bridging using libbridge
[strongswan.git] / src / dumm / guest.c
index 7848918..533599b 100644 (file)
 
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/wait.h>
+#include <sys/uio.h>
 #include <unistd.h>
 #include <stdio.h>
-#include <sys/uio.h>
-#include <sys/types.h>
 #include <fcntl.h>
 #include <signal.h>
+#include <dirent.h>
 
 #include <debug.h>
 #include <utils/linked_list.h>
@@ -31,6 +32,9 @@
 #include "guest.h"
 #include "mconsole.h"
 
+#define PERME (S_IRWXU | S_IRWXG)
+#define PERM (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP)
+
 typedef struct private_guest_t private_guest_t;
 
 struct private_guest_t {
@@ -38,8 +42,10 @@ struct private_guest_t {
        guest_t public;
        /** name of the guest */
        char *name;
-       /** read only master filesystem guest uses */
-       char *master;
+       /** 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 */
@@ -48,6 +54,8 @@ struct private_guest_t {
        guest_state_t state;
        /** log file for console 0 */
        int bootlog;
+       /** has the unionfs been mounted */
+       bool mounted;
        /** mconsole to control running UML */
        mconsole_t *mconsole;
        /** list of interfaces attached to the guest */
@@ -151,12 +159,29 @@ static char* write_arg(char **pos, size_t *left, char *format, ...)
 }
 
 /**
+ * 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);
+               while (this->state == GUEST_STOPPING)
+               {
+                       sched_yield();
+               }
+       }
+}
+
+/**
  * Implementation of guest_t.start.
  */
 static bool start(private_guest_t *this, char *kernel)
 {
-       char buf[1024];
-       char cwd[512];
+       char buf[2048];
        char *notify;
        char *pos = buf;
        char *args[16];
@@ -170,14 +195,13 @@ static bool start(private_guest_t *this, char *kernel)
        }
        this->state = GUEST_STARTING;
        
-       notify = write_arg(&pos, &left, "%s/%s/notify", RUN_DIR, this->name);
+       notify = write_arg(&pos, &left, "%s/%s", this->dirname, NOTIFY_FILE);
        
-       args[i++] = kernel;
+       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/%s",
-                                                 getcwd(cwd, sizeof(cwd)), MOUNT_DIR, this->name);
-       args[i++] = write_arg(&pos, &left, "uml_dir=%s/%s", RUN_DIR, this->name);
+       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);
@@ -199,10 +223,10 @@ static bool start(private_guest_t *this, char *kernel)
                        dup2(open("/dev/null", 0), 1);
                        dup2(open("/dev/null", 0), 2);
                        execvp(args[0], args);
-                       DBG1("starting UML kernel '%s' failed", args[0]);
+                       DBG1("starting UML kernel '%s' failed: %m", args[0]);
                        exit(1);
                case -1:
-                       this->pid = 0;
+                       this->state = GUEST_STOPPED;
                        return FALSE;
                default:
                        break;
@@ -212,8 +236,7 @@ static bool start(private_guest_t *this, char *kernel)
        if (this->mconsole == NULL)
        {
                DBG1("opening mconsole at '%s' failed, stopping guest", buf);
-               kill(this->pid, SIGINT);
-               this->pid = 0;
+               stop(this);
                return FALSE;
        }
        this->state = GUEST_RUNNING;
@@ -221,72 +244,34 @@ static bool start(private_guest_t *this, char *kernel)
 }
 
 /**
- * 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);
-               while (this->state == GUEST_STOPPING)
-               {
-                       sched_yield();
-               }
-       }
-}
-
-/**
  * Implementation of guest_t.sigchild.
  */
 static void sigchild(private_guest_t *this)
 {
+       waitpid(this->pid, NULL, WNOHANG);
        DESTROY_IF(this->mconsole);
        this->mconsole = NULL;
        this->state = GUEST_STOPPED;
-       this->pid = 0;
-}
-
-/**
- * Check if directory exists, create otherwise
- */
-static bool makedir(char *dir, char *name)
-{
-       struct stat st;
-       char buf[256];
-       size_t len;
-       
-       len = snprintf(buf, sizeof(buf), "%s/%s", dir, name);
-       if (len < 0 || len >= sizeof(buf))
-       {
-               return FALSE;
-       }
-       if (stat(buf, &st) != 0)
-       {
-               return mkdir(buf, S_IRWXU) == 0;
-       }
-       return S_ISDIR(st.st_mode);
 }
 
