--- /dev/null
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <sys/poll.h>
+
+#include "alloc-util.h"
+#include "errno-util.h"
+#include "fd-util.h"
+#include "hashmap.h"
+#include "list.h"
+#include "process-util.h"
+#include "set.h"
+#include "socket-util.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "strv.h"
+#include "time-util.h"
+#include "umask-util.h"
+#include "user-util.h"
+#include "varlink.h"
+
+#define VARLINK_DEFAULT_CONNECTIONS_MAX 4096U
+#define VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX 1024U
+
+#define VARLINK_DEFAULT_TIMEOUT_USEC (45U*USEC_PER_SEC)
+#define VARLINK_BUFFER_MAX (16U*1024U*1024U)
+#define VARLINK_READ_SIZE (64U*1024U)
+
+typedef enum VarlinkState {
+ /* Client side states */
+ VARLINK_IDLE_CLIENT,
+ VARLINK_AWAITING_REPLY,
+ VARLINK_CALLING,
+ VARLINK_CALLED,
+ VARLINK_PROCESSING_REPLY,
+
+ /* Server side states */
+ VARLINK_IDLE_SERVER,
+ VARLINK_PROCESSING_METHOD,
+ VARLINK_PROCESSING_METHOD_MORE,
+ VARLINK_PROCESSING_METHOD_ONEWAY,
+ VARLINK_PROCESSED_METHOD,
+ VARLINK_PROCESSED_METHOD_MORE,
+ VARLINK_PENDING_METHOD,
+ VARLINK_PENDING_METHOD_MORE,
+
+ /* Common states (only during shutdown) */
+ VARLINK_PENDING_DISCONNECT,
+ VARLINK_PENDING_TIMEOUT,
+ VARLINK_PROCESSING_DISCONNECT,
+ VARLINK_PROCESSING_TIMEOUT,
+ VARLINK_PROCESSING_FAILURE,
+ VARLINK_DISCONNECTED,
+
+ _VARLINK_STATE_MAX,
+ _VARLINK_STATE_INVALID = -1
+} VarlinkState;
+
+/* Tests whether we are not yet disconnected. Note that this is true during all states where the connection
+ * is still good for something, and false only when it's dead for good. This means: when we are
+ * asynchronously connecting to a peer and the connect() is still pending, then this will return 'true', as
+ * the connection is still good, and we are likely to be able to properly operate on it soon. */
+#define VARLINK_STATE_IS_ALIVE(state) \
+ IN_SET(state, \
+ VARLINK_IDLE_CLIENT, \
+ VARLINK_AWAITING_REPLY, \
+ VARLINK_CALLING, \
+ VARLINK_CALLED, \
+ VARLINK_PROCESSING_REPLY, \
+ VARLINK_IDLE_SERVER, \
+ VARLINK_PROCESSING_METHOD, \
+ VARLINK_PROCESSING_METHOD_MORE, \
+ VARLINK_PROCESSING_METHOD_ONEWAY, \
+ VARLINK_PROCESSED_METHOD, \
+ VARLINK_PROCESSED_METHOD_MORE, \
+ VARLINK_PENDING_METHOD, \
+ VARLINK_PENDING_METHOD_MORE)
+
+struct Varlink {
+ unsigned n_ref;
+
+ VarlinkServer *server;
+
+ VarlinkState state;
+ bool connecting; /* This boolean indicates whether the socket fd we are operating on is currently
+ * processing an asynchronous connect(). In that state we watch the socket for
+ * EPOLLOUT, but we refrain from calling read() or write() on the socket as that
+ * will trigger ENOTCONN. Note that this boolean is kept separate from the
+ * VarlinkState above on purpose: while the connect() is still not complete we
+ * already want to allow queuing of messages and similar. Thus it's nice to keep
+ * these two state concepts separate: the VarlinkState encodes what our own view of
+ * the connection is, i.e. whether we think it's a server, a client, and has
+ * something queued already, while 'connecting' tells us a detail about the
+ * transport used below, that should have no effect on how we otherwise accept and
+ * process operations from the user.
+ *
+ * Or to say this differently: VARLINK_STATE_IS_ALIVE(state) tells you whether the
+ * connection is good to use, even if it might not be fully connected
+ * yet. connecting=true then informs you that actually we are still connecting, and
+ * the connection is actually not established yet and thus any requests you enqueue
+ * now will still work fine but will be queued only, not sent yet, but that
+ * shouldn't stop you from using the connection, since eventually whatever you queue
+ * *will* be sent.
+ *
+ * Or to say this even differently: 'state' is a high-level ("application layer"
+ * high, if you so will) state, while 'conecting' is a low-level ("transport layer"
+ * low, if you so will) state, and while they are not entirely unrelated and
+ * sometimes propagate effects to each other they are only asynchronously connected
+ * at most. */
+ unsigned n_pending;
+
+ int fd;
+
+ char *input_buffer; /* valid data starts at input_buffer_index, ends at input_buffer_index+input_buffer_size */
+ size_t input_buffer_allocated;
+ size_t input_buffer_index;
+ size_t input_buffer_size;
+ size_t input_buffer_unscanned;
+
+ char *output_buffer; /* valid data starts at output_buffer_index, ends at output_buffer_index+output_buffer_size */
+ size_t output_buffer_allocated;
+ size_t output_buffer_index;
+ size_t output_buffer_size;
+
+ VarlinkReply reply_callback;
+
+ JsonVariant *current;
+ JsonVariant *reply;
+
+ struct ucred ucred;
+ bool ucred_acquired:1;
+
+ bool write_disconnected:1;
+ bool read_disconnected:1;
+ bool prefer_read_write:1;
+ bool got_pollhup:1;
+
+ usec_t timestamp;
+ usec_t timeout;
+
+ void *userdata;
+ char *description;
+
+ sd_event *event;
+ sd_event_source *io_event_source;
+ sd_event_source *time_event_source;
+ sd_event_source *quit_event_source;
+ sd_event_source *defer_event_source;
+};
+
+typedef struct VarlinkServerSocket VarlinkServerSocket;
+
+struct VarlinkServerSocket {
+ VarlinkServer *server;
+
+ int fd;
+ char *address;
+
+ sd_event_source *event_source;
+
+ LIST_FIELDS(VarlinkServerSocket, sockets);
+};
+
+struct VarlinkServer {
+ unsigned n_ref;
+ VarlinkServerFlags flags;
+
+ LIST_HEAD(VarlinkServerSocket, sockets);
+
+ Hashmap *methods;
+ VarlinkConnect connect_callback;
+
+ sd_event *event;
+ int64_t event_priority;
+
+ unsigned n_connections;
+ Hashmap *by_uid;
+
+ void *userdata;
+ char *description;
+
+ unsigned connections_max;
+ unsigned connections_per_uid_max;
+};
+
+static const char* const varlink_state_table[_VARLINK_STATE_MAX] = {
+ [VARLINK_IDLE_CLIENT] = "idle-client",
+ [VARLINK_AWAITING_REPLY] = "awaiting-reply",
+ [VARLINK_CALLING] = "calling",
+ [VARLINK_CALLED] = "called",
+ [VARLINK_PROCESSING_REPLY] = "processing-reply",
+ [VARLINK_IDLE_SERVER] = "idle-server",
+ [VARLINK_PROCESSING_METHOD] = "processing-method",
+ [VARLINK_PROCESSING_METHOD_MORE] = "processing-method-more",
+ [VARLINK_PROCESSING_METHOD_ONEWAY] = "processing-method-oneway",
+ [VARLINK_PROCESSED_METHOD] = "processed-method",
+ [VARLINK_PROCESSED_METHOD_MORE] = "processed-method-more",
+ [VARLINK_PENDING_METHOD] = "pending-method",
+ [VARLINK_PENDING_METHOD_MORE] = "pending-method-more",
+ [VARLINK_PENDING_DISCONNECT] = "pending-disconnect",
+ [VARLINK_PENDING_TIMEOUT] = "pending-timeout",
+ [VARLINK_PROCESSING_DISCONNECT] = "processing-disconnect",
+ [VARLINK_PROCESSING_TIMEOUT] = "processing-timeout",
+ [VARLINK_PROCESSING_FAILURE] = "processing-failure",
+ [VARLINK_DISCONNECTED] = "disconnected",
+};
+
+DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(varlink_state, VarlinkState);
+
+#define varlink_log_errno(v, error, fmt, ...) \
+ log_debug_errno(error, "%s: " fmt, varlink_description(v), ##__VA_ARGS__)
+
+#define varlink_log(v, fmt, ...) \
+ log_debug("%s: " fmt, varlink_description(v), ##__VA_ARGS__)
+
+#define varlink_server_log_errno(s, error, fmt, ...) \
+ log_debug_errno(error, "%s: " fmt, varlink_server_description(s), ##__VA_ARGS__)
+
+#define varlink_server_log(s, fmt, ...) \
+ log_debug("%s: " fmt, varlink_server_description(s), ##__VA_ARGS__)
+
