| /* |
| * INET An implementation of the TCP/IP protocol suite for the LINUX |
| * operating system. INET is implemented using the BSD Socket |
| * interface as the means of communication with the user level. |
| * |
| * Implementation of the Transmission Control Protocol(TCP). |
| * |
| * Version: $Id: tcp_ipv4.c,v 1.237 2001-12-05 08:54:10 davem Exp $ |
| * |
| * IPv4 specific functions |
| * |
| * |
| * code split from: |
| * linux/ipv4/tcp.c |
| * linux/ipv4/tcp_input.c |
| * linux/ipv4/tcp_output.c |
| * |
| * See tcp.c for author information |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| /* |
| * Changes: |
| * David S. Miller : New socket lookup architecture. |
| * This code is dedicated to John Dyson. |
| * David S. Miller : Change semantics of established hash, |
| * half is devoted to TIME_WAIT sockets |
| * and the rest go in the other half. |
| * Andi Kleen : Add support for syncookies and fixed |
| * some bugs: ip options weren't passed to |
| * the TCP layer, missed a check for an ACK bit. |
| * Andi Kleen : Implemented fast path mtu discovery. |
| * Fixed many serious bugs in the |
| * open_request handling and moved |
| * most of it into the af independent code. |
| * Added tail drop and some other bugfixes. |
| * Added new listen sematics. |
| * Mike McLagan : Routing by source |
| * Juan Jose Ciarlante: ip_dynaddr bits |
| * Andi Kleen: various fixes. |
| * Vitaly E. Lavrov : Transparent proxy revived after year coma. |
| * Andi Kleen : Fix new listen. |
| * Andi Kleen : Fix accept error reporting. |
| */ |
| |
| #include <linux/config.h> |
| #include <linux/types.h> |
| #include <linux/fcntl.h> |
| #include <linux/random.h> |
| #include <linux/cache.h> |
| #include <linux/init.h> |
| |
| #include <net/icmp.h> |
| #include <net/tcp.h> |
| #include <net/ipv6.h> |
| #include <net/inet_common.h> |
| |
| #include <linux/inet.h> |
| #include <linux/stddef.h> |
| #include <linux/ipsec.h> |
| |
| extern int sysctl_ip_dynaddr; |
| |
| /* Check TCP sequence numbers in ICMP packets. */ |
| #define ICMP_MIN_LENGTH 8 |
| |
| /* Socket used for sending RSTs */ |
| static struct inode tcp_inode; |
| static struct socket *tcp_socket=&tcp_inode.u.socket_i; |
| |
| void tcp_v4_send_check(struct sock *sk, struct tcphdr *th, int len, |
| struct sk_buff *skb); |
| |
| /* |
| * ALL members must be initialised to prevent gcc-2.7.2.3 miscompilation |
| */ |
| struct tcp_hashinfo __cacheline_aligned tcp_hashinfo = { |
| __tcp_ehash: NULL, |
| __tcp_bhash: NULL, |
| __tcp_bhash_size: 0, |
| __tcp_ehash_size: 0, |
| __tcp_listening_hash: { NULL, }, |
| __tcp_lhash_lock: RW_LOCK_UNLOCKED, |
| __tcp_lhash_users: ATOMIC_INIT(0), |
| __tcp_lhash_wait: |
| __WAIT_QUEUE_HEAD_INITIALIZER(tcp_hashinfo.__tcp_lhash_wait), |
| __tcp_portalloc_lock: SPIN_LOCK_UNLOCKED |
| }; |
| |
| /* |
| * This array holds the first and last local port number. |
| * For high-usage systems, use sysctl to change this to |
| * 32768-61000 |
| */ |
| int sysctl_local_port_range[2] = { 1024, 4999 }; |
| int tcp_port_rover = (1024 - 1); |
| |
| static __inline__ int tcp_hashfn(__u32 laddr, __u16 lport, |
| __u32 faddr, __u16 fport) |
| { |
| int h = ((laddr ^ lport) ^ (faddr ^ fport)); |
| h ^= h>>16; |
| h ^= h>>8; |
| return h & (tcp_ehash_size - 1); |
| } |
| |
| static __inline__ int tcp_sk_hashfn(struct sock *sk) |
| { |
| __u32 laddr = sk->rcv_saddr; |
| __u16 lport = sk->num; |
| __u32 faddr = sk->daddr; |
| __u16 fport = sk->dport; |
| |
| return tcp_hashfn(laddr, lport, faddr, fport); |
| } |
| |
| /* Allocate and initialize a new TCP local port bind bucket. |
| * The bindhash mutex for snum's hash chain must be held here. |
| */ |
| struct tcp_bind_bucket *tcp_bucket_create(struct tcp_bind_hashbucket *head, |
| unsigned short snum) |
| { |
| struct tcp_bind_bucket *tb; |
| |
| tb = kmem_cache_alloc(tcp_bucket_cachep, SLAB_ATOMIC); |
| if(tb != NULL) { |
| tb->port = snum; |
| tb->fastreuse = 0; |
| tb->owners = NULL; |
| if((tb->next = head->chain) != NULL) |
| tb->next->pprev = &tb->next; |
| head->chain = tb; |
| tb->pprev = &head->chain; |
| } |
| return tb; |
| } |
| |
| /* Caller must disable local BH processing. */ |
| static __inline__ void __tcp_inherit_port(struct sock *sk, struct sock *child) |
| { |
| struct tcp_bind_hashbucket *head = &tcp_bhash[tcp_bhashfn(child->num)]; |
| struct tcp_bind_bucket *tb; |
| |
| spin_lock(&head->lock); |
| tb = (struct tcp_bind_bucket *)sk->prev; |
| if ((child->bind_next = tb->owners) != NULL) |
| tb->owners->bind_pprev = &child->bind_next; |
| tb->owners = child; |
| child->bind_pprev = &tb->owners; |
| child->prev = (struct sock *) tb; |
| spin_unlock(&head->lock); |
| } |
| |
| __inline__ void tcp_inherit_port(struct sock *sk, struct sock *child) |
| { |
| local_bh_disable(); |
| __tcp_inherit_port(sk, child); |
| local_bh_enable(); |
| } |
| |
| static inline void tcp_bind_hash(struct sock *sk, struct tcp_bind_bucket *tb, unsigned short snum) |
| { |
| sk->num = snum; |
| if ((sk->bind_next = tb->owners) != NULL) |
| tb->owners->bind_pprev = &sk->bind_next; |
| tb->owners = sk; |
| sk->bind_pprev = &tb->owners; |
| sk->prev = (struct sock *) tb; |
| } |
| |
| static inline int tcp_bind_conflict(struct sock *sk, struct tcp_bind_bucket *tb) |
| { |
| struct sock *sk2 = tb->owners; |
| int sk_reuse = sk->reuse; |
| |
| for( ; sk2 != NULL; sk2 = sk2->bind_next) { |
| if (sk != sk2 && |
| sk->bound_dev_if == sk2->bound_dev_if) { |
| if (!sk_reuse || |
| !sk2->reuse || |
| sk2->state == TCP_LISTEN) { |
| if (!sk2->rcv_saddr || |
| !sk->rcv_saddr || |
| (sk2->rcv_saddr == sk->rcv_saddr)) |
| break; |
| } |
| } |
| } |
| return sk2 != NULL; |
| } |
| |
| /* Obtain a reference to a local port for the given sock, |
| * if snum is zero it means select any available local port. |
| */ |
| static int tcp_v4_get_port(struct sock *sk, unsigned short snum) |
| { |
| struct tcp_bind_hashbucket *head; |
| struct tcp_bind_bucket *tb; |
| int ret; |
| |
| local_bh_disable(); |
| if (snum == 0) { |
| int low = sysctl_local_port_range[0]; |
| int high = sysctl_local_port_range[1]; |
| int remaining = (high - low) + 1; |
| int rover; |
| |
| spin_lock(&tcp_portalloc_lock); |
| rover = tcp_port_rover; |
| do { rover++; |
| if ((rover < low) || (rover > high)) |
| rover = low; |
| head = &tcp_bhash[tcp_bhashfn(rover)]; |
| spin_lock(&head->lock); |
| for (tb = head->chain; tb; tb = tb->next) |
| if (tb->port == rover) |
| goto next; |
| break; |
| next: |
| spin_unlock(&head->lock); |
| } while (--remaining > 0); |
| tcp_port_rover = rover; |
| spin_unlock(&tcp_portalloc_lock); |
| |
| /* Exhausted local port range during search? */ |
| ret = 1; |
| if (remaining <= 0) |
| goto fail; |
| |
| /* OK, here is the one we will use. HEAD is |
| * non-NULL and we hold it's mutex. |
| */ |
| snum = rover; |
| tb = NULL; |
| } else { |
| head = &tcp_bhash[tcp_bhashfn(snum)]; |
| spin_lock(&head->lock); |
| for (tb = head->chain; tb != NULL; tb = tb->next) |
| if (tb->port == snum) |
| break; |
| } |
| if (tb != NULL && tb->owners != NULL) { |
| if (tb->fastreuse != 0 && sk->reuse != 0 && sk->state != TCP_LISTEN) { |
| goto success; |
| } else { |
| ret = 1; |
| if (tcp_bind_conflict(sk, tb)) |
| goto fail_unlock; |
| } |
| } |
| ret = 1; |
| if (tb == NULL && |
| (tb = tcp_bucket_create(head, snum)) == NULL) |
| goto fail_unlock; |
| if (tb->owners == NULL) { |
| if (sk->reuse && sk->state != TCP_LISTEN) |
| tb->fastreuse = 1; |
| else |
| tb->fastreuse = 0; |
| } else if (tb->fastreuse && |
