gisi: Refactor the client API

The new client API is a convenience wrapper on the modem API for
clients.

2 files changed, 155 insertions, 817 deletions

diff --git a/gisi/client.c b/gisi/client.c
index 8c0cc72e..d1fad2ea 100644
--- a/gisi/client.c
+++ b/gisi/client.c
@@ -27,853 +27,250 @@
 #include <stdint.h>
 #include <string.h>
 #include <stdlib.h>
-#include <search.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <sys/uio.h>
 #include <errno.h>
-#include "phonet.h"
 #include <glib.h>
 
-#include "socket.h"
 #include "client.h"
 
-#define PN_COMMGR			0x10
-#define PNS_SUBSCRIBED_RESOURCES_IND	0x10
-
-static const struct sockaddr_pn commgr = {
-	.spn_family = AF_PHONET,
-	.spn_resource = PN_COMMGR,
-};
-
-struct _GIsiRequest {
-	unsigned int id; /* don't move, see g_isi_cmp */
+struct pending_data {
 	GIsiClient *client;
-	guint timeout;
-	GIsiResponseFunc func;
+	GIsiNotifyFunc notify;
 	void *data;
-	GDestroyNotify notify;
+	GDestroyNotify destroy;
 };
 
-struct _GIsiIndication {
-	unsigned int type; /* don't move, see g_isi_cmp */
-	GIsiIndicationFunc func;
-	void *data;
-};
-typedef struct _GIsiIndication GIsiIndication;
-
 struct _GIsiClient {
-	uint8_t resource;
-	uint16_t server_obj;
-	struct {
-		int major;
-		int minor;
-	} version;
 	GIsiModem *modem;
-	int error;
-
-	/* Requests */
-	struct {
-		int fd;
-		guint source;
-		unsigned int last; /* last used transaction ID */
-		void *pending;
-	} reqs;
-
-	/* Indications */
-	struct {
-		int fd;
-		guint source;
-		unsigned int count;
-		void *subs;
-	} inds;
-
-	/* Debugging */
-	GIsiDebugFunc debug_func;
-	void *debug_data;
+	uint8_t resource;
+	GSList *pending;
 };
 
-static gboolean g_isi_callback(GIOChannel *channel, GIOCondition cond,
-				gpointer data);
-static gboolean g_isi_timeout(gpointer data);
-
-static void g_isi_vdebug(const struct iovec *__restrict iov,
-				size_t iovlen, size_t total_len,
-				GIsiDebugFunc func, void *data)
+static void pending_destroy(gpointer data)
 {
-	uint8_t debug[total_len];
-	uint8_t *ptr = debug;
-	size_t i;
-
-	for (i = 0; i < iovlen; i++) {
-		memcpy(ptr, iov[i].iov_base, iov[i].iov_len);
-		ptr += iov[i].iov_len;
-	}
-
-	func(debug, total_len, data);
-}
+	struct pending_data *pd = data;
 
+	if (!pd)
+		return;
 
-static int g_isi_cmp(const void *a, const void *b)
-{
-	const unsigned int *ua = (const unsigned int *)a;
-	const unsigned int *ub = (const unsigned int *)b;
+	if (pd->destroy)
+		pd->destroy(pd->data);
 
-	return *ua - *ub;
+	g_free(pd);
 }
 
-/**
- * Create an ISI client.
- * @param resource PhoNet resource ID for the client
- * @return NULL on error (see errno), a GIsiClient pointer on success,
- */
-GIsiClient *g_isi_client_create(GIsiModem *modem, uint8_t resource)
+static void pending_resp_notify(const GIsiMessage *msg, void *data)
 {
-	GIsiClient *client;
-	GIOChannel *channel;
-
-	client  = g_try_new0(GIsiClient, 1);
-	if (client == NULL) {
-		errno = ENOMEM;
-		return NULL;
-	}
-
-	client->resource = resource;
-	client->version.major = -1;
-	client->version.minor = -1;
-	client->modem = modem;
-	client->error = 0;
-	client->debug_func = NULL;
-
-	client->reqs.last = 0;
-	client->reqs.pending = NULL;
+	struct pending_data *pd = data;
 
