/*
* Process received multicast message and create the corresponding
* ip_vs_conn entries.
*/
static void ip_vs_process_message(const char *buffer, const size_t buflen)
{
struct ip_vs_sync_mesg *m = (struct ip_vs_sync_mesg *)buffer;
struct ip_vs_sync_conn *s;
struct ip_vs_sync_conn_options *opt;
struct ip_vs_conn *cp;
char *p;
int i;
if (buflen != m->size) {
IP_VS_ERR("bogus message\n");
return;
}
p = (char *)buffer + sizeof(struct ip_vs_sync_mesg);
for (i=0; i<m->nr_conns; i++) {
s = (struct ip_vs_sync_conn *)p;
cp = ip_vs_conn_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);
if (!cp) {
IP_VS_ERR("ip_vs_conn_new failed\n");
return;
}
cp->state = ntohs(s->state);
} 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;
} /* 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) {
opt = (struct ip_vs_sync_conn_options *)&s[1];
memcpy(&cp->in_seq, opt, sizeof(*opt));
p += FULL_CONN_SIZE;
} else
p += SIMPLE_CONN_SIZE;
atomic_set(&cp->in_pkts, sysctl_ip_vs_sync_threshold);
cp->timeout = IP_VS_SYNC_CONN_TIMEOUT;
ip_vs_conn_put(cp);
if (p > buffer+buflen) {
IP_VS_ERR("bogus message\n");
return;
}
}
}
/*
* 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 = 0;
enum ip_conntrack_info ctinfo;
struct nf_conn *ct;
struct net *net;
#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 (%pI4:%d) -> %pI4:%d detected\n",
&from.ip, ntohs(port), &cp->caddr.ip, 0);
/*
* Now update or create an connection entry for it
*/
{
struct ip_vs_conn_param p;
ip_vs_conn_fill_param(ip_vs_conn_net(cp), 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(ip_vs_conn_net(cp),
AF_INET, IPPROTO_TCP, &cp->caddr,
0, &cp->vaddr, port, &p);
n_cp = ip_vs_conn_new(&p, &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
*/
from.ip = n_cp->vaddr.ip;
port = n_cp->vport;
snprintf(buf, sizeof(buf), "%u,%u,%u,%u,%u,%u",
((unsigned char *)&from.ip)[0],
((unsigned char *)&from.ip)[1],
((unsigned char *)&from.ip)[2],
((unsigned char *)&from.ip)[3],
ntohs(port) >> 8,
ntohs(port) & 0xFF);
buf_len = strlen(buf);
ct = nf_ct_get(skb, &ctinfo);
if (ct && !nf_ct_is_untracked(ct) && nfct_nat(ct)) {
/* 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.
*/
ret = nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
start-data, end-start,
buf, buf_len);
if (ret) {
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;
}
}
/*
* Not setting 'diff' is intentional, otherwise the sequence
* would be adjusted twice.
*/
net = skb_net(skb);
cp->app_data = NULL;
ip_vs_tcp_conn_listen(net, n_cp);
ip_vs_conn_put(n_cp);
return ret;
}
/*
* Check if it's for virtual services, look it up,
* and send it on its way...
*/
static unsigned int
ip_vs_in(unsigned int hooknum, struct sk_buff **pskb,
const struct net_device *in, const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
struct sk_buff *skb = *pskb;
struct iphdr *iph;
struct ip_vs_protocol *pp;
struct ip_vs_conn *cp;
int ret, restart;
int ihl;
/*
* Big tappo: only PACKET_HOST (neither loopback nor mcasts)
* ... don't know why 1st test DOES NOT include 2nd (?)
*/
if (unlikely(skb->pkt_type != PACKET_HOST
|| skb->dev == &loopback_dev || skb->sk)) {
IP_VS_DBG(12, "packet type=%d proto=%d daddr=%d.%d.%d.%d ignored\n",
skb->pkt_type,
ip_hdr(skb)->protocol,
NIPQUAD(ip_hdr(skb)->daddr));
return NF_ACCEPT;
}
iph = ip_hdr(skb);
if (unlikely(iph->protocol == IPPROTO_ICMP)) {
int related, verdict = ip_vs_in_icmp(pskb, &related, hooknum);
if (related)
return verdict;
skb = *pskb;
iph = ip_hdr(skb);
}
/* Protocol supported? */
pp = ip_vs_proto_get(iph->protocol);
if (unlikely(!pp))
return NF_ACCEPT;
ihl = iph->ihl << 2;
/*
* Check if the packet belongs to an existing connection entry
*/
cp = pp->conn_in_get(skb, pp, iph, ihl, 0);
if (unlikely(!cp)) {
int v;
if (!pp->conn_schedule(skb, pp, &v, &cp))
return v;
}
if (unlikely(!cp)) {
/* sorry, all this trouble for a no-hit :) */
IP_VS_DBG_PKT(12, pp, skb, 0,
"packet continues traversal as normal");
return NF_ACCEPT;
}
IP_VS_DBG_PKT(11, pp, skb, 0, "Incoming packet");
/* Check the server status */
if (cp->dest && !(cp->dest->flags & IP_VS_DEST_F_AVAILABLE)) {
/* the destination server is not available */
if (sysctl_ip_vs_expire_nodest_conn) {
/* try to expire the connection immediately */
ip_vs_conn_expire_now(cp);
}
/* don't restart its timer, and silently
drop the packet. */
__ip_vs_conn_put(cp);
return NF_DROP;
}
ip_vs_in_stats(cp, skb);
restart = ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pp);
if (cp->packet_xmit)
ret = cp->packet_xmit(skb, cp, pp);
/* do not touch skb anymore */
else {
IP_VS_DBG_RL("warning: packet_xmit is null");
ret = NF_ACCEPT;
}
/* increase its packet counter and check if it is needed
to be synchronized */
atomic_inc(&cp->in_pkts);
if ((ip_vs_sync_state & IP_VS_STATE_MASTER) &&
(cp->protocol != IPPROTO_TCP ||
cp->state == IP_VS_TCP_S_ESTABLISHED) &&
(atomic_read(&cp->in_pkts) % sysctl_ip_vs_sync_threshold[1]
== sysctl_ip_vs_sync_threshold[0]))
ip_vs_sync_conn(cp);
ip_vs_conn_put(cp);
return ret;
}
/*
* It is hooked at the NF_IP_FORWARD chain, used only for VS/NAT.
* Check if outgoing packet belongs to the established ip_vs_conn,
* rewrite addresses of the packet and send it on its way...
*/
static unsigned int
ip_vs_out(unsigned int hooknum, struct sk_buff **pskb,
const struct net_device *in, const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
struct sk_buff *skb = *pskb;
struct iphdr *iph;
struct ip_vs_protocol *pp;
struct ip_vs_conn *cp;
int ihl;
EnterFunction(11);
if (skb->ipvs_property)
return NF_ACCEPT;
iph = ip_hdr(skb);
if (unlikely(iph->protocol == IPPROTO_ICMP)) {
int related, verdict = ip_vs_out_icmp(pskb, &related);
if (related)
return verdict;
skb = *pskb;
iph = ip_hdr(skb);
}
pp = ip_vs_proto_get(iph->protocol);
if (unlikely(!pp))
return NF_ACCEPT;
/* reassemble IP fragments */
if (unlikely(iph->frag_off & htons(IP_MF|IP_OFFSET) &&
!pp->dont_defrag)) {
skb = ip_vs_gather_frags(skb, IP_DEFRAG_VS_OUT);
if (!skb)
return NF_STOLEN;
iph = ip_hdr(skb);
*pskb = skb;
}
ihl = iph->ihl << 2;
/*
* Check if the packet belongs to an existing entry
*/
cp = pp->conn_out_get(skb, pp, iph, ihl, 0);
if (unlikely(!cp)) {
if (sysctl_ip_vs_nat_icmp_send &&
(pp->protocol == IPPROTO_TCP ||
pp->protocol == IPPROTO_UDP)) {
__be16 _ports[2], *pptr;
pptr = skb_header_pointer(skb, ihl,
sizeof(_ports), _ports);
if (pptr == NULL)
return NF_ACCEPT; /* Not for me */
if (ip_vs_lookup_real_service(iph->protocol,
iph->saddr, pptr[0])) {
/*
* Notify the real server: there is no
* existing entry if it is not RST
* packet or not TCP packet.
*/
if (iph->protocol != IPPROTO_TCP
|| !is_tcp_reset(skb)) {
icmp_send(skb,ICMP_DEST_UNREACH,
ICMP_PORT_UNREACH, 0);
return NF_DROP;
}
}
}
IP_VS_DBG_PKT(12, pp, skb, 0,
"packet continues traversal as normal");
return NF_ACCEPT;
}
IP_VS_DBG_PKT(11, pp, skb, 0, "Outgoing packet");
if (!ip_vs_make_skb_writable(pskb, ihl))
goto drop;
/* mangle the packet */
if (pp->snat_handler && !pp->snat_handler(pskb, pp, cp))
goto drop;
skb = *pskb;
ip_hdr(skb)->saddr = cp->vaddr;
ip_send_check(ip_hdr(skb));
/* For policy routing, packets originating from this
* machine itself may be routed differently to packets
* passing through. We want this packet to be routed as
* if it came from this machine itself. So re-compute
* the routing information.
