| Message ID | 1457636396-24983-5-git-send-email-berrange@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 03/10/2016 11:59 AM, Daniel P. Berrange wrote: > Add a QAuthZSimple object type that implements the QAuthZ > interface. This simple built-in implementation maintains > a trivial access control list with a sequence of match > rules and a final default policy. This replicates the > functionality currently provided by the qemu_acl module. > > To create an instance of this object via the QMP monitor, > the syntax used would be > > { > "execute": "object-add", > "arguments": { > "qom-type": "authz-simple", > "id": "auth0", > "parameters": { > "rules": [ > { "match": "fred", "policy": "allow" }, > { "match": "bob", "policy": "allow" }, > { "match": "danb", "policy": "deny" }, > { "match": "dan*", "policy": "allow" } > ], > "policy": "deny" > } > } > } So "match" appears to be a glob (as opposed to a regex). And order is important (the first rule matched ends the lookup), so you correctly used an array for the list of rules (a dict does not have to maintain order). > > Or via the -object command line > > $QEMU \ > -object authz-simple,id=acl0,policy=deny,\ > match.0.name=fred,match.0.policy=allow, \ > match.1.name=bob,match.1.policy=allow, \ > match.2.name=danb,match.2.policy=deny, \ > match.3.name=dan*,match.3.policy=allow The '*' in the command line will require shell quoting. > > This sets up an authorization rule that allows 'fred', > 'bob' and anyone whose name starts with 'dan', except > for 'danb'. Everyone unmatched is denied. > > Signed-off-by: Daniel P. Berrange <berrange@redhat.com> > --- > +/** > + * QAuthZSimple: > + * > + * This authorization driver provides a simple mechanism > + * for granting access by matching user names against a > + * list of globs. Each match rule has an associated policy > + * and a catch all policy applies if no rule matches > + * > + * To create an instace of this class via QMP: s/instace/instance/ > + * > + * Or via the CLI: > + * > + * $QEMU \ > + * -object authz-simple,id=acl0,policy=deny, \ > + * match.0.name=fred,match.0.policy=allow, \ > + * match.1.name=bob,match.1.policy=allow, \ > + * match.2.name=danb,match.2.policy=deny, \ > + * match.3.name=dan*,match.3.policy=allow Again, quoting the "*" is important, and maybe a comment that the whitespace is for display purposes but must be omitted on the command line. > +++ b/qapi-schema.json > @@ -5,6 +5,9 @@ > # QAPI common definitions > { 'include': 'qapi/common.json' } > > +# QAPI util definitions > +{ 'include': 'qapi/util.json' } > + > # QAPI crypto definitions > { 'include': 'qapi/crypto.json' } > > @@ -3652,7 +3655,8 @@ > # Since 2.5 > ## > { 'struct': 'DummyForceArrays', > - 'data': { 'unused': ['X86CPUFeatureWordInfo'] } } > + 'data': { 'unused': ['X86CPUFeatureWordInfo'], > + 'iamalsounused': ['QAuthZSimpleRule'] } } Cute. I might have renamed things and gone 'unused1' and 'unused2'. > +++ b/qapi/util.json > @@ -0,0 +1,31 @@ > +# -*- Mode: Python -*- > +# > +# QAPI util definitions > + > +## > +# QAuthZSimplePolicy: > +# > +# The authorization policy result > +# > +# @deny: deny access > +# @allow: allow access > +# > +# Since: 2.6 > +## > +{ 'enum': 'QAuthZSimplePolicy', > + 'prefix': 'QAUTHZ_SIMPLE_POLICY', > + 'data': ['deny', 'allow']} I know Markus isn't a big fan of 'prefix', but I don't mind it. We're awfully late in the 2.6 cycle; this feels like a feature addition rather than a bug fix, so should it be 2.7? > + > +## > +# QAuthZSimpleRule: > +# > +# A single authorization rule. > +# > +# @match: a glob to match against a user identity > +# @policy: the result to return if @match evaluates to true > +# > +# Since: 2.6 > +## > +{ 'struct': 'QAuthZSimpleRule', > + 'data': {'match': 'str', > + 'policy': 'QAuthZSimplePolicy'}} Hmm. I was expecting something like: { 'struct': 'QAuthZSimple', 'data': { 'rules': [ 'QAuthZSimpleRule' ], 'policy': 'QAuthZSimplePolicy' } } but I guess that's one of our short-comings of QOM: the top-level structure does not have to be specified anywhere in QAPI. > +++ b/tests/test-authz-simple.c > @@ -0,0 +1,156 @@ > +/* > + * QEMU simple authorization object > + * > + * Copyright (c) 2016 Red Hat, Inc. > + * > +static void test_authz_default_deny(void) > +{ > + QAuthZSimple *auth = qauthz_simple_new("auth0", > + QAUTHZ_SIMPLE_POLICY_DENY, > + &error_abort); > + > + g_assert(!qauthz_is_allowed(QAUTHZ(auth), "fred", &error_abort)); > + Okay, so you definitely intend to return false without setting errp, so it is a ternary result. > + > +#ifdef CONFIG_FNMATCH > +static void test_authz_complex(void) > +{ Wait - the behavior depends on whether fnmatch() is available? That is, a name is a literal match if fnmatch() is not present, and glob if present? I'd argue that if fnmatch() is not present, we must explicitly reject any "match" with glob metacharacters, rather than accidentally matching only a literal "*" when a glob was intended. > +++ b/util/authz-simple.c > + > +/* If no fnmatch, fallback to exact string matching > + * instead of allowing wildcards */ > +#ifdef CONFIG_FNMATCH > +#include <fnmatch.h> > +#define qauthz_match(pattern, string) fnmatch(pattern, string, 0) > +#else > +#define qauthz_match(pattern, string) strcmp(pattern, string) > +#endif As mentioned above, I'd be more comfortable if you also explicitly reject any attempt to add a pattern that resembles a glob when globbing is not enabled. Or maybe it's worth a more complex QAPI definition: # How to interpret 'match', as a literal string or a glob { 'enum': 'QAuthZSimpleStyle', 'data': [ 'literal', 'glob' ] } # @style: #optional, default to 'literal' { 'struct': 'QAuthZSimpleRule', 'data': { 'match': 'str', '*style': 'QAuthZSimpleStyle', 'policy': 'QAuthZSimplePolicy' } } and used as: "rules": [ { "match": "fred", "policy": "allow" }, { "match": "bob", "policy": "allow" }, { "match": "danb", "policy": "deny" }, { "match": "dan*", "policy": "allow", "style": "glob" } where you can then gracefully error out for ALL attempts to use "style":"glob" if fnmatch() is not present, and use strcmp() even when fnmatch() is present for rules that have the (default) "style":"literal". > +static void > +qauthz_simple_class_init(ObjectClass *oc, void *data) > +{ > + UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc); > + QAuthZClass *authz = QAUTHZ_CLASS(oc); > + > + ucc->complete = qauthz_simple_complete; > + authz->is_allowed = qauthz_simple_is_allowed; > + > + object_class_property_add_enum(oc, "policy", > + "QAuthZSimplePolicy", > + QAuthZSimplePolicy_lookup, > + qauthz_simple_prop_get_policy, > + qauthz_simple_prop_set_policy, > + NULL); > + > + object_class_property_add(oc, "rules", "QAuthZSimpleRule", > + qauthz_simple_prop_get_rules, > + qauthz_simple_prop_set_rules, > + NULL, NULL, NULL); > +} Not for this patch, but it would be cool if we had enough framework to just tell QOM to instantiate an object with callbacks by merely pointing to the name of a QAPI type that the object implements (referring back to my comment that I'm a bit surprised we didn't need a QAPI type for the overall QAuthZSimple). > + > +size_t qauthz_simple_append_rule(QAuthZSimple *auth, const char *match, > + QAuthZSimplePolicy policy) > +{ > + QAuthZSimpleRule *rule; > + QAuthZSimpleRuleList *rules, *tmp; > + size_t i = 0; > + > + rule = g_new0(QAuthZSimpleRule, 1); > + rule->policy = policy; > + rule->match = g_strdup(match); > + > + tmp = g_new0(QAuthZSimpleRuleList, 1); > + tmp->value = rule; > + > + rules = auth->rules; > + if (rules) { > + while (rules->next) { > + i++; > + rules = rules->next; > + } > + rules->next = tmp; > + return i + 1; No checks whether 'match' is already an existing rule... > +ssize_t qauthz_simple_delete_rule(QAuthZSimple *auth, const char *match) > +{ > + QAuthZSimpleRule *rule; > + QAuthZSimpleRuleList *rules, *prev; > + size_t i = 0; > + > + prev = NULL; > + rules = auth->rules; > + while (rules) { > + rule = rules->value; > + if (g_str_equal(rule->match, match)) { > + if (prev) { > + prev->next = rules->next; > + } else { > + auth->rules = rules->next; > + } > + rules->next = NULL; > + qapi_free_QAuthZSimpleRuleList(rules); > + return i; ...which means a rule can be inserted more than once, and this only removes the first instance of the rule. Do we care enough to add in additional checking that we aren't permitting duplicate 'match' strings in the list of rules? If you add the style=literal/glob to a rule, would you also want to be able to constrain deletion to a particular style (delete the glob 'dan*' but leave the literal 'dan*' intact)?
