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authorDavid Herrmann <dh.herrmann@gmail.com>2015-01-17 18:07:58 +0100
committerDavid Herrmann <dh.herrmann@gmail.com>2015-01-17 18:27:23 +0100
commitc4bc1a8434f2a34840ea6f63064fa998ecfae738 (patch)
treec10ae7cfd3864cc74fc83c997baaf45e81215b48 /src
parentb58d857136496ee463223cd90af46512e9eef152 (diff)
bus-proxy: share policy between threads
This implements a shared policy cache with read-write locks. We no longer parse the XML policy in each thread. This will allow us to easily implement ReloadConfig().
Diffstat (limited to 'src')
-rw-r--r--src/bus-proxyd/bus-proxyd.c17
-rw-r--r--src/bus-proxyd/bus-xml-policy.c116
-rw-r--r--src/bus-proxyd/bus-xml-policy.h22
-rw-r--r--src/bus-proxyd/driver.c14
-rw-r--r--src/bus-proxyd/driver.h2
-rw-r--r--src/bus-proxyd/proxy.c50
-rw-r--r--src/bus-proxyd/proxy.h5
-rw-r--r--src/bus-proxyd/stdio-bridge.c21
8 files changed, 203 insertions, 44 deletions
diff --git a/src/bus-proxyd/bus-proxyd.c b/src/bus-proxyd/bus-proxyd.c
index 15a79fc427..72e11467bd 100644
--- a/src/bus-proxyd/bus-proxyd.c
+++ b/src/bus-proxyd/bus-proxyd.c
@@ -61,6 +61,7 @@ static char **arg_configuration = NULL;
typedef struct {
int fd;
+ SharedPolicy *policy;
} ClientContext;
static ClientContext *client_context_free(ClientContext *c) {
@@ -75,14 +76,14 @@ static ClientContext *client_context_free(ClientContext *c) {
DEFINE_TRIVIAL_CLEANUP_FUNC(ClientContext*, client_context_free);
-static int client_context_new(ClientContext **out, int fd) {
+static int client_context_new(ClientContext **out) {
_cleanup_(client_context_freep) ClientContext *c = NULL;
c = new0(ClientContext, 1);
if (!c)
return log_oom();
- c->fd = fd;
+ c->fd = -1;
*out = c;
c = NULL;
@@ -105,7 +106,7 @@ static void *run_client(void *userdata) {
comm[sizeof(comm) - 2] = '*';
(void) prctl(PR_SET_NAME, comm);
- r = proxy_load_policy(p, arg_configuration);
+ r = proxy_set_policy(p, c->policy, arg_configuration);
if (r < 0)
goto exit;
@@ -120,6 +121,7 @@ exit:
}
static int loop_clients(int accept_fd) {
+ _cleanup_(shared_policy_freep) SharedPolicy *sp = NULL;
pthread_attr_t attr;
int r;
@@ -135,6 +137,10 @@ static int loop_clients(int accept_fd) {
goto exit_attr;
}
+ r = shared_policy_new(&sp);
+ if (r < 0)
+ goto exit_attr;
+
for (;;) {
ClientContext *c;
pthread_t tid;
@@ -149,13 +155,16 @@ static int loop_clients(int accept_fd) {
break;
}
- r = client_context_new(&c, fd);
+ r = client_context_new(&c);
if (r < 0) {
log_oom();
close(fd);
continue;
}
+ c->fd = fd;
+ c->policy = sp;
+
r = pthread_create(&tid, &attr, run_client, c);
if (r < 0) {
log_error("Cannot spawn thread: %m");
diff --git a/src/bus-proxyd/bus-xml-policy.c b/src/bus-proxyd/bus-xml-policy.c
index c0f3764ae2..b3daad5017 100644
--- a/src/bus-proxyd/bus-xml-policy.c
+++ b/src/bus-proxyd/bus-xml-policy.c
@@ -1106,6 +1106,122 @@ void policy_dump(Policy *p) {
fflush(stdout);
}
+int shared_policy_new(SharedPolicy **out) {
+ SharedPolicy *sp;
+ int r;
+
+ sp = new0(SharedPolicy, 1);
+ if (!sp)
+ return log_oom();
+
+ r = pthread_mutex_init(&sp->lock, NULL);
+ if (r < 0) {
+ log_error_errno(r, "Cannot initialize shared policy mutex: %m");
+ goto exit_free;
+ }
+
+ r = pthread_rwlock_init(&sp->rwlock, NULL);
+ if (r < 0) {
+ log_error_errno(r, "Cannot initialize shared policy rwlock: %m");
+ goto exit_mutex;
+ }
+
+ *out = sp;
+ sp = NULL;
+ return 0;
+
+ /* pthread lock destruction is not fail-safe... meh! */
+exit_mutex:
+ pthread_mutex_destroy(&sp->lock);
