From: Gary Tierney <gary.tierney@gmx.com>
To: selinux@tycho.nsa.gov
Subject: Re: [PATCH] genhomedircon: remove hardcoded refpolicy strings
Date: Wed, 7 Sep 2016 05:42:33 +0100 [thread overview]
Message-ID: <20160907044233.GA3000@home> (raw)
In-Reply-To: <045d3758-8c82-b12a-3cee-f31611161ac6@tycho.nsa.gov>
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On Tue, Sep 06, 2016 at 03:13:17PM -0400, Stephen Smalley wrote:
>On 09/06/2016 09:48 AM, Gary Tierney wrote:
>> Removes the "system_u" and "s0" string literals from refpolicy and
>> replaces the seuser and range in each homedir, uid, and username context
>> specification for every user.
>>
>> Signed-off-by: Gary Tierney <gary.tierney@gmx.com>
>> ---
>> libsemanage/src/genhomedircon.c | 79 ++++++++++++++++++++++++++++++++++-------
>> 1 file changed, 66 insertions(+), 13 deletions(-)
>>
>> diff --git a/libsemanage/src/genhomedircon.c b/libsemanage/src/genhomedircon.c
>> index cce3884..cca97f6 100644
>> --- a/libsemanage/src/genhomedircon.c
>> +++ b/libsemanage/src/genhomedircon.c
>> @@ -20,6 +20,7 @@
>> * 02110-1301 USA
>> */
>>
>> +#include <selinux/context.h>
>
>I think we likely want to use the sepol/context_record.h (already
>included here) functions instead. Those are already in use by
>libsemanage. I agree it is confusing and not helped by the fact that we
>lack man pages for most sepol functions. Sorry.
>
>
Thanks, wasn't aware of those. Will update to use the libsepol API.
>> #include <semanage/handle.h>
>> #include <semanage/seusers_policy.h>
>> #include <semanage/users_policy.h>
>> @@ -82,9 +83,6 @@
>> #define TEMPLATE_USERNAME "%{USERNAME}"
>> #define TEMPLATE_USERID "%{USERID}"
>>
>> -#define TEMPLATE_SEUSER "system_u"
>> -#define TEMPLATE_LEVEL "s0"
>> -
>> #define FALLBACK_SENAME "user_u"
>> #define FALLBACK_PREFIX "user"
>> #define FALLBACK_LEVEL "s0"
>> @@ -92,6 +90,8 @@
>> #define FALLBACK_UIDGID "[0-9]+"
>> #define DEFAULT_LOGIN "__default__"
>>
>> +#define CONTEXT_NONE "<<none>>"
>> +
>> typedef struct user_entry {
>> char *name;
>> char *uid;
>> @@ -599,14 +599,72 @@ static int write_replacements(genhomedircon_settings_t * s, FILE * out,
>> return STATUS_ERR;
>> }
>>
>> +static int write_user_replacements(genhomedircon_settings_t *s, FILE *out,
>> + semanage_list_t *tpl, const replacement_pair_t *repl,
>> + const genhomedircon_user_entry_t *user)
>> +{
>> + Ustr *line = USTR_NULL;
>> + context_t context = NULL;
>> +
>> + for (; tpl; tpl = tpl->next) {
>> + line = replace_all(tpl->data, repl);
>> + if (!line) {
>> + goto fail;
>> + }
>> +
>> + const char *old_context_str = extract_context(line);
>> + if (!old_context_str) {
>> + goto fail;
>> + }
>> +
>> + if (strcmp(old_context_str, CONTEXT_NONE) == 0) {
>> + if (check_line(s, line) &&
>> + !ustr_io_putfileline(&line, out)) {
>> + goto fail;
>> + }
>> +
>> + continue;
>> + }
>> +
>> + context = context_new(old_context_str);
>
>sepol_context_from_string()
>
>> + if (!context) {
>> + goto fail;
>> + }
>> +
>> + if (context_user_set(context, user->sename) != 0 ||
>
