|  | /* | 
|  | * Implementation of the extensible bitmap type. | 
|  | * | 
|  | * Author : Stephen Smalley, <sds@epoch.ncsc.mil> | 
|  | */ | 
|  | /* | 
|  | * Updated: Hewlett-Packard <paul.moore@hp.com> | 
|  | * | 
|  | *      Added support to import/export the NetLabel category bitmap | 
|  | * | 
|  | * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 | 
|  | */ | 
|  | /* | 
|  | * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com> | 
|  | *      Applied standard bit operations to improve bitmap scanning. | 
|  | */ | 
|  |  | 
|  | #include <linux/kernel.h> | 
|  | #include <linux/slab.h> | 
|  | #include <linux/errno.h> | 
|  | #include <net/netlabel.h> | 
|  | #include "ebitmap.h" | 
|  | #include "policydb.h" | 
|  |  | 
|  | int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2) | 
|  | { | 
|  | struct ebitmap_node *n1, *n2; | 
|  |  | 
|  | if (e1->highbit != e2->highbit) | 
|  | return 0; | 
|  |  | 
|  | n1 = e1->node; | 
|  | n2 = e2->node; | 
|  | while (n1 && n2 && | 
|  | (n1->startbit == n2->startbit) && | 
|  | !memcmp(n1->maps, n2->maps, EBITMAP_SIZE / 8)) { | 
|  | n1 = n1->next; | 
|  | n2 = n2->next; | 
|  | } | 
|  |  | 
|  | if (n1 || n2) | 
|  | return 0; | 
|  |  | 
|  | return 1; | 
|  | } | 
|  |  | 
|  | int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src) | 
|  | { | 
|  | struct ebitmap_node *n, *new, *prev; | 
|  |  | 
|  | ebitmap_init(dst); | 
|  | n = src->node; | 
|  | prev = NULL; | 
|  | while (n) { | 
|  | new = kzalloc(sizeof(*new), GFP_ATOMIC); | 
|  | if (!new) { | 
|  | ebitmap_destroy(dst); | 
|  | return -ENOMEM; | 
|  | } | 
|  | new->startbit = n->startbit; | 
|  | memcpy(new->maps, n->maps, EBITMAP_SIZE / 8); | 
|  | new->next = NULL; | 
|  | if (prev) | 
|  | prev->next = new; | 
|  | else | 
|  | dst->node = new; | 
|  | prev = new; | 
|  | n = n->next; | 
|  | } | 
|  |  | 
|  | dst->highbit = src->highbit; | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | #ifdef CONFIG_NETLABEL | 
|  | /** | 
|  | * ebitmap_netlbl_export - Export an ebitmap into a NetLabel category bitmap | 
|  | * @ebmap: the ebitmap to export | 
|  | * @catmap: the NetLabel category bitmap | 
|  | * | 
|  | * Description: | 
|  | * Export a SELinux extensibile bitmap into a NetLabel category bitmap. | 
|  | * Returns zero on success, negative values on error. | 
|  | * | 
|  | */ | 
|  | int ebitmap_netlbl_export(struct ebitmap *ebmap, | 
|  | struct netlbl_lsm_secattr_catmap **catmap) | 
|  | { | 
|  | struct ebitmap_node *e_iter = ebmap->node; | 
|  | struct netlbl_lsm_secattr_catmap *c_iter; | 
|  | u32 cmap_idx, cmap_sft; | 
|  | int i; | 
|  |  | 
|  | /* NetLabel's NETLBL_CATMAP_MAPTYPE is defined as an array of u64, | 
|  | * however, it is not always compatible with an array of unsigned long | 
|  | * in ebitmap_node. | 
|  | * In addition, you should pay attention the following implementation | 
|  | * assumes unsigned long has a width equal with or less than 64-bit. | 
|  | */ | 
|  |  | 
|  | if (e_iter == NULL) { | 
|  | *catmap = NULL; | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | c_iter = netlbl_secattr_catmap_alloc(GFP_ATOMIC); | 
