diff options
Diffstat (limited to 'src/lib/shm_du_map.c')
| -rw-r--r-- | src/lib/shm_du_map.c | 493 |
1 files changed, 493 insertions, 0 deletions
diff --git a/src/lib/shm_du_map.c b/src/lib/shm_du_map.c new file mode 100644 index 00000000..052b8868 --- /dev/null +++ b/src/lib/shm_du_map.c @@ -0,0 +1,493 @@ +/* + * Ouroboros - Copyright (C) 2016 + * + * Shared memory map for data units + * + * Dimitri Staessens <[email protected]> + * Sander Vrijders <[email protected]> + * + * 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. + */ + +#ifndef SHM_DU_MAP_C +#define SHM_DU_MAP_C + +#include <ouroboros/shm_du_map.h> + +#include <pthread.h> +#include <sys/mman.h> +#include <fcntl.h> +#include <malloc.h> +#include <string.h> + + +#define SHM_DU_BLOCK_DATA_SIZE (SHM_DU_BUFF_BLOCK_SIZE - \ + sizeof (struct shm_block)) +#define SHM_BLOCKS_IN_MAP (SHM_DU_MAP_SIZE / SHM_DU_BUFF_BLOCK_SIZE) +#define SHM_BLOCKS_SIZE (SHM_DU_BUFF_BLOCK_SIZE * SHM_BLOCKS_IN_MAP) +#define SHM_BUFFS_SIZE (SHM_BLOCKS_IN_MAP * sizeof (struct shm_du_buff)) +#define SHM_MGT_MAP_SIZE (SHM_BLOCKS_IN_MAP * sizeof (uint8_t)) +#define SHM_FILE_SIZE (SHM_BLOCKS_IN_MAP * (SHM_DU_BUFF_BLOCK_SIZE \ + + sizeof (struct shm_du_buff) \ + + sizeof (uint8_t)) \ + + sizeof(pthread_mutex_t)) + +#define idx_to_block_ptr(dum, i) ((struct shm_block *) \ + (dum->shm_base + i * SHM_DU_BUFF_BLOCK_SIZE)) +#define idx_to_du_buff_ptr(dum, i) (dum->ptr_du_buff + i) +#define du_buff_ptr_to_idx(dum, sdb) ((sdb - dum->ptr_du_buff) / sizeof *sdb) +#define block_ptr_to_idx(dum, sdb) (((uint8_t *)sdb - dum->shm_base) \ + / SHM_DU_BUFF_BLOCK_SIZE) + +struct shm_block { + size_t size; + long next; + long prev; +}; + +struct shm_du_buff { + size_t size; + size_t du_head; + size_t du_tail; +}; + +struct shm_du_map { + uint8_t * shm_base; /* start of buffer blocks */ + struct shm_du_buff * ptr_du_buff; /* start of du_buff structs */ + uint8_t * ptr_map; /* start of management map */ + pthread_mutex_t * shm_mutex; /* lock all free space in shm */ + int fd; +}; + +struct shm_du_map * shm_du_map_create() +{ + struct shm_du_map * dum; + int shm_fd; + uint8_t * shm_base; + uint8_t * ptr; + pthread_mutexattr_t attr; + int i; + + dum = malloc(sizeof *dum); + if (dum == NULL) { + LOG_ERR("Could not allocate struct."); + return NULL; + } + + shm_fd = shm_open(SHM_DU_MAP_FILENAME, O_CREAT | O_EXCL | O_RDWR, 0666); + if (shm_fd == -1) { + LOG_ERR("Failed creating shared memory map."); + free(dum); + return NULL; + } + + if (lseek (shm_fd,SHM_FILE_SIZE - 1, SEEK_SET) < 0) { + LOG_ERR("Failed to extend shared memory map."); + free(dum); + return NULL; + } + + if (write (shm_fd, "", 1) != 1) { + LOG_ERR("Failed to finalise extension of shared memory map."); + free(dum); + return NULL; + } + + shm_base = mmap(NULL, + SHM_FILE_SIZE, + PROT_READ | PROT_WRITE, + MAP_SHARED, + shm_fd, + 0); + + if (shm_base == MAP_FAILED) { + LOG_ERR("Failed to map shared memory."); + if (close(shm_fd) == -1) + LOG_ERR("Failed to close invalid shm."); + + if (shm_unlink(SHM_DU_MAP_FILENAME) == -1) + LOG_ERR("Failed to remove invalid shm."); + + free(dum); + return NULL; + } +#ifdef CONFIG_OUROBOROS_DEBUG + memset(shm_base, 0, SHM_FILE_SIZE); +#endif + dum->shm_base = shm_base; + dum->ptr_du_buff = (struct shm_du_buff *) + ((uint8_t *) dum->shm_base + SHM_BLOCKS_SIZE); + dum->ptr_map = (uint8_t *) dum->ptr_du_buff + SHM_BUFFS_SIZE; + dum->shm_mutex = (pthread_mutex_t *) + ((uint8_t *) dum->ptr_map + SHM_MGT_MAP_SIZE); + + pthread_mutexattr_init(&attr); + pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED); + pthread_mutex_init(dum->shm_mutex, &attr); + + ptr = dum->ptr_map; + for (i = 0; i < SHM_BLOCKS_IN_MAP; ++i) + *(ptr++) = 