Rename printf -> kprintf in sys/ and add some defines where necessary
[dragonfly.git] / sys / kern / sysv_msg.c
CommitLineData
984263bc 1/* $FreeBSD: src/sys/kern/sysv_msg.c,v 1.23.2.5 2002/12/31 08:54:53 maxim Exp $ */
6ea70f76 2/* $DragonFly: src/sys/kern/sysv_msg.c,v 1.16 2006/12/23 00:35:04 swildner Exp $ */
984263bc
MD
3
4/*
5 * Implementation of SVID messages
6 *
7 * Author: Daniel Boulet
8 *
9 * Copyright 1993 Daniel Boulet and RTMX Inc.
10 *
11 * This system call was implemented by Daniel Boulet under contract from RTMX.
12 *
13 * Redistribution and use in source forms, with and without modification,
14 * are permitted provided that this entire comment appears intact.
15 *
16 * Redistribution in binary form may occur without any restrictions.
17 * Obviously, it would be nice if you gave credit where credit is due
18 * but requiring it would be too onerous.
19 *
20 * This software is provided ``AS IS'' without any warranties of any kind.
21 */
22
23#include "opt_sysvipc.h"
24
25#include <sys/param.h>
26#include <sys/systm.h>
27#include <sys/sysproto.h>
28#include <sys/kernel.h>
29#include <sys/proc.h>
30#include <sys/msg.h>
31#include <sys/sysent.h>
32#include <sys/sysctl.h>
33#include <sys/malloc.h>
34#include <sys/jail.h>
35
36static MALLOC_DEFINE(M_MSG, "msg", "SVID compatible message queues");
37
402ed7e1 38static void msginit (void *);
984263bc
MD
39
40#define MSG_DEBUG
41#undef MSG_DEBUG_OK
42
402ed7e1 43static void msg_freehdr (struct msg *msghdr);
984263bc
MD
44
45/* XXX casting to (sy_call_t *) is bogus, as usual. */
46static sy_call_t *msgcalls[] = {
753fd850
MD
47 (sy_call_t *)sys_msgctl, (sy_call_t *)sys_msgget,
48 (sy_call_t *)sys_msgsnd, (sy_call_t *)sys_msgrcv
984263bc
MD
49};
50
51struct msg {
52 struct msg *msg_next; /* next msg in the chain */
53 long msg_type; /* type of this message */
54 /* >0 -> type of this message */
55 /* 0 -> free header */
56 u_short msg_ts; /* size of this message */
57 short msg_spot; /* location of start of msg in buffer */
58};
59
60
61#ifndef MSGSSZ
62#define MSGSSZ 8 /* Each segment must be 2^N long */
63#endif
64#ifndef MSGSEG
65#define MSGSEG 2048 /* must be less than 32767 */
66#endif
67#define MSGMAX (MSGSSZ*MSGSEG)
68#ifndef MSGMNB
69#define MSGMNB 2048 /* max # of bytes in a queue */
70#endif
71#ifndef MSGMNI
72#define MSGMNI 40
73#endif
74#ifndef MSGTQL
75#define MSGTQL 40
76#endif
77
78/*
79 * Based on the configuration parameters described in an SVR2 (yes, two)
80 * config(1m) man page.
81 *
82 * Each message is broken up and stored in segments that are msgssz bytes
83 * long. For efficiency reasons, this should be a power of two. Also,
84 * it doesn't make sense if it is less than 8 or greater than about 256.
85 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
86 * two between 8 and 1024 inclusive (and panic's if it isn't).
87 */
88struct msginfo msginfo = {
89 MSGMAX, /* max chars in a message */
90 MSGMNI, /* # of message queue identifiers */
91 MSGMNB, /* max chars in a queue */
92 MSGTQL, /* max messages in system */
93 MSGSSZ, /* size of a message segment */
94 /* (must be small power of 2 greater than 4) */
95 MSGSEG /* number of message segments */
96};
97
98/*
99 * macros to convert between msqid_ds's and msqid's.
100 * (specific to this implementation)
101 */
102#define MSQID(ix,ds) ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
103#define MSQID_IX(id) ((id) & 0xffff)
104#define MSQID_SEQ(id) (((id) >> 16) & 0xffff)
105
106/*
107 * The rest of this file is specific to this particular implementation.