-	client->inds.count = 0;
-	client->inds.subs = NULL;
-
-	channel = phonet_new(modem, resource);
-	if (channel == NULL) {
-		g_free(client);
-		return NULL;
-	}
-	client->reqs.fd = g_io_channel_unix_get_fd(channel);
-	client->reqs.source = g_io_add_watch(channel,
-					G_IO_IN|G_IO_ERR|G_IO_HUP|G_IO_NVAL,
-					g_isi_callback, client);
-	g_io_channel_unref(channel);
-
-	return client;
-}
-
-/**
- * Set the ISI resource version of @a client.
- * @param client client for the resource
- * @param major ISI major version
- * @param minor ISI minor version
- */
-void g_isi_version_set(GIsiClient *client, int major, int minor)
-{
-	if (client == NULL)
+	if (!pd)
 		return;
 
-	client->version.major = major;
-	client->version.minor = minor;
-}
+	if (pd->notify)
+		pd->notify(msg, pd->data);
 
-/**
- * Returns the ISI major version of the resource associated with @a
- * client.
- * @param client client for the resource
- * @return major version, -1 if not available
- */
-int g_isi_version_major(GIsiClient *client)
-{
-	return client ? client->version.major : -1;
+	pd->client->pending = g_slist_remove(pd->client->pending,
+						g_isi_pending_from_msg(msg));
 }
 
-/**
- * Returns the ISI minor version of the resource associated with @a
- * client.
- * @param client client for the resource
- * @return minor version, -1 if not available
- */
-int g_isi_version_minor(GIsiClient *client)
+static void pending_notify(const GIsiMessage *msg, void *data)
 {
-	return client ? client->version.minor : -1;
-}
+	struct pending_data *pd = data;
 
-/**
- * Set the server object for the resource associated with @a
- * client.
- * @param client client for the resource
- * @param server object
- */
-void g_isi_server_object_set(GIsiClient *client, uint16_t obj)
-{
-	if (client == NULL)
+	if (!pd)
 		return;
 
-	client->server_obj = obj;
+	if (pd->notify)
+		pd->notify(msg, pd->data);
 }
 
-/**
- * Returns the server object for the the resource associated with @a
- * client.
- * @param client client for the resource
- * @return server object
- */
-uint8_t g_isi_server_object(GIsiClient *client)
-{
-	return client ? client->server_obj : 0;
-}
-
-/**
- * Returns the resource associated with @a client
- * @param client client for the resource
- * @return PhoNet resource ID for the client
- */
 uint8_t g_isi_client_resource(GIsiClient *client)
 {
 	return client ? client->resource : 0;
 }
 
-/**
- * Set a debugging function for @a client. This function will be
- * called whenever an ISI protocol message is sent or received.
- * @param client client to debug
- * @param func debug function
- * @param opaque user data
- */
-void g_isi_client_set_debug(GIsiClient *client, GIsiDebugFunc func,
-				void *opaque)
+GIsiModem *g_isi_client_modem(GIsiClient *client)
 {
-	if (client == NULL)
-		return;
-
-	client->debug_func = func;
-	client->debug_data = opaque;
+	return client ? client->modem : NULL;
 }
 
-static void g_isi_cleanup_req(void *data)
+GIsiClient *g_isi_client_create(GIsiModem *modem, uint8_t resource)
 {
-	GIsiRequest *req = data;
-
-	if (req == NULL)
-		return;
+	GIsiClient *client;
 
-	/* Finalize any pending requests */
-	req->client->error = ESHUTDOWN;
-	if (req->func)
-		req->func(req->client, NULL, 0, 0, req->data);
-	req->client->error = 0;
+	if (!modem) {
+		errno = EINVAL;
+		return NULL;
+	}
 
-	if (req->notify)
-		req->notify(req->data);
+	client  = g_try_new0(GIsiClient, 1);
+	if (!client) {
+		errno = ENOMEM;
+		return NULL;
+	}
 
-	if (req->timeout > 0)
-		g_source_remove(req->timeout);
+	client->resource = resource;
+	client->modem = modem;
+	client->pending = NULL;
 
-	g_free(req);
+	return client;
 }
 
-static void g_isi_cleanup_ind(void *data)
+static void foreach_destroy(gpointer value, gpointer user)
 {
-	GIsiIndication *ind = data;
+	GIsiPending *op = value;
+	GIsiClient *client = user;
 
-	if (ind == NULL)
+	if (!op || !client)
 		return;
 
-	g_free(ind);
+	client->pending = g_slist_remove(client->pending, op);
+	g_isi_pending_remove(op);
 }
 
-/**
- * Destroys an ISI client, cancels all pending transactions and subscriptions.
- * @param client client to destroy (may be NULL)
- */
 void g_isi_client_destroy(GIsiClient *client)
 {
 	if (client == NULL)
 		return;
 
