X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=daemon%2Ffile.c;h=7600064595c50bebc88eafb9a33d47f7941e1c36;hp=db1991822ff86ca54e9021de96fac3096308af96;hb=9733d4746988b3a072d8bb1daac4b9795b8f4134;hpb=843514eef9dc6d04d71e031ba9ddb16e2beb9a04

diff --git a/daemon/file.c b/daemon/file.c
index db19918..7600064 100644
--- a/daemon/file.c
+++ b/daemon/file.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
@@ -18,8 +18,6 @@
 
 #include <config.h>
 
-#define _GNU_SOURCE		/* for futimens(2) */
-
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -27,6 +25,7 @@
 #include <fcntl.h>
 #include <sys/stat.h>
 
+#include "../src/guestfs_protocol.h"
 #include "daemon.h"
 #include "actions.h"
 
@@ -34,37 +33,599 @@ int
 do_touch (const char *path)
 {
   int fd;
+  int r;
+
+  CHROOT_IN;
+  fd = open (path, O_WRONLY | O_CREAT | O_NOCTTY, 0666);
+  CHROOT_OUT;
+
+  if (fd == -1) {
+    reply_with_perror ("open: %s", path);
+    return -1;
+  }
+
+  r = futimens (fd, NULL);
+  if (r == -1) {
+    reply_with_perror ("futimens: %s", path);
+    close (fd);
+    return -1;
+  }
+
+  if (close (fd) == -1) {
+    reply_with_perror ("close: %s", path);
+    return -1;
+  }
+
+  return 0;
+}
+
+char *
+do_cat (const char *path)
+{
+  int fd;
+  int alloc, size, r, max;
+  char *buf, *buf2;
+
+  CHROOT_IN;
+  fd = open (path, O_RDONLY);
+  CHROOT_OUT;
+
+  if (fd == -1) {
+    reply_with_perror ("open: %s", path);
+    return NULL;
+  }
+
+  /* Read up to GUESTFS_MESSAGE_MAX - <overhead> bytes.  If it's
+   * larger than that, we need to return an error instead (for
+   * correctness).
+   */
+  max = GUESTFS_MESSAGE_MAX - 1000;
+  buf = NULL;
+  size = alloc = 0;
+
+  for (;;) {
+    if (size >= alloc) {
+      alloc += 8192;
+      if (alloc > max) {
+        reply_with_error ("%s: file is too large for message buffer",
+                          path);
+        free (buf);
+        close (fd);
+        return NULL;
+      }
+      buf2 = realloc (buf, alloc);
+      if (buf2 == NULL) {
+        reply_with_perror ("realloc");
+        free (buf);
+        close (fd);
+        return NULL;
+      }
+      buf = buf2;
+    }
+
+    r = read (fd, buf + size, alloc - size);
+    if (r == -1) {
+      reply_with_perror ("read: %s", path);
+      free (buf);
+      close (fd);
+      return NULL;
+    }
+    if (r == 0) {
+      buf[size] = '\0';
+      break;
+    }
+    if (r > 0)
+      size += r;
+  }
+
+  if (close (fd) == -1) {
+    reply_with_perror ("close: %s", path);
+    free (buf);
+    return NULL;
+  }
+
+  return buf;			/* caller will free */
+}
+
+char **
+do_read_lines (const char *path)
+{
+  char **r = NULL;
+  int size = 0, alloc = 0;
+  FILE *fp;
+  char *line = NULL;
+  size_t len = 0;
+  ssize_t n;
+
+  CHROOT_IN;
+  fp = fopen (path, "r");
+  CHROOT_OUT;
+
+  if (!fp) {
+    reply_with_perror ("fopen: %s", path);
+    return NULL;
+  }
+
+  while ((n = getline (&line, &len, fp)) != -1) {
+    /* Remove either LF or CRLF. */
+    if (n >= 2 && line[n-2] == '\r' && line[n-1] == '\n')
+      line[n-2] = '\0';
+    else if (n >= 1 && line[n-1] == '\n')
+      line[n-1] = '\0';
+
+    if (add_string (&r, &size, &alloc, line) == -1) {
+      free (line);
+      fclose (fp);
+      return NULL;
+    }
+  }
+
+  free (line);
+
+  if (add_string (&r, &size, &alloc, NULL) == -1) {
+    fclose (fp);
+    return NULL;
+  }
+
+  if (fclose (fp) == EOF) {
+    reply_with_perror ("fclose: %s", path);
+    free_strings (r);
+    return NULL;
+  }
+
+  return r;
+}
+
+int
+do_rm (const char *path)
+{
+  int r;
+
+  CHROOT_IN;
+  r = unlink (path);
+  CHROOT_OUT;
+
+  if (r == -1) {
+    reply_with_perror ("%s", path);
+    return -1;
+  }
+
+  return 0;
+}
+
+int
+do_chmod (int mode, const char *path)
+{
+  int r;
+
+  if (mode < 0) {
+    reply_with_error ("%s: mode is negative", path);
+    return -1;
+  }
+
+  CHROOT_IN;
+  r = chmod (path, mode);
+  CHROOT_OUT;
+
+  if (r == -1) {
+    reply_with_perror ("%s: 0%o", path, mode);
+    return -1;
+  }
+
+  return 0;
+}
+
+int
+do_chown (int owner, int group, const char *path)
+{
+  int r;
+
+  CHROOT_IN;
+  r = chown (path, owner, group);
+  CHROOT_OUT;
+
+  if (r == -1) {
+    reply_with_perror ("%s: %d.%d", path, owner, group);
+    return -1;
+  }
+
+  return 0;
+}
+
+int
+do_lchown (int owner, int group, const char *path)
+{
+  int r;
+
+  CHROOT_IN;
+  r = lchown (path, owner, group);
+  CHROOT_OUT;
+
+  if (r == -1) {
+    reply_with_perror ("%s: %d.%d", path, owner, group);
+    return -1;
+  }
+
+  return 0;
+}
+
+int
+do_exists (const char *path)
+{
+  int r;
+
+  CHROOT_IN;
+  r = access (path, F_OK);
+  CHROOT_OUT;
+
+  return r == 0;
+}
+
+int
+do_is_file (const char *path)
+{
+  int r;
+  struct stat buf;
+
+  CHROOT_IN;
+  r = lstat (path, &buf);
+  CHROOT_OUT;
+
+  if (r == -1) {
+    if (errno != ENOENT && errno != ENOTDIR) {
+      reply_with_perror ("stat: %s", path);
+      return -1;
+    }
+    else
+      return 0;			/* Not a file. */
+  }
+
+  return S_ISREG (buf.st_mode);
+}
+
+int
+do_write_file (const char *path, const char *content, int size)
+{
+  int fd;
 