| ((sk->reuse == 0) || (sk->state == TCP_LISTEN))) |
| tb->fastreuse = 0; |
| success: |
| if (sk->prev == NULL) |
| tcp_bind_hash(sk, tb, snum); |
| BUG_TRAP(sk->prev == (struct sock *) tb); |
| ret = 0; |
| |
| fail_unlock: |
| spin_unlock(&head->lock); |
| fail: |
| local_bh_enable(); |
| return ret; |
| } |
| |
| /* Get rid of any references to a local port held by the |
| * given sock. |
| */ |
| __inline__ void __tcp_put_port(struct sock *sk) |
| { |
| struct tcp_bind_hashbucket *head = &tcp_bhash[tcp_bhashfn(sk->num)]; |
| struct tcp_bind_bucket *tb; |
| |
| spin_lock(&head->lock); |
| tb = (struct tcp_bind_bucket *) sk->prev; |
| if (sk->bind_next) |
| sk->bind_next->bind_pprev = sk->bind_pprev; |
| *(sk->bind_pprev) = sk->bind_next; |
| sk->prev = NULL; |
| sk->num = 0; |
| if (tb->owners == NULL) { |
| if (tb->next) |
| tb->next->pprev = tb->pprev; |
| *(tb->pprev) = tb->next; |
| kmem_cache_free(tcp_bucket_cachep, tb); |
| } |
| spin_unlock(&head->lock); |
| } |
| |
| void tcp_put_port(struct sock *sk) |
| { |
| local_bh_disable(); |
| __tcp_put_port(sk); |
| local_bh_enable(); |
| } |
| |
| /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it can be very bad on SMP. |
| * Look, when several writers sleep and reader wakes them up, all but one |
| * immediately hit write lock and grab all the cpus. Exclusive sleep solves |
| * this, _but_ remember, it adds useless work on UP machines (wake up each |
| * exclusive lock release). It should be ifdefed really. |
| */ |
| |
| void tcp_listen_wlock(void) |
| { |
| write_lock(&tcp_lhash_lock); |
| |
| if (atomic_read(&tcp_lhash_users)) { |
| DECLARE_WAITQUEUE(wait, current); |
| |
| add_wait_queue_exclusive(&tcp_lhash_wait, &wait); |
| for (;;) { |
| set_current_state(TASK_UNINTERRUPTIBLE); |
| if (atomic_read(&tcp_lhash_users) == 0) |
| break; |
| write_unlock_bh(&tcp_lhash_lock); |
| schedule(); |
| write_lock_bh(&tcp_lhash_lock); |
| } |
| |
| __set_current_state(TASK_RUNNING); |
| remove_wait_queue(&tcp_lhash_wait, &wait); |
| } |
| } |
| |
| static __inline__ void __tcp_v4_hash(struct sock *sk) |
| { |
| struct sock **skp; |
| rwlock_t *lock; |
| |
| BUG_TRAP(sk->pprev==NULL); |
| if(sk->state == TCP_LISTEN) { |
| skp = &tcp_listening_hash[tcp_sk_listen_hashfn(sk)]; |
| lock = &tcp_lhash_lock; |
| tcp_listen_wlock(); |
| } else { |
| skp = &tcp_ehash[(sk->hashent = tcp_sk_hashfn(sk))].chain; |
| lock = &tcp_ehash[sk->hashent].lock; |
| write_lock(lock); |
| } |
| if((sk->next = *skp) != NULL) |
| (*skp)->pprev = &sk->next; |
| *skp = sk; |
| sk->pprev = skp; |
| sock_prot_inc_use(sk->prot); |
| write_unlock(lock); |
| if (sk->state == TCP_LISTEN) |
| wake_up(&tcp_lhash_wait); |
| } |
| |
| static void tcp_v4_hash(struct sock *sk) |
| { |
| if (sk->state != TCP_CLOSE) { |
| local_bh_disable(); |
| __tcp_v4_hash(sk); |
| local_bh_enable(); |
| } |
| } |
| |
| void tcp_unhash(struct sock *sk) |
| { |
| rwlock_t *lock; |
| |
| if (sk->state == TCP_LISTEN) { |
| local_bh_disable(); |
| tcp_listen_wlock(); |
| lock = &tcp_lhash_lock; |
| } else { |
| struct tcp_ehash_bucket *head = &tcp_ehash[sk->hashent]; |
| lock = &head->lock; |
| write_lock_bh(&head->lock); |
| } |
| |
| if(sk->pprev) { |
| if(sk->next) |
| sk->next->pprev = sk->pprev; |
| *sk->pprev = sk->next; |
| sk->pprev = NULL; |
| sock_prot_dec_use(sk->prot); |
| } |
| write_unlock_bh(lock); |
| if (sk->state == TCP_LISTEN) |
| wake_up(&tcp_lhash_wait); |
| } |
| |
| /* Don't inline this cruft. Here are some nice properties to |
| * exploit here. The BSD API does not allow a listening TCP |
| * to specify the remote port nor the remote address for the |
| * connection. So always assume those are both wildcarded |
| * during the search since they can never be otherwise. |
| */ |
| static struct sock *__tcp_v4_lookup_listener(struct sock *sk, u32 daddr, unsigned short hnum, int dif) |
| { |
| struct sock *result = NULL; |
| int score, hiscore; |
| |
| hiscore=0; |
| for(; sk; sk = sk->next) { |
| if(sk->num == hnum) { |
| __u32 rcv_saddr = sk->rcv_saddr; |
| |
| score = 1; |
| if(rcv_saddr) { |
| if (rcv_saddr != daddr) |
| continue; |
| score++; |
| } |
| if (sk->bound_dev_if) { |
| if (sk->bound_dev_if != dif) |
| continue; |
| score++; |
| } |
| if (score == 3) |
| return sk; |
| if (score > hiscore) { |
| hiscore = score; |
| result = sk; |
| } |
| } |
| } |
| return result; |
| } |
| |
| /* Optimize the common listener case. */ |
| __inline__ struct sock *tcp_v4_lookup_listener(u32 daddr, unsigned short hnum, int dif) |
| { |
| struct sock *sk; |
| |
| read_lock(&tcp_lhash_lock); |
| sk = tcp_listening_hash[tcp_lhashfn(hnum)]; |
| if (sk) { |
| if (sk->num == hnum && |
| sk->next == NULL && |
| (!sk->rcv_saddr || sk->rcv_saddr == daddr) && |
| !sk->bound_dev_if) |
| goto sherry_cache; |
| sk = __tcp_v4_lookup_listener(sk, daddr, hnum, dif); |
| } |
| if (sk) { |
| sherry_cache: |
| sock_hold(sk); |
| } |
| read_unlock(&tcp_lhash_lock); |
| return sk; |
| } |
| |
| /* Sockets in TCP_CLOSE state are _always_ taken out of the hash, so |
| * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM |
| * |
| * Local BH must be disabled here. |
| */ |
| |
| static inline struct sock *__tcp_v4_lookup_established(u32 saddr, u16 sport, |
| u32 daddr, u16 hnum, int dif) |
| { |
| struct tcp_ehash_bucket *head; |
| TCP_V4_ADDR_COOKIE(acookie, saddr, daddr) |
| __u32 ports = TCP_COMBINED_PORTS(sport, hnum); |
| struct sock *sk; |
| int hash; |
| |
| /* Optimize here for direct hit, only listening connections can |
| * have wildcards anyways. |
| */ |
| hash = tcp_hashfn(daddr, hnum, saddr, sport); |
| head = &tcp_ehash[hash]; |
| read_lock(&head->lock); |
| for(sk = head->chain; sk; sk = sk->next) { |
| if(TCP_IPV4_MATCH(sk, acookie, saddr, daddr, ports, dif)) |
| goto hit; /* You sunk my battleship! */ |
| } |
| |
| /* Must check for a TIME_WAIT'er before going to listener hash. */ |
| for(sk = (head + tcp_ehash_size)->chain; sk; sk = sk->next) |
| if(TCP_IPV4_MATCH(sk, acookie, saddr, daddr, ports, dif)) |
| goto hit; |
| read_unlock(&head->lock); |
| |
| return NULL; |
| |
| hit: |
| sock_hold(sk); |
| read_unlock(&head->lock); |
| return sk; |
| } |
| |
| static inline struct sock *__tcp_v4_lookup(u32 saddr, u16 sport, |
| u32 daddr, u16 hnum, int dif) |
| { |
| struct sock *sk; |
| |
| sk = __tcp_v4_lookup_established(saddr, sport, daddr, hnum, dif); |
| |
| if (sk) |
| return sk; |
| |
| return tcp_v4_lookup_listener(daddr, hnum, dif); |
| } |
| |
| __inline__ struct sock *tcp_v4_lookup(u32 saddr, u16 sport, u32 daddr, u16 dport, int dif) |
| { |
| struct sock *sk; |
| |
| local_bh_disable(); |
| sk = __tcp_v4_lookup(saddr, sport, daddr, ntohs(dport), dif); |
| local_bh_enable(); |
| |
| return sk; |
| } |
| |
| static inline __u32 tcp_v4_init_sequence(struct sock *sk, struct sk_buff *skb) |
| { |
| return secure_tcp_sequence_number(skb->nh.iph->daddr, |
| skb->nh.iph->saddr, |
| skb->h.th->dest, |
| skb->h.th->source); |
| } |
| |
| static int tcp_v4_check_established(struct sock *sk) |
| { |
| u32 daddr = sk->rcv_saddr; |
| u32 saddr = sk->daddr; |
| int dif = sk->bound_dev_if; |
| TCP_V4_ADDR_COOKIE(acookie, saddr, daddr) |
| __u32 ports = TCP_COMBINED_PORTS(sk->dport, sk->num); |
| int hash = tcp_hashfn(daddr, sk->num, saddr, sk->dport); |
| struct tcp_ehash_bucket *head = &tcp_ehash[hash]; |
| struct sock *sk2, **skp; |
| struct tcp_tw_bucket *tw; |
| |
| write_lock_bh(&head->lock); |
| |
| /* Check TIME-WAIT sockets first. */ |
| for(skp = &(head + tcp_ehash_size)->chain; (sk2=*skp) != NULL; |