-	tdestroy(client->reqs.pending, g_isi_cleanup_req);
-	if (client->reqs.source > 0)
-		g_source_remove(client->reqs.source);
-
-	tdestroy(client->inds.subs, g_isi_cleanup_ind);
-	client->inds.subs = NULL;
-	client->inds.count = 0;
-	g_isi_commit_subscriptions(client);
-	if (client->inds.source > 0)
-		g_source_remove(client->inds.source);
-
+	g_slist_foreach(client->pending, foreach_destroy, client);
+	g_slist_free(client->pending);
 	g_free(client);
 }
 
-/**
- * Make an ISI request and register a callback to process the response(s) to
- * the resulting transaction.
- * @param cl ISI client (from g_isi_client_create())
- * @param buf pointer to request payload
- * @param len request payload byte length
- * @param timeout timeout in seconds
- * @param cb callback to process response(s)
- * @param opaque data for the callback
- */
-GIsiRequest *g_isi_request_make(GIsiClient *client, const void *__restrict buf,
-				size_t len, unsigned timeout,
-				GIsiResponseFunc cb, void *opaque)
+static struct pending_data *pending_data_create(GIsiClient *client,
+						GIsiNotifyFunc notify,
+						void *data,
+						GDestroyNotify destroy)
 {
-	return g_isi_send(client, buf, len, timeout, cb, opaque, NULL);
-}
-
-/**
- * Make an ISI request and register a callback to process the response(s) to
- * the resulting transaction.
- * @param cl ISI client (from g_isi_client_create())
- * @param iov scatter-gather array to the request payload
- * @param iovlen number of vectors in the scatter-gather array
- * @param timeout timeout in seconds
- * @param cb callback to process response(s)
- * @param opaque data for the callback
- */
-GIsiRequest *g_isi_request_vmake(GIsiClient *client, const struct iovec *iov,
-					size_t iovlen, unsigned timeout,
-					GIsiResponseFunc func, void *opaque)
-{
-	return g_isi_vsend(client, iov, iovlen, timeout, func, opaque, NULL);
-}
-
-/**
- * Send an ISI request to a specific Phonet address and register a callback
- * to process the response(s) to the resulting transaction.
- *
- * @param client ISI client (from g_isi_client_create())
- * @param dst Phonet destination address
- * @param buf pointer to request payload
- * @param len request payload byte length
- * @param timeout timeout in seconds
- * @param cb callback to process response(s)
- * @param opaque data for the callback
- * @param notify finalizer function for the @a opaque data (may be NULL)
- *
- * @return
- * A pointer to a newly created GIsiRequest.
- *
- * @errors
- * If an error occurs, @a errno is set accordingly and a NULL pointer is
- * returned.
- */
-GIsiRequest *g_isi_sendto(GIsiClient *client,
-				struct sockaddr_pn *dst,
-				const void *__restrict buf, size_t len,
-				unsigned timeout,
-				GIsiResponseFunc cb, void *opaque,
-				GDestroyNotify notify)
-{
-	const struct iovec iov = {
-		.iov_base = (void *)buf,
-		.iov_len = len,
-	};
-
-	return g_isi_vsendto(client, dst, &iov, 1, timeout, cb, opaque, notify);
-}
-
-
-/**
- * Send an ISI request and register a callback to process the response(s) to
- * the resulting transaction.
- *
- * @param cl ISI client (from g_isi_client_create())
- * @param buf pointer to request payload
- * @param len request payload byte length
- * @param timeout timeout in seconds
- * @param cb callback to process response(s)
- * @param opaque data for the callback
- * @param notify finalizer function for the @a opaque data (may be NULL)
- *
- * @return
- * A pointer to a newly created GIsiRequest.
- *
- * @errors
- * If an error occurs, @a errno is set accordingly and a NULL pointer is
- * returned.
- */
-GIsiRequest *g_isi_send(GIsiClient *client,
-			const void *__restrict buf, size_t len,
-			unsigned timeout,
-			GIsiResponseFunc cb, void *opaque,
-			GDestroyNotify notify)
-{
-	const struct iovec iov = {
-		.iov_base = (void *)buf,
-		.iov_len = len,
-	};
-
-	return g_isi_vsend(client, &iov, 1, timeout, cb, opaque, notify);
-}
-
-
-/**
- * Send an ISI request to a specific Phonet address and register a callback
- * to process the response(s) to the resulting transaction.
- *
- * @param client ISI client (from g_isi_client_create())
- * @param dst Phonet destination address
- * @param iov scatter-gather array to the request payload
- * @param iovlen number of vectors in the scatter-gather array
- * @param timeout timeout in seconds
- * @param cb callback to process response(s)
- * @param opaque data for the callback
- * @param notify finalizer function for the @a opaque data (may be NULL)
- *
- * @return
- * A pointer to a newly created GIsiRequest.
- *
- * @errors
- * If an error occurs, @a errno is set accordingly and a NULL pointer is
- * returned.
- */
-GIsiRequest *g_isi_vsendto(GIsiClient *client,
-				struct sockaddr_pn *dst,
-				const struct iovec *__restrict iov,
-				size_t iovlen, unsigned timeout,
-				GIsiResponseFunc cb, void *opaque,
-				GDestroyNotify notify)
-{
-	struct iovec _iov[1 + iovlen];
-	struct msghdr msg = {
-		.msg_name = (void *)dst,
-		.msg_namelen = sizeof(*dst),
-		.msg_iov = _iov,
-		.msg_iovlen = 1 + iovlen,
-		.msg_control = NULL,
-		.msg_controllen = 0,
-		.msg_flags = 0,
-	};
-	ssize_t ret;
-	size_t i, len;
-	unsigned int key;
-	uint8_t id;
-
-	GIsiRequest *req = NULL;
-	GIsiRequest **old;
+	struct pending_data *pd;
 
