Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2  * NET          An implementation of the SOCKET network access protocol.
  3  *
  4  * Version:     @(#)socket.c    1.1.93  18/02/95
  5  *
  6  * Authors:     Orest Zborowski, <obz@Kodak.COM>
  7  *              Ross Biro, <bir7@leland.Stanford.Edu>
  8  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  9  *
 10  * Fixes:
 11  *              Anonymous       :       NOTSOCK/BADF cleanup. Error fix in
 12  *                                      shutdown()
 13  *              Alan Cox        :       verify_area() fixes
 14  *              Alan Cox        :       Removed DDI
 15  *              Jonathan Kamens :       SOCK_DGRAM reconnect bug
 16  *              Alan Cox        :       Moved a load of checks to the very
 17  *                                      top level.
 18  *              Alan Cox        :       Move address structures to/from user
 19  *                                      mode above the protocol layers.
 20  *              Rob Janssen     :       Allow 0 length sends.
 21  *              Alan Cox        :       Asynchronous I/O support (cribbed from the
 22  *                                      tty drivers).
 23  *              Niibe Yutaka    :       Asynchronous I/O for writes (4.4BSD style)
 24  *              Jeff Uphoff     :       Made max number of sockets command-line
 25  *                                      configurable.
 26  *              Matti Aarnio    :       Made the number of sockets dynamic,
 27  *                                      to be allocated when needed, and mr.
 28  *                                      Uphoff's max is used as max to be
 29  *                                      allowed to allocate.
 30  *              Linus           :       Argh. removed all the socket allocation
 31  *                                      altogether: it's in the inode now.
 32  *              Alan Cox        :       Made sock_alloc()/sock_release() public
 33  *                                      for NetROM and future kernel nfsd type
 34  *                                      stuff.
 35  *              Alan Cox        :       sendmsg/recvmsg basics.
 36  *              Tom Dyas        :       Export net symbols.
 37  *              Marcin Dalecki  :       Fixed problems with CONFIG_NET="n".
 38  *              Alan Cox        :       Added thread locking to sys_* calls
 39  *                                      for sockets. May have errors at the
 40  *                                      moment.
 41  *              Kevin Buhr      :       Fixed the dumb errors in the above.
 42  *              Andi Kleen      :       Some small cleanups, optimizations,
 43  *                                      and fixed a copy_from_user() bug.
 44  *              Tigran Aivazian :       sys_send(args) calls sys_sendto(args, NULL, 0)
 45  *              Tigran Aivazian :       Made listen(2) backlog sanity checks 
 46  *                                      protocol-independent
 47  *
 48  *
 49  *              This program is free software; you can redistribute it and/or
 50  *              modify it under the terms of the GNU General Public License
 51  *              as published by the Free Software Foundation; either version
 52  *              2 of the License, or (at your option) any later version.
 53  *
 54  *
 55  *      This module is effectively the top level interface to the BSD socket
 56  *      paradigm. 
 57  *
 58  *      Based upon Swansea University Computer Society NET3.039
 59  */
 60 
 61 #include <linux/config.h>
 62 #include <linux/mm.h>
 63 #include <linux/smp_lock.h>
 64 #include <linux/socket.h>
 65 #include <linux/file.h>
 66 #include <linux/net.h>
 67 #include <linux/interrupt.h>
 68 #include <linux/netdevice.h>
 69 #include <linux/proc_fs.h>
 70 #include <linux/seq_file.h>
 71 #include <linux/wanrouter.h>
 72 #include <linux/if_bridge.h>
 73 #include <linux/init.h>
 74 #include <linux/poll.h>
 75 #include <linux/cache.h>
 76 #include <linux/module.h>
 77 #include <linux/highmem.h>
 78 #include <linux/divert.h>
 79 #include <linux/mount.h>
 80 #include <linux/security.h>
 81 #include <linux/syscalls.h>
 82 #include <linux/compat.h>
 83 #include <linux/kmod.h>
 84 
 85 #ifdef CONFIG_NET_RADIO
 86 #include <linux/wireless.h>             /* Note : will define WIRELESS_EXT */
 87 #endif  /* CONFIG_NET_RADIO */
 88 
 89 #include <asm/uaccess.h>
 90 #include <asm/unistd.h>
 91 
 92 #include <net/compat.h>
 93 
 94 #include <net/sock.h>
 95 #include <linux/netfilter.h>
 96 
 97 static int sock_no_open(struct inode *irrelevant, struct file *dontcare);
 98 static ssize_t sock_aio_read(struct kiocb *iocb, char __user *buf,
 99                          size_t size, loff_t pos);
100 static ssize_t sock_aio_write(struct kiocb *iocb, const char __user *buf,
101                           size_t size, loff_t pos);
102 static int sock_mmap(struct file *file, struct vm_area_struct * vma);
103 
104 static int sock_close(struct inode *inode, struct file *file);
105 static unsigned int sock_poll(struct file *file,
106                               struct poll_table_struct *wait);
107 static long sock_ioctl(struct file *file,
108                       unsigned int cmd, unsigned long arg);
109 static int sock_fasync(int fd, struct file *filp, int on);
110 static ssize_t sock_readv(struct file *file, const struct iovec *vector,
111                           unsigned long count, loff_t *ppos);
112 static ssize_t sock_writev(struct file *file, const struct iovec *vector,
113                           unsigned long count, loff_t *ppos);
114 static ssize_t sock_sendpage(struct file *file, struct page *page,
115                              int offset, size_t size, loff_t *ppos, int more);
116 
117 
118 /*
119  *      Socket files have a set of 'special' operations as well as the generic file ones. These don't appear
120  *      in the operation structures but are done directly via the socketcall() multiplexor.
121  */
122 
123 static struct file_operations socket_file_ops = {
124         .owner =        THIS_MODULE,
125         .llseek =       no_llseek,
126         .aio_read =     sock_aio_read,
127         .aio_write =    sock_aio_write,
128         .poll =         sock_poll,
129         .unlocked_ioctl = sock_ioctl,
130         .mmap =         sock_mmap,
131         .open =         sock_no_open,   /* special open code to disallow open via /proc */
132         .release =      sock_close,
133         .fasync =       sock_fasync,
134         .readv =        sock_readv,
135         .writev =       sock_writev,
136         .sendpage =     sock_sendpage
137 };
138 
139 /*
140  *      The protocol list. Each protocol is registered in here.
141  */
142 
143 static struct net_proto_family *net_families[NPROTO];
144 
145 #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
146 static atomic_t net_family_lockct = ATOMIC_INIT(0);
147 static DEFINE_SPINLOCK(net_family_lock);
148 
149 /* The strategy is: modifications net_family vector are short, do not
150    sleep and veeery rare, but read access should be free of any exclusive
151    locks.
152  */
153 
154 static void net_family_write_lock(void)
155 {
156         spin_lock(&net_family_lock);
157         while (atomic_read(&net_family_lockct) != 0) {
158                 spin_unlock(&net_family_lock);
159 
160                 yield();
161 
162                 spin_lock(&net_family_lock);
163         }
164 }
165 
166 static __inline__ void net_family_write_unlock(void)
167 {
168         spin_unlock(&net_family_lock);
169 }
170 
171 static __inline__ void net_family_read_lock(void)
172 {
173         atomic_inc(&net_family_lockct);
174         spin_unlock_wait(&net_family_lock);
175 }
176 
177 static __inline__ void net_family_read_unlock(void)
178 {
179         atomic_dec(&net_family_lockct);
180 }
181 
182 #else
183 #define net_family_write_lock() do { } while(0)
184 #define net_family_write_unlock() do { } while(0)
185 #define net_family_read_lock() do { } while(0)
186 #define net_family_read_unlock() do { } while(0)
187 #endif
188 
189 
190 /*
191  *      Statistics counters of the socket lists
192  */
193 
194 static DEFINE_PER_CPU(int, sockets_in_use) = 0;
195 
196 /*
197  *      Support routines. Move socket addresses back and forth across the kernel/user
198  *      divide and look after the messy bits.
199  */
200 
201 #define MAX_SOCK_ADDR   128             /* 108 for Unix domain - 
202                                            16 for IP, 16 for IPX,
203                                            24 for IPv6,
204                                            about 80 for AX.25 
205                                            must be at least one bigger than
206                                            the AF_UNIX size (see net/unix/af_unix.c
207                                            :unix_mkname()).  
208                                          */
209                                          
210 /**
211  *      move_addr_to_kernel     -       copy a socket address into kernel space
212  *      @uaddr: Address in user space
213  *      @kaddr: Address in kernel space
214  *      @ulen: Length in user space
215  *
216  *      The address is copied into kernel space. If the provided address is
217  *      too long an error code of -EINVAL is returned. If the copy gives
218  *      invalid addresses -EFAULT is returned. On a success 0 is returned.
219  */
220 
221 int move_addr_to_kernel(void __user *uaddr, int ulen, void *kaddr)
222 {
223         if(ulen<0||ulen>MAX_SOCK_ADDR)
224                 return -EINVAL;
225         if(ulen==0)
226                 return 0;
227         if(copy_from_user(kaddr,uaddr,ulen))
228                 return -EFAULT;
229         return 0;
230 }
231 
232 /**
233  *      move_addr_to_user       -       copy an address to user space
234  *      @kaddr: kernel space address
235  *      @klen: length of address in kernel
236  *      @uaddr: user space address
237  *      @ulen: pointer to user length field
238  *
239  *      The value pointed to by ulen on entry is the buffer length available.
