44b0aa227c95643cbe15c6dfb4b3b415e7aea8aa
[linux-2.6.git] / net / core / sock.c
1 /*
2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
3  *              operating system.  INET is implemented using the  BSD Socket
4  *              interface as the means of communication with the user level.
5  *
6  *              Generic socket support routines. Memory allocators, socket lock/release
7  *              handler for protocols to use and generic option handler.
8  *
9  *
10  * Version:     $Id: sock.c,v 1.117 2002/02/01 22:01:03 davem Exp $
11  *
12  * Authors:     Ross Biro, <bir7@leland.Stanford.Edu>
13  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
14  *              Florian La Roche, <flla@stud.uni-sb.de>
15  *              Alan Cox, <A.Cox@swansea.ac.uk>
16  *
17  * Fixes:
18  *              Alan Cox        :       Numerous verify_area() problems
19  *              Alan Cox        :       Connecting on a connecting socket
20  *                                      now returns an error for tcp.
21  *              Alan Cox        :       sock->protocol is set correctly.
22  *                                      and is not sometimes left as 0.
23  *              Alan Cox        :       connect handles icmp errors on a
24  *                                      connect properly. Unfortunately there
25  *                                      is a restart syscall nasty there. I
26  *                                      can't match BSD without hacking the C
27  *                                      library. Ideas urgently sought!
28  *              Alan Cox        :       Disallow bind() to addresses that are
29  *                                      not ours - especially broadcast ones!!
30  *              Alan Cox        :       Socket 1024 _IS_ ok for users. (fencepost)
31  *              Alan Cox        :       sock_wfree/sock_rfree don't destroy sockets,
32  *                                      instead they leave that for the DESTROY timer.
33  *              Alan Cox        :       Clean up error flag in accept
34  *              Alan Cox        :       TCP ack handling is buggy, the DESTROY timer
35  *                                      was buggy. Put a remove_sock() in the handler
36  *                                      for memory when we hit 0. Also altered the timer
37  *                                      code. The ACK stuff can wait and needs major 
38  *                                      TCP layer surgery.
39  *              Alan Cox        :       Fixed TCP ack bug, removed remove sock
40  *                                      and fixed timer/inet_bh race.
41  *              Alan Cox        :       Added zapped flag for TCP
42  *              Alan Cox        :       Move kfree_skb into skbuff.c and tidied up surplus code
43  *              Alan Cox        :       for new sk_buff allocations wmalloc/rmalloc now call alloc_skb
44  *              Alan Cox        :       kfree_s calls now are kfree_skbmem so we can track skb resources
45  *              Alan Cox        :       Supports socket option broadcast now as does udp. Packet and raw need fixing.
46  *              Alan Cox        :       Added RCVBUF,SNDBUF size setting. It suddenly occurred to me how easy it was so...
47  *              Rick Sladkey    :       Relaxed UDP rules for matching packets.
48  *              C.E.Hawkins     :       IFF_PROMISC/SIOCGHWADDR support
49  *      Pauline Middelink       :       identd support
50  *              Alan Cox        :       Fixed connect() taking signals I think.
51  *              Alan Cox        :       SO_LINGER supported
52  *              Alan Cox        :       Error reporting fixes
53  *              Anonymous       :       inet_create tidied up (sk->reuse setting)
54  *              Alan Cox        :       inet sockets don't set sk->type!
55  *              Alan Cox        :       Split socket option code
56  *              Alan Cox        :       Callbacks
57  *              Alan Cox        :       Nagle flag for Charles & Johannes stuff
58  *              Alex            :       Removed restriction on inet fioctl
59  *              Alan Cox        :       Splitting INET from NET core
60  *              Alan Cox        :       Fixed bogus SO_TYPE handling in getsockopt()
61  *              Adam Caldwell   :       Missing return in SO_DONTROUTE/SO_DEBUG code
62  *              Alan Cox        :       Split IP from generic code
63  *              Alan Cox        :       New kfree_skbmem()
64  *              Alan Cox        :       Make SO_DEBUG superuser only.
65  *              Alan Cox        :       Allow anyone to clear SO_DEBUG
66  *                                      (compatibility fix)
67  *              Alan Cox        :       Added optimistic memory grabbing for AF_UNIX throughput.
68  *              Alan Cox        :       Allocator for a socket is settable.
69  *              Alan Cox        :       SO_ERROR includes soft errors.
70  *              Alan Cox        :       Allow NULL arguments on some SO_ opts
71  *              Alan Cox        :       Generic socket allocation to make hooks
72  *                                      easier (suggested by Craig Metz).
73  *              Michael Pall    :       SO_ERROR returns positive errno again
74  *              Steve Whitehouse:       Added default destructor to free
75  *                                      protocol private data.
76  *              Steve Whitehouse:       Added various other default routines
77  *                                      common to several socket families.
78  *              Chris Evans     :       Call suser() check last on F_SETOWN
79  *              Jay Schulist    :       Added SO_ATTACH_FILTER and SO_DETACH_FILTER.
80  *              Andi Kleen      :       Add sock_kmalloc()/sock_kfree_s()
81  *              Andi Kleen      :       Fix write_space callback
82  *              Chris Evans     :       Security fixes - signedness again
83  *              Arnaldo C. Melo :       cleanups, use skb_queue_purge
84  *
85  * To Fix:
86  *
87  *
88  *              This program is free software; you can redistribute it and/or
89  *              modify it under the terms of the GNU General Public License
90  *              as published by the Free Software Foundation; either version
91  *              2 of the License, or (at your option) any later version.
