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qemu-cr16/net/dgram.c
Vladimir Sementsov-Ogievskiy 8cb17f9c36 util: drop qemu_socket_set_nonblock() 
Use common qemu_set_blocking() instead.

Note that pre-patch the behavior of Win32 and Linux realizations
are inconsistent: we ignore failure for Win32, and assert success
for Linux.

How do we convert the callers?

1. Most of callers call qemu_socket_set_nonblock() on a
freshly created socket fd, in conditions when we may simply
report an error. Seems correct switching to error handling
both for Windows (pre-patch error is ignored) and Linux
(pre-patch we assert success). Anyway, we normally don't
expect errors in these cases.

Still in tests let's use &error_abort for simplicity.

What are exclusions?

2. hw/virtio/vhost-user.c - we are inside #ifdef CONFIG_LINUX,
so no damage in switching to error handling from assertion.

3. io/channel-socket.c: here we convert both old calls to
qemu_socket_set_nonblock() and qemu_socket_set_block() to
one new call. Pre-patch we assert success for Linux in
qemu_socket_set_nonblock(), and ignore all other errors here.
So, for Windows switch is a bit dangerous: we may get
new errors or crashes(when error_abort is passed) in
cases where we have silently ignored the error before
(was it correct in all such cases, if they were?) Still,
there is no other way to stricter API than take
this risk.

4. util/vhost-user-server - compiled only for Linux (see
util/meson.build), so we are safe, switching from assertion to
&error_abort.

Note: In qga/channel-posix.c we use g_warning(), where g_printerr()
would actually be a better choice. Still let's for now follow
common style of qga, where g_warning() is commonly used to print
such messages, and no call to g_printerr(). Converting everything
to use g_printerr() should better be another series.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2025-09-19 12:46:07 +01:00

