/* * linux/ipc/msg.c * Copyright (C) 1992 Krishna Balasubramanian * * Removed all the remaining kerneld mess * Catch the -EFAULT stuff properly * Use GFP_KERNEL for messages as in 1.2 * Fixed up the unchecked user space derefs * Copyright (C) 1998 Alan Cox & Andi Kleen * * /proc/sysvipc/msg support (c) 1999 Dragos Acostachioaie <dragos@iname.com> * * mostly rewritten, threaded and wake-one semantics added * MSGMAX limit removed, sysctl's added * (c) 1999 Manfred Spraul <manfreds@colorfullife.com> */ #include <linux/config.h>#include <linux/slab.h>#include <linux/msg.h>#include <linux/spinlock.h>#include <linux/init.h>#include <linux/proc_fs.h>#include <linux/list.h>#include <linux/security.h>#include <linux/sched.h>#include <linux/syscalls.h>#include <asm/current.h>#include <asm/uaccess.h>#include "util.h" /* sysctl: */int msg_ctlmax = MSGMAX;int msg_ctlmnb = MSGMNB;int msg_ctlmni = MSGMNI; /* one msg_receiver structure for each sleeping receiver */struct msg_receiver { struct list_head r_list; struct task_struct* r_tsk; int r_mode; long r_msgtype; long r_maxsize; struct msg_msg* volatile r_msg;}; /* one msg_sender for each sleeping sender */struct msg_sender { struct list_head list; struct task_struct* tsk;}; #define SEARCH_ANY 1#define SEARCH_EQUAL 2#define SEARCH_NOTEQUAL 3#define SEARCH_LESSEQUAL 4 static atomic_t msg_bytes = ATOMIC_INIT(0);static atomic_t msg_hdrs = ATOMIC_INIT(0); static struct ipc_ids msg_ids; #define msg_lock(id) ((struct msg_queue*)ipc_lock(&msg_ids,id))#define msg_unlock(msq) ipc_unlock(&(msq)->q_perm)#define msg_rmid(id) ((struct msg_queue*)ipc_rmid(&msg_ids,id))#define msg_checkid(msq, msgid) \ ipc_checkid(&msg_ids,&msq->q_perm,msgid)#define msg_buildid(id, seq) \ ipc_buildid(&msg_ids, id, seq) static void freeque (struct msg_queue *msq, int id);static int newque (key_t key, int msgflg);#ifdef CONFIG_PROC_FSstatic int sysvipc_msg_read_proc(char *buffer, char **start, off_t offset, int length, int *eof, void *data);#endif void __init msg_init (void){ ipc_init_ids(&msg_ids,msg_ctlmni); #ifdef CONFIG_PROC_FS create_proc_read_entry("sysvipc/msg", 0, NULL, sysvipc_msg_read_proc, NULL);#endif} static int newque (key_t key, int msgflg){ int id; int retval; struct msg_queue *msq; msq = ipc_rcu_alloc(sizeof(*msq)); if (!msq) return -ENOMEM; msq->q_perm.mode = (msgflg & S_IRWXUGO); msq->q_perm.key = key; msq->q_perm.security = NULL; retval = security_msg_queue_alloc(msq); if (retval) { ipc_rcu_putref(msq); return retval; } id = ipc_addid(&msg_ids, &msq->q_perm, msg_ctlmni); if(id == -1) { security_msg_queue_free(msq); ipc_rcu_putref(msq); return -ENOSPC; } msq->q_stime = msq->q_rtime = 0; msq->q_ctime = get_seconds(); msq->q_cbytes = msq->q_qnum = 0; msq->q_qbytes = msg_ctlmnb; msq->q_lspid = msq->q_lrpid = 0; INIT_LIST_HEAD(&msq->q_messages); INIT_LIST_HEAD(&msq->q_receivers); INIT_LIST_HEAD(&msq->q_senders); msg_unlock(msq); return msg_buildid(id,msq->q_perm.seq);} static inline void ss_add(struct