+static inline const char *varlink_description(Varlink *v) {
+ return strna(v ? v->description : NULL);
+}
+
+static inline const char *varlink_server_description(VarlinkServer *s) {
+ return strna(s ? s->description : NULL);
+}
+
+static void varlink_set_state(Varlink *v, VarlinkState state) {
+ assert(v);
+
+ varlink_log(v, "varlink: changing state %s → %s",
+ varlink_state_to_string(v->state),
+ varlink_state_to_string(state));
+
+ v->state = state;
+}
+
+static int varlink_new(Varlink **ret) {
+ Varlink *v;
+
+ assert(ret);
+
+ v = new(Varlink, 1);
+ if (!v)
+ return -ENOMEM;
+
+ *v = (Varlink) {
+ .n_ref = 1,
+ .fd = -1,
+
+ .state = _VARLINK_STATE_INVALID,
+
+ .ucred.uid = UID_INVALID,
+ .ucred.gid = GID_INVALID,
+
+ .timestamp = USEC_INFINITY,
+ .timeout = VARLINK_DEFAULT_TIMEOUT_USEC
+ };
+
+ *ret = v;
+ return 0;
+}
+
+int varlink_connect_address(Varlink **ret, const char *address) {
+ _cleanup_(varlink_unrefp) Varlink *v = NULL;
+ union sockaddr_union sockaddr;
+ int r;
+
+ assert_return(ret, -EINVAL);
+ assert_return(address, -EINVAL);
+
+ r = sockaddr_un_set_path(&sockaddr.un, address);
+ if (r < 0)
+ return r;
+
+ r = varlink_new(&v);
+ if (r < 0)
+ return r;
+
+ v->fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+ if (v->fd < 0)
+ return -errno;
+
+ if (connect(v->fd, &sockaddr.sa, SOCKADDR_UN_LEN(sockaddr.un)) < 0) {
+ if (!IN_SET(errno, EAGAIN, EINPROGRESS))
+ return -errno;
+
+ v->connecting = true; /* We are asynchronously connecting, i.e. the connect() is being
+ * processed in the background. As long as that's the case the socket
+ * is in a special state: it's there, we can poll it for EPOLLOUT, but
+ * if we attempt to write() to it before we see EPOLLOUT we'll get
+ * ENOTCONN (and not EAGAIN, like we would for a normal connected
+ * socket that isn't writable at the moment). Since ENOTCONN on write()
+ * hence can mean two different things (i.e. connection not complete
+ * yet vs. already disconnected again), we store as a boolean whether
+ * we are still in connect(). */
+ }
+
+ varlink_set_state(v, VARLINK_IDLE_CLIENT);
+
+ *ret = TAKE_PTR(v);
+ return r;
+}
+
+int varlink_connect_fd(Varlink **ret, int fd) {
+ Varlink *v;
+ int r;
+
+ assert_return(ret, -EINVAL);
+ assert_return(fd >= 0, -EBADF);
+
+ r = fd_nonblock(fd, true);
+ if (r < 0)
+ return r;
+
+ r = varlink_new(&v);
+ if (r < 0)
+ return r;
+
+ v->fd = fd;
+ varlink_set_state(v, VARLINK_IDLE_CLIENT);
+
+ /* Note that if this function is called we assume the passed socket (if it is one) is already
+ * properly connected, i.e. any asynchronous connect() done on it already completed. Because of that
+ * we'll not set the 'connecting' boolean here, i.e. we don't need to avoid write()ing to the socket
+ * until the connection is fully set up. Behaviour here is hence a bit different from
+ * varlink_connect_address() above, as there we do handle asynchronous connections ourselves and
+ * avoid doing write() on it before we saw EPOLLOUT for the first time. */
+
+ *ret = v;
+ return 0;
+}
+
+static void varlink_detach_event_sources(Varlink *v) {
+ assert(v);
+
+ if (v->io_event_source) {
+ (void) sd_event_source_set_enabled(v->io_event_source, SD_EVENT_OFF);
+ v->io_event_source = sd_event_source_unref(v->io_event_source);
+ }
+
+ if (v->time_event_source) {
+ (void) sd_event_source_set_enabled(v->time_event_source, SD_EVENT_OFF);
+ v->time_event_source = sd_event_source_unref(v->time_event_source);
+ }
+
+ if (v->quit_event_source) {
+ (void) sd_event_source_set_enabled(v->quit_event_source, SD_EVENT_OFF);
+ v->quit_event_source = sd_event_source_unref(v->quit_event_source);
+ }
+
+ if (v->defer_event_source) {
+ (void) sd_event_source_set_enabled(v->defer_event_source, SD_EVENT_OFF);
+ v->defer_event_source = sd_event_source_unref(v->defer_event_source);
+ }
+}
+
+static void varlink_clear(Varlink *v) {
+ assert(v);
+
+ varlink_detach_event_sources(v);
+
+ v->fd = safe_close(v->fd);
+
+ v->input_buffer = mfree(v->input_buffer);
+ v->output_buffer = mfree(v->output_buffer);
+
+ v->current = json_variant_unref(v->current);
+ v->reply = json_variant_unref(v->reply);
+
+ v->event = sd_event_unref(v->event);
+}
+
+static Varlink* varlink_destroy(Varlink *v) {
+ if (!v)
+ return NULL;
+
+ /* If this is called the server object must already been unreffed here. Why that? because when we
+ * linked up the varlink connection with the server object we took one ref in each direction */
+ assert(!v->server);
+
+ varlink_clear(v);
+
+ free(v->description);
+ return mfree(v);
+}
+
+DEFINE_TRIVIAL_REF_UNREF_FUNC(Varlink, varlink, varlink_destroy);
+
+static int varlink_test_disconnect(Varlink *v) {
+ assert(v);
+
+ /* Tests whether we the the connection has been terminated. We are careful to not stop processing it
+ * prematurely, since we want to handle half-open connections as well as possible and want to flush
+ * out and read data before we close down if we can. */
+
+ /* Already disconnected? */
+ if (!VARLINK_STATE_IS_ALIVE(v->state))
+ return 0;
+
+ /* Wait until connection setup is complete, i.e. until asynchronous connect() completes */
+ if (v->connecting)
+ return 0;
+
+ /* Still something to write and we can write? Stay around */
+ if (v->output_buffer_size > 0 && !v->write_disconnected)
+ return 0;
+
+ /* Both sides gone already? Then there's no need to stick around */
+ if (v->read_disconnected && v->write_disconnected)
+ goto disconnect;
+
+ /* If we are waiting for incoming data but the read side is shut down, disconnect. */
+ if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING, VARLINK_IDLE_SERVER) && v->read_disconnected)
+ goto disconnect;
+
+ /* Similar, if are a client that hasn't written anything yet but the write side is dead, also
+ * disconnect. We also explicitly check for POLLHUP here since we likely won't notice the write side
+ * being down if we never wrote anything. */
+ if (IN_SET(v->state, VARLINK_IDLE_CLIENT) && (v->write_disconnected || v->got_pollhup))
+ goto disconnect;
+
+ return 0;
+
+disconnect:
+ varlink_set_state(v, VARLINK_PENDING_DISCONNECT);
+ return 1;
+}
+
+static int varlink_write(Varlink *v) {
+ ssize_t n;
+
+ assert(v);
+
+ if (!VARLINK_STATE_IS_ALIVE(v->state))
+ return 0;
+ if (v->connecting) /* Writing while we are still wait for a non-blocking connect() to complete will
+ * result in ENOTCONN, hence exit early here */
+ return 0;
+ if (v->output_buffer_size == 0)
+ return 0;
+ if (v->write_disconnected)
+ return 0;
+
+ assert(v->fd >= 0);
+
+ /* We generally prefer recv()/send() (mostly because of MSG_NOSIGNAL) but also want to be compatible
+ * with non-socket IO, hence fall back automatically */
+ if (!v->prefer_read_write) {
+ n = send(v->fd, v->output_buffer + v->output_buffer_index, v->output_buffer_size, MSG_DONTWAIT|MSG_NOSIGNAL);
+ if (n < 0 && errno == ENOTSOCK)
+ v->prefer_read_write = true;
+ }
+ if (v->prefer_read_write)
+ n = write(v->fd, v->output_buffer + v->output_buffer_index, v->output_buffer_size);
+ if (n < 0) {
+ if (errno == EAGAIN)
+ return 0;
+
+ if (ERRNO_IS_DISCONNECT(errno)) {
+ /* If we get informed about a disconnect on write, then let's remember that, but not
+ * act on it just yet. Let's wait for read() to report the issue first. */
+ v->write_disconnected = true;
+ return 1;
+ }
+
+ return -errno;
