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libvirt/src/network/bridge_driver_linux.c
Laine Stump f931c85fb0 network: eliminate unnecessary labels 
All these cleanup/error labels were reduced to having just "return
ret" by a previous patch, so get rid of them and return directly.

This patch coincidentally fixes a bug in
networkFindUnusedBridgeName(), where we would log an error yet still
return success if we failed to find a single unused "virbrNNN" name
after checking all values of "N" from 0 - 256. Said bug was introduced
when that function was originally written, in commit a28d3e485f
(libvirt 1.2.15, 2015)

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2020-07-20 19:11:35 -04:00

972 lines
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/*
* bridge_driver_linux.c: Linux implementation of bridge driver
*
* Copyright (C) 2006-2013 Red Hat, Inc.
* Copyright (C) 2006 Daniel P. Berrange
*
* This library 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.
*
* This library 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 this library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include "viralloc.h"
#include "virfile.h"
#include "viriptables.h"
#include "virstring.h"
#include "virlog.h"
#include "virfirewall.h"
#include "virfirewalld.h"
#define VIR_FROM_THIS VIR_FROM_NONE
VIR_LOG_INIT("network.bridge_driver_linux");
#define PROC_NET_ROUTE "/proc/net/route"
static virOnceControl createdOnce;
static bool chainInitDone; /* true iff networkSetupPrivateChains was ever called */
static bool createdChains; /* true iff networkSetupPrivateChains created chains during most recent call */
static virErrorPtr errInitV4;
static virErrorPtr errInitV6;
/* Usually only called via virOnce, but can also be called directly in
* response to firewalld reload (if chainInitDone == true)
*/
static void networkSetupPrivateChains(void)
{
int rc;
VIR_DEBUG("Setting up global firewall chains");
createdChains = false;
virFreeError(errInitV4);
errInitV4 = NULL;
virFreeError(errInitV6);
errInitV6 = NULL;
rc = iptablesSetupPrivateChains(VIR_FIREWALL_LAYER_IPV4);
if (rc < 0) {
VIR_DEBUG("Failed to create global IPv4 chains: %s",
virGetLastErrorMessage());
errInitV4 = virSaveLastError();
virResetLastError();
} else {
if (rc) {
VIR_DEBUG("Created global IPv4 chains");
createdChains = true;
} else {
VIR_DEBUG("Global IPv4 chains already exist");
}
}
rc = iptablesSetupPrivateChains(VIR_FIREWALL_LAYER_IPV6);
if (rc < 0) {
VIR_DEBUG("Failed to create global IPv6 chains: %s",
virGetLastErrorMessage());
errInitV6 = virSaveLastError();
virResetLastError();
} else {
if (rc) {
VIR_DEBUG("Created global IPv6 chains");
createdChains = true;
} else {
VIR_DEBUG("Global IPv6 chains already exist");
}
}
chainInitDone = true;
}
static int
networkHasRunningNetworksWithFWHelper(virNetworkObjPtr obj,
void *opaque)
{
bool *activeWithFW = opaque;
virObjectLock(obj);
if (virNetworkObjIsActive(obj)) {
virNetworkDefPtr def = virNetworkObjGetDef(obj);
switch ((virNetworkForwardType) def->forward.type) {
case VIR_NETWORK_FORWARD_NONE:
case VIR_NETWORK_FORWARD_NAT:
case VIR_NETWORK_FORWARD_ROUTE:
*activeWithFW = true;
break;
case VIR_NETWORK_FORWARD_OPEN:
case VIR_NETWORK_FORWARD_BRIDGE:
case VIR_NETWORK_FORWARD_PRIVATE:
case VIR_NETWORK_FORWARD_VEPA:
case VIR_NETWORK_FORWARD_PASSTHROUGH:
case VIR_NETWORK_FORWARD_HOSTDEV:
case VIR_NETWORK_FORWARD_LAST:
break;
}
}
virObjectUnlock(obj);
/*
* terminate ForEach early once we find an active network that
* adds Firewall rules (return status is ignored)
*/
if (*activeWithFW)
return -1;
return 0;
}
static bool
networkHasRunningNetworksWithFW(virNetworkDriverStatePtr driver)
{
bool activeWithFW = false;
virNetworkObjListForEach(driver->networks,
networkHasRunningNetworksWithFWHelper,
&activeWithFW);
return activeWithFW;
}
void
networkPreReloadFirewallRules(virNetworkDriverStatePtr driver,
bool startup,
bool force)
{
/*
* If there are any running networks, we need to
* create the global rules upfront. This allows us
* convert rules created by old libvirt into the new
* format.