92  */
93
94 #include <linux/config.h>
95 #include <linux/errno.h>
96 #include <linux/types.h>
97 #include <linux/socket.h>
98 #include <linux/in.h>
99 #include <linux/kernel.h>
100 #include <linux/major.h>
101 #include <linux/module.h>
102 #include <linux/sched.h>
103 #include <linux/timer.h>
104 #include <linux/string.h>
105 #include <linux/sockios.h>
106 #include <linux/net.h>
107 #include <linux/mm.h>
108 #include <linux/slab.h>
109 #include <linux/interrupt.h>
110 #include <linux/poll.h>
111 #include <linux/tcp.h>
112 #include <linux/init.h>
113
114 #include <asm/uaccess.h>
115 #include <asm/system.h>
116
117 #include <linux/netdevice.h>
118 #include <net/protocol.h>
119 #include <linux/skbuff.h>
120 #include <net/sock.h>
121 #include <linux/ipsec.h>
122
123 #include <linux/filter.h>
124 #include <linux/vs_socket.h>
125
126 #ifdef CONFIG_INET
127 #include <net/tcp.h>
128 #endif
129
130 /* Take into consideration the size of the struct sk_buff overhead in the
131  * determination of these values, since that is non-constant across
132  * platforms.  This makes socket queueing behavior and performance
133  * not depend upon such differences.
134  */
135 #define _SK_MEM_PACKETS         256
136 #define _SK_MEM_OVERHEAD        (sizeof(struct sk_buff) + 256)
137 #define SK_WMEM_MAX             (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
138 #define SK_RMEM_MAX             (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
139
140 /* Run time adjustable parameters. */
141 __u32 sysctl_wmem_max = SK_WMEM_MAX;
142 __u32 sysctl_rmem_max = SK_RMEM_MAX;
143 __u32 sysctl_wmem_default = SK_WMEM_MAX;
144 __u32 sysctl_rmem_default = SK_RMEM_MAX;
145
146 /* Maximal space eaten by iovec or ancilliary data plus some space */
147 int sysctl_optmem_max = sizeof(unsigned long)*(2*UIO_MAXIOV + 512);
148
149 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
150 {
151         struct timeval tv;
152
153         if (optlen < sizeof(tv))
154                 return -EINVAL;
155         if (copy_from_user(&tv, optval, sizeof(tv)))
156                 return -EFAULT;
157
158         *timeo_p = MAX_SCHEDULE_TIMEOUT;
159         if (tv.tv_sec == 0 && tv.tv_usec == 0)
160                 return 0;
161         if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
162                 *timeo_p = tv.tv_sec*HZ + (tv.tv_usec+(1000000/HZ-1))/(1000000/HZ);
163         return 0;
164 }
165
166 static void sock_warn_obsolete_bsdism(const char *name)
167 {
168         static int warned;
169         static char warncomm[16];
170         if (strcmp(warncomm, current->comm) && warned < 5) { 
171                 strcpy(warncomm,  current->comm); 
172                 printk(KERN_WARNING "process `%s' is using obsolete "
173                        "%s SO_BSDCOMPAT\n", warncomm, name);
174                 warned++;
175         }
176 }
177
178 /*
179  *      This is meant for all protocols to use and covers goings on
180  *      at the socket level. Everything here is generic.
181  */
182
183 int sock_setsockopt(struct socket *sock, int level, int optname,
184                     char __user *optval, int optlen)
185 {
186         struct sock *sk=sock->sk;
187         struct sk_filter *filter;
188         int val;
189         int valbool;
190         struct linger ling;
191         int ret = 0;
192         
193         /*
194          *      Options without arguments
195          */
196
197 #ifdef SO_DONTLINGER            /* Compatibility item... */
198         switch (optname) {
199                 case SO_DONTLINGER:
200                         sock_reset_flag(sk, SOCK_LINGER);
201                         return 0;
202         }
203 #endif  
204                 
205         if(optlen<sizeof(int))
206                 return(-EINVAL);
207         
208         if (get_user(val, (int __user *)optval))
209                 return -EFAULT;
210         
211         valbool = val?1:0;
212
213         lock_sock(sk);
214
215         switch(optname) 
216         {
217                 case SO_DEBUG:  
218                         if(val && !capable(CAP_NET_ADMIN))
219                         {
220                                 ret = -EACCES;
221                         }
222                         else
223                                 sk->sk_debug = valbool;
224                         break;
225                 case SO_REUSEADDR:
226                         sk->sk_reuse = valbool;
227                         break;
228                 case SO_TYPE:
229                 case SO_ERROR:
230                         ret = -ENOPROTOOPT;
231                         break;
232                 case SO_DONTROUTE:
233                         sk->sk_localroute = valbool;
234                         break;
235                 case SO_BROADCAST:
236                         sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
237                         break;
238                 case SO_SNDBUF:
239                         /* Don't error on this BSD doesn't and if you think
240                            about it this is right. Otherwise apps have to
241                            play 'guess the biggest size' games. RCVBUF/SNDBUF
242                            are treated in BSD as hints */
243                            
244                         if (val > sysctl_wmem_max)
245                                 val = sysctl_wmem_max;
246
247                         sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
248                         if ((val * 2) < SOCK_MIN_SNDBUF)
249                                 sk->sk_sndbuf = SOCK_MIN_SNDBUF;
250                         else
251                                 sk->sk_sndbuf = val * 2;
252
253                         /*
254                          *      Wake up sending tasks if we
255                          *      upped the value.