108 */
109
110struct msgmap {
111 short next; /* next segment in buffer */
112 /* -1 -> available */
113 /* 0..(MSGSEG-1) -> index of next segment */
114};
115
116#define MSG_LOCKED 01000 /* Is this msqid_ds locked? */
117
118static int nfree_msgmaps; /* # of free map entries */
119static short free_msgmaps; /* head of linked list of free map entries */
120static struct msg *free_msghdrs;/* list of free msg headers */
121static char *msgpool; /* MSGMAX byte long msg buffer pool */
122static struct msgmap *msgmaps; /* MSGSEG msgmap structures */
123static struct msg *msghdrs; /* MSGTQL msg headers */
124static struct msqid_ds *msqids; /* MSGMNI msqid_ds struct's */
125
126static void
127msginit(dummy)
128 void *dummy;
129{
1fd87d54 130 int i;
984263bc
MD
131
132 msginfo.msgmax = msginfo.msgseg * msginfo.msgssz;
efda3bd0 133 msgpool = kmalloc(msginfo.msgmax, M_MSG, M_WAITOK);
984263bc
MD
134 if (msgpool == NULL)
135 panic("msgpool is NULL");
efda3bd0 136 msgmaps = kmalloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK);
984263bc
MD
137 if (msgmaps == NULL)
138 panic("msgmaps is NULL");
efda3bd0 139 msghdrs = kmalloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK);
984263bc
MD
140 if (msghdrs == NULL)
141 panic("msghdrs is NULL");
efda3bd0 142 msqids = kmalloc(sizeof(struct msqid_ds) * msginfo.msgmni, M_MSG, M_WAITOK);
984263bc
MD
143 if (msqids == NULL)
144 panic("msqids is NULL");
145
146 /*
147 * msginfo.msgssz should be a power of two for efficiency reasons.
148 * It is also pretty silly if msginfo.msgssz is less than 8
149 * or greater than about 256 so ...
150 */
151
152 i = 8;
153 while (i < 1024 && i != msginfo.msgssz)
154 i <<= 1;
155 if (i != msginfo.msgssz) {
6ea70f76 156 kprintf("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz,
984263bc
MD
157 msginfo.msgssz);
158 panic("msginfo.msgssz not a small power of 2");
159 }
160
161 if (msginfo.msgseg > 32767) {
6ea70f76 162 kprintf("msginfo.msgseg=%d\n", msginfo.msgseg);
984263bc
MD
163 panic("msginfo.msgseg > 32767");
164 }
165
166 if (msgmaps == NULL)
167 panic("msgmaps is NULL");
168
169 for (i = 0; i < msginfo.msgseg; i++) {
170 if (i > 0)
171 msgmaps[i-1].next = i;
172 msgmaps[i].next = -1; /* implies entry is available */
173 }
174 free_msgmaps = 0;
175 nfree_msgmaps = msginfo.msgseg;
176
177 if (msghdrs == NULL)
178 panic("msghdrs is NULL");
179
180 for (i = 0; i < msginfo.msgtql; i++) {
181 msghdrs[i].msg_type = 0;
182 if (i > 0)
183 msghdrs[i-1].msg_next = &msghdrs[i];
184 msghdrs[i].msg_next = NULL;
185 }
186 free_msghdrs = &msghdrs[0];
187
188 if (msqids == NULL)
189 panic("msqids is NULL");
190
191 for (i = 0; i < msginfo.msgmni; i++) {
192 msqids[i].msg_qbytes = 0; /* implies entry is available */
193 msqids[i].msg_perm.seq = 0; /* reset to a known value */
194 msqids[i].msg_perm.mode = 0;
195 }
196}
197SYSINIT(sysv_msg, SI_SUB_SYSV_MSG, SI_ORDER_FIRST, msginit, NULL)
198
199/*
200 * Entry point for all MSG calls
41c20dac 201 *
180508ff 202 * msgsys_args(int which, int a2, ...) (VARARGS)
984263bc
MD
203 */
204int
753fd850 205sys_msgsys(struct msgsys_args *uap)
984263bc 206{
41c20dac 207 struct proc *p = curproc;
180508ff 208 unsigned int which = (unsigned int)uap->which;
984263bc 209
41c20dac 210 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
984263bc
MD
211 return (ENOSYS);
212
df44673d 213 if (which >= sizeof(msgcalls)/sizeof(msgcalls[0]))
984263bc 214 return (EINVAL);
df44673d
MD
215 bcopy(&uap->a2, &uap->which,
216 sizeof(struct msgsys_args) - offsetof(struct msgsys_args, a2));
217 return ((*msgcalls[which])(uap));
984263bc
MD
218}
219
220static void
41c20dac 221msg_freehdr(struct msg *msghdr)
984263bc
MD
222{
223 while (msghdr->msg_ts > 0) {
224 short next;
225 if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg)
