// SPDX-License-Identifier: GPL-2.0-or-later /* * 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 * Peter Kese * Julian Anastasov * * 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 #include #include #include #include #include #include #include /* for proc_net_* */ #include #include #include #include #include #include #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<>8)) & ip_vs_conn_tab_mask; #endif return (jhash_3words((__force u32)addr->ip, (__force u32)port, proto, ip_vs_conn_rnd) ^ ((size_t)ipvs>>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->ipvs, 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(cp->ipvs, 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 int 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_bh(hash); spin_lock(&cp->lock); if (!(cp->flags & IP_VS_CONN_F_HASHED)) { cp->flags |= IP_VS_CONN_F_HASHED; refcount_inc(&cp->refcnt); hlist_add_head_rcu(&cp->c_list, &ip_vs_conn_tab[hash]); ret = 1; } else { pr_err("%s(): request for already hashed, called from %pS\n", __func__, __builtin_return_address(0)); ret = 0; } spin_unlock(&cp->lock); ct_write_unlock_bh(hash); return ret; } /* * UNhashes ip_vs_conn from ip_vs_conn_tab. * returns bool success. Caller should hold conn reference. */ static inline int ip_vs_conn_unhash(struct ip_vs_conn *cp) { unsigned int hash; int ret; /* unhash it and decrease its reference counter */ hash = ip_vs_conn_hashkey_conn(cp); ct_write_lock_bh(hash); spin_lock(&cp->lock); if (cp->flags & IP_VS_CONN_F_HASHED) { hlist_del_rcu(&cp->c_list); cp->flags &= ~IP_VS_CONN_F_HASHED; refcount_dec(&cp->refcnt); ret = 1; } else ret = 0; spin_unlock(&cp->lock); ct_write_unlock_bh(hash); return ret; } /* Try to unlink ip_vs_conn from ip_vs_conn_tab. * returns bool success. */ static inline bool ip_vs_conn_unlink(struct ip_vs_conn *cp) { unsigned int hash; bool ret = false; if (cp->flags & IP_VS_CONN_F_ONE_PACKET) return refcount_dec_if_one(&cp->refcnt); hash = ip_vs_conn_hashkey_conn(cp); ct_write_lock_bh(hash); spin_lock(&cp->lock); if (cp->flags & IP_VS_CONN_F_HASHED) { /* Decrease refcnt and unlink conn only if we are last user */ if (refcount_dec_if_one(&cp->refcnt)) { hlist_del_rcu(&cp->c_list); cp->flags &= ~IP_VS_CONN_F_HASHED; ret = true; } } spin_unlock(&cp->lock); ct_write_unlock_bh(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 int hash; struct ip_vs_conn *cp; hash = ip_vs_conn_hashkey_param(p, false); rcu_read_lock(); hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) { if (p->cport == cp->cport && p->vport == cp->vport && cp->af == p->af && 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 && cp->ipvs == p->ipvs) { if (!__ip_vs_conn_get(cp)) continue; /* HIT */ rcu_read_unlock(); return cp; } } rcu_read_unlock(); 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(struct netns_ipvs *ipvs, int af, const struct sk_buff *skb, const struct ip_vs_iphdr *iph, struct ip_vs_conn_param *p) { __be16 _ports[2], *pptr; pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports); if (pptr == NULL) return 1; if (likely(!ip_vs_iph_inverse(iph))) ip_vs_conn_fill_param(ipvs, af, iph->protocol, &iph->saddr, pptr[0], &iph->daddr, pptr[1], p); else ip_vs_conn_fill_param(ipvs, af, iph->protocol, &iph->daddr, pptr[1], &iph->saddr, pptr[0], p); return 0; } struct ip_vs_conn * ip_vs_conn_in_get_proto(struct netns_ipvs *ipvs, int af, const struct sk_buff *skb, const struct ip_vs_iphdr *iph) { struct ip_vs_conn_param p; if (ip_vs_conn_fill_param_proto(ipvs, af, skb, iph, &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 int hash; struct ip_vs_conn *cp; hash = ip_vs_conn_hashkey_param(p, false); rcu_read_lock(); hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) { if (unlikely(p->pe_data && p->pe->ct_match)) { if (cp->ipvs != p->ipvs) continue; if (p->pe == cp->pe && p->pe->ct_match(p, cp)) { if (__ip_vs_conn_get(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->vport == cp->vport && p->cport == cp->cport && cp->flags & IP_VS_CONN_F_TEMPLATE && p->protocol == cp->protocol && cp->ipvs == p->ipvs) { if (__ip_vs_conn_get(cp)) goto out; } } cp = NULL; out: rcu_read_unlock(); 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 int hash; struct ip_vs_conn *cp, *ret=NULL; const union nf_inet_addr *saddr; __be16 sport; /* * Check for "full" addressed entries */ hash = ip_vs_conn_hashkey_param(p, true); rcu_read_lock(); hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) { if (p->vport != cp->cport) continue; if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ) { sport = cp->vport; saddr = &cp->vaddr; } else { sport = cp->dport; saddr = &cp->daddr; } if (p->cport == sport && cp->af == p->af && ip_vs_addr_equal(p->af, p->vaddr, &cp->caddr) && ip_vs_addr_equal(p->af, p->caddr, saddr) && p->protocol == cp->protocol && cp->ipvs == p->ipvs) { if (!__ip_vs_conn_get(cp)) continue; /* HIT */ ret = cp; break; } } rcu_read_unlock(); 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(struct netns_ipvs *ipvs, int af, const struct sk_buff *skb, const struct ip_vs_iphdr *iph) { struct ip_vs_conn_param p; if (ip_vs_conn_fill_param_proto(ipvs, af, skb, iph, &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 */ static void __ip_vs_conn_put_timer(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); } void ip_vs_conn_put(struct ip_vs_conn *cp) { if ((cp->flags & IP_VS_CONN_F_ONE_PACKET) && (refcount_read(&cp->refcnt) == 1) && !timer_pending(&cp->timer)) /* expire connection immediately */ ip_vs_conn_expire(&cp->timer); else __ip_vs_conn_put_timer(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_bh(&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_bh(&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: #ifdef CONFIG_IP_VS_IPV6 if (cp->daf == AF_INET6) cp->packet_xmit = ip_vs_tunnel_xmit_v6; else #endif 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: if (cp->daf == AF_INET6) cp->packet_xmit = ip_vs_tunnel_xmit_v6; else cp->packet_xmit = ip_vs_tunnel_xmit; 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; __u32 flags; /* if dest is NULL, then return directly */ if (!dest) return; /* Increase the refcnt counter of the dest */ ip_vs_dest_hold(dest); conn_flags = atomic_read(&dest->conn_flags); if (cp->protocol != IPPROTO_UDP) conn_flags &= ~IP_VS_CONN_F_ONE_PACKET; flags = cp->flags; /* Bind with the destination and its corresponding transmitter */ if (flags & IP_VS_CONN_F_SYNC) { /* if the connection is not template and is created * by sync, preserve the activity flag. */ if (!(flags & IP_VS_CONN_F_TEMPLATE)) conn_flags &= ~IP_VS_CONN_F_INACTIVE; /* connections inherit forwarding method from dest */ flags &= ~(IP_VS_CONN_F_FWD_MASK | IP_VS_CONN_F_NOOUTPUT); } flags |= conn_flags; cp->flags = 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->daf, &cp->daddr), ntohs(cp->dport), ip_vs_fwd_tag(cp), cp->state, cp->flags, refcount_read(&cp->refcnt), refcount_read(&dest->refcnt)); /* Update the connection counters */ if (!