diff options
Diffstat (limited to '')
| -rw-r--r-- | src/libsystemd/sd-bus/bus-convenience.c | 669 |
1 files changed, 669 insertions, 0 deletions
diff --git a/src/libsystemd/sd-bus/bus-convenience.c b/src/libsystemd/sd-bus/bus-convenience.c new file mode 100644 index 0000000..c4d4016 --- /dev/null +++ b/src/libsystemd/sd-bus/bus-convenience.c @@ -0,0 +1,669 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +#include "bus-internal.h" +#include "bus-message.h" +#include "bus-signature.h" +#include "bus-type.h" +#include "bus-util.h" +#include "string-util.h" + +_public_ int sd_bus_emit_signal( + sd_bus *bus, + const char *path, + const char *interface, + const char *member, + const char *types, ...) { + + _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL; + int r; + + assert_return(bus, -EINVAL); + assert_return(bus = bus_resolve(bus), -ENOPKG); + assert_return(!bus_pid_changed(bus), -ECHILD); + + if (!BUS_IS_OPEN(bus->state)) + return -ENOTCONN; + + r = sd_bus_message_new_signal(bus, &m, path, interface, member); + if (r < 0) + return r; + + if (!isempty(types)) { + va_list ap; + + va_start(ap, types); + r = sd_bus_message_appendv(m, types, ap); + va_end(ap); + if (r < 0) + return r; + } + + return sd_bus_send(bus, m, NULL); +} + +_public_ int sd_bus_call_method_async( + sd_bus *bus, + sd_bus_slot **slot, + const char *destination, + const char *path, + const char *interface, + const char *member, + sd_bus_message_handler_t callback, + void *userdata, + const char *types, ...) { + + _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL; + int r; + + assert_return(bus, -EINVAL); + assert_return(bus = bus_resolve(bus), -ENOPKG); + assert_return(!bus_pid_changed(bus), -ECHILD); + + if (!BUS_IS_OPEN(bus->state)) + return -ENOTCONN; + + r = sd_bus_message_new_method_call(bus, &m, destination, path, interface, member); + if (r < 0) + return r; + + if (!isempty(types)) { + va_list ap; + + va_start(ap, types); + r = sd_bus_message_appendv(m, types, ap); + va_end(ap); + if (r < 0) + return r; + } + + return sd_bus_call_async(bus, slot, m, callback, userdata, 0); +} + +_public_ int sd_bus_call_method( + sd_bus *bus, + const char *destination, + const char *path, + const char *interface, + const char *member, + sd_bus_error *error, + sd_bus_message **reply, + const char *types, ...) { + + _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL; + int r; + + bus_assert_return(bus, -EINVAL, error); + bus_assert_return(!bus_pid_changed(bus), -ECHILD, error); + + if (!BUS_IS_OPEN(bus->state)) { + r = -ENOTCONN; + goto fail; + } + + r = sd_bus_message_new_method_call(bus, &m, destination, path, interface, member); + if (r < 0) + goto fail; + + if (!isempty(types)) { + va_list ap; + + va_start(ap, types); + r = sd_bus_message_appendv(m, types, ap); + va_end(ap); + if (r < 0) + goto fail; + } + + return sd_bus_call(bus, m, 0, error, reply); + +fail: + return sd_bus_error_set_errno(error, r); +} + +_public_ int sd_bus_reply_method_return( + sd_bus_message *call, + const char *types, ...) { + + _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL; + int r; + + assert_return(call, -EINVAL); + assert_return(call->sealed, -EPERM); + assert_return(call->header->type == SD_BUS_MESSAGE_METHOD_CALL, -EINVAL); + assert_return(call->bus, -EINVAL); + assert_return(!bus_pid_changed(call->bus), -ECHILD); + + if (!BUS_IS_OPEN(call->bus->state)) + return -ENOTCONN; + + if (call->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) + return 0; + + r = sd_bus_message_new_method_return(call, &m); + if (r < 0) + return r; + + if (!isempty(types)) { + va_list ap; + + va_start(ap, types); + r = sd_bus_message_appendv(m, types, ap); + va_end(ap); + if (r < 0) + return r; + } + + return sd_bus_send(call->bus, m, NULL); +} + +_public_ int sd_bus_reply_method_error( + sd_bus_message *call, + const sd_bus_error *e) { + + _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL; + int r; + + assert_return(call, -EINVAL); + assert_return(call->sealed, -EPERM); + assert_return(call->header->type == SD_BUS_MESSAGE_METHOD_CALL, -EINVAL); + assert_return(sd_bus_error_is_set(e), -EINVAL); + assert_return(call->bus, -EINVAL); + assert_return(!bus_pid_changed(call->bus), -ECHILD); + + if (!BUS_IS_OPEN(call->bus->state)) + return -ENOTCONN; + + if (call->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) + return 0; + + r = sd_bus_message_new_method_error(call, &m, e); + if (r < 0) + return r; + + return sd_bus_send(call->bus, m, NULL); +} + +_public_ int sd_bus_reply_method_errorf( + sd_bus_message *call, + const char *name, + const char *format, + ...) { + + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + va_list ap; + + assert_return(call, -EINVAL); + assert_return(call->sealed, -EPERM); + assert_return(call->header->type == SD_BUS_MESSAGE_METHOD_CALL, -EINVAL); + assert_return(call->bus, -EINVAL); + assert_return(!bus_pid_changed(call->bus), -ECHILD); + + if (!BUS_IS_OPEN(call->bus->state)) + return -ENOTCONN; + + if (call->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) + return 0; + + va_start(ap, format); + bus_error_setfv(&error, name, format, ap); + va_end(ap); + + return sd_bus_reply_method_error(call, &error); +} + +_public_ int sd_bus_reply_method_errno( + sd_bus_message *call, + int error, + const sd_bus_error *p) { + + _cleanup_(sd_bus_error_free) sd_bus_error berror = SD_BUS_ERROR_NULL; + + assert_return(call, -EINVAL); + assert_return(call->sealed, -EPERM); + assert_return(call->header->type == SD_BUS_MESSAGE_METHOD_CALL, -EINVAL); + assert_return(call->bus, -EINVAL); + assert_return(!bus_pid_changed(call->bus), -ECHILD); + + if (!BUS_IS_OPEN(call->bus->state)) + return -ENOTCONN; + + if (call->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) + return 0; + + if (sd_bus_error_is_set(p)) + return sd_bus_reply_method_error(call, p); + + sd_bus_error_set_errno(&berror, error); + + return sd_bus_reply_method_error(call, &berror); +} + +_public_ int sd_bus_reply_method_errnof( + sd_bus_message *call, + int error, + const char *format, + ...) { + + _cleanup_(sd_bus_error_free) sd_bus_error berror = SD_BUS_ERROR_NULL; + va_list ap; + + assert_return(call, -EINVAL); + assert_return(call->sealed, -EPERM); + assert_return(call->header->type == SD_BUS_MESSAGE_METHOD_CALL, -EINVAL); + assert_return(call->bus, -EINVAL); + assert_return(!bus_pid_changed(call->bus), -ECHILD); + + if (!BUS_IS_OPEN(call->bus->state)) + return -ENOTCONN; + + if (call->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED) + return 0; + + va_start(ap, format); + sd_bus_error_set_errnofv(&berror, error, format, ap); + va_end(ap); + + return sd_bus_reply_method_error(call, &berror); +} + +_public_ int sd_bus_get_property( + sd_bus *bus, + const char *destination, + const char *path, + const char *interface, + const char *member, + sd_bus_error *error, + sd_bus_message **reply, + const char *type) { + + sd_bus_message *rep = NULL; + int