diff options
Diffstat (limited to 'source3/locking/shmem_sysv.c')
| -rw-r--r-- | source3/locking/shmem_sysv.c | 70 |
1 files changed, 55 insertions, 15 deletions
diff --git a/source3/locking/shmem_sysv.c b/source3/locking/shmem_sysv.c index 36d0cca27f..e3f40418d9 100644 --- a/source3/locking/shmem_sysv.c +++ b/source3/locking/shmem_sysv.c @@ -39,6 +39,14 @@ extern int DEBUGLEVEL; #define IPC_PERMS 0644 #endif +#ifdef SEMMSL +#define SHMEM_HASH_SIZE (SEMMSL-1) +#else +#define SHMEM_HASH_SIZE 63 +#endif + +#define MIN_SHM_SIZE 10240 + static int shm_id; static int sem_id; static int shm_size; @@ -487,6 +495,16 @@ static BOOL shm_get_usage(int *bytes_free, return True; } + +/******************************************************************* +hash a number into a hash_entry + ******************************************************************/ +static unsigned shm_hash_size(void) +{ + return hash_size; +} + + static struct shmem_ops shmops = { shm_close, shm_alloc, @@ -497,12 +515,13 @@ static struct shmem_ops shmops = { shm_lock_hash_entry, shm_unlock_hash_entry, shm_get_usage, + shm_hash_size, }; /******************************************************************* open the shared memory ******************************************************************/ -struct shmem_ops *sysv_shm_open(int size, int ronly) +struct shmem_ops *sysv_shm_open(int ronly) { BOOL created_new = False; BOOL other_processes; @@ -513,17 +532,23 @@ struct shmem_ops *sysv_shm_open(int size, int ronly) read_only = ronly; - shm_size = size; + shm_size = lp_shmem_size(); - DEBUG(4,("Trying sysv shmem open of size %d\n", size)); + DEBUG(4,("Trying sysv shmem open of size %d\n", shm_size)); /* first the semaphore */ sem_id = semget(SEMAPHORE_KEY, 0, 0); if (sem_id == -1) { if (read_only) return NULL; - sem_id = semget(SEMAPHORE_KEY, lp_shmem_hash_size()+1, - IPC_CREAT | IPC_EXCL | IPC_PERMS); + hash_size = SHMEM_HASH_SIZE; + + while (hash_size > 1) { + sem_id = semget(SEMAPHORE_KEY, hash_size+1, + IPC_CREAT | IPC_EXCL | IPC_PERMS); + if (sem_id != -1 || errno != EINVAL) break; + hash_size--; + } if (sem_id == -1) { DEBUG(0,("Can't create or use semaphore %s\n", @@ -532,7 +557,7 @@ struct shmem_ops *sysv_shm_open(int size, int ronly) if (sem_id != -1) { su.val = 1; - for (i=0;i<lp_shmem_hash_size()+1;i++) { + for (i=0;i<hash_size+1;i++) { if (semctl(sem_id, i, SETVAL, su) != 0) { DEBUG(1,("Failed to init semaphore %d\n", i)); } @@ -552,10 +577,16 @@ struct shmem_ops *sysv_shm_open(int size, int ronly) if (semctl(sem_id, 0, IPC_STAT, su) != 0) { DEBUG(0,("ERROR shm_open : can't IPC_STAT\n")); } - hash_size = sem_ds.sem_nsems; - if (hash_size != lp_shmem_hash_size()+1) { - DEBUG(0,("WARNING: nsems=%d\n", hash_size)); + hash_size = sem_ds.sem_nsems-1; + + if (!read_only) { + if (sem_ds.sem_perm.cuid != 0 || sem_ds.sem_perm.cgid != 0) { + DEBUG(0,("ERROR: root did not create the semaphore\n")); + return NULL; + } } + + if (!global_lock()) return NULL; @@ -566,7 +597,12 @@ struct shmem_ops *sysv_shm_open(int size, int ronly) /* if that failed then create one */ if (shm_id == -1) { if (read_only) return NULL; - shm_id = shmget(SHMEM_KEY, shm_size, IPC_CREAT | IPC_EXCL); + while (shm_size > MIN_SHM_SIZE) { + shm_id = shmget(SHMEM_KEY, shm_size, + IPC_CREAT | IPC_EXCL | IPC_PERMS); + if (shm_id != -1 || errno != EINVAL) break; + shm_size *= 0.9; + } created_new = (shm_id != -1); } @@ -592,19 +628,23 @@ struct shmem_ops *sysv_shm_open(int size, int ronly) DEBUG(0,("ERROR shm_open : can't IPC_STAT\n")); } - /* set the permissions */ if (!read_only) { - shm_ds.shm_perm.mode = IPC_PERMS; - shmctl(shm_id, IPC_SET, &shm_ds); + if (shm_ds.shm_perm.cuid != 0 || shm_ds.shm_perm.cgid != 0) { + DEBUG(0,("ERROR: root did not create the shmem\n")); + global_unlock(); + return NULL; + } } + shm_size = shm_ds.shm_segsz; + other_processes = (shm_ds.shm_nattch > 1); if (!read_only && !other_processes) { memset((char *)shm_header_p, 0, shm_size); shm_initialize(shm_size); - shm_create_hash_table(lp_shmem_hash_size()); - DEBUG(1,("Initialised IPC area of size %d\n", shm_size)); + shm_create_hash_table(hash_size); + DEBUG(3,("Initialised IPC area of size %d\n", shm_size)); } else if (!shm_validate_header(shm_size)) { /* existing file is corrupt, samba admin should remove it by hand */ |