+ }
+
+ v->output_buffer_size -= n;
+
+ if (v->output_buffer_size == 0)
+ v->output_buffer_index = 0;
+ else
+ v->output_buffer_index += n;
+
+ v->timestamp = now(CLOCK_MONOTONIC);
+ return 1;
+}
+
+static int varlink_read(Varlink *v) {
+ size_t rs;
+ ssize_t n;
+
+ assert(v);
+
+ if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING, VARLINK_IDLE_SERVER))
+ return 0;
+ if (v->connecting) /* read() on a socket while we are in connect() will fail with EINVAL, hence exit early here */
+ return 0;
+ if (v->current)
+ return 0;
+ if (v->input_buffer_unscanned > 0)
+ return 0;
+ if (v->read_disconnected)
+ return 0;
+
+ if (v->input_buffer_size >= VARLINK_BUFFER_MAX)
+ return -ENOBUFS;
+
+ assert(v->fd >= 0);
+
+ if (v->input_buffer_allocated <= v->input_buffer_index + v->input_buffer_size) {
+ size_t add;
+
+ add = MIN(VARLINK_BUFFER_MAX - v->input_buffer_size, VARLINK_READ_SIZE);
+
+ if (v->input_buffer_index == 0) {
+
+ if (!GREEDY_REALLOC(v->input_buffer, v->input_buffer_allocated, v->input_buffer_size + add))
+ return -ENOMEM;
+
+ } else {
+ char *b;
+
+ b = new(char, v->input_buffer_size + add);
+ if (!b)
+ return -ENOMEM;
+
+ memcpy(b, v->input_buffer + v->input_buffer_index, v->input_buffer_size);
+
+ free_and_replace(v->input_buffer, b);
+
+ v->input_buffer_allocated = v->input_buffer_size + add;
+ v->input_buffer_index = 0;
+ }
+ }
+
+ rs = v->input_buffer_allocated - (v->input_buffer_index + v->input_buffer_size);
+
+ if (!v->prefer_read_write) {
+ n = recv(v->fd, v->input_buffer + v->input_buffer_index + v->input_buffer_size, rs, MSG_DONTWAIT);
+ if (n < 0 && errno == ENOTSOCK)
+ v->prefer_read_write = true;
+ }
+ if (v->prefer_read_write)
+ n = read(v->fd, v->input_buffer + v->input_buffer_index + v->input_buffer_size, rs);
+ if (n < 0) {
+ if (errno == EAGAIN)
+ return 0;
+
+ if (ERRNO_IS_DISCONNECT(errno)) {
+ v->read_disconnected = true;
+ return 1;
+ }
+
+ return -errno;
+ }
+ if (n == 0) { /* EOF */
+ v->read_disconnected = true;
+ return 1;
+ }
+
+ v->input_buffer_size += n;
+ v->input_buffer_unscanned += n;
+
+ return 1;
+}
+
+static int varlink_parse_message(Varlink *v) {
+ const char *e, *begin;
+ size_t sz;
+ int r;
+
+ assert(v);
+
+ if (v->current)
+ return 0;
+ if (v->input_buffer_unscanned <= 0)
+ return 0;
+
+ assert(v->input_buffer_unscanned <= v->input_buffer_size);
+ assert(v->input_buffer_index + v->input_buffer_size <= v->input_buffer_allocated);
+
+ begin = v->input_buffer + v->input_buffer_index;
+
+ e = memchr(begin + v->input_buffer_size - v->input_buffer_unscanned, 0, v->input_buffer_unscanned);
+ if (!e) {
+ v->input_buffer_unscanned = 0;
+ return 0;
+ }
+
+ sz = e - begin + 1;
+
+ varlink_log(v, "New incoming message: %s", begin);
+
+ r = json_parse(begin, &v->current, NULL, NULL);
+ if (r < 0)
+ return r;
+
+ v->input_buffer_size -= sz;
+
+ if (v->input_buffer_size == 0)
+ v->input_buffer_index = 0;
+ else
+ v->input_buffer_index += sz;
+
+ v->input_buffer_unscanned = v->input_buffer_size;
+ return 1;
+}
+
+static int varlink_test_timeout(Varlink *v) {
+ assert(v);
+
+ if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING))
+ return 0;
+ if (v->timeout == USEC_INFINITY)
+ return 0;
+
+ if (now(CLOCK_MONOTONIC) < usec_add(v->timestamp, v->timeout))
+ return 0;
+
+ varlink_set_state(v, VARLINK_PENDING_TIMEOUT);
+
+ return 1;
+}
+
+static int varlink_dispatch_local_error(Varlink *v, const char *error) {
+ int r;
+
+ assert(v);
+ assert(error);
+
+ if (!v->reply_callback)
+ return 0;
+
+ r = v->reply_callback(v, NULL, error, VARLINK_REPLY_ERROR|VARLINK_REPLY_LOCAL, v->userdata);
+ if (r < 0)
+ log_debug_errno(r, "Reply callback returned error, ignoring: %m");
+
+ return 1;
+}
+
+static int varlink_dispatch_timeout(Varlink *v) {
+ assert(v);
+
+ if (v->state != VARLINK_PENDING_TIMEOUT)
+ return 0;
+
+ varlink_set_state(v, VARLINK_PROCESSING_TIMEOUT);
+ varlink_dispatch_local_error(v, VARLINK_ERROR_TIMEOUT);
+ varlink_close(v);
+
+ return 1;
+}
+
+static int varlink_dispatch_disconnect(Varlink *v) {
+ assert(v);
+
+ if (v->state != VARLINK_PENDING_DISCONNECT)
+ return 0;
+
+ varlink_set_state(v, VARLINK_PROCESSING_DISCONNECT);
+ varlink_dispatch_local_error(v, VARLINK_ERROR_DISCONNECTED);
+ varlink_close(v);
+
+ return 1;
+}
+
+static int varlink_sanitize_parameters(JsonVariant **v) {
+ assert(v);
+
+ /* Varlink always wants a parameters list, hence make one if the caller doesn't want any */
+ if (!*v)
+ return json_variant_new_object(v, NULL, 0);
+ else if (!json_variant_is_object(*v))
+ return -EINVAL;
+
+ return 0;
+}
+
+static int varlink_dispatch_reply(Varlink *v) {
+ _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
+ VarlinkReplyFlags flags = 0;
+ const char *error = NULL;
+ JsonVariant *e;
+ const char *k;
+ int r;
+
+ assert(v);
+
+ if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING))
+ return 0;
+ if (!v->current)
+ return 0;
+
+ assert(v->n_pending > 0);
+
+ if (!json_variant_is_object(v->current))
+ goto invalid;
+
+ JSON_VARIANT_OBJECT_FOREACH(k, e, v->current) {
+
+ if (streq(k, "error")) {
+ if (error)
+ goto invalid;
+ if (!json_variant_is_string(e))
+ goto invalid;
+
+ error = json_variant_string(e);
+ flags |= VARLINK_REPLY_ERROR;
+
+ } else if (streq(k, "parameters")) {
+ if (parameters)
+ goto invalid;
+ if (!json_variant_is_object(e))
+ goto invalid;
+
+ parameters = json_variant_ref(e);
+
+ } else if (streq(k, "continues")) {
+ if (FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
+ goto invalid;
+
+ if (!json_variant_is_boolean(e))
+ goto invalid;
+
+ if (json_variant_boolean(e))
+ flags |= VARLINK_REPLY_CONTINUES;
+ } else
+ goto invalid;
+ }
+
+ if (error && FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
+ goto invalid;
+
+ r = varlink_sanitize_parameters(¶meters);
+ if (r < 0)
+ goto invalid;
+
+ if (v->state == VARLINK_AWAITING_REPLY) {
+ varlink_set_state(v, VARLINK_PROCESSING_REPLY);
+
+ if (v->reply_callback) {
+ r = v->reply_callback(v, parameters, error, flags, v->userdata);
+ if (r < 0)
+ log_debug_errno(r, "Reply callback returned error, ignoring: %m");
+ }
+
+ v->current = json_variant_unref(v->current);
+
+ if (v->state == VARLINK_PROCESSING_REPLY) {
+ assert(v->n_pending > 0);
+ v->n_pending--;
+
+ varlink_set_state(v, v->n_pending == 0 ? VARLINK_IDLE_CLIENT : VARLINK_AWAITING_REPLY);
+ }
+ } else {
+ assert(v->state == VARLINK_CALLING);
+
+ if (FLAGS_SET(flags, VARLINK_REPLY_CONTINUES))
+ goto invalid;
+
+ varlink_set_state(v, VARLINK_CALLED);
+ }
+
+ return 1;
+
+invalid:
+ varlink_set_state(v, VARLINK_PROCESSING_FAILURE);
+ varlink_dispatch_local_error(v, VARLINK_ERROR_PROTOCOL);
+ varlink_close(v);
+
+ return 1;
+}
+
+static int varlink_dispatch_method(Varlink *v) {
+ _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
+ VarlinkMethodFlags flags = 0;
+ const char *method = NULL, *error;
+ JsonVariant *e;
+ VarlinkMethod callback;
+ const char *k;
+ int r;
+
+ assert(v);
+
+ if (v->state != VARLINK_IDLE_SERVER)
+ return 0;
+ if (!v->current)
+ return 0;
+
+ if (!json_variant_is_object(v->current))
+ goto invalid;
+
+ JSON_VARIANT_OBJECT_FOREACH(k, e, v->current) {
+
+ if (streq(k, "method")) {
+ if (method)
+ goto invalid;
+ if (!json_variant_is_string(e))
+ goto invalid;
+
+ method = json_variant_string(e);
+
+ } else if (streq(k, "parameters")) {
