/* * 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. * * Generic socket support routines. Memory allocators, socket lock/release * handler for protocols to use and generic option handler. * * * Version: $Id: sock.c,v 1.86 1999/09/01 08:11:49 davem Exp $ * * Authors: Ross Biro, * Fred N. van Kempen, * Florian La Roche, * Alan Cox, * * Fixes: * Alan Cox : Numerous verify_area() problems * Alan Cox : Connecting on a connecting socket * now returns an error for tcp. * Alan Cox : sock->protocol is set correctly. * and is not sometimes left as 0. * Alan Cox : connect handles icmp errors on a * connect properly. Unfortunately there * is a restart syscall nasty there. I * can't match BSD without hacking the C * library. Ideas urgently sought! * Alan Cox : Disallow bind() to addresses that are * not ours - especially broadcast ones!! * Alan Cox : Socket 1024 _IS_ ok for users. (fencepost) * Alan Cox : sock_wfree/sock_rfree don't destroy sockets, * instead they leave that for the DESTROY timer. * Alan Cox : Clean up error flag in accept * Alan Cox : TCP ack handling is buggy, the DESTROY timer * was buggy. Put a remove_sock() in the handler * for memory when we hit 0. Also altered the timer * code. The ACK stuff can wait and needs major * TCP layer surgery. * Alan Cox : Fixed TCP ack bug, removed remove sock * and fixed timer/inet_bh race. * Alan Cox : Added zapped flag for TCP * Alan Cox : Move kfree_skb into skbuff.c and tidied up surplus code * Alan Cox : for new sk_buff allocations wmalloc/rmalloc now call alloc_skb * Alan Cox : kfree_s calls now are kfree_skbmem so we can track skb resources * Alan Cox : Supports socket option broadcast now as does udp. Packet and raw need fixing. * Alan Cox : Added RCVBUF,SNDBUF size setting. It suddenly occurred to me how easy it was so... * Rick Sladkey : Relaxed UDP rules for matching packets. * C.E.Hawkins : IFF_PROMISC/SIOCGHWADDR support * Pauline Middelink : identd support * Alan Cox : Fixed connect() taking signals I think. * Alan Cox : SO_LINGER supported * Alan Cox : Error reporting fixes * Anonymous : inet_create tidied up (sk->reuse setting) * Alan Cox : inet sockets don't set sk->type! * Alan Cox : Split socket option code * Alan Cox : Callbacks * Alan Cox : Nagle flag for Charles & Johannes stuff * Alex : Removed restriction on inet fioctl * Alan Cox : Splitting INET from NET core * Alan Cox : Fixed bogus SO_TYPE handling in getsockopt() * Adam Caldwell : Missing return in SO_DONTROUTE/SO_DEBUG code * Alan Cox : Split IP from generic code * Alan Cox : New kfree_skbmem() * Alan Cox : Make SO_DEBUG superuser only. * Alan Cox : Allow anyone to clear SO_DEBUG * (compatibility fix) * Alan Cox : Added optimistic memory grabbing for AF_UNIX throughput. * Alan Cox : Allocator for a socket is settable. * Alan Cox : SO_ERROR includes soft errors. * Alan Cox : Allow NULL arguments on some SO_ opts * Alan Cox : Generic socket allocation to make hooks * easier (suggested by Craig Metz). * Michael Pall : SO_ERROR returns positive errno again * Steve Whitehouse: Added default destructor to free * protocol private data. * Steve Whitehouse: Added various other default routines * common to several socket families. * Chris Evans : Call suser() check last on F_SETOWN * Jay Schulist : Added SO_ATTACH_FILTER and SO_DETACH_FILTER. * Andi Kleen : Add sock_kmalloc()/sock_kfree_s() * Andi Kleen : Fix write_space callback * * To Fix: * * * 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 #ifdef CONFIG_FILTER #include #endif #define min(a,b) ((a)<(b)?