/* * 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. * * PF_INET protocol family socket handler. * * Version: $Id: af_inet.c,v 1.137 2002/02/01 22:01:03 davem Exp $ * * Authors: Ross Biro * Fred N. van Kempen, * Florian La Roche, * Alan Cox, * * Changes (see also sock.c) * * piggy, * Karl Knutson : Socket protocol table * A.N.Kuznetsov : Socket death error in accept(). * John Richardson : Fix non blocking error in connect() * so sockets that fail to connect * don't return -EINPROGRESS. * Alan Cox : Asynchronous I/O support * Alan Cox : Keep correct socket pointer on sock * structures * when accept() ed * Alan Cox : Semantics of SO_LINGER aren't state * moved to close when you look carefully. * With this fixed and the accept bug fixed * some RPC stuff seems happier. * Niibe Yutaka : 4.4BSD style write async I/O * Alan Cox, * Tony Gale : Fixed reuse semantics. * Alan Cox : bind() shouldn't abort existing but dead * sockets. Stops FTP netin:.. I hope. * Alan Cox : bind() works correctly for RAW sockets. * Note that FreeBSD at least was broken * in this respect so be careful with * compatibility tests... * Alan Cox : routing cache support * Alan Cox : memzero the socket structure for * compactness. * Matt Day : nonblock connect error handler * Alan Cox : Allow large numbers of pending sockets * (eg for big web sites), but only if * specifically application requested. * Alan Cox : New buffering throughout IP. Used * dumbly. * Alan Cox : New buffering now used smartly. * Alan Cox : BSD rather than common sense * interpretation of listen. * Germano Caronni : Assorted small races. * Alan Cox : sendmsg/recvmsg basic support. * Alan Cox : Only sendmsg/recvmsg now supported. * Alan Cox : Locked down bind (see security list). * Alan Cox : Loosened bind a little. * Mike McLagan : ADD/DEL DLCI Ioctls * Willy Konynenberg : Transparent proxying support. * David S. Miller : New socket lookup architecture. * Some other random speedups. * Cyrus Durgin : Cleaned up file for kmod hacks. * Andi Kleen : Fix inet_stream_connect TCP race. * * 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_IP_MROUTE #include #endif DEFINE_SNMP_STAT(struct linux_mib, net_statistics) __read_mostly; extern void ip_mc_drop_socket(struct sock *sk); /* The inetsw table contains everything that inet_create needs to * build a new socket. */ static struct list_head inetsw[SOCK_MAX]; static DEFINE_SPINLOCK(inetsw_lock); struct ipv4_config ipv4_config; EXPORT_SYMBOL(ipv4_config); /* New destruction routine */ void inet_sock_destruct(struct sock *sk) { struct inet_sock *inet = inet_sk(sk); __skb_queue_purge(&sk->sk_receive_queue); __skb_queue_purge(&sk->sk_error_queue); sk_mem_reclaim(sk); if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) { printk("Attempt to release TCP socket in state %d %p\n", sk->sk_state, sk); return; } if (!sock_flag(sk, SOCK_DEAD)) { printk("Attempt to release alive inet socket %p\n", sk); return; } BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc)); BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc)); BUG_TRAP(!sk->sk_wmem_queued); BUG_TRAP(!sk->sk_forward_alloc); kfree(inet->opt); dst_release(sk->sk_dst_cache); sk_refcnt_debug_dec(sk); } /* * The routines beyond this point handle the behaviour of an AF_INET * socket object. Mostly it punts to the subprotocols of IP to do * the work. */ /* * Automatically bind an unbound socket. */ static int inet_autobind(struct sock *sk) { struct inet_sock *inet; /* We may need to bind the socket. */ lock_sock(sk); inet = inet_sk(sk); if (!inet->num) { if (sk->sk_prot->get_port(sk, 0)) { release_sock(sk); return -EAGAIN; } inet->sport = htons(inet->num); } release_sock(sk); return 0; } /* * Move a socket into listening state. */ int inet_listen(struct socket *sock, int backlog) { struct sock *sk = sock->sk; unsigned char old_state; int err; lock_sock(sk); err = -EINVAL; if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM) goto out; old_state = sk->sk_state; if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN))) goto out; /* Really, if the socket is already in listen state * we can only allow the backlog to be adjusted. */ if (old_state != TCP_LISTEN) { err = inet_csk_listen_start(sk, backlog); if (err) goto out; } sk->sk_max_ack_backlog = backlog; err = 0; out: release_sock(sk); return err; } u32 inet_ehash_secret __read_mostly; EXPORT_SYMBOL(inet_ehash_secret); /* * inet_ehash_secret must be set exactly once * Instead of using a dedicated spinlock, we (ab)use inetsw_lock */ void build_ehash_secret(void) { u32 rnd; do { get_random_bytes(&rnd, sizeof(rnd)); } while (rnd == 0); spin_lock_bh(&inetsw_lock); if (!inet_ehash_secret) inet_ehash_secret = rnd; spin_unlock_bh(&inetsw_lock); } EXPORT_SYMBOL(build_ehash_secret); /* * Create an inet socket. */ static int inet_create(struct net *net, struct socket *sock, int protocol) { struct sock *sk; struct list_head *p; struct inet_protosw *answer; struct inet_sock *inet; struct proto *answer_prot; unsigned char answer_flags; char answer_no_check; int try_loading_module = 0; int err; if (net != &init_net) return -EAFNOSUPPORT; if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM && !inet_ehash_secret) build_ehash_secret(); sock->state = SS_UNCONNECTED; /* Look for the requested type/protocol pair. */ answer = NULL; lookup_protocol: err = -ESOCKTNOSUPPORT; rcu_read_lock(); list_for_each_rcu(p, &inetsw[sock->type]) { answer = list_entry(p, struct inet_protosw, list); /* Check the non-wild match. */ if (protocol == answer->protocol) { if (protocol != IPPROTO_IP) break; } else { /* Check for the two wild cases. */ if (IPPROTO_IP == protocol) { protocol = answer->protocol; break; } if (IPPROTO_IP == answer->protocol) break; } err = -EPROTONOSUPPORT; answer = NULL; } if (unlikely(answer == NULL)) { if (try_loading_module < 2) { rcu_read_unlock(); /* * Be more specific, e.g. net-pf-2-proto-132-type-1 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM) */ if (++try_loading_module == 1) request_module("net-pf-%d-proto-%d-type-%d", PF_INET, protocol, sock->type); /* * Fall back to generic, e.g. net-pf-2-proto-132 * (net-pf-PF_INET-proto-IPPROTO_SCTP) */ else request_module("net-pf-%d-proto-%d", PF_INET, protocol); goto lookup_protocol; } else goto out_rcu_unlock; } err = -EPERM; if (answer->capability > 0 && !capable(answer->capability)) goto out_rcu_unlock; sock->ops = answer->ops; answer_prot = answer->prot; answer_no_check = answer->no_check; answer_flags = answer->flags; rcu_read_unlock(); BUG_TRAP(answer_prot->slab != NULL); err = -ENOBUFS; sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot); if (sk == NULL) goto out; err = 0; sk->sk_no_check = answer_no_check; if (INET_PROTOSW_REUSE & answer_flags) sk->sk_reuse = 1; inet = inet_sk(sk); inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0; if (SOCK_RAW == sock->type) { inet->num = protocol; if (IPPROTO_RAW == protocol) inet->hdrincl = 1; } if (ipv4_config.no_pmtu_disc) inet->pmtudisc = IP_PMTUDISC_DONT; else inet->pmtudisc = IP_PMTUDISC_WANT; inet->id = 0; sock_init_data(sock, sk); sk->sk_destruct = inet_sock_destruct; sk->sk_family = PF_INET; sk->sk_protocol = protocol; sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv; inet->uc_ttl = -1; inet->mc_loop = 1; inet->mc_ttl = 1; inet->mc_index = 0; inet->mc_list = NULL; sk_refcnt_debug_inc(sk); if (inet->num) { /* It assumes that any protocol which allows * the user to assign a number at socket * creation time automatically * shares. */ inet->sport = htons(inet->num); /* Add to protocol hash chains. */ sk->sk_prot->hash(sk); } if (sk->sk_prot->init) { err = sk->sk_prot->init(sk); if (err) sk_common_release(sk); } out: return err; out_rcu_unlock: rcu_read_unlock(); goto out; } /* * The peer socket should always be NULL (or else). When we call this * function we are destroying the object and from then on nobody * should refer to it. */ int inet_release(struct socket *sock) { struct sock *sk = sock->sk; if (sk) { long timeout; /* Applications forget to leave groups before exiting */ ip_mc_drop_socket(sk); /* If linger is set, we don't return until the close * is complete. Otherwise we return immediately. The * actually closing is done the same either way. * * If the close is due to the process exiting, we never * linger.. */ timeout = 0; if (sock_flag(sk, SOCK_LINGER) && !