+ if (parameters)
+ goto invalid;
+ if (!json_variant_is_object(e))
+ goto invalid;
+
+ parameters = json_variant_ref(e);
+
+ } else if (streq(k, "oneway")) {
+
+ if ((flags & (VARLINK_METHOD_ONEWAY|VARLINK_METHOD_MORE)) != 0)
+ goto invalid;
+
+ if (!json_variant_is_boolean(e))
+ goto invalid;
+
+ if (json_variant_boolean(e))
+ flags |= VARLINK_METHOD_ONEWAY;
+
+ } else if (streq(k, "more")) {
+
+ if ((flags & (VARLINK_METHOD_ONEWAY|VARLINK_METHOD_MORE)) != 0)
+ goto invalid;
+
+ if (!json_variant_is_boolean(e))
+ goto invalid;
+
+ if (json_variant_boolean(e))
+ flags |= VARLINK_METHOD_MORE;
+
+ } else
+ goto invalid;
+ }
+
+ if (!method)
+ goto invalid;
+
+ r = varlink_sanitize_parameters(¶meters);
+ if (r < 0)
+ goto fail;
+
+ varlink_set_state(v, (flags & VARLINK_METHOD_MORE) ? VARLINK_PROCESSING_METHOD_MORE :
+ (flags & VARLINK_METHOD_ONEWAY) ? VARLINK_PROCESSING_METHOD_ONEWAY :
+ VARLINK_PROCESSING_METHOD);
+
+ assert(v->server);
+
+ if (STR_IN_SET(method, "org.varlink.service.GetInfo", "org.varlink.service.GetInterface")) {
+ /* For now, we don't implement a single of varlink's own methods */
+ callback = NULL;
+ error = VARLINK_ERROR_METHOD_NOT_IMPLEMENTED;
+ } else if (startswith(method, "org.varlink.service.")) {
+ callback = NULL;
+ error = VARLINK_ERROR_METHOD_NOT_FOUND;
+ } else {
+ callback = hashmap_get(v->server->methods, method);
+ error = VARLINK_ERROR_METHOD_NOT_FOUND;
+ }
+
+ if (callback) {
+ r = callback(v, parameters, flags, v->userdata);
+ if (r < 0) {
+ log_debug_errno(r, "Callback for %s returned error: %m", method);
+
+ /* We got an error back from the callback. Propagate it to the client if the method call remains unanswered. */
+ if (!FLAGS_SET(flags, VARLINK_METHOD_ONEWAY)) {
+ r = varlink_errorb(v, VARLINK_ERROR_SYSTEM, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("errno", JSON_BUILD_INTEGER(-r))));
+ if (r < 0)
+ return r;
+ }
+ }
+ } else if (!FLAGS_SET(flags, VARLINK_METHOD_ONEWAY)) {
+ assert(error);
+
+ r = varlink_errorb(v, error, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method))));
+ if (r < 0)
+ return r;
+ }
+
+ switch (v->state) {
+
+ case VARLINK_PROCESSED_METHOD: /* Method call is fully processed */
+ case VARLINK_PROCESSING_METHOD_ONEWAY: /* ditto */
+ v->current = json_variant_unref(v->current);
+ varlink_set_state(v, VARLINK_IDLE_SERVER);
+ break;
+
+ case VARLINK_PROCESSING_METHOD: /* Method call wasn't replied to, will be replied to later */
+ varlink_set_state(v, VARLINK_PENDING_METHOD);
+ break;
+
+ case VARLINK_PROCESSED_METHOD_MORE: /* One reply for a "more" message was sent, more to come */
+ case VARLINK_PROCESSING_METHOD_MORE: /* No reply for a "more" message was sent, more to come */
+ varlink_set_state(v, VARLINK_PENDING_METHOD_MORE);
+ break;
+
+ default:
+ assert_not_reached("Unexpected state");
+
+ }
+
+ return r;
+
+invalid:
+ r = -EINVAL;
+
+fail:
+ varlink_set_state(v, VARLINK_PROCESSING_FAILURE);
+ varlink_dispatch_local_error(v, VARLINK_ERROR_PROTOCOL);
+ varlink_close(v);
+
+ return r;
+}
+
+int varlink_process(Varlink *v) {
+ int r;
+
+ assert_return(v, -EINVAL);
+
+ if (v->state == VARLINK_DISCONNECTED)
+ return -ENOTCONN;
+
+ varlink_ref(v);
+
+ r = varlink_write(v);
+ if (r != 0)
+ goto finish;
+
+ r = varlink_dispatch_reply(v);
+ if (r != 0)
+ goto finish;
+
+ r = varlink_dispatch_method(v);
+ if (r != 0)
+ goto finish;
+
+ r = varlink_parse_message(v);
+ if (r != 0)
+ goto finish;
+
+ r = varlink_read(v);
+ if (r != 0)
+ goto finish;
+
+ r = varlink_test_disconnect(v);
+ if (r != 0)
+ goto finish;
+
+ r = varlink_dispatch_disconnect(v);
+ if (r != 0)
+ goto finish;
+
+ r = varlink_test_timeout(v);
+ if (r != 0)
+ goto finish;
+
+ r = varlink_dispatch_timeout(v);
+ if (r != 0)
+ goto finish;
+
+finish:
+ if (r >= 0 && v->defer_event_source) {
+ int q;
+
+ /* If we did some processing, make sure we are called again soon */
+ q = sd_event_source_set_enabled(v->defer_event_source, r > 0 ? SD_EVENT_ON : SD_EVENT_OFF);
+ if (q < 0)
+ r = q;
+ }
+
+ if (r < 0) {
+ if (VARLINK_STATE_IS_ALIVE(v->state))
+ /* Initiate disconnection */
+ varlink_set_state(v, VARLINK_PENDING_DISCONNECT);
+ else
+ /* We failed while disconnecting, in that case close right away */
+ varlink_close(v);
+ }
+
+ varlink_unref(v);
+ return r;
+}
+
+static void handle_revents(Varlink *v, int revents) {
+ assert(v);
+
+ if (v->connecting) {
+ /* If we have seen POLLOUT or POLLHUP on a socket we are asynchronously waiting a connect()
+ * to complete on, we know we are ready. We don't read the connection error here though,
+ * we'll get the error on the next read() or write(). */
+ if ((revents & (POLLOUT|POLLHUP)) == 0)
+ return;
+
+ varlink_log(v, "Anynchronous connection completed.");
+ v->connecting = false;
+ } else {
+ /* Note that we don't care much about POLLIN/POLLOUT here, we'll just try reading and writing
+ * what we can. However, we do care about POLLHUP to detect connection termination even if we
+ * momentarily don't want to read nor write anything. */
+
+ if (!FLAGS_SET(revents, POLLHUP))
+ return;
+
+ varlink_log(v, "Got POLLHUP from socket.");
+ v->got_pollhup = true;
+ }
+}
+
+int varlink_wait(Varlink *v, usec_t timeout) {
+ struct timespec ts;
+ struct pollfd pfd;
+ int r, fd, events;
+ usec_t t;
+
+ assert_return(v, -EINVAL);
+ assert_return(!v->server, -ENOTTY);
+
+ if (v->state == VARLINK_DISCONNECTED)
+ return -ENOTCONN;
+
+ r = varlink_get_timeout(v, &t);
+ if (r < 0)
+ return r;
+ if (t != USEC_INFINITY) {
+ usec_t n;
+
+ n = now(CLOCK_MONOTONIC);
+ if (t < n)
+ t = 0;
+ else
+ t = usec_sub_unsigned(t, n);
+ }
+
+ if (timeout != USEC_INFINITY &&
+ (t == USEC_INFINITY || timeout < t))
+ t = timeout;
+
+ fd = varlink_get_fd(v);
+ if (fd < 0)
+ return fd;
+
+ events = varlink_get_events(v);
+ if (events < 0)
+ return events;
+
+ pfd = (struct pollfd) {
+ .fd = fd,
+ .events = events,
+ };
+
+ r = ppoll(&pfd, 1,
+ t == USEC_INFINITY ? NULL : timespec_store(&ts, t),
+ NULL);
+ if (r < 0)
+ return -errno;
+
+ handle_revents(v, pfd.revents);
+
+ return r > 0 ? 1 : 0;
+}
+
+int varlink_get_fd(Varlink *v) {
+
+ assert_return(v, -EINVAL);
+
+ if (v->state == VARLINK_DISCONNECTED)
+ return -ENOTCONN;
+ if (v->fd < 0)
+ return -EBADF;
+
+ return v->fd;
+}
+
+int varlink_get_events(Varlink *v) {
+ int ret = 0;
+
+ assert_return(v, -EINVAL);
+
+ if (v->state == VARLINK_DISCONNECTED)
+ return -ENOTCONN;
+
+ if (v->connecting) /* When processing an asynchronous connect(), we only wait for EPOLLOUT, which
+ * tells us that the connection is now complete. Before that we should neither
+ * write() or read() from the fd. */
+ return EPOLLOUT;
+
+ if (!v->read_disconnected &&
+ IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING, VARLINK_IDLE_SERVER) &&
+ !v->current &&
+ v->input_buffer_unscanned <= 0)
+ ret |= EPOLLIN;
+
+ if (!v->write_disconnected &&
+ v->output_buffer_size > 0)
+ ret |= EPOLLOUT;
+
+ return ret;
+}
+
+int varlink_get_timeout(Varlink *v, usec_t *ret) {
+ assert_return(v, -EINVAL);
+
+ if (v->state == VARLINK_DISCONNECTED)
+ return -ENOTCONN;
+
+ if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING) &&
+ v->timeout != USEC_INFINITY) {
+ if (ret)
+ *ret = usec_add(v->timestamp, v->timeout);
+ return 1;
+ } else {
+ if (ret)
+ *ret = USEC_INFINITY;
+ return 0;
