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/***
This file is part of systemd.
Copyright 2015 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <systemd/sd-netlink.h>
#include "alloc-util.h"
#include "fd-util.h"
#include "firewall-util.h"
#include "in-addr-util.h"
#include "local-addresses.h"
#include "netlink-util.h"
#include "nspawn-expose-ports.h"
#include "parse-util.h"
#include "socket-util.h"
#include "string-util.h"
#include "util.h"
int expose_port_parse(ExposePort **l, const char *s) {
const char *split, *e;
uint16_t container_port, host_port;
int protocol;
ExposePort *p;
int r;
assert(l);
assert(s);
if ((e = startswith(s, "tcp:")))
protocol = IPPROTO_TCP;
else if ((e = startswith(s, "udp:")))
protocol = IPPROTO_UDP;
else {
e = s;
protocol = IPPROTO_TCP;
}
split = strchr(e, ':');
if (split) {
char v[split - e + 1];
memcpy(v, e, split - e);
v[split - e] = 0;
r = safe_atou16(v, &host_port);
if (r < 0 || host_port <= 0)
return -EINVAL;
r = safe_atou16(split + 1, &container_port);
} else {
r = safe_atou16(e, &container_port);
host_port = container_port;
}
if (r < 0 || container_port <= 0)
return -EINVAL;
LIST_FOREACH(ports, p, *l)
if (p->protocol == protocol && p->host_port == host_port)
return -EEXIST;
p = new(ExposePort, 1);
if (!p)
return -ENOMEM;
p->protocol = protocol;
p->host_port = host_port;
p->container_port = container_port;
LIST_PREPEND(ports, *l, p);
return 0;
}
void expose_port_free_all(ExposePort *p) {
while (p) {
ExposePort *q = p;
LIST_REMOVE(ports, p, q);
free(q);
}
}
int expose_port_flush(ExposePort* l, union in_addr_union *exposed) {
ExposePort *p;
int r, af = AF_INET;
assert(exposed);
if (!l)
return 0;
if (in_addr_is_null(af, exposed))
return 0;
log_debug("Lost IP address.");
LIST_FOREACH(ports, p, l) {
r = fw_add_local_dnat(false,
af,
p->protocol,
NULL,
NULL, 0,
NULL, 0,
p->host_port,
exposed,
p->container_port,
NULL);
if (r < 0)
log_warning_errno(r, "Failed to modify firewall: %m");
}
*exposed = IN_ADDR_NULL;
return 0;
}
int expose_port_execute(sd_netlink *rtnl, ExposePort *l, union in_addr_union *exposed) {
_cleanup_free_ struct local_address *addresses = NULL;
_cleanup_free_ char *pretty = NULL;
union in_addr_union new_exposed;
ExposePort *p;
bool add;
int af = AF_INET, r;
assert(exposed);
/* Invoked each time an address is added or removed inside the
* container */
if (!l)
return 0;
r = local_addresses(rtnl, 0, af, &addresses);
if (r < 0)
return log_error_errno(r, "Failed to enumerate local addresses: %m");
add = r > 0 &&
addresses[0].family == af &&
addresses[0].scope < RT_SCOPE_LINK;
if (!add)
return expose_port_flush(l, exposed);
new_exposed = addresses[0].address;
if (in_addr_equal(af, exposed, &new_exposed))
return 0;
in_addr_to_string(af, &new_exposed, &pretty);
log_debug("New container IP is %s.", strna(pretty));
LIST_FOREACH(ports, p, l) {
r = fw_add_local_dnat(true,
af,
p->protocol,
NULL,
NULL, 0,
NULL, 0,
p->host_port,
&new_exposed,
p->container_port,
in_addr_is_null(af, exposed) ? NULL : exposed);
if (r < 0)
log_warning_errno(r, "Failed to modify firewall: %m");
}
*exposed = new_exposed;
return 0;
}
int expose_port_send_rtnl(int send_fd) {
_cleanup_close_ int fd = -1;
int r;
assert(send_fd >= 0);
fd = socket(PF_NETLINK, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK, NETLINK_ROUTE);
if (fd < 0)
return log_error_errno(errno, "Failed to allocate container netlink: %m");
/* Store away the fd in the socket, so that it stays open as
* long as we run the child */
r = send_one_fd(send_fd, fd, 0);
if (r < 0)
return log_error_errno(r, "Failed to send netlink fd: %m");
return 0;
}
int expose_port_watch_rtnl(
sd_event *event,
int recv_fd,
sd_netlink_message_handler_t handler,
union in_addr_union *exposed,
sd_netlink **ret) {
_cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
int fd, r;
assert(event);
assert(recv_fd >= 0);
assert(ret);
fd = receive_one_fd(recv_fd, 0);
if (fd < 0)
return log_error_errno(fd, "Failed to recv netlink fd: %m");
r = sd_netlink_open_fd(&rtnl, fd);
if (r < 0) {
safe_close(fd);
return log_error_errno(r, "Failed to create rtnl object: %m");
}
r = sd_netlink_add_match(rtnl, RTM_NEWADDR, handler, exposed);
if (r < 0)
return log_error_errno(r, "Failed to subscribe to RTM_NEWADDR messages: %m");
r = sd_netlink_add_match(rtnl, RTM_DELADDR, handler, exposed);
if (r < 0)
return log_error_errno(r, "Failed to subscribe to RTM_DELADDR messages: %m");
r = sd_netlink_attach_event(rtnl, event, 0);
if (r < 0)
return log_error_errno(r, "Failed to add to even loop: %m");
*ret = rtnl;
rtnl = NULL;
return 0;
}
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