| skp = &sk2->next) { |
| tw = (struct tcp_tw_bucket*)sk2; |
| |
| if(TCP_IPV4_MATCH(sk2, acookie, saddr, daddr, ports, dif)) { |
| struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp); |
| |
| /* With PAWS, it is safe from the viewpoint |
| of data integrity. Even without PAWS it |
| is safe provided sequence spaces do not |
| overlap i.e. at data rates <= 80Mbit/sec. |
| |
| Actually, the idea is close to VJ's one, |
| only timestamp cache is held not per host, |
| but per port pair and TW bucket is used |
| as state holder. |
| |
| If TW bucket has been already destroyed we |
| fall back to VJ's scheme and use initial |
| timestamp retrieved from peer table. |
| */ |
| if (tw->ts_recent_stamp) { |
| if ((tp->write_seq = tw->snd_nxt+65535+2) == 0) |
| tp->write_seq = 1; |
| tp->ts_recent = tw->ts_recent; |
| tp->ts_recent_stamp = tw->ts_recent_stamp; |
| sock_hold(sk2); |
| skp = &head->chain; |
| goto unique; |
| } else |
| goto not_unique; |
| } |
| } |
| tw = NULL; |
| |
| /* And established part... */ |
| for(skp = &head->chain; (sk2=*skp)!=NULL; skp = &sk2->next) { |
| if(TCP_IPV4_MATCH(sk2, acookie, saddr, daddr, ports, dif)) |
| goto not_unique; |
| } |
| |
| unique: |
| BUG_TRAP(sk->pprev==NULL); |
| if ((sk->next = *skp) != NULL) |
| (*skp)->pprev = &sk->next; |
| |
| *skp = sk; |
| sk->pprev = skp; |
| sk->hashent = hash; |
| sock_prot_inc_use(sk->prot); |
| write_unlock_bh(&head->lock); |
| |
| if (tw) { |
| /* Silly. Should hash-dance instead... */ |
| local_bh_disable(); |
| tcp_tw_deschedule(tw); |
| tcp_timewait_kill(tw); |
| NET_INC_STATS_BH(TimeWaitRecycled); |
| local_bh_enable(); |
| |
| tcp_tw_put(tw); |
| } |
| |
| return 0; |
| |
| not_unique: |
| write_unlock_bh(&head->lock); |
| return -EADDRNOTAVAIL; |
| } |
| |
| /* Hash SYN-SENT socket to established hash table after |
| * checking that it is unique. Note, that without kernel lock |
| * we MUST make these two operations atomically. |
| * |
| * Optimization: if it is bound and tcp_bind_bucket has the only |
| * owner (us), we need not to scan established bucket. |
| */ |
| |
| int tcp_v4_hash_connecting(struct sock *sk) |
| { |
| unsigned short snum = sk->num; |
| struct tcp_bind_hashbucket *head = &tcp_bhash[tcp_bhashfn(snum)]; |
| struct tcp_bind_bucket *tb = (struct tcp_bind_bucket *)sk->prev; |
| |
| spin_lock_bh(&head->lock); |
| if (tb->owners == sk && sk->bind_next == NULL) { |
| __tcp_v4_hash(sk); |
| spin_unlock_bh(&head->lock); |
| return 0; |
| } else { |
| spin_unlock_bh(&head->lock); |
| |
| /* No definite answer... Walk to established hash table */ |
| return tcp_v4_check_established(sk); |
| } |
| } |
| |
| /* This will initiate an outgoing connection. */ |
| int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) |
| { |
| struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp); |
| struct sockaddr_in *usin = (struct sockaddr_in *) uaddr; |
| struct sk_buff *buff; |
| struct rtable *rt; |
| u32 daddr, nexthop; |
| int tmp; |
| int err; |
| |
| if (addr_len < sizeof(struct sockaddr_in)) |
| return(-EINVAL); |
| |
| if (usin->sin_family != AF_INET) |
| return(-EAFNOSUPPORT); |
| |
| nexthop = daddr = usin->sin_addr.s_addr; |
| if (sk->protinfo.af_inet.opt && sk->protinfo.af_inet.opt->srr) { |
| if (daddr == 0) |
| return -EINVAL; |
| nexthop = sk->protinfo.af_inet.opt->faddr; |
| } |
| |
| tmp = ip_route_connect(&rt, nexthop, sk->saddr, |
| RT_CONN_FLAGS(sk), sk->bound_dev_if); |
| if (tmp < 0) |
| return tmp; |
| |
| if (rt->rt_flags&(RTCF_MULTICAST|RTCF_BROADCAST)) { |
| ip_rt_put(rt); |
| return -ENETUNREACH; |
| } |
| |
| __sk_dst_set(sk, &rt->u.dst); |
| sk->route_caps = rt->u.dst.dev->features; |
| |
| if (!sk->protinfo.af_inet.opt || !sk->protinfo.af_inet.opt->srr) |
| daddr = rt->rt_dst; |
| |
| err = -ENOBUFS; |
| buff = alloc_skb(MAX_TCP_HEADER + 15, sk->allocation); |
| |
| if (buff == NULL) |
| goto failure; |
| |
| if (!sk->saddr) |
| sk->saddr = rt->rt_src; |
| sk->rcv_saddr = sk->saddr; |
| |
| if (tp->ts_recent_stamp && sk->daddr != daddr) { |
| /* Reset inherited state */ |
| tp->ts_recent = 0; |
| tp->ts_recent_stamp = 0; |
| tp->write_seq = 0; |
| } |
| |
| if (sysctl_tcp_tw_recycle && |
| !tp->ts_recent_stamp && |
| rt->rt_dst == daddr) { |
| struct inet_peer *peer = rt_get_peer(rt); |
| |
| /* VJ's idea. We save last timestamp seen from |
| * the destination in peer table, when entering state TIME-WAIT |
| * and initialize ts_recent from it, when trying new connection. |
| */ |
| |
| if (peer && peer->tcp_ts_stamp + TCP_PAWS_MSL >= xtime.tv_sec) { |
| tp->ts_recent_stamp = peer->tcp_ts_stamp; |
| tp->ts_recent = peer->tcp_ts; |
| } |
| } |
| |
| sk->dport = usin->sin_port; |
| sk->daddr = daddr; |
| |
| if (!tp->write_seq) |
| tp->write_seq = secure_tcp_sequence_number(sk->saddr, sk->daddr, |
| sk->sport, usin->sin_port); |
| |
| tp->ext_header_len = 0; |
| if (sk->protinfo.af_inet.opt) |
| tp->ext_header_len = sk->protinfo.af_inet.opt->optlen; |
| sk->protinfo.af_inet.id = tp->write_seq^jiffies; |
| |
| tp->mss_clamp = 536; |
| |
| err = tcp_connect(sk, buff); |
| if (err == 0) |
| return 0; |
| |
| failure: |
| __sk_dst_reset(sk); |
| sk->route_caps = 0; |
| sk->dport = 0; |
| return err; |
| } |
| |
| static __inline__ int tcp_v4_iif(struct sk_buff *skb) |
| { |
| return ((struct rtable*)skb->dst)->rt_iif; |
| } |
| |
| static __inline__ unsigned tcp_v4_synq_hash(u32 raddr, u16 rport) |
| { |
| unsigned h = raddr ^ rport; |
| h ^= h>>16; |
| h ^= h>>8; |
| return h&(TCP_SYNQ_HSIZE-1); |
| } |
| |
| static struct open_request *tcp_v4_search_req(struct tcp_opt *tp, |
| struct open_request ***prevp, |
| __u16 rport, |
| __u32 raddr, __u32 laddr) |
| { |
| struct tcp_listen_opt *lopt = tp->listen_opt; |
| struct open_request *req, **prev; |
| |
| for (prev = &lopt->syn_table[tcp_v4_synq_hash(raddr, rport)]; |
| (req = *prev) != NULL; |
| prev = &req->dl_next) { |
| if (req->rmt_port == rport && |
| req->af.v4_req.rmt_addr == raddr && |
| req->af.v4_req.loc_addr == laddr && |
| TCP_INET_FAMILY(req->class->family)) { |
| BUG_TRAP(req->sk == NULL); |
| *prevp = prev; |
| return req; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| static void tcp_v4_synq_add(struct sock *sk, struct open_request *req) |
| { |
| struct tcp_opt *tp = &sk->tp_pinfo.af_tcp; |
| struct tcp_listen_opt *lopt = tp->listen_opt; |
| unsigned h = tcp_v4_synq_hash(req->af.v4_req.rmt_addr, req->rmt_port); |
| |
| req->expires = jiffies + TCP_TIMEOUT_INIT; |
| req->retrans = 0; |
| req->sk = NULL; |
| req->index = h; |
| req->dl_next = lopt->syn_table[h]; |
| |
| write_lock(&tp->syn_wait_lock); |
| lopt->syn_table[h] = req; |
| write_unlock(&tp->syn_wait_lock); |
| |
| tcp_synq_added(sk); |
| } |
| |
| |
| /* |
| * This routine does path mtu discovery as defined in RFC1191. |
| */ |
| static inline void do_pmtu_discovery(struct sock *sk, struct iphdr *ip, unsigned mtu) |
| { |
| struct dst_entry *dst; |
| struct tcp_opt *tp = &sk->tp_pinfo.af_tcp; |
| |
| /* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs |
| * send out by Linux are always <576bytes so they should go through |
| * unfragmented). |
| */ |
| if (sk->state == TCP_LISTEN) |
| return; |
| |
| /* We don't check in the destentry if pmtu discovery is forbidden |
| * on this route. We just assume that no packet_to_big packets |
| * are send back when pmtu discovery is not active. |
| * There is a small race when the user changes this flag in the |
| * route, but I think that's acceptable. |
| */ |
| if ((dst = __sk_dst_check(sk, 0)) == NULL) |
