[libvirt] [PATCH 4/6] LXC: Wire up the virDomainCreate{XML}WithFiles methods
Daniel P. Berrange
berrange at redhat.com
Fri Jul 12 15:38:30 UTC 2013
From: "Daniel P. Berrange" <berrange at redhat.com>
Wire up the new virDomainCreate{XML}WithFiles methods in the
LXC driver, so that FDs get passed down to the init process.
The lxc_container code needs to do a little dance in order
to renumber the file descriptors it receives into linear
order, starting from STDERR_FILENO + 1.
Signed-off-by: Daniel P. Berrange <berrange at redhat.com>
---
src/lxc/lxc_container.c | 136 +++++++++++++++++++++++++++++++++++++----------
src/lxc/lxc_container.h | 6 ++-
src/lxc/lxc_controller.c | 36 +++++++++++--
src/lxc/lxc_driver.c | 45 +++++++++++++---
src/lxc/lxc_process.c | 16 +++++-
src/lxc/lxc_process.h | 1 +
6 files changed, 197 insertions(+), 43 deletions(-)
diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c
index 940233b..d59de08 100644
--- a/src/lxc/lxc_container.c
+++ b/src/lxc/lxc_container.c
@@ -103,8 +103,10 @@ struct __lxc_child_argv {
size_t nveths;
char **veths;
int monitor;
- char **ttyPaths;
+ size_t npassFDs;
+ int *passFDs;
size_t nttyPaths;
+ char **ttyPaths;
int handshakefd;
};
@@ -217,20 +219,28 @@ static virCommandPtr lxcContainerBuildInitCmd(virDomainDefPtr vmDef)
}
/**
- * lxcContainerSetStdio:
+ * lxcContainerSetupFDs:
* @control: control FD from parent
* @ttyfd: FD of tty to set as the container console
+ * @npassFDs: number of extra FDs
+ * @passFDs: list of extra FDs
*
- * Sets the given tty as the primary conosole for the container as well as
- * stdout, stdin and stderr.
+ * Setup file descriptors in the container. @ttyfd is set to be
+ * the container's stdin, stdout & stderr. Any FDs included in
+ * @passFDs, will be dup()'d such that they start from stderr+1
+ * with no gaps.
*
* Returns 0 on success or -1 in case of error
*/
-static int lxcContainerSetStdio(int control, int ttyfd, int handshakefd)
+static int lxcContainerSetupFDs(int *ttyfd,
+ size_t npassFDs, int *passFDs)
{
int rc = -1;
int open_max;
int fd;
+ int last_fd;
+ size_t i;
+ size_t j;
if (setsid() < 0) {
virReportSystemError(errno, "%s",
@@ -238,44 +248,99 @@ static int lxcContainerSetStdio(int control, int ttyfd, int handshakefd)
goto cleanup;
}
- if (ioctl(ttyfd, TIOCSCTTY, NULL) < 0) {
+ if (ioctl(*ttyfd, TIOCSCTTY, NULL) < 0) {
virReportSystemError(errno, "%s",
_("ioctl(TIOCSTTY) failed"));
goto cleanup;
}
- /* Just in case someone forget to set FD_CLOEXEC, explicitly
- * close all FDs before executing the container */
- open_max = sysconf(_SC_OPEN_MAX);
- if (open_max < 0) {
+ if (dup2(*ttyfd, STDIN_FILENO) < 0) {
virReportSystemError(errno, "%s",
- _("sysconf(_SC_OPEN_MAX) failed"));
+ _("dup2(stdin) failed"));
goto cleanup;
}
- for (fd = 0; fd < open_max; fd++)
- if (fd != ttyfd && fd != control && fd != handshakefd) {
- int tmpfd = fd;
- VIR_MASS_CLOSE(tmpfd);
- }
- if (dup2(ttyfd, 0) < 0) {
+ if (dup2(*ttyfd, STDOUT_FILENO) < 0) {
virReportSystemError(errno, "%s",
- _("dup2(stdin) failed"));
+ _("dup2(stdout) failed"));
goto cleanup;
}
- if (dup2(ttyfd, 1) < 0) {
