simple_selinux/Current_files_prop.thy
changeset 74 271e9818b6f6
equal deleted inserted replaced
73:924ab7a4e7fa 74:271e9818b6f6
       
     1 (*<*)
       
     2 theory Current_files_prop
       
     3 imports Main Flask_type Flask My_list_prefix Init_prop Valid_prop
       
     4 begin
       
     5 (*<*)
       
     6 
       
     7 context init begin
       
     8 
       
     9 lemma current_files_ndef: "f \<notin> current_files \<tau> \<Longrightarrow> inum_of_file \<tau> f = None"
       
    10 by (simp add:current_files_def)
       
    11 
       
    12 (************** file_of_proc_fd vs proc_fd_of_file *****************)
       
    13 lemma pfdof_simp1: "file_of_proc_fd \<tau> p fd = Some f \<Longrightarrow> (p, fd) \<in> proc_fd_of_file \<tau> f"
       
    14 by (simp add:proc_fd_of_file_def)
       
    15 
       
    16 lemma pfdof_simp2: "(p, fd) \<in> proc_fd_of_file \<tau> f \<Longrightarrow> file_of_proc_fd \<tau> p fd = Some f"
       
    17 by (simp add:proc_fd_of_file_def)
       
    18 
       
    19 lemma pfdof_simp3: "proc_fd_of_file \<tau> f = {(p, fd)} \<Longrightarrow> \<forall> p' fd'. (file_of_proc_fd \<tau> p' fd' = Some f \<longrightarrow> p = p' \<and> fd = fd')"
       
    20 by (simp add:proc_fd_of_file_def, auto)
       
    21 
       
    22 lemma pfdof_simp4: "\<lbrakk>file_of_proc_fd \<tau> p' fd' = Some f; proc_fd_of_file \<tau> f = {(p, fd)}\<rbrakk> \<Longrightarrow> p' = p \<and> fd' = fd"
       
    23 by (drule pfdof_simp3, auto)
       
    24 
       
    25 end
       
    26 
       
    27 context flask begin
       
    28 
       
    29 (***************** inode number lemmas *************************)
       
    30 
       
    31 lemma iof's_im_in_cim: "inum_of_file \<tau> f = Some im \<Longrightarrow> im \<in> current_inode_nums \<tau>"
       
    32 by (auto simp add:current_inode_nums_def current_file_inums_def)
       
    33 
       
    34 lemma ios's_im_in_cim: "inum_of_socket \<tau> s = Some im \<Longrightarrow> im \<in> current_inode_nums \<tau>"
       
    35 by (case_tac s, auto simp add:current_inode_nums_def current_sock_inums_def)
       
    36 
       
    37 lemma fim_noninter_sim_aux[rule_format]:
       
    38   "\<forall> f s. inum_of_file \<tau> f = Some im \<and> inum_of_socket \<tau> s = Some im \<and> valid \<tau> \<longrightarrow> False"
       
    39 apply (induct \<tau>)
       
    40 apply (clarsimp simp:inum_of_file.simps inum_of_socket.simps)
       
    41 apply (drule init_inum_sock_file_noninter, simp, simp)
       
    42 apply ((rule allI|rule impI|erule conjE)+)
       
    43 apply (frule vd_cons, frule vt_grant_os, simp, case_tac a) 
       
    44 apply (auto simp:inum_of_file.simps inum_of_socket.simps split:if_splits option.splits
       
    45             dest:ios's_im_in_cim iof's_im_in_cim)
       
    46 done
       
    47 
       
    48 lemma fim_noninter_sim':"\<lbrakk>inum_of_file \<tau> f = Some im; inum_of_socket \<tau> s = Some im; valid \<tau>\<rbrakk> \<Longrightarrow> False"
       
    49 by (auto intro:fim_noninter_sim_aux)
       
    50 
       
    51 lemma fim_noninter_sim'':"\<lbrakk>inum_of_socket \<tau> s = Some im; inum_of_file \<tau> f = Some im; valid \<tau>\<rbrakk> \<Longrightarrow> False"
       
    52 by (auto intro:fim_noninter_sim_aux)
       
    53 
       
    54 lemma fim_noninter_sim: "valid \<tau> \<Longrightarrow> (current_file_inums \<tau>) \<inter> (current_sock_inums \<tau>) = {}"
       
    55 by (auto simp:current_file_inums_def current_sock_inums_def intro:fim_noninter_sim_aux[rule_format])
       
    56 
       
    57 (******************* file inum has inode tag ************************)
       
    58 
       
    59 lemma finum_has_itag_aux[rule_format]: 
       
    60   "\<forall> f im. inum_of_file \<tau> f = Some im \<and> valid \<tau> \<longrightarrow> itag_of_inum \<tau> im \<noteq> None"
       
    61 apply (induct \<tau>)
       
    62 apply (clarsimp simp:inum_of_file.simps itag_of_inum.simps init_inum_of_file_props)
       
    63 apply (clarify, frule vt_grant_os, frule vd_cons, case_tac a) 
       
    64 apply (auto simp add:inum_of_file.simps itag_of_inum.simps os_grant.simps current_files_def 
       
    65                 dest:fim_noninter_sim'' split:option.splits if_splits t_socket_type.splits)
       
    66 done
       
    67 
       
    68 lemma finum_has_itag: "\<lbrakk>inum_of_file \<tau> f = Some im; valid \<tau>\<rbrakk> \<Longrightarrow> \<exists> tag. itag_of_inum \<tau> im = Some tag"
       
    69 by (auto dest:conjI[THEN finum_has_itag_aux])
       
    70 
       
    71 (*********************** file inum is file itag *************************)
       
    72 
       
    73 lemma finum_has_ftag_aux[rule_format]: 
       
    74   "\<forall> f tag. inum_of_file \<tau> f = Some im \<and> itag_of_inum \<tau> im = Some tag \<and> valid \<tau> \<longrightarrow> is_file_dir_itag tag"
       
    75 apply (induct \<tau>)
       
    76 apply (clarsimp simp:inum_of_file.simps itag_of_inum.simps init_inum_of_file_props)
       
    77 apply (clarify, frule vt_grant_os, frule vd_cons, case_tac a) 
       
    78 apply (auto simp:inum_of_file.simps os_grant.simps current_files_def itag_of_inum.simps 
       
    79            split:if_splits option.splits t_socket_type.splits
       
    80             dest:ios's_im_in_cim iof's_im_in_cim)
       
    81 done
       
    82 
       
    83 lemma finum_has_ftag:
       
    84   "\<lbrakk>inum_of_file \<tau> f = Some im; itag_of_inum \<tau> im = Some tag; valid \<tau>\<rbrakk> \<Longrightarrow> is_file_dir_itag tag"
       
    85 by (auto intro:finum_has_ftag_aux)
       
    86 
       
    87 lemma finum_has_ftag': 
       
    88   "\<lbrakk>inum_of_file \<tau> f = Some im; valid \<tau>\<rbrakk> \<Longrightarrow> itag_of_inum \<tau> im = Some Tag_FILE \<or> itag_of_inum \<tau> im = Some Tag_DIR"
       
    89 apply (frule finum_has_itag, simp, erule exE, drule finum_has_ftag, simp+)
       
    90 apply (case_tac tag, auto)
       
    91 done
       
    92 
       
    93 (******************* sock inum has inode tag ************************)
       
    94 
       
    95 lemma sinum_has_itag_aux[rule_format]: 
       
    96   "\<forall> s im. inum_of_socket \<tau> s = Some im \<and> valid \<tau> \<longrightarrow> itag_of_inum \<tau> im \<noteq> None"
       
    97 apply (induct \<tau>)
       
    98 apply (clarsimp simp:inum_of_socket.simps itag_of_inum.simps)
       
    99 apply (drule init_inumos_prop4, clarsimp)
       
   100 apply (clarify, frule vt_grant_os, frule vd_cons, case_tac a) 
       
   101 apply (auto simp add:inum_of_socket.simps itag_of_inum.simps os_grant.simps 
       
   102                 dest:fim_noninter_sim'' ios's_im_in_cim iof's_im_in_cim
       
   103                split:option.splits if_splits t_socket_type.splits)
       
   104 done
       
   105 
       
   106 lemma sinum_has_itag: "\<lbrakk>inum_of_socket \<tau> s = Some im; valid \<tau>\<rbrakk> \<Longrightarrow> \<exists> tag. itag_of_inum \<tau> im = Some tag"
       
   107 by (auto dest:conjI[THEN sinum_has_itag_aux])
       
   108 
       
   109 (********************** socket inum is socket itag **********************)
       