>sepol_context_set_user()
>
>> + context_range_set(context, user->level) != 0) {
>
>sepol_context_set_mls()
>
>> + goto fail;
>> + }
>> +
>> + const char *new_context_str = context_str(context);
>
>sepol_context_to_string()
>
>> + if (!ustr_replace_cstr(&line, old_context_str,
>> + new_context_str, 1)) {
>> + goto fail;
>> + }
>> +
>> + if (check_line(s, line) == STATUS_SUCCESS) {
>> + if (!ustr_io_putfileline(&line, out)) {
>> + goto fail;
>> + }
>> + }
>> +
>> + ustr_sc_free(&line);
>> + context_free(context);
>
>sepol_context_free()
>
>> + }
>> +
>> + return STATUS_SUCCESS;
>> +fail:
>> + ustr_sc_free(&line);
>> + context_free(context);
>> + return STATUS_ERR;
>> +}
>> +
>> static int write_home_dir_context(genhomedircon_settings_t * s, FILE * out,
>> semanage_list_t * tpl, const genhomedircon_user_entry_t *user)
>> {
>> replacement_pair_t repl[] = {
>> - {.search_for = TEMPLATE_SEUSER,.replace_with = user->sename},
>> {.search_for = TEMPLATE_HOME_DIR,.replace_with = user->home},
>> {.search_for = TEMPLATE_ROLE,.replace_with = user->prefix},
>> - {.search_for = TEMPLATE_LEVEL,.replace_with = user->level},
>> {NULL, NULL}
>> };
>>
>> @@ -618,7 +676,7 @@ static int write_home_dir_context(genhomedircon_settings_t * s, FILE * out,
>> return STATUS_ERR;
>> }
>>
>> - return write_replacements(s, out, tpl, repl);
>> + return write_user_replacements(s, out, tpl, repl, user);
>> }
>>
>> static int write_home_root_context(genhomedircon_settings_t * s, FILE * out,
>> @@ -640,11 +698,10 @@ static int write_username_context(genhomedircon_settings_t * s, FILE * out,
>> {.search_for = TEMPLATE_USERNAME,.replace_with = user->name},
>> {.search_for = TEMPLATE_USERID,.replace_with = user->uid},
>> {.search_for = TEMPLATE_ROLE,.replace_with = user->prefix},
>> - {.search_for = TEMPLATE_SEUSER,.replace_with = user->sename},
>> {NULL, NULL}
>> };
>>
>> - return write_replacements(s, out, tpl, repl);
>> + return write_user_replacements(s, out, tpl, repl, user);
>> }
>>
>> static int write_user_context(genhomedircon_settings_t * s, FILE * out,
>> @@ -653,11 +710,10 @@ static int write_user_context(genhomedircon_settings_t * s, FILE * out,
>> replacement_pair_t repl[] = {
>> {.search_for = TEMPLATE_USER,.replace_with = user->name},
>> {.search_for = TEMPLATE_ROLE,.replace_with = user->prefix},
>> - {.search_for = TEMPLATE_SEUSER,.replace_with = user->sename},
>> {NULL, NULL}
>> };
>>
>> - return write_replacements(s, out, tpl, repl);
>> + return write_user_replacements(s, out, tpl, repl, user);
>> }
>>
>> static int seuser_sort_func(const void *arg1, const void *arg2)
>> @@ -1074,9 +1130,6 @@ static genhomedircon_user_entry_t *get_users(genhomedircon_settings_t * s,
>> if (strcmp(name, DEFAULT_LOGIN) == 0)
>> continue;
>>
>> - if (strcmp(name, TEMPLATE_SEUSER) == 0)
>> - continue;
>> -
>
>This yields a warning/error on Fedora:
>$ sudo semodule -B
>libsemanage.add_user: user system_u not in password file
>
I can re-add this conditional to prevent outputting the warning, though
is there a reason for a login named "system_u" ?
