1 files changed, 567 insertions, 0 deletions
diff --git a/src/dumm/guest.c b/src/dumm/guest.c
new file mode 100644
index 000000000..bbb59f431
--- /dev/null
+++ b/src/dumm/guest.c
@@ -0,0 +1,567 @@
+/*
+ * Copyright (C) 2007 Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program 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 General Public License
+ * for more details.
+ */
+
+#define _GNU_SOURCE
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <sys/uio.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <dirent.h>
+#include <termios.h>
+
+#include <debug.h>
+#include <utils/linked_list.h>
+
+#include "dumm.h"
+#include "guest.h"
+#include "mconsole.h"
+#include "cowfs.h"
+
+#define PERME (S_IRWXU | S_IRWXG)
+#define PERM (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP)
+
+#define MASTER_DIR "master"
+#define DIFF_DIR "diff"
+#define UNION_DIR "union"
+#define MEMORY_FILE "mem"
+#define KERNEL_FILE "linux"
+#define LOG_FILE "boot.log"
+#define NOTIFY_FILE "notify"
+#define PTYS 0
+
+typedef struct private_guest_t private_guest_t;
+
+struct private_guest_t {
+	/** implemented public interface */
+	guest_t public;
+	/** name of the guest */
+	char *name;
+	/** directory of guest */
+	int dir;
+	/** directory name of guest */
+	char *dirname;
+	/** amount of memory for guest, in MB */
+	int mem;
+	/** pid of guest child process */
+	int pid;
+	/** state of guest */
+	guest_state_t state;
+	/** log file for console 0 */
+	int bootlog;
+	/** FUSE cowfs instance */
+	cowfs_t *cowfs;
+	/** mconsole to control running UML */
+	mconsole_t *mconsole;
+	/** list of interfaces attached to the guest */
+	linked_list_t *ifaces;
+};
+
+ENUM(guest_state_names, GUEST_STOPPED, GUEST_STOPPING,
+	"STOPPED",
+	"STARTING",
+	"RUNNING",
+	"PAUSED",
+	"STOPPING",
+);
+
+/**
+ * Implementation of guest_t.get_name.
+ */
+static char* get_name(private_guest_t *this)
+{
+	return this->name;
+}
+
+/**
+ * Implementation of guest_t.create_iface.
+ */
+static iface_t* create_iface(private_guest_t *this, char *name)
+{
+	iterator_t *iterator;
+	iface_t *iface;
+	
+	if (this->state != GUEST_RUNNING)
+	{
+		DBG1("guest '%s' not running, unable to add interface", this->name);
+		return NULL;
+	}
+	
+	iterator = this->ifaces->create_iterator(this->ifaces, TRUE);
+	while (iterator->iterate(iterator, (void**)&iface))
+	{
+		if (streq(name, iface->get_guestif(iface)))
+		{
+			DBG1("guest '%s' already has an interface '%s'", this->name, name);
+			iterator->destroy(iterator);
+			return NULL;
+		}
+	}
+	iterator->destroy(iterator);
+
+	iface = iface_create(this->name, name, this->mconsole);
+	if (iface)
+	{
+		this->ifaces->insert_last(this->ifaces, iface);
+	}
+	return iface;
+}
+
+/**
+ * Implementation of guest_t.create_iface_iterator.
+ */
+static iterator_t* create_iface_iterator(private_guest_t *this)
+{
+	return this->ifaces->create_iterator(this->ifaces, TRUE);
+}
+	
+/**
+ * Implementation of guest_t.get_state.
+ */
+static guest_state_t get_state(private_guest_t *this)
+{
+	return this->state;
+}
+
+/**
+ * Implementation of guest_t.get_pid.
+ */
+static pid_t get_pid(private_guest_t *this)
+{
+	return this->pid;
+}
+
+/**
+ * write format string to a buffer, and advance buffer position
+ */
+static char* write_arg(char **pos, size_t *left, char *format, ...)