240  *      This is overwritten with the buffer space used. -EINVAL is returned
241  *      if an overlong buffer is specified or a negative buffer size. -EFAULT
242  *      is returned if either the buffer or the length field are not
243  *      accessible.
244  *      After copying the data up to the limit the user specifies, the true
245  *      length of the data is written over the length limit the user
246  *      specified. Zero is returned for a success.
247  */
248  
249 int move_addr_to_user(void *kaddr, int klen, void __user *uaddr, int __user *ulen)
250 {
251         int err;
252         int len;
253 
254         if((err=get_user(len, ulen)))
255                 return err;
256         if(len>klen)
257                 len=klen;
258         if(len<0 || len> MAX_SOCK_ADDR)
259                 return -EINVAL;
260         if(len)
261         {
262                 if(copy_to_user(uaddr,kaddr,len))
263                         return -EFAULT;
264         }
265         /*
266          *      "fromlen shall refer to the value before truncation.."
267          *                      1003.1g
268          */
269         return __put_user(klen, ulen);
270 }
271 
272 #define SOCKFS_MAGIC 0x534F434B
273 
274 static kmem_cache_t * sock_inode_cachep;
275 
276 static struct inode *sock_alloc_inode(struct super_block *sb)
277 {
278         struct socket_alloc *ei;
279         ei = (struct socket_alloc *)kmem_cache_alloc(sock_inode_cachep, SLAB_KERNEL);
280         if (!ei)
281                 return NULL;
282         init_waitqueue_head(&ei->socket.wait);
283         
284         ei->socket.fasync_list = NULL;
285         ei->socket.state = SS_UNCONNECTED;
286         ei->socket.flags = 0;
287         ei->socket.ops = NULL;
288         ei->socket.sk = NULL;
289         ei->socket.file = NULL;
290         ei->socket.passcred = 0;
291 
292         return &ei->vfs_inode;
293 }
294 
295 static void sock_destroy_inode(struct inode *inode)
296 {
297         kmem_cache_free(sock_inode_cachep,
298                         container_of(inode, struct socket_alloc, vfs_inode));
299 }
300 
301 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
302 {
303         struct socket_alloc *ei = (struct socket_alloc *) foo;
304 
305         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
306             SLAB_CTOR_CONSTRUCTOR)
307                 inode_init_once(&ei->vfs_inode);
308 }
309  
310 static int init_inodecache(void)
311 {
312         sock_inode_cachep = kmem_cache_create("sock_inode_cache",
313                                 sizeof(struct socket_alloc),
314                                 0, SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT,
315                                 init_once, NULL);
316         if (sock_inode_cachep == NULL)
317                 return -ENOMEM;
318         return 0;
319 }
320 
321 static struct super_operations sockfs_ops = {
322         .alloc_inode =  sock_alloc_inode,
323         .destroy_inode =sock_destroy_inode,
324         .statfs =       simple_statfs,
325 };
326 
327 static struct super_block *sockfs_get_sb(struct file_system_type *fs_type,
328         int flags, const char *dev_name, void *data)
329 {
330         return get_sb_pseudo(fs_type, "socket:", &sockfs_ops, SOCKFS_MAGIC);
331 }
332 
333 static struct vfsmount *sock_mnt;
334 
335 static struct file_system_type sock_fs_type = {
336         .name =         "sockfs",
337         .get_sb =       sockfs_get_sb,
338         .kill_sb =      kill_anon_super,
339 };
340 static int sockfs_delete_dentry(struct dentry *dentry)
341 {
342         return 1;
343 }
344 static struct dentry_operations sockfs_dentry_operations = {
345         .d_delete =     sockfs_delete_dentry,
346 };
347 
348 /*
349  *      Obtains the first available file descriptor and sets it up for use.
350  *
351  *      This function creates file structure and maps it to fd space
352  *      of current process. On success it returns file descriptor
353  *      and file struct implicitly stored in sock->file.
354  *      Note that another thread may close file descriptor before we return
355  *      from this function. We use the fact that now we do not refer
356  *      to socket after mapping. If one day we will need it, this
357  *      function will increment ref. count on file by 1.
358  *
359  *      In any case returned fd MAY BE not valid!
360  *      This race condition is unavoidable
361  *      with shared fd spaces, we cannot solve it inside kernel,
362  *      but we take care of internal coherence yet.
363  */
364 
365 int sock_map_fd(struct socket *sock)
366 {
367         int fd;
368         struct qstr this;
369         char name[32];
370 
371         /*
372          *      Find a file descriptor suitable for return to the user. 
373          */
374 
375         fd = get_unused_fd();
376         if (fd >= 0) {
377                 struct file *file = get_empty_filp();
378 
379                 if (!file) {
380                         put_unused_fd(fd);
381                         fd = -ENFILE;
382                         goto out;
383                 }
384 
385                 sprintf(name, "[%lu]", SOCK_INODE(sock)->i_ino);
386                 this.name = name;
387                 this.len = strlen(name);
388                 this.hash = SOCK_INODE(sock)->i_ino;
389 
390                 file->f_dentry = d_alloc(sock_mnt->mnt_sb->s_root, &this);
391                 if (!file->f_dentry) {
392                         put_filp(file);
393                         put_unused_fd(fd);
394                         fd = -ENOMEM;
395                         goto out;
396                 }
397                 file->f_dentry->d_op = &sockfs_dentry_operations;
398                 d_add(file->f_dentry, SOCK_INODE(sock));
399                 file->f_vfsmnt = mntget(sock_mnt);
400                 file->f_mapping = file->f_dentry->d_inode->i_mapping;
401 
402                 sock->file = file;
403                 file->f_op = SOCK_INODE(sock)->i_fop = &socket_file_ops;
404                 file->f_mode = FMODE_READ | FMODE_WRITE;
405                 file->f_flags = O_RDWR;
406                 file->f_pos = 0;
407                 fd_install(fd, file);
408         }
409 
410 out:
411         return fd;
412 }
413 
414 /**
415  *      sockfd_lookup   -       Go from a file number to its socket slot
416  *      @fd: file handle
417  *      @err: pointer to an error code return
418  *
419  *      The file handle passed in is locked and the socket it is bound
420  *      too is returned. If an error occurs the err pointer is overwritten
421  *      with a negative errno code and NULL is returned. The function checks
422  *      for both invalid handles and passing a handle which is not a socket.
423  *
424  *      On a success the socket object pointer is returned.
425  */
426 
427 struct socket *sockfd_lookup(int fd, int *err)
428 {
429         struct file *file;
430         struct inode *inode;
431         struct socket *sock;
432 
433         if (!(file = fget(fd)))
434         {
435                 *err = -EBADF;
436                 return NULL;
437         }
438 
439         inode = file->f_dentry->d_inode;
440         if (!inode->i_sock || !(sock = SOCKET_I(inode)))
441         {
442                 *err = -ENOTSOCK;
443                 fput(file);
444                 return NULL;
445         }
446 
447         if (sock->file != file) {
448                 printk(KERN_ERR "socki_lookup: socket file changed!\n");
449                 sock->file = file;
450         }
451         return sock;
452 }
453 
454 /**
455  *      sock_alloc      -       allocate a socket
456  *      
457  *      Allocate a new inode and socket object. The two are bound together
458  *      and initialised. The socket is then returned. If we are out of inodes
459  *      NULL is returned.
460  */
461 
462 static struct socket *sock_alloc(void)
463 {
464         struct inode * inode;
465         struct socket * sock;
466 
467         inode = new_inode(sock_mnt->mnt_sb);
468         if (!inode)
469                 return NULL;
470 
471         sock = SOCKET_I(inode);
472 
473         inode->i_mode = S_IFSOCK|S_IRWXUGO;
474         inode->i_sock = 1;
475         inode->i_uid = current->fsuid;
476         inode->i_gid = current->fsgid;
477 
478         get_cpu_var(sockets_in_use)++;
479         put_cpu_var(sockets_in_use);
480         return sock;
481 }
482 
483 /*
484  *      In theory you can't get an open on this inode, but /proc provides
485  *      a back door. Remember to keep it shut otherwise you'll let the
486  *      creepy crawlies in.
487  */
488   
489 static int sock_no_open(struct inode *irrelevant, struct file *dontcare)
490 {
491         return -ENXIO;
492 }
493 
494 struct file_operations bad_sock_fops = {
495         .owner = THIS_MODULE,
496         .open = sock_no_open,
497 };
498 
499 /**
500  *      sock_release    -       close a socket
501  *      @sock: socket to close
502  *
503  *      The socket is released from the protocol stack if it has a release
504  *      callback, and the inode is then released if the socket is bound to
505  *      an inode not a file. 
