Root/net/socket.c

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
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/mm.h>
62#include <linux/socket.h>
63#include <linux/file.h>
64#include <linux/net.h>
65#include <linux/interrupt.h>
66#include <linux/thread_info.h>
67#include <linux/rcupdate.h>
68#include <linux/netdevice.h>
69#include <linux/proc_fs.h>
70#include <linux/seq_file.h>
71#include <linux/mutex.h>
72#include <linux/wanrouter.h>
73#include <linux/if_bridge.h>
74#include <linux/if_frad.h>
75#include <linux/if_vlan.h>
76#include <linux/init.h>
77#include <linux/poll.h>
78#include <linux/cache.h>
79#include <linux/module.h>
80#include <linux/highmem.h>
81#include <linux/mount.h>
82#include <linux/security.h>
83#include <linux/syscalls.h>
84#include <linux/compat.h>
85#include <linux/kmod.h>
86#include <linux/audit.h>
87#include <linux/wireless.h>
88#include <linux/nsproxy.h>
89#include <linux/magic.h>
90
91#include <asm/uaccess.h>
92#include <asm/unistd.h>
93
94#include <net/compat.h>
95#include <net/wext.h>
96
97#include <net/sock.h>
98#include <linux/netfilter.h>
99
100static int sock_no_open(struct inode *irrelevant, struct file *dontcare);
101static ssize_t sock_aio_read(struct kiocb *iocb, const struct iovec *iov,
102             unsigned long nr_segs, loff_t pos);
103static ssize_t sock_aio_write(struct kiocb *iocb, const struct iovec *iov,
104              unsigned long nr_segs, loff_t pos);
105static int sock_mmap(struct file *file, struct vm_area_struct *vma);
106
107static int sock_close(struct inode *inode, struct file *file);
108static unsigned int sock_poll(struct file *file,
109                  struct poll_table_struct *wait);
110static long sock_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
111#ifdef CONFIG_COMPAT
112static long compat_sock_ioctl(struct file *file,
113                  unsigned int cmd, unsigned long arg);
114#endif
115static int sock_fasync(int fd, struct file *filp, int on);
116static ssize_t sock_sendpage(struct file *file, struct page *page,
117                 int offset, size_t size, loff_t *ppos, int more);
118static ssize_t sock_splice_read(struct file *file, loff_t *ppos,
119                    struct pipe_inode_info *pipe, size_t len,
120                unsigned int flags);
121
122/*
123 * Socket files have a set of 'special' operations as well as the generic file ones. These don't appear
124 * in the operation structures but are done directly via the socketcall() multiplexor.
125 */
126
127static const struct file_operations socket_file_ops = {
128    .owner = THIS_MODULE,
129    .llseek = no_llseek,
130    .aio_read = sock_aio_read,
131    .aio_write = sock_aio_write,
132    .poll = sock_poll,
133    .unlocked_ioctl = sock_ioctl,
134#ifdef CONFIG_COMPAT
135    .compat_ioctl = compat_sock_ioctl,
136#endif
137    .mmap = sock_mmap,
138    .open = sock_no_open, /* special open code to disallow open via /proc */
139    .release = sock_close,
140    .fasync = sock_fasync,
141    .sendpage = sock_sendpage,
142    .splice_write = generic_splice_sendpage,
143    .splice_read = sock_splice_read,
144};
145
146/*
147 * The protocol list. Each protocol is registered in here.
148 */
149
150static DEFINE_SPINLOCK(net_family_lock);
151static const struct net_proto_family *net_families[NPROTO] __read_mostly;
152
153/*
154 * Statistics counters of the socket lists
155 */
156
157static DEFINE_PER_CPU(int, sockets_in_use) = 0;
158
159/*
160 * Support routines.
161 * Move socket addresses back and forth across the kernel/user
162 * divide and look after the messy bits.
163 */
164
165#define MAX_SOCK_ADDR 128 /* 108 for Unix domain -
166                       16 for IP, 16 for IPX,
167                       24 for IPv6,
168                       about 80 for AX.25
169                       must be at least one bigger than
170                       the AF_UNIX size (see net/unix/af_unix.c
171                       :unix_mkname()).
172                     */
173
174/**
175 * move_addr_to_kernel - copy a socket address into kernel space
176 * @uaddr: Address in user space
177 * @kaddr: Address in kernel space
178 * @ulen: Length in user space
179 *
180 * The address is copied into kernel space. If the provided address is
181 * too long an error code of -EINVAL is returned. If the copy gives
182 * invalid addresses -EFAULT is returned. On a success 0 is returned.
183 */
184
185int move_addr_to_kernel(void __user *uaddr, int ulen, struct sockaddr *kaddr)
186{
187    if (ulen < 0 || ulen > sizeof(struct sockaddr_storage))
188        return -EINVAL;
189    if (ulen == 0)
190        return 0;
191    if (copy_from_user(kaddr, uaddr, ulen))
192        return -EFAULT;
193    return audit_sockaddr(ulen, kaddr);
194}
195
196/**
197 * move_addr_to_user - copy an address to user space
198 * @kaddr: kernel space address
199 * @klen: length of address in kernel
200 * @uaddr: user space address
201 * @ulen: pointer to user length field
202 *
203 * The value pointed to by ulen on entry is the buffer length available.
204 * This is overwritten with the buffer space used. -EINVAL is returned
205 * if an overlong buffer is specified or a negative buffer size. -EFAULT
206 * is returned if either the buffer or the length field are not
207 * accessible.
208 * After copying the data up to the limit the user specifies, the true
209 * length of the data is written over the length limit the user
210 * specified. Zero is returned for a success.
211 */
212
213int move_addr_to_user(struct sockaddr *kaddr, int klen, void __user *uaddr,
214              int __user *ulen)
215{
216    int err;
217    int len;
218
219    err = get_user(len, ulen);
220    if (err)
221        return err;
222    if (len > klen)
223        len = klen;
224    if (len < 0 || len > sizeof(struct sockaddr_storage))
225        return -EINVAL;
226    if (len) {
227        if (audit_sockaddr(klen, kaddr))
228            return -ENOMEM;
229        if (copy_to_user(uaddr, kaddr, len))
230            return -EFAULT;
231    }
232    /*
233     * "fromlen shall refer to the value before truncation.."
234     * 1003.1g
235     */
236    return __put_user(klen, ulen);
237}
238
239static struct kmem_cache *sock_inode_cachep __read_mostly;
240
241static struct inode *sock_alloc_inode(struct super_block *sb)
242{
243    struct socket_alloc *ei;
244
245    ei = kmem_cache_alloc(sock_inode_cachep, GFP_KERNEL);
246    if (!ei)
247        return NULL;
248    init_waitqueue_head(&ei->socket.wait);
249
250    ei->socket.fasync_list = NULL;
251    ei->socket.state = SS_UNCONNECTED;
252    ei->socket.flags = 0;
253    ei->socket.ops = NULL;
254    ei->socket.sk = NULL;
255    ei->socket.file = NULL;
256
257    return &ei->vfs_inode;
258}
259
260static void sock_destroy_inode(struct inode *inode)
261{
262    kmem_cache_free(sock_inode_cachep,
263            container_of(inode, struct socket_alloc, vfs_inode));
264}
265
266static void init_once(void *foo)
267{
268    struct socket_alloc *ei = (struct socket_alloc *)foo;
269
270    inode_init_once(&ei->vfs_inode);
271}
272
273static int init_inodecache(void)
274{
275    sock_inode_cachep = kmem_cache_create("sock_inode_cache",
276                          sizeof(struct socket_alloc),
277                          0,
278                          (SLAB_HWCACHE_ALIGN |
279                           SLAB_RECLAIM_ACCOUNT |
280                           SLAB_MEM_SPREAD),
281                          init_once);
282    if (sock_inode_cachep == NULL)
283        return -ENOMEM;
284    return 0;
285}
286
287static const struct super_operations sockfs_ops = {
288    .alloc_inode = sock_alloc_inode,
289    .destroy_inode =sock_destroy_inode,
290    .statfs = simple_statfs,
291};
292
293static int sockfs_get_sb(struct file_system_type *fs_type,
294             int flags, const char *dev_name, void *data,
295             struct vfsmount *mnt)
296{
297    return get_sb_pseudo(fs_type, "socket:", &sockfs_ops, SOCKFS_MAGIC,
298                 mnt);
299}
300
301static struct vfsmount *sock_mnt __read_mostly;
302
303static struct file_system_type sock_fs_type = {
304    .name = "sockfs",
305    .get_sb = sockfs_get_sb,
306    .kill_sb = kill_anon_super,
307};
308
309static int sockfs_delete_dentry(struct dentry *dentry)
310{
311    /*
312     * At creation time, we pretended this dentry was hashed
313     * (by clearing DCACHE_UNHASHED bit in d_flags)
314     * At delete time, we restore the truth : not hashed.
315     * (so that dput() can proceed correctly)
316     */
317    dentry->d_flags |= DCACHE_UNHASHED;
318    return 0;
319}
320
321/*
322 * sockfs_dname() is called from d_path().
323 */
324static char *sockfs_dname(struct dentry *dentry, char *buffer, int buflen)
325{
326    return dynamic_dname(dentry, buffer, buflen, "socket:[%lu]",
327                dentry->d_inode->i_ino);
328}
329
330static const struct dentry_operations sockfs_dentry_operations = {
331    .d_delete = sockfs_delete_dentry,
332    .d_dname = sockfs_dname,
333};
334
335/*
336 * Obtains the first available file descriptor and sets it up for use.
337 *
338 * These functions create file structures and maps them to fd space
339 * of the current process. On success it returns file descriptor
340 * and file struct implicitly stored in sock->file.
341 * Note that another thread may close file descriptor before we return
342 * from this function. We use the fact that now we do not refer
343 * to socket after mapping. If one day we will need it, this
344 * function will increment ref. count on file by 1.
345 *
346 * In any case returned fd MAY BE not valid!
