diff options
Diffstat (limited to 'winsup/cygserver/sysv_msg.cc')
| -rw-r--r-- | winsup/cygserver/sysv_msg.cc | 1210 |
1 files changed, 0 insertions, 1210 deletions
diff --git a/winsup/cygserver/sysv_msg.cc b/winsup/cygserver/sysv_msg.cc deleted file mode 100644 index 90ea95325..000000000 --- a/winsup/cygserver/sysv_msg.cc +++ /dev/null @@ -1,1210 +0,0 @@ -/* - * Implementation of SVID messages - * - * Author: Daniel Boulet - * - * Copyright 1993 Daniel Boulet and RTMX Inc. - * - * This system call was implemented by Daniel Boulet under contract from RTMX. - * - * Redistribution and use in source forms, with and without modification, - * are permitted provided that this entire comment appears intact. - * - * Redistribution in binary form may occur without any restrictions. - * Obviously, it would be nice if you gave credit where credit is due - * but requiring it would be too onerous. - * - * This software is provided ``AS IS'' without any warranties of any kind. - */ - -/* - * This file is heavily changed to become part of Cygwin's cygserver. - */ - -#ifdef __OUTSIDE_CYGWIN__ -#include "woutsup.h" -#include <sys/cdefs.h> -#ifndef __FBSDID -#define __FBSDID(s) const char version[] = (s) -#endif -__FBSDID("$FreeBSD: /usr/local/www/cvsroot/FreeBSD/src/sys/kern/sysv_msg.c,v 1.52 2003/11/07 04:47:14 rwatson Exp $"); - -#define _KERNEL 1 -#define __BSD_VISIBLE 1 -#include <sys/types.h> -#include <sys/sysproto.h> -#include <sys/ipc.h> -#include <sys/param.h> -#include <sys/msg.h> -#include <malloc.h> -#include <errno.h> -#include <time.h> -#include "cygserver.h" -#include "process.h" -#include "cygserver_ipc.h" - -#ifdef __CYGWIN__ -#define MSG_DEBUG -#endif /* __CYGWIN__ */ - -#ifdef MSG_DEBUG -#define DPRINTF(a) debug_printf a -#else -#define DPRINTF(a) -#endif - -static void msg_freehdr(struct msg *msghdr); - -#ifndef __CYGWIN__ -int msgctl(struct thread *, struct msgctl_args *); -int msgget(struct thread *, struct msgget_args *); -int msgsnd(struct thread *, struct msgsnd_args *); -int msgrcv(struct thread *, struct msgrcv_args *); - -static sy_call_t *msgcalls[] = { - (sy_call_t *)msgctl, (sy_call_t *)msgget, - (sy_call_t *)msgsnd, (sy_call_t *)msgrcv -}; -#endif /* __CYGWIN__ */ - - -struct msg { - struct msg *msg_next; /* next msg in the chain */ - long msg_type; /* type of this message */ - /* >0 -> type of this message */ - /* 0 -> free header */ - u_short msg_ts; /* size of this message */ - short msg_spot; /* location of start of msg in buffer */ -}; - - -#ifndef MSGSSZ -#define MSGSSZ 8 /* Each segment must be 2^N long */ -#endif -#ifndef MSGSEG -#define MSGSEG 2048 /* must be less than 32767 */ -#endif -#define MSGMAX (MSGSSZ*MSGSEG) -#ifndef MSGMNB -#define MSGMNB 2048 /* max # of bytes in a queue */ -#endif -#ifndef MSGMNI -#define MSGMNI 40 -#endif -#ifndef MSGTQL -#define MSGTQL 40 -#endif - -/* - * Based on the configuration parameters described in an SVR2 (yes, two) - * config(1m) man page. - * - * Each message is broken up and stored in segments that are msgssz bytes - * long. For efficiency reasons, this should be a power of two. Also, - * it doesn't make sense if it is less than 8 or greater than about 256. - * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of - * two between 8 and 1024 inclusive (and panic's if it isn't). - */ -struct msginfo msginfo = { - MSGMAX, /* max chars in a message */ - MSGMNB, /* max chars in a queue */ - MSGMNI, /* # of message queue identifiers */ - MSGTQL, /* max messages in system */ - MSGSSZ, /* size of a message segment */ - /* (must be small power of 2 greater than 4) */ - MSGSEG /* number of message segments */ -}; - -/* - * macros to convert between msqid_ds's and msqid's. - * (specific to this implementation) - */ -#define MSQID(ix,ds) ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000)) -#define MSQID_IX(id) ((id) & 0xffff) -#define MSQID_SEQ(id) (((id) >> 16) & 0xffff) - -/* - * The rest of this file is specific to this particular implementation. - */ - -struct msgmap { - short next; /* next segment in buffer */ - /* -1 -> available */ - /* 0..