contrib/ivshmem-client/ivshmem-client.c - third_party/qemu - Git at Google

 /*
  * Copyright 6WIND S.A., 2014
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or
  * (at your option) any later version.  See the COPYING file in the
  * top-level directory.
  */

 #include "qemu/osdep.h"
 #include <sys/socket.h>
 #include <sys/un.h>

 #include "qemu/queue.h"

 #include "ivshmem-client.h"

 /* log a message on stdout if verbose=1 */
 #define IVSHMEM_CLIENT_DEBUG(client, fmt, ...) do { \
         if ((client)->verbose) {         \
             printf(fmt, ## __VA_ARGS__); \
         }                                \
     } while (0)

 /* read message from the unix socket */
 static int
 ivshmem_client_read_one_msg(IvshmemClient *client, int64_t *index, int *fd)
 {
     int ret;
     struct msghdr msg;
     struct iovec iov[1];
     union {
         struct cmsghdr cmsg;
         char control[CMSG_SPACE(sizeof(int))];
     } msg_control;
     struct cmsghdr *cmsg;

     iov[0].iov_base = index;
     iov[0].iov_len = sizeof(*index);

     memset(&msg, 0, sizeof(msg));
     msg.msg_iov = iov;
     msg.msg_iovlen = 1;
     msg.msg_control = &msg_control;
     msg.msg_controllen = sizeof(msg_control);

     ret = recvmsg(client->sock_fd, &msg, 0);
     if (ret < sizeof(*index)) {
         IVSHMEM_CLIENT_DEBUG(client, "cannot read message: %s\n",
                              strerror(errno));
         return -1;
     }
     if (ret == 0) {
         IVSHMEM_CLIENT_DEBUG(client, "lost connection to server\n");
         return -1;
     }

     *index = GINT64_FROM_LE(*index);
     *fd = -1;

     for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {

         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)) ||
             cmsg->cmsg_level != SOL_SOCKET ||
             cmsg->cmsg_type != SCM_RIGHTS) {
             continue;
         }

         memcpy(fd, CMSG_DATA(cmsg), sizeof(*fd));
     }

     return 0;
 }

 /* free a peer when the server advertises a disconnection or when the
  * client is freed */
 static void
 ivshmem_client_free_peer(IvshmemClient *client, IvshmemClientPeer *peer)
 {
     unsigned vector;

     QTAILQ_REMOVE(&client->peer_list, peer, next);
     for (vector = 0; vector < peer->vectors_count; vector++) {
         close(peer->vectors[vector]);
     }

     g_free(peer);
 }

 /* handle message coming from server (new peer, new vectors) */
 static int
 ivshmem_client_handle_server_msg(IvshmemClient *client)
 {
     IvshmemClientPeer *peer;
     int64_t peer_id;
     int ret, fd;

     ret = ivshmem_client_read_one_msg(client, &peer_id, &fd);
     if (ret < 0) {
         return -1;
     }

     /* can return a peer or the local client */
     peer = ivshmem_client_search_peer(client, peer_id);

     /* delete peer */
     if (fd == -1) {

         if (peer == NULL || peer == &client->local) {
             IVSHMEM_CLIENT_DEBUG(client, "receive delete for invalid "
                                  "peer %" PRId64 "\n", peer_id);
             return -1;
         }

         IVSHMEM_CLIENT_DEBUG(client, "delete peer id = %" PRId64 "\n", peer_id);
         ivshmem_client_free_peer(client, peer);
         return 0;
     }

     /* new peer */
     if (peer == NULL) {
         peer = g_malloc0(sizeof(*peer));
         peer->id = peer_id;
         peer->vectors_count = 0;
         QTAILQ_INSERT_TAIL(&client->peer_list, peer, next);
         IVSHMEM_CLIENT_DEBUG(client, "new peer id = %" PRId64 "\n", peer_id);
     }