347 * This race condition is unavoidable
348 * with shared fd spaces, we cannot solve it inside kernel,
349 * but we take care of internal coherence yet.
350 */
351
352static int sock_alloc_fd(struct file **filep, int flags)
353{
354    int fd;
355
356    fd = get_unused_fd_flags(flags);
357    if (likely(fd >= 0)) {
358        struct file *file = get_empty_filp();
359
360        *filep = file;
361        if (unlikely(!file)) {
362            put_unused_fd(fd);
363            return -ENFILE;
364        }
365    } else
366        *filep = NULL;
367    return fd;
368}
369
370static int sock_attach_fd(struct socket *sock, struct file *file, int flags)
371{
372    struct dentry *dentry;
373    struct qstr name = { .name = "" };
374
375    dentry = d_alloc(sock_mnt->mnt_sb->s_root, &name);
376    if (unlikely(!dentry))
377        return -ENOMEM;
378
379    dentry->d_op = &sockfs_dentry_operations;
380    /*
381     * We dont want to push this dentry into global dentry hash table.
382     * We pretend dentry is already hashed, by unsetting DCACHE_UNHASHED
383     * This permits a working /proc/$pid/fd/XXX on sockets
384     */
385    dentry->d_flags &= ~DCACHE_UNHASHED;
386    d_instantiate(dentry, SOCK_INODE(sock));
387
388    sock->file = file;
389    init_file(file, sock_mnt, dentry, FMODE_READ | FMODE_WRITE,
390          &socket_file_ops);
391    SOCK_INODE(sock)->i_fop = &socket_file_ops;
392    file->f_flags = O_RDWR | (flags & O_NONBLOCK);
393    file->f_pos = 0;
394    file->private_data = sock;
395
396    return 0;
397}
398
399int sock_map_fd(struct socket *sock, int flags)
400{
401    struct file *newfile;
402    int fd = sock_alloc_fd(&newfile, flags);
403
404    if (likely(fd >= 0)) {
405        int err = sock_attach_fd(sock, newfile, flags);
406
407        if (unlikely(err < 0)) {
408            put_filp(newfile);
409            put_unused_fd(fd);
410            return err;
411        }
412        fd_install(fd, newfile);
413    }
414    return fd;
415}
416
417static struct socket *sock_from_file(struct file *file, int *err)
418{
419    if (file->f_op == &socket_file_ops)
420        return file->private_data; /* set in sock_map_fd */
421
422    *err = -ENOTSOCK;
423    return NULL;
424}
425
426/**
427 * sockfd_lookup - Go from a file number to its socket slot
428 * @fd: file handle
429 * @err: pointer to an error code return
430 *
431 * The file handle passed in is locked and the socket it is bound
432 * too is returned. If an error occurs the err pointer is overwritten
433 * with a negative errno code and NULL is returned. The function checks
434 * for both invalid handles and passing a handle which is not a socket.
435 *
436 * On a success the socket object pointer is returned.
437 */
438
439struct socket *sockfd_lookup(int fd, int *err)
440{
441    struct file *file;
442    struct socket *sock;
443
444    file = fget(fd);
445    if (!file) {
446        *err = -EBADF;
447        return NULL;
448    }
449
450    sock = sock_from_file(file, err);
451    if (!sock)
452        fput(file);
453    return sock;
454}
455
456static struct socket *sockfd_lookup_light(int fd, int *err, int *fput_needed)
457{
458    struct file *file;
459    struct socket *sock;
460
461    *err = -EBADF;
462    file = fget_light(fd, fput_needed);
463    if (file) {
464        sock = sock_from_file(file, err);
465        if (sock)
466            return sock;
467        fput_light(file, *fput_needed);
468    }
469    return NULL;
470}
471
472/**
473 * sock_alloc - allocate a socket
474 *
475 * Allocate a new inode and socket object. The two are bound together
476 * and initialised. The socket is then returned. If we are out of inodes
477 * NULL is returned.
478 */
479
480static struct socket *sock_alloc(void)
481{
482    struct inode *inode;
483    struct socket *sock;
484
485    inode = new_inode(sock_mnt->mnt_sb);
486    if (!inode)
487        return NULL;
488
489    sock = SOCKET_I(inode);
490
491    kmemcheck_annotate_bitfield(sock, type);
492    inode->i_mode = S_IFSOCK | S_IRWXUGO;
493    inode->i_uid = current_fsuid();
494    inode->i_gid = current_fsgid();
495
496    percpu_add(sockets_in_use, 1);
497    return sock;
498}
499
500/*
501 * In theory you can't get an open on this inode, but /proc provides
502 * a back door. Remember to keep it shut otherwise you'll let the
503 * creepy crawlies in.
504 */
505
506static int sock_no_open(struct inode *irrelevant, struct file *dontcare)
507{
508    return -ENXIO;
509}
510
511const struct file_operations bad_sock_fops = {
512    .owner = THIS_MODULE,
513    .open = sock_no_open,
514};
515
516/**
517 * sock_release - close a socket
518 * @sock: socket to close
519 *
520 * The socket is released from the protocol stack if it has a release
521 * callback, and the inode is then released if the socket is bound to
522 * an inode not a file.
523 */
524
525void sock_release(struct socket *sock)
526{
527    if (sock->ops) {
528        struct module *owner = sock->ops->owner;
529
530        sock->ops->release(sock);
531        sock->ops = NULL;
532        module_put(owner);
533    }
534
535    if (sock->fasync_list)
536        printk(KERN_ERR "sock_release: fasync list not empty!\n");
537
538    percpu_sub(sockets_in_use, 1);
539    if (!sock->file) {
540        iput(SOCK_INODE(sock));
541        return;
542    }
543    sock->file = NULL;
544}
545
546int sock_tx_timestamp(struct msghdr *msg, struct sock *sk,
547              union skb_shared_tx *shtx)
548{
549    shtx->flags = 0;
550    if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
551        shtx->hardware = 1;
552    if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
553        shtx->software = 1;
554    return 0;
555}
556EXPORT_SYMBOL(sock_tx_timestamp);
557
558static inline int __sock_sendmsg(struct kiocb *iocb, struct socket *sock,
559                 struct msghdr *msg, size_t size)
560{
561    struct sock_iocb *si = kiocb_to_siocb(iocb);
562    int err;
563
564    si->sock = sock;
565    si->scm = NULL;
566    si->msg = msg;
567    si->size = size;
568
569    err = security_socket_sendmsg(sock, msg, size);
570    if (err)
571        return err;
572
573    return sock->ops->sendmsg(iocb, sock, msg, size);
574}
575
576int sock_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
577{
578    struct kiocb iocb;
579    struct sock_iocb siocb;
580    int ret;
581
582    init_sync_kiocb(&iocb, NULL);
583    iocb.private = &siocb;
584    ret = __sock_sendmsg(&iocb, sock, msg, size);
585    if (-EIOCBQUEUED == ret)
586        ret = wait_on_sync_kiocb(&iocb);
587    return ret;
588}
589
590int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
591           struct kvec *vec, size_t num, size_t size)
592{
593    mm_segment_t oldfs = get_fs();
594    int result;
595
596    set_fs(KERNEL_DS);
597    /*
598     * the following is safe, since for compiler definitions of kvec and
599     * iovec are identical, yielding the same in-core layout and alignment
600     */
601    msg->msg_iov = (struct iovec *)vec;
602    msg->msg_iovlen = num;
603    result = sock_sendmsg(sock, msg, size);
604    set_fs(oldfs);
605    return result;
606}
607
608static int ktime2ts(ktime_t kt, struct timespec *ts)
609{
610    if (kt.tv64) {
611        *ts = ktime_to_timespec(kt);
612        return 1;
613    } else {
614        return 0;
615    }
616}
617
618/*
619 * called from sock_recv_timestamp() if sock_flag(sk, SOCK_RCVTSTAMP)
620 */
621void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
622    struct sk_buff *skb)
623{
624    int need_software_tstamp = sock_flag(sk, SOCK_RCVTSTAMP);
625    struct timespec ts[3];
626    int empty = 1;
627    struct skb_shared_hwtstamps *shhwtstamps =
628        skb_hwtstamps(skb);
629
630    /* Race occurred between timestamp enabling and packet
631       receiving. Fill in the current time for now. */
632    if (need_software_tstamp && skb->tstamp.tv64 == 0)
633        __net_timestamp(skb);
634
635    if (need_software_tstamp) {
636        if (!sock_flag(sk, SOCK_RCVTSTAMPNS)) {
637            struct timeval tv;
638            skb_get_timestamp(skb, &tv);
639            put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMP,
640                 sizeof(tv), &tv);
641        } else {
642            struct timespec ts;
643            skb_get_timestampns(skb, &ts);
644            put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPNS,
645                 sizeof(ts), &ts);
646        }
647    }
648
649
650    memset(ts, 0, sizeof(ts));
651    if (skb->tstamp.tv64 &&
652        sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) {
653        skb_get_timestampns(skb, ts + 0);
654        empty = 0;
655    }
656    if (shhwtstamps) {
657        if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE) &&
658            ktime2ts(shhwtstamps->syststamp, ts + 1))
659            empty = 0;
660        if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE) &&
661            ktime2ts(shhwtstamps->hwtstamp, ts + 2))
662            empty = 0;
663    }