*
* If there are not any running networks, then we
* must not create rules, because the rules will
* cause the conntrack kernel module to be loaded.
* This imposes a significant performance hit on
* the networking stack. Thus we will only create
* rules if a network is later startup.
*
* Any errors here are saved to be reported at time
* of starting the network though as that makes them
* more likely to be seen by a human
*/
if (chainInitDone && force) {
/* The Private chains have already been initialized once
* during this run of libvirtd, so 1) we can't do it again via
* virOnce(), and 2) we need to re-add the private chains even
* if there are currently no running networks, because the
* next time a network is started, libvirt will expect that
* the chains have already been added. So we call directly
* instead of via virOnce().
*/
networkSetupPrivateChains();
} else {
if (!networkHasRunningNetworksWithFW(driver)) {
VIR_DEBUG("Delayed global rule setup as no networks with firewall rules are running");
return;
}
ignore_value(virOnce(&createdOnce, networkSetupPrivateChains));
/*
* If this is initial startup, and we just created the
* top level private chains we either
*
* - upgraded from old libvirt
* - freshly booted from clean state
*
* In the first case we must delete the old rules from
* the built-in chains, instead of our new private chains.
* In the second case it doesn't matter, since no existing
* rules will be present. Thus we can safely just tell it
* to always delete from the builin chain
*/
if (startup && createdChains) {
VIR_DEBUG("Requesting cleanup of legacy firewall rules");
iptablesSetDeletePrivate(false);
}
}
}
void networkPostReloadFirewallRules(bool startup G_GNUC_UNUSED)
{
iptablesSetDeletePrivate(true);
}
/* XXX: This function can be a lot more exhaustive, there are certainly
* other scenarios where we can ruin host network connectivity.
* XXX: Using a proper library is preferred over parsing /proc
*/
int networkCheckRouteCollision(virNetworkDefPtr def)
{
int len;
char *cur;
g_autofree char *buf = NULL;
/* allow for up to 100000 routes (each line is 128 bytes) */
enum {MAX_ROUTE_SIZE = 128*100000};
/* Read whole routing table into memory */
if ((len = virFileReadAll(PROC_NET_ROUTE, MAX_ROUTE_SIZE, &buf)) < 0)
return 0;
/* Dropping the last character shouldn't hurt */
if (len > 0)
buf[len-1] = '\0';
VIR_DEBUG("%s output:\n%s", PROC_NET_ROUTE, buf);
if (!STRPREFIX(buf, "Iface"))
return 0;
/* First line is just headings, skip it */
cur = strchr(buf, '\n');
if (cur)
cur++;
while (cur) {
char iface[17], dest[128], mask[128];
unsigned int addr_val, mask_val;
virNetworkIPDefPtr ipdef;
virNetDevIPRoutePtr routedef;
int num;
size_t i;
/* NUL-terminate the line, so sscanf doesn't go beyond a newline. */
char *nl = strchr(cur, '\n');
if (nl)
*nl++ = '\0';
num = sscanf(cur, "%16s %127s %*s %*s %*s %*s %*s %127s",
iface, dest, mask);
cur = nl;
if (num != 3) {
VIR_DEBUG("Failed to parse %s", PROC_NET_ROUTE);
continue;
}
if (virStrToLong_ui(dest, NULL, 16, &addr_val) < 0) {
VIR_DEBUG("Failed to convert network address %s to uint", dest);
continue;
}
if (virStrToLong_ui(mask, NULL, 16, &mask_val) < 0) {
VIR_DEBUG("Failed to convert network mask %s to uint", mask);
continue;
}
addr_val &= mask_val;
for (i = 0;
(ipdef = virNetworkDefGetIPByIndex(def, AF_INET, i));