633 lines
19 KiB
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/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
* Copyright (c) 2022 Red Hat, Inc.
*
* 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 "qemu/osdep.h"
#include "net/net.h"
#include "clients.h"
#include "monitor/monitor.h"
#include "qapi/error.h"
#include "qemu/error-report.h"
#include "qemu/option.h"
#include "qemu/sockets.h"
#include "qemu/iov.h"
#include "qemu/main-loop.h"
#include "qemu/cutils.h"
typedef struct NetDgramState {
NetClientState nc;
int fd;
SocketReadState rs;
bool read_poll; /* waiting to receive data? */
bool write_poll; /* waiting to transmit data? */
/* contains destination iff connectionless */
struct sockaddr *dest_addr;
socklen_t dest_len;
} NetDgramState;
static void net_dgram_send(void *opaque);
static void net_dgram_writable(void *opaque);
static void net_dgram_update_fd_handler(NetDgramState *s)
{
qemu_set_fd_handler(s->fd,
s->read_poll ? net_dgram_send : NULL,
s->write_poll ? net_dgram_writable : NULL,
s);
}
static void net_dgram_read_poll(NetDgramState *s, bool enable)
{
s->read_poll = enable;
net_dgram_update_fd_handler(s);
}
static void net_dgram_write_poll(NetDgramState *s, bool enable)
{
s->write_poll = enable;
net_dgram_update_fd_handler(s);
}
static void net_dgram_writable(void *opaque)
{
NetDgramState *s = opaque;
net_dgram_write_poll(s, false);
qemu_flush_queued_packets(&s->nc);
}
static ssize_t net_dgram_receive(NetClientState *nc,
const uint8_t *buf, size_t size)
{
NetDgramState *s = DO_UPCAST(NetDgramState, nc, nc);
ssize_t ret;
do {
if (s->dest_addr) {
ret = sendto(s->fd, buf, size, 0, s->dest_addr, s->dest_len);
} else {
ret = send(s->fd, buf, size, 0);
}
} while (ret == -1 && errno == EINTR);
if (ret == -1 && errno == EAGAIN) {
net_dgram_write_poll(s, true);
return 0;
}
return ret;
}
static void net_dgram_send_completed(NetClientState *nc, ssize_t len)
{
NetDgramState *s = DO_UPCAST(NetDgramState, nc, nc);
if (!s->read_poll) {
net_dgram_read_poll(s, true);
}
}
static void net_dgram_rs_finalize(SocketReadState *rs)
{
NetDgramState *s = container_of(rs, NetDgramState, rs);
if (qemu_send_packet_async(&s->nc, rs->buf,
rs->packet_len,
net_dgram_send_completed) == 0) {
net_dgram_read_poll(s, false);
}
}
static void net_dgram_send(void *opaque)
{
NetDgramState *s = opaque;
int size;
size = recv(s->fd, s->rs.buf, sizeof(s->rs.buf), 0);
if (size < 0) {
return;
}
if (size == 0) {
/* end of connection */
net_dgram_read_poll(s, false);
net_dgram_write_poll(s, false);
return;
}
if (qemu_send_packet_async(&s->nc, s->rs.buf, size,
net_dgram_send_completed) == 0) {
net_dgram_read_poll(s, false);
}
}
static int net_dgram_mcast_create(struct sockaddr_in *mcastaddr,
struct in_addr *localaddr,
Error **errp)
{
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))) {
error_setg(errp, "specified mcastaddr %s (0x%08x) "
"does not contain a multicast address",
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) {
error_setg_errno(errp, errno, "can't create datagram socket");
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 = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
if (ret < 0) {
error_setg_errno(errp, errno, "can't set socket option SO_REUSEADDR");
goto fail;
}
ret = bind(fd, (struct sockaddr *)mcastaddr, sizeof(*mcastaddr));
if (ret < 0) {
error_setg_errno(errp, errno, "can't bind ip=%s to socket",
inet_ntoa(mcastaddr->sin_addr));
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,
&imr, sizeof(struct ip_mreq));
if (ret < 0) {
error_setg_errno(errp, errno,
"can't add socket to multicast group %s",
inet_ntoa(imr.imr_multiaddr));
goto fail;
}
/* Force mcast msgs to loopback (eg. several QEMUs in same host */
loop = 1;
ret = setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,
&loop, sizeof(loop));
if (ret < 0) {
error_setg_errno(errp, errno,
"can't force multicast message to loopback");
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) {
error_setg_errno(errp, errno,
"can't set the default network send interface");
goto fail;
}
}
if (!qemu_set_blocking(fd, false, errp)) {
goto fail;
}
return fd;
fail:
if (fd >= 0) {
close(fd);
}
