diff options
Diffstat (limited to 'net/ipv4/ipvs/ip_vs_core.c')
| -rw-r--r-- | net/ipv4/ipvs/ip_vs_core.c | 1125 |
1 files changed, 0 insertions, 1125 deletions
diff --git a/net/ipv4/ipvs/ip_vs_core.c b/net/ipv4/ipvs/ip_vs_core.c deleted file mode 100644 index a7879eafc3b5..000000000000 --- a/net/ipv4/ipvs/ip_vs_core.c +++ /dev/null @@ -1,1125 +0,0 @@ -/* - * IPVS An implementation of the IP virtual server support for the - * LINUX operating system. IPVS is now implemented as a module - * over the Netfilter framework. IPVS can be used to build a - * high-performance and highly available server based on a - * cluster of servers. - * - * Authors: Wensong Zhang <wensong@linuxvirtualserver.org> - * Peter Kese <peter.kese@ijs.si> - * 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. - * - * The IPVS code for kernel 2.2 was done by Wensong Zhang and Peter Kese, - * with changes/fixes from Julian Anastasov, Lars Marowsky-Bree, Horms - * and others. - * - * Changes: - * Paul `Rusty' Russell properly handle non-linear skbs - * Harald Welte don't use nfcache - * - */ - -#include <linux/module.h> -#include <linux/kernel.h> -#include <linux/ip.h> -#include <linux/tcp.h> -#include <linux/icmp.h> - -#include <net/ip.h> -#include <net/tcp.h> -#include <net/udp.h> -#include <net/icmp.h> /* for icmp_send */ -#include <net/route.h> - -#include <linux/netfilter.h> -#include <linux/netfilter_ipv4.h> - -#include <net/ip_vs.h> - - -EXPORT_SYMBOL(register_ip_vs_scheduler); -EXPORT_SYMBOL(unregister_ip_vs_scheduler); -EXPORT_SYMBOL(ip_vs_skb_replace); -EXPORT_SYMBOL(ip_vs_proto_name); -EXPORT_SYMBOL(ip_vs_conn_new); -EXPORT_SYMBOL(ip_vs_conn_in_get); -EXPORT_SYMBOL(ip_vs_conn_out_get); -#ifdef CONFIG_IP_VS_PROTO_TCP -EXPORT_SYMBOL(ip_vs_tcp_conn_listen); -#endif -EXPORT_SYMBOL(ip_vs_conn_put); -#ifdef CONFIG_IP_VS_DEBUG -EXPORT_SYMBOL(ip_vs_get_debug_level); -#endif - - -/* ID used in ICMP lookups */ -#define icmp_id(icmph) (((icmph)->un).echo.id) - -const char *ip_vs_proto_name(unsigned proto) -{ - static char buf[20]; - - switch (proto) { - case IPPROTO_IP: - return "IP"; - case IPPROTO_UDP: - return "UDP"; - case IPPROTO_TCP: - return "TCP"; - case IPPROTO_ICMP: - return "ICMP"; - default: - sprintf(buf, "IP_%d", proto); - return buf; - } -} - -void ip_vs_init_hash_table(struct list_head *table, int rows) -{ - while (--rows >= 0) - INIT_LIST_HEAD(&table[rows]); -} - -static inline void -ip_vs_in_stats(struct ip_vs_conn *cp, struct sk_buff *skb) -{ - struct ip_vs_dest *dest = cp->dest; - if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) { - spin_lock(&dest->stats.lock); - dest->stats.inpkts++; - dest->stats.inbytes += skb->len; - spin_unlock(&dest->stats.lock); - - spin_lock(&dest->svc->stats.lock); - dest->svc->stats.inpkts++; - dest->svc->stats.inbytes += skb->len; - spin_unlock(&dest->svc->stats.lock); - - spin_lock(&ip_vs_stats.lock); - ip_vs_stats.inpkts++; - ip_vs_stats.inbytes += skb->len; - spin_unlock(&ip_vs_stats.lock); - } -} - - -static inline void -ip_vs_out_stats(struct ip_vs_conn *cp, struct sk_buff *skb) -{ - struct ip_vs_dest *dest = cp->dest; - if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) { - spin_lock(&dest->stats.lock); - dest->stats.outpkts++; - dest->stats.outbytes += skb->len; - spin_unlock(&dest->stats.lock); - - spin_lock(&dest->svc->stats.lock); - dest->svc->stats.outpkts++; - dest->svc->stats.outbytes += skb->len; - spin_unlock(&dest->svc->stats.lock); - - spin_lock(&ip_vs_stats.lock); - ip_vs_stats.outpkts++; - ip_vs_stats.outbytes += skb->len; - spin_unlock(&ip_vs_stats.lock); - } -} - - -static inline void -ip_vs_conn_stats(struct ip_vs_conn *cp, struct ip_vs_service *svc) -{ - spin_lock(&cp->dest->stats.lock); - cp->dest->stats.conns++; - spin_unlock(&cp->dest->stats.lock); - - spin_lock(&svc->stats.lock); - svc->stats.conns++; - spin_unlock(&svc->stats.lock); - - spin_lock(&ip_vs_stats.lock); - ip_vs_stats.conns++; - spin_unlock(&ip_vs_stats.lock); -} - - -static inline int -ip_vs_set_state(struct ip_vs_conn *cp, int direction, - const struct sk_buff *skb, - struct ip_vs_protocol *pp) -{ - if (unlikely(!pp->state_transition)) - return 0; - return pp->state_transition(cp, direction, skb, pp); -} - - -/* - * 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; -} - - -/* - * IPVS main scheduling function - * It selects a server according to the virtual service, and - * creates a connection entry. - * Protocols supported: TCP, UDP - */ -struct ip_vs_conn * -ip_vs_schedule(struct ip_vs_service *svc, const struct sk_buff *skb) -{ - struct ip_vs_conn *cp = NULL; - struct iphdr *iph = ip_hdr(skb); - struct ip_vs_dest *dest; - __be16 _ports[2], *pptr; - - pptr = skb_header_pointer(skb, iph->ihl*4, - sizeof(_ports), _ports); - if (pptr == NULL) - return NULL; - - /* - * Persistent service - */ - if (svc->flags & IP_VS_SVC_F_PERSISTENT) - return ip_vs_sched_persist(svc, skb, pptr); - - /* - * Non-persistent service - */ - if (!svc->fwmark && pptr[1] != svc->port) { - if (!svc->port) - IP_VS_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; - } - - /* - * Create a connection entry. - */ - cp = ip_vs_conn_new(iph->protocol, - iph->saddr, pptr[0], - iph->daddr, pptr[1], - dest->addr, dest->port?dest->port:pptr[1], - 0, - dest); - if (cp == NULL) - return NULL; - - IP_VS_DBG(6, "Schedule fwd:%c c:%u.%u.%u.%u:%u v:%u.%u.%u.%u:%u " - "d:%u.%u.%u.%u:%u conn->flags:%X conn->refcnt:%d\n", - ip_vs_fwd_tag(cp), - NIPQUAD(cp->caddr), ntohs(cp->cport), - NIPQUAD(cp->vaddr), ntohs(cp->vport), - NIPQUAD(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_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(&init_net, 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; -} - - -/* - * It is hooked before NF_IP_PRI_NAT_SRC at the NF_INET_POST_ROUTING - * chain, and is used for VS/NAT. - * It detects packets for VS/NAT connections and sends the packets - * immediately. This can avoid that iptable_nat mangles the packets - * for VS/NAT. - */ -static unsigned int ip_vs_post_routing(unsigned int hooknum, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) -{ - if (!skb->ipvs_property) - return NF_ACCEPT; - /* The packet was sent from IPVS, exit this chain */ - return NF_STOP; -} - -__sum16 ip_vs_checksum_complete(struct sk_buff *skb, int offset) -{ - return csum_fold(skb_checksum(skb, offset, skb->len - offset, 0)); -} - -static inline int ip_vs_gather_frags(struct sk_buff *skb, u_int32_t user) -{ - int err = ip_defrag(skb, user); - - if (!err) - ip_send_check(ip_hdr(skb)); - - return err; -} - -/* - * Packet has been made sufficiently writable in caller - * - inout: 1=in->out, 0=out->in - */ -void ip_vs_nat_icmp(struct sk_buff *skb, struct ip_vs_protocol *pp, - struct ip_vs_conn *cp, int inout) -{ - struct iphdr *iph = ip_hdr(skb); - unsigned int icmp_offset = iph->ihl*4; - struct icmphdr *icmph = (struct icmphdr *)(skb_network_header(skb) + - icmp_offset); - struct iphdr *ciph = (struct iphdr *)(icmph + 1); - - if (inout) { - iph->saddr = cp->vaddr; - ip_send_check(iph); - ciph->daddr = cp->vaddr; - ip_send_check(ciph); - } else { - iph->daddr = cp->daddr; - ip_send_check(iph); - ciph->saddr = cp->daddr; - ip_send_check(ciph); - } - - /* the TCP/UDP port */ - if (IPPROTO_TCP == ciph->protocol || IPPROTO_UDP == ciph->protocol) { - __be16 *ports = (void *)ciph + ciph->ihl*4; - - if (inout) - ports[1] = cp->vport; - else - ports[0] = cp->dport; - } - - /* And finally the ICMP checksum */ - icmph->checksum = 0; - icmph->checksum = ip_vs_checksum_complete(skb, icmp_offset); - skb->ip_summed = CHECKSUM_UNNECESSARY; - - if (inout) - IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph, - "Forwarding altered outgoing ICMP"); - else - IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph, - "Forwarding altered incoming ICMP"); -} - -/* - * 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, int *related) -{ - struct iphdr *iph; - struct icmphdr _icmph, *ic; - struct iphdr _ciph, *cih; /* The ip header contained within the ICMP */ - struct ip_vs_conn *cp; - struct ip_vs_protocol *pp; - unsigned int offset, ihl, verdict; - - *related = 1; - - /* reassemble IP fragments */ - if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) { - if (ip_vs_gather_frags(skb, IP_DEFRAG_VS_OUT)) - return NF_STOLEN; - } - - iph = ip_hdr(skb); - offset = ihl = iph->ihl * 4; - ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph); - if (ic == NULL) - return NF_DROP; - - IP_VS_DBG(12, "Outgoing ICMP (%d,%d) %u.%u.%u.%u->%u.%u.%u.%u\n", - ic->type, ntohs(icmp_id(ic)), - 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 ((ic->type != ICMP_DEST_UNREACH) && - (ic->type != ICMP_SOURCE_QUENCH) && - (ic->type != ICMP_TIME_EXCEEDED)) { - *related = 0; - return NF_ACCEPT; - } - - /* Now find the contained IP header */ - offset += sizeof(_icmph); - cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph); - if (cih == NULL) - return NF_ACCEPT; /* The packet looks wrong, ignore */ - - pp = ip_vs_proto_get(cih->protocol); - if (!pp) - return NF_ACCEPT; - - /* Is the embedded protocol header present? */ - if (unlikely(cih->frag_off & htons(IP_OFFSET) && - pp->dont_defrag)) - return NF_ACCEPT; - - IP_VS_DBG_PKT(11, pp, skb, offset, "Checking outgoing ICMP for"); - - offset += cih->ihl * 4; - - /* The embedded headers contain source and dest in reverse order */ - cp = pp->conn_out_get(skb, pp, cih, offset, 1); - if (!cp) - return NF_ACCEPT; - - verdict = NF_DROP; - - 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"); - } - - /* Ensure the checksum is correct */ - if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) { - /* Failed checksum! */ - IP_VS_DBG(1, "Forward ICMP: failed checksum from %d.%d.%d.%d!\n", - NIPQUAD(iph->saddr)); - goto out; - } - - if (IPPROTO_TCP == cih->protocol || IPPROTO_UDP == cih->protocol) - offset += 2 * sizeof(__u16); - if (!skb_make_writable(skb, offset)) - goto out; - - ip_vs_nat_icmp(skb, pp, cp, 1); - - /* do the statistics and put it back */ - ip_vs_out_stats(cp, skb); - - skb->ipvs_property = 1; - verdict = NF_ACCEPT; - - out: - __ip_vs_conn_put(cp); - - return verdict; -} - -static inline int is_tcp_reset(const struct sk_buff *skb) -{ - struct tcphdr _tcph, *th; - - th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph); - if (th == NULL) - return 0; - return th->rst; -} - -/* - * It is hooked at the NF_INET_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, - const