X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/d7e50217d7adf6e52786a38bcaa4cd698cb9a79e..c6bf4f310a33a9262d455ea4d3f0630b1255e3fe:/bsd/kern/posix_shm.c?ds=inline diff --git a/bsd/kern/posix_shm.c b/bsd/kern/posix_shm.c index 952b28833..29c89efb9 100644 --- a/bsd/kern/posix_shm.c +++ b/bsd/kern/posix_shm.c @@ -1,17 +1,20 @@ /* - * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2007 Apple Inc. All rights reserved. + * + * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * - * @APPLE_LICENSE_HEADER_START@ - * - * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved. - * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in - * compliance with the License. Please obtain a copy of the License at - * http://www.opensource.apple.com/apsl/ and read it before using this - * file. - * + * compliance with the License. The rights granted to you under the License + * may not be used to create, or enable the creation or redistribution of, + * unlawful or unlicensed copies of an Apple operating system, or to + * circumvent, violate, or enable the circumvention or violation of, any + * terms of an Apple operating system software license agreement. + * + * Please obtain a copy of the License at + * http://www.opensource.apple.com/apsl/ and read it before using this file. + * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, @@ -19,8 +22,8 @@ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. - * - * @APPLE_LICENSE_HEADER_END@ + * + * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * Copyright (c) 1990, 1996-1998 Apple Computer, Inc. @@ -37,867 +40,1131 @@ * Created for MacOSX * */ +/* + * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce + * support for mandatory and extensible security protections. This notice + * is included in support of clause 2.2 (b) of the Apple Public License, + * Version 2.0. + */ #include #include #include #include -#include +#include #include #include -#include -#include +#include +#include #include #include #include +#include #include #include #include #include #include +#include +#include +#include +#include +#include + +#if CONFIG_MACF +#include +#endif + #include +#include +#include #include #include #include #include +#include +#include -#define PSHMNAMLEN 31 /* maximum name segment length we bother with */ - -struct pshminfo { - unsigned int pshm_flags; - unsigned int pshm_usecount; - off_t pshm_length; - mode_t pshm_mode; - uid_t pshm_uid; - gid_t pshm_gid; - char pshm_name[PSHMNAMLEN + 1]; /* segment name */ - void * pshm_memobject; -#if DIAGNOSTIC - unsigned int pshm_readcount; - unsigned int pshm_writecount; - struct proc * pshm_proc; -#endif /* DIAGNOSTIC */ -}; -#define PSHMINFO_NULL (struct pshminfo *)0 - -#define PSHM_NONE 1 -#define PSHM_DEFINED 2 -#define PSHM_ALLOCATED 4 -#define PSHM_MAPPED 8 -#define PSHM_INUSE 0x10 -#define PSHM_REMOVED 0x20 -#define PSHM_INCREATE 0x40 -#define PSHM_INDELETE 0x80 - -struct pshmcache { - LIST_ENTRY(pshmcache) pshm_hash; /* hash chain */ - struct pshminfo *pshminfo; /* vnode the name refers to */ - int pshm_nlen; /* length of name */ - char pshm_name[PSHMNAMLEN + 1]; /* segment name */ -}; -#define PSHMCACHE_NULL (struct pshmcache *)0 - -struct pshmstats { - long goodhits; /* hits that we can really use */ - long neghits; /* negative hits that we can use */ - long badhits; /* hits we must drop */ - long falsehits; /* hits with id mismatch */ - long miss; /* misses */ - long longnames; /* long names that ignore cache */ -}; +#define f_flag f_fglob->fg_flag +#define f_type f_fglob->fg_ops->fo_type +#define f_msgcount f_fglob->fg_msgcount +#define f_cred f_fglob->fg_cred +#define f_ops f_fglob->fg_ops +#define f_offset f_fglob->fg_offset +#define f_data f_fglob->fg_data -struct pshmname { - char *pshm_nameptr; /* pointer to looked up name */ - long pshm_namelen; /* length of looked up component */ - u_long pshm_hash; /* hash value of looked up name */ -}; +/* + * Used to construct the list of memory objects + * assigned to a populated shared memory segment. + */ +typedef struct pshm_mobj { + void *pshmo_memobject; + memory_object_size_t pshmo_size; + SLIST_ENTRY(pshm_mobj) pshmo_next; +} pshm_mobj_t; -struct pshmnode { - off_t mapp_addr; - size_t map_size; - struct pshminfo *pinfo; - unsigned int pshm_usecount; -#if DIAGNOSTIC - unsigned int readcnt; - unsigned int writecnt; -#endif -}; -#define PSHMNODE_NULL (struct pshmnode *)0 +/* + * This represents an existing Posix shared memory object. + * + * It comes into existence with a shm_open(...O_CREAT...) + * call and goes away only after it has been shm_unlink()ed + * and the last remaining shm_open() file reference is closed. + * + * To keep track of that lifetime, pshm_usecount is used as a reference + * counter. It's incremented for every successful shm_open() and + * one extra time for the shm_unlink() to release. Internally + * you can temporarily use an additional reference whenever the + * subsystem lock has to be dropped for other reasons. + */ +typedef struct internal_pshminfo { + struct pshminfo pshm_hdr; + SLIST_HEAD(pshm_mobjhead, pshm_mobj) pshm_mobjs; + RB_ENTRY(internal_pshminfo) pshm_links; /* links for red/black tree */ +} pshm_info_t; +#define pshm_flags pshm_hdr.pshm_flags +#define pshm_usecount pshm_hdr.pshm_usecount +#define pshm_length pshm_hdr.pshm_length +#define pshm_mode pshm_hdr.pshm_mode +#define pshm_uid pshm_hdr.pshm_uid +#define pshm_gid pshm_hdr.pshm_gid +#define pshm_label pshm_hdr.pshm_label + +/* Values for pshm_flags that are still used */ +#define PSHM_ALLOCATED 0x004 /* backing storage is allocated */ +#define PSHM_MAPPED 0x008 /* mapped at least once */ +#define PSHM_INUSE 0x010 /* mapped at