+{
+	size_t len;
+	char *res = NULL;
+	va_list args;
+
+	va_start(args, format);
+	len = vsnprintf(*pos, *left, format, args);
+	va_end(args);
+	if (len < *left)
+	{
+		res = *pos;
+		len++;
+		*pos += len + 1;
+		*left -= len + 1;
+	}
+	return res;
+}
+
+/**
+ * Implementation of get_t.close_console.
+ */
+static char* get_console(private_guest_t *this, int console)
+{
+	if (this->state == GUEST_RUNNING)
+	{
+		return this->mconsole->get_console_pts(this->mconsole, console);
+	}
+	return NULL;
+}
+
+/**
+ * Implementation of guest_t.stop.
+ */
+static void stop(private_guest_t *this)
+{
+	if (this->state != GUEST_STOPPED)
+	{
+		this->state = GUEST_STOPPING;
+		this->ifaces->destroy_offset(this->ifaces, offsetof(iface_t, destroy));
+		this->ifaces = linked_list_create();
+		kill(this->pid, SIGINT);
+		waitpid(this->pid, NULL, 0);
+		this->state = GUEST_STOPPED;
+	}
+}
+
+/**
+ * Implementation of guest_t.start.
+ */
+static bool start(private_guest_t *this)
+{
+	char buf[2048];
+	char *notify;
+	char *pos = buf;
+	char *args[16];
+	int i = 0;
+	size_t left = sizeof(buf);
+	
+	if (this->state != GUEST_STOPPED)
+	{
+		DBG1("unable to start guest in state %N", guest_state_names, this->state);
+		return FALSE;
+	}
+	this->state = GUEST_STARTING;
+	
+	notify = write_arg(&pos, &left, "%s/%s", this->dirname, NOTIFY_FILE);
+	
+	args[i++] = write_arg(&pos, &left, "%s/%s", this->dirname, KERNEL_FILE);
+	args[i++] = write_arg(&pos, &left, "root=/dev/root");
+	args[i++] = write_arg(&pos, &left, "rootfstype=hostfs");
+	args[i++] = write_arg(&pos, &left, "rootflags=%s/%s", this->dirname, UNION_DIR);
+	args[i++] = write_arg(&pos, &left, "uml_dir=%s", this->dirname);
+	args[i++] = write_arg(&pos, &left, "umid=%s", this->name);
+	args[i++] = write_arg(&pos, &left, "mem=%dM", this->mem);
+	args[i++] = write_arg(&pos, &left, "mconsole=notify:%s", notify);
+	args[i++] = write_arg(&pos, &left, "con=pts");
+	args[i++] = write_arg(&pos, &left, "con0=none,fd:%d", this->bootlog);
+	args[i++] = NULL;
+	  
+	this->pid = fork();
+	switch (this->pid)
+	{
+		case 0: /* child,  */
+			dup2(open("/dev/null", 0), 0);
+			dup2(this->bootlog, 1);
+			dup2(this->bootlog, 2);
+			execvp(args[0], args);
+			DBG1("starting UML kernel '%s' failed: %m", args[0]);
+			exit(1);
+		case -1:
+			this->state = GUEST_STOPPED;
+			return FALSE;
+		default:
+			break;
+	}
+	/* open mconsole */
+	this->mconsole = mconsole_create(notify);
+	if (this->mconsole == NULL)
+	{
+		DBG1("opening mconsole at '%s' failed, stopping guest", buf);
+		stop(this);
+		return FALSE;
+	}
+	
+	this->state = GUEST_RUNNING;
+	return TRUE;
+}	
+	
+/**
+ * Implementation of guest_t.load_template.
+ */
+static bool load_template(private_guest_t *this, char *path)
+{
+	char dir[PATH_MAX];
+	size_t len;
+	
+	if (path == NULL)
+	{
+		return this->cowfs->set_overlay(this->cowfs, NULL);	
+	}
+	
+	len = snprintf(dir, sizeof(dir), "%s/%s", path, this->name);
+	if (len < 0 || len >= sizeof(dir))
+	{
+		return FALSE;
+	}
+	if (access(dir, F_OK) != 0)
+	{
+		if (mkdir(dir, PERME) != 0)
+		{
+			DBG1("creating overlay for guest '%s' failed: %m", this->name);
+			return FALSE;
+		}
+	}
+	return this->cowfs->set_overlay(this->cowfs, dir);
+}
+
+/**
+ * Implementation of guest_t.sigchild.
