diff options
Diffstat (limited to 'net/netfilter/ipvs/ip_vs_conn.c')
| -rw-r--r-- | net/netfilter/ipvs/ip_vs_conn.c | 1326 |
1 files changed, 1326 insertions, 0 deletions
diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c new file mode 100644 index 00000000..782db275 --- /dev/null +++ b/net/netfilter/ipvs/ip_vs_conn.c @@ -0,0 +1,1326 @@ +/* + * 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. Many code here is taken from IP MASQ code of kernel 2.2. + * + * Changes: + * + */ + +#define KMSG_COMPONENT "IPVS" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/interrupt.h> +#include <linux/in.h> +#include <linux/net.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/vmalloc.h> +#include <linux/proc_fs.h> /* for proc_net_* */ +#include <linux/slab.h> +#include <linux/seq_file.h> +#include <linux/jhash.h> +#include <linux/random.h> + +#include <net/net_namespace.h> +#include <net/ip_vs.h> + + +#ifndef CONFIG_IP_VS_TAB_BITS +#define CONFIG_IP_VS_TAB_BITS 12 +#endif + +/* + * Connection hash size. Default is what was selected at compile time. +*/ +static int ip_vs_conn_tab_bits = CONFIG_IP_VS_TAB_BITS; +module_param_named(conn_tab_bits, ip_vs_conn_tab_bits, int, 0444); +MODULE_PARM_DESC(conn_tab_bits, "Set connections' hash size"); + +/* size and mask values */ +int ip_vs_conn_tab_size __read_mostly; +static int ip_vs_conn_tab_mask __read_mostly; + +/* + * Connection hash table: for input and output packets lookups of IPVS + */ +static struct hlist_head *ip_vs_conn_tab __read_mostly; + +/* SLAB cache for IPVS connections */ +static struct kmem_cache *ip_vs_conn_cachep __read_mostly; + +/* counter for no client port connections */ +static atomic_t ip_vs_conn_no_cport_cnt = ATOMIC_INIT(0); + +/* random value for IPVS connection hash */ +static unsigned int ip_vs_conn_rnd __read_mostly; + +/* + * Fine locking granularity for big connection hash table + */ +#define CT_LOCKARRAY_BITS 5 +#define CT_LOCKARRAY_SIZE (1<<CT_LOCKARRAY_BITS) +#define CT_LOCKARRAY_MASK (CT_LOCKARRAY_SIZE-1) + +struct ip_vs_aligned_lock +{ + rwlock_t l; +} __attribute__((__aligned__(SMP_CACHE_BYTES))); + +/* lock array for conn table */ +static struct ip_vs_aligned_lock +__ip_vs_conntbl_lock_array[CT_LOCKARRAY_SIZE] __cacheline_aligned; + +static inline void ct_read_lock(unsigned key) +{ + read_lock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l); +} + +static inline void ct_read_unlock(unsigned key) +{ + read_unlock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l); +} + +static inline void ct_write_lock(unsigned key) +{ + write_lock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l); +} + +static inline void ct_write_unlock(unsigned key) +{ + write_unlock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l); +} + +static inline void ct_read_lock_bh(unsigned key) +{ + read_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l); +} + +static inline void ct_read_unlock_bh(unsigned key) +{ + read_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l); +} + +static inline void ct_write_lock_bh(unsigned key) +{ + write_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l); +} + +static inline void ct_write_unlock_bh(unsigned key) +{ + write_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l); +} + + +/* + * Returns hash value for IPVS connection entry + */ +static unsigned int ip_vs_conn_hashkey(struct net *net, int af, unsigned proto, + const union nf_inet_addr *addr, + __be16 port) +{ +#ifdef CONFIG_IP_VS_IPV6 + if (af == AF_INET6) + return (jhash_3words(jhash(addr, 16, ip_vs_conn_rnd), + (__force u32)port, proto, ip_vs_conn_rnd) ^ + ((size_t)net>>8)) & ip_vs_conn_tab_mask; +#endif + return (jhash_3words((__force u32)addr->ip, (__force u32)port, proto, + ip_vs_conn_rnd) ^ + ((size_t)net>>8)) & ip_vs_conn_tab_mask; +} + +static unsigned int ip_vs_conn_hashkey_param(const struct ip_vs_conn_param *p, + bool inverse) +{ + const union nf_inet_addr *addr; + __be16 port; + + if (p->pe_data && p->pe->hashkey_raw) + return p->pe->hashkey_raw(p, ip_vs_conn_rnd, inverse) & + ip_vs_conn_tab_mask; + + if (likely(!inverse)) { + addr = p->caddr; + port = p->cport; + } else { + addr = p->vaddr; + port = p->vport; + } + + return ip_vs_conn_hashkey(p->net, p->af, p->protocol, addr, port); +} + +static unsigned int ip_vs_conn_hashkey_conn(const struct ip_vs_conn *cp) +{ + struct ip_vs_conn_param p; + + ip_vs_conn_fill_param(ip_vs_conn_net(cp), cp->af, cp->protocol, + &cp->caddr, cp->cport, NULL, 0, &p); + + if (cp->pe) { + p.pe = cp->pe; + p.pe_data = cp->pe_data; + p.pe_data_len = cp->pe_data_len; + } + + return ip_vs_conn_hashkey_param(&p, false); +} + +/* + * Hashes ip_vs_conn in ip_vs_conn_tab by netns,proto,addr,port. + * returns bool success. + */ +static inline int ip_vs_conn_hash(struct ip_vs_conn *cp) +{ + unsigned hash; + int ret; + + if (cp->flags & IP_VS_CONN_F_ONE_PACKET) + return 0; + + /* Hash by protocol, client address and port */ + hash = ip_vs_conn_hashkey_conn(cp); + + ct_write_lock(hash); + spin_lock(&cp->lock); + + if (!(cp->flags & IP_VS_CONN_F_HASHED)) { + hlist_add_head(&cp->c_list, &ip_vs_conn_tab[hash]); + cp->flags |= IP_VS_CONN_F_HASHED; + atomic_inc(&cp->refcnt); + ret = 1; + } else { + pr_err("%s(): request for already hashed, called from %pF\n", + __func__, __builtin_return_address(0)); + ret = 0; + } + + spin_unlock(&cp->lock); + ct_write_unlock(hash); + + return ret; +} + + +/* + * UNhashes ip_vs_conn from ip_vs_conn_tab. + * returns bool success. + */ +static inline int ip_vs_conn_unhash(struct ip_vs_conn *cp) +{ + unsigned hash; + int ret; + + /* unhash it and decrease its reference counter */ + hash = ip_vs_conn_hashkey_conn(cp); + + ct_write_lock(hash); + spin_lock(&cp->lock); + + if (cp->flags & IP_VS_CONN_F_HASHED) { + hlist_del(&cp->c_list); + cp->flags &= ~IP_VS_CONN_F_HASHED; + atomic_dec(&cp->refcnt); + ret = 1; + } else + ret = 0; + + spin_unlock(&cp->lock); + ct_write_unlock(hash); + + return ret; +} + + +/* + * Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab. + * Called for pkts coming from OUTside-to-INside. + * p->caddr, p->cport: pkt source address (foreign host) + * p->vaddr, p->vport: pkt dest address (load balancer) + */ +static inline struct ip_vs_conn * +__ip_vs_conn_in_get(const struct ip_vs_conn_param *p) +{ + unsigned hash; + struct ip_vs_conn *cp; + struct hlist_node *n; + + hash = ip_vs_conn_hashkey_param(p, false); + + ct_read_lock(hash); + + hlist_for_each_entry(cp, n, &ip_vs_conn_tab[hash], c_list) { + if (cp->af == p->af && + p->cport == cp->cport && p->vport == cp->vport && + ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) && + ip_vs_addr_equal(p->af, p->vaddr, &cp->vaddr) && + ((!p->cport) ^ (!(cp->flags & IP_VS_CONN_F_NO_CPORT))) && + p->protocol == cp->protocol && + ip_vs_conn_net_eq(cp, p->net)) { + /* HIT */ + atomic_inc(&cp->refcnt); + ct_read_unlock(hash); + return cp; + } + } + + ct_read_unlock(hash); + + return NULL; +} + +struct ip_vs_conn *ip_vs_conn_in_get(const struct ip_vs_conn_param *p) +{ + struct ip_vs_conn *cp; + + cp = __ip_vs_conn_in_get(p); + if (!cp && atomic_read(&ip_vs_conn_no_cport_cnt)) { + struct ip_vs_conn_param cport_zero_p = *p; + cport_zero_p.cport = 0; + cp = __ip_vs_conn_in_get(&cport_zero_p); + } + + IP_VS_DBG_BUF(9, "lookup/in %s %s:%d->%s:%d %s\n", + ip_vs_proto_name(p->protocol), + IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport), + IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport), + cp ? "hit" : "not hit"); + + return cp; +} + +static int +ip_vs_conn_fill_param_proto(int af, const struct sk_buff *skb, + const struct ip_vs_iphdr *iph, + unsigned int proto_off, int inverse, + struct ip_vs_conn_param *p) +{ + __be16 _ports[2], *pptr; + struct net *net = skb_net(skb); + + pptr = skb_header_pointer(skb, proto_off, sizeof(_ports), _ports); + if (pptr == NULL) + return 1; + + if (likely(!inverse)) + ip_vs_conn_fill_param(net, af, iph->protocol, &iph->saddr, + pptr[0], &iph->daddr, pptr[1], p); + else + ip_vs_conn_fill_param(net, af, iph->protocol, &iph->daddr, + pptr[1], &iph->saddr, pptr[0], p); + return 0; +} + +struct ip_vs_conn * +ip_vs_conn_in_get_proto(int af, const struct sk_buff *skb, + const struct ip_vs_iphdr *iph, + unsigned int proto_off, int inverse) +{ + struct ip_vs_conn_param p; + + if (ip_vs_conn_fill_param_proto(af, skb, iph, proto_off, inverse, &p)) + return NULL; + + return ip_vs_conn_in_get(&p); +} +EXPORT_SYMBOL_GPL(ip_vs_conn_in_get_proto); + +/* Get reference to connection template */ +struct ip_vs_conn *ip_vs_ct_in_get(const struct ip_vs_conn_param *p) +{ + unsigned hash; + struct ip_vs_conn *cp; + struct hlist_node *n; + + hash = ip_vs_conn_hashkey_param(p, false); + + ct_read_lock(hash); + + hlist_for_each_entry(cp, n, &ip_vs_conn_tab[hash], c_list) { + if (!ip_vs_conn_net_eq(cp, p->net)) + continue; + if (p->pe_data && p->pe->ct_match) { + if (p->pe == cp->pe && p->pe->ct_match(p, cp)) + goto out; + continue; + } + + if (cp->af == p->af && + ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) && + /* protocol should only be IPPROTO_IP if + * p->vaddr is a fwmark */ + ip_vs_addr_equal(p->protocol == IPPROTO_IP ? AF_UNSPEC : + p->af, p->vaddr, &cp->vaddr) && + p->cport == cp->cport && p->vport == cp->vport && + cp->flags & IP_VS_CONN_F_TEMPLATE && + p->protocol == cp->protocol) + goto out; + } + cp = NULL; + + out: + if (cp) + atomic_inc(&cp->refcnt); + ct_read_unlock(hash); + + IP_VS_DBG_BUF(9, "template lookup/in %s %s:%d->%s:%d %s\n", + ip_vs_proto_name(p->protocol), + IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport), + IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport), + cp ? "hit" : "not hit"); + + return cp; +} + +/* Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab. + * Called for pkts coming from inside-to-OUTside. + * p->caddr, p->cport: pkt source address (inside host) + * p->vaddr, p->vport: pkt dest address (foreign host) */ +struct ip_vs_conn *ip_vs_conn_out_get(const struct ip_vs_conn_param *p) +{ + unsigned hash; + struct ip_vs_conn *cp, *ret=NULL; + struct hlist_node *n; + + /* + * Check for "full" addressed entries + */ + hash = ip_vs_conn_hashkey_param(p, true); + + ct_read_lock(hash); + + hlist_for_each_entry(cp, n, &ip_vs_conn_tab[hash], c_list) { + if (cp->af == p->af && + p->vport == cp->cport && p->cport == cp->dport && + ip_vs_addr_equal(p->af, p->vaddr, &cp->caddr) && + ip_vs_addr_equal(p->af, p->caddr, &cp->daddr) && + p->protocol == cp->protocol && + ip_vs_conn_net_eq(cp, p->net)) { + /* HIT */ + atomic_inc(&cp->refcnt); + ret = cp; + break; + } + } + + ct_read_unlock(hash); + + IP_VS_DBG_BUF(9, "lookup/out %s %s:%d->%s:%d %s\n", + ip_vs_proto_name(p->protocol), + IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport), + IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport), + ret ? "hit" : "not hit"); + + return ret; +} + +struct ip_vs_conn * +ip_vs_conn_out_get_proto(int af, const struct sk_buff *skb, + const struct ip_vs_iphdr *iph, + unsigned int proto_off, int inverse) +{ + struct ip_vs_conn_param p; + + if (ip_vs_conn_fill_param_proto(af, skb, iph, proto_off, inverse, &p)) + return NULL; + + return ip_vs_conn_out_get(&p); +} +EXPORT_SYMBOL_GPL(ip_vs_conn_out_get_proto); + +/* + * Put back the conn and restart its timer with its timeout + */ +void ip_vs_conn_put(struct ip_vs_conn *cp) +{ + unsigned long t = (cp->flags & IP_VS_CONN_F_ONE_PACKET) ? + 0 : cp->timeout; + mod_timer(&cp->timer, jiffies+t); + + __ip_vs_conn_put(cp); +} + + +/* + * Fill a no_client_port connection with a client port number + */ +void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __be16 cport) +{ + if (ip_vs_conn_unhash(cp)) { + spin_lock(&cp->lock); + if (cp->flags & IP_VS_CONN_F_NO_CPORT) { + atomic_dec(&ip_vs_conn_no_cport_cnt); + cp->flags &= ~IP_VS_CONN_F_NO_CPORT; + cp->cport = cport; + } + spin_unlock(&cp->lock); + + /* hash on new dport */ + ip_vs_conn_hash(cp); + } +} + + +/* + * Bind a connection entry with the corresponding packet_xmit. + * Called by ip_vs_conn_new. + */ +static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp) +{ + switch (IP_VS_FWD_METHOD(cp)) { + case IP_VS_CONN_F_MASQ: + cp->packet_xmit = ip_vs_nat_xmit; + break; + + case IP_VS_CONN_F_TUNNEL: + cp->packet_xmit = ip_vs_tunnel_xmit; + break; + + case IP_VS_CONN_F_DROUTE: + cp->packet_xmit = ip_vs_dr_xmit; + break; + + case IP_VS_CONN_F_LOCALNODE: + cp->packet_xmit = ip_vs_null_xmit; + break; + + case IP_VS_CONN_F_BYPASS: + cp->packet_xmit = ip_vs_bypass_xmit; + break; + } +} + +#ifdef CONFIG_IP_VS_IPV6 +static inline void ip_vs_bind_xmit_v6(struct ip_vs_conn *cp) +{ + switch (IP_VS_FWD_METHOD(cp)) { + case IP_VS_CONN_F_MASQ: + cp->packet_xmit = ip_vs_nat_xmit_v6; + break; + + case IP_VS_CONN_F_TUNNEL: + cp->packet_xmit = ip_vs_tunnel_xmit_v6; + break; + + case IP_VS_CONN_F_DROUTE: + cp->packet_xmit = ip_vs_dr_xmit_v6; + break; + + case IP_VS_CONN_F_LOCALNODE: + cp->packet_xmit = ip_vs_null_xmit; + break; + + case IP_VS_CONN_F_BYPASS: + cp->packet_xmit = ip_vs_bypass_xmit_v6; + break; + } +} +#endif + + +static inline int ip_vs_dest_totalconns(struct ip_vs_dest *dest) +{ + return atomic_read(&dest->activeconns) + + atomic_read(&dest->inactconns); +} + +/* + * Bind a connection entry with a virtual service destination + * Called just after a new connection entry is created. + */ +static inline void +ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest) +{ + unsigned int conn_flags; + + /* if dest is NULL, then return directly */ + if (!dest) + return; + + /* Increase the refcnt counter of the dest */ + atomic_inc(&dest->refcnt); + + conn_flags = atomic_read(&dest->conn_flags); + if (cp->protocol != IPPROTO_UDP) + conn_flags &= ~IP_VS_CONN_F_ONE_PACKET; + /* Bind with the destination and its corresponding transmitter */ + if (cp->flags & IP_VS_CONN_F_SYNC) { + /* if the connection is not template and is created + * by sync, preserve the activity flag. + */ + if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) + conn_flags &= ~IP_VS_CONN_F_INACTIVE; + /* connections inherit forwarding method from dest */ + cp->flags &= ~IP_VS_CONN_F_FWD_MASK; + } + cp->flags |= conn_flags; + cp->dest = dest; + + IP_VS_DBG_BUF(7, "Bind-dest %s c:%s:%d v:%s:%d " + "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d " + "dest->refcnt:%d\n", + ip_vs_proto_name(cp->protocol), + IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport), + IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport), + IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport), + ip_vs_fwd_tag(cp), cp->state, + cp->flags, atomic_read(&cp->refcnt), + atomic_read(&dest->refcnt)); + + /* Update the connection counters */ + if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) { + /* It is a normal connection, so increase the inactive + connection counter because it is in TCP SYNRECV + state (inactive) or other protocol inacive state */ + if ((cp->flags & IP_VS_CONN_F_SYNC) && + (!(cp->flags & IP_VS_CONN_F_INACTIVE))) + atomic_inc(&dest->activeconns); + else + atomic_inc(&dest->inactconns); + } else { + /* It is a persistent connection/template, so increase + the persistent connection counter */ + atomic_inc(&dest->persistconns); + } + + if (dest->u_threshold != 0 && + ip_vs_dest_totalconns(dest) >= dest->u_threshold) + dest->flags |= IP_VS_DEST_F_OVERLOAD; +} + + +/* + * Check if there is a destination for the connection, if so + * bind the connection to the destination. + */ +struct ip_vs_dest *ip_vs_try_bind_dest(struct ip_vs_conn *cp) +{ + struct ip_vs_dest *dest; + + if ((cp) && (!cp->dest)) { + dest = ip_vs_find_dest(ip_vs_conn_net(cp), cp->af, &cp->daddr, + cp->dport, &cp->vaddr, cp->vport, + cp->protocol, cp->fwmark); + ip_vs_bind_dest(cp, dest); + return dest; + } else + return NULL; +} + + +/* + * Unbind a connection entry with its VS destination + * Called by the ip_vs_conn_expire function. + */ +static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp) +{ + struct ip_vs_dest *dest = cp->dest; + + if (!dest) + return; + + IP_VS_DBG_BUF(7, "Unbind-dest %s c:%s:%d v:%s:%d " + "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d " + "dest->refcnt:%d\n", + ip_vs_proto_name(cp->protocol), + IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport), + IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport), + IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport), + ip_vs_fwd_tag(cp), cp->state, + cp->flags, atomic_read(&cp->refcnt), + atomic_read(&dest->refcnt)); + + /* Update the connection counters */ + if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) { + /* It is a normal connection, so decrease the inactconns + or