+ }
+}
+
+int varlink_flush(Varlink *v) {
+ int ret = 0, r;
+
+ assert_return(v, -EINVAL);
+
+ if (v->state == VARLINK_DISCONNECTED)
+ return -ENOTCONN;
+
+ for (;;) {
+ struct pollfd pfd;
+
+ if (v->output_buffer_size == 0)
+ break;
+ if (v->write_disconnected)
+ return -ECONNRESET;
+
+ r = varlink_write(v);
+ if (r < 0)
+ return r;
+ if (r > 0) {
+ ret = 1;
+ continue;
+ }
+
+ pfd = (struct pollfd) {
+ .fd = v->fd,
+ .events = POLLOUT,
+ };
+
+ if (poll(&pfd, 1, -1) < 0)
+ return -errno;
+
+ handle_revents(v, pfd.revents);
+ }
+
+ return ret;
+}
+
+static void varlink_detach_server(Varlink *v) {
+ assert(v);
+
+ if (!v->server)
+ return;
+
+ if (v->server->by_uid &&
+ v->ucred_acquired &&
+ uid_is_valid(v->ucred.uid)) {
+ unsigned c;
+
+ c = PTR_TO_UINT(hashmap_get(v->server->by_uid, UID_TO_PTR(v->ucred.uid)));
+ assert(c > 0);
+
+ if (c == 1)
+ (void) hashmap_remove(v->server->by_uid, UID_TO_PTR(v->ucred.uid));
+ else
+ (void) hashmap_replace(v->server->by_uid, UID_TO_PTR(v->ucred.uid), UINT_TO_PTR(c - 1));
+ }
+
+ assert(v->server->n_connections > 0);
+ v->server->n_connections--;
+
+ /* If this is a connection associated to a server, then let's disconnect the server and the
+ * connection from each other. This drops the dangling reference that connect_callback() set up. */
+ v->server = varlink_server_unref(v->server);
+ varlink_unref(v);
+}
+
+int varlink_close(Varlink *v) {
+
+ assert_return(v, -EINVAL);
+
+ if (v->state == VARLINK_DISCONNECTED)
+ return 0;
+
+ varlink_set_state(v, VARLINK_DISCONNECTED);
+
+ /* Let's take a reference first, since varlink_detach_server() might drop the final (dangling) ref
+ * which would destroy us before we can call varlink_clear() */
+ varlink_ref(v);
+ varlink_detach_server(v);
+ varlink_clear(v);
+ varlink_unref(v);
+
+ return 1;
+}
+
+Varlink* varlink_flush_close_unref(Varlink *v) {
+
+ if (!v)
+ return NULL;
+
+ (void) varlink_flush(v);
+ (void) varlink_close(v);
+
+ return varlink_unref(v);
+}
+
+static int varlink_enqueue_json(Varlink *v, JsonVariant *m) {
+ _cleanup_free_ char *text = NULL;
+ int r;
+
+ assert(v);
+ assert(m);
+
+ r = json_variant_format(m, 0, &text);
+ if (r < 0)
+ return r;
+
+ if (v->output_buffer_size + r + 1 > VARLINK_BUFFER_MAX)
+ return -ENOBUFS;
+
+ varlink_log(v, "Sending message: %s", text);
+
+ if (v->output_buffer_size == 0) {
+
+ free_and_replace(v->output_buffer, text);
+
+ v->output_buffer_size = v->output_buffer_allocated = r + 1;
+ v->output_buffer_index = 0;
+
+ } else if (v->output_buffer_index == 0) {
+
+ if (!GREEDY_REALLOC(v->output_buffer, v->output_buffer_allocated, v->output_buffer_size + r + 1))
+ return -ENOMEM;
+
+ memcpy(v->output_buffer + v->output_buffer_size, text, r + 1);
+ v->output_buffer_size += r + 1;
+
+ } else {
+ char *n;
+
+ n = new(char, v->output_buffer_size + r + 1);
+ if (!n)
+ return -ENOMEM;
+
+ memcpy(mempcpy(n, v->output_buffer + v->output_buffer_index, v->output_buffer_size), text, r + 1);
+
+ free_and_replace(v->output_buffer, n);
+ v->output_buffer_size += r + 1;
+ v->output_buffer_index = 0;
+ }
+
+ return 0;
+}
+
+int varlink_send(Varlink *v, const char *method, JsonVariant *parameters) {
+ _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
+ int r;
+
+ assert_return(v, -EINVAL);
+ assert_return(method, -EINVAL);
+
+ if (v->state == VARLINK_DISCONNECTED)
+ return -ENOTCONN;
+ if (!IN_SET(v->state, VARLINK_IDLE_CLIENT, VARLINK_AWAITING_REPLY))
+ return -EBUSY;
+
+ r = varlink_sanitize_parameters(¶meters);
+ if (r < 0)
+ return r;
+
+ r = json_build(&m, JSON_BUILD_OBJECT(
+ JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
+ JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters)),
+ JSON_BUILD_PAIR("oneway", JSON_BUILD_BOOLEAN(true))));
+ if (r < 0)
+ return r;
+
+ r = varlink_enqueue_json(v, m);
+ if (r < 0)
+ return r;
+
+ /* No state change here, this is one-way only after all */
+ v->timestamp = now(CLOCK_MONOTONIC);
+ return 0;
+}
+
+int varlink_sendb(Varlink *v, const char *method, ...) {
+ _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
+ va_list ap;
+ int r;
+
+ assert_return(v, -EINVAL);
+
+ va_start(ap, method);
+ r = json_buildv(¶meters, ap);
+ va_end(ap);
+
+ if (r < 0)
+ return r;
+
+ return varlink_send(v, method, parameters);
+}
+
+int varlink_invoke(Varlink *v, const char *method, JsonVariant *parameters) {
+ _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
+ int r;
+
+ assert_return(v, -EINVAL);
+ assert_return(method, -EINVAL);
+
+ if (v->state == VARLINK_DISCONNECTED)
+ return -ENOTCONN;
+ if (!IN_SET(v->state, VARLINK_IDLE_CLIENT, VARLINK_AWAITING_REPLY))
+ return -EBUSY;
+
+ r = varlink_sanitize_parameters(¶meters);
+ if (r < 0)
+ return r;
+
+ r = json_build(&m, JSON_BUILD_OBJECT(
+ JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
+ JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
+ if (r < 0)
+ return r;
+
+ r = varlink_enqueue_json(v, m);
+ if (r < 0)
+ return r;
+
+ varlink_set_state(v, VARLINK_AWAITING_REPLY);
+ v->n_pending++;
+ v->timestamp = now(CLOCK_MONOTONIC);
+
+ return 0;
+}
+
+int varlink_invokeb(Varlink *v, const char *method, ...) {
+ _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
+ va_list ap;
+ int r;
+
+ assert_return(v, -EINVAL);
+
+ va_start(ap, method);
+ r = json_buildv(¶meters, ap);
+ va_end(ap);
+
+ if (r < 0)
+ return r;
+
+ return varlink_invoke(v, method, parameters);
+}
+
+int varlink_call(
+ Varlink *v,
+ const char *method,
+ JsonVariant *parameters,
+ JsonVariant **ret_parameters,
+ const char **ret_error_id,
+ VarlinkReplyFlags *ret_flags) {
+
+ _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
+ int r;
+
+ assert_return(v, -EINVAL);
+ assert_return(method, -EINVAL);
+
+ if (v->state == VARLINK_DISCONNECTED)
+ return -ENOTCONN;
+ if (!IN_SET(v->state, VARLINK_IDLE_CLIENT))
+ return -EBUSY;
+
+ assert(v->n_pending == 0); /* n_pending can't be > 0 if we are in VARLINK_IDLE_CLIENT state */
+
+ r = varlink_sanitize_parameters(¶meters);
+ if (r < 0)
+ return r;
+
+ r = json_build(&m, JSON_BUILD_OBJECT(
+ JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)),
+ JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
+ if (r < 0)
+ return r;
+
+ r = varlink_enqueue_json(v, m);
+ if (r < 0)
+ return r;
+
+ varlink_set_state(v, VARLINK_CALLING);
+ v->n_pending++;
+ v->timestamp = now(CLOCK_MONOTONIC);
+
+ while (v->state == VARLINK_CALLING) {
+
+ r = varlink_process(v);
+ if (r < 0)
+ return r;
+ if (r > 0)
+ continue;
+
+ r = varlink_wait(v, USEC_INFINITY);
+ if (r < 0)
+ return r;
+ }
+
+ switch (v->state) {
+
+ case VARLINK_CALLED:
+ assert(v->current);
+
+ json_variant_unref(v->reply);
+ v->reply = TAKE_PTR(v->current);
+
+ varlink_set_state(v, VARLINK_IDLE_CLIENT);
+ assert(v->n_pending == 1);
+ v->n_pending--;
+
+ if (ret_parameters)
+ *ret_parameters = json_variant_by_key(v->reply, "parameters");
+ if (ret_error_id)
+ *ret_error_id = json_variant_string(json_variant_by_key(v->reply, "error"));
+ if (ret_flags)
+ *ret_flags = 0;
+
+ return 1;
+
+ case VARLINK_PENDING_DISCONNECT:
+ case VARLINK_DISCONNECTED:
+ return -ECONNRESET;
+
+ case VARLINK_PENDING_TIMEOUT:
+ return -ETIME;
+
+ default:
+ assert_not_reached("Unexpected state after method call.");
+ }
+}
+
+int varlink_callb(
+ Varlink *v,
+ const char *method,
