-/*
- * NET3: Implementation of BSD Unix domain sockets.
- *
- * Authors: Alan Cox, <alan@cymru.net>
- *
- * Currently this contains all but the file descriptor passing code.
- * Before that goes in the odd bugs in the iovec handlers need
- * fixing, and this bit testing. BSD fd passing is not a trivial part
- * of the exercise it turns out. Anyone like writing garbage collectors.
- *
- * 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.
- *
- * Fixes:
- * Linus Torvalds : Assorted bug cures.
- * Niibe Yutaka : async I/O support.
- * Carsten Paeth : PF_UNIX check, address fixes.
- * Alan Cox : Limit size of allocated blocks.
- */
-
-#include <linux/config.h>
-#include <linux/kernel.h>
-#include <linux/major.h>
-#include <linux/signal.h>
-#include <linux/sched.h>
-#include <linux/errno.h>
-#include <linux/string.h>
-#include <linux/stat.h>
-#include <linux/socket.h>
-#include <linux/un.h>
-#include <linux/fcntl.h>
-#include <linux/termios.h>
-#include <linux/socket.h>
-#include <linux/sockios.h>
-#include <linux/net.h>
-#include <linux/in.h>
-#include <linux/fs.h>
-#include <linux/malloc.h>
-#include <asm/segment.h>
-#include <linux/skbuff.h>
-#include <linux/netdevice.h>
-#include <net/sock.h>
-#include <net/tcp.h>
-#include <net/af_unix.h>
-#include <linux/proc_fs.h>
-
-static unix_socket *volatile unix_socket_list=NULL;
-
-#define min(a,b) (((a)<(b))?(a):(b))
-
-/*
- * Make sure the unix name is null-terminated.
- */
-static inline void unix_mkname(struct sockaddr_un * sun, unsigned long len)
-{
- if (len >= sizeof(*sun))
- len = sizeof(*sun)-1;
- ((char *)sun)[len]=0;
-}
-
-/*
- * Note: Sockets may not be removed _during_ an interrupt or net_bh
- * handler using this technique. They can be added although we do not
- * use this facility.
- */
-
-static void unix_remove_socket(unix_socket *sk)
-{
- unix_socket *s;
-
- cli();
- s=unix_socket_list;
- if(s==sk)
- {
- unix_socket_list=s->next;
- sti();
- return;
- }
- while(s && s->next)
- {
- if(s->next==sk)
- {
- s->next=sk->next;
- sti();
- return;
- }
- s=s->next;
- }
- sti();
-}
-
-static void unix_insert_socket(unix_socket *sk)
-{
- cli();
- sk->next=unix_socket_list;
- unix_socket_list=sk;
- sti();
-}
-
-static unix_socket *unix_find_socket(struct inode *i)
-{
- unix_socket *s;
- cli();
- s=unix_socket_list;
- while(s)
- {
- if(s->protinfo.af_unix.inode==i)
- {
- sti();
- return(s);
- }
- s=s->next;
- }
- sti();
- return(NULL);
-}
-
-/*
- * Delete a unix socket. We have to allow for deferring this on a timer.
- */
-
-static void unix_destroy_timer(unsigned long data)
-{
- unix_socket *sk=(unix_socket *)data;
- if(sk->protinfo.af_unix.locks==0 && sk->wmem_alloc==0)
- {
- if(sk->protinfo.af_unix.name)
- kfree(sk->protinfo.af_unix.name);
- kfree_s(sk,sizeof(*sk));
- return;
- }
-
- /*
- * Retry;
- */
-
- sk->timer.expires=jiffies+10*HZ; /* No real hurry try it every 10 seconds or so */
- add_timer(&sk->timer);
-}
-
-
-static void unix_delayed_delete(unix_socket *sk)
-{
- sk->timer.data=(unsigned long)sk;
- sk->timer.expires=jiffies+HZ; /* Normally 1 second after will clean up. After that we try every 10 */
- sk->timer.function=unix_destroy_timer;
- add_timer(&sk->timer);
-}
-
-static void unix_destroy_socket(unix_socket *sk)
-{
- struct sk_buff *skb;
- unix_remove_socket(sk);
-
- while((skb=skb_dequeue(&sk->receive_queue))!=NULL)
- {
- if(sk->state==TCP_LISTEN)
- {
- unix_socket *osk=skb->sk;
- osk->state=TCP_CLOSE;
- kfree_skb(skb, FREE_WRITE); /* Now surplus - free the skb first before the socket */
- osk->state_change(osk); /* So the connect wakes and cleans up (if any) */
- /* osk will be destroyed when it gets to close or the timer fires */
- }
- else
- {
-/* unix_kill_credentials(skb); *//* Throw out any passed fd's */
- kfree_skb(skb,FREE_WRITE);
- }
- }
-
- if(sk->protinfo.af_unix.inode!=NULL)
- {
- iput(sk->protinfo.af_unix.inode);
- sk->protinfo.af_unix.inode=NULL;
- }
-
- if(--sk->protinfo.af_unix.locks==0 && sk->wmem_alloc==0)
- {
- if(sk->protinfo.af_unix.name)
- kfree(sk->protinfo.af_unix.name);
- kfree_s(sk,sizeof(*sk));
- }
- else
- {
- sk->dead=1;
- unix_delayed_delete(sk); /* Try every so often until buffers are all freed */
- }
-}
-
-/*
- * Fixme: We need async I/O on AF_UNIX doing next.
- */
-
-static int unix_fcntl(struct socket *sock, unsigned int cmd, unsigned long arg)
-{
- return -EINVAL;
-}
-
-/*
- * Yes socket options work with the new unix domain socketry!!!!!!!
- */
-
-static int unix_setsockopt(struct socket *sock, int level, int optname, char *optval, int optlen)
-{
- unix_socket *sk=sock->data;
- if(level!=SOL_SOCKET)
- return -EOPNOTSUPP;
- return sock_setsockopt(sk,level,optname,optval,optlen);
-}
-
-static int unix_getsockopt(struct socket *sock, int level, int optname, char *optval, int *optlen)
-{
- unix_socket *sk=sock->data;
- if(level!=SOL_SOCKET)
- return -EOPNOTSUPP;
- return sock_getsockopt(sk,level,optname,optval,optlen);
-}
-
-static int unix_listen(struct socket *sock, int backlog)
-{
- unix_socket *sk=sock->data;
- if(sk->type!=SOCK_STREAM)
- return -EOPNOTSUPP; /* Only stream sockets accept */
- sk->max_ack_backlog=backlog;
- sk->state=TCP_LISTEN;
- return 0;
-}
-
-static void def_callback1(struct sock *sk)
-{
- if(!sk->dead)
- wake_up_interruptible(sk->sleep);
-}
-
-static void def_callback2(struct sock *sk, int len)
-{
- if(!sk->dead)
- {
- wake_up_interruptible(sk->sleep);
- sock_wake_async(sk->socket, 1);
- }
-}
-
-static void def_callback3(struct sock *sk)
-{
- if(!sk->dead)
- {
- wake_up_interruptible(sk->sleep);
- sock_wake_async(sk->socket, 2);
- }
-}
-
-static int unix_create(struct socket *sock, int protocol)
-{
- unix_socket *sk;
-/* printk("Unix create\n");*/
- if(protocol && protocol != PF_UNIX)
- return -EPROTONOSUPPORT;
- sk=(unix_socket *)kmalloc(sizeof(*sk),GFP_KERNEL);
- if(sk==NULL)
- return -ENOMEM;
- sk->type=sock->type;
- switch(sock->type)
- {
- case SOCK_STREAM:
- break;
- case SOCK_DGRAM:
- break;
- default:
- kfree_s(sk,sizeof(*sk));
- return -ESOCKTNOSUPPORT;
- }
- init_timer(&sk->timer);
- skb_queue_head_init(&sk->write_queue);
- skb_queue_head_init(&sk->receive_queue);
- skb_queue_head_init(&sk->back_log);
- sk->protinfo.af_unix.family=AF_UNIX;
- sk->protinfo.af_unix.inode=NULL;
- sk->protinfo.af_unix.locks=1; /* Us */
- sk->protinfo.af_unix.readsem=MUTEX; /* single task reading lock */
- sk->protinfo.af_unix.name=NULL;
- sk->protinfo.af_unix.other=NULL;
- sk->protocol=0;
- sk->rmem_alloc=0;
- sk->wmem_alloc=0;
- sk->dead=0;
- sk->next=NULL;
- sk->broadcast=0;
- sk->rcvbuf=SK_RMEM_MAX;
- sk->sndbuf=SK_WMEM_MAX;
- sk->inuse=0;
- sk->debug=0;
- sk->prot=NULL;
- sk->err=0;
- sk->localroute=0;
- sk->send_head=NULL;
- sk->state=TCP_CLOSE;
- sk->priority=SOPRI_NORMAL;
- sk->ack_backlog=0;
- sk->shutdown=0;
- sk->state_change=def_callback1;
- sk->data_ready=def_callback2;
- sk->write_space=def_callback3;
- sk->error_report=def_callback1;
- sk->mtu=4096;
- sk->socket=sock;
- sock->data=(void *)sk;
- sk->sleep=sock->wait;
- sk->zapped=0;
- unix_insert_socket(sk);
- return 0;
-}
-
-static int unix_dup(struct socket *newsock, struct socket *oldsock)
-{
- return unix_create(newsock,0);
-}
-
-static int unix_release(struct socket *sock, struct socket *peer)
-{
- unix_socket *sk=sock->data;
- unix_socket *skpair;
-
- /* May not have data attached */
-
- if(sk==NULL)
- return 0;
-
- sk->state_change(sk);
- sk->dead=1;
- skpair=(unix_socket *)sk->protinfo.af_unix.other; /* Person we send to (default) */
- if(sk->type==SOCK_STREAM && skpair!=NULL && skpair->state!=TCP_LISTEN)
- {
- skpair->shutdown=SHUTDOWN_MASK; /* No more writes */
- skpair->state_change(skpair); /* Wake any blocked writes */
- }
- if(skpair!=NULL)
- skpair->protinfo.af_unix.locks--; /* It may now die */