msg_queue* msq, struct msg_sender* mss){ mss->tsk=current; current->state=TASK_INTERRUPTIBLE; list_add_tail(&mss->list,&msq->q_senders);} static inline void ss_del(struct msg_sender* mss){ if(mss->list.next != NULL) list_del(&mss->list);} static void ss_wakeup(struct list_head* h, int kill){ struct list_head *tmp; tmp = h->next; while (tmp != h) { struct msg_sender* mss; mss = list_entry(tmp,struct msg_sender,list); tmp = tmp->next; if(kill) mss->list.next=NULL; wake_up_process(mss->tsk); }} static void expunge_all(struct msg_queue* msq, int res){ struct list_head *tmp; tmp = msq->q_receivers.next; while (tmp != &msq->q_receivers) { struct msg_receiver* msr; msr = list_entry(tmp,struct msg_receiver,r_list); tmp = tmp->next; msr->r_msg = NULL; wake_up_process(msr->r_tsk); smp_mb(); msr->r_msg = ERR_PTR(res); }}/* * freeque() wakes up waiters on the sender and receiver waiting queue, * removes the message queue from message queue ID * array, and cleans up all the messages associated with this queue. * * msg_ids.sem and the spinlock for this message queue is hold * before freeque() is called. msg_ids.sem remains locked on exit. */static void freeque (struct msg_queue *msq, int id){ struct list_head *tmp; expunge_all(msq,-EIDRM); ss_wakeup(&msq->q_senders,1); msq = msg_rmid(id); msg_unlock(msq); tmp = msq->q_messages.next; while(tmp != &msq->q_messages) { struct msg_msg* msg = list_entry(tmp,struct msg_msg,m_list); tmp = tmp->next; atomic_dec(&msg_hdrs); free_msg(msg); } atomic_sub(msq->q_cbytes, &msg_bytes); security_msg_queue_free(msq); ipc_rcu_putref(msq);} asmlinkage long sys_msgget (key_t key, int msgflg){ int id, ret = -EPERM; struct msg_queue *msq; down(&msg_ids.sem); if (key == IPC_PRIVATE) ret = newque(key, msgflg); else if ((id = ipc_findkey(&msg_ids, key)) == -1) { /* key not used */ if (!(msgflg & IPC_CREAT)) ret = -ENOENT; else ret = newque(key, msgflg); } else if (msgflg & IPC_CREAT && msgflg & IPC_EXCL) { ret = -EEXIST; } else { msq = msg_lock(id); if(msq==NULL) BUG(); if (ipcperms(&msq->q_perm, msgflg)) ret = -EACCES; else { int qid = msg_buildid(id, msq->q_perm.seq); ret = security_msg_queue_associate(msq, msgflg); if (!ret) ret = qid; } msg_unlock(msq); } up(&msg_ids.sem); return ret;} static inline unsigned long copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version){ switch(version) { case IPC_64: return copy_to_user (buf, in, sizeof(*in)); case IPC_OLD: { struct msqid_ds out; memset(&out,0,sizeof(out)); ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm); out.msg_stime = in->msg_stime; out.msg_rtime = in->msg_rtime; out.msg_ctime = in->msg_ctime; if(in->msg_cbytes > USHRT_MAX) out.msg_cbytes = USHRT_MAX; else out.msg_cbytes = in->msg_cbytes; out.msg_lcbytes = in->msg_cbytes; if(in->msg_qnum > USHRT_MAX) out.msg_qnum = USHRT_MAX; else out.msg_qnum = in->msg_qnum; if(in->msg_qbytes > USHRT_MAX) out.msg_qbytes = USHRT_MAX; else out.msg_qbytes = in->msg_qbytes; out.msg_lqbytes = in->msg_qbytes; out.msg_lspid = in->msg_lspid; out.msg_lrpid = in->msg_lrpid; return copy_to_user (buf, &out, sizeof(out)); } default: return -EINVAL; }} struct msq_setbuf { unsigned long qbytes; uid_t uid; gid_t gid; mode_t mode;}; static inline unsigned long copy_msqid_from_user(struct msq_setbuf *out, void __user *buf, int version){ switch(version) { case IPC_64: { struct msqid64_ds tbuf; if (copy_from_user (&tbuf, buf, sizeof (tbuf))) return -EFAULT; out->qbytes = tbuf.msg_qbytes; out->uid = tbuf.msg_perm.uid; out->gid = tbuf.msg_perm.gid; out->mode = tbuf.msg_perm.mode; return 0; } case IPC_OLD: { struct msqid_ds tbuf_old; if (copy_from_user (&tbuf_old, buf, sizeof (tbuf_old))) return -EFAULT; out->uid = tbuf_old.msg_perm.uid; out->gid = tbuf_old.msg_perm.gid; out->mode = tbuf_old.msg_perm.mode; if(tbuf_old.msg_qbytes == 0) out->qbytes = tbuf_old.msg_lqbytes; else out->qbytes = tbuf_old.msg_qbytes; return 0; } default: return -EINVAL; }} asmlinkage long sys_msgctl (int msqid, int cmd, struct msqid_ds __user *buf){ int err, version; struct msg_queue *msq; struct msq_setbuf setbuf; struct kern_ipc_perm *ipcp; if (msqid < 0 || cmd < 0) return -EINVAL; version = ipc_parse_version(&cmd); switch (cmd) { case IPC_INFO: case MSG_INFO: { struct msginfo msginfo; int max_id; if (!buf) return -EFAULT; /* We must not return kernel stack data. * due to padding, it's not enough * to set all member fields. */ err = security_msg_queue_msgctl(NULL, cmd); if (err) return err; memset(&msginfo,0,sizeof(msginfo)); msginfo.msgmni = msg_ctlmni; msginfo.msgmax = msg_ctlmax; msginfo.msgmnb = msg_ctlmnb; msginfo.msgssz = MSGSSZ; msginfo.msgseg = MSGSEG; down(&msg_ids.sem); if (cmd == MSG_INFO) { msginfo.msgpool = msg_ids.in_use; msginfo.msgmap = atomic_read(&msg_hdrs); msginfo.msgtql = atomic_read(&msg_bytes); } else { msginfo.msgmap = MSGMAP; msginfo.msgpool = MSGPOOL; msginfo.msgtql = MSGTQL; } max_id = msg_ids.max_id; up(&msg_ids.sem); if (copy_to_user (buf, &msginfo, sizeof(struct msginfo))) return -EFAULT; return (max_id < 0) ? 0: max_id; } case MSG_STAT: case IPC_STAT: { struct msqid64_ds tbuf; int success_return; if (!buf) return -EFAULT; if(cmd == MSG_STAT && msqid >= msg_ids.entries->size) return -EINVAL; memset(&tbuf,0,sizeof(tbuf)); msq = msg_lock(msqid); if (msq == NULL) return -EINVAL; if(cmd == MSG_STAT) { success_return = msg_buildid(msqid, msq->q_perm.seq); } else { err = -EIDRM; if (msg_checkid(msq,msqid)) goto out_unlock; success_return = 0; } err = -EACCES; if (ipcperms (&msq->q_perm, S_IRUGO)) goto out_unlock; err = security_msg_queue_msgctl(msq, cmd); if (err) goto out_unlock; kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm); tbuf.msg_stime = msq->q_stime; tbuf.msg_rtime = msq->q_rtime; tbuf.msg_ctime = msq->q_ctime; tbuf.msg_cbytes = msq->q_cbytes; tbuf.msg_qnum = msq->q_qnum; tbuf.msg_qbytes = msq->q_qbytes; tbuf.msg_lspid = msq->q_lspid; tbuf.msg_lrpid = msq->q_lrpid; msg_unlock(msq); if (copy_msqid_to_user(buf, &tbuf, version)) return -EFAULT; return success_return; } case IPC_SET: if (!buf) return -EFAULT; if (copy_msqid_from_user (&setbuf, buf, version)) return -EFAULT; break; case IPC_RMID: break; default: return -EINVAL; } down(&msg_ids.sem); msq = msg_lock(msqid); err=-EINVAL; if (msq == NULL) goto out_up; err = -EIDRM; if (msg_checkid(msq,msqid)) goto out_unlock_up; ipcp = &msq->q_perm; err = -EPERM; if (current->euid != ipcp->cuid && current->euid != ipcp->uid && !capable(CAP_SYS_ADMIN)) /* We _could_ check for CAP_CHOWN above, but we don't */ goto out_unlock_up; err = security_msg_queue_msgctl(msq, cmd); if (err) goto out_unlock_up; switch (cmd) { case IPC_SET: { err = -EPERM; if (setbuf.qbytes > msg_ctlmnb && !capable(CAP_SYS_RESOURCE)) goto out_unlock_up; msq->q_qbytes = setbuf.qbytes; ipcp->uid = setbuf.uid; ipcp->gid = setbuf.gid; ipcp->mode = (ipcp->mode & ~S_IRWXUGO) | (S_IRWXUGO & setbuf.mode); msq->q_ctime = get_seconds(); /* sleeping receivers might be excluded by * stricter permissions. */ expunge_all(msq,-EAGAIN); /* sleeping senders might be able to send * due to a larger queue size. */ ss_wakeup(&msq->q_senders,0); msg_unlock(msq); break; } case IPC_RMID: freeque (msq, msqid); break; } err = 0;out_up: up(&msg_ids.sem); return err;out_unlock_up: msg_unlock(msq); goto out_up;out_unlock: msg_unlock(msq); return err;} static int testmsg(struct msg_msg* msg,long type,int mode){ switch(mode) { case SEARCH_ANY:Lines 1–500 of 859. Load more
/* * linux/ipc/msg.c * Copyright (C) 1992 Krishna Balasubramanian * * Removed all the remaining kerneld mess * Catch the -EFAULT stuff properly * Use GFP_KERNEL for messages as in 1.2 * Fixed up the unchecked user space derefs * Copyright (C) 1998 Alan Cox & Andi Kleen * * /proc/sysvipc/msg support (c) 1999 Dragos Acostachioaie <dragos@iname.com> * * mostly rewritten, threaded and wake-one semantics added * MSGMAX limit removed, sysctl's added * (c) 1999 Manfred Spraul <manfreds@colorfullife.com> */ #include <linux/config.h> #include <linux/slab.h> #include <linux/msg.h> #include <linux/spinlock.h> #include <linux/init.h> #include <linux/proc_fs.h> #include <linux/list.h> #include <linux/security.h> #include <linux/sched.h> #include <linux/syscalls.h> #include <asm/current.h> #include <asm/uaccess.h> #include "util.h" /* sysctl: */ int msg_ctlmax = MSGMAX; int msg_ctlmnb = MSGMNB; int msg_ctlmni = MSGMNI; /* one msg_receiver structure for each sleeping receiver */ struct msg_receiver { struct list_head r_list; struct task_struct* r_tsk; int r_mode; long r_msgtype; long r_maxsize; struct msg_msg* volatile r_msg; }; /* one msg_sender for each sleeping sender */ struct msg_sender { struct list_head list; struct task_struct* tsk; }; #define SEARCH_ANY 1 #define SEARCH_EQUAL 2 #define SEARCH_NOTEQUAL 3 #define SEARCH_LESSEQUAL 4 static atomic_t msg_bytes = ATOMIC_INIT(0); static atomic_t msg_hdrs = ATOMIC_INIT(0); static struct ipc_ids msg_ids; #define msg_lock(id) ((struct