506  */
507  
508 void sock_release(struct socket *sock)
509 {
510         if (sock->ops) {
511                 struct module *owner = sock->ops->owner;
512 
513                 sock->ops->release(sock);
514                 sock->ops = NULL;
515                 module_put(owner);
516         }
517 
518         if (sock->fasync_list)
519                 printk(KERN_ERR "sock_release: fasync list not empty!\n");
520 
521         get_cpu_var(sockets_in_use)--;
522         put_cpu_var(sockets_in_use);
523         if (!sock->file) {
524                 iput(SOCK_INODE(sock));
525                 return;
526         }
527         sock->file=NULL;
528 }
529 
530 static inline int __sock_sendmsg(struct kiocb *iocb, struct socket *sock, 
531                                  struct msghdr *msg, size_t size)
532 {
533         struct sock_iocb *si = kiocb_to_siocb(iocb);
534         int err;
535 
536         si->sock = sock;
537         si->scm = NULL;
538         si->msg = msg;
539         si->size = size;
540 
541         err = security_socket_sendmsg(sock, msg, size);
542         if (err)
543                 return err;
544 
545         return sock->ops->sendmsg(iocb, sock, msg, size);
546 }
547 
548 int sock_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
549 {
550         struct kiocb iocb;
551         struct sock_iocb siocb;
552         int ret;
553 
554         init_sync_kiocb(&iocb, NULL);
555         iocb.private = &siocb;
556         ret = __sock_sendmsg(&iocb, sock, msg, size);
557         if (-EIOCBQUEUED == ret)
558                 ret = wait_on_sync_kiocb(&iocb);
559         return ret;
560 }
561 
562 int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
563                    struct kvec *vec, size_t num, size_t size)
564 {
565         mm_segment_t oldfs = get_fs();
566         int result;
567 
568         set_fs(KERNEL_DS);
569         /*
570          * the following is safe, since for compiler definitions of kvec and
571          * iovec are identical, yielding the same in-core layout and alignment
572          */
573         msg->msg_iov = (struct iovec *)vec,
574         msg->msg_iovlen = num;
575         result = sock_sendmsg(sock, msg, size);
576         set_fs(oldfs);
577         return result;
578 }
579 
580 static inline int __sock_recvmsg(struct kiocb *iocb, struct socket *sock, 
581                                  struct msghdr *msg, size_t size, int flags)
582 {
583         int err;
584         struct sock_iocb *si = kiocb_to_siocb(iocb);
585 
586         si->sock = sock;
587         si->scm = NULL;
588         si->msg = msg;
589         si->size = size;
590         si->flags = flags;
591 
592         err = security_socket_recvmsg(sock, msg, size, flags);
593         if (err)
594                 return err;
595 
596         return sock->ops->recvmsg(iocb, sock, msg, size, flags);
597 }
598 
599 int sock_recvmsg(struct socket *sock, struct msghdr *msg, 
600                  size_t size, int flags)
601 {
602         struct kiocb iocb;
603         struct sock_iocb siocb;
604         int ret;
605 
606         init_sync_kiocb(&iocb, NULL);
607         iocb.private = &siocb;
608         ret = __sock_recvmsg(&iocb, sock, msg, size, flags);
609         if (-EIOCBQUEUED == ret)
610                 ret = wait_on_sync_kiocb(&iocb);
611         return ret;
612 }
613 
614 int kernel_recvmsg(struct socket *sock, struct msghdr *msg, 
615                    struct kvec *vec, size_t num,
616                    size_t size, int flags)
617 {
618         mm_segment_t oldfs = get_fs();
619         int result;
620 
621         set_fs(KERNEL_DS);
622         /*
623          * the following is safe, since for compiler definitions of kvec and
624          * iovec are identical, yielding the same in-core layout and alignment
625          */
626         msg->msg_iov = (struct iovec *)vec,
627         msg->msg_iovlen = num;
628         result = sock_recvmsg(sock, msg, size, flags);
629         set_fs(oldfs);
630         return result;
631 }
632 
633 static void sock_aio_dtor(struct kiocb *iocb)
634 {
635         kfree(iocb->private);
636 }
637 
638 /*
639  *      Read data from a socket. ubuf is a user mode pointer. We make sure the user
640  *      area ubuf...ubuf+size-1 is writable before asking the protocol.
641  */
642 
643 static ssize_t sock_aio_read(struct kiocb *iocb, char __user *ubuf,
644                          size_t size, loff_t pos)
645 {
646         struct sock_iocb *x, siocb;
647         struct socket *sock;
648         int flags;
649 
650         if (pos != 0)
651                 return -ESPIPE;
652         if (size==0)            /* Match SYS5 behaviour */
653                 return 0;
654 
655         if (is_sync_kiocb(iocb))
656                 x = &siocb;
657         else {
658                 x = kmalloc(sizeof(struct sock_iocb), GFP_KERNEL);
659                 if (!x)
660                         return -ENOMEM;
661                 iocb->ki_dtor = sock_aio_dtor;
662         }
663         iocb->private = x;
664         x->kiocb = iocb;
665         sock = SOCKET_I(iocb->ki_filp->f_dentry->d_inode); 
666 
667         x->async_msg.msg_name = NULL;
668         x->async_msg.msg_namelen = 0;
669         x->async_msg.msg_iov = &x->async_iov;
670         x->async_msg.msg_iovlen = 1;
671         x->async_msg.msg_control = NULL;
672         x->async_msg.msg_controllen = 0;
673         x->async_iov.iov_base = ubuf;
674         x->async_iov.iov_len = size;
675         flags = !(iocb->ki_filp->f_flags & O_NONBLOCK) ? 0 : MSG_DONTWAIT;
676 
677         return __sock_recvmsg(iocb, sock, &x->async_msg, size, flags);
678 }
679 
680 
681 /*
682  *      Write data to a socket. We verify that the user area ubuf..ubuf+size-1
683  *      is readable by the user process.
684  */
685 
686 static ssize_t sock_aio_write(struct kiocb *iocb, const char __user *ubuf,
687                           size_t size, loff_t pos)
688 {
689         struct sock_iocb *x, siocb;
690         struct socket *sock;
691         
692         if (pos != 0)
693                 return -ESPIPE;
694         if(size==0)             /* Match SYS5 behaviour */
695                 return 0;
696 
697         if (is_sync_kiocb(iocb))
698                 x = &siocb;
699         else {
700                 x = kmalloc(sizeof(struct sock_iocb), GFP_KERNEL);
701                 if (!x)
702                         return -ENOMEM;
703                 iocb->ki_dtor = sock_aio_dtor;
704         }
705         iocb->private = x;
706         x->kiocb = iocb;
707         sock = SOCKET_I(iocb->ki_filp->f_dentry->d_inode); 
708 
709         x->async_msg.msg_name = NULL;
710         x->async_msg.msg_namelen = 0;
711         x->async_msg.msg_iov = &x->async_iov;
712         x->async_msg.msg_iovlen = 1;
713         x->async_msg.msg_control = NULL;
714         x->async_msg.msg_controllen = 0;
715         x->async_msg.msg_flags = !(iocb->ki_filp->f_flags & O_NONBLOCK) ? 0 : MSG_DONTWAIT;
716         if (sock->type == SOCK_SEQPACKET)
717                 x->async_msg.msg_flags |= MSG_EOR;
718         x->async_iov.iov_base = (void __user *)ubuf;
719         x->async_iov.iov_len = size;
720         
721         return __sock_sendmsg(iocb, sock, &x->async_msg, size);
722 }
723 
724 ssize_t sock_sendpage(struct file *file, struct page *page,
725                       int offset, size_t size, loff_t *ppos, int more)
726 {
727         struct socket *sock;
728         int flags;
729 
730         sock = SOCKET_I(file->f_dentry->d_inode);
731 
732         flags = !(file->f_flags & O_NONBLOCK) ? 0 : MSG_DONTWAIT;
733         if (more)
734                 flags |= MSG_MORE;
735 
736         return sock->ops->sendpage(sock, page, offset, size, flags);
737 }
738 
739 static int sock_readv_writev(int type, struct inode * inode,
740                              struct file * file, const struct iovec * iov,
741                              long count, size_t size)
742 {
743         struct msghdr msg;
744         struct socket *sock;
745 
746         sock = SOCKET_I(inode);
747 
748         msg.msg_name = NULL;
749         msg.msg_namelen = 0;
750         msg.msg_control = NULL;
751         msg.msg_controllen = 0;
752         msg.msg_iov = (struct iovec *) iov;
753         msg.msg_iovlen = count;
754         msg.msg_flags = (file->f_flags & O_NONBLOCK) ? MSG_DONTWAIT : 0;
755 
756         /* read() does a VERIFY_WRITE */
757         if (type == VERIFY_WRITE)
758                 return sock_recvmsg(sock, &msg, size, msg.msg_flags);
759 
760         if (sock->type == SOCK_SEQPACKET)
761                 msg.msg_flags |= MSG_EOR;
762 
763         return sock_sendmsg(sock, &msg, size);
764 }
765 
766 static ssize_t sock_readv(struct file *file, const struct iovec *vector,
767                           unsigned long count, loff_t *ppos)
768 {
769         size_t tot_len = 0;
770         int i;
771         for (i = 0 ; i < count ; i++)
772                 tot_len += vector[i].iov_len;
773         return sock_readv_writev(VERIFY_WRITE, file->f_dentry->d_inode,
774                                  file, vector, count, tot_len);
775 }
776         
777 static ssize_t sock_writev(struct file *file, const struct iovec *vector,
778                            unsigned long count, loff_t *ppos)
779 {
780         size_t tot_len = 0;
781         int i;
782         for (i = 0 ; i < count ; i++)
783                 tot_len += vector[i].iov_len;
784         return sock_readv_writev(VERIFY_READ, file->f_dentry->d_inode,
785                                  file, vector, count, tot_len);
786 }
787 
788 
789 /*
790  * Atomic setting of ioctl hooks to avoid race
791  * with module unload.
