[libvirt] [PATCH 15/23] qemu: add slirp helper unit
marcandre.lureau at redhat.com
marcandre.lureau at redhat.com
Mon Jul 8 07:07:39 UTC 2019
From: Marc-André Lureau <marcandre.lureau at redhat.com>
The unit provides the functions associated with a slirp-helper:
- probing / checking capabilities
- opening the socketpair
- starting / stoping the helper
- registering for dbus-vmstate migration
Signed-off-by: Marc-André Lureau <marcandre.lureau at redhat.com>
---
src/qemu/Makefile.inc.am | 2 +
src/qemu/qemu_domain.h | 4 +
src/qemu/qemu_slirp.c | 412 +++++++++++++++++++++++++++++++++++++++
src/qemu/qemu_slirp.h | 78 ++++++++
4 files changed, 496 insertions(+)
create mode 100644 src/qemu/qemu_slirp.c
create mode 100644 src/qemu/qemu_slirp.h
diff --git a/src/qemu/Makefile.inc.am b/src/qemu/Makefile.inc.am
index 248f3970c9..e09206cb53 100644
--- a/src/qemu/Makefile.inc.am
+++ b/src/qemu/Makefile.inc.am
@@ -56,6 +56,8 @@ QEMU_DRIVER_SOURCES = \
qemu/qemu_security.h \
qemu/qemu_qapi.c \
qemu/qemu_qapi.h \
+ qemu/qemu_slirp.c \
+ qemu/qemu_slirp.h \
qemu/qemu_tpm.c \
qemu/qemu_tpm.h \
qemu/qemu_dbus.c \
diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index 7ab44d3c43..a4463f96a3 100644
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -511,6 +511,10 @@ struct _qemuDomainGraphicsPrivate {
};
+typedef struct _qemuSlirp qemuSlirp;
+typedef struct _qemuSlirp *qemuSlirpPtr;
+
+
#define QEMU_DOMAIN_NETWORK_PRIVATE(dev) \
((qemuDomainNetworkPrivatePtr) (dev)->privateData)
diff --git a/src/qemu/qemu_slirp.c b/src/qemu/qemu_slirp.c
new file mode 100644
index 0000000000..6600f508db
--- /dev/null
+++ b/src/qemu/qemu_slirp.c
@@ -0,0 +1,412 @@
+/*
+ * qemu_slirp.c: QEMU Slirp support
+ *
+ * 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 "qemu_dbus.h"
+#include "qemu_extdevice.h"
+#include "qemu_security.h"
+#include "qemu_slirp.h"
+#include "viralloc.h"
+#include "virenum.h"
+#include "virerror.h"
+#include "virjson.h"
+#include "virlog.h"
+#include "virpidfile.h"
+#include "virstring.h"
+#include "virtime.h"
+
+#define VIR_FROM_THIS VIR_FROM_NONE
+
+VIR_LOG_INIT("qemu.slirp");
+
+VIR_ENUM_IMPL(qemuSlirpFeature,
+ QEMU_SLIRP_FEATURE_LAST,
+ "",
+ "ipv4",
+ "ipv6",
+ "tftp",
+ "dbus-address",
+ "migrate",
+ "restrict",
+ "exit-with-parent",
+);
+
+
+void
+qemuSlirpFree(qemuSlirpPtr slirp)
+{
+ VIR_FORCE_CLOSE(slirp->fd[0]);
+ VIR_FORCE_CLOSE(slirp->fd[1]);
+ virBitmapFree(slirp->features);
+ VIR_FREE(slirp);
+}
+
+
+void
+qemuSlirpSetFeature(qemuSlirpPtr slirp,
+ qemuSlirpFeature feature)
+{
+ ignore_value(virBitmapSetBit(slirp->features, feature));
+}
+
+
+bool
+qemuSlirpHasFeature(const qemuSlirpPtr slirp,
+ qemuSlirpFeature feature)
+{
+ return virBitmapIsBitSet(slirp->features, feature);
+}
+
+
+qemuSlirpPtr
+qemuSlirpNew(void)
+{
+ qemuSlirpPtr slirp = NULL;
+
+ if (VIR_ALLOC(slirp) < 0)
+ return NULL;
+
+ slirp->pid = (pid_t)-1;
+ slirp->fd[0] = slirp->fd[1] = -1;
+ slirp->features = virBitmapNew(QEMU_SLIRP_FEATURE_LAST);
+
+ return slirp;
+}
+
+
+qemuSlirpPtr
+qemuSlirpNewForHelper(const char *helper)
+{
+ VIR_AUTOPTR(qemuSlirp) slirp = NULL;
+ VIR_AUTOPTR(virCommand) cmd = NULL;
+ VIR_AUTOFREE(char *) output = NULL;
