From e7d718afdb28b1049d382604e5e7bf1d213a8291 Mon Sep 17 00:00:00 2001

From: Daniel Mack <zonque@gmail.com>

Date: Mon, 18 Aug 2014 19:58:42 +0200

Subject: [PATCH] bus: add code to create custom endpoints and set their policy

Custom endpoints are alternative connection points to a bus, allowing

specific policy to be uploaded.

Add two functions to bus-kernel. One to create such endpoints, and another

one for setting a policy for them.

---

 src/libsystemd/sd-bus/bus-kernel.c | 90 ++++++++++++++++++++++++++++++++++++++

 src/libsystemd/sd-bus/bus-kernel.h |  4 ++

 2 files changed, 94 insertions(+)

diff --git a/src/libsystemd/sd-bus/bus-kernel.c b/src/libsystemd/sd-bus/bus-kernel.c

index ca0eddb38d..505f335e07 100644

--- a/src/libsystemd/sd-bus/bus-kernel.c

+++ b/src/libsystemd/sd-bus/bus-kernel.c

@@ -25,6 +25,7 @@

 #include <fcntl.h>

 #include <malloc.h>

+#include <libgen.h>

 #include <sys/mman.h>

 #include <sys/prctl.h>

@@ -1408,6 +1409,95 @@ int bus_kernel_open_bus_fd(const char *bus, char **path) {

         return fd;

 }

+int bus_kernel_create_endpoint(const char *bus_name, const char *ep_name, char **ep_path) {

+        _cleanup_free_ char *path;

+        struct kdbus_cmd_make *make;

+        struct kdbus_item *n;

+        size_t size;

+        int fd;

+

+        fd = bus_kernel_open_bus_fd(bus_name, &path);

+        if (fd < 0)

+                return fd;

+

+        size = ALIGN8(offsetof(struct kdbus_cmd_make, items));

+        size += ALIGN8(offsetof(struct kdbus_item, str) + strlen(ep_name) + 1);

+

+        make = alloca0(size);

+        make->size = size;

+        make->flags = KDBUS_MAKE_ACCESS_WORLD;

+

+        n = make->items;

+

+        n->type = KDBUS_ITEM_MAKE_NAME;

+        n->size = offsetof(struct kdbus_item, str) + strlen(ep_name) + 1;

+        strcpy(n->str, ep_name);

+

+        if (ioctl(fd, KDBUS_CMD_EP_MAKE, make) < 0) {

+                safe_close(fd);

+                return -errno;

+        }

+

+        /* The higher 32bit of the flags field are considered

+         * 'incompatible flags'. Refuse them all for now. */

+        if (make->flags > 0xFFFFFFFFULL) {

+                safe_close(fd);

+                return -ENOTSUP;

+        }

+

+        if (ep_path) {

+                asprintf(ep_path, "%s/%s", dirname(path), ep_name);

+                if (!*ep_path)

+                        return -ENOMEM;

+        }

+

+        return fd;

+}

+

+int bus_kernel_set_endpoint_policy(int fd, uid_t uid, BusEndpoint *ep) {

+

+        struct kdbus_cmd_update *update;

+        struct kdbus_item *n;

+        BusEndpointPolicy *po;

+        Iterator i;

+        size_t size;

+        int r;

+

+        size = ALIGN8(offsetof(struct kdbus_cmd_update, items));

+

+        HASHMAP_FOREACH(po, ep->policy_hash, i) {

+                size += ALIGN8(offsetof(struct kdbus_item, str) + strlen(po->name) + 1);

+                size += ALIGN8(offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access));

+        }

+

+        update = alloca0(size);

+        update->size = size;

+

+        n = update->items;

+

+        HASHMAP_FOREACH(po, ep->policy_hash, i) {

+                n->type = KDBUS_ITEM_NAME;

+                n->size = offsetof(struct kdbus_item, str) + strlen(po->name) + 1;

+                strcpy(n->str, po->name);

+                n = KDBUS_ITEM_NEXT(n);

+

+                n->type = KDBUS_ITEM_POLICY_ACCESS;

+                n->size = offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access);

+

+                n->policy_access.type = KDBUS_POLICY_ACCESS_USER;

+                n->policy_access.access = bus_kernel_translate_access(po->access);

+                n->policy_access.id = uid;

+

+                n = KDBUS_ITEM_NEXT(n);

+        }

+

+        r = ioctl(fd, KDBUS_CMD_EP_UPDATE, update);

+        if (r < 0)

+                return -errno;

+

+        return 0;

+}

+

 int bus_kernel_make_starter(

                 int fd,

                 const char *name,

diff --git a/src/libsystemd/sd-bus/bus-kernel.h b/src/libsystemd/sd-bus/bus-kernel.h

index 182f953d47..f1d832a764 100644

--- a/src/libsystemd/sd-bus/bus-kernel.h

+++ b/src/libsystemd/sd-bus/bus-kernel.h

@@ -24,6 +24,7 @@

 #include <stdbool.h>

 #include "busname.h"

+#include "bus-endpoint.h"

 #include "sd-bus.h"

 #define KDBUS_ITEM_NEXT(item) \

@@ -69,8 +70,11 @@ int bus_kernel_open_bus_fd(const char *bus, char **path);

 int bus_kernel_make_starter(int fd, const char *name, bool activating, bool accept_fd, BusNamePolicy *policy, BusPolicyAccess world_policy);

 int bus_kernel_create_bus(const char *name, bool world, char **s);

+int bus_kernel_create_endpoint(const char *bus_name, const char *ep_name, char **path);

 int bus_kernel_create_domain(const char *name, char **s);

+int bus_kernel_set_endpoint_policy(int fd, uid_t uid, BusEndpoint *ep);

+

 int bus_kernel_pop_memfd(sd_bus *bus, void **address, size_t *mapped, size_t *allocated);

 void bus_kernel_push_memfd(sd_bus *bus, int fd, void *address, size_t mapped, size_t allocated);