(flags & IP_VS_CONN_F_TEMPLATE)) { /* It is a normal connection, so modify the counters * according to the flags, later the protocol can * update them on state change */ if (!(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. */ void ip_vs_try_bind_dest(struct ip_vs_conn *cp) { struct ip_vs_dest *dest; rcu_read_lock(); /* This function is only invoked by the synchronization code. We do * not currently support heterogeneous pools with synchronization, * so we can make the assumption that the svc_af is the same as the * dest_af */ dest = ip_vs_find_dest(cp->ipvs, cp->af, cp->af, &cp->daddr, cp->dport, &cp->vaddr, cp->vport, cp->protocol, cp->fwmark, cp->flags); if (dest) { struct ip_vs_proto_data *pd; spin_lock_bh(&cp->lock); if (cp->dest) { spin_unlock_bh(&cp->lock); rcu_read_unlock(); return; } /* Applications work depending on the forwarding method * but better to reassign them always when binding dest */ if (cp->app) ip_vs_unbind_app(cp); ip_vs_bind_dest(cp, dest); spin_unlock_bh(&cp->lock); /* Update its packet transmitter */ cp->packet_xmit = NULL; #ifdef CONFIG_IP_VS_IPV6 if (cp->af == AF_INET6) ip_vs_bind_xmit_v6(cp); else #endif ip_vs_bind_xmit(cp); pd = ip_vs_proto_data_get(cp->ipvs, cp->protocol); if (pd && atomic_read(&pd->appcnt)) ip_vs_bind_app(cp, pd->pp); } rcu_read_unlock(); } /* * 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->daf, &cp->daddr), ntohs(cp->dport), ip_vs_fwd_tag(cp), cp->state, cp->flags, refcount_read(&cp->refcnt), refcount_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; } ip_vs_dest_put(dest); } 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 *cdest) { struct ip_vs_dest *dest = ct->dest; struct netns_ipvs *ipvs = ct->ipvs; /* * Checking the dest server status. */ if ((dest == NULL) || !(dest->flags & IP_VS_DEST_F_AVAILABLE) || expire_quiescent_template(ipvs, dest) || (cdest && (dest != cdest))) { 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->daf, &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. */ __ip_vs_conn_put(ct); return 0; } return 1; } static void ip_vs_conn_rcu_free(struct rcu_head *head) { struct ip_vs_conn *cp = container_of(head, struct ip_vs_conn, rcu_head); ip_vs_pe_put(cp->pe); kfree(cp->pe_data); kmem_cache_free(ip_vs_conn_cachep, cp); } /* Try to delete connection while not holding reference */ static void ip_vs_conn_del(struct ip_vs_conn *cp) { if (del_timer(&cp->timer)) { /* Drop cp->control chain too */ if (cp->control) cp->timeout = 0; ip_vs_conn_expire(&cp->timer); } } /* Try to delete connection while holding reference */ static void ip_vs_conn_del_put(struct ip_vs_conn *cp) { if (del_timer(&cp->timer)) { /* Drop cp->control chain too */ if (cp->control) cp->timeout = 0; __ip_vs_conn_put(cp); ip_vs_conn_expire(&cp->timer); } else { __ip_vs_conn_put(cp); } } static void ip_vs_conn_expire(struct timer_list *t) { struct ip_vs_conn *cp = from_timer(cp, t, timer); struct netns_ipvs *ipvs = cp->ipvs; /* * do I control anybody? */ if (atomic_read(&cp->n_control)) goto expire_later; /* Unlink conn if not referenced anymore */ if (likely(ip_vs_conn_unlink(cp))) { struct ip_vs_conn *ct = cp->control; /* delete the timer if it is activated by other users */ del_timer(&cp->timer); /* does anybody control me? */ if (ct) { bool has_ref = !cp->timeout && __ip_vs_conn_get(ct); ip_vs_control_del(cp); /* Drop CTL or non-assured TPL if not used anymore */ if (has_ref && !atomic_read(&ct->n_control) && (!