r; + + bus_assert_return(bus, -EINVAL, error); + bus_assert_return(isempty(interface) || interface_name_is_valid(interface), -EINVAL, error); + bus_assert_return(member_name_is_valid(member), -EINVAL, error); + bus_assert_return(reply, -EINVAL, error); + bus_assert_return(signature_is_single(type, false), -EINVAL, error); + bus_assert_return(!bus_pid_changed(bus), -ECHILD, error); + + if (!BUS_IS_OPEN(bus->state)) { + r = -ENOTCONN; + goto fail; + } + + r = sd_bus_call_method(bus, destination, path, "org.freedesktop.DBus.Properties", "Get", error, &rep, "ss", strempty(interface), member); + if (r < 0) + return r; + + r = sd_bus_message_enter_container(rep, 'v', type); + if (r < 0) { + sd_bus_message_unref(rep); + goto fail; + } + + *reply = rep; + return 0; + +fail: + return sd_bus_error_set_errno(error, r); +} + +_public_ int sd_bus_get_property_trivial( + sd_bus *bus, + const char *destination, + const char *path, + const char *interface, + const char *member, + sd_bus_error *error, + char type, void *ptr) { + + _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL; + int r; + + bus_assert_return(bus, -EINVAL, error); + bus_assert_return(isempty(interface) || interface_name_is_valid(interface), -EINVAL, error); + bus_assert_return(member_name_is_valid(member), -EINVAL, error); + bus_assert_return(bus_type_is_trivial(type), -EINVAL, error); + bus_assert_return(ptr, -EINVAL, error); + bus_assert_return(!bus_pid_changed(bus), -ECHILD, error); + + if (!BUS_IS_OPEN(bus->state)) { + r = -ENOTCONN; + goto fail; + } + + r = sd_bus_call_method(bus, destination, path, "org.freedesktop.DBus.Properties", "Get", error, &reply, "ss", strempty(interface), member); + if (r < 0) + return r; + + r = sd_bus_message_enter_container(reply, 'v', CHAR_TO_STR(type)); + if (r < 0) + goto fail; + + r = sd_bus_message_read_basic(reply, type, ptr); + if (r < 0) + goto fail; + + return 0; + +fail: + return sd_bus_error_set_errno(error, r); +} + +_public_ int sd_bus_get_property_string( + sd_bus *bus, + const char *destination, + const char *path, + const char *interface, + const char *member, + sd_bus_error *error, + char **ret) { + + _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL; + const char *s; + char *n; + int r; + + bus_assert_return(bus, -EINVAL, error); + bus_assert_return(isempty(interface) || interface_name_is_valid(interface), -EINVAL, error); + bus_assert_return(member_name_is_valid(member), -EINVAL, error); + bus_assert_return(ret, -EINVAL, error); + bus_assert_return(!bus_pid_changed(bus), -ECHILD, error); + + if (!BUS_IS_OPEN(bus->state)) { + r = -ENOTCONN; + goto fail; + } + + r = sd_bus_call_method(bus, destination, path, "org.freedesktop.DBus.Properties", "Get", error, &reply, "ss", strempty(interface), member); + if (r < 0) + return r; + + r = sd_bus_message_enter_container(reply, 'v', "s"); + if (r < 0) + goto fail; + + r = sd_bus_message_read_basic(reply, 's', &s); + if (r < 0) + goto fail; + + n = strdup(s); + if (!n) { + r = -ENOMEM; + goto fail; + } + + *ret = n; + return 0; + +fail: + return sd_bus_error_set_errno(error, r); +} + +_public_ int sd_bus_get_property_strv( + sd_bus *bus, + const char *destination, + const char *path, + const char *interface, + const char *member, + sd_bus_error *error, + char ***ret) { + + _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL; + int r; + + bus_assert_return(bus, -EINVAL, error); + bus_assert_return(isempty(interface) || interface_name_is_valid(interface), -EINVAL, error); + bus_assert_return(member_name_is_valid(member), -EINVAL, error); + bus_assert_return(ret, -EINVAL, error); + bus_assert_return(!bus_pid_changed(bus), -ECHILD, error); + + if (!BUS_IS_OPEN(bus->state)) { + r = -ENOTCONN; + goto fail; + } + + r = sd_bus_call_method(bus, destination, path, "org.freedesktop.DBus.Properties", "Get", error, &reply, "ss", strempty(interface), member); + if (r < 0) + return r; + + r = sd_bus_message_enter_container(reply, 'v', NULL); + if (r < 0) + goto fail; + + r = sd_bus_message_read_strv(reply, ret); + if (r < 0) + goto fail; + + return 0; + +fail: + return sd_bus_error_set_errno(error, r); +} + +_public_ int sd_bus_set_property( + sd_bus *bus, + const char *destination, + const char *path, + const char *interface, + const char *member, + sd_bus_error *error, + const char *type, ...) { + + _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL; + va_list ap; + int r; + + bus_assert_return(bus, -EINVAL, error); + bus_assert_return(isempty(interface) || interface_name_is_valid(interface), -EINVAL, error); + bus_assert_return(member_name_is_valid(member), -EINVAL, error); + bus_assert_return(signature_is_single(type, false), -EINVAL, error); + bus_assert_return(!bus_pid_changed(bus), -ECHILD, error); + + if (!BUS_IS_OPEN(bus->state)) { + r = -ENOTCONN; + goto fail; + } + + r = sd_bus_message_new_method_call(bus, &m, destination, path, "org.freedesktop.DBus.Properties", "Set"); + if (r < 0) + goto fail; + + r = sd_bus_message_append(m, "ss", strempty(interface), member); + if (r < 0) + goto fail; + + r = sd_bus_message_open_container(m, 'v', type); + if (r < 0) + goto fail; + + va_start(ap, type); + r = sd_bus_message_appendv(m, type, ap); + va_end(ap); + if (r < 0) + goto fail; + + r = sd_bus_message_close_container(m); + if (r < 0) + goto fail; + + return sd_bus_call(bus, m, 0, error, NULL); + +fail: + return sd_bus_error_set_errno(error, r); +} + +_public_ int sd_bus_query_sender_creds(sd_bus_message *call, uint64_t mask, sd_bus_creds **creds) { + sd_bus_creds *c; + + assert_return(call, -EINVAL); + assert_return(call->sealed, -EPERM); + assert_return(call->bus, -EINVAL); + assert_return(!bus_pid_changed(call->bus), -ECHILD); + + if (!BUS_IS_OPEN(call->bus->state)) + return -ENOTCONN; + + c = sd_bus_message_get_creds(call); + + /* All data we need? */ + if (c && (mask & ~c->mask) == 0) { + *creds = sd_bus_creds_ref(c); + return 0; + } + + /* No data passed? Or not enough data passed to retrieve the missing bits? */ + if (!c || !(c->mask & SD_BUS_CREDS_PID)) { + /* We couldn't read anything from the call, let's try + * to get it from the sender or peer. */ + + if (call->sender) + /* There's a sender, but the creds are missing. */ + return sd_bus_get_name_creds(call->bus, call->sender, mask, creds); + else + /* There's no sender. For direct connections + * the credentials of the AF_UNIX peer matter, + * which may be queried via sd_bus_get_owner_creds(). */ + return sd_bus_get_owner_creds(call->bus, mask, creds); + } + + return bus_creds_extend_by_pid(c, mask, creds); +} + +_public_ int sd_bus_query_sender_privilege(sd_bus_message *call, int capability) { + _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL; + uid_t our_uid; + bool know_caps = false; + int r; + + assert_return(call, -EINVAL); + assert_return(call->sealed, -EPERM); + assert_return(call->bus, -EINVAL); + assert_return(!bus_pid_changed(call->bus), -ECHILD); + + if (!BUS_IS_OPEN(call->bus->state)) + return -ENOTCONN; + + if (capability >= 0) { + + r = sd_bus_query_sender_creds(call, SD_BUS_CREDS_UID|SD_BUS_CREDS_EUID|SD_BUS_CREDS_EFFECTIVE_CAPS, &creds); + if (r < 0) + return r; + + /* We