 /**
  * umount the union filesystem
  */
-static bool umount_unionfs(char *name)
+static bool umount_unionfs(private_guest_t *this)
 {
        char cmd[128];
        size_t len;
        
-       len = snprintf(cmd, sizeof(cmd), "fusermount -u %s/%s", MOUNT_DIR, name);
-       if (len < 0 || len >= sizeof(cmd))
-       {
-               return FALSE;
-       }
-       if (system(cmd) != 0)
+       if (this->mounted)
        {
-               DBG1("unmounting guest unionfs for %s failed", name);
-               return FALSE;
+               len = snprintf(cmd, sizeof(cmd), "fusermount -u %s/%s",
+                                          this->dirname, UNION_DIR);
+               if (len < 0 || len >= sizeof(cmd) || system(cmd) != 0)
+               {
+                       DBG1("unmounting guest unionfs failed");
+                       return FALSE;
+               }
+               this->mounted = FALSE;
        }
        return TRUE;
 }
@@ -294,21 +279,22 @@ static bool umount_unionfs(char *name)
 /**
  * mount the union filesystem
  */
-static bool mount_unionfs(char *name, char *master)
+static bool mount_unionfs(private_guest_t *this)
 {
        char cmd[256];
        size_t len;
        
-       len = snprintf(cmd, sizeof(cmd), "unionfs %s/%s:%s %s/%s",
-                                  HOST_DIR, name, master, MOUNT_DIR, name);
-       if (len < 0 || len >= sizeof(cmd))
+       if (!this->mounted)
        {
-               return FALSE;
-       }
-       if (system(cmd) != 0)
-       {
-               DBG1("mounting guest unionfs for %s using '%s' failed", name, cmd);
-               return FALSE;
+               len = snprintf(cmd, sizeof(cmd), "unionfs %s/%s:%s/%s %s/%s",
+                                          this->dirname, MASTER_DIR, this->dirname, DIFF_DIR,
+                                          this->dirname, UNION_DIR);
+               if (len < 0 || len >= sizeof(cmd) || system(cmd) != 0)
+               {
+                       DBG1("mounting guest unionfs failed");
+                       return FALSE;
+               }
+               this->mounted = TRUE;
        }
        return TRUE;
 }
@@ -316,43 +302,87 @@ static bool mount_unionfs(char *name, char *master)
 /**
  * open logfile for boot messages
  */
-static int open_bootlog(char *name)
+static int open_bootlog(private_guest_t *this)
 {
-       char blg[256];
-       size_t len;
        int fd;
        
-       len = snprintf(blg, sizeof(blg), "%s/%s/boot.log", RUN_DIR, name);
-       if (len < 0 || len >= sizeof(blg))
-       {
-               return 1;
-       }
-       fd = open(blg, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);
+       fd = openat(this->dir, LOG_FILE, O_WRONLY | O_CREAT, PERM);
        if (fd == -1)
        {
-               DBG1("opening bootlog '%s' for %s failed, using stdout", blg, name);
+               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->name);
+       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->master);
        free(this);
 }
 
 /**
- * create the guest instance, including required dirs and mounts 
+ * generic guest constructor
  */
-guest_t *guest_create(char *name, char *master, int mem)
+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;
@@ -365,22 +395,130 @@ guest_t *guest_create(char *name, char *master, int mem)
        this->public.sigchild = (void(*)(guest_t*))sigchild;
        this->public.destroy = (void*)destroy;
        
-       if (!makedir(HOST_DIR, name) || !makedir(MOUNT_DIR, name) ||
-               !makedir(RUN_DIR, name) || !mount_unionfs(name, master))
+       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->name = strdup(name);
-       this->master = strdup(master);
-       this->mem = mem;
        this->pid = 0;
        this->state = GUEST_STOPPED;
-       this->bootlog = open_bootlog(name);
        this->mconsole = NULL;
        this->ifaces = linked_list_create();
+       this->mem = 0;
+       this->bootlog = open_bootlog(this);
+       this->name = strdup(name);
+       this->mounted = FALSE;
+       
+       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;
+}
+