i++) {
unsigned int net_dest;
virSocketAddr netmask;
if (virNetworkIPDefNetmask(ipdef, &netmask) < 0) {
VIR_WARN("Failed to get netmask of '%s'",
def->bridge);
continue;
}
net_dest = (ipdef->address.data.inet4.sin_addr.s_addr &
netmask.data.inet4.sin_addr.s_addr);
if ((net_dest == addr_val) &&
(netmask.data.inet4.sin_addr.s_addr == mask_val)) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Network is already in use by interface %s"),
iface);
return -1;
}
}
for (i = 0;
(routedef = virNetworkDefGetRouteByIndex(def, AF_INET, i));
i++) {
virSocketAddr r_mask, r_addr;
virSocketAddrPtr tmp_addr = virNetDevIPRouteGetAddress(routedef);
int r_prefix = virNetDevIPRouteGetPrefix(routedef);
if (!tmp_addr ||
virSocketAddrMaskByPrefix(tmp_addr, r_prefix, &r_addr) < 0 ||
virSocketAddrPrefixToNetmask(r_prefix, &r_mask, AF_INET) < 0)
continue;
if ((r_addr.data.inet4.sin_addr.s_addr == addr_val) &&
(r_mask.data.inet4.sin_addr.s_addr == mask_val)) {
g_autofree char *addr_str = virSocketAddrFormat(&r_addr);
if (!addr_str)
virResetLastError();
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Route address '%s' conflicts "
"with IP address for '%s'"),
NULLSTR(addr_str), iface);
return -1;
}
}
}
return 0;
}
static const char networkLocalMulticastIPv4[] = "224.0.0.0/24";
static const char networkLocalMulticastIPv6[] = "ff02::/16";
static const char networkLocalBroadcast[] = "255.255.255.255/32";
static int
networkAddMasqueradingFirewallRules(virFirewallPtr fw,
virNetworkDefPtr def,
virNetworkIPDefPtr ipdef)
{
int prefix = virNetworkIPDefPrefix(ipdef);
const char *forwardIf = virNetworkDefForwardIf(def, 0);
bool isIPv4 = VIR_SOCKET_ADDR_IS_FAMILY(&ipdef->address, AF_INET);
if (prefix < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Invalid prefix or netmask for '%s'"),
def->bridge);
return -1;
}
/* allow forwarding packets from the bridge interface */
if (iptablesAddForwardAllowOut(fw,
&ipdef->address,
prefix,
def->bridge,
forwardIf) < 0)
return -1;
/* allow forwarding packets to the bridge interface if they are
* part of an existing connection
*/
if (iptablesAddForwardAllowRelatedIn(fw,
&ipdef->address,
prefix,
def->bridge,
forwardIf) < 0)
return -1;
/*
* Enable masquerading.
*
* We need to end up with 5 rules in the table in this order
*
* 1. do not masquerade packets targeting 224.0.0.0/24
* 2. do not masquerade packets targeting 255.255.255.255/32
* 3. masquerade protocol=tcp with sport mapping restriction
* 4. masquerade protocol=udp with sport mapping restriction
* 5. generic, masquerade any protocol
*
* 224.0.0.0/24 is the local network multicast range. Packets are not
* forwarded outside.
*
* 255.255.255.255/32 is the broadcast address of any local network. Again,
* such packets are never forwarded, but strict DHCP clients don't accept
* DHCP replies with changed source ports.
*
* The sport mappings are required, because default IPtables
* MASQUERADE maintain port numbers unchanged where possible.
*
* NFS can be configured to only "trust" port numbers < 1023.
*
* Guests using NAT thus need to be prevented from having port
* numbers < 1023, otherwise they can bypass the NFS "security"
* check on the source port number.
*
* Since we use '--insert' to add rules to the header of the
* chain, we actually need to add them in the reverse of the
* order just mentioned !