struct net_device *in, const struct net_device *out, - int (*okfn)(struct sk_buff *)) -{ - 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(skb, &related); - - if (related) - return verdict; - 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)) { - if (ip_vs_gather_frags(skb, IP_DEFRAG_VS_OUT)) - return NF_STOLEN; - iph = ip_hdr(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 (!skb_make_writable(skb, ihl)) - goto drop; - - /* mangle the packet */ - if (pp->snat_handler && !pp->snat_handler(skb, pp, cp)) - goto drop; - 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(skb, RTN_LOCAL) != 0) - goto drop; - - 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(skb); - return NF_STOLEN; -} - - -/* - * Handle ICMP messages in the outside-to-inside direction (incoming). - * 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, int *related, unsigned int hooknum) -{ - struct iphdr *iph; - struct icmphdr _icmph, *ic; - struct iphdr _ciph, *cih; /* The ip header contained within the ICMP */ - struct ip_vs_conn *cp; - struct ip_vs_protocol *pp; - unsigned int offset, ihl, verdict; - - *related = 1; - - /* reassemble IP fragments */ - if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) { - if (ip_vs_gather_frags(skb, hooknum == NF_INET_LOCAL_IN ? - IP_DEFRAG_VS_IN : IP_DEFRAG_VS_FWD)) - return NF_STOLEN; - } - - iph = ip_hdr(skb); - offset = ihl = iph->ihl * 4; - ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph); - if (ic == NULL) - return NF_DROP; - - IP_VS_DBG(12, "Incoming ICMP (%d,%d) %u.%u.%u.%u->%u.%u.%u.%u\n", - ic->type, ntohs(icmp_id(ic)), - 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 ((ic->type != ICMP_DEST_UNREACH) && - (ic->type != ICMP_SOURCE_QUENCH) && - (ic->type != ICMP_TIME_EXCEEDED)) { - *related = 0; - return NF_ACCEPT; - } - - /* Now find the contained IP header */ - offset += sizeof(_icmph); - cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph); - if (cih == NULL) - return NF_ACCEPT; /* The packet looks wrong, ignore */ - - pp = ip_vs_proto_get(cih->protocol); - if (!pp) - return NF_ACCEPT; - - /* Is the embedded protocol header present? */ - if (unlikely(cih->frag_off & htons(IP_OFFSET) && - pp->dont_defrag)) - return NF_ACCEPT; - - IP_VS_DBG_PKT(11, pp, skb, offset, "Checking incoming ICMP for"); - - offset += cih->ihl * 4; - - /* The embedded headers contain source and dest in reverse order */ - cp = pp->conn_in_get(skb, pp, cih, offset, 1); - if (!cp) - return NF_ACCEPT; - - verdict = NF_DROP; - - /* Ensure the checksum is correct */ - if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) { - /* Failed checksum! */ - IP_VS_DBG(1, "Incoming ICMP: failed checksum from %d.%d.%d.%d!\n", - NIPQUAD(iph->saddr)); - goto out; - } - - /* do the statistics and put it back */ - ip_vs_in_stats(cp, skb); - if (IPPROTO_TCP == cih->protocol || IPPROTO_UDP == cih->protocol) - offset += 2 * sizeof(__u16); - verdict = ip_vs_icmp_xmit(skb, cp, pp, offset); - /* do not touch skb anymore */ - - out: - __ip_vs_conn_put(cp); - - return verdict; -} - -/* - * 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, - const struct net_device *in, const struct net_device *out, - int (*okfn)(struct sk_buff *)) -{ - 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->flags & IFF_LOOPBACK || 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(skb, &related, hooknum); - - if (related) - return verdict; - 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 - * - * Sync connection if it is about to close to - * encorage the standby servers to update the connections timeout - */ - 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])) || - ((cp->protocol == IPPROTO_TCP) && (cp->old_state != cp->state) && - ((cp->state == IP_VS_TCP_S_FIN_WAIT) || - (cp->state == IP_VS_TCP_S_CLOSE_WAIT) || - (cp->state == IP_VS_TCP_S_TIME_WAIT))))) - ip_vs_sync_conn(cp); - cp->old_state = cp->state; - - ip_vs_conn_put(cp); - return ret; -} - - -/* - * It is hooked at the NF_INET_FORWARD chain, in order to catch ICMP - * related packets destined for 0.0.0.0/0. - * When fwmark-based virtual service is used, such as transparent - * cache cluster, TCP packets can be marked and routed to ip_vs_in, - * but ICMP destined for 0.0.0.0/0 cannot not be easily marked and - * sent to ip_vs_in_icmp. So, catch them at the NF_INET_FORWARD chain - * and send them to ip_vs_in_icmp. - */ -static unsigned int -ip_vs_forward_icmp(unsigned int hooknum, struct sk_buff *skb, - const struct net_device *in, const struct net_device *out, - int (*okfn)(struct sk_buff *)) -{ - int r; - - if (ip_hdr(skb)->protocol != IPPROTO_ICMP) - return NF_ACCEPT; - - return ip_vs_in_icmp(skb, &r, hooknum); -} - - -static struct nf_hook_ops ip_vs_ops[] __read_mostly = { - /* After packet filtering, forward packet through VS/DR, VS/TUN, - * or VS/NAT(change destination), so that filtering rules can be - * applied to IPVS. */ - { - .hook = ip_vs_in, - .owner = THIS_MODULE, - .pf = PF_INET, - .hooknum = NF_INET_LOCAL_IN, - .priority = 100, - }, - /* After packet filtering, change source only for VS/NAT */ - { - .hook = ip_vs_out, - .owner = THIS_MODULE, - .pf = PF_INET, - .hooknum = NF_INET_FORWARD, - .priority = 100, - }, - /* After packet filtering (but before ip_vs_out_icmp), catch icmp - * destined for 0.0.0.0/0, which is for incoming IPVS connections */ - { - .hook = ip_vs_forward_icmp, - .owner = THIS_MODULE, - .pf = PF_INET, - .hooknum = NF_INET_FORWARD, - .priority = 99, - }, - /* Before the netfilter connection tracking, exit from POST_ROUTING */ - { - .hook = ip_vs_post_routing, - .owner = THIS_MODULE, - .pf = PF_INET, - .hooknum = NF_INET_POST_ROUTING, - .priority = NF_IP_PRI_NAT_SRC-1, - }, -}; - - -/* - * Initialize IP Virtual Server - */ -static int __init ip_vs_init(void) -{ - int ret; - - ret = ip_vs_control_init(); - if (ret < 0) { - IP_VS_ERR("can't setup control.\n"); - goto cleanup_nothing; - } - - ip_vs_protocol_init(); - - ret = ip_vs_app_init(); - if (ret < 0) { - IP_VS_ERR("can't setup application helper.\n"); - goto cleanup_protocol; - } - - ret = ip_vs_conn_init(); - if (ret < 0) { - IP_VS_ERR("can't setup connection table.\n"); - goto cleanup_app; - } - - ret = nf_register_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops)); - if (ret < 0) { - IP_VS_ERR("can't register hooks.\n"); - goto cleanup_conn; - } - - IP_VS_INFO("ipvs loaded.\n"); - return ret; - - cleanup_conn: - ip_vs_conn_cleanup(); - cleanup_app: - ip_vs_app_cleanup(); - cleanup_protocol: - ip_vs_protocol_cleanup(); - ip_vs_control_cleanup(); - cleanup_nothing: - return ret; -} - -static void __exit ip_vs_cleanup(void) -{ - nf_unregister_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops)); - ip_vs_conn_cleanup(); - ip_vs_app_cleanup(); - ip_vs_protocol_cleanup(); - ip_vs_control_cleanup(); - IP_VS_INFO("ipvs unloaded.\n"); -} - -module_init(ip_vs_init); -module_exit(ip_vs_cleanup); -MODULE_LICENSE("GPL"); |