diff options
Diffstat (limited to 'contrib/ivshmem-client/ivshmem-client.c')
| -rw-r--r-- | contrib/ivshmem-client/ivshmem-client.c | 433 |
1 files changed, 433 insertions, 0 deletions
diff --git a/contrib/ivshmem-client/ivshmem-client.c b/contrib/ivshmem-client/ivshmem-client.c new file mode 100644 index 0000000000..fcc0930eb6 --- /dev/null +++ b/contrib/ivshmem-client/ivshmem-client.c @@ -0,0 +1,433 @@ +/* + * 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 <sys/types.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, long *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 < 0) { + 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; + } + + *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; + long 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 %ld\n", peer_id); + return -1; + } + + IVSHMEM_CLIENT_DEBUG(client, "delete peer id = %ld\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 = %ld\n", peer_id); + } + + /* new vector */ + IVSHMEM_CLIENT_DEBUG(client, " new vector %d (fd=%d) for peer id %ld\n", + peer->vectors_count, fd, peer->id); + 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; + long 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 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\n"); + goto err_close; + } + IVSHMEM_CLIENT_DEBUG(client, "our_id=%ld\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 (2)\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 %ld\n", + vector, peer->id); + return -1; + } + fd = peer->vectors[vector]; + IVSHMEM_CLIENT_DEBUG(client, "notify peer %ld 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, long 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 = %ld\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 = %ld\n", peer->id); + + for (vector = 0; vector < peer->vectors_count; vector++) { + printf(" vector %d is enabled (fd=%d)\n", vector, + peer->vectors[vector]); + } + } +} |