activeconns counter */ + if (cp->flags & IP_VS_CONN_F_INACTIVE) { + atomic_dec(&dest->inactconns); + } else { + atomic_dec(&dest->activeconns); + } + } else { + /* It is a persistent connection/template, so decrease + the persistent connection counter */ + atomic_dec(&dest->persistconns); + } + + if (dest->l_threshold != 0) { + if (ip_vs_dest_totalconns(dest) < dest->l_threshold) + dest->flags &= ~IP_VS_DEST_F_OVERLOAD; + } else if (dest->u_threshold != 0) { + if (ip_vs_dest_totalconns(dest) * 4 < dest->u_threshold * 3) + dest->flags &= ~IP_VS_DEST_F_OVERLOAD; + } else { + if (dest->flags & IP_VS_DEST_F_OVERLOAD) + dest->flags &= ~IP_VS_DEST_F_OVERLOAD; + } + + /* + * Simply decrease the refcnt of the dest, because the + * dest will be either in service's destination list + * or in the trash. + */ + atomic_dec(&dest->refcnt); +} + +static int expire_quiescent_template(struct netns_ipvs *ipvs, + struct ip_vs_dest *dest) +{ +#ifdef CONFIG_SYSCTL + return ipvs->sysctl_expire_quiescent_template && + (atomic_read(&dest->weight) == 0); +#else + return 0; +#endif +} + +/* + * Checking if the destination of a connection template is available. + * If available, return 1, otherwise invalidate this connection + * template and return 0. + */ +int ip_vs_check_template(struct ip_vs_conn *ct) +{ + struct ip_vs_dest *dest = ct->dest; + struct netns_ipvs *ipvs = net_ipvs(ip_vs_conn_net(ct)); + + /* + * Checking the dest server status. + */ + if ((dest == NULL) || + !(dest->flags & IP_VS_DEST_F_AVAILABLE) || + expire_quiescent_template(ipvs, dest)) { + IP_VS_DBG_BUF(9, "check_template: dest not available for " + "protocol %s s:%s:%d v:%s:%d " + "-> d:%s:%d\n", + ip_vs_proto_name(ct->protocol), + IP_VS_DBG_ADDR(ct->af, &ct->caddr), + ntohs(ct->cport), + IP_VS_DBG_ADDR(ct->af, &ct->vaddr), + ntohs(ct->vport), + IP_VS_DBG_ADDR(ct->af, &ct->daddr), + ntohs(ct->dport)); + + /* + * Invalidate the connection template + */ + if (ct->vport != htons(0xffff)) { + if (ip_vs_conn_unhash(ct)) { + ct->dport = htons(0xffff); + ct->vport = htons(0xffff); + ct->cport = 0; + ip_vs_conn_hash(ct); + } + } + + /* + * Simply decrease the refcnt of the template, + * don't restart its timer. + */ + atomic_dec(&ct->refcnt); + return 0; + } + return 1; +} + +static void ip_vs_conn_expire(unsigned long data) +{ + struct ip_vs_conn *cp = (struct ip_vs_conn *)data; + struct netns_ipvs *ipvs = net_ipvs(ip_vs_conn_net(cp)); + + cp->timeout = 60*HZ; + + /* + * hey, I'm using it + */ + atomic_inc(&cp->refcnt); + + /* + * do I control anybody? + */ + if (atomic_read(&cp->n_control)) + goto expire_later; + + /* + * unhash it if it is hashed in the conn table + */ + if (!ip_vs_conn_unhash(cp) && !(cp->flags & IP_VS_CONN_F_ONE_PACKET)) + goto expire_later; + + /* + * refcnt==1 implies I'm the only one referrer + */ + if (likely(atomic_read(&cp->refcnt) == 1)) { + /* delete the timer if it is activated by other users */ + if (timer_pending(&cp->timer)) + del_timer(&cp->timer); + + /* does anybody control me? */ + if (cp->control) + ip_vs_control_del(cp); + + if (cp->flags & IP_VS_CONN_F_NFCT) { + ip_vs_conn_drop_conntrack(cp); + /* Do not access conntracks during subsys cleanup + * because nf_conntrack_find_get can not be used after + * conntrack cleanup for the net. + */ + smp_rmb(); + if (ipvs->enable) + ip_vs_conn_drop_conntrack(cp); + } + + ip_vs_pe_put(cp->pe); + kfree(cp->pe_data); + if (unlikely(cp->app != NULL)) + ip_vs_unbind_app(cp); + ip_vs_unbind_dest(cp); + if (cp->flags & IP_VS_CONN_F_NO_CPORT) + atomic_dec(&ip_vs_conn_no_cport_cnt); + atomic_dec(&ipvs->conn_count); + + kmem_cache_free(ip_vs_conn_cachep, cp); + return; + } + + /* hash it back to the table */ + ip_vs_conn_hash(cp); + + expire_later: + IP_VS_DBG(7, "delayed: conn->refcnt-1=%d conn->n_control=%d\n", + atomic_read(&cp->refcnt)-1, + atomic_read(&cp->n_control)); + + ip_vs_conn_put(cp); +} + + +void ip_vs_conn_expire_now(struct ip_vs_conn *cp) +{ + if (del_timer(&cp->timer)) + mod_timer(&cp->timer, jiffies); +} + + +/* + * Create a new connection entry and hash it into the ip_vs_conn_tab + */ +struct ip_vs_conn * +ip_vs_conn_new(const struct ip_vs_conn_param *p, + const union nf_inet_addr *daddr, __be16 dport, unsigned flags, + struct ip_vs_dest *dest, __u32 fwmark) +{ + struct ip_vs_conn *cp; + struct netns_ipvs *ipvs = net_ipvs(p->net); + struct ip_vs_proto_data *pd = ip_vs_proto_data_get(p->net, + p->protocol); + + cp = kmem_cache_zalloc(ip_vs_conn_cachep, GFP_ATOMIC); + if (cp == NULL) { + IP_VS_ERR_RL("%s(): no memory\n", __func__); + return NULL; + } + + INIT_HLIST_NODE(&cp->c_list); + setup_timer(&cp->timer, ip_vs_conn_expire, (unsigned long)cp); + ip_vs_conn_net_set(cp, p->net); + cp->af = p->af; + cp->protocol = p->protocol; + ip_vs_addr_copy(p->af, &cp->caddr, p->caddr); + cp->cport = p->cport; + ip_vs_addr_copy(p->af, &cp->vaddr, p->vaddr); + cp->vport = p->vport; + /* proto should only be IPPROTO_IP if d_addr is a fwmark */ + ip_vs_addr_copy(p->protocol == IPPROTO_IP ? AF_UNSPEC : p->af, + &cp->daddr, daddr); + cp->dport = dport; + cp->flags = flags; + cp->fwmark = fwmark; + if (flags & IP_VS_CONN_F_TEMPLATE && p->pe) { + ip_vs_pe_get(p->pe); + cp->pe = p->pe; + cp->pe_data = p->pe_data; + cp->pe_data_len = p->pe_data_len; + } + spin_lock_init(&cp->lock); + + /* + * Set the entry is referenced by the current thread before hashing + * it in the table, so that other thread run ip_vs_random_dropentry + * but cannot drop this entry. + */ + atomic_set(&cp->refcnt, 1); + + atomic_set(&cp->n_control, 0); + atomic_set(&cp->in_pkts, 0); + + atomic_inc(&ipvs->conn_count); + if (flags & IP_VS_CONN_F_NO_CPORT) + atomic_inc(&ip_vs_conn_no_cport_cnt); + + /* Bind the connection with a destination server */ + ip_vs_bind_dest(cp, dest); + + /* Set its state and timeout */ + cp->state = 0; + cp->timeout = 3*HZ; + + /* Bind its packet transmitter */ +#ifdef CONFIG_IP_VS_IPV6 + if (p->af == AF_INET6) + ip_vs_bind_xmit_v6(cp); + else +#endif + ip_vs_bind_xmit(cp); + + if (unlikely(pd && atomic_read(&pd->appcnt))) + ip_vs_bind_app(cp, pd->pp); + + /* + * Allow conntrack to be preserved. By default, conntrack + * is created and destroyed for every packet. + * Sometimes keeping conntrack can be useful for + * IP_VS_CONN_F_ONE_PACKET too. + */ + + if (ip_vs_conntrack_enabled(ipvs)) + cp->flags |= IP_VS_CONN_F_NFCT; + + /* Hash it in the ip_vs_conn_tab finally */ + ip_vs_conn_hash(cp); + + return cp; +} + +/* + * /proc/net/ip_vs_conn entries + */ +#ifdef CONFIG_PROC_FS +struct ip_vs_iter_state { + struct seq_net_private p; + struct hlist_head *l; +}; + +static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos) +{ + int idx; + struct ip_vs_conn *cp; + struct ip_vs_iter_state *iter = seq->private; + struct hlist_node *n; + + for (idx = 0; idx < ip_vs_conn_tab_size; idx++) { + ct_read_lock_bh(idx); + hlist_for_each_entry(cp, n, &ip_vs_conn_tab[idx], c_list) { + if (pos-- == 0) { + iter->l = &ip_vs_conn_tab[idx]; + return cp; + } + } + ct_read_unlock_bh(idx); + } + + return NULL; +} + +static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos) +{ + struct ip_vs_iter_state *iter = seq->private; + + iter->l = NULL; + return *pos ? ip_vs_conn_array(seq, *pos - 1) :SEQ_START_TOKEN; +} + +static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct ip_vs_conn *cp = v; + struct ip_vs_iter_state *iter = seq->private; + struct hlist_node *e; + struct hlist_head *l = iter->l; + int idx; + + ++*pos; + if (v == SEQ_START_TOKEN) + return ip_vs_conn_array(seq, 0); + + /* more on same hash chain? */ + if ((e = cp->c_list.next)) + return hlist_entry(e, struct ip_vs_conn, c_list); + + idx = l - ip_vs_conn_tab; + ct_read_unlock_bh(idx); + + while (++idx < ip_vs_conn_tab_size) { + ct_read_lock_bh(idx); + hlist_for_each_entry(cp, e, &ip_vs_conn_tab[idx], c_list) { + iter->l = &ip_vs_conn_tab[idx]; + return cp; + } + ct_read_unlock_bh(idx); + } + iter->l = NULL; + return NULL; +} + +static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v) +{ + struct ip_vs_iter_state *iter = seq->private; + struct hlist_head *l = iter->l; + + if (l) + ct_read_unlock_bh(l - ip_vs_conn_tab); +} + +static int ip_vs_conn_seq_show(struct seq_file *seq, void *v) +{ + + if (v == SEQ_START_TOKEN) + seq_puts(seq, + "Pro FromIP FPrt ToIP TPrt DestIP DPrt State Expires PEName