+ VIR_AUTOPTR(virJSONValue) doc = NULL;
+ virJSONValuePtr featuresJSON;
+ size_t i, nfeatures;
+
+ if (!helper)
+ return NULL;
+
+ slirp = qemuSlirpNew();
+ if (!slirp) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Failed to allocate slirp for '%s'"), helper);
+ return NULL;
+ }
+
+ cmd = virCommandNewArgList(helper, "--print-capabilities", NULL);
+ virCommandSetOutputBuffer(cmd, &output);
+ if (virCommandRun(cmd, NULL) < 0)
+ return NULL;
+
+ if (!(doc = virJSONValueFromString(output)) ||
+ !(featuresJSON = virJSONValueObjectGetArray(doc, "features"))) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("unable to parse json capabilities '%s'"),
+ helper);
+ return NULL;
+ }
+
+ nfeatures = virJSONValueArraySize(featuresJSON);
+ for (i = 0; i < nfeatures; i++) {
+ virJSONValuePtr item = virJSONValueArrayGet(featuresJSON, i);
+ const char *tmpStr = virJSONValueGetString(item);
+ int tmp;
+
+ if ((tmp = qemuSlirpFeatureTypeFromString(tmpStr)) <= 0) {
+ VIR_WARN("unknown slirp feature %s", tmpStr);
+ continue;
+ }
+
+ qemuSlirpSetFeature(slirp, tmp);
+ }
+
+ VIR_RETURN_PTR(slirp);
+}
+
+
+static char *
+qemuSlirpCreatePidFilename(const char *stateDir,
+ const char *shortName,
+ const char *alias)
+{
+ VIR_AUTOFREE(char *) name = NULL;
+
+ if (virAsprintf(&name, "%s-%s-slirp", shortName, alias) < 0)
+ return NULL;
+
+ return virPidFileBuildPath(stateDir, name);
+}
+
+
+static int
+qemuSlirpGetPid(const char *binPath,
+ const char *stateDir,
+ const char *shortName,
+ const char *alias,
+ pid_t *pid)
+{
+ VIR_AUTOFREE(char *) pidfile = qemuSlirpCreatePidFilename(stateDir, shortName, alias);
+ if (!pidfile)
+ return -ENOMEM;
+
+ return virPidFileReadPathIfAlive(pidfile, pid, binPath);
+}
+
+
+int
+qemuSlirpOpen(qemuSlirpPtr slirp,
+ virQEMUDriverPtr driver,
+ virDomainDefPtr def)
+{
+ int rc, pair[2] = { -1, -1 };
+
+ if (qemuSecuritySetSocketLabel(driver->securityManager, def) < 0)
+ goto error;
+
+ rc = socketpair(AF_UNIX, SOCK_DGRAM, 0, pair);
+
+ if (qemuSecurityClearSocketLabel(driver->securityManager, def) < 0)
+ goto error;
+
+ if (rc < 0) {
+ virReportSystemError(errno, "%s", _("failed to create socketpair"));
+ goto error;
+ }
+
+ slirp->fd[0] = pair[0];
+ slirp->fd[1] = pair[1];
+
+ return 0;
+
+error:
+ VIR_FORCE_CLOSE(pair[0]);
+ VIR_FORCE_CLOSE(pair[1]);
+ return -1;
+}
+
+
+int
+qemuSlirpGetFD(qemuSlirpPtr slirp)
+{
+ int fd = slirp->fd[0];
+ slirp->fd[0] = -1;
+ return fd;
+}
+
+
+static char *
+qemuSlirpGetDBusVMStateId(virDomainNetDefPtr net)
+{
+ char macstr[VIR_MAC_STRING_BUFLEN] = "";
+ char *id = NULL;
+
+ /* can't use alias, because it's not stable across restarts */
+ if (virAsprintf(&id, "slirp-%s", virMacAddrFormat(&net->mac, macstr)) < 0)
+ return NULL;
+
+ return id;
+}
+
+
+void
+qemuSlirpStop(qemuSlirpPtr slirp,
+ virDomainObjPtr vm,
+ virQEMUDriverPtr driver,
+ virDomainNetDefPtr net)
+{
+ virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
+ VIR_AUTOFREE(char *) pidfile = NULL;
+ VIR_AUTOFREE(char *) shortName = virDomainDefGetShortName(vm->def);
+ VIR_AUTOFREE(char *) id = qemuSlirpGetDBusVMStateId(net);
+ virErrorPtr orig_err;
+ int rc;
+ pid_t pid;
+