(MSGSEG-1) -> index of next segment */ -}; - -#define MSG_LOCKED 01000 /* Is this msqid_ds locked? */ - -static int nfree_msgmaps; /* # of free map entries */ -static short free_msgmaps; /* head of linked list of free map entries */ -static struct msg *free_msghdrs;/* list of free msg headers */ -static char *msgpool; /* MSGMAX byte long msg buffer pool */ -static struct msgmap *msgmaps; /* MSGSEG msgmap structures */ -static struct msg *msghdrs; /* MSGTQL msg headers */ -static struct msqid_ds *msqids; /* MSGMNI msqid_ds struct's */ -static struct mtx msq_mtx; /* global mutex for message queues. */ - -#ifdef __CYGWIN__ -static struct msg_info msg_info; -#endif /* __CYGWIN__ */ - -void -msginit() -{ - int i; - - TUNABLE_INT_FETCH("kern.ipc.msgseg", &msginfo.msgseg); - TUNABLE_INT_FETCH("kern.ipc.msgssz", &msginfo.msgssz); - msginfo.msgmax = msginfo.msgseg * msginfo.msgssz; - TUNABLE_INT_FETCH("kern.ipc.msgmnb", &msginfo.msgmnb); - TUNABLE_INT_FETCH("kern.ipc.msgmni", &msginfo.msgmni); - TUNABLE_INT_FETCH("kern.ipc.msgtql", &msginfo.msgtql); - - msgpool = (char *) sys_malloc(msginfo.msgmax, M_MSG, M_WAITOK); - if (msgpool == NULL) - panic("msgpool is NULL"); - msgmaps = (msgmap *) sys_malloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK); - if (msgmaps == NULL) - panic("msgmaps is NULL"); - msghdrs = (msg *) sys_malloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK); - if (msghdrs == NULL) - panic("msghdrs is NULL"); - msqids = (msqid_ds *) sys_malloc(sizeof(struct msqid_ds) * msginfo.msgmni, M_MSG, M_WAITOK); - if (msqids == NULL) - panic("msqids is NULL"); - - /* - * msginfo.msgssz should be a power of two for efficiency reasons. - * It is also pretty silly if msginfo.msgssz is less than 8 - * or greater than about 256 so ... - */ - - i = 8; - while (i < 1024 && i != msginfo.msgssz) - i <<= 1; - if (i != msginfo.msgssz) { - DPRINTF(("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz, - msginfo.msgssz)); - panic("msginfo.msgssz not a small power of 2"); - } - - if (msginfo.msgseg > 32767) { - DPRINTF(("msginfo.msgseg=%d\n", msginfo.msgseg)); - panic("msginfo.msgseg > 32767"); - } - - if (msgmaps == NULL) - panic("msgmaps is NULL"); - - for (i = 0; i < msginfo.msgseg; i++) { - if (i > 0) - msgmaps[i-1].next = i; - msgmaps[i].next = -1; /* implies entry is available */ - } - free_msgmaps = 0; - nfree_msgmaps = msginfo.msgseg; - - if (msghdrs == NULL) - panic("msghdrs is NULL"); - - for (i = 0; i < msginfo.msgtql; i++) { - msghdrs[i].msg_type = 0; - if (i > 0) - msghdrs[i-1].msg_next = &msghdrs[i]; - msghdrs[i].msg_next = NULL; - } - free_msghdrs = &msghdrs[0]; - - if (msqids == NULL) - panic("msqids is NULL"); - - for (i = 0; i < msginfo.msgmni; i++) { - msqids[i].msg_qbytes = 0; /* implies entry is available */ - msqids[i].msg_perm.seq = 0; /* reset to a known value */ - msqids[i].msg_perm.mode = 0; - } - mtx_init(&msq_mtx, "msq", NULL, MTX_DEF); -} - -int -msgunload() -{ - struct msqid_ds *msqptr; - int msqid; - - for (msqid = 0; msqid < msginfo.msgmni; msqid++) { - /* - * Look for an unallocated and unlocked msqid_ds. - * msqid_ds's can be locked by msgsnd or msgrcv while - * they are copying the message in/out. We can't - * re-use the entry until they release it. - */ - msqptr = &msqids[msqid]; - if (msqptr->msg_qbytes != 0 || - (msqptr->msg_perm.mode & MSG_LOCKED) != 0) - break; - } -#ifndef __CYGWIN__ - if (msqid != msginfo.msgmni) - return (EBUSY); -#endif /* __CYGWIN__ */ - - sys_free(msgpool, M_MSG); - sys_free(msgmaps, M_MSG); - sys_free(msghdrs, M_MSG); - sys_free(msqids, M_MSG); - mtx_destroy(&msq_mtx); - return (0); -} - - -#ifndef __CYGWIN__ -static int -sysvmsg_modload(struct module *module, int cmd, void *arg) -{ - int error = 0; - - switch (cmd) { - case MOD_LOAD: - msginit(); - break; - case MOD_UNLOAD: - error = msgunload(); - break; - case MOD_SHUTDOWN: - break; - default: - error = EINVAL; - break; - } - return (error); -} - -static moduledata_t sysvmsg_mod = { - "sysvmsg", - &sysvmsg_modload, - NULL -}; - -SYSCALL_MODULE_HELPER(msgsys); -SYSCALL_MODULE_HELPER(msgctl); -SYSCALL_MODULE_HELPER(msgget); -SYSCALL_MODULE_HELPER(msgsnd); -SYSCALL_MODULE_HELPER(msgrcv); - -DECLARE_MODULE(sysvmsg, sysvmsg_mod, - SI_SUB_SYSV_MSG, SI_ORDER_FIRST); -MODULE_VERSION(sysvmsg, 1); - -/* - * Entry point for all MSG calls - * - * MPSAFE - */ -int -msgsys(thread *td, struct msgsys_args *uap) -{ - int error; - - if (!jail_sysvipc_allowed && jailed(td->td_ucred)) - return (ENOSYS); - if (uap->which < 0 || - (unsigned) uap->which >= sizeof(msgcalls)/sizeof(msgcalls[0])) - return (EINVAL); - error = (*msgcalls[uap->which])(td, &uap->a2); - return (error); -} -#endif - -static void -msg_freehdr(struct msg *msghdr) -{ - while (msghdr->msg_ts > 0) { - short next; - if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg) - panic("msghdr->msg_spot out of range"); - next = msgmaps[msghdr->msg_spot].next; - msgmaps[msghdr->msg_spot].next = free_msgmaps; - free_msgmaps = msghdr->msg_spot; - nfree_msgmaps++; - msghdr->msg_spot = next; - if (msghdr->msg_ts >= msginfo.msgssz) - msghdr->msg_ts -= msginfo.msgssz; - else - msghdr->msg_ts = 0; - } - if (msghdr->msg_spot != -1) - panic("msghdr->msg_spot != -1"); - msghdr->msg_next = free_msghdrs; - free_msghdrs = msghdr; -} - -#ifndef _SYS_SYSPROTO_H_ -struct msgctl_args { - int msqid; - int cmd; - struct msqid_ds *buf; -}; -#endif - -/* - * MPSAFE - */ -int -msgctl(struct thread *td, struct msgctl_args *uap) -{ - int msqid = uap->msqid; - int cmd = uap->cmd; - struct msqid_ds *user_msqptr = uap->buf; - int rval, error; - struct msqid_ds msqbuf; - register struct msqid_ds *msqptr; - - DPRINTF(("call to msgctl(%d, %d, 0x%x)\n", msqid, cmd, user_msqptr)); - - if (!jail_sysvipc_allowed && jailed(td->td_ucred)) - return (ENOSYS); - -#ifdef __CYGWIN__ - if (cmd == IPC_INFO) { - if (!msqid) { - error = copyout(&msginfo, user_msqptr, - sizeof(struct msginfo)); - td->td_retval[0] = error ? -1 : 0; - return (error); - } - if (msqid > msginfo.msgmni) - msqid = msginfo.msgmni; - error = copyout(msqids, user_msqptr, - msqid * sizeof(struct msqid_ds)); - td->td_retval[0] = error ? -1 : 0; - return (error); - } else if (cmd == MSG_INFO) { - mtx_lock(&msq_mtx); - error = copyout(&msg_info, user_msqptr, - sizeof(struct msg_info)); - td->td_retval[0] = error ? -1 : 0; - mtx_unlock(&msq_mtx); - return (error); - } -#endif /* __CYGWIN__ */ - msqid = IPCID_TO_IX(msqid); - - if (msqid < 0 || msqid >= msginfo.msgmni) { - DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqid, - msginfo.msgmni)); - return (EINVAL); - } - if (cmd == IPC_SET && - (error = copyin(user_msqptr, &msqbuf, sizeof(msqbuf))) != 0) - return (error); - - msqptr = &msqids[msqid]; - - mtx_lock(&msq_mtx); - if (msqptr->msg_qbytes == 0) { - DPRINTF(("no such msqid\n")); - error = EINVAL; - goto done2; - } - if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) { - DPRINTF(("wrong sequence number\n")); - error = EINVAL; - goto done2; - } - - error = 0; - rval = 0; - - switch (cmd) { - - case IPC_RMID: - { - struct msg *msghdr; - if ((error = ipcperm(td, &msqptr->msg_perm, IPC_M))) - goto done2; - /* Free the message headers */ - msghdr = msqptr->msg_first; - while (msghdr != NULL) { - struct msg *msghdr_tmp; - - /* Free the segments of each message */ - msqptr->msg_cbytes -= msghdr->msg_ts; - msqptr->msg_qnum--; - msghdr_tmp = msghdr; - msghdr = msghdr->msg_next; - msg_freehdr(msghdr_tmp); - } - - if (msqptr->msg_cbytes != 0) - panic("msg_cbytes is screwed up"); - if (msqptr->msg_qnum != 0) - panic("msg_qnum is screwed up"); - - msqptr->msg_qbytes = 0; /* Mark it as free */ -#ifdef __CYGWIN__ - msg_info.msg_ids--; -#endif /* __CYGWIN__ */ - - wakeup(msqptr); - } - - break; - - case IPC_SET: - if ((error = ipcperm(td, &msqptr->msg_perm, IPC_M))) - goto done2; - if (msqbuf.msg_qbytes > msqptr->msg_qbytes) { - error = suser(td); - if (error) - goto done2; - } - if (msqbuf.msg_qbytes > (unsigned long) msginfo.msgmnb) { - DPRINTF(("can't increase msg_qbytes beyond %d" - "(truncating)\n", msginfo.msgmnb)); - msqbuf.msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */ - } - if (msqbuf.msg_qbytes == 0) { - DPRINTF(("can't reduce msg_qbytes to 0\n")); - error = EINVAL; /* non-standard errno! */ - goto done2; - } - msqptr->msg_perm.uid = msqbuf.msg_perm.uid; /* change the owner */ - msqptr->msg_perm.gid = msqbuf.msg_perm.gid; /* change the owner */ - msqptr->msg_perm.mode = (msqptr->msg_perm.mode & ~0777) | - (msqbuf.msg_perm.mode & 0777); - msqptr->msg_qbytes = msqbuf.msg_qbytes; - msqptr->msg_ctime = time (NULL); - break; - - case IPC_STAT: - if ((error = ipcperm(td, &msqptr->msg_perm, IPC_R))) { - DPRINTF(("requester doesn't have read access\n")); - goto done2; - } - break; - - default: - DPRINTF(("invalid command %d\n", cmd)); - error = EINVAL; - goto done2; - } - - if (error == 0) - td->td_retval[0] = rval; -done2: - mtx_unlock(&msq_mtx); - if (cmd == IPC_STAT && error == 0) - error = copyout(msqptr, user_msqptr, sizeof(struct msqid_ds)); - return(error); -} - -#ifndef _SYS_SYSPROTO_H_ -struct msgget_args { - key_t key; - int msgflg; -}; -#endif - -/* - * MPSAFE - */ -int -msgget(struct thread *td, struct msgget_args *uap) -{ - int msqid, error = 0; - key_t key = uap->key; - unsigned msgflg = uap->msgflg; - register struct msqid_ds *msqptr = NULL; - - DPRINTF(("msgget(0x%x, 0%o)\n", key, msgflg)); - - if (!jail_sysvipc_allowed && jailed(td->td_ucred)) - return (ENOSYS); - - mtx_lock(&msq_mtx); - if (key != IPC_PRIVATE) { - for (msqid = 0; msqid < msginfo.msgmni; msqid++) { - msqptr = &msqids[msqid]; - if (msqptr->msg_qbytes != 0 && - msqptr->msg_perm.key == key) - break; - } - if (msqid < msginfo.msgmni) { - DPRINTF(("found public key\n")); - if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) { - DPRINTF(("not exclusive\n")); - error = EEXIST; - goto done2; - } - if ((error = ipcperm(td, &msqptr->msg_perm, msgflg & 0700))) { - DPRINTF(("requester doesn't have 0%o access\n", - msgflg & 0700)); - goto done2; - } - goto found; - } - } - - DPRINTF(("need to allocate the msqid_ds\n")); - if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) { - for (msqid = 0; msqid < msginfo.msgmni; msqid++) { - /* - * Look for an unallocated and unlocked msqid_ds. - * msqid_ds's can be locked by msgsnd or msgrcv while - * they are copying the message in/out. We can't - * re-use the entry until they release it. - */ - msqptr = &msqids[msqid]; - if (msqptr->msg_qbytes == 0 && - (msqptr->msg_perm.mode & MSG_LOCKED) == 0) - break; - } - if (msqid == msginfo.msgmni) { - DPRINTF(("no more msqid_ds's available\n")); - error = ENOSPC; - goto done2; - } - DPRINTF(("msqid %d is available\n", msqid)); - msqptr->msg_perm.key = key; -#ifdef __CYGWIN__ - msqptr->msg_perm.cuid = td->ipcblk->uid; - msqptr->msg_perm.uid = td->ipcblk->uid; - msqptr->msg_perm.cgid = td->ipcblk->gid; - msqptr->msg_perm.gid = td->ipcblk->gid; -#else - msqptr->msg_perm.cuid = cred->cr_uid; - msqptr->msg_perm.uid = cred->cr_uid; - msqptr->msg_perm.cgid = cred->cr_gid; - msqptr->msg_perm.gid = cred->cr_gid; -#endif /* __CYGWIN__ */ - msqptr->msg_perm.mode = (msgflg & 0777); - /* Make sure that the returned msqid is unique */ - msqptr->msg_perm.seq = (msqptr->msg_perm.seq + 1) & 0x7fff; - msqptr->msg_first = NULL; - msqptr->msg_last = NULL; - msqptr->msg_cbytes = 0; - msqptr->msg_qnum = 0; - msqptr->msg_qbytes = msginfo.msgmnb; - msqptr->msg_lspid = 0; - msqptr->msg_lrpid = 0; - msqptr->msg_stime = 0; - msqptr->msg_rtime = 0; - msqptr->msg_ctime = time (NULL); -#ifdef __CYGWIN__ - msg_info.msg_ids++; -#endif /* __CYGWIN__ */ - } else { - DPRINTF(("didn't find it and wasn't asked to create it\n")); - error = ENOENT; - goto done2; - } - -found: - /* Construct the unique msqid */ - td->td_retval[0] = IXSEQ_TO_IPCID(msqid, msqptr->msg_perm); -done2: - mtx_unlock(&msq_mtx); - return (error); -} - -#ifndef _SYS_SYSPROTO_H_ -struct msgsnd_args { - int msqid; - const void *msgp; - size_t msgsz; - int msgflg; -}; -#endif - -/* - * MPSAFE - */ -int -msgsnd(struct thread *td, struct msgsnd_args *uap) -{ - int msqid = uap->msqid; - const void *user_msgp = uap->msgp; - size_t msgsz = uap->msgsz; - int msgflg = uap->msgflg; - int segs_needed, error = 0; - register struct msqid_ds *msqptr; - register struct msg *msghdr; - short next; - - DPRINTF(("call to msgsnd(%d, 0x%x, %d, %d)\n", msqid, user_msgp, msgsz, - msgflg)); - - if (!jail_sysvipc_allowed && jailed(td->td_ucred)) - return (ENOSYS); - - mtx_lock(&msq_mtx); - msqid = IPCID_TO_IX(msqid); - - if (msqid < 0 || msqid >= msginfo.msgmni) { - DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqid, - msginfo.msgmni)); - error = EINVAL; - goto done2; - } - - msqptr = &msqids[msqid]; - if (msqptr->msg_qbytes == 0) { - DPRINTF(("no such message queue id\n")); - error = EINVAL; - goto done2; - } - if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) { - DPRINTF(("wrong sequence number\n")); - error = EINVAL; - goto done2; - } - - if ((error = ipcperm(td, &msqptr->msg_perm, IPC_W))) { - DPRINTF(("requester doesn't have write access\n")); - goto done2; - } - - segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz; - DPRINTF(("msgsz=%d, msgssz=%d, segs_needed=%d\n", msgsz, msginfo.msgssz, - segs_needed)); - for (;;) { - int need_more_resources = 0; - - /* - * check msgsz - * (inside this loop in case msg_qbytes changes while we sleep) - */ - - if (msgsz > msqptr->msg_qbytes) { - DPRINTF(("msgsz > msqptr->msg_qbytes\n")); - error = EINVAL; - goto done2; - } - - if (msqptr->msg_perm.mode & MSG_LOCKED) { - DPRINTF(("msqid is locked\n")); - need_more_resources = 1; - } - if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes) { - DPRINTF(("msgsz + msg_cbytes > msg_qbytes\n")); - need_more_resources = 1; - } - if (segs_needed > nfree_msgmaps) { - DPRINTF(("segs_needed > nfree_msgmaps\n")); - need_more_resources = 1; - } - if (free_msghdrs == NULL) { - DPRINTF(("no more msghdrs\n")); - need_more_resources = 1; - } - - if (need_more_resources) { - int we_own_it; - - if ((msgflg & IPC_NOWAIT) != 0) { - DPRINTF(("need more resources but caller " - "doesn't want to wait\n")); - error = EAGAIN; - goto done2; - } - - if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0) { - DPRINTF(("we don't own the msqid_ds\n")); - we_own_it = 0; - } else { - /* Force later arrivals to wait for our - request */ - DPRINTF(("we own the msqid_ds\n")); - msqptr->msg_perm.mode |= MSG_LOCKED; - we_own_it = 