PEData\n"); + else { + const struct ip_vs_conn *cp = v; + struct net *net = seq_file_net(seq); + char pe_data[IP_VS_PENAME_MAXLEN + IP_VS_PEDATA_MAXLEN + 3]; + size_t len = 0; + + if (!ip_vs_conn_net_eq(cp, net)) + return 0; + if (cp->pe_data) { + pe_data[0] = ' '; + len = strlen(cp->pe->name); + memcpy(pe_data + 1, cp->pe->name, len); + pe_data[len + 1] = ' '; + len += 2; + len += cp->pe->show_pe_data(cp, pe_data + len); + } + pe_data[len] = '\0'; + +#ifdef CONFIG_IP_VS_IPV6 + if (cp->af == AF_INET6) + seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X " + "%pI6 %04X %-11s %7lu%s\n", + ip_vs_proto_name(cp->protocol), + &cp->caddr.in6, ntohs(cp->cport), + &cp->vaddr.in6, ntohs(cp->vport), + &cp->daddr.in6, ntohs(cp->dport), + ip_vs_state_name(cp->protocol, cp->state), + (cp->timer.expires-jiffies)/HZ, pe_data); + else +#endif + seq_printf(seq, + "%-3s %08X %04X %08X %04X" + " %08X %04X %-11s %7lu%s\n", + ip_vs_proto_name(cp->protocol), + ntohl(cp->caddr.ip), ntohs(cp->cport), + ntohl(cp->vaddr.ip), ntohs(cp->vport), + ntohl(cp->daddr.ip), ntohs(cp->dport), + ip_vs_state_name(cp->protocol, cp->state), + (cp->timer.expires-jiffies)/HZ, pe_data); + } + return 0; +} + +static const struct seq_operations ip_vs_conn_seq_ops = { + .start = ip_vs_conn_seq_start, + .next = ip_vs_conn_seq_next, + .stop = ip_vs_conn_seq_stop, + .show = ip_vs_conn_seq_show, +}; + +static int ip_vs_conn_open(struct inode *inode, struct file *file) +{ + return seq_open_net(inode, file, &ip_vs_conn_seq_ops, + sizeof(struct ip_vs_iter_state)); +} + +static const struct file_operations ip_vs_conn_fops = { + .owner = THIS_MODULE, + .open = ip_vs_conn_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_net, +}; + +static const char *ip_vs_origin_name(unsigned flags) +{ + if (flags & IP_VS_CONN_F_SYNC) + return "SYNC"; + else + return "LOCAL"; +} + +static int ip_vs_conn_sync_seq_show(struct seq_file *seq, void *v) +{ + + if (v == SEQ_START_TOKEN) + seq_puts(seq, + "Pro FromIP FPrt ToIP TPrt DestIP DPrt State Origin Expires\n"); + else { + const struct ip_vs_conn *cp = v; + struct net *net = seq_file_net(seq); + + if (!ip_vs_conn_net_eq(cp, net)) + return 0; + +#ifdef CONFIG_IP_VS_IPV6 + if (cp->af == AF_INET6) + seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X %pI6 %04X %-11s %-6s %7lu\n", + ip_vs_proto_name(cp->protocol), + &cp->caddr.in6, ntohs(cp->cport), + &cp->vaddr.in6, ntohs(cp->vport), + &cp->daddr.in6, ntohs(cp->dport), + ip_vs_state_name(cp->protocol, cp->state), + ip_vs_origin_name(cp->flags), + (cp->timer.expires-jiffies)/HZ); + else +#endif + seq_printf(seq, + "%-3s %08X %04X %08X %04X " + "%08X %04X %-11s %-6s %7lu\n", + ip_vs_proto_name(cp->protocol), + ntohl(cp->caddr.ip), ntohs(cp->cport), + ntohl(cp->vaddr.ip), ntohs(cp->vport), + ntohl(cp->daddr.ip), ntohs(cp->dport), + ip_vs_state_name(cp->protocol, cp->state), + ip_vs_origin_name(cp->flags), + (cp->timer.expires-jiffies)/HZ); + } + return 0; +} + +static const struct seq_operations ip_vs_conn_sync_seq_ops = { + .start = ip_vs_conn_seq_start, + .next = ip_vs_conn_seq_next, + .stop = ip_vs_conn_seq_stop, + .show = ip_vs_conn_sync_seq_show, +}; + +static int ip_vs_conn_sync_open(struct inode *inode, struct file *file) +{ + return seq_open_net(inode, file, &ip_vs_conn_sync_seq_ops, + sizeof(struct ip_vs_iter_state)); +} + +static const struct file_operations ip_vs_conn_sync_fops = { + .owner = THIS_MODULE, + .open = ip_vs_conn_sync_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_net, +}; + +#endif + + +/* + * Randomly drop connection entries before running out of memory + */ +static inline int todrop_entry(struct ip_vs_conn *cp) +{ + /* + * The drop rate array needs tuning for real environments. + * Called from timer bh only => no locking + */ + static const char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8}; + static char todrop_counter[9] = {0}; + int i; + + /* if the conn entry hasn't lasted for 60 seconds, don't drop it. + This will leave enough time for normal connection to get + through. */ + if (time_before(cp->timeout + jiffies, cp->timer.expires + 60*HZ)) + return 0; + + /* Don't drop the entry if its number of