+exit_free:
+ free(sp);
+ return r;
+}
+
+SharedPolicy *shared_policy_free(SharedPolicy *sp) {
+ if (!sp)
+ return NULL;
+
+ policy_free(sp->policy);
+ pthread_rwlock_destroy(&sp->rwlock);
+ pthread_mutex_destroy(&sp->lock);
+ free(sp);
+
+ return NULL;
+}
+
+static int shared_policy_reload_unlocked(SharedPolicy *sp, char **configuration) {
+ Policy old, buffer = {};
+ bool free_old;
+ int r;
+
+ assert(sp);
+
+ r = policy_load(&buffer, configuration);
+ if (r < 0)
+ return log_error_errno(r, "Failed to load policy: %m");
+
+ /* policy_dump(&buffer); */
+
+ pthread_rwlock_wrlock(&sp->rwlock);
+ memcpy(&old, &sp->buffer, sizeof(old));
+ memcpy(&sp->buffer, &buffer, sizeof(buffer));
+ free_old = !!sp->policy;
+ sp->policy = &sp->buffer;
+ pthread_rwlock_unlock(&sp->rwlock);
+
+ if (free_old)
+ policy_free(&old);
+
+ return 0;
+}
+
+int shared_policy_reload(SharedPolicy *sp, char **configuration) {
+ int r;
+
+ assert(sp);
+
+ pthread_mutex_lock(&sp->lock);
+ r = shared_policy_reload_unlocked(sp, configuration);
+ pthread_mutex_unlock(&sp->lock);
+
+ return r;
+}
+
+int shared_policy_preload(SharedPolicy *sp, char **configuration) {
+ int r;
+
+ assert(sp);
+
+ pthread_mutex_lock(&sp->lock);
+ if (!sp->policy)
+ r = shared_policy_reload_unlocked(sp, configuration);
+ else
+ r = 0;
+ pthread_mutex_unlock(&sp->lock);
+
+ return r;
+}
+
+Policy *shared_policy_acquire(SharedPolicy *sp) {
+ assert(sp);
+
+ pthread_rwlock_rdlock(&sp->rwlock);
+ if (sp->policy)
+ return sp->policy;
+ pthread_rwlock_unlock(&sp->rwlock);
+
+ return NULL;
+}
+
+void shared_policy_release(SharedPolicy *sp, Policy *p) {
+ assert(sp);
+ assert(!p || sp->policy == p);
+
+ if (p)
+ pthread_rwlock_unlock(&sp->rwlock);
+}
+
static const char* const policy_item_type_table[_POLICY_ITEM_TYPE_MAX] = {
[_POLICY_ITEM_TYPE_UNSET] = "unset",
[POLICY_ITEM_ALLOW] = "allow",
diff --git a/src/bus-proxyd/bus-xml-policy.h b/src/bus-proxyd/bus-xml-policy.h
index 125c84cd6e..762cb663a0 100644
--- a/src/bus-proxyd/bus-xml-policy.h
+++ b/src/bus-proxyd/bus-xml-policy.h
@@ -22,6 +22,7 @@
***/
#include <inttypes.h>
+#include <pthread.h>
#include "list.h"
#include "hashmap.h"
@@ -75,6 +76,15 @@ typedef struct Policy {
Hashmap *group_items;
} Policy;
+typedef struct SharedPolicy {
+ pthread_mutex_t lock;
+ pthread_rwlock_t rwlock;
+ Policy buffer;
+ Policy *policy;
+} SharedPolicy;
+
+/* policy */
+
int policy_load(Policy *p, char **files);
void policy_free(Policy *p);
@@ -106,3 +116,15 @@ PolicyItemType policy_item_type_from_string(const char *s) _pure_;
const char* policy_item_class_to_string(PolicyItemClass t) _const_;
PolicyItemClass policy_item_class_from_string(const char *s) _pure_;
+
+/* shared policy */
+
+int shared_policy_new(SharedPolicy **out);
+SharedPolicy *shared_policy_free(SharedPolicy *sp);
+
+int shared_policy_reload(SharedPolicy *sp, char **configuration);
+int shared_policy_preload(SharedPolicy *sp, char **configuration);
+Policy *shared_policy_acquire(SharedPolicy *sp);
+void shared_policy_release(SharedPolicy *sp, Policy *p);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(SharedPolicy*, shared_policy_free);
diff --git a/src/bus-proxyd/driver.c b/src/bus-proxyd/driver.c
index c1f7fc4a3c..3d312f65a4 100644
--- a/src/bus-proxyd/driver.c
+++ b/src/bus-proxyd/driver.c
@@ -80,7 +80,7 @@ static int get_creds_by_message(sd_bus *bus, sd_bus_message *m, uint64_t mask, s
return get_creds_by_name(bus, name, mask, _creds, error);
}