| return; |
| |
| ip_rt_update_pmtu(dst, mtu); |
| |
| /* Something is about to be wrong... Remember soft error |
| * for the case, if this connection will not able to recover. |
| */ |
| if (mtu < dst->pmtu && ip_dont_fragment(sk, dst)) |
| sk->err_soft = EMSGSIZE; |
| |
| if (sk->protinfo.af_inet.pmtudisc != IP_PMTUDISC_DONT && |
| tp->pmtu_cookie > dst->pmtu) { |
| tcp_sync_mss(sk, dst->pmtu); |
| |
| /* Resend the TCP packet because it's |
| * clear that the old packet has been |
| * dropped. This is the new "fast" path mtu |
| * discovery. |
| */ |
| tcp_simple_retransmit(sk); |
| } /* else let the usual retransmit timer handle it */ |
| } |
| |
| /* |
| * This routine is called by the ICMP module when it gets some |
| * sort of error condition. If err < 0 then the socket should |
| * be closed and the error returned to the user. If err > 0 |
| * it's just the icmp type << 8 | icmp code. After adjustment |
| * header points to the first 8 bytes of the tcp header. We need |
| * to find the appropriate port. |
| * |
| * The locking strategy used here is very "optimistic". When |
| * someone else accesses the socket the ICMP is just dropped |
| * and for some paths there is no check at all. |
| * A more general error queue to queue errors for later handling |
| * is probably better. |
| * |
| */ |
| |
| void tcp_v4_err(struct sk_buff *skb, u32 info) |
| { |
| struct iphdr *iph = (struct iphdr*)skb->data; |
| struct tcphdr *th = (struct tcphdr*)(skb->data+(iph->ihl<<2)); |
| struct tcp_opt *tp; |
| int type = skb->h.icmph->type; |
| int code = skb->h.icmph->code; |
| struct sock *sk; |
| __u32 seq; |
| int err; |
| |
| if (skb->len < (iph->ihl << 2) + 8) { |
| ICMP_INC_STATS_BH(IcmpInErrors); |
| return; |
| } |
| |
| sk = tcp_v4_lookup(iph->daddr, th->dest, iph->saddr, th->source, tcp_v4_iif(skb)); |
| if (sk == NULL) { |
| ICMP_INC_STATS_BH(IcmpInErrors); |
| return; |
| } |
| if (sk->state == TCP_TIME_WAIT) { |
| tcp_tw_put((struct tcp_tw_bucket*)sk); |
| return; |
| } |
| |
| bh_lock_sock(sk); |
| /* If too many ICMPs get dropped on busy |
| * servers this needs to be solved differently. |
| */ |
| if (sk->lock.users != 0) |
| NET_INC_STATS_BH(LockDroppedIcmps); |
| |
| if (sk->state == TCP_CLOSE) |
| goto out; |
| |
| tp = &sk->tp_pinfo.af_tcp; |
| seq = ntohl(th->seq); |
| if (sk->state != TCP_LISTEN && !between(seq, tp->snd_una, tp->snd_nxt)) { |
| NET_INC_STATS(OutOfWindowIcmps); |
| goto out; |
| } |
| |
| switch (type) { |
| case ICMP_SOURCE_QUENCH: |
| /* This is deprecated, but if someone generated it, |
| * we have no reasons to ignore it. |
| */ |
| if (sk->lock.users == 0) |
| tcp_enter_cwr(tp); |
| goto out; |
| case ICMP_PARAMETERPROB: |
| err = EPROTO; |
| break; |
| case ICMP_DEST_UNREACH: |
| if (code > NR_ICMP_UNREACH) |
| goto out; |
| |
| if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */ |
| if (sk->lock.users == 0) |
| do_pmtu_discovery(sk, iph, info); |
| goto out; |
| } |
| |
| err = icmp_err_convert[code].errno; |
| break; |
| case ICMP_TIME_EXCEEDED: |
| err = EHOSTUNREACH; |
| break; |
| default: |
| goto out; |
| } |
| |
| switch (sk->state) { |
| struct open_request *req, **prev; |
| case TCP_LISTEN: |
| if (sk->lock.users != 0) |
| goto out; |
| |
| req = tcp_v4_search_req(tp, &prev, |
| th->dest, |
| iph->daddr, iph->saddr); |
| if (!req) |
| goto out; |
| |
| /* ICMPs are not backlogged, hence we cannot get |
| an established socket here. |
| */ |
| BUG_TRAP(req->sk == NULL); |
| |
| if (seq != req->snt_isn) { |
| NET_INC_STATS_BH(OutOfWindowIcmps); |
| goto out; |
| } |
| |
| /* |
| * Still in SYN_RECV, just remove it silently. |
| * There is no good way to pass the error to the newly |
| * created socket, and POSIX does not want network |
| * errors returned from accept(). |
| */ |
| tcp_synq_drop(sk, req, prev); |
| goto out; |
| |
| case TCP_SYN_SENT: |
| case TCP_SYN_RECV: /* Cannot happen. |
| It can f.e. if SYNs crossed. |
| */ |
| if (sk->lock.users == 0) { |
| TCP_INC_STATS_BH(TcpAttemptFails); |
| sk->err = err; |
| |
| sk->error_report(sk); |
| |
| tcp_done(sk); |
| } else { |
| sk->err_soft = err; |
| } |
| goto out; |
| } |
| |
| /* If we've already connected we will keep trying |
| * until we time out, or the user gives up. |
| * |
| * rfc1122 4.2.3.9 allows to consider as hard errors |
| * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too, |
| * but it is obsoleted by pmtu discovery). |
| * |
| * Note, that in modern internet, where routing is unreliable |
| * and in each dark corner broken firewalls sit, sending random |
| * errors ordered by their masters even this two messages finally lose |
| * their original sense (even Linux sends invalid PORT_UNREACHs) |
| * |
| * Now we are in compliance with RFCs. |
| * --ANK (980905) |
| */ |
| |
| if (sk->lock.users == 0 && sk->protinfo.af_inet.recverr) { |
| sk->err = err; |
| sk->error_report(sk); |
| } else { /* Only an error on timeout */ |
| sk->err_soft = err; |
| } |
| |
| out: |
| bh_unlock_sock(sk); |
| sock_put(sk); |
| } |
| |
| /* This routine computes an IPv4 TCP checksum. */ |
| void tcp_v4_send_check(struct sock *sk, struct tcphdr *th, int len, |
| struct sk_buff *skb) |
| { |
| if (skb->ip_summed == CHECKSUM_HW) { |
| th->check = ~tcp_v4_check(th, len, sk->saddr, sk->daddr, 0); |
| skb->csum = offsetof(struct tcphdr, check); |
| } else { |
| th->check = tcp_v4_check(th, len, sk->saddr, sk->daddr, |
| csum_partial((char *)th, th->doff<<2, skb->csum)); |
| } |
| } |
| |
| /* |
| * This routine will send an RST to the other tcp. |
| * |
| * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.) |
| * for reset. |
| * Answer: if a packet caused RST, it is not for a socket |
| * existing in our system, if it is matched to a socket, |
| * it is just duplicate segment or bug in other side's TCP. |
| * So that we build reply only basing on parameters |
| * arrived with segment. |
| * Exception: precedence violation. We do not implement it in any case. |
| */ |
| |
| static void tcp_v4_send_reset(struct sk_buff *skb) |
| { |
| struct tcphdr *th = skb->h.th; |
| struct tcphdr rth; |
| struct ip_reply_arg arg; |
| |
| /* Never send a reset in response to a reset. */ |
| if (th->rst) |
| return; |
| |
| if (((struct rtable*)skb->dst)->rt_type != RTN_LOCAL) |
| return; |
| |
| /* Swap the send and the receive. */ |
| memset(&rth, 0, sizeof(struct tcphdr)); |
| rth.dest = th->source; |
| rth.source = th->dest; |
| rth.doff = sizeof(struct tcphdr)/4; |
| rth.rst = 1; |
| |
| if (th->ack) { |
| rth.seq = th->ack_seq; |
| } else { |
| rth.ack = 1; |
| rth.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin |
| + skb->len - (th->doff<<2)); |
| } |
| |
| memset(&arg, 0, sizeof arg); |
| arg.iov[0].iov_base = (unsigned char *)&rth; |
| arg.iov[0].iov_len = sizeof rth; |
| arg.csum = csum_tcpudp_nofold(skb->nh.iph->daddr, |
| skb->nh.iph->saddr, /*XXX*/ |
| sizeof(struct tcphdr), |
| IPPROTO_TCP, |
| 0); |
| arg.n_iov = 1; |
| arg.csumoffset = offsetof(struct tcphdr, check) / 2; |
| |
| ip_send_reply(tcp_socket->sk, skb, &arg, sizeof rth); |
| |
| TCP_INC_STATS_BH(TcpOutSegs); |
| TCP_INC_STATS_BH(TcpOutRsts); |
| } |
| |
| /* The code following below sending ACKs in SYN-RECV and TIME-WAIT states |
| outside socket context is ugly, certainly. What can I do? |
| */ |
| |
| static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts) |
| { |
| struct tcphdr *th = skb->h.th; |
| struct { |
| struct tcphdr th; |
| u32 tsopt[3]; |
| } rep; |
| struct ip_reply_arg arg; |
| |