least once */ +#define PSHM_REMOVED 0x020 /* no longer in the name cache due to shm_unlink() */ +#define PSHM_ALLOCATING 0x100 /* storage is being allocated */ + +/* + * These handle reference counting pshm_info_t structs using pshm_usecount. + */ +static int pshm_ref(pshm_info_t *pinfo); +static void pshm_deref(pshm_info_t *pinfo); +#define PSHM_MAXCOUNT UINT_MAX + +/* + * For every shm_open, we get a new one of these. + * The only reason we don't just use pshm_info directly is that + * you can query the mapped memory objects via proc_pidinfo to + * query the mapped address. Note that even this is a hack. If + * you mmap() the same fd multiple times, we only save/report + * one address. + */ +typedef struct pshmnode { + off_t mapp_addr; + pshm_info_t *pinfo; +} pshmnode_t; -#define PSHMHASH(pnp) \ - (&pshmhashtbl[(pnp)->pshm_hash & pshmhash]) -LIST_HEAD(pshmhashhead, pshmcache) *pshmhashtbl; /* Hash Table */ -u_long pshmhash; /* size of hash table - 1 */ -long pshmnument; /* number of cache entries allocated */ -struct pshmstats pshmstats; /* cache effectiveness statistics */ +/* compare function for the red black tree */ +static int +pshm_compare(pshm_info_t *a, pshm_info_t *b) +{ + int cmp = strncmp(a->pshm_hdr.pshm_name, b->pshm_hdr.pshm_name, PSHMNAMLEN + 1); -static int pshm_read __P((struct file *fp, struct uio *uio, - struct ucred *cred, int flags, struct proc *p)); -static int pshm_write __P((struct file *fp, struct uio *uio, - struct ucred *cred, int flags, struct proc *p)); -static int pshm_ioctl __P((struct file *fp, u_long com, - caddr_t data, struct proc *p)); -static int pshm_select __P((struct file *fp, int which, void *wql, - struct proc *p)); -static int pshm_closefile __P((struct file *fp, struct proc *p)); + if (cmp < 0) { + return -1; + } + if (cmp > 0) { + return 1; + } + return 0; +} -struct fileops pshmops = - { pshm_read, pshm_write, pshm_ioctl, pshm_select, pshm_closefile }; /* - * Lookup an entry in the cache - * - * - * status of -1 is returned if matches - * If the lookup determines that the name does not exist - * (negative cacheing), a status of ENOENT is returned. If the lookup - * fails, a status of zero is returned. + * shared memory "paths" are stored in a red black tree for lookup */ +u_long pshmnument; /* count of entries allocated in the red black tree */ +RB_HEAD(pshmhead, internal_pshminfo) pshm_head; +RB_PROTOTYPE(pshmhead, internal_pshminfo, pshm_links, pshm_compare) +RB_GENERATE(pshmhead, internal_pshminfo, pshm_links, pshm_compare) + +/* lookup, add, remove functions */ +static pshm_info_t *pshm_cache_search(pshm_info_t * look); +static void pshm_cache_add(pshm_info_t *entry); +static void pshm_cache_delete(pshm_info_t *entry); + +static int pshm_closefile(struct fileglob *fg, vfs_context_t ctx); + +static int pshm_access(pshm_info_t *pinfo, int mode, kauth_cred_t cred, proc_t p); +int pshm_cache_purge_all(proc_t p); + +static int pshm_unlink_internal(pshm_info_t *pinfo); + +static const struct fileops pshmops = { + .fo_type = DTYPE_PSXSHM, + .fo_read = fo_no_read, + .fo_write = fo_no_write, + .fo_ioctl = fo_no_ioctl, + .fo_select = fo_no_select, + .fo_close = pshm_closefile, + .fo_drain = fo_no_drain, + .fo_kqfilter = fo_no_kqfilter, +}; -int -pshm_cache_search(pshmp, pnp, pcache) - struct pshminfo **pshmp; - struct pshmname *pnp; - struct pshmcache **pcache; -{ - register struct pshmcache *pcp, *nnp; - register struct pshmhashhead *pcpp; +/* + * Everything here is protected by a single mutex. + */ +static lck_grp_t *psx_shm_subsys_lck_grp; +static lck_grp_attr_t *psx_shm_subsys_lck_grp_attr; +static lck_attr_t *psx_shm_subsys_lck_attr; +static lck_mtx_t psx_shm_subsys_mutex; - if (pnp->pshm_namelen > PSHMNAMLEN) { - pshmstats.longnames++; - return (0); - } +#define PSHM_SUBSYS_LOCK() lck_mtx_lock(& psx_shm_subsys_mutex) +#define PSHM_SUBSYS_UNLOCK() lck_mtx_unlock(& psx_shm_subsys_mutex) +#define PSHM_SUBSYS_ASSERT_HELD() LCK_MTX_ASSERT(&psx_shm_subsys_mutex, LCK_MTX_ASSERT_OWNED) - pcpp = PSHMHASH(pnp); - for (pcp = pcpp->lh_first; pcp != 0; pcp = nnp) { - nnp = pcp->pshm_hash.le_next; - if (pcp->pshm_nlen == pnp->pshm_namelen && - !bcmp(pcp->pshm_name, pnp->pshm_nameptr, (u_int)pcp-> pshm_nlen)) - break; - } - if (pcp == 0) { - pshmstats.miss++; - return (0); - } +__private_extern__ void +pshm_lock_init( void ) +{ + psx_shm_subsys_lck_grp_attr = lck_grp_attr_alloc_init(); - /* We found a "positive" match, return the vnode */ - if (pcp->pshminfo) { - pshmstats.goodhits++; - /* TOUCH(ncp); */ - *pshmp = pcp->pshminfo; - *pcache = pcp; - return (-1); - } + psx_shm_subsys_lck_grp = + lck_grp_alloc_init("posix shared memory", psx_shm_subsys_lck_grp_attr); - /* - * We found a "negative" match, ENOENT notifies client of this match. - * The nc_vpid field records whether this is a whiteout. - */ - pshmstats.neghits++; - return (ENOENT); + psx_shm_subsys_lck_attr = lck_attr_alloc_init(); + lck_mtx_init(&psx_shm_subsys_mutex, psx_shm_subsys_lck_grp, psx_shm_subsys_lck_attr); } /* - * Add an entry to the cache. + * Lookup an entry in the cache. Only the name is used from "look". */ -int -pshm_cache_add(pshmp, pnp) - struct pshminfo *pshmp; - struct pshmname *pnp; +static pshm_info_t * +pshm_cache_search(pshm_info_t *look) { - register struct pshmcache *pcp; - register struct pshmhashhead *pcpp; - register struct pshminfo *dpinfo; - register struct pshmcache *dpcp; - -#if DIAGNOSTIC - if (pnp->pshm_namelen > NCHNAMLEN) - panic("cache_enter: name too long"); -#endif + PSHM_SUBSYS_ASSERT_HELD(); + return RB_FIND(pshmhead, &pshm_head, look); +} - /* - * We allocate a new entry if we are less than the maximum - * allowed and the one at the