Archipelago » qemu

/*

 * QEMU System Emulator

 *

 * Copyright (c) 2003-2008 Fabrice Bellard

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include "config-host.h"

#include "net/net.h"

#include "clients.h"

#include "monitor/monitor.h"

#include "qemu-common.h"

#include "qemu/error-report.h"

#include "qemu/option.h"

#include "qemu/sockets.h"

#include "qemu/iov.h"

#include "qemu/main-loop.h"

typedef struct NetSocketState {

    NetClientState nc;

    int listen_fd;

    int fd;

    int state; /* 0 = getting length, 1 = getting data */

    unsigned int index;

    unsigned int packet_len;

    unsigned int send_index;      /* number of bytes sent (only SOCK_STREAM) */

    uint8_t buf[NET_BUFSIZE];

    struct sockaddr_in dgram_dst; /* contains inet host and port destination iff connectionless (SOCK_DGRAM) */

    IOHandler *send_fn;           /* differs between SOCK_STREAM/SOCK_DGRAM */

    bool read_poll;               /* waiting to receive data? */

    bool write_poll;              /* waiting to transmit data? */

} NetSocketState;

static void net_socket_accept(void *opaque);

static void net_socket_writable(void *opaque);

/* Only read packets from socket when peer can receive them */

static int net_socket_can_send(void *opaque)

{

    NetSocketState *s = opaque;

    return qemu_can_send_packet(&s->nc);

}

static void net_socket_update_fd_handler(NetSocketState *s)

{

    qemu_set_fd_handler2(s->fd,

                         s->read_poll  ? net_socket_can_send : NULL,

                         s->read_poll  ? s->send_fn : NULL,

                         s->write_poll ? net_socket_writable : NULL,

                         s);

}

static void net_socket_read_poll(NetSocketState *s, bool enable)

{

    s->read_poll = enable;

    net_socket_update_fd_handler(s);

}

static void net_socket_write_poll(NetSocketState *s, bool enable)

{

    s->write_poll = enable;

    net_socket_update_fd_handler(s);

}

static void net_socket_writable(void *opaque)

{

    NetSocketState *s = opaque;

    net_socket_write_poll(s, false);

    qemu_flush_queued_packets(&s->nc);

}

static ssize_t net_socket_receive(NetClientState *nc, const uint8_t *buf, size_t size)

{

    NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);

    uint32_t len = htonl(size);

    struct iovec iov[] = {

        {

            .iov_base = &len,

            .iov_len  = sizeof(len),

        }, {

            .iov_base = (void *)buf,

            .iov_len  = size,

        },

    };

    size_t remaining;

    ssize_t ret;

    remaining = iov_size(iov, 2) - s->send_index;

    ret = iov_send(s->fd, iov, 2, s->send_index, remaining);

    if (ret == -1 && errno == EAGAIN) {

        ret = 0; /* handled further down */

    }

    if (ret == -1) {

        s->send_index = 0;

        return -errno;

    }

    if (ret < (ssize_t)remaining) {

        s->send_index += ret;

        net_socket_write_poll(s, true);

        return 0;

    }

    s->send_index = 0;

    return size;

}

static ssize_t net_socket_receive_dgram(NetClientState *nc, const uint8_t *buf, size_t size)

{

    NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);

    ssize_t ret;

    do {

        ret = qemu_sendto(s->fd, buf, size, 0,

                          (struct sockaddr *)&s->dgram_dst,

                          sizeof(s->dgram_dst));

    } while (ret == -1 && errno == EINTR);

    if (ret == -1 && errno == EAGAIN) {

        net_socket_write_poll(s, true);

        return 0;

    }

    return ret;

}

static void net_socket_send(void *opaque)

{

    NetSocketState *s = opaque;

    int size, err;

    unsigned l;

    uint8_t buf1[NET_BUFSIZE];

    const uint8_t *buf;

    size = qemu_recv(s->fd, buf1, sizeof(buf1), 0);

    if (size < 0) {

        err = socket_error();

        if (err != EWOULDBLOCK)

            goto eoc;

    } else if (size == 0) {

        /* end of connection */

    eoc:

        net_socket_read_poll(s, false);

        net_socket_write_poll(s, false);

        if (s->listen_fd != -1) {

            qemu_set_fd_handler(s->listen_fd, net_socket_accept, NULL, s);