   110 
       
   111 lemma sinum_has_stag_aux[rule_format]: 
       
   112   "\<forall> s tag. inum_of_socket \<tau> s = Some im \<and> itag_of_inum \<tau> im = Some tag \<and> valid \<tau> \<longrightarrow> is_sock_itag tag"
       
   113 apply (induct \<tau>)
       
   114 apply (clarsimp simp:inum_of_socket.simps itag_of_inum.simps)
       
   115 apply (drule init_inumos_prop4, clarsimp)
       
   116 apply (clarify, frule vt_grant_os, frule vd_cons, case_tac a) 
       
   117 apply (auto simp add:inum_of_socket.simps itag_of_inum.simps os_grant.simps 
       
   118                 dest:fim_noninter_sim'' ios's_im_in_cim iof's_im_in_cim
       
   119                split:option.splits if_splits t_socket_type.splits)
       
   120 done
       
   121 
       
   122 lemma sinum_has_stag: "\<lbrakk>inum_of_socket \<tau> s = Some im; itag_of_inum \<tau> im = Some tag; valid \<tau>\<rbrakk> \<Longrightarrow> is_sock_itag tag"
       
   123 by (auto dest:conjI[THEN sinum_has_stag_aux])
       
   124 
       
   125 lemma sinum_has_stag': 
       
   126   "\<lbrakk>inum_of_socket \<tau> s = Some im; valid \<tau>\<rbrakk> 
       
   127    \<Longrightarrow> itag_of_inum \<tau> im = Some Tag_UDP_SOCK \<or> itag_of_inum \<tau> im = Some Tag_TCP_SOCK"
       
   128 apply (frule sinum_has_itag, simp, erule exE)
       
   129 apply (drule sinum_has_stag, simp+, case_tac tag, simp+)
       
   130 done
       
   131 
       
   132 (************************************ 4 in 1 *************************************)
       
   133 
       
   134 lemma file_leveling: "valid \<tau> \<longrightarrow> (
       
   135                         (\<forall> f. f \<in> files_hung_by_del \<tau> \<longrightarrow> inum_of_file \<tau> f \<noteq> None) \<and>
       
   136                         (\<forall> f pf im. parent f = Some pf \<and> inum_of_file \<tau> f = Some im \<longrightarrow> inum_of_file \<tau> pf \<noteq> None) \<and>
       
   137                         (\<forall> f f' im. is_file \<tau> f \<and> parent f' = Some f \<and> inum_of_file \<tau> f' = Some im \<longrightarrow> False) \<and>
       
   138                         (\<forall> f f' im. f \<in> files_hung_by_del \<tau> \<and> inum_of_file \<tau> f' = Some im \<and> parent f' = Some f \<longrightarrow> False) )"
       
   139 proof (induct \<tau>)
       
   140   case Nil 
       
   141   show ?case
       
   142     apply (auto simp:inum_of_file.simps files_hung_by_del.simps is_file_def itag_of_inum.simps parent_file_in_init split:option.splits t_inode_tag.splits)
       
   143     apply (drule init_files_hung_by_del_props, simp add:init_file_has_inum)
       
   144     apply (rule init_parent_file_has_inum, simp+)
       
   145     apply (rule init_file_has_no_son', simp+)
       
   146     apply (rule init_file_hung_has_no_son, simp+)
       
   147     done   
       
   148 next
       
   149   case (Cons a \<tau>)  
       
   150   assume pre: "valid \<tau> \<longrightarrow>
       
   151   (\<forall> f. f \<in> files_hung_by_del \<tau> \<longrightarrow> inum_of_file \<tau> f \<noteq> None) \<and>
       
   152   (\<forall>f pf im. parent f = Some pf \<and> inum_of_file \<tau> f = Some im \<longrightarrow> inum_of_file \<tau> pf \<noteq> None) \<and>
       
   153   (\<forall>f f' im. is_file \<tau> f \<and> parent f' = Some f \<and> inum_of_file \<tau> f' = Some im \<longrightarrow> False) \<and> 
       
   154   (\<forall>f f' im. f \<in> files_hung_by_del \<tau> \<and> inum_of_file \<tau> f' = Some im \<and> parent f' = Some f \<longrightarrow> False)"
       
   155   show ?case
       
   156   proof 
       
   157     assume cons:"valid (a # \<tau>)"
       
   158     show "(\<forall>f. f \<in> files_hung_by_del (a # \<tau>) \<longrightarrow> inum_of_file (a # \<tau>) f \<noteq> None) \<and>
       
   159           (\<forall>f pf im. parent f = Some pf \<and> inum_of_file (a # \<tau>) f = Some im \<longrightarrow> inum_of_file (a # \<tau>) pf \<noteq> None) \<and>
       
   160           (\<forall>f f' im. is_file (a # \<tau>) f \<and> parent f' = Some f \<and> inum_of_file (a # \<tau>) f' = Some im \<longrightarrow> False) \<and>
       
   161           (\<forall>f f' im. f \<in> files_hung_by_del (a # \<tau>) \<and> inum_of_file (a # \<tau>) f' = Some im \<and> parent f' = Some f \<longrightarrow> False)"
       
   162     proof-
       
   163       have vt: "valid \<tau>" using cons by (auto dest:vd_cons)
       
   164       have os: "os_grant \<tau> a" using cons by (auto dest:vt_grant_os)  
       
   165       have fin: "\<forall>f. f \<in> files_hung_by_del \<tau> \<longrightarrow> inum_of_file \<tau> f \<noteq> None" using vt pre by auto
       
   166       have pin: "\<forall>f pf im. parent f = Some pf \<and> inum_of_file \<tau> f = Some im \<longrightarrow> inum_of_file \<tau> pf \<noteq> None" 
       
   167         using vt pre apply (erule_tac impE, simp) by ((erule_tac conjE)+, assumption)
       
   168       have fns: "\<forall>f f' im. is_file \<tau> f \<and> parent f' = Some f \<and> inum_of_file \<tau> f' = Some im \<longrightarrow> False"
       
   169         using vt pre apply (erule_tac impE, simp) by ((erule_tac conjE)+, assumption)
       
   170       have hns: "\<forall>f f' im. f \<in> files_hung_by_del \<tau> \<and> inum_of_file \<tau> f' = Some im \<and> parent f' = Some f \<longrightarrow> False" 
       
   171         using vt pre apply (erule_tac impE, simp) by ((erule_tac conjE)+, assumption)
       
   172       have ain: "\<forall>f' f im. f \<preceq> f' \<and> inum_of_file \<tau> f' = Some im \<longrightarrow> inum_of_file \<tau> f \<noteq> None"
       
   173       proof 
       
   174         fix f' 
       
   175         show " \<forall>f im. f \<preceq> f' \<and> inum_of_file \<tau> f' = Some im \<longrightarrow> inum_of_file \<tau> f \<noteq> None"
       
   176         proof (induct f')
       
   177           case Nil show ?case by (auto simp: no_junior_def)
       
   178         next
       
   179           case (Cons a f') 
       
   180           assume pre:"\<forall>f im. f \<preceq> f' \<and> inum_of_file \<tau> f' = Some im \<longrightarrow> inum_of_file \<tau> f \<noteq> None"
       
   181           show "\<forall>f im. f \<preceq> a # f' \<and> inum_of_file \<tau> (a # f') = Some im \<longrightarrow> inum_of_file \<tau> f \<noteq> None"
       
   182           proof clarify
       
   183             fix f im
       
   184             assume h1: "f \<preceq> a # f'"
       
   185               and  h2: "inum_of_file \<tau> (a # f') = Some im"
       
   186             show "\<exists>y. inum_of_file \<tau> f = Some y"
       
   187             proof-
       
   188               have h3: "\<exists> y. inum_of_file \<tau> f' = Some y" 
       
   189               proof-
       
   190                 have "parent (a # f') = Some f'" by simp
       
   191                 hence "\<exists> y. inum_of_file \<tau> f' = Some y" using pin h2 by blast
       
   192                 with h1 show ?thesis by simp
       
   193               qed
       
   194               from h1 have "f = a # f' \<or> f = f' \<or> f \<preceq> f'" by (induct f, auto simp:no_junior_def)
       
   195               moreover have "f = a # f' \<Longrightarrow> \<exists>y. inum_of_file \<tau> f = Some y" using h2 by simp
       
   196               moreover have "f = f' \<Longrightarrow> \<exists>y. inum_of_file \<tau> f = Some y"  using h3 by simp
       
   197               moreover have "f \<preceq> f' \<Longrightarrow> \<exists>y. inum_of_file \<tau> f = Some y" using pre h3 by simp
       
