diff options
Diffstat (limited to 'net/netfilter/ipvs/ip_vs_core.c')
-rw-r--r-- | net/netfilter/ipvs/ip_vs_core.c | 2050 |
1 files changed, 2050 insertions, 0 deletions
diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c new file mode 100644 index 00000000..0787bed0 --- /dev/null +++ b/net/netfilter/ipvs/ip_vs_core.c @@ -0,0 +1,2050 @@ +/* + * 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 + * + */ + +#define KMSG_COMPONENT "IPVS" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/ip.h> +#include <linux/tcp.h> +#include <linux/sctp.h> +#include <linux/icmp.h> +#include <linux/slab.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 <net/ip6_checksum.h> +#include <net/netns/generic.h> /* net_generic() */ + +#include <linux/netfilter.h> +#include <linux/netfilter_ipv4.h> + +#ifdef CONFIG_IP_VS_IPV6 +#include <net/ipv6.h> +#include <linux/netfilter_ipv6.h> +#include <net/ip6_route.h> +#endif + +#include <net/ip_vs.h> + + +EXPORT_SYMBOL(register_ip_vs_scheduler); +EXPORT_SYMBOL(unregister_ip_vs_scheduler); +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 + +int ip_vs_net_id __read_mostly; +#ifdef IP_VS_GENERIC_NETNS +EXPORT_SYMBOL(ip_vs_net_id); +#endif +/* netns cnt used for uniqueness */ +static atomic_t ipvs_netns_cnt = ATOMIC_INIT(0); + +/* ID used in ICMP lookups */ +#define icmp_id(icmph) (((icmph)->un).echo.id) +#define icmpv6_id(icmph) (icmph->icmp6_dataun.u_echo.identifier) + +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_SCTP: + return "SCTP"; + case IPPROTO_ICMP: + return "ICMP"; +#ifdef CONFIG_IP_VS_IPV6 + case IPPROTO_ICMPV6: + return "ICMPv6"; +#endif + 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; + struct netns_ipvs *ipvs = net_ipvs(skb_net(skb)); + + if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) { + struct ip_vs_cpu_stats *s; + + s = this_cpu_ptr(dest->stats.cpustats); + s->ustats.inpkts++; + u64_stats_update_begin(&s->syncp); + s->ustats.inbytes += skb->len; + u64_stats_update_end(&s->syncp); + + s = this_cpu_ptr(dest->svc->stats.cpustats); + s->ustats.inpkts++; + u64_stats_update_begin(&s->syncp); + s->ustats.inbytes += skb->len; + u64_stats_update_end(&s->syncp); + + s = this_cpu_ptr(ipvs->tot_stats.cpustats); + s->ustats.inpkts++; + u64_stats_update_begin(&s->syncp); + s->ustats.inbytes += skb->len; + u64_stats_update_end(&s->syncp); + } +} + + +static inline void +ip_vs_out_stats(struct ip_vs_conn *cp, struct sk_buff *skb) +{ + struct ip_vs_dest *dest = cp->dest; + struct netns_ipvs *ipvs = net_ipvs(skb_net(skb)); + + if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) { + struct ip_vs_cpu_stats *s; + + s = this_cpu_ptr(dest->stats.cpustats); + s->ustats.outpkts++; + u64_stats_update_begin(&s->syncp); + s->ustats.outbytes += skb->len; + u64_stats_update_end(&s->syncp); + + s = this_cpu_ptr(dest->svc->stats.cpustats); + s->ustats.outpkts++; + u64_stats_update_begin(&s->syncp); + s->ustats.outbytes += skb->len; + u64_stats_update_end(&s->syncp); + + s = this_cpu_ptr(ipvs->tot_stats.cpustats); + s->ustats.outpkts++; + u64_stats_update_begin(&s->syncp); + s->ustats.outbytes += skb->len; + u64_stats_update_end(&s->syncp); + } +} + + +static inline void +ip_vs_conn_stats(struct ip_vs_conn *cp, struct ip_vs_service *svc) +{ + struct netns_ipvs *ipvs = net_ipvs(svc->net); + struct ip_vs_cpu_stats *s; + + s = this_cpu_ptr(cp->dest->stats.cpustats); + s->ustats.conns++; + + s = this_cpu_ptr(svc->stats.cpustats); + s->ustats.conns++; + + s = this_cpu_ptr(ipvs->tot_stats.cpustats); + s->ustats.conns++; +} + + +static inline int +ip_vs_set_state(struct ip_vs_conn *cp, int direction, + const struct sk_buff *skb, + struct ip_vs_proto_data *pd) +{ + if (unlikely(!pd->pp->state_transition)) + return 0; + return pd->pp->state_transition(cp, direction, skb, pd); +} + +static inline int +ip_vs_conn_fill_param_persist(const struct ip_vs_service *svc, + struct sk_buff *skb, int protocol, + const union nf_inet_addr *caddr, __be16 cport, + const union nf_inet_addr *vaddr, __be16 vport, + struct ip_vs_conn_param *p) +{ + ip_vs_conn_fill_param(svc->net, svc->af, protocol, caddr, cport, vaddr, + vport, p); + p->pe = svc->pe; + if (p->pe && p->pe->fill_param) + return p->pe->fill_param(p, skb); + + return 0; +} + +/* + * 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_conn *cp = NULL; + struct ip_vs_iphdr iph; + 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 */ + + ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph); + + /* 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, 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)) { + /* + * No template found or the dest of the connection + * template