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-rw-r--r--net/dgram.c623
1 files changed, 623 insertions, 0 deletions
diff --git a/net/dgram.c b/net/dgram.c
new file mode 100644
index 0000000000..9f7bf38376
--- /dev/null
+++ b/net/dgram.c
@@ -0,0 +1,623 @@
+/*
+ * 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;
+ }
+ }
+
+ qemu_socket_set_nonblock(fd);
+ return fd;
+fail:
+ if (fd >= 0) {
+ closesocket(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);
+ closesocket(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);
+ closesocket(fd);
+ return -1;
+ }
+ /* clone dgram socket */
+ newfd = net_dgram_mcast_create(saddr, NULL, errp);
+ if (newfd < 0) {
+ g_free(saddr);
+ closesocket(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");
+ closesocket(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));
+ closesocket(fd);
+ return -1;
+ }
+ qemu_socket_set_nonblock(fd);
+
+ 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);
+ closesocket(fd);
+ return -1;
+ }
+ qemu_socket_set_nonblock(fd);
+
+ 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;
+}
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2025-04-27 02:49:32 +0200