*/
if (ip_route_me_harder(pskb, RTN_LOCAL) != 0)
goto drop;
skb = *pskb;
IP_VS_DBG_PKT(10, pp, skb, 0, "After SNAT");
ip_vs_out_stats(cp, skb);
ip_vs_set_state(cp, IP_VS_DIR_OUTPUT, skb, pp);
ip_vs_conn_put(cp);
skb->ipvs_property = 1;
LeaveFunction(11);
return NF_ACCEPT;
drop:
ip_vs_conn_put(cp);
kfree_skb(*pskb);
return NF_STOLEN;
}
/*
* Pass or drop the packet.
* Called by ip_vs_in, when the virtual service is available but
* no destination is available for a new connection.
*/
int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
struct ip_vs_protocol *pp)
{
__be16 _ports[2], *pptr;
struct iphdr *iph = ip_hdr(skb);
pptr = skb_header_pointer(skb, iph->ihl*4,
sizeof(_ports), _ports);
if (pptr == NULL) {
ip_vs_service_put(svc);
return NF_DROP;
}
/* if it is fwmark-based service, the cache_bypass sysctl is up
and the destination is RTN_UNICAST (and not local), then create
a cache_bypass connection entry */
if (sysctl_ip_vs_cache_bypass && svc->fwmark
&& (inet_addr_type(iph->daddr) == RTN_UNICAST)) {
int ret, cs;
struct ip_vs_conn *cp;
ip_vs_service_put(svc);
/* create a new connection entry */
IP_VS_DBG(6, "ip_vs_leave: create a cache_bypass entry\n");
cp = ip_vs_conn_new(iph->protocol,
iph->saddr, pptr[0],
iph->daddr, pptr[1],
0, 0,
IP_VS_CONN_F_BYPASS,
NULL);
if (cp == NULL)
return NF_DROP;
/* statistics */
ip_vs_in_stats(cp, skb);
/* set state */
cs = ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pp);
/* transmit the first SYN packet */
ret = cp->packet_xmit(skb, cp, pp);
/* do not touch skb anymore */
atomic_inc(&cp->in_pkts);
ip_vs_conn_put(cp);
return ret;
}
/*
* When the virtual ftp service is presented, packets destined
* for other services on the VIP may get here (except services
* listed in the ipvs table), pass the packets, because it is
* not ipvs job to decide to drop the packets.
*/
if ((svc->port == FTPPORT) && (pptr[1] != FTPPORT)) {
ip_vs_service_put(svc);
return NF_ACCEPT;
}
ip_vs_service_put(svc);
/*
* Notify the client that the destination is unreachable, and
* release the socket buffer.
* Since it is in IP layer, the TCP socket is not actually
* created, the TCP RST packet cannot be sent, instead that
* ICMP_PORT_UNREACH is sent here no matter it is TCP/UDP. --WZ
*/
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
return NF_DROP;
}
/*
* IPVS persistent scheduling function
* It creates a connection entry according to its template if exists,
* or selects a server and creates a connection entry plus a template.
* Locking: we are svc user (svc->refcnt), so we hold all dests too
* Protocols supported: TCP, UDP
*/
static struct ip_vs_conn *
ip_vs_sched_persist(struct ip_vs_service *svc,
const struct sk_buff *skb,
__be16 ports[2])
{
struct ip_vs_conn *cp = NULL;
struct iphdr *iph = ip_hdr(skb);
struct ip_vs_dest *dest;
struct ip_vs_conn *ct;
__be16 dport; /* destination port to forward */
__be32 snet; /* source network of the client, after masking */
/* Mask saddr with the netmask to adjust template granularity */
snet = iph->saddr & svc->netmask;
IP_VS_DBG(6, "p-schedule: src %u.%u.%u.%u:%u dest %u.%u.%u.%u:%u "
"mnet %u.%u.%u.%u\n",
NIPQUAD(iph->saddr), ntohs(ports[0]),
NIPQUAD(iph->daddr), ntohs(ports[1]),
NIPQUAD(snet));
/*
* As far as we know, FTP is a very complicated network protocol, and
* it uses control connection and data connections. For active FTP,
* FTP server initialize data connection to the client, its source port
* is often 20. For passive FTP, FTP server tells the clients the port
* that it passively listens to, and the client issues the data
* connection. In the tunneling or direct routing mode, the load
* balancer is on the client-to-server half of connection, the port
* number is unknown to the load balancer. So, a conn template like
* <caddr, 0, vaddr, 0, daddr, 0> is created for persistent FTP
* service, and a template like <caddr, 0, vaddr, vport, daddr, dport>
* is created for other persistent services.
*/
if (ports[1] == svc->port) {
/* Check if a template already exists */
if (svc->port != FTPPORT)
ct = ip_vs_ct_in_get(iph->protocol, snet, 0,
iph->daddr, ports[1]);
else
ct = ip_vs_ct_in_get(iph->protocol, snet, 0,
iph->daddr, 0);
if (!ct || !ip_vs_check_template(ct)) {
/*
* No template found or the dest of the connection
* template is not available.
*/
dest = svc->scheduler->schedule(svc, skb);
if (dest == NULL) {
IP_VS_DBG(1, "p-schedule: no dest found.\n");
return NULL;
}
/*
* Create a template like <protocol,caddr,0,
* vaddr,vport,daddr,dport> for non-ftp service,
* and <protocol,caddr,0,vaddr,0,daddr,0>
* for ftp service.
*/
if (svc->port != FTPPORT)
ct = ip_vs_conn_new(iph->protocol,
snet, 0,
iph->daddr,
ports[1],
dest->addr, dest->port,
IP_VS_CONN_F_TEMPLATE,
dest);
else
ct = ip_vs_conn_new(iph->protocol,
snet, 0,
iph->daddr, 0,
dest->addr, 0,
IP_VS_CONN_F_TEMPLATE,
dest);
if (ct == NULL)
return NULL;
ct->timeout = svc->timeout;
} else {
/* set destination with the found template */
dest = ct->dest;
}
dport = dest->port;
} else {
/*
* Note: persistent fwmark-based services and persistent
* port zero service are handled here.
* fwmark template: <IPPROTO_IP,caddr,0,fwmark,0,daddr,0>
* port zero template: <protocol,caddr,0,vaddr,0,daddr,0>
*/
if (svc->fwmark)
ct = ip_vs_ct_in_get(IPPROTO_IP, snet, 0,
htonl(svc->fwmark), 0);
else
ct = ip_vs_ct_in_get(iph->protocol, snet, 0,
iph->daddr, 0);
if (!ct || !ip_vs_check_template(ct)) {
/*
* If it is not persistent port zero, return NULL,
* otherwise create a connection template.
*/
if (svc->port)
return NULL;
dest = svc->scheduler->schedule(svc, skb);
if (dest == NULL) {
IP_VS_DBG(1, "p-schedule: no dest found.\n");
return NULL;
}
/*
* Create a template according to the service
*/
if (svc->fwmark)
ct = ip_vs_conn_new(IPPROTO_IP,
snet, 0,
htonl(svc->fwmark), 0,
dest->addr, 0,
IP_VS_CONN_F_TEMPLATE,
dest);
else
ct = ip_vs_conn_new(iph->protocol,
snet, 0,
iph->daddr, 0,
dest->addr, 0,
IP_VS_CONN_F_TEMPLATE,
dest);
if (ct == NULL)
return NULL;
ct->timeout = svc->timeout;
} else {
/* set destination with the found template */
dest = ct->dest;
}
dport = ports[1];
}
/*
* Create a new connection according to the template
*/
cp = ip_vs_conn_new(iph->protocol,
iph->saddr, ports[0],
iph->daddr, ports[1],
dest->addr, dport,
0,
dest);
if (cp == NULL) {
ip_vs_conn_put(ct);
return NULL;
}
/*
* Add its control
*/
ip_vs_control_add(cp, ct);
ip_vs_conn_put(ct);
ip_vs_conn_stats(cp, svc);
return cp;
}
/*
* 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;
}
/*
* IPVS persistent scheduling function
* It creates a connection entry according to its template if exists,
* or selects a server and creates a connection entry plus a template.