 	if (client == NULL) {
 		errno = EINVAL;
 		return NULL;
 	}
 
-	key = 1 + ((client->reqs.last + 1) % 255);
-
-	if (cb) {
-		req = g_try_new0(GIsiRequest, 1);
-		if (req == NULL) {
-			errno = ENOMEM;
-			return NULL;
-		}
-
-		req->client = client;
-		req->id = key;
-		req->func = cb;
-		req->data = opaque;
-		req->notify = notify;
-
-		old = tsearch(req, &client->reqs.pending, g_isi_cmp);
-		if (old == NULL) {
-			errno = ENOMEM;
-			goto error;
-		}
-		if (*old == req)
-			old = NULL;
-
-	} else
-		old = tfind(&key, &client->reqs.pending, g_isi_cmp);
-
-	if (old) {
-		/* FIXME: perhaps retry with randomized access after
-		 * initial miss. Although if the rate at which
-		 * requests are sent is so high that the transaction
-		 * ID wraps it's likely there is something wrong and
-		 * we might as well fail here. */
-		errno = EBUSY;
-		goto error;
+	pd = g_try_new0(struct pending_data, 1);
+	if (!pd) {
+		errno = ENOMEM;
+		return NULL;
 	}
 
-	id = key;
-	_iov[0].iov_base = &id;
-	_iov[0].iov_len = 1;
+	pd->client = client;
+	pd->notify = notify;
+	pd->data = data;
+	pd->destroy = destroy;
 
-	for (i = 0, len = 1; i < iovlen; i++) {
-		_iov[1 + i] = iov[i];
-		len += iov[i].iov_len;
-	}
+	return pd;
+}
 
-	if (client->debug_func)
-		g_isi_vdebug(iov, iovlen, len - 1, client->debug_func,
-				client->debug_data);
+GIsiPending *g_isi_client_send(GIsiClient *client, const void *__restrict buf,
+				size_t len, unsigned timeout,
+				GIsiNotifyFunc notify, void *data,
+				GDestroyNotify destroy)
+{
+	struct pending_data *pd;
+	GIsiPending *op;
 
-	ret = sendmsg(client->reqs.fd, &msg, MSG_NOSIGNAL);
-	if (ret == -1)
-		goto error;
+	pd = pending_data_create(client, notify, data, destroy);
+	if (!pd)
+		return NULL;
 
-	if (ret != (ssize_t)len) {
-		errno = EMSGSIZE;
-		goto error;
+	op = g_isi_request_send(client->modem, client->resource, buf, len, timeout,
+				pending_resp_notify, pd, pending_destroy);
+	if (!op) {
+		g_free(pd);
+		return NULL;
 	}
 
-	if (req && timeout)
-		req->timeout = g_timeout_add_seconds(timeout, g_isi_timeout,
-							req);
-	client->reqs.last = key;
-	return req;
-
-error:
-	tdelete(req, &client->reqs.pending, g_isi_cmp);
-	g_free(req);
-
-	return NULL;
+	client->pending = g_slist_append(client->pending, op);
+	return op;
 }
 
