Bugs related to OptString handling.

[libguestfs.git] / daemon / guestfsd.c

diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c
index ba4035e..406c104 100644 (file)
--- a/daemon/guestfsd.c
+++ b/daemon/guestfsd.c
@@ -378,14 +378,75 @@ command (char **stdoutput, char **stderror, const char *name, ...)
   return r;
 }
 
+/* Same as 'command', but we allow the status code from the
+ * subcommand to be non-zero, and return that status code.
+ * We still return -1 if there was some other error.
+ */
+int
+commandr (char **stdoutput, char **stderror, const char *name, ...)
+{
+  va_list args;
+  char **argv, **p;
+  char *s;
+  int i, r;
+
+  /* Collect the command line arguments into an array. */
+  i = 2;
+  argv = malloc (sizeof (char *) * i);
+  if (argv == NULL) {
+    perror ("malloc");
+    return -1;
+  }
+  argv[0] = (char *) name;
+  argv[1] = NULL;
+
+  va_start (args, name);
+
+  while ((s = va_arg (args, char *)) != NULL) {
+    p = realloc (argv, sizeof (char *) * (++i));
+    if (p == NULL) {
+      perror ("realloc");
+      free (argv);
+      va_end (args);
+      return -1;
+    }
+    argv = p;
+    argv[i-2] = s;
+    argv[i-1] = NULL;
+  }
+
+  va_end (args);
+
+  r = commandrv (stdoutput, stderror, argv);
+
+  /* NB: Mustn't free the strings which are on the stack. */
+  free (argv);
+
+  return r;
+}
+
+/* Same as 'command', but passing an argv. */
 int
 commandv (char **stdoutput, char **stderror, char * const* const argv)
 {
+  int r;
+
+  r = commandrv (stdoutput, stderror, argv);
+  if (r == 0)
+    return 0;
+  else
+    return -1;
+}
+
+int
+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;
   fd_set rset, rset2;
   char buf[256];
+  char *p;
 
   if (stdoutput) *stdoutput = NULL;
   if (stderror) *stderror = NULL;
@@ -440,6 +501,9 @@ commandv (char **stdoutput, char **stderror, char * const* const argv)
     r = select (MAX (so_fd[0], se_fd[0]) + 1, &rset2, NULL, NULL, NULL);
     if (r == -1) {
       perror ("select");
+    quit:
+      if (stdoutput) free (*stdoutput);
+      if (stderror) free (*stderror);
       close (so_fd[0]);
       close (se_fd[0]);
       waitpid (pid, NULL, 0);
@@ -450,21 +514,18 @@ commandv (char **stdoutput, char **stderror, char * const* const argv)
       r = read (so_fd[0], buf, sizeof buf);
       if (r == -1) {
        perror ("read");
-       close (so_fd[0]);
-       close (se_fd[0]);
-       waitpid (pid, NULL, 0);
-       return -1;
+       goto quit;
       }
       if (r == 0) { FD_CLR (so_fd[0], &rset); quit++; }
 
       if (r > 0 && stdoutput) {
        so_size += r;
-       *stdoutput = realloc (*stdoutput, so_size);
-       if (*stdoutput == NULL) {
+       p = realloc (*stdoutput, so_size);
+       if (p == NULL) {
          perror ("realloc");
-         *stdoutput = NULL;
-         continue;
+         goto quit;
        }
+       *stdoutput = p;
        memcpy (*stdoutput + so_size - r, buf, r);
       }
     }
@@ -473,21 +534,18 @@ commandv (char **stdoutput, char **stderror, char * const* const argv)
       r = read (se_fd[0], buf, sizeof buf);
       if (r == -1) {
        perror ("read");
-       close (so_fd[0]);
-       close (se_fd[0]);
-       waitpid (pid, NULL, 0);
-       return -1;
+       goto quit;
       }
       if (r == 0) { FD_CLR (se_fd[0], &rset); quit++; }
 
       if (r > 0 && stderror) {
        se_size += r;
-       *stderror = realloc (*stderror, se_size);
-       if (*stderror == NULL) {
+       p = realloc (*stderror, se_size);
+       if (p == NULL) {
          perror ("realloc");
-         *stderror = NULL;
-         continue;
+         goto quit;
        }
+       *stderror = p;
        memcpy (*stderror + se_size - r, buf, r);
       }
     }
@@ -524,14 +582,65 @@ commandv (char **stdoutput, char **stderror, char * const* const argv)
   waitpid (pid, &r, 0);
 
   if (WIFEXITED (r)) {
-    if (WEXITSTATUS (r) == 0)
-      return 0;
-    else
-      return -1;
+    return WEXITSTATUS (r);
   } else
     return -1;
 }
 
+/* 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:
+ *
+ *   "" -> []
+ *   "\n" -> [""]
+ *   "a\nb" -> ["a"; "b"]
+ *   "a\nb\n" -> ["a"; "b"]
+ *   "a\nb\n\n" -> ["a"; "b"; ""]
+ *
+ * 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.
+ */
+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;
+}
+
 /* Quote 'in' for the shell, and write max len-1 bytes to out.  The
  * result will be NUL-terminated, even if it is truncated.
  *