*/
/* First the generic masquerade rule for other protocols */
if (iptablesAddForwardMasquerade(fw,
&ipdef->address,
prefix,
forwardIf,
&def->forward.addr,
&def->forward.port,
NULL) < 0)
return -1;
/* UDP with a source port restriction */
if (iptablesAddForwardMasquerade(fw,
&ipdef->address,
prefix,
forwardIf,
&def->forward.addr,
&def->forward.port,
"udp") < 0)
return -1;
/* TCP with a source port restriction */
if (iptablesAddForwardMasquerade(fw,
&ipdef->address,
prefix,
forwardIf,
&def->forward.addr,
&def->forward.port,
"tcp") < 0)
return -1;
/* exempt local network broadcast address as destination */
if (isIPv4 &&
iptablesAddDontMasquerade(fw,
&ipdef->address,
prefix,
forwardIf,
networkLocalBroadcast) < 0)
return -1;
/* exempt local multicast range as destination */
if (iptablesAddDontMasquerade(fw,
&ipdef->address,
prefix,
forwardIf,
isIPv4 ? networkLocalMulticastIPv4 :
networkLocalMulticastIPv6) < 0)
return -1;
return 0;
}
static int
networkRemoveMasqueradingFirewallRules(virFirewallPtr fw,
virNetworkDefPtr def,
virNetworkIPDefPtr ipdef)
{
int prefix = virNetworkIPDefPrefix(ipdef);
const char *forwardIf = virNetworkDefForwardIf(def, 0);
bool isIPv4 = VIR_SOCKET_ADDR_IS_FAMILY(&ipdef->address, AF_INET);
if (prefix < 0)
return 0;
if (iptablesRemoveDontMasquerade(fw,
&ipdef->address,
prefix,
forwardIf,
isIPv4 ? networkLocalMulticastIPv4 :
networkLocalMulticastIPv6) < 0)
return -1;
if (isIPv4 &&
iptablesRemoveDontMasquerade(fw,
&ipdef->address,
prefix,
forwardIf,
networkLocalBroadcast) < 0)
return -1;
if (iptablesRemoveForwardMasquerade(fw,
&ipdef->address,
prefix,
forwardIf,
&def->forward.addr,
&def->forward.port,
"tcp") < 0)
return -1;
if (iptablesRemoveForwardMasquerade(fw,
&ipdef->address,
prefix,
forwardIf,
&def->forward.addr,
&def->forward.port,
"udp") < 0)
return -1;
if (iptablesRemoveForwardMasquerade(fw,
&ipdef->address,
prefix,
forwardIf,
&def->forward.addr,
&def->forward.port,
NULL) < 0)
return -1;
if (iptablesRemoveForwardAllowRelatedIn(fw,
&ipdef->address,
prefix,
def->bridge,
forwardIf) < 0)
return -1;
if (iptablesRemoveForwardAllowOut(fw,
&ipdef->address,
prefix,
def->bridge,
forwardIf) < 0)
return -1;
return 0;
}
static int
networkAddRoutingFirewallRules(virFirewallPtr fw,
virNetworkDefPtr def,
virNetworkIPDefPtr ipdef)
{
int prefix = virNetworkIPDefPrefix(ipdef);
const char *forwardIf = virNetworkDefForwardIf(def, 0);
if (prefix < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Invalid prefix or netmask for '%s'"),
def->bridge);
return -1;
}
/* allow routing packets from the bridge interface */
if (iptablesAddForwardAllowOut(fw,
&ipdef->address,
prefix,
def->bridge,
forwardIf) < 0)
return -1;
/* allow routing packets to the bridge interface */
if (iptablesAddForwardAllowIn(fw,
&ipdef->address,
prefix,
def->bridge,
forwardIf) < 0)
return -1;
return 0;
}
static int
networkRemoveRoutingFirewallRules(virFirewallPtr fw,
virNetworkDefPtr def,
virNetworkIPDefPtr ipdef)
{
int prefix = virNetworkIPDefPrefix(ipdef);
const char *forwardIf = virNetworkDefForwardIf(def, 0);
if (prefix < 0)
return 0;
if (iptablesRemoveForwardAllowIn(fw,
&ipdef->address,
prefix,
def->bridge,
forwardIf) < 0)
return -1;
if (iptablesRemoveForwardAllowOut(fw,
&ipdef->address,
prefix,
def->bridge,
forwardIf) < 0)
return -1;
return 0;
}
static void
networkAddGeneralIPv4FirewallRules(virFirewallPtr fw,
virNetworkDefPtr def)
{
size_t i;
virNetworkIPDefPtr ipv4def;
/* First look for first IPv4 address that has dhcp or tftpboot defined. */
/* We support dhcp config on 1 IPv4 interface only. */
for (i = 0;
(ipv4def = virNetworkDefGetIPByIndex(def, AF_INET, i));
i++) {
if (ipv4def->nranges || ipv4def->nhosts || ipv4def->tftproot)
break;
}
/* allow DHCP requests through to dnsmasq & back out */
iptablesAddTcpInput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 67);
iptablesAddUdpInput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 67);