792  */
793 
794 static DECLARE_MUTEX(br_ioctl_mutex);
795 static int (*br_ioctl_hook)(unsigned int cmd, void __user *arg) = NULL;
796 
797 void brioctl_set(int (*hook)(unsigned int, void __user *))
798 {
799         down(&br_ioctl_mutex);
800         br_ioctl_hook = hook;
801         up(&br_ioctl_mutex);
802 }
803 EXPORT_SYMBOL(brioctl_set);
804 
805 static DECLARE_MUTEX(vlan_ioctl_mutex);
806 static int (*vlan_ioctl_hook)(void __user *arg);
807 
808 void vlan_ioctl_set(int (*hook)(void __user *))
809 {
810         down(&vlan_ioctl_mutex);
811         vlan_ioctl_hook = hook;
812         up(&vlan_ioctl_mutex);
813 }
814 EXPORT_SYMBOL(vlan_ioctl_set);
815 
816 static DECLARE_MUTEX(dlci_ioctl_mutex);
817 static int (*dlci_ioctl_hook)(unsigned int, void __user *);
818 
819 void dlci_ioctl_set(int (*hook)(unsigned int, void __user *))
820 {
821         down(&dlci_ioctl_mutex);
822         dlci_ioctl_hook = hook;
823         up(&dlci_ioctl_mutex);
824 }
825 EXPORT_SYMBOL(dlci_ioctl_set);
826 
827 /*
828  *      With an ioctl, arg may well be a user mode pointer, but we don't know
829  *      what to do with it - that's up to the protocol still.
830  */
831 
832 static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
833 {
834         struct socket *sock;
835         void __user *argp = (void __user *)arg;
836         int pid, err;
837 
838         sock = SOCKET_I(file->f_dentry->d_inode);
839         if (cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15)) {
840                 err = dev_ioctl(cmd, argp);
841         } else
842 #ifdef WIRELESS_EXT
843         if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) {
844                 err = dev_ioctl(cmd, argp);
845         } else
846 #endif  /* WIRELESS_EXT */
847         switch (cmd) {
848                 case FIOSETOWN:
849                 case SIOCSPGRP:
850                         err = -EFAULT;
851                         if (get_user(pid, (int __user *)argp))
852                                 break;
853                         err = f_setown(sock->file, pid, 1);
854                         break;
855                 case FIOGETOWN:
856                 case SIOCGPGRP:
857                         err = put_user(sock->file->f_owner.pid, (int __user *)argp);
858                         break;
859                 case SIOCGIFBR:
860                 case SIOCSIFBR:
861                 case SIOCBRADDBR:
862                 case SIOCBRDELBR:
863                         err = -ENOPKG;
864                         if (!br_ioctl_hook)
865                                 request_module("bridge");
866 
867                         down(&br_ioctl_mutex);
868                         if (br_ioctl_hook) 
869                                 err = br_ioctl_hook(cmd, argp);
870                         up(&br_ioctl_mutex);
871                         break;
872                 case SIOCGIFVLAN:
873                 case SIOCSIFVLAN:
874                         err = -ENOPKG;
875                         if (!vlan_ioctl_hook)
876                                 request_module("8021q");
877 
878                         down(&vlan_ioctl_mutex);
879                         if (vlan_ioctl_hook)
880                                 err = vlan_ioctl_hook(argp);
881                         up(&vlan_ioctl_mutex);
882                         break;
883                 case SIOCGIFDIVERT:
884                 case SIOCSIFDIVERT:
885                 /* Convert this to call through a hook */
886                         err = divert_ioctl(cmd, argp);
887                         break;
888                 case SIOCADDDLCI:
889                 case SIOCDELDLCI:
890                         err = -ENOPKG;
891                         if (!dlci_ioctl_hook)
892                                 request_module("dlci");
893 
894                         if (dlci_ioctl_hook) {
895                                 down(&dlci_ioctl_mutex);
896                                 err = dlci_ioctl_hook(cmd, argp);
897                                 up(&dlci_ioctl_mutex);
898                         }
899                         break;
900                 default:
901                         err = sock->ops->ioctl(sock, cmd, arg);
902                         break;
903         }
904         return err;
905 }
906 
907 int sock_create_lite(int family, int type, int protocol, struct socket **res)
908 {
909         int err;
910         struct socket *sock = NULL;
911         
912         err = security_socket_create(family, type, protocol, 1);
913         if (err)
914                 goto out;
915 
916         sock = sock_alloc();
917         if (!sock) {
918                 err = -ENOMEM;
919                 goto out;
920         }
921 
922         security_socket_post_create(sock, family, type, protocol, 1);
923         sock->type = type;
924 out:
925         *res = sock;
926         return err;
927 }
928 
929 /* No kernel lock held - perfect */
930 static unsigned int sock_poll(struct file *file, poll_table * wait)
931 {
932         struct socket *sock;
933 
934         /*
935          *      We can't return errors to poll, so it's either yes or no. 
936          */
937         sock = SOCKET_I(file->f_dentry->d_inode);
938         return sock->ops->poll(file, sock, wait);
939 }
940 
941 static int sock_mmap(struct file * file, struct vm_area_struct * vma)
942 {
943         struct socket *sock = SOCKET_I(file->f_dentry->d_inode);
944 
945         return sock->ops->mmap(file, sock, vma);
946 }
947 
948 int sock_close(struct inode *inode, struct file *filp)
949 {
950         /*
951          *      It was possible the inode is NULL we were 
952          *      closing an unfinished socket. 
953          */
954 
955         if (!inode)
956         {
957                 printk(KERN_DEBUG "sock_close: NULL inode\n");
958                 return 0;
959         }
960         sock_fasync(-1, filp, 0);
961         sock_release(SOCKET_I(inode));
962         return 0;
963 }
964 
965 /*
966  *      Update the socket async list
967  *
968  *      Fasync_list locking strategy.
969  *
970  *      1. fasync_list is modified only under process context socket lock
971  *         i.e. under semaphore.
972  *      2. fasync_list is used under read_lock(&sk->sk_callback_lock)
973  *         or under socket lock.
974  *      3. fasync_list can be used from softirq context, so that
975  *         modification under socket lock have to be enhanced with
976  *         write_lock_bh(&sk->sk_callback_lock).
977  *                                                      --ANK (990710)
978  */
979 
980 static int sock_fasync(int fd, struct file *filp, int on)
981 {
982         struct fasync_struct *fa, *fna=NULL, **prev;
983         struct socket *sock;
984         struct sock *sk;
985 
986         if (on)
987         {
988                 fna=(struct fasync_struct *)kmalloc(sizeof(struct fasync_struct), GFP_KERNEL);
989                 if(fna==NULL)
990                         return -ENOMEM;
991         }
992 
993         sock = SOCKET_I(filp->f_dentry->d_inode);
994 
995         if ((sk=sock->sk) == NULL) {
996                 if (fna)
997                         kfree(fna);
998                 return -EINVAL;
999         }
1000 
1001         lock_sock(sk);
1002 
1003         prev=&(sock->fasync_list);
1004 
1005         for (fa=*prev; fa!=NULL; prev=&fa->fa_next,fa=*prev)
1006                 if (fa->fa_file==filp)
1007                         break;
1008 
1009         if(on)
1010         {
1011                 if(fa!=NULL)
1012                 {
1013                         write_lock_bh(&sk->sk_callback_lock);
1014                         fa->fa_fd=fd;
1015                         write_unlock_bh(&sk->sk_callback_lock);
1016 
1017                         kfree(fna);
1018                         goto out;
1019                 }
1020                 fna->fa_file=filp;
1021                 fna->fa_fd=fd;
1022                 fna->magic=FASYNC_MAGIC;
1023                 fna->fa_next=sock->fasync_list;
1024                 write_lock_bh(&sk->sk_callback_lock);
1025                 sock->fasync_list=fna;
1026                 write_unlock_bh(&sk->sk_callback_lock);
1027         }
1028         else
1029         {
1030                 if (fa!=NULL)
1031                 {
1032                         write_lock_bh(&sk->sk_callback_lock);
1033                         *prev=fa->fa_next;
1034                         write_unlock_bh(&sk->sk_callback_lock);
1035                         kfree(fa);
1036                 }
1037         }
1038 
1039 out:
1040         release_sock(sock->sk);
1041         return 0;
1042 }
1043 
1044 /* This function may be called only under socket lock or callback_lock */
1045 
1046 int sock_wake_async(struct socket *sock, int how, int band)
1047 {
1048         if (!sock || !sock->fasync_list)
1049                 return -1;
1050         switch (how)
1051         {
1052         case 1:
1053                 
1054                 if (test_bit(SOCK_ASYNC_WAITDATA, &sock->flags))
1055                         break;
1056                 goto call_kill;
1057         case 2:
1058                 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags))
1059                         break;
1060                 /* fall through */
1061         case 0:
1062         call_kill:
1063                 __kill_fasync(sock->fasync_list, SIGIO, band);
1064                 break;
1065         case 3:
1066                 __kill_fasync(sock->fasync_list, SIGURG, band);
1067         }
1068         return 0;
1069 }
1070 
1071 static int __sock_create(int family, int type, int protocol, struct socket **res, int kern)
1072 {
1073         int err;
1074         struct socket *sock;
1075 
1076         /*
1077          *      Check protocol is in range
1078          */
1079         if (family < 0 || family >= NPROTO)
1080                 return -EAFNOSUPPORT;
1081         if (type < 0 || type >= SOCK_MAX)
1082                 return -EINVAL;
1083 
1084         /* Compatibility.
