[libvirt] [PATCH v4 1/2] net: support set public ip range for forward mode nat

Support setting which public ip to use for NAT via attribute address in subelement <nat> in <forward>: ... <forward mode='nat'> <address start='1.2.3.4' end='1.2.3.10'/> </forward> ... This will construct an iptables line using: '-j SNAT --to-source <start>-<end>' instead of: '-j MASQUERADE' Signed-off-by: Natanael Copa <ncopa(a)alpinelinux.org&gt; --- docs/formatnetwork.html.in | 18 ++++++ src/conf/network_conf.c | 152 ++++++++++++++++++++++++++++++++++++++++++-- src/conf/network_conf.h | 3 + src/network/bridge_driver.c | 16 +++++ src/util/viriptables.c | 56 +++++++++++++--- src/util/viriptables.h | 4 ++ 6 files changed, 235 insertions(+), 14 deletions(-) diff --git a/docs/formatnetwork.html.in b/docs/formatnetwork.html.in index 7b42529..5fbd0a9 100644 --- a/docs/formatnetwork.html.in +++ b/docs/formatnetwork.html.in @@ -136,6 +136,24 @@ network, and to/from the host to the guests, are unrestricted and not NATed.<span class="since">Since 0.4.2</span> + + <p><span class="since">Since 1.0.3</span> it is possible to + specify a public IPv4 address range to be used for the NAT by + using the <code>&lt;nat&gt;</code> and + <code>&lt;address&gt;</code> subelements. + <pre> +... + &lt;forward mode='nat'&gt; + &lt;nat&gt; + &lt;address start='1.2.3.4' end='1.2.3.10'/&gt; + &lt;/nat&gt; + &lt;/forward&gt; +... + </pre> + An singe IPv4 address can be set by setting + <code>start</code> and <code>end</code> attributes to + the same value. + </p> </dd> <dt><code>route</code></dt> diff --git a/src/conf/network_conf.c b/src/conf/network_conf.c index 3604ff7..61d086a 100644 --- a/src/conf/network_conf.c +++ b/src/conf/network_conf.c @@ -1325,6 +1325,80 @@ cleanup: } static int +virNetworkForwardNatDefParseXML(const char *networkName, + xmlNodePtr node, + xmlXPathContextPtr ctxt, + virNetworkForwardDefPtr def) +{ + int ret = -1; + xmlNodePtr *natAddrNodes = NULL; + int nNatAddrs; + char *addr_start = NULL; + char *addr_end = NULL; + xmlNodePtr save = ctxt->node; + + ctxt->node = node; + + if (def->type != VIR_NETWORK_FORWARD_NAT) { + virReportError(VIR_ERR_XML_ERROR, + _("The <nat> element can only be used when <forward> 'mode' is 'nat' in network %s"), + networkName); + goto cleanup; + } + + /* addresses for SNAT */ + nNatAddrs = virXPathNodeSet("./address", ctxt, &natAddrNodes); + if (nNatAddrs < 0) { + virReportError(VIR_ERR_XML_ERROR, + _("invalid <address> element found in <forward> of " + "network %s"), networkName); + goto cleanup; + } else if (nNatAddrs > 1) { + virReportError(VIR_ERR_XML_ERROR, + _("Only one <address> element is allowed in <nat> in " + "<forward> in network %s"), networkName); + goto cleanup; + } else if (nNatAddrs == 1) { + addr_start = virXMLPropString(*natAddrNodes, "start"); + if (addr_start == NULL) { + virReportError(VIR_ERR_XML_ERROR, + _("missing 'start' attribute in <address> element in <nat> in " + "<forward> in network %s"), networkName); + goto cleanup; + } + addr_end = virXMLPropString(*natAddrNodes, "end"); + if (addr_end == NULL) { + virReportError(VIR_ERR_XML_ERROR, + _("missing 'end' attribute in <address> element in <nat> in " + "<forward> in network %s"), networkName); + goto cleanup; + } + } + + if (addr_start && virSocketAddrParse(&def->addr_start, addr_start, AF_INET) < 0) { + virReportError(VIR_ERR_XML_ERROR, + _("Bad ipv4 start address '%s' in <nat> in <forward> in " + "network '%s'"), addr_start, networkName); + goto cleanup; + } + + if (addr_end && virSocketAddrParse(&def->addr_end, addr_end, AF_INET) < 0) { + virReportError(VIR_ERR_XML_ERROR, + _("Bad ipv4 end address '%s' in <nat> in <forward> in " + "network '%s'"), addr_end, networkName); + goto cleanup; + } + + ret = 0; + +cleanup: + VIR_FREE(addr_start); + VIR_FREE(addr_end); + ctxt->node = save; + return ret; +} + +static int virNetworkForwardDefParseXML(const char *networkName, xmlNodePtr node, xmlXPathContextPtr ctxt, @@ -1334,7 +1408,8 @@ virNetworkForwardDefParseXML(const char *networkName, xmlNodePtr *forwardIfNodes = NULL; xmlNodePtr *forwardPfNodes = NULL; xmlNodePtr *forwardAddrNodes = NULL; - int nForwardIfs, nForwardAddrs, nForwardPfs; + xmlNodePtr *forwardNatNodes = NULL; + int nForwardIfs, nForwardAddrs, nForwardPfs, nForwardNats; char *forwardDev = NULL; char *forwardManaged = NULL; char *type = NULL; @@ -1384,6 +1459,24 @@ virNetworkForwardDefParseXML(const char *networkName, goto cleanup; } + nForwardNats = virXPathNodeSet("./nat", ctxt, &forwardNatNodes); + if (nForwardNats < 0) { + virReportError(VIR_ERR_XML_ERROR, + _("invalid <nat> element found in <forward> of network %s"), + networkName); + goto cleanup; + } else if (nForwardNats > 1) { + virReportError(VIR_ERR_XML_ERROR, + _("Only one <nat> element is allowed in <forward> of network %s"), + networkName); + goto cleanup; + } else if (nForwardNats == 1) { + if (virNetworkForwardNatDefParseXML(networkName, + *forwardNatNodes, + ctxt, def) < 0) + goto cleanup; + } + if (((nForwardIfs > 0) + (nForwardAddrs > 0) + (nForwardPfs > 0)) > 1) { virReportError(VIR_ERR_XML_ERROR, _("<address>, <interface>, and <pf> elements in <forward> " @@ -1525,6 +1618,7 @@ cleanup: VIR_FREE(forwardPfNodes); VIR_FREE(forwardIfNodes); VIR_FREE(forwardAddrNodes); + VIR_FREE(forwardNatNodes); ctxt->node = save; return ret; } @@ -2079,13 +2173,54 @@ virPortGroupDefFormat(virBufferPtr buf, } static int +virNatDefFormat(virBufferPtr buf, + const virNetworkForwardDefPtr fwd) +{ + char *addr_start = NULL; + char *addr_end = NULL; + int ret = -1; + + if (VIR_SOCKET_ADDR_VALID(&fwd->addr_start)) { + addr_start = virSocketAddrFormat(&fwd->addr_start); + if (!addr_start) + goto cleanup; + } + + if (VIR_SOCKET_ADDR_VALID(&fwd->addr_end)) { + addr_end = virSocketAddrFormat(&fwd->addr_end); + if (!addr_end) + goto cleanup; + } + + if (!addr_end && !addr_start) + return 0; + + virBufferAddLit(buf, "<nat>\n"); + virBufferAdjustIndent(buf, 2); + + virBufferAsprintf(buf, "<address start='%s'", addr_start); + if (addr_end) + virBufferAsprintf(buf, " end='%s'", addr_end); + virBufferAsprintf(buf, "/>\n"); + + virBufferAdjustIndent(buf, -2); + virBufferAsprintf(buf, "</nat>\n"); + ret = 0; + +cleanup: + VIR_FREE(addr_start); + VIR_FREE(addr_end); + return ret; +} + +static int virNetworkDefFormatInternal(virBufferPtr buf, const virNetworkDefPtr def, unsigned int flags) { unsigned char *uuid; char uuidstr[VIR_UUID_STRING_BUFLEN]; - int ii; + int ii, shortforward; virBufferAddLit(buf, "<network"); if (!(flags & VIR_NETWORK_XML_INACTIVE) && (def->connections > 0)) { @@ -2122,10 +2257,17 @@ virNetworkDefFormatInternal(virBufferPtr buf, else virBufferAddLit(buf, " managed='no'"); } - virBufferAsprintf(buf, "%s>\n", - (def->forward.nifs || def->forward.npfs) ? "" : "/"); + shortforward = !