On Tue, Mar 22, 2016 at 11:38:53AM -0600, Eric Blake wrote: > On 03/10/2016 11:59 AM, Daniel P. Berrange wrote: > > Add a QAuthZSimple object type that implements the QAuthZ > > interface. This simple built-in implementation maintains > > a trivial access control list with a sequence of match > > rules and a final default policy. This replicates the > > functionality currently provided by the qemu_acl module. > > > > To create an instance of this object via the QMP monitor, > > the syntax used would be > > > > { > > "execute": "object-add", > > "arguments": { > > "qom-type": "authz-simple", > > "id": "auth0", > > "parameters": { > > "rules": [ > > { "match": "fred", "policy": "allow" }, > > { "match": "bob", "policy": "allow" }, > > { "match": "danb", "policy": "deny" }, > > { "match": "dan*", "policy": "allow" } > > ], > > "policy": "deny" > > } > > } > > } > > So "match" appears to be a glob (as opposed to a regex). And order is > important (the first rule matched ends the lookup), so you correctly > used an array for the list of rules (a dict does not have to maintain > order). Yes, its a glob (as defined by fnmatch) > > > > Or via the -object command line > > > > $QEMU \ > > -object authz-simple,id=acl0,policy=deny,\ > > match.0.name=fred,match.0.policy=allow, \ > > match.1.name=bob,match.1.policy=allow, \ > > match.2.name=danb,match.2.policy=deny, \ > > match.3.name=dan*,match.3.policy=allow > > The '*' in the command line will require shell quoting. Yeah, CLI syntax escaping from shell is horrible, but fortunately libvirt doesn't use shell :-) None the less I'll update the example. > > +## > > +# QAuthZSimplePolicy: > > +# > > +# The authorization policy result > > +# > > +# @deny: deny access > > +# @allow: allow access > > +# > > +# Since: 2.6 > > +## > > +{ 'enum': 'QAuthZSimplePolicy', > > + 'prefix': 'QAUTHZ_SIMPLE_POLICY', > > + 'data': ['deny', 'allow']} > > I know Markus isn't a big fan of 'prefix', but I don't mind it. It doesn't affect public API anyway, so we can change it at will later if desired. > We're awfully late in the 2.6 cycle; this feels like a feature addition > rather than a bug fix, so should it be 2.7? It is definitely a feature addition. I was hoping to get it into 2.6 since it is logically associated with the TLS enhancements I've been doing. It isn't the end of the world if it waits until 2.7 though, so I'm open minded either way. Basically TLS provides encryption, x509 certs provide authentication, and this ACL stuff provides the authorization piece of the puzzel. If we miss the authorization piece in 2.6 we're still in a far better position than we were historically because we at least have encryption and authentication still :-) You can mitigate the lack of authorization by having a dedicated CA certificate just for QEMU services, so that you limit who has access to client certs. This is a crude authorization setup that is none the less acceptable in many scenarios. > > +## > > +# QAuthZSimpleRule: > > +# > > +# A single authorization rule. > > +# > > +# @match: a glob to match against a user identity > > +# @policy: the result to return if @match evaluates to true > > +# > > +# Since: 2.6 > > +## > > +{ 'struct': 'QAuthZSimpleRule', > > + 'data': {'match': 'str', > > + 'policy': 'QAuthZSimplePolicy'}} > > Hmm. I was expecting something like: > > { 'struct': 'QAuthZSimple', > 'data': { 'rules': [ 'QAuthZSimpleRule' ], > 'policy': 'QAuthZSimplePolicy' } } > > but I guess that's one of our short-comings of QOM: the top-level > structure does not have to be specified anywhere in QAPI. I'm not sure I'd call it a short-coming but rather its just a difference in approach. For anything that is a user-defined object, the QAPI schema is defined implicitly by the QOM object or class definition. With the ability to define QOM properties against the class instad of object, we are actally in a position where we could auto-generate a QAPI schema to represent each user-defined object type if desired. Alternatively we could equally extend QAPI to have an 'object' type (which is a specialization of the 'struct' type) and auto-generate the basic boilerplate code to define a QOM object class from it. > > +static void test_authz_default_deny(void) > > +{ > > + QAuthZSimple *auth = qauthz_simple_new("auth0", > > + QAUTHZ_SIMPLE_POLICY_DENY, > > + &error_abort); > > + > > + g_assert(!qauthz_is_allowed(QAUTHZ(auth), "fred", &error_abort)); > > + > > Okay, so you definitely intend to return false without setting errp, so > it is a ternary result. Yep > > +#ifdef CONFIG_FNMATCH > > +static void test_authz_complex(void) > > +{ > > Wait - the behavior depends on whether fnmatch() is available? That is, > a name is a literal match if fnmatch() is not present, and glob if > present? I'd argue that if fnmatch() is not present, we must explicitly > reject any "match" with glob metacharacters, rather than accidentally > matching only a literal "*" when a glob was intended. Historically we have the qemu/acl.c code which uses fnmatch and falls back to plain strcmp if not available. Since this was intended to be an exact drop-in replacement, I tried to implement the same logic here. We could do something slightly different though - define a property against the QAuthzSimple object which enumerates the type of matching scheme - exact, glob or regex. The acl.c compatibility layer could then simply set matchtype=exact when !CONFIG_FNMATCH, which would in turn allow the QAuthzSimple impl to raise a fatall error for use of globbing when fnmatch is missing. > # How to interpret 'match', as a literal string or a glob > { 'enum': 'QAuthZSimpleStyle', 'data': [ 'literal', 'glob' ] } > # @style: #optional, default to 'literal' > { 'struct': 'QAuthZSimpleRule', > 'data': { 'match': 'str', '*style': 'QAuthZSimpleStyle', > 'policy': 'QAuthZSimplePolicy' } } > > and used as: > > "rules": [ > { "match": "fred", "policy": "allow" }, > { "match": "bob", "policy": "allow" }, > { "match": "danb", "policy": "deny" }, > { "match": "dan*", "policy": "allow", "style": "glob" } > > where you can then gracefully error out for ALL attempts to use > "style":"glob" if fnmatch() is not present, and use strcmp() even when > fnmatch() is present for rules that have the (default) "style":"literal". Yep, allowing style to be set per rule is another option - I wonder if it is better todo it per-rule or per-ACL applying to all rules. > > +static void > > +qauthz_simple_class_init(ObjectClass *oc, void *data) > > +{ > > + UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc); > > + QAuthZClass *authz = QAUTHZ_CLASS(oc); > > + > > + ucc->complete = qauthz_simple_complete; > > + authz->is_allowed = qauthz_simple_is_allowed; > > + > > + object_class_property_add_enum(oc, "policy", > > + "QAuthZSimplePolicy", > > + QAuthZSimplePolicy_lookup, > > + qauthz_simple_prop_get_policy, > > + qauthz_simple_prop_set_policy, > > + NULL); > > + > > + object_class_property_add(oc, "rules", "QAuthZSimpleRule", > > + qauthz_simple_prop_get_rules, > > + qauthz_simple_prop_set_rules, > > + NULL, NULL, NULL); > > +} > > Not for this patch, but it would be cool if we had enough framework to > just tell QOM to instantiate an object with callbacks by merely pointing > to the name of a QAPI type that the object implements (referring back to > my comment that I'm a bit surprised we didn't need a QAPI type for the > overall QAuthZSimple). Yep, as mentioned above this is just the difference between QAPI and QOM user creatable objects that needs resolving somehow. > > +size_t qauthz_simple_append_rule(QAuthZSimple *auth, const char *match, > > + QAuthZSimplePolicy policy) > > +{ > > + QAuthZSimpleRule *rule; > > + QAuthZSimpleRuleList *rules, *tmp; > > + size_t i = 0; > > + > > + rule = g_new0(QAuthZSimpleRule, 1); > > + rule->policy = policy; > > + rule->match = g_strdup(match); > > + > > + tmp = g_new0(QAuthZSimpleRuleList, 1); > > + tmp->value = rule; > > + > > + rules = auth->rules; > > + if (rules) { > > + while (rules->next) { > > + i++; > > + rules = rules->next; > > + } > > + rules->next = tmp; > > + return i + 1; > > No checks whether 'match' is already an existing rule... > > > > +ssize_t qauthz_simple_delete_rule(QAuthZSimple *auth, const char *match) > > +{ > > + QAuthZSimpleRule *rule; > > + QAuthZSimpleRuleList *rules, *prev; > > + size_t i = 0; > > + > > + prev = NULL; > > + rules = auth->rules; > > + while (rules) { > > + rule = rules->value; > > + if (g_str_equal(rule->match, match)) { > > + if (prev) { > > + prev->next = rules->next; > > + } else { > > + auth->rules = rules->next; > > + } > > + rules->next = NULL; > > + qapi_free_QAuthZSimpleRuleList(rules); > > + return i; > > ...which means a rule can be inserted more than once, and this only > removes the first instance of the rule. Do we care enough to add in > additional checking that we aren't permitting duplicate 'match' strings > in the list of rules? I don't think it really matters much - if you add 2 rules with the same string, you still need 2 calls to delete it. The order of deletion can be left undefined I think. Regards, Daniel
