X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=daemon%2Fguestfsd.c;h=7bd384e2b51cdcb369d6832a34182205c83fb8f1;hp=eeb84bd1c29f738e4e09e8fddef7fb462b984e39;hb=0f2e9c84e9ff1071260770930068642ecc8ac0d9;hpb=427b5f079fd344919ecf568bab2084825aacf606

diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c
index eeb84bd..7bd384e 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
@@ -32,8 +32,11 @@
 #include <sys/select.h>
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <sys/stat.h>
+#include <fcntl.h>
 #include <ctype.h>
 #include <signal.h>
+#include <printf.h>
 
 #include "daemon.h"
 
@@ -45,6 +48,22 @@ static void usage (void);
 
 int verbose = 0;
 
+static int print_shell_quote (FILE *stream, const struct printf_info *info, const void *const *args);
+static int print_sysroot_shell_quote (FILE *stream, const struct printf_info *info, const void *const *args);
+#ifdef HAVE_REGISTER_PRINTF_SPECIFIER
+static int print_arginfo (const struct printf_info *info, size_t n, int *argtypes, int *size);
+#else
+#ifdef HAVE_REGISTER_PRINTF_FUNCTION
+static int print_arginfo (const struct printf_info *info, size_t n, int *argtypes);
+#else
+#error "HAVE_REGISTER_PRINTF_{SPECIFIER|FUNCTION} not defined"
+#endif
+#endif
+
+/* Location to mount root device. */
+const char *sysroot = "/sysroot"; /* No trailing slash. */
+int sysroot_len = 8;
+
 int
 main (int argc, char *argv[])
 {
@@ -70,6 +89,19 @@ main (int argc, char *argv[])
   uint32_t len;
   struct sigaction sa;
 
+#ifdef HAVE_REGISTER_PRINTF_SPECIFIER
+  /* http://udrepper.livejournal.com/20948.html */
+  register_printf_specifier ('Q', print_shell_quote, print_arginfo);
+  register_printf_specifier ('R', print_sysroot_shell_quote, print_arginfo);
+#else
+#ifdef HAVE_REGISTER_PRINTF_FUNCTION
+  register_printf_function ('Q', print_shell_quote, print_arginfo);
+  register_printf_function ('R', print_sysroot_shell_quote, print_arginfo);
+#else
+#error "HAVE_REGISTER_PRINTF_{SPECIFIER|FUNCTION} not defined"
+#endif
+#endif
+
   for (;;) {
     c = getopt_long (argc, argv, options, long_options, NULL);
     if (c == -1) break;
@@ -150,6 +182,17 @@ main (int argc, char *argv[])
   if (sigaction (SIGPIPE, &sa, NULL) == -1)
     perror ("sigaction SIGPIPE"); /* but try to continue anyway ... */
 
+  /* Set up a basic environment.  After we are called by /init the
+   * environment is essentially empty.
+   * https://bugzilla.redhat.com/show_bug.cgi?id=502074#c5
+   */
+  setenv ("PATH", "/usr/bin:/bin", 1);
+  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;
@@ -208,6 +251,27 @@ main (int argc, char *argv[])
   exit (0);
 }
 
+/* Turn "/path" into "/sysroot/path".
+ *
+ * Caller must check for NULL and call reply_with_perror ("malloc")
+ * if it is.  Caller must also free the string.
+ *
+ * See also the custom %R printf formatter which does shell quoting too.
+ */
+char *
+sysroot_path (const char *path)
+{
+  char *r;
+  int len = strlen (path) + sysroot_len + 1;
+
+  r = malloc (len);
+  if (r == NULL)
+    return NULL;
+
+  snprintf (r, len, "%s%s", sysroot, path);
+  return r;
+}
+
 int
 xwrite (int sock, const void *buf, size_t len)
 {
@@ -443,7 +507,8 @@ 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;
@@ -558,19 +623,23 @@ 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')
@@ -579,7 +648,10 @@ 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);
@@ -587,39 +659,177 @@ commandrv (char **stdoutput, char **stderror, char * const* const argv)
     return -1;
 }
 