664    if (!empty)
665        put_cmsg(msg, SOL_SOCKET,
666             SCM_TIMESTAMPING, sizeof(ts), &ts);
667}
668
669EXPORT_SYMBOL_GPL(__sock_recv_timestamp);
670
671static inline int __sock_recvmsg(struct kiocb *iocb, struct socket *sock,
672                 struct msghdr *msg, size_t size, int flags)
673{
674    int err;
675    struct sock_iocb *si = kiocb_to_siocb(iocb);
676
677    si->sock = sock;
678    si->scm = NULL;
679    si->msg = msg;
680    si->size = size;
681    si->flags = flags;
682
683    err = security_socket_recvmsg(sock, msg, size, flags);
684    if (err)
685        return err;
686
687    return sock->ops->recvmsg(iocb, sock, msg, size, flags);
688}
689
690int sock_recvmsg(struct socket *sock, struct msghdr *msg,
691         size_t size, int flags)
692{
693    struct kiocb iocb;
694    struct sock_iocb siocb;
695    int ret;
696
697    init_sync_kiocb(&iocb, NULL);
698    iocb.private = &siocb;
699    ret = __sock_recvmsg(&iocb, sock, msg, size, flags);
700    if (-EIOCBQUEUED == ret)
701        ret = wait_on_sync_kiocb(&iocb);
702    return ret;
703}
704
705int kernel_recvmsg(struct socket *sock, struct msghdr *msg,
706           struct kvec *vec, size_t num, size_t size, int flags)
707{
708    mm_segment_t oldfs = get_fs();
709    int result;
710
711    set_fs(KERNEL_DS);
712    /*
713     * the following is safe, since for compiler definitions of kvec and
714     * iovec are identical, yielding the same in-core layout and alignment
715     */
716    msg->msg_iov = (struct iovec *)vec, msg->msg_iovlen = num;
717    result = sock_recvmsg(sock, msg, size, flags);
718    set_fs(oldfs);
719    return result;
720}
721
722static void sock_aio_dtor(struct kiocb *iocb)
723{
724    kfree(iocb->private);
725}
726
727static ssize_t sock_sendpage(struct file *file, struct page *page,
728                 int offset, size_t size, loff_t *ppos, int more)
729{
730    struct socket *sock;
731    int flags;
732
733    sock = file->private_data;
734
735    flags = !(file->f_flags & O_NONBLOCK) ? 0 : MSG_DONTWAIT;
736    if (more)
737        flags |= MSG_MORE;
738
739    return kernel_sendpage(sock, page, offset, size, flags);
740}
741
742static ssize_t sock_splice_read(struct file *file, loff_t *ppos,
743                    struct pipe_inode_info *pipe, size_t len,
744                unsigned int flags)
745{
746    struct socket *sock = file->private_data;
747
748    if (unlikely(!sock->ops->splice_read))
749        return -EINVAL;
750
751    return sock->ops->splice_read(sock, ppos, pipe, len, flags);
752}
753
754static struct sock_iocb *alloc_sock_iocb(struct kiocb *iocb,
755                     struct sock_iocb *siocb)
756{
757    if (!is_sync_kiocb(iocb)) {
758        siocb = kmalloc(sizeof(*siocb), GFP_KERNEL);
759        if (!siocb)
760            return NULL;
761        iocb->ki_dtor = sock_aio_dtor;
762    }
763
764    siocb->kiocb = iocb;
765    iocb->private = siocb;
766    return siocb;
767}
768
769static ssize_t do_sock_read(struct msghdr *msg, struct kiocb *iocb,
770        struct file *file, const struct iovec *iov,
771        unsigned long nr_segs)
772{
773    struct socket *sock = file->private_data;
774    size_t size = 0;
775    int i;
776
777    for (i = 0; i < nr_segs; i++)
778        size += iov[i].iov_len;
779
780    msg->msg_name = NULL;
781    msg->msg_namelen = 0;
782    msg->msg_control = NULL;
783    msg->msg_controllen = 0;
784    msg->msg_iov = (struct iovec *)iov;
785    msg->msg_iovlen = nr_segs;
786    msg->msg_flags = (file->f_flags & O_NONBLOCK) ? MSG_DONTWAIT : 0;
787
788    return __sock_recvmsg(iocb, sock, msg, size, msg->msg_flags);
789}
790
791static ssize_t sock_aio_read(struct kiocb *iocb, const struct iovec *iov,
792                unsigned long nr_segs, loff_t pos)
793{
794    struct sock_iocb siocb, *x;
795
796    if (pos != 0)
797        return -ESPIPE;
798
799    if (iocb->ki_left == 0) /* Match SYS5 behaviour */
800        return 0;
801
802
803    x = alloc_sock_iocb(iocb, &siocb);
804    if (!x)
805        return -ENOMEM;
806    return do_sock_read(&x->async_msg, iocb, iocb->ki_filp, iov, nr_segs);
807}
808
809static ssize_t do_sock_write(struct msghdr *msg, struct kiocb *iocb,
810            struct file *file, const struct iovec *iov,
811            unsigned long nr_segs)
812{
813    struct socket *sock = file->private_data;
814    size_t size = 0;
815    int i;
816
817    for (i = 0; i < nr_segs; i++)
818        size += iov[i].iov_len;
819
820    msg->msg_name = NULL;
821    msg->msg_namelen = 0;
822    msg->msg_control = NULL;
823    msg->msg_controllen = 0;
824    msg->msg_iov = (struct iovec *)iov;
825    msg->msg_iovlen = nr_segs;
826    msg->msg_flags = (file->f_flags & O_NONBLOCK) ? MSG_DONTWAIT : 0;
827    if (sock->type == SOCK_SEQPACKET)
828        msg->msg_flags |= MSG_EOR;
829
830    return __sock_sendmsg(iocb, sock, msg, size);
831}
832
833static ssize_t sock_aio_write(struct kiocb *iocb, const struct iovec *iov,
834              unsigned long nr_segs, loff_t pos)
835{
836    struct sock_iocb siocb, *x;
837
838    if (pos != 0)
839        return -ESPIPE;
840
841    x = alloc_sock_iocb(iocb, &siocb);
842    if (!x)
843        return -ENOMEM;
844
845    return do_sock_write(&x->async_msg, iocb, iocb->ki_filp, iov, nr_segs);
846}
847
848/*
849 * Atomic setting of ioctl hooks to avoid race
850 * with module unload.
851 */
852
853static DEFINE_MUTEX(br_ioctl_mutex);
854static int (*br_ioctl_hook) (struct net *, unsigned int cmd, void __user *arg) = NULL;
855
856void brioctl_set(int (*hook) (struct net *, unsigned int, void __user *))
857{
858    mutex_lock(&br_ioctl_mutex);
859    br_ioctl_hook = hook;
860    mutex_unlock(&br_ioctl_mutex);
861}
862
863EXPORT_SYMBOL(brioctl_set);
864
865static DEFINE_MUTEX(vlan_ioctl_mutex);
866static int (*vlan_ioctl_hook) (struct net *, void __user *arg);
867
868void vlan_ioctl_set(int (*hook) (struct net *, void __user *))
869{
870    mutex_lock(&vlan_ioctl_mutex);
871    vlan_ioctl_hook = hook;
872    mutex_unlock(&vlan_ioctl_mutex);
873}
874
875EXPORT_SYMBOL(vlan_ioctl_set);
876
877static DEFINE_MUTEX(dlci_ioctl_mutex);
878static int (*dlci_ioctl_hook) (unsigned int, void __user *);
879
880void dlci_ioctl_set(int (*hook) (unsigned int, void __user *))
881{
882    mutex_lock(&dlci_ioctl_mutex);
883    dlci_ioctl_hook = hook;
884    mutex_unlock(&dlci_ioctl_mutex);
885}
886
887EXPORT_SYMBOL(dlci_ioctl_set);
888
889/*
890 * With an ioctl, arg may well be a user mode pointer, but we don't know
891 * what to do with it - that's up to the protocol still.
892 */
893
894static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
895{
896    struct socket *sock;
897    struct sock *sk;
898    void __user *argp = (void __user *)arg;
899    int pid, err;
900    struct net *net;
901
902    sock = file->private_data;
903    sk = sock->sk;
904    net = sock_net(sk);
905    if (cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15)) {
906        err = dev_ioctl(net, cmd, argp);
907    } else
908#ifdef CONFIG_WIRELESS_EXT
909    if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) {
910        err = dev_ioctl(net, cmd, argp);
911    } else
912#endif /* CONFIG_WIRELESS_EXT */
913        switch (cmd) {
914        case FIOSETOWN:
915        case SIOCSPGRP:
916            err = -EFAULT;
917            if (get_user(pid, (int __user *)argp))
918                break;
919            err = f_setown(sock->file, pid, 1);
920            break;
921        case FIOGETOWN:
922        case SIOCGPGRP:
923            err = put_user(f_getown(sock->file),
924                       (int __user *)argp);
925            break;
926        case SIOCGIFBR:
927        case SIOCSIFBR:
928        case SIOCBRADDBR:
929        case SIOCBRDELBR:
930            err = -ENOPKG;
931            if (!br_ioctl_hook)
932                request_module("bridge");
933
934            mutex_lock(&br_ioctl_mutex);
935            if (br_ioctl_hook)
936                err = br_ioctl_hook(net, cmd, argp);
937            mutex_unlock(&br_ioctl_mutex);
938            break;
939        case SIOCGIFVLAN:
940        case SIOCSIFVLAN:
941            err = -ENOPKG;
942            if (!vlan_ioctl_hook)
943                request_module("8021q");
944
945            mutex_lock(&vlan_ioctl_mutex);
946            if (vlan_ioctl_hook)
947                err = vlan_ioctl_hook(net, argp);
948            mutex_unlock(&vlan_ioctl_mutex);
949            break;
950        case SIOCADDDLCI:
951        case SIOCDELDLCI:
952            err = -ENOPKG;
953            if (!dlci_ioctl_hook)
954                request_module("dlci");
955
956            mutex_lock(&dlci_ioctl_mutex);
957            if (dlci_ioctl_hook)
958                err = dlci_ioctl_hook(cmd, argp);
959            mutex_unlock(&dlci_ioctl_mutex);
960            break;
961        default:
962            err = sock->ops->ioctl(sock, cmd, arg);
963
964            /*
965             * If this ioctl is unknown try to hand it down
966             * to the NIC driver.