        }

        closesocket(s->fd);

        s->fd = -1;

        s->state = 0;

        s->index = 0;

        s->packet_len = 0;

        s->nc.link_down = true;

        memset(s->buf, 0, sizeof(s->buf));

        memset(s->nc.info_str, 0, sizeof(s->nc.info_str));

        return;

    }

    buf = buf1;

    while (size > 0) {

        /* reassemble a packet from the network */

        switch(s->state) {

        case 0:

            l = 4 - s->index;

            if (l > size)

                l = size;

            memcpy(s->buf + s->index, buf, l);

            buf += l;

            size -= l;

            s->index += l;

            if (s->index == 4) {

                /* got length */

                s->packet_len = ntohl(*(uint32_t *)s->buf);

                s->index = 0;

                s->state = 1;

            }

            break;

        case 1:

            l = s->packet_len - s->index;

            if (l > size)

                l = size;

            if (s->index + l <= sizeof(s->buf)) {

                memcpy(s->buf + s->index, buf, l);

            } else {

                fprintf(stderr, "serious error: oversized packet received,"

                    "connection terminated.\n");

                s->state = 0;

                goto eoc;

            }

            s->index += l;

            buf += l;

            size -= l;

            if (s->index >= s->packet_len) {

                qemu_send_packet(&s->nc, s->buf, s->packet_len);

                s->index = 0;

                s->state = 0;

            }

            break;

        }

    }

}

static void net_socket_send_dgram(void *opaque)

{

    NetSocketState *s = opaque;

    int size;

    size = qemu_recv(s->fd, s->buf, sizeof(s->buf), 0);

    if (size < 0)

        return;

    if (size == 0) {

        /* end of connection */

        net_socket_read_poll(s, false);

        net_socket_write_poll(s, false);

        return;

    }

    qemu_send_packet(&s->nc, s->buf, size);

}

static int net_socket_mcast_create(struct sockaddr_in *mcastaddr, struct in_addr *localaddr)

{

    struct ip_mreq imr;

    int fd;

    int val, ret;

#ifdef __OpenBSD__

    unsigned char loop;

#else

    int loop;

#endif

    if (!IN_MULTICAST(ntohl(mcastaddr->sin_addr.s_addr))) {

        fprintf(stderr, "qemu: error: specified mcastaddr \"%s\" (0x%08x) "

                "does not contain a multicast address\n",

                inet_ntoa(mcastaddr->sin_addr),

                (int)ntohl(mcastaddr->sin_addr.s_addr));

        return -1;

    }

    fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);

    if (fd < 0) {

        perror("socket(PF_INET, SOCK_DGRAM)");

        return -1;

    }

    /* Allow multiple sockets to bind the same multicast ip and port by setting

     * SO_REUSEADDR. This is the only situation where SO_REUSEADDR should be set

     * on windows. Use socket_set_fast_reuse otherwise as it sets SO_REUSEADDR

     * only on posix systems.

     */

    val = 1;

    ret = qemu_setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));

    if (ret < 0) {

        perror("setsockopt(SOL_SOCKET, SO_REUSEADDR)");

        goto fail;

    }

    ret = bind(fd, (struct sockaddr *)mcastaddr, sizeof(*mcastaddr));

    if (ret < 0) {

        perror("bind");

        goto fail;

    }

    /* Add host to multicast group */

    imr.imr_multiaddr = mcastaddr->sin_addr;

    if (localaddr) {

        imr.imr_interface = *localaddr;

    } else {

        imr.imr_interface.s_addr = htonl(INADDR_ANY);

    }

    ret = qemu_setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,

                          &imr, sizeof(struct ip_mreq));

    if (ret < 0) {

        perror("setsockopt(IP_ADD_MEMBERSHIP)");

        goto fail;

    }

    /* Force mcast msgs to loopback (eg. several QEMUs in same host */

    loop = 1;

    ret = qemu_setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,

                          &loop, sizeof(loop));

    if (ret < 0) {

        perror("setsockopt(SOL_IP, IP_MULTICAST_LOOP)");

        goto fail;

    }

    /* If a bind address is given, only send packets from that address */

    if (localaddr != NULL) {

        ret = qemu_setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF,

                              localaddr, sizeof(*localaddr));

        if (ret < 0) {

            perror("setsockopt(IP_MULTICAST_IF)");

            goto fail;

        }

    }

    qemu_set_nonblock(fd);

    return fd;

fail:

    if (fd >= 0)

        closesocket(fd);

    return -1;

}

static void net_socket_cleanup(NetClientState *nc)

{

    NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);

    if (s->fd != -1) {

        net_socket_read_poll(s, false);

        net_socket_write_poll(s, false);

        close(s->fd);

        s->fd = -1;

    }

    if (s->listen_fd != -1) {

        qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);

        closesocket(s->listen_fd);

        s->listen_fd = -1;

    }

}

static NetClientInfo net_dgram_socket_info = {

    .type = NET_CLIENT_OPTIONS_KIND_SOCKET,

    .size = sizeof(NetSocketState),

    .receive = net_socket_receive_dgram,

    .cleanup = net_socket_cleanup,

};

static NetSocketState *net_socket_fd_init_dgram(NetClientState *peer,

                                                const char *model,

                                                const char *name,

                                                int fd, int is_connected)

{

    struct sockaddr_in saddr;

    int newfd;

    socklen_t saddr_len;

    NetClientState *nc;

    NetSocketState *s;

    /* fd passed: multicast: "learn" dgram_dst address from bound address and save it

     * Because this may be "shared" socket from a "master" process, datagrams would be recv()

     * by ONLY ONE process: we must "clone" this dgram socket --jjo

     */

    if (is_connected) {

        if (getsockname(fd, (struct sockaddr *) &saddr, &saddr_len) == 0) {

            /* must be bound */

            if (saddr.sin_addr.s_addr == 0) {

                fprintf(stderr, "qemu: error: init_dgram: fd=%d unbound, "

                        "cannot setup multicast dst addr\n", fd);

                goto err;

            }

            /* clone dgram socket */

            newfd = net_socket_mcast_create(&saddr, NULL);

            if (newfd < 0) {

                /* error already reported by net_socket_mcast_create() */

                goto err;

            }

            /* clone newfd to fd, close newfd */

            dup2(newfd, fd);

            close(newfd);

        } else {

            fprintf(stderr,

                    "qemu: error: init_dgram: fd=%d failed getsockname(): %s\n",

                    fd, strerror(errno));

            goto err;

        }

    }

    nc = qemu_new_net_client(&net_dgram_socket_info, peer, model, name);

    snprintf(nc->info_str, sizeof(nc->info_str),

            "socket: fd=%d (%s mcast=%s:%d)",

            fd, is_connected ? "cloned" : "",

            inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));

    s = DO_UPCAST(NetSocketState, nc, nc);

    s->fd = fd;

    s->listen_fd = -1;

    s->send_fn = net_socket_send_dgram;

    net_socket_read_poll(s, true);

    /* mcast: save bound address as dst */

    if (is_connected) {

        s->dgram_dst = saddr;

    }

    return s;

err:

    closesocket(fd);

    return NULL;

}

static void net_socket_connect(void *opaque)

{

    NetSocketState *s = opaque;

    s->send_fn = net_socket_send;

    net_socket_read_poll(s, true);

}

static NetClientInfo net_socket_info = {

    .type = NET_CLIENT_OPTIONS_KIND_SOCKET,

    .size = sizeof(NetSocketState),

    .receive = net_socket_receive,

    .cleanup = net_socket_cleanup,

};

static NetSocketState *net_socket_fd_init_stream(NetClientState *peer,

                                                 const char *model,

                                                 const char *name,

                                                 int fd, int is_connected)

{

    NetClientState *nc;

    NetSocketState *s;

    nc = qemu_new_net_client(&net_socket_info, peer, model, name);

    snprintf(nc->info_str, sizeof(nc->info_str), "socket: fd=%d", fd);

    s = DO_UPCAST(NetSocketState, nc, nc);

    s->fd = fd;

    s->listen_fd = -1;

    /* Disable Nagle algorithm on TCP sockets to reduce latency */

    socket_set_nodelay(fd);

    if (is_connected) {

        net_socket_connect(s);

    } else {

        qemu_set_fd_handler(s->fd, NULL, net_socket_connect, s);

    }

    return s;

}

static NetSocketState *net_socket_fd_init(NetClientState *peer,

                                          const char *model, const char *name,

                                          int fd, int is_connected)

{

    int so_type = -1, optlen=sizeof(so_type);

    if(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&so_type,

        (socklen_t *)&optlen)< 0) {

        fprintf(stderr, "qemu: error: getsockopt(SO_TYPE) for fd=%d failed\n",

                fd);

        closesocket(fd);

        return NULL;

    }

    switch(so_type) {

    case SOCK_DGRAM:

        return net_socket_fd_init_dgram(peer, model, name, fd, is_connected);

    case SOCK_STREAM:

        return net_socket_fd_init_stream(peer, model, name, fd, is_connected);

    default:

        /* who knows ... this could be a eg. a pty, do warn and continue as stream */

        fprintf(stderr, "qemu: warning: socket type=%d for fd=%d is not SOCK_DGRAM or SOCK_STREAM\n", so_type, fd);

        return net_socket_fd_init_stream(peer, model, name, fd, is_connected);

    }

    return NULL;

}

static void net_socket_accept(void *opaque)

{

    NetSocketState *s = opaque;

    struct sockaddr_in saddr;

    socklen_t len;

    int fd;

    for(;;) {

        len = sizeof(saddr);

        fd = qemu_accept(s->listen_fd, (struct sockaddr *)&saddr, &len);

        if (fd < 0 && errno != EINTR) {

            return;

        } else if (fd >= 0) {

            qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);

            break;

        }

    }

    s->fd = fd;

    s->nc.link_down = false;

    net_socket_connect(s);

    snprintf(s->nc.info_str, sizeof(s->nc.info_str),

             "socket: connection from %s:%d",

             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));

}

static int net_socket_listen_init(NetClientState *peer,

                                  const char *model,

                                  const char *name,

                                  const char *host_str)

{

    NetClientState *nc;

    NetSocketState *s;

    struct sockaddr_in saddr;

    int fd, ret;

    if (parse_host_port(&saddr, host_str) < 0)

        return -1;

    fd = qemu_socket(PF_INET, SOCK_STREAM, 0);

    if (fd < 0) {

        perror("socket");

        return -1;

    }

    qemu_set_nonblock(fd);

    socket_set_fast_reuse(fd);

    ret = bind(fd, (struct sockaddr *)&saddr, sizeof(saddr));

    if (ret < 0) {

        perror("bind");

        closesocket(fd);

        return -1;

    }

    ret = listen(fd, 0);

    if (ret < 0) {

        perror("listen");

        closesocket(fd);

        return -1;

    }

    nc = qemu_new_net_client(&net_socket_info, peer, model, name);

    s = DO_UPCAST(NetSocketState, nc, nc);

    s->fd = -1;

    s->listen_fd = fd;

    s->nc.link_down = true;

    qemu_set_fd_handler(s->listen_fd, net_socket_accept, NULL, s);

    return 0;

}

static int net_socket_connect_init(NetClientState *peer,

                                   const char *model,

                                   const char *name,

                                   const char *host_str)

{

    NetSocketState *s;

    int fd, connected, ret, err;

    struct sockaddr_in saddr;

    if (parse_host_port(&saddr, host_str) < 0)

        return -1;

    fd = qemu_socket(PF_INET, SOCK_STREAM, 0);

    if (fd < 0) {

        perror("socket");

        return -1;

    }

    qemu_set_nonblock(fd);

    connected = 0;

    for(;;) {

        ret = connect(fd, (struct sockaddr *)&saddr, sizeof(saddr));

        if (ret < 0) {

            err = socket_error();

            if (err == EINTR || err == EWOULDBLOCK) {

            } else if (err == EINPROGRESS) {

                break;

#ifdef _WIN32

            } else if (err == WSAEALREADY || err == WSAEINVAL) {

                break;

#endif

            } else {

                perror("connect");

                closesocket(fd);

                return -1;

            }

        } else {

            connected = 1;

            break;

        }

    }

    s = net_socket_fd_init(peer, model, name, fd, connected);

    if (!s)

        return -1;

    snprintf(s->nc.info_str, sizeof(s->nc.info_str),

             "socket: connect to %s:%d",

             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));

    return 0;

}

static int net_socket_mcast_init(NetClientState *peer,

                                 const char *model,

                                 const char *name,

                                 const char *host_str,

                                 const char *localaddr_str)

{

    NetSocketState *s;

    int fd;

    struct sockaddr_in saddr;

    struct in_addr localaddr, *param_localaddr;

    if (parse_host_port(&saddr, host_str) < 0)

        return -1;

    if (localaddr_str != NULL) {

        if (inet_aton(localaddr_str, &localaddr) == 0)

            return -1;

        param_localaddr = &localaddr;

    } else {

        param_localaddr = NULL;

    }

    fd = net_socket_mcast_create(&saddr, param_localaddr);

    if (fd < 0)

        return -1;

    s = net_socket_fd_init(peer, model, name, fd, 0);

    if (!s)

        return -1;

    s->dgram_dst = saddr;

    snprintf(s->nc.info_str, sizeof(s->nc.info_str),

             "socket: mcast=%s:%d",

             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));

    return 0;

}

static int net_socket_udp_init(NetClientState *peer,

                                 const char *model,

                                 const char *name,

                                 const char *rhost,

                                 const char *lhost)

{

    NetSocketState *s;

    int fd, ret;

    struct sockaddr_in laddr, raddr;

    if (parse_host_port(&laddr, lhost) < 0) {

        return -1;

    }

    if (parse_host_port(&raddr, rhost) < 0) {

        return -1;

    }

    fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);

    if (fd < 0) {

        perror("socket(PF_INET, SOCK_DGRAM)");

        return -1;

    }

    ret = socket_set_fast_reuse(fd);

    if (ret < 0) {

        closesocket(fd);

        return -1;

    }

    ret = bind(fd, (struct sockaddr *)&laddr, sizeof(laddr));

    if (ret < 0) {

        perror("bind");

        closesocket(fd);

        return -1;

    }

    qemu_set_nonblock(fd);

    s = net_socket_fd_init(peer, model, name, fd, 0);

    if (!s) {

        return -1;

    }

    s->dgram_dst = raddr;

    snprintf(s->nc.info_str, sizeof(s->nc.info_str),

             "socket: udp=%s:%d",

             inet_ntoa(raddr.sin_addr), ntohs(raddr.sin_port));

    return 0;

}

int net_init_socket(const NetClientOptions *opts, const char *name,

                    NetClientState *peer)

{

    const NetdevSocketOptions *sock;

    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_SOCKET);

    sock = opts->socket;

    if (sock->has_fd + sock->has_listen + sock->has_connect + sock->has_mcast +

        sock->has_udp != 1) {

        error_report("exactly one of fd=, listen=, connect=, mcast= or udp="

                     " is required");

        return -1;

    }

    if (sock->has_localaddr && !sock->has_mcast && !sock->has_udp) {

        error_report("localaddr= is only valid with mcast= or udp=");

        return -1;

    }

    if (sock->has_fd) {

        int fd;

        fd = monitor_handle_fd_param(cur_mon, sock->fd);

        if (fd == -1) {

            return -1;

        }

        qemu_set_nonblock(fd);

        if (!net_socket_fd_init(peer, "socket", name, fd, 1)) {

            return -1;

        }

        return 0;

    }

    if (sock->has_listen) {

        if (net_socket_listen_init(peer, "socket", name, sock->listen) == -1) {

            return -1;

        }

        return 0;

    }

    if (sock->has_connect) {

        if (net_socket_connect_init(peer, "socket", name, sock->connect) ==

            -1) {

            return -1;

        }

        return 0;

    }

    if (sock->has_mcast) {

        /* if sock->localaddr is missing, it has been initialized to "all bits

         * zero" */

        if (net_socket_mcast_init(peer, "socket", name, sock->mcast,

            sock->localaddr) == -1) {

            return -1;

        }

        return 0;

    }

    assert(sock->has_udp);

    if (!sock->has_localaddr) {

        error_report("localaddr= is mandatory with udp=");

        return -1;

    }

    if (net_socket_udp_init(peer, "socket", name, sock->udp, sock->localaddr) ==

        -1) {

        return -1;

    }

    return 0;

}