[apparmor] [PATCH 4/6] parser: stop splitting the namespace from the named transition targets
John Johansen
john.johansen at canonical.com
Fri Mar 4 22:34:28 UTC 2016
On 03/04/2016 09:01 AM, Tyler Hicks wrote:
> On 2016-03-04 08:28:45, John Johansen wrote:
>> On 03/04/2016 12:16 AM, Tyler Hicks wrote:
>>> The parser was splitting up the namespace and profile name from named
>>> transition targets only to rejoin it later when creating the binary
>>> policy. This complicated the changes needed to support the stacking
>>> identifier '&' in named transition targets.
>>>
>>> To keep the stacking support simple, this patch keeps the entire named
>>> transition target string intact from initial profile parsing to writing
>>> out the binary.
>>>
>>> All of these changes are straightforward except the hunk that removes
>>> the namespace string addition to the vector in the process_dfa_entry()
>>> function. After speaking with John, the kernel has never expected the
>>> namespace to be separated from the profile name.
>>>
>> not quite right, the kernel never did for pivotroot transitions but
>> it actually does for x transitions. With that said this is a better
>> way to handle it and the current kernel handles either.
>>
>> We can add the null terminated ns as a conditional in the final
>> encode step.
>
> The conditional would test if the kernel supports the domain/stack
> feature?
Yes, that is probably the best one to test. There is also an abi bump
that could be tested and a few other feature files add.
>
>>
>> ie. don't change this patch we can add a new one on top, for the
>> file x transitions.
>>
>>> Signed-off-by: Tyler Hicks <tyhicks at canonical.com>
>>
>> Acked-by: John Johansen <john.johansen at canonical.com>
>
> Thanks for all of your reviews!
>
> Tyler
>
>>
>>
>>> ---
>>> parser/parser.h | 13 ++-----------
>>> parser/parser_merge.c | 12 ------------
>>> parser/parser_misc.c | 32 +++++++++++---------------------
>>> parser/parser_policy.c | 17 +++--------------
>>> parser/parser_regex.c | 5 -----
>>> parser/parser_yacc.y | 45 +++++++++++++++++++--------------------------
>>> 6 files changed, 35 insertions(+), 89 deletions(-)
>>>
>>> diff --git a/parser/parser.h b/parser/parser.h
>>> index 581a87a..ab55a74 100644
>>> --- a/parser/parser.h
>>> +++ b/parser/parser.h
>>> @@ -66,13 +66,6 @@ struct prefixes {
>>> int owner;
>>> };
>>>
>>> -
>>> -struct named_transition {
>>> - int present;
>>> - char *ns;
>>> - char *name;
>>> -};
>>> -
>>> struct cod_pattern {
>>> char *regex; // posix regex
>>> };
>>> @@ -98,7 +91,6 @@ struct cond_entry_list {
>>> };
>>>
>>> struct cod_entry {
>>> - char *ns;
>>> char *name;
>>> union {
>>> char *link_name;
>>> @@ -393,10 +385,9 @@ extern int get_rlimit(const char *name);
>>> extern char *process_var(const char *var);
>>> extern int parse_mode(const char *mode);
>>> extern int parse_X_mode(const char *X, int valid, const char *str_mode, int *mode, int fail);
>>> +bool label_contains_ns(const char *label);
>>> void parse_label(char **ns, char **name, const char *label);
>>> -void parse_named_transition_target(struct named_transition *nt,
>>> - const char *target);
>>> -extern struct cod_entry *new_entry(char *ns, char *id, int mode, char *link_id);
>>> +extern struct cod_entry *new_entry(char *id, int mode, char *link_id);
>>>
>>> /* returns -1 if value != true or false, otherwise 0 == false, 1 == true */
>>> extern int str_to_boolean(const char* str);
