diff options
Diffstat (limited to 'winsup/cygserver/shm.cc')
| -rw-r--r-- | winsup/cygserver/shm.cc | 665 |
1 files changed, 0 insertions, 665 deletions
diff --git a/winsup/cygserver/shm.cc b/winsup/cygserver/shm.cc deleted file mode 100644 index dc5632355..000000000 --- a/winsup/cygserver/shm.cc +++ /dev/null @@ -1,665 +0,0 @@ -/* cygserver_shm.cc: Single unix specification IPC interface for Cygwin - -Copyright 2001, 2002 Red Hat, Inc. - -Originally written by Robert Collins <robert.collins@hotmail.com> - -This file is part of Cygwin. - -This software is a copyrighted work licensed under the terms of the -Cygwin license. Please consult the file "CYGWIN_LICENSE" for -details. */ - -#ifdef __OUTSIDE_CYGWIN__ -#undef __INSIDE_CYGWIN__ -#else -#include "winsup.h" -#endif - -#ifndef __INSIDE_CYGWIN__ -#define DEBUG 0 -#define system_printf printf -#define debug_printf if (DEBUG) printf -#define api_fatal printf -#include <stdio.h> -#include <windows.h> -#endif - -#include <sys/stat.h> -#include <errno.h> -#include "cygerrno.h" -#include <unistd.h> -#include "security.h" -//#include "fhandler.h" -//#include "dtable.h" -//#include "cygheap.h" -#include <stdio.h> -//#include "thread.h" -#ifndef __INSIDE_CYGWIN__ -#define __INSIDE_CYGWIN__ -#include "cygwin_shm.h" -#undef __INSIDE_CYGWIN__ -#else -#include "cygwin_shm.h" -#endif -//#include "perprocess.h" -#include <threaded_queue.h> -#include <cygwin/cygserver_process.h> -#include "cygserver_shm.h" - -// FIXME IS THIS CORRECT -/* Implementation notes: We use two shared memory regions per key: - * One for the control structure, and one for the shared memory. - * While this has a higher overhead tham a single shared area, - * It allows more flexability. As the entire code is transparent to the user - * We can merge these in the future should it be needed. - * Also, IPC_PRIVATE keys create unique mappings each time. The shm_ids just - * keep monotonically incrementing - system wide. - */ -size_t -getsystemallocgranularity () -{ - SYSTEM_INFO sysinfo; - static size_t buffer_offset = 0; - if (buffer_offset) - return buffer_offset; - GetSystemInfo (&sysinfo); - buffer_offset = sysinfo.dwAllocationGranularity; - return buffer_offset; -} - - -client_request_shm::client_request_shm ():client_request (CYGSERVER_REQUEST_SHM_GET, - sizeof (parameters)) -{ - buffer = (char *) ¶meters; -} - -/* FIXME: If building on a 64-bit compiler, the address->int typecast will fail. - * Solution: manually calculate the next id value - */ - -#if 0 -extern -"C" void * -shmat (int shmid, const void *shmaddr, int parameters.in.shmflg) -{ - class shmid_ds * - shm = (class shmid_ds *) - shmid; //FIXME: verifyable object test - - if (shmaddr) - { - //FIXME: requested base address ?! - set_errno (EINVAL); - return (void *) -1; - } - - void * - rv = - MapViewOfFile (shm->attachmap, - - - (parameters.in.shmflg & SHM_RDONLY) ? - FILE_MAP_READ : FILE_MAP_WRITE, 0, - 0, 0); - - if (!rv) - { - //FIXME: translate GetLastError() - set_errno (EACCES); - return (void *) -1; - } - -/* FIXME: this needs to be globally protected to prevent a mismatch betwen - * attach count and attachees list - */ - - InterlockedIncrement (&shm->shm_nattch); - _shmattach * - attachnode = - new - _shmattach; - - attachnode->data = rv; - attachnode->next = - (_shmattach *) InterlockedExchangePointer ((LONG *) & shm->attachhead, - (long int) attachnode); - return rv; -} -#endif - -/* FIXME: evaluate getuid() and getgid() against the requested mode. Then - * choose