v4.19.13 snapshot.
diff --git a/arch/um/drivers/umcast_user.c b/arch/um/drivers/umcast_user.c
new file mode 100644
index 0000000..6074184
--- /dev/null
+++ b/arch/um/drivers/umcast_user.c
@@ -0,0 +1,184 @@
+/*
+ * user-mode-linux networking multicast transport
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Copyright (C) 2001 by Harald Welte <laforge@gnumonks.org>
+ *
+ * based on the existing uml-networking code, which is
+ * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
+ * James Leu (jleu@mindspring.net).
+ * Copyright (C) 2001 by various other people who didn't put their name here.
+ *
+ * Licensed under the GPL.
+ *
+ */
+
+#include <unistd.h>
+#include <errno.h>
+#include <netinet/in.h>
+#include "umcast.h"
+#include <net_user.h>
+#include <um_malloc.h>
+
+static struct sockaddr_in *new_addr(char *addr, unsigned short port)
+{
+ struct sockaddr_in *sin;
+
+ sin = uml_kmalloc(sizeof(struct sockaddr_in), UM_GFP_KERNEL);
+ if (sin == NULL) {
+ printk(UM_KERN_ERR "new_addr: allocation of sockaddr_in "
+ "failed\n");
+ return NULL;
+ }
+ sin->sin_family = AF_INET;
+ if (addr)
+ sin->sin_addr.s_addr = in_aton(addr);
+ else
+ sin->sin_addr.s_addr = INADDR_ANY;
+ sin->sin_port = htons(port);
+ return sin;
+}
+
+static int umcast_user_init(void *data, void *dev)
+{
+ struct umcast_data *pri = data;
+
+ pri->remote_addr = new_addr(pri->addr, pri->rport);
+ if (pri->unicast)
+ pri->listen_addr = new_addr(NULL, pri->lport);
+ else
+ pri->listen_addr = pri->remote_addr;
+ pri->dev = dev;
+ return 0;
+}
+
+static void umcast_remove(void *data)
+{
+ struct umcast_data *pri = data;
+
+ kfree(pri->listen_addr);
+ if (pri->unicast)
+ kfree(pri->remote_addr);
+ pri->listen_addr = pri->remote_addr = NULL;
+}
+
+static int umcast_open(void *data)
+{
+ struct umcast_data *pri = data;
+ struct sockaddr_in *lsin = pri->listen_addr;
+ struct sockaddr_in *rsin = pri->remote_addr;
+ struct ip_mreq mreq;
+ int fd, yes = 1, err = -EINVAL;
+
+
+ if ((!pri->unicast && lsin->sin_addr.s_addr == 0) ||
+ (rsin->sin_addr.s_addr == 0) ||
+ (lsin->sin_port == 0) || (rsin->sin_port == 0))
+ goto out;
+
+ fd = socket(AF_INET, SOCK_DGRAM, 0);
+
+ if (fd < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "umcast_open : data socket failed, "
+ "errno = %d\n", errno);
+ goto out;
+ }
+
+ if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "umcast_open: SO_REUSEADDR failed, "
+ "errno = %d\n", errno);
+ goto out_close;
+ }
+
+ if (!pri->unicast) {
+ /* set ttl according to config */
+ if (setsockopt(fd, SOL_IP, IP_MULTICAST_TTL, &pri->ttl,
+ sizeof(pri->ttl)) < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "umcast_open: IP_MULTICAST_TTL "
+ "failed, error = %d\n", errno);
+ goto out_close;
+ }
+
+ /* set LOOP, so data does get fed back to local sockets */
+ if (setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP,
+ &yes, sizeof(yes)) < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "umcast_open: IP_MULTICAST_LOOP "
+ "failed, error = %d\n", errno);
+ goto out_close;
+ }
+ }
+
+ /* bind socket to the address */
+ if (bind(fd, (struct sockaddr *) lsin, sizeof(*lsin)) < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "umcast_open : data bind failed, "
+ "errno = %d\n", errno);
+ goto out_close;
+ }
+
+ if (!pri->unicast) {
+ /* subscribe to the multicast group */
+ mreq.imr_multiaddr.s_addr = lsin->sin_addr.s_addr;
+ mreq.imr_interface.s_addr = 0;
+ if (setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP,
+ &mreq, sizeof(mreq)) < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "umcast_open: IP_ADD_MEMBERSHIP "
+ "failed, error = %d\n", errno);
+ printk(UM_KERN_ERR "There appears not to be a "
+ "multicast-capable network interface on the "
+ "host.\n");
+ printk(UM_KERN_ERR "eth0 should be configured in order "
+ "to use the multicast transport.\n");
+ goto out_close;
+ }
+ }
+
+ return fd;
+
+ out_close:
+ close(fd);
+ out:
+ return err;
+}
+
+static void umcast_close(int fd, void *data)
+{
+ struct umcast_data *pri = data;
+
+ if (!pri->unicast) {
+ struct ip_mreq mreq;
+ struct sockaddr_in *lsin = pri->listen_addr;
+
+ mreq.imr_multiaddr.s_addr = lsin->sin_addr.s_addr;
+ mreq.imr_interface.s_addr = 0;
+ if (setsockopt(fd, SOL_IP, IP_DROP_MEMBERSHIP,
+ &mreq, sizeof(mreq)) < 0) {
+ printk(UM_KERN_ERR "umcast_close: IP_DROP_MEMBERSHIP "
+ "failed, error = %d\n", errno);
+ }
+ }
+
+ close(fd);
+}
+
+int umcast_user_write(int fd, void *buf, int len, struct umcast_data *pri)
+{
+ struct sockaddr_in *data_addr = pri->remote_addr;
+
+ return net_sendto(fd, buf, len, data_addr, sizeof(*data_addr));
+}
+
+const struct net_user_info umcast_user_info = {
+ .init = umcast_user_init,
+ .open = umcast_open,
+ .close = umcast_close,
+ .remove = umcast_remove,
+ .add_address = NULL,
+ .delete_address = NULL,
+ .mtu = ETH_MAX_PACKET,
+ .max_packet = ETH_MAX_PACKET + ETH_HEADER_OTHER,
+};