diff options
Diffstat (limited to 'security/selinux/ss/mls.c')
| -rw-r--r-- | security/selinux/ss/mls.c | 514 |
1 files changed, 315 insertions, 199 deletions
diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c index aaefac2921f..d307b37ddc2 100644 --- a/security/selinux/ss/mls.c +++ b/security/selinux/ss/mls.c @@ -8,13 +8,21 @@ * * Support for enhanced MLS infrastructure. * - * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. + * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. + */ +/* + * Updated: Hewlett-Packard <paul@paul-moore.com> + * + * Added support to import/export the MLS label from NetLabel + * + * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 */ #include <linux/kernel.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/errno.h> +#include <net/netlabel.h> #include "sidtab.h" #include "mls.h" #include "policydb.h" @@ -24,41 +32,45 @@ * Return the length in bytes for the MLS fields of the * security context string representation of `context'. */ -int mls_compute_context_len(struct context * context) +int mls_compute_context_len(struct context *context) { - int i, l, len, range; + int i, l, len, head, prev; + char *nm; + struct ebitmap *e; struct ebitmap_node *node; - if (!selinux_mls_enabled) + if (!policydb.mls_enabled) return 0; len = 1; /* for the beginning ":" */ for (l = 0; l < 2; l++) { - range = 0; - len += strlen(policydb.p_sens_val_to_name[context->range.level[l].sens - 1]); - - ebitmap_for_each_bit(&context->range.level[l].cat, node, i) { - if (ebitmap_node_get_bit(node, i)) { - if (range) { - range++; - continue; - } + int index_sens = context->range.level[l].sens; + len += strlen(sym_name(&policydb, SYM_LEVELS, index_sens - 1)); - len += strlen(policydb.p_cat_val_to_name[i]) + 1; - range++; - } else { - if (range > 1) - len += strlen(policydb.p_cat_val_to_name[i - 1]) + 1; - range = 0; + /* categories */ + head = -2; + prev = -2; + e = &context->range.level[l].cat; + ebitmap_for_each_positive_bit(e, node, i) { + if (i - prev > 1) { + /* one or more negative bits are skipped */ + if (head != prev) { + nm = sym_name(&policydb, SYM_CATS, prev); + len += strlen(nm) + 1; + } + nm = sym_name(&policydb, SYM_CATS, i); + len += strlen(nm) + 1; + head = i; } + prev = i; + } + if (prev != head) { + nm = sym_name(&policydb, SYM_CATS, prev); + len += strlen(nm) + 1; } - /* Handle case where last category is the end of range */ - if (range > 1) - len += strlen(policydb.p_cat_val_to_name[i - 1]) + 1; - if (l == 0) { if (mls_level_eq(&context->range.level[0], - &context->range.level[1])) + &context->range.level[1])) break; else len++; @@ -74,13 +86,14 @@ int mls_compute_context_len(struct context * context) * Update `*scontext' to point to the end of the MLS fields. */ void mls_sid_to_context(struct context *context, - char **scontext) + char **scontext) { - char *scontextp; - int i, l, range, wrote_sep; + char *scontextp, *nm; + int i, l, head, prev; + struct ebitmap *e; struct ebitmap_node *node; - if (!selinux_mls_enabled) + if (!policydb.mls_enabled) return; scontextp = *scontext; @@ -89,61 +102,54 @@ void mls_sid_to_context(struct context *context, scontextp++; for (l = 0; l < 2; l++) { - range = 0; - wrote_sep = 0; - strcpy(scontextp, - policydb.p_sens_val_to_name[context->range.level[l].sens - 1]); - scontextp += strlen(policydb.p_sens_val_to_name[context->range.level[l].sens - 1]); + strcpy(scontextp, sym_name(&policydb, SYM_LEVELS, + context->range.level[l].sens - 1)); + scontextp += strlen(scontextp); /* categories */ - ebitmap_for_each_bit(&context->range.level[l].cat, node, i) { - if (ebitmap_node_get_bit(node, i)) { - if (range) { - range++; - continue; - } - - if (!wrote_sep) { - *scontextp++ = ':'; - wrote_sep = 1; - } else - *scontextp++ = ','; - strcpy(scontextp, policydb.p_cat_val_to_name[i]); - scontextp += strlen(policydb.p_cat_val_to_name[i]); - range++; - } else { - if (range > 1) { - if (range > 2) + head = -2; + prev = -2; + e = &context->range.level[l].cat; + ebitmap_for_each_positive_bit(e, node, i) { + if (i - prev > 1) { + /* one or more negative bits are skipped */ + if (prev != head) { + if (prev - head > 1) *scontextp++ = '.'; else *scontextp++ = ','; - - strcpy(scontextp, policydb.p_cat_val_to_name[i - 1]); - scontextp += strlen(policydb.p_cat_val_to_name[i - 1]); + nm = sym_name(&policydb, SYM_CATS, prev); + strcpy(scontextp, nm); + scontextp += strlen(nm); } - range = 0; + if (prev < 0) + *scontextp++ = ':'; + else + *scontextp++ = ','; + nm = sym_name(&policydb, SYM_CATS, i); + strcpy(scontextp, nm); + scontextp += strlen(nm); + head = i; } + prev = i; } - /* Handle case where last category is the end of range */ - if (range > 1) { - if (range > 2) + if (prev != head) { + if (prev - head > 1) *scontextp++ = '.'; else *scontextp++ = ','; - - strcpy(scontextp, policydb.p_cat_val_to_name[i - 1]); - scontextp += strlen(policydb.p_cat_val_to_name[i - 1]); + nm = sym_name(&policydb, SYM_CATS, prev); + strcpy(scontextp, nm); + scontextp += strlen(nm); } if (l == 0) { if (mls_level_eq(&context->range.level[0], - &context->range.level[1])) + &context->range.level[1])) break; - else { - *scontextp = '-'; - scontextp++; - } + else + *scontextp++ = '-'; } } @@ -151,51 +157,47 @@ void mls_sid_to_context(struct context *context, return; } +int mls_level_isvalid(struct policydb *p, struct mls_level *l) +{ + struct level_datum *levdatum; + + if (!l->sens || l->sens > p->p_levels.nprim) + return 0; + levdatum = hashtab_search(p->p_levels.table, + sym_name(p, SYM_LEVELS, l->sens - 1)); + if (!levdatum) + return 0; + + /* + * Return 1 iff all the bits set in l->cat are also be set in + * levdatum->level->cat and no bit in l->cat is larger than + * p->p_cats.nprim. + */ + return ebitmap_contains(&levdatum->level->cat, &l->cat, + p->p_cats.nprim); +} + +int mls_range_isvalid(struct policydb *p, struct mls_range *r) +{ + return (mls_level_isvalid(p, &r->level[0]) && + mls_level_isvalid(p, &r->level[1]) && + mls_level_dom(&r->level[1], &r->level[0])); +} + /* * Return 1 if the MLS fields in the security context * structure `c' are valid. Return 0 otherwise. */ int mls_context_isvalid(struct policydb *p, struct context *c) { - struct level_datum *levdatum; struct user_datum *usrdatum; - struct ebitmap_node *node; - int i, l; - if (!selinux_mls_enabled) + if (!p->mls_enabled) return 1; - /* - * MLS range validity checks: high must dominate low, low level must - * be valid (category set <-> sensitivity check), and high level must - * be valid (category set <-> sensitivity check) - */ - if (!mls_level_dom(&c->range.level[1], &c->range.level[0])) - /* High does not dominate low. */ + if (!mls_range_isvalid(p, &c->range)) return 0; - for (l = 0; l < 2; l++) { - if (!c->range.level[l].sens || c->range.level[l].sens > p->p_levels.nprim) - return 0; - levdatum = hashtab_search(p->p_levels.table, - p->p_sens_val_to_name[c->range.level[l].sens - 1]); - if (!levdatum) - return 0; - - ebitmap_for_each_bit(&c->range.level[l].cat, node, i) { - if (ebitmap_node_get_bit(node, i)) { - if (i > p->p_cats.nprim) - return 0; - if (!ebitmap_get_bit(&levdatum->level->cat, i)) - /* - * Category may not be associated with - * sensitivity in low level. - */ - return 0; - } - } - } - if (c->role == OBJECT_R_VAL) return 1; @@ -212,26 +214,6 @@ int mls_context_isvalid(struct policydb *p, struct context *c) } /* - * Copies the MLS range from `src' into `dst'. - */ -static inline int mls_copy_context(struct context *dst, - struct context *src) -{ - int l, rc = 0; - - /* Copy the MLS range from the source context */ - for (l = 0; l < 2; l++) { - dst->range.level[l].sens = src->range.level[l].sens; - rc = ebitmap_cpy(&dst->range.level[l].cat, - &src->range.level[l].cat); - if (rc) - break; - } - - return rc; -} - -/* * Set the MLS fields in the security context structure * `context' based on the string representation in * the string `*scontext'. Update `*scontext' to @@ -249,7 +231,8 @@ static inline int mls_copy_context(struct context *dst, * Policy read-lock must be held for sidtab lookup. * */ -int mls_context_to_sid(char oldc, +int mls_context_to_sid(struct policydb *pol, + char oldc, char **scontext, struct context *context, struct sidtab *s, @@ -262,8 +245,11 @@ int mls_context_to_sid(char oldc, struct cat_datum *catdatum, *rngdatum; int l, rc = -EINVAL; - if (!selinux_mls_enabled) + if (!pol->mls_enabled) { + if (def_sid != SECSID_NULL && oldc) + *scontext += strlen(*scontext) + 1; return 0; + } /* * No MLS component to the security context, try and map to @@ -279,7 +265,7 @@ int mls_context_to_sid(char oldc, if (!defcon) goto out; - rc = mls_copy_context(context, defcon); + rc = mls_context_cpy(context, defcon); goto out; } @@ -289,11 +275,11 @@ int mls_context_to_sid(char oldc, p++; delim = *p; - if (delim != 0) - *p++ = 0; + if (delim != '\0') + *p++ = '\0'; for (l = 0; l < 2; l++) { - levdatum = hashtab_search(policydb.p_levels.table, scontextp); + levdatum = hashtab_search(pol->p_levels.table, scontextp); if (!levdatum) { rc = -EINVAL; goto out; @@ -308,24 +294,25 @@ int mls_context_to_sid(char oldc, while (*p && *p != ',' && *p != '-') p++; delim = *p; - if (delim != 0) - *p++ = 0; + if (delim != '\0') + *p++ = '\0'; /* Separate into range if exists */ - if ((rngptr = strchr(scontextp, '.')) != NULL) { + rngptr = strchr(scontextp, '.'); + if (rngptr != NULL) { /* Remove '.' */ - *rngptr++ = 0; + *rngptr++ = '\0'; } - catdatum = hashtab_search(policydb.p_cats.table, - scontextp); + catdatum = hashtab_search(pol->p_cats.table, + scontextp); if (!catdatum) { rc = -EINVAL; goto out; } rc = ebitmap_set_bit(&context->range.level[l].cat, - catdatum->value - 1, 1); + catdatum->value - 1, 1); if (rc) goto out; @@ -333,7 +320,7 @@ int mls_context_to_sid(char oldc, if (rngptr) { int i; - rngdatum = hashtab_search(policydb.p_cats.table, rngptr); + rngdatum = hashtab_search(pol->p_cats.table, rngptr); if (!rngdatum) { rc = -EINVAL; goto out; @@ -362,8 +349,8 @@ int mls_context_to_sid(char oldc, p++; delim = *p; - if (delim != 0) - *p++ = 0; + if (delim != '\0') + *p++ = '\0'; } else break; } @@ -382,20 +369,28 @@ out: } /* - * Copies the effective MLS range from `src' into `dst'. + * Set the MLS fields in the security context structure + * `context' based on the string representation in + * the string `str'. This function will allocate temporary memory with the + * given constraints of gfp_mask. */ -static inline int mls_scopy_context(struct context *dst, - struct context *src) +int mls_from_string(char *str, struct context *context, gfp_t gfp_mask) { - int l, rc = 0; + char *tmpstr, *freestr; + int rc; - /* Copy the MLS range from the source context */ - for (l = 0; l < 2; l++) { - dst->range.level[l].sens = src->range.level[0].sens; - rc = ebitmap_cpy(&dst->range.level[l].cat, - &src->range.level[0].cat); - if (rc) - break; + if (!policydb.mls_enabled) + return -EINVAL; + + /* we need freestr because mls_context_to_sid will change + the value of tmpstr */ + tmpstr = freestr = kstrdup(str, gfp_mask); + if (!tmpstr) { + rc = -ENOMEM; + } else { + rc = mls_context_to_sid(&policydb, ':', &tmpstr, context, + NULL, SECSID_NULL); + kfree(freestr); } return rc; @@ -404,8 +399,8 @@ static inline int mls_scopy_context(struct context *dst, /* * Copies the MLS range `range' into `context'. */ -static inline int mls_range_set(struct context *context, - struct mls_range *range) +int mls_range_set(struct context *context, + struct mls_range *range) { int l, rc = 0; @@ -422,9 +417,9 @@ static inline int mls_range_set(struct context *context, } int mls_setup_user_range(struct context *fromcon, struct user_datum *user, - struct context *usercon) + struct context *usercon) { - if (selinux_mls_enabled) { + if (policydb.mls_enabled) { struct mls_level *fromcon_sen = &(fromcon->range.level[0]); struct mls_level *fromcon_clr = &(fromcon->range.level[1]); struct mls_level *user_low = &(user->range.level[0]); @@ -434,13 +429,13 @@ int mls_setup_user_range(struct context *fromcon, struct user_datum *user, struct mls_level *usercon_clr = &(usercon->range.level[1]); /* Honor the user's default level if we can */ - if (mls_level_between(user_def, fromcon_sen, fromcon_clr)) { + if (mls_level_between(user_def, fromcon_sen, fromcon_clr)) *usercon_sen = *user_def; - } else if (mls_level_between(fromcon_sen, user_def, user_clr)) { + else if (mls_level_between(fromcon_sen, user_def, user_clr)) *usercon_sen = *fromcon_sen; - } else if (mls_level_between(fromcon_clr, user_low, user_def)) { + else if (mls_level_between(fromcon_clr, user_low, user_def)) *usercon_sen = *user_low; - } else + else return -EINVAL; /* Lower the clearance of available contexts @@ -448,11 +443,11 @@ int mls_setup_user_range(struct context *fromcon, struct user_datum *user, that of the user's default clearance (but only if the "fromcon" clearance dominates the user's computed sensitivity level) */ - if (mls_level_dom(user_clr, fromcon_clr)) { + if (mls_level_dom(user_clr, fromcon_clr)) *usercon_clr = *fromcon_clr; - } else if (mls_level_dom(fromcon_clr, user_clr)) { + else if (mls_level_dom(fromcon_clr, user_clr)) *usercon_clr = *user_clr; - } else + else return -EINVAL; } @@ -474,30 +469,31 @@ int mls_convert_context(struct policydb *oldp, struct ebitmap_node *node; int l, i; - if (!selinux_mls_enabled) + if (!policydb.mls_enabled) return 0; for (l = 0; l < 2; l++) { levdatum = hashtab_search(newp->p_levels.table, - oldp->p_sens_val_to_name[c->range.level[l].sens - 1]); + sym_name(oldp, SYM_LEVELS, + c->range.level[l].sens - 1)); if (!levdatum) return -EINVAL; c->range.level[l].sens = levdatum->level->sens; ebitmap_init(&bitmap); - ebitmap_for_each_bit(&c->range.level[l].cat, node, i) { - if (ebitmap_node_get_bit(node, i)) { - int rc; - - catdatum = hashtab_search(newp->p_cats.table, - oldp->p_cat_val_to_name[i]); - if (!catdatum) - return -EINVAL; - rc = ebitmap_set_bit(&bitmap, catdatum->value - 1, 1); - if (rc) - return rc; - } + ebitmap_for_each_positive_bit(&c->range.level[l].cat, node, i) { + int rc; + + catdatum = hashtab_search(newp->p_cats.table, + sym_name(oldp, SYM_CATS, i)); + if (!catdatum) + return -EINVAL; + rc = ebitmap_set_bit(&bitmap, catdatum->value - 1, 1); + if (rc) + return rc; + + cond_resched(); } ebitmap_destroy(&c->range.level[l].cat); c->range.level[l].cat = bitmap; @@ -510,47 +506,167 @@ int mls_compute_sid(struct context *scontext, struct context *tcontext, u16 tclass, u32 specified, - struct context *newcontext) + struct context *newcontext, + bool sock) { - if (!selinux_mls_enabled) + struct range_trans rtr; + struct mls_range *r; + struct class_datum *cladatum; + int default_range = 0; + + if (!policydb.mls_enabled) return 0; switch (specified) { case AVTAB_TRANSITION: - if (tclass == SECCLASS_PROCESS) { - struct range_trans *rangetr; - /* Look for a range transition rule. */ - for (rangetr = policydb.range_tr; rangetr; - rangetr = rangetr->next) { - if (rangetr->dom == scontext->type && - rangetr->type == tcontext->type) { - /* Set the range from the rule */ - return mls_range_set(newcontext, - &rangetr->range); - } - } + /* Look for a range transition rule. */ + rtr.source_type = scontext->type; + rtr.target_type = tcontext->type; + rtr.target_class = tclass; + r = hashtab_search(policydb.range_tr, &rtr); + if (r) + return mls_range_set(newcontext, r); + + if (tclass && tclass <= policydb.p_classes.nprim) { + cladatum = policydb.class_val_to_struct[tclass - 1]; + if (cladatum) + default_range = cladatum->default_range; + } + + switch (default_range) { + case DEFAULT_SOURCE_LOW: + return mls_context_cpy_low(newcontext, scontext); + case DEFAULT_SOURCE_HIGH: + return mls_context_cpy_high(newcontext, scontext); + case DEFAULT_SOURCE_LOW_HIGH: + return mls_context_cpy(newcontext, scontext); + case DEFAULT_TARGET_LOW: + return mls_context_cpy_low(newcontext, tcontext); + case DEFAULT_TARGET_HIGH: + return mls_context_cpy_high(newcontext, tcontext); + case DEFAULT_TARGET_LOW_HIGH: + return mls_context_cpy(newcontext, tcontext); } + /* Fallthrough */ case AVTAB_CHANGE: - if (tclass == SECCLASS_PROCESS) + if ((tclass == policydb.process_class) || (sock == true)) /* Use the process MLS attributes. */ - return mls_copy_context(newcontext, scontext); + return mls_context_cpy(newcontext, scontext); else /* Use the process effective MLS attributes. */ - return mls_scopy_context(newcontext, scontext); + return mls_context_cpy_low(newcontext, scontext); case AVTAB_MEMBER: - /* Only polyinstantiate the MLS attributes if - the type is being polyinstantiated */ - if (newcontext->type != tcontext->type) { - /* Use the process effective MLS attributes. */ - return mls_scopy_context(newcontext, scontext); - } else { - /* Use the related object MLS attributes. */ - return mls_copy_context(newcontext, tcontext); - } - default: - return -EINVAL; + /* Use the process effective MLS attributes. */ + return mls_context_cpy_low(newcontext, scontext); + + /* fall through */ } return -EINVAL; } +#ifdef CONFIG_NETLABEL +/** + * mls_export_netlbl_lvl - Export the MLS sensitivity levels to NetLabel + * @context: the security context + * @secattr: the NetLabel security attributes + * + * Description: + * Given the security context copy the low MLS sensitivity level into the + * NetLabel MLS sensitivity level field. + * + */ +void mls_export_netlbl_lvl(struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + if (!policydb.mls_enabled) + return; + + secattr->attr.mls.lvl = context->range.level[0].sens - 1; + secattr->flags |= NETLBL_SECATTR_MLS_LVL; +} + +/** + * mls_import_netlbl_lvl - Import the NetLabel MLS sensitivity levels + * @context: the security context + * @secattr: the NetLabel security attributes + * + * Description: + * Given the security context and the NetLabel security attributes, copy the + * NetLabel MLS sensitivity level into the context. + * + */ +void mls_import_netlbl_lvl(struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + if (!policydb.mls_enabled) + return; + + context->range.level[0].sens = secattr->attr.mls.lvl + 1; + context->range.level[1].sens = context->range.level[0].sens; +} + +/** + * mls_export_netlbl_cat - Export the MLS categories to NetLabel + * @context: the security context + * @secattr: the NetLabel security attributes + * + * Description: + * Given the security context copy the low MLS categories into the NetLabel + * MLS category field. Returns zero on success, negative values on failure. + * + */ +int mls_export_netlbl_cat(struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + int rc; + + if (!policydb.mls_enabled) + return 0; + + rc = ebitmap_netlbl_export(&context->range.level[0].cat, + &secattr->attr.mls.cat); + if (rc == 0 && secattr->attr.mls.cat != NULL) + secattr->flags |= NETLBL_SECATTR_MLS_CAT; + + return rc; +} + +/** + * mls_import_netlbl_cat - Import the MLS categories from NetLabel + * @context: the security context + * @secattr: the NetLabel security attributes + * + * Description: + * Copy the NetLabel security attributes into the SELinux context; since the + * NetLabel security attribute only contains a single MLS category use it for + * both the low and high categories of the context. Returns zero on success, + * negative values on failure. + * + */ +int mls_import_netlbl_cat(struct context *context, + struct netlbl_lsm_secattr *secattr) +{ + int rc; + + if (!policydb.mls_enabled) + return 0; + + rc = ebitmap_netlbl_import(&context->range.level[0].cat, + secattr->attr.mls.cat); + if (rc != 0) + goto import_netlbl_cat_failure; + + rc = ebitmap_cpy(&context->range.level[1].cat, + &context->range.level[0].cat); + if (rc != 0) + goto import_netlbl_cat_failure; + + return 0; + +import_netlbl_cat_failure: + ebitmap_destroy(&context->range.level[0].cat); + ebitmap_destroy(&context->range.level[1].cat); + return rc; +} +#endif /* CONFIG_NETLABEL */ |