967             */
968            if (err == -ENOIOCTLCMD)
969                err = dev_ioctl(net, cmd, argp);
970            break;
971        }
972    return err;
973}
974
975int sock_create_lite(int family, int type, int protocol, struct socket **res)
976{
977    int err;
978    struct socket *sock = NULL;
979
980    err = security_socket_create(family, type, protocol, 1);
981    if (err)
982        goto out;
983
984    sock = sock_alloc();
985    if (!sock) {
986        err = -ENOMEM;
987        goto out;
988    }
989
990    sock->type = type;
991    err = security_socket_post_create(sock, family, type, protocol, 1);
992    if (err)
993        goto out_release;
994
995out:
996    *res = sock;
997    return err;
998out_release:
999    sock_release(sock);
1000    sock = NULL;
1001    goto out;
1002}
1003
1004/* No kernel lock held - perfect */
1005static unsigned int sock_poll(struct file *file, poll_table *wait)
1006{
1007    struct socket *sock;
1008
1009    /*
1010     * We can't return errors to poll, so it's either yes or no.
1011     */
1012    sock = file->private_data;
1013    return sock->ops->poll(file, sock, wait);
1014}
1015
1016static int sock_mmap(struct file *file, struct vm_area_struct *vma)
1017{
1018    struct socket *sock = file->private_data;
1019
1020    return sock->ops->mmap(file, sock, vma);
1021}
1022
1023static int sock_close(struct inode *inode, struct file *filp)
1024{
1025    /*
1026     * It was possible the inode is NULL we were
1027     * closing an unfinished socket.
1028     */
1029
1030    if (!inode) {
1031        printk(KERN_DEBUG "sock_close: NULL inode\n");
1032        return 0;
1033    }
1034    sock_release(SOCKET_I(inode));
1035    return 0;
1036}
1037
1038/*
1039 * Update the socket async list
1040 *
1041 * Fasync_list locking strategy.
1042 *
1043 * 1. fasync_list is modified only under process context socket lock
1044 * i.e. under semaphore.
1045 * 2. fasync_list is used under read_lock(&sk->sk_callback_lock)
1046 * or under socket lock.
1047 * 3. fasync_list can be used from softirq context, so that
1048 * modification under socket lock have to be enhanced with
1049 * write_lock_bh(&sk->sk_callback_lock).
1050 * --ANK (990710)
1051 */
1052
1053static int sock_fasync(int fd, struct file *filp, int on)
1054{
1055    struct fasync_struct *fa, *fna = NULL, **prev;
1056    struct socket *sock;
1057    struct sock *sk;
1058
1059    if (on) {
1060        fna = kmalloc(sizeof(struct fasync_struct), GFP_KERNEL);
1061        if (fna == NULL)
1062            return -ENOMEM;
1063    }
1064
1065    sock = filp->private_data;
1066
1067    sk = sock->sk;
1068    if (sk == NULL) {
1069        kfree(fna);
1070        return -EINVAL;
1071    }
1072
1073    lock_sock(sk);
1074
1075    spin_lock(&filp->f_lock);
1076    if (on)
1077        filp->f_flags |= FASYNC;
1078    else
1079        filp->f_flags &= ~FASYNC;
1080    spin_unlock(&filp->f_lock);
1081
1082    prev = &(sock->fasync_list);
1083
1084    for (fa = *prev; fa != NULL; prev = &fa->fa_next, fa = *prev)
1085        if (fa->fa_file == filp)
1086            break;
1087
1088    if (on) {
1089        if (fa != NULL) {
1090            write_lock_bh(&sk->sk_callback_lock);
1091            fa->fa_fd = fd;
1092            write_unlock_bh(&sk->sk_callback_lock);
1093
1094            kfree(fna);
1095            goto out;
1096        }
1097        fna->fa_file = filp;
1098        fna->fa_fd = fd;
1099        fna->magic = FASYNC_MAGIC;
1100        fna->fa_next = sock->fasync_list;
1101        write_lock_bh(&sk->sk_callback_lock);
1102        sock->fasync_list = fna;
1103        write_unlock_bh(&sk->sk_callback_lock);
1104    } else {
1105        if (fa != NULL) {
1106            write_lock_bh(&sk->sk_callback_lock);
1107            *prev = fa->fa_next;
1108            write_unlock_bh(&sk->sk_callback_lock);
1109            kfree(fa);
1110        }
1111    }
1112
1113out:
1114    release_sock(sock->sk);
1115    return 0;
1116}
1117
1118/* This function may be called only under socket lock or callback_lock */
1119
1120int sock_wake_async(struct socket *sock, int how, int band)
1121{
1122    if (!sock || !sock->fasync_list)
1123        return -1;
1124    switch (how) {
1125    case SOCK_WAKE_WAITD:
1126        if (test_bit(SOCK_ASYNC_WAITDATA, &sock->flags))
1127            break;
1128        goto call_kill;
1129    case SOCK_WAKE_SPACE:
1130        if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags))
1131            break;
1132        /* fall through */
1133    case SOCK_WAKE_IO:
1134call_kill:
1135        __kill_fasync(sock->fasync_list, SIGIO, band);
1136        break;
1137    case SOCK_WAKE_URG:
1138        __kill_fasync(sock->fasync_list, SIGURG, band);
1139    }
1140    return 0;
1141}
1142
1143static int __sock_create(struct net *net, int family, int type, int protocol,
1144             struct socket **res, int kern)
1145{
1146    int err;
1147    struct socket *sock;
1148    const struct net_proto_family *pf;
1149
1150    /*
1151     * Check protocol is in range
1152     */
1153    if (family < 0 || family >= NPROTO)
1154        return -EAFNOSUPPORT;
1155    if (type < 0 || type >= SOCK_MAX)
1156        return -EINVAL;
1157
1158    /* Compatibility.
1159
1160       This uglymoron is moved from INET layer to here to avoid
1161       deadlock in module load.
1162     */
1163    if (family == PF_INET && type == SOCK_PACKET) {
1164        static int warned;
1165        if (!warned) {
1166            warned = 1;
1167            printk(KERN_INFO "%s uses obsolete (PF_INET,SOCK_PACKET)\n",
1168                   current->comm);
1169        }
1170        family = PF_PACKET;
1171    }
1172
1173    err = security_socket_create(family, type, protocol, kern);
1174    if (err)
1175        return err;
1176
1177    /*
1178     * Allocate the socket and allow the family to set things up. if
1179     * the protocol is 0, the family is instructed to select an appropriate
1180     * default.
1181     */
1182    sock = sock_alloc();
1183    if (!sock) {
1184        if (net_ratelimit())
1185            printk(KERN_WARNING "socket: no more sockets\n");
1186        return -ENFILE; /* Not exactly a match, but its the
1187                   closest posix thing */
1188    }
1189
1190    sock->type = type;
1191
1192#ifdef CONFIG_MODULES
1193    /* Attempt to load a protocol module if the find failed.
1194     *
1195     * 12/09/1996 Marcin: But! this makes REALLY only sense, if the user
1196     * requested real, full-featured networking support upon configuration.
1197     * Otherwise module support will break!
1198     */
1199    if (net_families[family] == NULL)
1200        request_module("net-pf-%d", family);
1201#endif
1202
1203    rcu_read_lock();
1204    pf = rcu_dereference(net_families[family]);
1205    err = -EAFNOSUPPORT;
1206    if (!pf)
1207        goto out_release;
1208
1209    /*
1210     * We will call the ->create function, that possibly is in a loadable
1211     * module, so we have to bump that loadable module refcnt first.
1212     */
1213    if (!try_module_get(pf->owner))
1214        goto out_release;
1215
1216    /* Now protected by module ref count */
1217    rcu_read_unlock();
1218
1219    err = pf->create(net, sock, protocol);
1220    if (err < 0)
1221        goto out_module_put;
1222
1223    /*
1224     * Now to bump the refcnt of the [loadable] module that owns this
1225     * socket at sock_release time we decrement its refcnt.
1226     */
1227    if (!try_module_get(sock->ops->owner))
1228        goto out_module_busy;
1229
1230    /*
1231     * Now that we're done with the ->create function, the [loadable]
1232     * module can have its refcnt decremented
1233     */
1234    module_put(pf->owner);
1235    err = security_socket_post_create(sock, family, type, protocol, kern);
1236    if (err)
1237        goto out_sock_release;
1238    *res = sock;
1239
1240    return 0;
1241
1242out_module_busy:
1243    err = -EAFNOSUPPORT;
1244out_module_put:
1245    sock->ops = NULL;
1246    module_put(pf->owner);
1247out_sock_release:
1248    sock_release(sock);
1249    return err;
1250
1251out_release:
1252    rcu_read_unlock();
1253    goto out_sock_release;
1254}
1255
1256int sock_create(int family, int type, int protocol, struct socket **res)
1257{
1258    return __sock_create(current->nsproxy->net_ns, family, type, protocol, res, 0);
1259}
1260
1261int sock_create_kern(int family, int type, int protocol, struct socket **res)
1262{
1263    return __sock_create(&init_net, family, type, protocol, res, 1);
1264}
1265
1266SYSCALL_DEFINE3(socket, int, family, int, type, int, protocol)
1267{
1268    int retval;
1269    struct socket *sock;
1270    int flags;
1271
1272    /* Check the SOCK_* constants for consistency. */
1273    BUILD_BUG_ON(SOCK_CLOEXEC != O_CLOEXEC);
1274    BUILD_BUG_ON((SOCK_MAX | SOCK_TYPE_MASK) != SOCK_TYPE_MASK);
1275    BUILD_BUG_ON(SOCK_CLOEXEC & SOCK_TYPE_MASK);
1276    BUILD_BUG_ON(SOCK_NONBLOCK & SOCK_TYPE_MASK);
1277
1278    flags = type & ~SOCK_TYPE_MASK;
1279    if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1280        return -EINVAL;
1281    type &= SOCK_TYPE_MASK;
1282
1283    if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
1284        flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1285
1286    retval = sock_create(family, type, protocol, &sock);
1287    if (retval < 0)
1288        goto out;
1289
1290    retval = sock_map_fd(sock, flags & (O_CLOEXEC | O_NONBLOCK));
1291    if (retval < 0)
1292        goto out_release;
1293
1294out:
1295    /* It may be already another descriptor 8) Not kernel problem. */
1296    return retval;
1297
1298out_release:
1299    sock_release(sock);
1300    return retval;
1301}
1302
1303/*
1304 * Create a pair of connected sockets.