-/**
- * Send an ISI request and register a callback to process the response(s) to
- * the resulting transaction.
- *
- * @param cl ISI client (from g_isi_client_create())
- * @param iov scatter-gather array to the request payload
- * @param iovlen number of vectors in the scatter-gather array
- * @param timeout timeout in seconds
- * @param cb callback to process response(s)
- * @param opaque data for the callback
- * @param notify finalizer function for the @a opaque data (may be NULL)
- *
- * @return
- * A pointer to a newly created GIsiRequest.
- *
- * @errors
- * If an error occurs, @a errno is set accordingly and a NULL pointer is
- * returned.
- */
-GIsiRequest *g_isi_vsend(GIsiClient *client,
+GIsiPending *g_isi_client_vsend(GIsiClient *client,
 				const struct iovec *__restrict iov,
 				size_t iovlen, unsigned timeout,
-				GIsiResponseFunc cb, void *opaque,
-				GDestroyNotify notify)
+				GIsiNotifyFunc notify, void *data,
+				GDestroyNotify destroy)
 {
-	struct sockaddr_pn dst = {
-		.spn_family = AF_PHONET,
-	};
+	struct pending_data *pd;
+	GIsiPending *op;
 
-	if (client == NULL) {
-		errno = EINVAL;
+	pd = pending_data_create(client, notify, data, destroy);
+	if (!pd)
 		return NULL;
-	}
-
-	dst.spn_resource = client->resource;
-
-	return g_isi_vsendto(client, &dst, iov, iovlen, timeout,
-				cb, opaque, notify);
-}
-
-/**
- * Cancels a pending request, i.e. stop waiting for responses and cancels the
- * timeout.
- * @param req request to cancel
- */
-void g_isi_request_cancel(GIsiRequest *req)
-{
-	if (req == NULL)
-		return;
 
-	if (req->timeout > 0)
-		g_source_remove(req->timeout);
-
-	tdelete(req, &req->client->reqs.pending, g_isi_cmp);
-
-	if (req->notify)
-		req->notify(req->data);
-
-	g_free(req);
-}
-
-static uint8_t *__msg;
-static void build_subscribe_msg(const void *nodep,
-				const VISIT which,
-				const int depth)
-{
-	GIsiIndication *ind = *(GIsiIndication **)nodep;
-	uint8_t res = ind->type >> 8;
-
-	switch (which) {
-	case postorder:
-	case leaf:
-		if (__msg[2] && res == __msg[2+__msg[2]])
-			break;
-		__msg[2]++;
-		__msg[2+__msg[2]] = res;
-		break;
-	default:
-		break;
-	}
-}
-
-/**
- * Subscribe indications from the modem.
- * @param client ISI client (from g_isi_client_create())
- * @return 0 on success, a system error code otherwise.
- */
-int g_isi_commit_subscriptions(GIsiClient *client)
-{
-	GIOChannel *channel;
-	uint8_t msg[3+256] = {
-		0, PNS_SUBSCRIBED_RESOURCES_IND,
-		0,
-	};
-
-	if (client == NULL)
-		return -EINVAL;
-
-	if (!client->inds.source) {
-		if (client->inds.count == 0)
-			return 0;
-
-		channel = phonet_new(client->modem, PN_COMMGR);
-		if (channel == NULL)
-			return -errno;
-
-		client->inds.fd = g_io_channel_unix_get_fd(channel);
-
-		client->inds.source = g_io_add_watch(channel,
-						G_IO_IN|G_IO_ERR|
-						G_IO_HUP|G_IO_NVAL,
-						g_isi_callback, client);
-
-		g_io_channel_unref(channel);
+	op = g_isi_request_vsend(client->modem, client->resource, iov, iovlen,
+					timeout, pending_resp_notify, pd,
+					pending_destroy);
+	if (!op) {
+		g_free(pd);
+		return NULL;
 	}
 
-	__msg = msg;
-	twalk(client->inds.subs, build_subscribe_msg);
-
-	/* Subscribe by sending an indication */
-	sendto(client->inds.fd, msg, 3+msg[2], MSG_NOSIGNAL, (void *)&commgr,
-		sizeof(commgr));
-	return 0;
+	client->pending = g_slist_append(client->pending, op);
+	return op;
 }
 