is not available. + * return *ignored=0 i.e. ICMP and NF_DROP + */ + 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; + + /* 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->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->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_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; + + /* + * 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, 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; + } + + /* + * Persistent service + */ + if (svc->flags & IP_VS_SVC_F_PERSISTENT) + return ip_vs_sched_persist(svc, skb, pptr[0], pptr[1], ignored); + + *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; + } + + 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; + + /* + * 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->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; +} + + +/* + * 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) +{ + __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); + + /* 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, cs; + 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); + + /* 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, &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 */ + cs = ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd); + + /* transmit the first SYN packet */ + ret = cp->packet_xmit(skb, cp, pd->pp); + /* do not touch skb anymore */ + + atomic_inc(&cp->in_pkts); + ip_vs_conn_put(cp); + return ret; + } +#endif + + /* + * 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 + */ +#ifdef CONFIG_IP_VS_IPV6 + if (svc->af == AF_INET6) { + if (!skb->dev) { + struct net *net = dev_net(skb_dst(skb)->dev); + + skb->dev = net->loopback_dev; + } + icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0); + } else +#endif + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); + + return NF_DROP; +} + +#ifdef CONFIG_SYSCTL + +static int sysctl_snat_reroute(struct sk_buff *skb) +{ + struct netns_ipvs *ipvs = net_ipvs(skb_net(skb)); + return ipvs->sysctl_snat_reroute; +} + +static int sysctl_nat_icmp_send(struct net *net) +{ + struct netns_ipvs *ipvs = net_ipvs(net); + return ipvs->sysctl_nat_icmp_send; +} + +static int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs) +{ + return ipvs->sysctl_expire_nodest_conn; +} + +#else + +static int sysctl_snat_reroute(struct sk_buff *skb) { return 0; } +static int sysctl_nat_icmp_send(struct net *net) { return 0; } +static int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs) { return 0; } + +#endif + +__sum16 ip_vs_checksum_complete(struct sk_buff *skb, int offset) +{ + return csum_fold(skb_checksum(skb, offset, skb->len - offset, 0)); +} + +static inline enum ip_defrag_users ip_vs_defrag_user(unsigned int hooknum) +{ + if (NF_INET_LOCAL_IN == hooknum) + return IP_DEFRAG_VS_IN; + if (NF_INET_FORWARD == hooknum) + return IP_DEFRAG_VS_FWD; + return IP_DEFRAG_VS_OUT; +} + +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; +} + +#ifdef CONFIG_IP_VS_IPV6 +static inline int ip_vs_gather_frags_v6(struct sk_buff *skb, u_int32_t user) +{ + /* TODO IPv6: Find out what to do here for IPv6 */ + return 0; +} +#endif + +static int ip_vs_route_me_harder(int af, struct sk_buff *skb) +{ +#ifdef CONFIG_IP_VS_IPV6 + if (af == AF_INET6) { + if (sysctl_snat_reroute(skb) && ip6_route_me_harder(skb) != 0) + return 1; + } else +#endif + if ((sysctl_snat_reroute(skb) || + skb_rtable(skb)->rt_flags & RTCF_LOCAL) && + ip_route_me_harder(skb, RTN_LOCAL) != 0) + return 1; + + return 0; +} + +/* + * 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; + ip_send_check(iph); + ciph->daddr = cp->vaddr.ip; + ip_send_check(ciph); + } else { + iph->daddr = cp->daddr.ip; + ip_send_check(iph); + ciph->saddr = cp->daddr.ip; + ip_send_check(ciph); + } + + /* the TCP/UDP/SCTP port */ + if (IPPROTO_TCP == ciph->protocol || IPPROTO_UDP == ciph->protocol || + IPPROTO_SCTP == 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, AF_INET, pp, skb, (void *)ciph - (void *)iph, + "Forwarding altered outgoing ICMP"); + else + IP_VS_DBG_PKT(11, AF_INET, pp, skb, (void *)ciph - (void *)iph, + "Forwarding altered incoming ICMP"); +} + +#ifdef CONFIG_IP_VS_IPV6 +void ip_vs_nat_icmp_v6(struct sk_buff *skb, struct ip_vs_protocol *pp, + struct ip_vs_conn *cp, int inout) +{ + struct ipv6hdr *iph = ipv6_hdr(skb); + unsigned int icmp_offset = sizeof(struct ipv6hdr); + struct icmp6hdr *icmph = (struct icmp6hdr *)(skb_network_header(skb) + + icmp_offset); + struct ipv6hdr *ciph = (struct ipv6hdr *)(icmph + 1); + + if (inout) { + iph->saddr = cp->vaddr.in6; + ciph->daddr = cp->vaddr.in6; + } else { + iph->daddr = cp->daddr.in6; + ciph->saddr = cp->daddr.in6; + } + + /* the TCP/UDP/SCTP port */ + if (IPPROTO_TCP == ciph->nexthdr || IPPROTO_UDP == ciph->nexthdr || + IPPROTO_SCTP == ciph->nexthdr) { + __be16 *ports = (void *)ciph + sizeof(struct ipv6hdr); + + if (inout) + ports[1] = cp->vport; + else + ports[0] = cp->dport; + } + + /* And finally the ICMP checksum */ + icmph->icmp6_cksum = ~csum_ipv6_magic(&iph->saddr, &iph->daddr, + skb->len - icmp_offset, + IPPROTO_ICMPV6, 0); + skb->csum_start = skb_network_header(skb) - skb->head + icmp_offset; + skb->csum_offset = offsetof(struct icmp6hdr, icmp6_cksum); + skb->ip_summed = CHECKSUM_PARTIAL; + + if (inout) + IP_VS_DBG_PKT(11, AF_INET6, pp, skb, + (void *)ciph - (void *)iph, + "Forwarding altered outgoing ICMPv6"); + else + IP_VS_DBG_PKT(11, AF_INET6, pp, skb, + (void *)ciph - (void *)iph, + "Forwarding altered incoming ICMPv6"); +} +#endif + +/* Handle relevant response ICMP messages - forward to the right + * destination host. + */ +static int handle_response_icmp(int af, struct sk_buff *skb, + union nf_inet_addr *snet, + __u8 protocol, struct ip_vs_conn *cp, + struct ip_vs_protocol *pp, + unsigned int offset, unsigned int ihl) +{ + unsigned int verdict = NF_DROP; + + if (IP_VS_FWD_METHOD(cp) != 0) { + pr_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_BUF(1, "Forward ICMP: failed checksum from %s!\n", + IP_VS_DBG_ADDR(af, snet)); + goto out; + } + + if (IPPROTO_TCP == protocol || IPPROTO_UDP == protocol || + IPPROTO_SCTP == protocol) + offset += 2 * sizeof(__u16); + if (!skb_make_writable(skb, offset)) + goto out; + +#ifdef CONFIG_IP_VS_IPV6 + if (af == AF_INET6) + ip_vs_nat_icmp_v6(skb, pp, cp, 1); + else +#endif + ip_vs_nat_icmp(skb, pp, cp, 1); + + if (ip_vs_route_me_harder(af, skb)) + goto out; + + /* do the statistics and put it back */ + ip_vs_out_stats(cp, skb); + + skb->ipvs_property = 1; + if (!(cp->flags & IP_VS_CONN_F_NFCT)) + ip_vs_notrack(skb); + else + ip_vs_update_conntrack(skb, cp, 0); + verdict = NF_ACCEPT; + +out: + __ip_vs_conn_put(cp); + + return verdict; +} + +/* + * Handle ICMP messages in the inside-to-outside direction (outgoing). + * Find any that might be relevant, check against existing connections. + * Currently handles error types - unreachable, quench, ttl exceeded. + */ +static int ip_vs_out_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_iphdr ciph; + struct ip_vs_conn *cp; + struct ip_vs_protocol *pp; + unsigned int offset, ihl; + union nf_inet_addr snet; + + *related = 1; + + /* reassemble IP fragments */ + if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) { + if (ip_vs_gather_frags(skb, ip_vs_defrag_user(hooknum))) + 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) %pI4->%pI4\n", + ic->type, ntohs(icmp_id(ic)), + &iph->saddr, &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, AF_INET, pp, skb, offset, + "Checking outgoing ICMP for"); + + offset += cih->ihl * 4; + + ip_vs_fill_iphdr(AF_INET, cih, &ciph); + /* The embedded headers contain source and dest in reverse order */ + cp = pp->conn_out_get(AF_INET, skb, &ciph, offset, 1); + if (!cp) + return NF_ACCEPT; + + snet.ip = iph->saddr; + return handle_response_icmp(AF_INET, skb, &snet, cih->protocol, cp, + pp, offset, ihl); +} + +#ifdef CONFIG_IP_VS_IPV6 +static int ip_vs_out_icmp_v6(struct sk_buff *skb, int *related, + unsigned int hooknum) +{ + struct ipv6hdr *iph; + struct icmp6hdr _icmph, *ic; + struct ipv6hdr _ciph, *cih; /* The ip header contained + within the ICMP */ + struct ip_vs_iphdr ciph; + struct ip_vs_conn *cp; + struct ip_vs_protocol *pp; + unsigned int offset; + union nf_inet_addr snet; + + *related = 1; + + /* reassemble IP fragments */ + if (ipv6_hdr(skb)->nexthdr == IPPROTO_FRAGMENT) { + if (ip_vs_gather_frags_v6(skb, ip_vs_defrag_user(hooknum))) + return NF_STOLEN; + } + + iph = ipv6_hdr(skb); + offset = sizeof(struct ipv6hdr); + ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph); + if (ic == NULL) + return NF_DROP; + + IP_VS_DBG(12, "Outgoing ICMPv6 (%d,%d) %pI6->%pI6\n", + ic->icmp6_type, ntohs(icmpv6_id(ic)), + &iph->saddr, &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->icmp6_type != ICMPV6_DEST_UNREACH) && + (ic->icmp6_type != ICMPV6_PKT_TOOBIG) && + (ic->icmp6_type != ICMPV6_TIME_EXCEED)) { + *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->nexthdr); + if (!pp) + return NF_ACCEPT; + + /* Is the embedded protocol header present? */ + /* TODO: we don't support fragmentation at the moment anyways */ + if (unlikely(cih->nexthdr == IPPROTO_FRAGMENT && pp->dont_defrag)) + return NF_ACCEPT; + + IP_VS_DBG_PKT(11, AF_INET6, pp, skb, offset, + "Checking outgoing ICMPv6 