1305 */
1306
1307SYSCALL_DEFINE4(socketpair, int, family, int, type, int, protocol,
1308        int __user *, usockvec)
1309{
1310    struct socket *sock1, *sock2;
1311    int fd1, fd2, err;
1312    struct file *newfile1, *newfile2;
1313    int flags;
1314
1315    flags = type & ~SOCK_TYPE_MASK;
1316    if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1317        return -EINVAL;
1318    type &= SOCK_TYPE_MASK;
1319
1320    if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
1321        flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1322
1323    /*
1324     * Obtain the first socket and check if the underlying protocol
1325     * supports the socketpair call.
1326     */
1327
1328    err = sock_create(family, type, protocol, &sock1);
1329    if (err < 0)
1330        goto out;
1331
1332    err = sock_create(family, type, protocol, &sock2);
1333    if (err < 0)
1334        goto out_release_1;
1335
1336    err = sock1->ops->socketpair(sock1, sock2);
1337    if (err < 0)
1338        goto out_release_both;
1339
1340    fd1 = sock_alloc_fd(&newfile1, flags & O_CLOEXEC);
1341    if (unlikely(fd1 < 0)) {
1342        err = fd1;
1343        goto out_release_both;
1344    }
1345
1346    fd2 = sock_alloc_fd(&newfile2, flags & O_CLOEXEC);
1347    if (unlikely(fd2 < 0)) {
1348        err = fd2;
1349        put_filp(newfile1);
1350        put_unused_fd(fd1);
1351        goto out_release_both;
1352    }
1353
1354    err = sock_attach_fd(sock1, newfile1, flags & O_NONBLOCK);
1355    if (unlikely(err < 0)) {
1356        goto out_fd2;
1357    }
1358
1359    err = sock_attach_fd(sock2, newfile2, flags & O_NONBLOCK);
1360    if (unlikely(err < 0)) {
1361        fput(newfile1);
1362        goto out_fd1;
1363    }
1364
1365    audit_fd_pair(fd1, fd2);
1366    fd_install(fd1, newfile1);
1367    fd_install(fd2, newfile2);
1368    /* fd1 and fd2 may be already another descriptors.
1369     * Not kernel problem.
1370     */
1371
1372    err = put_user(fd1, &usockvec[0]);
1373    if (!err)
1374        err = put_user(fd2, &usockvec[1]);
1375    if (!err)
1376        return 0;
1377
1378    sys_close(fd2);
1379    sys_close(fd1);
1380    return err;
1381
1382out_release_both:
1383    sock_release(sock2);
1384out_release_1:
1385    sock_release(sock1);
1386out:
1387    return err;
1388
1389out_fd2:
1390    put_filp(newfile1);
1391    sock_release(sock1);
1392out_fd1:
1393    put_filp(newfile2);
1394    sock_release(sock2);
1395    put_unused_fd(fd1);
1396    put_unused_fd(fd2);
1397    goto out;
1398}
1399
1400/*
1401 * Bind a name to a socket. Nothing much to do here since it's
1402 * the protocol's responsibility to handle the local address.
1403 *
1404 * We move the socket address to kernel space before we call
1405 * the protocol layer (having also checked the address is ok).
1406 */
1407
1408SYSCALL_DEFINE3(bind, int, fd, struct sockaddr __user *, umyaddr, int, addrlen)
1409{
1410    struct socket *sock;
1411    struct sockaddr_storage address;
1412    int err, fput_needed;
1413
1414    sock = sockfd_lookup_light(fd, &err, &fput_needed);
1415    if (sock) {
1416        err = move_addr_to_kernel(umyaddr, addrlen, (struct sockaddr *)&address);
1417        if (err >= 0) {
1418            err = security_socket_bind(sock,
1419                           (struct sockaddr *)&address,
1420                           addrlen);
1421            if (!err)
1422                err = sock->ops->bind(sock,
1423                              (struct sockaddr *)
1424                              &address, addrlen);
1425        }
1426        fput_light(sock->file, fput_needed);
1427    }
1428    return err;
1429}
1430
1431/*
1432 * Perform a listen. Basically, we allow the protocol to do anything
1433 * necessary for a listen, and if that works, we mark the socket as
1434 * ready for listening.
1435 */
1436
1437SYSCALL_DEFINE2(listen, int, fd, int, backlog)
1438{
1439    struct socket *sock;
1440    int err, fput_needed;
1441    int somaxconn;
1442
1443    sock = sockfd_lookup_light(fd, &err, &fput_needed);
1444    if (sock) {
1445        somaxconn = sock_net(sock->sk)->core.sysctl_somaxconn;
1446        if ((unsigned)backlog > somaxconn)
1447            backlog = somaxconn;
1448
1449        err = security_socket_listen(sock, backlog);
1450        if (!err)
1451            err = sock->ops->listen(sock, backlog);
1452
1453        fput_light(sock->file, fput_needed);
1454    }
1455    return err;
1456}
1457
1458/*
1459 * For accept, we attempt to create a new socket, set up the link
1460 * with the client, wake up the client, then return the new
1461 * connected fd. We collect the address of the connector in kernel
1462 * space and move it to user at the very end. This is unclean because
1463 * we open the socket then return an error.
1464 *
1465 * 1003.1g adds the ability to recvmsg() to query connection pending
1466 * status to recvmsg. We need to add that support in a way thats
1467 * clean when we restucture accept also.
1468 */
1469
1470SYSCALL_DEFINE4(accept4, int, fd, struct sockaddr __user *, upeer_sockaddr,
1471        int __user *, upeer_addrlen, int, flags)
1472{
1473    struct socket *sock, *newsock;
1474    struct file *newfile;
1475    int err, len, newfd, fput_needed;
1476    struct sockaddr_storage address;
1477
1478    if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1479        return -EINVAL;
1480
1481    if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
1482        flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1483
1484    sock = sockfd_lookup_light(fd, &err, &fput_needed);
1485    if (!sock)
1486        goto out;
1487
1488    err = -ENFILE;
1489    if (!(newsock = sock_alloc()))
1490        goto out_put;
1491
1492    newsock->type = sock->type;
1493    newsock->ops = sock->ops;
1494
1495    /*
1496     * We don't need try_module_get here, as the listening socket (sock)
1497     * has the protocol module (sock->ops->owner) held.
1498     */
1499    __module_get(newsock->ops->owner);
1500
1501    newfd = sock_alloc_fd(&newfile, flags & O_CLOEXEC);
1502    if (unlikely(newfd < 0)) {
1503        err = newfd;
1504        sock_release(newsock);
1505        goto out_put;
1506    }
1507
1508    err = sock_attach_fd(newsock, newfile, flags & O_NONBLOCK);
1509    if (err < 0)
1510        goto out_fd_simple;
1511
1512    err = security_socket_accept(sock, newsock);
1513    if (err)
1514        goto out_fd;
1515
1516    err = sock->ops->accept(sock, newsock, sock->file->f_flags);
1517    if (err < 0)
1518        goto out_fd;
1519
1520    if (upeer_sockaddr) {
1521        if (newsock->ops->getname(newsock, (struct sockaddr *)&address,
1522                      &len, 2) < 0) {
1523            err = -ECONNABORTED;
1524            goto out_fd;
1525        }
1526        err = move_addr_to_user((struct sockaddr *)&address,
1527                    len, upeer_sockaddr, upeer_addrlen);
1528        if (err < 0)
1529            goto out_fd;
1530    }
1531
1532    /* File flags are not inherited via accept() unlike another OSes. */
1533
1534    fd_install(newfd, newfile);
1535    err = newfd;
1536
1537out_put:
1538    fput_light(sock->file, fput_needed);
1539out:
1540    return err;
1541out_fd_simple:
1542    sock_release(newsock);
1543    put_filp(newfile);
1544    put_unused_fd(newfd);
1545    goto out_put;
1546out_fd:
1547    fput(newfile);
1548    put_unused_fd(newfd);
1549    goto out_put;
1550}
1551
1552SYSCALL_DEFINE3(accept, int, fd, struct sockaddr __user *, upeer_sockaddr,
1553        int __user *, upeer_addrlen)
1554{
1555    return sys_accept4(fd, upeer_sockaddr, upeer_addrlen, 0);
1556}
1557
1558/*
1559 * Attempt to connect to a socket with the server address. The address
1560 * is in user space so we verify it is OK and move it to kernel space.
1561 *
1562 * For 1003.1g we need to add clean support for a bind to AF_UNSPEC to
1563 * break bindings
1564 *
1565 * NOTE: 1003.1g draft 6.3 is broken with respect to AX.25/NetROM and
1566 * other SEQPACKET protocols that take time to connect() as it doesn't
1567 * include the -EINPROGRESS status for such sockets.
1568 */
1569
1570SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr,
1571        int, addrlen)
1572{
1573    struct socket *sock;
1574    struct sockaddr_storage address;
1575    int err, fput_needed;
1576
1577    sock = sockfd_lookup_light(fd, &err, &fput_needed);
1578    if (!sock)
1579        goto out;
1580    err = move_addr_to_kernel(uservaddr, addrlen, (struct sockaddr *)&address);
1581    if (err < 0)
1582        goto out_put;
1583
1584    err =
1585        security_socket_connect(sock, (struct sockaddr *)&address, addrlen);
1586    if (err)
1587        goto out_put;
1588
1589    err = sock->ops->connect(sock, (struct sockaddr *)&address, addrlen,
1590                 sock->file->f_flags);
1591out_put:
1592    fput_light(sock->file, fput_needed);
1593out:
1594    return err;
1595}
1596
1597/*
1598 * Get the local address ('name') of a socket object. Move the obtained
1599 * name to user space.
