diff options
Diffstat (limited to 'source3/locking/shmem.c')
| -rw-r--r-- | source3/locking/shmem.c | 963 |
1 files changed, 0 insertions, 963 deletions
diff --git a/source3/locking/shmem.c b/source3/locking/shmem.c deleted file mode 100644 index bf2802c9ec..0000000000 --- a/source3/locking/shmem.c +++ /dev/null @@ -1,963 +0,0 @@ -/* - Unix SMB/Netbios implementation. - Version 1.9. - Shared memory functions - Copyright (C) Erik Devriendt 1996-1998 - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - -*/ - -#include "includes.h" - - -#ifdef USE_SHARED_MMAP - - -extern int DEBUGLEVEL; - - -#define SMB_SHM_MAGIC 0x53484100 -/* = "SHM" in hex */ - -#define SMB_SHM_VERSION 2 - -/* we need world read for smbstatus to function correctly */ -#ifdef SECURE_SHARE_MODES -#define SHM_FILE_MODE 0600 -#else -#define SHM_FILE_MODE 0644 -#endif - -#define SHMEM_HASH_SIZE 13 - - -/* WARNING : offsets are used because mmap() does not guarantee that all processes have the - shared memory mapped to the same address */ - -struct SmbShmHeader -{ - int smb_shm_magic; - int smb_shm_version; - int total_size; /* in bytes */ - BOOL consistent; - int first_free_off; - int userdef_off; /* a userdefined offset. can be used to store root of tree or list */ - struct { /* a cell is a range of bytes of sizeof(struct SmbShmBlockDesc) size */ - int cells_free; - int cells_used; - int cells_system; /* number of cells used as allocated block descriptors */ - } statistics; -}; - -#define SMB_SHM_NOT_FREE_OFF (-1) -struct SmbShmBlockDesc -{ - int next; /* offset of next block in the free list or SMB_SHM_NOT_FREE_OFF when block in use */ - int size; /* user size in BlockDescSize units */ -}; - -#define EOList_Addr (struct SmbShmBlockDesc *)( 0 ) -#define EOList_Off 0 - -#define CellSize sizeof(struct SmbShmBlockDesc) - -/* HeaderSize aligned on 8 byte boundary */ -#define AlignedHeaderSize ((sizeof(struct SmbShmHeader)+7) & ~7) - -static int smb_shm_fd = -1; -static pstring smb_shm_processreg_name = ""; - -static struct SmbShmHeader *smb_shm_header_p = (struct SmbShmHeader *)0; -static int smb_shm_times_locked = 0; - -static BOOL smb_shm_initialize_called = False; - -static int read_only; - -static BOOL smb_shm_global_lock(void) -{ - if (smb_shm_fd < 0) - { - DEBUG(0,("ERROR smb_shm_global_lock : bad smb_shm_fd (%d)\n",smb_shm_fd)); - return False; - } - - smb_shm_times_locked++; - - if(smb_shm_times_locked > 1) - { - DEBUG(5,("smb_shm_global_lock : locked %d times\n",smb_shm_times_locked)); - return True; - } - - if (read_only) - return True; - - /* Do an exclusive wait lock on the first byte of the file */ - if (fcntl_lock(smb_shm_fd, SMB_F_SETLKW, 0, 1, F_WRLCK) == False) - { - DEBUG(0,("ERROR smb_shm_global_lock : fcntl_lock failed with code %s\n",strerror(errno))); - smb_shm_times_locked--; - return False; - } - - return True; - -} - -static BOOL smb_shm_global_unlock(void) -{ - if (smb_shm_fd < 0) - { - DEBUG(0,("ERROR smb_shm_global_unlock : bad smb_shm_fd (%d)\n",smb_shm_fd)); - return False; - } - - if(smb_shm_times_locked == 0) - { - DEBUG(0,("ERROR smb_shm_global_unlock : shmem not locked\n")); - return False; - } - - smb_shm_times_locked--; - - if(smb_shm_times_locked > 0) - { - DEBUG(5,("smb_shm_global_unlock : still locked %d times\n",smb_shm_times_locked)); - return True; - } - - if (read_only) - return True; - - /* Do a wait unlock on the first byte of the file */ - if (fcntl_lock(smb_shm_fd, SMB_F_SETLKW, 0, 1, F_UNLCK) == False) - { - DEBUG(0,("ERROR smb_shm_global_unlock : fcntl_lock failed with code %s\n",strerror(errno))); - smb_shm_times_locked++; - return False; - } - - return