1085 
1086            This uglymoron is moved from INET layer to here to avoid
1087            deadlock in module load.
1088          */
1089         if (family == PF_INET && type == SOCK_PACKET) {
1090                 static int warned; 
1091                 if (!warned) {
1092                         warned = 1;
1093                         printk(KERN_INFO "%s uses obsolete (PF_INET,SOCK_PACKET)\n", current->comm);
1094                 }
1095                 family = PF_PACKET;
1096         }
1097 
1098         err = security_socket_create(family, type, protocol, kern);
1099         if (err)
1100                 return err;
1101                 
1102 #if defined(CONFIG_KMOD)
1103         /* Attempt to load a protocol module if the find failed. 
1104          * 
1105          * 12/09/1996 Marcin: But! this makes REALLY only sense, if the user 
1106          * requested real, full-featured networking support upon configuration.
1107          * Otherwise module support will break!
1108          */
1109         if (net_families[family]==NULL)
1110         {
1111                 request_module("net-pf-%d",family);
1112         }
1113 #endif
1114 
1115         net_family_read_lock();
1116         if (net_families[family] == NULL) {
1117                 err = -EAFNOSUPPORT;
1118                 goto out;
1119         }
1120 
1121 /*
1122  *      Allocate the socket and allow the family to set things up. if
1123  *      the protocol is 0, the family is instructed to select an appropriate
1124  *      default.
1125  */
1126 
1127         if (!(sock = sock_alloc())) {
1128                 printk(KERN_WARNING "socket: no more sockets\n");
1129                 err = -ENFILE;          /* Not exactly a match, but its the
1130                                            closest posix thing */
1131                 goto out;
1132         }
1133 
1134         sock->type  = type;
1135 
1136         /*
1137          * We will call the ->create function, that possibly is in a loadable
1138          * module, so we have to bump that loadable module refcnt first.
1139          */
1140         err = -EAFNOSUPPORT;
1141         if (!try_module_get(net_families[family]->owner))
1142                 goto out_release;
1143 
1144         if ((err = net_families[family]->create(sock, protocol)) < 0)
1145                 goto out_module_put;
1146         /*
1147          * Now to bump the refcnt of the [loadable] module that owns this
1148          * socket at sock_release time we decrement its refcnt.
1149          */
1150         if (!try_module_get(sock->ops->owner)) {
1151                 sock->ops = NULL;
1152                 goto out_module_put;
1153         }
1154         /*
1155          * Now that we're done with the ->create function, the [loadable]
1156          * module can have its refcnt decremented
1157          */
1158         module_put(net_families[family]->owner);
1159         *res = sock;
1160         security_socket_post_create(sock, family, type, protocol, kern);
1161 
1162 out:
1163         net_family_read_unlock();
1164         return err;
1165 out_module_put:
1166         module_put(net_families[family]->owner);
1167 out_release:
1168         sock_release(sock);
1169         goto out;
1170 }
1171 
1172 int sock_create(int family, int type, int protocol, struct socket **res)
1173 {
1174         return __sock_create(family, type, protocol, res, 0);
1175 }
1176 
1177 int sock_create_kern(int family, int type, int protocol, struct socket **res)
1178 {
1179         return __sock_create(family, type, protocol, res, 1);
1180 }
1181 
1182 asmlinkage long sys_socket(int family, int type, int protocol)
1183 {
1184         int retval;
1185         struct socket *sock;
1186 
1187         retval = sock_create(family, type, protocol, &sock);
1188         if (retval < 0)
1189                 goto out;
1190 
1191         retval = sock_map_fd(sock);
1192         if (retval < 0)
1193                 goto out_release;
1194 
1195 out:
1196         /* It may be already another descriptor 8) Not kernel problem. */
1197         return retval;
1198 
1199 out_release:
1200         sock_release(sock);
1201         return retval;
1202 }
1203 
1204 /*
1205  *      Create a pair of connected sockets.
1206  */
1207 
1208 asmlinkage long sys_socketpair(int family, int type, int protocol, int __user *usockvec)
1209 {
1210         struct socket *sock1, *sock2;
1211         int fd1, fd2, err;
1212 
1213         /*
1214          * Obtain the first socket and check if the underlying protocol
1215          * supports the socketpair call.
1216          */
1217 
1218         err = sock_create(family, type, protocol, &sock1);
1219         if (err < 0)
1220                 goto out;
1221 
1222         err = sock_create(family, type, protocol, &sock2);
1223         if (err < 0)
1224                 goto out_release_1;
1225 
1226         err = sock1->ops->socketpair(sock1, sock2);
1227         if (err < 0) 
1228                 goto out_release_both;
1229 
1230         fd1 = fd2 = -1;
1231 
1232         err = sock_map_fd(sock1);
1233         if (err < 0)
1234                 goto out_release_both;
1235         fd1 = err;
1236 
1237         err = sock_map_fd(sock2);
1238         if (err < 0)
1239                 goto out_close_1;
1240         fd2 = err;
1241 
1242         /* fd1 and fd2 may be already another descriptors.
1243          * Not kernel problem.
1244          */
1245 
1246         err = put_user(fd1, &usockvec[0]); 
1247         if (!err)
1248                 err = put_user(fd2, &usockvec[1]);
1249         if (!err)
1250                 return 0;
1251 
1252         sys_close(fd2);
1253         sys_close(fd1);
1254         return err;
1255 
1256 out_close_1:
1257         sock_release(sock2);
1258         sys_close(fd1);
1259         return err;
1260 
1261 out_release_both:
1262         sock_release(sock2);
1263 out_release_1:
1264         sock_release(sock1);
1265 out:
1266         return err;
1267 }
1268 
1269 
1270 /*
1271  *      Bind a name to a socket. Nothing much to do here since it's
1272  *      the protocol's responsibility to handle the local address.
1273  *
1274  *      We move the socket address to kernel space before we call
1275  *      the protocol layer (having also checked the address is ok).
1276  */
1277 
1278 asmlinkage long sys_bind(int fd, struct sockaddr __user *umyaddr, int addrlen)
1279 {
1280         struct socket *sock;
1281         char address[MAX_SOCK_ADDR];
1282         int err;
1283 
1284         if((sock = sockfd_lookup(fd,&err))!=NULL)
1285         {
1286                 if((err=move_addr_to_kernel(umyaddr,addrlen,address))>=0) {
1287                         err = security_socket_bind(sock, (struct sockaddr *)address, addrlen);
1288                         if (err) {
1289                                 sockfd_put(sock);
1290                                 return err;
1291                         }
1292                         err = sock->ops->bind(sock, (struct sockaddr *)address, addrlen);
1293                 }
1294                 sockfd_put(sock);
1295         }                       
1296         return err;
1297 }
1298 
1299 
1300 /*
1301  *      Perform a listen. Basically, we allow the protocol to do anything
1302  *      necessary for a listen, and if that works, we mark the socket as
1303  *      ready for listening.
1304  */
1305 
1306 int sysctl_somaxconn = SOMAXCONN;
1307 
1308 asmlinkage long sys_listen(int fd, int backlog)
1309 {
1310         struct socket *sock;
1311         int err;
1312         
1313         if ((sock = sockfd_lookup(fd, &err)) != NULL) {
1314                 if ((unsigned) backlog > sysctl_somaxconn)
1315                         backlog = sysctl_somaxconn;
1316 
1317                 err = security_socket_listen(sock, backlog);
1318                 if (err) {
1319                         sockfd_put(sock);
1320                         return err;
1321                 }
1322 
1323                 err=sock->ops->listen(sock, backlog);
1324                 sockfd_put(sock);
1325         }
1326         return err;
1327 }
1328 
1329 
1330 /*
1331  *      For accept, we attempt to create a new socket, set up the link
1332  *      with the client, wake up the client, then return the new
1333  *      connected fd. We collect the address of the connector in kernel
1334  *      space and move it to user at the very end. This is unclean because
1335  *      we open the socket then return an error.
1336  *
1337  *      1003.1g adds the ability to recvmsg() to query connection pending
1338  *      status to recvmsg. We need to add that support in a way thats
1339  *      clean when we restucture accept also.