(ct->flags & IP_VS_CONN_F_TEMPLATE) || !(ct->state & IP_VS_CTPL_S_ASSURED))) { IP_VS_DBG(4, "drop controlling connection\n"); ip_vs_conn_del_put(ct); } else if (has_ref) { __ip_vs_conn_put(ct); } } if ((cp->flags & IP_VS_CONN_F_NFCT) && !(cp->flags & IP_VS_CONN_F_ONE_PACKET)) { /* 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); } 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); if (cp->flags & IP_VS_CONN_F_ONE_PACKET) ip_vs_conn_rcu_free(&cp->rcu_head); else call_rcu(&cp->rcu_head, ip_vs_conn_rcu_free); atomic_dec(&ipvs->conn_count); return; } expire_later: IP_VS_DBG(7, "delayed: conn->refcnt=%d conn->n_control=%d\n", refcount_read(&cp->refcnt), atomic_read(&cp->n_control)); refcount_inc(&cp->refcnt); cp->timeout = 60*HZ; if (ipvs->sync_state & IP_VS_STATE_MASTER) ip_vs_sync_conn(ipvs, cp, sysctl_sync_threshold(ipvs)); __ip_vs_conn_put_timer(cp); } /* Modify timer, so that it expires as soon as possible. * Can be called without reference only if under RCU lock. * We can have such chain of conns linked with ->control: DATA->CTL->TPL * - DATA (eg. FTP) and TPL (persistence) can be present depending on setup * - cp->timeout=0 indicates all conns from chain should be dropped but * TPL is not dropped if in assured state */ void ip_vs_conn_expire_now(struct ip_vs_conn *cp) { /* Using mod_timer_pending will ensure the timer is not * modified after the final del_timer in ip_vs_conn_expire. */ if (timer_pending(&cp->timer) && time_after(cp->timer.expires, jiffies)) mod_timer_pending(&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, int dest_af, const union nf_inet_addr *daddr, __be16 dport, unsigned int flags, struct ip_vs_dest *dest, __u32 fwmark) { struct ip_vs_conn *cp; struct netns_ipvs *ipvs = p->ipvs; struct ip_vs_proto_data *pd = ip_vs_proto_data_get(p->ipvs, p->protocol); cp = kmem_cache_alloc(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); timer_setup(&cp->timer, ip_vs_conn_expire, 0); cp->ipvs = ipvs; cp->af = p->af; cp->daf = dest_af; cp->protocol = p->protocol; ip_vs_addr_set(p->af, &cp->caddr, p->caddr); cp->cport = p->cport; /* proto should only be IPPROTO_IP if p->vaddr is a fwmark */ ip_vs_addr_set(p->protocol == IPPROTO_IP ? AF_UNSPEC : p->af, &cp->vaddr, p->vaddr); cp->vport = p->vport; ip_vs_addr_set(cp->daf, &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; } else { cp->pe = NULL; cp->pe_data = NULL; cp->pe_data_len = 0; } 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. */ refcount_set(&cp->refcnt, 1); cp->control = NULL; atomic_set(&cp->n_control, 0); atomic_set(&cp->in_pkts, 0); cp->packet_xmit = NULL; cp->app = NULL; cp->app_data = NULL; /* reset struct ip_vs_seq */ cp->in_seq.delta = 0; cp->out_seq.delta = 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 */ cp->dest = NULL; ip_vs_bind_dest(cp, dest); /* Set its state and timeout */ cp->state = 0; cp->old_state = 0; cp->timeout = 3*HZ; cp->sync_endtime = jiffies & ~3UL; /* 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; for (idx = 0; idx < ip_vs_conn_tab_size; idx++) { hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) { /* __ip_vs_conn_get() is not needed by * ip_vs_conn_seq_show and ip_vs_conn_sync_seq_show */ if (pos-- == 0) { iter->l = &ip_vs_conn_tab[idx]; return cp; } } cond_resched_rcu(); } return NULL; } static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos) __acquires(RCU) { struct ip_vs_iter_state *iter = seq->private; iter->l = NULL; rcu_read_lock(); 