* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
-#include <alloca.h>
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE 1
+#endif
#include <errno.h>
#include <fcntl.h>
#include <sched.h>
#include <signal.h>
-#include <unistd.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
+#include <unistd.h>
+#include "config.h"
#include "log.h"
+#include "memory_utils.h"
#include "namespace.h"
#include "utils.h"
-lxc_log_define(lxc_namespace, lxc);
+lxc_log_define(namespace, lxc);
struct clone_arg {
int (*fn)(void *);
return clone_arg->fn(clone_arg->arg);
}
-pid_t lxc_clone(int (*fn)(void *), void *arg, int flags)
+#define __LXC_STACK_SIZE 4096
+pid_t lxc_clone(int (*fn)(void *), void *arg, int flags, int *pidfd)
{
+ pid_t ret;
struct clone_arg clone_arg = {
- .fn = fn,
- .arg = arg,
+ .fn = fn,
+ .arg = arg,
};
+ void *stack;
- size_t stack_size = lxc_getpagesize();
- void *stack = alloca(stack_size);
- pid_t ret;
+ stack = malloc(__LXC_STACK_SIZE);
+ if (!stack) {
+ SYSERROR("Failed to allocate clone stack");
+ return -ENOMEM;
+ }
#ifdef __ia64__
- ret = __clone2(do_clone, stack, stack_size, flags | SIGCHLD, &clone_arg);
+ ret = __clone2(fn, stack, __LXC_STACK_SIZE, flags | SIGCHLD, &clone_arg, pidfd);
#else
- ret = clone(do_clone, stack + stack_size, flags | SIGCHLD, &clone_arg);
+ ret = clone(fn, stack + __LXC_STACK_SIZE, flags | SIGCHLD, &clone_arg, pidfd);
#endif
if (ret < 0)
- ERROR("Failed to clone (%#x): %s.", flags, strerror(errno));
+ SYSERROR("Failed to clone (%#x)", flags);
return ret;
}
-/**
- * This is based on raw_clone in systemd but adapted to our needs. This uses
- * copy on write semantics and doesn't pass a stack. CLONE_VM is tricky and
- * doesn't really matter to us so disallow it.
- *
- * The nice thing about this is that we get fork() behavior. That is
- * lxc_raw_clone() returns 0 in the child and the child pid in the parent.
- */
-pid_t lxc_raw_clone(unsigned long flags)
-{
-
- /* These flags don't interest at all so we don't jump through any hoopes
- * of retrieving them and passing them to the kernel.
- */
- errno = EINVAL;
- if ((flags & (CLONE_VM | CLONE_PARENT_SETTID | CLONE_CHILD_SETTID |
- CLONE_CHILD_CLEARTID | CLONE_SETTLS)))
- return -EINVAL;
-
-#if defined(__s390x__) || defined(__s390__) || defined(__CRIS__)
- /* On s390/s390x and cris the order of the first and second arguments
- * of the system call is reversed.
- */
- return (int)syscall(__NR_clone, NULL, flags | SIGCHLD);
-#elif defined(__sparc__) && defined(__arch64__)
- {
- /**
- * sparc64 always returns the other process id in %o0, and
- * a boolean flag whether this is the child or the parent in
- * %o1. Inline assembly is needed to get the flag returned
- * in %o1.
- */
- int in_child;
- int child_pid;
- asm volatile("mov %2, %%g1\n\t"
- "mov %3, %%o0\n\t"
- "mov 0 , %%o1\n\t"
- "t 0x6d\n\t"
- "mov %%o1, %0\n\t"
- "mov %%o0, %1"
- : "=r"(in_child), "=r"(child_pid)
- : "i"(__NR_clone), "r"(flags | SIGCHLD)
- : "%o1", "%o0", "%g1");
- if (in_child)
- return 0;
- else
- return child_pid;
- }
-#elif defined(__ia64__)
- /* On ia64 the stack and stack size are passed as separate arguments. */
- return (int)syscall(__NR_clone, flags | SIGCHLD, NULL, 0);
-#else
- return (int)syscall(__NR_clone, flags | SIGCHLD, NULL);
-#endif
-}
-
/* Leave the user namespace at the first position in the array of structs so
* that we always attach to it first when iterating over the struct and using
* setns() to switch namespaces. This especially affects lxc_attach(): Suppose
int lxc_namespace_2_cloneflag(const char *namespace)
{
int i;
+
for (i = 0; i < LXC_NS_MAX; i++)
if (!strcasecmp(ns_info[i].proc_name, namespace))
return ns_info[i].clone_flag;
int lxc_namespace_2_ns_idx(const char *namespace)
{
int i;
+
for (i = 0; i < LXC_NS_MAX; i++)
if (!strcmp(ns_info[i].proc_name, namespace))
return i;
return -EINVAL;
}
+extern int lxc_namespace_2_std_identifiers(char *namespaces)
+{
+ char **it;
+ char *del;
+
+ /* The identifiers for namespaces used with lxc-attach and lxc-unshare
+ * as given on the manpage do not align with the standard identifiers.
+ * This affects network, mount, and uts namespaces. The standard identifiers
+ * are: "mnt", "uts", and "net" whereas lxc-attach and lxc-unshare uses
+ * "MOUNT", "UTSNAME", and "NETWORK". So let's use some cheap memmove()s
+ * to replace them by their standard identifiers.
+ * Let's illustrate this with an example:
+ * Assume the string:
+ *
+ * "IPC|MOUNT|PID"
+ *
+ * then we memmove()
+ *
+ * dest: del + 1 == OUNT|PID
+ * src: del + 3 == NT|PID
+ */
+ if (!namespaces)
+ return -1;
+
+ while ((del = strstr(namespaces, "MOUNT")))
+ memmove(del + 1, del + 3, strlen(del) - 2);
+
+ for (it = (char *[]){"NETWORK", "UTSNAME", NULL}; it && *it; it++)
+ while ((del = strstr(namespaces, *it)))
+ memmove(del + 3, del + 7, strlen(del) - 6);
+
+ return 0;
+}
+
int lxc_fill_namespace_flags(char *flaglist, int *flags)
{
- char *token, *saveptr = NULL;
+ char *token;
int aflag;
if (!flaglist) {
return -1;
}
- token = strtok_r(flaglist, "|", &saveptr);
- while (token) {
-
+ lxc_iterate_parts(token, flaglist, "|") {
aflag = lxc_namespace_2_cloneflag(token);
if (aflag < 0)
return -1;
*flags |= aflag;
-
- token = strtok_r(NULL, "|", &saveptr);
}
+
return 0;
}
projects / mirror_lxc.git / blobdiff