* Locking: we are svc user (svc->refcnt), so we hold all dests too
* Protocols supported: TCP, UDP
*/
static struct ip_vs_conn *
ip_vs_sched_persist(struct ip_vs_service *svc,
struct sk_buff *skb, __be16 src_port, __be16 dst_port,
int *ignored, struct ip_vs_iphdr *iph)
{
struct ip_vs_conn *cp = NULL;
struct ip_vs_dest *dest;
struct ip_vs_conn *ct;
__be16 dport = 0; /* destination port to forward */
unsigned int flags;
struct ip_vs_conn_param param;
const union nf_inet_addr fwmark = { .ip = htonl(svc->fwmark) };
union nf_inet_addr snet; /* source network of the client,
after masking */
/* Mask saddr with the netmask to adjust template granularity */
#ifdef CONFIG_IP_VS_IPV6
if (svc->af == AF_INET6)
ipv6_addr_prefix(&snet.in6, &iph->saddr.in6,
(__force __u32) svc->netmask);
else
#endif
snet.ip = iph->saddr.ip & svc->netmask;
IP_VS_DBG_BUF(6, "p-schedule: src %s:%u dest %s:%u "
"mnet %s\n",
IP_VS_DBG_ADDR(svc->af, &iph->saddr), ntohs(src_port),
IP_VS_DBG_ADDR(svc->af, &iph->daddr), ntohs(dst_port),
IP_VS_DBG_ADDR(svc->af, &snet));
/*
* As far as we know, FTP is a very complicated network protocol, and
* it uses control connection and data connections. For active FTP,
* FTP server initialize data connection to the client, its source port
* is often 20. For passive FTP, FTP server tells the clients the port
* that it passively listens to, and the client issues the data
* connection. In the tunneling or direct routing mode, the load
* balancer is on the client-to-server half of connection, the port
* number is unknown to the load balancer. So, a conn template like
* <caddr, 0, vaddr, 0, daddr, 0> is created for persistent FTP
* service, and a template like <caddr, 0, vaddr, vport, daddr, dport>
* is created for other persistent services.
*/
{
int protocol = iph->protocol;
const union nf_inet_addr *vaddr = &iph->daddr;
__be16 vport = 0;
if (dst_port == svc->port) {
/* non-FTP template:
* <protocol, caddr, 0, vaddr, vport, daddr, dport>
* FTP template:
* <protocol, caddr, 0, vaddr, 0, daddr, 0>
*/
if (svc->port != FTPPORT)
vport = dst_port;
} else {
/* Note: persistent fwmark-based services and
* persistent port zero service are handled here.
* fwmark template:
* <IPPROTO_IP,caddr,0,fwmark,0,daddr,0>
* port zero template:
* <protocol,caddr,0,vaddr,0,daddr,0>
*/
if (svc->fwmark) {
protocol = IPPROTO_IP;
vaddr = &fwmark;
}
}
/* return *ignored = -1 so NF_DROP can be used */
if (ip_vs_conn_fill_param_persist(svc, skb, protocol, &snet, 0,
vaddr, vport, ¶m) < 0) {
*ignored = -1;
return NULL;
}
}
/* Check if a template already exists */
ct = ip_vs_ct_in_get(¶m);
if (!ct || !ip_vs_check_template(ct)) {
struct ip_vs_scheduler *sched;
/*
* No template found or the dest of the connection
* template is not available.
* return *ignored=0 i.e. ICMP and NF_DROP
*/
sched = rcu_dereference(svc->scheduler);
if (sched) {
/* read svc->sched_data after svc->scheduler */
smp_rmb();
dest = sched->schedule(svc, skb, iph);
} else {
dest = NULL;
}
if (!dest) {
IP_VS_DBG(1, "p-schedule: no dest found.\n");
kfree(param.pe_data);
*ignored = 0;
return NULL;
}
if (dst_port == svc->port && svc->port != FTPPORT)
dport = dest->port;
/* Create a template
* This adds param.pe_data to the template,
* and thus param.pe_data will be destroyed
* when the template expires */
ct = ip_vs_conn_new(¶m, dest->af, &dest->addr, dport,
IP_VS_CONN_F_TEMPLATE, dest, skb->mark);
if (ct == NULL) {
kfree(param.pe_data);
*ignored = -1;
return NULL;
}
ct->timeout = svc->timeout;
} else {
/* set destination with the found template */
dest = ct->dest;
kfree(param.pe_data);
}
dport = dst_port;
if (dport == svc->port && dest->port)
dport = dest->port;
flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
&& iph->protocol == IPPROTO_UDP) ?
IP_VS_CONN_F_ONE_PACKET : 0;
/*
* Create a new connection according to the template
*/
ip_vs_conn_fill_param(svc->net, svc->af, iph->protocol, &iph->saddr,
src_port, &iph->daddr, dst_port, ¶m);
cp = ip_vs_conn_new(¶m, dest->af, &dest->addr, dport, flags, dest,
skb->mark);
if (cp == NULL) {
ip_vs_conn_put(ct);
*ignored = -1;
return NULL;
}
/*
* Add its control
*/
ip_vs_control_add(cp, ct);
ip_vs_conn_put(ct);
ip_vs_conn_stats(cp, svc);
return cp;
}
/*
* IPVS main scheduling function
* It selects a server according to the virtual service, and
* creates a connection entry.
* Protocols supported: TCP, UDP
*
* Usage of *ignored
*
* 1 : protocol tried to schedule (eg. on SYN), found svc but the
* svc/scheduler decides that this packet should be accepted with
* NF_ACCEPT because it must not be scheduled.
*
* 0 : scheduler can not find destination, so try bypass or
* return ICMP and then NF_DROP (ip_vs_leave).
*
* -1 : scheduler tried to schedule but fatal error occurred, eg.
* ip_vs_conn_new failure (ENOMEM) or ip_vs_sip_fill_param
* failure such as missing Call-ID, ENOMEM on skb_linearize
* or pe_data. In this case we should return NF_DROP without
* any attempts to send ICMP with ip_vs_leave.
*/
struct ip_vs_conn *
ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
struct ip_vs_proto_data *pd, int *ignored,
struct ip_vs_iphdr *iph)
{
struct ip_vs_protocol *pp = pd->pp;
struct ip_vs_conn *cp = NULL;
struct ip_vs_scheduler *sched;
struct ip_vs_dest *dest;
__be16 _ports[2], *pptr;
unsigned int flags;
*ignored = 1;
/*
* IPv6 frags, only the first hit here.
*/
pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports, iph);
if (pptr == NULL)
return NULL;
/*
* FTPDATA needs this check when using local real server.
* Never schedule Active FTPDATA connections from real server.
* For LVS-NAT they must be already created. For other methods
* with persistence the connection is created on SYN+ACK.
*/
if (pptr[0] == FTPDATA) {
IP_VS_DBG_PKT(12, svc->af, pp, skb, 0,
"Not scheduling FTPDATA");
return NULL;
}
/*
* Do not schedule replies from local real server.
*/
if ((!skb->dev || skb->dev->flags & IFF_LOOPBACK) &&
(cp = pp->conn_in_get(svc->af, skb, iph, 1))) {
IP_VS_DBG_PKT(12, svc->af, pp, skb, 0,
"Not scheduling reply for existing connection");
__ip_vs_conn_put(cp);
return NULL;
}
/*
* Persistent service
*/
if (svc->flags & IP_VS_SVC_F_PERSISTENT)
return ip_vs_sched_persist(svc, skb, pptr[0], pptr[1], ignored,
iph);
*ignored = 0;
/*
* Non-persistent service
*/
if (!svc->fwmark && pptr[1] != svc->port) {
if (!svc->port)
pr_err("Schedule: port zero only supported "
"in persistent services, "
"check your ipvs configuration\n");
return NULL;
}
sched = rcu_dereference(svc->scheduler);
if (sched) {
/* read svc->sched_data after svc->scheduler */
smp_rmb();
dest = sched->schedule(svc, skb, iph);
} else {
dest = NULL;
}
if (dest == NULL) {
IP_VS_DBG(1, "Schedule: no dest found.\n");
return NULL;
}
flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
&& iph->protocol == IPPROTO_UDP) ?
IP_VS_CONN_F_ONE_PACKET : 0;
/*
* Create a connection entry.
*/
{
struct ip_vs_conn_param p;
ip_vs_conn_fill_param(svc->net, svc->af, iph->protocol,
&iph->saddr, pptr[0], &iph->daddr,
pptr[1], &p);
cp = ip_vs_conn_new(&p, dest->af, &dest->addr,
dest->port ? dest->port : pptr[1],
flags, dest, skb->mark);
if (!cp) {
*ignored = -1;
return NULL;
}
}
IP_VS_DBG_BUF(6, "Schedule fwd:%c c:%s:%u v:%s:%u "
"d:%s:%u conn->flags:%X conn->refcnt:%d\n",
ip_vs_fwd_tag(cp),
IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
cp->flags, atomic_read(&cp->refcnt));
ip_vs_conn_stats(cp, svc);
return cp;
}
/*
* Pass or drop the packet.
* Called by ip_vs_in, when the virtual service is available but
* no destination is available for a new connection.