>>> diff --git a/parser/parser_merge.c b/parser/parser_merge.c
>>> index 06d0b0e..4898218 100644
>>> --- a/parser/parser_merge.c
>>> +++ b/parser/parser_merge.c
>>> @@ -32,18 +32,6 @@ static int file_comp(const void *c1, const void *c2)
>>> e2 = (struct cod_entry **)c2;
>>> int res = 0;
>>>
>>> - //PERROR("strcmp %s %s\n", (*e1)->name, (*e2)->name);
>>> - if ((*e1)->ns) {
>>> - if ((*e2)->ns)
>>> - res = strcmp((*e1)->ns, (*e2)->ns);
>>> - else
>>> - return 1;
>>> - } else if ((*e2)->ns) {
>>> - return -1;
>>> - }
>>> - if (res)
>>> - return res;
>>> -
>>> if ((*e1)->link_name) {
>>> if ((*e2)->link_name)
>>> res = strcmp((*e1)->link_name, (*e2)->link_name);
>>> diff --git a/parser/parser_misc.c b/parser/parser_misc.c
>>> index d0d8115..aa29675 100644
>>> --- a/parser/parser_misc.c
>>> +++ b/parser/parser_misc.c
>>> @@ -637,6 +637,16 @@ static int _parse_label(char **ns, size_t *ns_len,
>>> return 0;
>>> }
>>>
>>> +bool label_contains_ns(const char *label)
>>> +{
>>> + char *ns = NULL;
>>> + char *name = NULL;
>>> + size_t ns_len = 0;
>>> + size_t name_len = 0;
>>> +
>>> + return _parse_label(&ns, &ns_len, &name, &name_len, label) == 0 && ns;
>>> +}
>>> +
>>> void parse_label(char **_ns, char **_name, const char *label)
>>> {
>>> char *ns = NULL;
>>> @@ -671,20 +681,7 @@ void parse_label(char **_ns, char **_name, const char *label)
>>> }
>>> }
>>>
>>> -void parse_named_transition_target(struct named_transition *nt,
>>> - const char *target)
>>> -{
>>> - memset(nt, 0, sizeof(*nt));
>>> - if (!target) {
>>> - /* Return with nt->present set to 0 (thanks to the memset) */
>>> - return;
>>> - }
>>> -
>>> - parse_label(&nt->ns, &nt->name, target);
>>> - nt->present = 1;
>>> -}
>>> -
>>> -struct cod_entry *new_entry(char *ns, char *id, int mode, char *link_id)
>>> +struct cod_entry *new_entry(char *id, int mode, char *link_id)
>>> {
>>> struct cod_entry *entry = NULL;
>>>
>>> @@ -692,7 +689,6 @@ struct cod_entry *new_entry(char *ns, char *id, int mode, char *link_id)
>>> if (!entry)
>>> return NULL;
>>>
>>> - entry->ns = ns;
>>> entry->name = id;
>>> entry->link_name = link_id;
>>> entry->mode = mode;
>>> @@ -716,7 +712,6 @@ struct cod_entry *copy_cod_entry(struct cod_entry *orig)
>>> if (!entry)
>>> return NULL;
>>>
>>> - DUP_STRING(orig, entry, ns, err);
>>> DUP_STRING(orig, entry, name, err);
>>> DUP_STRING(orig, entry, link_name, err);
>>> DUP_STRING(orig, entry, nt_name, err);
>>> @@ -743,8 +738,6 @@ void free_cod_entries(struct cod_entry *list)
>>> return;
>>> if (list->next)
>>> free_cod_entries(list->next);
>>> - if (list->ns)
>>> - free(list->ns);
>>> if (list->name)
>>> free(list->name);
>>> if (list->link_name)
>>> @@ -797,9 +790,6 @@ void debug_cod_entries(struct cod_entry *list)
>>> else
>>> printf("\tName:\tNULL\n");
>>>
>>> - if (item->ns)
>>> - printf("\tNs:\t(%s)\n", item->ns);
>>> -
>>> if (AA_LINK_BITS & item->mode)
>>> printf("\tlink:\t(%s)\n", item->link_name ? item->link_name : "/**");
>>>
>>> diff --git a/parser/parser_policy.c b/parser/parser_policy.c
>>> index 292abff..545f613 100644
>>> --- a/parser/parser_policy.c
>>> +++ b/parser/parser_policy.c
>>> @@ -91,7 +91,7 @@ static int add_named_transition(Profile *prof, struct cod_entry *entry)
>>> char *name = NULL;
>>>
>>> /* check to see if it is a local transition */
>>> - if (!entry->ns) {
>>> + if (!label_contains_ns(entry->nt_name)) {
>>> char *sub = strstr(entry->nt_name, "//");
>>> /* does the subprofile name match the rule */