+ JsonVariant **ret_parameters,
+ const char **ret_error_id,
+ VarlinkReplyFlags *ret_flags, ...) {
+
+ _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
+ va_list ap;
+ int r;
+
+ assert_return(v, -EINVAL);
+
+ va_start(ap, ret_flags);
+ r = json_buildv(¶meters, ap);
+ va_end(ap);
+
+ if (r < 0)
+ return r;
+
+ return varlink_call(v, method, parameters, ret_parameters, ret_error_id, ret_flags);
+}
+
+int varlink_reply(Varlink *v, JsonVariant *parameters) {
+ _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
+ int r;
+
+ assert_return(v, -EINVAL);
+
+ if (v->state == VARLINK_DISCONNECTED)
+ return -ENOTCONN;
+ if (!IN_SET(v->state,
+ VARLINK_PROCESSING_METHOD, VARLINK_PROCESSING_METHOD_MORE,
+ VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE))
+ return -EBUSY;
+
+ r = varlink_sanitize_parameters(¶meters);
+ if (r < 0)
+ return r;
+
+ r = json_build(&m, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
+ if (r < 0)
+ return r;
+
+ r = varlink_enqueue_json(v, m);
+ if (r < 0)
+ return r;
+
+ if (IN_SET(v->state, VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE)) {
+ /* We just replied to a method call that was let hanging for a while (i.e. we were outside of
+ * the varlink_dispatch_method() stack frame), which means with this reply we are ready to
+ * process further messages. */
+ v->current = json_variant_unref(v->current);
+ varlink_set_state(v, VARLINK_IDLE_SERVER);
+ } else
+ /* We replied to a method call from within the varlink_dispatch_method() stack frame), which
+ * means we should it handle the rest of the state engine. */
+ varlink_set_state(v, VARLINK_PROCESSED_METHOD);
+
+ return 1;
+}
+
+int varlink_replyb(Varlink *v, ...) {
+ _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
+ va_list ap;
+ int r;
+
+ assert_return(v, -EINVAL);
+
+ va_start(ap, v);
+ r = json_buildv(¶meters, ap);
+ va_end(ap);
+
+ if (r < 0)
+ return r;
+
+ return varlink_reply(v, parameters);
+}
+
+int varlink_error(Varlink *v, const char *error_id, JsonVariant *parameters) {
+ _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
+ int r;
+
+ assert_return(v, -EINVAL);
+ assert_return(error_id, -EINVAL);
+
+ if (v->state == VARLINK_DISCONNECTED)
+ return -ENOTCONN;
+ if (!IN_SET(v->state,
+ VARLINK_PROCESSING_METHOD, VARLINK_PROCESSING_METHOD_MORE,
+ VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE))
+ return -EBUSY;
+
+ r = varlink_sanitize_parameters(¶meters);
+ if (r < 0)
+ return r;
+
+ r = json_build(&m, JSON_BUILD_OBJECT(
+ JSON_BUILD_PAIR("error", JSON_BUILD_STRING(error_id)),
+ JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters))));
+ if (r < 0)
+ return r;
+
+ r = varlink_enqueue_json(v, m);
+ if (r < 0)
+ return r;
+
+ if (IN_SET(v->state, VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE)) {
+ v->current = json_variant_unref(v->current);
+ varlink_set_state(v, VARLINK_IDLE_SERVER);
+ } else
+ varlink_set_state(v, VARLINK_PROCESSED_METHOD);
+
+ return 1;
+}
+
+int varlink_errorb(Varlink *v, const char *error_id, ...) {
+ _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
+ va_list ap;
+ int r;
+
+ assert_return(v, -EINVAL);
+ assert_return(error_id, -EINVAL);
+
+ va_start(ap, error_id);
+ r = json_buildv(¶meters, ap);
+ va_end(ap);
+
+ if (r < 0)
+ return r;
+
+ return varlink_error(v, error_id, parameters);
+}
+
+int varlink_error_invalid_parameter(Varlink *v, JsonVariant *parameters) {
+
+ assert_return(v, -EINVAL);
+ assert_return(parameters, -EINVAL);
+
+ /* We expect to be called in one of two ways: the 'parameters' argument is a string variant in which
+ * case it is the parameter key name that is invalid. Or the 'parameters' argument is an object
+ * variant in which case we'll pull out the first key. The latter mode is useful in functions that
+ * don't expect any arguments. */
+
+ if (json_variant_is_string(parameters))
+ return varlink_error(v, VARLINK_ERROR_INVALID_PARAMETER, parameters);
+
+ if (json_variant_is_object(parameters) &&
+ json_variant_elements(parameters) > 0)
+ return varlink_error(v, VARLINK_ERROR_INVALID_PARAMETER,
+ json_variant_by_index(parameters, 0));
+
+ return -EINVAL;
+}
+
+int varlink_notify(Varlink *v, JsonVariant *parameters) {
+ _cleanup_(json_variant_unrefp) JsonVariant *m = NULL;
+ int r;
+
+ assert_return(v, -EINVAL);
+
+ if (v->state == VARLINK_DISCONNECTED)
+ return -ENOTCONN;
+ if (!IN_SET(v->state, VARLINK_PROCESSING_METHOD_MORE, VARLINK_PENDING_METHOD_MORE))
+ return -EBUSY;
+
+ r = varlink_sanitize_parameters(¶meters);
+ if (r < 0)
+ return r;
+
+ r = json_build(&m, JSON_BUILD_OBJECT(
+ JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters)),
+ JSON_BUILD_PAIR("continues", JSON_BUILD_BOOLEAN(true))));
+ if (r < 0)
+ return r;
+
+ r = varlink_enqueue_json(v, m);
+ if (r < 0)
+ return r;
+
+ /* No state change, as more is coming */
+ return 1;
+}
+
+int varlink_notifyb(Varlink *v, ...) {
+ _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL;
+ va_list ap;
+ int r;
+
+ assert_return(v, -EINVAL);
+
+ va_start(ap, v);
+ r = json_buildv(¶meters, ap);
+ va_end(ap);
+
+ if (r < 0)
+ return r;
+
+ return varlink_notify(v, parameters);
+}
+
+int varlink_bind_reply(Varlink *v, VarlinkReply callback) {
+ assert_return(v, -EINVAL);
+
+ if (callback && v->reply_callback && callback != v->reply_callback)
+ return -EBUSY;
+
+ v->reply_callback = callback;
+
+ return 0;
+}
+
+void* varlink_set_userdata(Varlink *v, void *userdata) {
+ void *old;
+
+ assert_return(v, NULL);
+
+ old = v->userdata;
+ v->userdata = userdata;
+
+ return old;
+}
+
+void* varlink_get_userdata(Varlink *v) {
+ assert_return(v, NULL);
+
+ return v->userdata;
+}
+
+static int varlink_acquire_ucred(Varlink *v) {
+ int r;
+
+ assert(v);
+
+ if (v->ucred_acquired)
+ return 0;
+
+ r = getpeercred(v->fd, &v->ucred);
+ if (r < 0)
+ return r;
+
+ v->ucred_acquired = true;
+ return 0;
+}
+
+int varlink_get_peer_uid(Varlink *v, uid_t *ret) {
+ int r;
+
+ assert_return(v, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ r = varlink_acquire_ucred(v);
+ if (r < 0)
+ return r;
+
+ if (!uid_is_valid(v->ucred.uid))
+ return -ENODATA;
+
+ *ret = v->ucred.uid;
+ return 0;
+}
+
+int varlink_get_peer_pid(Varlink *v, pid_t *ret) {
+ int r;
+
+ assert_return(v, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ r = varlink_acquire_ucred(v);
+ if (r < 0)
+ return r;
+
+ if (!pid_is_valid(v->ucred.pid))
+ return -ENODATA;
+
+ *ret = v->ucred.pid;
+ return 0;
+}
+
+int varlink_set_relative_timeout(Varlink *v, usec_t timeout) {
+ assert_return(v, -EINVAL);
+ assert_return(timeout > 0, -EINVAL);
+
+ v->timeout = timeout;
+ return 0;
+}
+
+VarlinkServer *varlink_get_server(Varlink *v) {
+ assert_return(v, NULL);
+
+ return v->server;
+}
+
+int varlink_set_description(Varlink *v, const char *description) {
+ assert_return(v, -EINVAL);
+
+ return free_and_strdup(&v->description, description);
+}
+
+static int io_callback(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+ Varlink *v = userdata;
+
+ assert(s);
+ assert(v);
+
+ handle_revents(v, revents);
+ (void) varlink_process(v);
+
+ return 1;
+}
+
+static int time_callback(sd_event_source *s, uint64_t usec, void *userdata) {
+ Varlink *v = userdata;
+
+ assert(s);
+ assert(v);
+
+ (void) varlink_process(v);
+ return 1;
+}
+
+static int defer_callback(sd_event_source *s, void *userdata) {