-  NEED_ROOT;
+  /* This call is deprecated, and it has a broken interface.  New code
+   * should use the 'guestfs_write' call instead.  Because we used an
+   * XDR string type, 'content' cannot contain ASCII NUL and 'size'
+   * must never be longer than the string.  We must check this to
+   * ensure random stuff from XDR or daemon memory isn't written to
+   * the file (RHBZ#597135).
+   */
+  if (size < 0) {
+    reply_with_error ("size cannot be negative");
+    return -1;
+  }
 
-  if (path[0] != '/') {
-    reply_with_error ("touch: path must start with a / character");
+  /* Note content_len must be small because of the limits on protocol
+   * message size.
+   */
+  int content_len = (int) strlen (content);
+
+  if (size == 0)
+    size = content_len;
+  else if (size > content_len) {
+    reply_with_error ("size parameter is larger than string content");
     return -1;
   }
 
   CHROOT_IN;
-  fd = open (path, O_WRONLY | O_CREAT | O_NOCTTY | O_NONBLOCK, 0666);
+  fd = open (path, O_WRONLY | O_TRUNC | O_CREAT | O_NOCTTY, 0666);
   CHROOT_OUT;
 
   if (fd == -1) {
     reply_with_perror ("open: %s", path);
+    return -1;
+  }
+
+  if (xwrite (fd, content, size) == -1) {
+    reply_with_perror ("write");
     close (fd);
     return -1;
   }
 
