/* $NetBSD: sysv_ipc.c,v 1.41 2020/02/21 00:26:22 joerg Exp $ */ /*- * Copyright (c) 1998, 2007 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Charles M. Hannum. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include __KERNEL_RCSID(0, "$NetBSD: sysv_ipc.c,v 1.41 2020/02/21 00:26:22 joerg Exp $"); #ifdef _KERNEL_OPT #include "opt_sysv.h" #include "opt_sysvparam.h" #include "opt_compat_netbsd.h" #endif #include #include #include #include #include #include #include #ifdef SYSVMSG #include #endif #ifdef SYSVSEM #include #endif #ifdef SYSVSHM #include #endif #include #include #include #include #include #include #include #include #include #include /* for sysctl routine vector */ /* * Values in support of System V compatible shared memory. XXX * (originally located in sys/conf/param.c) */ #ifdef SYSVSHM #if !defined(SHMMAX) && defined(SHMMAXPGS) #define SHMMAX SHMMAXPGS /* shminit() performs a `*= PAGE_SIZE' */ #elif !defined(SHMMAX) #define SHMMAX 0 #endif #ifndef SHMMIN #define SHMMIN 1 #endif #ifndef SHMMNI #define SHMMNI 128 /* <64k, see IPCID_TO_IX in ipc.h */ #endif #ifndef SHMSEG #define SHMSEG 128 #endif struct shminfo shminfo = { SHMMAX, SHMMIN, SHMMNI, SHMSEG, 0 }; #endif /* * Values in support of System V compatible semaphores. */ #ifdef SYSVSEM struct seminfo seminfo = { SEMMAP, /* # of entries in semaphore map */ SEMMNI, /* # of semaphore identifiers */ SEMMNS, /* # of semaphores in system */ SEMMNU, /* # of undo structures in system */ SEMMSL, /* max # of semaphores per id */ SEMOPM, /* max # of operations per semop call */ SEMUME, /* max # of undo entries per process */ SEMUSZ, /* size in bytes of undo structure */ SEMVMX, /* semaphore maximum value */ SEMAEM /* adjust on exit max value */ }; #endif /* * Values in support of System V compatible messages. */ #ifdef SYSVMSG struct msginfo msginfo = { MSGMAX, /* max chars in a message */ MSGMNI, /* # of message queue identifiers */ MSGMNB, /* max chars in a queue */ 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 */ }; #endif MODULE(MODULE_CLASS_EXEC, sysv_ipc, NULL); SYSCTL_SETUP_PROTO(sysctl_ipc_setup); static const struct syscall_package sysvipc_syscalls[] = { #if defined(SYSVSHM) { SYS___shmctl50, 0, (sy_call_t *)sys___shmctl50 }, { SYS_shmat, 0, (sy_call_t *)sys_shmat }, { SYS_shmdt, 0, (sy_call_t *)sys_shmdt }, { SYS_shmget, 0, (sy_call_t *)sys_shmget }, #endif /* SYSVSHM */ #if defined(SYSVSEM) { SYS_____semctl50, 0, (sy_call_t *)sys_____semctl50 }, { SYS_semget, 0, (sy_call_t *)sys_semget }, { SYS_semop, 0, (sy_call_t *)sys_semop }, { SYS_semconfig, 0, (sy_call_t *)sys_semconfig }, #endif /* SYSVSEM */ #if defined(SYSVMSG) { SYS___msgctl50, 0, (sy_call_t *)sys___msgctl50 }, { SYS_msgget, 0, (sy_call_t *)sys_msgget }, { SYS_msgsnd, 0, (sy_call_t *)sys_msgsnd }, { SYS_msgrcv, 0, (sy_call_t *)sys_msgrcv }, #endif /* SYSVMSG */ { 0, 0, NULL } }; static int sysv_ipc_modcmd(modcmd_t cmd, void *arg) { int error = 0; switch (cmd) { case MODULE_CMD_INIT: /* Set up the kauth listener */ sysvipcinit(); /* Link the system calls */ error = syscall_establish(NULL, sysvipc_syscalls); if (error) { sysvipcfini(); return error; } /* * Initialize each sub-component, including their * sysctl data */ #ifdef SYSVSHM error = shminit(); if (error != 0) return error; #endif #ifdef SYSVSEM error = seminit(); if (error != 0) { #ifdef SYSVSHM shmfini(); #endif return error; } #endif #ifdef SYSVMSG error = msginit(); if (error != 0) { #ifdef SYSVSEM semfini(); #endif #ifdef SYSVSHM shmfini(); #endif return error; } #endif break; case MODULE_CMD_FINI: /* * Make sure no subcomponents are active. Each one * tells us if it is busy, and if it was _not_ busy, * we assume it has already done its own clean-up. * So we might need to re-init any components that * are successfully fini'd if we find one that is * still busy. */ #ifdef SYSVSHM if (shmfini()) { return EBUSY; } #endif #ifdef SYSVSEM if (semfini()) { #ifdef SYSVSHM shminit(); #endif return EBUSY; } #endif #ifdef SYSVMSG if (msgfini()) { #ifdef SYSVSEM seminit(); #endif #ifdef SYSVSHM shminit(); #endif return EBUSY; } #endif /* Unlink the system calls. */ error = syscall_disestablish(NULL, sysvipc_syscalls); if (error) return error; /* Remove the kauth listener */ sysvipcfini(); break; default: return ENOTTY; } return error; } static kauth_listener_t sysvipc_listener = NULL; static int sysvipc_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, void *arg0, void *arg1, void *arg2, void *arg3) { mode_t mask; int ismember = 0; struct ipc_perm *perm; int mode; enum kauth_system_req req; req = (enum kauth_system_req)(uintptr_t)arg0; if (!(action == KAUTH_SYSTEM_SYSVIPC && req == KAUTH_REQ_SYSTEM_SYSVIPC_BYPASS)) return KAUTH_RESULT_DEFER; perm = arg1; mode = (int)(uintptr_t)arg2; if (mode == IPC_M) { if (kauth_cred_geteuid(cred) == perm->uid || kauth_cred_geteuid(cred) == perm->cuid) return (KAUTH_RESULT_ALLOW); return (KAUTH_RESULT_DEFER); /* EPERM */ } mask = 0; if (kauth_cred_geteuid(cred) == perm->uid || kauth_cred_geteuid(cred) == perm->cuid) { if (mode & IPC_R) mask |= S_IRUSR; if (mode & IPC_W) mask |= S_IWUSR; return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); } if (kauth_cred_getegid(cred) == perm->gid || (kauth_cred_ismember_gid(cred, perm->gid, &ismember) == 0 && ismember) || kauth_cred_getegid(cred) == perm->cgid || (kauth_cred_ismember_gid(cred, perm->cgid, &ismember) == 0 && ismember)) { if (mode & IPC_R) mask |= S_IRGRP; if (mode & IPC_W) mask |= S_IWGRP; return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); } if (mode & IPC_R) mask |= S_IROTH; if (mode & IPC_W) mask |= S_IWOTH; return ((perm->mode & mask) == mask ? KAUTH_RESULT_ALLOW : KAUTH_RESULT_DEFER /* EACCES */); } /* * Check for ipc permission */ int ipcperm(kauth_cred_t cred, struct ipc_perm *perm, int mode) { int error; error = kauth_authorize_system(cred, KAUTH_SYSTEM_SYSVIPC, KAUTH_REQ_SYSTEM_SYSVIPC_BYPASS, perm, KAUTH_ARG(mode), NULL); if (error == 0) return (0); /* Adjust EPERM and EACCES errors until there's a better way to do this. */ if (mode != IPC_M) error = EACCES; return error; } void sysvipcfini(void) { KASSERT(sysvipc_listener != NULL); kauth_unlisten_scope(sysvipc_listener); sysvipc_listener = NULL; } void sysvipcinit(void) { KASSERT(sysvipc_listener == NULL); sysvipc_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM, sysvipc_listener_cb, NULL); } static int stub_sysvipc50_sysctl(SYSCTLFN_ARGS) { return EPASSTHROUGH; } static int sysctl_kern_sysvipc(SYSCTLFN_ARGS) { void *where = oldp; size_t sz, *sizep = oldlenp; #ifdef SYSVMSG