1340  */
1341 
1342 asmlinkage long sys_accept(int fd, struct sockaddr __user *upeer_sockaddr, int __user *upeer_addrlen)
1343 {
1344         struct socket *sock, *newsock;
1345         int err, len;
1346         char address[MAX_SOCK_ADDR];
1347 
1348         sock = sockfd_lookup(fd, &err);
1349         if (!sock)
1350                 goto out;
1351 
1352         err = -ENFILE;
1353         if (!(newsock = sock_alloc())) 
1354                 goto out_put;
1355 
1356         newsock->type = sock->type;
1357         newsock->ops = sock->ops;
1358 
1359         err = security_socket_accept(sock, newsock);
1360         if (err)
1361                 goto out_release;
1362 
1363         /*
1364          * We don't need try_module_get here, as the listening socket (sock)
1365          * has the protocol module (sock->ops->owner) held.
1366          */
1367         __module_get(newsock->ops->owner);
1368 
1369         err = sock->ops->accept(sock, newsock, sock->file->f_flags);
1370         if (err < 0)
1371                 goto out_release;
1372 
1373         if (upeer_sockaddr) {
1374                 if(newsock->ops->getname(newsock, (struct sockaddr *)address, &len, 2)<0) {
1375                         err = -ECONNABORTED;
1376                         goto out_release;
1377                 }
1378                 err = move_addr_to_user(address, len, upeer_sockaddr, upeer_addrlen);
1379                 if (err < 0)
1380                         goto out_release;
1381         }
1382 
1383         /* File flags are not inherited via accept() unlike another OSes. */
1384 
1385         if ((err = sock_map_fd(newsock)) < 0)
1386                 goto out_release;
1387 
1388         security_socket_post_accept(sock, newsock);
1389 
1390 out_put:
1391         sockfd_put(sock);
1392 out:
1393         return err;
1394 out_release:
1395         sock_release(newsock);
1396         goto out_put;
1397 }
1398 
1399 
1400 /*
1401  *      Attempt to connect to a socket with the server address.  The address
1402  *      is in user space so we verify it is OK and move it to kernel space.
1403  *
1404  *      For 1003.1g we need to add clean support for a bind to AF_UNSPEC to
1405  *      break bindings
1406  *
1407  *      NOTE: 1003.1g draft 6.3 is broken with respect to AX.25/NetROM and
1408  *      other SEQPACKET protocols that take time to connect() as it doesn't
1409  *      include the -EINPROGRESS status for such sockets.
1410  */
1411 
1412 asmlinkage long sys_connect(int fd, struct sockaddr __user *uservaddr, int addrlen)
1413 {
1414         struct socket *sock;
1415         char address[MAX_SOCK_ADDR];
1416         int err;
1417 
1418         sock = sockfd_lookup(fd, &err);
1419         if (!sock)
1420                 goto out;
1421         err = move_addr_to_kernel(uservaddr, addrlen, address);
1422         if (err < 0)
1423                 goto out_put;
1424 
1425         err = security_socket_connect(sock, (struct sockaddr *)address, addrlen);
1426         if (err)
1427                 goto out_put;
1428 
1429         err = sock->ops->connect(sock, (struct sockaddr *) address, addrlen,
1430                                  sock->file->f_flags);
1431 out_put:
1432         sockfd_put(sock);
1433 out:
1434         return err;
1435 }
1436 
1437 /*
1438  *      Get the local address ('name') of a socket object. Move the obtained
1439  *      name to user space.
1440  */
1441 
1442 asmlinkage long sys_getsockname(int fd, struct sockaddr __user *usockaddr, int __user *usockaddr_len)
1443 {
1444         struct socket *sock;
1445         char address[MAX_SOCK_ADDR];
1446         int len, err;
1447         
1448         sock = sockfd_lookup(fd, &err);
1449         if (!sock)
1450                 goto out;
1451 
1452         err = security_socket_getsockname(sock);
1453         if (err)
1454                 goto out_put;
1455 
1456         err = sock->ops->getname(sock, (struct sockaddr *)address, &len, 0);
1457         if (err)
1458                 goto out_put;
1459         err = move_addr_to_user(address, len, usockaddr, usockaddr_len);
1460 
1461 out_put:
1462         sockfd_put(sock);
1463 out:
1464         return err;
1465 }
1466 
1467 /*
1468  *      Get the remote address ('name') of a socket object. Move the obtained
1469  *      name to user space.
1470  */
1471 
1472 asmlinkage long sys_getpeername(int fd, struct sockaddr __user *usockaddr, int __user *usockaddr_len)
1473 {
1474         struct socket *sock;
1475         char address[MAX_SOCK_ADDR];
1476         int len, err;
1477 
1478         if ((sock = sockfd_lookup(fd, &err))!=NULL)
1479         {
1480                 err = security_socket_getpeername(sock);
1481                 if (err) {
1482                         sockfd_put(sock);
1483                         return err;
1484                 }
1485 
1486                 err = sock->ops->getname(sock, (struct sockaddr *)address, &len, 1);
1487                 if (!err)
1488                         err=move_addr_to_user(address,len, usockaddr, usockaddr_len);
1489                 sockfd_put(sock);
1490         }
1491         return err;
1492 }
1493 
1494 /*
1495  *      Send a datagram to a given address. We move the address into kernel
1496  *      space and check the user space data area is readable before invoking
1497  *      the protocol.
1498  */
1499 
1500 asmlinkage long sys_sendto(int fd, void __user * buff, size_t len, unsigned flags,
1501                            struct sockaddr __user *addr, int addr_len)
1502 {
1503         struct socket *sock;
1504         char address[MAX_SOCK_ADDR];
1505         int err;
1506         struct msghdr msg;
1507         struct iovec iov;
1508         
1509         sock = sockfd_lookup(fd, &err);
1510         if (!sock)
1511                 goto out;
1512         iov.iov_base=buff;
1513         iov.iov_len=len;
1514         msg.msg_name=NULL;
1515         msg.msg_iov=&iov;
1516         msg.msg_iovlen=1;
1517         msg.msg_control=NULL;
1518         msg.msg_controllen=0;
1519         msg.msg_namelen=0;
1520         if(addr)
1521         {
1522                 err = move_addr_to_kernel(addr, addr_len, address);
1523                 if (err < 0)
1524                         goto out_put;
1525                 msg.msg_name=address;
1526                 msg.msg_namelen=addr_len;
1527         }
1528         if (sock->file->f_flags & O_NONBLOCK)
1529                 flags |= MSG_DONTWAIT;
1530         msg.msg_flags = flags;
1531         err = sock_sendmsg(sock, &msg, len);
1532 
1533 out_put:                
1534         sockfd_put(sock);
1535 out:
1536         return err;
1537 }
1538 
1539 /*
1540  *      Send a datagram down a socket. 
1541  */
1542 
1543 asmlinkage long sys_send(int fd, void __user * buff, size_t len, unsigned flags)
1544 {
1545         return sys_sendto(fd, buff, len, flags, NULL, 0);
1546 }
1547 
1548 /*
1549  *      Receive a frame from the socket and optionally record the address of the 
1550  *      sender. We verify the buffers are writable and if needed move the
1551  *      sender address from kernel to user space.
1552  */
1553 
1554 asmlinkage long sys_recvfrom(int fd, void __user * ubuf, size_t size, unsigned flags,
1555                              struct sockaddr __user *addr, int __user *addr_len)
1556 {
1557         struct socket *sock;
1558         struct iovec iov;
1559         struct msghdr msg;
1560         char address[MAX_SOCK_ADDR];
1561         int err,err2;
1562 
1563         sock = sockfd_lookup(fd, &err);
1564         if (!sock)
1565                 goto out;
1566 
1567         msg.msg_control=NULL;
1568         msg.msg_controllen=0;
1569         msg.msg_iovlen=1;
1570         msg.msg_iov=&iov;
1571         iov.iov_len=size;
1572         iov.iov_base=ubuf;
1573         msg.msg_name=address;
1574         msg.msg_namelen=MAX_SOCK_ADDR;
1575         if (sock->file->f_flags & O_NONBLOCK)
1576                 flags |= MSG_DONTWAIT;
1577         err=sock_recvmsg(sock, &msg, size, flags);
1578 
1579         if(err >= 0 && addr != NULL)
1580         {
1581                 err2=move_addr_to_user(address, msg.msg_namelen, addr, addr_len);
1582                 if(err2<0)
1583                         err=err2;
1584         }
1585         sockfd_put(sock);                       
1586 out:
1587         return err;
1588 }
1589 
1590 /*
1591  *      Receive a datagram from a socket. 
1592  */
1593 
1594 asmlinkage long sys_recv(int fd, void __user * ubuf, size_t size, unsigned flags)
1595 {
1596         return sys_recvfrom(fd, ubuf, size, flags, NULL, NULL);
1597 }
1598 
1599 /*
1600  *      Set a socket option. Because we don't know the option lengths we have
1601  *      to pass the user mode parameter for the protocols to sort out.
1602  */
1603 
1604 asmlinkage long sys_setsockopt(int fd, int level, int optname, char __user *optval, int optlen)
1605 {
1606         int err;
1607         struct socket *sock;
1608 
1609         if (optlen < 0)
1610                 return -EINVAL;
1611                         
1612         if ((sock = sockfd_lookup(fd, &err))!=NULL)
1613         {
1614                 err = security_socket_setsockopt(sock,level,optname);
1615                 if (err) {
1616                         sockfd_put(sock);
1617                         return err;
1618                 }
1619 
1620                 if (level == SOL_SOCKET)
1621                         err=sock_setsockopt(sock,level,optname,optval,optlen);
1622                 else
1623                         err=sock->ops->setsockopt(sock, level, optname, optval, optlen);
1624                 sockfd_put(sock);
1625         }
1626         return err;
1627 }
1628 
1629 /*
1630  *      Get a socket option. Because we don't know the option lengths we have
1631  *      to pass a user mode parameter for the protocols to sort out.