*/
int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
struct ip_vs_proto_data *pd, struct ip_vs_iphdr *iph)
{
__be16 _ports[2], *pptr;
#ifdef CONFIG_SYSCTL
struct net *net;
struct netns_ipvs *ipvs;
int unicast;
#endif
pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports, iph);
if (pptr == NULL) {
return NF_DROP;
}
#ifdef CONFIG_SYSCTL
net = skb_net(skb);
#ifdef CONFIG_IP_VS_IPV6
if (svc->af == AF_INET6)
unicast = ipv6_addr_type(&iph->daddr.in6) & IPV6_ADDR_UNICAST;
else
#endif
unicast = (inet_addr_type(net, iph->daddr.ip) == RTN_UNICAST);
/* if it is fwmark-based service, the cache_bypass sysctl is up
and the destination is a non-local unicast, then create
a cache_bypass connection entry */
ipvs = net_ipvs(net);
if (ipvs->sysctl_cache_bypass && svc->fwmark && unicast) {
int ret;
struct ip_vs_conn *cp;
unsigned int flags = (svc->flags & IP_VS_SVC_F_ONEPACKET &&
iph->protocol == IPPROTO_UDP) ?
IP_VS_CONN_F_ONE_PACKET : 0;
union nf_inet_addr daddr = { .all = { 0, 0, 0, 0 } };
/* create a new connection entry */
IP_VS_DBG(6, "%s(): create a cache_bypass entry\n", __func__);
{
struct ip_vs_conn_param p;
ip_vs_conn_fill_param(svc->net, svc->af, iph->protocol,
&iph->saddr, pptr[0],
&iph->daddr, pptr[1], &p);
cp = ip_vs_conn_new(&p, svc->af, &daddr, 0,
IP_VS_CONN_F_BYPASS | flags,
NULL, skb->mark);
if (!cp)
return NF_DROP;
}
/* statistics */
ip_vs_in_stats(cp, skb);
/* set state */
ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd);
/* transmit the first SYN packet */
ret = cp->packet_xmit(skb, cp, pd->pp, iph);
/* do not touch skb anymore */
atomic_inc(&cp->in_pkts);
ip_vs_conn_put(cp);
return ret;
}
/*
* It is hooked at the NF_IP_FORWARD chain, used only for VS/NAT.
* Check if outgoing packet belongs to the established ip_vs_conn,
* rewrite addresses of the packet and send it on its way...
*/
static unsigned int ip_vs_out(unsigned int hooknum,
struct sk_buff **skb_p,
const struct net_device *in,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
struct sk_buff *skb = *skb_p;
struct iphdr *iph;
union ip_vs_tphdr h;
struct ip_vs_conn *cp;
int size;
int ihl;
EnterFunction(11);
if (skb->nfcache & NFC_IPVS_PROPERTY)
return NF_ACCEPT;
iph = skb->nh.iph;
if (iph->protocol == IPPROTO_ICMP)
return ip_vs_out_icmp(skb_p);
/* let it go if other IP protocols */
if (iph->protocol != IPPROTO_TCP && iph->protocol != IPPROTO_UDP)
return NF_ACCEPT;
/* reassemble IP fragments */
if (iph->frag_off & __constant_htons(IP_MF|IP_OFFSET)) {
skb = ip_defrag(skb, IP_DEFRAG_VS_OUT);
if (!skb)
return NF_STOLEN;
iph = skb->nh.iph;
*skb_p = skb;
}
/* make sure that protocol header available in skb data area,
note that skb data area may be reallocated. */
ihl = iph->ihl << 2;
if (ip_vs_header_check(skb, iph->protocol, ihl) == -1)
return NF_DROP;
iph = skb->nh.iph;
h.raw = (char*) iph + ihl;
/*
* Check if the packet belongs to an old entry
*/
cp = ip_vs_conn_out_get(iph->protocol, iph->saddr, h.portp[0],
iph->daddr, h.portp[1]);
if (!cp) {
if (sysctl_ip_vs_nat_icmp_send &&
ip_vs_lookup_real_service(iph->protocol,
iph->saddr, h.portp[0])) {
/*
* Notify the real server: there is no existing
* entry if it is not RST packet or not TCP packet.
*/
if (!h.th->rst || iph->protocol != IPPROTO_TCP) {
icmp_send(skb, ICMP_DEST_UNREACH,
ICMP_PORT_UNREACH, 0);
kfree_skb(skb);
return NF_STOLEN;
}
}
IP_VS_DBG(12, "packet for %s %d.%d.%d.%d:%d "
"continue traversal as normal.\n",
ip_vs_proto_name(iph->protocol),
NIPQUAD(iph->daddr),
ntohs(h.portp[1]));
if (skb_is_nonlinear(skb))
ip_send_check(iph);
return NF_ACCEPT;
}
/*
* If it has ip_vs_app helper, the helper may change the payload,
* so it needs full checksum checking and checksum calculation.
* If not, only the header (addr/port) is changed, so it is fast
* to do incremental checksum update, and let the destination host
* do final checksum checking.
*/
if (cp->app && skb_is_nonlinear(skb)) {
if (skb_linearize(skb, GFP_ATOMIC) != 0) {
ip_vs_conn_put(cp);
return NF_DROP;
}
iph = skb->nh.iph;
h.raw = (char*) iph + ihl;
}
size = skb->len - ihl;
IP_VS_DBG(11, "O-pkt: %s size=%d\n",
ip_vs_proto_name(iph->protocol), size);
/* do TCP/UDP checksum checking if it has application helper */
if (cp->app && (iph->protocol != IPPROTO_UDP || h.uh->check != 0)) {
switch (skb->ip_summed) {
case CHECKSUM_NONE:
skb->csum = csum_partial(h.raw, size, 0);
case CHECKSUM_HW:
if (csum_tcpudp_magic(iph->saddr, iph->daddr, size,
iph->protocol, skb->csum)) {
ip_vs_conn_put(cp);
IP_VS_DBG_RL("Outgoing failed %s checksum "
"from %d.%d.%d.%d (size=%d)!\n",
ip_vs_proto_name(iph->protocol),
NIPQUAD(iph->saddr),
size);
return NF_DROP;
}
break;
default:
/* CHECKSUM_UNNECESSARY */
break;
}
}
IP_VS_DBG(11, "Outgoing %s %u.%u.%u.%u:%d->%u.%u.%u.%u:%d\n",
ip_vs_proto_name(iph->protocol),
NIPQUAD(iph->saddr), ntohs(h.portp[0]),
NIPQUAD(iph->daddr), ntohs(h.portp[1]));
/* mangle the packet */
iph->saddr = cp->vaddr;
h.portp[0] = cp->vport;
/*
* Call application helper if needed
*/
if (ip_vs_app_pkt_out(cp, skb) != 0) {
/* skb data has probably changed, update pointers */
iph = skb->nh.iph;
h.raw = (char*)iph + ihl;
size = skb->len - ihl;
}
/*
* Adjust TCP/UDP checksums
*/
if (!cp->app && (iph->protocol != IPPROTO_UDP || h.uh->check != 0)) {
/* Only port and addr are changed, do fast csum update */
ip_vs_fast_check_update(&h, cp->daddr, cp->vaddr,
cp->dport, cp->vport, iph->protocol);
if (skb->ip_summed == CHECKSUM_HW)
skb->ip_summed = CHECKSUM_NONE;
} else {
/* full checksum calculation */
switch (iph->protocol) {
case IPPROTO_TCP:
h.th->check = 0;
skb->csum = csum_partial(h.raw, size, 0);
h.th->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
size, iph->protocol,
skb->csum);
IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%d)\n",
ip_vs_proto_name(iph->protocol), h.th->check,
(char*)&(h.th->check) - (char*)h.raw);
break;
case IPPROTO_UDP:
h.uh->check = 0;
skb->csum = csum_partial(h.raw, size, 0);
h.uh->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
size, iph->protocol,
skb->csum);
if (h.uh->check == 0)
h.uh->check = 0xFFFF;
IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%d)\n",
ip_vs_proto_name(iph->protocol), h.uh->check,
(char*)&(h.uh->check) - (char*)h.raw);
break;
}
}
ip_send_check(iph);
ip_vs_out_stats(cp, skb);
ip_vs_set_state(cp, VS_STATE_OUTPUT, iph, h.portp);
ip_vs_conn_put(cp);
skb->nfcache |= NFC_IPVS_PROPERTY;
LeaveFunction(11);
return NF_ACCEPT;
}
/*
* Handle ICMP messages in the inside-to-outside direction (outgoing).
* Find any that might be relevant, check against existing connections,
* forward to the right destination host if relevant.
* Currently handles error types - unreachable, quench, ttl exceeded.
