs/ip_vs_conn.c
index 5994521..f828fa2 100644
--- a/net/ipv4/ipvs/ip_vs_conn.c
+++ b/net/ipv4/ipvs/ip_vs_conn.c
@@ -196,6 +196,7 @@
list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
if (s_addr==cp->caddr && s_port==cp->cport &&
d_port==cp->vport && d_addr==cp->vaddr &&
+ ((!s_port) ^ (!(cp->flags & IP_VS_CONN_F_NO_CPORT))) &&
protocol==cp->protocol) {
/* HIT */
atomic_inc(&cp->refcnt);
@@ -227,6 +228,40 @@
return cp;
}
+/* Get reference to connection template */
+struct ip_vs_conn *ip_vs_ct_in_get
+(int protocol, __u32 s_addr, __u16 s_port, __u32 d_addr, __u16 d_port)
+{
+ unsigned hash;
+ struct ip_vs_conn *cp;
+
+ hash = ip_vs_conn_hashkey(protocol, s_addr, s_port);
+
+ ct_read_lock(hash);
+
+ list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
+ if (s_addr==cp->caddr && s_port==cp->cport &&
+ d_port==cp->vport && d_addr==cp->vaddr &&
+ cp->flags & IP_VS_CONN_F_TEMPLATE &&
+ protocol==cp->protocol) {
+ /* HIT */
+ atomic_inc(&cp->refcnt);
+ goto out;
+ }
+ }
+ cp = NULL;
+
+ out:
+ ct_read_unlock(hash);
+
+ IP_VS_DBG(7, "template lookup/in %s %u.%u.%u.%u:%d->%u.%u.%u.%u:%d %s\n",
+ ip_vs_proto_name(protocol),
+ NIPQUAD(s_addr), ntohs(s_port),
+ NIPQUAD(d_addr), ntohs(d_port),
+ cp?"hit":"not hit");
+
+ return cp;
+}
/*
* Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
@@ -367,7 +402,7 @@
atomic_read(&dest->refcnt));
/* Update the connection counters */
- if (cp->cport || (cp->flags & IP_VS_CONN_F_NO_CPORT)) {
+ if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
/* It is a normal connection, so increase the inactive
connection counter because it is in TCP SYNRECV
state (inactive) or other protocol inacive state */
@@ -406,7 +441,7 @@
atomic_read(&dest->refcnt));
/* Update the connection counters */
- if (cp->cport || (cp->flags & IP_VS_CONN_F_NO_CPORT)) {
+ if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
/* It is a normal connection, so decrease the inactconns
or activeconns counter */
if (cp->flags & IP_VS_CONN_F_INACTIVE) {
@@ -776,7 +811,7 @@
ct_write_lock_bh(hash);
list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
- if (!cp->cport && !(cp->flags & IP_VS_CONN_F_NO_CPORT))
+ if (cp->flags & IP_VS_CONN_F_TEMPLATE)
/* connection template */
continue;
diff --git a/net/ipv4/ipvs/ip_vs_core.c b/net/ipv4/ipvs/ip_vs_core.c
index 3ac7eec..981cc32 100644
--- a/net/ipv4/ipvs/ip_vs_core.c
+++ b/net/ipv4/ipvs/ip_vs_core.c
@@ -243,10 +243,10 @@
if (ports[1] == svc->port) {
/* Check if a template already exists */
if (svc->port != FTPPORT)
- ct = ip_vs_conn_in_get(iph->protocol, snet, 0,
+ ct = ip_vs_ct_in_get(iph->protocol, snet, 0,
iph->daddr, ports[1]);
else
- ct = ip_vs_conn_in_get(iph->protocol, snet, 0,
+ ct = ip_vs_ct_in_get(iph->protocol, snet, 0,
iph->daddr, 0);
if (!ct || !ip_vs_check_template(ct)) {
@@ -272,14 +272,14 @@
iph->daddr,
ports[1],
dest->addr, dest->port,
- 0,
+ IP_VS_CONN_F_TEMPLATE,
dest);
else
ct = ip_vs_conn_new(iph->protocol,
snet, 0,
iph->daddr, 0,
dest->addr, 0,
- 0,
+ IP_VS_CONN_F_TEMPLATE,
dest);
if (ct == NULL)
return NULL;
@@ -298,10 +298,10 @@
* port zero template: <protocol,caddr,0,vaddr,0,daddr,0>
*/
if (svc->fwmark)
- ct = ip_vs_conn_in_get(IPPROTO_IP, snet, 0,
+ ct = ip_vs_ct_in_get(IPPROTO_IP, snet, 0,
htonl(svc->fwmark), 0);
else
- ct = ip_vs_conn_in_get(iph->protocol, snet, 0,
+ ct = ip_vs_ct_in_get(iph->protocol, snet, 0,
iph->daddr, 0);
if (!ct || !ip_vs_check_template(ct)) {
@@ -326,14 +326,14 @@
snet, 0,
htonl(svc->fwmark), 0,
dest->addr, 0,
- 0,
+ IP_VS_CONN_F_TEMPLATE,
dest);
else
ct = ip_vs_conn_new(iph->protocol,
snet, 0,
iph->daddr, 0,
dest->addr, 0,
- 0,
+ IP_VS_CONN_F_TEMPLATE,
dest);
if (ct == NULL)
return NULL;
diff --git a/net/ipv4/ipvs/ip_vs_sync.c b/net/ipv4/ipvs/ip_vs_sync.c
index 574d1f5..2e5ced3 100644
--- a/net/ipv4/ipvs/ip_vs_sync.c
+++ b/net/ipv4/ipvs/ip_vs_sync.c
@@ -297,16 +297,24 @@
p = (char *)buffer + sizeof(struct ip_vs_sync_mesg);
for (i=0; i<m->nr_conns; i++) {
+ unsigned flags;
+
s = (struct ip_vs_sync_conn *)p;
- cp = ip_vs_conn_in_get(s->protocol,
- s->caddr, s->cport,
- s->vaddr, s->vport);
+ flags = ntohs(s->flags);
+ if (!(flags & IP_VS_CONN_F_TEMPLATE))
+ cp = ip_vs_conn_in_get(s->protocol,
+ s->caddr, s->cport,
+ s->vaddr, s->vport);
+ else
+ cp = ip_vs_ct_in_get(s->protocol,
+ s->caddr, s->cport,
+ s->vaddr, s->vport);
if (!cp) {
cp = ip_vs_conn_new(s->protocol,
s->caddr, s->cport,
s->vaddr, s->vport,
s->daddr, s->dport,
- ntohs(s->flags), NULL);
+ flags, NULL);
if (!cp) {
IP_VS_ERR("ip_vs_conn_new failed\n");
return;
@@ -315,11 +323,11 @@
} else if (!cp->dest) {
/* it is an entry created by the synchronization */
cp->state = ntohs(s->state);
- cp->flags = ntohs(s->flags) | IP_VS_CONN_F_HASHED;
+ cp->flags = flags | IP_VS_CONN_F_HASHED;
} /* Note that we don't touch its state and flags
if it is a normal entry. */
- if (ntohs(s->flags) & IP_VS_CONN_F_SEQ_MASK) {
+ if (flags & IP_VS_CONN_F_SEQ_MASK) {
opt = (struct ip_vs_sync_conn_options *)&s[1];
memcpy(&cp->in_seq, opt, sizeof(*opt));
p += FULL_CONN_SIZE;