True; - -} - - -static void *smb_shm_offset2addr(int offset) -{ - if (offset == 0 ) - return (void *)(0); - - if (!smb_shm_header_p) - return (void *)(0); - - return (void *)((char *)smb_shm_header_p + offset ); -} - -static int smb_shm_addr2offset(void *addr) -{ - if (!addr) - return 0; - - if (!smb_shm_header_p) - return 0; - - return (int)((char *)addr - (char *)smb_shm_header_p); -} - - - -static int smb_shm_alloc(int size) -{ - unsigned num_cells ; - struct SmbShmBlockDesc *scanner_p; - struct SmbShmBlockDesc *prev_p; - struct SmbShmBlockDesc *new_p; - int result_offset; - - - if( !smb_shm_header_p ) - { - /* not mapped yet */ - DEBUG(0,("ERROR smb_shm_alloc : shmem not mapped\n")); - return 0; - } - - smb_shm_global_lock(); - - if( !smb_shm_header_p->consistent) - { - DEBUG(0,("ERROR smb_shm_alloc : shmem not consistent\n")); - smb_shm_global_unlock(); - return 0; - } - - - /* calculate the number of cells */ - num_cells = (size + CellSize -1) / CellSize; - - /* set start of scan */ - prev_p = (struct SmbShmBlockDesc *)smb_shm_offset2addr(smb_shm_header_p->first_free_off); - scanner_p = prev_p ; - - /* scan the free list to find a matching free space */ - while ( ( scanner_p != EOList_Addr ) && ( scanner_p->size < num_cells ) ) - { - prev_p = scanner_p; - scanner_p = (struct SmbShmBlockDesc *)smb_shm_offset2addr(scanner_p->next); - } - - /* at this point scanner point to a block header or to the end of the list */ - if ( scanner_p == EOList_Addr ) - { - DEBUG(0,("ERROR smb_shm_alloc : alloc of %d bytes failed, no free space found\n",size)); - smb_shm_global_unlock(); - return (0); - } - - /* going to modify shared mem */ - smb_shm_header_p->consistent = False; - - /* if we found a good one : scanner == the good one */ - if ( scanner_p->size <= num_cells + 2 ) - { - /* there is no use in making a new one, it will be too small anyway - * we will link out scanner - */ - if ( prev_p == scanner_p ) - { - smb_shm_header_p->first_free_off = scanner_p->next ; - } - else - { - prev_p->next = scanner_p->next ; - } - smb_shm_header_p->statistics.cells_free -= scanner_p->size; - smb_shm_header_p->statistics.cells_used += scanner_p->size; - } - else - { - /* Make a new one */ - new_p = scanner_p + 1 + num_cells; - new_p->size = scanner_p->size - num_cells - 1; - new_p->next = scanner_p->next; - scanner_p->size = num_cells; - scanner_p->next = smb_shm_addr2offset(new_p); - - if ( prev_p != scanner_p ) - { - prev_p->next = smb_shm_addr2offset(new_p) ; - } - else - { - smb_shm_header_p->first_free_off = smb_shm_addr2offset(new_p) ; - } - smb_shm_header_p->statistics.cells_free -= num_cells+1; - smb_shm_header_p->statistics.cells_used += num_cells; - smb_shm_header_p->statistics.cells_system += 1; - } - - result_offset = smb_shm_addr2offset( &(scanner_p[1]) ); - scanner_p->next = SMB_SHM_NOT_FREE_OFF ; - - /* end modification of shared mem */ - smb_shm_header_p->consistent = True; - - DEBUG(6,("smb_shm_alloc : request for %d bytes, allocated %d bytes at offset %d\n",size,scanner_p->size*CellSize,result_offset )); - - smb_shm_global_unlock(); - return ( result_offset ); -} - - - - -/* - * Function to create the hash table for the share mode entries. Called - * when smb shared memory is global locked. - */ -static BOOL smb_shm_create_hash_table( unsigned int size ) -{ - size *= sizeof(int); - - smb_shm_global_lock(); - smb_shm_header_p->userdef_off = smb_shm_alloc( size ); - - if(smb_shm_header_p->userdef_off == 0) - { - DEBUG(0,("smb_shm_create_hash_table: Failed to create hash table of size %d\n",size)); - smb_shm_global_unlock(); - return False; - } - - /* Clear hash buckets. */ - memset( smb_shm_offset2addr(smb_shm_header_p->userdef_off), '\0', size); - smb_shm_global_unlock(); - return True; -} - -static BOOL smb_shm_register_process(char *processreg_file, pid_t pid, BOOL *other_processes) -{ - int smb_shm_processes_fd = -1; - int nb_read; - pid_t other_pid; - SMB_OFF_T seek_back = -((SMB_OFF_T)sizeof(other_pid)); - SMB_OFF_T free_slot = -1; - SMB_OFF_T erased_slot; - - smb_shm_processes_fd = sys_open(processreg_file, - read_only?O_RDONLY:(O_RDWR|O_CREAT), - SHM_FILE_MODE); - - if ( smb_shm_processes_fd < 0 ) - { - DEBUG(0, ("ERROR smb_shm_register_process : processreg_file \ -open failed with code %s\n",strerror(errno))); - return False; - } - - *other_processes = False; - - while ((nb_read = read(smb_shm_processes_fd, &other_pid, sizeof(other_pid))) > 0) - { - if(other_pid) - { - if(process_exists(other_pid)) - *other_processes = True; - else - { - /* erase old pid */ - DEBUG(5,("smb_shm_register_process : erasing stale record \ -for pid %d (seek_back = %.0f)\n", (int)other_pid, (double)seek_back)); - other_pid = (pid_t)0; - if((erased_slot = sys_lseek(smb_shm_processes_fd, - seek_back, SEEK_CUR)) == -1) - { - DEBUG(0, ("ERROR smb_shm_register_process : sys_lseek failed \ -with error %s\n", strerror(errno))); - close(smb_shm_processes_fd); - return False; - } - - if(write(smb_shm_processes_fd, &other_pid, sizeof(other_pid)) == -1) - { - DEBUG(0, ("ERROR smb_shm_register_process : write failed \ -with error %s\n", strerror(errno))); - close(smb_shm_processes_fd); - return False; - } - - if(free_slot < 0) - free_slot = erased_slot; - } - } - else - { - if(free_slot < 0) - { - if((free_slot = sys_lseek(smb_shm_processes_fd, - seek_back, SEEK_CUR))==-1) - { - DEBUG(0, ("ERROR smb_shm_register_process : sys_lseek \ -failed with error %s\n", strerror(errno))); - close(smb_shm_processes_fd); - return False; - } - } /* end if free_slot */ - } /* end else */ - } /* end if other_pid */ - - if (nb_read < 0) - { - DEBUG(0,("ERROR smb_shm_register_process : processreg_file read \ -failed with code %s\n",strerror(errno))); - close(smb_shm_processes_fd); - return False; - } - - if(free_slot < 0) - { - if((free_slot = sys_lseek(smb_shm_processes_fd, 0, SEEK_END)) == -1) - { - DEBUG(0,("ERROR smb_shm_register_process : sys_lseek failed with code %s\n",strerror(errno))); - close(smb_shm_processes_fd); - return False; - } - } - - DEBUG(5,("smb_shm_register_process : writing record for pid %d at offset %.0f\n", - (int)pid, (double)free_slot)); - - if(sys_lseek(smb_shm_processes_fd, free_slot, SEEK_SET) == -1) - { - DEBUG(0,("ERROR smb_shm_register_process : sys_lseek failed with code %s\n",strerror(errno))); - close(smb_shm_processes_fd); - return False; - } - - if(write(smb_shm_processes_fd, &pid, sizeof(pid)) == -1) - { - DEBUG(0,("ERROR smb_shm_register_process : processreg_file write failed with code %s\n",strerror(errno))); - close(smb_shm_processes_fd); - return False; - } - - close(smb_shm_processes_fd); - - return True; -} - -static BOOL smb_shm_unregister_process(char *processreg_file, pid_t pid) -{ - int smb_shm_processes_fd = -1; - int nb_read; - pid_t other_pid; - SMB_OFF_T seek_back = -((SMB_OFF_T)sizeof(other_pid)); - BOOL found = False; - - - smb_shm_processes_fd = sys_open(processreg_file, O_RDWR, 0); - if ( smb_shm_processes_fd < 0 ) - { - DEBUG(0,("ERROR smb_shm_unregister_process : processreg_file open failed with code %s\n",strerror(errno))); - return False; - } - - while ((nb_read = read(smb_shm_processes_fd, &other_pid, sizeof(other_pid))) > 0) - { - DEBUG(5,("smb_shm_unregister_process : read record for pid %d\n",(int)other_pid)); - if(other_pid == pid) - { - /* erase pid */ - DEBUG(5,("smb_shm_unregister_process : erasing record for pid %d (seek_val = %.0f)\n", - (int)other_pid, (double)seek_back)); - other_pid = (pid_t)0; - if(sys_lseek(smb_shm_processes_fd, seek_back, SEEK_CUR) == -1) - { - DEBUG(0,("ERROR smb_shm_unregister_process : processreg_file sys_lseek failed with code %s\n",strerror(errno))); - close(smb_shm_processes_fd); - return False; - } - if(write(smb_shm_processes_fd, &other_pid, sizeof(other_pid)) < 0) - { - DEBUG(0,("ERROR smb_shm_unregister_process : processreg_file write failed with code %s\n",strerror(errno))); - close(smb_shm_processes_fd); - return False; - } - - found = True; - break; - } - } - if (nb_read < 0) - { - DEBUG(0,("ERROR smb_shm_unregister_process : processreg_file read failed with code %s\n",strerror(errno))); - close(smb_shm_processes_fd); - return False; - } - - if(!found) - { - DEBUG(0,("ERROR smb_shm_unregister_process : couldn't find pid %d in file %s\n", - (int)pid,processreg_file)); - close(smb_shm_processes_fd); - return False; - } - - - close(smb_shm_processes_fd); - - return True; -} - - -static BOOL smb_shm_validate_header(int size) -{ - if( !smb_shm_header_p ) - { - /* not mapped yet */ - DEBUG(0,("ERROR smb_shm_validate_header : shmem not mapped\n")); - return False; - } - - if(smb_shm_header_p->smb_shm_magic != SMB_SHM_MAGIC) - { - DEBUG(0,("ERROR smb_shm_validate_header : bad magic\n")); - return False; - } - if(smb_shm_header_p->smb_shm_version != SMB_SHM_VERSION) - { - DEBUG(0,("ERROR smb_shm_validate_header : bad version %X\n",smb_shm_header_p->smb_shm_version)); - return False; - } - - if(smb_shm_header_p->total_size != size) - { - DEBUG(0,("ERROR smb_shm_validate_header : shmem size mismatch (old = %d, new = %d)\n",smb_shm_header_p->total_size,size)); - return False; - } - - if(!smb_shm_header_p->consistent) - { - DEBUG(0,("ERROR smb_shm_validate_header : shmem not consistent\n")); - return False; - } - return True; -} - -static BOOL smb_shm_initialize(int size) -{ - struct SmbShmBlockDesc * first_free_block_p; - - DEBUG(5,("smb_shm_initialize : initializing shmem file of size %d\n",size)); - - if( !smb_shm_header_p ) - { - /* not mapped yet */ - DEBUG(0,("ERROR smb_shm_initialize : shmem not mapped\n")); - return False; - } - - smb_shm_header_p->smb_shm_magic = SMB_SHM_MAGIC; - smb_shm_header_p->smb_shm_version = SMB_SHM_VERSION; - smb_shm_header_p->total_size = size; - smb_shm_header_p->first_free_off = AlignedHeaderSize; - smb_shm_header_p->userdef_off = 0; - - first_free_block_p = (struct SmbShmBlockDesc *)smb_shm_offset2addr(smb_shm_header_p->first_free_off); - first_free_block_p->next = EOList_Off; - first_free_block_p->size = ( size - AlignedHeaderSize - CellSize ) / CellSize ; - - smb_shm_header_p->statistics.cells_free = first_free_block_p->size; - smb_shm_header_p->statistics.cells_used = 0; - smb_shm_header_p->statistics.cells_system = 1; - - smb_shm_header_p->consistent = True; - - smb_shm_initialize_called = True; - - return True; -} - -static void smb_shm_solve_neighbors(struct SmbShmBlockDesc *head_p ) -{ - struct SmbShmBlockDesc *next_p; - - /* Check if head_p and head_p->next are neighbors and if so join them */ - if ( head_p == EOList_Addr ) return ; - if ( head_p->next == EOList_Off ) return ; - - next_p = (struct SmbShmBlockDesc *)smb_shm_offset2addr(head_p->next); - if ( ( head_p + head_p->size + 1 ) == next_p) - { - head_p->size += next_p->size +1 ; /* adapt size */ - head_p->next = next_p->next ; /* link out */ - - smb_shm_header_p->statistics.cells_free += 1; - smb_shm_header_p->statistics.cells_system -= 1; - } -} - - - -static BOOL