-int bus_proxy_process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *policy, const struct ucred *ucred, Set *owned_names) {
+int bus_proxy_process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, SharedPolicy *sp, const struct ucred *ucred, Set *owned_names) {
int r;
assert(a);
@@ -455,8 +455,16 @@ int bus_proxy_process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *po
if (r < 0)
return synthetic_reply_method_errno(m, r, NULL);
- if (policy && !policy_check_own(policy, ucred->uid, ucred->gid, name))
- return synthetic_reply_method_errno(m, -EPERM, NULL);
+ if (sp) {
+ Policy *policy;
+ bool denied;
+
+ policy = shared_policy_acquire(sp);
+ denied = !policy_check_own(policy, ucred->uid, ucred->gid, name);
+ shared_policy_release(sp, policy);
+ if (denied)
+ return synthetic_reply_method_errno(m, -EPERM, NULL);
+ }
if ((flags & ~(BUS_NAME_ALLOW_REPLACEMENT|BUS_NAME_REPLACE_EXISTING|BUS_NAME_DO_NOT_QUEUE)) != 0)
return synthetic_reply_method_errno(m, -EINVAL, NULL);
diff --git a/src/bus-proxyd/driver.h b/src/bus-proxyd/driver.h
index eb7a6e3e50..b8cedf5ce5 100644
--- a/src/bus-proxyd/driver.h
+++ b/src/bus-proxyd/driver.h
@@ -24,4 +24,4 @@
#include "sd-bus.h"
#include "bus-xml-policy.h"
-int bus_proxy_process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *policy, const struct ucred *ucred, Set *owned_names);
+int bus_proxy_process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, SharedPolicy *sp, const struct ucred *ucred, Set *owned_names);
diff --git a/src/bus-proxyd/proxy.c b/src/bus-proxyd/proxy.c
index 744b11da5c..ab164474fa 100644
--- a/src/bus-proxyd/proxy.c
+++ b/src/bus-proxyd/proxy.c
@@ -255,16 +255,27 @@ Proxy *proxy_free(Proxy *p) {
return NULL;
}
-int proxy_load_policy(Proxy *p, char **configuration) {
+int proxy_set_policy(Proxy *p, SharedPolicy *sp, char **configuration) {
_cleanup_strv_free_ char **strv = NULL;
+ Policy *policy;
int r;
assert(p);
+ assert(sp);
/* no need to load legacy policy if destination is not kdbus */
if (!p->dest_bus->is_kernel)
return 0;
+ p->policy = sp;
+
+ policy = shared_policy_acquire(sp);
+ if (policy) {
+ /* policy already pre-loaded */
+ shared_policy_release(sp, policy);
+ return 0;
+ }
+
if (!configuration) {
const char *scope;
@@ -291,30 +302,30 @@ int proxy_load_policy(Proxy *p, char **configuration) {
configuration = strv;
}
- r = policy_load(&p->policy_buffer, configuration);
- if (r < 0)
- return log_error_errno(r, "Failed to load policy: %m");
-
- p->policy = &p->policy_buffer;
- /* policy_dump(p->policy); */
-
- return 0;
+ return shared_policy_preload(sp, configuration);
}
int proxy_hello_policy(Proxy *p, uid_t original_uid) {
+ Policy *policy;
+ int r = 0;
+
assert(p);
if (!p->policy)
return 0;
+ policy = shared_policy_acquire(p->policy);
+
if (p->local_creds.uid == original_uid)
log_debug("Permitting access, since bus owner matches bus client.");
- else if (policy_check_hello(p->policy, p->local_creds.uid, p->local_creds.gid))
+ else if (policy_check_hello(policy, p->local_creds.uid, p->local_creds.gid))
log_debug("Permitting access due to XML policy.");
else
- return log_error_errno(EPERM, "Policy denied connection.");
+ r = log_error_errno(EPERM, "Policy denied connection.");
- return 0;
+ shared_policy_release(p->policy, policy);
+
+ return r;
}
static int proxy_wait(Proxy *p) {
@@ -384,7 +395,7 @@ static int handle_policy_error(sd_bus_message *m, int r) {
return r;
}
-static int process_policy(sd_bus *from, sd_bus *to, sd_bus_message *m, Policy *policy, const struct ucred *our_ucred, Set *owned_names) {