(def->forward.nifs || def->forward.npfs + || VIR_SOCKET_ADDR_VALID(&def->forward.addr_start) + || VIR_SOCKET_ADDR_VALID(&def->forward.addr_end)); + virBufferAsprintf(buf, "%s>\n", shortforward ? "/" : ""); virBufferAdjustIndent(buf, 2); + if (def->forward.type == VIR_NETWORK_FORWARD_NAT) { + if (virNatDefFormat(buf, &def->forward) < 0) + goto error; + } + /* For now, hard-coded to at most 1 forward.pfs */ if (def->forward.npfs) virBufferEscapeString(buf, "<pf dev='%s'/>\n", @@ -2155,7 +2297,7 @@ virNetworkDefFormatInternal(virBufferPtr buf, } } virBufferAdjustIndent(buf, -2); - if (def->forward.npfs || def->forward.nifs) + if (!shortforward) virBufferAddLit(buf, "</forward>\n"); } diff --git a/src/conf/network_conf.h b/src/conf/network_conf.h index 4c634ed..1a598e3 100644 --- a/src/conf/network_conf.h +++ b/src/conf/network_conf.h @@ -174,6 +174,9 @@ struct _virNetworkForwardDef { size_t nifs; virNetworkForwardIfDefPtr ifs; + + /* adresses for SNAT */ + virSocketAddr addr_start, addr_end; }; typedef struct _virPortGroupDef virPortGroupDef; diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c index c834f83..6d74c1f 100644 --- a/src/network/bridge_driver.c +++ b/src/network/bridge_driver.c @@ -1587,6 +1587,8 @@ networkAddMasqueradingIptablesRules(struct network_driver *driver, &ipdef->address, prefix, forwardIf, + &network->def->forward.addr_start, + &network->def->forward.addr_end, NULL) < 0) { virReportError(VIR_ERR_SYSTEM_ERROR, forwardIf ? @@ -1601,6 +1603,8 @@ networkAddMasqueradingIptablesRules(struct network_driver *driver, &ipdef->address, prefix, forwardIf, + &network->def->forward.addr_start, + &network->def->forward.addr_end, "udp") < 0) { virReportError(VIR_ERR_SYSTEM_ERROR, forwardIf ? @@ -1615,6 +1619,8 @@ networkAddMasqueradingIptablesRules(struct network_driver *driver, &ipdef->address, prefix, forwardIf, + &network->def->forward.addr_start, + &network->def->forward.addr_end, "tcp") < 0) { virReportError(VIR_ERR_SYSTEM_ERROR, forwardIf ? @@ -1631,12 +1637,16 @@ networkAddMasqueradingIptablesRules(struct network_driver *driver, &ipdef->address, prefix, forwardIf, + &network->def->forward.addr_start, + &network->def->forward.addr_end, "udp"); masqerr4: iptablesRemoveForwardMasquerade(driver->iptables, &ipdef->address, prefix, forwardIf, + &network->def->forward.addr_start, + &network->def->forward.addr_end, NULL); masqerr3: iptablesRemoveForwardAllowRelatedIn(driver->iptables, @@ -1667,16 +1677,22 @@ networkRemoveMasqueradingIptablesRules(struct network_driver *driver, &ipdef->address, prefix, forwardIf, + &network->def->forward.addr_start, + &network->def->forward.addr_end, "tcp"); iptablesRemoveForwardMasquerade(driver->iptables, &ipdef->address, prefix, forwardIf, + &network->def->forward.addr_start, + &network->def->forward.addr_end, "udp"); iptablesRemoveForwardMasquerade(driver->iptables, &ipdef->address, prefix, forwardIf, + &network->def->forward.addr_start, + &network->def->forward.addr_end, NULL); iptablesRemoveForwardAllowRelatedIn(driver->iptables, diff --git a/src/util/viriptables.c b/src/util/viriptables.c index 41fe780..3f0dcf0 100644 --- a/src/util/viriptables.c +++ b/src/util/viriptables.c @@ -805,11 +805,15 @@ iptablesForwardMasquerade(iptablesContext *ctx, virSocketAddr *netaddr, unsigned int prefix, const char *physdev, + virSocketAddr *addr_start, + virSocketAddr *addr_end, const char *protocol, int action) { - int ret; - char *networkstr; + int ret = -1; + char *networkstr = NULL; + char *addr_start_str = NULL; + char *addr_end_str = NULL; virCommandPtr cmd = NULL; if (!