diff --git a/Makefile b/Makefile index 903dc35..60ad13e 100644 --- a/Makefile +++ b/Makefile @@ -274,7 +274,7 @@ qapi-modules = $(SRC_PATH)/qapi-schema.json $(SRC_PATH)/qapi/common.json \ $(SRC_PATH)/qapi/block.json $(SRC_PATH)/qapi/block-core.json \ $(SRC_PATH)/qapi/event.json $(SRC_PATH)/qapi/introspect.json \ $(SRC_PATH)/qapi/crypto.json $(SRC_PATH)/qapi/rocker.json \ - $(SRC_PATH)/qapi/trace.json + $(SRC_PATH)/qapi/trace.json $(SRC_PATH)/qapi/util.json qapi-types.c qapi-types.h :\ $(qapi-modules) $(SRC_PATH)/scripts/qapi-types.py $(qapi-py) diff --git a/include/qemu/authz-simple.h b/include/qemu/authz-simple.h new file mode 100644 index 0000000..74c09e3 --- /dev/null +++ b/include/qemu/authz-simple.h @@ -0,0 +1,107 @@ +/* + * QEMU simple authorization driver + * + * Copyright (c) 2016 Red Hat, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see <http://www.gnu.org/licenses/>. + * + */ + +#ifndef QAUTHZ_SIMPLE_H__ +#define QAUTHZ_SIMPLE_H__ + +#include "qemu/authz.h" + + +#define TYPE_QAUTHZ_SIMPLE "authz-simple" + +#define QAUTHZ_SIMPLE_CLASS(klass) \ + OBJECT_CLASS_CHECK(QAuthZSimpleClass, (klass), \ + TYPE_QAUTHZ_SIMPLE) +#define QAUTHZ_SIMPLE_GET_CLASS(obj) \ + OBJECT_GET_CLASS(QAuthZSimpleClass, (obj), \ + TYPE_QAUTHZ_SIMPLE) +#define QAUTHZ_SIMPLE(obj) \ + INTERFACE_CHECK(QAuthZSimple, (obj), \ + TYPE_QAUTHZ_SIMPLE) + +typedef struct QAuthZSimple QAuthZSimple; +typedef struct QAuthZSimpleClass QAuthZSimpleClass; + + +/** + * QAuthZSimple: + * + * This authorization driver provides a simple mechanism + * for granting access by matching user names against a + * list of globs. Each match rule has an associated policy + * and a catch all policy applies if no rule matches + * + * To create an instace of this class via QMP: + * + * { + * "execute": "object-add", + * "arguments": { + * "qom-type": "authz-simple", + * "id": "auth0", + * "parameters": { + * "rules": [ + * { "match": "fred", "policy": "allow" }, + * { "match": "bob", "policy": "allow" }, + * { "match": "danb", "policy": "deny" }, + * { "match": "dan*", "policy": "allow" } + * ], + * "policy": "deny" + * } + * } + * } + * + * Or via the CLI: + * + * $QEMU \ + * -object authz-simple,id=acl0,policy=deny, \ + * match.0.name=fred,match.0.policy=allow, \ + * match.1.name=bob,match.1.policy=allow, \ + * match.2.name=danb,match.2.policy=deny, \ + * match.3.name=dan*,match.3.policy=allow + * + */ +struct QAuthZSimple { + QAuthZ parent_obj; + + QAuthZSimplePolicy policy; + QAuthZSimpleRuleList *rules; +}; + + +struct QAuthZSimpleClass { + QAuthZClass parent_class; +}; + + +QAuthZSimple *qauthz_simple_new(const char *id, + QAuthZSimplePolicy policy, + Error **errp); + +size_t qauthz_simple_append_rule(QAuthZSimple *auth, const char *match, + QAuthZSimplePolicy policy); + +size_t qauthz_simple_insert_rule(QAuthZSimple *auth, const char *match, + QAuthZSimplePolicy policy, size_t index); + +ssize_t qauthz_simple_delete_rule(QAuthZSimple *auth, const char *match); + + +#endif /* QAUTHZ_SIMPLE_H__ */ + diff --git a/qapi-schema.json b/qapi-schema.json index 362c9d8..b6769de 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -5,6 +5,9 @@ # QAPI common definitions { 'include': 'qapi/common.json' } +# QAPI util definitions +{ 'include': 'qapi/util.json' } + # QAPI crypto definitions { 'include': 'qapi/crypto.json' } @@ -3652,7 +3655,8 @@ # Since 2.5 ## { 'struct': 'DummyForceArrays', - 'data': { 'unused': ['X86CPUFeatureWordInfo'] } } + 'data': { 'unused': ['X86CPUFeatureWordInfo'], + 'iamalsounused': ['QAuthZSimpleRule'] } } ## diff --git a/qapi/util.json b/qapi/util.json new file mode 100644 index 0000000..d903497 --- /dev/null +++ b/qapi/util.json @@ -0,0 +1,31 @@ +# -*- Mode: Python -*- +# +# QAPI util definitions + +## +# QAuthZSimplePolicy: +# +# The authorization policy result +# +# @deny: deny access +# @allow: allow access +# +# Since: 2.6 +## +{ 'enum': 