- sk->protinfo.af_unix.other=NULL; /* No pair */
- unix_destroy_socket(sk); /* Try and flush out this socket. Throw our buffers at least */
- return 0;
-}
-
-
-static unix_socket *unix_find_other(char *path, int *error)
-{
- int old_fs;
- int err;
- struct inode *inode;
- unix_socket *u;
-
- old_fs=get_fs();
- set_fs(get_ds());
- err = open_namei(path, 2, S_IFSOCK, &inode, NULL);
- set_fs(old_fs);
- if(err<0)
- {
- *error=err;
- return NULL;
- }
- u=unix_find_socket(inode);
- iput(inode);
- if(u==NULL)
- {
- *error=-ECONNREFUSED;
- return NULL;
- }
- return u;
-}
-
-
-static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
-{
- struct sockaddr_un *sun=(struct sockaddr_un *)uaddr;
- unix_socket *sk=sock->data;
- int old_fs;
- int err;
-
- if(addr_len>sizeof(struct sockaddr_un) || addr_len<3 || sun->sun_family!=AF_UNIX)
- return -EINVAL;
- unix_mkname(sun, addr_len);
- /*
- * Put ourselves in the filesystem
- */
- if(sk->protinfo.af_unix.inode!=NULL)
- return -EINVAL;
-
- sk->protinfo.af_unix.name=kmalloc(addr_len+1, GFP_KERNEL);
- if(sk->protinfo.af_unix.name==NULL)
- return -ENOMEM;
- memcpy(sk->protinfo.af_unix.name, sun->sun_path, addr_len+1);
-
- old_fs=get_fs();
- set_fs(get_ds());
-
- err=do_mknod(sk->protinfo.af_unix.name,S_IFSOCK|S_IRWXUGO,0);
- if(err==0)
- err=open_namei(sk->protinfo.af_unix.name, 2, S_IFSOCK, &sk->protinfo.af_unix.inode, NULL);
-
- set_fs(old_fs);
-
- if(err<0)
- {
- kfree_s(sk->protinfo.af_unix.name,addr_len+1);
- sk->protinfo.af_unix.name=NULL;
- if(err==-EEXIST)
- return -EADDRINUSE;
- else
- return err;
- }
-
- return 0;
-
-}
-
-static int unix_connect(struct socket *sock, struct sockaddr *uaddr, int addr_len, int flags)
-{
- unix_socket *sk=sock->data;
- struct sockaddr_un *sun=(struct sockaddr_un *)uaddr;
- unix_socket *other;
- struct sk_buff *skb;
- int err;
-
- if(sk->type==SOCK_STREAM && sk->protinfo.af_unix.other)
- {
- if(sock->state==SS_CONNECTING && sk->state==TCP_ESTABLISHED)
- {
- sock->state=SS_CONNECTED;
- return 0;
- }
- if(sock->state==SS_CONNECTING && sk->state == TCP_CLOSE)
- {
- sock->state=SS_UNCONNECTED;
- return -ECONNREFUSED;
- }
- if(sock->state==SS_CONNECTING)
- return -EALREADY;
- return -EISCONN;
- }
-
- if(addr_len < sizeof(sun->sun_family)+1 || sun->sun_family!=AF_UNIX)
- return -EINVAL;
-
- unix_mkname(sun, addr_len);
-
- if(sk->type==SOCK_DGRAM && sk->protinfo.af_unix.other)
- {
- sk->protinfo.af_unix.other->protinfo.af_unix.locks--;
- sk->protinfo.af_unix.other=NULL;
- sock->state=SS_UNCONNECTED;
- }
-
- if(sock->type==SOCK_DGRAM)
- {
- other=unix_find_other(sun->sun_path, &err);
- if(other==NULL)
- return err;
- other->protinfo.af_unix.locks++;
- sk->protinfo.af_unix.other=other;
- sock->state=SS_CONNECTED;
- sk->state=TCP_ESTABLISHED;
- return 0; /* Done */
- }
-
-
- if(sock->state==SS_UNCONNECTED)
- {
- /*
- * Now ready to connect
- */
-
- skb=sock_alloc_send_skb(sk, 0, 0, 0, &err); /* Marker object */
- if(skb==NULL)
- return err;
- skb->sk=sk; /* So they know it is us */
- skb->free=1;
- sk->state=TCP_CLOSE;
- unix_mkname(sun, addr_len);
- other=unix_find_other(sun->sun_path, &err);
- if(other==NULL)
- {
- kfree_skb(skb, FREE_WRITE);
- return err;
- }
- other->protinfo.af_unix.locks++; /* Lock the other socket so it doesn't run off for a moment */
- other->ack_backlog++;
- sk->protinfo.af_unix.other=other;
- skb_queue_tail(&other->receive_queue,skb);
- sk->state=TCP_SYN_SENT;
- sock->state=SS_CONNECTING;
- sti();
- other->data_ready(other,0); /* Wake up ! */
- }
-
-
- /* Wait for an accept */
-
- cli();
- while(sk->state==TCP_SYN_SENT)
- {
- if(flags&O_NONBLOCK)
- {
- sti();
- return -EINPROGRESS;
- }
- interruptible_sleep_on(sk->sleep);
- if(current->signal & ~current->blocked)
- {
- sti();
- return -ERESTARTSYS;
- }
- }
-
- /*
- * Has the other end closed on us ?
- */
-
- if(sk->state==TCP_CLOSE)
- {
- sk->protinfo.af_unix.other->protinfo.af_unix.locks--;
- sk->protinfo.af_unix.other=NULL;
- sock->state=SS_UNCONNECTED;
- sti();
- return -ECONNREFUSED;
- }
-
- /*
- * Amazingly it has worked
- */
-
- sock->state=SS_CONNECTED;
- sti();
- return 0;
-
-}
-
-static int unix_socketpair(struct socket *a, struct socket *b)
-{
- int err;
- unix_socket *ska,*skb;
-
- err=unix_create(a, 0);
- if(err)
- return err;
- err=unix_create(b, 0);
- if(err)
- {
- unix_release(a, NULL);
- a->data=NULL;
- return err;
- }
-
- ska=a->data;
- skb=b->data;
-
- /* Join our sockets back to back */
- ska->protinfo.af_unix.locks++;
- skb->protinfo.af_unix.locks++;
- ska->protinfo.af_unix.other=skb;
- skb->protinfo.af_unix.other=ska;
- ska->state=TCP_ESTABLISHED;
- skb->state=TCP_ESTABLISHED;
- return 0;
-}
-
-static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
-{
- unix_socket *sk=sock->data;
- unix_socket *newsk, *tsk;
- struct sk_buff *skb;
-
- if(sk->type!=SOCK_STREAM)
- {
- return -EOPNOTSUPP;
- }
- if(sk->state!=TCP_LISTEN)
- {
- return -EINVAL;
- }
-
- newsk=newsock->data;
- if(sk->protinfo.af_unix.name!=NULL)
- {
- newsk->protinfo.af_unix.name=kmalloc(strlen(sk->protinfo.af_unix.name)+1, GFP_KERNEL);
- if(newsk->protinfo.af_unix.name==NULL)
- return -ENOMEM;
- strcpy(newsk->protinfo.af_unix.name, sk->protinfo.af_unix.name);
- }
-
- do
- {
- cli();
- skb=skb_dequeue(&sk->receive_queue);
- if(skb==NULL)
- {
- if(flags&O_NONBLOCK)
- {
- sti();
- return -EAGAIN;
- }
- interruptible_sleep_on(sk->sleep);
- if(current->signal & ~current->blocked)
- {
- sti();
- return -ERESTARTSYS;
- }
- sti();
- }
- }
- while(skb==NULL);
- tsk=skb->sk;
- kfree_skb(skb, FREE_WRITE); /* The buffer is just used as a tag */
- sk->ack_backlog--;
- newsk->protinfo.af_unix.other=tsk;
- tsk->protinfo.af_unix.other=newsk;
- tsk->state=TCP_ESTABLISHED;
- newsk->state=TCP_ESTABLISHED;
- newsk->protinfo.af_unix.locks++; /* Swap lock over */
- sk->protinfo.af_unix.locks--; /* Locked to child socket not master */
- tsk->protinfo.af_unix.locks++; /* Back lock */
- sti();
- tsk->state_change(tsk); /* Wake up any sleeping connect */
- sock_wake_async(tsk->socket, 0);
- return 0;
-}
-
-static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer)
-{
- unix_socket *sk=sock->data;
- struct sockaddr_un *sun=(struct sockaddr_un *)uaddr;
-
- if(peer)
- {
- if(sk->protinfo.af_unix.other==NULL)
- return -ENOTCONN;
- sk=sk->protinfo.af_unix.other;
- }
- sun->sun_family=AF_UNIX;
- if(sk->protinfo.af_unix.name==NULL)
- {
- *sun->sun_path=0;
- *uaddr_len=sizeof(sun->sun_family)+1;
- return 0; /* Not bound */
- }
- *uaddr_len=sizeof(sun->sun_family)+strlen(sk->protinfo.af_unix.name)+1;
- strcpy(sun->sun_path,sk->protinfo.af_unix.name); /* 108 byte limited */
- return 0;
-}
-
-static int unix_sendmsg(struct socket *sock, struct msghdr *msg, int len, int nonblock, int flags)
-{
- unix_socket *sk=sock->data;
- unix_socket *other;
- struct sockaddr_un *sun=msg->msg_name;
- int err,size;
- struct sk_buff *skb;
- int limit=0;
- int sent=0;
-
- if(sk->err)
- {
- cli();
- err=sk->err;
- sk->err=0;
- sti();
- return -err;
- }
-
- if(flags || msg->msg_accrights) /* For now */
- return -EINVAL;
-
- if(sun!=NULL)
- {
- if(sock->type==SOCK_STREAM)
- {
- if(sk->state==TCP_ESTABLISHED)
- return -EISCONN;
- else
- return -EOPNOTSUPP;
- }
- }
- if(sun==NULL)
- {
- if(sk->protinfo.af_unix.other==NULL)
- return -ENOTCONN;
- }
-
-
- while(sent < len)
- {
- /*
- * Optimisation for the fact that under 0.01% of X messages typically
- * need breaking up.
- */
-
- size=len-sent;
-
- if(size>(sk->sndbuf-sizeof(struct sk_buff))/2) /* Keep two messages in the pipe so it schedules better */
- {
- if(sock->type==SOCK_DGRAM)
- return -EMSGSIZE;
- size=(sk->sndbuf-sizeof(struct sk_buff))/2;
- }
- /*
- * Keep to page sized kmalloc()'s as various people
- * have suggested. Big mallocs stress the vm too
- * much.
