mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-24 09:50:04 +00:00
![Linus Torvalds](/assets/img/avatar_default.png)
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
427 lines
9.8 KiB
C
427 lines
9.8 KiB
C
/*
|
|
* ip_vs_proto_udp.c: UDP load balancing support for IPVS
|
|
*
|
|
* Version: $Id: ip_vs_proto_udp.c,v 1.3 2002/11/30 01:50:35 wensong Exp $
|
|
*
|
|
* Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
|
|
* Julian Anastasov <ja@ssi.bg>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*
|
|
* Changes:
|
|
*
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/netfilter_ipv4.h>
|
|
|
|
#include <net/ip_vs.h>
|
|
|
|
|
|
static struct ip_vs_conn *
|
|
udp_conn_in_get(const struct sk_buff *skb, struct ip_vs_protocol *pp,
|
|
const struct iphdr *iph, unsigned int proto_off, int inverse)
|
|
{
|
|
struct ip_vs_conn *cp;
|
|
__u16 _ports[2], *pptr;
|
|
|
|
pptr = skb_header_pointer(skb, proto_off, sizeof(_ports), _ports);
|
|
if (pptr == NULL)
|
|
return NULL;
|
|
|
|
if (likely(!inverse)) {
|
|
cp = ip_vs_conn_in_get(iph->protocol,
|
|
iph->saddr, pptr[0],
|
|
iph->daddr, pptr[1]);
|
|
} else {
|
|
cp = ip_vs_conn_in_get(iph->protocol,
|
|
iph->daddr, pptr[1],
|
|
iph->saddr, pptr[0]);
|
|
}
|
|
|
|
return cp;
|
|
}
|
|
|
|
|
|
static struct ip_vs_conn *
|
|
udp_conn_out_get(const struct sk_buff *skb, struct ip_vs_protocol *pp,
|
|
const struct iphdr *iph, unsigned int proto_off, int inverse)
|
|
{
|
|
struct ip_vs_conn *cp;
|
|
__u16 _ports[2], *pptr;
|
|
|
|
pptr = skb_header_pointer(skb, skb->nh.iph->ihl*4,
|
|
sizeof(_ports), _ports);
|
|
if (pptr == NULL)
|
|
return NULL;
|
|
|
|
if (likely(!inverse)) {
|
|
cp = ip_vs_conn_out_get(iph->protocol,
|
|
iph->saddr, pptr[0],
|
|
iph->daddr, pptr[1]);
|
|
} else {
|
|
cp = ip_vs_conn_out_get(iph->protocol,
|
|
iph->daddr, pptr[1],
|
|
iph->saddr, pptr[0]);
|
|
}
|
|
|
|
return cp;
|
|
}
|
|
|
|
|
|
static int
|
|
udp_conn_schedule(struct sk_buff *skb, struct ip_vs_protocol *pp,
|
|
int *verdict, struct ip_vs_conn **cpp)
|
|
{
|
|
struct ip_vs_service *svc;
|
|
struct udphdr _udph, *uh;
|
|
|
|
uh = skb_header_pointer(skb, skb->nh.iph->ihl*4,
|
|
sizeof(_udph), &_udph);
|
|
if (uh == NULL) {
|
|
*verdict = NF_DROP;
|
|
return 0;
|
|
}
|
|
|
|
if ((svc = ip_vs_service_get(skb->nfmark, skb->nh.iph->protocol,
|
|
skb->nh.iph->daddr, uh->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;
|
|
}
|
|
|
|
/*
|
|
* Let the virtual server select a real server for the
|
|
* incoming connection, and create a connection entry.