smb_shm_close( void ) -{ - - if(smb_shm_initialize_called == False) - return True; - - DEBUG(5,("smb_shm_close\n")); - if(smb_shm_times_locked > 0) - DEBUG(0,("WARNING smb_shm_close : shmem was still locked %d times\n",smb_shm_times_locked));; - if ((smb_shm_header_p != NULL) && - (munmap((caddr_t)smb_shm_header_p, smb_shm_header_p->total_size) < 0)) - { - DEBUG(0,("ERROR smb_shm_close : munmap failed with code %s\n",strerror(errno))); - } - - smb_shm_global_lock(); - DEBUG(5,("calling smb_shm_unregister_process(%s, %d)\n", - smb_shm_processreg_name, (int)getpid())); - smb_shm_unregister_process(smb_shm_processreg_name, getpid()); - smb_shm_global_unlock(); - - close(smb_shm_fd); - - smb_shm_fd = -1; - smb_shm_processreg_name[0] = '\0'; - - smb_shm_header_p = (struct SmbShmHeader *)0; - smb_shm_times_locked = 0; - - return True; -} - - -static BOOL smb_shm_free(int offset) -{ - struct SmbShmBlockDesc *header_p ; /* pointer to header of block to free */ - struct SmbShmBlockDesc *scanner_p ; /* used to scan the list */ - struct SmbShmBlockDesc *prev_p ; /* holds previous in the list */ - - if( !smb_shm_header_p ) - { - /* not mapped yet */ - DEBUG(0,("ERROR smb_shm_free : shmem not mapped\n")); - return False; - } - - smb_shm_global_lock(); - - if( !smb_shm_header_p->consistent) - { - DEBUG(0,("ERROR smb_shm_free : shmem not consistent\n")); - smb_shm_global_unlock(); - return False; - } - - header_p = ( (struct SmbShmBlockDesc *)smb_shm_offset2addr(offset) - 1); /* make pointer to header of block */ - - if (header_p->next != SMB_SHM_NOT_FREE_OFF) - { - DEBUG(0,("ERROR smb_shm_free : bad offset (%d)\n",offset)); - smb_shm_global_unlock(); - return False; - } - - /* find a place in the free_list to put the header in */ - - /* set scanner and previous pointer to start of list */ - prev_p = (struct SmbShmBlockDesc *)smb_shm_offset2addr(smb_shm_header_p->first_free_off); - scanner_p = prev_p ; - - while ( ( scanner_p != EOList_Addr) && (scanner_p < header_p) ) /* while we didn't scan past its position */ - { - prev_p = scanner_p ; - scanner_p = (struct SmbShmBlockDesc *)smb_shm_offset2addr(scanner_p->next); - } - - smb_shm_header_p->consistent = False; - - DEBUG(6,("smb_shm_free : freeing %d bytes at offset %d\n",header_p->size*CellSize,offset)); - - /* zero the area being freed - this allows us to find bugs faster */ - memset(smb_shm_offset2addr(offset), 0, header_p->size*CellSize); - - if ( scanner_p == prev_p ) - { - smb_shm_header_p->statistics.cells_free += header_p->size; - smb_shm_header_p->statistics.cells_used -= header_p->size; - - /* we must free it at the beginning of the list */ - smb_shm_header_p->first_free_off = smb_shm_addr2offset(header_p); /* set the free_list_pointer to this block_header */ - - /* scanner is the one that was first in the list */ - header_p->next = smb_shm_addr2offset(scanner_p); - smb_shm_solve_neighbors( header_p ); /* if neighbors then link them */ - - smb_shm_header_p->consistent = True; - smb_shm_global_unlock(); - return True; - } - else - { - smb_shm_header_p->statistics.cells_free += header_p->size; - smb_shm_header_p->statistics.cells_used -= header_p->size; - - prev_p->next = smb_shm_addr2offset(header_p); - header_p->next = smb_shm_addr2offset(scanner_p); - smb_shm_solve_neighbors(header_p) ; - smb_shm_solve_neighbors(prev_p) ; - - smb_shm_header_p->consistent = True; - smb_shm_global_unlock(); - return True; - } -} - -static int smb_shm_get_userdef_off(void) -{ - if (!smb_shm_header_p) - return 0; - else - return smb_shm_header_p->userdef_off; -} - -/******************************************************************* - Lock a particular