+ Varlink *v = userdata;
+
+ assert(s);
+ assert(v);
+
+ (void) varlink_process(v);
+ return 1;
+}
+
+static int prepare_callback(sd_event_source *s, void *userdata) {
+ Varlink *v = userdata;
+ int r, e;
+ usec_t until;
+
+ assert(s);
+ assert(v);
+
+ e = varlink_get_events(v);
+ if (e < 0)
+ return e;
+
+ r = sd_event_source_set_io_events(v->io_event_source, e);
+ if (r < 0)
+ return r;
+
+ r = varlink_get_timeout(v, &until);
+ if (r < 0)
+ return r;
+ if (r > 0) {
+ r = sd_event_source_set_time(v->time_event_source, until);
+ if (r < 0)
+ return r;
+ }
+
+ r = sd_event_source_set_enabled(v->time_event_source, r > 0 ? SD_EVENT_ON : SD_EVENT_OFF);
+ if (r < 0)
+ return r;
+
+ return 1;
+}
+
+static int quit_callback(sd_event_source *event, void *userdata) {
+ Varlink *v = userdata;
+
+ assert(event);
+ assert(v);
+
+ varlink_flush(v);
+ varlink_close(v);
+
+ return 1;
+}
+
+int varlink_attach_event(Varlink *v, sd_event *e, int64_t priority) {
+ int r;
+
+ assert_return(v, -EINVAL);
+ assert_return(!v->event, -EBUSY);
+
+ if (e)
+ v->event = sd_event_ref(e);
+ else {
+ r = sd_event_default(&v->event);
+ if (r < 0)
+ return r;
+ }
+
+ r = sd_event_add_time(v->event, &v->time_event_source, CLOCK_MONOTONIC, 0, 0, time_callback, v);
+ if (r < 0)
+ goto fail;
+
+ r = sd_event_source_set_priority(v->time_event_source, priority);
+ if (r < 0)
+ goto fail;
+
+ (void) sd_event_source_set_description(v->time_event_source, "varlink-time");
+
+ r = sd_event_add_exit(v->event, &v->quit_event_source, quit_callback, v);
+ if (r < 0)
+ goto fail;
+
+ r = sd_event_source_set_priority(v->quit_event_source, priority);
+ if (r < 0)
+ goto fail;
+
+ (void) sd_event_source_set_description(v->quit_event_source, "varlink-quit");
+
+ r = sd_event_add_io(v->event, &v->io_event_source, v->fd, 0, io_callback, v);
+ if (r < 0)
+ goto fail;
+
+ r = sd_event_source_set_prepare(v->io_event_source, prepare_callback);
+ if (r < 0)
+ goto fail;
+
+ r = sd_event_source_set_priority(v->io_event_source, priority);
+ if (r < 0)
+ goto fail;
+
+ (void) sd_event_source_set_description(v->io_event_source, "varlink-io");
+
+ r = sd_event_add_defer(v->event, &v->defer_event_source, defer_callback, v);
+ if (r < 0)
+ goto fail;
+
+ r = sd_event_source_set_priority(v->defer_event_source, priority);
+ if (r < 0)
+ goto fail;
+
+ (void) sd_event_source_set_description(v->defer_event_source, "varlink-defer");
+
+ return 0;
+
+fail:
+ varlink_detach_event(v);
+ return r;
+}
+
+
+void varlink_detach_event(Varlink *v) {
+ if (!v)
+ return;
+
+ varlink_detach_event_sources(v);
+
+ v->event = sd_event_unref(v->event);
+}
+
+sd_event *varlink_get_event(Varlink *v) {
+ assert_return(v, NULL);
+
+ return v->event;
+}
+
+int varlink_server_new(VarlinkServer **ret, VarlinkServerFlags flags) {
+ VarlinkServer *s;
+
+ assert_return(ret, -EINVAL);
+ assert_return((flags & ~_VARLINK_SERVER_FLAGS_ALL) == 0, -EINVAL);
+
+ s = new(VarlinkServer, 1);
+ if (!s)
+ return -ENOMEM;
+
+ *s = (VarlinkServer) {
+ .n_ref = 1,
+ .flags = flags,
+ .connections_max = varlink_server_connections_max(NULL),
+ .connections_per_uid_max = varlink_server_connections_per_uid_max(NULL),
+ };
+
+ *ret = s;
+ return 0;
+}
+
+static VarlinkServer* varlink_server_destroy(VarlinkServer *s) {
+ char *m;
+
+ if (!s)
+ return NULL;
+
+ varlink_server_shutdown(s);
+
+ while ((m = hashmap_steal_first_key(s->methods)))
+ free(m);
+
+ hashmap_free(s->methods);
+ hashmap_free(s->by_uid);
+
+ sd_event_unref(s->event);
+
+ free(s->description);
+
+ return mfree(s);
+}
+
+DEFINE_TRIVIAL_REF_UNREF_FUNC(VarlinkServer, varlink_server, varlink_server_destroy);
+
+static int validate_connection(VarlinkServer *server, const struct ucred *ucred) {
+ int allowed = -1;
+
+ assert(server);
+ assert(ucred);
+
+ if (FLAGS_SET(server->flags, VARLINK_SERVER_ROOT_ONLY))
+ allowed = ucred->uid == 0;
+
+ if (FLAGS_SET(server->flags, VARLINK_SERVER_MYSELF_ONLY))
+ allowed = allowed > 0 || ucred->uid == getuid();
+
+ if (allowed == 0) { /* Allow access when it is explicitly allowed or when neither
+ * VARLINK_SERVER_ROOT_ONLY nor VARLINK_SERVER_MYSELF_ONLY are specified. */
+ varlink_server_log(server, "Unprivileged client attempted connection, refusing.");
+ return 0;
+ }
+
+ if (server->n_connections >= server->connections_max) {
+ varlink_server_log(server, "Connection limit of %u reached, refusing.", server->connections_max);
+ return 0;
+ }
+
+ if (FLAGS_SET(server->flags, VARLINK_SERVER_ACCOUNT_UID)) {
+ unsigned c;
+
+ if (!uid_is_valid(ucred->uid)) {
+ varlink_server_log(server, "Client with invalid UID attempted connection, refusing.");
+ return 0;
+ }
+
+ c = PTR_TO_UINT(hashmap_get(server->by_uid, UID_TO_PTR(ucred->uid)));
+ if (c >= server->connections_per_uid_max) {
+ varlink_server_log(server, "Per-UID connection limit of %u reached, refusing.",
+ server->connections_per_uid_max);
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
+static int count_connection(VarlinkServer *server, struct ucred *ucred) {
+ unsigned c;
+ int r;
+
+ assert(server);
+ assert(ucred);
+
+ server->n_connections++;
+
+ if (FLAGS_SET(server->flags, VARLINK_SERVER_ACCOUNT_UID)) {
+ r = hashmap_ensure_allocated(&server->by_uid, NULL);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to allocate UID hash table: %m");
+
+ c = PTR_TO_UINT(hashmap_get(server->by_uid, UID_TO_PTR(ucred->uid)));
+
+ varlink_server_log(server, "Connections of user " UID_FMT ": %u (of %u max)",
+ ucred->uid, c, server->connections_per_uid_max);
+
+ r = hashmap_replace(server->by_uid, UID_TO_PTR(ucred->uid), UINT_TO_PTR(c + 1));
+ if (r < 0)
+ return log_debug_errno(r, "Failed to increment counter in UID hash table: %m");
+ }
+
+ return 0;
+}
+
+int varlink_server_add_connection(VarlinkServer *server, int fd, Varlink **ret) {
+ _cleanup_(varlink_unrefp) Varlink *v = NULL;
+ bool ucred_acquired;
+ struct ucred ucred;
+ int r;
+
+ assert_return(server, -EINVAL);
+ assert_return(fd >= 0, -EBADF);
+
+ if ((server->flags & (VARLINK_SERVER_ROOT_ONLY|VARLINK_SERVER_ACCOUNT_UID)) != 0) {
+ r = getpeercred(fd, &ucred);
+ if (r < 0)
+ return varlink_server_log_errno(server, r, "Failed to acquire peer credentials of incoming socket, refusing: %m");
+
+ ucred_acquired = true;
+
+ r = validate_connection(server, &ucred);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ return -EPERM;
+ } else
+ ucred_acquired = false;
+
+ r = varlink_new(&v);
+ if (r < 0)
+ return varlink_server_log_errno(server, r, "Failed to allocate connection object: %m");
+
+ r = count_connection(server, &ucred);
+ if (r < 0)
+ return r;
+
+ v->fd = fd;
+ v->userdata = server->userdata;
+ if (ucred_acquired) {
+ v->ucred = ucred;
+ v->ucred_acquired = true;
+ }
+
+ (void) asprintf(&v->description, "%s-%i", server->description ?: "varlink", v->fd);
+
+ /* Link up the server and the connection, and take reference in both directions. Note that the
+ * reference on the connection is left dangling. It will be dropped when the connection is closed,
+ * which happens in varlink_close(), including in the event loop quit callback. */
+ v->server = varlink_server_ref(server);
+ varlink_ref(v);
+
+ varlink_set_state(v, VARLINK_IDLE_SERVER);
+
+ r = varlink_attach_event(v, server->event, server->event_priority);
+ if (r < 0) {