-/**
- * Add subscription for a given indication type from the given resource.
- * If the same type was already subscribed, the old subscription
- * is overriden. Subscriptions for newly added resources do not become
- * effective until g_isi_commit_subscriptions() has been called.
- * @param client ISI client (from g_isi_client_create())
- * @param res resource id
- * @param type indication type
- * @param cb callback to process received indications
- * @param data data for the callback
- * @return 0 on success, a system error code otherwise.
- */
-int g_isi_add_subscription(GIsiClient *client, uint8_t res, uint8_t type,
-				GIsiIndicationFunc cb, void *data)
+GIsiPending *g_isi_client_ind_subscribe(GIsiClient *client, uint8_t type,
+					GIsiNotifyFunc notify, void *data)
 {
-	GIsiIndication *ind;
-	GIsiIndication **old;
-
-	if (client == NULL || cb == NULL)
-		return -EINVAL;
+	struct pending_data *pd;
+	GIsiPending *op;
 
-	ind = g_try_new0(GIsiIndication, 1);
-	if (ind == NULL)
-		return -ENOMEM;
-
-	ind->type = (res << 8) | type;
+	pd = pending_data_create(client, notify, data, NULL);
+	if (!pd)
+		return NULL;
 
-	old = tsearch(ind, &client->inds.subs, g_isi_cmp);
-	if (old == NULL) {
-		g_free(ind);
-		return -ENOMEM;
+	op = g_isi_ind_subscribe(client->modem, client->resource, type,
+					pending_notify, pd, pending_destroy);
+	if (!op) {
+		g_free(pd);
+		return NULL;
 	}
 
-	/* FIXME: This overrides any existing subscription. We should
-	 * enable multiple subscriptions to a single indication in
-	 * order to allow efficient client sharing. */
-	if (*old != ind) {
-		g_free(ind);
-		ind = *old;
-	} else
-		client->inds.count++;
-
-	ind->func = cb;
-	ind->data = data;
-
-	return 0;
-}
-
-/**
- * Subscribe to a given indication type for the resource that an ISI client
- * is associated with. If the same type was already subscribed, the old
- * subscription is overriden. For multiple subscriptions,
- * g_isi_add_subcription() and g_isi_commit_subscriptions() should be used
- * instead.
- * @param cl ISI client (from g_isi_client_create())
- * @param type indication type
- * @param cb callback to process received indications
- * @param data data for the callback
- * @return 0 on success, a system error code otherwise.
- */
-int g_isi_subscribe(GIsiClient *client, uint8_t type,
-			GIsiIndicationFunc cb, void *data)
-{
-	int ret;
-
-	if (client == NULL)
-		return -EINVAL;
-
-	ret = g_isi_add_subscription(client, client->resource, type, cb, data);
-	if (ret)
-		return ret;
-
-	return g_isi_commit_subscriptions(client);
-}
-
-/**
- * Remove subscription for a given indication type from the given resource.
- * g_isi_commit_subcsriptions() should be called after modifications to
- * cancel unnecessary resource subscriptions from the modem.
- * @param client ISI client (from g_isi_client_create())
- * @param res resource id
- * @param type indication type
- */
-void g_isi_remove_subscription(GIsiClient *client, uint8_t res, uint8_t type)
-{
-	void *ret;
-	GIsiIndication *ind;
-	unsigned int id = (res << 8) | type;
-
-	if (client == NULL)
-		return;
-
-	ret = tfind(&id, &client->inds.subs, g_isi_cmp);
-	if (ret == NULL)
-		return;
-
-	ind = *(GIsiIndication **)ret;
-	tdelete(ind, &client->inds.subs, g_isi_cmp);
-	client->inds.count--;
-	g_free(ind);
+	client->pending = g_slist_append(client->pending, op);
+	return op;
 }
 
-/**
- * Unsubscribe from a given indication type. For removing multiple
- * subscriptions, g_isi_remove_subcription() and
- * g_isi_commit_subscriptions() should be used instead.
- * @param client ISI client (from g_isi_client_create())
- * @param type indication type.
- */
-void g_isi_unsubscribe(GIsiClient *client, uint8_t type)
+GIsiPending *g_isi_client_ntf_subscribe(GIsiClient *client, uint8_t type,
+					GIsiNotifyFunc notify, void *data)
 {
-	if (client == NULL)
-		return;
+	struct pending_data *pd;
+	GIsiPending *op;
 