1600 */
1601
1602SYSCALL_DEFINE3(getsockname, int, fd, struct sockaddr __user *, usockaddr,
1603        int __user *, usockaddr_len)
1604{
1605    struct socket *sock;
1606    struct sockaddr_storage address;
1607    int len, err, fput_needed;
1608
1609    sock = sockfd_lookup_light(fd, &err, &fput_needed);
1610    if (!sock)
1611        goto out;
1612
1613    err = security_socket_getsockname(sock);
1614    if (err)
1615        goto out_put;
1616
1617    err = sock->ops->getname(sock, (struct sockaddr *)&address, &len, 0);
1618    if (err)
1619        goto out_put;
1620    err = move_addr_to_user((struct sockaddr *)&address, len, usockaddr, usockaddr_len);
1621
1622out_put:
1623    fput_light(sock->file, fput_needed);
1624out:
1625    return err;
1626}
1627
1628/*
1629 * Get the remote address ('name') of a socket object. Move the obtained
1630 * name to user space.
1631 */
1632
1633SYSCALL_DEFINE3(getpeername, int, fd, struct sockaddr __user *, usockaddr,
1634        int __user *, usockaddr_len)
1635{
1636    struct socket *sock;
1637    struct sockaddr_storage address;
1638    int len, err, fput_needed;
1639
1640    sock = sockfd_lookup_light(fd, &err, &fput_needed);
1641    if (sock != NULL) {
1642        err = security_socket_getpeername(sock);
1643        if (err) {
1644            fput_light(sock->file, fput_needed);
1645            return err;
1646        }
1647
1648        err =
1649            sock->ops->getname(sock, (struct sockaddr *)&address, &len,
1650                       1);
1651        if (!err)
1652            err = move_addr_to_user((struct sockaddr *)&address, len, usockaddr,
1653                        usockaddr_len);
1654        fput_light(sock->file, fput_needed);
1655    }
1656    return err;
1657}
1658
1659/*
1660 * Send a datagram to a given address. We move the address into kernel
1661 * space and check the user space data area is readable before invoking
1662 * the protocol.
1663 */
1664
1665SYSCALL_DEFINE6(sendto, int, fd, void __user *, buff, size_t, len,
1666        unsigned, flags, struct sockaddr __user *, addr,
1667        int, addr_len)
1668{
1669    struct socket *sock;
1670    struct sockaddr_storage address;
1671    int err;
1672    struct msghdr msg;
1673    struct iovec iov;
1674    int fput_needed;
1675
1676    sock = sockfd_lookup_light(fd, &err, &fput_needed);
1677    if (!sock)
1678        goto out;
1679
1680    iov.iov_base = buff;
1681    iov.iov_len = len;
1682    msg.msg_name = NULL;
1683    msg.msg_iov = &iov;
1684    msg.msg_iovlen = 1;
1685    msg.msg_control = NULL;
1686    msg.msg_controllen = 0;
1687    msg.msg_namelen = 0;
1688    if (addr) {
1689        err = move_addr_to_kernel(addr, addr_len, (struct sockaddr *)&address);
1690        if (err < 0)
1691            goto out_put;
1692        msg.msg_name = (struct sockaddr *)&address;
1693        msg.msg_namelen = addr_len;
1694    }
1695    if (sock->file->f_flags & O_NONBLOCK)
1696        flags |= MSG_DONTWAIT;
1697    msg.msg_flags = flags;
1698    err = sock_sendmsg(sock, &msg, len);
1699
1700out_put:
1701    fput_light(sock->file, fput_needed);
1702out:
1703    return err;
1704}
1705
1706/*
1707 * Send a datagram down a socket.
1708 */
1709
1710SYSCALL_DEFINE4(send, int, fd, void __user *, buff, size_t, len,
1711        unsigned, flags)
1712{
1713    return sys_sendto(fd, buff, len, flags, NULL, 0);
1714}
1715
1716/*
1717 * Receive a frame from the socket and optionally record the address of the
1718 * sender. We verify the buffers are writable and if needed move the
1719 * sender address from kernel to user space.
1720 */
1721
1722SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size,
1723        unsigned, flags, struct sockaddr __user *, addr,
1724        int __user *, addr_len)
1725{
1726    struct socket *sock;
1727    struct iovec iov;
1728    struct msghdr msg;
1729    struct sockaddr_storage address;
1730    int err, err2;
1731    int fput_needed;
1732
1733    sock = sockfd_lookup_light(fd, &err, &fput_needed);
1734    if (!sock)
1735        goto out;
1736
1737    msg.msg_control = NULL;
1738    msg.msg_controllen = 0;
1739    msg.msg_iovlen = 1;
1740    msg.msg_iov = &iov;
1741    iov.iov_len = size;
1742    iov.iov_base = ubuf;
1743    msg.msg_name = (struct sockaddr *)&address;
1744    msg.msg_namelen = sizeof(address);
1745    if (sock->file->f_flags & O_NONBLOCK)
1746        flags |= MSG_DONTWAIT;
1747    err = sock_recvmsg(sock, &msg, size, flags);
1748
1749    if (err >= 0 && addr != NULL) {
1750        err2 = move_addr_to_user((struct sockaddr *)&address,
1751                     msg.msg_namelen, addr, addr_len);
1752        if (err2 < 0)
1753            err = err2;
1754    }
1755
1756    fput_light(sock->file, fput_needed);
1757out:
1758    return err;
1759}
1760
1761/*
1762 * Receive a datagram from a socket.
1763 */
1764
1765asmlinkage long sys_recv(int fd, void __user *ubuf, size_t size,
1766             unsigned flags)
1767{
1768    return sys_recvfrom(fd, ubuf, size, flags, NULL, NULL);
1769}
1770
1771/*
1772 * Set a socket option. Because we don't know the option lengths we have
1773 * to pass the user mode parameter for the protocols to sort out.
1774 */
1775
1776SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname,
1777        char __user *, optval, int, optlen)
1778{
1779    int err, fput_needed;
1780    struct socket *sock;
1781
1782    if (optlen < 0)
1783        return -EINVAL;
1784
1785    sock = sockfd_lookup_light(fd, &err, &fput_needed);
1786    if (sock != NULL) {
1787        err = security_socket_setsockopt(sock, level, optname);
1788        if (err)
1789            goto out_put;
1790
1791        if (level == SOL_SOCKET)
1792            err =
1793                sock_setsockopt(sock, level, optname, optval,
1794                        optlen);
1795        else
1796            err =
1797                sock->ops->setsockopt(sock, level, optname, optval,
1798                          optlen);
1799out_put:
1800        fput_light(sock->file, fput_needed);
1801    }
1802    return err;
1803}
1804
1805/*
1806 * Get a socket option. Because we don't know the option lengths we have
1807 * to pass a user mode parameter for the protocols to sort out.
1808 */
1809
1810SYSCALL_DEFINE5(getsockopt, int, fd, int, level, int, optname,
1811        char __user *, optval, int __user *, optlen)
1812{
1813    int err, fput_needed;
1814    struct socket *sock;
1815
1816    sock = sockfd_lookup_light(fd, &err, &fput_needed);
1817    if (sock != NULL) {
1818        err = security_socket_getsockopt(sock, level, optname);
1819        if (err)
1820            goto out_put;
1821
1822        if (level == SOL_SOCKET)
1823            err =
1824                sock_getsockopt(sock, level, optname, optval,
1825                        optlen);
1826        else
1827            err =
1828                sock->ops->getsockopt(sock, level, optname, optval,
1829                          optlen);
1830out_put:
1831        fput_light(sock->file, fput_needed);
1832    }
1833    return err;
1834}
1835
1836/*
1837 * Shutdown a socket.
1838 */
1839
1840SYSCALL_DEFINE2(shutdown, int, fd, int, how)
1841{
1842    int err, fput_needed;
1843    struct socket *sock;
1844
1845    sock = sockfd_lookup_light(fd, &err, &fput_needed);
1846    if (sock != NULL) {
1847        err = security_socket_shutdown(sock, how);
1848        if (!err)
1849            err = sock->ops->shutdown(sock, how);
1850        fput_light(sock->file, fput_needed);
1851    }
1852    return err;
1853}
1854
1855/* A couple of helpful macros for getting the address of the 32/64 bit
1856 * fields which are the same type (int / unsigned) on our platforms.
1857 */
1858#define COMPAT_MSG(msg, member) ((MSG_CMSG_COMPAT & flags) ? &msg##_compat->member : &msg->member)
1859#define COMPAT_NAMELEN(msg) COMPAT_MSG(msg, msg_namelen)
1860#define COMPAT_FLAGS(msg) COMPAT_MSG(msg, msg_flags)
1861
1862/*
1863 * BSD sendmsg interface
1864 */
1865
1866SYSCALL_DEFINE3(sendmsg, int, fd, struct msghdr __user *, msg, unsigned, flags)
1867{
1868    struct compat_msghdr __user *msg_compat =
1869        (struct compat_msghdr __user *)msg;
1870    struct socket *sock;
1871    struct sockaddr_storage address;
1872    struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
1873    unsigned char ctl[sizeof(struct cmsghdr) + 20]
1874        __attribute__ ((aligned(sizeof(__kernel_size_t))));
1875    /* 20 is size of ipv6_pktinfo */
1876    unsigned char *ctl_buf = ctl;
1877    struct msghdr msg_sys;
1878    int err, ctl_len, iov_size, total_len;
1879    int fput_needed;
1880
1881    err = -EFAULT;
1882    if (MSG_CMSG_COMPAT & flags) {
1883        if (get_compat_msghdr(&msg_sys, msg_compat))
1884            return -EFAULT;
1885    }
1886    else if (copy_from_user(&msg_sys, msg, sizeof(struct msghdr)))
1887        return -EFAULT;
1888
1889    sock = sockfd_lookup_light(fd, &err, &fput_needed);
1890    if (!sock)
1891        goto out;
1892
1893    /* do not move before msg_sys is valid */
1894    err = -EMSGSIZE;
1895    if (msg_sys.msg_iovlen > UIO_MAXIOV)
1896        goto out_put;
1897
1898    /* Check whether to allocate the iovec area */
1899    err = -ENOMEM;
1900    iov_size = msg_sys.msg_iovlen * sizeof(struct iovec);
1901    if (msg_sys.msg_iovlen > UIO_FASTIOV) {
1902        iov = sock_kmalloc(sock->sk, iov_size, GFP_KERNEL);
1903        if (!iov)
1904            goto out_put;
1905    }
1906
1907    /* This will also move the address data into kernel space */
1908    if (MSG_CMSG_COMPAT & flags) {
1909        err = verify_compat_iovec(&msg_sys, iov,
1910                      (struct sockaddr *)&address,
1911                      VERIFY_READ);
1912    } else
1913        err = verify_iovec(&msg_sys, iov,
1914                   (struct sockaddr *)&address,
1915                   VERIFY_READ);
1916    if (err < 0)
1917        goto out_freeiov;
1918    total_len = err;
1919
1920    err = -ENOBUFS;
1921
1922    if (msg_sys.msg_controllen > INT_MAX)
1923        goto out_freeiov;
1924    ctl_len = msg_sys.msg_controllen;
1925    if ((MSG_CMSG_COMPAT & flags) && ctl_len) {
1926        err =
1927            cmsghdr_from_user_compat_to_kern(&msg_sys, sock->sk, ctl,
1928                             sizeof(ctl));
1929        if (err)
1930            goto out_freeiov;
1931        ctl_buf = msg_sys.msg_control;
1932        ctl_len = msg_sys.msg_controllen;
1933    } else if (ctl_len) {
1934        if (ctl_len > sizeof(ctl)) {
1935            ctl_buf = sock_kmalloc(sock->sk, ctl_len, GFP_KERNEL);
1936            if (ctl_buf == NULL)
1937                goto out_freeiov;
1938        }
1939        err = -EFAULT;
1940        /*
1941         * Careful! Before this, msg_sys.msg_control contains a user pointer.