msg_queue*)ipc_lock(&msg_ids,id)) #define msg_unlock(msq) ipc_unlock(&(msq)->q_perm) #define msg_rmid(id) ((struct msg_queue*)ipc_rmid(&msg_ids,id)) #define msg_checkid(msq, msgid) \ ipc_checkid(&msg_ids,&msq->q_perm,msgid) #define msg_buildid(id, seq) \ ipc_buildid(&msg_ids, id, seq) static void freeque (struct msg_queue *msq, int id); static int newque (key_t key, int msgflg); #ifdef CONFIG_PROC_FS static int sysvipc_msg_read_proc(char *buffer, char **start, off_t offset, int length, int *eof, void *data); #endif void __init msg_init (void) { ipc_init_ids(&msg_ids,msg_ctlmni); #ifdef CONFIG_PROC_FS create_proc_read_entry("sysvipc/msg", 0, NULL, sysvipc_msg_read_proc, NULL); #endif } static int newque (key_t key, int msgflg) { int id; int retval; struct msg_queue *msq; msq = ipc_rcu_alloc(sizeof(*msq)); if (!msq) return -ENOMEM; msq->q_perm.mode = (msgflg & S_IRWXUGO); msq->q_perm.key = key; msq->q_perm.security = NULL; retval = security_msg_queue_alloc(msq); if (retval) { ipc_rcu_putref(msq); return retval; } id = ipc_addid(&msg_ids, &msq->q_perm, msg_ctlmni); if(id == -1) { security_msg_queue_free(msq); ipc_rcu_putref(msq); return -ENOSPC; } msq->q_stime = msq->q_rtime = 0; msq->q_ctime = get_seconds(); msq->q_cbytes = msq->q_qnum = 0; msq->q_qbytes = msg_ctlmnb; msq->q_lspid = msq->q_lrpid = 0; INIT_LIST_HEAD(&msq->q_messages); INIT_LIST_HEAD(&msq->q_receivers); INIT_LIST_HEAD(&msq->q_senders); msg_unlock(msq); return msg_buildid(id,msq->q_perm.seq); } static inline void ss_add(struct msg_queue* msq, struct msg_sender* mss) { mss->tsk=current; current->state=TASK_INTERRUPTIBLE; list_add_tail(&mss->list,&msq->q_senders); } static inline void ss_del(struct msg_sender* mss) { if(mss->list.next != NULL) list_del(&mss->list); } static void ss_wakeup(struct list_head* h, int kill) { struct list_head *tmp; tmp = h->next; while (tmp != h) { struct msg_sender* mss; mss = list_entry(tmp,struct msg_sender,list); tmp = tmp->next; if(kill) mss->list.next=NULL; wake_up_process(mss->tsk); } } static void expunge_all(struct msg_queue* msq, int res) { struct list_head *tmp; tmp = msq->q_receivers.next; while (tmp != &msq->q_receivers) { struct msg_receiver* msr; msr = list_entry(tmp,struct msg_receiver,r_list); tmp = tmp->next; msr->r_msg = NULL; wake_up_process(msr->r_tsk); smp_mb(); msr->r_msg = ERR_PTR(res); } } /* * freeque() wakes up waiters on the sender and receiver waiting queue, * removes the message queue from message queue ID * array, and cleans up all the messages associated with this queue. * * msg_ids.sem and the spinlock for this message queue is hold * before freeque() is called. msg_ids.sem remains locked on exit. */ static void freeque (struct msg_queue *msq, int id) { struct list_head *tmp; expunge_all(msq,-EIDRM); ss_wakeup(&msq->q_senders,1); msq = msg_rmid(id); msg_unlock(msq); tmp = msq->q_messages.next; while(tmp != &msq->q_messages) { struct msg_msg* msg = list_entry(tmp,struct msg_msg,m_list); tmp = tmp->next; atomic_dec(&msg_hdrs); free_msg(msg); } atomic_sub(msq->q_cbytes, &msg_bytes); security_msg_queue_free(msq); ipc_rcu_putref(msq); } asmlinkage long sys_msgget (key_t key, int msgflg) { int id, ret = -EPERM; struct msg_queue *msq; down(&msg_ids.sem); if (key == IPC_PRIVATE) ret = newque(key, msgflg); else if ((id = ipc_findkey(&msg_ids, key)) == -1) { /* key not used */ if (!