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? */ e = rcu_dereference(hlist_next_rcu(&cp->c_list)); if (e) return hlist_entry(e, struct ip_vs_conn, c_list); idx = l - ip_vs_conn_tab; while (++idx < ip_vs_conn_tab_size) { hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) { iter->l = &ip_vs_conn_tab[idx]; return cp; } cond_resched_rcu(); } iter->l = NULL; return NULL; } static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v) __releases(RCU) { rcu_read_unlock(); } 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; char dbuf[IP_VS_ADDRSTRLEN]; if (!net_eq(cp->ipvs->net, 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->daf == AF_INET6) snprintf(dbuf, sizeof(dbuf), "%pI6", &cp->daddr.in6); else #endif snprintf(dbuf, sizeof(dbuf), "%08X", ntohl(cp->daddr.ip)); #ifdef CONFIG_IP_VS_IPV6 if (cp->af == AF_INET6) seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X " "%s %04X %-11s %7u%s\n", ip_vs_proto_name(cp->protocol), &cp->caddr.in6, ntohs(cp->cport), &cp->vaddr.in6, ntohs(cp->vport), dbuf, ntohs(cp->dport), ip_vs_state_name(cp), jiffies_delta_to_msecs(cp->timer.expires - jiffies) / 1000, pe_data); else #endif seq_printf(seq, "%-3s %08X %04X %08X %04X" " %s %04X %-11s %7u%s\n", ip_vs_proto_name(cp->protocol), ntohl(cp->caddr.ip), ntohs(cp->cport), ntohl(cp->vaddr.ip), ntohs(cp->vport), dbuf, ntohs(cp->dport), ip_vs_state_name(cp), jiffies_delta_to_msecs(cp->timer.expires - jiffies) / 1000, 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 const char *ip_vs_origin_name(unsigned int 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) { char dbuf[IP_VS_ADDRSTRLEN]; 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 (!net_eq(cp->ipvs->net, net)) return 0; #ifdef CONFIG_IP_VS_IPV6 if (cp->daf == AF_INET6) snprintf(dbuf, sizeof(dbuf), "%pI6", &cp->daddr.in6); else #endif snprintf(dbuf, sizeof(dbuf), "%08X", ntohl(cp->daddr.ip)); #ifdef CONFIG_IP_VS_IPV6 if (cp->af == AF_INET6) seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X " "%s %04X %-11s %-6s %7u\n", ip_vs_proto_name(cp->protocol), &cp->caddr.in6, ntohs(cp->cport), &cp->vaddr.in6, ntohs(cp->vport), dbuf, ntohs(cp->dport), ip_vs_state_name(cp), ip_vs_origin_name(cp->flags), jiffies_delta_to_msecs(cp->timer.expires - jiffies) / 1000); else #endif seq_printf(seq, "%-3s %08X %04X %08X %04X " "%s %04X %-11s %-6s %7u\n", ip_vs_proto_name(cp->protocol), ntohl(cp->caddr.ip), ntohs(cp->cport), ntohl(cp->vaddr.ip), ntohs(cp->vport), dbuf, ntohs(cp->dport), ip_vs_state_name(cp), ip_vs_origin_name(cp->flags), jiffies_delta_to_msecs(cp->timer.expires - jiffies) / 1000); } 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, }; #endif /* Randomly drop connection entries before running out of memory * Can be used for DATA and CTL conns. For TPL conns there are exceptions: * - traffic for services in OPS mode increases ct->in_pkts, so it is supported * - traffic for services not in OPS mode does not increase ct->in_pkts in * all cases, so it is not supported */ 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; } static inline bool ip_vs_conn_ops_mode(struct ip_vs_conn *cp) { struct ip_vs_service *svc; if (!cp->dest) return false; svc = rcu_dereference(cp->dest->svc); return svc && (svc->flags & IP_VS_SVC_F_ONEPACKET); } /* Called from keventd and must protect itself from softirqs */ void ip_vs_random_dropentry(struct netns_ipvs *ipvs) { int idx; struct ip_vs_conn *cp; rcu_read_lock(); /* * Randomly scan 1/32 of the whole table every second */ for (idx = 0; idx < (ip_vs_conn_tab_size>>5); idx++) { unsigned int hash = prandom_u32() & ip_vs_conn_tab_mask; hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) { if (cp->ipvs != ipvs) continue; if (atomic_read(&cp->n_control)) continue; if (cp->flags & IP_VS_CONN_F_TEMPLATE) { /* connection template of OPS */ if (ip_vs_conn_ops_mode(cp)) goto try_drop; if (!