incoming packets is not + located in [0, 8] */ + i = atomic_read(&cp->in_pkts); + if (i > 8 || i < 0) return 0; + + if (!todrop_rate[i]) return 0; + if (--todrop_counter[i] > 0) return 0; + + todrop_counter[i] = todrop_rate[i]; + return 1; +} + +/* Called from keventd and must protect itself from softirqs */ +void ip_vs_random_dropentry(struct net *net) +{ + int idx; + struct ip_vs_conn *cp; + + /* + * Randomly scan 1/32 of the whole table every second + */ + for (idx = 0; idx < (ip_vs_conn_tab_size>>5); idx++) { + unsigned hash = net_random() & ip_vs_conn_tab_mask; + struct hlist_node *n; + + /* + * Lock is actually needed in this loop. + */ + ct_write_lock_bh(hash); + + hlist_for_each_entry(cp, n, &ip_vs_conn_tab[hash], c_list) { + if (cp->flags & IP_VS_CONN_F_TEMPLATE) + /* connection template */ + continue; + if (!ip_vs_conn_net_eq(cp, net)) + continue; + if (cp->protocol == IPPROTO_TCP) { + switch(cp->state) { + case IP_VS_TCP_S_SYN_RECV: + case IP_VS_TCP_S_SYNACK: + break; + + case IP_VS_TCP_S_ESTABLISHED: + if (todrop_entry(cp)) + break; + continue; + + default: + continue; + } + } else { + if (!todrop_entry(cp)) + continue; + } + + IP_VS_DBG(4, "del connection\n"); + ip_vs_conn_expire_now(cp); + if (cp->control) { + IP_VS_DBG(4, "del conn template\n"); + ip_vs_conn_expire_now(cp->control); + } + } + ct_write_unlock_bh(hash); + } +} + + +/* + * Flush all the connection entries in the ip_vs_conn_tab + */ +static void ip_vs_conn_flush(struct net *net) +{ + int idx; + struct ip_vs_conn *cp; + struct netns_ipvs *ipvs = net_ipvs(net); + +flush_again: + for (idx = 0; idx < ip_vs_conn_tab_size; idx++) { + struct hlist_node *n; + + /* + * Lock is actually needed in this loop. + */ + ct_write_lock_bh(idx); + + hlist_for_each_entry(cp, n, &ip_vs_conn_tab[idx], c_list) { + if (!ip_vs_conn_net_eq(cp, net)) + continue; + IP_VS_DBG(4, "del connection\n"); + ip_vs_conn_expire_now(cp); + if (cp->control) { + IP_VS_DBG(4, "del conn template\n"); + ip_vs_conn_expire_now(cp->control); + } + } + ct_write_unlock_bh(idx); + } + + /* the counter may be not NULL, because maybe some conn entries + are run by slow timer handler or unhashed but still referred */ + if (atomic_read(&ipvs->conn_count) != 0) { + schedule(); + goto flush_again; + } +} +/* + * per netns init and exit + */ +int __net_init __ip_vs_conn_init(struct net *net) +{ + struct netns_ipvs *ipvs = net_ipvs(net); + + atomic_set(&ipvs->conn_count, 0); + + proc_net_fops_create(net, "ip_vs_conn", 0, &ip_vs_conn_fops); + proc_net_fops_create(net, "ip_vs_conn_sync", 0, &ip_vs_conn_sync_fops); + return 0; +} + +void __net_exit __ip_vs_conn_cleanup(struct net *net) +{ + /* flush all the connection entries first */ + ip_vs_conn_flush(net); + proc_net_remove(net, "ip_vs_conn"); + proc_net_remove(net, "ip_vs_conn_sync"); +} + +int __init ip_vs_conn_init(void) +{ + int idx; + + /* Compute size and mask */ + ip_vs_conn_tab_size = 1 << ip_vs_conn_tab_bits; + ip_vs_conn_tab_mask = ip_vs_conn_tab_size - 1; + + /* + * Allocate the connection hash table and initialize its list heads + */ + ip_vs_conn_tab = vmalloc(ip_vs_conn_tab_size * sizeof(*ip_vs_conn_tab)); + if (!ip_vs_conn_tab) + return -ENOMEM; + + /* Allocate ip_vs_conn slab cache */ + ip_vs_conn_cachep = kmem_cache_create("ip_vs_conn", + sizeof(struct ip_vs_conn), 0, + SLAB_HWCACHE_ALIGN, NULL); + if (!ip_vs_conn_cachep) { + vfree(ip_vs_conn_tab); + return -ENOMEM; + } + + pr_info("Connection hash table configured " + "(size=%d, memory=%ldKbytes)\n", + ip_vs_conn_tab_size, + (long)(ip_vs_conn_tab_size*sizeof(struct list_head))/1024); + IP_VS_DBG(0, "Each connection entry needs %Zd bytes at least\n", + sizeof(struct ip_vs_conn)); + + for (idx = 0; idx < ip_vs_conn_tab_size; idx++) + INIT_HLIST_HEAD(&ip_vs_conn_tab[idx]); + + for (idx = 0; idx < CT_LOCKARRAY_SIZE; idx++) { + rwlock_init(&__ip_vs_conntbl_lock_array[idx].l); + } + + /* calculate the random value for connection hash */ + get_random_bytes(&ip_vs_conn_rnd, sizeof(ip_vs_conn_rnd)); + + return 0; +} + +void ip_vs_conn_cleanup(void) +{ + /* Release the empty cache */ + kmem_cache_destroy(ip_vs_conn_cachep); + vfree(ip_vs_conn_tab); +} |