(current->flags & PF_EXITING)) timeout = sk->sk_lingertime; sock->sk = NULL; sk->sk_prot->close(sk, timeout); } return 0; } /* It is off by default, see below. */ int sysctl_ip_nonlocal_bind __read_mostly; int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) { struct sockaddr_in *addr = (struct sockaddr_in *)uaddr; struct sock *sk = sock->sk; struct inet_sock *inet = inet_sk(sk); unsigned short snum; int chk_addr_ret; int err; /* If the socket has its own bind function then use it. (RAW) */ if (sk->sk_prot->bind) { err = sk->sk_prot->bind(sk, uaddr, addr_len); goto out; } err = -EINVAL; if (addr_len < sizeof(struct sockaddr_in)) goto out; chk_addr_ret = inet_addr_type(&init_net, addr->sin_addr.s_addr); /* Not specified by any standard per-se, however it breaks too * many applications when removed. It is unfortunate since * allowing applications to make a non-local bind solves * several problems with systems using dynamic addressing. * (ie. your servers still start up even if your ISDN link * is temporarily down) */ err = -EADDRNOTAVAIL; if (!sysctl_ip_nonlocal_bind && !inet->freebind && addr->sin_addr.s_addr != INADDR_ANY && chk_addr_ret != RTN_LOCAL && chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST) goto out; snum = ntohs(addr->sin_port); err = -EACCES; if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE)) goto out; /* We keep a pair of addresses. rcv_saddr is the one * used by hash lookups, and saddr is used for transmit. * * In the BSD API these are the same except where it * would be illegal to use them (multicast/broadcast) in * which case the sending device address is used. */ lock_sock(sk); /* Check these errors (active socket, double bind). */ err = -EINVAL; if (sk->sk_state != TCP_CLOSE || inet->num) goto out_release_sock; inet->rcv_saddr = inet->saddr = addr->sin_addr.s_addr; if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST) inet->saddr = 0; /* Use device */ /* Make sure we are allowed to bind here. */ if (sk->sk_prot->get_port(sk, snum)) { inet->saddr = inet->rcv_saddr = 0; err = -EADDRINUSE; goto out_release_sock; } if (inet->rcv_saddr) sk->sk_userlocks |= SOCK_BINDADDR_LOCK; if (snum) sk->sk_userlocks |= SOCK_BINDPORT_LOCK; inet->sport = htons(inet->num); inet->daddr = 0; inet->dport = 0; sk_dst_reset(sk); err = 0; out_release_sock: release_sock(sk); out: return err; } int inet_dgram_connect(struct socket *sock, struct sockaddr * uaddr, int addr_len, int flags) { struct sock *sk = sock->sk; if (uaddr->sa_family == AF_UNSPEC) return sk->sk_prot->disconnect(sk, flags); if (!inet_sk(sk)->num && inet_autobind(sk)) return -EAGAIN; return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len); } static long inet_wait_for_connect(struct sock *sk, long timeo) { DEFINE_WAIT(wait); prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); /* Basic assumption: if someone sets sk->sk_err, he _must_ * change state of the socket from TCP_SYN_*. * Connect() does not allow to get error notifications * without closing the socket. */ while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { release_sock(sk); timeo = schedule_timeout(timeo); lock_sock(sk); if (signal_pending(current) || !timeo) break; prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); } finish_wait(sk->sk_sleep, &wait); return timeo; } /* * Connect to a remote host. There is regrettably still a little * TCP 'magic' in here. */ int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr, int addr_len, int flags) { struct sock *sk = sock->sk; int err; long