* (Only used in VS/NAT)
*/
static int ip_vs_out_icmp(struct sk_buff **skb_p)
{
struct sk_buff *skb = *skb_p;
struct iphdr *iph;
struct icmphdr *icmph;
struct iphdr *ciph; /* The ip header contained within the ICMP */
__u16 *pptr; /* port numbers from TCP/UDP contained header */
unsigned short ihl;
unsigned short len;
unsigned short clen, csize;
struct ip_vs_conn *cp;
/* reassemble IP fragments, but will it happen in ICMP packets?? */
if (skb->nh.iph->frag_off & __constant_htons(IP_MF|IP_OFFSET)) {
skb = ip_defrag(skb, IP_DEFRAG_VS_OUT);
if (!skb)
return NF_STOLEN;
*skb_p = skb;
}
if (skb_is_nonlinear(skb)) {
if (skb_linearize(skb, GFP_ATOMIC) != 0)
return NF_DROP;
ip_send_check(skb->nh.iph);
}
iph = skb->nh.iph;
ihl = iph->ihl << 2;
icmph = (struct icmphdr *)((char *)iph + ihl);
len = ntohs(iph->tot_len) - ihl;
if (len < sizeof(struct icmphdr))
return NF_DROP;
IP_VS_DBG(12, "outgoing ICMP (%d,%d) %u.%u.%u.%u->%u.%u.%u.%u\n",
icmph->type, ntohs(icmp_id(icmph)),
NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
/*
* Work through seeing if this is for us.
* These checks are supposed to be in an order that means easy
* things are checked first to speed up processing.... however
* this means that some packets will manage to get a long way
* down this stack and then be rejected, but that's life.
*/
if ((icmph->type != ICMP_DEST_UNREACH) &&
(icmph->type != ICMP_SOURCE_QUENCH) &&
(icmph->type != ICMP_TIME_EXCEEDED))
return NF_ACCEPT;
/* Now find the contained IP header */
clen = len - sizeof(struct icmphdr);
if (clen < sizeof(struct iphdr))
return NF_DROP;
ciph = (struct iphdr *) (icmph + 1);
csize = ciph->ihl << 2;
if (clen < csize)
return NF_DROP;
/* We are only interested ICMPs generated from TCP or UDP packets */
if (ciph->protocol != IPPROTO_UDP && ciph->protocol != IPPROTO_TCP)
return NF_ACCEPT;
/* Skip non-first embedded TCP/UDP fragments */
if (ciph->frag_off & __constant_htons(IP_OFFSET))
return NF_ACCEPT;
/* We need at least TCP/UDP ports here */
if (clen < csize + sizeof(struct udphdr))
return NF_DROP;
/*
* Find the ports involved - this packet was
* incoming so the ports are right way round
* (but reversed relative to outer IP header!)
*/
pptr = (__u16 *)&(((char *)ciph)[csize]);
/* Ensure the checksum is correct */
if (ip_compute_csum((unsigned char *) icmph, len)) {
/* Failed checksum! */
IP_VS_DBG(1, "forward ICMP: failed checksum from %d.%d.%d.%d!\n",
NIPQUAD(iph->saddr));
return NF_DROP;
}
IP_VS_DBG(11, "Handling outgoing ICMP for "
"%u.%u.%u.%u:%d -> %u.%u.%u.%u:%d\n",
NIPQUAD(ciph->saddr), ntohs(pptr[0]),
NIPQUAD(ciph->daddr), ntohs(pptr[1]));
/* ciph content is actually <protocol, caddr, cport, daddr, dport> */
cp = ip_vs_conn_out_get(ciph->protocol, ciph->daddr, pptr[1],
ciph->saddr, pptr[0]);
if (!cp)
return NF_ACCEPT;
if (IP_VS_FWD_METHOD(cp) != 0) {
IP_VS_ERR("shouldn't reach here, because the box is on the"
"half connection in the tun/dr module.\n");
}
/* Now we do real damage to this packet...! */
/* First change the source IP address, and recalc checksum */
iph->saddr = cp->vaddr;
ip_send_check(iph);
/* Now change the *dest* address in the contained IP */
ciph->daddr = cp->vaddr;
ip_send_check(ciph);
/* the TCP/UDP dest port - cannot redo check */
pptr[1] = cp->vport;
/* And finally the ICMP checksum */
icmph->checksum = 0;
icmph->checksum = ip_compute_csum((unsigned char *) icmph, len);
skb->ip_summed = CHECKSUM_UNNECESSARY;
/* do the statistics and put it back */
ip_vs_out_stats(cp, skb);
ip_vs_conn_put(cp);
IP_VS_DBG(11, "Forwarding correct outgoing ICMP to "
"%u.%u.%u.%u:%d -> %u.%u.%u.%u:%d\n",
NIPQUAD(ciph->saddr), ntohs(pptr[0]),
NIPQUAD(ciph->daddr), ntohs(pptr[1]));
skb->nfcache |= NFC_IPVS_PROPERTY;
return NF_ACCEPT;
}
/*
* Pass or drop the packet.
* Called by ip_vs_in, when the virtual service is available but
* no destination is available for a new connection.
*/
static int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb)
{
struct iphdr *iph = skb->nh.iph;
__u16 *portp = (__u16 *)&(((char *)iph)[iph->ihl*4]);
/* if it is fwmark-based service, the cache_bypass sysctl is up
and the destination is RTN_UNICAST (and not local), then create
a cache_bypass connection entry */
if (sysctl_ip_vs_cache_bypass && svc->fwmark
&& (inet_addr_type(iph->daddr) == RTN_UNICAST)) {
int ret;
struct ip_vs_conn *cp;
ip_vs_service_put(svc);
/* create a new connection entry */
IP_VS_DBG(6, "ip_vs_leave: create a cache_bypass entry\n");
cp = ip_vs_conn_new(iph->protocol,
iph->saddr, portp[0],
iph->daddr, portp[1],
0, 0,
IP_VS_CONN_F_BYPASS,
NULL);
if (cp == NULL) {
kfree_skb(skb);
return NF_STOLEN;
}
/* statistics */
ip_vs_in_stats(cp, skb);
/* set state */
ip_vs_set_state(cp, VS_STATE_INPUT, iph, portp);
/* transmit the first SYN packet */
ret = cp->packet_xmit(skb, cp);
atomic_inc(&cp->in_pkts);
ip_vs_conn_put(cp);
return ret;
}
/*
* When the virtual ftp service is presented, packets destined
* for other services on the VIP may get here (except services
* listed in the ipvs table), pass the packets, because it is
* not ipvs job to decide to drop the packets.
*/
if ((svc->port == FTPPORT) && (portp[1] != FTPPORT)) {
ip_vs_service_put(svc);
return NF_ACCEPT;
}
ip_vs_service_put(svc);
/*
* Notify the client that the destination is unreachable, and
* release the socket buffer.
* Since it is in IP layer, the TCP socket is not actually
* created, the TCP RST packet cannot be sent, instead that
* ICMP_PORT_UNREACH is sent here no matter it is TCP/UDP. --WZ
*/
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
kfree_skb(skb);
return NF_STOLEN;
}
/*
* Check if it's for virtual services, look it up,
* and send it on its way...
*/
static unsigned int ip_vs_in(unsigned int hooknum,
struct sk_buff **skb_p,
const struct net_device *in,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
struct sk_buff *skb = *skb_p;
struct iphdr *iph = skb->nh.iph;
union ip_vs_tphdr h;
struct ip_vs_conn *cp;
struct ip_vs_service *svc;
int ihl;
int ret;
/*
* Big tappo: only PACKET_HOST (nor loopback neither mcasts)
* ... don't know why 1st test DOES NOT include 2nd (?)
*/
if (skb->pkt_type != PACKET_HOST || skb->dev == &loopback_dev) {
IP_VS_DBG(12, "packet type=%d proto=%d daddr=%d.%d.%d.%d ignored\n",
skb->pkt_type,
iph->protocol,
NIPQUAD(iph->daddr));
return NF_ACCEPT;
}
if (iph->protocol == IPPROTO_ICMP)
return ip_vs_in_icmp(skb_p);
/* let it go if other IP protocols */
if (iph->protocol != IPPROTO_TCP && iph->protocol != IPPROTO_UDP)
return NF_ACCEPT;
/* make sure that protocol header available in skb data area,
note that skb data area may be reallocated. */
ihl = iph->ihl << 2;
if (ip_vs_header_check(skb, iph->protocol, ihl) == -1)
return NF_DROP;
iph = skb->nh.iph;
h.raw = (char*) iph + ihl;
/*
* Check if the packet belongs to an existing connection entry
*/
cp = ip_vs_conn_in_get(iph->protocol, iph->saddr, h.portp[0],
iph->daddr, h.portp[1]);
if (!cp &&
(h.th->syn || (iph->protocol!=IPPROTO_TCP)) &&
(svc = ip_vs_service_get(skb->nfmark, iph->protocol,
iph->daddr, h.portp[1]))) {
if (ip_vs_todrop()) {
/*
* It seems that we are very loaded.
* We have to drop this packet :(
*/
ip_vs_service_put(svc);
return NF_DROP;
}
/*
* Let the virtual server select a real server for the
* incoming connection, and create a connection entry.