+ */
+static void sigchild(private_guest_t *this)
+{
+	if (this->state != GUEST_STOPPING)
+	{	/* collect zombie if uml crashed */
+		waitpid(this->pid, NULL, WNOHANG);
+	}
+	DESTROY_IF(this->mconsole);
+	this->mconsole = NULL;
+	this->state = GUEST_STOPPED;
+}
+
+/**
+ * umount the union filesystem
+ */
+static bool umount_unionfs(private_guest_t *this)
+{
+	if (this->cowfs)
+	{
+		this->cowfs->destroy(this->cowfs);
+		this->cowfs = NULL;
+		return TRUE;
+	}
+	return FALSE;
+}
+
+/**
+ * mount the union filesystem
+ */
+static bool mount_unionfs(private_guest_t *this)
+{
+	char master[PATH_MAX];
+	char diff[PATH_MAX];
+	char mount[PATH_MAX];
+
+	if (this->cowfs == NULL)
+	{
+		snprintf(master, sizeof(master), "%s/%s", this->dirname, MASTER_DIR);
+		snprintf(diff, sizeof(diff), "%s/%s", this->dirname, DIFF_DIR);
+		snprintf(mount, sizeof(mount), "%s/%s", this->dirname, UNION_DIR);
+		
+		this->cowfs = cowfs_create(master, diff, mount);
+		if (this->cowfs)
+		{
+			return TRUE;
+		}
+	}
+	return FALSE;
+}
+
+/**
+ * open logfile for boot messages
+ */
+static int open_bootlog(private_guest_t *this)
+{
+	int fd;
+	
+	fd = openat(this->dir, LOG_FILE, O_WRONLY | O_CREAT, PERM);
+	if (fd == -1)
+	{
+		DBG1("opening bootlog failed, using stdout");
+		return 1;
+	}
+	return fd;
+}
+
+/**
+ * load memory configuration from file
+ */
+int loadmem(private_guest_t *this)
+{
+	FILE *file;
+	int mem = 0;
+	
+	file = fdopen(openat(this->dir, MEMORY_FILE, O_RDONLY, PERM), "r");
+	if (file)
+	{
+		if (fscanf(file, "%d", &mem) <= 0)
+		{
+			mem = 0;
+		}
+		fclose(file);
+	}
+	return mem;
+}
+
+/**
+ * save memory configuration to file
+ */
+bool savemem(private_guest_t *this, int mem)
+{
+	FILE *file;
+	bool retval = FALSE;
+	
+	file = fdopen(openat(this->dir, MEMORY_FILE, O_RDWR | O_CREAT | O_TRUNC,
+						 PERM), "w");
+	if (file)
+	{
+		if (fprintf(file, "%d", mem) > 0)
+		{
+			retval = TRUE;
+		}
+		fclose(file);
+	}
+	return retval;
+}
+
+/**
+ * Implementation of guest_t.destroy.