>And I end up with a slightly different file_contexts.homedirs:
>@@ -39,7 +39,6 @@
> /home/[^/]+/\.xauth.* -- unconfined_u:object_r:xauth_home_t:s0
> /home/[^/]+/\.Xauth.* -- unconfined_u:object_r:xauth_home_t:s0
> /home/[^/]+/\.local.* unconfined_u:object_r:gconf_home_t:s0
>-/home/[^/]+/\.gvfs/.* <<none>>
> /home/[^/]+/\.cache(/.*)? unconfined_u:object_r:cache_home_t:s0
> /home/[^/]+/\.gnupg(/.+)? unconfined_u:object_r:gpg_secret_t:s0
> /home/[^/]+/\.irssi(/.*)? unconfined_u:object_r:irc_home_t:s0
>@@ -51,7 +50,6 @@
> /home/[^/]+/\.pyzor(/.*)? unconfined_u:object_r:spamc_home_t:s0
> /home/[^/]+/\.razor(/.*)? unconfined_u:object_r:spamc_home_t:s0
> /home/[^/]+/\.spamd(/.*)? unconfined_u:object_r:spamc_home_t:s0
>-/home/[^/]+/\.debug(/.*)? <<none>>
> /home/[^/]+/vmware(/.*)? unconfined_u:object_r:vmware_file_t:s0
> /home/[^/]+/\.fonts(/.*)? unconfined_u:object_r:user_fonts_t:s0
> /home/[^/]+/\.gconf(d)?(/.*)? unconfined_u:object_r:gconf_home_t:s0
>
>The homedir_template has:
>...
>HOME_DIR/\.gvfs/.* <<none>>
>HOME_DIR/\.cache(/.*)? system_u:object_r:cache_home_t:s0
>HOME_DIR/\.gnupg(/.+)? system_u:object_r:gpg_secret_t:s0
>HOME_DIR/\.irssi(/.*)? system_u:object_r:irc_home_t:s0
>HOME_DIR/irclog(/.*)? system_u:object_r:irc_home_t:s0
>HOME_DIR/\.adobe(/.*)? system_u:object_r:mozilla_home_t:s0
>HOME_DIR/\.gnash(/.*)? system_u:object_r:mozilla_home_t:s0
>HOME_DIR/\.webex(/.*)? system_u:object_r:mozilla_home_t:s0
>HOME_DIR/\.pulse(/.*)? system_u:object_r:pulseaudio_home_t:s0
>HOME_DIR/\.pyzor(/.*)? system_u:object_r:spamc_home_t:s0
>HOME_DIR/\.razor(/.*)? system_u:object_r:spamc_home_t:s0
>HOME_DIR/\.spamd(/.*)? system_u:object_r:spamc_home_t:s0
>HOME_DIR/\.debug(/.*)? <<none>>
>...
>
>
Ah, sorry, missed a comparison in a check_line() call. Will send a v2
with this fixed.
>> /* find the user structure given the name */
>> u = bsearch(seuname, user_list, nusers, sizeof(semanage_user_t *),
>> (int (*)(const void *, const void *))
>>
>
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next prev parent reply other threads:[~2016-09-07 4:42 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-06 13:48 [PATCH] remove system_u and s0 hardcoded strings Gary Tierney
2016-09-06 13:48 ` [PATCH] genhomedircon: remove hardcoded refpolicy strings Gary Tierney
2016-09-06 19:13 ` Stephen Smalley
2016-09-07 4:42 ` Gary Tierney [this message]
2016-09-07 7:15 ` Dominick Grift
2016-09-07 12:45 ` Stephen Smalley
2016-09-07 12:45 ` Dominick Grift
2016-09-07 12:36 ` Stephen Smalley
2016-09-07 12:47 ` Dominick Grift
2016-09-07 12:55 ` Dominick Grift
2016-09-07 13:00 ` Stephen Smalley
2016-09-07 13:04 ` Dominick Grift
2016-09-07 13:08 ` Stephen Smalley
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