From 2463c26d50adc282d19317013ba0ff473823ca47 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Thu, 28 Apr 2011 15:11:21 -0400 Subject: [PATCH] SELinux: put name based create rules in a hashtable To shorten the list we need to run if filename trans rules exist for the type of the given parent directory I put them in a hashtable. Given the policy we are expecting to use in Fedora this takes the worst case list run from about 5,000 entries to 17. Signed-off-by: Eric Paris Reviewed-by: James Morris --- security/selinux/ss/policydb.c | 167 +++++++++++++++++++++++---------- security/selinux/ss/policydb.h | 9 +- security/selinux/ss/services.c | 20 ++-- 3 files changed, 135 insertions(+), 61 deletions(-) diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index ca7a7231b5a..549120c56ed 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -184,6 +184,43 @@ out: return rc; } +static u32 filenametr_hash(struct hashtab *h, const void *k) +{ + const struct filename_trans *ft = k; + unsigned long hash; + unsigned int byte_num; + unsigned char focus; + + hash = ft->stype ^ ft->ttype ^ ft->tclass; + + byte_num = 0; + while ((focus = ft->name[byte_num++])) + hash = partial_name_hash(focus, hash); + return hash & (h->size - 1); +} + +static int filenametr_cmp(struct hashtab *h, const void *k1, const void *k2) +{ + const struct filename_trans *ft1 = k1; + const struct filename_trans *ft2 = k2; + int v; + + v = ft1->stype - ft2->stype; + if (v) + return v; + + v = ft1->ttype - ft2->ttype; + if (v) + return v; + + v = ft1->tclass - ft2->tclass; + if (v) + return v; + + return strcmp(ft1->name, ft2->name); + +} + static u32 rangetr_hash(struct hashtab *h, const void *k) { const struct range_trans *key = k; @@ -236,6 +273,10 @@ static int policydb_init(struct policydb *p) if (rc) goto out; + p->filename_trans = hashtab_create(filenametr_hash, filenametr_cmp, (1 << 10)); + if (!p->filename_trans) + goto out; + p->range_tr = hashtab_create(rangetr_hash, rangetr_cmp, 256); if (!p->range_tr) goto out; @@ -246,6 +287,8 @@ static int policydb_init(struct policydb *p) return 0; out: + hashtab_destroy(p->filename_trans); + hashtab_destroy(p->range_tr); for (i = 0; i < SYM_NUM; i++) hashtab_destroy(p->symtab[i].table); return rc; @@ -675,6 +718,16 @@ static int (*destroy_f[SYM_NUM]) (void *key, void *datum, void *datap) = cat_destroy, }; +static int filenametr_destroy(void *key, void *datum, void *p) +{ + struct filename_trans *ft = key; + kfree(ft->name); + kfree(key); + kfree(datum); + cond_resched(); + return 0; +} + static int range_tr_destroy(void *key, void *datum, void *p) { struct mls_range *rt = datum; @@ -709,7 +762,6 @@ void policydb_destroy(struct policydb *p) int i; struct role_allow *ra, *lra = NULL; struct role_trans *tr, *ltr = NULL; - struct filename_trans *ft, *nft; for (i = 0; i < SYM_NUM; i++) { cond_resched(); @@ -773,6 +825,9 @@ void policydb_destroy(struct policydb *p) } kfree(lra); + hashtab_map(p->filename_trans, filenametr_destroy, NULL); + hashtab_destroy(p->filename_trans); + hashtab_map(p->range_tr, range_tr_destroy, NULL); hashtab_destroy(p->range_tr); @@ -788,14 +843,6 @@ void policydb_destroy(struct policydb *p) flex_array_free(p->type_attr_map_array); } - ft = p->filename_trans; - while (ft) { - nft = ft->next; - kfree(ft->name); - kfree(ft); - ft = nft; - } - ebitmap_destroy(&p->filename_trans_ttypes); ebitmap_destroy(&p->policycaps); ebitmap_destroy(&p->permissive_map); @@ -1806,9 +1853,10 @@ out: static int filename_trans_read(struct policydb *p, void *fp) { - struct filename_trans *ft, *last; - u32 nel, len; + struct filename_trans *ft; + struct filename_trans_datum *otype; char *name; + u32 nel, len; __le32 buf[4]; int rc, i; @@ -1817,25 +1865,23 @@ static int filename_trans_read(struct policydb *p, void *fp) rc = next_entry(buf, fp, sizeof(u32)); if (rc) - goto out; + return rc; nel = le32_to_cpu(buf[0]); - last = p->filename_trans; - while (last && last->next) - last = last->next; - for (i = 0; i < nel; i++) { + ft = NULL; + otype = NULL; + name = NULL; + rc = -ENOMEM; ft = kzalloc(sizeof(*ft), GFP_KERNEL); if (!ft) goto out; - /* add it to the tail of the list */ - if (!last) - p->filename_trans = ft; - else - last->next = ft; - last = ft; + rc = -ENOMEM; + otype = kmalloc(sizeof(*otype), GFP_KERNEL); + if (!otype) + goto out; /* length of the path component string */ rc = next_entry(buf, fp, sizeof(u32)); @@ -1863,14 +1909,22 @@ static int filename_trans_read(struct policydb *p, void *fp) ft->stype = le32_to_cpu(buf[0]); ft->ttype = le32_to_cpu(buf[1]); ft->tclass = le32_to_cpu(buf[2]); - ft->otype = le32_to_cpu(buf[3]); + + otype->otype = le32_to_cpu(buf[3]); rc = ebitmap_set_bit(&p->filename_trans_ttypes, ft->ttype, 1); if (rc) goto out; + + hashtab_insert(p->filename_trans, ft, otype); } - rc = 0; + hash_eval(p->filename_trans, "filenametr"); + return 0; out: + kfree(ft); + kfree(name); + kfree(otype); + return rc; } @@ -3131,43 +3185,60 @@ static int range_write(struct policydb *p, void *fp) return 0; } -static int filename_trans_write(struct policydb *p, void *fp) +static int filename_write_helper(void *key, void *data, void *ptr) { - struct filename_trans *ft; - u32 len, nel = 0; __le32 buf[4]; + struct filename_trans *ft = key; + struct filename_trans_datum *otype = data; + void *fp = ptr; int rc; + u32 len; - for (ft = p->filename_trans; ft; ft = ft->next) - nel++; - - buf[0] = cpu_to_le32(nel); + len = strlen(ft->name); + buf[0] = cpu_to_le32(len); rc = put_entry(buf, sizeof(u32), 1, fp); if (rc) return rc; - for (ft = p->filename_trans; ft; ft = ft->next) { - len = strlen(ft->name); - buf[0] = cpu_to_le32(len); - rc = put_entry(buf, sizeof(u32), 1, fp); - if (rc) - return rc; + rc = put_entry(ft->name, sizeof(char), len, fp); + if (rc) + return rc; - rc = put_entry(ft->name, sizeof(char), len, fp); - if (rc) - return rc; + buf[0] = ft->stype; + buf[1] = ft->ttype; + buf[2] = ft->tclass; + buf[3] = otype->otype; - buf[0] = ft->stype; - buf[1] = ft->ttype; - buf[2] = ft->tclass; - buf[3] = ft->otype; + rc = put_entry(buf, sizeof(u32), 4, fp); + if (rc) + return rc; - rc = put_entry(buf, sizeof(u32), 4, fp); - if (rc) - return rc; - } return 0; } + +static int filename_trans_write(struct policydb *p, void *fp) +{ + u32 nel; + __le32 buf[1]; + int rc; + + nel = 0; + rc = hashtab_map(p->filename_trans, hashtab_cnt, &nel); + if (rc) + return rc; + + buf[0] = cpu_to_le32(nel); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return rc; + + rc = hashtab_map(p->filename_trans, filename_write_helper, fp); + if (rc) + return rc; + + return 0; +} + /* * Write the configuration data in a policy database * structure to a policy database binary representation diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h index f054a9d4d11..b846c038718 100644 --- a/security/selinux/ss/policydb.h +++ b/security/selinux/ss/policydb.h @@ -79,11 +79,13 @@ struct role_trans { }; struct filename_trans { - struct filename_trans *next; u32 stype; /* current process */ u32 ttype; /* parent dir context */ u16 tclass; /* class of new object */ const char *name; /* last path component */ +}; + +struct filename_trans_datum { u32 otype; /* expected of new object */ }; @@ -227,10 +229,11 @@ struct policydb { /* role transitions */ struct role_trans *role_tr; + /* file transitions with the last path component */ /* quickly exclude lookups when parent ttype has no rules */ struct ebitmap filename_trans_ttypes; - /* file transitions with the last path component */ - struct filename_trans *filename_trans; + /* actual set of filename_trans rules */ + struct hashtab *filename_trans; /* bools indexed by (value - 1) */ struct cond_bool_datum **bool_val_to_struct; diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 6a22eaebf3b..e11b4b038f4 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -1362,7 +1362,8 @@ static void filename_compute_type(struct policydb *p, struct context *newcontext u32 stype, u32 ttype, u16 tclass, const char *objname) { - struct filename_trans *ft; + struct filename_trans ft; + struct filename_trans_datum *otype; /* * Most filename trans rules are going to live in specific directories @@ -1372,15 +1373,14 @@ static void filename_compute_type(struct policydb *p, struct context *newcontext if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype)) return; - for (ft = p->filename_trans; ft; ft = ft->next) { - if (ft->stype == stype && - ft->ttype == ttype && - ft->tclass == tclass && - !strcmp(ft->name, objname)) { - newcontext->type = ft->otype; - return; - } - } + ft.stype = stype; + ft.ttype = ttype; + ft.tclass = tclass; + ft.name = objname; + + otype = hashtab_search(p->filename_trans, &ft); + if (otype) + newcontext->type = otype->otype; } static int security_compute_sid(u32 ssid, -- 2.20.1