-  if (futimens (fd, NULL) == -1) {
-    reply_with_perror ("futimens: %s", path);
+  if (close (fd) == -1) {
+    reply_with_perror ("close: %s", path);
+    return -1;
+  }
+
+  return 0;
+}
+
+int
+do_write (const char *path, const char *content, size_t size)
+{
+  int fd;
+
+  CHROOT_IN;
+  fd = open (path, O_WRONLY | O_TRUNC | O_CREAT | O_NOCTTY, 0666);
+  CHROOT_OUT;
+
+  if (fd == -1) {
+    reply_with_perror ("open: %s", path);
+    return -1;
+  }
+
+  if (xwrite (fd, content, size) == -1) {
+    reply_with_perror ("write");
     close (fd);
     return -1;
   }
 
-  close (fd);
+  if (close (fd) == -1) {
+    reply_with_perror ("close: %s", path);
+    return -1;
+  }
+
   return 0;
 }
 
 char *
-do_cat (const char *path)
+do_read_file (const char *path, size_t *size_r)
+{
+  int fd;
+  struct stat statbuf;
+  char *r;
+
+  CHROOT_IN;
+  fd = open (path, O_RDONLY);
+  CHROOT_OUT;
+
+  if (fd == -1) {
+    reply_with_perror ("open: %s", path);
+    return NULL;
+  }
+
+  if (fstat (fd, &statbuf) == -1) {
+    reply_with_perror ("fstat: %s", path);
+    close (fd);
+    return NULL;
+  }
+
+  /* The actual limit on messages is smaller than this.  This
+   * check just limits the amount of memory we'll try and allocate
+   * here.  If the message is larger than the real limit, that will
+   * be caught later when we try to serialize the message.
+   */
+  if (statbuf.st_size >= GUESTFS_MESSAGE_MAX) {
+    reply_with_error ("%s: file is too large for the protocol, use guestfs_download instead", path);
+    close (fd);
+    return NULL;
+  }
+  r = malloc (statbuf.st_size);
+  if (r == NULL) {
+    reply_with_perror ("malloc");
+    close (fd);
+    return NULL;
+  }
+
+  if (xread (fd, r, statbuf.st_size) == -1) {
+    reply_with_perror ("read: %s", path);
+    close (fd);
+    free (r);
+    return NULL;
+  }
+
+  if (close (fd) == -1) {
+    reply_with_perror ("close: %s", path);
+    free (r);
+    return NULL;
+  }
+
+  /* Mustn't touch *size_r until we are sure that we won't return any
+   * error (RHBZ#589039).
+   */
+  *size_r = statbuf.st_size;
+  return r;
+}
+
+char *
+do_pread (const char *path, int count, int64_t offset, size_t *size_r)
+{
+  int fd;
+  ssize_t r;
+  char *buf;
+
+  /* The actual limit on messages is smaller than this.  This check
+   * just limits the amount of memory we'll try and allocate in the
+   * function.  If the message is larger than the real limit, that
+   * will be caught later when we try to serialize the message.
+   */
+  if (count >= GUESTFS_MESSAGE_MAX) {
+    reply_with_error ("%s: count is too large for the protocol, use smaller reads", path);
+    return NULL;
+  }
+
+  CHROOT_IN;
+  fd = open (path, O_RDONLY);
+  CHROOT_OUT;
+
+  if (fd == -1) {
+    reply_with_perror ("open: %s", path);
+    return NULL;
+  }
+
+  buf = malloc (count);
+  if (buf == NULL) {
+    reply_with_perror ("malloc");
+    close (fd);
+    return NULL;
+  }
+
+  r = pread (fd, buf, count, offset);
+  if (r == -1) {
+    reply_with_perror ("pread: %s", path);
+    close (fd);
+    free (buf);
+    return NULL;
+  }
+
+  if (close (fd) == -1) {
+    reply_with_perror ("close: %s", path);
+    close (fd);
+    free (buf);