   198               ultimately show ?thesis by auto
       
   199             qed
       
   200           qed
       
   201         qed
       
   202       qed
       
   203 
       
   204       have fin': "\<And> f. f \<in> files_hung_by_del \<tau> \<Longrightarrow> \<exists> im. inum_of_file \<tau> f = Some im" using fin by auto
       
   205       have pin': "\<And> f pf im. \<lbrakk>parent f = Some pf; inum_of_file \<tau> f = Some im\<rbrakk> \<Longrightarrow> \<exists> im'. inum_of_file \<tau> pf = Some im'"
       
   206         using pin by auto
       
   207       have fns': "\<And> f f' im. \<lbrakk>is_file \<tau> f; parent f' = Some f; inum_of_file \<tau> f' = Some im\<rbrakk> \<Longrightarrow> False" using fns by auto
       
   208       have fns'': "\<And> f f' im im'. \<lbrakk>itag_of_inum \<tau> im = Some Tag_FILE; inum_of_file \<tau> f = Some im; parent f' = Some f; inum_of_file \<tau> f' = Some im'\<rbrakk> \<Longrightarrow> False"
       
   209         by (rule_tac f = f and f' = f' in fns', auto simp:is_file_def)
       
   210       have hns': "\<And> f f' im. \<lbrakk>f \<in> files_hung_by_del \<tau>; inum_of_file \<tau> f' = Some im; parent f' = Some f\<rbrakk> \<Longrightarrow> False" using hns by auto
       
   211       have ain': "\<And> f f' im. \<lbrakk>f \<preceq> f'; inum_of_file \<tau> f' = Some im\<rbrakk> \<Longrightarrow> \<exists> im'. inum_of_file \<tau> f = Some im'" using ain by auto
       
   212       have dns': "\<And> f f' im. \<lbrakk>dir_is_empty \<tau> f; parent f' = Some f; inum_of_file \<tau> f' = Some im\<rbrakk> \<Longrightarrow> False"
       
   213         apply (auto simp:dir_is_empty_def current_files_def is_dir_def split:option.splits)
       
   214         by (erule_tac x = f' in allE, simp add:noJ_Anc parent_is_ancen, drule parent_is_parent, simp+)
       
   215 
       
   216       have "\<forall> f. f \<in> files_hung_by_del (a # \<tau>) \<longrightarrow> inum_of_file (a # \<tau>) f \<noteq> None"
       
   217         apply (clarify, case_tac a) using os fin
       
   218         apply (auto simp:files_hung_by_del.simps inum_of_file.simps os_grant.simps current_files_def is_file_def 
       
   219                    split:if_splits option.splits)
       
   220         done
       
   221       moreover 
       
   222       have "\<forall>f pf im. parent f = Some pf \<and> inum_of_file (a # \<tau>) f = Some im \<longrightarrow> inum_of_file (a # \<tau>) pf \<noteq> None" 
       
   223         apply (clarify, case_tac a)
       
   224         using vt os pin'
       
   225         apply (auto simp:os_grant.simps current_files_def inum_of_file.simps is_file_def is_dir_def 
       
   226                    split:if_splits option.splits t_inode_tag.splits)
       
   227         apply (drule_tac f = pf and f' = f in hns', simp, simp, simp)
       
   228         apply (rule_tac f = list and f' = f in fns', simp add:is_file_def, simp, simp)
       
   229         apply (rule_tac f = list and f' = f in dns', simp add:is_dir_def, simp, simp)
       
   230         done
       
   231       moreover have "\<forall>f f' im. is_file (a # \<tau>) f \<and> parent f' = Some f \<and> inum_of_file (a # \<tau>) f' = Some im \<longrightarrow> False"
       
   232         apply (clarify, case_tac a)    
       
   233         using vt os fns'' cons
       
   234         apply (auto simp:os_grant.simps current_files_def inum_of_file.simps itag_of_inum.simps 
       
   235                          is_file_def is_dir_def 
       
   236                     dest:ios's_im_in_cim iof's_im_in_cim
       
   237                    split:if_splits option.splits t_inode_tag.splits t_socket_type.splits) 
       
   238         apply (rule_tac im = a and f = f and f' = f' in fns'', simp+)
       
   239         apply (drule_tac f = f' and pf = list in pin', simp, simp)
       
   240         done
       
   241       moreover have "\<forall>f f' im. f \<in> files_hung_by_del (a # \<tau>) \<and> inum_of_file (a # \<tau>) f' = Some im \<and> 
       
   242                                parent f' = Some f \<longrightarrow> False"
       
   243         apply (clarify, case_tac a)     
       
   244         using vt os hns'
       
   245         apply (auto simp:os_grant.simps current_files_def inum_of_file.simps files_hung_by_del.simps 
       
   246                    split:if_splits option.splits t_sock_addr.splits)
       
   247         apply (drule fns', simp+)
       
   248         done
       
   249       ultimately show ?thesis by blast
       
   250     qed
       
   251   qed
       
   252 qed
       
   253     
       
   254 (**************** hung file in current ***********************)
       
   255 
       
   256 lemma hung_file_has_inum:"\<lbrakk>f \<in> files_hung_by_del \<tau>; valid \<tau>\<rbrakk> \<Longrightarrow> inum_of_file \<tau> f \<noteq> None"
       
   257 by (drule file_leveling[rule_format], blast)
       
   258 
       
   259 lemma hung_file_has_inum': "\<lbrakk>f \<in> files_hung_by_del \<tau>; valid \<tau>\<rbrakk> \<Longrightarrow> \<exists> im. inum_of_file \<tau> f = Some im"
       
   260 by (auto dest:hung_file_has_inum)
       
   261 
       
   262 lemma hung_file_in_current: "\<lbrakk>f \<in> files_hung_by_del \<tau>; valid \<tau>\<rbrakk> \<Longrightarrow> f \<in> current_files \<tau>"
       
   263 by (clarsimp simp add:current_files_def hung_file_has_inum')
       
   264 
       
   265 lemma parentf_has_inum: "\<lbrakk>parent f = Some pf; inum_of_file \<tau> f = Some im; valid \<tau>\<rbrakk> \<Longrightarrow> inum_of_file \<tau> pf \<noteq> None"
       
   266 by (drule file_leveling[rule_format], blast)
       
   267 
       
   268 lemma parentf_has_inum': "\<lbrakk>parent f = Some pf; inum_of_file \<tau> f = Some im; valid \<tau>\<rbrakk> \<Longrightarrow> \<exists> im'. inum_of_file \<tau> pf = Some im'"
       
   269 by (auto dest:parentf_has_inum)
       
   270 
       
   271 lemma parentf_in_current: "\<lbrakk>parent f = Some pf; f \<in> current_files \<tau>; valid \<tau>\<rbrakk> \<Longrightarrow> pf \<in> current_files \<tau>"
       
   272 by (clarsimp simp add:current_files_def parentf_has_inum')
       
   273 
       
   274 lemma parentf_in_current': "\<lbrakk>a # pf \<in> current_files \<tau>; valid \<tau>\<rbrakk> \<Longrightarrow> pf \<in> current_files \<tau>"
       
   275 apply (subgoal_tac "parent (a # pf) = Some pf")
       
   276 by (erule parentf_in_current, simp+)
       
   277 
       
   278 lemma ancenf_has_inum_aux: "\<forall> f im. f \<preceq> f' \<and> inum_of_file \<tau> f' = Some im \<and> valid \<tau> \<longrightarrow> inum_of_file \<tau> f \<noteq> None"
       
   279 proof (induct f')
       
   280   case Nil show ?case by (auto simp: no_junior_def)
       
   281 next
       
   282   case (Cons a f') 
       
   283   assume pre:"\<forall>f im. f \<preceq> f' \<and> inum_of_file \<tau> f' = Some im \<and> valid \<tau> \<longrightarrow> inum_of_file \<tau> f \<noteq> None"
       
   284   show "\<forall>f im. f \<preceq> a # f' \<and> inum_of_file \<tau> (a # f') = Some im \<and> valid \<tau> \<longrightarrow> inum_of_file \<tau> f \<noteq> None"
       
   285   proof clarify
       
   286     fix f im
       
   287     assume h1: "f \<preceq> a # f'"
       
   288       and  h2: "inum_of_file \<tau> (a # f') = Some im"
       
   289       and  h3: "valid \<tau>"
       
   290     show "\<exists>y. inum_of_file \<tau> f = Some y"
       
   291     proof-
       
   292       have h4: "\<exists> y. inum_of_file \<tau> f' = Some y" 
       