iptablesAddTcpOutput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 68);
iptablesAddUdpOutput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 68);
/* allow DNS requests through to dnsmasq & back out */
iptablesAddTcpInput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 53);
iptablesAddUdpInput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 53);
iptablesAddTcpOutput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 53);
iptablesAddUdpOutput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 53);
/* allow TFTP requests through to dnsmasq if necessary & back out */
if (ipv4def && ipv4def->tftproot) {
iptablesAddUdpInput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 69);
iptablesAddUdpOutput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 69);
}
/* Catch all rules to block forwarding to/from bridges */
iptablesAddForwardRejectOut(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge);
iptablesAddForwardRejectIn(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge);
/* Allow traffic between guests on the same bridge */
iptablesAddForwardAllowCross(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge);
}
static void
networkRemoveGeneralIPv4FirewallRules(virFirewallPtr fw,
virNetworkDefPtr def)
{
size_t i;
virNetworkIPDefPtr ipv4def;
for (i = 0;
(ipv4def = virNetworkDefGetIPByIndex(def, AF_INET, i));
i++) {
if (ipv4def->nranges || ipv4def->nhosts || ipv4def->tftproot)
break;
}
iptablesRemoveForwardAllowCross(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge);
iptablesRemoveForwardRejectIn(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge);
iptablesRemoveForwardRejectOut(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge);
if (ipv4def && ipv4def->tftproot) {
iptablesRemoveUdpInput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 69);
iptablesRemoveUdpOutput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 69);
}
iptablesRemoveUdpInput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 53);
iptablesRemoveTcpInput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 53);
iptablesRemoveUdpOutput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 53);
iptablesRemoveTcpOutput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 53);
iptablesRemoveUdpOutput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 68);
iptablesRemoveTcpOutput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 68);
iptablesRemoveUdpInput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 67);
iptablesRemoveTcpInput(fw, VIR_FIREWALL_LAYER_IPV4, def->bridge, 67);
}
/* Add all once/network rules required for IPv6.
* If no IPv6 addresses are defined and <network ipv6='yes'> is
* specified, then allow IPv6 communications between virtual systems.
* If any IPv6 addresses are defined, then add the rules for regular operation.
*/
static void
networkAddGeneralIPv6FirewallRules(virFirewallPtr fw,
virNetworkDefPtr def)
{
if (!virNetworkDefGetIPByIndex(def, AF_INET6, 0) &&
!def->ipv6nogw) {
return;
}
/* Catch all rules to block forwarding to/from bridges */
iptablesAddForwardRejectOut(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge);
iptablesAddForwardRejectIn(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge);
/* Allow traffic between guests on the same bridge */
iptablesAddForwardAllowCross(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge);
if (virNetworkDefGetIPByIndex(def, AF_INET6, 0)) {
/* allow DNS over IPv6 & back out */
iptablesAddTcpInput(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge, 53);
iptablesAddUdpInput(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge, 53);
iptablesAddTcpOutput(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge, 53);
iptablesAddUdpOutput(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge, 53);
/* allow DHCPv6 & back out */
iptablesAddUdpInput(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge, 547);