226 panic("msghdr->msg_spot out of range");
227 next = msgmaps[msghdr->msg_spot].next;
228 msgmaps[msghdr->msg_spot].next = free_msgmaps;
229 free_msgmaps = msghdr->msg_spot;
230 nfree_msgmaps++;
231 msghdr->msg_spot = next;
232 if (msghdr->msg_ts >= msginfo.msgssz)
233 msghdr->msg_ts -= msginfo.msgssz;
234 else
235 msghdr->msg_ts = 0;
236 }
237 if (msghdr->msg_spot != -1)
238 panic("msghdr->msg_spot != -1");
239 msghdr->msg_next = free_msghdrs;
240 free_msghdrs = msghdr;
241}
242
984263bc 243int
753fd850 244sys_msgctl(struct msgctl_args *uap)
984263bc 245{
dadab5e9
MD
246 struct thread *td = curthread;
247 struct proc *p = td->td_proc;
984263bc
MD
248 int msqid = uap->msqid;
249 int cmd = uap->cmd;
250 struct msqid_ds *user_msqptr = uap->buf;
251 int rval, eval;
252 struct msqid_ds msqbuf;
1fd87d54 253 struct msqid_ds *msqptr;
984263bc
MD
254
255#ifdef MSG_DEBUG_OK
6ea70f76 256 kprintf("call to msgctl(%d, %d, 0x%x)\n", msqid, cmd, user_msqptr);
984263bc
MD
257#endif
258
41c20dac 259 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
984263bc
MD
260 return (ENOSYS);
261
262 msqid = IPCID_TO_IX(msqid);
263
264 if (msqid < 0 || msqid >= msginfo.msgmni) {
265#ifdef MSG_DEBUG_OK
6ea70f76 266 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
984263bc
MD
267 msginfo.msgmni);
268#endif
269 return(EINVAL);
270 }
271
272 msqptr = &msqids[msqid];
273
274 if (msqptr->msg_qbytes == 0) {
275#ifdef MSG_DEBUG_OK
6ea70f76 276 kprintf("no such msqid\n");
984263bc
MD
277#endif
278 return(EINVAL);
279 }
280 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
281#ifdef MSG_DEBUG_OK
6ea70f76 282 kprintf("wrong sequence number\n");
984263bc
MD
283#endif
284 return(EINVAL);
285 }
286
287 eval = 0;
288 rval = 0;
289
290 switch (cmd) {
291
292 case IPC_RMID:
293 {
294 struct msg *msghdr;
295 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_M)))
296 return(eval);
297 /* Free the message headers */
298 msghdr = msqptr->msg_first;
299 while (msghdr != NULL) {
300 struct msg *msghdr_tmp;
301
302 /* Free the segments of each message */
303 msqptr->msg_cbytes -= msghdr->msg_ts;
304 msqptr->msg_qnum--;
305 msghdr_tmp = msghdr;
306 msghdr = msghdr->msg_next;
307 msg_freehdr(msghdr_tmp);
308 }
309
310 if (msqptr->msg_cbytes != 0)
311 panic("msg_cbytes is screwed up");
312 if (msqptr->msg_qnum != 0)
313 panic("msg_qnum is screwed up");
314
315 msqptr->msg_qbytes = 0; /* Mark it as free */
316
317 wakeup((caddr_t)msqptr);
318 }
319
320 break;
321
322 case IPC_SET:
323 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_M)))
324 return(eval);
325 if ((eval = copyin(user_msqptr, &msqbuf, sizeof(msqbuf))) != 0)
326 return(eval);
327 if (msqbuf.msg_qbytes > msqptr->msg_qbytes) {
dadab5e9 328 eval = suser(td);
984263bc
MD
329 if (eval)
330 return(eval);
331 }
332 if (msqbuf.msg_qbytes > msginfo.msgmnb) {
333#ifdef MSG_DEBUG_OK
6ea70f76 334 kprintf("can't increase msg_qbytes beyond %d (truncating)\n",
984263bc
MD
335 msginfo.msgmnb);
336#endif
337 msqbuf.msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */
338 }
339 if (msqbuf.msg_qbytes == 0) {
340#ifdef MSG_DEBUG_OK
6ea70f76 341 kprintf("can't reduce msg_qbytes to 0\n");
984263bc
MD
342#endif
343 return(EINVAL); /* non-standard errno! */
344 }
345 msqptr->msg_perm.uid = msqbuf.msg_perm.uid; /* change the owner */
346 msqptr->msg_perm.gid = msqbuf.msg_perm.gid; /* change the owner */
347 msqptr->msg_perm.mode = (msqptr->msg_perm.mode & ~0777) |
348 (msqbuf.msg_perm.mode & 0777);
349 msqptr->msg_qbytes = msqbuf.msg_qbytes;
350 msqptr->msg_ctime = time_second;
351 break;
352
353 case IPC_STAT:
354 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_R))) {
355#ifdef MSG_DEBUG_OK
6ea70f76 356 kprintf("requester doesn't have read access\n");
984263bc
MD
357#endif
358 return(eval);
359 }
360 eval = copyout((caddr_t)msqptr, user_msqptr,