   293       proof-
       
   294         have "parent (a # f') = Some f'" by simp
       
   295         hence "\<exists> y. inum_of_file \<tau> f' = Some y" using parentf_has_inum' h2 h3 by blast
       
   296         with h1 show ?thesis by simp
       
   297       qed
       
   298       from h1 have "f = a # f' \<or> f = f' \<or> f \<preceq> f'" by (induct f, auto simp:no_junior_def)
       
   299       moreover have "f = a # f' \<Longrightarrow> \<exists>y. inum_of_file \<tau> f = Some y" using h2 by simp
       
   300       moreover have "f = f' \<Longrightarrow> \<exists>y. inum_of_file \<tau> f = Some y"  using h4 by simp
       
   301       moreover have "f \<preceq> f' \<Longrightarrow> \<exists>y. inum_of_file \<tau> f = Some y" using pre h3 h4 by simp
       
   302       ultimately show ?thesis by auto
       
   303     qed
       
   304   qed
       
   305 qed
       
   306 
       
   307 lemma ancenf_has_inum: "\<lbrakk>f \<preceq> f'; inum_of_file \<tau> f' = Some im; valid \<tau>\<rbrakk> \<Longrightarrow> inum_of_file \<tau> f \<noteq> None"
       
   308 by (rule ancenf_has_inum_aux[rule_format], auto)
       
   309 
       
   310 lemma ancenf_has_inum': "\<lbrakk>f \<preceq> f'; inum_of_file \<tau> f' = Some im; valid \<tau>\<rbrakk> \<Longrightarrow> \<exists> im'. inum_of_file \<tau> f = Some im'"
       
   311 by (auto dest:ancenf_has_inum)
       
   312 
       
   313 lemma ancenf_in_current: "\<lbrakk>f \<preceq> f'; f' \<in> current_files \<tau>; valid \<tau>\<rbrakk> \<Longrightarrow> f \<in> current_files \<tau>"
       
   314 by (simp add:current_files_def, erule exE, simp add:ancenf_has_inum')
       
   315 
       
   316 lemma file_has_no_son: "\<lbrakk>is_file \<tau> f; parent f' = Some f; inum_of_file \<tau> f' = Some im; valid \<tau>\<rbrakk> \<Longrightarrow> False"
       
   317 by (drule file_leveling[rule_format], blast)
       
   318 
       
   319 lemma file_has_no_son': "\<lbrakk>is_file \<tau> f; parent f' = Some f; f' \<in> current_files \<tau>; valid \<tau>\<rbrakk> \<Longrightarrow> False"
       
   320 by (simp add:current_files_def, erule exE, auto intro:file_has_no_son)
       
   321 
       
   322 lemma hung_file_no_son: "\<lbrakk>f \<in> files_hung_by_del \<tau>; valid \<tau>; inum_of_file \<tau> f' = Some im; parent f' = Some f\<rbrakk> \<Longrightarrow> False"
       
   323 by (drule file_leveling[rule_format], blast)
       
   324 
       
   325 lemma hung_file_no_son': "\<lbrakk>f \<in> files_hung_by_del \<tau>; valid \<tau>; f' \<in> current_files \<tau>; parent f' = Some f\<rbrakk> \<Longrightarrow> False"
       
   326 by (simp add:current_files_def, erule exE, auto intro:hung_file_no_son)
       
   327 
       
   328 lemma hung_file_no_des_aux: "\<forall> f. f \<in> files_hung_by_del \<tau> \<and> valid \<tau> \<and> f' \<in> current_files \<tau> \<and> f \<preceq> f' \<and> f \<noteq> f' \<longrightarrow> False"
       
   329 proof (induct f')
       
   330   case Nil 
       
   331   show ?case
       
   332     by (auto simp:files_hung_by_del.simps current_files_def inum_of_file.simps no_junior_def split:if_splits option.splits)
       
   333 next
       
   334   case (Cons a pf)
       
   335   assume pre: "\<forall>f. f \<in> files_hung_by_del \<tau> \<and> valid \<tau> \<and> pf \<in> current_files \<tau> \<and> f \<preceq> pf \<and> f \<noteq> pf\<longrightarrow> False"
       
   336   show ?case
       
   337   proof clarify
       
   338     fix f
       
   339     assume h1: "f \<in> files_hung_by_del \<tau>"
       
   340       and  h2: "valid \<tau>"
       
   341       and  h3: "a # pf \<in> current_files \<tau>"
       
   342       and  h4: "f \<preceq> a # pf"
       
   343       and  h5: "f \<noteq> a # pf"
       
   344     have h6: "parent (a # pf) = Some pf" by simp
       
   345     with h2 h3 have h7: "pf \<in> current_files \<tau>" by (drule_tac parentf_in_current, auto)
       
   346     from h4 h5 have h8: "f \<preceq> pf" by (erule_tac no_juniorE, case_tac zs, auto simp:no_junior_def)
       
   347     show False
       
   348     proof (cases "f = pf")
       
   349       case True with h6 h2 h3 h1
       
   350       show False by (auto intro!:hung_file_no_son')
       
   351     next
       
   352       case False with pre h1 h2 h7 h8 
       
   353       show False by blast
       
   354     qed
       
   355   qed
       
   356 qed
       
   357 
       
   358 lemma hung_file_no_des: "\<lbrakk>f \<in> files_hung_by_del \<tau>; valid \<tau>; f' \<in> current_files \<tau>; f \<preceq> f'; f \<noteq> f'\<rbrakk> \<Longrightarrow> False"
       
   359 by (rule hung_file_no_des_aux[rule_format], blast)
       
   360 
       
   361 (* current version, dir can not be opened, so hung_files are all files 
       
   362 lemma hung_file_is_leaf: "\<lbrakk>f \<in> files_hung_by_del \<tau>; valid \<tau>\<rbrakk> \<Longrightarrow> is_file \<tau> f \<or> dir_is_empty \<tau> f"
       
   363 apply (frule hung_file_has_inum', simp, erule exE)
       
   364 apply (auto simp add:is_file_def dir_is_empty_def is_dir_def  dest:finum_has_itag finum_has_ftag split:option.splits if_splits t_inode_tag.splits)
       
   365 by (simp add: noJ_Anc, auto dest:hung_file_no_des)
       
   366 *)
       
   367 
       
   368 lemma hung_file_has_filetag:
       
   369   "\<lbrakk>f \<in> files_hung_by_del s; inum_of_file s f = Some im; valid s\<rbrakk> \<Longrightarrow> itag_of_inum s im = Some Tag_FILE"
       
   370 apply (induct s)
       
   371 apply (simp add:files_hung_by_del.simps)
       
   372 apply (drule init_files_hung_prop2, (erule exE)+)
       
   373 apply (drule init_filefd_prop5, clarsimp simp:is_init_file_def split:t_inode_tag.splits option.splits)
       
   374 
       
   375 apply (frule vd_cons, frule vt_grant_os, case_tac a)
       
   376 apply (auto simp:files_hung_by_del.simps is_file_def is_dir_def current_files_def current_inode_nums_def
       
   377     split:if_splits option.splits t_inode_tag.splits t_socket_type.splits 
       
   378      dest:hung_file_has_inum iof's_im_in_cim)
       
   379 done
       
   380 
       
   381 lemma hung_file_is_file: "\<lbrakk>f \<in> files_hung_by_del \<tau>; valid \<tau>\<rbrakk> \<Longrightarrow> is_file \<tau> f"
       
   382 apply (frule hung_file_has_inum', simp, erule exE)
       
   383 apply (drule hung_file_has_filetag, auto simp:is_file_def)
       
   384 done
       
   385 
       
   386 (*********************** 2 in 1 *********************)
       
   387 
       
   388 lemma file_of_pfd_2in1: "valid s \<Longrightarrow> ( 
       
   389    (\<forall> p fd f. file_of_proc_fd s p fd = Some f \<longrightarrow> inum_of_file s f \<noteq> None) \<and>
       
   390    (\<forall> p fd f. file_of_proc_fd s p fd = Some f \<longrightarrow> is_file s f) )"
       
   391 proof (induct s)
       
   392   case Nil
       
   393   show ?case
       
   394     by (auto dest:init_filefd_valid simp:is_file_def)
       
   395 next
       
   396   case (Cons e s)
       
   397   hence vd_e: "valid (e # s)" and vd_s: "valid s"  and os: "os_grant s e"
       
   398     and pfd: "\<And> p fd f. file_of_proc_fd s p fd = Some f \<Longrightarrow> inum_of_file s f \<noteq> None"
       