|  | if (c_iter == NULL) | 
|  | return -ENOMEM; | 
|  | *catmap = c_iter; | 
|  | c_iter->startbit = e_iter->startbit & ~(NETLBL_CATMAP_SIZE - 1); | 
|  |  | 
|  | while (e_iter) { | 
|  | for (i = 0; i < EBITMAP_UNIT_NUMS; i++) { | 
|  | unsigned int delta, e_startbit, c_endbit; | 
|  |  | 
|  | e_startbit = e_iter->startbit + i * EBITMAP_UNIT_SIZE; | 
|  | c_endbit = c_iter->startbit + NETLBL_CATMAP_SIZE; | 
|  | if (e_startbit >= c_endbit) { | 
|  | c_iter->next | 
|  | = netlbl_secattr_catmap_alloc(GFP_ATOMIC); | 
|  | if (c_iter->next == NULL) | 
|  | goto netlbl_export_failure; | 
|  | c_iter = c_iter->next; | 
|  | c_iter->startbit | 
|  | = e_startbit & ~(NETLBL_CATMAP_SIZE - 1); | 
|  | } | 
|  | delta = e_startbit - c_iter->startbit; | 
|  | cmap_idx = delta / NETLBL_CATMAP_MAPSIZE; | 
|  | cmap_sft = delta % NETLBL_CATMAP_MAPSIZE; | 
|  | c_iter->bitmap[cmap_idx] | 
|  | |= e_iter->maps[i] << cmap_sft; | 
|  | } | 
|  | e_iter = e_iter->next; | 
|  | } | 
|  |  | 
|  | return 0; | 
|  |  | 
|  | netlbl_export_failure: | 
|  | netlbl_secattr_catmap_free(*catmap); | 
|  | return -ENOMEM; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * ebitmap_netlbl_import - Import a NetLabel category bitmap into an ebitmap | 
|  | * @ebmap: the ebitmap to import | 
|  | * @catmap: the NetLabel category bitmap | 
|  | * | 
|  | * Description: | 
|  | * Import a NetLabel category bitmap into a SELinux extensibile bitmap. | 
|  | * Returns zero on success, negative values on error. | 
|  | * | 
|  | */ | 
|  | int ebitmap_netlbl_import(struct ebitmap *ebmap, | 
|  | struct netlbl_lsm_secattr_catmap *catmap) | 
|  | { | 
|  | struct ebitmap_node *e_iter = NULL; | 
|  | struct ebitmap_node *emap_prev = NULL; | 
|  | struct netlbl_lsm_secattr_catmap *c_iter = catmap; | 
|  | u32 c_idx, c_pos, e_idx, e_sft; | 
|  |  | 
|  | /* NetLabel's NETLBL_CATMAP_MAPTYPE is defined as an array of u64, | 
|  | * however, it is not always compatible with an array of unsigned long | 
|  | * in ebitmap_node. | 
|  | * In addition, you should pay attention the following implementation | 
|  | * assumes unsigned long has a width equal with or less than 64-bit. | 
|  | */ | 
|  |  | 
|  | do { | 
|  | for (c_idx = 0; c_idx < NETLBL_CATMAP_MAPCNT; c_idx++) { | 
|  | unsigned int delta; | 
|  | u64 map = c_iter->bitmap[c_idx]; | 
|  |  | 
|  | if (!map) | 
|  | continue; | 
|  |  | 
|  | c_pos = c_iter->startbit | 
|  | + c_idx * NETLBL_CATMAP_MAPSIZE; | 
|  | if (!e_iter | 
|  | || c_pos >= e_iter->startbit + EBITMAP_SIZE) { | 
|  | e_iter = kzalloc(sizeof(*e_iter), GFP_ATOMIC); | 
|  | if (!e_iter) | 
|  | goto netlbl_import_failure; | 
|  | e_iter->startbit | 
|  | = c_pos - (c_pos % EBITMAP_SIZE); | 
|  | if (emap_prev == NULL) | 
|  | ebmap->node = e_iter; | 
|  | else | 
|  | emap_prev->next = e_iter; | 
|  | emap_prev = e_iter; | 
|  | } | 
|  | delta = c_pos - e_iter->startbit; | 
|  | e_idx = delta / EBITMAP_UNIT_SIZE; | 
|  | e_sft = delta % EBITMAP_UNIT_SIZE; | 
|  | while (map) { | 
|  | e_iter->maps[e_idx++] |= map & (-1UL); | 
|  | map = EBITMAP_SHIFT_UNIT_SIZE(map); | 
