--- /dev/null
+/*
+ * 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-common.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 sun;
+ 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;
+ }
+
+ sun.sun_family = AF_UNIX;
+ ret = snprintf(sun.sun_path, sizeof(sun.sun_path), "%s",
+ client->unix_sock_path);
+ if (ret < 0 || ret >= sizeof(sun.sun_path)) {
+ IVSHMEM_CLIENT_DEBUG(client, "could not copy unix socket path\n");
+ goto err_close;
+ }
+
+ if (connect(client->sock_fd, (struct sockaddr *)&sun, sizeof(sun)) < 0) {
+ IVSHMEM_CLIENT_DEBUG(client, "cannot connect to %s: %s\n", sun.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]);
+ }
+ }
+}
Code Review / kvmfornfv.git / blobdiff