hash bucket entry. - ******************************************************************/ -static BOOL smb_shm_lock_hash_entry( unsigned int entry) -{ - int start = (smb_shm_header_p->userdef_off + (entry * sizeof(int))); - - if (smb_shm_fd < 0) - { - DEBUG(0,("ERROR smb_shm_lock_hash_entry : bad smb_shm_fd (%d)\n",smb_shm_fd)); - return False; - } - - if (read_only) - return True; - - /* Do an exclusive wait lock on the 4 byte region mapping into this entry */ - if (fcntl_lock(smb_shm_fd, SMB_F_SETLKW, start, sizeof(int), F_WRLCK) == False) - { - DEBUG(0,("ERROR smb_shm_lock_hash_entry : fcntl_lock failed with code %s\n",strerror(errno))); - return False; - } - - DEBUG(9,("smb_shm_lock_hash_entry: locked hash bucket %d\n", entry)); - return True; -} - -/******************************************************************* - Unlock a particular hash bucket entry. - ******************************************************************/ -static BOOL smb_shm_unlock_hash_entry( unsigned int entry ) -{ - int start = (smb_shm_header_p->userdef_off + (entry * sizeof(int))); - - if (smb_shm_fd < 0) - { - DEBUG(0,("ERROR smb_shm_unlock_hash_entry : bad smb_shm_fd (%d)\n",smb_shm_fd)); - return False; - } - - if (read_only) - return True; - - /* Do a wait lock on the 4 byte region mapping into this entry */ - if (fcntl_lock(smb_shm_fd, SMB_F_SETLKW, start, sizeof(int), F_UNLCK) == False) - { - DEBUG(0,("ERROR smb_shm_unlock_hash_entry : fcntl_lock failed with code %s\n",strerror(errno))); - return False; - } - - DEBUG(9,("smb_shm_unlock_hash_entry: unlocked hash bucket %d\n", entry)); - return True; -} - -/******************************************************************* - Gather statistics on shared memory usage. - ******************************************************************/ -static BOOL smb_shm_get_usage(int *bytes_free, - int *bytes_used, - int *bytes_overhead) -{ - if( !smb_shm_header_p ) - { - /* not mapped yet */ - DEBUG(0,("ERROR smb_shm_free : shmem not mapped\n")); - return False; - } - *bytes_free = smb_shm_header_p->statistics.cells_free * CellSize; - *bytes_used = smb_shm_header_p->statistics.cells_used * CellSize; - *bytes_overhead = smb_shm_header_p->statistics.cells_system * CellSize + AlignedHeaderSize; - - return True; -} - -/******************************************************************* -hash a number into a hash_entry - ******************************************************************/ -static unsigned smb_shm_hash_size(void) -{ - return SHMEM_HASH_SIZE; -} - -static struct shmem_ops shmops = { - smb_shm_close, - smb_shm_alloc, - smb_shm_free, - smb_shm_get_userdef_off, - smb_shm_offset2addr, - smb_shm_addr2offset, - smb_shm_lock_hash_entry, - smb_shm_unlock_hash_entry, - smb_shm_get_usage, - smb_shm_hash_size, -}; - -/******************************************************************* - open the shared memory - ******************************************************************/ -struct shmem_ops *smb_shm_open(int ronly) -{ - pstring file_name; - SMB_OFF_T filesize; - BOOL created_new = False; - BOOL other_processes = True; - SMB_OFF_T size = (SMB_OFF_T)lp_shmem_size(); - - read_only = ronly; - - pstrcpy(file_name,lp_lockdir()); - if (!directory_exist(file_name,NULL)) { - if (read_only) - return NULL; - mkdir(file_name,0755); - } - trim_string(file_name,"","/"); - if (!