From f7112e6c9abf1c70f001dcf097c1d6e218a93f5c Mon Sep 17 00:00:00 2001 From: Casey Schaufler Date: Sun, 6 May 2012 15:22:02 -0700 Subject: Smack: allow for significantly longer Smack labels v4 V4 updated to current linux-security#next Targeted for git://gitorious.org/smack-next/kernel.git Modern application runtime environments like to use naming schemes that are structured and generated without human intervention. Even though the Smack limit of 23 characters for a label name is perfectly rational for human use there have been complaints that the limit is a problem in environments where names are composed from a set or sources, including vendor, author, distribution channel and application name. Names like softwarehouse-pgwodehouse-coolappstore-mellowmuskrats are becoming harder to avoid. This patch introduces long label support in Smack. Labels are now limited to 255 characters instead of the old 23. The primary reason for limiting the labels to 23 characters was so they could be directly contained in CIPSO category sets. This is still done were possible, but for labels that are too large a mapping is required. This is perfectly safe for communication that stays "on the box" and doesn't require much coordination between boxes beyond what would have been required to keep label names consistent. The bulk of this patch is in smackfs, adding and updating administrative interfaces. Because existing APIs can't be changed new ones that do much the same things as old ones have been introduced. The Smack specific CIPSO data representation has been removed and replaced with the data format used by netlabel. The CIPSO header is now computed when a label is imported rather than on use. This results in improved IP performance. The smack label is now allocated separately from the containing structure, allowing for larger strings. Four new /smack interfaces have been introduced as four of the old interfaces strictly required labels be specified in fixed length arrays. The access interface is supplemented with the check interface: access "Subject Object rwxat" access2 "Subject Object rwaxt" The load interface is supplemented with the rules interface: load "Subject Object rwxat" load2 "Subject Object rwaxt" The load-self interface is supplemented with the self-rules interface: load-self "Subject Object rwxat" load-self2 "Subject Object rwaxt" The cipso interface is supplemented with the wire interface: cipso "Subject lvl cnt c1 c2 ..." cipso2 "Subject lvl cnt c1 c2 ..." The old interfaces are maintained for compatibility. Signed-off-by: Casey Schaufler --- security/smack/smack.h | 56 ++++++++++++++++++-------------------------------- 1 file changed, 20 insertions(+), 36 deletions(-) (limited to 'security/smack/smack.h') diff --git a/security/smack/smack.h b/security/smack/smack.h index cf2594dfa933..5e031a2e4c36 100644 --- a/security/smack/smack.h +++ b/security/smack/smack.h @@ -23,13 +23,19 @@ #include /* + * Smack labels were limited to 23 characters for a long time. + */ +#define SMK_LABELLEN 24 +#define SMK_LONGLABEL 256 + +/* + * Maximum number of bytes for the levels in a CIPSO IP option. * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is * bigger than can be used, and 24 is the next lower multiple * of 8, and there are too many issues if there isn't space set * aside for the terminating null byte. */ -#define SMK_MAXLEN 23 -#define SMK_LABELLEN (SMK_MAXLEN+1) +#define SMK_CIPSOLEN 24 struct superblock_smack { char *smk_root; @@ -78,15 +84,6 @@ struct smack_rule { int smk_access; }; -/* - * An entry in the table mapping smack values to - * CIPSO level/category-set values. - */ -struct smack_cipso { - int smk_level; - char smk_catset[SMK_LABELLEN]; -}; - /* * An entry in the table identifying hosts. */ @@ -114,22 +111,19 @@ struct smk_netlbladdr { * interfaces don't. The secid should go away when all of * these components have been repaired. * - * If there is a cipso value associated with the label it - * gets stored here, too. This will most likely be rare as - * the cipso direct mapping in used internally. + * The cipso value associated with the label gets stored here, too. * * Keep the access rules for this subject label here so that * the entire set of rules does not need to be examined every * time. */ struct smack_known { - struct list_head list; - char smk_known[SMK_LABELLEN]; - u32 smk_secid; - struct smack_cipso *smk_cipso; - spinlock_t smk_cipsolock; /* for changing cipso map */ - struct list_head smk_rules; /* access rules */ - struct mutex smk_rules_lock; /* lock for the rules */ + struct list_head list; + char *smk_known; + u32 smk_secid; + struct netlbl_lsm_secattr smk_netlabel; /* on wire labels */ + struct list_head smk_rules; /* access rules */ + struct mutex smk_rules_lock; /* lock for rules */ }; /* @@ -166,6 +160,7 @@ struct smack_known { #define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ +#define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ #define SMACK_CIPSO_MAXCATVAL 63 /* Bigger gets harder */ #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ #define SMACK_CIPSO_MAXCATNUM 239 /* CIPSO 2.2 standard */ @@ -216,10 +211,9 @@ struct inode_smack *new_inode_smack(char *); int smk_access_entry(char *, char *, struct list_head *); int smk_access(char *, char *, int, struct smk_audit_info *); int smk_curacc(char *, u32, struct smk_audit_info *); -int smack_to_cipso(const char *, struct smack_cipso *); -char *smack_from_cipso(u32, char *); char *smack_from_secid(const u32); -void smk_parse_smack(const char *string, int len, char *smack); +char *smk_parse_smack(const char *string, int len); +int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); char *smk_import(const char *, int); struct smack_known *smk_import_entry(const char *, int); struct smack_known *smk_find_entry(const char *); @@ -229,6 +223,7 @@ u32 smack_to_secid(const char *); * Shared data. */ extern int smack_cipso_direct; +extern int smack_cipso_mapped; extern char *smack_net_ambient; extern char *smack_onlycap; extern const char *smack_cipso_option; @@ -240,23 +235,12 @@ extern struct smack_known smack_known_invalid; extern struct smack_known smack_known_star; extern struct smack_known smack_known_web; +extern struct mutex smack_known_lock; extern struct list_head smack_known_list; extern struct list_head smk_netlbladdr_list; extern struct security_operations smack_ops; -/* - * Stricly for CIPSO level manipulation. - * Set the category bit number in a smack label sized buffer. - */ -static inline void smack_catset_bit(int cat, char *catsetp) -{ - if (cat > SMK_LABELLEN * 8) - return; - - catsetp[(cat - 1) / 8] |= 0x80 >> ((cat - 1) % 8); -} - /* * Is the directory transmuting? */ -- cgit v1.2.3