|
|
*/
|
|
*cpp = ip_vs_schedule(svc, skb);
|
|
if (!*cpp) {
|
|
*verdict = ip_vs_leave(svc, skb, pp);
|
|
return 0;
|
|
}
|
|
ip_vs_service_put(svc);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
|
|
static inline void
|
|
udp_fast_csum_update(struct udphdr *uhdr, u32 oldip, u32 newip,
|
|
u16 oldport, u16 newport)
|
|
{
|
|
uhdr->check =
|
|
ip_vs_check_diff(~oldip, newip,
|
|
ip_vs_check_diff(oldport ^ 0xFFFF,
|
|
newport, uhdr->check));
|
|
if (!uhdr->check)
|
|
uhdr->check = 0xFFFF;
|
|
}
|
|
|
|
static int
|
|
udp_snat_handler(struct sk_buff **pskb,
|
|
struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
|
|
{
|
|
struct udphdr *udph;
|
|
unsigned int udphoff = (*pskb)->nh.iph->ihl * 4;
|
|
|
|
/* csum_check requires unshared skb */
|
|
if (!ip_vs_make_skb_writable(pskb, udphoff+sizeof(*udph)))
|
|
return 0;
|
|
|
|
if (unlikely(cp->app != NULL)) {
|
|
/* Some checks before mangling */
|
|
if (pp->csum_check && !pp->csum_check(*pskb, pp))
|
|
return 0;
|
|
|
|
/*
|
|
* Call application helper if needed
|
|
*/
|
|
if (!ip_vs_app_pkt_out(cp, pskb))
|
|
return 0;
|
|
}
|
|
|
|
udph = (void *)(*pskb)->nh.iph + udphoff;
|
|
udph->source = cp->vport;
|
|
|
|
/*
|
|
* Adjust UDP checksums
|
|
*/
|
|
if (!cp->app && (udph->check != 0)) {
|
|
/* Only port and addr are changed, do fast csum update */
|
|
udp_fast_csum_update(udph, cp->daddr, cp->vaddr,
|
|
cp->dport, cp->vport);
|
|
if ((*pskb)->ip_summed == CHECKSUM_HW)
|
|
(*pskb)->ip_summed = CHECKSUM_NONE;
|
|
} else {
|
|
/* full checksum calculation */
|
|
udph->check = 0;
|
|
(*pskb)->csum = skb_checksum(*pskb, udphoff,
|
|
(*pskb)->len - udphoff, 0);
|
|
udph->check = csum_tcpudp_magic(cp->vaddr, cp->caddr,
|
|
(*pskb)->len - udphoff,
|
|
cp->protocol,
|
|
(*pskb)->csum);
|
|
if (udph->check == 0)
|
|
udph->check = 0xFFFF;
|
|
IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
|
|
pp->name, udph->check,
|
|
(char*)&(udph->check) - (char*)udph);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
|
|
static int
|
|
udp_dnat_handler(struct sk_buff **pskb,
|
|
struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
|
|
{
|
|
struct udphdr *udph;
|
|
unsigned int udphoff = (*pskb)->nh.iph->ihl * 4;
|
|
|
|
/* csum_check requires unshared skb */
|
|
if (!ip_vs_make_skb_writable(pskb, udphoff+sizeof(*udph)))
|
|
return 0;
|
|
|
|
if (unlikely(cp->app != NULL)) {
|
|
/* Some checks before mangling */
|
|
if (pp->csum_check && !pp->csum_check(*pskb, pp))
|
|
return 0;
|
|
|
|
/*
|
|
* Attempt ip_vs_app call.