-	g_isi_remove_subscription(client, client->resource, type);
-	g_isi_commit_subscriptions(client);
-}
-
-static void g_isi_dispatch_indication(GIsiClient *client, uint8_t res,
-					uint16_t obj, uint8_t *msg,
-					size_t len)
-{
-	void *ret;
-	GIsiIndication *ind;
-	unsigned type = (res << 8) | msg[0];
-
-	ret = tfind(&type, &client->inds.subs, g_isi_cmp);
-	if (ret == NULL)
-		return;
-
-	ind = *(GIsiIndication **)ret;
-
-	if (ind->func)
-		ind->func(client, msg, len, obj, ind->data);
-}
+	pd = pending_data_create(client, notify, data, NULL);
+	if (!pd)
+		return NULL;
 
-static void g_isi_dispatch_response(GIsiClient *client, uint8_t res,
-					uint16_t obj, uint8_t *msg,
-					size_t len)
-{
-	void *ret;
-	GIsiRequest *req;
-	unsigned id = msg[0];
-
-	ret = tfind(&id, &client->reqs.pending, g_isi_cmp);
-	if (ret == NULL) {
-		/* This could either be an unsolicited response, which
-		 * we will ignore, or an incoming request, which we
-		 * handle just like an incoming indication */
-		g_isi_dispatch_indication(client, res, obj, msg + 1, len - 1);
-		return;
+	op = g_isi_ntf_subscribe(client->modem, client->resource, type,
+					pending_notify, pd, pending_destroy);
+	if (!op) {
+		g_free(pd);
+		return NULL;
 	}
 
-	req = *(GIsiRequest **)ret;
-
-	if (!req->func || req->func(client, msg + 1, len - 1, obj, req->data))
-		g_isi_request_cancel(req);
+	client->pending = g_slist_append(client->pending, op);
+	return op;
 }
 
-/* Data callback for both responses and indications */
-static gboolean g_isi_callback(GIOChannel *channel, GIOCondition cond,
-				gpointer data)
+GIsiPending *g_isi_client_verify(GIsiClient *client, GIsiNotifyFunc notify,
+					void *data, GDestroyNotify destroy)
 {
-	GIsiClient *client = data;
-	int fd = g_io_channel_unix_get_fd(channel);
-	int len;
-
-	if (cond & (G_IO_NVAL|G_IO_HUP)) {
-		g_warning("Unexpected event on Phonet channel %p", channel);
-		return FALSE;
-	}
-
-	len = phonet_peek_length(channel);
+	struct pending_data *pd;
+	GIsiPending *op;
 
-	if (len > 0) {
-		uint32_t buf[(len + 3) / 4];
-		uint8_t *msg;
-		uint16_t obj;
-		uint8_t res;
-
-		len = phonet_read(channel, buf, len, &obj, &res);
-		if (len < 2)
-			return TRUE;
-
-		msg = (uint8_t *)buf;
-
-		if (client->debug_func)
-			client->debug_func(msg + 1, len - 1,
-						client->debug_data);
+	pd = pending_data_create(client, notify, data, destroy);
+	if (!pd)
+		return NULL;
 
-		if (fd == client->reqs.fd)
-			g_isi_dispatch_response(client, res, obj, msg, len);
-		else
-			/* Transaction field at first byte is
-			 * discarded with indications */
-			g_isi_dispatch_indication(client, res, obj, msg + 1,
-							len - 1);
+	op = g_isi_resource_ping(client->modem, client->resource,
+					pending_resp_notify, pd,
+					pending_destroy);
+	if (!op) {
+		g_free(pd);
+		return NULL;
 	}
-	return TRUE;
-}
 
-static gboolean g_isi_timeout(gpointer data)
-{
-	GIsiRequest *req = data;
-
-	req->client->error = ETIMEDOUT;
-	if (req->func)
-		req->func(req->client, NULL, 0, 0, req->data);
-	req->client->error = 0;
-
-	g_isi_request_cancel(req);
-	return FALSE;
-}
-
-int g_isi_client_error(const GIsiClient *client)
-{
-	return -client->error;
+	client->pending = g_slist_append(client->pending, op);
+	return op;
 }
diff --git a/gisi/client.h b/gisi/client.h
index 16c459f0..51acf0aa 100644
--- a/gisi/client.h
+++ b/gisi/client.h
@@ -28,93 +28,34 @@ extern "C" {
 
 #include <stdint.h>
 #include <glib/gtypes.h>
-#include <gisi/modem.h>
-#include "phonet.h"
+
+#include "modem.h"
 
 struct _GIsiClient;
 typedef struct _GIsiClient GIsiClient;
 