+ varlink_log_errno(v, r, "Failed to attach new connection: %m");
+ v->fd = -1; /* take the fd out of the connection again */
+ varlink_close(v);
+ return r;
+ }
+
+ if (ret)
+ *ret = v;
+
+ return 0;
+}
+
+static int connect_callback(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
+ VarlinkServerSocket *ss = userdata;
+ _cleanup_close_ int cfd = -1;
+ Varlink *v = NULL;
+ int r;
+
+ assert(source);
+ assert(ss);
+
+ varlink_server_log(ss->server, "New incoming connection.");
+
+ cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
+ if (cfd < 0) {
+ if (ERRNO_IS_ACCEPT_AGAIN(errno))
+ return 0;
+
+ return varlink_server_log_errno(ss->server, errno, "Failed to accept incoming socket: %m");
+ }
+
+ r = varlink_server_add_connection(ss->server, cfd, &v);
+ if (r < 0)
+ return 0;
+
+ TAKE_FD(cfd);
+
+ if (ss->server->connect_callback) {
+ r = ss->server->connect_callback(ss->server, v, ss->server->userdata);
+ if (r < 0) {
+ varlink_log_errno(v, r, "Connection callback returned error, disconnecting client: %m");
+ varlink_close(v);
+ return 0;
+ }
+ }
+
+ return 0;
+}
+
+int varlink_server_listen_fd(VarlinkServer *s, int fd) {
+ _cleanup_free_ VarlinkServerSocket *ss = NULL;
+ int r;
+
+ assert_return(s, -EINVAL);
+ assert_return(fd >= 0, -EBADF);
+
+ r = fd_nonblock(fd, true);
+ if (r < 0)
+ return r;
+
+ ss = new(VarlinkServerSocket, 1);
+ if (!ss)
+ return -ENOMEM;
+
+ *ss = (VarlinkServerSocket) {
+ .server = s,
+ .fd = fd,
+ };
+
+ if (s->event) {
+ _cleanup_(sd_event_source_unrefp) sd_event_source *es = NULL;
+
+ r = sd_event_add_io(s->event, &es, fd, EPOLLIN, connect_callback, ss);
+ if (r < 0)
+ return r;
+
+ r = sd_event_source_set_priority(ss->event_source, s->event_priority);
+ if (r < 0)
+ return r;
+ }
+
+ LIST_PREPEND(sockets, s->sockets, TAKE_PTR(ss));
+ return 0;
+}
+
+int varlink_server_listen_address(VarlinkServer *s, const char *address, mode_t m) {
+ union sockaddr_union sockaddr;
+ _cleanup_close_ int fd = -1;
+ int r;
+
+ assert_return(s, -EINVAL);
+ assert_return(address, -EINVAL);
+ assert_return((m & ~0777) == 0, -EINVAL);
+
+ r = sockaddr_un_set_path(&sockaddr.un, address);
+ if (r < 0)
+ return r;
+
+ fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+ if (fd < 0)
+ return -errno;
+
+ (void) sockaddr_un_unlink(&sockaddr.un);
+
+ RUN_WITH_UMASK(~m & 0777)
+ if (bind(fd, &sockaddr.sa, SOCKADDR_UN_LEN(sockaddr.un)) < 0)
+ return -errno;
+
+ if (listen(fd, SOMAXCONN) < 0)
+ return -errno;
+
+ r = varlink_server_listen_fd(s, fd);
+ if (r < 0)
+ return r;
+
+ TAKE_FD(fd);
+ return 0;
+}
+
+void* varlink_server_set_userdata(VarlinkServer *s, void *userdata) {
+ void *ret;
+
+ assert_return(s, NULL);
+
+ ret = s->userdata;
+ s->userdata = userdata;
+
+ return ret;
+}
+
+void* varlink_server_get_userdata(VarlinkServer *s) {
+ assert_return(s, NULL);
+
+ return s->userdata;
+}
+
+static VarlinkServerSocket* varlink_server_socket_destroy(VarlinkServerSocket *ss) {
+ if (!ss)
+ return NULL;
+
+ if (ss->server)
+ LIST_REMOVE(sockets, ss->server->sockets, ss);
+
+ if (ss->event_source) {
+ (void) sd_event_source_set_enabled(ss->event_source, SD_EVENT_OFF);
+ sd_event_source_unref(ss->event_source);
+ }
+
+ free(ss->address);
+ safe_close(ss->fd);
+
+ return mfree(ss);
+}
+
+int varlink_server_shutdown(VarlinkServer *s) {
+ assert_return(s, -EINVAL);
+
+ while (s->sockets)
+ varlink_server_socket_destroy(s->sockets);
+
+ return 0;
+}
+
+int varlink_server_attach_event(VarlinkServer *s, sd_event *e, int64_t priority) {
+ VarlinkServerSocket *ss;
+ int r;
+
+ assert_return(s, -EINVAL);
+ assert_return(!s->event, -EBUSY);
+
+ if (e)
+ s->event = sd_event_ref(e);
+ else {
+ r = sd_event_default(&s->event);
+ if (r < 0)
+ return r;
+ }
+
+ LIST_FOREACH(sockets, ss, s->sockets) {
+ assert(!ss->event_source);
+
+ r = sd_event_add_io(s->event, &ss->event_source, ss->fd, EPOLLIN, connect_callback, ss);
+ if (r < 0)
+ goto fail;
+
+ r = sd_event_source_set_priority(ss->event_source, priority);
+ if (r < 0)
+ goto fail;
+ }
+
+ s->event_priority = priority;
+ return 0;
+
+fail:
+ varlink_server_detach_event(s);
+ return r;
+}
+
+int varlink_server_detach_event(VarlinkServer *s) {
+ VarlinkServerSocket *ss;
+
+ assert_return(s, -EINVAL);
+
+ LIST_FOREACH(sockets, ss, s->sockets) {
+
+ if (!ss->event_source)
+ continue;
+
+ (void) sd_event_source_set_enabled(ss->event_source, SD_EVENT_OFF);
+ ss->event_source = sd_event_source_unref(ss->event_source);
+ }
+
+ sd_event_unref(s->event);
+ return 0;
+}
+
+sd_event *varlink_server_get_event(VarlinkServer *s) {
+ assert_return(s, NULL);
+
+ return s->event;
+}
+
+int varlink_server_bind_method(VarlinkServer *s, const char *method, VarlinkMethod callback) {
+ char *m;
+ int r;
+
+ assert_return(s, -EINVAL);
+ assert_return(method, -EINVAL);
+ assert_return(callback, -EINVAL);
+
+ if (startswith(method, "org.varlink.service."))
+ return -EEXIST;
+
+ r = hashmap_ensure_allocated(&s->methods, &string_hash_ops);
+ if (r < 0)
+ return r;
+
+ m = strdup(method);
+ if (!m)
+ return -ENOMEM;
+
+ r = hashmap_put(s->methods, m, callback);
+ if (r < 0) {
+ free(m);
+ return r;
+ }
+
+ return 0;
+}
+
+int varlink_server_bind_method_many_internal(VarlinkServer *s, ...) {
+ va_list ap;
+ int r;
+
+ assert_return(s, -EINVAL);
+
+ va_start(ap, s);
+ for (;;) {
+ VarlinkMethod callback;
+ const char *method;
+
+ method = va_arg(ap, const char *);
+ if (!method)
+ break;
+
+ callback = va_arg(ap, VarlinkMethod);
+
+ r = varlink_server_bind_method(s, method, callback);
+ if (r < 0)
+ return r;
+ }
+
+ return 0;
+}
+
+int varlink_server_bind_connect(VarlinkServer *s, VarlinkConnect callback) {
+ assert_return(s, -EINVAL);
+
+ if (callback && s->connect_callback && callback != s->connect_callback)
+ return -EBUSY;
+
+ s->connect_callback = callback;
+ return 0;
+}
+
+unsigned varlink_server_connections_max(VarlinkServer *s) {
+ struct rlimit rl;
+
+ /* If a server is specified, return the setting for that server, otherwise the default value */
+ if (s)
+ return s->connections_max;
+
+ assert_se(getrlimit(RLIMIT_NOFILE, &rl) >= 0);
+
+ /* Make sure we never use up more than ¾th of RLIMIT_NOFILE for IPC */
+ if (VARLINK_DEFAULT_CONNECTIONS_MAX > rl.rlim_cur / 4 * 3)
+ return rl.rlim_cur / 4 * 3;
+
+ return VARLINK_DEFAULT_CONNECTIONS_MAX;
+}
+
+unsigned varlink_server_connections_per_uid_max(VarlinkServer *s) {
+ unsigned m;
+
+ if (s)
+ return s->connections_per_uid_max;
+
+ /* Make sure to never use up more than ¾th of available connections for a single user */
+ m = varlink_server_connections_max(NULL);
+ if (VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX > m)
+ return m / 4 * 3;
+
+ return VARLINK_DEFAULT_CONNECTIONS_PER_UID_MAX;
+}
+
+int varlink_server_set_connections_per_uid_max(VarlinkServer *s, unsigned m) {
+ assert_return(s, -EINVAL);
+ assert_return(m > 0, -EINVAL);
+
+ s->connections_per_uid_max = m;
+ return 0;
+}
+
+int varlink_server_set_connections_max(VarlinkServer *s, unsigned m) {
+ assert_return(s, -EINVAL);
+ assert_return(m > 0, -EINVAL);
+
+ s->connections_max = m;
+ return 0;
+}
+
+int varlink_server_set_description(VarlinkServer *s, const char *description) {
+ assert_return(s, -EINVAL);
+
+ return free_and_strdup(&s->description, description);
+}
projects / thirdparty / systemd.git / commitdiff