|
|
* It will fix ip_vs_conn
|
|
*/
|
|
if (!ip_vs_app_pkt_in(cp, pskb))
|
|
return 0;
|
|
}
|
|
|
|
udph = (void *)(*pskb)->nh.iph + udphoff;
|
|
udph->dest = cp->dport;
|
|
|
|
/*
|
|
* Adjust UDP checksums
|
|
*/
|
|
if (!cp->app && (udph->check != 0)) {
|
|
/* Only port and addr are changed, do fast csum update */
|
|
udp_fast_csum_update(udph, cp->vaddr, cp->daddr,
|
|
cp->vport, cp->dport);
|
|
if ((*pskb)->ip_summed == CHECKSUM_HW)
|
|
(*pskb)->ip_summed = CHECKSUM_NONE;
|
|
} else {
|
|
/* full checksum calculation */
|
|
udph->check = 0;
|
|
(*pskb)->csum = skb_checksum(*pskb, udphoff,
|
|
(*pskb)->len - udphoff, 0);
|
|
udph->check = csum_tcpudp_magic(cp->caddr, cp->daddr,
|
|
(*pskb)->len - udphoff,
|
|
cp->protocol,
|
|
(*pskb)->csum);
|
|
if (udph->check == 0)
|
|
udph->check = 0xFFFF;
|
|
(*pskb)->ip_summed = CHECKSUM_UNNECESSARY;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
|
|
static int
|
|
udp_csum_check(struct sk_buff *skb, struct ip_vs_protocol *pp)
|
|
{
|
|
struct udphdr _udph, *uh;
|
|
unsigned int udphoff = skb->nh.iph->ihl*4;
|
|
|
|
uh = skb_header_pointer(skb, udphoff, sizeof(_udph), &_udph);
|
|
if (uh == NULL)
|
|
return 0;
|
|
|
|
if (uh->check != 0) {
|
|
switch (skb->ip_summed) {
|
|
case CHECKSUM_NONE:
|
|
skb->csum = skb_checksum(skb, udphoff,
|
|
skb->len - udphoff, 0);
|
|
case CHECKSUM_HW:
|
|
if (csum_tcpudp_magic(skb->nh.iph->saddr,
|
|
skb->nh.iph->daddr,
|
|
skb->len - udphoff,
|
|
skb->nh.iph->protocol,
|
|
skb->csum)) {
|
|
IP_VS_DBG_RL_PKT(0, pp, skb, 0,
|
|
"Failed checksum for");
|
|
return 0;
|
|
}
|
|
break;
|
|
default:
|
|
/* CHECKSUM_UNNECESSARY */
|
|
break;
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
|
|
/*
|
|
* Note: the caller guarantees that only one of register_app,
|
|
* unregister_app or app_conn_bind is called each time.
|
|
*/
|
|
|
|
#define UDP_APP_TAB_BITS 4
|
|
#define UDP_APP_TAB_SIZE (1 << UDP_APP_TAB_BITS)
|
|
#define UDP_APP_TAB_MASK (UDP_APP_TAB_SIZE - 1)
|
|
|
|
static struct list_head udp_apps[UDP_APP_TAB_SIZE];
|
|
static DEFINE_SPINLOCK(udp_app_lock);
|
|
|
|
static inline __u16 udp_app_hashkey(__u16 port)
|
|
{
|
|
return ((port >> UDP_APP_TAB_BITS) ^ port) & UDP_APP_TAB_MASK;
|
|
}
|
|
|
|
|
|
static int udp_register_app(struct ip_vs_app *inc)
|
|
{
|
|
struct ip_vs_app *i;
|
|
__u16 hash, port = inc->port;
|
|
int ret = 0;
|
|
|
|
hash = udp_app_hashkey(port);
|
|
|
|
|
|
spin_lock_bh(&udp_app_lock);
|
|
list_for_each_entry(i, &udp_apps[hash], p_list) {
|
|
if (i->port == port) {
|
|
ret = -EEXIST;
|
|
goto out;
|
|
}
|
|
}
|
|
list_add(&inc->p_list, &udp_apps[hash]);
|
|
atomic_inc(&ip_vs_protocol_udp.appcnt);
|
|
|
|
out:
|
|
spin_unlock_bh(&udp_app_lock);
|
|
return ret;
|
|
}
|
|
|
|
|
|
static void
|
|
udp_unregister_app(struct ip_vs_app *inc)
|
|
{
|
|
spin_lock_bh(&udp_app_lock);
|
|
atomic_dec(&ip_vs_protocol_udp.appcnt);
|
|
list_del(&inc->p_list);