     /* new vector */
     IVSHMEM_CLIENT_DEBUG(client, "  new vector %d (fd=%d) for peer id %"
                          PRId64 "\n", peer->vectors_count, fd, peer->id);
     if (peer->vectors_count >= G_N_ELEMENTS(peer->vectors)) {
         IVSHMEM_CLIENT_DEBUG(client, "Too many vectors received, failing");
         return -1;
     }

     peer->vectors[peer->vectors_count] = fd;
     peer->vectors_count++;

     return 0;
 }

 /* init a new ivshmem client */
 int
 ivshmem_client_init(IvshmemClient *client, const char *unix_sock_path,
                     IvshmemClientNotifCb notif_cb, void *notif_arg,
                     bool verbose)
 {
     int ret;
     unsigned i;

     memset(client, 0, sizeof(*client));

     ret = snprintf(client->unix_sock_path, sizeof(client->unix_sock_path),
                    "%s", unix_sock_path);

     if (ret < 0 || ret >= sizeof(client->unix_sock_path)) {
         IVSHMEM_CLIENT_DEBUG(client, "could not copy unix socket path\n");
         return -1;
     }

     for (i = 0; i < IVSHMEM_CLIENT_MAX_VECTORS; i++) {
         client->local.vectors[i] = -1;
     }

     QTAILQ_INIT(&client->peer_list);
     client->local.id = -1;

     client->notif_cb = notif_cb;
     client->notif_arg = notif_arg;
     client->verbose = verbose;
     client->shm_fd = -1;
     client->sock_fd = -1;

     return 0;
 }

 /* create and connect to the unix socket */
 int
 ivshmem_client_connect(IvshmemClient *client)
 {
     struct sockaddr_un s_un;
     int fd, ret;
     int64_t tmp;

     IVSHMEM_CLIENT_DEBUG(client, "connect to client %s\n",
                          client->unix_sock_path);

     client->sock_fd = socket(AF_UNIX, SOCK_STREAM, 0);
     if (client->sock_fd < 0) {
         IVSHMEM_CLIENT_DEBUG(client, "cannot create socket: %s\n",
                              strerror(errno));
         return -1;
     }

     s_un.sun_family = AF_UNIX;
     ret = snprintf(s_un.sun_path, sizeof(s_un.sun_path), "%s",
                    client->unix_sock_path);
     if (ret < 0 || ret >= sizeof(s_un.sun_path)) {
         IVSHMEM_CLIENT_DEBUG(client, "could not copy unix socket path\n");
         goto err_close;
     }

     if (connect(client->sock_fd, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) {
         IVSHMEM_CLIENT_DEBUG(client, "cannot connect to %s: %s\n", s_un.sun_path,
                              strerror(errno));
         goto err_close;
     }

     /* first, we expect a protocol version */
     if (ivshmem_client_read_one_msg(client, &tmp, &fd) < 0 ||
         (tmp != IVSHMEM_PROTOCOL_VERSION) || fd != -1) {
         IVSHMEM_CLIENT_DEBUG(client, "cannot read from server\n");
         goto err_close;
     }

     /* then, we expect our index + a fd == -1 */
     if (ivshmem_client_read_one_msg(client, &client->local.id, &fd) < 0 ||
         client->local.id < 0 || fd != -1) {
         IVSHMEM_CLIENT_DEBUG(client, "cannot read from server (2)\n");
         goto err_close;
     }
     IVSHMEM_CLIENT_DEBUG(client, "our_id=%" PRId64 "\n", client->local.id);

     /* now, we expect shared mem fd + a -1 index, note that shm fd
      * is not used */
     if (ivshmem_client_read_one_msg(client, &tmp, &fd) < 0 ||
         tmp != -1 || fd < 0) {
         if (fd >= 0) {
             close(fd);
         }
         IVSHMEM_CLIENT_DEBUG(client, "cannot read from server (3)\n");
         goto err_close;
     }
     client->shm_fd = fd;
     IVSHMEM_CLIENT_DEBUG(client, "shm_fd=%d\n", fd);

     return 0;

 err_close:
     close(client->sock_fd);
     client->sock_fd = -1;
     return -1;
 }

 /* close connection to the server, and free all peer structures */
 void
 ivshmem_client_close(IvshmemClient *client)
 {
     IvshmemClientPeer *peer;
     unsigned i;