1942         * Afterwards, it will be a kernel pointer. Thus the compiler-assisted
1943         * checking falls down on this.
1944         */
1945        if (copy_from_user(ctl_buf, (void __user *)msg_sys.msg_control,
1946                   ctl_len))
1947            goto out_freectl;
1948        msg_sys.msg_control = ctl_buf;
1949    }
1950    msg_sys.msg_flags = flags;
1951
1952    if (sock->file->f_flags & O_NONBLOCK)
1953        msg_sys.msg_flags |= MSG_DONTWAIT;
1954    err = sock_sendmsg(sock, &msg_sys, total_len);
1955
1956out_freectl:
1957    if (ctl_buf != ctl)
1958        sock_kfree_s(sock->sk, ctl_buf, ctl_len);
1959out_freeiov:
1960    if (iov != iovstack)
1961        sock_kfree_s(sock->sk, iov, iov_size);
1962out_put:
1963    fput_light(sock->file, fput_needed);
1964out:
1965    return err;
1966}
1967
1968/*
1969 * BSD recvmsg interface
1970 */
1971
1972SYSCALL_DEFINE3(recvmsg, int, fd, struct msghdr __user *, msg,
1973        unsigned int, flags)
1974{
1975    struct compat_msghdr __user *msg_compat =
1976        (struct compat_msghdr __user *)msg;
1977    struct socket *sock;
1978    struct iovec iovstack[UIO_FASTIOV];
1979    struct iovec *iov = iovstack;
1980    struct msghdr msg_sys;
1981    unsigned long cmsg_ptr;
1982    int err, iov_size, total_len, len;
1983    int fput_needed;
1984
1985    /* kernel mode address */
1986    struct sockaddr_storage addr;
1987
1988    /* user mode address pointers */
1989    struct sockaddr __user *uaddr;
1990    int __user *uaddr_len;
1991
1992    if (MSG_CMSG_COMPAT & flags) {
1993        if (get_compat_msghdr(&msg_sys, msg_compat))
1994            return -EFAULT;
1995    }
1996    else if (copy_from_user(&msg_sys, msg, sizeof(struct msghdr)))
1997        return -EFAULT;
1998
1999    sock = sockfd_lookup_light(fd, &err, &fput_needed);
2000    if (!sock)
2001        goto out;
2002
2003    err = -EMSGSIZE;
2004    if (msg_sys.msg_iovlen > UIO_MAXIOV)
2005        goto out_put;
2006
2007    /* Check whether to allocate the iovec area */
2008    err = -ENOMEM;
2009    iov_size = msg_sys.msg_iovlen * sizeof(struct iovec);
2010    if (msg_sys.msg_iovlen > UIO_FASTIOV) {
2011        iov = sock_kmalloc(sock->sk, iov_size, GFP_KERNEL);
2012        if (!iov)
2013            goto out_put;
2014    }
2015
2016    /*
2017     * Save the user-mode address (verify_iovec will change the
2018     * kernel msghdr to use the kernel address space)
2019     */
2020
2021    uaddr = (__force void __user *)msg_sys.msg_name;
2022    uaddr_len = COMPAT_NAMELEN(msg);
2023    if (MSG_CMSG_COMPAT & flags) {
2024        err = verify_compat_iovec(&msg_sys, iov,
2025                      (struct sockaddr *)&addr,
2026                      VERIFY_WRITE);
2027    } else
2028        err = verify_iovec(&msg_sys, iov,
2029                   (struct sockaddr *)&addr,
2030                   VERIFY_WRITE);
2031    if (err < 0)
2032        goto out_freeiov;
2033    total_len = err;
2034
2035    cmsg_ptr = (unsigned long)msg_sys.msg_control;
2036    msg_sys.msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
2037
2038    if (sock->file->f_flags & O_NONBLOCK)
2039        flags |= MSG_DONTWAIT;
2040    err = sock_recvmsg(sock, &msg_sys, total_len, flags);
2041    if (err < 0)
2042        goto out_freeiov;
2043    len = err;
2044
2045    if (uaddr != NULL) {
2046        err = move_addr_to_user((struct sockaddr *)&addr,
2047                    msg_sys.msg_namelen, uaddr,
2048                    uaddr_len);
2049        if (err < 0)
2050            goto out_freeiov;
2051    }
2052    err = __put_user((msg_sys.msg_flags & ~MSG_CMSG_COMPAT),
2053             COMPAT_FLAGS(msg));
2054    if (err)
2055        goto out_freeiov;
2056    if (MSG_CMSG_COMPAT & flags)
2057        err = __put_user((unsigned long)msg_sys.msg_control - cmsg_ptr,
2058                 &msg_compat->msg_controllen);
2059    else
2060        err = __put_user((unsigned long)msg_sys.msg_control - cmsg_ptr,
2061                 &msg->msg_controllen);
2062    if (err)
2063        goto out_freeiov;
2064    err = len;
2065
2066out_freeiov:
2067    if (iov != iovstack)
2068        sock_kfree_s(sock->sk, iov, iov_size);
2069out_put:
2070    fput_light(sock->file, fput_needed);
2071out:
2072    return err;
2073}
2074
2075#ifdef __ARCH_WANT_SYS_SOCKETCALL
2076
2077/* Argument list sizes for sys_socketcall */
2078#define AL(x) ((x) * sizeof(unsigned long))
2079static const unsigned char nargs[19]={
2080    AL(0),AL(3),AL(3),AL(3),AL(2),AL(3),
2081    AL(3),AL(3),AL(4),AL(4),AL(4),AL(6),
2082    AL(6),AL(2),AL(5),AL(5),AL(3),AL(3),
2083    AL(4)
2084};
2085
2086#undef AL
2087
2088/*
2089 * System call vectors.
2090 *
2091 * Argument checking cleaned up. Saved 20% in size.
2092 * This function doesn't need to set the kernel lock because
2093 * it is set by the callees.
2094 */
2095
2096SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
2097{
2098    unsigned long a[6];
2099    unsigned long a0, a1;
2100    int err;
2101    unsigned int len;
2102
2103    if (call < 1 || call > SYS_ACCEPT4)
2104        return -EINVAL;
2105
2106    len = nargs[call];
2107    if (len > sizeof(a))
2108        return -EINVAL;
2109
2110    /* copy_from_user should be SMP safe. */
2111    if (copy_from_user(a, args, len))
2112        return -EFAULT;
2113
2114    audit_socketcall(nargs[call] / sizeof(unsigned long), a);
2115
2116    a0 = a[0];
2117    a1 = a[1];
2118
2119    switch (call) {
2120    case SYS_SOCKET:
2121        err = sys_socket(a0, a1, a[2]);
2122        break;
2123    case SYS_BIND:
2124        err = sys_bind(a0, (struct sockaddr __user *)a1, a[2]);
2125        break;
2126    case SYS_CONNECT:
2127        err = sys_connect(a0, (struct sockaddr __user *)a1, a[2]);
2128        break;
2129    case SYS_LISTEN:
2130        err = sys_listen(a0, a1);
2131        break;
2132    case SYS_ACCEPT:
2133        err = sys_accept4(a0, (struct sockaddr __user *)a1,
2134                  (int __user *)a[2], 0);
2135        break;
2136    case SYS_GETSOCKNAME:
2137        err =
2138            sys_getsockname(a0, (struct sockaddr __user *)a1,
2139                    (int __user *)a[2]);
2140        break;
2141    case SYS_GETPEERNAME:
2142        err =
2143            sys_getpeername(a0, (struct sockaddr __user *)a1,
2144                    (int __user *)a[2]);
2145        break;
2146    case SYS_SOCKETPAIR:
2147        err = sys_socketpair(a0, a1, a[2], (int __user *)a[3]);
2148        break;
2149    case SYS_SEND:
2150        err = sys_send(a0, (void __user *)a1, a[2], a[3]);
2151        break;
2152    case SYS_SENDTO:
2153        err = sys_sendto(a0, (void __user *)a1, a[2], a[3],
2154                 (struct sockaddr __user *)a[4], a[5]);
2155        break;
2156    case SYS_RECV:
2157        err = sys_recv(a0, (void __user *)a1, a[2], a[3]);
2158        break;
2159    case SYS_RECVFROM:
2160        err = sys_recvfrom(a0, (void __user *)a1, a[2], a[3],
2161                   (struct sockaddr __user *)a[4],
2162                   (int __user *)a[5]);
2163        break;
2164    case SYS_SHUTDOWN:
2165        err = sys_shutdown(a0, a1);
2166        break;
2167    case SYS_SETSOCKOPT:
2168        err = sys_setsockopt(a0, a1, a[2], (char __user *)a[3], a[4]);
2169        break;
2170    case SYS_GETSOCKOPT:
2171        err =
2172            sys_getsockopt(a0, a1, a[2], (char __user *)a[3],
2173                   (int __user *)a[4]);
2174        break;
2175    case SYS_SENDMSG:
2176        err = sys_sendmsg(a0, (struct msghdr __user *)a1, a[2]);
2177        break;
2178    case SYS_RECVMSG:
2179        err = sys_recvmsg(a0, (struct msghdr __user *)a1, a[2]);
2180        break;
2181    case SYS_ACCEPT4:
2182        err = sys_accept4(a0, (struct sockaddr __user *)a1,
2183                  (int __user *)a[2], a[3]);
2184        break;
2185    default:
2186        err = -EINVAL;
2187        break;
2188    }
2189    return err;
2190}
2191
2192#endif /* __ARCH_WANT_SYS_SOCKETCALL */
2193
2194/**
2195 * sock_register - add a socket protocol handler
2196 * @ops: description of protocol
2197 *
2198 * This function is called by a protocol handler that wants to
2199 * advertise its address family, and have it linked into the
2200 * socket interface. The value ops->family coresponds to the
2201 * socket system call protocol family.