(networkstr = iptablesFormatNetwork(netaddr, prefix))) @@ -820,8 +824,18 @@ iptablesForwardMasquerade(iptablesContext *ctx, virReportError(VIR_ERR_INTERNAL_ERROR, _("Attempted to NAT '%s'. NAT is only supported for IPv4."), networkstr); - VIR_FREE(networkstr); - return -1; + goto cleanup; + } + + if (VIR_SOCKET_ADDR_IS_FAMILY(addr_start, AF_INET)) { + addr_start_str = virSocketAddrFormat(addr_start); + if (!addr_start_str) + goto cleanup; + if (VIR_SOCKET_ADDR_IS_FAMILY(addr_end, AF_INET)) { + addr_end_str = virSocketAddrFormat(addr_end); + if (!addr_end_str) + goto cleanup; + } } cmd = iptablesCommandNew(ctx->nat_postrouting, AF_INET, action); @@ -835,12 +849,32 @@ iptablesForwardMasquerade(iptablesContext *ctx, if (physdev && physdev[0]) virCommandAddArgList(cmd, "--out-interface", physdev, NULL); - virCommandAddArgList(cmd, "--jump", "MASQUERADE", NULL); + /* Use --jump SNAT if public addr is specified */ + if (addr_start_str && addr_start_str[0]) { + char tmpstr[sizeof("123.123.123.123-123.123.123.123:65535-65535")]; + const char *portstr = ""; + + memset(tmpstr, 0, sizeof(tmpstr)); + if (protocol && protocol[0]) + portstr = ":1024-65535"; + if (addr_end_str && addr_end_str[0]) { + snprintf(tmpstr, sizeof(tmpstr), "%s-%s%s", + addr_start_str, addr_end_str, portstr); + } else { + snprintf(tmpstr, sizeof(tmpstr), "%s%s", addr_start_str, portstr); + } - if (protocol && protocol[0]) - virCommandAddArgList(cmd, "--to-ports", "1024-65535", NULL); + virCommandAddArgList(cmd, "--jump", "SNAT", + "--to-source", tmpstr, NULL); + } else { + virCommandAddArgList(cmd, "--jump", "MASQUERADE", NULL); + + if (protocol && protocol[0]) + virCommandAddArgList(cmd, "--to-ports", "1024-65535", NULL); + } ret = iptablesCommandRunAndFree(cmd); +cleanup: VIR_FREE(networkstr); return ret; } @@ -863,9 +897,11 @@ iptablesAddForwardMasquerade(iptablesContext *ctx, virSocketAddr *netaddr, unsigned int prefix, const char *physdev, + virSocketAddr *addr_start, + virSocketAddr *addr_end, const char *protocol) { - return iptablesForwardMasquerade(ctx, netaddr, prefix, physdev, protocol, ADD); + return iptablesForwardMasquerade(ctx, netaddr, prefix, physdev, addr_start, addr_end, protocol, ADD); } /** @@ -886,9 +922,11 @@ iptablesRemoveForwardMasquerade(iptablesContext *ctx, virSocketAddr *netaddr, unsigned int prefix, const char *physdev, + virSocketAddr *addr_start, + virSocketAddr *addr_end, const char *protocol) { - return iptablesForwardMasquerade(ctx, netaddr, prefix, physdev, protocol, REMOVE); + return iptablesForwardMasquerade(ctx, netaddr, prefix, physdev, addr_start, addr_end, protocol, REMOVE); } diff --git a/src/util/viriptables.h b/src/util/viriptables.h index d7fa731..4241380 100644 --- a/src/util/viriptables.h +++ b/src/util/viriptables.h @@ -107,11 +107,15 @@ int iptablesAddForwardMasquerade (iptablesContext *ctx, virSocketAddr *netaddr, unsigned int prefix, const char *physdev, + virSocketAddr *addr_start, + virSocketAddr *addr_end, const char *protocol); int iptablesRemoveForwardMasquerade (iptablesContext *ctx, virSocketAddr *netaddr, unsigned int prefix, const char *physdev, + virSocketAddr *addr_start, + virSocketAddr *addr_end, const char *protocol); int iptablesAddOutputFixUdpChecksum (iptablesContext *ctx, const char *iface, -- 1.8.1.2