   399     and isf: "\<And> p fd f. file_of_proc_fd s p fd = Some f \<Longrightarrow> is_file s f"
       
   400     by (auto dest:vd_cons vt_grant_os)
       
   401   from pfd have pfd': "\<And> p fd f. inum_of_file s f = None \<Longrightarrow> file_of_proc_fd s p fd \<noteq> Some f"
       
   402     by (rule_tac notI, drule_tac pfd, simp)
       
   403   
       
   404   have "\<forall>p fd f. file_of_proc_fd (e # s) p fd = Some f \<longrightarrow> inum_of_file (e # s) f \<noteq> None"
       
   405     apply (case_tac e)  using os
       
   406     apply (auto simp:inum_of_file.simps file_of_proc_fd.simps os_grant.simps current_files_def
       
   407                  dir_is_empty_def is_file_def is_dir_def
       
   408                split:if_splits option.splits dest:pfd)
       
   409     apply (simp add:pfdof_simp3)+
       
   410     apply (simp add:proc_fd_of_file_def)  
       
   411     apply (drule isf, simp add:is_file_def split:t_inode_tag.splits)
       
   412     done
       
   413   moreover 
       
   414   have "\<forall>p fd f. file_of_proc_fd (e # s) p fd = Some f \<longrightarrow> is_file (e # s) f"
       
   415     apply (case_tac e)  using os
       
   416     apply (auto split:option.splits t_inode_tag.splits if_splits t_socket_type.splits 
       
   417                  dest:pfd isf iof's_im_in_cim
       
   418                  simp:is_file_def is_dir_def dir_is_empty_def current_files_def)
       
   419     apply (simp add:pfdof_simp3)+
       
   420     apply (simp add:proc_fd_of_file_def)  
       
   421     done
       
   422   ultimately show ?case by auto
       
   423 qed
       
   424 
       
   425 
       
   426 (************** file_of_proc_fd in current ********************)
       
   427 
       
   428 lemma file_of_pfd_imp_inode': "\<lbrakk>file_of_proc_fd \<tau> p fd = Some f; valid \<tau>\<rbrakk> \<Longrightarrow> inum_of_file \<tau> f \<noteq> None"
       
   429 by (drule file_of_pfd_2in1, blast)
       
   430 
       
   431 lemma file_of_pfd_imp_inode: "\<lbrakk>file_of_proc_fd \<tau> p fd = Some f; valid \<tau>\<rbrakk> \<Longrightarrow> \<exists> im. inum_of_file \<tau> f = Some im"
       
   432 by (auto dest!:file_of_pfd_imp_inode')
       
   433 
       
   434 lemma file_of_pfd_in_current: "\<lbrakk>file_of_proc_fd \<tau> p fd = Some f; valid \<tau>\<rbrakk> \<Longrightarrow> f \<in> current_files \<tau>"
       
   435 by (auto dest!:file_of_pfd_imp_inode' simp:current_files_def)
       
   436 
       
   437 
       
   438 (*************** file_of_proc_fd is file *********************)
       
   439 
       
   440 lemma file_of_pfd_is_file:
       
   441   "\<lbrakk>file_of_proc_fd \<tau> p fd = Some f; valid \<tau>\<rbrakk> \<Longrightarrow> is_file \<tau> f"
       
   442 by (drule file_of_pfd_2in1, auto simp:is_file_def)
       
   443 
       
   444 lemma file_of_pfd_is_file':
       
   445   "\<lbrakk>file_of_proc_fd \<tau> p fd = Some f; is_dir \<tau> f; valid \<tau>\<rbrakk> \<Longrightarrow> False"
       
   446 by (drule file_of_pfd_is_file, auto simp:is_file_def is_dir_def split:option.splits t_inode_tag.splits)
       
   447 
       
   448 lemma file_of_pfd_is_file_tag:
       
   449   "\<lbrakk>file_of_proc_fd \<tau> p fd = Some f; valid \<tau>; inum_of_file \<tau> f = Some im\<rbrakk> \<Longrightarrow> itag_of_inum \<tau> im = Some Tag_FILE"
       
   450 by (drule file_of_pfd_is_file, auto simp:is_file_def split:option.splits t_inode_tag.splits)
       
   451 
       
   452 (************** parent file / ancestral file is dir *******************)
       
   453 
       
   454 lemma parentf_is_dir_aux: "\<forall> f pf. parent f = Some pf \<and> inum_of_file \<tau> f = Some im \<and> inum_of_file \<tau> pf = Some ipm \<and> valid \<tau> \<longrightarrow> itag_of_inum \<tau> ipm = Some Tag_DIR"
       
   455 apply (induct \<tau>)
       
   456 apply (clarsimp simp:inum_of_file.simps itag_of_inum.simps init_parent_file_is_dir')
       
   457 apply (clarify, frule vd_cons, frule vt_grant_os, case_tac a)
       
   458 apply (auto simp:inum_of_file.simps itag_of_inum.simps os_grant.simps 
       
   459                  current_files_def is_dir_def is_file_def 
       
   460             dest: ios's_im_in_cim iof's_im_in_cim
       
   461            split:if_splits option.splits t_sock_addr.splits t_inode_tag.splits t_socket_type.splits)
       
   462 apply (drule parentf_has_inum', simp, simp, simp)+
       
   463 done
       
   464 
       
   465 lemma parentf_has_dirtag: 
       
   466   "\<lbrakk>parent f = Some pf; inum_of_file \<tau> f = Some im; inum_of_file \<tau> pf = Some ipm; valid \<tau>\<rbrakk> 
       
   467    \<Longrightarrow> itag_of_inum \<tau> ipm = Some Tag_DIR"
       
   468 by (auto intro:parentf_is_dir_aux[rule_format])
       
   469 
       
   470 lemma parentf_is_dir': "\<lbrakk>parent f = Some pf; inum_of_file \<tau> f = Some im; valid \<tau>\<rbrakk> \<Longrightarrow> is_dir \<tau> pf"
       
   471 apply (frule parentf_has_inum', simp+, erule exE, simp add:is_dir_def split:t_inode_tag.splits option.splits)
       
   472 by (auto dest:parentf_has_dirtag)
       
   473 
       
   474 lemma parentf_is_dir: "\<lbrakk>parent f = Some pf; f \<in> current_files \<tau>; valid \<tau>\<rbrakk> \<Longrightarrow> is_dir \<tau> pf"
       
   475 by (clarsimp simp:current_files_def parentf_is_dir')
       
   476 
       
   477 lemma parentf_is_dir'': "\<lbrakk>f # pf \<in> current_files \<tau>; valid \<tau>\<rbrakk> \<Longrightarrow> is_dir \<tau> pf"
       
   478 by (auto intro!:parentf_is_dir)
       
   479 
       
   480 lemma ancenf_is_dir_aux: "\<forall> f. f \<preceq> f' \<and> f \<noteq> f' \<and> f' \<in> current_files \<tau> \<and> valid \<tau> \<longrightarrow> is_dir \<tau> f"
       
   481 proof (induct f')
       
   482   case Nil show ?case
       
   483     by (auto simp:current_files_def no_junior_def)
       
   484 next 
       
   485   case (Cons a pf)
       
   486   assume pre: "\<forall>f. f \<preceq> pf \<and> f \<noteq> pf \<and> pf \<in> current_files \<tau> \<and> valid \<tau> \<longrightarrow> is_dir \<tau> f"
       
   487   show ?case
       
   488   proof clarify
       
   489     fix f
       
   490     assume h1: "f \<preceq> a # pf"
       
   491       and  h2: "f \<noteq> a # pf"
       
   492       and  h3: "a # pf \<in> current_files \<tau>"
       
   493       and  h4: "valid \<tau>"
       
   494     have h5: "parent (a # pf) = Some pf" by simp
       
   495     with h3 h4 have h6: "pf \<in> current_files \<tau>" by (drule_tac parentf_in_current, auto)
       
   496     from h1 h2 have h7: "f \<preceq> pf" by (erule_tac no_juniorE, case_tac zs, auto simp:no_junior_def)
       
   497     show "is_dir \<tau> f"
       
   498     proof (cases "f = pf")
       
   499       case True with h3 h4 h5 show "is_dir \<tau> f" by (drule_tac parentf_is_dir, auto)
       
   500     next
       
   501       case False with pre h6 h7 h4 show "is_dir \<tau> f" by blast
       
   502     qed
       
   503   qed
       
   504 qed
       
   505 
       
   506 lemma ancenf_is_dir: "\<lbrakk>f \<preceq> f'; f \<noteq> f'; f' \<in> current_files \<tau>; valid \<tau>\<rbrakk> \<Longrightarrow> is_dir \<tau> f"
       