- */
-
- if(size > 4000 && sock->type!=SOCK_DGRAM)
- limit = 4000; /* Fall back to 4K if we can't grab a big buffer this instant */
- else
- limit = 0; /* Otherwise just grab and wait */
-
- /*
- * Grab a buffer
- */
-
- skb=sock_alloc_send_skb(sk,size,limit,nonblock, &err);
-
- if(skb==NULL)
- {
- if(sent)
- {
- sk->err=-err;
- return sent;
- }
- return err;
- }
- size=skb_tailroom(skb); /* If we dropped back on a limit then our skb is smaller */
-
- skb->sk=sk;
- skb->free=1;
-
- memcpy_fromiovec(skb_put(skb,size),msg->msg_iov, size);
-
- cli();
- if(sun==NULL)
- {
- other=sk->protinfo.af_unix.other;
- if(sock->type==SOCK_DGRAM && other->dead)
- {
- other->protinfo.af_unix.locks--;
- sk->protinfo.af_unix.other=NULL;
- sock->state=SS_UNCONNECTED;
- sti();
- if(!sent)
- return -ECONNRESET;
- else
- return sent;
- }
- }
- else
- {
- unix_mkname(sun, msg->msg_namelen);
- other=unix_find_other(sun->sun_path, &err);
- if(other==NULL)
- {
- kfree_skb(skb, FREE_WRITE);
- sti();
- if(sent)
- return sent;
- else
- return err;
- }
- }
- skb_queue_tail(&other->receive_queue, skb);
- sti();
- other->data_ready(other,size);
- sent+=size;
- }
- return sent;
-}
-
-static int unix_recvmsg(struct socket *sock, struct msghdr *msg, int size, int noblock, int flags, int *addr_len)
-{
- unix_socket *sk=sock->data;
- struct sockaddr_un *sun=msg->msg_name;
- int err;
- struct sk_buff *skb;
- int copied=0;
- unsigned char *sp;
- int len;
- int num;
- struct iovec *iov=msg->msg_iov;
- int ct=msg->msg_iovlen;
-
- if(addr_len)
- *addr_len=0;
-
- if(sk->err)
- {
- cli();
- err=sk->err;
- sk->err=0;
- sti();
- return -err;
- }
-
-/* printk("get rcv sem\n");*/
- down(&sk->protinfo.af_unix.readsem); /* Lock the socket */
-/* printk("got rcv sem\n");*/
-
- while(ct--)
- {
- int done=0;
- sp=iov->iov_base;
- len=iov->iov_len;
- iov++;
-
- while(done<len)
- {
- if(copied & (flags&MSG_PEEK))
- {
- up(&sk->protinfo.af_unix.readsem);
- return copied;
- }
- cli();
- skb=skb_peek(&sk->receive_queue);
- if(skb==NULL)
- {
- up(&sk->protinfo.af_unix.readsem);
- if(sk->shutdown & RCV_SHUTDOWN)
- {
- sti();
- return copied;
- }
- if(copied)
- {
- sti();
- return copied;
- }
- if(noblock)
- {
- sti();
- return -EAGAIN;
- }
- sk->socket->flags |= SO_WAITDATA;
- interruptible_sleep_on(sk->sleep);
- sk->socket->flags &= ~SO_WAITDATA;
- if( current->signal & ~current->blocked)
- {
- sti();
- if(copied)
- return copied;
- return -ERESTARTSYS;
- }
- sti();
- down(&sk->protinfo.af_unix.readsem);
- continue;
- }
- if(msg->msg_name!=NULL)
- {
- sun->sun_family=AF_UNIX;
- if(skb->sk->protinfo.af_unix.name)
- {
- memcpy(sun->sun_path, skb->sk->protinfo.af_unix.name, 108);
- if(addr_len)
- *addr_len=strlen(sun->sun_path)+sizeof(short);
- }
- else
- if(addr_len)
- *addr_len=sizeof(short);
- }
- num=min(skb->len,size-copied);
- copied+=num;
- done+=num;
- if(flags&MSG_PEEK)
- {
- memcpy_tofs(sp, skb->data, num);
- break;
- }
- else
- {
- memcpy_tofs(sp, skb->data,num);
- skb_pull(skb,num);
- sp+=num;
- if(skb->len==0)
- {
- skb_unlink(skb);
- kfree_skb(skb, FREE_WRITE);
- if(sock->type==SOCK_DGRAM)
- break;
- }
- }
- sti();
- }
- }
- up(&sk->protinfo.af_unix.readsem);
- return copied;
-}
-
-static int unix_shutdown(struct socket *sock, int mode)
-{
- unix_socket *sk=(unix_socket *)sock->data;
- unix_socket *other=sk->protinfo.af_unix.other;
- if(mode&SEND_SHUTDOWN)
- {
- sk->shutdown|=SEND_SHUTDOWN;
- sk->state_change(sk);
- if(other)
- {
- other->shutdown|=RCV_SHUTDOWN;
- other->state_change(other);
- }
- }
- other=sk->protinfo.af_unix.other;
- if(mode&RCV_SHUTDOWN)
- {
- sk->shutdown|=RCV_SHUTDOWN;
- sk->state_change(sk);
- if(other)
- {
- other->shutdown|=SEND_SHUTDOWN;
- other->state_change(other);
- }
- }
- return 0;
-}
-
-
-static int unix_select(struct socket *sock, int sel_type, select_table *wait)
-{
- return datagram_select(sock->data,sel_type,wait);
-}
-
-static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
-{
- unix_socket *sk=sock->data;
- int err;
- long amount=0;
-
- switch(cmd)
- {
-
- case TIOCOUTQ:
- err=verify_area(VERIFY_WRITE,(void *)arg,sizeof(unsigned long));
- if(err)
- return err;
- amount=sk->sndbuf-sk->wmem_alloc;
- if(amount<0)
- amount=0;
- put_fs_long(amount,(unsigned long *)arg);
- return 0;
- case TIOCINQ:
- {
- struct sk_buff *skb;
- if(sk->state==TCP_LISTEN)
- return -EINVAL;
- /* These two are safe on a single CPU system as only user tasks fiddle here */
- if((skb=skb_peek(&sk->receive_queue))!=NULL)
- amount=skb->len;
- err=verify_area(VERIFY_WRITE,(void *)arg,sizeof(unsigned long));
- put_fs_long(amount,(unsigned long *)arg);
- return 0;
- }
-
- default:
- return -EINVAL;
- }
- /*NOTREACHED*/
- return(0);
-}
-
-static int unix_get_info(char *buffer, char **start, off_t offset, int length, int dummy)
-{
- off_t pos=0;
- off_t begin=0;
- int len=0;
- unix_socket *s=unix_socket_list;
-
- len+= sprintf(buffer,"Num RefCount Protocol Flags Type St Path\n");
-
- while(s!=NULL)
- {
- len+=sprintf(buffer+len,"%p: %08X %08X %08lX %04X %02X",
- s,
- s->protinfo.af_unix.locks,
- 0,
- s->socket->flags,
- s->socket->type,
- s->socket->state);
- if(s->protinfo.af_unix.name!=NULL)
- len+=sprintf(buffer+len, " %s\n", s->protinfo.af_unix.name);
- else
- buffer[len++]='\n';
-
- pos=begin+len;
- if(pos<offset)
- {
- len=0;
- begin=pos;
- }
- if(pos>offset+length)
- break;
- s=s->next;
- }
- *start=buffer+(offset-begin);
- len-=(offset-begin);
- if(len>length)
- len=length;
- return len;
-}
-
-/*
- * For AF_UNIX we flip everything into an iovec. If this doesnt do any speed harm then it will
- * be easier for all the low levels to be totally iovec based.
- */
-
-static int unix_recvfrom(struct socket *sock, void *ubuf, int size, int noblock, unsigned flags,
- struct sockaddr *sa, int *addr_len)
-{
- struct iovec iov;
- struct msghdr msg;
- iov.iov_base=ubuf;
- iov.iov_len=size;
- msg.msg_name=(void *)sa;
- msg.msg_namelen=0;
- if (addr_len)
- msg.msg_namelen = *addr_len;
- msg.msg_accrights=NULL;
- msg.msg_iov=&iov;
- msg.msg_iovlen=1;
- return unix_recvmsg(sock,&msg,size,noblock,flags,addr_len);
-}
-
-static int unix_read(struct socket *sock, char *ubuf, int size, int noblock)
-{
- return unix_recvfrom(sock,ubuf,size,noblock,0,NULL,NULL);
-}
-
-static int unix_recv(struct socket *sock, void *ubuf, int size, int noblock, unsigned int flags)
-{
- return unix_recvfrom(sock,ubuf,size,noblock,flags,NULL,NULL);
-}
-
-static int unix_sendto(struct socket *sock, const void *ubuf, int size, int noblock, unsigned flags,
- struct sockaddr *sa, int addr_len)
-{
- struct iovec iov;
- struct msghdr msg;
- iov.iov_base=(void *)ubuf;
- iov.iov_len=size;
- msg.msg_name=(void *)sa;
- msg.msg_namelen=addr_len;
- msg.msg_accrights=NULL;
- msg.msg_iov=&iov;
- msg.msg_iovlen=1;
- return unix_sendmsg(sock,&msg,size,noblock,flags);
-}
-
-static int unix_write(struct socket *sock, const char *ubuf, int size, int noblock)
-{
- return unix_sendto(sock,ubuf,size,noblock, 0, NULL, 0);
-}
-
-static int unix_send(struct socket *sock, const void *ubuf, int size, int noblock, unsigned int flags)
-{
- return unix_sendto(sock,ubuf,size,noblock, flags, NULL, 0);
-}
-
-
-static struct proto_ops unix_proto_ops = {
- AF_UNIX,
-
- unix_create,
- unix_dup,
- unix_release,
- unix_bind,
- unix_connect,
- unix_socketpair,
- unix_accept,
- unix_getname,
- unix_read,
- unix_write,
- unix_select,
- unix_ioctl,
- unix_listen,
- unix_send,
- unix_recv,
- unix_sendto,
- unix_recvfrom,
- unix_shutdown,
- unix_setsockopt,
- unix_getsockopt,
- unix_fcntl,
- unix_sendmsg,
- unix_recvmsg
-};
-
-
-void unix_proto_init(struct net_proto *pro)
-{
- printk("NET3: Unix domain sockets 0.09 BETA for Linux NET3.030.\n");
- sock_register(unix_proto_ops.family, &unix_proto_ops);
- proc_net_register(&(struct proc_dir_entry) {
- PROC_NET_UNIX, 4, "unix",
- S_IFREG | S_IRUGO, 1, 0, 0,
- 0, &proc_net_inode_operations,
- unix_get_info
- });
-}
-/*
- * Local variables:
- * compile-command: "gcc -g -D__KERNEL__ -Wall -O6 -I/usr/src/linux/include -c af_unix.c"
- * End:
- */
+/*
+ * NET3: Implementation of BSD Unix domain sockets.
+ *
+ * Authors: Alan Cox, <alan.cox@linux.org>
+ *
+ * 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.
+ *
+ * Version: $Id: af_unix.c,v 1.84 1999/09/08 03:47:18 davem Exp $
+ *
+ * Fixes:
+ * Linus Torvalds : Assorted bug cures.
+ * Niibe Yutaka : async I/O support.
+ * Carsten Paeth : PF_UNIX check, address fixes.
+ * Alan Cox : Limit size of allocated blocks.