timeo; lock_sock(sk); if (uaddr->sa_family == AF_UNSPEC) { err = sk->sk_prot->disconnect(sk, flags); sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED; goto out; } switch (sock->state) { default: err = -EINVAL; goto out; case SS_CONNECTED: err = -EISCONN; goto out; case SS_CONNECTING: err = -EALREADY; /* Fall out of switch with err, set for this state */ break; case SS_UNCONNECTED: err = -EISCONN; if (sk->sk_state != TCP_CLOSE) goto out; err = sk->sk_prot->connect(sk, uaddr, addr_len); if (err < 0) goto out; sock->state = SS_CONNECTING; /* Just entered SS_CONNECTING state; the only * difference is that return value in non-blocking * case is EINPROGRESS, rather than EALREADY. */ err = -EINPROGRESS; break; } timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { /* Error code is set above */ if (!timeo || !inet_wait_for_connect(sk, timeo)) goto out; err = sock_intr_errno(timeo); if (signal_pending(current)) goto out; } /* Connection was closed by RST, timeout, ICMP error * or another process disconnected us. */ if (sk->sk_state == TCP_CLOSE) goto sock_error; /* sk->sk_err may be not zero now, if RECVERR was ordered by user * and error was received after socket entered established state. * Hence, it is handled normally after connect() return successfully. */ sock->state = SS_CONNECTED; err = 0; out: release_sock(sk); return err; sock_error: err = sock_error(sk) ? : -ECONNABORTED; sock->state = SS_UNCONNECTED; if (sk->sk_prot->disconnect(sk, flags)) sock->state = SS_DISCONNECTING; goto out; } /* * Accept a pending connection. The TCP layer now gives BSD semantics. */ int inet_accept(struct socket *sock, struct socket *newsock, int flags) { struct sock *sk1 = sock->sk; int err = -EINVAL; struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err); if (!sk2) goto do_err; lock_sock(sk2); BUG_TRAP((1 << sk2->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE)); sock_graft(sk2, newsock); newsock->state = SS_CONNECTED; err = 0; release_sock(sk2); do_err: return err; } /* * This does both peername and sockname. */ int inet_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) { struct sock *sk = sock->sk; struct inet_sock *inet = inet_sk(sk); struct sockaddr_in *sin = (struct sockaddr_in *)uaddr; sin->sin_family = AF_INET; if (peer) { if (!inet->dport || (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) && peer == 1)) return -ENOTCONN; sin->sin_port = inet->dport; sin->sin_addr.s_addr = inet->daddr; } else { __be32 addr = inet->rcv_saddr; if (!addr) addr = inet->saddr; sin->sin_port = inet->sport; sin->sin_addr.s_addr = addr; } memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); *uaddr_len = sizeof(*sin); return 0; } int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, size_t size) { struct sock *sk = sock->sk; /* We may need to bind the socket. */ if (!inet_sk(sk)->num && inet_autobind(sk)) return -EAGAIN; return sk->sk_prot->sendmsg(iocb, sk, msg, size); } static ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags) { struct sock *sk = sock->sk; /* We may need to bind the socket. */ if (!inet_sk(sk)->num && inet_autobind(sk)) return -EAGAIN; if (sk->sk_prot->sendpage) return sk->sk_prot->sendpage(sk, page, offset, size, flags); return sock_no_sendpage(sock, page, offset, size, flags); } int inet_shutdown(struct socket *sock, int how) { struct sock *sk = sock->sk; int err = 0; /* This should really check to make sure * the socket is a TCP socket. (WHY AC...) */ how++; /* maps 0->1 has the advantage of making bit 1 rcvs and 1->2 bit 2 snds. 2->3 */ if ((how & ~SHUTDOWN_MASK) || !how) /* MAXINT->0 */ return -EINVAL; lock_sock(sk); if (sock->state == SS_CONNECTING) { if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE)) sock->state = SS_DISCONNECTING; else sock->state = SS_CONNECTED; } switch (sk->sk_state) { case TCP_CLOSE: err = -ENOTCONN; /* Hack to wake up other listeners, who can poll for POLLHUP, even on eg. unconnected UDP sockets -- RR */ default: sk->sk_shutdown |= how; if (sk->sk_prot->shutdown) sk->sk_prot->shutdown(sk, how); break; /* Remaining two branches are temporary solution for missing * close() in multithreaded environment. It is _not_ a good idea, * but we have no choice until close() is repaired at VFS level. */ case TCP_LISTEN: if (!