   507 by (auto intro:ancenf_is_dir_aux[rule_format])
       
   508 
       
   509 (************* rebuild current_files simpset ***********************)
       
   510 
       
   511 lemma current_files_nil: "current_files [] = init_files"
       
   512 apply (simp add:current_files_def inum_of_file.simps)
       
   513 by (auto dest:inof_has_file_tag init_file_has_inum)
       
   514 
       
   515 lemma current_files_open: "current_files (Open p f flags fd (Some i) # \<tau>) = insert f (current_files \<tau>)"
       
   516 by (auto simp add:current_files_def inum_of_file.simps split:option.splits)
       
   517 
       
   518 lemma current_files_open': "current_files (Open p f flags fd None # \<tau>) = current_files \<tau>"
       
   519 by (simp add:current_files_def inum_of_file.simps split:option.splits)
       
   520 
       
   521 lemma current_files_closefd: "current_files (CloseFd p fd # \<tau>) = (
       
   522      case (file_of_proc_fd \<tau> p fd) of
       
   523        Some f \<Rightarrow> ( if ((proc_fd_of_file \<tau> f = {(p, fd)}) \<and> (f \<in> files_hung_by_del \<tau>))
       
   524                    then current_files \<tau> - {f}
       
   525                    else current_files \<tau>)
       
   526      | _      \<Rightarrow> current_files \<tau>                                  )"
       
   527 by (auto simp:current_files_def inum_of_file.simps split:option.splits)
       
   528 
       
   529 lemma current_files_unlink: "current_files (UnLink p f # \<tau>) = (if (proc_fd_of_file \<tau> f = {}) then (current_files \<tau>) - {f} else current_files \<tau>)"
       
   530 by (auto simp:current_files_def inum_of_file.simps split:option.splits)
       
   531 
       
   532 lemma current_files_rmdir: "current_files (Rmdir p f # \<tau>) = current_files \<tau> - {f}"
       
   533 by (auto simp:current_files_def inum_of_file.simps split:option.splits)
       
   534 
       
   535 lemma current_files_mkdir: "current_files (Mkdir p f ino # \<tau>) = insert f (current_files \<tau>)"
       
   536 by (auto simp:current_files_def inum_of_file.simps split:option.splits)
       
   537 
       
   538 (*
       
   539 lemma rename_renaming_decom:
       
   540   "\<lbrakk>f\<^isub>3 \<preceq> file_after_rename f\<^isub>2 f\<^isub>3 f; Rename p f\<^isub>2 f\<^isub>3 # valid \<tau>; f \<in> current_files \<tau>\<rbrakk> \<Longrightarrow> f\<^isub>2 \<preceq> f"
       
   541 apply (case_tac "f\<^isub>2 \<preceq> f", simp)
       
   542 apply (simp add:file_after_rename_def split:if_splits)
       
   543 by (frule vd_cons, frule vt_grant_os, auto simp:os_grant.simps dest!:ancenf_in_current)
       
   544 
       
   545 lemma rename_renaming_decom':
       
   546   "\<lbrakk>\<not> f\<^isub>3 \<preceq> file_after_rename f\<^isub>2 f\<^isub>3 f; Rename p f\<^isub>2 f\<^isub>3 # valid \<tau>; f \<in> current_files \<tau>\<rbrakk> \<Longrightarrow> \<not> f\<^isub>2 \<preceq> f"
       
   547 by (case_tac "f\<^isub>2 \<preceq> f", drule_tac f\<^isub>3 = f\<^isub>3 in file_renaming_prop1, simp+)
       
   548 
       
   549 lemma current_files_rename: "Rename p f\<^isub>2 f\<^isub>3 # valid \<tau> \<Longrightarrow> current_files (Rename p f\<^isub>2 f\<^isub>3 # \<tau>) = {file_after_rename f\<^isub>2 f\<^isub>3 f\<^isub>1| f\<^isub>1. f\<^isub>1 \<in> current_files \<tau>}"
       
   550 apply (frule vt_grant_os, frule vd_cons)
       
   551 apply (auto simp:current_files_def inum_of_file.simps os_grant.simps split:if_splits option.splits)
       
   552 apply (rule_tac x = x in exI, simp add:file_after_rename_def)
       
   553 apply (frule_tac f\<^isub>2 = f\<^isub>2 in file_renaming_prop1', drule_tac f\<^isub>2 = f\<^isub>2 in file_renaming_prop5')
       
   554 apply (erule_tac x = "file_before_rename f\<^isub>2 f\<^isub>3 x" in allE, simp)
       
   555 apply (rule_tac x = x in exI, simp add:file_after_rename_def)
       
   556 apply (drule_tac a = f\<^isub>3 and b = f\<^isub>2 in no_junior_conf, simp, simp)
       
   557 apply (drule_tac f = f\<^isub>3 and f' = f\<^isub>2 in ancenf_has_inum', simp, simp, simp)
       
   558 apply (drule_tac f\<^isub>2 = f\<^isub>2 in rename_renaming_decom, simp, simp add:current_files_def, simp add:file_renaming_prop5)
       
   559 apply (drule_tac f\<^isub>2 = f\<^isub>2 in rename_renaming_decom', simp, simp add:current_files_def)
       
   560 apply (simp add:file_after_rename_def)
       
   561 apply (drule_tac f\<^isub>2 = f\<^isub>2 in rename_renaming_decom', simp, simp add:current_files_def)
       
   562 apply (simp add:file_after_rename_def)
       
   563 done
       
   564 *)
       
   565 
       
   566 lemma current_files_other:
       
   567   "\<lbrakk>\<forall> p f flag fd opt. e \<noteq> Open p f flag fd opt;
       
   568     \<forall> p fd. e \<noteq> CloseFd p fd;
       
   569     \<forall> p f. e \<noteq> UnLink p f;
       
   570     \<forall> p f. e \<noteq> Rmdir p f;
       
   571     \<forall> p f i. e \<noteq> Mkdir p f i\<rbrakk> \<Longrightarrow> current_files (e # \<tau>) = current_files \<tau>"
       
   572 by (case_tac e, auto simp:current_files_def inum_of_file.simps)
       
   573 
       
   574 lemmas current_files_simps = current_files_nil current_files_open current_files_open' 
       
   575                              current_files_closefd current_files_unlink current_files_rmdir 
       
   576                              current_files_mkdir current_files_other
       
   577 
       
   578 
       
   579 (******************** is_file simpset *********************)
       
   580 
       
   581 lemma is_file_open:
       
   582   "valid (Open p f flags fd opt # s) \<Longrightarrow> 
       
   583    is_file (Open p f flags fd opt # s) = (if (opt = None) then is_file s else (is_file s) (f:= True))"
       
   584 apply (frule vd_cons, drule vt_grant_os, rule ext)
       
   585 apply (auto dest:finum_has_itag iof's_im_in_cim 
       
   586            split:if_splits option.splits t_inode_tag.splits 
       
   587             simp:is_file_def current_files_def)
       
   588 done
       
   589 
       
   590 lemma is_file_closefd:
       
   591   "valid (CloseFd p fd # s) \<Longrightarrow> is_file (CloseFd p fd # s) = (
       
   592      case (file_of_proc_fd s p fd) of
       
   593        Some f \<Rightarrow> ( if ((proc_fd_of_file s f = {(p, fd)}) \<and> (f \<in> files_hung_by_del s))
       
   594                    then (is_file s) (f := False) 
       
   595                    else is_file s)
       
   596      | _      \<Rightarrow> is_file s                                   )"
       
   597 apply (frule vd_cons, drule vt_grant_os, rule ext)
       
   598 apply (auto dest:finum_has_itag iof's_im_in_cim 
       
   599            split:if_splits option.splits t_inode_tag.splits 
       
   600             simp:is_file_def)
       
   601 done
       
   602 
       
   603 lemma is_file_unlink:
       
   604   "valid (UnLink p f # s) \<Longrightarrow> is_file (UnLink p f # s) = (
       
   605      if (proc_fd_of_file s f = {}) then (is_file s) (f := False) else is_file s)"
       
   606 apply (frule vd_cons, drule vt_grant_os, rule ext)
       
   607 apply (auto dest:finum_has_itag iof's_im_in_cim 
       
   608            split:if_splits option.splits t_inode_tag.splits 
       
   609             simp:is_file_def)
       
   610 done
       
   611 
       
   612 lemma is_file_other:
       
   613   "\<lbrakk>valid (e # \<tau>); 
       
   614     \<forall> p f flag fd opt. e \<noteq> Open p f flag fd opt;
       