| memset(&rep.th, 0, sizeof(struct tcphdr)); |
| memset(&arg, 0, sizeof arg); |
| |
| arg.iov[0].iov_base = (unsigned char *)&rep; |
| arg.iov[0].iov_len = sizeof(rep.th); |
| arg.n_iov = 1; |
| if (ts) { |
| rep.tsopt[0] = __constant_htonl((TCPOPT_NOP << 24) | |
| (TCPOPT_NOP << 16) | |
| (TCPOPT_TIMESTAMP << 8) | |
| TCPOLEN_TIMESTAMP); |
| rep.tsopt[1] = htonl(tcp_time_stamp); |
| rep.tsopt[2] = htonl(ts); |
| arg.iov[0].iov_len = sizeof(rep); |
| } |
| |
| /* Swap the send and the receive. */ |
| rep.th.dest = th->source; |
| rep.th.source = th->dest; |
| rep.th.doff = arg.iov[0].iov_len/4; |
| rep.th.seq = htonl(seq); |
| rep.th.ack_seq = htonl(ack); |
| rep.th.ack = 1; |
| rep.th.window = htons(win); |
| |
| arg.csum = csum_tcpudp_nofold(skb->nh.iph->daddr, |
| skb->nh.iph->saddr, /*XXX*/ |
| arg.iov[0].iov_len, |
| IPPROTO_TCP, |
| 0); |
| arg.csumoffset = offsetof(struct tcphdr, check) / 2; |
| |
| ip_send_reply(tcp_socket->sk, skb, &arg, arg.iov[0].iov_len); |
| |
| TCP_INC_STATS_BH(TcpOutSegs); |
| } |
| |
| static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb) |
| { |
| struct tcp_tw_bucket *tw = (struct tcp_tw_bucket *)sk; |
| |
| tcp_v4_send_ack(skb, tw->snd_nxt, tw->rcv_nxt, |
| tw->rcv_wnd>>tw->rcv_wscale, tw->ts_recent); |
| |
| tcp_tw_put(tw); |
| } |
| |
| static void tcp_v4_or_send_ack(struct sk_buff *skb, struct open_request *req) |
| { |
| tcp_v4_send_ack(skb, req->snt_isn+1, req->rcv_isn+1, req->rcv_wnd, |
| req->ts_recent); |
| } |
| |
| static struct dst_entry* tcp_v4_route_req(struct sock *sk, struct open_request *req) |
| { |
| struct rtable *rt; |
| struct ip_options *opt; |
| |
| opt = req->af.v4_req.opt; |
| if(ip_route_output(&rt, ((opt && opt->srr) ? |
| opt->faddr : |
| req->af.v4_req.rmt_addr), |
| req->af.v4_req.loc_addr, |
| RT_CONN_FLAGS(sk), sk->bound_dev_if)) { |
| IP_INC_STATS_BH(IpOutNoRoutes); |
| return NULL; |
| } |
| if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) { |
| ip_rt_put(rt); |
| IP_INC_STATS_BH(IpOutNoRoutes); |
| return NULL; |
| } |
| return &rt->u.dst; |
| } |
| |
| /* |
| * Send a SYN-ACK after having received an ACK. |
| * This still operates on a open_request only, not on a big |
| * socket. |
| */ |
| static int tcp_v4_send_synack(struct sock *sk, struct open_request *req, |
| struct dst_entry *dst) |
| { |
| int err = -1; |
| struct sk_buff * skb; |
| |
| /* First, grab a route. */ |
| if (dst == NULL && |
| (dst = tcp_v4_route_req(sk, req)) == NULL) |
| goto out; |
| |
| skb = tcp_make_synack(sk, dst, req); |
| |
| if (skb) { |
| struct tcphdr *th = skb->h.th; |
| |
| th->check = tcp_v4_check(th, skb->len, |
| req->af.v4_req.loc_addr, req->af.v4_req.rmt_addr, |
| csum_partial((char *)th, skb->len, skb->csum)); |
| |
| err = ip_build_and_send_pkt(skb, sk, req->af.v4_req.loc_addr, |
| req->af.v4_req.rmt_addr, req->af.v4_req.opt); |
| if (err == NET_XMIT_CN) |
| err = 0; |
| } |
| |
| out: |
| dst_release(dst); |
| return err; |
| } |
| |
| /* |
| * IPv4 open_request destructor. |
| */ |
| static void tcp_v4_or_free(struct open_request *req) |
| { |
| if (req->af.v4_req.opt) |
| kfree(req->af.v4_req.opt); |
| } |
| |
| static inline void syn_flood_warning(struct sk_buff *skb) |
| { |
| static unsigned long warntime; |
| |
| if (jiffies - warntime > HZ*60) { |
| warntime = jiffies; |
| printk(KERN_INFO |
| "possible SYN flooding on port %d. Sending cookies.\n", |
| ntohs(skb->h.th->dest)); |
| } |
| } |
| |
| /* |
| * Save and compile IPv4 options into the open_request if needed. |
| */ |
| static inline struct ip_options * |
| tcp_v4_save_options(struct sock *sk, struct sk_buff *skb) |
| { |
| struct ip_options *opt = &(IPCB(skb)->opt); |
| struct ip_options *dopt = NULL; |
| |
| if (opt && opt->optlen) { |
| int opt_size = optlength(opt); |
| dopt = kmalloc(opt_size, GFP_ATOMIC); |
| if (dopt) { |
| if (ip_options_echo(dopt, skb)) { |
| kfree(dopt); |
| dopt = NULL; |
| } |
| } |
| } |
| return dopt; |
| } |
| |
| /* |
| * Maximum number of SYN_RECV sockets in queue per LISTEN socket. |
| * One SYN_RECV socket costs about 80bytes on a 32bit machine. |
| * It would be better to replace it with a global counter for all sockets |
| * but then some measure against one socket starving all other sockets |
| * would be needed. |
| * |
| * It was 128 by default. Experiments with real servers show, that |
| * it is absolutely not enough even at 100conn/sec. 256 cures most |
| * of problems. This value is adjusted to 128 for very small machines |
| * (<=32Mb of memory) and to 1024 on normal or better ones (>=256Mb). |
| * Further increasing requires to change hash table size. |
| */ |
| int sysctl_max_syn_backlog = 256; |
| |
| struct or_calltable or_ipv4 = { |
| PF_INET, |
| tcp_v4_send_synack, |
| tcp_v4_or_send_ack, |
| tcp_v4_or_free, |
| tcp_v4_send_reset |
| }; |
| |
| int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) |
| { |
| struct tcp_opt tp; |
| struct open_request *req; |
| __u32 saddr = skb->nh.iph->saddr; |
| __u32 daddr = skb->nh.iph->daddr; |
| __u32 isn = TCP_SKB_CB(skb)->when; |
| struct dst_entry *dst = NULL; |
| #ifdef CONFIG_SYN_COOKIES |
| int want_cookie = 0; |
| #else |
| #define want_cookie 0 /* Argh, why doesn't gcc optimize this :( */ |
| #endif |
| |
| /* Never answer to SYNs send to broadcast or multicast */ |
| if (((struct rtable *)skb->dst)->rt_flags & |
| (RTCF_BROADCAST|RTCF_MULTICAST)) |
| goto drop; |
| |
| /* TW buckets are converted to open requests without |
| * limitations, they conserve resources and peer is |
| * evidently real one. |
| */ |
| if (tcp_synq_is_full(sk) && !isn) { |
| #ifdef CONFIG_SYN_COOKIES |
| if (sysctl_tcp_syncookies) { |
| want_cookie = 1; |
| } else |
| #endif |
| goto drop; |
| } |
| |
| /* Accept backlog is full. If we have already queued enough |
| * of warm entries in syn queue, drop request. It is better than |
| * clogging syn queue with openreqs with exponentially increasing |
| * timeout. |
| */ |
| if (tcp_acceptq_is_full(sk) && tcp_synq_young(sk) > 1) |
| goto drop; |
| |
| req = tcp_openreq_alloc(); |
| if (req == NULL) |
| goto drop; |
| |
| tcp_clear_options(&tp); |
| tp.mss_clamp = 536; |
| tp.user_mss = sk->tp_pinfo.af_tcp.user_mss; |
| |
| tcp_parse_options(skb, &tp, 0); |
| |
| if (want_cookie) { |
| tcp_clear_options(&tp); |
| tp.saw_tstamp = 0; |
| } |
| |
| if (tp.saw_tstamp && tp.rcv_tsval == 0) { |
| /* Some OSes (unknown ones, but I see them on web server, which |
| * contains information interesting only for windows' |
| * users) do not send their stamp in SYN. It is easy case. |
| * We simply do not advertise TS support. |
| */ |
| tp.saw_tstamp = 0; |
| tp.tstamp_ok = 0; |
| } |
| tp.tstamp_ok = tp.saw_tstamp; |
| |
| tcp_openreq_init(req, &tp, skb); |
| |
| req->af.v4_req.loc_addr = daddr; |
| req->af.v4_req.rmt_addr = saddr; |
| req->af.v4_req.opt = tcp_v4_save_options(sk, skb); |
| req->class = &or_ipv4; |
| if (!want_cookie) |
| TCP_ECN_create_request(req, skb->h.th); |
| |
| if (want_cookie) { |
| #ifdef CONFIG_SYN_COOKIES |
| syn_flood_warning(skb); |
| #endif |
| isn = cookie_v4_init_sequence(sk, skb, &req->mss); |
| } else if (isn == 0) { |
| struct inet_peer *peer = NULL; |
| |
| /* VJ's idea. We save last timestamp seen |
| * from the destination in peer table, when entering |
| * state TIME-WAIT, and check against it before |
| * accepting new connection request. |
| * |
| * If "isn" is not zero, this request hit alive |
| * timewait bucket, so that all the necessary checks |
| * are made in the function processing timewait state. |
