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qemu/net/socket.c
Mike Ryan 3a75e74c76 net/sock: option to specify local address 
Add an option to specify the host IP to send multicast packets from,
when using a multicast socket for networking. The option takes an IP
address and sets the IP_MULTICAST_IF socket option, which causes the
packets to use that IP's interface as an egress.

This is useful if the host machine has several interfaces with several
virtual networks across disparate interfaces.

Signed-off-by: Mike Ryan <mikeryan@ISI.EDU>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-12-09 12:45:50 +02:00

600 lines
17 KiB
C
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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 "net/socket.h"
#include "config-host.h"
#include "net.h"
#include "qemu-char.h"
#include "qemu-common.h"
#include "qemu-error.h"
#include "qemu-option.h"
#include "qemu_socket.h"
typedef struct NetSocketState {
VLANClientState nc;
int fd;
int state; /* 0 = getting length, 1 = getting data */
unsigned int index;
unsigned int packet_len;
uint8_t buf[4096];
struct sockaddr_in dgram_dst; /* contains inet host and port destination iff connectionless (SOCK_DGRAM) */
} NetSocketState;
typedef struct NetSocketListenState {
VLANState *vlan;
char *model;
char *name;
int fd;
} NetSocketListenState;
/* XXX: we consider we can send the whole packet without blocking */
static ssize_t net_socket_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
{
NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
uint32_t len;
len = htonl(size);
send_all(s->fd, (const uint8_t *)&len, sizeof(len));
return send_all(s->fd, buf, size);
}
static ssize_t net_socket_receive_dgram(VLANClientState *nc, const uint8_t *buf, size_t size)
{
NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
return sendto(s->fd, (const void *)buf, size, 0,
(struct sockaddr *)&s->dgram_dst, sizeof(s->dgram_dst));
}
static void net_socket_send(void *opaque)
{
NetSocketState *s = opaque;
int size, err;
unsigned l;
uint8_t buf1[4096];
const uint8_t *buf;
size = recv(s->fd, (void *)buf1, sizeof(buf1), 0);
if (size < 0) {
err = socket_error();
if (err != EWOULDBLOCK)
goto eoc;
} else if (size == 0) {
/* end of connection */
eoc:
qemu_set_fd_handler(s->fd, NULL, NULL, NULL);
closesocket(s->fd);
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 = recv(s->fd, (void *)s->buf, sizeof(s->buf), 0);
if (size < 0)
return;
if (size == 0) {
/* end of connection */
qemu_set_fd_handler(s->fd, NULL, NULL, NULL);
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;
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;
}
val = 1;
ret=setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
(const char *)&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 = setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
(const char *)&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 */
val = 1;
ret=setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,
(const char *)&val, sizeof(val));
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 = setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF, localaddr, sizeof(*localaddr));
if (ret < 0) {
perror("setsockopt(IP_MULTICAST_IF)");
goto fail;
}
}
socket_set_nonblock(fd);
return fd;
fail:
if (fd >= 0)
closesocket(fd);
return -1;
}
static void net_socket_cleanup(VLANClientState *nc)
{
NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
qemu_set_fd_handler(s->fd, NULL, NULL, NULL);
close(s->fd);
}
static NetClientInfo net_dgram_socket_info = {
.type = NET_CLIENT_TYPE_SOCKET,
.size = sizeof(NetSocketState),
.receive = net_socket_receive_dgram,
.cleanup = net_socket_cleanup,
};
static NetSocketState *net_socket_fd_init_dgram(VLANState *vlan,
const char *model,
const char *name,
int fd, int is_connected)
{
struct sockaddr_in saddr;
int newfd;
socklen_t saddr_len;
VLANClientState *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);
return NULL;
}
/* clone dgram socket */
newfd = net_socket_mcast_create(&saddr, NULL);
if (newfd < 0) {
/* error already reported by net_socket_mcast_create() */
close(fd);
return NULL;
}
/* 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));
return NULL;
}
}
nc = qemu_new_net_client(&net_dgram_socket_info, vlan, NULL, 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;
qemu_set_fd_handler(s->fd, net_socket_send_dgram, NULL, s);
/* mcast: save bound address as dst */
if (is_connected) s->dgram_dst=saddr;
return s;
}
static void net_socket_connect(void *opaque)
{
NetSocketState *s = opaque;
qemu_set_fd_handler(s->fd, net_socket_send, NULL, s);
}
static NetClientInfo net_socket_info = {
.type = NET_CLIENT_TYPE_SOCKET,