for"); + + offset += sizeof(struct ipv6hdr); + + ip_vs_fill_iphdr(AF_INET6, cih, &ciph); + /* The embedded headers contain source and dest in reverse order */ + cp = pp->conn_out_get(AF_INET6, skb, &ciph, offset, 1); + if (!cp) + return NF_ACCEPT; + + ipv6_addr_copy(&snet.in6, &iph->saddr); + return handle_response_icmp(AF_INET6, skb, &snet, cih->nexthdr, cp, + pp, offset, sizeof(struct ipv6hdr)); +} +#endif + +/* + * Check if sctp chunc is ABORT chunk + */ +static inline int is_sctp_abort(const struct sk_buff *skb, int nh_len) +{ + sctp_chunkhdr_t *sch, schunk; + sch = skb_header_pointer(skb, nh_len + sizeof(sctp_sctphdr_t), + sizeof(schunk), &schunk); + if (sch == NULL) + return 0; + if (sch->type == SCTP_CID_ABORT) + return 1; + return 0; +} + +static inline int is_tcp_reset(const struct sk_buff *skb, int nh_len) +{ + struct tcphdr _tcph, *th; + + th = skb_header_pointer(skb, nh_len, sizeof(_tcph), &_tcph); + if (th == NULL) + return 0; + return th->rst; +} + +/* Handle response packets: rewrite addresses and send away... + */ +static unsigned int +handle_response(int af, struct sk_buff *skb, struct ip_vs_proto_data *pd, + struct ip_vs_conn *cp, int ihl) +{ + struct ip_vs_protocol *pp = pd->pp; + + IP_VS_DBG_PKT(11, af, 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; + +#ifdef CONFIG_IP_VS_IPV6 + if (af == AF_INET6) + ipv6_hdr(skb)->saddr = cp->vaddr.in6; + else +#endif + { + ip_hdr(skb)->saddr = cp->vaddr.ip; + ip_send_check(ip_hdr(skb)); + } + + /* + * nf_iterate does not expect change in the skb->dst->dev. + * It looks like it is not fatal to enable this code for hooks + * where our handlers are at the end of the chain list and + * when all next handlers use skb->dst->dev and not outdev. + * It will definitely route properly the inout NAT traffic + * when multiple paths are used. + */ + + /* 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_vs_route_me_harder(af, skb)) + goto drop; + + IP_VS_DBG_PKT(10, af, pp, skb, 0, "After SNAT"); + + ip_vs_out_stats(cp, skb); + ip_vs_set_state(cp, IP_VS_DIR_OUTPUT, skb, pd); + skb->ipvs_property = 1; + if (!(cp->flags & IP_VS_CONN_F_NFCT)) + ip_vs_notrack(skb); + else + ip_vs_update_conntrack(skb, cp, 0); + ip_vs_conn_put(cp); + + LeaveFunction(11); + return NF_ACCEPT; + +drop: + ip_vs_conn_put(cp); + kfree_skb(skb); + LeaveFunction(11); + return NF_STOLEN; +} + +/* + * Check if outgoing packet belongs to the established ip_vs_conn. + */ +static unsigned int +ip_vs_out(unsigned int hooknum, struct sk_buff *skb, int af) +{ + struct net *net = NULL; + struct ip_vs_iphdr iph; + struct ip_vs_protocol *pp; + struct ip_vs_proto_data *pd; + struct ip_vs_conn *cp; + + EnterFunction(11); + + /* Already marked as IPVS request or reply? */ + if (skb->ipvs_property) + return NF_ACCEPT; + + /* Bad... Do not break raw sockets */ + if (unlikely(skb->sk != NULL && hooknum == NF_INET_LOCAL_OUT && + af == AF_INET)) { + struct sock *sk = skb->sk; + struct inet_sock *inet = inet_sk(skb->sk); + + if (inet && sk->sk_family == PF_INET && inet->nodefrag) + return NF_ACCEPT; + } + + if (unlikely(!skb_dst(skb))) + return NF_ACCEPT; + + net = skb_net(skb); + if (!net_ipvs(net)->enable) + return NF_ACCEPT; + + ip_vs_fill_iphdr(af, skb_network_header(skb), &iph); +#ifdef CONFIG_IP_VS_IPV6 + if (af == AF_INET6) { + if (unlikely(iph.protocol == IPPROTO_ICMPV6)) { + int related; + int verdict = ip_vs_out_icmp_v6(skb, &related, + hooknum); + + if (related) + return verdict; + ip_vs_fill_iphdr(af, skb_network_header(skb), &iph); + } + } else +#endif + if (unlikely(iph.protocol == IPPROTO_ICMP)) { + int related; + int verdict = ip_vs_out_icmp(skb, &related, hooknum); + + if (related) + return verdict; + ip_vs_fill_iphdr(af, skb_network_header(skb), &iph); + } + + pd = ip_vs_proto_data_get(net, iph.protocol); + if (unlikely(!pd)) + return NF_ACCEPT; + pp = pd->pp; + + /* reassemble IP fragments */ +#ifdef CONFIG_IP_VS_IPV6 + if (af == AF_INET6) { + if (ipv6_hdr(skb)->nexthdr == IPPROTO_FRAGMENT) { + if (ip_vs_gather_frags_v6(skb, + ip_vs_defrag_user(hooknum))) + return NF_STOLEN; + } + + ip_vs_fill_iphdr(af, skb_network_header(skb), &iph); + } else +#endif + if (unlikely(ip_hdr(skb)->frag_off & htons(IP_MF|IP_OFFSET) && + !pp->dont_defrag)) { + if (ip_vs_gather_frags(skb, + ip_vs_defrag_user(hooknum))) + return NF_STOLEN; + + ip_vs_fill_iphdr(af, skb_network_header(skb), &iph); + } + + /* + * Check if the packet belongs to an existing entry + */ + cp = pp->conn_out_get(af, skb, &iph, iph.len, 0); + + if (likely(cp)) + return handle_response(af, skb, pd, cp, iph.len); + if (sysctl_nat_icmp_send(net) && + (pp->protocol == IPPROTO_TCP || + pp->protocol == IPPROTO_UDP || + pp->protocol == IPPROTO_SCTP)) { + __be16 _ports[2], *pptr; + + pptr = skb_header_pointer(skb, iph.len, + sizeof(_ports), _ports); + if (pptr == NULL) + return NF_ACCEPT; /* Not for me */ + if (ip_vs_lookup_real_service(net, af, 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 && + iph.protocol != IPPROTO_SCTP) + || ((iph.protocol == IPPROTO_TCP + && !is_tcp_reset(skb, iph.len)) + || (iph.protocol == IPPROTO_SCTP + && !is_sctp_abort(skb, + iph.len)))) { +#ifdef CONFIG_IP_VS_IPV6 + if (af == AF_INET6) { + struct net *net = + dev_net(skb_dst(skb)->dev); + + if (!skb->dev) + skb->dev = net->loopback_dev; + icmpv6_send(skb, + ICMPV6_DEST_UNREACH, + ICMPV6_PORT_UNREACH, + 0); + } else +#endif + icmp_send(skb, + ICMP_DEST_UNREACH, + ICMP_PORT_UNREACH, 0); + return NF_DROP; + } + } + } + IP_VS_DBG_PKT(12, af, pp, skb, 0, + "ip_vs_out: packet continues traversal as normal"); + return NF_ACCEPT; +} + +/* + * It is hooked at the NF_INET_FORWARD and NF_INET_LOCAL_IN chain, + * used only for VS/NAT. + * Check if packet is reply for established ip_vs_conn. + */ +static unsigned int +ip_vs_reply4(unsigned int hooknum, struct sk_buff *skb, + const struct net_device *in, const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ + return ip_vs_out(hooknum, skb, AF_INET); +} + +/* + * It is hooked at the NF_INET_LOCAL_OUT chain, used only for VS/NAT. + * Check if packet is reply for established ip_vs_conn. + */ +static unsigned int +ip_vs_local_reply4(unsigned int hooknum, struct sk_buff *skb, + const struct net_device *in, const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ + unsigned int verdict; + + /* Disable BH in LOCAL_OUT until all places are fixed */ + local_bh_disable(); + verdict = ip_vs_out(hooknum, skb, AF_INET); + local_bh_enable(); + return verdict; +} + +#ifdef CONFIG_IP_VS_IPV6 + +/* + * It is hooked at the NF_INET_FORWARD and NF_INET_LOCAL_IN chain, + * used only for VS/NAT. + * Check if packet is reply for established ip_vs_conn. + */ +static unsigned int +ip_vs_reply6(unsigned int hooknum, struct sk_buff *skb, + const struct net_device *in, const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ + return ip_vs_out(hooknum, skb, AF_INET6); +} + +/* + * It is hooked at the NF_INET_LOCAL_OUT chain, used only for VS/NAT. + * Check if packet is reply for established ip_vs_conn. + */ +static unsigned int +ip_vs_local_reply6(unsigned int hooknum, struct sk_buff *skb, + const struct net_device *in, const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ + unsigned int verdict; + + /* Disable BH in LOCAL_OUT until all places are fixed */ + local_bh_disable(); + verdict = ip_vs_out(hooknum, skb, AF_INET6); + local_bh_enable(); + return verdict; +} + +#endif + +/* + * 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 net *net = NULL; + struct iphdr *iph; + struct icmphdr _icmph, *ic; + struct iphdr _ciph, *cih; /* The ip header contained within the ICMP */ + struct ip_vs_iphdr ciph; + struct ip_vs_conn *cp; + struct ip_vs_protocol *pp; + struct ip_vs_proto_data *pd; + 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_vs_defrag_user(hooknum))) + 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) %pI4->%pI4\n", + ic->type, ntohs(icmp_id(ic)), + &iph->saddr, &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 */ + + net = skb_net(skb); + + pd = ip_vs_proto_data_get(net, cih->protocol); + if (!pd) + return NF_ACCEPT; + pp = pd->pp; + + /* 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, AF_INET, pp, skb, offset, + "Checking incoming ICMP for"); + + offset += cih->ihl * 4; + + ip_vs_fill_iphdr(AF_INET, cih, &ciph); + /* The embedded headers contain source and dest in reverse order */ + cp = pp->conn_in_get(AF_INET, skb, &ciph, 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 %pI4!\n", + &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, hooknum); + + out: + __ip_vs_conn_put(cp); + + return verdict; +} + +#ifdef CONFIG_IP_VS_IPV6 +static int +ip_vs_in_icmp_v6(struct sk_buff *skb, int *related, unsigned int hooknum) +{ + struct net *net = NULL; + struct ipv6hdr *iph; + struct icmp6hdr _icmph, *ic; + struct ipv6hdr _ciph, *cih; /* The ip header contained + within the ICMP */ + struct ip_vs_iphdr ciph; + struct ip_vs_conn *cp; + struct ip_vs_protocol *pp; + struct ip_vs_proto_data *pd; + unsigned int offset, verdict; + + *related = 1; + + /* reassemble IP fragments */ + if (ipv6_hdr(skb)->nexthdr == IPPROTO_FRAGMENT) { + if (ip_vs_gather_frags_v6(skb, ip_vs_defrag_user(hooknum))) + return NF_STOLEN; + } + + iph = ipv6_hdr(skb); + offset = sizeof(struct ipv6hdr); + ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph); + if (ic == NULL) + return NF_DROP; + + IP_VS_DBG(12, "Incoming ICMPv6 (%d,%d) %pI6->%pI6\n", + ic->icmp6_type, ntohs(icmpv6_id(ic)), + &iph->saddr, &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->icmp6_type != ICMPV6_DEST_UNREACH) && + (ic->icmp6_type != ICMPV6_PKT_TOOBIG) && + (ic->icmp6_type != ICMPV6_TIME_EXCEED)) { + *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 */ + + net = skb_net(skb); + pd = ip_vs_proto_data_get(net, cih->nexthdr); + if (!pd) + return NF_ACCEPT; + pp = pd->pp; + + /* Is the embedded protocol header present? */ + /* TODO: we don't support fragmentation at the moment anyways */ + if (unlikely(cih->nexthdr == IPPROTO_FRAGMENT && pp->dont_defrag)) + return NF_ACCEPT; + + IP_VS_DBG_PKT(11, AF_INET6, pp, skb, offset, + "Checking incoming ICMPv6 for"); + + offset += sizeof(struct ipv6hdr); + + ip_vs_fill_iphdr(AF_INET6, cih, &ciph); + /* The embedded headers contain source and dest in reverse order */ + cp = pp->conn_in_get(AF_INET6, skb, &ciph, offset, 1); + if (!cp) + return NF_ACCEPT; + + /* do the statistics and put it back */ + ip_vs_in_stats(cp, skb); + if (IPPROTO_TCP == cih->nexthdr || IPPROTO_UDP == cih->nexthdr || + IPPROTO_SCTP == cih->nexthdr) + offset += 2 * sizeof(__u16); + verdict = ip_vs_icmp_xmit_v6(skb, cp, pp, offset, hooknum); + + __ip_vs_conn_put(cp); + + return verdict; +} +#endif + + +/* + * 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, int af) +{ + struct net *net; + struct ip_vs_iphdr iph; + struct ip_vs_protocol *pp; + struct ip_vs_proto_data *pd; + struct ip_vs_conn *cp; + int ret, restart, pkts; + struct netns_ipvs *ipvs; + + /* Already marked as IPVS request or reply? */ + if (skb->ipvs_property) + return NF_ACCEPT; + + /* + * Big tappo: + * - remote client: only PACKET_HOST + * - route: used for struct net when skb->dev is unset + */ + if (unlikely((skb->pkt_type != PACKET_HOST && + hooknum != NF_INET_LOCAL_OUT) || + !skb_dst(skb))) { + ip_vs_fill_iphdr(af, skb_network_header(skb), &iph); + IP_VS_DBG_BUF(12, "packet type=%d proto=%d daddr=%s" + " ignored in hook %u\n", + skb->pkt_type, iph.protocol, + IP_VS_DBG_ADDR(af, &iph.daddr), hooknum); + return NF_ACCEPT; + } + /* ipvs enabled in this netns ? */ + net = skb_net(skb); + if (!net_ipvs(net)->enable) + return NF_ACCEPT; + + ip_vs_fill_iphdr(af, skb_network_header(skb), &iph); + + /* Bad... Do not break raw sockets */ + if (unlikely(skb->sk != NULL && hooknum == NF_INET_LOCAL_OUT && + af == AF_INET)) { + struct sock *sk = skb->sk; + struct inet_sock *inet = inet_sk(skb->sk); + + if (inet && sk->sk_family == PF_INET && inet->nodefrag) + return NF_ACCEPT; + } + +#ifdef CONFIG_IP_VS_IPV6 + if (af == AF_INET6) { + if (unlikely(iph.protocol == IPPROTO_ICMPV6)) { + int related; + int verdict = ip_vs_in_icmp_v6(skb, &related, hooknum); + + if (related) + return verdict; + ip_vs_fill_iphdr(af, skb_network_header(skb), &iph); + } + } else +#endif + if (unlikely(iph.protocol == IPPROTO_ICMP)) { + int related; + int verdict = ip_vs_in_icmp(skb, &related, hooknum); + + if (related) + return verdict; + ip_vs_fill_iphdr(af, skb_network_header(skb), &iph); + } + + /* Protocol supported? */ + pd = ip_vs_proto_data_get(net, iph.protocol); + if (unlikely(!pd)) + return NF_ACCEPT; + pp = pd->pp; + /* + * Check if the packet belongs to an existing connection entry + */ + cp = pp->conn_in_get(af, skb, &iph, iph.len, 0); + + if (unlikely(!cp)) { + int v; + + if (!pp->conn_schedule(af, skb, pd, &v, &cp)) + return v; + } + + if (unlikely(!cp)) { + /* sorry, all this trouble for a no-hit :) */ + IP_VS_DBG_PKT(12, af, pp, skb, 0, + "ip_vs_in: packet continues traversal as normal"); + return NF_ACCEPT; + } + + IP_VS_DBG_PKT(11, af, pp, skb, 0, "Incoming packet"); + ipvs = net_ipvs(net); + /* Check the server status */ + if (cp->dest && !(cp->dest->flags & IP_VS_DEST_F_AVAILABLE)) { + /* the destination server is not available */ + + if (sysctl_expire_nodest_conn(ipvs)) { + /* 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, pd); + 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 + * + * For ONE_PKT let ip_vs_sync_conn() do the filter work. + */ + + if (cp->flags & IP_VS_CONN_F_ONE_PACKET) + pkts = sysctl_sync_threshold(ipvs); + else + pkts = atomic_add_return(1, &cp->in_pkts); + + if ((ipvs->sync_state & IP_VS_STATE_MASTER) && + cp->protocol == IPPROTO_SCTP) { + if ((cp->state == IP_VS_SCTP_S_ESTABLISHED && + (pkts % sysctl_sync_period(ipvs) + == sysctl_sync_threshold(ipvs))) || + (cp->old_state != cp->state && + ((cp->state == IP_VS_SCTP_S_CLOSED) || + (cp->state == IP_VS_SCTP_S_SHUT_ACK_CLI) || + (cp->state == IP_VS_SCTP_S_SHUT_ACK_SER)))) { + ip_vs_sync_conn(net, cp); + goto