(a):(b)) /* Run time adjustable parameters. */ __u32 sysctl_wmem_max = SK_WMEM_MAX; __u32 sysctl_rmem_max = SK_RMEM_MAX; __u32 sysctl_wmem_default = SK_WMEM_MAX; __u32 sysctl_rmem_default = SK_RMEM_MAX; /* Maximal space eaten by iovec or ancilliary data plus some space */ int sysctl_optmem_max = sizeof(unsigned long)*(2*UIO_MAXIOV + 512); /* * This is meant for all protocols to use and covers goings on * at the socket level. Everything here is generic. */ int sock_setsockopt(struct socket *sock, int level, int optname, char *optval, int optlen) { struct sock *sk=sock->sk; #ifdef CONFIG_FILTER struct sk_filter *filter; #endif int val; int valbool; int err; struct linger ling; int ret = 0; /* * Options without arguments */ #ifdef SO_DONTLINGER /* Compatibility item... */ switch(optname) { case SO_DONTLINGER: sk->linger=0; return 0; } #endif if(optlendebug=valbool; break; case SO_REUSEADDR: sk->reuse = valbool; break; case SO_TYPE: case SO_ERROR: ret = -ENOPROTOOPT; break; case SO_DONTROUTE: sk->localroute=valbool; break; case SO_BROADCAST: sk->broadcast=valbool; break; case SO_SNDBUF: /* Don't error on this BSD doesn't and if you think about it this is right. Otherwise apps have to play 'guess the biggest size' games. RCVBUF/SNDBUF are treated in BSD as hints */ if (val > sysctl_wmem_max) val = sysctl_wmem_max; sk->sndbuf = max(val*2,2048); /* * Wake up sending tasks if we * upped the value. */ sk->write_space(sk); break; case SO_RCVBUF: /* Don't error on this BSD doesn't and if you think about it this is right. Otherwise apps have to play 'guess the biggest size' games. RCVBUF/SNDBUF are treated in BSD as hints */ if (val > sysctl_rmem_max) val = sysctl_rmem_max; /* FIXME: is this lower bound the right one? */ sk->rcvbuf = max(val*2,256); break; case SO_KEEPALIVE: #ifdef CONFIG_INET if (sk->protocol == IPPROTO_TCP) { tcp_set_keepalive(sk, valbool); } #endif sk->keepopen = valbool; break; case SO_OOBINLINE: sk->urginline = valbool; break; case SO_NO_CHECK: sk->no_check = valbool; break; case SO_PRIORITY: if ((val >= 0 && val <= 6) || capable(CAP_NET_ADMIN)) sk->priority = val; else ret = -EPERM; break; case SO_LINGER: if(optlenlinger=0; else { sk->lingertime=ling.l_linger; sk->linger=1; } break; case SO_BSDCOMPAT: sk->bsdism = valbool; break; case SO_PASSCRED: sock->passcred = valbool; break; #ifdef CONFIG_NETDEVICES case SO_BINDTODEVICE: { char devname[IFNAMSIZ]; /* Sorry... */ if (!capable(CAP_NET_RAW)) { ret = -EPERM; break; } /* Bind this socket to a particular device like "eth0", * as specified in the passed interface name. If the * name is "" or the option length is zero the socket * is not bound. */ if (!valbool) { sk->bound_dev_if = 0; } else { if (optlen > IFNAMSIZ) optlen = IFNAMSIZ; if (copy_from_user(devname, optval, optlen)) { ret = -EFAULT; break; } /* Remove any cached route for this socket. */ sk_dst_reset(sk); if (devname[0] == '\0') { sk->bound_dev_if = 0; } else { struct net_device *dev = dev_get_by_name(devname); if (!dev) { ret = -ENODEV; break; } sk->bound_dev_if = dev->ifindex; dev_put(dev); } } break; } #endif #ifdef CONFIG_FILTER case SO_ATTACH_FILTER: ret = -EINVAL; if (optlen == sizeof(struct sock_fprog)) { struct sock_fprog fprog; ret = -EFAULT; if (copy_from_user(&fprog, optval, sizeof(fprog))) break; ret = sk_attach_filter(&fprog, sk); } break; case SO_DETACH_FILTER: spin_lock_bh(&sk->lock.slock); filter = sk->filter; if (filter) { sk->filter = NULL; spin_unlock_bh(&sk->lock.slock); sk_filter_release(sk, filter); break; } spin_unlock_bh(&sk->lock.slock); ret = -ENONET; break; #endif /* We implement the SO_SNDLOWAT etc to not be settable (1003.1g 5.3) */ default: ret = -ENOPROTOOPT; break; } release_sock(sk); return ret; } int sock_getsockopt(struct socket *sock, int level, int optname, char *optval, int *optlen) { struct sock *sk = sock->sk; union { int val; struct linger ling; struct timeval tm; } v; int lv=sizeof(int),len; if(get_user(len,optlen)) return -EFAULT; switch(optname) { case SO_DEBUG: v.val = sk->debug; break; case SO_DONTROUTE: v.val = sk->localroute; break; case SO_BROADCAST: v.val= sk->broadcast; break; case SO_SNDBUF: v.val=sk->sndbuf; break; case SO_RCVBUF: v.val =sk->rcvbuf; break; case SO_REUSEADDR: v.val = sk->reuse; break; case SO_KEEPALIVE: v.val = sk->keepopen; break; case SO_TYPE: v.val = sk->type; break; case SO_ERROR: v.val = -sock_error(sk); if(v.val==0) v.val=xchg(&sk->err_soft,0); break; case SO_OOBINLINE: v.val = sk->urginline; break; case SO_NO_CHECK: v.val = sk->no_check; break; case SO_PRIORITY: v.val = sk->priority; break; case SO_LINGER: lv=sizeof(v.ling); v.ling.l_onoff=sk->linger; v.ling.l_linger=sk->lingertime; break; case SO_BSDCOMPAT: v.val = sk->bsdism; break; case SO_RCVTIMEO: case SO_SNDTIMEO: lv=sizeof(struct timeval); v.tm.tv_sec=0; v.tm.tv_usec=0; break; case SO_RCVLOWAT: case SO_SNDLOWAT: v.val=1; break; case SO_PASSCRED: v.val = sock->passcred; break; case SO_PEERCRED: lv=sizeof(sk->peercred); len=min(len, lv); if(copy_to_user((void*)optval, &sk->peercred, len)) return -EFAULT; goto lenout; default: return(-ENOPROTOOPT); } len=min(len,lv); if(copy_to_user(optval,&v,len)) return -EFAULT; lenout: if(put_user(len, optlen)) return -EFAULT; return 0; } static kmem_cache_t *sk_cachep; /* * All socket objects are allocated here. This is for future * usage. */ struct sock *sk_alloc(int family, int priority, int zero_it) { struct sock *sk = kmem_cache_alloc(sk_cachep, priority); if(sk && zero_it) { memset(sk, 0, sizeof(struct sock)); sk->family = family; sock_lock_init(sk); } return sk; } void sk_free(struct sock *sk) { #ifdef CONFIG_FILTER struct sk_filter *filter; #endif if (sk->destruct) sk->destruct(sk); #ifdef CONFIG_FILTER filter = sk->filter; if (filter) { sk_filter_release(sk, filter); sk->filter = NULL; } #endif if (atomic_read(&sk->omem_alloc)) printk(KERN_DEBUG "sk_free: optmem leakage (%d bytes) detected.\n", atomic_read(&sk->omem_alloc)); kmem_cache_free(sk_cachep, sk); } void __init sk_init(void) { sk_cachep = kmem_cache_create("sock", sizeof(struct sock), 0, SLAB_HWCACHE_ALIGN, 0, 0); } /* * Simple resource managers for sockets. */ /* * Write buffer destructor automatically called from kfree_skb. */ void sock_wfree(struct sk_buff *skb) { struct sock *sk = skb->sk; /* In case it might be waiting for more memory. */ atomic_sub(skb->truesize, &sk->wmem_alloc); sk->write_space(sk); sock_put(sk); } /* * Read buffer destructor automatically called from kfree_skb. */ void sock_rfree(struct sk_buff *skb) { struct sock *sk = skb->sk; atomic_sub(skb->truesize, &sk->rmem_alloc); } void sock_cfree(struct sk_buff *skb) { sock_put(skb->sk); } /* * Allocate a skb from the socket's send buffer. */ struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force, int priority) { if (force || atomic_read(&sk->wmem_alloc) < sk->sndbuf) { struct sk_buff * skb = alloc_skb(size, priority); if (skb) { skb_set_owner_w(skb, sk); return skb; } } return