361 sizeof(struct msqid_ds));
362 break;
363
364 default:
365#ifdef MSG_DEBUG_OK
6ea70f76 366 kprintf("invalid command %d\n", cmd);
984263bc
MD
367#endif
368 return(EINVAL);
369 }
370
371 if (eval == 0)
c7114eea 372 uap->sysmsg_result = rval;
984263bc
MD
373 return(eval);
374}
375
984263bc 376int
753fd850 377sys_msgget(struct msgget_args *uap)
984263bc 378{
41c20dac 379 struct proc *p = curproc;
984263bc
MD
380 int msqid, eval;
381 int key = uap->key;
382 int msgflg = uap->msgflg;
383 struct ucred *cred = p->p_ucred;
1fd87d54 384 struct msqid_ds *msqptr = NULL;
984263bc
MD
385
386#ifdef MSG_DEBUG_OK
6ea70f76 387 kprintf("msgget(0x%x, 0%o)\n", key, msgflg);
984263bc
MD
388#endif
389
41c20dac 390 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
984263bc
MD
391 return (ENOSYS);
392
393 if (key != IPC_PRIVATE) {
394 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
395 msqptr = &msqids[msqid];
396 if (msqptr->msg_qbytes != 0 &&
397 msqptr->msg_perm.key == key)
398 break;
399 }
400 if (msqid < msginfo.msgmni) {
401#ifdef MSG_DEBUG_OK
6ea70f76 402 kprintf("found public key\n");
984263bc
MD
403#endif
404 if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) {
405#ifdef MSG_DEBUG_OK
6ea70f76 406 kprintf("not exclusive\n");
984263bc
MD
407#endif
408 return(EEXIST);
409 }
410 if ((eval = ipcperm(p, &msqptr->msg_perm, msgflg & 0700 ))) {
411#ifdef MSG_DEBUG_OK
6ea70f76 412 kprintf("requester doesn't have 0%o access\n",
984263bc
MD
413 msgflg & 0700);
414#endif
415 return(eval);
416 }
417 goto found;
418 }
419 }
420
421#ifdef MSG_DEBUG_OK
6ea70f76 422 kprintf("need to allocate the msqid_ds\n");
984263bc
MD
423#endif
424 if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) {
425 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
426 /*
427 * Look for an unallocated and unlocked msqid_ds.
428 * msqid_ds's can be locked by msgsnd or msgrcv while
429 * they are copying the message in/out. We can't
430 * re-use the entry until they release it.
431 */
432 msqptr = &msqids[msqid];
433 if (msqptr->msg_qbytes == 0 &&
434 (msqptr->msg_perm.mode & MSG_LOCKED) == 0)
435 break;
436 }
437 if (msqid == msginfo.msgmni) {
438#ifdef MSG_DEBUG_OK
6ea70f76 439 kprintf("no more msqid_ds's available\n");
984263bc
MD
440#endif
441 return(ENOSPC);
442 }
443#ifdef MSG_DEBUG_OK
6ea70f76 444 kprintf("msqid %d is available\n", msqid);
984263bc
MD
445#endif
446 msqptr->msg_perm.key = key;
447 msqptr->msg_perm.cuid = cred->cr_uid;
448 msqptr->msg_perm.uid = cred->cr_uid;
449 msqptr->msg_perm.cgid = cred->cr_gid;
450 msqptr->msg_perm.gid = cred->cr_gid;
451 msqptr->msg_perm.mode = (msgflg & 0777);
452 /* Make sure that the returned msqid is unique */
453 msqptr->msg_perm.seq = (msqptr->msg_perm.seq + 1) & 0x7fff;
454 msqptr->msg_first = NULL;
455 msqptr->msg_last = NULL;
456 msqptr->msg_cbytes = 0;
457 msqptr->msg_qnum = 0;
458 msqptr->msg_qbytes = msginfo.msgmnb;
459 msqptr->msg_lspid = 0;
460 msqptr->msg_lrpid = 0;
461 msqptr->msg_stime = 0;
462 msqptr->msg_rtime = 0;
463 msqptr->msg_ctime = time_second;
464 } else {
465#ifdef MSG_DEBUG_OK
6ea70f76 466 kprintf("didn't find it and wasn't asked to create it\n");
984263bc
MD
467#endif
468 return(ENOENT);
469 }
470
471found:
472 /* Construct the unique msqid */
c7114eea 473 uap->sysmsg_result = IXSEQ_TO_IPCID(msqid, msqptr->msg_perm);
984263bc
MD
474 return(0);
475}
476
984263bc 477int
753fd850 478sys_msgsnd(struct msgsnd_args *uap)
984263bc 479{
41c20dac 480 struct proc *p = curproc;
984263bc
MD
481 int msqid = uap->msqid;
482 void *user_msgp = uap->msgp;
483 size_t msgsz = uap->msgsz;
484 int msgflg = uap->msgflg;
485 int segs_needed, eval;
1fd87d54
RG
486 struct msqid_ds *msqptr;
487 struct msg *msghdr;
984263bc
MD
488 short next;
489
490#ifdef MSG_DEBUG_OK