(msgflg & IPC_CREAT)) ret = -ENOENT; else ret = newque(key, msgflg); } else if (msgflg & IPC_CREAT && msgflg & IPC_EXCL) { ret = -EEXIST; } else { msq = msg_lock(id); if(msq==NULL) BUG(); if (ipcperms(&msq->q_perm, msgflg)) ret = -EACCES; else { int qid = msg_buildid(id, msq->q_perm.seq); ret = security_msg_queue_associate(msq, msgflg); if (!ret) ret = qid; } msg_unlock(msq); } up(&msg_ids.sem); return ret; } static inline unsigned long copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version) { switch(version) { case IPC_64: return copy_to_user (buf, in, sizeof(*in)); case IPC_OLD: { struct msqid_ds out; memset(&out,0,sizeof(out)); ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm); out.msg_stime = in->msg_stime; out.msg_rtime = in->msg_rtime; out.msg_ctime = in->msg_ctime; if(in->msg_cbytes > USHRT_MAX) out.msg_cbytes = USHRT_MAX; else out.msg_cbytes = in->msg_cbytes; out.msg_lcbytes = in->msg_cbytes; if(in->msg_qnum > USHRT_MAX) out.msg_qnum = USHRT_MAX; else out.msg_qnum = in->msg_qnum; if(in->msg_qbytes > USHRT_MAX) out.msg_qbytes = USHRT_MAX; else out.msg_qbytes = in->msg_qbytes; out.msg_lqbytes = in->msg_qbytes; out.msg_lspid = in->msg_lspid; out.msg_lrpid = in->msg_lrpid; return copy_to_user (buf, &out, sizeof(out)); } default: return -EINVAL; } } struct msq_setbuf { unsigned long qbytes; uid_t uid; gid_t gid; mode_t mode; }; static inline unsigned long copy_msqid_from_user(struct msq_setbuf *out, void __user *buf, int version) { switch(version) { case IPC_64: { struct msqid64_ds tbuf; if (copy_from_user (&tbuf, buf, sizeof (tbuf))) return -EFAULT; out->qbytes = tbuf.msg_qbytes; out->uid = tbuf.msg_perm.uid; out->gid = tbuf.msg_perm.gid; out->mode = tbuf.msg_perm.mode; return 0; } case IPC_OLD: { struct msqid_ds tbuf_old; if (copy_from_user (&tbuf_old, buf, sizeof (tbuf_old))) return -EFAULT; out->uid = tbuf_old.msg_perm.uid; out->gid = tbuf_old.msg_perm.gid; out->mode = tbuf_old.msg_perm.mode; if(tbuf_old.msg_qbytes == 0) out->qbytes = tbuf_old.msg_lqbytes; else out->qbytes = tbuf_old.msg_qbytes; return 0; } default: return -EINVAL; } } asmlinkage long sys_msgctl (int msqid, int cmd, struct msqid_ds __user *buf) { int err, version; struct msg_queue *msq; struct msq_setbuf setbuf; struct kern_ipc_perm *ipcp; if (msqid < 0 || cmd < 0) return -EINVAL; version = ipc_parse_version(&cmd); switch (cmd) { case IPC_INFO: case MSG_INFO: { struct msginfo msginfo; int max_id; if (!buf) return -EFAULT; /* We must not return kernel stack data. * due to padding, it's not enough * to set all member fields. */ err = security_msg_queue_msgctl(NULL, cmd); if (err) return err; memset(&msginfo,0,sizeof(msginfo)); msginfo.msgmni = msg_ctlmni; msginfo.msgmax = msg_ctlmax; msginfo.msgmnb = msg_ctlmnb; msginfo.msgssz = MSGSSZ; msginfo.msgseg = MSGSEG; down(&msg_ids.sem); if (cmd == MSG_INFO) { msginfo.msgpool = msg_ids.in_use; msginfo.msgmap = atomic_read(&msg_hdrs); msginfo.msgtql = atomic_read(&msg_bytes); } else { msginfo.msgmap = MSGMAP; msginfo.msgpool = MSGPOOL; msginfo.msgtql = MSGTQL; } max_id = msg_ids.max_id; up(&msg_ids.sem); if (copy_to_user (buf, &msginfo, sizeof(struct msginfo))) return -EFAULT; return (max_id < 0) ? 0: max_id; } case MSG_STAT: case IPC_STAT: { struct msqid64_ds tbuf; int success_return; if (!buf) return -EFAULT; if(cmd == MSG_STAT && msqid >= msg_ids.entries->size) return -EINVAL; memset(&tbuf,0,sizeof(tbuf)); msq = msg_lock(msqid); if (msq == NULL) return -EINVAL; if(cmd == MSG_STAT) { success_return = msg_buildid(msqid, msq->q_perm.seq); } else { err = -EIDRM; if (msg_checkid(msq,msqid)) goto out_unlock; success_return = 0; } err = -EACCES; if (ipcperms (&msq->q_perm, S_IRUGO)) goto out_unlock; err = security_msg_queue_msgctl(msq, cmd); if (err) goto out_unlock; kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm); tbuf.msg_stime = msq->q_stime; tbuf.msg_rtime = msq->q_rtime; tbuf.msg_ctime = msq->q_ctime; tbuf.msg_cbytes = msq->q_cbytes; tbuf.msg_qnum = msq->q_qnum; tbuf.msg_qbytes = msq->q_qbytes; tbuf.msg_lspid = msq->q_lspid; tbuf.msg_lrpid = msq->q_lrpid; msg_unlock(msq); if (copy_msqid_to_user(buf, &tbuf, version)) return -EFAULT; return success_return; } case IPC_SET: if (!buf) return -EFAULT; if (copy_msqid_from_user (&setbuf, buf, version)) return -EFAULT; break; case IPC_RMID: break; default: return -EINVAL; } down(&msg_ids.sem); msq = msg_lock(msqid); err=-EINVAL; if (msq == NULL) goto out_up; err = -EIDRM; if (msg_checkid(msq,msqid)) goto out_unlock_up; ipcp = &msq->q_perm; err = -EPERM; if (current->euid != ipcp->cuid && current->euid != ipcp->uid && !capable(CAP_SYS_ADMIN)) /* We _could_ check for CAP_CHOWN above, but we don't */ goto out_unlock_up; err = security_msg_queue_msgctl(msq, cmd); if (err) goto out_unlock_up; switch (cmd) { case IPC_SET: { err = -EPERM; if (setbuf.qbytes > msg_ctlmnb && !capable(CAP_SYS_RESOURCE)) goto out_unlock_up; msq->q_qbytes = setbuf.qbytes; ipcp->uid = setbuf.uid; ipcp->gid = setbuf.gid; ipcp->mode = (ipcp->mode & ~S_IRWXUGO) | (S_IRWXUGO & setbuf.mode); msq->q_ctime = get_seconds(); /* sleeping receivers might be excluded by * stricter permissions. */ expunge_all(msq,-EAGAIN); /* sleeping senders might be able to send * due to a larger queue size. */ ss_wakeup(&msq->q_senders,0); msg_unlock(msq); break; } case IPC_RMID: freeque (msq, msqid); break; } err = 0; out_up: up(&msg_ids.sem); return err; out_unlock_up: msg_unlock(msq); goto out_up; out_unlock: msg_unlock(msq); return err; } static int testmsg(struct msg_msg* msg,long type,int mode) { switch(mode) { case SEARCH_ANY: