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xemu/net/socket.c
Sebastian Ottlik bcbe92fb08 net: call socket_set_fast_reuse instead of setting SO_REUSEADDR 
SO_REUSEADDR should be avoided on Windows but is desired on other operating
systems. So instead of setting it we call socket_set_fast_reuse that will result
in the appropriate behaviour on all operating systems.

An exception to this rule are multicast sockets where it is sensible to have
multiple sockets listen on the same ip and port and we should set SO_REUSEADDR
on windows.

Signed-off-by: Sebastian Ottlik <ottlik@fzi.de>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
2013-10-02 19:20:31 +02:00

764 lines
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/*
* 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;
}
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