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Refactor LXC driver to pass tty/socket state directly

This commit is contained in:
Daniel P. Berrange 2008-08-13 10:14:47 +00:00
parent 415b92101f
commit e82c913680
6 changed files with 111 additions and 196 deletions
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7
ChangeLog
View File

@ -1,3 +1,10 @@
Wed Aug 13 10:55:36 BST 2008 Daniel Berrange <berrange@redhat.com>
* src/lxc_conf.h, src/lxc_conf.c, src/lxc_container.h,
src/lxc_container.c, src/lxc_driver.c: Don't store socket
or tty state in lxc_vm_t struct. Pass it around as args
to functions when needed
Wed Aug 13 11:43:36 CEST 2008 Daniel Veillard <veillard@redhat.com>
* docs/storage.html[.in] src/storage_backend_disk.c: revert previous

1
src/lxc_conf.c
View File

@ -1041,7 +1041,6 @@ void lxcFreeVMs(lxc_vm_t *vms)
void lxcFreeVM(lxc_vm_t *vm)
{
lxcFreeVMDef(vm->def);
VIR_FREE(vm->containerTty);
VIR_FREE(vm);
}

12
src/lxc_conf.h
View File

@ -35,12 +35,6 @@
#define LXC_MAX_XML_LENGTH 16384
#define LXC_MAX_ERROR_LEN 1024
#define LXC_DOMAIN_TYPE "lxc"
#define LXC_PARENT_SOCKET 0
#define LXC_CONTAINER_SOCKET 1
/* messages between parent and container */
typedef char lxc_message_t;
#define LXC_CONTINUE_MSG 'c'
/* types of networks for containers */
enum lxc_net_type {
@ -99,12 +93,6 @@ struct __lxc_vm {
char ttyPidFile[PATH_MAX];
int parentTty;
int containerTtyFd;
char *containerTty;
int sockpair[2];
lxc_vm_def_t *def;
lxc_vm_t *next;