+ * Alan Cox : Fixed the stupid socketpair bug.
+ * Alan Cox : BSD compatibility fine tuning.
+ * Alan Cox : Fixed a bug in connect when interrupted.
+ * Alan Cox : Sorted out a proper draft version of
+ * file descriptor passing hacked up from
+ * Mike Shaver's work.
+ * Marty Leisner : Fixes to fd passing
+ * Nick Nevin : recvmsg bugfix.
+ * Alan Cox : Started proper garbage collector
+ * Heiko EiBfeldt : Missing verify_area check
+ * Alan Cox : Started POSIXisms
+ * Andreas Schwab : Replace inode by dentry for proper
+ * reference counting
+ * Kirk Petersen : Made this a module
+ * Christoph Rohland : Elegant non-blocking accept/connect algorithm.
+ * Lots of bug fixes.
+ * Alexey Kuznetosv : Repaired (I hope) bugs introduces
+ * by above two patches.
+ * Andrea Arcangeli : If possible we block in connect(2)
+ * if the max backlog of the listen socket
+ * is been reached. This won't break
+ * old apps and it will avoid huge amount
+ * of socks hashed (this for unix_gc()
+ * performances reasons).
+ * Security fix that limits the max
+ * number of socks to 2*max_files and
+ * the number of skb queueable in the
+ * dgram receiver.
+ * Artur Skawina : Hash function optimizations
+ * Alexey Kuznetsov : Full scale SMP. Lot of bugs are introduced 8)
+ *
+ *
+ * Known differences from reference BSD that was tested:
+ *
+ * [TO FIX]
+ * ECONNREFUSED is not returned from one end of a connected() socket to the
+ * other the moment one end closes.
+ * fstat() doesn't return st_dev=NODEV, and give the blksize as high water mark
+ * and a fake inode identifier (nor the BSD first socket fstat twice bug).
+ * [NOT TO FIX]
+ * accept() returns a path name even if the connecting socket has closed
+ * in the meantime (BSD loses the path and gives up).
+ * accept() returns 0 length path for an unbound connector. BSD returns 16
+ * and a null first byte in the path (but not for gethost/peername - BSD bug ??)
+ * socketpair(...SOCK_RAW..) doesn't panic the kernel.
+ * BSD af_unix apparently has connect forgetting to block properly.
+ * (need to check this with the POSIX spec in detail)
+ *
+ * Differences from 2.0.0-11-... (ANK)
+ * Bug fixes and improvements.
+ * - client shutdown killed server socket.
+ * - removed all useless cli/sti pairs.
+ *
+ * Semantic changes/extensions.
+ * - generic control message passing.
+ * - SCM_CREDENTIALS control message.
+ * - "Abstract" (not FS based) socket bindings.
+ * Abstract names are sequences of bytes (not zero terminated)
+ * started by 0, so that this name space does not intersect
+ * with BSD names.
+ */
+
+#include <linux/module.h>
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/stat.h>
+#include <linux/socket.h>
+#include <linux/un.h>
+#include <linux/fcntl.h>
+#include <linux/termios.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/in.h>
+#include <linux/fs.h>
+#include <linux/malloc.h>
+#include <asm/uaccess.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <net/sock.h>
+#include <net/tcp.h>
+#include <net/af_unix.h>
+#include <linux/proc_fs.h>
+#include <net/scm.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/smp_lock.h>
+
+#include <asm/checksum.h>
+
+#define min(a,b) (((a)<(b))?(a):(b))
+
+int sysctl_unix_max_dgram_qlen = 10;
+
+unix_socket *unix_socket_table[UNIX_HASH_SIZE+1];
+rwlock_t unix_table_lock = RW_LOCK_UNLOCKED;
+static atomic_t unix_nr_socks = ATOMIC_INIT(0);
+
+#define unix_sockets_unbound (unix_socket_table[UNIX_HASH_SIZE])
+
+#define UNIX_ABSTRACT(sk) ((sk)->protinfo.af_unix.addr->hash!=UNIX_HASH_SIZE)
+
+/*
+ SMP locking strategy.
+ * hash table is protceted with rwlock unix_table_lock
+ * each socket state is protected by separate rwlock.
+
+ */
+
+extern __inline__ unsigned unix_hash_fold(unsigned hash)
+{
+ hash ^= hash>>16;
+ hash ^= hash>>8;
+ return hash&(UNIX_HASH_SIZE-1);
+}
+
+#define unix_peer(sk) ((sk)->pair)
+
+extern __inline__ int unix_our_peer(unix_socket *sk, unix_socket *osk)
+{
+ return unix_peer(osk) == sk;
+}
+
+extern __inline__ int unix_may_send(unix_socket *sk, unix_socket *osk)
+{
+ return (unix_peer(osk) == NULL || unix_our_peer(sk, osk));
+}
+
+static __inline__ unix_socket * unix_peer_get(unix_socket *s)
+{
+ unix_socket *peer;
+
+ unix_state_rlock(s);
+ peer = unix_peer(s);
+ if (peer)
+ sock_hold(peer);
+ unix_state_runlock(s);
+ return peer;
+}
+
+extern __inline__ void unix_release_addr(struct unix_address *addr)
+{
+ if (atomic_dec_and_test(&addr->refcnt))
+ kfree(addr);
+}
+
+/*
+ * Check unix socket name:
+ * - should be not zero length.
+ * - if started by not zero, should be NULL terminated (FS object)
+ * - if started by zero, it is abstract name.
+ */
+
+static int unix_mkname(struct sockaddr_un * sunaddr, int len, unsigned *hashp)
+{
+ if (len <= sizeof(short) || len > sizeof(*sunaddr))
+ return -EINVAL;
+ if (!sunaddr || sunaddr->sun_family != AF_UNIX)
+ return -EINVAL;
+ if (sunaddr->sun_path[0])
+ {
+ /*
+ * This may look like an off by one error but it is
+ * a bit more subtle. 108 is the longest valid AF_UNIX
+ * path for a binding. sun_path[108] doesnt as such
+ * exist. However in kernel space we are guaranteed that
+ * it is a valid memory location in our kernel
+ * address buffer.
+ */
+ if (len > sizeof(*sunaddr))
+ len = sizeof(*sunaddr);
+ ((char *)sunaddr)[len]=0;
+ len = strlen(sunaddr->sun_path)+1+sizeof(short);
+ return len;
+ }
+
+ *hashp = unix_hash_fold(csum_partial((char*)sunaddr, len, 0));
+ return len;
+}
+
+static void __unix_remove_socket(unix_socket *sk)
+{
+ unix_socket **list = sk->protinfo.af_unix.list;
+ if (list) {
+ if (sk->next)
+ sk->next->prev = sk->prev;
+ if (sk->prev)
+ sk->prev->next = sk->next;
+ if (*list == sk)
+ *list = sk->next;
+ sk->protinfo.af_unix.list = NULL;
+ sk->prev = NULL;
+ sk->next = NULL;
+ __sock_put(sk);
+ }
+}
+
+static void __unix_insert_socket(unix_socket **list, unix_socket *sk)
+{
+ BUG_TRAP(sk->protinfo.af_unix.list==NULL);
+
+ sk->protinfo.af_unix.list = list;
+ sk->prev = NULL;
+ sk->next = *list;
+ if (*list)
+ (*list)->prev = sk;
+ *list=sk;
+ sock_hold(sk);
+}
+
+static __inline__ void unix_remove_socket(unix_socket *sk)
+{
+ write_lock(&unix_table_lock);
+ __unix_remove_socket(sk);
+ write_unlock(&unix_table_lock);
+}
+
+static __inline__ void unix_insert_socket(unix_socket **list, unix_socket *sk)
+{
+ write_lock(&unix_table_lock);
+ __unix_insert_socket(list, sk);
+ write_unlock(&unix_table_lock);
+}
+
+static unix_socket *__unix_find_socket_byname(struct sockaddr_un *sunname,
+ int len, int type, unsigned hash)
+{
+ unix_socket *s;
+
+ for (s=unix_socket_table[hash^type]; s; s=s->next) {
+ if(s->protinfo.af_unix.addr->len==len &&
+ memcmp(s->protinfo.af_unix.addr->name, sunname, len) == 0)
+ return s;
+ }
+ return NULL;
+}
+
+static __inline__ unix_socket *
+unix_find_socket_byname(struct sockaddr_un *sunname,
+ int len, int type, unsigned hash)
+{
+ unix_socket *s;
+
+ read_lock(&unix_table_lock);
+ s = __unix_find_socket_byname(sunname, len, type, hash);
+ if (s)
+ sock_hold(s);
+ read_unlock(&unix_table_lock);
+ return s;
+}
+
+static unix_socket *unix_find_socket_byinode(struct inode *i)
+{
+ unix_socket *s;
+
+ read_lock(&unix_table_lock);
+ for (s=unix_socket_table[i->i_ino & (UNIX_HASH_SIZE-1)]; s; s=s->next)
+ {
+ struct dentry *dentry = s->protinfo.af_unix.dentry;
+
+ if(dentry && dentry->d_inode == i)
+ {
+ sock_hold(s);
+ break;
+ }
+ }
+ read_unlock(&unix_table_lock);
+ return s;
+}
+
+static __inline__ int unix_writable(struct sock *sk)
+{
+ return ((atomic_read(&sk->wmem_alloc)<<2) <= sk->sndbuf);
+}
+
+static void unix_write_space(struct sock *sk)
+{
+ read_lock(&sk->callback_lock);
+ if (!sk->dead && unix_writable(sk)) {
+ wake_up_interruptible(sk->sleep);
+ sock_wake_async(sk->socket, 2);
+ }
+ read_unlock(&sk->callback_lock);
+}
+
+static void unix_sock_destructor(struct sock *sk)
+{
+ skb_queue_purge(&sk->receive_queue);
+
+ BUG_TRAP(atomic_read(&sk->wmem_alloc) == 0);
+ BUG_TRAP(sk->protinfo.af_unix.list==NULL);
+ BUG_TRAP(sk->socket==NULL);
+ if (sk->dead==0) {
+ printk("Attempt to release alive unix socket: %p\n", sk);
+ return;
+ }
+
+ if (sk->protinfo.af_unix.addr)
+ unix_release_addr(sk->protinfo.af_unix.addr);
+
+ atomic_dec(&unix_nr_socks);
+#ifdef UNIX_REFCNT_DEBUG
+ printk(KERN_DEBUG "UNIX %p is destroyed, %d are still alive.\n", sk, atomic_read(&unix_nr_socks));
+#endif
+ MOD_DEC_USE_COUNT;
+}
+
+static int unix_release_sock (unix_socket *sk, int embrion)
+{
+ struct dentry *dentry;
+ unix_socket *skpair;
+ struct sk_buff *skb;
+ int state;
+
+ unix_remove_socket(sk);
+
+ /* Clear state */
+ unix_state_wlock(sk);
+ write_lock(&sk->callback_lock);
+ sk->dead = 1;
+ sk->socket = NULL;
+ write_unlock(&sk->callback_lock);
+ sk->shutdown = SHUTDOWN_MASK;
+ dentry = sk->protinfo.af_unix.dentry;
+ sk->protinfo.af_unix.dentry=NULL;
+ state = sk->state;
+ sk->state = TCP_CLOSE;
+ unix_state_wunlock(sk);
+
+ wake_up_interruptible(sk->sleep);
+ wake_up_interruptible(&sk->protinfo.af_unix.peer_wait);
+
+ skpair=unix_peer(sk);
+
+ if (skpair!=NULL) {
+ if (sk->type==SOCK_STREAM) {
+ unix_state_wlock(skpair);
+ skpair->shutdown=SHUTDOWN_MASK; /* No more writes*/
+ if (!skb_queue_empty(&sk->receive_queue) || embrion)
+ skpair->err = ECONNRESET;
+ unix_state_wunlock(skpair);
+ sk->data_ready(skpair,0);
+ }
+ sock_put(skpair); /* It may now die */
+ unix_peer(sk) = NULL;
+ }
+
+ /* Try to flush out this socket. Throw out buffers at least */
+
+ while((skb=skb_dequeue(&sk->receive_queue))!=NULL)
+ {
+ if (state==TCP_LISTEN)
+ unix_release_sock(skb->sk, 1);
+ /* passed fds are erased in the kfree_skb hook */
+ kfree_skb(skb);
+ }
+
+ if (dentry) {
+ lock_kernel();
+ dput(dentry);
+ unlock_kernel();
+ }
+
+ sock_put(sk);
+
+ /* ---- Socket is dead now and most probably destroyed ---- */
+
+ /*
+ * Fixme: BSD difference: In BSD all sockets connected to use get
+ * ECONNRESET and we die on the spot. In Linux we behave
+ * like files and pipes do and wait for the last
+ * dereference.