.size = sizeof(NetSocketState),
.receive = net_socket_receive,
.cleanup = net_socket_cleanup,
};
static NetSocketState *net_socket_fd_init_stream(VLANState *vlan,
const char *model,
const char *name,
int fd, int is_connected)
{
VLANClientState *nc;
NetSocketState *s;
nc = qemu_new_net_client(&net_socket_info, vlan, NULL, model, name);
snprintf(nc->info_str, sizeof(nc->info_str), "socket: fd=%d", fd);
s = DO_UPCAST(NetSocketState, nc, nc);
s->fd = 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(VLANState *vlan,
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);
return NULL;
}
switch(so_type) {
case SOCK_DGRAM:
return net_socket_fd_init_dgram(vlan, model, name, fd, is_connected);
case SOCK_STREAM:
return net_socket_fd_init_stream(vlan, 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(vlan, model, name, fd, is_connected);
}
return NULL;
}
static void net_socket_accept(void *opaque)
{
NetSocketListenState *s = opaque;
NetSocketState *s1;
struct sockaddr_in saddr;
socklen_t len;
int fd;
for(;;) {
len = sizeof(saddr);
fd = qemu_accept(s->fd, (struct sockaddr *)&saddr, &len);
if (fd < 0 && errno != EINTR) {
return;
} else if (fd >= 0) {
break;
}
}
s1 = net_socket_fd_init(s->vlan, s->model, s->name, fd, 1);
if (!s1) {
closesocket(fd);
} else {
snprintf(s1->nc.info_str, sizeof(s1->nc.info_str),
"socket: connection from %s:%d",
inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
}
}
static int net_socket_listen_init(VLANState *vlan,
const char *model,
const char *name,
const char *host_str)
{
NetSocketListenState *s;
int fd, val, ret;
struct sockaddr_in saddr;
if (parse_host_port(&saddr, host_str) < 0)
return -1;
s = qemu_mallocz(sizeof(NetSocketListenState));
fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
if (fd < 0) {
perror("socket");
return -1;
}
socket_set_nonblock(fd);
/* allow fast reuse */
val = 1;
setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (const char *)&val, sizeof(val));
ret = bind(fd, (struct sockaddr *)&saddr, sizeof(saddr));
if (ret < 0) {
perror("bind");
return -1;
}
ret = listen(fd, 0);
if (ret < 0) {
perror("listen");
return -1;
}
s->vlan = vlan;
s->model = qemu_strdup(model);
s->name = name ? qemu_strdup(name) : NULL;
s->fd = fd;
qemu_set_fd_handler(fd, net_socket_accept, NULL, s);
return 0;
}
static int net_socket_connect_init(VLANState *vlan,
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;
}
socket_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) {
break;
#endif
} else {
perror("connect");
closesocket(fd);
return -1;
}
} else {
connected = 1;
break;
}
}
s = net_socket_fd_init(vlan, 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(VLANState *vlan,
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(vlan, 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;
}
int net_init_socket(QemuOpts *opts,
Monitor *mon,
const char *name,
VLANState *vlan)
{
if (qemu_opt_get(opts, "fd")) {
int fd;
if (qemu_opt_get(opts, "listen") ||
qemu_opt_get(opts, "connect") ||
qemu_opt_get(opts, "mcast") ||
qemu_opt_get(opts, "localaddr")) {
error_report("listen=, connect=, mcast= and localaddr= is invalid with fd=\n");
return -1;
}
fd = net_handle_fd_param(mon, qemu_opt_get(opts, "fd"));
if (fd == -1) {
return -1;
}
if (!net_socket_fd_init(vlan, "socket", name, fd, 1)) {
close(fd);
return -1;
}
} else if (qemu_opt_get(opts, "listen")) {
const char *listen;
if (qemu_opt_get(opts, "fd") ||
qemu_opt_get(opts, "connect") ||
qemu_opt_get(opts, "mcast") ||
qemu_opt_get(opts, "localaddr")) {
error_report("fd=, connect=, mcast= and localaddr= is invalid with listen=\n");
return -1;
}
listen = qemu_opt_get(opts, "listen");
if (net_socket_listen_init(vlan, "socket", name, listen) == -1) {
return -1;
}
} else if (qemu_opt_get(opts, "connect")) {
const char *connect;
if (qemu_opt_get(opts, "fd") ||
qemu_opt_get(opts, "listen") ||
qemu_opt_get(opts, "mcast") ||
qemu_opt_get(opts, "localaddr")) {
error_report("fd=, listen=, mcast= and localaddr= is invalid with connect=\n");
return -1;
}
connect = qemu_opt_get(opts, "connect");
if (net_socket_connect_init(vlan, "socket", name, connect) == -1) {
return -1;
}
} else if (qemu_opt_get(opts, "mcast")) {
const char *mcast, *localaddr;
if (qemu_opt_get(opts, "fd") ||
qemu_opt_get(opts, "connect") ||
qemu_opt_get(opts, "listen")) {
error_report("fd=, connect= and listen= is invalid with mcast=");
return -1;
}
mcast = qemu_opt_get(opts, "mcast");
localaddr = qemu_opt_get(opts, "localaddr");
if (net_socket_mcast_init(vlan, "socket", name, mcast, localaddr) == -1) {
return -1;
}
} else {
error_report("-socket requires fd=, listen=, connect= or mcast=");
return -1;
}
return 0;
}
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