struct msg_sysctl_info *msgsi = NULL; #endif #ifdef SYSVSEM struct sem_sysctl_info *semsi = NULL; #endif #ifdef SYSVSHM struct shm_sysctl_info *shmsi = NULL; #endif size_t infosize, dssize, tsize, buflen; void *bf = NULL; char *start; int32_t nds; int i, error, ret; /* * If present, call the compat sysctl() code. If it handles the request * completely (either success or error), return. Otherwise fallthrough * to the non-compat sysctl code. */ MODULE_HOOK_CALL(sysvipc_sysctl_50_hook, (SYSCTLFN_CALL(rnode)), stub_sysvipc50_sysctl(SYSCTLFN_CALL(rnode)), error); if (error != EPASSTHROUGH) return error; if (namelen != 1) return EINVAL; start = where; buflen = *sizep; switch (*name) { case KERN_SYSVIPC_MSG_INFO: #ifdef SYSVMSG infosize = sizeof(msgsi->msginfo); nds = msginfo.msgmni; dssize = sizeof(msgsi->msgids[0]); break; #else return EINVAL; #endif case KERN_SYSVIPC_SEM_INFO: #ifdef SYSVSEM infosize = sizeof(semsi->seminfo); nds = seminfo.semmni; dssize = sizeof(semsi->semids[0]); break; #else return EINVAL; #endif case KERN_SYSVIPC_SHM_INFO: #ifdef SYSVSHM infosize = sizeof(shmsi->shminfo); nds = shminfo.shmmni; dssize = sizeof(shmsi->shmids[0]); break; #else return EINVAL; #endif default: return EINVAL; } /* * Round infosize to 64 bit boundary if requesting more than just * the info structure or getting the total data size. */ if (where == NULL || *sizep > infosize) infosize = roundup(infosize, sizeof(quad_t)); tsize = infosize + nds * dssize; /* Return just the total size required. */ if (where == NULL) { *sizep = tsize; return 0; } /* Not enough room for even the info struct. */ if (buflen < infosize) { *sizep = 0; return ENOMEM; } sz = uimin(tsize, buflen); bf = kmem_zalloc(sz, KM_SLEEP); switch (*name) { #ifdef SYSVMSG case KERN_SYSVIPC_MSG_INFO: msgsi = (struct msg_sysctl_info *)bf; msgsi->msginfo = msginfo; break; #endif #ifdef SYSVSEM case KERN_SYSVIPC_SEM_INFO: semsi = (struct sem_sysctl_info *)bf; semsi->seminfo = seminfo; break; #endif #ifdef SYSVSHM case KERN_SYSVIPC_SHM_INFO: shmsi = (struct shm_sysctl_info *)bf; shmsi->shminfo = shminfo; break; #endif } buflen -= infosize; ret = 0; if (buflen > 0) { /* Fill in the IPC data structures. */ for (i = 0; i < nds; i++) { if (buflen < dssize) { ret = ENOMEM; break; } switch (*name) { #ifdef SYSVMSG case KERN_SYSVIPC_MSG_INFO: mutex_enter(&msgmutex); SYSCTL_FILL_MSG(msqs[i].msq_u, msgsi->msgids[i]); mutex_exit(&msgmutex); break; #endif #ifdef SYSVSEM case KERN_SYSVIPC_SEM_INFO: SYSCTL_FILL_SEM(sema[i], semsi->semids[i]); break; #endif #ifdef SYSVSHM case KERN_SYSVIPC_SHM_INFO: SYSCTL_FILL_SHM(shmsegs[i], shmsi->shmids[i]); break; #endif } buflen -= dssize; } } *sizep -= buflen; error = copyout(bf, start, *sizep); /* If copyout succeeded, use return code set earlier. */ if (error == 0) error = ret; if (bf) kmem_free(bf, sz); return error; } SYSCTL_SETUP(sysctl_ipc_setup, "sysctl kern.ipc subtree setup") { sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT, CTLTYPE_NODE, "ipc", SYSCTL_DESCR("SysV IPC options"), NULL, 0, NULL, 0, CTL_KERN, KERN_SYSVIPC, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT, CTLTYPE_STRUCT, "sysvipc_info", SYSCTL_DESCR("System V style IPC information"), sysctl_kern_sysvipc, 0, NULL, 0, CTL_KERN, KERN_SYSVIPC, KERN_SYSVIPC_INFO, CTL_EOL); }