+ *
+ * Can't we simply set sock->err?
+ *
+ * What the above comment does talk about? --ANK(980817)
+ */
+
+ if (atomic_read(&unix_tot_inflight))
+ unix_gc(); /* Garbage collect fds */
+
+ return 0;
+}
+
+static int unix_listen(struct socket *sock, int backlog)
+{
+ int err;
+ struct sock *sk = sock->sk;
+
+ err = -EOPNOTSUPP;
+ if (sock->type!=SOCK_STREAM)
+ goto out; /* Only stream sockets accept */
+ err = -EINVAL;
+ if (!sk->protinfo.af_unix.addr)
+ goto out; /* No listens on an unbound socket */
+ unix_state_wlock(sk);
+ if (sk->state != TCP_CLOSE && sk->state != TCP_LISTEN)
+ goto out_unlock;
+ if (backlog > sk->max_ack_backlog)
+ wake_up_interruptible(&sk->protinfo.af_unix.peer_wait);
+ sk->max_ack_backlog=backlog;
+ sk->state=TCP_LISTEN;
+ sock->flags |= SO_ACCEPTCON;
+ /* set credentials so connect can copy them */
+ sk->peercred.pid = current->pid;
+ sk->peercred.uid = current->euid;
+ sk->peercred.gid = current->egid;
+ err = 0;
+
+out_unlock:
+ unix_state_wunlock(sk);
+out:
+ return err;
+}
+
+extern struct proto_ops unix_stream_ops;
+extern struct proto_ops unix_dgram_ops;
+
+static struct sock * unix_create1(struct socket *sock)
+{
+ struct sock *sk;
+
+ if (atomic_read(&unix_nr_socks) >= 2*max_files)
+ return NULL;
+
+ MOD_INC_USE_COUNT;
+ sk = sk_alloc(PF_UNIX, GFP_KERNEL, 1);
+ if (!sk) {
+ MOD_DEC_USE_COUNT;
+ return NULL;
+ }
+
+ atomic_inc(&unix_nr_socks);
+
+ sock_init_data(sock,sk);
+
+ sk->write_space = unix_write_space;
+
+ sk->max_ack_backlog = sysctl_unix_max_dgram_qlen;
+ sk->destruct = unix_sock_destructor;
+ sk->protinfo.af_unix.dentry=NULL;
+ sk->protinfo.af_unix.lock = RW_LOCK_UNLOCKED;
+ atomic_set(&sk->protinfo.af_unix.inflight, 0);
+ init_MUTEX(&sk->protinfo.af_unix.readsem);/* single task reading lock */
+ init_waitqueue_head(&sk->protinfo.af_unix.peer_wait);
+ sk->protinfo.af_unix.list=NULL;
+ unix_insert_socket(&unix_sockets_unbound, sk);
+
+ return sk;
+}
+
+static int unix_create(struct socket *sock, int protocol)
+{
+ if (protocol && protocol != PF_UNIX)
+ return -EPROTONOSUPPORT;
+
+ sock->state = SS_UNCONNECTED;
+
+ switch (sock->type) {
+ case SOCK_STREAM:
+ sock->ops = &unix_stream_ops;
+ break;
+ /*
+ * Believe it or not BSD has AF_UNIX, SOCK_RAW though
+ * nothing uses it.
+ */
+ case SOCK_RAW:
+ sock->type=SOCK_DGRAM;
+ case SOCK_DGRAM:
+ sock->ops = &unix_dgram_ops;
+ break;
+ default:
+ return -ESOCKTNOSUPPORT;
+ }
+
+ return unix_create1(sock) ? 0 : -ENOMEM;
+}
+
+static int unix_release(struct socket *sock)
+{
+ unix_socket *sk = sock->sk;
+
+ if (!sk)
+ return 0;
+
+ sock->sk = NULL;
+
+ return unix_release_sock (sk, 0);
+}
+
+static int unix_autobind(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+ static u32 ordernum = 1;
+ struct unix_address * addr;
+ int err;
+
+ down(&sk->protinfo.af_unix.readsem);
+
+ err = 0;
+ if (sk->protinfo.af_unix.addr)
+ goto out;
+
+ err = -ENOMEM;
+ addr = kmalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL);
+ if (!addr)
+ goto out;
+
+ memset(addr, 0, sizeof(*addr) + sizeof(short) + 16);
+ addr->name->sun_family = AF_UNIX;
+ atomic_set(&addr->refcnt, 1);
+
+retry:
+ addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short);
+ addr->hash = unix_hash_fold(csum_partial((void*)addr->name, addr->len, 0));
+
+ write_lock(&unix_table_lock);
+ ordernum = (ordernum+1)&0xFFFFF;
+
+ if (__unix_find_socket_byname(addr->name, addr->len, sock->type,
+ addr->hash)) {
+ write_unlock(&unix_table_lock);
+ /* Sanity yield. It is unusual case, but yet... */
+ if (!(ordernum&0xFF)) {
+ current->policy |= SCHED_YIELD;
+ schedule();
+ }
+ goto retry;
+ }
+ addr->hash ^= sk->type;
+
+ __unix_remove_socket(sk);
+ sk->protinfo.af_unix.addr = addr;
+ __unix_insert_socket(&unix_socket_table[addr->hash], sk);
+ write_unlock(&unix_table_lock);
+ err = 0;
+
+out:
+ up(&sk->protinfo.af_unix.readsem);
+ return err;
+}
+
+static unix_socket *unix_find_other(struct sockaddr_un *sunname, int len,
+ int type, unsigned hash, int *error)
+{
+ unix_socket *u;
+
+ if (sunname->sun_path[0])
+ {
+ struct dentry *dentry;
+
+ /* Do not believe to VFS, grab kernel lock */
+ lock_kernel();
+ dentry = open_namei(sunname->sun_path, 2, S_IFSOCK);
+ if (IS_ERR(dentry)) {
+ *error = PTR_ERR(dentry);
+ unlock_kernel();
+ return NULL;
+ }
+ u=unix_find_socket_byinode(dentry->d_inode);
+ dput(dentry);
+ unlock_kernel();
+
+ if (u && u->type != type)
+ {
+ *error=-EPROTOTYPE;
+ sock_put(u);
+ return NULL;
+ }
+ }
+ else
+ u=unix_find_socket_byname(sunname, len, type, hash);
+
+ if (u==NULL)
+ {
+ *error=-ECONNREFUSED;
+ return NULL;
+ }
+ return u;
+}
+
+
+static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
+{
+ struct sock *sk = sock->sk;
+ struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
+ struct dentry * dentry = NULL;
+ int err;
+ unsigned hash;
+ struct unix_address *addr;
+ unix_socket **list;
+
+ err = -EINVAL;
+ if (sunaddr->sun_family != AF_UNIX)
+ goto out;
+
+ if (addr_len==sizeof(short)) {
+ err = unix_autobind(sock);
+ goto out;
+ }
+
+ err = unix_mkname(sunaddr, addr_len, &hash);
+ if (err < 0)
+ goto out;
+ addr_len = err;
+
+ down(&sk->protinfo.af_unix.readsem);
+
+ err = -EINVAL;
+ if (sk->protinfo.af_unix.addr)
+ goto out_up;
+
+ err = -ENOMEM;
+ addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
+ if (!addr)
+ goto out_up;
+
+ memcpy(addr->name, sunaddr, addr_len);
+ addr->len = addr_len;
+ addr->hash = hash^sk->type;
+ atomic_set(&addr->refcnt, 1);
+
+ if (sunaddr->sun_path[0]) {
+ lock_kernel();
+ dentry = do_mknod(sunaddr->sun_path, S_IFSOCK|sock->inode->i_mode, 0);
+ if (IS_ERR(dentry)) {
+ err = PTR_ERR(dentry);
+ unlock_kernel();
+ if (err==-EEXIST)
+ err=-EADDRINUSE;
+ unix_release_addr(addr);
+ goto out_up;
+ }
+ unlock_kernel();
+
+ addr->hash = UNIX_HASH_SIZE;
+ }
+
+ write_lock(&unix_table_lock);
+
+ if (!sunaddr->sun_path[0]) {
+ err = -EADDRINUSE;
+ if (__unix_find_socket_byname(sunaddr, addr_len,
+ sk->type, hash)) {
+ unix_release_addr(addr);
+ goto out_unlock;
+ }
+
+ list = &unix_socket_table[addr->hash];
+ } else {
+ list = &unix_socket_table[dentry->d_inode->i_ino & (UNIX_HASH_SIZE-1)];
+ sk->protinfo.af_unix.dentry = dentry;
+ }
+
+ err = 0;
+ __unix_remove_socket(sk);
+ sk->protinfo.af_unix.addr = addr;
+ __unix_insert_socket(list, sk);
+
+out_unlock:
+ write_unlock(&unix_table_lock);
+out_up:
+ up(&sk->protinfo.af_unix.readsem);
+out:
+ return err;
+}
+
+static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
+ int alen, int flags)
+{
+ struct sock *sk = sock->sk;
+ struct sockaddr_un *sunaddr=(struct sockaddr_un*)addr;
+ struct sock *other;
+ unsigned hash;
+ int err;
+
+ if (addr->sa_family != AF_UNSPEC) {
+ err = unix_mkname(sunaddr, alen, &hash);
+ if (err < 0)
+ goto out;
+ alen = err;
+
+ if (sock->passcred && !sk->protinfo.af_unix.addr &&
+ (err = unix_autobind(sock)) != 0)
+ goto out;
+
+ other=unix_find_other(sunaddr, alen, sock->type, hash, &err);
+ if (!other)
+ goto out;
+
+ unix_state_wlock(sk);
+
+ err = -EPERM;
+ if (!unix_may_send(sk, other))
+ goto out_unlock;
+ } else {
+ /*
+ * 1003.1g breaking connected state with AF_UNSPEC
+ */
+ other = NULL;
+ unix_state_wlock(sk);
+ }
+
+ /*
+ * If it was connected, reconnect.
+ */
+ if (unix_peer(sk)) {
+ sock_put(unix_peer(sk));
+ unix_peer(sk)=NULL;
+ }
+ unix_peer(sk)=other;
+ unix_state_wunlock(sk);
+ return 0;
+
+out_unlock:
+ unix_state_wunlock(sk);
+ sock_put(other);
+out:
+ return err;
+}
+
+static void unix_wait_for_peer(unix_socket *other)
+{
+ int sched;
+ DECLARE_WAITQUEUE(wait, current);
+
+ __set_current_state(TASK_INTERRUPTIBLE);
+ add_wait_queue(&other->protinfo.af_unix.peer_wait, &wait);
+
+ sched = (!other->dead &&
+ !(other->shutdown&RCV_SHUTDOWN) &&
+ !signal_pending(current) &&
+ skb_queue_len(&other->receive_queue) >= other->max_ack_backlog);
+
+ unix_state_runlock(other);
+
+ if (sched)
+ schedule();
+
+ __set_current_state(TASK_RUNNING);
+ remove_wait_queue(&other->protinfo.af_unix.peer_wait, &wait);
+}
+
+static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
+ int addr_len, int flags)
+{
+ struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
+ struct sock *sk = sock->sk;
+ struct sock *newsk = NULL;
+ unix_socket *other = NULL;
+ struct sk_buff *skb = NULL;
+ unsigned hash;
+ int st;
+ int err;
+
+ err = unix_mkname(sunaddr, addr_len, &hash);
+ if (err < 0)
+ goto out;
+ addr_len = err;
+
+ if (sock->passcred && !sk->protinfo.af_unix.addr &&
+ (err = unix_autobind(sock)) != 0)
+ goto out;
+
+ /* First of all allocate resources.
+ If we will make it after state is locked,
+ we will have to recheck all again in any case.
+ */
+
+ err = -ENOMEM;
+
+ /* create new sock for complete connection */
+ newsk = unix_create1(NULL);
+ if (newsk == NULL)
+ goto out;
+
+ /* Allocate skb for sending to listening sock */
+ skb = sock_wmalloc(newsk, 1, 0, GFP_KERNEL);
+ if (skb == NULL)
+ goto out;
+
+restart:
+ /* Find listening sock. */
+ other=unix_find_other(sunaddr, addr_len, sk->type, hash, &err);
+ if (!other)
+ goto out;
+
+ /* Latch state of peer */
+ unix_state_rlock(other);
+
+ /* Apparently VFS overslept socket death. Retry. */
+ if (other->dead) {
+ unix_state_runlock(other);
+ sock_put(other);
+ goto restart;
+ }
+
+ err = -ECONNREFUSED;
+ if (other->state != TCP_LISTEN)
+ goto out_unlock;
+
+ if (skb_queue_len(&other->receive_queue) >= other->max_ack_backlog) {
+ err = -EAGAIN;
+ if (flags & O_NONBLOCK)
+ goto out_unlock;
+
+ unix_wait_for_peer(other);
+
+ err = -ERESTARTSYS;
+ if (signal_pending(current))
+ goto out;
+ sock_put(other);
+ goto restart;
+ }
+
+ /* Latch our state.
+
+ It is tricky place. We need to grab write lock and cannot
+ drop lock on peer. It is dangerous because deadlock is
+ possible. Connect to self case and simultaneous
+ attempt to connect are eliminated by checking socket
+ state. other is TCP_LISTEN, if sk is TCP_LISTEN we
+ check this before attempt to grab lock.
+
+ Well, and we have to recheck the state after socket locked.
+ */
+ st = sk->state;
+
+ switch (st) {
+ case TCP_CLOSE:
+ /* This is ok... continue with connect */
+ break;
+ case TCP_ESTABLISHED:
+ /* Socket is already connected */
+ err = -EISCONN;
+ goto out_unlock;
+ default:
+ err = -EINVAL;
+ goto out_unlock;
+ }
+
+ unix_state_wlock(sk);
+
+ if (sk->state != st) {
+ unix_state_wunlock(sk);
+ unix_state_runlock(other);
+ sock_put(other);
+ goto restart;
+ }
+
+ /* The way is open! Fastly set all the necessary fields... */
+
+ sock_hold(sk);
+ unix_peer(newsk)=sk;
+ newsk->state=TCP_ESTABLISHED;
+ newsk->type=SOCK_STREAM;
+ newsk->peercred.pid = current->pid;
+ newsk->peercred.uid = current->euid;
+ newsk->peercred.gid = current->egid;
+ newsk->sleep = &newsk->protinfo.af_unix.peer_wait;
+
+ /* copy address information from listening to new sock*/
+ if (other->protinfo.af_unix.addr)
+ {
+ atomic_inc(&other->protinfo.af_unix.addr->refcnt);
+ newsk->protinfo.af_unix.addr=other->protinfo.af_unix.addr;
+ }
+ if (other->protinfo.af_unix.dentry) {
+ /* Damn, even dget is not SMP safe. It becomes ridiculous... */
+ lock_kernel();
+ newsk->protinfo.af_unix.dentry=dget(other->protinfo.af_unix.dentry);
+ unlock_kernel();
+ }
+
+ /* Set credentials */
+ sk->peercred = other->peercred;
+
+ sock_hold(newsk);
+ unix_peer(sk)=newsk;
+ sock->state=SS_CONNECTED;
+ sk->state=TCP_ESTABLISHED;
+
+ unix_state_wunlock(sk);
+
+ /* take ten and and send info to listening sock */
+ skb_queue_tail(&other->receive_queue,skb);
+ unix_state_runlock(other);
+ other->data_ready(other, 0);
+ sock_put(other);
+ return 0;
+
+out_unlock:
+ if (other)
+ unix_state_runlock(other);
+
+out:
+ if (skb)
+ kfree_skb(skb);
+ if (newsk)
+ unix_release_sock(newsk, 0);
+ if (other)
+ sock_put(other);
+ return err;
+}
+
+static int unix_socketpair(struct socket *socka, struct socket *sockb)
+{
+ struct sock *ska=socka->sk, *skb = sockb->sk;
+
+ /* Join our sockets back to back */
+ sock_hold(ska);
+ sock_hold(skb);
+ unix_peer(ska)=skb;
+ unix_peer(skb)=ska;
+
+ if (ska->type != SOCK_DGRAM)
+ {
+ ska->state=TCP_ESTABLISHED;
+ skb->state=TCP_ESTABLISHED;
+ socka->state=SS_CONNECTED;
+ sockb->state=SS_CONNECTED;
+ }
+ return 0;
+}
+
+static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
+{
+ unix_socket *sk = sock->sk;
+ unix_socket *tsk;
+ struct sk_buff *skb;
+ int err;
+
+ err = -EOPNOTSUPP;
+ if (sock->type!=SOCK_STREAM)
+ goto out;
+
+ err = -EINVAL;
+ if (sk->state!=TCP_LISTEN)
+ goto out;
+
+ /* If socket state is TCP_LISTEN it cannot change,
+ so that no locks are necessary.
+ */
+
+ skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err);
+ if (!skb)
+ goto out;
+
+ tsk = skb->sk;
+ if (skb_queue_len(&sk->receive_queue) <= sk->max_ack_backlog/2)
+ wake_up_interruptible(&sk->protinfo.af_unix.peer_wait);
+ skb_free_datagram(sk, skb);
+
+ /* attach accepted sock to socket */
+ unix_state_wlock(tsk);
+ newsock->state = SS_CONNECTED;
+ newsock->sk = tsk;
+ tsk->sleep = &newsock->wait;
+ tsk->socket = newsock;
+ unix_state_wunlock(tsk);
+ return 0;
+
+out:
+ return err;
+}
+
+
+static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer)
+{
+ struct sock *sk = sock->sk;
+ struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
+ int err = 0;
+
+ if (peer) {
+ sk = unix_peer_get(sk);
+
+ err = -ENOTCONN;
+ if (!sk)
+ goto out;
+ err = 0;
+ } else {
+ sock_hold(sk);
+ }
+
+ unix_state_rlock(sk);
+ if (!sk->protinfo.af_unix.addr) {
+ sunaddr->sun_family = AF_UNIX;
+ sunaddr->sun_path[0] = 0;
+ *uaddr_len = sizeof(short);
+ } else {
+ struct unix_address *addr = sk->protinfo.af_unix.addr;
+
+ *uaddr_len = addr->len;
+ memcpy(sunaddr, addr->name, *uaddr_len);
+ }
+ unix_state_runlock(sk);
+ sock_put(sk);
+out:
+ return err;
+}
+
+static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
+{
+ int i;
+
+ scm->fp = UNIXCB(skb).fp;
+ skb->destructor = sock_wfree;
+ UNIXCB(skb).fp = NULL;
+
+ for (i=scm->fp->count-1; i>=0; i--)
+ unix_notinflight(scm->fp->fp[i]);
+}
+
+static void unix_destruct_fds(struct sk_buff *skb)
+{
+ struct scm_cookie scm;
+ memset(&scm, 0, sizeof(scm));
+ unix_detach_fds(&scm, skb);
+
+ /* Alas, it calls VFS */
+ lock_kernel();
+ scm_destroy(&scm);
+ unlock_kernel();
+ sock_wfree(skb);
+}
+
+static void unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
+{
+ int i;
+ for (i=scm->fp->count-1; i>=0; i--)
+ unix_inflight(scm->fp->fp[i]);
+ UNIXCB(skb).fp = scm->fp;
+ skb->destructor = unix_destruct_fds;
+ scm->fp = NULL;
+}
+
+/*
+ * Send AF_UNIX data.