6ea70f76 491 kprintf("call to msgsnd(%d, 0x%x, %d, %d)\n", msqid, user_msgp, msgsz,
984263bc
MD
492 msgflg);
493#endif
494
41c20dac 495 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
984263bc
MD
496 return (ENOSYS);
497
498 msqid = IPCID_TO_IX(msqid);
499
500 if (msqid < 0 || msqid >= msginfo.msgmni) {
501#ifdef MSG_DEBUG_OK
6ea70f76 502 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
984263bc
MD
503 msginfo.msgmni);
504#endif
505 return(EINVAL);
506 }
507
508 msqptr = &msqids[msqid];
509 if (msqptr->msg_qbytes == 0) {
510#ifdef MSG_DEBUG_OK
6ea70f76 511 kprintf("no such message queue id\n");
984263bc
MD
512#endif
513 return(EINVAL);
514 }
515 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
516#ifdef MSG_DEBUG_OK
6ea70f76 517 kprintf("wrong sequence number\n");
984263bc
MD
518#endif
519 return(EINVAL);
520 }
521
522 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_W))) {
523#ifdef MSG_DEBUG_OK
6ea70f76 524 kprintf("requester doesn't have write access\n");
984263bc
MD
525#endif
526 return(eval);
527 }
528
529 segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz;
530#ifdef MSG_DEBUG_OK
6ea70f76 531 kprintf("msgsz=%d, msgssz=%d, segs_needed=%d\n", msgsz, msginfo.msgssz,
984263bc
MD
532 segs_needed);
533#endif
534 for (;;) {
535 int need_more_resources = 0;
536
537 /*
538 * check msgsz
539 * (inside this loop in case msg_qbytes changes while we sleep)
540 */
541
542 if (msgsz > msqptr->msg_qbytes) {
543#ifdef MSG_DEBUG_OK
6ea70f76 544 kprintf("msgsz > msqptr->msg_qbytes\n");
984263bc
MD
545#endif
546 return(EINVAL);
547 }
548
549 if (msqptr->msg_perm.mode & MSG_LOCKED) {
550#ifdef MSG_DEBUG_OK
6ea70f76 551 kprintf("msqid is locked\n");
984263bc
MD
552#endif
553 need_more_resources = 1;
554 }
555 if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes) {
556#ifdef MSG_DEBUG_OK
6ea70f76 557 kprintf("msgsz + msg_cbytes > msg_qbytes\n");
984263bc
MD
558#endif
559 need_more_resources = 1;
560 }
561 if (segs_needed > nfree_msgmaps) {
562#ifdef MSG_DEBUG_OK
6ea70f76 563 kprintf("segs_needed > nfree_msgmaps\n");
984263bc
MD
564#endif
565 need_more_resources = 1;
566 }
567 if (free_msghdrs == NULL) {
568#ifdef MSG_DEBUG_OK
6ea70f76 569 kprintf("no more msghdrs\n");
984263bc
MD
570#endif
571 need_more_resources = 1;
572 }
573
574 if (need_more_resources) {
575 int we_own_it;
576
577 if ((msgflg & IPC_NOWAIT) != 0) {
578#ifdef MSG_DEBUG_OK
6ea70f76 579 kprintf("need more resources but caller doesn't want to wait\n");
984263bc
MD
580#endif
581 return(EAGAIN);
582 }
583
584 if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0) {
585#ifdef MSG_DEBUG_OK
6ea70f76 586 kprintf("we don't own the msqid_ds\n");
984263bc
MD
587#endif
588 we_own_it = 0;
589 } else {
590 /* Force later arrivals to wait for our
591 request */
592#ifdef MSG_DEBUG_OK
6ea70f76 593 kprintf("we own the msqid_ds\n");
984263bc
MD
594#endif
595 msqptr->msg_perm.mode |= MSG_LOCKED;
596 we_own_it = 1;
597 }
598#ifdef MSG_DEBUG_OK
6ea70f76 599 kprintf("goodnight\n");
984263bc 600#endif
377d4740 601 eval = tsleep((caddr_t)msqptr, PCATCH, "msgwait", 0);
984263bc 602#ifdef MSG_DEBUG_OK
6ea70f76 603 kprintf("good morning, eval=%d\n", eval);
984263bc
MD
604#endif
605 if (we_own_it)
606 msqptr->msg_perm.mode &= ~MSG_LOCKED;
607 if (eval != 0) {
608#ifdef MSG_DEBUG_OK
6ea70f76 609 kprintf("msgsnd: interrupted system call\n");
984263bc
MD
610#endif
611 return(EINTR);
612 }
613
614 /*
615 * Make sure that the msq queue still exists
616 */
617
618 if (msqptr->msg_qbytes == 0) {
619#ifdef MSG_DEBUG_OK
6ea70f76 620 kprintf("msqid deleted\n");
984263bc
MD
621#endif
622 return(EIDRM);
623 }
624
625 } else {
626#ifdef MSG_DEBUG_OK
6ea70f76 627 kprintf("got all the resources that we need\n");
984263bc
MD
628#endif
629 break;
630 }
631 }
632
633 /*
634 * We have the resources that we need.
635 * Make sure!