*/
cp = ip_vs_schedule(svc, iph);
if (!cp)
return ip_vs_leave(svc, skb);
ip_vs_conn_stats(cp, svc);
ip_vs_service_put(svc);
}
if (!cp) {
/* sorry, all this trouble for a no-hit :) */
IP_VS_DBG(12, "packet for %s %d.%d.%d.%d:%d continue "
"traversal as normal.\n",
ip_vs_proto_name(iph->protocol),
NIPQUAD(iph->daddr),
ntohs(h.portp[1]));
return NF_ACCEPT;
}
IP_VS_DBG(11, "Incoming %s %u.%u.%u.%u:%d->%u.%u.%u.%u:%d\n",
ip_vs_proto_name(iph->protocol),
NIPQUAD(iph->saddr), ntohs(h.portp[0]),
NIPQUAD(iph->daddr), ntohs(h.portp[1]));
/* Check the server status */
if (cp->dest && !(cp->dest->flags & IP_VS_DEST_F_AVAILABLE)) {
/* the destination server is not available */
if (sysctl_ip_vs_expire_nodest_conn) {
/* try to expire the connection immediately */
ip_vs_conn_expire_now(cp);
} else {
/* don't restart its timer, and silently
drop the packet. */
__ip_vs_conn_put(cp);
}
return NF_DROP;
}
ip_vs_in_stats(cp, skb);
ip_vs_set_state(cp, VS_STATE_INPUT, iph, h.portp);
if (cp->packet_xmit)
ret = cp->packet_xmit(skb, cp);
else {
IP_VS_DBG_RL("warning: packet_xmit is null");
ret = NF_ACCEPT;
}
/* increase its packet counter and check if it is needed
to be synchronized */
atomic_inc(&cp->in_pkts);
if (ip_vs_sync_state & IP_VS_STATE_MASTER &&
(cp->protocol != IPPROTO_TCP ||
cp->state == IP_VS_S_ESTABLISHED) &&
(atomic_read(&cp->in_pkts) % 50 == sysctl_ip_vs_sync_threshold))
ip_vs_sync_conn(cp);
ip_vs_conn_put(cp);
return ret;
}
/*
* It is hooked at the NF_IP_FORWARD chain, used only for VS/NAT.
* Check if outgoing packet belongs to the established ip_vs_conn,
* rewrite addresses of the packet and send it on its way...
*/
static unsigned int
ip_vs_out(unsigned int hooknum, struct sk_buff **pskb,
const struct net_device *in, const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
struct sk_buff *skb = *pskb;
struct iphdr *iph;
struct ip_vs_protocol *pp;
struct ip_vs_conn *cp;
int ihl;
EnterFunction(11);
if (skb->nfcache & NFC_IPVS_PROPERTY)
return NF_ACCEPT;
if (skb->ip_summed == CHECKSUM_HW) {
if (skb_checksum_help(pskb, (out == NULL)))
return NF_DROP;
if (skb != *pskb)
skb = *pskb;
}
iph = skb->nh.iph;
if (unlikely(iph->protocol == IPPROTO_ICMP)) {
int related, verdict = ip_vs_out_icmp(pskb, &related);
if (related)
return verdict;
skb = *pskb;
iph = skb->nh.iph;
}
pp = ip_vs_proto_get(iph->protocol);
if (unlikely(!pp))
return NF_ACCEPT;
/* reassemble IP fragments */
if (unlikely(iph->frag_off & __constant_htons(IP_MF|IP_OFFSET) &&
!pp->dont_defrag)) {
skb = ip_vs_gather_frags(skb);
if (!skb)
return NF_STOLEN;
iph = skb->nh.iph;
*pskb = skb;
}
ihl = iph->ihl << 2;
/*
* Check if the packet belongs to an existing entry
*/
cp = pp->conn_out_get(skb, pp, iph, ihl, 0);
if (unlikely(!cp)) {
if (sysctl_ip_vs_nat_icmp_send &&
(pp->protocol == IPPROTO_TCP ||
pp->protocol == IPPROTO_UDP)) {
__u16 ports[2];
if (skb_copy_bits(skb, ihl, ports, sizeof(ports)) < 0)
return NF_ACCEPT; /* Not for me */
if (ip_vs_lookup_real_service(iph->protocol,
iph->saddr, ports[0])) {
/*
* Notify the real server: there is no
* existing entry if it is not RST
* packet or not TCP packet.
*/
if (iph->protocol != IPPROTO_TCP
|| !is_tcp_reset(skb)) {
icmp_send(skb,ICMP_DEST_UNREACH,
ICMP_PORT_UNREACH, 0);
return NF_DROP;
}
}
}
IP_VS_DBG_PKT(12, pp, skb, 0,
"packet continues traversal as normal");
return NF_ACCEPT;
}
IP_VS_DBG_PKT(11, pp, skb, 0, "Outgoing packet");
if (!ip_vs_make_skb_writable(pskb, ihl))
goto drop;
/* mangle the packet */
if (pp->snat_handler && !pp->snat_handler(pskb, pp, cp))
goto drop;
skb = *pskb;
skb->nh.iph->saddr = cp->vaddr;
ip_send_check(skb->nh.iph);
IP_VS_DBG_PKT(10, pp, skb, 0, "After SNAT");
ip_vs_out_stats(cp, skb);
ip_vs_set_state(cp, IP_VS_DIR_OUTPUT, skb, pp);
ip_vs_conn_put(cp);
skb->nfcache |= NFC_IPVS_PROPERTY;
LeaveFunction(11);
return NF_ACCEPT;
drop:
ip_vs_conn_put(cp);
kfree_skb(*pskb);
return NF_STOLEN;
}
static struct ip_vs_conn *
ip_vs_sched_persist(struct ip_vs_service *svc,
struct sk_buff *skb,
__be16 src_port, __be16 dst_port, int *ignored)
{
struct ip_vs_conn *cp = NULL;
struct ip_vs_iphdr iph;
struct ip_vs_dest *dest;
struct ip_vs_conn *ct;
__be16 dport = 0;
unsigned int flags;
struct ip_vs_conn_param param;
const union nf_inet_addr fwmark = { .ip = htonl(svc->fwmark) };
union nf_inet_addr snet;
ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph);
#ifdef CONFIG_IP_VS_IPV6
if (svc->af == AF_INET6)
ipv6_addr_prefix(&snet.in6, &iph.saddr.in6, svc->netmask);
else
#endif
snet.ip = iph.saddr.ip & svc->netmask;
IP_VS_DBG_BUF(6, "p-schedule: src %s:%u dest %s:%u "
"mnet %s\n",
IP_VS_DBG_ADDR(svc->af, &iph.saddr), ntohs(src_port),
IP_VS_DBG_ADDR(svc->af, &iph.daddr), ntohs(dst_port),
IP_VS_DBG_ADDR(svc->af, &snet));
{
int protocol = iph.protocol;
const union nf_inet_addr *vaddr = &iph.daddr;
__be16 vport = 0;
if (dst_port == svc->port) {
if (svc->port != FTPPORT)
vport = dst_port;
} else {
if (svc->fwmark) {
protocol = IPPROTO_IP;
vaddr = &fwmark;
}
}
if (ip_vs_conn_fill_param_persist(svc, skb, protocol, &snet, 0,
vaddr, vport, ¶m) < 0) {
*ignored = -1;
return NULL;
}
}
ct = ip_vs_ct_in_get(¶m);
if (!ct || !ip_vs_check_template(ct)) {
dest = svc->scheduler->schedule(svc, skb);
if (!dest) {
IP_VS_DBG(1, "p-schedule: no dest found.\n");
kfree(param.pe_data);
*ignored = 0;
return NULL;
}
if (dst_port == svc->port && svc->port != FTPPORT)
dport = dest->port;
ct = ip_vs_conn_new(¶m, &dest->addr, dport,
IP_VS_CONN_F_TEMPLATE, dest, skb->mark);
if (ct == NULL) {
kfree(param.pe_data);
*ignored = -1;
return NULL;
}
ct->timeout = svc->timeout;
} else {
dest = ct->dest;
kfree(param.pe_data);
}
dport = dst_port;
if (dport == svc->port && dest->port)
dport = dest->port;
flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
&& iph.protocol == IPPROTO_UDP)?