1632  */
1633 
1634 asmlinkage long sys_getsockopt(int fd, int level, int optname, char __user *optval, int __user *optlen)
1635 {
1636         int err;
1637         struct socket *sock;
1638 
1639         if ((sock = sockfd_lookup(fd, &err))!=NULL)
1640         {
1641                 err = security_socket_getsockopt(sock, level, 
1642                                                            optname);
1643                 if (err) {
1644                         sockfd_put(sock);
1645                         return err;
1646                 }
1647 
1648                 if (level == SOL_SOCKET)
1649                         err=sock_getsockopt(sock,level,optname,optval,optlen);
1650                 else
1651                         err=sock->ops->getsockopt(sock, level, optname, optval, optlen);
1652                 sockfd_put(sock);
1653         }
1654         return err;
1655 }
1656 
1657 
1658 /*
1659  *      Shutdown a socket.
1660  */
1661 
1662 asmlinkage long sys_shutdown(int fd, int how)
1663 {
1664         int err;
1665         struct socket *sock;
1666 
1667         if ((sock = sockfd_lookup(fd, &err))!=NULL)
1668         {
1669                 err = security_socket_shutdown(sock, how);
1670                 if (err) {
1671                         sockfd_put(sock);
1672                         return err;
1673                 }
1674                                 
1675                 err=sock->ops->shutdown(sock, how);
1676                 sockfd_put(sock);
1677         }
1678         return err;
1679 }
1680 
1681 /* A couple of helpful macros for getting the address of the 32/64 bit 
1682  * fields which are the same type (int / unsigned) on our platforms.
1683  */
1684 #define COMPAT_MSG(msg, member) ((MSG_CMSG_COMPAT & flags) ? &msg##_compat->member : &msg->member)
1685 #define COMPAT_NAMELEN(msg)     COMPAT_MSG(msg, msg_namelen)
1686 #define COMPAT_FLAGS(msg)       COMPAT_MSG(msg, msg_flags)
1687 
1688 
1689 /*
1690  *      BSD sendmsg interface
1691  */
1692 
1693 asmlinkage long sys_sendmsg(int fd, struct msghdr __user *msg, unsigned flags)
1694 {
1695         struct compat_msghdr __user *msg_compat = (struct compat_msghdr __user *)msg;
1696         struct socket *sock;
1697         char address[MAX_SOCK_ADDR];
1698         struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
1699         unsigned char ctl[sizeof(struct cmsghdr) + 20]; /* 20 is size of ipv6_pktinfo */
1700         unsigned char *ctl_buf = ctl;
1701         struct msghdr msg_sys;
1702         int err, ctl_len, iov_size, total_len;
1703         
1704         err = -EFAULT;
1705         if (MSG_CMSG_COMPAT & flags) {
1706                 if (get_compat_msghdr(&msg_sys, msg_compat))
1707                         return -EFAULT;
1708         } else if (copy_from_user(&msg_sys, msg, sizeof(struct msghdr)))
1709                 return -EFAULT;
1710 
1711         sock = sockfd_lookup(fd, &err);
1712         if (!sock) 
1713                 goto out;
1714 
1715         /* do not move before msg_sys is valid */
1716         err = -EMSGSIZE;
1717         if (msg_sys.msg_iovlen > UIO_MAXIOV)
1718                 goto out_put;
1719 
1720         /* Check whether to allocate the iovec area*/
1721         err = -ENOMEM;
1722         iov_size = msg_sys.msg_iovlen * sizeof(struct iovec);
1723         if (msg_sys.msg_iovlen > UIO_FASTIOV) {
1724                 iov = sock_kmalloc(sock->sk, iov_size, GFP_KERNEL);
1725                 if (!iov)
1726                         goto out_put;
1727         }
1728 
1729         /* This will also move the address data into kernel space */
1730         if (MSG_CMSG_COMPAT & flags) {
1731                 err = verify_compat_iovec(&msg_sys, iov, address, VERIFY_READ);
1732         } else
1733                 err = verify_iovec(&msg_sys, iov, address, VERIFY_READ);
1734         if (err < 0) 
1735                 goto out_freeiov;
1736         total_len = err;
1737 
1738         err = -ENOBUFS;
1739 
1740         if (msg_sys.msg_controllen > INT_MAX)
1741                 goto out_freeiov;
1742         ctl_len = msg_sys.msg_controllen; 
1743         if ((MSG_CMSG_COMPAT & flags) && ctl_len) {
1744                 err = cmsghdr_from_user_compat_to_kern(&msg_sys, ctl, sizeof(ctl));
1745                 if (err)
1746                         goto out_freeiov;
1747                 ctl_buf = msg_sys.msg_control;
1748         } else if (ctl_len) {
1749                 if (ctl_len > sizeof(ctl))
1750                 {
1751                         ctl_buf = sock_kmalloc(sock->sk, ctl_len, GFP_KERNEL);
1752                         if (ctl_buf == NULL) 
1753                                 goto out_freeiov;
1754                 }
1755                 err = -EFAULT;
1756                 /*
1757                  * Careful! Before this, msg_sys.msg_control contains a user pointer.
1758                  * Afterwards, it will be a kernel pointer. Thus the compiler-assisted
1759                  * checking falls down on this.
1760                  */
1761                 if (copy_from_user(ctl_buf, (void __user *) msg_sys.msg_control, ctl_len))
1762                         goto out_freectl;
1763                 msg_sys.msg_control = ctl_buf;
1764         }
1765         msg_sys.msg_flags = flags;
1766 
1767         if (sock->file->f_flags & O_NONBLOCK)
1768                 msg_sys.msg_flags |= MSG_DONTWAIT;
1769         err = sock_sendmsg(sock, &msg_sys, total_len);
1770 
1771 out_freectl:
1772         if (ctl_buf != ctl)    
1773                 sock_kfree_s(sock->sk, ctl_buf, ctl_len);
1774 out_freeiov:
1775         if (iov != iovstack)
1776                 sock_kfree_s(sock->sk, iov, iov_size);
1777 out_put:
1778         sockfd_put(sock);
1779 out:       
1780         return err;
1781 }
1782 
1783 /*
1784  *      BSD recvmsg interface
1785  */
1786 
1787 asmlinkage long sys_recvmsg(int fd, struct msghdr __user *msg, unsigned int flags)
1788 {
1789         struct compat_msghdr __user *msg_compat = (struct compat_msghdr __user *)msg;
1790         struct socket *sock;
1791         struct iovec iovstack[UIO_FASTIOV];
1792         struct iovec *iov=iovstack;
1793         struct msghdr msg_sys;
1794         unsigned long cmsg_ptr;
1795         int err, iov_size, total_len, len;
1796 
1797         /* kernel mode address */
1798         char addr[MAX_SOCK_ADDR];
1799 
1800         /* user mode address pointers */
1801         struct sockaddr __user *uaddr;
1802         int __user *uaddr_len;
1803         
1804         if (MSG_CMSG_COMPAT & flags) {
1805                 if (get_compat_msghdr(&msg_sys, msg_compat))
1806                         return -EFAULT;
1807         } else
1808                 if (copy_from_user(&msg_sys,msg,sizeof(struct msghdr)))
1809                         return -EFAULT;
1810 
1811         sock = sockfd_lookup(fd, &err);
1812         if (!sock)
1813                 goto out;
1814 
1815         err = -EMSGSIZE;
1816         if (msg_sys.msg_iovlen > UIO_MAXIOV)
1817                 goto out_put;
1818         
1819         /* Check whether to allocate the iovec area*/
1820         err = -ENOMEM;
1821         iov_size = msg_sys.msg_iovlen * sizeof(struct iovec);
1822         if (msg_sys.msg_iovlen > UIO_FASTIOV) {
1823                 iov = sock_kmalloc(sock->sk, iov_size, GFP_KERNEL);
1824                 if (!iov)
1825                         goto out_put;
1826         }
1827 
1828         /*
1829          *      Save the user-mode address (verify_iovec will change the
1830          *      kernel msghdr to use the kernel address space)
1831          */
1832          
1833         uaddr = (void __user *) msg_sys.msg_name;
1834         uaddr_len = COMPAT_NAMELEN(msg);
1835         if (MSG_CMSG_COMPAT & flags) {
1836                 err = verify_compat_iovec(&msg_sys, iov, addr, VERIFY_WRITE);
1837         } else
1838                 err = verify_iovec(&msg_sys, iov, addr, VERIFY_WRITE);
1839         if (err < 0)
1840                 goto out_freeiov;
1841         total_len=err;
1842 
1843         cmsg_ptr = (unsigned long)msg_sys.msg_control;
1844         msg_sys.msg_flags = 0;
1845         if (MSG_CMSG_COMPAT & flags)
1846                 msg_sys.msg_flags = MSG_CMSG_COMPAT;
1847         
1848         if (sock->file->f_flags & O_NONBLOCK)
1849                 flags |= MSG_DONTWAIT;
1850         err = sock_recvmsg(sock, &msg_sys, total_len, flags);
1851         if (err < 0)
1852                 goto out_freeiov;
1853         len = err;
1854 
1855         if (uaddr != NULL) {
1856                 err = move_addr_to_user(addr, msg_sys.msg_namelen, uaddr, uaddr_len);
1857                 if (err < 0)
1858                         goto out_freeiov;
1859         }
1860         err = __put_user(msg_sys.msg_flags, COMPAT_FLAGS(msg));
1861         if (err)
1862                 goto out_freeiov;
1863         if (MSG_CMSG_COMPAT & flags)
1864                 err = __put_user((unsigned long)msg_sys.msg_control-cmsg_ptr, 
1865                                  &msg_compat->msg_controllen);
1866         else
1867                 err = __put_user((unsigned long)msg_sys.msg_control-cmsg_ptr, 
1868                                  &msg->msg_controllen);
1869         if (err)
1870                 goto out_freeiov;
1871         err = len;
1872 
1873 out_freeiov:
1874         if (iov != iovstack)
1875                 sock_kfree_s(sock->sk, iov, iov_size);
1876 out_put:
1877         sockfd_put(sock);
1878 out:
1879         return err;
1880 }
1881 
1882 #ifdef __ARCH_WANT_SYS_SOCKETCALL
1883 
1884 /* Argument list sizes for sys_socketcall */
1885 #define AL(x) ((x) * sizeof(unsigned long))
1886 static unsigned char nargs[18]={AL(0),AL(3),AL(3),AL(3),AL(2),AL(3),
1887                                 AL(3),AL(3),AL(4),AL(4),AL(4),AL(6),
1888                                 AL(6),AL(2),AL(5),AL(5),AL(3),AL(3)};
1889 #undef AL
1890 
1891 /*
1892  *      System call vectors. 