-/* Quote 'in' for the shell, and write max len-1 bytes to out.  The
- * result will be NUL-terminated, even if it is truncated.
+/* Split an output string into a NULL-terminated list of lines.
+ * Typically this is used where we have run an external command
+ * which has printed out a list of things, and we want to return
+ * an actual list.
+ *
+ * The corner cases here are quite tricky.  Note in particular:
  *
- * Returns number of bytes needed, so if result >= len then the buffer
- * should have been longer.
+ *   "" -> []
+ *   "\n" -> [""]
+ *   "a\nb" -> ["a"; "b"]
+ *   "a\nb\n" -> ["a"; "b"]
+ *   "a\nb\n\n" -> ["a"; "b"; ""]
  *
- * XXX This doesn't quote \n correctly (but is still safe).
+ * The original string is written over and destroyed by this
+ * function (which is usually OK because it's the 'out' string
+ * from command()).  You can free the original string, because
+ * add_string() strdups the strings.
  */
-int
-shell_quote (char *out, int len, const char *in)
+char **
+split_lines (char *str)
+{
+  char **lines = NULL;
+  int size = 0, alloc = 0;
+  char *p, *pend;
+
+  if (strcmp (str, "") == 0)
+    goto empty_list;
+
+  p = str;
+  while (p) {
+    /* Empty last line? */
+    if (p[0] == '\0')
+      break;
+
+    pend = strchr (p, '\n');
+    if (pend) {
+      *pend = '\0';
+      pend++;
+    }
+
+    if (add_string (&lines, &size, &alloc, p) == -1) {
+      return NULL;
+    }
+
+    p = pend;
+  }
+
+ empty_list:
+  if (add_string (&lines, &size, &alloc, NULL) == -1)
+    return NULL;
+
+  return lines;
+}
+
+/* printf helper function so we can use %Q ("quoted") and %R to print
+ * shell-quoted strings.  See HACKING file for more details.
+ */
+static int
+print_shell_quote (FILE *stream,
+                   const struct printf_info *info,
+                   const void *const *args)
+{
+#define SAFE(c) (isalnum((c)) ||					\
+		 (c) == '/' || (c) == '-' || (c) == '_' || (c) == '.')
+  int i, len;
+  const char *str = *((const char **) (args[0]));
+
+  for (i = len = 0; str[i]; ++i) {
+    if (!SAFE(str[i])) {
+      putc ('\\', stream);
+      len ++;
+    }
+    putc (str[i], stream);
+    len ++;
+  }
+
+  return len;
+}
+
+static int
+print_sysroot_shell_quote (FILE *stream,
+			   const struct printf_info *info,
+			   const void *const *args)
 {
 #define SAFE(c) (isalnum((c)) ||					\
 		 (c) == '/' || (c) == '-' || (c) == '_' || (c) == '.')
-  int i, j;
-  int outlen = strlen (in);
+  fputs (sysroot, stream);
+  return sysroot_len + print_shell_quote (stream, info, args);
+}
 
-  /* Calculate how much output space this really needs. */
-  for (i = 0; in[i]; ++i)
-    if (!SAFE (in[i])) outlen++;
+#ifdef HAVE_REGISTER_PRINTF_SPECIFIER
+static int
+print_arginfo (const struct printf_info *info,
+	       size_t n, int *argtypes, int *size)
+{
+  if (n > 0) {
+    argtypes[0] = PA_STRING;
+    size[0] = sizeof (const char *);
+  }
+  return 1;
+}
+#else
+#ifdef HAVE_REGISTER_PRINTF_FUNCTION
+static int
+print_arginfo (const struct printf_info *info, size_t n, int *argtypes)
+{
+  if (n > 0)
+    argtypes[0] = PA_STRING;
+  return 1;
+}
+#else
+#error "HAVE_REGISTER_PRINTF_{SPECIFIER|FUNCTION} not defined"
+#endif
+#endif
 
-  /* Now copy the string, but only up to len-1 bytes. */
-  for (i = 0, j = 0; in[i]; ++i) {
-    int is_safe = SAFE (in[i]);
+/* Perform device name translation.  Don't call this directly -
+ * 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)
+{
+  int fd;
 
-    /* Enough space left to write this character? */
-    if (j >= len-1 || (!is_safe && j >= len-2))
-      break;
+  fd = open (device, O_RDONLY);
+  if (fd >= 0) {
+    close (fd);
+    return 0;
+  }
+
+  if (errno != ENXIO && errno != ENOENT) {
+  error:
+    reply_with_perror ("%s: %s", func, device);
+    return -1;
+  }
 
-    if (!is_safe) out[j++] = '\\';
-    out[j++] = in[i];
+  /* If the name begins with "/dev/sd" then try the alternatives. */
+  if (strncmp (device, "/dev/sd", 7) != 0)
+    goto error;
+
+  device[5] = 'h';		/* /dev/hd (old IDE driver) */
+  fd = open (device, O_RDONLY);
+  if (fd >= 0) {
+    close (fd);
+    return 0;
   }
 
-  out[j] = '\0';
+  device[5] = 'v';		/* /dev/vd (for virtio devices) */
+  fd = open (device, O_RDONLY);
+  if (fd >= 0) {
+    close (fd);
+    return 0;
+  }
 
-  return outlen;
+  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);
 }