256                          */
257                         sk->sk_write_space(sk);
258                         break;
259
260                 case SO_RCVBUF:
261                         /* Don't error on this BSD doesn't and if you think
262                            about it this is right. Otherwise apps have to
263                            play 'guess the biggest size' games. RCVBUF/SNDBUF
264                            are treated in BSD as hints */
265                           
266                         if (val > sysctl_rmem_max)
267                                 val = sysctl_rmem_max;
268
269                         sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
270                         /* FIXME: is this lower bound the right one? */
271                         if ((val * 2) < SOCK_MIN_RCVBUF)
272                                 sk->sk_rcvbuf = SOCK_MIN_RCVBUF;
273                         else
274                                 sk->sk_rcvbuf = val * 2;
275                         break;
276
277                 case SO_KEEPALIVE:
278 #ifdef CONFIG_INET
279                         if (sk->sk_protocol == IPPROTO_TCP)
280                                 tcp_set_keepalive(sk, valbool);
281 #endif
282                         sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
283                         break;
284
285                 case SO_OOBINLINE:
286                         sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
287                         break;
288
289                 case SO_NO_CHECK:
290                         sk->sk_no_check = valbool;
291                         break;
292
293                 case SO_PRIORITY:
294                         if ((val >= 0 && val <= 6) || capable(CAP_NET_ADMIN)) 
295                                 sk->sk_priority = val;
296                         else
297                                 ret = -EPERM;
298                         break;
299
300                 case SO_LINGER:
301                         if(optlen<sizeof(ling)) {
302                                 ret = -EINVAL;  /* 1003.1g */
303                                 break;
304                         }
305                         if (copy_from_user(&ling,optval,sizeof(ling))) {
306                                 ret = -EFAULT;
307                                 break;
308                         }
309                         if (!ling.l_onoff)
310                                 sock_reset_flag(sk, SOCK_LINGER);
311                         else {
312 #if (BITS_PER_LONG == 32)
313                                 if (ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
314                                         sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
315                                 else
316 #endif
317                                         sk->sk_lingertime = ling.l_linger * HZ;
318                                 sock_set_flag(sk, SOCK_LINGER);
319                         }
320                         break;
321
322                 case SO_BSDCOMPAT:
323                         sock_warn_obsolete_bsdism("setsockopt");
324                         break;
325
326                 case SO_PASSCRED:
327                         if (valbool)
328                                 set_bit(SOCK_PASS_CRED, &sock->flags);
329                         else
330                                 clear_bit(SOCK_PASS_CRED, &sock->flags);
331                         break;
332
333                 case SO_TIMESTAMP:
334                         sk->sk_rcvtstamp = valbool;
335                         if (valbool) 
336                                 sock_enable_timestamp(sk);
337                         break;
338
339                 case SO_RCVLOWAT:
340                         if (val < 0)
341                                 val = INT_MAX;
342                         sk->sk_rcvlowat = val ? : 1;
343                         break;
344
345                 case SO_RCVTIMEO:
346                         ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
347                         break;
348
349                 case SO_SNDTIMEO:
350                         ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
351                         break;
352
353 #ifdef CONFIG_NETDEVICES
354                 case SO_BINDTODEVICE:
355                 {
356                         char devname[IFNAMSIZ]; 
357
358                         /* Sorry... */ 
359                         if (!capable(CAP_NET_RAW)) {
360                                 ret = -EPERM;
361                                 break;
362                         }
363
364                         /* Bind this socket to a particular device like "eth0",
365                          * as specified in the passed interface name. If the
366                          * name is "" or the option length is zero the socket 
367                          * is not bound. 
368                          */ 
369
370                         if (!valbool) {
371                                 sk->sk_bound_dev_if = 0;
372                         } else {
373                                 if (optlen > IFNAMSIZ) 
374                                         optlen = IFNAMSIZ; 
375                                 if (copy_from_user(devname, optval, optlen)) {
376                                         ret = -EFAULT;
377                                         break;
378                                 }
379
380                                 /* Remove any cached route for this socket. */
381                                 sk_dst_reset(sk);
382
383                                 if (devname[0] == '\0') {
384                                         sk->sk_bound_dev_if = 0;
385                                 } else {
386                                         struct net_device *dev = dev_get_by_name(devname);
387                                         if (!dev) {
388                                                 ret = -ENODEV;
389                                                 break;
390                                         }
391                                         sk->sk_bound_dev_if = dev->ifindex;
392                                         dev_put(dev);
393                                 }
394                         }
395                         break;
396                 }
397 #endif
398
399
400                 case SO_ATTACH_FILTER:
401                         ret = -EINVAL;
402                         if (optlen == sizeof(struct sock_fprog)) {
403                                 struct sock_fprog fprog;
404
405                                 ret = -EFAULT;
406                                 if (copy_from_user(&fprog, optval, sizeof(fprog)))
407                                         break;
408
409                                 ret = sk_attach_filter(&fprog, sk);
410                         }
411                         break;
412
413                 case SO_DETACH_FILTER:
414                         spin_lock_bh(&sk->sk_lock.slock);
415                         filter = sk->sk_filter;
416                         if (filter) {
417                                 sk->sk_filter = NULL;
418                                 spin_unlock_bh(&sk->sk_lock.slock);
419                                 sk_filter_release(sk, filter);
420                                 break;