+ if (dup2(*ttyfd, STDERR_FILENO) < 0) {
virReportSystemError(errno, "%s",
- _("dup2(stdout) failed"));
+ _("dup2(stderr) failed"));
goto cleanup;
}
- if (dup2(ttyfd, 2) < 0) {
+ VIR_FORCE_CLOSE(*ttyfd);
+
+ /* Any FDs in @passFDs need to be moved around so that
+ * they are numbered, without gaps, starting from
+ * STDERR_FILENO + 1
+ */
+ for (i = 0; i < npassFDs; i++) {
+ int wantfd;
+
+ wantfd = STDERR_FILENO + i + 1;
+ VIR_DEBUG("Pass %d onto %d", passFDs[i], wantfd);
+
+ /* If we already have desired FD number, life
+ * is easy. Nothing needs renumbering */
+ if (passFDs[i] == wantfd)
+ continue;
+
+ /*
+ * Lets check to see if any later FDs are occupying
+ * our desired FD number. If so, we must move them
+ * out of the way
+ */
+ for (j = i + 1; j < npassFDs; j++) {
+ if (passFDs[j] == wantfd) {
+ VIR_DEBUG("Clash %zu", j);
+ int newfd = dup(passFDs[j]);
+ if (newfd < 0) {
+ virReportSystemError(errno,
+ _("Cannot move fd %d out of the way"),
+ passFDs[j]);
+ goto cleanup;
+ }
+ /* We're intentionally not closing the
+ * old value of passFDs[j], because we
+ * don't want later iterations of the
+ * loop to take it back. dup2() will
+ * cause it to be closed shortly anyway
+ */
+ VIR_DEBUG("Moved clash onto %d", newfd);
+ passFDs[j] = newfd;
+ }
+ }
+
+ /* Finally we can move into our desired FD number */
+ if (dup2(passFDs[i], wantfd) < 0) {
+ virReportSystemError(errno,
+ _("Cannot duplicate fd %d onto fd %d"),
+ passFDs[i], wantfd);
+ goto cleanup;
+ }
+ VIR_FORCE_CLOSE(passFDs[i]);
+ }
+
+ last_fd = STDERR_FILENO + npassFDs;
+
+ /* Just in case someone forget to set FD_CLOEXEC, explicitly
+ * close all remaining FDs before executing the container */
+ open_max = sysconf(_SC_OPEN_MAX);
+ if (open_max < 0) {
virReportSystemError(errno, "%s",
- _("dup2(stderr) failed"));
+ _("sysconf(_SC_OPEN_MAX) failed"));
goto cleanup;
}
+ for (fd = last_fd + 1; fd < open_max; fd++) {
+ int tmpfd = fd;
+ VIR_MASS_CLOSE(tmpfd);
+ }
+
rc = 0;
cleanup:
@@ -2044,9 +2109,11 @@ static int lxcContainerChild(void *data)
if (virSecurityManagerSetProcessLabel(argv->securityDriver, vmDef) < 0)
goto cleanup;
- if (lxcContainerSetStdio(argv->monitor, ttyfd, argv->handshakefd) < 0) {
+ VIR_FORCE_CLOSE(argv->handshakefd);
+ VIR_FORCE_CLOSE(argv->monitor);
+ if (lxcContainerSetupFDs(&ttyfd,
+ argv->npassFDs, argv->passFDs) < 0)
goto cleanup;
- }
ret = 0;
cleanup:
@@ -2129,18 +2196,29 @@ int lxcContainerStart(virDomainDefPtr def,
virSecurityManagerPtr securityDriver,
size_t nveths,
char **veths,
+ size_t npassFDs,
+ int *passFDs,
int control,
int handshakefd,
- char **ttyPaths,
- size_t nttyPaths)
+ size_t nttyPaths,
+ char **ttyPaths)
{
pid_t pid;
int cflags;
int stacksize = getpagesize() * 4;
char *stack, *stacktop;
- lxc_child_argv_t args = { def, securityDriver,
- nveths, veths, control,
- ttyPaths, nttyPaths, handshakefd};
+ lxc_child_argv_t args = {
+ .config = def,
+ .securityDriver = securityDriver,
+ .nveths = nveths,
+ .veths = veths,
+ .npassFDs = npassFDs,
+ .passFDs = passFDs,
+ .monitor = control,
+ .nttyPaths = nttyPaths,
+ .ttyPaths = ttyPaths,
+ .handshakefd = handshakefd
+ };