cannot use augmented caps for authorization, + * since then data is acquired raceful from + * /proc. This can never actually happen, but let's + * better be safe than sorry, and do an extra check + * here. */ + assert_return((sd_bus_creds_get_augmented_mask(creds) & SD_BUS_CREDS_EFFECTIVE_CAPS) == 0, -EPERM); + + r = sd_bus_creds_has_effective_cap(creds, capability); + if (r > 0) + return 1; + if (r == 0) + know_caps = true; + } else { + r = sd_bus_query_sender_creds(call, SD_BUS_CREDS_UID|SD_BUS_CREDS_EUID, &creds); + if (r < 0) + return r; + } + + /* Now, check the UID, but only if the capability check wasn't + * sufficient */ + our_uid = getuid(); + if (our_uid != 0 || !know_caps || capability < 0) { + uid_t sender_uid; + + /* We cannot use augmented uid/euid for authorization, + * since then data is acquired raceful from + * /proc. This can never actually happen, but let's + * better be safe than sorry, and do an extra check + * here. */ + assert_return((sd_bus_creds_get_augmented_mask(creds) & (SD_BUS_CREDS_UID|SD_BUS_CREDS_EUID)) == 0, -EPERM); + + /* Try to use the EUID, if we have it. */ + r = sd_bus_creds_get_euid(creds, &sender_uid); + if (r < 0) + r = sd_bus_creds_get_uid(creds, &sender_uid); + + if (r >= 0) { + /* Sender has same UID as us, then let's grant access */ + if (sender_uid == our_uid) + return 1; + + /* Sender is root, we are not root. */ + if (our_uid != 0 && sender_uid == 0) + return 1; + } + } + + return 0; +} + +#define make_expression(sender, path, interface, member) \ + strjoina( \ + "type='signal'", \ + sender ? ",sender='" : "", \ + sender ?: "", \ + sender ? "'" : "", \ + path ? ",path='" : "", \ + path ?: "", \ + path ? "'" : "", \ + interface ? ",interface='" : "", \ + interface ?: "", \ + interface ? "'" : "", \ + member ? ",member='" : "", \ + member ?: "", \ + member ? "'" : "" \ + ) + +_public_ int sd_bus_match_signal( + sd_bus *bus, + sd_bus_slot **ret, + const char *sender, + const char *path, + const char *interface, + const char *member, + sd_bus_message_handler_t callback, + void *userdata) { + + const char *expression; + + assert_return(bus, -EINVAL); + assert_return(bus = bus_resolve(bus), -ENOPKG); + assert_return(!bus_pid_changed(bus), -ECHILD); + assert_return(!sender || service_name_is_valid(sender), -EINVAL); + assert_return(!path || object_path_is_valid(path), -EINVAL); + assert_return(!interface || interface_name_is_valid(interface), -EINVAL); + assert_return(!member || member_name_is_valid(member), -EINVAL); + + expression = make_expression(sender, path, interface, member); + + return sd_bus_add_match(bus, ret, expression, callback, userdata); +} + +_public_ int sd_bus_match_signal_async( + sd_bus *bus, + sd_bus_slot **ret, + const char *sender, + const char *path, + const char *interface, + const char *member, + sd_bus_message_handler_t callback, + sd_bus_message_handler_t install_callback, + void *userdata) { + + const char *expression; + + assert_return(bus, -EINVAL); + assert_return(bus = bus_resolve(bus), -ENOPKG); + assert_return(!bus_pid_changed(bus), -ECHILD); + assert_return(!sender || service_name_is_valid(sender), -EINVAL); + assert_return(!path || object_path_is_valid(path), -EINVAL); + assert_return(!interface || interface_name_is_valid(interface), -EINVAL); + assert_return(!member || member_name_is_valid(member), -EINVAL); + + expression = make_expression(sender, path, interface, member); + + return sd_bus_add_match_async(bus, ret, expression, callback, install_callback, userdata); +} |