PAGE_READWRITE | PAGE_READONLY and FILE_MAP_WRITE | FILE_MAP_READ - * appropriately - */ - -/* Test result from openbsd: shm ids are persistent cross process if a handle is left - * open. This could lead to resource starvation: we're not copying that behaviour - * unless we have to. (It will involve acygwin1.dll gloal shared list :[ ). - */ -/* FIXME: shmid should be a verifyable object - */ - -/* FIXME: on NT we should check everything against the SD. On 95 we just emulate. - */ - -extern GENERIC_MAPPING - access_mapping; - -extern int -check_and_dup_handle (HANDLE from_process, HANDLE to_process, - HANDLE from_process_token, - DWORD access, - HANDLE from_handle, - HANDLE * to_handle_ptr, BOOL bInheritHandle); - -//FIXME: where should this live -static shmnode * - shm_head = - NULL; -//FIXME: ditto. -static shmnode * - deleted_head = NULL; -/* must be long for InterlockedIncrement */ -static long - new_id = - 0; -static long - new_private_key = - 0; - -static void -delete_shmnode (shmnode **nodeptr) -{ - shmnode *node = *nodeptr; - - // remove from the list - if (node == shm_head) - shm_head = shm_head->next; - else - { - shmnode *tempnode = shm_head; - while (tempnode && tempnode->next != node) - tempnode = tempnode->next; - if (tempnode) - tempnode->next = node->next; - // else log the unexpected ! - } - - // release the shared data view - UnmapViewOfFile (node->shmds->mapptr); - delete node->shmds; - CloseHandle (node->filemap); - CloseHandle (node->attachmap); - - // free the memory - delete node; - nodeptr = NULL; -} - -void -client_request_shm::serve (transport_layer_base * conn, process_cache * cache) -{ -// DWORD sd_size = 4096; -// char sd_buf[4096]; - PSECURITY_DESCRIPTOR psd = (PSECURITY_DESCRIPTOR) parameters.in.sd_buf; -// /* create a sd for our open requests based on shmflag & 0x01ff */ -// psd = alloc_sd (getuid (), getgid (), cygheap->user.logsrv (), -// parameters.in.shmflg & 0x01ff, psd, &sd_size); - - HANDLE from_process_handle = NULL; - HANDLE token_handle = NULL; - DWORD rc; - - from_process_handle = cache->process (parameters.in.pid)->handle (); - /* possible TODO: reduce the access on the handle before we use it */ - /* Note that unless we do this, we don't need to call CloseHandle - it's kept open - * by the process cache until the process terminates. - * We may need a refcount on the cache however... - */ - if (!from_process_handle) - { - debug_printf ("error opening process (%lu)\n", GetLastError ()); - header.error_code = EACCES; - return; - } - - conn->impersonate_client (); - - rc = OpenThreadToken (GetCurrentThread (), - TOKEN_QUERY, TRUE, &token_handle); - - conn->revert_to_self (); - - if (!rc) - { - debug_printf ("error opening thread token (%lu)\n", GetLastError ()); - header.error_code = EACCES; - CloseHandle (from_process_handle); - return; - } - - - /* we trust the clients request - we will be doing it as them, and - * the worst they can do is open their own permissions - */ - - - SECURITY_ATTRIBUTES sa; - sa.nLength = sizeof (sa); - sa.lpSecurityDescriptor = psd; - sa.bInheritHandle = TRUE; /* the memory structures inherit ok */ - - char *shmname = NULL, *shmaname = NULL; - char stringbuf[29], stringbuf1[29]; - - /* TODO: make this code block a function! */ - if (parameters.in.type == SHM_REATTACH) - { - /* just find and fill out the existing shm_id */ - shmnode *tempnode = shm_head; - while (tempnode) - { - if (tempnode->shm_id == parameters.in.shm_id) - { - parameters.out.shm_id = tempnode->shm_id; - parameters.out.key = tempnode->key; - if (check_and_dup_handle - (GetCurrentProcess (), from_process_handle, token_handle, - DUPLICATE_SAME_ACCESS, tempnode->filemap, - ¶meters.out.filemap, TRUE) != 0) - { - debug_printf ("error duplicating filemap handle (%lu)\n", - GetLastError ()); - header.error_code = EACCES; - } - if (check_and_dup_handle - (GetCurrentProcess (), from_process_handle, token_handle, - DUPLICATE_SAME_ACCESS, tempnode->attachmap, - ¶meters.out.attachmap, TRUE) != 0) - { - debug_printf ("error duplicating attachmap handle (%lu)\n", - GetLastError ()); - header.error_code = EACCES; - } - CloseHandle (token_handle); - return; - } - tempnode = tempnode->next; - } - header.error_code = EINVAL; - CloseHandle (token_handle); - return; - } - - /* someone attached */ - /* someone can send shm_id's they don't have and currently we will increment those - * attach counts. If someone wants to fix that, please go ahead. - * The problem is that shm_get has nothing to do with the ability to attach. Attach - * requires a permission check, which we get the OS to do in MapViewOfFile. - */ - if (parameters.in.type == SHM_ATTACH) - { - shmnode *tempnode = shm_head; - while (tempnode) - { - if (tempnode->shm_id == parameters.in.shm_id) - { - InterlockedIncrement (&tempnode->shmds->shm_nattch); - header.error_code = 0; - CloseHandle (token_handle); - return; - } - tempnode = tempnode->next; - } - header.error_code = EINVAL; - CloseHandle (token_handle); - return; - } - - /* Someone detached */ - if (parameters.in.type == SHM_DETACH) - { - shmnode *tempnode = shm_head; - while (tempnode) - { - if (tempnode->shm_id == parameters.in.shm_id) - { - InterlockedDecrement (&tempnode->shmds->shm_nattch); - header.error_code = 0; - CloseHandle (token_handle); - return; - } - tempnode = tempnode->next; - } - header.error_code = EINVAL; - CloseHandle (token_handle); - return; - } - - /* Someone wants the ID removed. */ - if (parameters.in.type == SHM_DEL) - { - shmnode **tempnode = &shm_head; - while (*tempnode) - { - if ((*tempnode)->shm_id == parameters.in.shm_id) - { - // unlink from the accessible node list - shmnode *temp2 = *tempnode; - *tempnode = temp2->next; - // link into the deleted list - temp2->next = deleted_head; - deleted_head = temp2; - - // FIXME: when/where do we delete the handles? - if (temp2->shmds->shm_nattch) - { - // FIXME: add to a pending queue? - } - else - { - delete_shmnode (&temp2); - } - - header.error_code = 0; - CloseHandle (token_handle); - return; - } - tempnode = &(*tempnode)->next; - } - header.error_code = EINVAL; - CloseHandle (token_handle); - return; - } - - - if (parameters.in.type == SHM_CREATE) - { - /* FIXME: enter the checking for existing keys mutex. This mutex _must_ be system wide - * to prevent races on shmget. - */ - - if (parameters.in.key == IPC_PRIVATE) - { - /* create the mapping name (CYGWINSHMKPRIVATE_0x01234567 */ - /* The K refers to Key, the actual mapped area has D */ - long private_key = (int) InterlockedIncrement (&new_private_key); - snprintf (stringbuf, 29, "CYGWINSHMKPRIVATE_0x%0x", private_key); - shmname = stringbuf; - snprintf (stringbuf1, 29, "CYGWINSHMDPRIVATE_0x%0x", private_key); - shmaname = stringbuf1; - } - else - { - /* create the mapping name (CYGWINSHMK0x0123456789abcdef */ - /* The K refers to Key, the actual mapped area has D */ - - snprintf (stringbuf, 29, "CYGWINSHMK0x%0qx", parameters.in.key); - shmname = stringbuf; - snprintf (stringbuf1, 29, "CYGWINSHMD0x%0qx", parameters.in.key); - shmaname = stringbuf1; - debug_printf ("system id strings are \n%s\n%s\n", shmname, - shmaname); - debug_printf ("key input value is 0x%0qx\n", parameters.in.key); - } - - /* attempt to open the key */ - - /* get an existing key */ - /* On unix the same shmid identifier is returned on multiple calls to shm_get - * with the same key and size. Different modes is a ?. - */ - - - - /* walk the list of known keys and return the id if found. remember, we are - * authoritative... - */ - - shmnode *tempnode = shm_head; - while (tempnode) - { - if (tempnode->key == parameters.in.key - && parameters.in.key != IPC_PRIVATE) - { - // FIXME: free the mutex - if (parameters.in.size - && tempnode->shmds->shm_segsz < parameters.in.size) - { - header.error_code = EINVAL; - CloseHandle (token_handle); - return; - } - /* FIXME: can the same process call this twice without error ? test - * on unix - */ - if ((parameters.in.shmflg & IPC_CREAT) - && (parameters.in.shmflg & IPC_EXCL)) - { - header.error_code = EEXIST; - debug_printf - ("attempt to exclusively create already created shm_area with key 0x%0qx\n", - parameters.in.key); - // FIXME: free the mutex - CloseHandle (token_handle); - return; - } - // FIXME: do we need to other tests of the requested mode with the - // tempnode->shm_id mode ? testcase on unix needed. - // FIXME how do we do the security test? or - // do we wait for shmat to bother with that? - /* One possibly solution: impersonate the client, and then test we can - * reopen the area. In fact we'll probably have to do that to get - * handles back to them, alternatively just tell them the id, and then - * let them attempt the open. - */ - parameters.out.shm_id = tempnode->shm_id; - if (check_and_dup_handle - (GetCurrentProcess (), from_process_handle, token_handle, - DUPLICATE_SAME_ACCESS, tempnode->filemap, - ¶meters.out.filemap, TRUE) != 0) - { - printf ("error duplicating filemap handle (%lu)\n", - GetLastError ()); - header.error_code = EACCES; -/*mutex*/ - CloseHandle (token_handle); - return; - } - if (check_and_dup_handle - (GetCurrentProcess (), from_process_handle, token_handle, - DUPLICATE_SAME_ACCESS, tempnode->attachmap, - ¶meters.out.attachmap, TRUE) != 0) - { - printf ("error duplicating attachmap handle (%lu)\n", - GetLastError ()); - header.error_code = EACCES; -/*mutex*/ - CloseHandle (token_handle); - return; - } - - CloseHandle (token_handle); - return; - } - tempnode = tempnode->next; - } - /* couldn't find a currently open shm area. */ - - /* create one */ - /* do this as the client */ - conn->impersonate_client (); - /* This may need sh_none... it's only a control structure */ - HANDLE filemap = CreateFileMapping (INVALID_HANDLE_VALUE, // system pagefile. - &sa, - PAGE_READWRITE, // protection - 0x00000000, - getsystemallocgranularity (), - shmname // object name - ); - int lasterr = GetLastError (); - conn->revert_to_self (); - - if (filemap == NULL) - { - /* We failed to open the filemapping ? */ - system_printf ("failed to open file mapping: %lu\n", - GetLastError ()); - // free the mutex - // we can assume that it exists, and that it was an access problem. - header.error_code = EACCES; - CloseHandle (token_handle); - return; - } - - /* successfully opened the control region mapping */ - /* did we create it ? */ - int oldmapping = lasterr == ERROR_ALREADY_EXISTS; - if (oldmapping) - { - /* should never happen - we are the global daemon! */ -#if 0 - if ((parameters.in.shmflg & IPC_CREAT) - && (parameters.in.shmflg & IPC_EXCL)) -#endif - { - /* FIXME free mutex */ - CloseHandle (filemap); - header.error_code = EEXIST; - CloseHandle (token_handle); - return; - } - } - - /* we created a new mapping */ - if (parameters.in.key != IPC_PRIVATE && - (parameters.in.shmflg & IPC_CREAT) == 0) - { - CloseHandle (filemap); - /* FIXME free mutex */ - header.error_code = ENOENT; - CloseHandle (token_handle); - return; - } - - conn->impersonate_client (); - void *mapptr = MapViewOfFile (filemap, FILE_MAP_WRITE, 0, 0, 0); - conn->revert_to_self (); - - if (!mapptr) - { - CloseHandle (filemap); - //FIXME: close filemap and free the mutex - /* we couldn't access the mapped area with the requested permissions */ - header.error_code = EACCES; - CloseHandle (token_handle); - return; - } - - conn->impersonate_client (); - /* Now get the user data */ - HANDLE attachmap = CreateFileMapping (INVALID_HANDLE_VALUE, // system pagefile - &sa, - PAGE_READWRITE, // protection (FIXME) - 0x00000000, - parameters.in.size + - parameters.in.size % - getsystemallocgranularity (), - shmaname // object name - ); - conn->revert_to_self (); - - if (attachmap == NULL) - { - system_printf ("failed to get shm attachmap\n"); - header.error_code = ENOMEM; - UnmapViewOfFile (mapptr); - CloseHandle (filemap); - /* FIXME exit the mutex */ - CloseHandle (token_handle); - return; - } - - shmid_ds *shmtemp = new shmid_ds; - if (!shmtemp) - { - system_printf ("failed to malloc shm node\n"); - header.error_code = ENOMEM; - UnmapViewOfFile (mapptr); - CloseHandle (filemap); - CloseHandle (attachmap); - /* FIXME exit mutex */ - CloseHandle (token_handle); - return; - } - - /* fill out the node data */ - shmtemp->shm_perm.cuid = getuid (); - shmtemp->shm_perm.uid = shmtemp->shm_perm.cuid; - shmtemp->shm_perm.cgid = getgid (); - shmtemp->shm_perm.gid = shmtemp->shm_perm.cgid; - shmtemp->shm_perm.mode = parameters.in.shmflg & 0x01ff; - shmtemp->shm_lpid = 0; - shmtemp->shm_nattch = 0; - shmtemp->shm_atime = 0; - shmtemp->shm_dtime = 0; - shmtemp->shm_ctime = time (NULL); - shmtemp->shm_segsz = parameters.in.size; - *(shmid_ds *) mapptr = *shmtemp; - shmtemp->mapptr = mapptr; - - /* no need for InterlockedExchange here, we're serialised by the global mutex */ - tempnode = new shmnode; - tempnode->shmds = shmtemp; - tempnode->shm_id = (int) InterlockedIncrement (&new_id); - tempnode->key = parameters.in.key; - tempnode->filemap = filemap; - tempnode->attachmap = attachmap; - tempnode->next = shm_head; - shm_head = tempnode; - - /* we now have the area in the daemon list, opened. - - FIXME: leave the system wide shm mutex */ - - parameters.out.shm_id = tempnode->shm_id; - if (check_and_dup_handle (GetCurrentProcess (), from_process_handle, - token_handle, - DUPLICATE_SAME_ACCESS, - tempnode->filemap, ¶meters.out.filemap, - TRUE) != 0) - { - printf ("error duplicating filemap handle (%lu)\n", - GetLastError ()); - header.error_code = EACCES; - CloseHandle (token_handle); -/* mutex et al */ - return; - } - if (check_and_dup_handle (GetCurrentProcess (), from_process_handle, - token_handle, - DUPLICATE_SAME_ACCESS, - tempnode->attachmap, - ¶meters.out.attachmap, TRUE) != 0) - { - printf ("error duplicating attachmap handle (%lu)\n", - GetLastError ()); - header.error_code = EACCES; - CloseHandle (from_process_handle); - CloseHandle (token_handle); -/* more cleanup... yay! */ - return; - } - CloseHandle (token_handle); - - return; - } - - header.error_code = ENOSYS; - CloseHandle (token_handle); - - - return; -} |