Move _sudo_printf from src/conversation.c to common/sudo_printf.c.

Add sudo_printf function pointer that is initialized to _sudo_printf()
instead of requiring a sudo_conv function pointer everywhere.  The
plugin will reset sudo_printf to point to the version passed in via
the plugin open function.  Now plugin_error.c can just call sudo_printf
in all cases.  The sudoers binaries no longer need their own version
of sudo_printf.

common/sudo_printf.c

@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2010-2012 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <config.h>
+
+#include <sys/types.h>
+#include <stdio.h>
+#ifdef STDC_HEADERS
+# include <stdlib.h>
+# include <stddef.h>
+#else
+# ifdef HAVE_STDLIB_H
+#  include <stdlib.h>
+# endif
+#endif /* STDC_HEADERS */
+#include <stdarg.h>
+#include <errno.h>
+
+#include "sudo_plugin.h"
+#include "sudo_debug.h"
+
+int
+_sudo_printf(int msg_type, const char *fmt, ...)
+{
+    va_list ap;
+    FILE *fp;
+    int len;
+
+    switch (msg_type) {
+    case SUDO_CONV_INFO_MSG:
+	fp = stdout;
+	break;
+    case SUDO_CONV_ERROR_MSG:
+	fp = stderr;
+	break;
+    case SUDO_CONV_DEBUG_MSG:
+    {
+	char *buf;
+	va_list ap;
+
+	/* XXX - add debug version of vfprintf()? */
+	va_start(ap, fmt);
+	len = vasprintf(&buf, fmt, ap);
+	va_end(ap);
+	if (len == -1)
+	    return -1;
+	sudo_debug_write(buf, len, 0);
+	break;
+    }
+    default:
+	errno = EINVAL;
+	return -1;
+    }
+
+    va_start(ap, fmt);
+    len = vfprintf(fp, fmt, ap);
+    va_end(ap);
+
+    return len;
+}
+
+int (*sudo_printf)(int msg_type, const char *fmt, ...) = _sudo_printf;