     IVSHMEM_CLIENT_DEBUG(client, "close client\n");

     while ((peer = QTAILQ_FIRST(&client->peer_list)) != NULL) {
         ivshmem_client_free_peer(client, peer);
     }

     close(client->shm_fd);
     client->shm_fd = -1;
     close(client->sock_fd);
     client->sock_fd = -1;
     client->local.id = -1;
     for (i = 0; i < IVSHMEM_CLIENT_MAX_VECTORS; i++) {
         close(client->local.vectors[i]);
         client->local.vectors[i] = -1;
     }
     client->local.vectors_count = 0;
 }

 /* get the fd_set according to the unix socket and peer list */
 void
 ivshmem_client_get_fds(const IvshmemClient *client, fd_set *fds, int *maxfd)
 {
     int fd;
     unsigned vector;

     FD_SET(client->sock_fd, fds);
     if (client->sock_fd >= *maxfd) {
         *maxfd = client->sock_fd + 1;
     }

     for (vector = 0; vector < client->local.vectors_count; vector++) {
         fd = client->local.vectors[vector];
         FD_SET(fd, fds);
         if (fd >= *maxfd) {
             *maxfd = fd + 1;
         }
     }
 }

 /* handle events from eventfd: just print a message on notification */
 static int
 ivshmem_client_handle_event(IvshmemClient *client, const fd_set *cur, int maxfd)
 {
     IvshmemClientPeer *peer;
     uint64_t kick;
     unsigned i;
     int ret;

     peer = &client->local;

     for (i = 0; i < peer->vectors_count; i++) {
         if (peer->vectors[i] >= maxfd || !FD_ISSET(peer->vectors[i], cur)) {
             continue;
         }

         ret = read(peer->vectors[i], &kick, sizeof(kick));
         if (ret < 0) {
             return ret;
         }
         if (ret != sizeof(kick)) {
             IVSHMEM_CLIENT_DEBUG(client, "invalid read size = %d\n", ret);
             errno = EINVAL;
             return -1;
         }
         IVSHMEM_CLIENT_DEBUG(client, "received event on fd %d vector %d: %"
                              PRIu64 "\n", peer->vectors[i], i, kick);
         if (client->notif_cb != NULL) {
             client->notif_cb(client, peer, i, client->notif_arg);
         }
     }

     return 0;
 }

 /* read and handle new messages on the given fd_set */
 int
 ivshmem_client_handle_fds(IvshmemClient *client, fd_set *fds, int maxfd)
 {
     if (client->sock_fd < maxfd && FD_ISSET(client->sock_fd, fds) &&
         ivshmem_client_handle_server_msg(client) < 0 && errno != EINTR) {
         IVSHMEM_CLIENT_DEBUG(client, "ivshmem_client_handle_server_msg() "
                              "failed\n");
         return -1;
     } else if (ivshmem_client_handle_event(client, fds, maxfd) < 0 &&
                errno != EINTR) {
         IVSHMEM_CLIENT_DEBUG(client, "ivshmem_client_handle_event() failed\n");
         return -1;
     }

     return 0;
 }

 /* send a notification on a vector of a peer */
 int
 ivshmem_client_notify(const IvshmemClient *client,
                       const IvshmemClientPeer *peer, unsigned vector)
 {
     uint64_t kick;
     int fd;

     if (vector >= peer->vectors_count) {
         IVSHMEM_CLIENT_DEBUG(client, "invalid vector %u on peer %" PRId64 "\n",
                              vector, peer->id);
         return -1;
     }
     fd = peer->vectors[vector];
     IVSHMEM_CLIENT_DEBUG(client, "notify peer %" PRId64
                          " on vector %d, fd %d\n", peer->id, vector, fd);

     kick = 1;
     if (write(fd, &kick, sizeof(kick)) != sizeof(kick)) {
         fprintf(stderr, "could not write to %d: %s\n", peer->vectors[vector],
                 strerror(errno));
         return -1;
     }
     return 0;
 }