*file_name) - return(False); - pstrcat(file_name, "/SHARE_MEM_FILE"); - - DEBUG(5,("smb_shm_open : using shmem file %s to be of size %.0f\n", - file_name,(double)size)); - - smb_shm_fd = sys_open(file_name, read_only?O_RDONLY:(O_RDWR|O_CREAT), - SHM_FILE_MODE); - - if ( smb_shm_fd < 0 ) - { - DEBUG(0,("ERROR smb_shm_open : open failed with code %s\n",strerror(errno))); - return NULL; - } - - if (!smb_shm_global_lock()) - { - DEBUG(0,("ERROR smb_shm_open : can't do smb_shm_global_lock\n")); - return NULL; - } - - if( (filesize = sys_lseek(smb_shm_fd, 0, SEEK_END)) == -1) - { - DEBUG(0,("ERROR smb_shm_open : sys_lseek failed with code %s\n", - strerror(errno))); - smb_shm_global_unlock(); - close(smb_shm_fd); - return NULL; - } - - /* - * Return the file offset to 0 to save on later seeks. - */ - if(sys_lseek(smb_shm_fd,0,SEEK_SET) == -1) - { - DEBUG(0,("ERROR smb_shm_open : sys_lseek failed with code %s\n", - strerror(errno))); - smb_shm_global_unlock(); - close(smb_shm_fd); - return NULL; - } - - if (filesize == 0) - { - /* - * We just created a new one. - */ - created_new = True; - } - - /* - * To find out if some other process is already mapping the file, - * we use a registration file containing the processids of the file - * mapping processes. - */ - - /* construct processreg file name */ - pstrcpy(smb_shm_processreg_name, file_name); - pstrcat(smb_shm_processreg_name, ".processes"); - - if (!read_only && !smb_shm_register_process(smb_shm_processreg_name, - getpid(), &other_processes)) - { - smb_shm_global_unlock(); - close(smb_shm_fd); - return NULL; - } - - if (!read_only && (created_new || !other_processes)) - { - /* we just created a new one, or are the first opener, lets set it size */ - if( sys_ftruncate(smb_shm_fd, size) <0) - { - DEBUG(0,("ERROR smb_shm_open : ftruncate failed with code %s\n", - strerror(errno))); - smb_shm_unregister_process(smb_shm_processreg_name, getpid()); - smb_shm_global_unlock(); - close(smb_shm_fd); - return NULL; - } - - /* paranoia */ - if(sys_lseek(smb_shm_fd,0,SEEK_SET) == -1) - { - DEBUG(0,("ERROR smb_shm_open : sys_lseek failed with code %s\n", - strerror(errno))); - smb_shm_unregister_process(smb_shm_processreg_name, getpid()); - smb_shm_global_unlock(); - close(smb_shm_fd); - return NULL; - } - - filesize = size; - } - - if (size != filesize ) - { - /* the existing file has a different size and we are not the first opener. - Since another process is still using it, we will use the file size */ - DEBUG(0,("WARNING smb_shm_open : filesize (%.0f) != expected \ -size (%.0f), using filesize\n", (double)filesize, (double)size)); - - size = filesize; - } - - smb_shm_header_p = (struct SmbShmHeader *)sys_mmap(NULL, size, - read_only?PROT_READ: (PROT_READ | PROT_WRITE), - MAP_FILE | MAP_SHARED, smb_shm_fd, (SMB_OFF_T)0); - - /* - * WARNING, smb_shm_header_p can be different for different - * processes mapping the same file ! - */ - if (smb_shm_header_p == (struct SmbShmHeader *)(-1)) - { - DEBUG(0,("ERROR smb_shm_open : mmap failed with code %s\n",strerror(errno))); - smb_shm_unregister_process(smb_shm_processreg_name, getpid()); - smb_shm_global_unlock(); - close(smb_shm_fd); - return NULL; - } - - - if (!read_only && (created_new || !other_processes)) - { - smb_shm_initialize(size); - /* Create the hash buckets for the share file entries. */ - smb_shm_create_hash_table(SHMEM_HASH_SIZE); - } - else if (!smb_shm_validate_header(size) ) - { - /* existing file is corrupt, samba admin should remove it by hand */ - DEBUG(0,("ERROR smb_shm_open : corrupt shared mem file, remove it manually\n")); - munmap((caddr_t)smb_shm_header_p, size); - smb_shm_unregister_process(smb_shm_processreg_name, getpid()); - smb_shm_global_unlock(); - close(smb_shm_fd); - return NULL; - } - - smb_shm_global_unlock(); - return &shmops; -} - - -#else /* HAVE_SHARED_MMAP */ - int shmem_dummy_procedure(void) -{return 0;} -#endif /* HAVE_SHARED_MMAP */ |