sd-bus: add support for policy upload on activator connections

zonque · zonque · commit 1683342af1fc · 2014-03-07T19:14:05.000+01:00
Activator connections may upload policy when registering to the bus.
This patch contains code to translate between BusNamePolicy objects and
the kdbus specific items.
diff --git a/src/core/busname.c b/src/core/busname.c
@@ -233,7 +233,8 @@ static int busname_open_fd(BusName *n) {
         if (n->starter_fd >= 0)
                 return 0;
 
-        n->starter_fd = bus_kernel_create_starter(UNIT(n)->manager->running_as == SYSTEMD_SYSTEM ? "system" : "user", n->name);
+        n->starter_fd = bus_kernel_create_starter(UNIT(n)->manager->running_as == SYSTEMD_SYSTEM ? "system" : "user",
+                                                  n->name, n->policy);
         if (n->starter_fd < 0) {
                 log_warning_unit(UNIT(n)->id, "Failed to create starter fd: %s", strerror(-n->starter_fd));
                 return n->starter_fd;
diff --git a/src/libsystemd/sd-bus/bus-kernel.c b/src/libsystemd/sd-bus/bus-kernel.c
@@ -1338,9 +1338,51 @@ int bus_kernel_create_bus(const char *name, bool world, char **s) {
         return fd;
 }
 
-int bus_kernel_create_starter(const char *bus, const char *name) {
+static void bus_kernel_translate_policy(const BusNamePolicy *policy, struct kdbus_item *item)
+{
+        switch (policy->type) {
+        case BUSNAME_POLICY_TYPE_USER:
+                item->policy_access.type = KDBUS_POLICY_ACCESS_USER;
+                item->policy_access.id = policy->uid;
+                break;
+
+        case BUSNAME_POLICY_TYPE_GROUP:
+                item->policy_access.type = KDBUS_POLICY_ACCESS_GROUP;
+                item->policy_access.id = policy->gid;
+                break;
+
+        case BUSNAME_POLICY_TYPE_WORLD:
+                item->policy_access.type = KDBUS_POLICY_ACCESS_WORLD;
+                break;
+
+        default:
+                assert_not_reached("Unknown policy type");
+        }
+
+        switch (policy->access) {
+        case BUSNAME_POLICY_ACCESS_SEE:
+                item->policy_access.access = KDBUS_POLICY_SEE;
+                break;
+
+        case BUSNAME_POLICY_ACCESS_TALK:
+                item->policy_access.access = KDBUS_POLICY_TALK;
+                break;
+
+        case BUSNAME_POLICY_ACCESS_OWN:
+                item->policy_access.access = KDBUS_POLICY_OWN;
+                break;
+
+        default:
+                assert_not_reached("Unknown policy access");
+        }
+}
+
+int bus_kernel_create_starter(const char *bus, const char *name, BusNamePolicy *policy) {
         struct kdbus_cmd_hello *hello;
         struct kdbus_item *n;
+        size_t policy_cnt = 0;
+        BusNamePolicy *po;
+        size_t size;
         char *p;
         int fd;
 
@@ -1354,16 +1396,29 @@ int bus_kernel_create_starter(const char *bus, const char *name) {
         if (fd < 0)
                 return -errno;
 
-        hello = alloca0(ALIGN8(offsetof(struct kdbus_cmd_hello, items) +
-                               offsetof(struct kdbus_item, str) +
-                               strlen(name) + 1));
+        LIST_FOREACH(policy, po, policy)
+                policy_cnt++;
+
+        size = ALIGN8(offsetof(struct kdbus_cmd_hello, items)) +
+               ALIGN8(offsetof(struct kdbus_item, str) + strlen(name) + 1) +
+               policy_cnt * ALIGN8(offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access));
+
+        hello = alloca0(size);
 
         n = hello->items;
         strcpy(n->str, name);
         n->size = offsetof(struct kdbus_item, str) + strlen(n->str) + 1;
         n->type = KDBUS_ITEM_NAME;
+        n = KDBUS_ITEM_NEXT(n);
+
+        LIST_FOREACH(policy, po, policy) {
+                n->type = KDBUS_ITEM_POLICY_ACCESS;
+                n->size = offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access);
+                bus_kernel_translate_policy(po, n);
+                n = KDBUS_ITEM_NEXT(n);
+        }
 
-        hello->size = ALIGN8(offsetof(struct kdbus_cmd_hello, items) + n->size);
+        hello->size = size;
         hello->conn_flags = KDBUS_HELLO_ACTIVATOR;
         hello->pool_size = KDBUS_POOL_SIZE;
 
diff --git a/src/libsystemd/sd-bus/bus-kernel.h b/src/libsystemd/sd-bus/bus-kernel.h
@@ -23,6 +23,7 @@
 
 #include <stdbool.h>
 
+#include "busname.h"
 #include "sd-bus.h"
 
 #define KDBUS_ITEM_NEXT(item) \
@@ -65,7 +66,7 @@ int bus_kernel_read_message(sd_bus *bus, bool hint_priority, int64_t priority);
 
 int bus_kernel_create_bus(const char *name, bool world, char **s);
 int bus_kernel_create_domain(const char *name, char **s);
-int bus_kernel_create_starter(const char *bus, const char *name);
+int bus_kernel_create_starter(const char *bus, const char *name, BusNamePolicy *policy);
 int bus_kernel_create_monitor(const char *bus);
 
 int bus_kernel_pop_memfd(sd_bus *bus, void **address, size_t *mapped, size_t *allocated);