/* allocate a stack for the container */
if (VIR_ALLOC_N(stack, stacksize) < 0)
diff --git a/src/lxc/lxc_container.h b/src/lxc/lxc_container.h
index 6f270d7..538154a 100644
--- a/src/lxc/lxc_container.h
+++ b/src/lxc/lxc_container.h
@@ -56,10 +56,12 @@ int lxcContainerStart(virDomainDefPtr def,
virSecurityManagerPtr securityDriver,
size_t nveths,
char **veths,
+ size_t npassFDs,
+ int *passFDs,
int control,
int handshakefd,
- char **ttyPaths,
- size_t nttyPaths);
+ size_t nttyPaths,
+ char **ttyPaths);
int lxcContainerAvailable(int features);
diff --git a/src/lxc/lxc_controller.c b/src/lxc/lxc_controller.c
index 3f3d93b..f2eba33 100644
--- a/src/lxc/lxc_controller.c
+++ b/src/lxc/lxc_controller.c
@@ -108,6 +108,9 @@ struct _virLXCController {
size_t nveths;
char **veths;
+ size_t npassFDs;
+ int *passFDs;
+
size_t nconsoles;
virLXCControllerConsolePtr consoles;
char *devptmx;
@@ -253,6 +256,10 @@ static void virLXCControllerFree(virLXCControllerPtr ctrl)
VIR_FREE(ctrl->veths[i]);
VIR_FREE(ctrl->veths);
+ for (i = 0; i < ctrl->npassFDs; i++)
+ VIR_FORCE_CLOSE(ctrl->passFDs[i]);
+ VIR_FREE(ctrl->passFDs);
+
for (i = 0; i < ctrl->nconsoles; i++)
virLXCControllerConsoleClose(&(ctrl->consoles[i]));
VIR_FREE(ctrl->consoles);
@@ -1737,14 +1744,19 @@ virLXCControllerRun(virLXCControllerPtr ctrl)
ctrl->securityManager,
ctrl->nveths,
ctrl->veths,
+ ctrl->npassFDs,
+ ctrl->passFDs,
control[1],
containerhandshake[1],
- containerTTYPaths,
- ctrl->nconsoles)) < 0)
+ ctrl->nconsoles,
+ containerTTYPaths)) < 0)
goto cleanup;
VIR_FORCE_CLOSE(control[1]);
VIR_FORCE_CLOSE(containerhandshake[1]);
+ for (i = 0; i < ctrl->npassFDs; i++)
+ VIR_FORCE_CLOSE(ctrl->passFDs[i]);
+
if (virLXCControllerSetupUserns(ctrl) < 0)
goto cleanup;
@@ -1811,6 +1823,7 @@ int main(int argc, char *argv[])
{ "name", 1, NULL, 'n' },
{ "veth", 1, NULL, 'v' },
{ "console", 1, NULL, 'c' },
+ { "passfd", 1, NULL, 'p' },
{ "handshakefd", 1, NULL, 's' },
{ "security", 1, NULL, 'S' },
{ "help", 0, NULL, 'h' },
@@ -1818,6 +1831,8 @@ int main(int argc, char *argv[])
};
int *ttyFDs = NULL;
size_t nttyFDs = 0;
+ int *passFDs = NULL;
+ size_t npassFDs = 0;
virLXCControllerPtr ctrl = NULL;
size_t i;
const char *securityDriver = "none";
@@ -1835,7 +1850,7 @@ int main(int argc, char *argv[])
while (1) {
int c;
- c = getopt_long(argc, argv, "dn:v:m:c:s:h:S:",
+ c = getopt_long(argc, argv, "dn:v:p:m:c:s:h:S:",
options, NULL);
if (c == -1)
@@ -1867,6 +1882,15 @@ int main(int argc, char *argv[])
}
break;
+ case 'p':
+ if (VIR_REALLOC_N(passFDs, npassFDs + 1) < 0)
+ goto cleanup;
+ if (virStrToLong_i(optarg, NULL, 10, &passFDs[npassFDs++]) < 0) {
+ fprintf(stderr, "malformed --passfd argument '%s'", optarg);
+ goto cleanup;
+ }
+ break;
+
case 's':
if (virStrToLong_i(optarg, NULL, 10, &handshakeFd) < 0) {
fprintf(stderr, "malformed --handshakefd argument '%s'",
@@ -1939,6 +1963,9 @@ int main(int argc, char *argv[])
ctrl->veths = veths;
ctrl->nveths = nveths;
+ ctrl->passFDs = passFDs;
+ ctrl->npassFDs = npassFDs;
+
for (i = 0; i < nttyFDs; i++) {
if (virLXCControllerAddConsole(ctrl, ttyFDs[i]) < 0)
goto cleanup;
@@ -2004,6 +2031,9 @@ cleanup:
