0275276035
The original NetLabel category bitmap was a straight char bitmap which worked fine for the initial release as it only supported 240 bits due to limitations in the CIPSO restricted bitmap tag (tag type 0x01). This patch converts that straight char bitmap into an extensibile/sparse bitmap in order to lay the foundation for other CIPSO tag types and protocols. This patch also has a nice side effect in that all of the security attributes passed by NetLabel into the LSM are now in a format which is in the host's native byte/bit ordering which makes the LSM specific code much simpler; look at the changes in security/selinux/ss/ebitmap.c as an example. Signed-off-by: Paul Moore <paul.moore@hp.com> Signed-off-by: James Morris <jmorris@namei.org>
99 lines
2.7 KiB
C
99 lines
2.7 KiB
C
/*
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* An extensible bitmap is a bitmap that supports an
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* arbitrary number of bits. Extensible bitmaps are
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* used to represent sets of values, such as types,
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* roles, categories, and classes.
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*
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* Each extensible bitmap is implemented as a linked
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* list of bitmap nodes, where each bitmap node has
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* an explicitly specified starting bit position within
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* the total bitmap.
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*
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* Author : Stephen Smalley, <sds@epoch.ncsc.mil>
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*/
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#ifndef _SS_EBITMAP_H_
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#define _SS_EBITMAP_H_
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#include <net/netlabel.h>
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#define MAPTYPE u64 /* portion of bitmap in each node */
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#define MAPSIZE (sizeof(MAPTYPE) * 8) /* number of bits in node bitmap */
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#define MAPBIT 1ULL /* a bit in the node bitmap */
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struct ebitmap_node {
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u32 startbit; /* starting position in the total bitmap */
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MAPTYPE map; /* this node's portion of the bitmap */
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struct ebitmap_node *next;
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};
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struct ebitmap {
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struct ebitmap_node *node; /* first node in the bitmap */
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u32 highbit; /* highest position in the total bitmap */
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};
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#define ebitmap_length(e) ((e)->highbit)
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#define ebitmap_startbit(e) ((e)->node ? (e)->node->startbit : 0)
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static inline unsigned int ebitmap_start(struct ebitmap *e,
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struct ebitmap_node **n)
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{
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*n = e->node;
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return ebitmap_startbit(e);
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}
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static inline void ebitmap_init(struct ebitmap *e)
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{
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memset(e, 0, sizeof(*e));
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}
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static inline unsigned int ebitmap_next(struct ebitmap_node **n,
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unsigned int bit)
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{
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if ((bit == ((*n)->startbit + MAPSIZE - 1)) &&
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(*n)->next) {
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*n = (*n)->next;
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return (*n)->startbit;
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}
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return (bit+1);
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}
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static inline int ebitmap_node_get_bit(struct ebitmap_node * n,
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unsigned int bit)
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{
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if (n->map & (MAPBIT << (bit - n->startbit)))
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return 1;
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return 0;
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}
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#define ebitmap_for_each_bit(e, n, bit) \
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for (bit = ebitmap_start(e, &n); bit < ebitmap_length(e); bit = ebitmap_next(&n, bit)) \
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int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2);
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int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
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int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2);
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int ebitmap_get_bit(struct ebitmap *e, unsigned long bit);
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int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value);
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void ebitmap_destroy(struct ebitmap *e);
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int ebitmap_read(struct ebitmap *e, void *fp);
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#ifdef CONFIG_NETLABEL
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int ebitmap_netlbl_export(struct ebitmap *ebmap,
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struct netlbl_lsm_secattr_catmap **catmap);
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int ebitmap_netlbl_import(struct ebitmap *ebmap,
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struct netlbl_lsm_secattr_catmap *catmap);
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#else
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static inline int ebitmap_netlbl_export(struct ebitmap *ebmap,
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struct netlbl_lsm_secattr_catmap **catmap)
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{
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return -ENOMEM;
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}
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static inline int ebitmap_netlbl_import(struct ebitmap *ebmap,
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struct netlbl_lsm_secattr_catmap *catmap)
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{
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return -ENOMEM;
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}
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#endif
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#endif /* _SS_EBITMAP_H_ */
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