iptablesAddUdpOutput(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge, 546);
}
}
static void
networkRemoveGeneralIPv6FirewallRules(virFirewallPtr fw,
virNetworkDefPtr def)
{
if (!virNetworkDefGetIPByIndex(def, AF_INET6, 0) &&
!def->ipv6nogw) {
return;
}
if (virNetworkDefGetIPByIndex(def, AF_INET6, 0)) {
iptablesRemoveUdpOutput(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge, 546);
iptablesRemoveUdpInput(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge, 547);
iptablesRemoveUdpOutput(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge, 53);
iptablesRemoveTcpOutput(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge, 53);
iptablesRemoveUdpInput(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge, 53);
iptablesRemoveTcpInput(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge, 53);
}
/* the following rules are there if no IPv6 address has been defined
* but def->ipv6nogw == true
*/
iptablesRemoveForwardAllowCross(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge);
iptablesRemoveForwardRejectIn(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge);
iptablesRemoveForwardRejectOut(fw, VIR_FIREWALL_LAYER_IPV6, def->bridge);
}
static void
networkAddGeneralFirewallRules(virFirewallPtr fw,
virNetworkDefPtr def)
{
networkAddGeneralIPv4FirewallRules(fw, def);
networkAddGeneralIPv6FirewallRules(fw, def);
}
static void
networkRemoveGeneralFirewallRules(virFirewallPtr fw,
virNetworkDefPtr def)
{
networkRemoveGeneralIPv4FirewallRules(fw, def);
networkRemoveGeneralIPv6FirewallRules(fw, def);
}
static void
networkAddChecksumFirewallRules(virFirewallPtr fw,
virNetworkDefPtr def)
{
size_t i;
virNetworkIPDefPtr ipv4def;
/* First look for first IPv4 address that has dhcp or tftpboot defined. */
/* We support dhcp config on 1 IPv4 interface only. */
for (i = 0;
(ipv4def = virNetworkDefGetIPByIndex(def, AF_INET, i));
i++) {
if (ipv4def->nranges || ipv4def->nhosts)
break;
}
/* If we are doing local DHCP service on this network, attempt to
* add a rule that will fixup the checksum of DHCP response
* packets back to the guests (but report failure without
* aborting, since not all iptables implementations support it).
*/
if (ipv4def)
iptablesAddOutputFixUdpChecksum(fw, def->bridge, 68);
}
static void
networkRemoveChecksumFirewallRules(virFirewallPtr fw,
virNetworkDefPtr def)
{
size_t i;
virNetworkIPDefPtr ipv4def;
/* First look for first IPv4 address that has dhcp or tftpboot defined. */
/* We support dhcp config on 1 IPv4 interface only. */
for (i = 0;
(ipv4def = virNetworkDefGetIPByIndex(def, AF_INET, i));
i++) {
if (ipv4def->nranges || ipv4def->nhosts)
break;
}
if (ipv4def)
iptablesRemoveOutputFixUdpChecksum(fw, def->bridge, 68);
}
static int
networkAddIPSpecificFirewallRules(virFirewallPtr fw,
virNetworkDefPtr def,
virNetworkIPDefPtr ipdef)
{
/* NB: in the case of IPv6, routing rules are added when the
* forward mode is NAT. This is because IPv6 has no NAT.
*/
if (def->forward.type == VIR_NETWORK_FORWARD_NAT) {
if (VIR_SOCKET_ADDR_IS_FAMILY(&ipdef->address, AF_INET) ||
def->forward.natIPv6 == VIR_TRISTATE_BOOL_YES)
return networkAddMasqueradingFirewallRules(fw, def, ipdef);
else if (VIR_SOCKET_ADDR_IS_FAMILY(&ipdef->address, AF_INET6))
return networkAddRoutingFirewallRules(fw, def, ipdef);
} else if (def->forward.type == VIR_NETWORK_FORWARD_ROUTE) {
return networkAddRoutingFirewallRules(fw, def, ipdef);
}
return 0;
}
static int
networkRemoveIPSpecificFirewallRules(virFirewallPtr fw,
virNetworkDefPtr def,
virNetworkIPDefPtr ipdef)
{
if (def->forward.type == VIR_NETWORK_FORWARD_NAT) {
if (VIR_SOCKET_ADDR_IS_FAMILY(&ipdef->address, AF_INET) ||
def->forward.natIPv6 == VIR_TRISTATE_BOOL_YES)
return networkRemoveMasqueradingFirewallRules(fw, def, ipdef);
else if (VIR_SOCKET_ADDR_IS_FAMILY(&ipdef->address, AF_INET6))
return networkRemoveRoutingFirewallRules(fw, def, ipdef);
} else if (def->forward.type == VIR_NETWORK_FORWARD_ROUTE) {
