a Bi!@sbdZddlZddlmZddlmZddlmZGdddejZGd d d ZGd d d Z dS) zI Classes and algorithms for matching requested access to access vectors. N)access) objectmodel)utilc@seZdZdddZddZdS)MatchNrcCs||_||_d|_d|_dSNF) interfacedistinfo_dir_change__hash__)selfrr r 5/usr/lib/python3.9/site-packages/sepolgen/matching.py__init__ szMatch.__init__c CsDz$|j|jf}|j|jf}|||WSttfy>tYS0dSN)r r AttributeError TypeErrorNotImplemented)r othermethodabr r r_compare(s    zMatch._compare)Nr)__name__ __module__ __qualname__rrr r r rrs rc@sHeZdZdZddZddZddZdd Zd d Zd d Z ddZ dS) MatchListcCs$g|_g|_|j|_d|_d|_dSr)childrenbastardsDEFAULT_THRESHOLD thresholdallow_info_dir_changeavr r r rr3s zMatchList.__init__cCs,t|jr|jdSt|jr(|jdSdSNrlenrrr$r r rbest<s     zMatchList.bestcCst|jt|jSrr&r$r r r__len__CszMatchList.__len__cCs t|jSr)iterrr$r r r__iter__IszMatchList.__iter__cCst|j|jSr) itertoolschainrrr$r r rallLsz MatchList.allcCsD|j|jkr4|jr|jr&|j|q@|j|n |j|dSr)r r!r r"rappendr)r matchr r rr/Os   zMatchList.appendcCs|j|jdSr)rsortrr$r r rr1Xs zMatchList.sortN) rrrr rr(r)r+r.r/r1r r r rr1s  rc@s>eZdZdddZddZddZdd Zd d Zd d ZdS) AccessMatcherNcCs,d|_d|_|r||_n t|_d|_dS)N d) type_penalty obj_penalty perm_mapsrZ PermMappingsinfo_dir_penalty)r r7r r rr^s  zAccessMatcher.__init__cCs"||kst|rdS|j SdSr%)r is_idparamr5)r rrr r r type_distancejszAccessMatcher.type_distancecCsR|j|j}t|dkr0|j|j|}| S|j|j}|j|j|SdSr%)perms differencer'r7getdefault_distance obj_class)r Zav_reqZav_provdifftotalr r r perm_distanceqs  zAccessMatcher.perm_distancecCsd}|||j|j7}|||j|j7}|j|jkrNt|jsN||j8}|dkrj|j|j|j }n | ||}|dkr|dkr||S||Sn |dkr|dkr||S||SdS)a,Determine the 'distance' between 2 access vectors. This function is used to find an access vector that matches a 'required' access. To do this we comput a signed numeric value that indicates how close the req access is to the 'provided' access vector. The closer the value is to 0 the closer the match, with 0 being an exact match. A value over 0 indicates that the prov access vector provides more access than the req (in practice, this means that the source type, target type, and object class is the same and the perms in prov is a superset of those in req. A value under 0 indicates that the prov access less - or unrelated - access to the req access. A different type or object class will result in a very low value. The values other than 0 should only be interpreted relative to one another - they have no exact meaning and are likely to change. Params: req - [AccessVector] The access that is required. This is the access being matched. prov - [AccessVector] The access provided. This is the potential match that is being evaluated for req. Returns: 0 : Exact match between the access vectors. < 0 : The prov av does not provide all of the access in req. A smaller value indicates that the access is further. > 0 : The prov av provides more access than req. The larger the value the more access over req. rN) r:Zsrc_typetgt_typer>rr9r6r7r=r;rA)r ZreqZprovr Zpdistr r r av_distance|s '   zAccessMatcher.av_distancecCsd}|D]^}|||}|dur&|}q|dkrL|dkr@||7}qf|| }q|dkr^||7}q||8}q|j|j|j}|jdurtj|_|D]}|j|j|j|jB|_q|tj@dkr|jtj@r|dkr||j 8}n ||j 7}|S)z Nr) rCr7Zgetdefault_directionr>r;Zinfo_dirrZ FLOW_NONEZ FLOW_WRITEr8)r Zav_setr#r xtmpZav_dirr r r av_set_matchs0        zAccessMatcher.av_set_matchcCsd||_t|j|j|jgD]6}|js,q ||j |}|dkr t ||}| |q | dSr%) r#r,r-Z tgt_type_allZ tgt_type_mapgetrBZenabledrFrrr/r1)r Zifsetr#Z match_listZivr mr r r search_ifss  zAccessMatcher.search_ifs)N) rrrrr:rArCrFrIr r r rr2]s   H(r2) __doc__r,rrrZ Comparisonrrr2r r r rs   ,