-struct _GIsiRequest;
-typedef struct _GIsiRequest GIsiRequest;
-
-typedef void (*GIsiVerifyFunc)(GIsiClient *client, gboolean alive,
-				uint16_t object, void *opaque);
-
-typedef gboolean (*GIsiResponseFunc)(GIsiClient *client,
-					const void *restrict data, size_t len,
-					uint16_t object, void *opaque);
-
-typedef void (*GIsiIndicationFunc) (GIsiClient *client,
-					const void *restrict data, size_t len,
-					uint16_t object, void *opaque);
-
 GIsiClient *g_isi_client_create(GIsiModem *modem, uint8_t resource);
-
-GIsiRequest *g_isi_verify(GIsiClient *client, GIsiVerifyFunc func,
-				void *opaque);
-
-GIsiRequest *g_isi_verify_resource(GIsiClient *client, uint8_t resource,
-					GIsiVerifyFunc func, void *opaque);
-
+GIsiModem *g_isi_client_modem(GIsiClient *client);
 uint8_t g_isi_client_resource(GIsiClient *client);
-
-void g_isi_version_set(GIsiClient *client, int major, int minor);
-int g_isi_version_major(GIsiClient *client);
-int g_isi_version_minor(GIsiClient *client);
-
-void g_isi_server_object_set(GIsiClient *client, uint16_t obj);
-uint8_t g_isi_server_object(GIsiClient *client);
-
-void g_isi_client_set_debug(GIsiClient *client, GIsiDebugFunc func,
-				void *opaque);
-
 void g_isi_client_destroy(GIsiClient *client);
 
-int g_isi_client_error(const GIsiClient *client);
-
-GIsiRequest *g_isi_request_make(GIsiClient *client, const void *data,
+GIsiPending *g_isi_client_send(GIsiClient *client, const void *__restrict msg,
 				size_t len, unsigned timeout,
-				GIsiResponseFunc func, void *opaque);
-struct iovec;
-GIsiRequest *g_isi_request_vmake(GIsiClient *client, const struct iovec *iov,
-					size_t iovlen, unsigned timeout,
-					GIsiResponseFunc func, void *opaque);
-
-GIsiRequest *g_isi_sendto(GIsiClient *client,
-				struct sockaddr_pn *dst,
-				const void *data, size_t len,
-				unsigned timeout,
-				GIsiResponseFunc func, void *opaque,
-				GDestroyNotify notify);
-
-GIsiRequest *g_isi_send(GIsiClient *client, const void *data, size_t len,
-			unsigned timeout,
-			GIsiResponseFunc func, void *opaque,
-			GDestroyNotify notify);
-
-GIsiRequest *g_isi_vsendto(GIsiClient *client,
-				struct sockaddr_pn *dst,
-				const struct iovec *iov, size_t iovlen,
-				unsigned timeout,
-				GIsiResponseFunc func, void *opaque,
-				GDestroyNotify notify);
-
-GIsiRequest *g_isi_vsend(GIsiClient *client,
-				const struct iovec *iov, size_t iovlen,
-				unsigned timeout,
-				GIsiResponseFunc func, void *opaque,
-				GDestroyNotify notify);
+				GIsiNotifyFunc notify, void *data,
+				GDestroyNotify destroy);
 
-void g_isi_request_cancel(GIsiRequest *req);
+GIsiPending *g_isi_client_vsend(GIsiClient *client, const struct iovec *iov,
+				size_t iovlen, unsigned timeout,
+				GIsiNotifyFunc notify, void *data,
+				GDestroyNotify destroy);
 
-int g_isi_commit_subscriptions(GIsiClient *client);
-int g_isi_add_subscription(GIsiClient *client, uint8_t res, uint8_t type,
-				GIsiIndicationFunc cb, void *data);
-void g_isi_remove_subscription(GIsiClient *client, uint8_t res, uint8_t type);
+GIsiPending *g_isi_client_ind_subscribe(GIsiClient *client, uint8_t type,
+					GIsiNotifyFunc notify, void *data);
+GIsiPending *g_isi_client_ntf_subscribe(GIsiClient *client, uint8_t type,
+					GIsiNotifyFunc notify, void *data);
 
-int g_isi_subscribe(GIsiClient *client, uint8_t type,
-			GIsiIndicationFunc func, void *opaque);
-void g_isi_unsubscribe(GIsiClient *client, uint8_t type);
+GIsiPending *g_isi_client_verify(GIsiClient *client, GIsiNotifyFunc notify,
+					void *data, GDestroyNotify destroy);
 
 #ifdef __cplusplus
 }