for (i = 0; i < nttyFDs; i++)
VIR_FORCE_CLOSE(ttyFDs[i]);
VIR_FREE(ttyFDs);
+ for (i = 0; i < npassFDs; i++)
+ VIR_FORCE_CLOSE(passFDs[i]);
+ VIR_FREE(passFDs);
virLXCControllerFree(ctrl);
diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c
index 1279edf..6d71f6a 100644
--- a/src/lxc/lxc_driver.c
+++ b/src/lxc/lxc_driver.c
@@ -1021,7 +1021,10 @@ cleanup:
*
* Returns 0 on success or -1 in case of error
*/
-static int lxcDomainCreateWithFlags(virDomainPtr dom, unsigned int flags)
+static int lxcDomainCreateWithFiles(virDomainPtr dom,
+ unsigned int nfiles,
+ int *files,
+ unsigned int flags)
{
virLXCDriverPtr driver = dom->conn->privateData;
virDomainObjPtr vm;
@@ -1040,7 +1043,7 @@ static int lxcDomainCreateWithFlags(virDomainPtr dom, unsigned int flags)
goto cleanup;
}
- if (virDomainCreateWithFlagsEnsureACL(dom->conn, vm->def) < 0)
+ if (virDomainCreateWithFilesEnsureACL(dom->conn, vm->def) < 0)
goto cleanup;
if ((vm->def->nets != NULL) && !(driver->have_netns)) {
@@ -1056,6 +1059,7 @@ static int lxcDomainCreateWithFlags(virDomainPtr dom, unsigned int flags)
}
ret = virLXCProcessStart(dom->conn, driver, vm,
+ nfiles, files,
(flags & VIR_DOMAIN_START_AUTODESTROY),
VIR_DOMAIN_RUNNING_BOOTED);
@@ -1087,7 +1091,21 @@ cleanup:
*/
static int lxcDomainCreate(virDomainPtr dom)
{
- return lxcDomainCreateWithFlags(dom, 0);
+ return lxcDomainCreateWithFiles(dom, 0, NULL, 0);
+}
+
+/**
+ * lxcDomainCreateWithFlags:
+ * @dom: domain to start
+ *
+ * Looks up domain and starts it.
+ *
+ * Returns 0 on success or -1 in case of error
+ */
+static int lxcDomainCreateWithFlags(virDomainPtr dom,
+ unsigned int flags)
+{
+ return lxcDomainCreateWithFiles(dom, 0, NULL, flags);
}
/**
@@ -1101,9 +1119,11 @@ static int lxcDomainCreate(virDomainPtr dom)
* Returns 0 on success or -1 in case of error
*/
static virDomainPtr
-lxcDomainCreateXML(virConnectPtr conn,
- const char *xml,
- unsigned int flags) {
+lxcDomainCreateXMLWithFiles(virConnectPtr conn,
+ const char *xml,
+ unsigned int nfiles,
+ int *files,
+ unsigned int flags) {
virLXCDriverPtr driver = conn->privateData;
virDomainObjPtr vm = NULL;
virDomainDefPtr def;
@@ -1118,7 +1138,7 @@ lxcDomainCreateXML(virConnectPtr conn,
VIR_DOMAIN_XML_INACTIVE)))
goto cleanup;
- if (virDomainCreateXMLEnsureACL(conn, def) < 0)
+ if (virDomainCreateXMLWithFilesEnsureACL(conn, def) < 0)
goto cleanup;
if (virSecurityManagerVerify(driver->securityManager, def) < 0)
@@ -1139,6 +1159,7 @@ lxcDomainCreateXML(virConnectPtr conn,
def = NULL;
if (virLXCProcessStart(conn, driver, vm,
+ nfiles, files,
(flags & VIR_DOMAIN_START_AUTODESTROY),
VIR_DOMAIN_RUNNING_BOOTED) < 0) {
virDomainAuditStart(vm, "booted", false);
@@ -1167,6 +1188,14 @@ cleanup:
}
+static virDomainPtr
+lxcDomainCreateXML(virConnectPtr conn,
+ const char *xml,
+ unsigned int flags) {
+ return lxcDomainCreateXMLWithFiles(conn, xml, 0, NULL, flags);
+}
+
+
static int lxcDomainGetSecurityLabel(virDomainPtr dom, virSecurityLabelPtr seclabel)
{
virLXCDriverPtr driver = dom->conn->privateData;
@@ -4836,6 +4865,7 @@ static virDriver lxcDriver = {
.connectNumOfDomains = lxcConnectNumOfDomains, /* 0.4.2 */