0; + + dum->fd = shm_fd; + + return dum; +} + +struct shm_du_map * shm_du_map_open() +{ + struct shm_du_map * dum; + int shm_fd; + uint8_t * shm_base; + + shm_fd = shm_open(SHM_DU_MAP_FILENAME, O_RDWR, 0666); + if (shm_fd == -1) { + LOG_ERR("Failed opening shared memory for du_buff."); + return NULL; + } + + shm_base = mmap(NULL, + SHM_FILE_SIZE, + PROT_READ | PROT_WRITE, + MAP_SHARED, + shm_fd, + 0); + if (shm_base == MAP_FAILED) { + LOG_ERR("Failed to map shared memory."); + + if (close(shm_fd) == -1) + LOG_ERR("Failed to close invalid shm."); + + if (shm_unlink(SHM_DU_MAP_FILENAME) == -1) + LOG_ERR("Failed to unlink invalid shm."); + + return NULL; + } + + dum = malloc(sizeof *dum); + if (dum == NULL) { + LOG_ERR("Could not allocate struct."); + return NULL; + } + + dum->shm_base = shm_base; + dum->ptr_du_buff = (struct shm_du_buff *) + ((uint8_t *) dum->shm_base + SHM_BLOCKS_SIZE); + dum->ptr_map = (uint8_t *) dum->ptr_du_buff + SHM_BUFFS_SIZE; + dum->shm_mutex = (pthread_mutex_t *) + ((uint8_t *) dum->ptr_map + SHM_MGT_MAP_SIZE); + + return dum; +} + +void shm_du_map_close(struct shm_du_map * dum) +{ + if (dum == NULL) { + LOG_DBGF("Bogus input. Bugging out."); + return; + } + + if (munmap(dum->shm_base, SHM_FILE_SIZE) == -1) + LOG_DBGF("Couldn't unmap shared memory."); + + if (shm_unlink(SHM_DU_MAP_FILENAME) == -1) + LOG_DBGF("Failed to unlink shm."); + + free(dum); +} + +static struct shm_du_buff * alloc_du_buff(struct shm_du_map * dum) +{ + uint8_t * ptr = dum->ptr_map; + + pthread_mutex_lock(dum->shm_mutex); + + while (*ptr == 1 && ptr < (uint8_t *) dum->shm_mutex) + ++ptr; + + if (ptr < (uint8_t *) dum->shm_mutex) { + *ptr = 1; + } else { + pthread_mutex_unlock(dum->shm_mutex); + return NULL; + } + + pthread_mutex_unlock(dum->shm_mutex); + + return dum->ptr_du_buff + (ptr - dum->ptr_map); +} + +static struct shm_block * alloc_block(struct shm_du_map * dum) +{ + + pthread_mutex_lock(dum->shm_mutex); + + uint8_t * ptr = dum->ptr_map; + + while (*ptr == 1 && ptr < (uint8_t *) dum->shm_mutex) + ++ptr; + + if (ptr < (uint8_t *) dum->shm_mutex) { + *ptr = 1; + } + else { + pthread_mutex_unlock(dum->shm_mutex); + return NULL; + } + + pthread_mutex_unlock(dum->shm_mutex); + + + return (struct shm_block *) + (dum->shm_base + ((ptr - dum->ptr_map) + * SHM_DU_BUFF_BLOCK_SIZE)); +} + +struct shm_du_buff * shm_create_du_buff(struct shm_du_map * dum, + size_t size, + size_t headspace, + uint8_t * data, + size_t len) +{ + struct shm_du_buff * sdb; + long index; + long prev_index = -1; + size_t remaining = size; + size_t ts = size - (headspace + len); + uint8_t * read_pos = data; + + if (dum == NULL || data == NULL) { + LOG_DBGF("Bogus input, bugging out."); + return NULL; + } + + if (headspace >= size) { + LOG_DBGF("Index out of bounds."); + return NULL; + } + + if (headspace + len > size) { + LOG_DBGF("Buffer too small for data."); + return NULL; + } + + if (headspace > SHM_DU_BLOCK_DATA_SIZE || ts > SHM_DU_BLOCK_DATA_SIZE) { + LOG_ERR("Illegal du_buff: Cannot fit PCI in DU_BUFF_BLOCK."); + return NULL; + } + + sdb = alloc_du_buff(dum); + if (sdb == NULL) { + LOG_DBGF("Allocation failed, Out of Memory."); + return NULL; + } + + index = du_buff_ptr_to_idx(dum, sdb); + sdb->size = size; + sdb->du_head = headspace; + sdb->du_tail = sdb->du_head + len; + + while (remaining > 0) { + struct shm_block * shm_buf; + unsigned long bytes_to_copy = len; + uint8_t * write_pos; + + if (prev_index == -1) + shm_buf = idx_to_block_ptr(dum, index); + else + shm_buf = alloc_block(dum); + + if (shm_buf == NULL) { + shm_release_du_buff(dum, sdb); + return NULL; + } + + write_pos = (uint8_t *) shm_buf + sizeof *shm_buf; + + index = block_ptr_to_idx(dum, shm_buf); + + if (size > SHM_DU_BLOCK_DATA_SIZE + && remaining - ts <= SHM_DU_BLOCK_DATA_SIZE + && remaining != ts) { + shm_buf->size = remaining - ts; + bytes_to_copy = shm_buf->size; + } else if (size > SHM_DU_BLOCK_DATA_SIZE && remaining == ts) { + shm_buf->size = ts; + bytes_to_copy = 0; + } else { + shm_buf->size = remaining < SHM_DU_BLOCK_DATA_SIZE ? + remaining : SHM_DU_BLOCK_DATA_SIZE; + bytes_to_copy =shm_buf->size; + if (remaining == shm_buf->size) + bytes_to_copy -= ts; + } + + remaining -= shm_buf->size; + + if (prev_index == -1) { +#ifdef CONFIG_OUROBOROS_DEBUG + memset(write_pos, 0, sdb->du_head); +#endif + + write_pos += sdb->du_head; + bytes_to_copy -= sdb->du_head; + } + + if (prev_index != -1) + idx_to_block_ptr(dum, prev_index)->next = index; + + memcpy(write_pos, read_pos, bytes_to_copy); + + read_pos += bytes_to_copy; +#ifdef CONFIG_OUROBOROS_DEBUG + if (remaining == 0) { + write_pos + = bytes_to_copy; + memset(write_pos, 0, ts); + } +#endif + shm_buf->next = -1; + shm_buf->prev = prev_index; + + prev_index = index; + } + + return sdb; +} + +void shm_release_du_buff(struct shm_du_map * dum, struct shm_du_buff * sdb) +{ + long index = 0; + + if (sdb == NULL) { + LOG_DBGF("Bogus input, bugging out."); + return; + } + + if (sdb < dum->ptr_du_buff || sdb > dum->ptr_du_buff + SHM_BUFFS_SIZE) { + LOG_DBGF("Refused to free sdb outside of region."); + return; + } + + if ((sdb - dum->ptr_du_buff) % sizeof *sdb != 0) { + LOG_DBGF("Refused to free sdb at incorrect offset."); + return; + } + + index = du_buff_ptr_to_idx(dum, sdb); + + pthread_mutex_lock(dum->shm_mutex); + + if (dum->ptr_map[index] == 0) { + LOG_DBGF("Attempt to free unused sdb. Nothing to do."); + pthread_mutex_unlock(dum->shm_mutex); + return; + } + + /* release all blocks in the structure */ + dum->ptr_map[index] = 0; + + index = idx_to_block_ptr(dum, index)->next; + while (index != -1) { + dum->ptr_map[index] = 0; + index = idx_to_block_ptr(dum, index)->next; + } + + pthread_mutex_unlock(dum->shm_mutex); + +} + +uint8_t * shm_du_buff_head_alloc(struct shm_du_map * dum, + struct shm_du_buff * sdb, + size_t size) +{ + uint8_t * ret; + + if (sdb == NULL) { + LOG_DBGF("Bogus input, bugging out."); + return NULL; + } + + if ((long) (sdb->du_head - size) < 0) { + LOG_DBGF("Failed to allocate PCI headspace."); + return NULL; + } + + sdb->du_head -= size; + + ret = (uint8_t *) idx_to_block_ptr(dum, du_buff_ptr_to_idx(dum,sdb)); + + return ret + sizeof(struct shm_block) + sdb->du_head; +} + +uint8_t * shm_du_buff_tail_alloc(struct shm_du_map * dum, + struct shm_du_buff * sdb, + size_t size) +{ + uint8_t * ret; + + if (sdb == NULL) { + LOG_DBGF("Bogus input, bugging out."); + return NULL; + } + + if (sdb->du_tail + size >= sdb->size) { + LOG_DBGF("Failed to allocate PCI tailspace."); + return NULL; + } + + sdb->du_tail += size; + + ret = (uint8_t *) idx_to_block_ptr(dum, du_buff_ptr_to_idx(dum,sdb)); + + return ret + sizeof(struct shm_block) + sdb->du_tail; +} + +int shm_du_buff_head_release(struct shm_du_buff * sdb, + size_t size) +{ + if (sdb == NULL) { + LOG_DBGF("Bogus input, bugging out."); + return -EINVAL; + } + + if (size > sdb->du_tail - sdb->du_head) { + LOG_DBGF("Tried to release beyond sdu boundary."); + return -EOVERFLOW; + } + + sdb->du_head += size; + + return sdb->du_head; +} + +int shm_du_buff_tail_release(struct shm_du_buff * sdb, + size_t size) +{ + if (sdb == NULL) { + LOG_DBGF("Bogus input, bugging out."); + return -EINVAL; + } + + if (size > sdb->du_tail - sdb->du_head) { + LOG_DBGF("Tried to release beyond sdu boundary."); + return -EOVERFLOW; + } + + sdb->du_tail -= size; + + return sdb->du_tail; +} + +#endif |