IP_VS_CONN_F_ONE_PACKET : 0;
ip_vs_conn_fill_param(svc->net, svc->af, iph.protocol, &iph.saddr,
src_port, &iph.daddr, dst_port, ¶m);
cp = ip_vs_conn_new(¶m, &dest->addr, dport, flags, dest, skb->mark);
if (cp == NULL) {
ip_vs_conn_put(ct);
*ignored = -1;
return NULL;
}
ip_vs_control_add(cp, ct);
ip_vs_conn_put(ct);
ip_vs_conn_stats(cp, svc);
return cp;
}
struct ip_vs_conn *
ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
struct ip_vs_proto_data *pd, int *ignored)
{
struct ip_vs_protocol *pp = pd->pp;
struct ip_vs_conn *cp = NULL;
struct ip_vs_iphdr iph;
struct ip_vs_dest *dest;
__be16 _ports[2], *pptr;
unsigned int flags;
*ignored = 1;
ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph);
pptr = skb_header_pointer(skb, iph.len, sizeof(_ports), _ports);
if (pptr == NULL)
return NULL;
if (pptr[0] == FTPDATA) {
IP_VS_DBG_PKT(12, svc->af, pp, skb, 0,
"Not scheduling FTPDATA");
return NULL;
}
if ((!skb->dev || skb->dev->flags & IFF_LOOPBACK) &&
(cp = pp->conn_in_get(svc->af, skb, &iph, iph.len, 1))) {
IP_VS_DBG_PKT(12, svc->af, pp, skb, 0,
"Not scheduling reply for existing connection");
__ip_vs_conn_put(cp);
return NULL;
}
if (svc->flags & IP_VS_SVC_F_PERSISTENT)
return ip_vs_sched_persist(svc, skb, pptr[0], pptr[1], ignored);
*ignored = 0;
if (!svc->fwmark && pptr[1] != svc->port) {
if (!svc->port)
pr_err("Schedule: port zero only supported "
"in persistent services, "
"check your ipvs configuration\n");
return NULL;
}
dest = svc->scheduler->schedule(svc, skb);
if (dest == NULL) {
IP_VS_DBG(1, "Schedule: no dest found.\n");
return NULL;
}
flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
&& iph.protocol == IPPROTO_UDP)?
IP_VS_CONN_F_ONE_PACKET : 0;
{
struct ip_vs_conn_param p;
ip_vs_conn_fill_param(svc->net, svc->af, iph.protocol,
&iph.saddr, pptr[0], &iph.daddr, pptr[1],
&p);
cp = ip_vs_conn_new(&p, &dest->addr,
dest->port ? dest->port : pptr[1],
flags, dest, skb->mark);
if (!cp) {
*ignored = -1;
return NULL;
}
}
IP_VS_DBG_BUF(6, "Schedule fwd:%c c:%s:%u v:%s:%u "
"d:%s:%u conn->flags:%X conn->refcnt:%d\n",
ip_vs_fwd_tag(cp),
IP_VS_DBG_ADDR(svc->af, &cp->caddr), ntohs(cp->cport),
IP_VS_DBG_ADDR(svc->af, &cp->vaddr), ntohs(cp->vport),
IP_VS_DBG_ADDR(svc->af, &cp->daddr), ntohs(cp->dport),
cp->flags, atomic_read(&cp->refcnt));
ip_vs_conn_stats(cp, svc);
return cp;
}
int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
struct ip_vs_proto_data *pd)
{
__be16 _ports[2], *pptr;
struct ip_vs_iphdr iph;
#ifdef CONFIG_SYSCTL
struct net *net;
struct netns_ipvs *ipvs;
int unicast;
#endif
ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph);
pptr = skb_header_pointer(skb, iph.len, sizeof(_ports), _ports);
if (pptr == NULL) {
ip_vs_service_put(svc);
return NF_DROP;
}
#ifdef CONFIG_SYSCTL
net = skb_net(skb);
#ifdef CONFIG_IP_VS_IPV6
if (svc->af == AF_INET6)
unicast = ipv6_addr_type(&iph.daddr.in6) & IPV6_ADDR_UNICAST;
else
#endif
unicast = (inet_addr_type(net, iph.daddr.ip) == RTN_UNICAST);
ipvs = net_ipvs(net);
if (ipvs->sysctl_cache_bypass && svc->fwmark && unicast) {
int ret;
struct ip_vs_conn *cp;
unsigned int flags = (svc->flags & IP_VS_SVC_F_ONEPACKET &&
iph.protocol == IPPROTO_UDP)?
IP_VS_CONN_F_ONE_PACKET : 0;
union nf_inet_addr daddr = { .all = { 0, 0, 0, 0 } };
ip_vs_service_put(svc);
IP_VS_DBG(6, "%s(): create a cache_bypass entry\n", __func__);
{
struct ip_vs_conn_param p;
ip_vs_conn_fill_param(svc->net, svc->af, iph.protocol,
&iph.saddr, pptr[0],
&iph.daddr, pptr[1], &p);
cp = ip_vs_conn_new(&p, &daddr, 0,
IP_VS_CONN_F_BYPASS | flags,
NULL, skb->mark);
if (!cp)
return NF_DROP;
}
ip_vs_in_stats(cp, skb);
ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd);
ret = cp->packet_xmit(skb, cp, pd->pp);
atomic_inc(&cp->in_pkts);
ip_vs_conn_put(cp);
return ret;
}
/*
* 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 *vapp,
struct ip_vs_conn *cp, struct sk_buff *skb)
{
struct iphdr *iph;
struct tcphdr *th;
char *data, *data_limit;
char *start, *end;
__u32 from;
__u16 port;
struct ip_vs_conn *n_cp;
char buf[24]; /* xxx.xxx.xxx.xxx,ppp,ppp\000 */
unsigned buf_len;
int diff;
/* Only useful for established sessions */
if (cp->state != IP_VS_S_ESTABLISHED)
return 0;
if (cp->app_data == &ip_vs_ftp_pasv) {
iph = skb->nh.iph;
th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]);
data = (char *)th + (th->doff << 2);
data_limit = skb->tail;
if (ip_vs_ftp_get_addrport(data, data_limit,
SERVER_STRING,
sizeof(SERVER_STRING)-1, ')',
&from, &port,
&start, &end) != 1)
return 0;
IP_VS_DBG(1-debug, "PASV response (%u.%u.%u.%u:%d) -> "
"%u.%u.%u.%u:%d detected\n",
NIPQUAD(from), ntohs(port), NIPQUAD(cp->caddr), 0);
/*
* Now update or create an connection entry for it
*/
n_cp = ip_vs_conn_out_get(iph->protocol, from, port,
cp->caddr, 0);
if (!n_cp) {
n_cp = ip_vs_conn_new(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);
/* increase dest's inactive connection counter */
if (cp->dest)
atomic_inc(&cp->dest->inactconns);
}
/*
* Replace the old passive address with the new one
*/
from = n_cp->vaddr;
port = n_cp->vport;
sprintf(buf,"%d,%d,%d,%d,%d,%d", NIPQUAD(from),
port&255, port>>8&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);
} else {
/* fixme: return value isn't checked here */
ip_vs_skb_replace(skb, GFP_ATOMIC, start,
end-start, buf, buf_len);
}
cp->app_data = NULL;
ip_vs_conn_listen(n_cp);
ip_vs_conn_put(n_cp);
return diff;
}
/*
* 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 **pskb, int *diff)
{
struct iphdr *iph;
struct tcphdr *th;
char *data, *data_limit;
char *start, *end;
__u32 from;
__u16 port;
struct ip_vs_conn *n_cp;
char buf[24]; /* xxx.xxx.xxx.xxx,ppp,ppp\000 */
unsigned buf_len;
int ret;
*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 (!ip_vs_make_skb_writable(pskb, (*pskb)->len))
return 0;
if (cp->app_data == &ip_vs_ftp_pasv) {
iph = (*pskb)->nh.iph;
th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]);
data = (char *)th + (th->doff << 2);
data_limit = (*pskb)->tail;
if (ip_vs_ftp_get_addrport(data, data_limit,
SERVER_STRING,
sizeof(SERVER_STRING)-1, ')',
&from, &port,
&start, &end) != 1)
return 1;
IP_VS_DBG(1-debug, "PASV response (%u.%u.%u.%u:%d) -> "
"%u.%u.%u.%u:%d detected\n",
NIPQUAD(from), ntohs(port), NIPQUAD(cp->caddr), 0);
/*
* Now update or create an connection entry for it
*/
n_cp = ip_vs_conn_out_get(iph->protocol, from, port,
cp->caddr, 0);
if (!n_cp) {
n_cp = ip_vs_conn_new(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 = n_cp->vaddr;
port = n_cp->vport;
sprintf(buf,"%d,%d,%d,%d,%d,%d", NIPQUAD(from),
port&255, (port>>8)&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(*pskb, 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;
}
/*
* Syn-proxy step 2 logic
* Receive client's 3-handshakes Ack packet, do cookie check
* and then send syn to rs after creating a session.
*
*/
int
ip_vs_synproxy_ack_rcv(int af, struct sk_buff *skb, struct tcphdr *th,
struct ip_vs_protocol *pp, struct ip_vs_conn **cpp,
struct ip_vs_iphdr *iph, int *verdict)
{
struct ip_vs_synproxy_opt opt;
struct ip_vs_service *svc;
int res_cookie_check;
/*
* Don't check svc syn-proxy flag, as it may
* be changed after syn-proxy step 1.
*/
if (!th->syn && th->ack && !th->rst && !th->fin &&
(svc =
ip_vs_service_get(af, skb->mark, iph->protocol, &iph->daddr,
th->dest))) {
if (ip_vs_todrop()) {
/*
* It seems that we are very loaded.