front of the LRU list is in use. - * Otherwise we use the one at the front of the LRU list. - */ - pcp = (struct pshmcache *)_MALLOC(sizeof(struct pshmcache), M_SHM, M_WAITOK); - /* if the entry has already been added by some one else return */ - if (pshm_cache_search(&dpinfo, pnp, &dpcp) == -1) { - _FREE(pcp, M_SHM); - return(EEXIST); +/* + * Add a new entry to the cache. + */ +static void +pshm_cache_add(pshm_info_t *entry) +{ + pshm_info_t *conflict; + + PSHM_SUBSYS_ASSERT_HELD(); + conflict = RB_INSERT(pshmhead, &pshm_head, entry); + if (conflict != NULL) { + panic("pshm_cache_add() found %p", conflict); } pshmnument++; +} - bzero(pcp, sizeof(struct pshmcache)); - /* - * Fill in cache info, if vp is NULL this is a "negative" cache entry. - * For negative entries, we have to record whether it is a whiteout. - * the whiteout flag is stored in the nc_vpid field which is - * otherwise unused. - */ - pcp->pshminfo = pshmp; - pcp->pshm_nlen = pnp->pshm_namelen; - bcopy(pnp->pshm_nameptr, pcp->pshm_name, (unsigned)pcp->pshm_nlen); - pcpp = PSHMHASH(pnp); -#if DIAGNOSTIC - { - register struct pshmcache *p; - - for (p = pcpp->lh_first; p != 0; p = p->pshm_hash.le_next) - if (p == pcp) - panic("cache_enter: duplicate"); - } -#endif - LIST_INSERT_HEAD(pcpp, pcp, pshm_hash); - return(0); +/* + * Remove the given entry from the red black tree. + */ +static void +pshm_cache_delete(pshm_info_t *entry) +{ + PSHM_SUBSYS_ASSERT_HELD(); + assert(!(entry->pshm_flags & PSHM_REMOVED)); + RB_REMOVE(pshmhead, &pshm_head, entry); + pshmnument--; } /* - * Name cache initialization, from vfs_init() when we are booting + * Initialize the red black tree. */ void -pshm_cache_init() +pshm_cache_init(void) { - pshmhashtbl = hashinit(desiredvnodes, M_SHM, &pshmhash); + RB_INIT(&pshm_head); } /* - * Invalidate a all entries to particular vnode. - * - * We actually just increment the v_id, that will do it. The entries will - * be purged by lookup as they get found. If the v_id wraps around, we - * need to ditch the entire cache, to avoid confusion. No valid vnode will - * ever have (v_id == 0). + * Invalidate all entries and delete all objects associated with them + * XXX - due to the reference counting, this only works if all userland + * references to it via file descriptors are also closed already. Is this + * known to be called after all user processes are killed? */ -void -pshm_cache_purge(void) +int +pshm_cache_purge_all(__unused proc_t proc) { - struct pshmcache *pcp; - struct pshmhashhead *pcpp; + pshm_info_t *p; + pshm_info_t *tmp; + int error = 0; + + if (kauth_cred_issuser(kauth_cred_get()) == 0) { + return EPERM; + } + + PSHM_SUBSYS_LOCK(); + RB_FOREACH_SAFE(p, pshmhead, &pshm_head, tmp) { + error = pshm_unlink_internal(p); + if (error) { /* XXX: why give up on failure, should keep going */ + goto out; + } + } + assert(pshmnument == 0); - for (pcpp = &pshmhashtbl[pshmhash]; pcpp >= pshmhashtbl; pcpp--) { - while (pcp = pcpp->lh_first) - pshm_cache_delete(pcp); +out: + PSHM_SUBSYS_UNLOCK(); + + if (error) { + printf("%s: Error %d removing posix shm cache: %ld remain!\n", + __func__, error, pshmnument); } + return error; } -pshm_cache_delete(pcp) - struct pshmcache *pcp; +/* + * Utility to get the shared memory name from userspace and + * populate a pshm_info_t with it. If there's a problem + * reading the name or it's malformed, will return an error code. + */ +static int +pshm_get_name(pshm_info_t *pinfo, const user_addr_t user_addr) { -#if DIAGNOSTIC - if (pcp->pshm_hash.le_prev == 0) - panic("namecache purge le_prev"); - if (pcp->pshm_hash.le_next == pcp) - panic("namecache purge le_next"); -#endif /* DIAGNOSTIC */ - LIST_REMOVE(pcp, pshm_hash); - pcp->pshm_hash.le_prev = 0; - pshmnument--; -} + size_t bytes_copied = 0; + int error; -struct shm_open_args { - const char *name; - int oflag; - int mode; -}; + error = copyinstr(user_addr, &pinfo->pshm_hdr.pshm_name[0], PSHMNAMLEN + 1, &bytes_copied); + if (error != 0) { + return error; + } + assert(bytes_copied <= PSHMNAMLEN + 1); + assert(pinfo->pshm_hdr.pshm_name[bytes_copied - 1] == 0); + if (bytes_copied < 2) { /* 2: expect at least one character and terminating zero */ + return EINVAL; + } + AUDIT_ARG(text, &pinfo->pshm_hdr.pshm_name[0]); + return 0; +} +/* + * Process a shm_open() system call. + */ int -shm_open(p, uap, retval) - struct proc *p; - register struct shm_open_args *uap; - register_t *retval; +shm_open(proc_t p, struct shm_open_args *uap, int32_t *retval) { - register struct filedesc *fdp = p->p_fd; - register struct file *fp; - register struct vnode *vp; - int i; - struct file *nfp; - int type, indx, error; - struct pshmname nd; - struct pshminfo *pinfo; - extern struct fileops pshmops; - char * pnbuf; - char * nameptr; - char * cp; - size_t pathlen, plen; - int fmode ; - int cmode = uap->mode; - int incache = 0; - struct pshmnode * pnode = PSHMNODE_NULL; - struct pshmcache * pcache = PSHMCACHE_NULL; - int pinfo_alloc=0; - - - pinfo = PSHMINFO_NULL; - - MALLOC_ZONE(pnbuf, caddr_t, - MAXPATHLEN, M_NAMEI, M_WAITOK); - pathlen = MAXPATHLEN; - error = copyinstr(uap->name, pnbuf, - MAXPATHLEN, &pathlen); - if (error) { + int indx; + int error = 0; + pshm_info_t *pinfo = NULL; + pshm_info_t *new_pinfo = NULL; + pshmnode_t *new_pnode = NULL; + struct fileproc *fp = NULL; + int fmode; + int cmode = uap->mode; + bool incache = false; + bool have_label = false; + + AUDIT_ARG(fflags, uap->oflag); + AUDIT_ARG(mode, uap->mode); + + /* + * Allocate data structures we need. We parse the userspace name into + * a pshm_info_t, even when we don't need to O_CREAT. + */ + MALLOC(new_pinfo, pshm_info_t *, sizeof(pshm_info_t), M_SHM, M_WAITOK | M_ZERO); + if (new_pinfo == NULL) { + error = ENOSPC; goto bad; } - if (pathlen > PSHMNAMLEN) { - error = ENAMETOOLONG; + + /* + * Get and check the name. + */ + error = pshm_get_name(new_pinfo, uap->name); + if (error != 0) { goto bad; } - -#ifdef PSXSHM_NAME_RESTRICT - nameptr = pnbuf; - if (*nameptr == '/') { - while (*(nameptr++) == '/') { - plen--; - error = EINVAL; - goto bad; - } - } else { - error = EINVAL; + /* + * Attempt to allocate a new fp. If unsuccessful, the fp will be + * left unmodified (NULL). + */ + error = falloc(p, &fp, &indx, vfs_context_current()); + if (error) { goto bad; } -#endif /* PSXSHM_NAME_RESTRICT */ - plen = pathlen; - nameptr = pnbuf; - nd.pshm_nameptr = nameptr; - nd.pshm_namelen = plen; - nd. pshm_hash =0; + cmode &= ALLPERMS; - for (cp = nameptr, i=1; *cp != 0 && i <= plen; i++, cp++) { - nd.pshm_hash += (unsigned char)*cp * i; + fmode = FFLAGS(uap->oflag); + if ((fmode & (FREAD | FWRITE)) == 0) { + error = EINVAL; + goto bad; } - error = pshm_cache_search(&pinfo, &nd, &pcache); - - if (error == ENOENT) { - error = EINVAL; + /* + * Will need a new pnode for the file pointer + */ + MALLOC(new_pnode, pshmnode_t *, sizeof(pshmnode_t), M_SHM, M_WAITOK | M_ZERO); + if (new_pnode == NULL) { + error = ENOSPC; goto bad; + } + /* + * If creating a new segment, fill in its information. + * If we find a pre-exisitng one in cache lookup we'll just toss this one later. + */ + if (fmode & O_CREAT) { + new_pinfo->pshm_usecount = 2; /* one each for: file pointer, shm_unlink */ + new_pinfo->pshm_length = 0; + new_pinfo->pshm_mode = cmode; + new_pinfo->pshm_uid = kauth_getuid(); + new_pinfo->pshm_gid = kauth_getgid(); + SLIST_INIT(&new_pinfo->pshm_mobjs); +#if CONFIG_MACF + mac_posixshm_label_init(&new_pinfo->pshm_hdr); + have_label = true; + error = mac_posixshm_check_create(kauth_cred_get(), new_pinfo->pshm_hdr.pshm_name); + if (error) { + goto bad; + } +#endif } - if (!error) { - incache = 0; - } else - incache = 1; - fmode = FFLAGS(uap->oflag); - if ((fmode & (FREAD | FWRITE))==0) - return(EINVAL); - if (error = falloc(p, &nfp, &indx)) - return (error); - fp = nfp; + /* + * Look up the named shared memory segment in the cache, possibly adding + * it for O_CREAT. + */ + PSHM_SUBSYS_LOCK(); - cmode &= ALLPERMS; + pinfo = pshm_cache_search(new_pinfo); + if (pinfo != NULL) { + incache = true; - if (fmode & O_CREAT) { - if ((fmode & O_EXCL) && incache) { - /* shm obj exists and opened O_EXCL */ -#if notyet - if (pinfo->pshm_flags & PSHM_INDELETE) { - } -#endif - error = EEXIST; - goto bad1; - } - if (!incache) { - /* create a new one */ - pinfo = (struct pshminfo *)_MALLOC(sizeof(struct pshminfo), M_SHM, M_WAITOK); - bzero(pinfo, sizeof(struct pshminfo)); - pinfo_alloc = 1; - pinfo->pshm_flags = PSHM_DEFINED | PSHM_INCREATE; - pinfo->pshm_usecount = 1; - pinfo->pshm_mode = cmode; - pinfo->pshm_uid = p->p_ucred->cr_uid; - pinfo->pshm_gid = p->p_ucred->cr_gid; - } else { - /* already exists */ - if( pinfo->pshm_flags & PSHM_INDELETE) { - error = ENOENT; - goto bad1; - } - if (error = pshm_access(pinfo, fmode, p->p_ucred, p)) - goto bad1; - } + /* Get a new reference to go with the file pointer.*/ + error = pshm_ref(pinfo); + if (error) { + pinfo = NULL; /* so cleanup code doesn't deref */ + goto bad_locked; + } + + /* can't have pre-existing if O_EXCL */ + if ((fmode & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) { + error = EEXIST; + goto bad_locked; + } + + /* O_TRUNC is only valid while length is not yet set */ + if ((fmode & O_TRUNC) && + (pinfo->pshm_flags & (PSHM_ALLOCATING | PSHM_ALLOCATED))) { + error = EINVAL; + goto bad_locked; + } } else { - if (!incache) { - /* O_CREAT is not set and the shm obecj does not exist */ + incache = false; + + /* if it wasn't found, must have O_CREAT */ + if (!(fmode & O_CREAT)) { error = ENOENT; - goto bad1; + goto bad_locked; } - if( pinfo->pshm_flags & PSHM_INDELETE) { - error = ENOENT; - goto bad1; - } - if (error = pshm_access(pinfo, fmode, p->p_ucred, p)) - goto bad1; - } - if (fmode & O_TRUNC) { - error = EINVAL; - goto bad2; + + /* Add the new region to the cache. */ + pinfo = new_pinfo; + pshm_cache_add(pinfo); + new_pinfo = NULL; /* so that it doesn't get free'd */ } -#if DIAGNOSTIC - if (fmode & FWRITE) - pinfo->pshm_writecount++; - if (fmode & FREAD) - pinfo->pshm_readcount++; -#endif - pnode = (struct pshmnode *)_MALLOC(sizeof(struct pshmnode), M_SHM, M_WAITOK); - bzero(pnode, sizeof(struct pshmnode)); - if (!incache) { - if (error = pshm_cache_add(pinfo, &nd)) { - goto bad3; + PSHM_SUBSYS_UNLOCK(); + + /* + * Check we have permission to access any pre-existing segment + */ + if (incache) { + if (fmode & O_CREAT) { + AUDIT_ARG(posix_ipc_perm, pinfo->pshm_uid, + pinfo->pshm_gid, pinfo->pshm_mode); + } +#if CONFIG_MACF + if ((error = mac_posixshm_check_open(kauth_cred_get(), &pinfo->pshm_hdr, fmode))) { + goto bad; } +#endif + if ((error = pshm_access(pinfo, fmode, kauth_cred_get(), p))) { + goto bad; + } + } else { +#if CONFIG_MACF + mac_posixshm_label_associate(kauth_cred_get(), &pinfo->pshm_hdr, pinfo->pshm_hdr.pshm_name); +#endif } - pinfo->pshm_flags &= ~PSHM_INCREATE; - pinfo->pshm_usecount++; - pnode->pinfo = pinfo; + + proc_fdlock(p); fp->f_flag = fmode & FMASK; - fp->f_type = DTYPE_PSXSHM; fp->f_ops = &pshmops; - fp->f_data = (caddr_t)pnode; - *fdflags(p, indx) &= ~UF_RESERVED; + new_pnode->pinfo = pinfo; + fp->f_data = (caddr_t)new_pnode; + *fdflags(p, indx) |= UF_EXCLOSE; + procfdtbl_releasefd(p, indx, NULL); + fp_drop(p, indx, fp, 1); + proc_fdunlock(p); + *retval = indx; - _FREE_ZONE(pnbuf, MAXPATHLEN, M_NAMEI); - return (0); -bad3: - _FREE(pnode, M_SHM); - -bad2: - if (pinfo_alloc) - _FREE(pinfo, M_SHM); -bad1: - fdrelse(p, indx); - ffree(nfp); + error = 0; + goto done; + +bad_locked: + PSHM_SUBSYS_UNLOCK(); bad: - _FREE_ZONE(pnbuf, MAXPATHLEN, M_NAMEI); - return (error); + /* + * Drop any new reference to a pre-existing shared memory region. + */ + if (incache && pinfo != NULL) { + PSHM_SUBSYS_LOCK(); + pshm_deref(pinfo); + PSHM_SUBSYS_UNLOCK(); + } + + /* + * Delete any allocated unused data structures. + */ + if (new_pnode != NULL) { + FREE(new_pnode, M_SHM); + } + + if (fp != NULL) { + fp_free(p, indx, fp); + } + +done: + if (new_pinfo != NULL) { +#if CONFIG_MACF + if (have_label) { + mac_posixshm_label_destroy(&new_pinfo->pshm_hdr); + } +#endif + FREE(new_pinfo, M_SHM); + } + return error; } -/* ARGSUSED */ +/* + * The truncate call associates memory with shared memory region. It can + * only be succesfully done with a non-zero length once per shared memory region. + */ int -pshm_truncate(p, fp, fd, length, retval) - struct proc *p; - struct file *fp; - int fd; - off_t length; - register_t *retval; +pshm_truncate( + __unused proc_t p, + struct fileproc *fp, + __unused int fd, + off_t length, + __unused int32_t *retval) { - struct pshminfo * pinfo; - struct pshmnode * pnode ; - kern_return_t kret; - vm_offset_t user_addr; - void * mem_object; - vm_size_t size; + pshm_info_t *pinfo; + pshmnode_t *pnode; + kern_return_t kret; + mem_entry_name_port_t mem_object; + mach_vm_size_t total_size, alloc_size; + memory_object_size_t mosize; + pshm_mobj_t *pshmobj, *pshmobj_last; + vm_map_t user_map; + int error; + + user_map = current_map(); if (fp->f_type != DTYPE_PSXSHM) { - return(EINVAL); + return EINVAL; + } + +#if 0 + /* + * Can't enforce this yet, some third party tools don't + * specify O_RDWR like they ought to. See radar 48692182 + */ + /* ftruncate() requires write permission */ + if (!(fp->f_flag & FWRITE)) { + return EINVAL; } - +#endif - if (((pnode = (struct pshmnode *)fp->f_data)) == PSHMNODE_NULL ) - return(EINVAL); + PSHM_SUBSYS_LOCK(); + if (((pnode = (pshmnode_t *)fp->f_data)) == NULL) { + PSHM_SUBSYS_UNLOCK(); + return EINVAL; + } - if ((pinfo = pnode->pinfo) == PSHMINFO_NULL) - return(EINVAL); - if ((pinfo->pshm_flags & (PSHM_DEFINED | PSHM_ALLOCATED)) - != PSHM_DEFINED) { - return(EINVAL); + if ((pinfo = pnode->pinfo) == NULL) { + PSHM_SUBSYS_UNLOCK(); + return EINVAL; } - size = round_page_64(length); - kret = vm_allocate(current_map(), &user_addr, size, TRUE); - if (kret != KERN_SUCCESS) - goto out; + /* We only allow one ftruncate() per lifetime of the shm object. */ + if (pinfo->pshm_flags & (PSHM_ALLOCATING | PSHM_ALLOCATED)) { + PSHM_SUBSYS_UNLOCK(); + return EINVAL; + } - kret = mach_make_memory_entry (current_map(), &size, - user_addr, VM_PROT_DEFAULT, &mem_object, 0); +#if CONFIG_MACF + error = mac_posixshm_check_truncate(kauth_cred_get(), &pinfo->pshm_hdr, length); + if (error) { + PSHM_SUBSYS_UNLOCK(); + return error; + } +#endif + /* + * Grab an extra reference, so we can drop the lock while allocating and + * ensure the objects don't disappear. + */ + error = pshm_ref(pinfo); + if (error) { + PSHM_SUBSYS_UNLOCK(); + return error; + } - if (kret != KERN_SUCCESS) - goto out; - - vm_deallocate(current_map(), user_addr, size); + /* set ALLOCATING, so another truncate can't start */ + pinfo->pshm_flags |= PSHM_ALLOCATING; + total_size = vm_map_round_page(length, vm_map_page_mask(user_map)); - pinfo->pshm_flags &= ~PSHM_DEFINED; - pinfo->pshm_flags = PSHM_ALLOCATED; - pinfo->pshm_memobject = mem_object; - pinfo->pshm_length = size; - return(0); + pshmobj_last = NULL; + for (alloc_size = 0; alloc_size < total_size; alloc_size += mosize) { + PSHM_SUBSYS_UNLOCK(); + + /* get a memory object back some of the shared memory */ + mosize = MIN(total_size - alloc_size, ANON_MAX_SIZE); + kret = mach_make_memory_entry_64(VM_MAP_NULL, &mosize, 0, + MAP_MEM_NAMED_CREATE | VM_PROT_DEFAULT, &mem_object, 0); + + if (kret != KERN_SUCCESS) { + goto out; + } + + /* get a list entry to track the memory object */ + MALLOC(pshmobj, pshm_mobj_t *, sizeof(pshm_mobj_t), M_SHM, M_WAITOK); + if (pshmobj == NULL) { + kret = KERN_NO_SPACE; + mach_memory_entry_port_release(mem_object); + mem_object = NULL; + goto out; + } + + PSHM_SUBSYS_LOCK(); + + /* link in the new entry */ + pshmobj->pshmo_memobject = (void *)mem_object; + pshmobj->pshmo_size = mosize; + SLIST_NEXT(pshmobj, pshmo_next) = NULL; + + if (pshmobj_last == NULL) { + SLIST_FIRST(&pinfo->pshm_mobjs) = pshmobj; + } else { + SLIST_INSERT_AFTER(pshmobj_last, pshmobj, pshmo_next); + } + pshmobj_last = pshmobj; + } + + /* all done, change flags to ALLOCATED and return success */ + pinfo->pshm_flags |= PSHM_ALLOCATED; + pinfo->pshm_flags &= ~(PSHM_ALLOCATING); + pinfo->pshm_length = total_size; + pshm_deref(pinfo); /* drop the "allocating" reference */ + PSHM_SUBSYS_UNLOCK(); + return 0; out: + /* clean up any partially allocated objects */ + PSHM_SUBSYS_LOCK(); + while ((pshmobj = SLIST_FIRST(&pinfo->pshm_mobjs)) != NULL) { + SLIST_REMOVE_HEAD(&pinfo->pshm_mobjs, pshmo_next); + PSHM_SUBSYS_UNLOCK(); + mach_memory_entry_port_release(pshmobj->pshmo_memobject); + FREE(pshmobj, M_SHM); + PSHM_SUBSYS_LOCK(); + } + pinfo->pshm_flags &= ~PSHM_ALLOCATING; + pshm_deref(pinfo); /* drop the "allocating" reference */ + PSHM_SUBSYS_UNLOCK(); + switch (kret) { case KERN_INVALID_ADDRESS: case KERN_NO_SPACE: - return (ENOMEM); + return ENOMEM; case KERN_PROTECTION_FAILURE: - return (EACCES); + return EACCES; default: - return (EINVAL); - + return EINVAL; } } int -pshm_stat(pnode, sb) -struct pshmnode *pnode; -struct stat *sb; +pshm_stat(pshmnode_t *pnode, void *ub, int isstat64) { - struct pshminfo *pinfo; - - if ((pinfo = pnode->pinfo) == PSHMINFO_NULL) - return(EINVAL); - - bzero(sb, sizeof(struct stat)); - sb->st_mode = pinfo->pshm_mode; - sb->st_uid = pinfo->pshm_uid; - sb->st_gid = pinfo->pshm_gid; - sb->st_size = pinfo->pshm_length; - - return(0); + struct stat *sb = (struct stat *)0; /* warning avoidance ; protected by isstat64 */ + struct stat64 * sb64 = (struct stat64 *)0; /* warning avoidance ; protected by isstat64 */ + pshm_info_t *pinfo; +#if CONFIG_MACF + int error; +#endif + + PSHM_SUBSYS_LOCK(); + if ((pinfo = pnode->pinfo) == NULL) { + PSHM_SUBSYS_UNLOCK(); + return EINVAL; + } + +#if CONFIG_MACF + error = mac_posixshm_check_stat(kauth_cred_get(), &pinfo->pshm_hdr); + if (error) { + PSHM_SUBSYS_UNLOCK(); + return error; + } +#endif + + if (isstat64 != 0) { + sb64 = (struct stat64 *)ub; + bzero(sb64, sizeof(struct stat64)); + sb64->st_mode = pinfo->pshm_mode; + sb64->st_uid = pinfo->pshm_uid; + sb64->st_gid = pinfo->pshm_gid; + sb64->st_size = pinfo->pshm_length; + } else { + sb = (struct stat *)ub; + bzero(sb, sizeof(struct stat)); + sb->st_mode = pinfo->pshm_mode; + sb->st_uid = pinfo->pshm_uid; + sb->st_gid = pinfo->pshm_gid; + sb->st_size = pinfo->pshm_length; + } + PSHM_SUBSYS_UNLOCK(); + + return 0; } -int -pshm_access(struct pshminfo *pinfo, int mode, struct ucred *cred, struct proc *p) +/* + * Verify access to a shared memory region. + */ +static int +pshm_access(pshm_info_t *pinfo, int mode, kauth_cred_t cred, __unused proc_t p) { - mode_t mask; - register gid_t *gp; - int i, error; + int mode_req = ((mode & FREAD) ? S_IRUSR : 0) | + ((mode & FWRITE) ? S_IWUSR : 0); /* Otherwise, user id 0 always gets access. */ - if (cred->cr_uid == 0) - return (0); - - mask = 0; - - /* Otherwise, check the owner. */ - if (cred->cr_uid == pinfo->pshm_uid) { - if (mode & FREAD) - mask |= S_IRUSR; - if (mode & FWRITE) - mask |= S_IWUSR; - return ((pinfo->pshm_mode & mask) == mask ? 0 : EACCES); - } - - /* Otherwise, check the groups. */ - for (i = 0, gp = cred->cr_groups; i < cred->cr_ngroups; i++, gp++) - if (pinfo->pshm_gid == *gp) { - if (mode & FREAD) - mask |= S_IRGRP; - if (mode & FWRITE) - mask |= S_IWGRP; - return ((pinfo->pshm_mode & mask) == mask ? 0 : EACCES); - } + if (!suser(cred, NULL)) { + return 0; + } - /* Otherwise, check everyone else. */ - if (mode & FREAD) - mask |= S_IROTH; - if (mode & FWRITE) - mask |= S_IWOTH; - return ((pinfo->pshm_mode & mask) == mask ? 0 : EACCES); + return posix_cred_access(cred, pinfo->pshm_uid, pinfo->pshm_gid, pinfo->pshm_mode, mode_req); } -struct mmap_args { - caddr_t addr; - size_t len; - int prot; - int flags; - int fd; -#ifdef DOUBLE_ALIGN_PARAMS - long pad; -#endif - off_t pos; -}; - int -pshm_mmap(struct proc *p, struct mmap_args *uap, register_t *retval, struct file *fp, vm_size_t pageoff) +pshm_mmap( + __unused proc_t p, + struct mmap_args *uap, + user_addr_t *retval, + struct fileproc *fp, + off_t pageoff) { - vm_offset_t user_addr = uap->addr; - vm_size_t user_size = uap->len ; - int prot = uap->prot; - int flags = uap->flags; + vm_map_offset_t user_addr = (vm_map_offset_t)uap->addr; + vm_map_size_t user_size = (vm_map_size_t)uap->len; + vm_map_offset_t user_start_addr; + vm_map_size_t map_size, mapped_size; + int prot = uap->prot; + int max_prot = VM_PROT_DEFAULT; + int flags = uap->flags; vm_object_offset_t file_pos = (vm_object_offset_t)uap->pos; - int fd = uap->fd; - vm_map_t user_map; - boolean_t find_space,docow; - kern_return_t kret; - struct pshminfo * pinfo; - struct pshmnode * pnode; - void * mem_object; + vm_object_offset_t map_pos; + vm_map_t user_map; + int alloc_flags; + vm_map_kernel_flags_t vmk_flags; + bool docow; + kern_return_t kret = KERN_SUCCESS; + pshm_info_t *pinfo; + pshmnode_t *pnode; + pshm_mobj_t *pshmobj; + int error; + + if (user_size == 0) { + return 0; + } - if (user_size == 0) - return(0); + if (!(flags & MAP_SHARED)) { + return EINVAL; + } - if ((flags & MAP_SHARED) == 0) - return(EINVAL); + /* Can't allow write permission if the shm_open() didn't allow them. */ + if (!(fp->f_flag & FWRITE)) { + if (prot & VM_PROT_WRITE) { + return EPERM; + } + max_prot &= ~VM_PROT_WRITE; + } + PSHM_SUBSYS_LOCK(); + pnode = (pshmnode_t *)fp->f_data; + if (pnode == NULL) { + PSHM_SUBSYS_UNLOCK(); + return EINVAL; + } - if ((prot & PROT_WRITE) && ((fp->f_flag & FWRITE) == 0)) { - return(EPERM); + pinfo = pnode->pinfo; + if (pinfo == NULL) { + PSHM_SUBSYS_UNLOCK(); + return EINVAL; } - if (((pnode = (struct pshmnode *)fp->f_data)) == PSHMNODE_NULL ) - return(EINVAL); + if (!(pinfo->pshm_flags & PSHM_ALLOCATED)) { + PSHM_SUBSYS_UNLOCK(); + return EINVAL; + } - if ((pinfo = pnode->pinfo) == PSHMINFO_NULL) - return(EINVAL); + if (user_size > (vm_map_size_t)pinfo->pshm_length) { + PSHM_SUBSYS_UNLOCK(); + return EINVAL; + } - if ((pinfo->pshm_flags & PSHM_ALLOCATED) != PSHM_ALLOCATED) { - return(EINVAL); + vm_map_size_t end_pos = 0; + if (os_add_overflow(user_size, file_pos, &end_pos)) { + PSHM_SUBSYS_UNLOCK(); + return EINVAL; + } + if (end_pos > (vm_map_size_t)pinfo->pshm_length) { + PSHM_SUBSYS_UNLOCK(); + return EINVAL; } - if (user_size > pinfo->pshm_length) { - return(EINVAL); + + pshmobj = SLIST_FIRST(&pinfo->pshm_mobjs); + if (pshmobj == NULL) { + PSHM_SUBSYS_UNLOCK(); + return EINVAL; } - if ((off_t)user_size + file_pos > pinfo->pshm_length) { - return(EINVAL); + +#if CONFIG_MACF + error = mac_posixshm_check_mmap(kauth_cred_get(), &pinfo->pshm_hdr, prot, flags); + if (error) { + PSHM_SUBSYS_UNLOCK(); + return error; } - if ((mem_object = pinfo->pshm_memobject) == NULL) { - return(EINVAL); +#endif + /* Grab an extra reference, so we can drop the lock while mapping. */ + error = pshm_ref(pinfo); + if (error) { + PSHM_SUBSYS_UNLOCK(); + return error; } - + PSHM_SUBSYS_UNLOCK(); user_map = current_map(); - if ((flags & MAP_FIXED) == 0) { - find_space = TRUE; - user_addr = round_page_32(user_addr); + if (!