60
src/lxc_container.c
View File

@ -33,7 +33,6 @@
#include <unistd.h>
#include "lxc_container.h"
#include "lxc_conf.h"
#include "util.h"
#include "memory.h"
#include "veth.h"
@ -83,10 +82,11 @@ error_out:
*
* Returns 0 on success or -1 in case of error
*/
static int lxcSetContainerStdio(const char *ttyName)
static int lxcSetContainerStdio(const char *ttyPath)
{
int rc = -1;
int ttyfd;
int open_max, i;
if (setsid() < 0) {
lxcError(NULL, NULL, VIR_ERR_INTERNAL_ERROR,
@ -94,10 +94,10 @@ static int lxcSetContainerStdio(const char *ttyName)
goto error_out;
}
ttyfd = open(ttyName, O_RDWR|O_NOCTTY);
ttyfd = open(ttyPath, O_RDWR|O_NOCTTY);
if (ttyfd < 0) {
lxcError(NULL, NULL, VIR_ERR_INTERNAL_ERROR,
_("open(%s) failed: %s"), ttyName, strerror(errno));
_("open(%s) failed: %s"), ttyPath, strerror(errno));
goto error_out;
}
@ -107,7 +107,12 @@ static int lxcSetContainerStdio(const char *ttyName)
goto cleanup;
}
close(0); close(1); close(2);
/* Just in case someone forget to set FD_CLOEXEC, explicitly
* close all FDs before executing the container */
open_max = sysconf (_SC_OPEN_MAX);
for (i = 0; i < open_max; i++)
if (i != ttyfd)
close(i);
if (dup2(ttyfd, 0) < 0) {
lxcError(NULL, NULL, VIR_ERR_INTERNAL_ERROR,
@ -144,12 +149,11 @@ error_out:
*
* Returns 0 on success or -1 in case of error
*/
static int lxcExecWithTty(lxc_vm_t *vm)
static int lxcExecWithTty(lxc_vm_def_t *vmDef, char *ttyPath)
{
int rc = -1;
lxc_vm_def_t *vmDef = vm->def;
if(lxcSetContainerStdio(vm->containerTty) < 0) {
if(lxcSetContainerStdio(ttyPath) < 0) {
goto exit_with_error;
}
@ -161,7 +165,7 @@ exit_with_error:
/**
* lxcWaitForContinue:
* @vm: Pointer to vm structure
* @monitor: monitor FD from parent
*
* This function will wait for the container continue message from the
* parent process. It will send this message on the socket pair stored in
@ -169,31 +173,23 @@ exit_with_error:
*
* Returns 0 on success or -1 in case of error
*/
static int lxcWaitForContinue(lxc_vm_t *vm)
static int lxcWaitForContinue(int monitor)
{
int rc = -1;
lxc_message_t msg;
int readLen;
readLen = saferead(vm->sockpair[LXC_CONTAINER_SOCKET], &msg, sizeof(msg));
if (readLen != sizeof(msg)) {
readLen = saferead(monitor, &msg, sizeof(msg));
if (readLen != sizeof(msg) ||
msg != LXC_CONTINUE_MSG) {
lxcError(NULL, NULL, VIR_ERR_INTERNAL_ERROR,
_("Failed to read the container continue message: %s"),
strerror(errno));
goto error_out;
return -1;
}
DEBUG0("Received container continue message");
close(vm->sockpair[LXC_PARENT_SOCKET]);
vm->sockpair[LXC_PARENT_SOCKET] = -1;
close(vm->sockpair[LXC_CONTAINER_SOCKET]);
vm->sockpair[LXC_CONTAINER_SOCKET] = -1;
rc = 0;
error_out:
return rc;
return 0;
}
/**
@ -204,12 +200,12 @@ error_out:
*
* Returns 0 on success or nonzero in case of error
*/
static int lxcEnableInterfaces(const lxc_vm_t *vm)
static int lxcEnableInterfaces(const lxc_vm_def_t *def)
{
int rc = 0;
const lxc_net_def_t *net;
for (net = vm->def->nets; net; net = net->next) {
for (net = def->nets; net; net = net->next) {
DEBUG("Enabling %s", net->containerVeth);
rc = vethInterfaceUpOrDown(net->containerVeth, 1);
if (0 != rc) {
@ -218,7 +214,7 @@ static int lxcEnableInterfaces(const lxc_vm_t *vm)
}
/* enable lo device only if there were other net devices */
if (vm->def->nets)
if (def->nets)
rc = vethInterfaceUpOrDown("lo", 1);
error_out:
@ -237,11 +233,11 @@ error_out:
*
* Returns 0 on success or -1 in case of error
*/
int lxcChild( void *argv )
int lxcChild( void *data )
{
int rc = -1;
lxc_vm_t *vm = (lxc_vm_t *)argv;
lxc_vm_def_t *vmDef = vm->def;
lxc_child_argv_t *argv = data;
lxc_vm_def_t *vmDef = argv->config;
lxc_mount_t *curMount;
int i;
@ -278,16 +274,16 @@ int lxcChild( void *argv )
}
/* Wait for interface devices to show up */
if (0 != (rc = lxcWaitForContinue(vm))) {
if (0 != (rc = lxcWaitForContinue(argv->monitor))) {
goto cleanup;
}
/* enable interfaces */
if (0 != (rc = lxcEnableInterfaces(vm))) {
if (0 != (rc = lxcEnableInterfaces(vmDef))) {
goto cleanup;
}
rc = lxcExecWithTty(vm);
rc = lxcExecWithTty(vmDef, argv->ttyPath);
/* this function will only return if an error occured */
cleanup:

14
src/lxc_container.h
View File

@ -24,8 +24,22 @@
#ifndef LXC_CONTAINER_H
#define LXC_CONTAINER_H
#include "lxc_conf.h"
#ifdef WITH_LXC
typedef struct __lxc_child_argv lxc_child_argv_t;
struct __lxc_child_argv {
lxc_vm_def_t *config;
int monitor;
char *ttyPath;
};
/* messages between parent and container */
typedef char lxc_message_t;
#define LXC_CONTINUE_MSG 'c'
/* Function declarations */
int lxcChild( void *argv );

213
src/lxc_driver.c
View File

@ -561,27 +561,23 @@ static int lxcCleanupInterfaces(const lxc_vm_t *vm)
/**
* lxcSendContainerContinue:
* @vm: pointer to virtual machine structure
* @monitor: FD for communicating with child
*
* Sends the continue message via the socket pair stored in the vm
* structure.
*
* Returns 0 on success or -1 in case of error
*/
static int lxcSendContainerContinue(const lxc_vm_t *vm)
static int lxcSendContainerContinue(virConnectPtr conn,
int monitor)
{
int rc = -1;
lxc_message_t msg = LXC_CONTINUE_MSG;
int writeCount = 0;
if (NULL == vm) {
goto error_out;
}
writeCount = safewrite(vm->sockpair[LXC_PARENT_SOCKET], &msg,
sizeof(msg));
writeCount = safewrite(monitor, &msg, sizeof(msg));
if (writeCount != sizeof(msg)) {
lxcError(NULL, NULL, VIR_ERR_INTERNAL_ERROR,
lxcError(conn, NULL, VIR_ERR_INTERNAL_ERROR,
_("unable to send container continue message: %s"),
strerror(errno));
goto error_out;
@ -605,12 +601,15 @@ error_out:
*/
static int lxcStartContainer(virConnectPtr conn,
lxc_driver_t* driver,
lxc_vm_t *vm)
lxc_vm_t *vm,
int monitor,
char *ttyPath)
{
int rc = -1;
int flags;
int stacksize = getpagesize() * 4;
char *stack, *stacktop;
lxc_child_argv_t args = { vm->def, monitor, ttyPath };
/* allocate a stack for the container */
if (VIR_ALLOC_N(stack, stacksize) < 0) {
@ -625,7 +624,7 @@ static int lxcStartContainer(virConnectPtr conn,
if (vm->def->nets != NULL)
flags |= CLONE_NEWNET;
vm->def->id = clone(lxcChild, stacktop, flags, (void *)vm);
vm->def->id = clone(lxcChild, stacktop, flags, &args);
DEBUG("clone() returned, %d", vm->def->id);
@ -643,117 +642,9 @@ error_exit:
return rc;
}
/**
* lxcPutTtyInRawMode:
* @conn: pointer to connection
* @ttyDev: file descriptor for tty
*
* Sets tty attributes via cfmakeraw()
*
* Returns 0 on success or -1 in case of error
*/
static int lxcPutTtyInRawMode(virConnectPtr conn, int ttyDev)
{
int rc = -1;
struct termios ttyAttr;
if (tcgetattr(ttyDev, &ttyAttr) < 0) {
lxcError(conn, NULL, VIR_ERR_INTERNAL_ERROR,
"tcgetattr() failed: %s", strerror(errno));
goto cleanup;
}
cfmakeraw(&ttyAttr);
if (tcsetattr(ttyDev, TCSADRAIN, &ttyAttr) < 0) {
lxcError(conn, NULL, VIR_ERR_INTERNAL_ERROR,
"tcsetattr failed: %s", strerror(errno));
goto cleanup;
}
rc = 0;
cleanup:
return rc;
}
/**
* lxcSetupTtyTunnel:
* @conn: pointer to connection
* @vmDef: pointer to virtual machine definition structure