(cp->state & IP_VS_CTPL_S_ASSURED)) goto drop; 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 (cp->protocol == IPPROTO_SCTP) { switch (cp->state) { case IP_VS_SCTP_S_INIT1: case IP_VS_SCTP_S_INIT: break; case IP_VS_SCTP_S_ESTABLISHED: if (todrop_entry(cp)) break; continue; default: continue; } } else { try_drop: if (!todrop_entry(cp)) continue; } drop: IP_VS_DBG(4, "drop connection\n"); ip_vs_conn_del(cp); } cond_resched_rcu(); } rcu_read_unlock(); } /* * Flush all the connection entries in the ip_vs_conn_tab */ static void ip_vs_conn_flush(struct netns_ipvs *ipvs) { int idx; struct ip_vs_conn *cp, *cp_c; flush_again: rcu_read_lock(); for (idx = 0; idx < ip_vs_conn_tab_size; idx++) { hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) { if (cp->ipvs != ipvs) continue; if (atomic_read(&cp->n_control)) continue; cp_c = cp->control; IP_VS_DBG(4, "del connection\n"); ip_vs_conn_del(cp); if (cp_c && !atomic_read(&cp_c->n_control)) { IP_VS_DBG(4, "del controlling connection\n"); ip_vs_conn_del(cp_c); } } cond_resched_rcu(); } rcu_read_unlock(); /* 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; } } #ifdef CONFIG_SYSCTL void ip_vs_expire_nodest_conn_flush(struct netns_ipvs *ipvs) { int idx; struct ip_vs_conn *cp, *cp_c; struct ip_vs_dest *dest; rcu_read_lock(); for (idx = 0; idx < ip_vs_conn_tab_size; idx++) { hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) { if (cp->ipvs != ipvs) continue; dest = cp->dest; if (!dest || (dest->flags & IP_VS_DEST_F_AVAILABLE)) continue; if (atomic_read(&cp->n_control)) continue; cp_c = cp->control; IP_VS_DBG(4, "del connection\n"); ip_vs_conn_del(cp); if (cp_c && !atomic_read(&cp_c->n_control)) { IP_VS_DBG(4, "del controlling connection\n"); ip_vs_conn_del(cp_c); } } cond_resched_rcu(); /* netns clean up started, abort delayed work */ if (!ipvs->enable) break; } rcu_read_unlock(); } #endif /* * per netns init and exit */ int __net_init ip_vs_conn_net_init(struct netns_ipvs *ipvs) { atomic_set(&ipvs->conn_count, 0); proc_create_net("ip_vs_conn", 0, ipvs->net->proc_net, &ip_vs_conn_seq_ops, sizeof(struct ip_vs_iter_state)); proc_create_net("ip_vs_conn_sync", 0, ipvs->net->proc_net, &ip_vs_conn_sync_seq_ops, sizeof(struct ip_vs_iter_state)); return 0; } void __net_exit ip_vs_conn_net_cleanup(struct netns_ipvs *ipvs) { /* flush all the connection entries first */ ip_vs_conn_flush(ipvs); remove_proc_entry("ip_vs_conn", ipvs->net->proc_net); remove_proc_entry("ip_vs_conn_sync", ipvs->net->proc_net); } int __init ip_vs_conn_init(void) { int idx; /* Compute size and mask */ if (ip_vs_conn_tab_bits < 8 || ip_vs_conn_tab_bits > 20) { pr_info("conn_tab_bits not in [8, 20]. Using default value\n"); ip_vs_conn_tab_bits = CONFIG_IP_VS_TAB_BITS; } 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(array_size(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++) { spin_lock_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) { /* Wait all ip_vs_conn_rcu_free() callbacks to complete */ rcu_barrier(); /* Release the empty cache */ kmem_cache_destroy(ip_vs_conn_cachep); vfree(ip_vs_conn_tab); }