1; - } - DPRINTF(("goodnight\n")); - error = msleep(msqptr, &msq_mtx, (PZERO - 4) | PCATCH, - "msgwait", 0); - DPRINTF(("good morning, error=%d\n", error)); - if (we_own_it) - msqptr->msg_perm.mode &= ~MSG_LOCKED; - if (error != 0) { - DPRINTF(("msgsnd: interrupted system call\n")); -#ifdef __CYGWIN__ - if (error != EIDRM) -#endif /* __CYGWIN__ */ - error = EINTR; - goto done2; - } - - /* - * Make sure that the msq queue still exists - */ - - if (msqptr->msg_qbytes == 0) { - DPRINTF(("msqid deleted\n")); - error = EIDRM; - goto done2; - } - - } else { - DPRINTF(("got all the resources that we need\n")); - break; - } - } - - /* - * We have the resources that we need. - * Make sure! - */ - - if (msqptr->msg_perm.mode & MSG_LOCKED) - panic("msg_perm.mode & MSG_LOCKED"); - if (segs_needed > nfree_msgmaps) - panic("segs_needed > nfree_msgmaps"); - if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes) - panic("msgsz + msg_cbytes > msg_qbytes"); - if (free_msghdrs == NULL) - panic("no more msghdrs"); - - /* - * Re-lock the msqid_ds in case we page-fault when copying in the - * message - */ - - if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0) - panic("msqid_ds is already locked"); - msqptr->msg_perm.mode |= MSG_LOCKED; - - /* - * Allocate a message header - */ - - msghdr = free_msghdrs; - free_msghdrs = msghdr->msg_next; - msghdr->msg_spot = -1; - msghdr->msg_ts = msgsz; - - /* - * Allocate space for the message - */ - - while (segs_needed > 0) { - if (nfree_msgmaps <= 0) - panic("not enough msgmaps"); - if (free_msgmaps == -1) - panic("nil free_msgmaps"); - next = free_msgmaps; - if (next <= -1) - panic("next too low #1"); - if (next >= msginfo.msgseg) - panic("next out of range #1"); - DPRINTF(("allocating segment %d to message\n", next)); - free_msgmaps = msgmaps[next].next; - nfree_msgmaps--; - msgmaps[next].next = msghdr->msg_spot; - msghdr->msg_spot = next; - segs_needed--; - } - - /* - * Copy in the message type - */ - - mtx_unlock(&msq_mtx); - if ((error = copyin(user_msgp, &msghdr->msg_type, - sizeof(msghdr->msg_type))) != 0) { - mtx_lock(&msq_mtx); - DPRINTF(("error %d copying the message type\n", error)); - msg_freehdr(msghdr); - msqptr->msg_perm.mode &= ~MSG_LOCKED; - wakeup(msqptr); - goto done2; - } - mtx_lock(&msq_mtx); - user_msgp = (const char *)user_msgp + sizeof(msghdr->msg_type); - - /* - * Validate the message type - */ - - if (msghdr->msg_type < 1) { - msg_freehdr(msghdr); - msqptr->msg_perm.mode &= ~MSG_LOCKED; - wakeup(msqptr); - DPRINTF(("mtype (%d) < 1\n", msghdr->msg_type)); - error = EINVAL; - goto done2; - } - - /* - * Copy in the message body - */ - - next = msghdr->msg_spot; - while (msgsz > 0) { - size_t tlen; - if (msgsz > (unsigned long) msginfo.msgssz) - tlen = msginfo.msgssz; - else - tlen = msgsz; - if (next <= -1) - panic("next too low #2"); - if (next >= msginfo.msgseg) - panic("next out of range #2"); - mtx_unlock(&msq_mtx); - if ((error = copyin(user_msgp, &msgpool[next * msginfo.msgssz], - tlen)) != 0) { - mtx_lock(&msq_mtx); - DPRINTF(("error %d copying in message segment\n", - error)); - msg_freehdr(msghdr); - msqptr->msg_perm.mode &= ~MSG_LOCKED; - wakeup(msqptr); - goto done2; - } - mtx_lock(&msq_mtx); - msgsz -= tlen; - user_msgp = (const char *)user_msgp + tlen; - next = msgmaps[next].next; - } - if (next != -1) - panic("didn't use all the msg segments"); - - /* - * We've got the message. Unlock the msqid_ds. - */ - - msqptr->msg_perm.mode &= ~MSG_LOCKED; - - /* - * Make sure that the msqid_ds is still allocated. - */ - - if (msqptr->msg_qbytes == 0) { - msg_freehdr(msghdr); - wakeup(msqptr); - error = EIDRM; - goto done2; - } - - /* - * Put the message into the queue - */ - - if (msqptr->msg_first == NULL) { - msqptr->msg_first = msghdr; - msqptr->msg_last = msghdr; - } else { - msqptr->msg_last->msg_next = msghdr; - msqptr->msg_last = msghdr; - } - msqptr->msg_last->msg_next = NULL; - - msqptr->msg_cbytes += msghdr->msg_ts; - msqptr->msg_qnum++; - msqptr->msg_lspid = td->td_proc->p_pid; - msqptr->msg_stime = time (NULL); - -#ifdef __CYGWIN__ - msg_info.msg_num++; - msg_info.msg_tot += uap->msgsz; -#endif /* __CYGWIN__ */ - - wakeup(msqptr); - td->td_retval[0] = 0; -done2: - mtx_unlock(&msq_mtx); - return (error); -} - -#ifndef _SYS_SYSPROTO_H_ -struct msgrcv_args { - int msqid; - void *msgp; - size_t msgsz; - long msgtyp; - int msgflg; -}; -#endif - -/* - * MPSAFE - */ -int -msgrcv(struct thread *td, struct msgrcv_args *uap) -{ - int msqid = uap->msqid; - void *user_msgp = uap->msgp; - size_t msgsz = uap->msgsz; - long msgtyp = uap->msgtyp; - int msgflg = uap->msgflg; - size_t len; - register struct msqid_ds *msqptr; - register struct msg *msghdr; - int error = 0; - short next; - - DPRINTF(("call to msgrcv(%d, 0x%x, %d, %ld, %d)\n", msqid, user_msgp, - msgsz, msgtyp, msgflg)); - - if (!jail_sysvipc_allowed && jailed(td->td_ucred)) - return (ENOSYS); - - msqid = IPCID_TO_IX(msqid); - - if (msqid < 0 || msqid >= msginfo.msgmni) { - DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqid, - msginfo.msgmni)); - return (EINVAL); - } - - msqptr = &msqids[msqid]; - mtx_lock(&msq_mtx); - if (msqptr->msg_qbytes == 0) { - DPRINTF(("no such message queue id\n")); - error = EINVAL; - goto done2; - } - if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) { - DPRINTF(("wrong sequence number\n")); - error = EINVAL; - goto done2; - } - - if ((error = ipcperm(td, &msqptr->msg_perm, IPC_R))) { - DPRINTF(("requester doesn't have read access\n")); - goto done2; - } - - msghdr = NULL; - while (msghdr == NULL) { - if (msgtyp == 0) { - msghdr = msqptr->msg_first; - if (msghdr != NULL) { - if (msgsz < msghdr->msg_ts && - (msgflg & MSG_NOERROR) == 0) { - DPRINTF(("first message on the queue " - "is too big (want %d, got %d)\n", - msgsz, msghdr->msg_ts)); - error = E2BIG; - goto done2; - } - if (msqptr->msg_first == msqptr->msg_last) { - msqptr->msg_first = NULL; - msqptr->msg_last = NULL; - } else { - msqptr->msg_first = msghdr->msg_next; - if (msqptr->msg_first == NULL) - panic("msg_first/last screwed up #1"); - } - } - } else { - struct msg *previous; - struct msg **prev; - - previous = NULL; - prev = &(msqptr->msg_first); - while ((msghdr = *prev) != NULL) { - /* - * Is this message's type an exact match or is - * this message's type less than or equal to - * the absolute value of a negative msgtyp? - * Note that the second half of this test can - * NEVER be true if msgtyp is positive since - * msg_type is always positive! - */ - - if (msgtyp == msghdr->msg_type || - msghdr->msg_type <= -msgtyp) { - DPRINTF(("found message type %d, " - "requested %d\n", - msghdr->msg_type, msgtyp)); - if (msgsz < msghdr->msg_ts && - (msgflg & MSG_NOERROR) == 0) { - DPRINTF(("requested message " - "on the queue is too big " - "(want %d, got %d)\n", - msgsz, msghdr->msg_ts)); - error = E2BIG; - goto done2; - } - *prev = msghdr->msg_next; - if (msghdr == msqptr->msg_last) { - if (previous == NULL) { - if (prev != - &msqptr->msg_first) - panic("msg_first/last screwed up #2"); - msqptr->msg_first = - NULL; - msqptr->msg_last = - NULL; - } else { - if (prev == - &msqptr->msg_first) - panic("msg_first/last screwed up #3"); - msqptr->msg_last = - previous; - } - } - break; - } - previous = msghdr; - prev = &(msghdr->msg_next); - } - } - - /* - * We've either extracted the msghdr for the appropriate - * message or there isn't one. - * If there is one then bail