Commit b412eb61 authored by Alexander Graf's avatar Alexander Graf Committed by Jan Kiszka

slirp: add 'cmd:' target for guestfwd

When using guestfwd=, Qemu only connects the virtual server's TCP port
to a single chardev. This is useless in most cases, as we usually want
to have more than a single connection from the guest to the outside world.

This patch adds a new cmd: target to guestfwd= that allows for execution
of a command on every TCP connection. This leverages the same code as
the -smb parameter, just that here the command is user defined.
Reported-by: 's avatarSascha Wilde <wilde@intevation.de>
Signed-off-by: 's avatarAlexander Graf <agraf@suse.de>
Signed-off-by: 's avatarJan Kiszka <jan.kiszka@siemens.com>
parent 1cb1c5d1
......@@ -626,25 +626,35 @@ static int slirp_guestfwd(SlirpState *s, const char *config_str,
fwd = g_malloc(sizeof(struct GuestFwd));
snprintf(buf, sizeof(buf), "guestfwd.tcp.%d", port);
fwd->hd = qemu_chr_new(buf, p, NULL);
if (!fwd->hd) {
error_report("could not open guest forwarding device '%s'", buf);
g_free(fwd);
return -1;
}
if (slirp_add_exec(s->slirp, 3, fwd->hd, &server, port) < 0) {
error_report("conflicting/invalid host:port in guest forwarding "
"rule '%s'", config_str);
g_free(fwd);
return -1;
}
fwd->server = server;
fwd->port = port;
fwd->slirp = s->slirp;
if ((strlen(p) > 4) && !strncmp(p, "cmd:", 4)) {
if (slirp_add_exec(s->slirp, 0, &p[4], &server, port) < 0) {
error_report("conflicting/invalid host:port in guest forwarding "
"rule '%s'", config_str);
g_free(fwd);
return -1;
}
} else {
fwd->hd = qemu_chr_new(buf, p, NULL);
if (!fwd->hd) {
error_report("could not open guest forwarding device '%s'", buf);
g_free(fwd);
return -1;
}
if (slirp_add_exec(s->slirp, 3, fwd->hd, &server, port) < 0) {
error_report("conflicting/invalid host:port in guest forwarding "
"rule '%s'", config_str);
g_free(fwd);
return -1;
}
fwd->server = server;
fwd->port = port;
fwd->slirp = s->slirp;
qemu_chr_add_handlers(fwd->hd, guestfwd_can_read, guestfwd_read,
NULL, fwd);
qemu_chr_add_handlers(fwd->hd, guestfwd_can_read, guestfwd_read,
NULL, fwd);
}
return 0;
fail_syntax:
......
......@@ -1421,8 +1421,28 @@ Then when you use on the host @code{telnet localhost 5555}, you
connect to the guest telnet server.
@item guestfwd=[tcp]:@var{server}:@var{port}-@var{dev}
@item guestfwd=[tcp]:@var{server}:@var{port}-@var{cmd:command}
Forward guest TCP connections to the IP address @var{server} on port @var{port}
to the character device @var{dev}. This option can be given multiple times.
to the character device @var{dev} or to a program executed by @var{cmd:command}
which gets spawned for each connection. This option can be given multiple times.
You can either use a chardev directly and have that one used throughout Qemu's
lifetime, like in the following example:
@example
# open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
# the guest accesses it
qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...]
@end example
Or you can execute a command on every TCP connection established by the guest,
so that Qemu behaves similar to an inetd process for that virtual server:
@example
# call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
# and connect the TCP stream to its stdin/stdout
qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
@end example
@end table
......
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