X-Git-Url: http://git.annexia.org/?a=blobdiff_plain;f=daemon%2Fguestfsd.c;h=87065b9de30e666555acb72cf06da5bb93e84025;hb=7428b0a70caed014d0cb4126fe8a77432d8957c6;hp=dc839ceac87e7e873669cc73767dfee7a17daf58;hpb=1e97e406c36031617a86a4fa6bb78a112848ee87;p=libguestfs.git

diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c
index dc839ce..87065b9 100644
--- a/daemon/guestfsd.c
+++ b/daemon/guestfsd.c
@@ -1,5 +1,5 @@
 /* libguestfs - the guestfsd daemon
- * Copyright (C) 2009 Red Hat Inc. 
+ * Copyright (C) 2009 Red Hat Inc.
  *
  * 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
@@ -33,6 +33,7 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <sys/stat.h>
+#include <fcntl.h>
 #include <ctype.h>
 #include <signal.h>
 
@@ -159,6 +160,9 @@ main (int argc, char *argv[])
   setenv ("SHELL", "/bin/sh", 1);
   setenv ("LANG", "C", 1);
 
+  /* We document that umask defaults to 022 (it should be this anyway). */
+  umask (022);
+
   /* Resolve the hostname. */
   memset (&hints, 0, sizeof hints);
   hints.ai_socktype = SOCK_STREAM;
@@ -452,7 +456,8 @@ commandrv (char **stdoutput, char **stderror, char * const* const argv)
 {
   int so_size = 0, se_size = 0;
   int so_fd[2], se_fd[2];
-  int pid, r, quit, i;
+  pid_t pid;
+  int r, quit, i;
   fd_set rset, rset2;
   char buf[256];
   char *p;
@@ -567,19 +572,23 @@ commandrv (char **stdoutput, char **stderror, char * const* const argv)
    * trailing \n characters from the error buffer (not from stdout).
    */
   if (stdoutput) {
-    *stdoutput = realloc (*stdoutput, so_size+1);
-    if (*stdoutput == NULL) {
+    void *q = realloc (*stdoutput, so_size+1);
+    if (q == NULL) {
       perror ("realloc");
-      *stdoutput = NULL;
-    } else
+      free (*stdoutput);
+    }
+    *stdoutput = q;
+    if (*stdoutput)
       (*stdoutput)[so_size] = '\0';
   }
   if (stderror) {
-    *stderror = realloc (*stderror, se_size+1);
-    if (*stderror == NULL) {
+    void *q = realloc (*stderror, se_size+1);
+    if (q == NULL) {
       perror ("realloc");
-      *stderror = NULL;
-    } else {
+      free (*stderror);
+    }
+    *stderror = q;
+    if (*stderror) {
       (*stderror)[se_size] = '\0';
       se_size--;
       while (se_size >= 0 && (*stderror)[se_size] == '\n')
@@ -588,7 +597,10 @@ commandrv (char **stdoutput, char **stderror, char * const* const argv)
   }
 
   /* Get the exit status of the command. */
-  waitpid (pid, &r, 0);
+  if (waitpid (pid, &r, 0) != pid) {
+    perror ("waitpid");
+    return -1;
+  }
 
   if (WIFEXITED (r)) {
     return WEXITSTATUS (r);
@@ -691,30 +703,58 @@ shell_quote (char *out, int len, const char *in)
  * use the IS_DEVICE macro.
  *
  * See guestfs(3) for the algorithm.
+ *
+ * We have to open the device and test for ENXIO, because
+ * the device nodes themselves will exist in the appliance.
  */
 int
 device_name_translation (char *device, const char *func)
 {
-  struct stat statbuf;
+  int fd;
 
-  if (stat (device, &statbuf) == -1) {
-    /* If the name begins with "/dev/sd" then try the alternatives. */
-    if (strncmp (device, "/dev/sd", 7) != 0)
-      goto error;
+  fd = open (device, O_RDONLY);
+  if (fd >= 0) {
+    close (fd);
+    return 0;
+  }
 
-    device[5] = 'h';		/* /dev/hd (old IDE driver) */
-    if (stat (device, &statbuf) == 0)
-      return 0;
+  if (errno != ENXIO && errno != ENOENT) {
+  error:
+    reply_with_perror ("%s: %s", func, device);
+    return -1;
+  }
 
-    device[5] = 'v';		/* /dev/vd (for virtio devices) */
-    if (stat (device, &statbuf) == 0)
-      return 0;
+  /* If the name begins with "/dev/sd" then try the alternatives. */
+  if (strncmp (device, "/dev/sd", 7) != 0)
+    goto error;
 
-    device[5] = 's';		/* Restore original device name. */
+  device[5] = 'h';		/* /dev/hd (old IDE driver) */
+  fd = open (device, O_RDONLY);
+  if (fd >= 0) {
+    close (fd);
+    return 0;
+  }
 
-   error:
-    reply_with_perror ("%s: %s", func, device);
-    return -1;
+  device[5] = 'v';		/* /dev/vd (for virtio devices) */
+  fd = open (device, O_RDONLY);
+  if (fd >= 0) {
+    close (fd);
+    return 0;
   }
-  return 0;
+
+  device[5] = 's';		/* Restore original device name. */
+  goto error;
+}
+
+/* LVM and other commands aren't synchronous, especially when udev is
+ * involved.  eg. You can create or remove some device, but the /dev
+ * device node won't appear until some time later.  This means that
+ * you get an error if you run one command followed by another.
+ * Use 'udevadm settle' after certain commands, but don't be too
+ * fussed if it fails.
+ */
+void
+udev_settle (void)
+{
+  command (NULL, NULL, "/sbin/udevadm", "settle", NULL);
 }