return networkRemoveRoutingFirewallRules(fw, def, ipdef);
}
return 0;
}
/* Add all rules for all ip addresses (and general rules) on a network */
int networkAddFirewallRules(virNetworkDefPtr def)
{
size_t i;
virNetworkIPDefPtr ipdef;
g_autoptr(virFirewall) fw = virFirewallNew();
if (virOnce(&createdOnce, networkSetupPrivateChains) < 0)
return -1;
if (errInitV4 &&
(virNetworkDefGetIPByIndex(def, AF_INET, 0) ||
virNetworkDefGetRouteByIndex(def, AF_INET, 0))) {
virSetError(errInitV4);
return -1;
}
if (errInitV6 &&
(virNetworkDefGetIPByIndex(def, AF_INET6, 0) ||
virNetworkDefGetRouteByIndex(def, AF_INET6, 0) ||
def->ipv6nogw)) {
virSetError(errInitV6);
return -1;
}
if (def->bridgeZone) {
/* if a firewalld zone has been specified, fail/log an error
* if we can't honor it
*/
if (virFirewallDIsRegistered() < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("zone %s requested for network %s "
"but firewalld is not active"),
def->bridgeZone, def->name);
return -1;
}
if (virFirewallDInterfaceSetZone(def->bridge, def->bridgeZone) < 0)
return -1;
} else {
/* if firewalld is active, try to set the "libvirt" zone. This is
* desirable (for consistency) if firewalld is using the iptables
* backend, but is necessary (for basic network connectivity) if
* firewalld is using the nftables backend
*/
if (virFirewallDIsRegistered() == 0) {
/* if the "libvirt" zone exists, then set it. If not, and
* if firewalld is using the nftables backend, then we
* need to log an error because the combination of
* nftables + default zone means that traffic cannot be
* forwarded (and even DHCP and DNS from guest to host
* will probably no be permitted by the default zone
*/
if (virFirewallDZoneExists("libvirt")) {
if (virFirewallDInterfaceSetZone(def->bridge, "libvirt") < 0)
return -1;
} else {
unsigned long version;
int vresult = virFirewallDGetVersion(&version);
if (vresult < 0)
return -1;
/* Support for nftables backend was added in firewalld
* 0.6.0. Support for rule priorities (required by the
* 'libvirt' zone, which should be installed by a
* libvirt package, *not* by firewalld) was not added
* until firewalld 0.7.0 (unless it was backported).
*/
if (version >= 6000 &&
virFirewallDGetBackend() == VIR_FIREWALLD_BACKEND_NFTABLES) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("firewalld is set to use the nftables "
"backend, but the required firewalld "
"'libvirt' zone is missing. Either set "
"the firewalld backend to 'iptables', or "
"ensure that firewalld has a 'libvirt' "
"zone by upgrading firewalld to a "
"version supporting rule priorities "
"(0.7.0+) and/or rebuilding "
"libvirt with --with-firewalld-zone"));
return -1;
}
}
}
}
virFirewallStartTransaction(fw, 0);
networkAddGeneralFirewallRules(fw, def);
for (i = 0;
(ipdef = virNetworkDefGetIPByIndex(def, AF_UNSPEC, i));
i++) {
if (networkAddIPSpecificFirewallRules(fw, def, ipdef) < 0)
return -1;
}
virFirewallStartRollback(fw, 0);
for (i = 0;
(ipdef = virNetworkDefGetIPByIndex(def, AF_UNSPEC, i));
i++) {
if (networkRemoveIPSpecificFirewallRules(fw, def, ipdef) < 0)
return -1;
}
networkRemoveGeneralFirewallRules(fw, def);
virFirewallStartTransaction(fw, VIR_FIREWALL_TRANSACTION_IGNORE_ERRORS);
networkAddChecksumFirewallRules(fw, def);
return virFirewallApply(fw);
}
/* Remove all rules for all ip addresses (and general rules) on a network */
void networkRemoveFirewallRules(virNetworkDefPtr def)
{
size_t i;
virNetworkIPDefPtr ipdef;
g_autoptr(virFirewall) fw = virFirewallNew();
virFirewallStartTransaction(fw, VIR_FIREWALL_TRANSACTION_IGNORE_ERRORS);
networkRemoveChecksumFirewallRules(fw, def);
virFirewallStartTransaction(fw, VIR_FIREWALL_TRANSACTION_IGNORE_ERRORS);
for (i = 0;
(ipdef = virNetworkDefGetIPByIndex(def, AF_UNSPEC, i));
i++) {
if (networkRemoveIPSpecificFirewallRules(fw, def, ipdef) < 0)
return;
}
networkRemoveGeneralFirewallRules(fw, def);
virFirewallApply(fw);
}
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