out of this loop. - */ - - if (msghdr != NULL) - break; - - /* - * Hmph! No message found. Does the user want to wait? - */ - - if ((msgflg & IPC_NOWAIT) != 0) { - DPRINTF(("no appropriate message found (msgtyp=%d)\n", - msgtyp)); - /* The SVID says to return ENOMSG. */ - error = ENOMSG; - goto done2; - } - - /* - * Wait for something to happen - */ - - DPRINTF(("msgrcv: goodnight\n")); - error = msleep(msqptr, &msq_mtx, (PZERO - 4) | PCATCH, - "msgwait", 0); - DPRINTF(("msgrcv: good morning (error=%d)\n", error)); - - if (error != 0) { - DPRINTF(("msgsnd: interrupted system call\n")); -#ifdef __CYGWIN__ - if (error != EIDRM) -#endif /* __CYGWIN__ */ - error = EINTR; - goto done2; - } - - /* - * Make sure that the msq queue still exists - */ - - if (msqptr->msg_qbytes == 0 || - msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) { - DPRINTF(("msqid deleted\n")); - error = EIDRM; - goto done2; - } - } - - /* - * Return the message to the user. - * - * First, do the bookkeeping (before we risk being interrupted). - */ - - msqptr->msg_cbytes -= msghdr->msg_ts; - msqptr->msg_qnum--; - msqptr->msg_lrpid = td->td_proc->p_pid; - msqptr->msg_rtime = time (NULL); - - /* - * Make msgsz the actual amount that we'll be returning. - * Note that this effectively truncates the message if it is too long - * (since msgsz is never increased). - */ - - DPRINTF(("found a message, msgsz=%d, msg_ts=%d\n", msgsz, - msghdr->msg_ts)); - if (msgsz > msghdr->msg_ts) - msgsz = msghdr->msg_ts; - - /* - * Return the type to the user. - */ - - mtx_unlock(&msq_mtx); - error = copyout(&(msghdr->msg_type), user_msgp, - sizeof(msghdr->msg_type)); - mtx_lock(&msq_mtx); - if (error != 0) { - DPRINTF(("error (%d) copying out message type\n", error)); - msg_freehdr(msghdr); - wakeup(msqptr); - goto done2; - } - user_msgp = (char *)user_msgp + sizeof(msghdr->msg_type); - - /* - * Return the segments to the user - */ - - next = msghdr->msg_spot; - for (len = 0; len < msgsz; len += msginfo.msgssz) { - size_t tlen; - - if (msgsz - len > (unsigned long) msginfo.msgssz) - tlen = msginfo.msgssz; - else - tlen = msgsz - len; - if (next <= -1) - panic("next too low #3"); - if (next >= msginfo.msgseg) - panic("next out of range #3"); - mtx_unlock(&msq_mtx); - error = copyout(&msgpool[next * msginfo.msgssz], - user_msgp, tlen); - mtx_lock(&msq_mtx); - if (error != 0) { - DPRINTF(("error (%d) copying out message segment\n", - error)); - msg_freehdr(msghdr); - wakeup(msqptr); - goto done2; - } - user_msgp = (char *)user_msgp + tlen; - next = msgmaps[next].next; - } - - /* - * Done, return the actual number of bytes copied out. - */ - -#ifdef __CYGWIN__ - msg_info.msg_num--; - msg_info.msg_tot -= msgsz; -#endif /* __CYGWIN__ */ - - msg_freehdr(msghdr); - wakeup(msqptr); - td->td_retval[0] = msgsz; -done2: - mtx_unlock(&msq_mtx); - return (error); -} - -#ifndef __CYGWIN__ -static int -sysctl_msqids(SYSCTL_HANDLER_ARGS) -{ - - return (SYSCTL_OUT(req, msqids, - sizeof(struct msqid_ds) * msginfo.msgmni)); -} - -SYSCTL_DECL(_kern_ipc); -SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0, ""); -SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RDTUN, &msginfo.msgmni, 0, ""); -SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RD, &msginfo.msgmnb, 0, ""); -SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RD, &msginfo.msgtql, 0, ""); -SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RDTUN, &msginfo.msgssz, 0, ""); -SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RDTUN, &msginfo.msgseg, 0, ""); -SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLFLAG_RD, - NULL, 0, sysctl_msqids, "", "Message queue IDs"); -#endif /* __CYGWIN__ */ -#endif /* __OUTSIDE_CYGWIN__ */ |