|  | } | 
|  | } | 
|  | c_iter = c_iter->next; | 
|  | } while (c_iter); | 
|  | if (e_iter != NULL) | 
|  | ebmap->highbit = e_iter->startbit + EBITMAP_SIZE; | 
|  | else | 
|  | ebitmap_destroy(ebmap); | 
|  |  | 
|  | return 0; | 
|  |  | 
|  | netlbl_import_failure: | 
|  | ebitmap_destroy(ebmap); | 
|  | return -ENOMEM; | 
|  | } | 
|  | #endif /* CONFIG_NETLABEL */ | 
|  |  | 
|  | int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2) | 
|  | { | 
|  | struct ebitmap_node *n1, *n2; | 
|  | int i; | 
|  |  | 
|  | if (e1->highbit < e2->highbit) | 
|  | return 0; | 
|  |  | 
|  | n1 = e1->node; | 
|  | n2 = e2->node; | 
|  | while (n1 && n2 && (n1->startbit <= n2->startbit)) { | 
|  | if (n1->startbit < n2->startbit) { | 
|  | n1 = n1->next; | 
|  | continue; | 
|  | } | 
|  | for (i = 0; i < EBITMAP_UNIT_NUMS; i++) { | 
|  | if ((n1->maps[i] & n2->maps[i]) != n2->maps[i]) | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | n1 = n1->next; | 
|  | n2 = n2->next; | 
|  | } | 
|  |  | 
|  | if (n2) | 
|  | return 0; | 
|  |  | 
|  | return 1; | 
|  | } | 
|  |  | 
|  | int ebitmap_get_bit(struct ebitmap *e, unsigned long bit) | 
|  | { | 
|  | struct ebitmap_node *n; | 
|  |  | 
|  | if (e->highbit < bit) | 
|  | return 0; | 
|  |  | 
|  | n = e->node; | 
|  | while (n && (n->startbit <= bit)) { | 
|  | if ((n->startbit + EBITMAP_SIZE) > bit) | 
|  | return ebitmap_node_get_bit(n, bit); | 
|  | n = n->next; | 
|  | } | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value) | 
|  | { | 
|  | struct ebitmap_node *n, *prev, *new; | 
|  |  | 
|  | prev = NULL; | 
|  | n = e->node; | 
|  | while (n && n->startbit <= bit) { | 
|  | if ((n->startbit + EBITMAP_SIZE) > bit) { | 
|  | if (value) { | 
|  | ebitmap_node_set_bit(n, bit); | 
|  | } else { | 
|  | unsigned int s; | 
|  |  | 
|  | ebitmap_node_clr_bit(n, bit); | 
|  |  | 
|  | s = find_first_bit(n->maps, EBITMAP_SIZE); | 
|  | if (s < EBITMAP_SIZE) | 
|  | return 0; | 
|  |  | 
|  | /* drop this node from the bitmap */ | 
|  | if (!n->next) { | 
|  | /* | 
|  | * this was the highest map | 
|  | * within the bitmap | 
|  | */ | 
|  | if (prev) | 
|  | e->highbit = prev->startbit | 
|  | + EBITMAP_SIZE; | 
|  | else | 
|  | e->highbit = 0; | 
|  | } | 
|  | if (prev) | 
|  | prev->next = n->next; | 
|  | else | 
|  | e->node = n->next; | 
|  | kfree(n); | 
|  | } | 
|  | return 0; | 
|  | } | 
|  | prev = n; | 
|  | n = n->next; | 
|  | } | 
|  |  | 
|  | if (!value) | 
|  | return 0; | 
|  |  | 
|  | new = kzalloc(sizeof(*new), GFP_ATOMIC); | 
|  | if (!new) | 
|  | return -ENOMEM; | 
|  |  | 
|  | new->startbit = bit - (bit % EBITMAP_SIZE); | 
|  | ebitmap_node_set_bit(new, bit); | 
|  |  | 
|  | if (!n) | 
|  | /* this node will be the highest map within the bitmap */ | 
|  | e->highbit = new->startbit + EBITMAP_SIZE; | 
|  |  | 
|  | if (prev) { | 
|  | new->next = prev->next; | 
|  | prev->next = new; | 
|  | } else { | 
|  | new->next = e->node; | 
|  | e->node = new; | 
|  | } | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | void ebitmap_destroy(struct ebitmap *e) | 
|  | { | 