421                         }
422                         spin_unlock_bh(&sk->sk_lock.slock);
423                         ret = -ENONET;
424                         break;
425
426                 /* We implement the SO_SNDLOWAT etc to
427                    not be settable (1003.1g 5.3) */
428                 default:
429                         ret = -ENOPROTOOPT;
430                         break;
431         }
432         release_sock(sk);
433         return ret;
434 }
435
436
437 int sock_getsockopt(struct socket *sock, int level, int optname,
438                     char __user *optval, int __user *optlen)
439 {
440         struct sock *sk = sock->sk;
441         
442         union
443         {
444                 int val;
445                 struct linger ling;
446                 struct timeval tm;
447         } v;
448         
449         unsigned int lv=sizeof(int),len;
450         
451         if(get_user(len,optlen))
452                 return -EFAULT;
453         if(len < 0)
454                 return -EINVAL;
455                 
456         switch(optname) 
457         {
458                 case SO_DEBUG:          
459                         v.val = sk->sk_debug;
460                         break;
461                 
462                 case SO_DONTROUTE:
463                         v.val = sk->sk_localroute;
464                         break;
465                 
466                 case SO_BROADCAST:
467                         v.val = !!sock_flag(sk, SOCK_BROADCAST);
468                         break;
469
470                 case SO_SNDBUF:
471                         v.val = sk->sk_sndbuf;
472                         break;
473                 
474                 case SO_RCVBUF:
475                         v.val = sk->sk_rcvbuf;
476                         break;
477
478                 case SO_REUSEADDR:
479                         v.val = sk->sk_reuse;
480                         break;
481
482                 case SO_KEEPALIVE:
483                         v.val = !!sock_flag(sk, SOCK_KEEPOPEN);
484                         break;
485
486                 case SO_TYPE:
487                         v.val = sk->sk_type;                            
488                         break;
489
490                 case SO_ERROR:
491                         v.val = -sock_error(sk);
492                         if(v.val==0)
493                                 v.val = xchg(&sk->sk_err_soft, 0);
494                         break;
495
496                 case SO_OOBINLINE:
497                         v.val = !!sock_flag(sk, SOCK_URGINLINE);
498                         break;
499         
500                 case SO_NO_CHECK:
501                         v.val = sk->sk_no_check;
502                         break;
503
504                 case SO_PRIORITY:
505                         v.val = sk->sk_priority;
506                         break;
507                 
508                 case SO_LINGER: 
509                         lv              = sizeof(v.ling);
510                         v.ling.l_onoff  = !!sock_flag(sk, SOCK_LINGER);
511                         v.ling.l_linger = sk->sk_lingertime / HZ;
512                         break;
513                                         
514                 case SO_BSDCOMPAT:
515                         sock_warn_obsolete_bsdism("getsockopt");
516                         break;
517
518                 case SO_TIMESTAMP:
519                         v.val = sk->sk_rcvtstamp;
520                         break;
521
522                 case SO_RCVTIMEO:
523                         lv=sizeof(struct timeval);
524                         if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
525                                 v.tm.tv_sec = 0;
526                                 v.tm.tv_usec = 0;
527                         } else {
528                                 v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
529                                 v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000) / HZ;
530                         }
531                         break;
532
533                 case SO_SNDTIMEO:
534                         lv=sizeof(struct timeval);
535                         if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
536                                 v.tm.tv_sec = 0;
537                                 v.tm.tv_usec = 0;
538                         } else {
539                                 v.tm.tv_sec = sk->sk_sndtimeo / HZ;
540                                 v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000) / HZ;
541                         }
542                         break;
543
544                 case SO_RCVLOWAT:
545                         v.val = sk->sk_rcvlowat;
546                         break;
547
548                 case SO_SNDLOWAT:
549                         v.val=1;
550                         break; 
551
552                 case SO_PASSCRED:
553                         v.val = test_bit(SOCK_PASS_CRED, &sock->flags)?1:0;
554                         break;
555
556                 case SO_PEERCRED:
557                         if (len > sizeof(sk->sk_peercred))
558                                 len = sizeof(sk->sk_peercred);
559                         if (copy_to_user(optval, &sk->sk_peercred, len))
560                                 return -EFAULT;
561                         goto lenout;
562
563                 case SO_PEERNAME:
564                 {
565                         char address[128];
566
567                         if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
568                                 return -ENOTCONN;
569                         if (lv < len)
570                                 return -EINVAL;
571                         if (copy_to_user(optval, address, len))
572                                 return -EFAULT;
573                         goto lenout;
574                 }
575
576                 /* Dubious BSD thing... Probably nobody even uses it, but
577                  * the UNIX standard wants it for whatever reason... -DaveM
578                  */
579                 case SO_ACCEPTCONN:
580                         v.val = sk->sk_state == TCP_LISTEN;
581                         break;
582
583                 case SO_PEERSEC:
584                         return security_socket_getpeersec(sock, optval, optlen, len);
585
586                 default:
587                         return(-ENOPROTOOPT);
588         }
589         if (len > lv)
590                 len = lv;
591         if (copy_to_user(optval, &v, len))
592                 return -EFAULT;
593 lenout:
594         if (put_user(len, optlen))
595                 return -EFAULT;
596         return 0;
597 }
598
599 static kmem_cache_t *sk_cachep;
600
601 /**
602  *      sk_alloc - All socket objects are allocated here
603  *      @family - protocol family
604  *      @priority - for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
605  *      @zero_it - zeroes the allocated sock
606  *      @slab - alternate slab
607  *
608  *      All socket objects are allocated here. If @zero_it is non-zero
609  *      it should have the size of the are to be zeroed, because the
610  *      private slabcaches have different sizes of the generic struct sock.
611  *      1 has been kept as a way to say sizeof(struct sock).