(how & RCV_SHUTDOWN)) break; /* Fall through */ case TCP_SYN_SENT: err = sk->sk_prot->disconnect(sk, O_NONBLOCK); sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED; break; } /* Wake up anyone sleeping in poll. */ sk->sk_state_change(sk); release_sock(sk); return err; } /* * ioctl() calls you can issue on an INET socket. Most of these are * device configuration and stuff and very rarely used. Some ioctls * pass on to the socket itself. * * NOTE: I like the idea of a module for the config stuff. ie ifconfig * loads the devconfigure module does its configuring and unloads it. * There's a good 20K of config code hanging around the kernel. */ int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) { struct sock *sk = sock->sk; int err = 0; switch (cmd) { case SIOCGSTAMP: err = sock_get_timestamp(sk, (struct timeval __user *)arg); break; case SIOCGSTAMPNS: err = sock_get_timestampns(sk, (struct timespec __user *)arg); break; case SIOCADDRT: case SIOCDELRT: case SIOCRTMSG: err = ip_rt_ioctl(cmd, (void __user *)arg); break; case SIOCDARP: case SIOCGARP: case SIOCSARP: err = arp_ioctl(sk->sk_net, cmd, (void __user *)arg); break; case SIOCGIFADDR: case SIOCSIFADDR: case SIOCGIFBRDADDR: case SIOCSIFBRDADDR: case SIOCGIFNETMASK: case SIOCSIFNETMASK: case SIOCGIFDSTADDR: case SIOCSIFDSTADDR: case SIOCSIFPFLAGS: case SIOCGIFPFLAGS: case SIOCSIFFLAGS: err = devinet_ioctl(cmd, (void __user *)arg); break; default: if (sk->sk_prot->ioctl) err = sk->sk_prot->ioctl(sk, cmd, arg); else err = -ENOIOCTLCMD; break; } return err; } const struct proto_ops inet_stream_ops = { .family = PF_INET, .owner = THIS_MODULE, .release = inet_release, .bind = inet_bind, .connect = inet_stream_connect, .socketpair = sock_no_socketpair, .accept = inet_accept, .getname = inet_getname, .poll = tcp_poll, .ioctl = inet_ioctl, .listen = inet_listen, .shutdown = inet_shutdown, .setsockopt = sock_common_setsockopt, .getsockopt = sock_common_getsockopt, .sendmsg = tcp_sendmsg, .recvmsg = sock_common_recvmsg, .mmap = sock_no_mmap, .sendpage = tcp_sendpage, .splice_read = tcp_splice_read, #ifdef CONFIG_COMPAT .compat_setsockopt = compat_sock_common_setsockopt, .compat_getsockopt = compat_sock_common_getsockopt, #endif }; const struct proto_ops inet_dgram_ops = { .family = PF_INET, .owner = THIS_MODULE, .release = inet_release, .bind = inet_bind, .connect = inet_dgram_connect, .socketpair = sock_no_socketpair, .accept = sock_no_accept, .getname = inet_getname, .poll = udp_poll, .ioctl = inet_ioctl, .listen = sock_no_listen, .shutdown = inet_shutdown, .setsockopt = sock_common_setsockopt, .getsockopt = sock_common_getsockopt, .sendmsg = inet_sendmsg, .recvmsg = sock_common_recvmsg, .mmap = sock_no_mmap, .sendpage = inet_sendpage, #ifdef CONFIG_COMPAT .compat_setsockopt = compat_sock_common_setsockopt, .compat_getsockopt = compat_sock_common_getsockopt, #endif }; /* * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without * udp_poll */ static const struct proto_ops inet_sockraw_ops = { .family = PF_INET, .owner = THIS_MODULE, .release = inet_release, .bind = inet_bind, .connect = inet_dgram_connect, .socketpair = sock_no_socketpair, .accept = sock_no_accept, .getname = inet_getname, .poll = datagram_poll, .ioctl = inet_ioctl, .listen = sock_no_listen, .shutdown = inet_shutdown, .setsockopt = sock_common_setsockopt, .getsockopt = sock_common_getsockopt, .sendmsg = inet_sendmsg, .recvmsg = sock_common_recvmsg, .mmap = sock_no_mmap, .sendpage = inet_sendpage, #ifdef CONFIG_COMPAT .compat_setsockopt = compat_sock_common_setsockopt, .compat_getsockopt = compat_sock_common_getsockopt, #endif }; static struct net_proto_family inet_family_ops = { .family = PF_INET, .create = inet_create, .owner = THIS_MODULE, }; /* Upon startup we insert all the elements in inetsw_array[] into * the linked list inetsw. */ static struct inet_protosw inetsw_array[] = { { .type = SOCK_STREAM, .protocol = IPPROTO_TCP, .prot = &tcp_prot, .ops = &inet_stream_ops, .capability = -1, .no_check = 0, .flags = INET_PROTOSW_PERMANENT | INET_PROTOSW_ICSK, }, { .type = SOCK_DGRAM, .protocol = IPPROTO_UDP, .prot = &udp_prot, .ops = &inet_dgram_ops, .capability = -1, .no_check = UDP_CSUM_DEFAULT, .flags = INET_PROTOSW_PERMANENT, }, { .type = SOCK_RAW, .protocol = IPPROTO_IP, /* wild card */ .prot = &raw_prot, .ops = &inet_sockraw_ops, .capability = CAP_NET_RAW, .no_check = UDP_CSUM_DEFAULT, .flags = INET_PROTOSW_REUSE, } }; #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array) void inet_register_protosw(struct inet_protosw *p) { struct list_head *lh; struct inet_protosw *answer; int protocol = p->protocol; struct list_head *last_perm; spin_lock_bh(&inetsw_lock); if (p->type >= SOCK_MAX) goto out_illegal; /* If we are trying to override a permanent protocol, bail. */ answer = NULL; last_perm = &inetsw[p->type]; list_for_each(lh, &inetsw[p->type]) { answer = list_entry(lh, struct inet_protosw, list); /* Check only the non-wild match. */ if (INET_PROTOSW_PERMANENT & answer->flags) { if (protocol == answer->protocol) break; last_perm = lh; } answer = NULL; } if (answer) goto out_permanent; /* Add the new entry after the last permanent entry if any, so that * the new entry does not override a permanent entry when matched with * a wild-card protocol. But it is allowed to override any existing * non-permanent entry. This means that when we remove this entry, the * system automatically returns to the old behavior. */ list_add_rcu(&p->list, last_perm); out: spin_unlock_bh(&inetsw_lock); synchronize_net(); return; out_permanent: printk(KERN_ERR "Attempt to override permanent protocol %d.\n", protocol); goto out; out_illegal: printk(KERN_ERR "Ignoring attempt to register invalid socket type %d.\n", p->type); goto out; } void inet_unregister_protosw(struct inet_protosw *p) { if (INET_PROTOSW_PERMANENT & p->flags) { printk(KERN_ERR "Attempt to unregister permanent protocol %d.\n", p->protocol); } else { spin_lock_bh(&inetsw_lock); list_del_rcu(&p->list); spin_unlock_bh(&inetsw_lock); synchronize_net(); } } /* * Shall we try to damage output packets if routing dev changes? */ int sysctl_ip_dynaddr __read_mostly; static int inet_sk_reselect_saddr(struct sock *sk) { struct inet_sock *inet = inet_sk(sk); int err; struct rtable *rt; __be32 old_saddr = inet->saddr; __be32 new_saddr; __be32 daddr = inet->daddr; if (inet->opt && inet->opt->srr) daddr = inet->opt->faddr; /* Query new route. */ err = ip_route_connect(&rt, daddr, 0, RT_CONN_FLAGS(sk), sk->sk_bound_dev_if, sk->sk_protocol, inet->sport, inet->dport, sk, 0); if (err) return err; sk_setup_caps(sk, &rt->u.dst); new_saddr = rt->rt_src; if (new_saddr == old_saddr) return 0; if (sysctl_ip_dynaddr > 1) { printk(KERN_INFO "%s(): shifting inet->" "saddr from %d.%d.%d.%d to %d.%d.%d.%d\n", __FUNCTION__, NIPQUAD(old_saddr), NIPQUAD(new_saddr)); } inet->saddr = inet->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. */ __sk_prot_rehash(sk); return 0; } int inet_sk_rebuild_header(struct sock *sk) { struct inet_sock *inet = inet_sk(sk); struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0); __be32 daddr; int err; /* Route is OK, nothing to do. */ if (rt) return 0; /* Reroute. */ daddr = inet->daddr; if (inet->opt && inet->opt->srr) daddr = inet->opt->faddr; { struct flowi fl = { .oif = sk->sk_bound_dev_if, .nl_u = { .ip4_u = { .daddr = daddr, .saddr = inet->saddr, .tos = RT_CONN_FLAGS(sk), }, }, .proto = sk->sk_protocol, .uli_u = { .ports = { .sport = inet->sport, .dport = inet->dport, }, }, }; security_sk_classify_flow(sk, &fl); err = ip_route_output_flow(&rt, &fl, sk, 0); } if (!err) sk_setup_caps(sk, &rt->u.dst); else { /* Routing failed... */ sk->sk_route_caps = 0; /* * Other protocols have to map its equivalent state to TCP_SYN_SENT. * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme */ if (!sysctl_ip_dynaddr || sk->sk_state != TCP_SYN_SENT || (sk->sk_userlocks & SOCK_BINDADDR_LOCK) || (err = inet_sk_reselect_saddr(sk)) != 0) sk->sk_err_soft = -err; } return err; } EXPORT_SYMBOL(inet_sk_rebuild_header); static int inet_gso_send_check(struct sk_buff *skb) { struct iphdr *iph; struct net_protocol *ops; int proto; int ihl; int err = -EINVAL; if (unlikely(!pskb_may_pull(skb, sizeof(*iph)))) goto out; iph = ip_hdr(skb); ihl = iph->ihl * 4; if (ihl < sizeof(*iph)) goto out; if (unlikely(!pskb_may_pull(skb, ihl))) goto out; __skb_pull(skb, ihl); skb_reset_transport_header(skb); iph = ip_hdr(skb); proto = iph->protocol & (MAX_INET_PROTOS - 1); err = -EPROTONOSUPPORT; rcu_read_lock(); ops = rcu_dereference(inet_protos[proto]); if (likely(ops && ops->gso_send_check)) err = ops->gso_send_check(skb); rcu_read_unlock(); out: return err; } static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int features) { struct sk_buff *segs = ERR_PTR(-EINVAL); struct iphdr *iph; struct net_protocol *ops; int proto; int ihl; int id; if (!(features & NETIF_F_V4_CSUM)) features &= ~NETIF_F_SG; if (unlikely(skb_shinfo(skb)->gso_type & ~(SKB_GSO_TCPV4 | SKB_GSO_UDP | SKB_GSO_DODGY | SKB_GSO_TCP_ECN | 0))) goto out; if (unlikely(!pskb_may_pull(skb, sizeof(*iph)))) goto out; iph = ip_hdr(skb); ihl = iph->ihl * 4; if (ihl < sizeof(*iph)) goto out; if (unlikely(!pskb_may_pull(skb, ihl))) goto out; __skb_pull(skb, ihl); skb_reset_transport_header(skb); iph = ip_hdr(skb); id = ntohs(iph->id); proto = iph->protocol & (MAX_INET_PROTOS - 1); segs = ERR_PTR(-EPROTONOSUPPORT); rcu_read_lock(); ops = rcu_dereference(inet_protos[proto]); if (likely(ops && ops->gso_segment)) segs = ops->gso_segment(skb, features); rcu_read_unlock(); if (!segs || unlikely(IS_ERR(segs))) goto out; skb = segs; do { iph = ip_hdr(skb); iph->id = htons(id++); iph->tot_len = htons(skb->len - skb->mac_len); iph->check = 0; iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl); } while ((skb = skb->next)); out: return segs; } unsigned long snmp_fold_field(void *mib[], int offt) { unsigned long res = 0; int i; for_each_possible_cpu(i) { res += *(((unsigned long *) per_cpu_ptr(mib[0], i)) + offt); res += *(((unsigned long *) per_cpu_ptr(mib[1], i)) + offt); } return res; } EXPORT_SYMBOL_GPL(snmp_fold_field); int snmp_mib_init(void *ptr[2], size_t mibsize) { BUG_ON(ptr == NULL); ptr[0] = __alloc_percpu(mibsize); if (!ptr[0]) goto err0; ptr[1] = __alloc_percpu(mibsize); if (!ptr[1]) goto err1; return 0; err1: free_percpu(ptr[0]); ptr[0] = NULL; err0: return -ENOMEM; } EXPORT_SYMBOL_GPL(snmp_mib_init); void snmp_mib_free(void *ptr[2]) { BUG_ON(ptr == NULL); free_percpu(ptr[0]); free_percpu(ptr[1]); ptr[0] = ptr[1] = NULL; } EXPORT_SYMBOL_GPL(snmp_mib_free); #ifdef CONFIG_IP_MULTICAST static struct net_protocol igmp_protocol = { .handler = igmp_rcv, }; #endif static struct net_protocol tcp_protocol = { .handler = tcp_v4_rcv, .err_handler = tcp_v4_err, .gso_send_check = tcp_v4_gso_send_check, .gso_segment = tcp_tso_segment, .no_policy = 1, }; static struct net_protocol udp_protocol = { .handler = udp_rcv, .err_handler = udp_err, .no_policy = 1, }; static struct net_protocol icmp_protocol = { .handler = icmp_rcv, .no_policy = 1, }; static int __init init_ipv4_mibs(void) { if (snmp_mib_init((void **)net_statistics, sizeof(struct linux_mib)) < 0) goto err_net_mib; if (snmp_mib_init((void **)ip_statistics, sizeof(struct ipstats_mib)) < 0) goto err_ip_mib; if (snmp_mib_init((void **)icmp_statistics, sizeof(struct icmp_mib)) < 0) goto err_icmp_mib; if (snmp_mib_init((void **)icmpmsg_statistics, sizeof(struct icmpmsg_mib)) < 0) goto err_icmpmsg_mib; if (snmp_mib_init((void **)tcp_statistics, sizeof(struct tcp_mib)) < 0) goto err_tcp_mib; if (snmp_mib_init((void **)udp_statistics, sizeof(struct udp_mib)) < 0) goto err_udp_mib; if (snmp_mib_init((void **)udplite_statistics, sizeof(struct udp_mib)) < 0) goto err_udplite_mib; tcp_mib_init(); return 0; err_udplite_mib: snmp_mib_free((void **)udp_statistics); err_udp_mib: snmp_mib_free((void **)tcp_statistics); err_tcp_mib: snmp_mib_free((void **)icmpmsg_statistics); err_icmpmsg_mib: snmp_mib_free((void **)icmp_statistics); err_icmp_mib: snmp_mib_free((void **)ip_statistics); err_ip_mib: snmp_mib_free((void **)net_statistics); err_net_mib: return -ENOMEM; } static int ipv4_proc_init(void); /* * IP protocol layer initialiser */ static struct packet_type ip_packet_type = { .type = __constant_htons(ETH_P_IP), .func = ip_rcv, .gso_send_check = inet_gso_send_check, .gso_segment = inet_gso_segment, }; static int __init inet_init(void) { struct sk_buff *dummy_skb; struct inet_protosw *q; struct list_head *r; int rc = -EINVAL; BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb)); rc = proto_register(&tcp_prot, 1); if (rc) goto out; rc = proto_register(&udp_prot, 1); if (rc) goto out_unregister_tcp_proto; rc = proto_register(&raw_prot, 1); if (rc) goto out_unregister_udp_proto; /* * Tell SOCKET that we are alive... */ (void)sock_register(&inet_family_ops); /* * Add all the base protocols. */ if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0) printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n"); if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0) printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n"); if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0) printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n"); #ifdef CONFIG_IP_MULTICAST if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0) printk(KERN_CRIT "inet_init: Cannot add IGMP protocol\n"); #endif /* Register the socket-side information for inet_create. */ for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r) INIT_LIST_HEAD(r); for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q) inet_register_protosw(q); /* * Set the ARP module up */ arp_init(); /* * Set the IP module up */ ip_init(); tcp_v4_init(&inet_family_ops); /* Setup TCP slab cache for open requests. */ tcp_init(); /* Setup UDP memory threshold */ udp_init(); /* Add UDP-Lite (RFC 3828) */ udplite4_register(); /* * Set the ICMP layer up */ icmp_init(&inet_family_ops); /* * Initialise the multicast router */ #if defined(CONFIG_IP_MROUTE) ip_mr_init(); #endif /* * Initialise per-cpu ipv4 mibs */ if (init_ipv4_mibs()) printk(KERN_CRIT "inet_init: Cannot init ipv4 mibs\n"); ; ipv4_proc_init(); ipfrag_init(); dev_add_pack(&ip_packet_type); rc = 0; out: return rc; out_unregister_udp_proto: proto_unregister(&udp_prot); out_unregister_tcp_proto: proto_unregister(&tcp_prot); goto out; } fs_initcall(inet_init); /* ------------------------------------------------------------------------ */ #ifdef CONFIG_PROC_FS static int __init ipv4_proc_init(void) { int rc = 0; if (raw_proc_init()) goto out_raw; if (tcp4_proc_init()) goto out_tcp; if (udp4_proc_init()) goto out_udp; if (ip_misc_proc_init()) goto out_misc; out: return rc; out_misc: udp4_proc_exit(); out_udp: tcp4_proc_exit(); out_tcp: raw_proc_exit(); out_raw: rc = -ENOMEM; goto out; } #else /* CONFIG_PROC_FS */ static int __init ipv4_proc_init(void) { return 0; } #endif /* CONFIG_PROC_FS */ MODULE_ALIAS_NETPROTO(PF_INET); EXPORT_SYMBOL(inet_accept); EXPORT_SYMBOL(inet_bind); EXPORT_SYMBOL(inet_dgram_connect); EXPORT_SYMBOL(inet_dgram_ops); EXPORT_SYMBOL(inet_getname); EXPORT_SYMBOL(inet_ioctl); EXPORT_SYMBOL(inet_listen); EXPORT_SYMBOL(inet_register_protosw); EXPORT_SYMBOL(inet_release); EXPORT_SYMBOL(inet_sendmsg); EXPORT_SYMBOL(inet_shutdown); EXPORT_SYMBOL(inet_sock_destruct); EXPORT_SYMBOL(inet_stream_connect); EXPORT_SYMBOL(inet_stream_ops); EXPORT_SYMBOL(inet_unregister_protosw); EXPORT_SYMBOL(net_statistics); EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);