+ */
+static void destroy(private_guest_t *this)
+{
+	stop(this);
+	umount_unionfs(this);
+	if (this->bootlog > 1)
+	{
+		close(this->bootlog);
+	}
+	if (this->dir > 0)
+	{
+		close(this->dir);
+	}
+	free(this->dirname);
+	free(this->name);
+	free(this);
+}
+
+/**
+ * generic guest constructor
+ */
+static private_guest_t *guest_create_generic(char *parent, char *name,
+											 bool create)
+{
+	char cwd[PATH_MAX];
+	private_guest_t *this = malloc_thing(private_guest_t);
+	
+	this->public.get_name = (void*)get_name;
+	this->public.get_pid = (pid_t(*)(guest_t*))get_pid;
+	this->public.get_state = (guest_state_t(*)(guest_t*))get_state;
+	this->public.create_iface = (iface_t*(*)(guest_t*,char*))create_iface;
+	this->public.create_iface_iterator = (iterator_t*(*)(guest_t*))create_iface_iterator;
+	this->public.start = (void*)start;
+	this->public.stop = (void*)stop;
+	this->public.get_console = (char*(*)(guest_t*,int))get_console;
+	this->public.load_template = (bool(*)(guest_t*, char *path))load_template;
+	this->public.sigchild = (void(*)(guest_t*))sigchild;
+	this->public.destroy = (void*)destroy;
+		
+	if (*parent == '/' || getcwd(cwd, sizeof(cwd)) == NULL)
+	{
+		asprintf(&this->dirname, "%s/%s", parent, name);
+	}
+	else
+	{
+		asprintf(&this->dirname, "%s/%s/%s", cwd, parent, name);
+	}
+	if (create)
+	{
+		mkdir(this->dirname, PERME);
+	}
+	this->dir = open(this->dirname, O_DIRECTORY, PERME);
+	if (this->dir < 0)
+	{
+		DBG1("opening guest directory '%s' failed: %m", this->dirname);
+		free(this->dirname);
+		free(this);
+		return NULL;
+	}
+	
+	this->pid = 0;
+	this->state = GUEST_STOPPED;
+	this->mconsole = NULL;
+	this->ifaces = linked_list_create();
+	this->mem = 0;
+	this->bootlog = open_bootlog(this);
+	this->name = strdup(name);
+	this->cowfs = NULL;
+	
+	return this;
+}
+
+/**
+ * create a symlink to old called new in our working dir
+ */
+static bool make_symlink(private_guest_t *this, char *old, char *new)
+{
+	char cwd[PATH_MAX];
+	char buf[PATH_MAX];
+	
+	if (*old == '/' || getcwd(cwd, sizeof(cwd)) == NULL)
+	{
+		snprintf(buf, sizeof(buf), "%s", old);
+	}
+	else
+	{
+		snprintf(buf, sizeof(buf), "%s/%s", cwd, old);
+	}
+	return symlinkat(buf, this->dir, new) == 0;
+}
+
+
+/**
+ * create the guest instance, including required dirs and mounts 
+ */
+guest_t *guest_create(char *parent, char *name, char *kernel,
+					  char *master, int mem)
+{
+	private_guest_t *this = guest_create_generic(parent, name, TRUE);
+	
+	if (this == NULL)
+	{
+		return NULL;
+	}
+	
+	if (!make_symlink(this, master, MASTER_DIR) ||
+		!make_symlink(this, kernel, KERNEL_FILE))
+	{
+		DBG1("creating master/kernel symlink failed: %m");
+		destroy(this);
+		return NULL;
+	}
+	
+	if (mkdirat(this->dir, UNION_DIR, PERME) != 0 || 
+		mkdirat(this->dir, DIFF_DIR, PERME) != 0)
+	{
+		DBG1("unable to create directories for '%s': %m", name);
+		destroy(this);
+		return NULL;
+	}
+	
+	this->mem = mem;
+	if (!savemem(this, mem))
+	{
+		destroy(this);
+		return NULL;
+	}
+	
+	if (!mount_unionfs(this))
+	{
+		destroy(this);
+		return NULL;
+	}
+
+	return &this->public;
+}
+
+/**
+ * load an already created guest
+ */
+guest_t *guest_load(char *parent, char *name)
+{
+	private_guest_t *this = guest_create_generic(parent, name, FALSE);
+	
+	if (this == NULL)
+	{
+		return NULL;
+	}
+	
+	this->mem = loadmem(this);
+	if (this->mem == 0)
+	{
+		DBG1("unable to open memory configuration file: %m", name);
+		destroy(this);
+		return NULL;
+	}
+	
+	if (!mount_unionfs(this))
+	{
+		destroy(this);
+		return NULL;
+	}
+	
+	return &this->public;
+}
+