612  */
613 struct sock *sk_alloc(int family, int priority, int zero_it, kmem_cache_t *slab)
614 {
615         struct sock *sk = NULL;
616
617         if (!slab)
618                 slab = sk_cachep;
619         sk = kmem_cache_alloc(slab, priority);
620         if (sk) {
621                 if (zero_it) {
622                         memset(sk, 0,
623                                zero_it == 1 ? sizeof(struct sock) : zero_it);
624                         sk->sk_family = family;
625                         sock_lock_init(sk);
626                 }
627                 sk->sk_slab = slab;
628                 sock_vx_init(sk);
629                 sock_nx_init(sk);
630                 
631                 if (security_sk_alloc(sk, family, priority)) {
632                         kmem_cache_free(slab, sk);
633                         sk = NULL;
634                 }
635         }
636         return sk;
637 }
638
639 void sk_free(struct sock *sk)
640 {
641         struct sk_filter *filter;
642         struct module *owner = sk->sk_owner;
643
644         if (sk->sk_destruct)
645                 sk->sk_destruct(sk);
646
647         filter = sk->sk_filter;
648         if (filter) {
649                 sk_filter_release(sk, filter);
650                 sk->sk_filter = NULL;
651         }
652
653         sock_disable_timestamp(sk);
654
655         if (atomic_read(&sk->sk_omem_alloc))
656                 printk(KERN_DEBUG "%s: optmem leakage (%d bytes) detected.\n",
657                        __FUNCTION__, atomic_read(&sk->sk_omem_alloc));
658
659         security_sk_free(sk);
660         BUG_ON(sk->sk_vx_info);
661         BUG_ON(sk->sk_nx_info);
662 /*      clr_vx_info(&sk->sk_vx_info);
663         clr_nx_info(&sk->sk_nx_info);   */
664         kmem_cache_free(sk->sk_slab, sk);
665         module_put(owner);
666 }
667
668 void __init sk_init(void)
669 {
670         sk_cachep = kmem_cache_create("sock", sizeof(struct sock), 0,
671                                       SLAB_HWCACHE_ALIGN, 0, 0);
672         if (!sk_cachep)
673                 printk(KERN_CRIT "sk_init: Cannot create sock SLAB cache!");
674
675         if (num_physpages <= 4096) {
676                 sysctl_wmem_max = 32767;
677                 sysctl_rmem_max = 32767;
678                 sysctl_wmem_default = 32767;
679                 sysctl_rmem_default = 32767;
680         } else if (num_physpages >= 131072) {
681                 sysctl_wmem_max = 131071;
682                 sysctl_rmem_max = 131071;
683         }
684 }
685
686 /*
687  *      Simple resource managers for sockets.
688  */
689
690
691 /* 
692  * Write buffer destructor automatically called from kfree_skb. 
693  */
694 void sock_wfree(struct sk_buff *skb)
695 {
696         struct sock *sk = skb->sk;
697
698         /* In case it might be waiting for more memory. */
699         atomic_sub(skb->truesize, &sk->sk_wmem_alloc);
700         if (!sk->sk_use_write_queue)
701                 sk->sk_write_space(sk);
702         sock_put(sk);
703 }
704
705 /* 
706  * Read buffer destructor automatically called from kfree_skb. 
707  */
708 void sock_rfree(struct sk_buff *skb)
709 {
710         struct sock *sk = skb->sk;
711
712         atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
713 }
714
715 /*
716  * Allocate a skb from the socket's send buffer.
717  */
718 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force, int priority)
719 {
720         if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
721                 struct sk_buff * skb = alloc_skb(size, priority);
722                 if (skb) {
723                         skb_set_owner_w(skb, sk);
724                         return skb;
725                 }
726         }
727         return NULL;
728 }
729
730 /*
731  * Allocate a skb from the socket's receive buffer.
732  */ 
733 struct sk_buff *sock_rmalloc(struct sock *sk, unsigned long size, int force, int priority)
734 {
735         if (force || atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
736                 struct sk_buff *skb = alloc_skb(size, priority);
737                 if (skb) {
738                         skb_set_owner_r(skb, sk);
739                         return skb;
740                 }
741         }
742         return NULL;
743 }
744
745 /* 
746  * Allocate a memory block from the socket's option memory buffer.
747  */ 
748 void *sock_kmalloc(struct sock *sk, int size, int priority)
749 {
750         if ((unsigned)size <= sysctl_optmem_max &&
751             atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
752                 void *mem;
753                 /* First do the add, to avoid the race if kmalloc
754                  * might sleep.
755                  */
756                 atomic_add(size, &sk->sk_omem_alloc);
757                 mem = kmalloc(size, priority);
758                 if (mem)
759                         return mem;
760                 atomic_sub(size, &sk->sk_omem_alloc);
761         }
762         return NULL;
763 }
764
765 /*
766  * Free an option memory block.
767  */
768 void sock_kfree_s(struct sock *sk, void *mem, int size)
769 {
770         kfree(mem);
771         atomic_sub(size, &sk->sk_omem_alloc);
