daemon: count_strings function returns size_t

[libguestfs.git] / daemon / parted.c

diff --git a/daemon/parted.c b/daemon/parted.c
index ff6cca1..bf45f8b 100644 (file)
--- a/daemon/parted.c
+++ b/daemon/parted.c
@@ -159,6 +159,18 @@ do_part_add (const char *device, const char *prlogex,
 }
 
 int
+do_part_del (const char *device, int partnum)
+{
+  char partnum_str[16];
+  snprintf (partnum_str, sizeof partnum_str, "%d", partnum);
+
+  RUN_PARTED (return -1, device, "rm", partnum_str, NULL);
+
+  udev_settle ();
+  return 0;
+}
+
+int
 do_part_disk (const char *device, const char *parttype)
 {
   const char *startstr;
@@ -224,6 +236,36 @@ do_part_set_name (const char *device, int partnum, const char *name)
   return 0;
 }
 
+/* Return the nth field from a string of ':'/';'-delimited strings.
+ * Useful for parsing the return value from print_partition_table
+ * function below.
+ */
+static char *
+get_table_field (const char *line, int n)
+{
+  const char *p = line;
+
+  while (*p && n > 0) {
+    p += strcspn (p, ":;") + 1;
+    n--;
+  }
+
+  if (n > 0) {
+    reply_with_error ("not enough fields in output of parted print command: %s",
+                      line);
+    return NULL;
+  }
+
+  size_t len = strcspn (p, ":;");
+  char *q = strndup (p, len);
+  if (q == NULL) {
+    reply_with_perror ("strndup");
+    return NULL;
+  }
+
+  return q;
+}
+
 static char **
 print_partition_table (const char *device)
 {
@@ -269,31 +311,15 @@ print_partition_table (const char *device)
 char *
 do_part_get_parttype (const char *device)
 {
-  char **lines;
-  char *r;
-
-  lines = print_partition_table (device);
+  char **lines = print_partition_table (device);
   if (!lines)
     return NULL;
 
   /* lines[1] is something like:
    * "/dev/sda:1953525168s:scsi:512:512:msdos:ATA Hitachi HDT72101;"
    */
-  if (strtok (lines[1], ":") == NULL /* device */
-      || strtok (NULL, ":") == NULL  /* size */
-      || strtok (NULL, ":") == NULL  /* transport */
-      || strtok (NULL, ":") == NULL  /* sector size */
-      || strtok (NULL, ":") == NULL  /* physical sector size */
-      || (r = strtok (NULL, ":")) == NULL /* return value */
-      ) {
-    reply_with_error ("too few fields in output from parted print command: %s", lines[1]);
-    free_strings (lines);
-    return NULL;
-  }
-
-  r = strdup (r);
-  if (!r) {
-    reply_with_perror ("strdup");
+  char *r = get_table_field (lines[1], 5);
+  if (r == NULL) {
     free_strings (lines);
     return NULL;
   }
@@ -357,3 +383,92 @@ do_part_list (const char *device)
   free_strings (lines);
   return NULL;
 }
+
+int
+do_part_get_bootable (const char *device, int partnum)
+{
+  char **lines = print_partition_table (device);
+  if (!lines)
+    return -1;
+
+  /* We want lines[1+partnum]. */
+  if (count_strings (lines) < (size_t) (1+partnum)) {
+    reply_with_error ("partition number out of range: %d", partnum);
+    free_strings (lines);
+    return -1;
+  }
+
+  char *boot = get_table_field (lines[1+partnum], 6);
+  if (boot == NULL) {
+    free_strings (lines);
+    return -1;
+  }
+
+  int r = STREQ (boot, "boot");
+
+  free (boot);
+  free_strings (lines);
+
+  return r;
+}
+
+/* Currently we use sfdisk for getting and setting the ID byte.  In
+ * future, extend parted to provide this functionality.  As a result
+ * of using sfdisk, this won't work for non-MBR-style partitions, but
+ * that limitation is noted in the documentation and we can extend it
+ * later without breaking the ABI.
+ */
+int
+do_part_get_mbr_id (const char *device, int partnum)
+{
+  char partnum_str[16];
+  snprintf (partnum_str, sizeof partnum_str, "%d", partnum);
+
+  char *out, *err;
+  int r;
+
+  r = command (&out, &err, "sfdisk", "--print-id", device, partnum_str, NULL);
+  if (r == -1) {
+    reply_with_error ("sfdisk --print-id: %s", err);
+    free (out);
+    free (err);
+    return -1;
+  }
+
+  free (err);
+
+  /* It's printed in hex ... */
+  int id;
+  if (sscanf (out, "%x", &id) != 1) {
+    reply_with_error ("sfdisk --print-id: cannot parse output: %s", out);
+    free (out);
+    return -1;
+  }
+
+  free (out);
+  return id;
+}
+
+int
+do_part_set_mbr_id (const char *device, int partnum, int idbyte)
+{
+  char partnum_str[16];
+  snprintf (partnum_str, sizeof partnum_str, "%d", partnum);
+
+  char idbyte_str[16];
+  snprintf (idbyte_str, sizeof partnum_str, "%x", idbyte); /* NB: hex */
+
+  char *err;
+  int r;
+
+  r = command (NULL, &err, "sfdisk",
+               "--change-id", device, partnum_str, idbyte_str, NULL);
+  if (r == -1) {
+    reply_with_error ("sfdisk --change-id: %s", err);
+    free (err);
+    return -1;
+  }
+
+  free (err);
+  return 0;
+}