* @ttyDev: pointer to int. On success will be set to fd for master
* end of tty
*
* Opens and configures the parent side tty
*
* Returns 0 on success or -1 in case of error
*/
static int lxcSetupTtyTunnel(virConnectPtr conn,
lxc_vm_def_t *vmDef,
int* ttyDev)
{
int rc = -1;
char *ptsStr;
if (0 < strlen(vmDef->tty)) {
*ttyDev = posix_openpt(O_RDWR|O_NOCTTY|O_NONBLOCK);
if (*ttyDev < 0) {
lxcError(conn, NULL, VIR_ERR_INTERNAL_ERROR,
"open() tty failed: %s", strerror(errno));
goto setup_complete;
}
rc = grantpt(*ttyDev);
if (rc < 0) {
lxcError(conn, NULL, VIR_ERR_INTERNAL_ERROR,
"grantpt() failed: %s", strerror(errno));
goto setup_complete;
}
rc = unlockpt(*ttyDev);
if (rc < 0) {
lxcError(conn, NULL, VIR_ERR_INTERNAL_ERROR,
"unlockpt() failed: %s", strerror(errno));
goto setup_complete;
}
/* get the name and print it to stdout */
ptsStr = ptsname(*ttyDev);
if (ptsStr == NULL) {
lxcError(conn, NULL, VIR_ERR_INTERNAL_ERROR,
"ptsname() failed");
goto setup_complete;
}
/* This value needs to be stored in the container configuration file */
VIR_FREE(vmDef->tty);
if (!(vmDef->tty = strdup(ptsStr))) {
lxcError(conn, NULL, VIR_ERR_NO_MEMORY,
_("unable to get storage for vm tty name"));
goto setup_complete;
}
/* Enter raw mode, so all characters are passed directly to child */
if (lxcPutTtyInRawMode(conn, *ttyDev) < 0) {
goto setup_complete;
}
} else {
*ttyDev = -1;
}
rc = 0;
setup_complete:
if((0 != rc) && (*ttyDev > 0)) {
close(*ttyDev);
}
return rc;
}
/**
* lxcSetupContainerTty:
* lxcOpenTty:
* @conn: pointer to connection
* @ttymaster: pointer to int. On success, set to fd for master end
* @ttyName: On success, will point to string slave end of tty. Caller
@ -763,12 +654,12 @@ setup_complete:
*
* Returns 0 on success or -1 in case of error
*/
static int lxcSetupContainerTty(virConnectPtr conn,
int *ttymaster,
char **ttyName)
static int lxcOpenTty(virConnectPtr conn,
int *ttymaster,
char **ttyName,
int rawmode)
{
int rc = -1;
char tempTtyName[PATH_MAX];
*ttymaster = posix_openpt(O_RDWR|O_NOCTTY|O_NONBLOCK);
if (*ttymaster < 0) {
@ -783,27 +674,43 @@ static int lxcSetupContainerTty(virConnectPtr conn,
goto cleanup;
}
if (0 != ptsname_r(*ttymaster, tempTtyName, sizeof(tempTtyName))) {
lxcError(conn, NULL, VIR_ERR_INTERNAL_ERROR,
_("ptsname_r failed: %s"), strerror(errno));
goto cleanup;
if (rawmode) {
struct termios ttyAttr;
if (tcgetattr(*ttymaster, &ttyAttr) < 0) {
lxcError(conn, NULL, VIR_ERR_INTERNAL_ERROR,
"tcgetattr() failed: %s", strerror(errno));
goto cleanup;
}
cfmakeraw(&ttyAttr);
if (tcsetattr(*ttymaster, TCSADRAIN, &ttyAttr) < 0) {
lxcError(conn, NULL, VIR_ERR_INTERNAL_ERROR,
"tcsetattr failed: %s", strerror(errno));
goto cleanup;
}
}
if (VIR_ALLOC_N(*ttyName, strlen(tempTtyName) + 1) < 0) {
lxcError(conn, NULL, VIR_ERR_NO_MEMORY,