1893  *
1894  *      Argument checking cleaned up. Saved 20% in size.
1895  *  This function doesn't need to set the kernel lock because
1896  *  it is set by the callees. 
1897  */
1898 
1899 asmlinkage long sys_socketcall(int call, unsigned long __user *args)
1900 {
1901         unsigned long a[6];
1902         unsigned long a0,a1;
1903         int err;
1904 
1905         if(call<1||call>SYS_RECVMSG)
1906                 return -EINVAL;
1907 
1908         /* copy_from_user should be SMP safe. */
1909         if (copy_from_user(a, args, nargs[call]))
1910                 return -EFAULT;
1911                 
1912         a0=a[0];
1913         a1=a[1];
1914         
1915         switch(call) 
1916         {
1917                 case SYS_SOCKET:
1918                         err = sys_socket(a0,a1,a[2]);
1919                         break;
1920                 case SYS_BIND:
1921                         err = sys_bind(a0,(struct sockaddr __user *)a1, a[2]);
1922                         break;
1923                 case SYS_CONNECT:
1924                         err = sys_connect(a0, (struct sockaddr __user *)a1, a[2]);
1925                         break;
1926                 case SYS_LISTEN:
1927                         err = sys_listen(a0,a1);
1928                         break;
1929                 case SYS_ACCEPT:
1930                         err = sys_accept(a0,(struct sockaddr __user *)a1, (int __user *)a[2]);
1931                         break;
1932                 case SYS_GETSOCKNAME:
1933                         err = sys_getsockname(a0,(struct sockaddr __user *)a1, (int __user *)a[2]);
1934                         break;
1935                 case SYS_GETPEERNAME:
1936                         err = sys_getpeername(a0, (struct sockaddr __user *)a1, (int __user *)a[2]);
1937                         break;
1938                 case SYS_SOCKETPAIR:
1939                         err = sys_socketpair(a0,a1, a[2], (int __user *)a[3]);
1940                         break;
1941                 case SYS_SEND:
1942                         err = sys_send(a0, (void __user *)a1, a[2], a[3]);
1943                         break;
1944                 case SYS_SENDTO:
1945                         err = sys_sendto(a0,(void __user *)a1, a[2], a[3],
1946                                          (struct sockaddr __user *)a[4], a[5]);
1947                         break;
1948                 case SYS_RECV:
1949                         err = sys_recv(a0, (void __user *)a1, a[2], a[3]);
1950                         break;
1951                 case SYS_RECVFROM:
1952                         err = sys_recvfrom(a0, (void __user *)a1, a[2], a[3],
1953                                            (struct sockaddr __user *)a[4], (int __user *)a[5]);
1954                         break;
1955                 case SYS_SHUTDOWN:
1956                         err = sys_shutdown(a0,a1);
1957                         break;
1958                 case SYS_SETSOCKOPT:
1959                         err = sys_setsockopt(a0, a1, a[2], (char __user *)a[3], a[4]);
1960                         break;
1961                 case SYS_GETSOCKOPT:
1962                         err = sys_getsockopt(a0, a1, a[2], (char __user *)a[3], (int __user *)a[4]);
1963                         break;
1964                 case SYS_SENDMSG:
1965                         err = sys_sendmsg(a0, (struct msghdr __user *) a1, a[2]);
1966                         break;
1967                 case SYS_RECVMSG:
1968                         err = sys_recvmsg(a0, (struct msghdr __user *) a1, a[2]);
1969                         break;
1970                 default:
1971                         err = -EINVAL;
1972                         break;
1973         }
1974         return err;
1975 }
1976 
1977 #endif /* __ARCH_WANT_SYS_SOCKETCALL */
1978 
1979 /*
1980  *      This function is called by a protocol handler that wants to
1981  *      advertise its address family, and have it linked into the
1982  *      SOCKET module.
1983  */
1984 
1985 int sock_register(struct net_proto_family *ops)
1986 {
1987         int err;
1988 
1989         if (ops->family >= NPROTO) {
1990                 printk(KERN_CRIT "protocol %d >= NPROTO(%d)\n", ops->family, NPROTO);
1991                 return -ENOBUFS;
1992         }
1993         net_family_write_lock();
1994         err = -EEXIST;
1995         if (net_families[ops->family] == NULL) {
1996                 net_families[ops->family]=ops;
1997                 err = 0;
1998         }
1999         net_family_write_unlock();
2000         printk(KERN_INFO "NET: Registered protocol family %d\n",
2001                ops->family);
2002         return err;
2003 }
2004 
2005 /*
2006  *      This function is called by a protocol handler that wants to
2007  *      remove its address family, and have it unlinked from the
2008  *      SOCKET module.
2009  */
2010 
2011 int sock_unregister(int family)
2012 {
2013         if (family < 0 || family >= NPROTO)
2014                 return -1;
2015 
2016         net_family_write_lock();
2017         net_families[family]=NULL;
2018         net_family_write_unlock();
2019         printk(KERN_INFO "NET: Unregistered protocol family %d\n",
2020                family);
2021         return 0;
2022 }
2023 
2024 
2025 extern void sk_init(void);
2026 
2027 void __init sock_init(void)
2028 {
2029         /*
2030          *      Initialize sock SLAB cache.
2031          */
2032          
2033         sk_init();
2034 
2035 #ifdef SLAB_SKB
2036         /*
2037          *      Initialize skbuff SLAB cache 
2038          */
2039         skb_init();
2040 #endif
2041 
2042         /*
2043          *      Initialize the protocols module. 
2044          */
2045 
2046         init_inodecache();
2047         register_filesystem(&sock_fs_type);
2048         sock_mnt = kern_mount(&sock_fs_type);
2049         /* The real protocol initialization is performed when
2050          *  do_initcalls is run.  
2051          */
2052 
2053 #ifdef CONFIG_NETFILTER
2054         netfilter_init();
2055 #endif
2056 }
2057 
2058 #ifdef CONFIG_PROC_FS
2059 void socket_seq_show(struct seq_file *seq)
2060 {
2061         int cpu;
2062         int counter = 0;
2063 
2064         for (cpu = 0; cpu < NR_CPUS; cpu++)
2065                 counter += per_cpu(sockets_in_use, cpu);
2066 
2067         /* It can be negative, by the way. 8) */
2068         if (counter < 0)
2069                 counter = 0;
2070 
2071         seq_printf(seq, "sockets: used %d\n", counter);
2072 }
2073 #endif /* CONFIG_PROC_FS */
2074 
2075 /* ABI emulation layers need these two */
2076 EXPORT_SYMBOL(move_addr_to_kernel);
2077 EXPORT_SYMBOL(move_addr_to_user);
2078 EXPORT_SYMBOL(sock_create);
2079 EXPORT_SYMBOL(sock_create_kern);
2080 EXPORT_SYMBOL(sock_create_lite);
2081 EXPORT_SYMBOL(sock_map_fd);
2082 EXPORT_SYMBOL(sock_recvmsg);
2083 EXPORT_SYMBOL(sock_register);
2084 EXPORT_SYMBOL(sock_release);
2085 EXPORT_SYMBOL(sock_sendmsg);
2086 EXPORT_SYMBOL(sock_unregister);
2087 EXPORT_SYMBOL(sock_wake_async);
2088 EXPORT_SYMBOL(sockfd_lookup);
2089 EXPORT_SYMBOL(kernel_sendmsg);
2090 EXPORT_SYMBOL(kernel_recvmsg);
2091 
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