|
|
spin_unlock_bh(&udp_app_lock);
|
|
}
|
|
|
|
|
|
static int udp_app_conn_bind(struct ip_vs_conn *cp)
|
|
{
|
|
int hash;
|
|
struct ip_vs_app *inc;
|
|
int result = 0;
|
|
|
|
/* Default binding: bind app only for NAT */
|
|
if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
|
|
return 0;
|
|
|
|
/* Lookup application incarnations and bind the right one */
|
|
hash = udp_app_hashkey(cp->vport);
|
|
|
|
spin_lock(&udp_app_lock);
|
|
list_for_each_entry(inc, &udp_apps[hash], p_list) {
|
|
if (inc->port == cp->vport) {
|
|
if (unlikely(!ip_vs_app_inc_get(inc)))
|
|
break;
|
|
spin_unlock(&udp_app_lock);
|
|
|
|
IP_VS_DBG(9, "%s: Binding conn %u.%u.%u.%u:%u->"
|
|
"%u.%u.%u.%u:%u to app %s on port %u\n",
|
|
__FUNCTION__,
|
|
NIPQUAD(cp->caddr), ntohs(cp->cport),
|
|
NIPQUAD(cp->vaddr), ntohs(cp->vport),
|
|
inc->name, ntohs(inc->port));
|
|
cp->app = inc;
|
|
if (inc->init_conn)
|
|
result = inc->init_conn(inc, cp);
|
|
goto out;
|
|
}
|
|
}
|
|
spin_unlock(&udp_app_lock);
|
|
|
|
out:
|
|
return result;
|
|
}
|
|
|
|
|
|
static int udp_timeouts[IP_VS_UDP_S_LAST+1] = {
|
|
[IP_VS_UDP_S_NORMAL] = 5*60*HZ,
|
|
[IP_VS_UDP_S_LAST] = 2*HZ,
|
|
};
|
|
|
|
static char * udp_state_name_table[IP_VS_UDP_S_LAST+1] = {
|
|
[IP_VS_UDP_S_NORMAL] = "UDP",
|
|
[IP_VS_UDP_S_LAST] = "BUG!",
|
|
};
|
|
|
|
|
|
static int
|
|
udp_set_state_timeout(struct ip_vs_protocol *pp, char *sname, int to)
|
|
{
|
|
return ip_vs_set_state_timeout(pp->timeout_table, IP_VS_UDP_S_LAST,
|
|
udp_state_name_table, sname, to);
|
|
}
|
|
|
|
static const char * udp_state_name(int state)
|
|
{
|
|
if (state >= IP_VS_UDP_S_LAST)
|
|
return "ERR!";
|
|
return udp_state_name_table[state] ? udp_state_name_table[state] : "?";
|
|
}
|
|
|
|
static int
|
|
udp_state_transition(struct ip_vs_conn *cp, int direction,
|
|
const struct sk_buff *skb,
|
|
struct ip_vs_protocol *pp)
|
|
{
|
|
cp->timeout = pp->timeout_table[IP_VS_UDP_S_NORMAL];
|
|
return 1;
|
|
}
|
|
|
|
static void udp_init(struct ip_vs_protocol *pp)
|
|
{
|
|
IP_VS_INIT_HASH_TABLE(udp_apps);
|
|
pp->timeout_table = udp_timeouts;
|
|
}
|
|
|
|
static void udp_exit(struct ip_vs_protocol *pp)
|
|
{
|
|
}
|
|
|
|
|
|
struct ip_vs_protocol ip_vs_protocol_udp = {
|
|
.name = "UDP",
|
|
.protocol = IPPROTO_UDP,
|
|
.dont_defrag = 0,
|
|
.init = udp_init,
|
|
.exit = udp_exit,
|
|
.conn_schedule = udp_conn_schedule,
|
|
.conn_in_get = udp_conn_in_get,
|
|
.conn_out_get = udp_conn_out_get,
|
|
.snat_handler = udp_snat_handler,
|
|
.dnat_handler = udp_dnat_handler,
|
|
.csum_check = udp_csum_check,
|
|
.state_transition = udp_state_transition,
|
|
.state_name = udp_state_name,
|
|
.register_app = udp_register_app,
|
|
.unregister_app = udp_unregister_app,
|
|
.app_conn_bind = udp_app_conn_bind,
|
|
.debug_packet = ip_vs_tcpudp_debug_packet,
|
|
.timeout_change = NULL,
|
|
.set_state_timeout = udp_set_state_timeout,
|
|
};
|