_("unable to allocate container name string"));
goto cleanup;
}
if (ttyName) {
char tempTtyName[PATH_MAX];
if (0 != ptsname_r(*ttymaster, tempTtyName, sizeof(tempTtyName))) {
lxcError(conn, NULL, VIR_ERR_INTERNAL_ERROR,
_("ptsname_r failed: %s"), strerror(errno));
goto cleanup;
}
strcpy(*ttyName, tempTtyName);
if ((*ttyName = strdup(tempTtyName)) == NULL) {
lxcError(conn, NULL, VIR_ERR_NO_MEMORY, NULL);
goto cleanup;
}
}
rc = 0;
cleanup:
if (0 != rc) {
if (-1 != *ttymaster) {
close(*ttymaster);
}
if (rc != 0 &&
*ttymaster != -1) {
close(*ttymaster);
}
return rc;
@ -989,15 +896,18 @@ static int lxcVmStart(virConnectPtr conn,
lxc_vm_t * vm)
{
int rc = -1;
lxc_vm_def_t *vmDef = vm->def;
int sockpair[2] = { -1, -1 };
int containerTty, parentTty;
char *containerTtyPath = NULL;
/* open parent tty */
if (lxcSetupTtyTunnel(conn, vmDef, &vm->parentTty) < 0) {
VIR_FREE(vm->def->tty);
if (lxcOpenTty(conn, &parentTty, &vm->def->tty, 1) < 0) {
goto cleanup;
}
/* open container tty */
if (lxcSetupContainerTty(conn, &(vm->containerTtyFd), &(vm->containerTty)) < 0) {
if (lxcOpenTty(conn, &containerTty, &containerTtyPath, 0) < 0) {
goto cleanup;
}
@ -1011,15 +921,15 @@ static int lxcVmStart(virConnectPtr conn,
if (vm->pid == 0) {
/* child process calls forward routine */
lxcTtyForward(vm->parentTty, vm->containerTtyFd);
lxcTtyForward(parentTty, containerTty);
}
if (lxcStoreTtyPid(driver, vm)) {
DEBUG0("unable to store tty pid");
}
close(vm->parentTty);
close(vm->containerTtyFd);
close(parentTty);
close(containerTty);
if (0 != (rc = lxcSetupInterfaces(conn, vm))) {
goto cleanup;
@ -1027,7 +937,7 @@ static int lxcVmStart(virConnectPtr conn,
/* create a socket pair to send continue message to the container once */
/* we've completed the post clone configuration */
if (0 != socketpair(PF_UNIX, SOCK_STREAM, 0, vm->sockpair)) {
if (0 != socketpair(PF_UNIX, SOCK_STREAM, 0, sockpair)) {
lxcError(conn, NULL, VIR_ERR_INTERNAL_ERROR,
_("sockpair failed: %s"), strerror(errno));
goto cleanup;
@ -1035,7 +945,9 @@ static int lxcVmStart(virConnectPtr conn,
/* check this rc */
rc = lxcStartContainer(conn, driver, vm);
rc = lxcStartContainer(conn, driver, vm,
sockpair[1],
containerTtyPath);
if (rc != 0)
goto cleanup;
@ -1043,7 +955,7 @@ static int lxcVmStart(virConnectPtr conn,
if (rc != 0)
goto cleanup;
rc = lxcSendContainerContinue(vm);
rc = lxcSendContainerContinue(conn, sockpair[0]);
if (rc != 0)
goto cleanup;
@ -1052,10 +964,9 @@ static int lxcVmStart(virConnectPtr conn,
driver->nactivevms++;
cleanup:
close(vm->sockpair[LXC_PARENT_SOCKET]);
vm->sockpair[LXC_PARENT_SOCKET] = -1;
close(vm->sockpair[LXC_CONTAINER_SOCKET]);
vm->sockpair[LXC_CONTAINER_SOCKET] = -1;
if (sockpair[0] != -1) close(sockpair[0]);
if (sockpair[1] != -1) close(sockpair[1]);
VIR_FREE(containerTtyPath);
return rc;
}