On Mon, Nov 22, 2010 at 10:48:45AM -0800, Mike Ryan wrote:
> Michael, this patch implements the feature with a bind address instead
> of a bind interface. It should address the cross-platform issues that
> were raised.
>
> Others: any comments?
Looks ok. This does not handle IPv6 but the rest of the code doesn't,
either.
> On Wed, Nov 17, 2010 at 05:16:26PM -0800, Mike Ryan wrote:
> > 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.
> > ---
> > net.c | 4 ++++
> > net/socket.c | 46 ++++++++++++++++++++++++++++++++++------------
> > qemu-options.hx | 11 +++++++++--
> > 3 files changed, 47 insertions(+), 14 deletions(-)
> >
> > diff --git a/net.c b/net.c
> > index c5e6063..9ba5be2 100644
> > --- a/net.c
> > +++ b/net.c
> > @@ -1050,6 +1050,10 @@ static const struct {
> > .name = "mcast",
> > .type = QEMU_OPT_STRING,
> > .help = "UDP multicast address and port number",
> > + }, {
> > + .name = "localaddr",
> > + .type = QEMU_OPT_STRING,
> > + .help = "source address for multicast packets",
> > },
> > { /* end of list */ }
> > },
> > diff --git a/net/socket.c b/net/socket.c
> > index 1c4e153..d443f4c 100644
> > --- a/net/socket.c
> > +++ b/net/socket.c
> > @@ -149,7 +149,7 @@ static void net_socket_send_dgram(void *opaque)
> > qemu_send_packet(&s->nc, s->buf, size);
> > }
> >
> > -static int net_socket_mcast_create(struct sockaddr_in *mcastaddr)
> > +static int net_socket_mcast_create(struct sockaddr_in *mcastaddr, struct
> > in_addr *localaddr)
> > {
> > struct ip_mreq imr;
> > int fd;
> > @@ -201,6 +201,15 @@ static int net_socket_mcast_create(struct sockaddr_in
> > *mcastaddr)
> > 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:
> > @@ -248,7 +257,7 @@ static NetSocketState
> > *net_socket_fd_init_dgram(VLANState *vlan,
> > return NULL;
> > }
> > /* clone dgram socket */
> > - newfd = net_socket_mcast_create(&saddr);
> > + newfd = net_socket_mcast_create(&saddr, NULL);
> > if (newfd < 0) {
> > /* error already reported by net_socket_mcast_create() */
> > close(fd);
> > @@ -468,17 +477,26 @@ static int net_socket_connect_init(VLANState *vlan,
> > static int net_socket_mcast_init(VLANState *vlan,
> > const char *model,
> > const char *name,
> > - const char *host_str)
> > + 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);
> > + fd = net_socket_mcast_create(&saddr, param_localaddr);
> > if (fd < 0)
> > return -1;
> >
> > @@ -505,8 +523,9 @@ int net_init_socket(QemuOpts *opts,
> >
> > if (qemu_opt_get(opts, "listen") ||
> > qemu_opt_get(opts, "connect") ||
> > - qemu_opt_get(opts, "mcast")) {
> > - error_report("listen=, connect= and mcast= is invalid with
> > fd=");
> > + qemu_opt_get(opts, "mcast") ||
> > + qemu_opt_get(opts, "localaddr")) {
> > + error_report("listen=, connect=, mcast= and localaddr= is
> > invalid with fd=\n");
> > return -1;
> > }
> >
> > @@ -524,8 +543,9 @@ int net_init_socket(QemuOpts *opts,
> >
> > if (qemu_opt_get(opts, "fd") ||
> > qemu_opt_get(opts, "connect") ||
> > - qemu_opt_get(opts, "mcast")) {
> > - error_report("fd=, connect= and mcast= is invalid with
> > listen=");
> > + qemu_opt_get(opts, "mcast") ||
> > + qemu_opt_get(opts, "localaddr")) {
> > + error_report("fd=, connect=, mcast= and localaddr= is invalid