636 */
637
638 if (msqptr->msg_perm.mode & MSG_LOCKED)
639 panic("msg_perm.mode & MSG_LOCKED");
640 if (segs_needed > nfree_msgmaps)
641 panic("segs_needed > nfree_msgmaps");
642 if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes)
643 panic("msgsz + msg_cbytes > msg_qbytes");
644 if (free_msghdrs == NULL)
645 panic("no more msghdrs");
646
647 /*
648 * Re-lock the msqid_ds in case we page-fault when copying in the
649 * message
650 */
651
652 if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0)
653 panic("msqid_ds is already locked");
654 msqptr->msg_perm.mode |= MSG_LOCKED;
655
656 /*
657 * Allocate a message header
658 */
659
660 msghdr = free_msghdrs;
661 free_msghdrs = msghdr->msg_next;
662 msghdr->msg_spot = -1;
663 msghdr->msg_ts = msgsz;
664
665 /*
666 * Allocate space for the message
667 */
668
669 while (segs_needed > 0) {
670 if (nfree_msgmaps <= 0)
671 panic("not enough msgmaps");
672 if (free_msgmaps == -1)
673 panic("nil free_msgmaps");
674 next = free_msgmaps;
675 if (next <= -1)
676 panic("next too low #1");
677 if (next >= msginfo.msgseg)
678 panic("next out of range #1");
679#ifdef MSG_DEBUG_OK
6ea70f76 680 kprintf("allocating segment %d to message\n", next);
984263bc
MD
681#endif
682 free_msgmaps = msgmaps[next].next;
683 nfree_msgmaps--;
684 msgmaps[next].next = msghdr->msg_spot;
685 msghdr->msg_spot = next;
686 segs_needed--;
687 }
688
689 /*
690 * Copy in the message type
691 */
692
693 if ((eval = copyin(user_msgp, &msghdr->msg_type,
694 sizeof(msghdr->msg_type))) != 0) {
695#ifdef MSG_DEBUG_OK
6ea70f76 696 kprintf("error %d copying the message type\n", eval);
984263bc
MD
697#endif
698 msg_freehdr(msghdr);
699 msqptr->msg_perm.mode &= ~MSG_LOCKED;
700 wakeup((caddr_t)msqptr);
701 return(eval);
702 }
703 user_msgp = (char *)user_msgp + sizeof(msghdr->msg_type);
704
705 /*
706 * Validate the message type
707 */
708
709 if (msghdr->msg_type < 1) {
710 msg_freehdr(msghdr);
711 msqptr->msg_perm.mode &= ~MSG_LOCKED;
712 wakeup((caddr_t)msqptr);
713#ifdef MSG_DEBUG_OK
6ea70f76 714 kprintf("mtype (%d) < 1\n", msghdr->msg_type);
984263bc
MD
715#endif
716 return(EINVAL);
717 }
718
719 /*
720 * Copy in the message body
721 */
722
723 next = msghdr->msg_spot;
724 while (msgsz > 0) {
725 size_t tlen;
726 if (msgsz > msginfo.msgssz)
727 tlen = msginfo.msgssz;
728 else
729 tlen = msgsz;
730 if (next <= -1)
731 panic("next too low #2");
732 if (next >= msginfo.msgseg)
733 panic("next out of range #2");
734 if ((eval = copyin(user_msgp, &msgpool[next * msginfo.msgssz],
735 tlen)) != 0) {
736#ifdef MSG_DEBUG_OK
6ea70f76 737 kprintf("error %d copying in message segment\n", eval);
984263bc
MD
738#endif
739 msg_freehdr(msghdr);
740 msqptr->msg_perm.mode &= ~MSG_LOCKED;
741 wakeup((caddr_t)msqptr);
742 return(eval);
743 }
744 msgsz -= tlen;
745 user_msgp = (char *)user_msgp + tlen;
746 next = msgmaps[next].next;
747 }
748 if (next != -1)
749 panic("didn't use all the msg segments");
750
751 /*
752 * We've got the message. Unlock the msqid_ds.
753 */
754
755 msqptr->msg_perm.mode &= ~MSG_LOCKED;
756
757 /*
758 * Make sure that the msqid_ds is still allocated.