* We have to drop this packet :(
*/
ip_vs_service_put(svc);
*verdict = NF_DROP;
return 0;
}
if (sysctl_ip_vs_synproxy_defer &&
!syn_proxy_ack_has_data(skb, iph, th)) {
/* update statistics */
IP_VS_INC_ESTATS(ip_vs_esmib, SYNPROXY_NULL_ACK);
/*
* When expecting ack packet with payload,
* we get a pure ack, so have to drop it.
*/
ip_vs_service_put(svc);
*verdict = NF_DROP;
return 0;
}
/*
* Import: set tcp hdr before cookie check, as it
* will be used in cookie_check funcs.
*/
skb_set_transport_header(skb, iph->len);
#ifdef CONFIG_IP_VS_IPV6
if (af == AF_INET6) {
res_cookie_check = ip_vs_synproxy_v6_cookie_check(skb,
ntohl
(th->
ack_seq)
- 1,
&opt);
} else
#endif
{
res_cookie_check = ip_vs_synproxy_v4_cookie_check(skb,
ntohl
(th->
ack_seq)
- 1,
&opt);
}
if (!res_cookie_check) {
/* update statistics */
IP_VS_INC_ESTATS(ip_vs_esmib, SYNPROXY_BAD_ACK);
/*
* Cookie check fail, drop it.
*/
IP_VS_DBG(6, "syn_cookie check failed seq=%u\n",
ntohl(th->ack_seq) - 1);
ip_vs_service_put(svc);
*verdict = NF_DROP;
return 0;
}
/* update statistics */
IP_VS_INC_ESTATS(ip_vs_esmib, SYNPROXY_OK_ACK);
/*
* Let the virtual server select a real server for the
* incoming connection, and create a connection entry.
*/
*cpp = ip_vs_schedule(svc, skb, 1);
if (!*cpp) {
IP_VS_DBG(6, "ip_vs_schedule failed\n");
*verdict = ip_vs_leave(svc, skb, pp);
return 0;
}
/*
* Release service, we don't need it any more.
*/
ip_vs_service_put(svc);
/*
* Do anything but print a error msg when fail.
* Because session will be correctly freed in ip_vs_conn_expire.
*/
if (!syn_proxy_send_rs_syn(af, th, *cpp, skb, pp, &opt)) {
IP_VS_ERR_RL("syn_proxy_send_rs_syn failed!\n");
}
/* count in the ack packet (STOLEN by synproxy) */
ip_vs_in_stats(*cpp, skb);
/*
* Active sesion timer, and dec refcnt.
* Also stole the skb, and let caller return immediately.
*/
ip_vs_conn_put(*cpp);
*verdict = NF_STOLEN;
return 0;
}
return 1;
}
/*
* Handle ICMP messages in the outside-to-inside direction (incoming)
* and sometimes in outgoing direction from ip_vs_forward_icmp.
* Find any that might be relevant, check against existing connections,
* forward to the right destination host if relevant.
* Currently handles error types - unreachable, quench, ttl exceeded.
*/
static int ip_vs_in_icmp(struct sk_buff **skb_p)
{
struct sk_buff *skb = *skb_p;
struct iphdr *iph;
struct icmphdr *icmph;
struct iphdr *ciph; /* The ip header contained within the ICMP */
__u16 *pptr; /* port numbers from TCP/UDP contained header */
unsigned short len;
unsigned short clen, csize;
struct ip_vs_conn *cp;
struct rtable *rt; /* Route to the other host */
int mtu;
if (skb_is_nonlinear(skb)) {
if (skb_linearize(skb, GFP_ATOMIC) != 0)
return NF_DROP;
}
iph = skb->nh.iph;
ip_send_check(iph);
icmph = (struct icmphdr *)((char *)iph + (iph->ihl << 2));
len = ntohs(iph->tot_len) - (iph->ihl<<2);
if (len < sizeof(struct icmphdr))
return NF_DROP;
IP_VS_DBG(12, "icmp in (%d,%d) %u.%u.%u.%u -> %u.%u.%u.%u\n",
icmph->type, ntohs(icmp_id(icmph)),
NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
if ((icmph->type != ICMP_DEST_UNREACH) &&
(icmph->type != ICMP_SOURCE_QUENCH) &&
(icmph->type != ICMP_TIME_EXCEEDED))
return NF_ACCEPT;
/*
* If we get here we have an ICMP error of one of the above 3 types
* Now find the contained IP header
*/
clen = len - sizeof(struct icmphdr);
if (clen < sizeof(struct iphdr))
return NF_DROP;
ciph = (struct iphdr *) (icmph + 1);
csize = ciph->ihl << 2;
if (clen < csize)
return NF_DROP;
/* We are only interested ICMPs generated from TCP or UDP packets */
if (ciph->protocol != IPPROTO_UDP && ciph->protocol != IPPROTO_TCP)
return NF_ACCEPT;
/* Skip non-first embedded TCP/UDP fragments */
if (ciph->frag_off & __constant_htons(IP_OFFSET))
return NF_ACCEPT;
/* We need at least TCP/UDP ports here */
if (clen < csize + sizeof(struct udphdr))
return NF_DROP;
/* Ensure the checksum is correct */
if (ip_compute_csum((unsigned char *) icmph, len)) {
/* Failed checksum! */
IP_VS_ERR_RL("incoming ICMP: failed checksum from "
"%d.%d.%d.%d!\n", NIPQUAD(iph->saddr));
return NF_DROP;
}
pptr = (__u16 *)&(((char *)ciph)[csize]);
IP_VS_DBG(11, "Handling incoming ICMP for "
"%u.%u.%u.%u:%d -> %u.%u.%u.%u:%d\n",
NIPQUAD(ciph->saddr), ntohs(pptr[0]),
NIPQUAD(ciph->daddr), ntohs(pptr[1]));
/* This is pretty much what ip_vs_conn_in_get() does,
except parameters are in the reverse order */
cp = ip_vs_conn_in_get(ciph->protocol,
ciph->daddr, pptr[1],
ciph->saddr, pptr[0]);
if (cp == NULL)
return NF_ACCEPT;
ip_vs_in_stats(cp, skb);
/* The ICMP packet for VS/TUN, VS/DR and LOCALNODE will be
forwarded directly here, because there is no need to
translate address/port back */
if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ) {
int ret;
if (cp->packet_xmit)
ret = cp->packet_xmit(skb, cp);
else
ret = NF_ACCEPT;
atomic_inc(&cp->in_pkts);
ip_vs_conn_put(cp);
return ret;
}
/*
* mangle and send the packet here
*/
if (!(rt = __ip_vs_get_out_rt(cp, RT_TOS(iph->tos))))
goto tx_error_icmp;
/* MTU checking */
mtu = rt->u.dst.pmtu;
if ((skb->len > mtu) && (iph->frag_off&__constant_htons(IP_DF))) {
ip_rt_put(rt);
icmp_send(skb, ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED, htonl(mtu));
IP_VS_DBG_RL("ip_vs_in_icmp(): frag needed\n");
goto tx_error;
}
/* drop old route */
dst_release(skb->dst);
skb->dst = &rt->u.dst;
/* copy-on-write the packet before mangling it */
if (ip_vs_skb_cow(skb, rt->u.dst.dev->hard_header_len,
&iph, (unsigned char**)&icmph)) {
ip_vs_conn_put(cp);
return NF_DROP;
}
ciph = (struct iphdr *) (icmph + 1);
pptr = (__u16 *)&(((char *)ciph)[csize]);
/* The ICMP packet for VS/NAT must be written to correct addresses
before being forwarded to the right server */
/* First change the dest IP address, and recalc checksum */
iph->daddr = cp->daddr;
ip_send_check(iph);
/* Now change the *source* address in the contained IP */
ciph->saddr = cp->daddr;
ip_send_check(ciph);
/* the TCP/UDP source port - cannot redo check */
pptr[0] = cp->dport;
/* And finally the ICMP checksum */
icmph->checksum = 0;
icmph->checksum = ip_compute_csum((unsigned char *) icmph, len);
skb->ip_summed = CHECKSUM_UNNECESSARY;
IP_VS_DBG(11, "Forwarding incoming ICMP to "
"%u.%u.%u.%u:%d -> %u.%u.%u.%u:%d\n",
NIPQUAD(ciph->saddr), ntohs(pptr[0]),
NIPQUAD(ciph->daddr), ntohs(pptr[1]));
#ifdef CONFIG_NETFILTER_DEBUG
skb->nf_debug = 1 << NF_IP_LOCAL_OUT;
#endif /* CONFIG_NETFILTER_DEBUG */
ip_send(skb);
ip_vs_conn_put(cp);
return NF_STOLEN;
tx_error_icmp:
dst_link_failure(skb);
tx_error:
dev_kfree_skb(skb);
ip_vs_conn_put(cp);
return NF_STOLEN;
}