'QAuthZSimplePolicy', + 'prefix': 'QAUTHZ_SIMPLE_POLICY', + 'data': ['deny', 'allow']} + +## +# QAuthZSimpleRule: +# +# A single authorization rule. +# +# @match: a glob to match against a user identity +# @policy: the result to return if @match evaluates to true +# +# Since: 2.6 +## +{ 'struct': 'QAuthZSimpleRule', + 'data': {'match': 'str', + 'policy': 'QAuthZSimplePolicy'}} diff --git a/tests/.gitignore b/tests/.gitignore index 787c95c..1e73a2f 100644 --- a/tests/.gitignore +++ b/tests/.gitignore @@ -8,6 +8,7 @@ check-qom-interface check-qom-proplist rcutorture test-aio +test-authz-simple test-base64 test-bitops test-blockjob-txn diff --git a/tests/Makefile b/tests/Makefile index cd4bbd4..7a1d959 100644 --- a/tests/Makefile +++ b/tests/Makefile @@ -92,6 +92,7 @@ check-unit-$(CONFIG_GNUTLS) += tests/test-io-channel-tls$(EXESUF) check-unit-y += tests/test-io-channel-command$(EXESUF) check-unit-y += tests/test-io-channel-buffer$(EXESUF) check-unit-y += tests/test-base64$(EXESUF) +check-unit-y += tests/test-authz-simple$(EXESUF) check-block-$(CONFIG_POSIX) += tests/qemu-iotests-quick.sh @@ -430,6 +431,8 @@ tests/test-timed-average$(EXESUF): tests/test-timed-average.o qemu-timer.o \ $(test-util-obj-y) tests/test-base64$(EXESUF): tests/test-base64.o \ libqemuutil.a libqemustub.a +tests/test-authz-simple$(EXESUF): tests/test-authz-simple.o \ + libqemuutil.a libqemustub.a $(util-qom-obj-y) $(qom-obj-y) tests/test-qapi-types.c tests/test-qapi-types.h :\ $(SRC_PATH)/tests/qapi-schema/qapi-schema-test.json $(SRC_PATH)/scripts/qapi-types.py $(qapi-py) diff --git a/tests/test-authz-simple.c b/tests/test-authz-simple.c new file mode 100644 index 0000000..4b1dd0c --- /dev/null +++ b/tests/test-authz-simple.c @@ -0,0 +1,156 @@ +/* + * QEMU simple authorization object + * + * Copyright (c) 2016 Red Hat, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see <http://www.gnu.org/licenses/>. + * + */ + +#include "qemu/osdep.h" +#include <glib.h> + +#include "qemu/authz-simple.h" + +static void test_authz_default_deny(void) +{ + QAuthZSimple *auth = qauthz_simple_new("auth0", + QAUTHZ_SIMPLE_POLICY_DENY, + &error_abort); + + g_assert(!qauthz_is_allowed(QAUTHZ(auth), "fred", &error_abort)); + + object_unparent(OBJECT(auth)); +} + +static void test_authz_default_allow(void) +{ + QAuthZSimple *auth = qauthz_simple_new("auth0", + QAUTHZ_SIMPLE_POLICY_ALLOW, + &error_abort); + + g_assert(qauthz_is_allowed(QAUTHZ(auth), "fred", &error_abort)); + + object_unparent(OBJECT(auth)); +} + +static void test_authz_explicit_deny(void) +{ + QAuthZSimple *auth = qauthz_simple_new("auth0", + QAUTHZ_SIMPLE_POLICY_ALLOW, + &error_abort); + + qauthz_simple_append_rule(auth, "fred", QAUTHZ_SIMPLE_POLICY_DENY); + + g_assert(!qauthz_is_allowed(QAUTHZ(auth), "fred", &error_abort)); + + object_unparent(OBJECT(auth)); +} + +static void test_authz_explicit_allow(void) +{ + QAuthZSimple *auth = qauthz_simple_new("auth0", + QAUTHZ_SIMPLE_POLICY_DENY, + &error_abort); + + qauthz_simple_append_rule(auth, "fred", QAUTHZ_SIMPLE_POLICY_ALLOW); + + g_assert(qauthz_is_allowed(QAUTHZ(auth), "fred", &error_abort)); + + object_unparent(OBJECT(auth)); +} + + +#ifdef CONFIG_FNMATCH +static void test_authz_complex(void) +{ + QAuthZSimple *auth = qauthz_simple_new("auth0", + QAUTHZ_SIMPLE_POLICY_DENY, + &error_abort); + + qauthz_simple_append_rule(auth, "fred", QAUTHZ_SIMPLE_POLICY_ALLOW); + qauthz_simple_append_rule(auth, "bob", QAUTHZ_SIMPLE_POLICY_ALLOW); + qauthz_simple_append_rule(auth, "dan", QAUTHZ_SIMPLE_POLICY_DENY); + qauthz_simple_append_rule(auth, "dan*", QAUTHZ_SIMPLE_POLICY_ALLOW); + + g_assert(qauthz_is_allowed(QAUTHZ(auth), "fred", &error_abort)); + g_assert(qauthz_is_allowed(QAUTHZ(auth), "bob", &error_abort)); + g_assert(!qauthz_is_allowed(QAUTHZ(auth), "dan", &error_abort)); + g_assert(qauthz_is_allowed(QAUTHZ(auth), "danb", &error_abort)); + + object_unparent(OBJECT(auth)); +} +#endif + +static void test_authz_add_remove(void) +{ + QAuthZSimple *auth = qauthz_simple_new("auth0", + QAUTHZ_SIMPLE_POLICY_DENY, + &error_abort); + + g_assert_cmpint(qauthz_simple_append_rule(auth, "fred", + QAUTHZ_SIMPLE_POLICY_ALLOW), + ==, 0); + g_assert_cmpint(qauthz_simple_append_rule(auth, "bob", + QAUTHZ_SIMPLE_POLICY_ALLOW), + ==, 1); + g_assert_cmpint(qauthz_simple_append_rule(auth, "dan", + QAUTHZ_SIMPLE_POLICY_DENY), + ==, 