   615     \<forall> p fd. e \<noteq> CloseFd p fd;
       
   616     \<forall> p f. e \<noteq> UnLink p f\<rbrakk> \<Longrightarrow> is_file (e # \<tau>) = is_file \<tau>"
       
   617 apply (frule vd_cons, drule vt_grant_os, rule_tac ext, case_tac e)
       
   618 apply (auto dest:finum_has_itag iof's_im_in_cim intro!:ext
       
   619            split:if_splits option.splits t_inode_tag.split t_socket_type.splits
       
   620             simp:is_file_def dir_is_empty_def is_dir_def current_files_def)
       
   621 done
       
   622 
       
   623 lemma file_dir_conflict: "\<lbrakk>is_file s f; is_dir s f\<rbrakk> \<Longrightarrow> False"
       
   624 by (auto simp:is_file_def is_dir_def split:option.splits t_inode_tag.splits)
       
   625 
       
   626 lemma is_file_not_dir: "is_file s f \<Longrightarrow> \<not> is_dir s f"
       
   627 by (rule notI, erule file_dir_conflict, simp)
       
   628 
       
   629 lemma is_dir_not_file: "is_dir s f \<Longrightarrow> \<not> is_file s f"
       
   630 by (rule notI, erule file_dir_conflict, simp)
       
   631 
       
   632 lemmas is_file_simps = is_file_nil is_file_open is_file_closefd is_file_unlink is_file_other
       
   633 
       
   634 (********* is_dir simpset **********)
       
   635 
       
   636 lemma is_dir_mkdir: "valid (Mkdir p f i # s) \<Longrightarrow> is_dir (Mkdir p f i # s) = (is_dir s) (f := True)"
       
   637 apply (frule vd_cons, drule vt_grant_os, rule_tac ext)
       
   638 apply (auto dest:finum_has_itag iof's_im_in_cim intro!:ext
       
   639            split:if_splits option.splits t_inode_tag.split t_socket_type.splits
       
   640             simp:is_dir_def dir_is_empty_def is_dir_def current_files_def)
       
   641 done
       
   642 
       
   643 lemma is_dir_rmdir: "valid (Rmdir p f # s) \<Longrightarrow> is_dir (Rmdir p f # s) = (is_dir s) (f := False)"
       
   644 apply (frule vd_cons, drule vt_grant_os, rule_tac ext)
       
   645 apply (auto dest:finum_has_itag iof's_im_in_cim intro!:ext
       
   646            split:if_splits option.splits t_inode_tag.split t_socket_type.splits
       
   647             simp:is_dir_def dir_is_empty_def is_dir_def current_files_def)
       
   648 done
       
   649 
       
   650 lemma is_dir_other:
       
   651   "\<lbrakk>valid (e # s);
       
   652     \<forall> p f. e \<noteq> Rmdir p f;
       
   653     \<forall> p f i. e \<noteq> Mkdir p f i\<rbrakk> \<Longrightarrow> is_dir (e # s) = is_dir s"
       
   654 apply (frule vd_cons, drule vt_grant_os, rule_tac ext, case_tac e)
       
   655 apply (auto dest:finum_has_itag iof's_im_in_cim intro!:ext
       
   656            split:if_splits option.splits t_inode_tag.split t_socket_type.splits
       
   657             simp:is_file_def dir_is_empty_def is_dir_def current_files_def)
       
   658 apply (drule file_of_pfd_is_file, simp)
       
   659 apply (simp add:is_file_def split:t_inode_tag.splits option.splits)
       
   660 done
       
   661 
       
   662 lemmas is_dir_simps = is_dir_nil is_dir_mkdir is_dir_rmdir is_dir_other
       
   663 
       
   664 (*********** no root dir involved ***********)
       
   665 
       
   666 lemma root_is_dir: "valid s \<Longrightarrow> is_dir s []"
       
   667 apply (induct s, simp add:is_dir_nil root_is_init_dir)
       
   668 apply (frule vd_cons, frule vt_grant_os, case_tac a)
       
   669 apply (auto simp:is_dir_simps)
       
   670 done
       
   671 
       
   672 lemma root_is_dir': "\<lbrakk>is_file s []; valid s\<rbrakk> \<Longrightarrow> False"
       
   673 apply (drule root_is_dir)
       
   674 apply (erule file_dir_conflict, simp)
       
   675 done
       
   676 
       
   677 lemma noroot_execve:
       
   678   "valid (Execve p f fds # s) \<Longrightarrow> f \<noteq> []"
       
   679 by (frule vd_cons, drule vt_grant_os, auto dest!:root_is_dir')
       
   680 
       
   681 lemma noroot_execve':
       
   682   "valid (Execve p [] fds # s) \<Longrightarrow> False"
       
   683 by (drule noroot_execve, simp)
       
   684 
       
   685 lemma noroot_open:
       
   686   "valid (Open p f flags fd opt # s) \<Longrightarrow> f \<noteq> []"
       
   687 by (frule vd_cons, drule vt_grant_os, auto dest!:root_is_dir' split:option.splits)
       
   688 
       
   689 lemma noroot_open':
       
   690   "valid (Open p [] flags fd opt # s) \<Longrightarrow> False"
       
   691 by (drule noroot_open, simp)
       
   692 
       
   693 lemma noroot_filefd':
       
   694   "\<lbrakk>file_of_proc_fd s p fd = Some []; valid s\<rbrakk> \<Longrightarrow> False"
       
   695 apply (induct s arbitrary:p, simp) 
       
   696 apply (drule init_filefd_prop5, erule root_is_init_dir')
       
   697 apply (frule vd_cons, frule vt_grant_os, case_tac a)
       
   698 apply (auto split:if_splits option.splits dest!:root_is_dir')
       
   699 done
       
   700 
       
   701 lemma noroot_filefd:
       
   702   "\<lbrakk>file_of_proc_fd s p fd = Some f; valid s\<rbrakk> \<Longrightarrow> f \<noteq> []"
       
   703 by (rule notI, simp, erule noroot_filefd', simp)
       
   704 
       
   705 lemma noroot_unlink:
       
   706   "valid (UnLink p f # s) \<Longrightarrow> f \<noteq> []"
       
   707 by (frule vd_cons, drule vt_grant_os, auto dest!:root_is_dir')
       
   708 
       
   709 lemma noroot_unlink':
       
   710   "valid (UnLink p [] # s) \<Longrightarrow> False"
       
   711 by (drule noroot_unlink, simp)
       
   712 
       
   713 lemma noroot_rmdir:
       
   714   "valid (Rmdir p f # s) \<Longrightarrow> f \<noteq> []"
       
   715 by (frule vd_cons, drule vt_grant_os, auto dest!:root_is_dir')
       
   716 
       
   717 lemma noroot_rmdir':
       
   718   "valid (Rmdir p [] # s) \<Longrightarrow> False"
       
   719 by (drule noroot_rmdir, simp)
       
   720 
       
   721 lemma noroot_mkdir:
       
   722   "valid (Mkdir p f inum # s) \<Longrightarrow> f \<noteq> []"
       
   723 by (frule vd_cons, drule vt_grant_os, auto dest!:root_is_dir')
       
   724 
       
   725 lemma noroot_mkdir':
       
   726   "valid (Mkdir p [] inum # s) \<Longrightarrow> False"
       
   727 by (drule noroot_mkdir, simp)
       
   728 
       
   729 lemma noroot_truncate:
       
   730   "valid (Truncate p f len # s) \<Longrightarrow> f \<noteq> []"
       
   731 by (frule vd_cons, drule vt_grant_os, auto dest!:root_is_dir')
       
   732 
       
   733 lemma noroot_truncate':
       
   734   "valid (Truncate p [] len # s) \<Longrightarrow> False"
       
   735 by (drule noroot_truncate, simp)
       
   736 
       
   737 lemmas noroot_events = noroot_execve noroot_open noroot_filefd noroot_unlink noroot_rmdir
       
   738   noroot_mkdir noroot_truncate
       
   739 
       
   740 lemmas noroot_events' = noroot_execve' noroot_open' noroot_filefd' noroot_unlink' noroot_rmdir'
       
   741   noroot_mkdir' noroot_truncate'
       
   742 
       
   743 
       
   744 lemma is_file_in_current:
       
   745   "is_file s f \<Longrightarrow> f \<in> current_files s"
       
   746 by (auto simp:is_file_def current_files_def split:option.splits)
       
   747 
       
   748 lemma is_dir_in_current:
       
   749   "is_dir s f \<Longrightarrow> f \<in> current_files s"
       
   750 by (auto simp:is_dir_def current_files_def split:option.splits)
       
   751 
       
   752 
       
   753 (* simpset for same_inode_files: Current_files_prop.thy *)
       
   754 (*
       
   755 lemma same_inode_files_nil:
       
   756   "same_inode_files [] = init_same_inode_files"
       
   757 by (rule ext, simp add:same_inode_files_def init_same_inode_files_def is_file_nil)
       
   758 
       
   759 lemma iof's_im_in_cim': "Some im = inum_of_file \<tau> f \<Longrightarrow> im \<in> current_inode_nums \<tau>"
       
   760 by (auto simp add:current_inode_nums_def current_file_inums_def)
       
   761 
       
   762 lemma same_inode_files_open:
       
   763   "valid (Open p f flags fd opt # s) \<Longrightarrow> same_inode_files (Open p f flags fd opt # s) = (\<lambda> f'.
       