out; + } + } + + /* Keep this block last: TCP and others with pp->num_states <= 1 */ + else if ((ipvs->sync_state & IP_VS_STATE_MASTER) && + (((cp->protocol != IPPROTO_TCP || + cp->state == IP_VS_TCP_S_ESTABLISHED) && + (pkts % sysctl_sync_period(ipvs) + == sysctl_sync_threshold(ipvs))) || + ((cp->protocol == IPPROTO_TCP) && (cp->old_state != cp->state) && + ((cp->state == IP_VS_TCP_S_FIN_WAIT) || + (cp->state == IP_VS_TCP_S_CLOSE) || + (cp->state == IP_VS_TCP_S_CLOSE_WAIT) || + (cp->state == IP_VS_TCP_S_TIME_WAIT))))) + ip_vs_sync_conn(net, cp); +out: + cp->old_state = cp->state; + + ip_vs_conn_put(cp); + return ret; +} + +/* + * AF_INET handler in NF_INET_LOCAL_IN chain + * Schedule and forward packets from remote clients + */ +static unsigned int +ip_vs_remote_request4(unsigned int hooknum, struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ + return ip_vs_in(hooknum, skb, AF_INET); +} + +/* + * AF_INET handler in NF_INET_LOCAL_OUT chain + * Schedule and forward packets from local clients + */ +static unsigned int +ip_vs_local_request4(unsigned int hooknum, struct sk_buff *skb, + const struct net_device *in, const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ + unsigned int verdict; + + /* Disable BH in LOCAL_OUT until all places are fixed */ + local_bh_disable(); + verdict = ip_vs_in(hooknum, skb, AF_INET); + local_bh_enable(); + return verdict; +} + +#ifdef CONFIG_IP_VS_IPV6 + +/* + * AF_INET6 handler in NF_INET_LOCAL_IN chain + * Schedule and forward packets from remote clients + */ +static unsigned int +ip_vs_remote_request6(unsigned int hooknum, struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ + return ip_vs_in(hooknum, skb, AF_INET6); +} + +/* + * AF_INET6 handler in NF_INET_LOCAL_OUT chain + * Schedule and forward packets from local clients + */ +static unsigned int +ip_vs_local_request6(unsigned int hooknum, struct sk_buff *skb, + const struct net_device *in, const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ + unsigned int verdict; + + /* Disable BH in LOCAL_OUT until all places are fixed */ + local_bh_disable(); + verdict = ip_vs_in(hooknum, skb, AF_INET6); + local_bh_enable(); + return verdict; +} + +#endif + + +/* + * 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; + struct net *net; + + if (ip_hdr(skb)->protocol != IPPROTO_ICMP) + return NF_ACCEPT; + + /* ipvs enabled in this netns ? */ + net = skb_net(skb); + if (!net_ipvs(net)->enable) + return NF_ACCEPT; + + return ip_vs_in_icmp(skb, &r, hooknum); +} + +#ifdef CONFIG_IP_VS_IPV6 +static unsigned int +ip_vs_forward_icmp_v6(unsigned int hooknum, struct sk_buff *skb, + const struct net_device *in, const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ + int r; + struct net *net; + + if (ipv6_hdr(skb)->nexthdr != IPPROTO_ICMPV6) + return NF_ACCEPT; + + /* ipvs enabled in this netns ? */ + net = skb_net(skb); + if (!net_ipvs(net)->enable) + return NF_ACCEPT; + + return ip_vs_in_icmp_v6(skb, &r, hooknum); +} +#endif + + +static struct nf_hook_ops ip_vs_ops[] __read_mostly = { + /* After packet filtering, change source only for VS/NAT */ + { + .hook = ip_vs_reply4, + .owner = THIS_MODULE, + .pf = PF_INET, + .hooknum = NF_INET_LOCAL_IN, + .priority = NF_IP_PRI_NAT_SRC - 2, + }, + /* 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_remote_request4, + .owner = THIS_MODULE, + .pf = PF_INET, + .hooknum = NF_INET_LOCAL_IN, + .priority = NF_IP_PRI_NAT_SRC - 1, + }, + /* Before ip_vs_in, change source only for VS/NAT */ + { + .hook = ip_vs_local_reply4, + .owner = THIS_MODULE, + .pf = PF_INET, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP_PRI_NAT_DST + 1, + }, + /* After mangle, schedule and forward local requests */ + { + .hook = ip_vs_local_request4, + .owner = THIS_MODULE, + .pf = PF_INET, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP_PRI_NAT_DST + 2, + }, + /* 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, + }, + /* After packet filtering, change source only for VS/NAT */ + { + .hook = ip_vs_reply4, + .owner = THIS_MODULE, + .pf = PF_INET, + .hooknum = NF_INET_FORWARD, + .priority = 100, + }, +#ifdef CONFIG_IP_VS_IPV6 + /* After packet filtering, change source only for VS/NAT */ + { + .hook = ip_vs_reply6, + .owner = THIS_MODULE, + .pf = PF_INET6, + .hooknum = NF_INET_LOCAL_IN, + .priority = NF_IP6_PRI_NAT_SRC - 2, + }, + /* 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_remote_request6, + .owner = THIS_MODULE, + .pf = PF_INET6, + .hooknum = NF_INET_LOCAL_IN, + .priority = NF_IP6_PRI_NAT_SRC - 1, + }, + /* Before ip_vs_in, change source only for VS/NAT */ + { + .hook = ip_vs_local_reply6, + .owner = THIS_MODULE, + .pf = PF_INET, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP6_PRI_NAT_DST + 1, + }, + /* After mangle, schedule and forward local requests */ + { + .hook = ip_vs_local_request6, + .owner = THIS_MODULE, + .pf = PF_INET6, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP6_PRI_NAT_DST + 2, + }, + /* 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_v6, + .owner = THIS_MODULE, + .pf = PF_INET6, + .hooknum = NF_INET_FORWARD, + .priority = 99, + }, + /* After packet filtering, change source only for VS/NAT */ + { + .hook = ip_vs_reply6, + .owner = THIS_MODULE, + .pf = PF_INET6, + .hooknum = NF_INET_FORWARD, + .priority = 100, + }, +#endif +}; +/* + * Initialize IP Virtual Server netns mem. + */ +static int __net_init __ip_vs_init(struct net *net) +{ + struct netns_ipvs *ipvs; + + ipvs = net_generic(net, ip_vs_net_id); + if (ipvs == NULL) { + pr_err("%s(): no memory.\n", __func__); + return -ENOMEM; + } + /* Hold the beast until a service is registerd */ + ipvs->enable = 0; + ipvs->net = net; + /* Counters used for creating unique names */ + ipvs->gen = atomic_read(&ipvs_netns_cnt); + atomic_inc(&ipvs_netns_cnt); + net->ipvs = ipvs; + + if (__ip_vs_estimator_init(net) < 0) + goto estimator_fail; + + if (__ip_vs_control_init(net) < 0) + goto control_fail; + + if (__ip_vs_protocol_init(net) < 0) + goto protocol_fail; + + if (__ip_vs_app_init(net) < 0) + goto app_fail; + + if (__ip_vs_conn_init(net) < 0) + goto conn_fail; + + if (__ip_vs_sync_init(net) < 0) + goto sync_fail; + + printk(KERN_INFO "IPVS: Creating netns size=%zu id=%d\n", + sizeof(struct netns_ipvs), ipvs->gen); + return 0; +/* + * Error handling + */ + +sync_fail: + __ip_vs_conn_cleanup(net); +conn_fail: + __ip_vs_app_cleanup(net); +app_fail: + __ip_vs_protocol_cleanup(net); +protocol_fail: + __ip_vs_control_cleanup(net); +control_fail: + __ip_vs_estimator_cleanup(net); +estimator_fail: + return -ENOMEM; +} + +static void __net_exit __ip_vs_cleanup(struct net *net) +{ + __ip_vs_service_cleanup(net); /* ip_vs_flush() with locks */ + __ip_vs_conn_cleanup(net); + __ip_vs_app_cleanup(net); + __ip_vs_protocol_cleanup(net); + __ip_vs_control_cleanup(net); + __ip_vs_estimator_cleanup(net); + IP_VS_DBG(2, "ipvs netns %d released\n", net_ipvs(net)->gen); +} + +static void __net_exit __ip_vs_dev_cleanup(struct net *net) +{ + EnterFunction(2); + net_ipvs(net)->enable = 0; /* Disable packet reception */ + smp_wmb(); + __ip_vs_sync_cleanup(net); + LeaveFunction(2); +} + +static struct pernet_operations ipvs_core_ops = { + .init = __ip_vs_init, + .exit = __ip_vs_cleanup, + .id = &ip_vs_net_id, + .size = sizeof(struct netns_ipvs), +}; + +static struct pernet_operations ipvs_core_dev_ops = { + .exit = __ip_vs_dev_cleanup, +}; + +/* + * Initialize IP Virtual Server + */ +static int __init ip_vs_init(void) +{ + int ret; + + ip_vs_estimator_init(); + ret = ip_vs_control_init(); + if (ret < 0) { + pr_err("can't setup control.\n"); + goto cleanup_estimator; + } + + ip_vs_protocol_init(); + + ret = ip_vs_app_init(); + if (ret < 0) { + pr_err("can't setup application helper.\n"); + goto cleanup_protocol; + } + + ret = ip_vs_conn_init(); + if (ret < 0) { + pr_err("can't setup connection table.\n"); + goto cleanup_app; + } + + ret = ip_vs_sync_init(); + if (ret < 0) { + pr_err("can't setup sync data.\n"); + goto cleanup_conn; + } + + ret = register_pernet_subsys(&ipvs_core_ops); /* Alloc ip_vs struct */ + if (ret < 0) + goto cleanup_sync; + + ret = register_pernet_device(&ipvs_core_dev_ops); + if (ret < 0) + goto cleanup_sub; + + ret = nf_register_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops)); + if (ret < 0) { + pr_err("can't register hooks.\n"); + goto cleanup_dev; + } + + pr_info("ipvs loaded.\n"); + + return ret; + +cleanup_dev: + unregister_pernet_device(&ipvs_core_dev_ops); +cleanup_sub: + unregister_pernet_subsys(&ipvs_core_ops); +cleanup_sync: + ip_vs_sync_cleanup(); + cleanup_conn: + ip_vs_conn_cleanup(); + cleanup_app: + ip_vs_app_cleanup(); + cleanup_protocol: + ip_vs_protocol_cleanup(); + ip_vs_control_cleanup(); + cleanup_estimator: + ip_vs_estimator_cleanup(); + return ret; +} + +static void __exit ip_vs_cleanup(void) +{ + nf_unregister_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops)); + unregister_pernet_device(&ipvs_core_dev_ops); + unregister_pernet_subsys(&ipvs_core_ops); /* free ip_vs struct */ + ip_vs_sync_cleanup(); + ip_vs_conn_cleanup(); + ip_vs_app_cleanup(); + ip_vs_protocol_cleanup(); + ip_vs_control_cleanup(); + ip_vs_estimator_cleanup(); + pr_info("ipvs unloaded.\n"); +} + +module_init(ip_vs_init); +module_exit(ip_vs_cleanup); +MODULE_LICENSE("GPL"); |