772 }
773
774 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
775    I think, these locks should be removed for datagram sockets.
776  */
777 static long sock_wait_for_wmem(struct sock * sk, long timeo)
778 {
779         DEFINE_WAIT(wait);
780
781         clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
782         for (;;) {
783                 if (!timeo)
784                         break;
785                 if (signal_pending(current))
786                         break;
787                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
788                 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
789                 if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
790                         break;
791                 if (sk->sk_shutdown & SEND_SHUTDOWN)
792                         break;
793                 if (sk->sk_err)
794                         break;
795                 timeo = schedule_timeout(timeo);
796         }
797         finish_wait(sk->sk_sleep, &wait);
798         return timeo;
799 }
800
801
802 /*
803  *      Generic send/receive buffer handlers
804  */
805
806 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
807                                      unsigned long data_len, int noblock, int *errcode)
808 {
809         struct sk_buff *skb;
810         unsigned int gfp_mask;
811         long timeo;
812         int err;
813
814         gfp_mask = sk->sk_allocation;
815         if (gfp_mask & __GFP_WAIT)
816                 gfp_mask |= __GFP_REPEAT;
817
818         timeo = sock_sndtimeo(sk, noblock);
819         while (1) {
820                 err = sock_error(sk);
821                 if (err != 0)
822                         goto failure;
823
824                 err = -EPIPE;
825                 if (sk->sk_shutdown & SEND_SHUTDOWN)
826                         goto failure;
827
828                 if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
829                         skb = alloc_skb(header_len, sk->sk_allocation);
830                         if (skb) {
831                                 int npages;
832                                 int i;
833
834                                 /* No pages, we're done... */
835                                 if (!data_len)
836                                         break;
837
838                                 npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
839                                 skb->truesize += data_len;
840                                 skb_shinfo(skb)->nr_frags = npages;
841                                 for (i = 0; i < npages; i++) {
842                                         struct page *page;
843                                         skb_frag_t *frag;
844
845                                         page = alloc_pages(sk->sk_allocation, 0);
846                                         if (!page) {
847                                                 err = -ENOBUFS;
848                                                 skb_shinfo(skb)->nr_frags = i;
849                                                 kfree_skb(skb);
850                                                 goto failure;
851                                         }
852
853                                         frag = &skb_shinfo(skb)->frags[i];
854                                         frag->page = page;
855                                         frag->page_offset = 0;
856                                         frag->size = (data_len >= PAGE_SIZE ?
857                                                       PAGE_SIZE :
858                                                       data_len);
859                                         data_len -= PAGE_SIZE;
860                                 }
861
862                                 /* Full success... */
863                                 break;
864                         }
865                         err = -ENOBUFS;
866                         goto failure;
867                 }
868                 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
869                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
870                 err = -EAGAIN;
871                 if (!timeo)
872                         goto failure;
873                 if (signal_pending(current))
874                         goto interrupted;
875                 timeo = sock_wait_for_wmem(sk, timeo);
876         }
877
878         skb_set_owner_w(skb, sk);
879         return skb;
880
881 interrupted:
882         err = sock_intr_errno(timeo);
883 failure:
884         *errcode = err;
885         return NULL;
886 }
887
888 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size, 
889                                     int noblock, int *errcode)
890 {
891         return sock_alloc_send_pskb(sk, size, 0, noblock, errcode);
892 }
893
894 void __lock_sock(struct sock *sk)
895 {
896         DEFINE_WAIT(wait);
897
898         for(;;) {
899                 prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
900                                         TASK_UNINTERRUPTIBLE);
901                 spin_unlock_bh(&sk->sk_lock.slock);
902                 schedule();
903                 spin_lock_bh(&sk->sk_lock.slock);
904                 if(!sock_owned_by_user(sk))
905                         break;
906         }
907         finish_wait(&sk->sk_lock.wq, &wait);
908 }
909
910 void __release_sock(struct sock *sk)
911 {
912         struct sk_buff *skb = sk->sk_backlog.head;
913
914         do {
915                 sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
916                 bh_unlock_sock(sk);
917
918                 do {
919                         struct sk_buff *next = skb->next;
920
921                         skb->next = NULL;
922                         sk->sk_backlog_rcv(sk, skb);
923                         skb = next;
924                 } while (skb != NULL);
925
926                 bh_lock_sock(sk);
927         } while((skb = sk->sk_backlog.head) != NULL);
928 }
929
930 /**
931  * sk_wait_data - wait for data to arrive at sk_receive_queue
932  * sk - sock to wait on
933  * timeo - for how long
934  *
935  * Now socket state including sk->sk_err is changed only under lock,
936  * hence we may omit checks after joining wait queue.
937  * We check receive queue before schedule() only as optimization;
938  * it is very likely that release_sock() added new data.
939  */
940 int sk_wait_data(struct sock *sk, long *timeo)
941 {
942         int rc;
943         DEFINE_WAIT(wait);
944
945         prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
946         set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
947         rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
948         clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
949         finish_wait(sk->sk_sleep, &wait);
950         return rc;
951 }
952
953 EXPORT_SYMBOL(sk_wait_data);
954
955 /*
956  * Set of default routines for initialising struct proto_ops when
957  * the protocol does not support a particular function. In certain
958  * cases where it makes no sense for a protocol to have a "do nothing"
959  * function, some default processing is provided.