> > with listen=\n");
> > return -1;
> > }
> >
> > @@ -539,8 +559,9 @@ int net_init_socket(QemuOpts *opts,
> >
> > if (qemu_opt_get(opts, "fd") ||
> > qemu_opt_get(opts, "listen") ||
> > - qemu_opt_get(opts, "mcast")) {
> > - error_report("fd=, listen= and mcast= is invalid with
> > connect=");
> > + qemu_opt_get(opts, "mcast") ||
> > + qemu_opt_get(opts, "localaddr")) {
> > + error_report("fd=, listen=, mcast= and localaddr= is invalid
> > with connect=\n");
> > return -1;
> > }
> >
> > @@ -550,7 +571,7 @@ int net_init_socket(QemuOpts *opts,
> > return -1;
> > }
> > } else if (qemu_opt_get(opts, "mcast")) {
> > - const char *mcast;
> > + const char *mcast, *localaddr;
> >
> > if (qemu_opt_get(opts, "fd") ||
> > qemu_opt_get(opts, "connect") ||
> > @@ -560,8 +581,9 @@ int net_init_socket(QemuOpts *opts,
> > }
> >
> > mcast = qemu_opt_get(opts, "mcast");
> > + localaddr = qemu_opt_get(opts, "localaddr");
> >
> > - if (net_socket_mcast_init(vlan, "socket", name, mcast) == -1) {
> > + if (net_socket_mcast_init(vlan, "socket", name, mcast, localaddr)
> > == -1) {
> > return -1;
> > }
> > } else {
> > diff --git a/qemu-options.hx b/qemu-options.hx
> > index 4d99a58..accd16a 100644
> > --- a/qemu-options.hx
> > +++ b/qemu-options.hx
> > @@ -1061,8 +1061,9 @@ DEF("net", HAS_ARG, QEMU_OPTION_net,
> > #endif
> > "-net
> > socket[,vlan=n][,name=str][,fd=h][,listen=[host]:port][,connect=host:port]\n"
> > " connect the vlan 'n' to another VLAN using a socket
> > connection\n"
> > - "-net socket[,vlan=n][,name=str][,fd=h][,mcast=maddr:port]\n"
> > + "-net
> > socket[,vlan=n][,name=str][,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
> > " connect the vlan 'n' to multicast maddr and port\n"
> > + " use 'localaddr=addr' to specify the host address to
> > send packets from\n"
> > #ifdef CONFIG_VDE
> > "-net
> > vde[,vlan=n][,name=str][,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
> > " connect the vlan 'n' to port 'n' of a vde switch
> > running\n"
> > @@ -1256,7 +1257,7 @@ qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
> > -net socket,connect=127.0.0.1:1234
> > @end example
> >
> > -...@item -net socket[,vl...@var{n}][,na...@var{name}][,f...@var{h}]
> > [,mca...@var{maddr}:@var{port}]
> > +...@item -net
> > socket[,vl...@var{n}][,na...@var{name}][,f...@var{h}][,mca...@var{maddr}:@var{port}[,localad...@var{addr}]]
> >
> > Create a VLAN @var{n} shared with another QEMU virtual
> > machines using a UDP multicast socket, effectively making a bus for
> > @@ -1296,6 +1297,12 @@ qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
> > /path/to/linux ubd0=/path/to/root_fs eth0=mcast
> > @end example
> >
> > +Example (send packets from host's 1.2.3.4):
> > +...@example
> > +qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
> > + -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
> > +...@end example
> > +
> > @item -net vde[,vl...@var{n}][,na...@var{name}][,so...@var{socketpath}]
> > [,po...@var{n}][,gro...@var{groupname}][,mo...@var{octalmode}]
> > Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
> > listening for incoming connections on @var{socketpath}. Use GROUP
> > @var{groupname}
> > --
> > 1.7.0.4
> >