| */ |
| if (tp.saw_tstamp && |
| sysctl_tcp_tw_recycle && |
| (dst = tcp_v4_route_req(sk, req)) != NULL && |
| (peer = rt_get_peer((struct rtable*)dst)) != NULL && |
| peer->v4daddr == saddr) { |
| if (xtime.tv_sec < peer->tcp_ts_stamp + TCP_PAWS_MSL && |
| (s32)(peer->tcp_ts - req->ts_recent) > TCP_PAWS_WINDOW) { |
| NET_INC_STATS_BH(PAWSPassiveRejected); |
| dst_release(dst); |
| goto drop_and_free; |
| } |
| } |
| /* Kill the following clause, if you dislike this way. */ |
| else if (!sysctl_tcp_syncookies && |
| (sysctl_max_syn_backlog - tcp_synq_len(sk) |
| < (sysctl_max_syn_backlog>>2)) && |
| (!peer || !peer->tcp_ts_stamp) && |
| (!dst || !dst->rtt)) { |
| /* Without syncookies last quarter of |
| * backlog is filled with destinations, proven to be alive. |
| * It means that we continue to communicate |
| * to destinations, already remembered |
| * to the moment of synflood. |
| */ |
| NETDEBUG(if (net_ratelimit()) \ |
| printk(KERN_DEBUG "TCP: drop open request from %u.%u.%u.%u/%u\n", \ |
| NIPQUAD(saddr), ntohs(skb->h.th->source))); |
| TCP_INC_STATS_BH(TcpAttemptFails); |
| dst_release(dst); |
| goto drop_and_free; |
| } |
| |
| isn = tcp_v4_init_sequence(sk, skb); |
| } |
| req->snt_isn = isn; |
| |
| if (tcp_v4_send_synack(sk, req, dst)) |
| goto drop_and_free; |
| |
| if (want_cookie) { |
| tcp_openreq_free(req); |
| } else { |
| tcp_v4_synq_add(sk, req); |
| } |
| return 0; |
| |
| drop_and_free: |
| tcp_openreq_free(req); |
| drop: |
| TCP_INC_STATS_BH(TcpAttemptFails); |
| return 0; |
| } |
| |
| |
| /* |
| * The three way handshake has completed - we got a valid synack - |
| * now create the new socket. |
| */ |
| struct sock * tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb, |
| struct open_request *req, |
| struct dst_entry *dst) |
| { |
| struct tcp_opt *newtp; |
| struct sock *newsk; |
| |
| if (tcp_acceptq_is_full(sk)) |
| goto exit_overflow; |
| |
| if (dst == NULL && |
| (dst = tcp_v4_route_req(sk, req)) == NULL) |
| goto exit; |
| |
| newsk = tcp_create_openreq_child(sk, req, skb); |
| if (!newsk) |
| goto exit; |
| |
| newsk->dst_cache = dst; |
| newsk->route_caps = dst->dev->features; |
| |
| newtp = &(newsk->tp_pinfo.af_tcp); |
| newsk->daddr = req->af.v4_req.rmt_addr; |
| newsk->saddr = req->af.v4_req.loc_addr; |
| newsk->rcv_saddr = req->af.v4_req.loc_addr; |
| newsk->protinfo.af_inet.opt = req->af.v4_req.opt; |
| req->af.v4_req.opt = NULL; |
| newsk->protinfo.af_inet.mc_index = tcp_v4_iif(skb); |
| newsk->protinfo.af_inet.mc_ttl = skb->nh.iph->ttl; |
| newtp->ext_header_len = 0; |
| if (newsk->protinfo.af_inet.opt) |
| newtp->ext_header_len = newsk->protinfo.af_inet.opt->optlen; |
| newsk->protinfo.af_inet.id = newtp->write_seq^jiffies; |
| |
| tcp_sync_mss(newsk, dst->pmtu); |
| newtp->advmss = dst->advmss; |
| tcp_initialize_rcv_mss(newsk); |
| |
| __tcp_v4_hash(newsk); |
| __tcp_inherit_port(sk, newsk); |
| |
| return newsk; |
| |
| exit_overflow: |
| NET_INC_STATS_BH(ListenOverflows); |
| exit: |
| NET_INC_STATS_BH(ListenDrops); |
| dst_release(dst); |
| return NULL; |
| } |
| |
| static struct sock *tcp_v4_hnd_req(struct sock *sk,struct sk_buff *skb) |
| { |
| struct open_request *req, **prev; |
| struct tcphdr *th = skb->h.th; |
| struct iphdr *iph = skb->nh.iph; |
| struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp); |
| struct sock *nsk; |
| |
| /* Find possible connection requests. */ |
| req = tcp_v4_search_req(tp, &prev, |
| th->source, |
| iph->saddr, iph->daddr); |
| if (req) |
| return tcp_check_req(sk, skb, req, prev); |
| |
| nsk = __tcp_v4_lookup_established(skb->nh.iph->saddr, |
| th->source, |
| skb->nh.iph->daddr, |
| ntohs(th->dest), |
| tcp_v4_iif(skb)); |
| |
| if (nsk) { |
| if (nsk->state != TCP_TIME_WAIT) { |
| bh_lock_sock(nsk); |
| return nsk; |
| } |
| tcp_tw_put((struct tcp_tw_bucket*)nsk); |
| return NULL; |
| } |
| |
| #ifdef CONFIG_SYN_COOKIES |
| if (!th->rst && !th->syn && th->ack) |
| sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt)); |
| #endif |
| return sk; |
| } |
| |
| static int tcp_v4_checksum_init(struct sk_buff *skb) |
| { |
| if (skb->ip_summed == CHECKSUM_HW) { |
| skb->ip_summed = CHECKSUM_UNNECESSARY; |
| if (!tcp_v4_check(skb->h.th,skb->len,skb->nh.iph->saddr, |
| skb->nh.iph->daddr,skb->csum)) |
| return 0; |
| |
| NETDEBUG(if (net_ratelimit()) printk(KERN_DEBUG "hw tcp v4 csum failed\n")); |
| skb->ip_summed = CHECKSUM_NONE; |
| } |
| if (skb->len <= 76) { |
| if (tcp_v4_check(skb->h.th,skb->len,skb->nh.iph->saddr, |
| skb->nh.iph->daddr, |
| skb_checksum(skb, 0, skb->len, 0))) |
| return -1; |
| skb->ip_summed = CHECKSUM_UNNECESSARY; |
| } else { |
| skb->csum = ~tcp_v4_check(skb->h.th,skb->len,skb->nh.iph->saddr, |
| skb->nh.iph->daddr,0); |
| } |
| return 0; |
| } |
| |
| |
| /* The socket must have it's spinlock held when we get |
| * here. |
| * |
| * We have a potential double-lock case here, so even when |
| * doing backlog processing we use the BH locking scheme. |
| * This is because we cannot sleep with the original spinlock |
| * held. |
| */ |
| int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb) |
| { |
| #ifdef CONFIG_FILTER |
| struct sk_filter *filter = sk->filter; |
| if (filter && sk_filter(skb, filter)) |
| goto discard; |
| #endif /* CONFIG_FILTER */ |
| |
| IP_INC_STATS_BH(IpInDelivers); |
| |
| if (sk->state == TCP_ESTABLISHED) { /* Fast path */ |
| TCP_CHECK_TIMER(sk); |
| if (tcp_rcv_established(sk, skb, skb->h.th, skb->len)) |
| goto reset; |
| TCP_CHECK_TIMER(sk); |
| return 0; |
| } |
| |
| if (skb->len < (skb->h.th->doff<<2) || tcp_checksum_complete(skb)) |
| goto csum_err; |
| |
| if (sk->state == TCP_LISTEN) { |
| struct sock *nsk = tcp_v4_hnd_req(sk, skb); |
| if (!nsk) |
| goto discard; |
| |
| if (nsk != sk) { |
| if (tcp_child_process(sk, nsk, skb)) |
| goto reset; |
| return 0; |
| } |
| } |
| |
| TCP_CHECK_TIMER(sk); |
| if (tcp_rcv_state_process(sk, skb, skb->h.th, skb->len)) |
| goto reset; |
| TCP_CHECK_TIMER(sk); |
| return 0; |
| |
| reset: |
| tcp_v4_send_reset(skb); |
| discard: |
| kfree_skb(skb); |
| /* Be careful here. If this function gets more complicated and |
| * gcc suffers from register pressure on the x86, sk (in %ebx) |
| * might be destroyed here. This current version compiles correctly, |
| * but you have been warned. |
| */ |
| return 0; |
| |
| csum_err: |
| TCP_INC_STATS_BH(TcpInErrs); |
| goto discard; |
| } |
| |
| /* |
| * From tcp_input.c |
| */ |
| |
| int tcp_v4_rcv(struct sk_buff *skb) |
| { |
| struct tcphdr *th; |
| struct sock *sk; |
| int ret; |
| |
| if (skb->pkt_type!=PACKET_HOST) |
| goto discard_it; |
| |
| /* Count it even if it's bad */ |
| TCP_INC_STATS_BH(TcpInSegs); |
| |
| if (!pskb_may_pull(skb, sizeof(struct tcphdr))) |
| goto discard_it; |
| |
| th = skb->h.th; |
| |
| if (th->doff < sizeof(struct tcphdr)/4) |
| goto bad_packet; |
| if (!pskb_may_pull(skb, th->doff*4)) |
| goto discard_it; |
| |
| /* An explanation is required here, I think. |
| * Packet length and doff are validated by header prediction, |
| * provided case of th->doff==0 is elimineted. |
| * So, we defer the checks. */ |
| if ((skb->ip_summed != CHECKSUM_UNNECESSARY && |
| tcp_v4_checksum_init(skb) < 0)) |
| goto bad_packet; |
| |
| th = skb->h.th; |
| TCP_SKB_CB(skb)->seq = ntohl(th->seq); |
| TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + |
| skb->len - th->doff*4); |
| TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); |
| TCP_SKB_CB(skb)->when = 0; |
| TCP_SKB_CB(skb)->flags = skb->nh.iph->tos; |