NULL; } /* * Allocate a skb from the socket's receive buffer. */ struct sk_buff *sock_rmalloc(struct sock *sk, unsigned long size, int force, int priority) { if (force || atomic_read(&sk->rmem_alloc) < sk->rcvbuf) { struct sk_buff *skb = alloc_skb(size, priority); if (skb) { skb_set_owner_r(skb, sk); return skb; } } return NULL; } /* * Allocate a memory block from the socket's option memory buffer. */ void *sock_kmalloc(struct sock *sk, int size, int priority) { if ((unsigned)size <= sysctl_optmem_max && atomic_read(&sk->omem_alloc)+size < sysctl_optmem_max) { void *mem; /* First do the add, to avoid the race if kmalloc * might sleep. */ atomic_add(size, &sk->omem_alloc); mem = kmalloc(size, priority); if (mem) return mem; atomic_sub(size, &sk->omem_alloc); } return NULL; } /* * Free an option memory block. */ void sock_kfree_s(struct sock *sk, void *mem, int size) { kfree_s(mem, size); atomic_sub(size, &sk->omem_alloc); } /* FIXME: this is insane. We are trying suppose to be controlling how * how much space we have for data bytes, not packet headers. * This really points out that we need a better system for doing the * receive buffer. -- erics * WARNING: This is currently ONLY used in tcp. If you need it else where * this will probably not be what you want. Possibly these two routines * should move over to the ipv4 directory. */ unsigned long sock_rspace(struct sock *sk) { int amt = 0; if (sk != NULL) { /* This used to have some bizarre complications that * to attempt to reserve some amount of space. This doesn't * make sense, since the number returned here does not * actually reflect allocated space, but rather the amount * of space we committed to. We gamble that we won't * run out of memory, and returning a smaller number does * not change the gamble. If we lose the gamble tcp still * works, it may just slow down for retransmissions. */ amt = sk->rcvbuf - atomic_read(&sk->rmem_alloc); if (amt < 0) amt = 0; } return amt; } /* It is almost wait_for_tcp_memory minus release_sock/lock_sock. I think, these locks should be removed for datagram sockets. */ static void sock_wait_for_wmem(struct sock * sk) { DECLARE_WAITQUEUE(wait, current); sk->socket->flags &= ~SO_NOSPACE; add_wait_queue(sk->sleep, &wait); for (;;) { if (signal_pending(current)) break; set_current_state(TASK_INTERRUPTIBLE); if (atomic_read(&sk->wmem_alloc) < sk->sndbuf) break; if (sk->shutdown & SEND_SHUTDOWN) break; if (sk->err) break; schedule(); } __set_current_state(TASK_RUNNING); remove_wait_queue(sk->sleep, &wait); } /* * Generic send/receive buffer handlers */ struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size, unsigned long fallback, int noblock, int *errcode) { int err; struct sk_buff *skb; while (1) { unsigned long try_size = size; err = sock_error(sk); if (err != 0) goto failure; /* * We should send SIGPIPE in these cases according to * 1003.1g draft 6.4. If we (the user) did a shutdown() * call however we should not. * * Note: This routine isnt just used for datagrams and * anyway some datagram protocols have a notion of * close down. */ err = -EPIPE; if (sk->shutdown&SEND_SHUTDOWN) goto failure; if (fallback) { /* The buffer get won't block, or use the atomic queue. * It does produce annoying no free page messages still. */ skb = sock_wmalloc(sk, size, 0, GFP_BUFFER); if (skb) break; try_size = fallback; } skb = sock_wmalloc(sk, try_size, 0, sk->allocation); if (skb) break; /* * This means we have too many buffers for this socket already. */ sk->socket->flags |= SO_NOSPACE; err = -EAGAIN; if (noblock) goto failure; err = -ERESTARTSYS; if (signal_pending(current)) goto failure; sock_wait_for_wmem(sk); } return skb; failure: *errcode = err; return NULL; } void __lock_sock(struct sock *sk) { DECLARE_WAITQUEUE(wait, current); add_wait_queue_exclusive(&sk->lock.wq, &wait); for(;;) { current->state = TASK_EXCLUSIVE | TASK_UNINTERRUPTIBLE; spin_unlock_bh(&sk->lock.slock); schedule(); spin_lock_bh(&sk->lock.slock); if(!sk->lock.users) break; } current->state = TASK_RUNNING; remove_wait_queue(&sk->lock.wq, &wait); } void __release_sock(struct sock *sk) { struct sk_buff *skb = sk->backlog.head; do { struct sk_buff *next = skb->next; skb->next = NULL; sk->backlog_rcv(sk, skb); skb = next; } while(skb != NULL); sk->backlog.head = sk->backlog.tail = NULL; } /* * Generic socket manager library. Most simpler socket families * use this to manage their socket lists. At some point we should * hash these. By making this generic we get the lot hashed for free. * * It is broken by design. All the protocols using it must be fixed. --ANK */ rwlock_t net_big_sklist_lock = RW_LOCK_UNLOCKED; void sklist_remove_socket(struct sock **list, struct sock *sk) { struct sock *s; write_lock_bh(&net_big_sklist_lock); s= *list; if(s==sk) { *list = s->next; write_unlock_bh(&net_big_sklist_lock); sock_put(sk); return; } while(s && s->next) { if(s->next==sk) { s->next=sk->next; break; } s=s->next; } write_unlock_bh(&net_big_sklist_lock); } void sklist_insert_socket(struct sock **list, struct sock *sk) { write_lock_bh(&net_big_sklist_lock); sk->next= *list; *list=sk; sock_hold(sk); write_unlock_bh(&net_big_sklist_lock); } /* * This is only called from user mode. Thus it protects itself against * interrupt users but doesn't worry about being called during work. * Once it is removed from the queue no interrupt or bottom half will * touch it and we are (fairly 8-) ) safe. */ void sklist_destroy_socket(struct sock **list, struct sock *sk); /* * Handler for deferred kills. */ static void sklist_destroy_timer(unsigned long data) { struct sock *sk=(struct sock *)data; sklist_destroy_socket(NULL,sk); } /* * Destroy a socket. We pass NULL for a list if we know the * socket is not on a list. */ void sklist_destroy_socket(struct sock **list,struct sock *sk) { struct sk_buff *skb; if(list) sklist_remove_socket(list, sk); while((skb=skb_dequeue(&sk->receive_queue))!=NULL) { kfree_skb(skb); } if(atomic_read(&sk->wmem_alloc) == 0 && atomic_read(&sk->rmem_alloc) == 0 && sk->dead) { sock_put(sk); } else { /* * Someone is using our buffers still.. defer */ init_timer(&sk->timer); sk->timer.expires=jiffies+SOCK_DESTROY_TIME; sk->timer.function=sklist_destroy_timer; sk->timer.data = (unsigned long)sk; add_timer(&sk->timer); } } /* * Set of default routines for initialising struct proto_ops when * the protocol does not support a particular function. In certain * cases where it makes no sense for a protocol to have a "do nothing" * function, some default processing is provided. */ int sock_no_release(struct socket *sock) { return 0; } int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len) { return -EOPNOTSUPP; } int sock_no_connect(struct socket *sock, struct sockaddr *saddr, int len, int flags) { return -EOPNOTSUPP; } int sock_no_socketpair(struct socket *sock1, struct socket *sock2) { return -EOPNOTSUPP; } int sock_no_accept(struct socket *sock, struct socket *newsock, int flags) { return -EOPNOTSUPP; } int