.connectListAllDomains = lxcConnectListAllDomains, /* 0.9.13 */
.domainCreateXML = lxcDomainCreateXML, /* 0.4.4 */
+ .domainCreateXMLWithFiles = lxcDomainCreateXMLWithFiles, /* 1.1.1 */
.domainLookupByID = lxcDomainLookupByID, /* 0.4.2 */
.domainLookupByUUID = lxcDomainLookupByUUID, /* 0.4.2 */
.domainLookupByName = lxcDomainLookupByName, /* 0.4.2 */
@@ -4860,6 +4890,7 @@ static virDriver lxcDriver = {
.connectNumOfDefinedDomains = lxcConnectNumOfDefinedDomains, /* 0.4.2 */
.domainCreate = lxcDomainCreate, /* 0.4.4 */
.domainCreateWithFlags = lxcDomainCreateWithFlags, /* 0.8.2 */
+ .domainCreateWithFiles = lxcDomainCreateWithFiles, /* 1.1.1 */
.domainDefineXML = lxcDomainDefineXML, /* 0.4.2 */
.domainUndefine = lxcDomainUndefine, /* 0.4.2 */
.domainUndefineFlags = lxcDomainUndefineFlags, /* 0.9.4 */
diff --git a/src/lxc/lxc_process.c b/src/lxc/lxc_process.c
index 396e0eb..dd908b8 100644
--- a/src/lxc/lxc_process.c
+++ b/src/lxc/lxc_process.c
@@ -192,7 +192,8 @@ virLXCProcessReboot(virLXCDriverPtr driver,
vm->newDef = NULL;
virLXCProcessStop(driver, vm, VIR_DOMAIN_SHUTOFF_SHUTDOWN);
vm->newDef = savedDef;
- if (virLXCProcessStart(conn, driver, vm, autodestroy, reason) < 0) {
+ if (virLXCProcessStart(conn, driver, vm,
+ 0, NULL, autodestroy, reason) < 0) {
VIR_WARN("Unable to handle reboot of vm %s",
vm->def->name);
goto cleanup;
@@ -803,6 +804,8 @@ virLXCProcessBuildControllerCmd(virLXCDriverPtr driver,
char **veths,
int *ttyFDs,
size_t nttyFDs,
+ int *files,
+ size_t nfiles,
int handshakefd)
{
size_t i;
@@ -853,6 +856,12 @@ virLXCProcessBuildControllerCmd(virLXCDriverPtr driver,
virCommandPreserveFD(cmd, ttyFDs[i]);
}
+ for (i = 0; i < nfiles; i++) {
+ virCommandAddArg(cmd, "--passfd");
+ virCommandAddArgFormat(cmd, "%d", files[i]);
+ virCommandPreserveFD(cmd, files[i], 0);
+ }
+
virCommandAddArgPair(cmd, "--security",
virSecurityManagerGetModel(driver->securityManager));
@@ -1024,6 +1033,7 @@ error:
int virLXCProcessStart(virConnectPtr conn,
virLXCDriverPtr driver,
virDomainObjPtr vm,
+ unsigned int nfiles, int *files,
bool autoDestroy,
virDomainRunningReason reason)
{
@@ -1189,6 +1199,7 @@ int virLXCProcessStart(virConnectPtr conn,
vm,
nveths, veths,
ttyFDs, nttyFDs,
+ files, nfiles,
handshakefds[1])))
goto cleanup;
virCommandSetOutputFD(cmd, &logfd);
@@ -1382,7 +1393,8 @@ virLXCProcessAutostartDomain(virDomainObjPtr vm,
virObjectLock(vm);
if (vm->autostart &&
!virDomainObjIsActive(vm)) {
- ret = virLXCProcessStart(data->conn, data->driver, vm, false,
+ ret = virLXCProcessStart(data->conn, data->driver, vm,
+ 0, NULL, false,
VIR_DOMAIN_RUNNING_BOOTED);
virDomainAuditStart(vm, "booted", ret >= 0);
if (ret < 0) {
diff --git a/src/lxc/lxc_process.h b/src/lxc/lxc_process.h
index 779cc5f..9eb06f5 100644
--- a/src/lxc/lxc_process.h
+++ b/src/lxc/lxc_process.h
@@ -27,6 +27,7 @@
int virLXCProcessStart(virConnectPtr conn,
virLXCDriverPtr driver,
virDomainObjPtr vm,
+ unsigned int nfiles, int *files,
bool autoDestroy,
virDomainRunningReason reason);
int virLXCProcessStop(virLXCDriverPtr driver,
--
1.8.1.4
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