   764      if (f' = f \<and> opt \<noteq> None) then {f} else same_inode_files s f')"
       
   765 apply (frule vt_grant_os, frule vd_cons, rule ext)
       
   766 apply (auto simp:same_inode_files_def is_file_simps split:if_splits option.splits
       
   767             dest:iof's_im_in_cim iof's_im_in_cim')
       
   768 apply (drule is_file_in_current)
       
   769 apply (simp add:current_files_def)
       
   770 done
       
   771 
       
   772 lemma same_inode_files_linkhard:
       
   773   "valid (LinkHard p oldf f # s) \<Longrightarrow> same_inode_files (LinkHard p oldf f # s) = (\<lambda> f'. 
       
   774      if (f' = f \<or> f' \<in> same_inode_files s oldf) 
       
   775      then same_inode_files s oldf \<union> {f}
       
   776      else same_inode_files s f')"
       
   777 apply (frule vt_grant_os, frule vd_cons, rule ext)
       
   778 apply (auto simp:same_inode_files_def is_file_simps split:if_splits option.splits
       
   779             dest:iof's_im_in_cim iof's_im_in_cim')
       
   780 apply (drule is_file_in_current)
       
   781 apply (simp add:current_files_def is_file_def)
       
   782 apply (simp add:is_file_def)
       
   783 done
       
   784 
       
   785 lemma inum_of_file_none_prop:
       
   786   "\<lbrakk>inum_of_file s f = None; valid s\<rbrakk> \<Longrightarrow> f \<notin> current_files s"
       
   787 by (simp add:current_files_def)
       
   788 
       
   789 lemma same_inode_files_closefd:
       
   790   "\<lbrakk>valid (CloseFd p fd # s); f' \<in> current_files (CloseFd p fd # s)\<rbrakk> \<Longrightarrow> 
       
   791    same_inode_files (CloseFd p fd # s) f' = (
       
   792      case (file_of_proc_fd s p fd) of 
       
   793        Some f \<Rightarrow> (if ((proc_fd_of_file s f = {(p, fd)}) \<and> (f \<in> files_hung_by_del s))
       
   794                  then same_inode_files s f' - {f}
       
   795                  else same_inode_files s f' )
       
   796      | None   \<Rightarrow> same_inode_files s f' )"
       
   797 apply (frule vt_grant_os, frule vd_cons)
       
   798 apply (auto simp:same_inode_files_def is_file_closefd current_files_closefd 
       
   799            split:if_splits option.splits
       
   800             dest:iof's_im_in_cim iof's_im_in_cim' inum_of_file_none_prop)
       
   801 done
       
   802 
       
   803 lemma same_inode_files_unlink:
       
   804   "\<lbrakk>valid (UnLink p f # s); f' \<in> current_files (UnLink p f # s)\<rbrakk> 
       
   805    \<Longrightarrow> same_inode_files (UnLink p f # s) f' = (
       
   806      if (proc_fd_of_file s f = {}) 
       
   807      then same_inode_files s f' - {f}
       
   808      else same_inode_files s f')"
       
   809 apply (frule vt_grant_os, frule vd_cons)
       
   810 apply (auto simp:same_inode_files_def is_file_unlink current_files_unlink 
       
   811            split:if_splits option.splits
       
   812             dest:iof's_im_in_cim iof's_im_in_cim' inum_of_file_none_prop)
       
   813 done
       
   814 
       
   815 lemma same_inode_files_mkdir:
       
   816   "valid (Mkdir p f inum # s) \<Longrightarrow> same_inode_files (Mkdir p f inum # s) = (same_inode_files s)"
       
   817 apply (frule vt_grant_os, frule vd_cons, rule ext)
       
   818 apply (auto simp:same_inode_files_def is_file_simps current_files_simps 
       
   819            split:if_splits option.splits
       
   820             dest:iof's_im_in_cim iof's_im_in_cim' inum_of_file_none_prop is_file_in_current)
       
   821 apply (simp add:current_files_def is_file_def)
       
   822 done
       
   823 
       
   824 lemma same_inode_files_other:
       
   825   "\<lbrakk>valid (e # s); 
       
   826     \<forall> p f flag fd opt. e \<noteq> Open p f flag fd opt;
       
   827     \<forall> p fd. e \<noteq> CloseFd p fd;
       
   828     \<forall> p f. e \<noteq> UnLink p f;
       
   829     \<forall> p f f'. e \<noteq> LinkHard p f f'\<rbrakk> \<Longrightarrow> same_inode_files (e # s)  = same_inode_files s"
       
   830 apply (frule vt_grant_os, frule vd_cons, rule ext, case_tac e)
       
   831 apply (auto simp:same_inode_files_def is_file_simps current_files_simps dir_is_empty_def
       
   832            split:if_splits option.splits
       
   833             dest:iof's_im_in_cim iof's_im_in_cim' inum_of_file_none_prop is_file_not_dir)
       
   834 apply (simp add:is_file_def is_dir_def current_files_def split:option.splits t_inode_tag.splits)+
       
   835 done
       
   836  
       
   837 lemmas same_inode_files_simps = same_inode_files_nil same_inode_files_open same_inode_files_linkhard
       
   838   same_inode_files_closefd same_inode_files_unlink same_inode_files_mkdir same_inode_files_other
       
   839 
       
   840 lemma same_inode_files_prop1:
       
   841   "f \<in> same_inode_files s f' \<Longrightarrow> f \<in> current_files s"
       
   842 by (simp add:same_inode_files_def is_file_def current_files_def split:if_splits option.splits)
       
   843 
       
   844 lemma same_inode_files_prop2:
       
   845   "\<lbrakk>f \<in> same_inode_files s f'; f'' \<notin> current_files s\<rbrakk> \<Longrightarrow> f \<noteq> f''"
       
   846 by (auto dest:same_inode_files_prop1)
       
   847 
       
   848 lemma same_inode_files_prop3:
       
   849   "\<lbrakk>f \<in> same_inode_files s f'; is_dir s f''\<rbrakk> \<Longrightarrow> f \<noteq> f''"
       
   850 apply (rule notI)
       
   851 apply (simp add:same_inode_files_def is_file_def is_dir_def 
       
   852           split:if_splits option.splits t_inode_tag.splits)
       
   853 done
       
   854 
       
   855 lemma same_inode_files_prop4:
       
   856   "\<lbrakk>f' \<in> same_inode_files s f; f'' \<in> same_inode_files s f'\<rbrakk> \<Longrightarrow> f'' \<in> same_inode_files s f"
       
   857 by (auto simp:same_inode_files_def split:if_splits)
       
   858 
       
   859 lemma same_inode_files_prop5:
       
   860   "f' \<in> same_inode_files s f \<Longrightarrow> f \<in> same_inode_files s f'"
       
   861 by (auto simp:same_inode_files_def is_file_def split:if_splits)
       
   862 
       
   863 lemma same_inode_files_prop6:
       
   864   "f' \<in> same_inode_files s f \<Longrightarrow> same_inode_files s f' = same_inode_files s f"
       
   865 by (auto simp:same_inode_files_def is_file_def split:if_splits)
       
   866 
       
   867 lemma same_inode_files_prop7:
       
   868   "f' \<in> same_inode_files s f \<Longrightarrow> has_same_inode s f f'"
       
   869 by (auto simp:same_inode_files_def is_file_def has_same_inode_def split:if_splits option.splits)
       
   870 
       
   871 lemma same_inode_files_prop8:
       
   872   "f' \<in> same_inode_files s f \<Longrightarrow> has_same_inode s f' f"
       
   873 by (auto simp:same_inode_files_def is_file_def has_same_inode_def split:if_splits option.splits)
       
   874 *)
       
   875 
       
   876 end
       
   877 
       
   878 end