+ if (!(pidfile = qemuSlirpCreatePidFilename(
+ cfg->stateDir, shortName, net->info.alias))) {
+ VIR_WARN("Unable to construct slirp pidfile path");
+ return;
+ }
+
+ qemuDBusVMStateRemove(vm, id);
+
+ rc = qemuSlirpGetPid(cfg->slirpHelperName,
+ cfg->stateDir, shortName, net->info.alias, &pid);
+ if (rc == 0 && pid != (pid_t)-1) {
+ char ebuf[1024];
+
+ VIR_DEBUG("Killing slirp process %lld", (long long)pid);
+ if (virProcessKill(pid, SIGKILL) < 0 && errno != ESRCH)
+ VIR_ERROR(_("Failed to kill process %lld: %s"),
+ (long long)pid,
+ virStrerror(errno, ebuf, sizeof(ebuf)));
+ }
+
+ virErrorPreserveLast(&orig_err);
+ if (virPidFileForceCleanupPath(pidfile) < 0) {
+ VIR_WARN("Unable to kill slirp process");
+ } else {
+ if (unlink(pidfile) < 0 &&
+ errno != ENOENT) {
+ virReportSystemError(errno,
+ _("Unable to remove stale pidfile %s"),
+ pidfile);
+ }
+ }
+ virErrorRestore(&orig_err);
+ slirp->pid = 0;
+}
+
+
+int
+qemuSlirpStart(qemuSlirpPtr slirp,
+ virDomainObjPtr vm,
+ virQEMUDriverPtr driver,
+ virDomainNetDefPtr net,
+ qemuProcessIncomingDefPtr incoming)
+{
+ virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
+ VIR_AUTOPTR(virCommand) cmd = NULL;
+ VIR_AUTOFREE(char *) cmdstr = NULL;
+ VIR_AUTOFREE(char *) addr = NULL;
+ VIR_AUTOFREE(char *) pidfile = NULL;
+ VIR_AUTOFREE(char *) shortName = virDomainDefGetShortName(vm->def);
+ size_t i;
+ virTimeBackOffVar timebackoff;
+ const unsigned long long timeout = 500 * 1000; /* ms */
+ pid_t pid;
+ int cmdret = 0, exitstatus = 0;
+
+ if (incoming &&
+ !qemuSlirpHasFeature(slirp, QEMU_SLIRP_FEATURE_MIGRATE)) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("The slirp-helper doesn't support migration"));
+ }
+
+ if (!(pidfile = qemuSlirpCreatePidFilename(
+ cfg->stateDir, shortName, net->info.alias)))
+ return -1;
+
+ if (!(cmd = virCommandNew(cfg->slirpHelperName)))
+ return -1;
+
+ virCommandClearCaps(cmd);
+ virCommandSetPidFile(cmd, pidfile);
+ virCommandDaemonize(cmd);
+
+ virCommandAddArgFormat(cmd, "--fd=%d", slirp->fd[1]);
+ virCommandPassFD(cmd, slirp->fd[1],
+ VIR_COMMAND_PASS_FD_CLOSE_PARENT);
+ slirp->fd[1] = -1;
+
+ for (i = 0; i < net->guestIP.nips; i++) {
+ const virNetDevIPAddr *ip = net->guestIP.ips[i];
+ const char *opt = "";
+
+ if (!(addr = virSocketAddrFormat(&ip->address)))
+ return -1;
+
+ if (VIR_SOCKET_ADDR_IS_FAMILY(&ip->address, AF_INET))
+ opt = "--net";
+ if (VIR_SOCKET_ADDR_IS_FAMILY(&ip->address, AF_INET6))
+ opt = "--prefix-ipv6";
+
+ virCommandAddArgFormat(cmd, "%s=%s", opt, addr);
+ VIR_FREE(addr);
+
+ if (ip->prefix) {
+ if (VIR_SOCKET_ADDR_IS_FAMILY(&ip->address, AF_INET)) {
+ virSocketAddr netmask;
+ VIR_AUTOFREE(char *) netmaskStr = NULL;
+
+ if (virSocketAddrPrefixToNetmask(ip->prefix, &netmask, AF_INET) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Failed to translate prefix %d to netmask"),
+ ip->prefix);
+ return -1;
+ }
+ if (!(netmaskStr = virSocketAddrFormat(&netmask)))
+ return -1;
+ virCommandAddArgFormat(cmd, "--mask=%s", netmaskStr);
+ }
+ if (VIR_SOCKET_ADDR_IS_FAMILY(&ip->address, AF_INET6))
+ virCommandAddArgFormat(cmd, "--prefix-length-ipv6=%u", ip->prefix);
+ }
+ }
+
+ if (qemuSlirpHasFeature(slirp,