+ */
+
+static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg, int len,
+ struct scm_cookie *scm)
+{
+ struct sock *sk = sock->sk;
+ struct sockaddr_un *sunaddr=msg->msg_name;
+ unix_socket *other = NULL;
+ int namelen = 0; /* fake GCC */
+ int err;
+ unsigned hash;
+ struct sk_buff *skb;
+
+ err = -EOPNOTSUPP;
+ if (msg->msg_flags&MSG_OOB)
+ goto out;
+
+ err = -EINVAL;
+ if (msg->msg_flags&~(MSG_DONTWAIT|MSG_NOSIGNAL))
+ goto out;
+
+ if (msg->msg_namelen) {
+ err = unix_mkname(sunaddr, msg->msg_namelen, &hash);
+ if (err < 0)
+ goto out;
+ namelen = err;
+ } else {
+ sunaddr = NULL;
+ err = -ENOTCONN;
+ other = unix_peer_get(sk);
+ if (!other)
+ goto out;
+ }
+
+ if (sock->passcred && !sk->protinfo.af_unix.addr &&
+ (err = unix_autobind(sock)) != 0)
+ goto out;
+
+ skb = sock_alloc_send_skb(sk, len, 0, msg->msg_flags&MSG_DONTWAIT, &err);
+ if (skb==NULL)
+ goto out;
+
+ memcpy(UNIXCREDS(skb), &scm->creds, sizeof(struct ucred));
+ if (scm->fp)
+ unix_attach_fds(scm, skb);
+
+ skb->h.raw = skb->data;
+ err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len);
+ if (err)
+ goto out_free;
+
+restart:
+ if (!other) {
+ err = -ECONNRESET;
+ if (sunaddr == NULL)
+ goto out_free;
+
+ other = unix_find_other(sunaddr, namelen, sk->type, hash, &err);
+ if (other==NULL)
+ goto out_free;
+ }
+
+ unix_state_rlock(other);
+ err = -EPERM;
+ if (!unix_may_send(sk, other))
+ goto out_unlock;
+
+ if (other->dead) {
+ /*
+ * Check with 1003.1g - what should
+ * datagram error
+ */
+ unix_state_runlock(other);
+ sock_put(other);
+
+ err = 0;
+ unix_state_wlock(sk);
+ if (unix_peer(sk) == other) {
+ sock_put(other);
+ unix_peer(sk)=NULL;
+ err = -ECONNREFUSED;
+ }
+ unix_state_wunlock(sk);
+
+ other = NULL;
+ if (err)
+ goto out_free;
+ goto restart;
+ }
+
+ err = -EPIPE;
+ if (other->shutdown&RCV_SHUTDOWN)
+ goto out_unlock;
+
+ if (0/*other->user_callback &&
+ other->user_callback(other->user_data, skb) == 0*/) {
+ unix_state_runlock(other);
+ sock_put(other);
+ return len;
+ }
+
+ if (skb_queue_len(&other->receive_queue) >= other->max_ack_backlog) {
+ if (msg->msg_flags & MSG_DONTWAIT) {
+ err = -EAGAIN;
+ goto out_unlock;
+ }
+
+ unix_wait_for_peer(other);
+
+ err = -ERESTARTSYS;
+ if (signal_pending(current))
+ goto out_free;
+
+ goto restart;
+ }
+
+ skb_queue_tail(&other->receive_queue, skb);
+ unix_state_runlock(other);
+ other->data_ready(other, len);
+ sock_put(other);
+ return len;
+
+out_unlock:
+ unix_state_runlock(other);
+out_free:
+ kfree_skb(skb);
+out:
+ if (other)
+ sock_put(other);
+ return err;
+}
+
+
+static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, int len,
+ struct scm_cookie *scm)
+{
+ struct sock *sk = sock->sk;
+ unix_socket *other = NULL;
+ struct sockaddr_un *sunaddr=msg->msg_name;
+ int err,size;
+ struct sk_buff *skb;
+ int limit=0;
+ int sent=0;
+
+ err = -EOPNOTSUPP;
+ if (msg->msg_flags&MSG_OOB)
+ goto out_err;
+
+ err = -EINVAL;
+ if (msg->msg_flags&~(MSG_DONTWAIT|MSG_NOSIGNAL))
+ goto out_err;
+
+ if (msg->msg_namelen) {
+ err = (sk->state==TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP);
+ goto out_err;
+ } else {
+ sunaddr = NULL;
+ err = -ENOTCONN;
+ other = unix_peer_get(sk);
+ if (!other)
+ goto out_err;
+ }
+
+ if (sk->shutdown&SEND_SHUTDOWN)
+ goto pipe_err;
+
+ while(sent < len)
+ {
+ /*
+ * Optimisation for the fact that under 0.01% of X messages typically
+ * need breaking up.
+ */
+
+ size=len-sent;
+
+ /* Keep two messages in the pipe so it schedules better */
+ if (size > sk->sndbuf/2 - 16)
+ size = sk->sndbuf/2 - 16;
+
+ /*
+ * Keep to page sized kmalloc()'s as various people
+ * have suggested. Big mallocs stress the vm too
+ * much.
+ */
+
+ if (size > 4096-16)
+ limit = 4096-16; /* Fall back to a page if we can't grab a big buffer this instant */
+ else
+ limit = 0; /* Otherwise just grab and wait */
+
+ /*
+ * Grab a buffer
+ */
+
+ skb=sock_alloc_send_skb(sk,size,limit,msg->msg_flags&MSG_DONTWAIT, &err);
+
+ if (skb==NULL)
+ goto out_err;
+
+ /*
+ * If you pass two values to the sock_alloc_send_skb
+ * it tries to grab the large buffer with GFP_BUFFER
+ * (which can fail easily), and if it fails grab the
+ * fallback size buffer which is under a page and will
+ * succeed. [Alan]
+ */
+ size = min(size, skb_tailroom(skb));
+
+ memcpy(UNIXCREDS(skb), &scm->creds, sizeof(struct ucred));
+ if (scm->fp)
+ unix_attach_fds(scm, skb);
+
+ if ((err = memcpy_fromiovec(skb_put(skb,size), msg->msg_iov, size)) != 0) {
+ kfree_skb(skb);
+ goto out_err;
+ }
+
+ unix_state_rlock(other);
+
+ if (other->dead || (other->shutdown & RCV_SHUTDOWN))
+ goto pipe_err_free;
+
+ skb_queue_tail(&other->receive_queue, skb);
+ unix_state_runlock(other);
+ other->data_ready(other, size);
+ sent+=size;
+ }
+ sock_put(other);
+ return sent;
+
+pipe_err_free:
+ kfree_skb(skb);
+ unix_state_runlock(other);
+pipe_err:
+ if (sent==0 && !(msg->msg_flags&MSG_NOSIGNAL))
+ send_sig(SIGPIPE,current,0);
+ err = -EPIPE;
+out_err:
+ if (other)
+ sock_put(other);
+ return sent ? : err;
+}
+
+static void unix_copy_addr(struct msghdr *msg, struct sock *sk)
+{
+ msg->msg_namelen = sizeof(short);
+ if (sk->protinfo.af_unix.addr) {
+ msg->msg_namelen=sk->protinfo.af_unix.addr->len;
+ memcpy(msg->msg_name,
+ sk->protinfo.af_unix.addr->name,
+ sk->protinfo.af_unix.addr->len);
+ }
+}
+
+static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg, int size,
+ int flags, struct scm_cookie *scm)
+{
+ struct sock *sk = sock->sk;
+ int noblock = flags & MSG_DONTWAIT;
+ struct sk_buff *skb;
+ int err;
+
+ err = -EOPNOTSUPP;
+ if (flags&MSG_OOB)
+ goto out;
+
+ msg->msg_namelen = 0;
+
+ skb = skb_recv_datagram(sk, flags, noblock, &err);
+ if (!skb)
+ goto out;
+
+ if (skb_queue_len(&sk->receive_queue) <= sk->max_ack_backlog/2)
+ wake_up_interruptible(&sk->protinfo.af_unix.peer_wait);
+
+ if (msg->msg_name)
+ unix_copy_addr(msg, skb->sk);
+
+ if (size > skb->len)
+ size = skb->len;
+ else if (size < skb->len)
+ msg->msg_flags |= MSG_TRUNC;
+
+ err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size);
+ if (err)
+ goto out_free;
+
+ scm->creds = *UNIXCREDS(skb);
+
+ if (!(flags & MSG_PEEK))
+ {
+ if (UNIXCB(skb).fp)
+ unix_detach_fds(scm, skb);
+ }
+ else
+ {
+ /* It is questionable: on PEEK we could:
+ - do not return fds - good, but too simple 8)
+ - return fds, and do not return them on read (old strategy,
+ apparently wrong)
+ - clone fds (I choosed it for now, it is the most universal
+ solution)
+
+ POSIX 1003.1g does not actually define this clearly
+ at all. POSIX 1003.1g doesn't define a lot of things
+ clearly however!
+
+ */
+ if (UNIXCB(skb).fp)
+ scm->fp = scm_fp_dup(UNIXCB(skb).fp);
+ }
+ err = size;
+
+out_free:
+ skb_free_datagram(sk,skb);
+out:
+ return err;
+}
+
+/*
+ * Sleep until data has arrive. But check for races..
+ */
+
+static void unix_stream_data_wait(unix_socket * sk)
+{
+ DECLARE_WAITQUEUE(wait, current);
+
+ unix_state_rlock(sk);
+
+ add_wait_queue(sk->sleep, &wait);
+
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ if (skb_queue_len(&sk->receive_queue) ||
+ sk->err ||
+ (sk->shutdown & RCV_SHUTDOWN) ||
+ signal_pending(current))
+ break;
+
+ sk->socket->flags |= SO_WAITDATA;
+ unix_state_runlock(sk);
+ schedule();
+ unix_state_rlock(sk);
+ sk->socket->flags &= ~SO_WAITDATA;
+ }
+
+ __set_current_state(TASK_RUNNING);
+ remove_wait_queue(sk->sleep, &wait);
+ unix_state_runlock(sk);
+}
+
+
+
+static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg, int size,
+ int flags, struct scm_cookie *scm)
+{
+ struct sock *sk = sock->sk;
+ int noblock = flags & MSG_DONTWAIT;
+ struct sockaddr_un *sunaddr=msg->msg_name;
+ int copied = 0;
+ int check_creds = 0;
+ int target = 1;
+ int err = 0;
+
+ err = -EINVAL;
+ if (sk->state != TCP_ESTABLISHED)
+ goto out;
+
+ err = -EOPNOTSUPP;
+ if (flags&MSG_OOB)
+ goto out;
+
+ if (flags&MSG_WAITALL)
+ target = size;
+
+
+ msg->msg_namelen = 0;
+
+ /* Lock the socket to prevent queue disordering
+ * while sleeps in memcpy_tomsg
+ */
+
+ down(&sk->protinfo.af_unix.readsem);
+
+ do
+ {
+ int chunk;
+ struct sk_buff *skb;
+
+ skb=skb_dequeue(&sk->receive_queue);
+ if (skb==NULL)
+ {
+ if (copied >= target)
+ break;
+
+ /*
+ * POSIX 1003.1g mandates this order.