+    return NULL;
+  }
+
+  /* Mustn't touch *size_r until we are sure that we won't return any
+   * error (RHBZ#589039).
+   */
+  *size_r = r;
+  return buf;
+}
+
+int
+do_pwrite (const char *path, const char *content, size_t size, int64_t offset)
+{
+  int fd;
+  ssize_t r;
+
+  CHROOT_IN;
+  fd = open (path, O_WRONLY);
+  CHROOT_OUT;
+
+  if (fd == -1) {
+    reply_with_perror ("open: %s", path);
+    return -1;
+  }
+
+  r = pwrite (fd, content, size, offset);
+  if (r == -1) {
+    reply_with_perror ("pwrite: %s", path);
+    close (fd);
+    return -1;
+  }
+
+  if (close (fd) == -1) {
+    reply_with_perror ("close: %s", path);
+    close (fd);
+    return -1;
+  }
+
+  return r;
+}
+
+/* This runs the 'file' command. */
+char *
+do_file (const char *path)
 {
-  reply_with_error ("cat command is not yet implemented");
-  return NULL;
+  char *out, *err;
+  int r, freeit = 0;
+  char *buf;
+  int len;
+
+  if (STREQLEN (path, "/dev/", 5))
+    buf = (char *) path;
+  else {
+    buf = sysroot_path (path);
+    if (!buf) {
+      reply_with_perror ("malloc");
+      return NULL;
+    }
+    freeit = 1;
+  }
+
+  /* file(1) manpage claims "file returns 0 on success, and non-zero on
+   * error", but this is evidently not true.  It always returns 0, in
+   * every scenario I can think up.  So check the target is readable
+   * first.
+   */
+  if (access (buf, R_OK) == -1) {
+    if (freeit) free (buf);
+    reply_with_perror ("access: %s", path);
+    return NULL;
+  }
+
+  r = command (&out, &err, "file", "-zbsL", buf, NULL);
+  if (freeit) free (buf);
+
+  if (r == -1) {
+    free (out);
+    reply_with_error ("%s: %s", path, err);
+    free (err);
+    return NULL;
+  }
+  free (err);
+
+  /* We need to remove the trailing \n from output of file(1). */
+  len = strlen (out);
+  if (out[len-1] == '\n')
+    out[len-1] = '\0';
+
+  return out;			/* caller frees */
+}
+
+/* zcat | file */
+char *
+do_zfile (const char *method, const char *path)
+{
+  int len;
+  const char *zcat;
+  char *cmd;
+  FILE *fp;
+  char line[256];
+
+  if (STREQ (method, "gzip") || STREQ (method, "compress"))
+    zcat = "zcat";
+  else if (STREQ (method, "bzip2"))
+    zcat = "bzcat";
+  else {
+    reply_with_error ("unknown method");
+    return NULL;
+  }
+
+  if (asprintf_nowarn (&cmd, "%s %R | file -bsL -", zcat, path) == -1) {
+    reply_with_perror ("asprintf");
+    return NULL;
+  }
+
+  if (verbose)
+    fprintf (stderr, "%s\n", cmd);
+
+  fp = popen (cmd, "r");
+  if (fp == NULL) {
+    reply_with_perror ("%s", cmd);
+    free (cmd);
+    return NULL;
+  }
+
+  free (cmd);
+
+  if (fgets (line, sizeof line, fp) == NULL) {
+    reply_with_perror ("fgets");
+    fclose (fp);
+    return NULL;
+  }
+
+  if (fclose (fp) == -1) {
+    reply_with_perror ("fclose");
+    return NULL;
+  }
+
+  len = strlen (line);
+  if (len > 0 && line[len-1] == '\n')
+    line[len-1] = '\0';
+
+  return strdup (line);
+}
+
+int64_t
+do_filesize (const char *path)
+{
+  int r;
+  struct stat buf;
+
+  CHROOT_IN;
+  r = stat (path, &buf);        /* follow symlinks */
+  CHROOT_OUT;
+
+  if (r == -1) {
+    reply_with_perror ("%s", path);
+    return -1;
+  }
+
+  return buf.st_size;
 }