sock_no_getname(struct socket *sock, struct sockaddr *saddr, int *len, int peer) { return -EOPNOTSUPP; } unsigned int sock_no_poll(struct file * file, struct socket *sock, poll_table *pt) { return 0; } int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) { return -EOPNOTSUPP; } int sock_no_listen(struct socket *sock, int backlog) { return -EOPNOTSUPP; } int sock_no_shutdown(struct socket *sock, int how) { return -EOPNOTSUPP; } int sock_no_setsockopt(struct socket *sock, int level, int optname, char *optval, int optlen) { return -EOPNOTSUPP; } int sock_no_getsockopt(struct socket *sock, int level, int optname, char *optval, int *optlen) { return -EOPNOTSUPP; } /* * Note: if you add something that sleeps here then change sock_fcntl() * to do proper fd locking. */ int sock_no_fcntl(struct socket *sock, unsigned int cmd, unsigned long arg) { struct sock *sk = sock->sk; switch(cmd) { case F_SETOWN: /* * This is a little restrictive, but it's the only * way to make sure that you can't send a sigurg to * another process. */ if (current->pgrp != -arg && current->pid != arg && !capable(CAP_KILL)) return(-EPERM); sk->proc = arg; return(0); case F_GETOWN: return(sk->proc); default: return(-EINVAL); } } int sock_no_sendmsg(struct socket *sock, struct msghdr *m, int flags, struct scm_cookie *scm) { return -EOPNOTSUPP; } int sock_no_recvmsg(struct socket *sock, struct msghdr *m, int flags, struct scm_cookie *scm) { return -EOPNOTSUPP; } int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma) { /* Mirror missing mmap method error code */ return -ENODEV; } /* * Default Socket Callbacks */ void sock_def_wakeup(struct sock *sk) { read_lock(&sk->callback_lock); if(!sk->dead) wake_up_interruptible(sk->sleep); read_unlock(&sk->callback_lock); } void sock_def_error_report(struct sock *sk) { read_lock(&sk->callback_lock); if (!sk->dead) { wake_up_interruptible(sk->sleep); sock_wake_async(sk->socket,0); } read_unlock(&sk->callback_lock); } void sock_def_readable(struct sock *sk, int len) { read_lock(&sk->callback_lock); if(!sk->dead) { wake_up_interruptible(sk->sleep); sock_wake_async(sk->socket,1); } read_unlock(&sk->callback_lock); } void sock_def_write_space(struct sock *sk) { read_lock(&sk->callback_lock); /* Do not wake up a writer until he can make "significant" * progress. --DaveM */ if(!sk->dead && ((atomic_read(&sk->wmem_alloc) << 1) <= sk->sndbuf)) { wake_up_interruptible(sk->sleep); /* Should agree with poll, otherwise some programs break */ if (sock_writeable(sk)) sock_wake_async(sk->socket, 2); } read_unlock(&sk->callback_lock); } void sock_def_destruct(struct sock *sk) { if (sk->protinfo.destruct_hook) kfree(sk->protinfo.destruct_hook); } void sock_init_data(struct socket *sock, struct sock *sk) { skb_queue_head_init(&sk->receive_queue); skb_queue_head_init(&sk->write_queue); skb_queue_head_init(&sk->error_queue); spin_lock_init(&sk->timer_lock); init_timer(&sk->timer); sk->allocation = GFP_KERNEL; sk->rcvbuf = sysctl_rmem_default; sk->sndbuf = sysctl_wmem_default; sk->state = TCP_CLOSE; sk->zapped = 1; sk->socket = sock; if(sock) { sk->type = sock->type; sk->sleep = &sock->wait; sock->sk = sk; } else sk->sleep = NULL; sk->callback_lock = RW_LOCK_UNLOCKED; sk->state_change = sock_def_wakeup; sk->data_ready = sock_def_readable; sk->write_space = sock_def_write_space; sk->error_report = sock_def_error_report; sk->destruct = sock_def_destruct; sk->peercred.pid = 0; sk->peercred.uid = -1; sk->peercred.gid = -1; atomic_set(&sk->refcnt, 1); }