960  */
961
962 int sock_no_release(struct socket *sock)
963 {
964         return 0;
965 }
966
967 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
968 {
969         return -EOPNOTSUPP;
970 }
971
972 int sock_no_connect(struct socket *sock, struct sockaddr *saddr, 
973                     int len, int flags)
974 {
975         return -EOPNOTSUPP;
976 }
977
978 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
979 {
980         return -EOPNOTSUPP;
981 }
982
983 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
984 {
985         return -EOPNOTSUPP;
986 }
987
988 int sock_no_getname(struct socket *sock, struct sockaddr *saddr, 
989                     int *len, int peer)
990 {
991         return -EOPNOTSUPP;
992 }
993
994 unsigned int sock_no_poll(struct file * file, struct socket *sock, poll_table *pt)
995 {
996         return 0;
997 }
998
999 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1000 {
1001         return -EOPNOTSUPP;
1002 }
1003
1004 int sock_no_listen(struct socket *sock, int backlog)
1005 {
1006         return -EOPNOTSUPP;
1007 }
1008
1009 int sock_no_shutdown(struct socket *sock, int how)
1010 {
1011         return -EOPNOTSUPP;
1012 }
1013
1014 int sock_no_setsockopt(struct socket *sock, int level, int optname,
1015                     char __user *optval, int optlen)
1016 {
1017         return -EOPNOTSUPP;
1018 }
1019
1020 int sock_no_getsockopt(struct socket *sock, int level, int optname,
1021                     char __user *optval, int __user *optlen)
1022 {
1023         return -EOPNOTSUPP;
1024 }
1025
1026 int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1027                     size_t len)
1028 {
1029         return -EOPNOTSUPP;
1030 }
1031
1032 int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1033                     size_t len, int flags)
1034 {
1035         return -EOPNOTSUPP;
1036 }
1037
1038 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
1039 {
1040         /* Mirror missing mmap method error code */
1041         return -ENODEV;
1042 }
1043
1044 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
1045 {
1046         ssize_t res;
1047         struct msghdr msg;
1048         struct iovec iov;
1049         mm_segment_t old_fs;
1050         char *kaddr;
1051
1052         kaddr = kmap(page);
1053
1054         msg.msg_name = NULL;
1055         msg.msg_namelen = 0;
1056         msg.msg_iov = &iov;
1057         msg.msg_iovlen = 1;
1058         msg.msg_control = NULL;
1059         msg.msg_controllen = 0;
1060         msg.msg_flags = flags;
1061
1062         /* This cast is ok because of the "set_fs(KERNEL_DS)" */
1063         iov.iov_base = (void __user *) (kaddr + offset);
1064         iov.iov_len = size;
1065
1066         old_fs = get_fs();
1067         set_fs(KERNEL_DS);
1068         res = sock_sendmsg(sock, &msg, size);
1069         set_fs(old_fs);
1070
1071         kunmap(page);
1072         return res;
1073 }
1074
1075 /*
1076  *      Default Socket Callbacks
1077  */
1078
1079 void sock_def_wakeup(struct sock *sk)
1080 {
1081         read_lock(&sk->sk_callback_lock);
1082         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
1083                 wake_up_interruptible_all(sk->sk_sleep);
1084         read_unlock(&sk->sk_callback_lock);
1085 }
1086
1087 void sock_def_error_report(struct sock *sk)
1088 {
1089         read_lock(&sk->sk_callback_lock);
1090         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
1091                 wake_up_interruptible(sk->sk_sleep);
1092         sk_wake_async(sk,0,POLL_ERR); 
1093         read_unlock(&sk->sk_callback_lock);
1094 }
1095
1096 void sock_def_readable(struct sock *sk, int len)
1097 {
1098         read_lock(&sk->sk_callback_lock);
1099         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
1100                 wake_up_interruptible(sk->sk_sleep);
1101         sk_wake_async(sk,1,POLL_IN);
1102         read_unlock(&sk->sk_callback_lock);
1103 }
1104
1105 void sock_def_write_space(struct sock *sk)
1106 {
1107         read_lock(&sk->sk_callback_lock);
1108
1109         /* Do not wake up a writer until he can make "significant"
1110          * progress.  --DaveM
1111          */
1112         if((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
1113                 if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
1114                         wake_up_interruptible(sk->sk_sleep);
1115
1116                 /* Should agree with poll, otherwise some programs break */
1117                 if (sock_writeable(sk))
1118                         sk_wake_async(sk, 2, POLL_OUT);
1119         }
1120
1121         read_unlock(&sk->sk_callback_lock);
1122 }
1123
1124 void sock_def_destruct(struct sock *sk)
1125 {
1126         if (sk->sk_protinfo)
1127                 kfree(sk->sk_protinfo);
1128 }
1129
1130 void sk_send_sigurg(struct sock *sk)
1131 {
1132         if (sk->sk_socket && sk->sk_socket->file)
1133                 if (send_sigurg(&sk->sk_socket->file->f_owner))
1134                         sk_wake_async(sk, 3, POLL_PRI);
1135 }
1136
1137 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1138                     unsigned long expires)
1139 {
1140         if (!mod_timer(timer, expires))
1141                 sock_hold(sk);
1142 }
1143
1144 EXPORT_SYMBOL(sk_reset_timer);
1145
1146 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
1147 {
1148         if (timer_pending(timer) && del_timer(timer))
1149                 __sock_put(sk);