return -1;
}
static void net_dgram_cleanup(NetClientState *nc)
{
NetDgramState *s = DO_UPCAST(NetDgramState, nc, nc);
if (s->fd != -1) {
net_dgram_read_poll(s, false);
net_dgram_write_poll(s, false);
close(s->fd);
s->fd = -1;
}
g_free(s->dest_addr);
s->dest_addr = NULL;
s->dest_len = 0;
}
static NetClientInfo net_dgram_socket_info = {
.type = NET_CLIENT_DRIVER_DGRAM,
.size = sizeof(NetDgramState),
.receive = net_dgram_receive,
.cleanup = net_dgram_cleanup,
};
static NetDgramState *net_dgram_fd_init(NetClientState *peer,
const char *model,
const char *name,
int fd,
Error **errp)
{
NetClientState *nc;
NetDgramState *s;
nc = qemu_new_net_client(&net_dgram_socket_info, peer, model, name);
s = DO_UPCAST(NetDgramState, nc, nc);
s->fd = fd;
net_socket_rs_init(&s->rs, net_dgram_rs_finalize, false);
net_dgram_read_poll(s, true);
return s;
}
static int net_dgram_mcast_init(NetClientState *peer,
const char *model,
const char *name,
SocketAddress *remote,
SocketAddress *local,
Error **errp)
{
NetDgramState *s;
int fd, ret;
struct sockaddr_in *saddr;
if (remote->type != SOCKET_ADDRESS_TYPE_INET) {
error_setg(errp, "multicast only support inet type");
return -1;
}
saddr = g_new(struct sockaddr_in, 1);
if (convert_host_port(saddr, remote->u.inet.host, remote->u.inet.port,
errp) < 0) {
g_free(saddr);
return -1;
}
if (!local) {
fd = net_dgram_mcast_create(saddr, NULL, errp);
if (fd < 0) {
g_free(saddr);
return -1;
}
} else {
switch (local->type) {
case SOCKET_ADDRESS_TYPE_INET: {
struct in_addr localaddr;
if (inet_aton(local->u.inet.host, &localaddr) == 0) {
g_free(saddr);
error_setg(errp, "localaddr '%s' is not a valid IPv4 address",
local->u.inet.host);
return -1;
}
fd = net_dgram_mcast_create(saddr, &localaddr, errp);
if (fd < 0) {
g_free(saddr);
return -1;
}
break;
}
case SOCKET_ADDRESS_TYPE_FD: {
int newfd;
fd = monitor_fd_param(monitor_cur(), local->u.fd.str, errp);
if (fd == -1) {
g_free(saddr);
return -1;
}
ret = qemu_socket_try_set_nonblock(fd);
if (ret < 0) {
g_free(saddr);
error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
name, fd);
return -1;
}
/*
* fd passed: multicast: "learn" dest_addr 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
*/
saddr = g_new(struct sockaddr_in, 1);
if (convert_host_port(saddr, local->u.inet.host, local->u.inet.port,
errp) < 0) {
g_free(saddr);
close(fd);
return -1;
}
/* must be bound */
if (saddr->sin_addr.s_addr == 0) {
error_setg(errp, "can't setup multicast destination address");
g_free(saddr);
close(fd);
return -1;
}
/* clone dgram socket */
newfd = net_dgram_mcast_create(saddr, NULL, errp);
if (newfd < 0) {
g_free(saddr);
close(fd);
return -1;
}
/* clone newfd to fd, close newfd */
dup2(newfd, fd);
close(newfd);
break;
}
default:
g_free(saddr);
error_setg(errp, "only support inet or fd type for local");
return -1;
}
}
s = net_dgram_fd_init(peer, model, name, fd, errp);
if (!s) {
g_free(saddr);
return -1;
}
g_assert(s->dest_addr == NULL);
s->dest_addr = (struct sockaddr *)saddr;
s->dest_len = sizeof(*saddr);
if (!local) {
qemu_set_info_str(&s->nc, "mcast=%s:%d",
inet_ntoa(saddr->sin_addr),
ntohs(saddr->sin_port));
} else {
switch (local->type) {
case SOCKET_ADDRESS_TYPE_INET:
qemu_set_info_str(&s->nc, "mcast=%s:%d",
inet_ntoa(saddr->sin_addr),
ntohs(saddr->sin_port));
break;
case SOCKET_ADDRESS_TYPE_FD:
qemu_set_info_str(&s->nc, "fd=%d (cloned mcast=%s:%d)",
fd, inet_ntoa(saddr->sin_addr),
ntohs(saddr->sin_port));
break;
default:
g_assert_not_reached();
}
}
return 0;
}
int net_init_dgram(const Netdev *netdev, const char *name,
NetClientState *peer, Error **errp)
{
NetDgramState *s;
int fd, ret;
SocketAddress *remote, *local;
struct sockaddr *dest_addr;
struct sockaddr_in laddr_in, raddr_in;
struct sockaddr_un laddr_un, raddr_un;
socklen_t dest_len;
assert(netdev->type == NET_CLIENT_DRIVER_DGRAM);
remote = netdev->u.dgram.remote;
local = netdev->u.dgram.local;
/* detect multicast address */
if (remote && remote->type == SOCKET_ADDRESS_TYPE_INET) {
struct sockaddr_in mcastaddr;
if (convert_host_port(&mcastaddr, remote->u.inet.host,
remote->u.inet.port, errp) < 0) {
return -1;
}
if (IN_MULTICAST(ntohl(mcastaddr.sin_addr.s_addr))) {