2202 */
2203int sock_register(const struct net_proto_family *ops)
2204{
2205    int err;
2206
2207    if (ops->family >= NPROTO) {
2208        printk(KERN_CRIT "protocol %d >= NPROTO(%d)\n", ops->family,
2209               NPROTO);
2210        return -ENOBUFS;
2211    }
2212
2213    spin_lock(&net_family_lock);
2214    if (net_families[ops->family])
2215        err = -EEXIST;
2216    else {
2217        net_families[ops->family] = ops;
2218        err = 0;
2219    }
2220    spin_unlock(&net_family_lock);
2221
2222    printk(KERN_INFO "NET: Registered protocol family %d\n", ops->family);
2223    return err;
2224}
2225
2226/**
2227 * sock_unregister - remove a protocol handler
2228 * @family: protocol family to remove
2229 *
2230 * This function is called by a protocol handler that wants to
2231 * remove its address family, and have it unlinked from the
2232 * new socket creation.
2233 *
2234 * If protocol handler is a module, then it can use module reference
2235 * counts to protect against new references. If protocol handler is not
2236 * a module then it needs to provide its own protection in
2237 * the ops->create routine.
2238 */
2239void sock_unregister(int family)
2240{
2241    BUG_ON(family < 0 || family >= NPROTO);
2242
2243    spin_lock(&net_family_lock);
2244    net_families[family] = NULL;
2245    spin_unlock(&net_family_lock);
2246
2247    synchronize_rcu();
2248
2249    printk(KERN_INFO "NET: Unregistered protocol family %d\n", family);
2250}
2251
2252static int __init sock_init(void)
2253{
2254    /*
2255     * Initialize sock SLAB cache.
2256     */
2257
2258    sk_init();
2259
2260    /*
2261     * Initialize skbuff SLAB cache
2262     */
2263    skb_init();
2264
2265    /*
2266     * Initialize the protocols module.
2267     */
2268
2269    init_inodecache();
2270    register_filesystem(&sock_fs_type);
2271    sock_mnt = kern_mount(&sock_fs_type);
2272
2273    /* The real protocol initialization is performed in later initcalls.
2274     */
2275
2276#ifdef CONFIG_NETFILTER
2277    netfilter_init();
2278#endif
2279
2280    return 0;
2281}
2282
2283core_initcall(sock_init); /* early initcall */
2284
2285#ifdef CONFIG_PROC_FS
2286void socket_seq_show(struct seq_file *seq)
2287{
2288    int cpu;
2289    int counter = 0;
2290
2291    for_each_possible_cpu(cpu)
2292        counter += per_cpu(sockets_in_use, cpu);
2293
2294    /* It can be negative, by the way. 8) */
2295    if (counter < 0)
2296        counter = 0;
2297
2298    seq_printf(seq, "sockets: used %d\n", counter);
2299}
2300#endif /* CONFIG_PROC_FS */
2301
2302#ifdef CONFIG_COMPAT
2303static long compat_sock_ioctl(struct file *file, unsigned cmd,
2304                  unsigned long arg)
2305{
2306    struct socket *sock = file->private_data;
2307    int ret = -ENOIOCTLCMD;
2308    struct sock *sk;
2309    struct net *net;
2310
2311    sk = sock->sk;
2312    net = sock_net(sk);
2313
2314    if (sock->ops->compat_ioctl)
2315        ret = sock->ops->compat_ioctl(sock, cmd, arg);
2316
2317    if (ret == -ENOIOCTLCMD &&
2318        (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST))
2319        ret = compat_wext_handle_ioctl(net, cmd, arg);
2320
2321    return ret;
2322}
2323#endif
2324
2325int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
2326{
2327    return sock->ops->bind(sock, addr, addrlen);
2328}
2329
2330int kernel_listen(struct socket *sock, int backlog)
2331{
2332    return sock->ops->listen(sock, backlog);
2333}
2334
2335int kernel_accept(struct socket *sock, struct socket **newsock, int flags)
2336{
2337    struct sock *sk = sock->sk;
2338    int err;
2339
2340    err = sock_create_lite(sk->sk_family, sk->sk_type, sk->sk_protocol,
2341                   newsock);
2342    if (err < 0)
2343        goto done;
2344
2345    err = sock->ops->accept(sock, *newsock, flags);
2346    if (err < 0) {
2347        sock_release(*newsock);
2348        *newsock = NULL;
2349        goto done;
2350    }
2351
2352    (*newsock)->ops = sock->ops;
2353    __module_get((*newsock)->ops->owner);
2354
2355done:
2356    return err;
2357}
2358
2359int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
2360           int flags)
2361{
2362    return sock->ops->connect(sock, addr, addrlen, flags);
2363}
2364
2365int kernel_getsockname(struct socket *sock, struct sockaddr *addr,
2366             int *addrlen)
2367{
2368    return sock->ops->getname(sock, addr, addrlen, 0);
2369}
2370
2371int kernel_getpeername(struct socket *sock, struct sockaddr *addr,
2372             int *addrlen)
2373{
2374    return sock->ops->getname(sock, addr, addrlen, 1);
2375}
2376
2377int kernel_getsockopt(struct socket *sock, int level, int optname,
2378            char *optval, int *optlen)
2379{
2380    mm_segment_t oldfs = get_fs();
2381    int err;
2382
2383    set_fs(KERNEL_DS);
2384    if (level == SOL_SOCKET)
2385        err = sock_getsockopt(sock, level, optname, optval, optlen);
2386    else
2387        err = sock->ops->getsockopt(sock, level, optname, optval,
2388                        optlen);
2389    set_fs(oldfs);
2390    return err;
2391}
2392
2393int kernel_setsockopt(struct socket *sock, int level, int optname,
2394            char *optval, unsigned int optlen)
2395{
2396    mm_segment_t oldfs = get_fs();
2397    int err;
2398
2399    set_fs(KERNEL_DS);
2400    if (level == SOL_SOCKET)
2401        err = sock_setsockopt(sock, level, optname, optval, optlen);
2402    else
2403        err = sock->ops->setsockopt(sock, level, optname, optval,
2404                        optlen);
2405    set_fs(oldfs);
2406    return err;
2407}
2408
2409int kernel_sendpage(struct socket *sock, struct page *page, int offset,
2410            size_t size, int flags)
2411{
2412    if (sock->ops->sendpage)
2413        return sock->ops->sendpage(sock, page, offset, size, flags);
2414
2415    return sock_no_sendpage(sock, page, offset, size, flags);
2416}
2417
2418int kernel_sock_ioctl(struct socket *sock, int cmd, unsigned long arg)
2419{
2420    mm_segment_t oldfs = get_fs();
2421    int err;
2422
2423    set_fs(KERNEL_DS);
2424    err = sock->ops->ioctl(sock, cmd, arg);
2425    set_fs(oldfs);
2426
2427    return err;
2428}
2429
2430int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how)
2431{
2432    return sock->ops->shutdown(sock, how);
2433}
2434
2435EXPORT_SYMBOL(sock_create);
2436EXPORT_SYMBOL(sock_create_kern);
2437EXPORT_SYMBOL(sock_create_lite);
2438EXPORT_SYMBOL(sock_map_fd);
2439EXPORT_SYMBOL(sock_recvmsg);
2440EXPORT_SYMBOL(sock_register);
2441EXPORT_SYMBOL(sock_release);
2442EXPORT_SYMBOL(sock_sendmsg);
2443EXPORT_SYMBOL(sock_unregister);
2444EXPORT_SYMBOL(sock_wake_async);
2445EXPORT_SYMBOL(sockfd_lookup);
2446EXPORT_SYMBOL(kernel_sendmsg);
2447EXPORT_SYMBOL(kernel_recvmsg);
2448EXPORT_SYMBOL(kernel_bind);
2449EXPORT_SYMBOL(kernel_listen);
2450EXPORT_SYMBOL(kernel_accept);
2451EXPORT_SYMBOL(kernel_connect);
2452EXPORT_SYMBOL(kernel_getsockname);
2453EXPORT_SYMBOL(kernel_getpeername);
2454EXPORT_SYMBOL(kernel_getsockopt);
2455EXPORT_SYMBOL(kernel_setsockopt);
2456EXPORT_SYMBOL(kernel_sendpage);
2457EXPORT_SYMBOL(kernel_sock_ioctl);
2458EXPORT_SYMBOL(kernel_sock_shutdown);
2459

Archive Download this file



interactive