+static int process_policy_unlocked(sd_bus *from, sd_bus *to, sd_bus_message *m, Policy *policy, const struct ucred *our_ucred, Set *owned_names) {
int r;
assert(from);
@@ -584,6 +595,19 @@ static int process_policy(sd_bus *from, sd_bus *to, sd_bus_message *m, Policy *p
return 0;
}
+static int process_policy(sd_bus *from, sd_bus *to, sd_bus_message *m, SharedPolicy *sp, const struct ucred *our_ucred, Set *owned_names) {
+ Policy *policy;
+ int r;
+
+ assert(sp);
+
+ policy = shared_policy_acquire(sp);
+ r = process_policy_unlocked(from, to, m, policy, our_ucred, owned_names);
+ shared_policy_release(sp, policy);
+
+ return r;
+}
+
static int process_hello(Proxy *p, sd_bus_message *m) {
_cleanup_bus_message_unref_ sd_bus_message *n = NULL;
bool is_hello;
diff --git a/src/bus-proxyd/proxy.h b/src/bus-proxyd/proxy.h
index 08994fe502..21c34f1d38 100644
--- a/src/bus-proxyd/proxy.h
+++ b/src/bus-proxyd/proxy.h
@@ -37,8 +37,7 @@ struct Proxy {
sd_bus *dest_bus;
Set *owned_names;
- Policy policy_buffer;
- Policy *policy;
+ SharedPolicy *policy;
bool got_hello : 1;
};
@@ -46,7 +45,7 @@ struct Proxy {
int proxy_new(Proxy **out, int in_fd, int out_fd, const char *dest);
Proxy *proxy_free(Proxy *p);
-int proxy_load_policy(Proxy *p, char **configuration);
+int proxy_set_policy(Proxy *p, SharedPolicy *policy, char **configuration);
int proxy_hello_policy(Proxy *p, uid_t original_uid);
int proxy_run(Proxy *p);
diff --git a/src/bus-proxyd/stdio-bridge.c b/src/bus-proxyd/stdio-bridge.c
index 711f74cacf..c17047b7e9 100644
--- a/src/bus-proxyd/stdio-bridge.c
+++ b/src/bus-proxyd/stdio-bridge.c
@@ -54,7 +54,6 @@
static char *arg_address = NULL;
static char *arg_command_line_buffer = NULL;
-static char **arg_configuration = NULL;
static int help(void) {
@@ -62,7 +61,6 @@ static int help(void) {
"Connect STDIO to a given bus address.\n\n"
" -h --help Show this help\n"
" --version Show package version\n"
- " --configuration=PATH Configuration file or directory\n"
" --machine=MACHINE Connect to specified machine\n"
" --address=ADDRESS Connect to the bus specified by ADDRESS\n"
" (default: " DEFAULT_SYSTEM_BUS_ADDRESS ")\n",
@@ -76,7 +74,6 @@ static int parse_argv(int argc, char *argv[]) {
enum {
ARG_VERSION = 0x100,
ARG_ADDRESS,
- ARG_CONFIGURATION,
ARG_MACHINE,
};
@@ -84,12 +81,11 @@ static int parse_argv(int argc, char *argv[]) {
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, ARG_VERSION },
{ "address", required_argument, NULL, ARG_ADDRESS },
- { "configuration", required_argument, NULL, ARG_CONFIGURATION },
{ "machine", required_argument, NULL, ARG_MACHINE },
{},
};
- int c, r;
+ int c;
assert(argc >= 0);
assert(argv);
@@ -119,12 +115,6 @@ static int parse_argv(int argc, char *argv[]) {
break;
}
- case ARG_CONFIGURATION:
- r = strv_extend(&arg_configuration, optarg);
- if (r < 0)
- return log_oom();
- break;
-
case ARG_MACHINE: {
_cleanup_free_ char *e = NULL;
char *a;
@@ -256,14 +246,6 @@ int main(int argc, char *argv[]) {
if (r < 0)
goto finish;
- r = proxy_load_policy(p, arg_configuration);
- if (r < 0)
- goto finish;
-
- r = proxy_hello_policy(p, getuid());
- if (r < 0)
- goto finish;
-
r = rename_service(p->dest_bus, p->local_bus);
if (r < 0)
log_debug_errno(r, "Failed to rename process: %m");
@@ -275,7 +257,6 @@ finish:
"STOPPING=1\n"
"STATUS=Shutting down.");
- strv_free(arg_configuration);
free(arg_address);
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;