(flags & MAP_FIXED)) { + alloc_flags = VM_FLAGS_ANYWHERE; + user_addr = vm_map_round_page(user_addr, + vm_map_page_mask(user_map)); } else { - if (user_addr != trunc_page_32(user_addr)) - return (EINVAL); - find_space = FALSE; - (void) vm_deallocate(user_map, user_addr, user_size); + if (user_addr != vm_map_round_page(user_addr, + vm_map_page_mask(user_map))) { + error = EINVAL; + goto out_deref; + } + + /* + * We do not get rid of the existing mappings here because + * it wouldn't be atomic (see comment in mmap()). We let + * Mach VM know that we want it to replace any existing + * mapping with the new one. + */ + alloc_flags = VM_FLAGS_FIXED | VM_FLAGS_OVERWRITE; + } + docow = false; + + mapped_size = 0; + vmk_flags = VM_MAP_KERNEL_FLAGS_NONE; + /* reserve the entire space first... */ + kret = vm_map_enter_mem_object(user_map, + &user_addr, + user_size, + 0, + alloc_flags, + vmk_flags, + VM_KERN_MEMORY_NONE, + IPC_PORT_NULL, + 0, + false, + VM_PROT_NONE, + VM_PROT_NONE, + VM_INHERIT_NONE); + user_start_addr = user_addr; + if (kret != KERN_SUCCESS) { + goto out_deref; } - docow = FALSE; - kret = vm_map_64(user_map, &user_addr, user_size, - 0, find_space, pinfo->pshm_memobject, file_pos, docow, - prot, VM_PROT_DEFAULT, - VM_INHERIT_DEFAULT); + /* Now overwrite with the real mappings. */ + for (map_pos = 0, pshmobj = SLIST_FIRST(&pinfo->pshm_mobjs); + user_size != 0; + map_pos += pshmobj->pshmo_size, pshmobj = SLIST_NEXT(pshmobj, pshmo_next)) { + if (pshmobj == NULL) { + /* nothing there to map !? */ + goto out_deref; + } + if (file_pos >= map_pos + pshmobj->pshmo_size) { + continue; + } + map_size = pshmobj->pshmo_size - (file_pos - map_pos); + if (map_size > user_size) { + map_size = user_size; + } + vmk_flags = VM_MAP_KERNEL_FLAGS_NONE; + kret = vm_map_enter_mem_object( + user_map, + &user_addr, + map_size, + 0, + VM_FLAGS_FIXED | VM_FLAGS_OVERWRITE, + vmk_flags, + VM_KERN_MEMORY_NONE, + pshmobj->pshmo_memobject, + file_pos - map_pos, + docow, + prot, + max_prot, + VM_INHERIT_SHARE); + if (kret != KERN_SUCCESS) { + goto out_deref; + } - if (kret != KERN_SUCCESS) - goto out; - kret = vm_inherit(user_map, user_addr, user_size, - VM_INHERIT_SHARE); - if (kret != KERN_SUCCESS) { - (void) vm_deallocate(user_map, user_addr, user_size); - goto out; + user_addr += map_size; + user_size -= map_size; + mapped_size += map_size; + file_pos += map_size; } - pnode->mapp_addr = user_addr; - pnode->map_size = user_size; + + PSHM_SUBSYS_LOCK(); + pnode->mapp_addr = user_start_addr; pinfo->pshm_flags |= (PSHM_MAPPED | PSHM_INUSE); -out: + PSHM_SUBSYS_UNLOCK(); +out_deref: + PSHM_SUBSYS_LOCK(); + pshm_deref(pinfo); /* drop the extra reference we had while mapping. */ + PSHM_SUBSYS_UNLOCK(); + if (kret != KERN_SUCCESS) { + if (mapped_size != 0) { + (void) mach_vm_deallocate(current_map(), + user_start_addr, + mapped_size); + } + } + switch (kret) { case KERN_SUCCESS: - *fdflags(p, fd) |= UF_MAPPED; - *retval = (register_t)(user_addr + pageoff); - return (0); + *retval = (user_start_addr + pageoff); + return 0; case KERN_INVALID_ADDRESS: case KERN_NO_SPACE: - return (ENOMEM); + return ENOMEM; case KERN_PROTECTION_FAILURE: - return (EACCES); + return EACCES; default: - return (EINVAL); + return EINVAL; } - } -struct shm_unlink_args { - const char *name; -}; - -int -shm_unlink(p, uap, retval) - struct proc *p; - register struct shm_unlink_args *uap; - register_t *retval; +/* + * Remove a shared memory region name from the name lookup cache. + */ +static int +pshm_unlink_internal(pshm_info_t *pinfo) { - register struct filedesc *fdp = p->p_fd; - register struct file *fp; - int flags, i; - int error=0; - struct pshmname nd; - struct pshminfo *pinfo; - extern struct fileops pshmops; - char * pnbuf; - char * nameptr; - char * cp; - size_t pathlen, plen; - int fmode, cmode ; - int incache = 0; - struct pshmnode * pnode = PSHMNODE_NULL; - struct pshmcache *pcache = PSHMCACHE_NULL; - kern_return_t kret; - - pinfo = PSHMINFO_NULL; - - MALLOC_ZONE(pnbuf, caddr_t, - MAXPATHLEN, M_NAMEI, M_WAITOK); - pathlen = MAXPATHLEN; - error = copyinstr(uap->name, pnbuf, - MAXPATHLEN, &pathlen); - if (error) { - goto bad; - } - if (pathlen > PSHMNAMLEN) { - error = ENAMETOOLONG; - goto bad; - } + PSHM_SUBSYS_ASSERT_HELD(); - -#ifdef PSXSHM_NAME_RESTRICT - nameptr = pnbuf; - if (*nameptr == '/') { - while (*(nameptr++) == '/') { - plen--; - error = EINVAL; - goto bad; - } - } else { - error = EINVAL; - goto bad; + if (pinfo == NULL) { + return EINVAL; } -#endif /* PSXSHM_NAME_RESTRICT */ - plen = pathlen; - nameptr = pnbuf; - nd.pshm_nameptr = nameptr; - nd.pshm_namelen = plen; - nd. pshm_hash =0; + pshm_cache_delete(pinfo); + pinfo->pshm_flags |= PSHM_REMOVED; - for (cp = nameptr, i=1; *cp != 0 && i <= plen; i++, cp++) { - nd.pshm_hash += (unsigned char)*cp * i; - } + /* release the "unlink" reference */ + pshm_deref(pinfo); - error = pshm_cache_search(&pinfo, &nd, &pcache); + return 0; +} - if (error == ENOENT) { - error = EINVAL; - goto bad; +int +shm_unlink(proc_t p, struct shm_unlink_args *uap, __unused int32_t *retval) +{ + int error = 0; + pshm_info_t *pinfo = NULL; + pshm_info_t *name_pinfo = NULL; + /* + * Get the name from user args. + */ + MALLOC(name_pinfo, pshm_info_t *, sizeof(pshm_info_t), M_SHM, M_WAITOK | M_ZERO); + if (name_pinfo == NULL) { + error = ENOSPC; + goto bad; } - if (!error) { + error = pshm_get_name(name_pinfo, uap->name); + if (error != 0) { error = EINVAL; goto bad; - } else - incache = 1; + } + + PSHM_SUBSYS_LOCK(); + pinfo = pshm_cache_search(name_pinfo); - if ((pinfo->pshm_flags & (PSHM_DEFINED | PSHM_ALLOCATED))==0) { - return (EINVAL); + if (pinfo == NULL) { + error = ENOENT; + goto bad_unlock; } - if (pinfo->pshm_flags & PSHM_INDELETE) { - error = 0; - goto bad; +#if CONFIG_MACF + error = mac_posixshm_check_unlink(kauth_cred_get(), &pinfo->pshm_hdr, name_pinfo->pshm_hdr.pshm_name); + if (error) { + goto bad_unlock; } +#endif - if (pinfo->pshm_memobject == NULL) { - error = EINVAL; - goto bad; + AUDIT_ARG(posix_ipc_perm, pinfo->pshm_uid, pinfo->pshm_gid, pinfo->pshm_mode); + + /* + * Following file semantics, unlink should normally be allowed + * for users with write permission only. We also allow the creator + * of a segment to be able to delete, even w/o write permission. + * That's because there's no equivalent of write permission for the + * directory containing a file. + */ + error = pshm_access(pinfo, FWRITE, kauth_cred_get(), p); + if (error != 0 && pinfo->pshm_uid != kauth_getuid()) { + goto bad_unlock; } - pinfo->pshm_flags |= PSHM_INDELETE; - pinfo->pshm_usecount--; - kret = mach_destroy_memory_entry(pinfo->pshm_memobject); - pshm_cache_delete(pcache); - _FREE(pcache, M_SHM); - pinfo->pshm_flags |= PSHM_REMOVED; - error = 0; + error = pshm_unlink_internal(pinfo); +bad_unlock: + PSHM_SUBSYS_UNLOCK(); bad: - _FREE_ZONE(pnbuf, MAXPATHLEN, M_NAMEI); - return (error); -out: - switch (kret) { - case KERN_INVALID_ADDRESS: - case KERN_PROTECTION_FAILURE: - return (EACCES); - default: - return (EINVAL); + if (name_pinfo != NULL) { + FREE(name_pinfo, M_SHM); } + return error; } -int -pshm_close(pnode, flags, cred, p) - register struct pshmnode *pnode; - int flags; - struct ucred *cred; - struct proc *p; +/* + * Add a new reference to a shared memory region. + * Fails if we will overflow the reference counter. + */ +static int +pshm_ref(pshm_info_t *pinfo) { - int error=0; - kern_return_t kret; - register struct pshminfo *pinfo; + PSHM_SUBSYS_ASSERT_HELD(); - if ((pinfo = pnode->pinfo) == PSHMINFO_NULL) - return(EINVAL); - - if ((pinfo->pshm_flags & PSHM_ALLOCATED) != PSHM_ALLOCATED) { - return(EINVAL); + if (pinfo->pshm_usecount == PSHM_MAXCOUNT) { + return EMFILE; } -#if DIAGNOSTIC - if(!pinfo->pshm_usecount) { - kprintf("negative usecount in pshm_close\n"); + pinfo->pshm_usecount++; + return 0; +} + +/* + * Dereference a pshm_info_t. Delete the region if + * this was the final reference count. + */ +static void +pshm_deref(pshm_info_t *pinfo) +{ + pshm_mobj_t *pshmobj; + + PSHM_SUBSYS_ASSERT_HELD(); + if (pinfo->pshm_usecount == 0) { + panic("negative usecount in pshm_close\n"); } -#endif /* DIAGNOSTIC */ - pinfo->pshm_usecount--; + pinfo->pshm_usecount--; /* release this fd's reference */ + + if (pinfo->pshm_usecount == 0) { +#if CONFIG_MACF + mac_posixshm_label_destroy(&pinfo->pshm_hdr); +#endif + PSHM_SUBSYS_UNLOCK(); + + /* + * Release references to any backing objects. + */ + while ((pshmobj = SLIST_FIRST(&pinfo->pshm_mobjs)) != NULL) { + SLIST_REMOVE_HEAD(&pinfo->pshm_mobjs, pshmo_next); + mach_memory_entry_port_release(pshmobj->pshmo_memobject); + FREE(pshmobj, M_SHM); + } + + /* free the pinfo itself */ + FREE(pinfo, M_SHM); - if ((pinfo->pshm_flags & PSHM_REMOVED) && !pinfo->pshm_usecount) { - _FREE(pinfo,M_SHM); + PSHM_SUBSYS_LOCK(); } - _FREE(pnode, M_SHM); - return (error); } +/* vfs_context_t passed to match prototype for struct fileops */ static int -pshm_closefile(fp, p) - struct file *fp; - struct proc *p; +pshm_closefile(struct fileglob *fg, __unused vfs_context_t ctx) { - return (pshm_close(((struct pshmnode *)fp->f_data), fp->f_flag, - fp->f_cred, p)); -} + int error = EINVAL; + pshmnode_t *pnode; -static int -pshm_read(fp, uio, cred, flags, p) - struct file *fp; - struct uio *uio; - struct ucred *cred; - int flags; - struct proc *p; -{ - return(EOPNOTSUPP); -} + PSHM_SUBSYS_LOCK(); -static int -pshm_write(fp, uio, cred, flags, p) - struct file *fp; - struct uio *uio; - struct ucred *cred; - int flags; - struct proc *p; -{ - return(EOPNOTSUPP); + pnode = (pshmnode_t *)fg->fg_data; + if (pnode != NULL) { + error = 0; + fg->fg_data = NULL; /* set fg_data to NULL to avoid racing close()es */ + if (pnode->pinfo != NULL) { + pshm_deref(pnode->pinfo); + pnode->pinfo = NULL; + } + } + + PSHM_SUBSYS_UNLOCK(); + if (pnode != NULL) { + FREE(pnode, M_SHM); + } + + return error; } -static int -pshm_ioctl(fp, com, data, p) - struct file *fp; - u_long com; - caddr_t data; - struct proc *p; +int +fill_pshminfo(pshmnode_t * pshm, struct pshm_info * info) { - return(EOPNOTSUPP); + pshm_info_t *pinfo; + struct vinfo_stat *sb; + + PSHM_SUBSYS_LOCK(); + if ((pinfo = pshm->pinfo) == NULL) { + PSHM_SUBSYS_UNLOCK(); + return EINVAL; + } + + sb = &info->pshm_stat; + + bzero(sb, sizeof(struct vinfo_stat)); + sb->vst_mode = pinfo->pshm_mode; + sb->vst_uid = pinfo->pshm_uid; + sb->vst_gid = pinfo->pshm_gid; + sb->vst_size = pinfo->pshm_length; + + info->pshm_mappaddr = pshm->mapp_addr; + bcopy(&pinfo->pshm_hdr.pshm_name[0], &info->pshm_name[0], PSHMNAMLEN + 1); + + PSHM_SUBSYS_UNLOCK(); + return 0; } -static int -pshm_select(fp, which, wql, p) - struct file *fp; - int which; - void *wql; - struct proc *p; +#if CONFIG_MACF +void +pshm_label_associate(struct fileproc *fp, struct vnode *vp, vfs_context_t ctx) { - return(EOPNOTSUPP); + pshmnode_t *pnode; + pshm_info_t *pshm; + + PSHM_SUBSYS_LOCK(); + pnode = (pshmnode_t *)fp->f_data; + if (pnode != NULL) { + pshm = pnode->pinfo; + if (pshm != NULL) { + mac_posixshm_vnode_label_associate( + vfs_context_ucred(ctx), &pshm->pshm_hdr, pshm->pshm_label, + vp, vp->v_label); + } + } + PSHM_SUBSYS_UNLOCK(); } +#endif