return net_dgram_mcast_init(peer, "dram", name, remote, local,
errp);
}
}
/* unicast address */
if (!local) {
error_setg(errp, "dgram requires local= parameter");
return -1;
}
if (remote) {
if (local->type == SOCKET_ADDRESS_TYPE_FD) {
error_setg(errp, "don't set remote with local.fd");
return -1;
}
if (remote->type != local->type) {
error_setg(errp, "remote and local types must be the same");
return -1;
}
} else {
if (local->type != SOCKET_ADDRESS_TYPE_FD) {
error_setg(errp,
"type=inet or type=unix requires remote parameter");
return -1;
}
}
switch (local->type) {
case SOCKET_ADDRESS_TYPE_INET:
if (convert_host_port(&laddr_in, local->u.inet.host, local->u.inet.port,
errp) < 0) {
return -1;
}
if (convert_host_port(&raddr_in, remote->u.inet.host,
remote->u.inet.port, errp) < 0) {
return -1;
}
fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
if (fd < 0) {
error_setg_errno(errp, errno, "can't create datagram socket");
return -1;
}
ret = socket_set_fast_reuse(fd);
if (ret < 0) {
error_setg_errno(errp, errno,
"can't set socket option SO_REUSEADDR");
close(fd);
return -1;
}
ret = bind(fd, (struct sockaddr *)&laddr_in, sizeof(laddr_in));
if (ret < 0) {
error_setg_errno(errp, errno, "can't bind ip=%s to socket",
inet_ntoa(laddr_in.sin_addr));
close(fd);
return -1;
}
if (!qemu_set_blocking(fd, false, errp)) {
close(fd);
return -1;
}
dest_len = sizeof(raddr_in);
dest_addr = g_malloc(dest_len);
memcpy(dest_addr, &raddr_in, dest_len);
break;
case SOCKET_ADDRESS_TYPE_UNIX:
ret = unlink(local->u.q_unix.path);
if (ret < 0 && errno != ENOENT) {
error_setg_errno(errp, errno, "failed to unlink socket %s",
local->u.q_unix.path);
return -1;
}
laddr_un.sun_family = PF_UNIX;
ret = snprintf(laddr_un.sun_path, sizeof(laddr_un.sun_path), "%s",
local->u.q_unix.path);
if (ret < 0 || ret >= sizeof(laddr_un.sun_path)) {
error_setg(errp, "UNIX socket path '%s' is too long",
local->u.q_unix.path);
error_append_hint(errp, "Path must be less than %zu bytes\n",
sizeof(laddr_un.sun_path));
}
raddr_un.sun_family = PF_UNIX;
ret = snprintf(raddr_un.sun_path, sizeof(raddr_un.sun_path), "%s",
remote->u.q_unix.path);
if (ret < 0 || ret >= sizeof(raddr_un.sun_path)) {
error_setg(errp, "UNIX socket path '%s' is too long",
remote->u.q_unix.path);
error_append_hint(errp, "Path must be less than %zu bytes\n",
sizeof(raddr_un.sun_path));
}
fd = qemu_socket(PF_UNIX, SOCK_DGRAM, 0);
if (fd < 0) {
error_setg_errno(errp, errno, "can't create datagram socket");
return -1;
}
ret = bind(fd, (struct sockaddr *)&laddr_un, sizeof(laddr_un));
if (ret < 0) {
error_setg_errno(errp, errno, "can't bind unix=%s to socket",
laddr_un.sun_path);
close(fd);
return -1;
}
if (!qemu_set_blocking(fd, false, errp)) {
close(fd);
return -1;
}
dest_len = sizeof(raddr_un);
dest_addr = g_malloc(dest_len);
memcpy(dest_addr, &raddr_un, dest_len);
break;
case SOCKET_ADDRESS_TYPE_FD:
fd = monitor_fd_param(monitor_cur(), local->u.fd.str, errp);
if (fd == -1) {
return -1;
}
ret = qemu_socket_try_set_nonblock(fd);
if (ret < 0) {
error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
name, fd);
return -1;
}
dest_addr = NULL;
dest_len = 0;
break;
default:
error_setg(errp, "only support inet or fd type for local");
return -1;
}
s = net_dgram_fd_init(peer, "dgram", name, fd, errp);
if (!s) {
return -1;
}
if (remote) {
g_assert(s->dest_addr == NULL);
s->dest_addr = dest_addr;
s->dest_len = dest_len;
}
switch (local->type) {
case SOCKET_ADDRESS_TYPE_INET:
qemu_set_info_str(&s->nc, "udp=%s:%d/%s:%d",
inet_ntoa(laddr_in.sin_addr),
ntohs(laddr_in.sin_port),
inet_ntoa(raddr_in.sin_addr),
ntohs(raddr_in.sin_port));
break;
case SOCKET_ADDRESS_TYPE_UNIX:
qemu_set_info_str(&s->nc, "udp=%s:%s",
laddr_un.sun_path, raddr_un.sun_path);
break;
case SOCKET_ADDRESS_TYPE_FD: {
SocketAddress *sa;
SocketAddressType sa_type;
sa = socket_local_address(fd, errp);
if (sa) {
sa_type = sa->type;
qapi_free_SocketAddress(sa);
qemu_set_info_str(&s->nc, "fd=%d %s", fd,
SocketAddressType_str(sa_type));
} else {
qemu_set_info_str(&s->nc, "fd=%d", fd);
}
break;
}
default:
g_assert_not_reached();
}
return 0;
}
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