759 */
760
761 if (msqptr->msg_qbytes == 0) {
762 msg_freehdr(msghdr);
763 wakeup((caddr_t)msqptr);
764 return(EIDRM);
765 }
766
767 /*
768 * Put the message into the queue
769 */
770
771 if (msqptr->msg_first == NULL) {
772 msqptr->msg_first = msghdr;
773 msqptr->msg_last = msghdr;
774 } else {
775 msqptr->msg_last->msg_next = msghdr;
776 msqptr->msg_last = msghdr;
777 }
778 msqptr->msg_last->msg_next = NULL;
779
780 msqptr->msg_cbytes += msghdr->msg_ts;
781 msqptr->msg_qnum++;
782 msqptr->msg_lspid = p->p_pid;
783 msqptr->msg_stime = time_second;
784
785 wakeup((caddr_t)msqptr);
c7114eea 786 uap->sysmsg_result = 0;
984263bc
MD
787 return(0);
788}
789
984263bc 790int
753fd850 791sys_msgrcv(struct msgrcv_args *uap)
984263bc 792{
41c20dac 793 struct proc *p = curproc;
984263bc
MD
794 int msqid = uap->msqid;
795 void *user_msgp = uap->msgp;
796 size_t msgsz = uap->msgsz;
797 long msgtyp = uap->msgtyp;
798 int msgflg = uap->msgflg;
799 size_t len;
1fd87d54
RG
800 struct msqid_ds *msqptr;
801 struct msg *msghdr;
984263bc
MD
802 int eval;
803 short next;
804
805#ifdef MSG_DEBUG_OK
6ea70f76 806 kprintf("call to msgrcv(%d, 0x%x, %d, %ld, %d)\n", msqid, user_msgp,
984263bc
MD
807 msgsz, msgtyp, msgflg);
808#endif
809
41c20dac 810 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
984263bc
MD
811 return (ENOSYS);
812
813 msqid = IPCID_TO_IX(msqid);
814
815 if (msqid < 0 || msqid >= msginfo.msgmni) {
816#ifdef MSG_DEBUG_OK
6ea70f76 817 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
984263bc
MD
818 msginfo.msgmni);
819#endif
820 return(EINVAL);
821 }
822
823 msqptr = &msqids[msqid];
824 if (msqptr->msg_qbytes == 0) {
825#ifdef MSG_DEBUG_OK
6ea70f76 826 kprintf("no such message queue id\n");
984263bc
MD
827#endif
828 return(EINVAL);
829 }
830 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
831#ifdef MSG_DEBUG_OK
6ea70f76 832 kprintf("wrong sequence number\n");
984263bc
MD
833#endif
834 return(EINVAL);
835 }
836
837 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_R))) {
838#ifdef MSG_DEBUG_OK
6ea70f76 839 kprintf("requester doesn't have read access\n");
984263bc
MD
840#endif
841 return(eval);
842 }
843
844 msghdr = NULL;
845 while (msghdr == NULL) {
846 if (msgtyp == 0) {
847 msghdr = msqptr->msg_first;
848 if (msghdr != NULL) {
849 if (msgsz < msghdr->msg_ts &&
850 (msgflg & MSG_NOERROR) == 0) {
851#ifdef MSG_DEBUG_OK
6ea70f76 852 kprintf("first message on the queue is too big (want %d, got %d)\n",
984263bc
MD
853 msgsz, msghdr->msg_ts);
854#endif
855 return(E2BIG);
856 }
857 if (msqptr->msg_first == msqptr->msg_last) {
858 msqptr->msg_first = NULL;
859 msqptr->msg_last = NULL;
860 } else {
861 msqptr->msg_first = msghdr->msg_next;
862 if (msqptr->msg_first == NULL)
863 panic("msg_first/last screwed up #1");
864 }
865 }
866 } else {
867 struct msg *previous;
868 struct msg **prev;
869
870 previous = NULL;
871 prev = &(msqptr->msg_first);
872 while ((msghdr = *prev) != NULL) {
873 /*
874 * Is this message's type an exact match or is
875 * this message's type less than or equal to
876 * the absolute value of a negative msgtyp?
877 * Note that the second half of this test can
878 * NEVER be true if msgtyp is positive since
879 * msg_type is always positive!
880 */
881
882 if (msgtyp == msghdr->msg_type ||
883 msghdr->msg_type <= -msgtyp) {
884#ifdef MSG_DEBUG_OK
6ea70f76 885 kprintf("found message type %d, requested %d\n",
984263bc
MD
886 msghdr->msg_type, msgtyp);
887#endif
888 if (msgsz < msghdr->msg_ts &&
889 (msgflg & MSG_NOERROR) == 0) {
890#ifdef MSG_DEBUG_OK
6ea70f76 891 kprintf("requested message on the queue is too big (want %d, got %d)\n",
984263bc
MD
892 msgsz, msghdr->msg_ts);
893#endif
894 return(E2BIG);
895 }
896 *prev = msghdr->msg_next;
897 if (msghdr == msqptr->msg_last) {
898 if (previous == NULL) {
899 if (prev !=
900 &msqptr->msg_first)
901 panic("msg_first/last screwed up #2");
902 msqptr->msg_first =
903 NULL;
904 msqptr->msg_last =
905 NULL;
906 } else {
907 if (prev ==
908 &msqptr->msg_first)
909 panic("msg_first/last screwed up #3");
910 msqptr->msg_last =
911 previous;
912 }
913 }
914 break;
915 }
916 previous = msghdr;
917 prev = &(msghdr->msg_next);
918 }
919 }
920
921 /*
922 * We've either extracted the msghdr for the appropriate
923 * message or there isn't one.
924 * If there is one then bail out of this loop.
925 */
926
927 if (msghdr != NULL)
928 break;
929
930 /*
931 * Hmph! No message found. Does the user want to wait?