>>>
>>> @@ -127,17 +127,6 @@ static int add_named_transition(Profile *prof, struct cod_entry *entry)
>>> name = entry->nt_name;
>>> entry->nt_name = NULL;
>>> }
>>> - } else {
>>> - name = (char *) malloc(strlen(entry->ns) + strlen(entry->nt_name) + 3);
>>> - if (!name) {
>>> - PERROR("Memory allocation error\n");
>>> - exit(1);
>>> - }
>>> - sprintf(name, ":%s:%s", entry->ns, entry->nt_name);
>>> - free(entry->ns);
>>> - free(entry->nt_name);
>>> - entry->ns = NULL;
>>> - entry->nt_name = NULL;
>>> }
>>>
>>> return add_entry_to_x_table(prof, name);
>>> @@ -184,7 +173,7 @@ void post_process_file_entries(Profile *prof)
>>> PERROR("Memory allocation error\n");
>>> exit(1);
>>> }
>>> - new_ent = new_entry(NULL, buffer, AA_MAY_WRITE, NULL);
>>> + new_ent = new_entry(buffer, AA_MAY_WRITE, NULL);
>>> if (!new_ent) {
>>> PERROR("Memory allocation error\n");
>>> exit(1);
>>> @@ -214,7 +203,7 @@ static int profile_add_hat_rules(Profile *prof)
>>> return 0;
>>>
>>> /* add entry to hat */
>>> - entry = new_entry(NULL, strdup(CHANGEHAT_PATH), AA_MAY_WRITE, NULL);
>>> + entry = new_entry(strdup(CHANGEHAT_PATH), AA_MAY_WRITE, NULL);
>>> if (!entry)
>>> return ENOMEM;
>>>
>>> diff --git a/parser/parser_regex.c b/parser/parser_regex.c
>>> index ca781d4..9270076 100644
>>> --- a/parser/parser_regex.c
>>> +++ b/parser/parser_regex.c
>>> @@ -585,11 +585,6 @@ static int process_dfa_entry(aare_rules *dfarules, struct cod_entry *entry)
>>> /* allow change_profile for all execs */
>>> vec[0] = "/[^/\\x00][^\\x00]*";
>>>
>>> - if (entry->ns) {
>>> - int pos;
>>> - ptype = convert_aaregex_to_pcre(entry->ns, 0, glob_default, lbuf, &pos);
>>> - vec[index++] = lbuf.c_str();
>>> - }
>>> vec[index++] = tbuf.c_str();
>>>
>>> /* regular change_profile rule */
>>> diff --git a/parser/parser_yacc.y b/parser/parser_yacc.y
>>> index 7af78ce..69fa4ff 100644
>>> --- a/parser/parser_yacc.y
>>> +++ b/parser/parser_yacc.y
>>> @@ -71,8 +71,7 @@
>>>
>>> int parser_token = 0;
>>>
>>> -struct cod_entry *do_file_rule(char *ns, char *id, int mode,
>>> - char *link_id, char *nt);
>>> +struct cod_entry *do_file_rule(char *id, int mode, char *link_id, char *nt);
>>> mnt_rule *do_mnt_rule(struct cond_entry *src_conds, char *src,
>>> struct cond_entry *dst_conds, char *dst,
>>> int mode);
>>> @@ -212,7 +211,6 @@ void add_local_entry(Profile *prof);
>>> struct cond_entry *cond_entry;
>>> struct cond_entry_list cond_entry_list;
>>> int boolean;
>>> - struct named_transition transition;
>>> struct prefixes prefix;
>>> }
>>>
>>> @@ -277,7 +275,7 @@ void add_local_entry(Profile *prof);
>>> %type <fmode> opt_net_perm
>>> %type <unix_entry> unix_rule
>>> %type <id> opt_target
>>> -%type <transition> opt_named_transition
>>> +%type <id> opt_named_transition
>>> %type <boolean> opt_unsafe
>>> %type <boolean> opt_file
>>> %%
>>> @@ -1048,14 +1046,10 @@ id_or_var: TOK_SET_VAR { $$ = $1; };
>>> opt_target: /* nothing */ { $$ = NULL; }
>>> opt_target: TOK_ARROW id_or_var { $$ = $2; };
>>>
>>> -opt_named_transition:
>>> - { /* nothing */
>>> - parse_named_transition_target(&$$, NULL);
>>> - }
>>> +opt_named_transition: { /* nothing */ $$ = NULL; }
>>> | TOK_ARROW id_or_var
>>> {
>>> - parse_named_transition_target(&$$, $2);
>>> - free($2);
>>> + $$ = $2;
>>> };
>>>
>>> rule: file_rule { $$ = $1; }
>>> @@ -1070,23 +1064,24 @@ opt_file: { /* nothing */ $$ = 0; }
>>>
>>> frule: id_or_var file_mode opt_named_transition TOK_END_OF_RULE