+ QEMU_SLIRP_FEATURE_DBUS_ADDRESS)) {
+ VIR_AUTOFREE(char *) id = qemuSlirpGetDBusVMStateId(net);
+ VIR_AUTOFREE(char *) dbus_addr = qemuDBusGetAddress(driver, vm);
+
+ if (qemuDBusStart(driver, vm) < 0)
+ return -1;
+
+ virCommandAddArgFormat(cmd, "--dbus-id=%s", id);
+
+ virCommandAddArgFormat(cmd, "--dbus-address=%s", dbus_addr);
+
+ if (qemuSlirpHasFeature(slirp,
+ QEMU_SLIRP_FEATURE_MIGRATE)) {
+ if (qemuDBusVMStateAdd(vm, id) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Failed to register slirp migration"));
+ return -1;
+ }
+ if (incoming) {
+ virCommandAddArg(cmd, "--dbus-incoming");
+ }
+ }
+ }
+
+ if (qemuSlirpHasFeature(slirp,
+ QEMU_SLIRP_FEATURE_EXIT_WITH_PARENT)) {
+ virCommandAddArg(cmd, "--exit-with-parent");
+ }
+
+ if (qemuExtDeviceLogCommand(driver, vm, cmd, "slirp") < 0)
+ return -1;
+
+ if (qemuSecurityCommandRun(driver, vm, cmd,
+ &exitstatus, &cmdret) < 0)
+ return -1;
+
+ if (cmdret < 0 || exitstatus != 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Could not start 'slirp'. exitstatus: %d"), exitstatus);
+ return -1;
+ }
+
+ /* check that the helper has written its pid into the file */
+ if (virTimeBackOffStart(&timebackoff, 1, timeout) < 0)
+ return -1;
+ while (virTimeBackOffWait(&timebackoff)) {
+ int rc = qemuSlirpGetPid(cfg->slirpHelperName,
+ cfg->stateDir, shortName, net->info.alias, &pid);
+ if (rc < 0)
+ continue;
+ if (rc == 0 && pid == (pid_t)-1)
+ return -1;
+ break;
+ }
+
+ slirp->pid = pid;
+ return 0;
+}
diff --git a/src/qemu/qemu_slirp.h b/src/qemu/qemu_slirp.h
new file mode 100644
index 0000000000..78a01b9dd0
--- /dev/null
+++ b/src/qemu/qemu_slirp.h
@@ -0,0 +1,78 @@
+/*
+ * qemu_slirp.h: QEMU Slirp support
+ *
+ * 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/>.
+ */
+
+#pragma once
+
+#include "qemu_conf.h"
+#include "qemu_domain.h"
+#include "qemu_process.h"
+#include "vircommand.h"
+
+typedef enum {
+ QEMU_SLIRP_FEATURE_NONE = 0,
+ QEMU_SLIRP_FEATURE_IPV4,
+ QEMU_SLIRP_FEATURE_IPV6,
+ QEMU_SLIRP_FEATURE_TFTP,
+ QEMU_SLIRP_FEATURE_DBUS_ADDRESS,
+ QEMU_SLIRP_FEATURE_MIGRATE,
+ QEMU_SLIRP_FEATURE_RESTRICT,
+ QEMU_SLIRP_FEATURE_EXIT_WITH_PARENT,
+
+ QEMU_SLIRP_FEATURE_LAST,
+} qemuSlirpFeature;
+
+VIR_ENUM_DECL(qemuSlirpFeature);
+
+
+struct _qemuSlirp {
+ int fd[2];
+ virBitmapPtr features;
+ pid_t pid;
+};
+
+
+qemuSlirpPtr qemuSlirpNew(void);
+
+qemuSlirpPtr qemuSlirpNewForHelper(const char *helper);
+
+void qemuSlirpFree(qemuSlirpPtr slirp);
+
+void qemuSlirpSetFeature(qemuSlirpPtr slirp,
+ qemuSlirpFeature feature);
+
+bool qemuSlirpHasFeature(const qemuSlirpPtr slirp,
+ qemuSlirpFeature feature);
+
+int qemuSlirpOpen(qemuSlirpPtr slirp,
+ virQEMUDriverPtr driver,
+ virDomainDefPtr def);
+
+int qemuSlirpStart(qemuSlirpPtr slirp,
+ virDomainObjPtr vm,
+ virQEMUDriverPtr driver,
+ virDomainNetDefPtr net,
+ qemuProcessIncomingDefPtr incoming);
+
+void qemuSlirpStop(qemuSlirpPtr slirp,
+ virDomainObjPtr vm,
+ virQEMUDriverPtr driver,
+ virDomainNetDefPtr net);
+
+int qemuSlirpGetFD(qemuSlirpPtr slirp);
+
+VIR_DEFINE_AUTOPTR_FUNC(qemuSlirp, qemuSlirpFree);
--
2.22.0.214.g8dca754b1e
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