+ */
+
+ if ((err = sock_error(sk)) != 0)
+ break;
+ if (sk->shutdown & RCV_SHUTDOWN)
+ break;
+ err = -EAGAIN;
+ if (noblock)
+ break;
+ up(&sk->protinfo.af_unix.readsem);
+
+ unix_stream_data_wait(sk);
+
+ if (signal_pending(current)) {
+ err = -ERESTARTSYS;
+ goto out;
+ }
+ down(&sk->protinfo.af_unix.readsem);
+ continue;
+ }
+
+ if (check_creds) {
+ /* Never glue messages from different writers */
+ if (memcmp(UNIXCREDS(skb), &scm->creds, sizeof(scm->creds)) != 0) {
+ skb_queue_head(&sk->receive_queue, skb);
+ break;
+ }
+ } else {
+ /* Copy credentials */
+ scm->creds = *UNIXCREDS(skb);
+ check_creds = 1;
+ }
+
+ /* Copy address just once */
+ if (sunaddr)
+ {
+ unix_copy_addr(msg, skb->sk);
+ sunaddr = NULL;
+ }
+
+ chunk = min(skb->len, size);
+ if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
+ skb_queue_head(&sk->receive_queue, skb);
+ if (copied == 0)
+ copied = -EFAULT;
+ break;
+ }
+ copied += chunk;
+ size -= chunk;
+
+ /* Mark read part of skb as used */
+ if (!(flags & MSG_PEEK))
+ {
+ skb_pull(skb, chunk);
+
+ if (UNIXCB(skb).fp)
+ unix_detach_fds(scm, skb);
+
+ /* put the skb back if we didn't use it up.. */
+ if (skb->len)
+ {
+ skb_queue_head(&sk->receive_queue, skb);
+ break;
+ }
+
+ kfree_skb(skb);
+
+ if (scm->fp)
+ break;
+ }
+ else
+ {
+ /* It is questionable, see note in unix_dgram_recvmsg.
+ */
+ if (UNIXCB(skb).fp)
+ scm->fp = scm_fp_dup(UNIXCB(skb).fp);
+
+ /* put message back and return */
+ skb_queue_head(&sk->receive_queue, skb);
+ break;
+ }
+ } while (size);
+
+ up(&sk->protinfo.af_unix.readsem);
+out:
+ return copied ? : err;
+}
+
+static int unix_shutdown(struct socket *sock, int mode)
+{
+ struct sock *sk = sock->sk;
+ unix_socket *other;
+
+ mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN);
+
+ if (mode) {
+ unix_state_wlock(sk);
+ sk->shutdown |= mode;
+ other=unix_peer(sk);
+ if (other)
+ sock_hold(other);
+ unix_state_wunlock(sk);
+ sk->state_change(sk);
+
+ if (other && sk->type == SOCK_STREAM) {
+ int peer_mode = 0;
+
+ if (mode&RCV_SHUTDOWN)
+ peer_mode |= SEND_SHUTDOWN;
+ if (mode&SEND_SHUTDOWN)
+ peer_mode |= RCV_SHUTDOWN;
+ unix_state_wlock(other);
+ other->shutdown |= peer_mode;
+ unix_state_wunlock(other);
+ if (peer_mode&RCV_SHUTDOWN)
+ other->data_ready(other,0);
+ else
+ other->state_change(other);
+ }
+ if (other)
+ sock_put(other);
+ }
+ return 0;
+}
+
+
+static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+ struct sock *sk = sock->sk;
+ long amount=0;
+ int err;
+
+ switch(cmd)
+ {
+
+ case TIOCOUTQ:
+ amount = sk->sndbuf - atomic_read(&sk->wmem_alloc);
+ if(amount<0)
+ amount=0;
+ err = put_user(amount, (int *)arg);
+ break;
+ case TIOCINQ:
+ {
+ struct sk_buff *skb;
+ if (sk->state==TCP_LISTEN) {
+ err = -EINVAL;
+ break;
+ }
+
+ spin_lock(&sk->receive_queue.lock);
+ if((skb=skb_peek(&sk->receive_queue))!=NULL)
+ amount=skb->len;
+ spin_unlock(&sk->receive_queue.lock);
+ err = put_user(amount, (int *)arg);
+ break;
+ }
+
+ default:
+ err = -EINVAL;
+ break;
+ }
+ return err;
+}
+
+static unsigned int unix_poll(struct file * file, struct socket *sock, poll_table *wait)
+{
+ struct sock *sk = sock->sk;
+ unsigned int mask;
+
+ poll_wait(file, sk->sleep, wait);
+ mask = 0;
+
+ /* exceptional events? */
+ if (sk->err)
+ mask |= POLLERR;
+ if (sk->shutdown & RCV_SHUTDOWN)
+ mask |= POLLHUP;
+
+ /* readable? */
+ if (!skb_queue_empty(&sk->receive_queue))
+ mask |= POLLIN | POLLRDNORM;
+
+ /* Connection-based need to check for termination and startup */
+ if (sk->type == SOCK_STREAM && sk->state==TCP_CLOSE)
+ mask |= POLLHUP;
+
+ /*
+ * we set writable also when the other side has shut down the
+ * connection. This prevents stuck sockets.
+ */
+ if (unix_writable(sk))
+ mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
+
+ return mask;
+}
+
+
+#ifdef CONFIG_PROC_FS
+static int unix_read_proc(char *buffer, char **start, off_t offset,
+ int length, int *eof, void *data)
+{
+ off_t pos=0;
+ off_t begin=0;
+ int len=0;
+ int i;
+ unix_socket *s;
+
+ len+= sprintf(buffer,"Num RefCount Protocol Flags Type St "
+ "Inode Path\n");
+
+ read_lock(&unix_table_lock);
+ forall_unix_sockets (i,s)
+ {
+ unix_state_rlock(s);
+
+ len+=sprintf(buffer+len,"%p: %08X %08X %08X %04X %02X %5ld",
+ s,
+ atomic_read(&s->refcnt),
+ 0,
+ s->state == TCP_LISTEN ? SO_ACCEPTCON : 0,
+ s->type,
+ s->socket ?
+ (s->state == TCP_ESTABLISHED ? SS_CONNECTED : SS_UNCONNECTED) :
+ (s->state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING),
+ s->socket ? s->socket->inode->i_ino : 0);
+
+ if (s->protinfo.af_unix.addr)
+ {
+ buffer[len++] = ' ';
+ memcpy(buffer+len, s->protinfo.af_unix.addr->name->sun_path,
+ s->protinfo.af_unix.addr->len-sizeof(short));
+ if (!UNIX_ABSTRACT(s))
+ len--;
+ else
+ buffer[len] = '@';
+ len += s->protinfo.af_unix.addr->len - sizeof(short);
+ }
+ unix_state_runlock(s);
+
+ buffer[len++]='\n';
+
+ pos = begin + len;
+ if(pos<offset)
+ {
+ len=0;
+ begin=pos;
+ }
+ if(pos>offset+length)
+ goto done;
+ }
+ *eof = 1;
+done:
+ read_unlock(&unix_table_lock);
+ *start=buffer+(offset-begin);
+ len-=(offset-begin);
+ if(len>length)
+ len=length;
+ if (len < 0)
+ len = 0;
+ return len;
+}
+#endif
+
+struct proto_ops unix_stream_ops = {
+ PF_UNIX,
+
+ unix_release,
+ unix_bind,
+ unix_stream_connect,
+ unix_socketpair,
+ unix_accept,
+ unix_getname,
+ unix_poll,
+ unix_ioctl,
+ unix_listen,
+ unix_shutdown,
+ sock_no_setsockopt,
+ sock_no_getsockopt,
+ sock_no_fcntl,
+ unix_stream_sendmsg,
+ unix_stream_recvmsg,
+ sock_no_mmap
+};
+
+struct proto_ops unix_dgram_ops = {
+ PF_UNIX,
+
+ unix_release,
+ unix_bind,
+ unix_dgram_connect,
+ unix_socketpair,
+ sock_no_accept,
+ unix_getname,
+ datagram_poll,
+ unix_ioctl,
+ sock_no_listen,
+ unix_shutdown,
+ sock_no_setsockopt,
+ sock_no_getsockopt,
+ sock_no_fcntl,
+ unix_dgram_sendmsg,
+ unix_dgram_recvmsg,
+ sock_no_mmap
+};
+
+struct net_proto_family unix_family_ops = {
+ PF_UNIX,
+ unix_create
+};
+
+#ifdef MODULE
+#ifdef CONFIG_SYSCTL
+extern void unix_sysctl_register(void);
+extern void unix_sysctl_unregister(void);
+#endif
+
+int init_module(void)
+#else
+void __init unix_proto_init(struct net_proto *pro)
+#endif
+{
+ struct sk_buff *dummy_skb;
+ struct proc_dir_entry *ent;
+
+ printk(KERN_INFO "NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.\n");
+ if (sizeof(struct unix_skb_parms) > sizeof(dummy_skb->cb))
+ {
+ printk(KERN_CRIT "unix_proto_init: panic\n");
+#ifdef MODULE
+ return -1;
+#else
+ return;
+#endif
+ }
+ sock_register(&unix_family_ops);
+#ifdef CONFIG_PROC_FS
+ ent = create_proc_entry("net/unix", 0, 0);
+ ent->read_proc = unix_read_proc;
+#endif
+
+#ifdef MODULE
+#ifdef CONFIG_SYSCTL
+ unix_sysctl_register();
+#endif
+
+ return 0;
+#endif
+}
+
+#ifdef MODULE
+void cleanup_module(void)
+{
+ sock_unregister(PF_UNIX);
+#ifdef CONFIG_SYSCTL
+ unix_sysctl_unregister();
+#endif
+#ifdef CONFIG_PROC_FS
+ remove_proc_entry("net/unix", 0);
+#endif
+}
+#endif
+
+/*
+ * Local variables:
+ * compile-command: "gcc -g -D__KERNEL__ -Wall -O6 -I/usr/src/linux/include -c af_unix.c"
+ * End:
+ */