| TCP_SKB_CB(skb)->sacked = 0; |
| |
| sk = __tcp_v4_lookup(skb->nh.iph->saddr, th->source, |
| skb->nh.iph->daddr, ntohs(th->dest), tcp_v4_iif(skb)); |
| |
| if (!sk) |
| goto no_tcp_socket; |
| |
| process: |
| if(!ipsec_sk_policy(sk,skb)) |
| goto discard_and_relse; |
| |
| if (sk->state == TCP_TIME_WAIT) |
| goto do_time_wait; |
| |
| skb->dev = NULL; |
| |
| bh_lock_sock(sk); |
| ret = 0; |
| if (!sk->lock.users) { |
| if (!tcp_prequeue(sk, skb)) |
| ret = tcp_v4_do_rcv(sk, skb); |
| } else |
| sk_add_backlog(sk, skb); |
| bh_unlock_sock(sk); |
| |
| sock_put(sk); |
| |
| return ret; |
| |
| no_tcp_socket: |
| if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) { |
| bad_packet: |
| TCP_INC_STATS_BH(TcpInErrs); |
| } else { |
| tcp_v4_send_reset(skb); |
| } |
| |
| discard_it: |
| /* Discard frame. */ |
| kfree_skb(skb); |
| return 0; |
| |
| discard_and_relse: |
| sock_put(sk); |
| goto discard_it; |
| |
| do_time_wait: |
| if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) { |
| TCP_INC_STATS_BH(TcpInErrs); |
| goto discard_and_relse; |
| } |
| switch(tcp_timewait_state_process((struct tcp_tw_bucket *)sk, |
| skb, th, skb->len)) { |
| case TCP_TW_SYN: |
| { |
| struct sock *sk2; |
| |
| sk2 = tcp_v4_lookup_listener(skb->nh.iph->daddr, ntohs(th->dest), tcp_v4_iif(skb)); |
| if (sk2 != NULL) { |
| tcp_tw_deschedule((struct tcp_tw_bucket *)sk); |
| tcp_timewait_kill((struct tcp_tw_bucket *)sk); |
| tcp_tw_put((struct tcp_tw_bucket *)sk); |
| sk = sk2; |
| goto process; |
| } |
| /* Fall through to ACK */ |
| } |
| case TCP_TW_ACK: |
| tcp_v4_timewait_ack(sk, skb); |
| break; |
| case TCP_TW_RST: |
| goto no_tcp_socket; |
| case TCP_TW_SUCCESS:; |
| } |
| goto discard_it; |
| } |
| |
| /* With per-bucket locks this operation is not-atomic, so that |
| * this version is not worse. |
| */ |
| static void __tcp_v4_rehash(struct sock *sk) |
| { |
| sk->prot->unhash(sk); |
| sk->prot->hash(sk); |
| } |
| |
| static int tcp_v4_reselect_saddr(struct sock *sk) |
| { |
| int err; |
| struct rtable *rt; |
| __u32 old_saddr = sk->saddr; |
| __u32 new_saddr; |
| __u32 daddr = sk->daddr; |
| |
| if(sk->protinfo.af_inet.opt && sk->protinfo.af_inet.opt->srr) |
| daddr = sk->protinfo.af_inet.opt->faddr; |
| |
| /* Query new route. */ |
| err = ip_route_connect(&rt, daddr, 0, |
| RT_TOS(sk->protinfo.af_inet.tos)|sk->localroute, |
| sk->bound_dev_if); |
| if (err) |
| return err; |
| |
| __sk_dst_set(sk, &rt->u.dst); |
| sk->route_caps = rt->u.dst.dev->features; |
| |
| new_saddr = rt->rt_src; |
| |
| if (new_saddr == old_saddr) |
| return 0; |
| |
| if (sysctl_ip_dynaddr > 1) { |
| printk(KERN_INFO "tcp_v4_rebuild_header(): shifting sk->saddr " |
| "from %d.%d.%d.%d to %d.%d.%d.%d\n", |
| NIPQUAD(old_saddr), |
| NIPQUAD(new_saddr)); |
| } |
| |
| sk->saddr = new_saddr; |
| sk->rcv_saddr = new_saddr; |
| |
| /* XXX The only one ugly spot where we need to |
| * XXX really change the sockets identity after |
| * XXX it has entered the hashes. -DaveM |
| * |
| * Besides that, it does not check for connection |
| * uniqueness. Wait for troubles. |
| */ |
| __tcp_v4_rehash(sk); |
| return 0; |
| } |
| |
| int tcp_v4_rebuild_header(struct sock *sk) |
| { |
| struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0); |
| u32 daddr; |
| int err; |
| |
| /* Route is OK, nothing to do. */ |
| if (rt != NULL) |
| return 0; |
| |
| /* Reroute. */ |
| daddr = sk->daddr; |
| if(sk->protinfo.af_inet.opt && sk->protinfo.af_inet.opt->srr) |
| daddr = sk->protinfo.af_inet.opt->faddr; |
| |
| err = ip_route_output(&rt, daddr, sk->saddr, |
| RT_CONN_FLAGS(sk), sk->bound_dev_if); |
| if (!err) { |
| __sk_dst_set(sk, &rt->u.dst); |
| sk->route_caps = rt->u.dst.dev->features; |
| return 0; |
| } |
| |
| /* Routing failed... */ |
| sk->route_caps = 0; |
| |
| if (!sysctl_ip_dynaddr || |
| sk->state != TCP_SYN_SENT || |
| (sk->userlocks & SOCK_BINDADDR_LOCK) || |
| (err = tcp_v4_reselect_saddr(sk)) != 0) |
| sk->err_soft=-err; |
| |
| return err; |
| } |
| |
| static void v4_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr) |
| { |
| struct sockaddr_in *sin = (struct sockaddr_in *) uaddr; |
| |
| sin->sin_family = AF_INET; |
| sin->sin_addr.s_addr = sk->daddr; |
| sin->sin_port = sk->dport; |
| } |
| |
| /* VJ's idea. Save last timestamp seen from this destination |
| * and hold it at least for normal timewait interval to use for duplicate |
| * segment detection in subsequent connections, before they enter synchronized |
| * state. |
| */ |
| |
| int tcp_v4_remember_stamp(struct sock *sk) |
| { |
| struct tcp_opt *tp = &sk->tp_pinfo.af_tcp; |
| struct rtable *rt = (struct rtable*)__sk_dst_get(sk); |
| struct inet_peer *peer = NULL; |
| int release_it = 0; |
| |
| if (rt == NULL || rt->rt_dst != sk->daddr) { |
| peer = inet_getpeer(sk->daddr, 1); |
| release_it = 1; |
| } else { |
| if (rt->peer == NULL) |
| rt_bind_peer(rt, 1); |
| peer = rt->peer; |
| } |
| |
| if (peer) { |
| if ((s32)(peer->tcp_ts - tp->ts_recent) <= 0 || |
| (peer->tcp_ts_stamp + TCP_PAWS_MSL < xtime.tv_sec && |
| peer->tcp_ts_stamp <= tp->ts_recent_stamp)) { |
| peer->tcp_ts_stamp = tp->ts_recent_stamp; |
| peer->tcp_ts = tp->ts_recent; |
| } |
| if (release_it) |
| inet_putpeer(peer); |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| int tcp_v4_tw_remember_stamp(struct tcp_tw_bucket *tw) |
| { |
| struct inet_peer *peer = NULL; |
| |
| peer = inet_getpeer(tw->daddr, 1); |
| |
| if (peer) { |
| if ((s32)(peer->tcp_ts - tw->ts_recent) <= 0 || |
| (peer->tcp_ts_stamp + TCP_PAWS_MSL < xtime.tv_sec && |
| peer->tcp_ts_stamp <= tw->ts_recent_stamp)) { |
| peer->tcp_ts_stamp = tw->ts_recent_stamp; |
| peer->tcp_ts = tw->ts_recent; |
| } |
| inet_putpeer(peer); |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| struct tcp_func ipv4_specific = { |
| ip_queue_xmit, |
| tcp_v4_send_check, |
| tcp_v4_rebuild_header, |
| tcp_v4_conn_request, |
| tcp_v4_syn_recv_sock, |
| tcp_v4_hash_connecting, |
| tcp_v4_remember_stamp, |
| sizeof(struct iphdr), |
| |
| ip_setsockopt, |
| ip_getsockopt, |
| v4_addr2sockaddr, |
| sizeof(struct sockaddr_in) |
| }; |
| |
| /* NOTE: A lot of things set to zero explicitly by call to |
| * sk_alloc() so need not be done here. |
| */ |
| static int tcp_v4_init_sock(struct sock *sk) |
| { |
| struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp); |
| |
| skb_queue_head_init(&tp->out_of_order_queue); |
| tcp_init_xmit_timers(sk); |
| tcp_prequeue_init(tp); |
| |
| tp->rto = TCP_TIMEOUT_INIT; |
| tp->mdev = TCP_TIMEOUT_INIT; |
| |
| /* So many TCP implementations out there (incorrectly) count the |
| * initial SYN frame in their delayed-ACK and congestion control |
| * algorithms that we must have the following bandaid to talk |
| * efficiently to them. -DaveM |
| */ |
| tp->snd_cwnd = 2; |
| |
| /* See draft-stevens-tcpca-spec-01 for discussion of the |
| * initialization of these values. |
| */ |
| tp->snd_ssthresh = 0x7fffffff; /* Infinity */ |
| tp->snd_cwnd_clamp = ~0; |
| tp->mss_cache = 536; |
| |
| tp->reordering = sysctl_tcp_reordering; |
| |
| sk->state = TCP_CLOSE; |
| |
| sk->write_space = tcp_write_space; |
| sk->use_write_queue = 1; |
| |
| sk->tp_pinfo.af_tcp.af_specific = &ipv4_specific; |
| |
| sk->sndbuf = sysctl_tcp_wmem[1]; |
| sk->rcvbuf = sysctl_tcp_rmem[1]; |
| |
| atomic_inc(&tcp_sockets_allocated); |
| |
| return 0; |
| } |
| |
| static int tcp_v4_destroy_sock(struct sock *sk) |
| { |
| struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp); |
| |
| tcp_clear_xmit_timers(sk); |
| |