|  | struct ebitmap_node *n, *temp; | 
|  |  | 
|  | if (!e) | 
|  | return; | 
|  |  | 
|  | n = e->node; | 
|  | while (n) { | 
|  | temp = n; | 
|  | n = n->next; | 
|  | kfree(temp); | 
|  | } | 
|  |  | 
|  | e->highbit = 0; | 
|  | e->node = NULL; | 
|  | return; | 
|  | } | 
|  |  | 
|  | int ebitmap_read(struct ebitmap *e, void *fp) | 
|  | { | 
|  | struct ebitmap_node *n = NULL; | 
|  | u32 mapunit, count, startbit, index; | 
|  | u64 map; | 
|  | __le32 buf[3]; | 
|  | int rc, i; | 
|  |  | 
|  | ebitmap_init(e); | 
|  |  | 
|  | rc = next_entry(buf, fp, sizeof buf); | 
|  | if (rc < 0) | 
|  | goto out; | 
|  |  | 
|  | mapunit = le32_to_cpu(buf[0]); | 
|  | e->highbit = le32_to_cpu(buf[1]); | 
|  | count = le32_to_cpu(buf[2]); | 
|  |  | 
|  | if (mapunit != sizeof(u64) * 8) { | 
|  | printk(KERN_ERR "SELinux: ebitmap: map size %u does not " | 
|  | "match my size %Zd (high bit was %d)\n", | 
|  | mapunit, sizeof(u64) * 8, e->highbit); | 
|  | goto bad; | 
|  | } | 
|  |  | 
|  | /* round up e->highbit */ | 
|  | e->highbit += EBITMAP_SIZE - 1; | 
|  | e->highbit -= (e->highbit % EBITMAP_SIZE); | 
|  |  | 
|  | if (!e->highbit) { | 
|  | e->node = NULL; | 
|  | goto ok; | 
|  | } | 
|  |  | 
|  | for (i = 0; i < count; i++) { | 
|  | rc = next_entry(&startbit, fp, sizeof(u32)); | 
|  | if (rc < 0) { | 
|  | printk(KERN_ERR "SELinux: ebitmap: truncated map\n"); | 
|  | goto bad; | 
|  | } | 
|  | startbit = le32_to_cpu(startbit); | 
|  |  | 
|  | if (startbit & (mapunit - 1)) { | 
|  | printk(KERN_ERR "SELinux: ebitmap start bit (%d) is " | 
|  | "not a multiple of the map unit size (%u)\n", | 
|  | startbit, mapunit); | 
|  | goto bad; | 
|  | } | 
|  | if (startbit > e->highbit - mapunit) { | 
|  | printk(KERN_ERR "SELinux: ebitmap start bit (%d) is " | 
|  | "beyond the end of the bitmap (%u)\n", | 
|  | startbit, (e->highbit - mapunit)); | 
|  | goto bad; | 
|  | } | 
|  |  | 
|  | if (!n || startbit >= n->startbit + EBITMAP_SIZE) { | 
|  | struct ebitmap_node *tmp; | 
|  | tmp = kzalloc(sizeof(*tmp), GFP_KERNEL); | 
|  | if (!tmp) { | 
|  | printk(KERN_ERR | 
|  | "SELinux: ebitmap: out of memory\n"); | 
|  | rc = -ENOMEM; | 
|  | goto bad; | 
|  | } | 
|  | /* round down */ | 
|  | tmp->startbit = startbit - (startbit % EBITMAP_SIZE); | 
|  | if (n) | 
|  | n->next = tmp; | 
|  | else | 
|  | e->node = tmp; | 
|  | n = tmp; | 
|  | } else if (startbit <= n->startbit) { | 
|  | printk(KERN_ERR "SELinux: ebitmap: start bit %d" | 
|  | " comes after start bit %d\n", | 
|  | startbit, n->startbit); | 
|  | goto bad; | 
|  | } | 
|  |  | 
|  | rc = next_entry(&map, fp, sizeof(u64)); | 
|  | if (rc < 0) { | 
|  | printk(KERN_ERR "SELinux: ebitmap: truncated map\n"); | 
|  | goto bad; | 
|  | } | 
|  | map = le64_to_cpu(map); | 
|  |  | 
|  | index = (startbit - n->startbit) / EBITMAP_UNIT_SIZE; | 
|  | while (map) { | 
|  | n->maps[index++] = map & (-1UL); | 
|  | map = EBITMAP_SHIFT_UNIT_SIZE(map); | 
|  | } | 
|  | } | 
|  | ok: | 
|  | rc = 0; | 
|  | out: | 
|  | return rc; | 
|  | bad: | 
|  | if (!rc) | 
|  | rc = -EINVAL; | 
|  | ebitmap_destroy(e); | 
|  | goto out; | 
|  | } |