 /* send a notification to all vectors of a peer */
 int
 ivshmem_client_notify_all_vects(const IvshmemClient *client,
                                 const IvshmemClientPeer *peer)
 {
     unsigned vector;
     int ret = 0;

     for (vector = 0; vector < peer->vectors_count; vector++) {
         if (ivshmem_client_notify(client, peer, vector) < 0) {
             ret = -1;
         }
     }

     return ret;
 }

 /* send a notification to all peers */
 int
 ivshmem_client_notify_broadcast(const IvshmemClient *client)
 {
     IvshmemClientPeer *peer;
     int ret = 0;

     QTAILQ_FOREACH(peer, &client->peer_list, next) {
         if (ivshmem_client_notify_all_vects(client, peer) < 0) {
             ret = -1;
         }
     }

     return ret;
 }

 /* lookup peer from its id */
 IvshmemClientPeer *
 ivshmem_client_search_peer(IvshmemClient *client, int64_t peer_id)
 {
     IvshmemClientPeer *peer;

     if (peer_id == client->local.id) {
         return &client->local;
     }

     QTAILQ_FOREACH(peer, &client->peer_list, next) {
         if (peer->id == peer_id) {
             return peer;
         }
     }
     return NULL;
 }

 /* dump our info, the list of peers their vectors on stdout */
 void
 ivshmem_client_dump(const IvshmemClient *client)
 {
     const IvshmemClientPeer *peer;
     unsigned vector;

     /* dump local infos */
     peer = &client->local;
     printf("our_id = %" PRId64 "\n", peer->id);
     for (vector = 0; vector < peer->vectors_count; vector++) {
         printf("  vector %d is enabled (fd=%d)\n", vector,
                peer->vectors[vector]);
     }

     /* dump peers */
     QTAILQ_FOREACH(peer, &client->peer_list, next) {
         printf("peer_id = %" PRId64 "\n", peer->id);

         for (vector = 0; vector < peer->vectors_count; vector++) {
             printf("  vector %d is enabled (fd=%d)\n", vector,
                    peer->vectors[vector]);
         }
     }
 }
	/*
	* Copyright 6WIND S.A., 2014
	*
	* This work is licensed under the terms of the GNU GPL, version 2 or
	* (at your option) any later version. See the COPYING file in the
	* top-level directory.
	*/

	#include "qemu/osdep.h"
	#include <sys/socket.h>
	#include <sys/un.h>

	#include "qemu/queue.h"

	#include "ivshmem-client.h"

	/* log a message on stdout if verbose=1 */
	#define IVSHMEM_CLIENT_DEBUG(client, fmt, ...) do { \
	if ((client)->verbose) { \
	printf(fmt, ## __VA_ARGS__); \
	} \
	} while (0)

	/* read message from the unix socket */
	static int
	ivshmem_client_read_one_msg(IvshmemClient client, int64_t index, int *fd)
	{
	int ret;
	struct msghdr msg;
	struct iovec iov[1];
	union {
	struct cmsghdr cmsg;
	char control[CMSG_SPACE(sizeof(int))];
	} msg_control;
	struct cmsghdr *cmsg;

	iov[0].iov_base = index;
	iov[0].iov_len = sizeof(*index);

	memset(&msg, 0, sizeof(msg));
	msg.msg_iov = iov;
	msg.msg_iovlen = 1;
	msg.msg_control = &msg_control;
	msg.msg_controllen = sizeof(msg_control);

	ret = recvmsg(client->sock_fd, &msg, 0);
	if (ret < sizeof(*index)) {
	IVSHMEM_CLIENT_DEBUG(client, "cannot read message: %s\n",
	strerror(errno));
	return -1;
	}
	if (ret == 0) {
	IVSHMEM_CLIENT_DEBUG(client, "lost connection to server\n");
	return -1;
	}

	index = GINT64_FROM_LE(index);
	*fd = -1;