932 */
933
934 if ((msgflg & IPC_NOWAIT) != 0) {
935#ifdef MSG_DEBUG_OK
6ea70f76 936 kprintf("no appropriate message found (msgtyp=%d)\n",
984263bc
MD
937 msgtyp);
938#endif
939 /* The SVID says to return ENOMSG. */
940#ifdef ENOMSG
941 return(ENOMSG);
942#else
943 /* Unfortunately, BSD doesn't define that code yet! */
944 return(EAGAIN);
945#endif
946 }
947
948 /*
949 * Wait for something to happen
950 */
951
952#ifdef MSG_DEBUG_OK
6ea70f76 953 kprintf("msgrcv: goodnight\n");
984263bc 954#endif
377d4740 955 eval = tsleep((caddr_t)msqptr, PCATCH, "msgwait", 0);
984263bc 956#ifdef MSG_DEBUG_OK
6ea70f76 957 kprintf("msgrcv: good morning (eval=%d)\n", eval);
984263bc
MD
958#endif
959
960 if (eval != 0) {
961#ifdef MSG_DEBUG_OK
6ea70f76 962 kprintf("msgsnd: interrupted system call\n");
984263bc
MD
963#endif
964 return(EINTR);
965 }
966
967 /*
968 * Make sure that the msq queue still exists
969 */
970
971 if (msqptr->msg_qbytes == 0 ||
972 msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
973#ifdef MSG_DEBUG_OK
6ea70f76 974 kprintf("msqid deleted\n");
984263bc
MD
975#endif
976 return(EIDRM);
977 }
978 }
979
980 /*
981 * Return the message to the user.
982 *
983 * First, do the bookkeeping (before we risk being interrupted).
984 */
985
986 msqptr->msg_cbytes -= msghdr->msg_ts;
987 msqptr->msg_qnum--;
988 msqptr->msg_lrpid = p->p_pid;
989 msqptr->msg_rtime = time_second;
990
991 /*
992 * Make msgsz the actual amount that we'll be returning.
993 * Note that this effectively truncates the message if it is too long
994 * (since msgsz is never increased).
995 */
996
997#ifdef MSG_DEBUG_OK
6ea70f76 998 kprintf("found a message, msgsz=%d, msg_ts=%d\n", msgsz,
984263bc
MD
999 msghdr->msg_ts);
1000#endif
1001 if (msgsz > msghdr->msg_ts)
1002 msgsz = msghdr->msg_ts;
1003
1004 /*
1005 * Return the type to the user.
1006 */
1007
1008 eval = copyout((caddr_t)&(msghdr->msg_type), user_msgp,
1009 sizeof(msghdr->msg_type));
1010 if (eval != 0) {
1011#ifdef MSG_DEBUG_OK
6ea70f76 1012 kprintf("error (%d) copying out message type\n", eval);
984263bc
MD
1013#endif
1014 msg_freehdr(msghdr);
1015 wakeup((caddr_t)msqptr);
1016 return(eval);
1017 }
1018 user_msgp = (char *)user_msgp + sizeof(msghdr->msg_type);
1019
1020 /*
1021 * Return the segments to the user
1022 */
1023
1024 next = msghdr->msg_spot;
1025 for (len = 0; len < msgsz; len += msginfo.msgssz) {
1026 size_t tlen;
1027
1028 if (msgsz - len > msginfo.msgssz)
1029 tlen = msginfo.msgssz;
1030 else
1031 tlen = msgsz - len;
1032 if (next <= -1)
1033 panic("next too low #3");
1034 if (next >= msginfo.msgseg)
1035 panic("next out of range #3");
1036 eval = copyout((caddr_t)&msgpool[next * msginfo.msgssz],
1037 user_msgp, tlen);
1038 if (eval != 0) {
1039#ifdef MSG_DEBUG_OK
6ea70f76 1040 kprintf("error (%d) copying out message segment\n",
984263bc
MD
1041 eval);
1042#endif
1043 msg_freehdr(msghdr);
1044 wakeup((caddr_t)msqptr);
1045 return(eval);
1046 }
1047 user_msgp = (char *)user_msgp + tlen;
1048 next = msgmaps[next].next;
1049 }
1050
1051 /*
1052 * Done, return the actual number of bytes copied out.
1053 */
1054
1055 msg_freehdr(msghdr);
1056 wakeup((caddr_t)msqptr);
c7114eea 1057 uap->sysmsg_result = msgsz;
984263bc
MD
1058 return(0);
1059}
1060
1061static int
1062sysctl_msqids(SYSCTL_HANDLER_ARGS)
1063{
1064
1065 return (SYSCTL_OUT(req, msqids,
1066 sizeof(struct msqid_ds) * msginfo.msgmni));
1067}
1068
1069TUNABLE_INT("kern.ipc.msgseg", &msginfo.msgseg);
1070TUNABLE_INT("kern.ipc.msgssz", &msginfo.msgssz);
1071TUNABLE_INT("kern.ipc.msgmni", &msginfo.msgmni);
1072
984263bc
MD
1073SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0, "");
1074SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RD, &msginfo.msgmni, 0, "");
1075SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RD, &msginfo.msgmnb, 0, "");
1076SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RD, &msginfo.msgtql, 0, "");
1077SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RD, &msginfo.msgssz, 0, "");
1078SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RD, &msginfo.msgseg, 0, "");
1079SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLFLAG_RD,
1080 NULL, 0, sysctl_msqids, "", "Message queue IDs");