2); + g_assert_cmpint(qauthz_simple_append_rule(auth, "dan*", + QAUTHZ_SIMPLE_POLICY_ALLOW), + ==, 3); + + g_assert(!qauthz_is_allowed(QAUTHZ(auth), "dan", &error_abort)); + + g_assert_cmpint(qauthz_simple_delete_rule(auth, "dan"), + ==, 2); + + g_assert(qauthz_is_allowed(QAUTHZ(auth), "dan", &error_abort)); + + g_assert_cmpint(qauthz_simple_append_rule(auth, "dan", + QAUTHZ_SIMPLE_POLICY_DENY), + ==, 3); + + g_assert(qauthz_is_allowed(QAUTHZ(auth), "dan", &error_abort)); + + g_assert_cmpint(qauthz_simple_delete_rule(auth, "dan"), + ==, 3); + + g_assert_cmpint(qauthz_simple_insert_rule(auth, "dan", + QAUTHZ_SIMPLE_POLICY_DENY, 2), + ==, 2); + + g_assert(!qauthz_is_allowed(QAUTHZ(auth), "dan", &error_abort)); + + object_unparent(OBJECT(auth)); +} + +int main(int argc, char **argv) +{ + g_test_init(&argc, &argv, NULL); + + module_call_init(MODULE_INIT_QOM); + + g_test_add_func("/auth/simple/default/deny", test_authz_default_deny); + g_test_add_func("/auth/simple/default/allow", test_authz_default_allow); + g_test_add_func("/auth/simple/explicit/deny", test_authz_explicit_deny); + g_test_add_func("/auth/simple/explicit/allow", test_authz_explicit_allow); +#ifdef CONFIG_FNMATCH + g_test_add_func("/auth/simple/complex", test_authz_complex); +#endif + g_test_add_func("/auth/simple/add-remove", test_authz_add_remove); + + return g_test_run(); +} diff --git a/util/Makefile.objs b/util/Makefile.objs index b29fb45..4870905 100644 --- a/util/Makefile.objs +++ b/util/Makefile.objs @@ -34,3 +34,4 @@ util-obj-y += base64.o util-obj-y += log.o util-qom-obj-y += authz.o +util-qom-obj-y += authz-simple.o diff --git a/util/authz-simple.c b/util/authz-simple.c new file mode 100644 index 0000000..ab82f72 --- /dev/null +++ b/util/authz-simple.c @@ -0,0 +1,256 @@ +/* + * QEMU simple authorization driver + * + * Copyright (c) 2016 Red Hat, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see <http://www.gnu.org/licenses/>. + * + */ + +#include "qemu/osdep.h" +#include "qemu/authz-simple.h" +#include "qom/object_interfaces.h" +#include "qapi-visit.h" + +/* If no fnmatch, fallback to exact string matching + * instead of allowing wildcards */ +#ifdef CONFIG_FNMATCH +#include <fnmatch.h> +#define qauthz_match(pattern, string) fnmatch(pattern, string, 0) +#else +#define qauthz_match(pattern, string) strcmp(pattern, string) +#endif + +static bool qauthz_simple_is_allowed(QAuthZ *authz, + const char *identity, + Error **errp) +{ + QAuthZSimple *sauthz = QAUTHZ_SIMPLE(authz); + QAuthZSimpleRuleList *rules = sauthz->rules; + + while (rules) { + QAuthZSimpleRule *rule = rules->value; + if (qauthz_match(rule->match, identity) == 0) { + return rule->policy == QAUTHZ_SIMPLE_POLICY_ALLOW; + } + rules = rules->next; + } + + return sauthz->policy == QAUTHZ_SIMPLE_POLICY_ALLOW; +} + + +static void +qauthz_simple_prop_set_policy(Object *obj, + int value, + Error **errp G_GNUC_UNUSED) +{ + QAuthZSimple *sauthz = QAUTHZ_SIMPLE(obj); + + sauthz->policy = value; +} + + +static int +qauthz_simple_prop_get_policy(Object *obj, + Error **errp G_GNUC_UNUSED) +{ + QAuthZSimple *sauthz = QAUTHZ_SIMPLE(obj); + + return sauthz->policy; +} + + +static void +qauthz_simple_prop_get_rules(Object *obj, Visitor *v, const char *name, + void *opaque, Error **errp) +{ + QAuthZSimple *sauthz = QAUTHZ_SIMPLE(obj); + + visit_type_QAuthZSimpleRuleList(v, name, &sauthz->rules, errp); +} + +static void +qauthz_simple_prop_set_rules(Object *obj, Visitor *v, const char *name, + void *opaque, Error **errp) +{ + QAuthZSimple *sauthz = QAUTHZ_SIMPLE(obj); + + qapi_free_QAuthZSimpleRuleList(sauthz->rules); + visit_type_QAuthZSimpleRuleList(v, name, &sauthz->rules, errp); +} + + +static void +qauthz_simple_complete(UserCreatable *uc, Error **errp) +{ +} + + +static void +qauthz_simple_finalize(Object *obj) +{ + QAuthZSimple *sauthz = QAUTHZ_SIMPLE(obj); + + qapi_free_QAuthZSimpleRuleList(sauthz->rules); +} + + +static void +qauthz_simple_class_init(ObjectClass *oc, void *data) +{ + UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc); + QAuthZClass *authz = QAUTHZ_CLASS(oc); + + ucc->complete = qauthz_simple_complete; + authz->is_allowed = qauthz_simple_is_allowed; + + object_class_property_add_enum(oc, "policy", + "QAuthZSimplePolicy", + QAuthZSimplePolicy_lookup, + qauthz_simple_prop_get_policy, + qauthz_simple_prop_set_policy, + NULL); + + object_class_property_add(oc, "rules", "QAuthZSimpleRule", + qauthz_simple_prop_get_rules, + qauthz_simple_prop_set_rules, + NULL, NULL, NULL); +} + + +QAuthZSimple *qauthz_simple_new(const char *id, + QAuthZSimplePolicy policy, + Error **errp) +{ + return QAUTHZ_SIMPLE( + object_new_with_props(TYPE_QAUTHZ_SIMPLE, + object_get_objects_root(), + id, errp, + "policy", QAuthZSimplePolicy_lookup[policy], + NULL)); +} + + +size_t qauthz_simple_append_rule(QAuthZSimple *auth, const char *match, + QAuthZSimplePolicy policy) +{ + QAuthZSimpleRule *rule; + QAuthZSimpleRuleList *rules, *tmp; + size_t i = 0; + + rule = g_new0(QAuthZSimpleRule, 1); + rule->policy = policy; + rule->match = g_strdup(match); + + tmp = g_new0(QAuthZSimpleRuleList, 1); + tmp->value = rule; + + rules = auth->rules; + if (rules) { + while (rules->next) { + i++; + rules = rules->next; + } + rules->next = tmp; + return i + 1; + } else { + auth->rules = tmp; + return 0; + } +} + + +size_t qauthz_simple_insert_rule(QAuthZSimple *auth, const char *match, + QAuthZSimplePolicy policy, size_t index) +{ + QAuthZSimpleRule *rule; + QAuthZSimpleRuleList *rules, *tmp; + size_t i = 0; + + rule = g_new0(QAuthZSimpleRule, 1); + rule->policy = policy; + rule->match = g_strdup(match); + + tmp = g_new0(QAuthZSimpleRuleList, 1); + tmp->value = rule; + + rules = auth->rules; + if (rules && index > 0) { + while (rules->next && i < (index - 1)) { + i++; + rules = rules->next; + } + tmp->next = rules->next; + rules->next = tmp; + return i + 1; + } else { + tmp->next = auth->rules; + auth->rules = tmp; + return 0; + } +} + + +ssize_t qauthz_simple_delete_rule(QAuthZSimple *auth, const char *match) +{ + QAuthZSimpleRule *rule; + QAuthZSimpleRuleList *rules, *prev; + size_t i = 0; + + prev = NULL; + rules = auth->rules; + while (rules) { + rule = rules->value; + if (g_str_equal(rule->match, match)) { + if (prev) { + prev->next = rules->next; + } else { + auth->rules = rules->next; + } + rules->next = NULL; + qapi_free_QAuthZSimpleRuleList(rules); + return i; + } + prev = rules; + rules = rules->next; + i++; + } + + return -1; +} + + +static const TypeInfo qauthz_simple_info = { + .parent = TYPE_QAUTHZ, + .name = TYPE_QAUTHZ_SIMPLE, + .instance_size = sizeof(QAuthZSimple), + .instance_finalize = qauthz_simple_finalize, + .class_size = sizeof(QAuthZSimpleClass), + .class_init = qauthz_simple_class_init, + .interfaces = (InterfaceInfo[]) { + { TYPE_USER_CREATABLE }, + { } + } +}; + + +static void +qauthz_simple_register_types(void) +{ + type_register_static(&qauthz_simple_info); +} + + +type_init(qauthz_simple_register_types);
Add a QAuthZSimple object type that implements the QAuthZ interface. This simple built-in implementation maintains a trivial access control list with a sequence of match rules and a final default policy. This replicates the functionality currently provided by the qemu_acl module. To create an instance of this object via the QMP monitor, the syntax used would be { "execute": "object-add", "arguments": { "qom-type": "authz-simple", "id": "auth0", "parameters": { "rules": [ { "match": "fred", "policy": "allow" }, { "match": "bob", "policy": "allow" }, { "match": "danb", "policy": "deny" }, { "match": "dan*", "policy": "allow" } ], "policy": "deny" } } } Or via the -object command line $QEMU \ -object authz-simple,id=acl0,policy=deny,\ match.0.name=fred,match.0.policy=allow, \ match.1.name=bob,match.1.policy=allow, \ match.2.name=danb,match.2.policy=deny, \ match.3.name=dan*,match.3.policy=allow This sets up an authorization rule that allows 'fred', 'bob' and anyone whose name starts with 'dan', except for 'danb'. Everyone unmatched is denied. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> --- Makefile | 2 +- include/qemu/authz-simple.h | 107 ++++++++++++++++++ qapi-schema.json | 6 +- qapi/util.json | 31 ++++++ tests/.gitignore | 1 + tests/Makefile | 3 + tests/test-authz-simple.c | 156 +++++++++++++++++++++++++++ util/Makefile.objs | 1 + util/authz-simple.c | 256 ++++++++++++++++++++++++++++++++++++++++++++ 9 files changed, 561 insertions(+), 2 deletions(-) create mode 100644 include/qemu/authz-simple.h create mode 100644 qapi/util.json create mode 100644 tests/test-authz-simple.c create mode 100644 util/authz-simple.c