	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {

	if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)) \|\|
	cmsg->cmsg_level != SOL_SOCKET \|\|
	cmsg->cmsg_type != SCM_RIGHTS) {
	continue;
	}

	memcpy(fd, CMSG_DATA(cmsg), sizeof(*fd));
	}

	return 0;
	}

	/* free a peer when the server advertises a disconnection or when the
	* client is freed */
	static void
	ivshmem_client_free_peer(IvshmemClient client, IvshmemClientPeer peer)
	{
	unsigned vector;

	QTAILQ_REMOVE(&client->peer_list, peer, next);
	for (vector = 0; vector < peer->vectors_count; vector++) {
	close(peer->vectors[vector]);
	}

	g_free(peer);
	}

	/* handle message coming from server (new peer, new vectors) */
	static int
	ivshmem_client_handle_server_msg(IvshmemClient *client)
	{
	IvshmemClientPeer *peer;
	int64_t peer_id;
	int ret, fd;

	ret = ivshmem_client_read_one_msg(client, &peer_id, &fd);
	if (ret < 0) {
	return -1;
	}

	/* can return a peer or the local client */
	peer = ivshmem_client_search_peer(client, peer_id);

	/* delete peer */
	if (fd == -1) {

	if (peer == NULL \|\| peer == &client->local) {
	IVSHMEM_CLIENT_DEBUG(client, "receive delete for invalid "
	"peer %" PRId64 "\n", peer_id);
	return -1;
	}

	IVSHMEM_CLIENT_DEBUG(client, "delete peer id = %" PRId64 "\n", peer_id);
	ivshmem_client_free_peer(client, peer);
	return 0;
	}

	/* new peer */
	if (peer == NULL) {
	peer = g_malloc0(sizeof(*peer));
	peer->id = peer_id;
	peer->vectors_count = 0;
	QTAILQ_INSERT_TAIL(&client->peer_list, peer, next);
	IVSHMEM_CLIENT_DEBUG(client, "new peer id = %" PRId64 "\n", peer_id);
	}

	/* new vector */
	IVSHMEM_CLIENT_DEBUG(client, " new vector %d (fd=%d) for peer id %"
	PRId64 "\n", peer->vectors_count, fd, peer->id);
	if (peer->vectors_count >= G_N_ELEMENTS(peer->vectors)) {
	IVSHMEM_CLIENT_DEBUG(client, "Too many vectors received, failing");
	return -1;
	}

	peer->vectors[peer->vectors_count] = fd;
	peer->vectors_count++;

	return 0;
	}

	/* init a new ivshmem client */
	int
	ivshmem_client_init(IvshmemClient client, const char unix_sock_path,
	IvshmemClientNotifCb notif_cb, void *notif_arg,
	bool verbose)
	{
	int ret;
	unsigned i;

	memset(client, 0, sizeof(*client));

	ret = snprintf(client->unix_sock_path, sizeof(client->unix_sock_path),
	"%s", unix_sock_path);

	if (ret < 0 \|\| ret >= sizeof(client->unix_sock_path)) {
	IVSHMEM_CLIENT_DEBUG(client, "could not copy unix socket path\n");
	return -1;
	}

	for (i = 0; i < IVSHMEM_CLIENT_MAX_VECTORS; i++) {
	client->local.vectors[i] = -1;
	}

	QTAILQ_INIT(&client->peer_list);
	client->local.id = -1;

	client->notif_cb = notif_cb;
	client->notif_arg = notif_arg;
	client->verbose = verbose;
	client->shm_fd = -1;
	client->sock_fd = -1;

	return 0;
	}

	/* create and connect to the unix socket */
	int
	ivshmem_client_connect(IvshmemClient *client)
	{
	struct sockaddr_un s_un;
	int fd, ret;
	int64_t tmp;

	IVSHMEM_CLIENT_DEBUG(client, "connect to client %s\n",
	client->unix_sock_path);

	client->sock_fd = socket(AF_UNIX, SOCK_STREAM, 0);
	if (client->sock_fd < 0) {
	IVSHMEM_CLIENT_DEBUG(client, "cannot create socket: %s\n",
	strerror(errno));
	return -1;
	}

	s_un.sun_family = AF_UNIX;
	ret = snprintf(s_un.sun_path, sizeof(s_un.sun_path), "%s",
	client->unix_sock_path);
	if (ret < 0 \|\| ret >= sizeof(s_un.sun_path)) {
	IVSHMEM_CLIENT_DEBUG(client, "could not copy unix socket path\n");
	goto err_close;
	}

	if (connect(client->sock_fd, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) {
	IVSHMEM_CLIENT_DEBUG(client, "cannot connect to %s: %s\n", s_un.sun_path,
	strerror(errno));
	goto err_close;
	}