>>> {
>>> - $$ = do_file_rule($3.ns, $1, $2, NULL, $3.name);
>>> + $$ = do_file_rule($1, $2, NULL, $3);
>>> };
>>>
>>> frule: file_mode opt_subset_flag id_or_var opt_named_transition TOK_END_OF_RULE
>>> {
>>> if ($2 && ($1 & ~AA_LINK_BITS))
>>> yyerror(_("subset can only be used with link rules."));
>>> - if ($4.present && ($1 & AA_LINK_BITS) && ($1 & AA_EXEC_BITS))
>>> + if ($4 && ($1 & AA_LINK_BITS) && ($1 & AA_EXEC_BITS))
>>> yyerror(_("link and exec perms conflict on a file rule using ->"));
>>> - if ($4.present && $4.ns && ($1 & AA_LINK_BITS))
>>> + if ($4 && label_contains_ns($4) && ($1 & AA_LINK_BITS))
>>> yyerror(_("link perms are not allowed on a named profile transition.\n"));
>>> +
>>> if (($1 & AA_LINK_BITS)) {
>>> - $$ = do_file_rule(NULL, $3, $1, $4.name, NULL);
>>> + $$ = do_file_rule($3, $1, $4, NULL);
>>> $$->subset = $2;
>>>
>>> } else {
>>> - $$ = do_file_rule($4.ns, $3, $1, NULL, $4.name);
>>> + $$ = do_file_rule($3, $1, NULL, $4);
>>> }
>>> };
>>>
>>> @@ -1099,7 +1094,7 @@ file_rule: TOK_FILE TOK_END_OF_RULE
>>> perms |= perms << AA_OTHER_SHIFT;
>>> if (!path)
>>> yyerror(_("Memory allocation error."));
>>> - $$ = do_file_rule(NULL, path, perms, NULL, NULL);
>>> + $$ = do_file_rule(path, perms, NULL, NULL);
>>> }
>>> | opt_file file_rule_tail { $$ = $2; }
>>>
>>> @@ -1132,7 +1127,7 @@ link_rule: TOK_LINK opt_subset_flag id_or_var TOK_ARROW id_or_var TOK_END_OF_RUL
>>> {
>>> struct cod_entry *entry;
>>> PDEBUG("Matched: link tok_id (%s) -> (%s)\n", $3, $5);
>>> - entry = new_entry(NULL, $3, AA_LINK_BITS, $5);
>>> + entry = new_entry($3, AA_LINK_BITS, $5);
>>> entry->subset = $2;
>>> PDEBUG("rule.entry: link (%s)\n", entry->name);
>>> $$ = entry;
>>> @@ -1486,17 +1481,16 @@ change_profile: change_profile_head opt_named_transition TOK_END_OF_RULE
>>> {
>>> struct cod_entry *entry;
>>>
>>> - if ($2.present) {
>>> - PDEBUG("Matched change_profile: tok_id (:%s://%s)\n",
>>> - $2.ns ? $2.ns : "", $2.name);
>>> - entry = new_entry($2.ns, $2.name, AA_CHANGE_PROFILE, $1);
>>> + if ($2) {
>>> + PDEBUG("Matched change_profile: tok_id (%s)\n", $2);
>>> + entry = new_entry($2, AA_CHANGE_PROFILE, $1);
>>> } else {
>>> char *rule = strdup("**");
>>> if (!rule)
>>> yyerror(_("Memory allocation error."));
>>>
>>> PDEBUG("Matched change_profile,\n");
>>> - entry = new_entry(NULL, rule, AA_CHANGE_PROFILE, $1);
>>> + entry = new_entry(rule, AA_CHANGE_PROFILE, $1);
>>> }
>>> if (!entry)
>>> yyerror(_("Memory allocation error."));
>>> @@ -1567,12 +1561,11 @@ void yyerror(const char *msg, ...)
>>> exit(1);
>>> }
>>>
>>> -struct cod_entry *do_file_rule(char *ns, char *id, int mode,
>>> - char *link_id, char *nt)
>>> +struct cod_entry *do_file_rule(char *id, int mode, char *link_id, char *nt)
>>> {
>>> struct cod_entry *entry;
>>> PDEBUG("Matched: tok_id (%s) tok_mode (0x%x)\n", id, mode);
>>> - entry = new_entry(ns, id, mode, link_id);
>>> + entry = new_entry(id, mode, link_id);
>>> if (!entry)
>>> yyerror(_("Memory allocation error."));
>>> entry->nt_name = nt;
>>> @@ -1595,7 +1588,7 @@ void add_local_entry(Profile *prof)
>>> yyerror(_("Memory allocation error."));
>>> sprintf(name, "%s//%s", prof->parent->name, prof->name);
>>>
>>> - entry = new_entry(NULL, name, prof->local_mode, NULL);
>>> + entry = new_entry(name, prof->local_mode, NULL);
>>> entry->audit = prof->local_audit;
>>> entry->nt_name = trans;
>>> if (!entry)
>>>
>>
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