| /* Cleanup up the write buffer. */ |
| tcp_writequeue_purge(sk); |
| |
| /* Cleans up our, hopefully empty, out_of_order_queue. */ |
| __skb_queue_purge(&tp->out_of_order_queue); |
| |
| /* Clean prequeue, it must be empty really */ |
| __skb_queue_purge(&tp->ucopy.prequeue); |
| |
| /* Clean up a referenced TCP bind bucket. */ |
| if(sk->prev != NULL) |
| tcp_put_port(sk); |
| |
| /* If sendmsg cached page exists, toss it. */ |
| if (tp->sndmsg_page != NULL) |
| __free_page(tp->sndmsg_page); |
| |
| atomic_dec(&tcp_sockets_allocated); |
| |
| return 0; |
| } |
| |
| /* Proc filesystem TCP sock list dumping. */ |
| static void get_openreq(struct sock *sk, struct open_request *req, char *tmpbuf, int i, int uid) |
| { |
| int ttd = req->expires - jiffies; |
| |
| sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X" |
| " %02X %08X:%08X %02X:%08X %08X %5d %8d %u %d %p", |
| i, |
| req->af.v4_req.loc_addr, |
| ntohs(sk->sport), |
| req->af.v4_req.rmt_addr, |
| ntohs(req->rmt_port), |
| TCP_SYN_RECV, |
| 0,0, /* could print option size, but that is af dependent. */ |
| 1, /* timers active (only the expire timer) */ |
| ttd, |
| req->retrans, |
| uid, |
| 0, /* non standard timer */ |
| 0, /* open_requests have no inode */ |
| atomic_read(&sk->refcnt), |
| req |
| ); |
| } |
| |
| static void get_tcp_sock(struct sock *sp, char *tmpbuf, int i) |
| { |
| unsigned int dest, src; |
| __u16 destp, srcp; |
| int timer_active; |
| unsigned long timer_expires; |
| struct tcp_opt *tp = &sp->tp_pinfo.af_tcp; |
| |
| dest = sp->daddr; |
| src = sp->rcv_saddr; |
| destp = ntohs(sp->dport); |
| srcp = ntohs(sp->sport); |
| if (tp->pending == TCP_TIME_RETRANS) { |
| timer_active = 1; |
| timer_expires = tp->timeout; |
| } else if (tp->pending == TCP_TIME_PROBE0) { |
| timer_active = 4; |
| timer_expires = tp->timeout; |
| } else if (timer_pending(&sp->timer)) { |
| timer_active = 2; |
| timer_expires = sp->timer.expires; |
| } else { |
| timer_active = 0; |
| timer_expires = jiffies; |
| } |
| |
| sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X" |
| " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %u %u %u %u %d", |
| i, src, srcp, dest, destp, sp->state, |
| tp->write_seq-tp->snd_una, tp->rcv_nxt-tp->copied_seq, |
| timer_active, timer_expires-jiffies, |
| tp->retransmits, |
| sock_i_uid(sp), |
| tp->probes_out, |
| sock_i_ino(sp), |
| atomic_read(&sp->refcnt), sp, |
| tp->rto, tp->ack.ato, (tp->ack.quick<<1)|tp->ack.pingpong, |
| tp->snd_cwnd, tp->snd_ssthresh>=0xFFFF?-1:tp->snd_ssthresh |
| ); |
| } |
| |
| static void get_timewait_sock(struct tcp_tw_bucket *tw, char *tmpbuf, int i) |
| { |
| unsigned int dest, src; |
| __u16 destp, srcp; |
| int ttd = tw->ttd - jiffies; |
| |
| if (ttd < 0) |
| ttd = 0; |
| |
| dest = tw->daddr; |
| src = tw->rcv_saddr; |
| destp = ntohs(tw->dport); |
| srcp = ntohs(tw->sport); |
| |
| sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X" |
| " %02X %08X:%08X %02X:%08X %08X %5d %8d %d %d %p", |
| i, src, srcp, dest, destp, tw->substate, 0, 0, |
| 3, ttd, 0, 0, 0, 0, |
| atomic_read(&tw->refcnt), tw); |
| } |
| |
| #define TMPSZ 150 |
| |
| int tcp_get_info(char *buffer, char **start, off_t offset, int length) |
| { |
| int len = 0, num = 0, i; |
| off_t begin, pos = 0; |
| char tmpbuf[TMPSZ+1]; |
| |
| if (offset < TMPSZ) |
| len += sprintf(buffer, "%-*s\n", TMPSZ-1, |
| " sl local_address rem_address st tx_queue " |
| "rx_queue tr tm->when retrnsmt uid timeout inode"); |
| |
| pos = TMPSZ; |
| |
| /* First, walk listening socket table. */ |
| tcp_listen_lock(); |
| for(i = 0; i < TCP_LHTABLE_SIZE; i++) { |
| struct sock *sk = tcp_listening_hash[i]; |
| struct tcp_listen_opt *lopt; |
| int k; |
| |
| for (sk = tcp_listening_hash[i]; sk; sk = sk->next, num++) { |
| struct open_request *req; |
| int uid; |
| struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp); |
| |
| if (!TCP_INET_FAMILY(sk->family)) |
| goto skip_listen; |
| |
| pos += TMPSZ; |
| if (pos >= offset) { |
| get_tcp_sock(sk, tmpbuf, num); |
| len += sprintf(buffer+len, "%-*s\n", TMPSZ-1, tmpbuf); |
| if (pos >= offset + length) { |
| tcp_listen_unlock(); |
| goto out_no_bh; |
| } |
| } |
| |
| skip_listen: |
| uid = sock_i_uid(sk); |
| read_lock_bh(&tp->syn_wait_lock); |
| lopt = tp->listen_opt; |
| if (lopt && lopt->qlen != 0) { |
| for (k=0; k<TCP_SYNQ_HSIZE; k++) { |
| for (req = lopt->syn_table[k]; req; req = req->dl_next, num++) { |
| if (!TCP_INET_FAMILY(req->class->family)) |
| continue; |
| |
| pos += TMPSZ; |
| if (pos <= offset) |
| continue; |
| get_openreq(sk, req, tmpbuf, num, uid); |
| len += sprintf(buffer+len, "%-*s\n", TMPSZ-1, tmpbuf); |
| if (pos >= offset + length) { |
| read_unlock_bh(&tp->syn_wait_lock); |
| tcp_listen_unlock(); |
| goto out_no_bh; |
| } |
| } |
| } |
| } |
| read_unlock_bh(&tp->syn_wait_lock); |
| |
| /* Completed requests are in normal socket hash table */ |
| } |
| } |
| tcp_listen_unlock(); |
| |
| local_bh_disable(); |
| |
| /* Next, walk established hash chain. */ |
| for (i = 0; i < tcp_ehash_size; i++) { |
| struct tcp_ehash_bucket *head = &tcp_ehash[i]; |
| struct sock *sk; |
| struct tcp_tw_bucket *tw; |
| |
| read_lock(&head->lock); |
| for(sk = head->chain; sk; sk = sk->next, num++) { |
| if (!TCP_INET_FAMILY(sk->family)) |
| continue; |
| pos += TMPSZ; |
| if (pos <= offset) |
| continue; |
| get_tcp_sock(sk, tmpbuf, num); |
| len += sprintf(buffer+len, "%-*s\n", TMPSZ-1, tmpbuf); |
| if (pos >= offset + length) { |
| read_unlock(&head->lock); |
| goto out; |
| } |
| } |
| for (tw = (struct tcp_tw_bucket *)tcp_ehash[i+tcp_ehash_size].chain; |
| tw != NULL; |
| tw = (struct tcp_tw_bucket *)tw->next, num++) { |
| if (!TCP_INET_FAMILY(tw->family)) |
| continue; |
| pos += TMPSZ; |
| if (pos <= offset) |
| continue; |
| get_timewait_sock(tw, tmpbuf, num); |
| len += sprintf(buffer+len, "%-*s\n", TMPSZ-1, tmpbuf); |
| if (pos >= offset + length) { |
| read_unlock(&head->lock); |
| goto out; |
| } |
| } |
| read_unlock(&head->lock); |
| } |
| |
| out: |
| local_bh_enable(); |
| out_no_bh: |
| |
| begin = len - (pos - offset); |
| *start = buffer + begin; |
| len -= begin; |
| if (len > length) |
| len = length; |
| if (len < 0) |
| len = 0; |
| return len; |
| } |
| |
| struct proto tcp_prot = { |
| name: "TCP", |
| close: tcp_close, |
| connect: tcp_v4_connect, |
| disconnect: tcp_disconnect, |
| accept: tcp_accept, |
| ioctl: tcp_ioctl, |
| init: tcp_v4_init_sock, |
| destroy: tcp_v4_destroy_sock, |
| shutdown: tcp_shutdown, |
| setsockopt: tcp_setsockopt, |
| getsockopt: tcp_getsockopt, |
| sendmsg: tcp_sendmsg, |
| recvmsg: tcp_recvmsg, |
| backlog_rcv: tcp_v4_do_rcv, |
| hash: tcp_v4_hash, |
| unhash: tcp_unhash, |
| get_port: tcp_v4_get_port, |
| }; |
| |
| |
| |
| void __init tcp_v4_init(struct net_proto_family *ops) |
| { |
| int err; |
| |
| tcp_inode.i_mode = S_IFSOCK; |
| tcp_inode.i_sock = 1; |
| tcp_inode.i_uid = 0; |
| tcp_inode.i_gid = 0; |
| init_waitqueue_head(&tcp_inode.i_wait); |
| init_waitqueue_head(&tcp_inode.u.socket_i.wait); |
| |
| tcp_socket->inode = &tcp_inode; |
| tcp_socket->state = SS_UNCONNECTED; |
| tcp_socket->type=SOCK_RAW; |
| |
| if ((err=ops->create(tcp_socket, IPPROTO_TCP))<0) |
| panic("Failed to create the TCP control socket.\n"); |
| tcp_socket->sk->allocation=GFP_ATOMIC; |
| tcp_socket->sk->protinfo.af_inet.ttl = MAXTTL; |
| |
| /* Unhash it so that IP input processing does not even |
| * see it, we do not wish this socket to see incoming |
| * packets. |
| */ |
| tcp_socket->sk->prot->unhash(tcp_socket->sk); |
| } |