	/* first, we expect a protocol version */
	if (ivshmem_client_read_one_msg(client, &tmp, &fd) < 0 \|\|
	(tmp != IVSHMEM_PROTOCOL_VERSION) \|\| fd != -1) {
	IVSHMEM_CLIENT_DEBUG(client, "cannot read from server\n");
	goto err_close;
	}

	/* then, we expect our index + a fd == -1 */
	if (ivshmem_client_read_one_msg(client, &client->local.id, &fd) < 0 \|\|
	client->local.id < 0 \|\| fd != -1) {
	IVSHMEM_CLIENT_DEBUG(client, "cannot read from server (2)\n");
	goto err_close;
	}
	IVSHMEM_CLIENT_DEBUG(client, "our_id=%" PRId64 "\n", client->local.id);

	/* now, we expect shared mem fd + a -1 index, note that shm fd
	* is not used */
	if (ivshmem_client_read_one_msg(client, &tmp, &fd) < 0 \|\|
	tmp != -1 \|\| fd < 0) {
	if (fd >= 0) {
	close(fd);
	}
	IVSHMEM_CLIENT_DEBUG(client, "cannot read from server (3)\n");
	goto err_close;
	}
	client->shm_fd = fd;
	IVSHMEM_CLIENT_DEBUG(client, "shm_fd=%d\n", fd);

	return 0;

	err_close:
	close(client->sock_fd);
	client->sock_fd = -1;
	return -1;
	}

	/* close connection to the server, and free all peer structures */
	void
	ivshmem_client_close(IvshmemClient *client)
	{
	IvshmemClientPeer *peer;
	unsigned i;

	IVSHMEM_CLIENT_DEBUG(client, "close client\n");

	while ((peer = QTAILQ_FIRST(&client->peer_list)) != NULL) {
	ivshmem_client_free_peer(client, peer);
	}

	close(client->shm_fd);
	client->shm_fd = -1;
	close(client->sock_fd);
	client->sock_fd = -1;
	client->local.id = -1;
	for (i = 0; i < IVSHMEM_CLIENT_MAX_VECTORS; i++) {
	close(client->local.vectors[i]);
	client->local.vectors[i] = -1;
	}
	client->local.vectors_count = 0;
	}

	/* get the fd_set according to the unix socket and peer list */
	void
	ivshmem_client_get_fds(const IvshmemClient client, fd_set fds, int *maxfd)
	{
	int fd;
	unsigned vector;

	FD_SET(client->sock_fd, fds);
	if (client->sock_fd >= *maxfd) {
	*maxfd = client->sock_fd + 1;
	}

	for (vector = 0; vector < client->local.vectors_count; vector++) {
	fd = client->local.vectors[vector];
	FD_SET(fd, fds);
	if (fd >= *maxfd) {
	*maxfd = fd + 1;
	}
	}
	}

	/* handle events from eventfd: just print a message on notification */
	static int
	ivshmem_client_handle_event(IvshmemClient client, const fd_set cur, int maxfd)
	{
	IvshmemClientPeer *peer;
	uint64_t kick;
	unsigned i;
	int ret;

	peer = &client->local;

	for (i = 0; i < peer->vectors_count; i++) {
	if (peer->vectors[i] >= maxfd \|\| !FD_ISSET(peer->vectors[i], cur)) {
	continue;
	}