1150 }
1151
1152 EXPORT_SYMBOL(sk_stop_timer);
1153
1154 void sock_init_data(struct socket *sock, struct sock *sk)
1155 {
1156         skb_queue_head_init(&sk->sk_receive_queue);
1157         skb_queue_head_init(&sk->sk_write_queue);
1158         skb_queue_head_init(&sk->sk_error_queue);
1159
1160         init_timer(&sk->sk_timer);
1161         
1162         sk->sk_allocation       =       GFP_KERNEL;
1163         sk->sk_rcvbuf           =       sysctl_rmem_default;
1164         sk->sk_sndbuf           =       sysctl_wmem_default;
1165         sk->sk_state            =       TCP_CLOSE;
1166         sk->sk_zapped           =       1;
1167         sk->sk_socket           =       sock;
1168
1169         if(sock)
1170         {
1171                 sk->sk_type     =       sock->type;
1172                 sk->sk_sleep    =       &sock->wait;
1173                 sock->sk        =       sk;
1174         } else
1175                 sk->sk_sleep    =       NULL;
1176
1177         sk->sk_dst_lock         =       RW_LOCK_UNLOCKED;
1178         sk->sk_callback_lock    =       RW_LOCK_UNLOCKED;
1179
1180         sk->sk_state_change     =       sock_def_wakeup;
1181         sk->sk_data_ready       =       sock_def_readable;
1182         sk->sk_write_space      =       sock_def_write_space;
1183         sk->sk_error_report     =       sock_def_error_report;
1184         sk->sk_destruct         =       sock_def_destruct;
1185
1186         sk->sk_peercred.pid     =       0;
1187         sk->sk_peercred.uid     =       -1;
1188         sk->sk_peercred.gid     =       -1;
1189         sk->sk_rcvlowat         =       1;
1190         sk->sk_rcvtimeo         =       MAX_SCHEDULE_TIMEOUT;
1191         sk->sk_sndtimeo         =       MAX_SCHEDULE_TIMEOUT;
1192         sk->sk_owner            =       NULL;
1193
1194         sk->sk_stamp.tv_sec     = -1L;
1195         sk->sk_stamp.tv_usec    = -1L;
1196
1197         sk->sk_vx_info          =       NULL;
1198         sk->sk_xid              =       0;
1199         sk->sk_nx_info          =       NULL;
1200         sk->sk_nid              =       0;
1201
1202         atomic_set(&sk->sk_refcnt, 1);
1203 }
1204
1205 void fastcall lock_sock(struct sock *sk)
1206 {
1207         might_sleep();
1208         spin_lock_bh(&(sk->sk_lock.slock));
1209         if (sk->sk_lock.owner)
1210                 __lock_sock(sk);
1211         sk->sk_lock.owner = (void *)1;
1212         spin_unlock_bh(&(sk->sk_lock.slock));
1213 }
1214
1215 EXPORT_SYMBOL(lock_sock);
1216
1217 void fastcall release_sock(struct sock *sk)
1218 {
1219         spin_lock_bh(&(sk->sk_lock.slock));
1220         if (sk->sk_backlog.tail)
1221                 __release_sock(sk);
1222         sk->sk_lock.owner = NULL;
1223         if (waitqueue_active(&(sk->sk_lock.wq)))
1224                 wake_up(&(sk->sk_lock.wq));
1225         spin_unlock_bh(&(sk->sk_lock.slock));
1226 }
1227 EXPORT_SYMBOL(release_sock);
1228
1229 /* When > 0 there are consumers of rx skb time stamps */
1230 atomic_t netstamp_needed = ATOMIC_INIT(0); 
1231
1232 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
1233
1234         if (!sock_flag(sk, SOCK_TIMESTAMP))
1235                 sock_enable_timestamp(sk);
1236         if (sk->sk_stamp.tv_sec == -1) 
1237                 return -ENOENT;
1238         if (sk->sk_stamp.tv_sec == 0)
1239                 do_gettimeofday(&sk->sk_stamp);
1240         return copy_to_user(userstamp, &sk->sk_stamp, sizeof(struct timeval)) ?
1241                 -EFAULT : 0; 
1242
1243 EXPORT_SYMBOL(sock_get_timestamp);
1244
1245 void sock_enable_timestamp(struct sock *sk)
1246 {       
1247         if (!sock_flag(sk, SOCK_TIMESTAMP)) { 
1248                 sock_set_flag(sk, SOCK_TIMESTAMP);
1249                 atomic_inc(&netstamp_needed);
1250         }
1251 }
1252 EXPORT_SYMBOL(sock_enable_timestamp); 
1253
1254 void sock_disable_timestamp(struct sock *sk)
1255 {       
1256         if (sock_flag(sk, SOCK_TIMESTAMP)) { 
1257                 sock_reset_flag(sk, SOCK_TIMESTAMP);
1258                 atomic_dec(&netstamp_needed);
1259         }
1260 }
1261 EXPORT_SYMBOL(sock_disable_timestamp);
1262
1263 EXPORT_SYMBOL(__lock_sock);
1264 EXPORT_SYMBOL(__release_sock);
1265 EXPORT_SYMBOL(sk_alloc);
1266 EXPORT_SYMBOL(sk_free);
1267 EXPORT_SYMBOL(sk_send_sigurg);
1268 EXPORT_SYMBOL(sock_alloc_send_pskb);
1269 EXPORT_SYMBOL(sock_alloc_send_skb);
1270 EXPORT_SYMBOL(sock_getsockopt);
1271 EXPORT_SYMBOL(sock_init_data);
1272 EXPORT_SYMBOL(sock_kfree_s);
1273 EXPORT_SYMBOL(sock_kmalloc);
1274 EXPORT_SYMBOL(sock_no_accept);
1275 EXPORT_SYMBOL(sock_no_bind);
1276 EXPORT_SYMBOL(sock_no_connect);
1277 EXPORT_SYMBOL(sock_no_getname);
1278 EXPORT_SYMBOL(sock_no_getsockopt);
1279 EXPORT_SYMBOL(sock_no_ioctl);
1280 EXPORT_SYMBOL(sock_no_listen);
1281 EXPORT_SYMBOL(sock_no_mmap);
1282 EXPORT_SYMBOL(sock_no_poll);
1283 EXPORT_SYMBOL(sock_no_recvmsg);
1284 EXPORT_SYMBOL(sock_no_release);
1285 EXPORT_SYMBOL(sock_no_sendmsg);
1286 EXPORT_SYMBOL(sock_no_sendpage);
1287 EXPORT_SYMBOL(sock_no_setsockopt);
1288 EXPORT_SYMBOL(sock_no_shutdown);
1289 EXPORT_SYMBOL(sock_no_socketpair);
1290 EXPORT_SYMBOL(sock_rfree);
1291 EXPORT_SYMBOL(sock_rmalloc);
1292 EXPORT_SYMBOL(sock_setsockopt);
1293 EXPORT_SYMBOL(sock_wfree);
1294 EXPORT_SYMBOL(sock_wmalloc);
1295 #ifdef CONFIG_SYSCTL
1296 EXPORT_SYMBOL(sysctl_optmem_max);
1297 EXPORT_SYMBOL(sysctl_rmem_max);
1298 EXPORT_SYMBOL(sysctl_wmem_max);
1299 #endif