	ret = read(peer->vectors[i], &kick, sizeof(kick));
	if (ret < 0) {
	return ret;
	}
	if (ret != sizeof(kick)) {
	IVSHMEM_CLIENT_DEBUG(client, "invalid read size = %d\n", ret);
	errno = EINVAL;
	return -1;
	}
	IVSHMEM_CLIENT_DEBUG(client, "received event on fd %d vector %d: %"
	PRIu64 "\n", peer->vectors[i], i, kick);
	if (client->notif_cb != NULL) {
	client->notif_cb(client, peer, i, client->notif_arg);
	}
	}

	return 0;
	}

	/* read and handle new messages on the given fd_set */
	int
	ivshmem_client_handle_fds(IvshmemClient client, fd_set fds, int maxfd)
	{
	if (client->sock_fd < maxfd && FD_ISSET(client->sock_fd, fds) &&
	ivshmem_client_handle_server_msg(client) < 0 && errno != EINTR) {
	IVSHMEM_CLIENT_DEBUG(client, "ivshmem_client_handle_server_msg() "
	"failed\n");
	return -1;
	} else if (ivshmem_client_handle_event(client, fds, maxfd) < 0 &&
	errno != EINTR) {
	IVSHMEM_CLIENT_DEBUG(client, "ivshmem_client_handle_event() failed\n");
	return -1;
	}

	return 0;
	}

	/* send a notification on a vector of a peer */
	int
	ivshmem_client_notify(const IvshmemClient *client,
	const IvshmemClientPeer *peer, unsigned vector)
	{
	uint64_t kick;
	int fd;

	if (vector >= peer->vectors_count) {
	IVSHMEM_CLIENT_DEBUG(client, "invalid vector %u on peer %" PRId64 "\n",
	vector, peer->id);
	return -1;
	}
	fd = peer->vectors[vector];
	IVSHMEM_CLIENT_DEBUG(client, "notify peer %" PRId64
	" on vector %d, fd %d\n", peer->id, vector, fd);

	kick = 1;
	if (write(fd, &kick, sizeof(kick)) != sizeof(kick)) {
	fprintf(stderr, "could not write to %d: %s\n", peer->vectors[vector],
	strerror(errno));
	return -1;
	}
	return 0;
	}

	/* send a notification to all vectors of a peer */
	int
	ivshmem_client_notify_all_vects(const IvshmemClient *client,
	const IvshmemClientPeer *peer)
	{
	unsigned vector;
	int ret = 0;

	for (vector = 0; vector < peer->vectors_count; vector++) {
	if (ivshmem_client_notify(client, peer, vector) < 0) {
	ret = -1;
	}
	}

	return ret;
	}

	/* send a notification to all peers */
	int
	ivshmem_client_notify_broadcast(const IvshmemClient *client)
	{
	IvshmemClientPeer *peer;
	int ret = 0;

	QTAILQ_FOREACH(peer, &client->peer_list, next) {
	if (ivshmem_client_notify_all_vects(client, peer) < 0) {
	ret = -1;
	}
	}

	return ret;
	}

	/* lookup peer from its id */
	IvshmemClientPeer *
	ivshmem_client_search_peer(IvshmemClient *client, int64_t peer_id)
	{
	IvshmemClientPeer *peer;

	if (peer_id == client->local.id) {
	return &client->local;
	}

	QTAILQ_FOREACH(peer, &client->peer_list, next) {
	if (peer->id == peer_id) {
	return peer;
	}
	}
	return NULL;
	}

	/* dump our info, the list of peers their vectors on stdout */
	void
	ivshmem_client_dump(const IvshmemClient *client)
	{
	const IvshmemClientPeer *peer;
	unsigned vector;

	/* dump local infos */
	peer = &client->local;
	printf("our_id = %" PRId64 "\n", peer->id);
	for (vector = 0; vector < peer->vectors_count; vector++) {
	printf(" vector %d is enabled (fd=%d)\n", vector,
	peer->vectors[vector]);
	}

	/* dump peers */
	QTAILQ_FOREACH(peer, &client->peer_list, next) {
	printf("peer_id = %" PRId64 "\n", peer->id);

	for (vector = 0; vector < peer->vectors_count; vector++) {
	printf(" vector %d is enabled (fd=%d)\n", vector,
	peer->vectors[vector]);
	}
	}
	}