Merge remote-tracking branch 'kiszka/master'

[jailhouse.git] / inmates / lib / cmdline.c

diff --git a/inmates/lib/cmdline.c b/inmates/lib/cmdline.c
new file mode 100644 (file)
index 0000000..bcbedb0
--- /dev/null
+++ b/inmates/lib/cmdline.c
@@ -0,0 +1,111 @@
+/*
+ * Jailhouse, a Linux-based partitioning hypervisor
+ *
+ * Copyright (c) Siemens AG, 2016
+ *
+ * Authors:
+ *  Jan Kiszka <jan.kiszka@siemens.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ */
+
+#include <inmate.h>
+
+extern const char cmdline[];
+
+static bool get_param(const char *param, char *value_buffer,
+                     unsigned long buffer_size)
+{
+       unsigned long param_len = strlen(param);
+       const char *p = cmdline;
+
+       while (1) {
+               /* read over leading blanks */
+               while (*p == ' ')
+                       p++;
+
+               if (strncmp(p, param, param_len) == 0) {
+                       p += param_len;
+
+                       /* check for boolean parameter */
+                       if ((buffer_size == 0 && (*p == ' ' || *p == 0)))
+                               return true;
+
+                       /* extract parameter value */
+                       if (*p == '=') {
+                               p++;
+                               while (buffer_size > 1) {
+                                       if (*p == ' ' || *p == 0)
+                                               break;
+                                       *value_buffer++ = *p++;
+                                       buffer_size--;
+                               }
+                               if (buffer_size > 0)
+                                       *value_buffer = 0;
+                               return true;
+                       }
+               }
+
+               /* search for end of this parameter */
+               while (*p != ' ') {
+                       if (*p == 0)
+                               return false;
+                       p++;
+               }
+       }
+}
+
+const char *cmdline_parse_str(const char *param, char *value_buffer,
+                             unsigned long buffer_size,
+                             const char *default_value)
+{
+       if (get_param(param, value_buffer, buffer_size))
+               return value_buffer;
+       else
+               return default_value;
+}
+
+long long cmdline_parse_int(const char *param, long long default_value)
+{
+       char value_buffer[32];
+       char *p = value_buffer;
+       bool negative = false;
+       long long value = 0;
+
+       if (!get_param(param, value_buffer, sizeof(value_buffer)))
+               return default_value;
+
+       if (strncmp(p, "0x", 2) == 0) {
+               p += 2;
+               do {
+                       if (*p >= '0' && *p <= '9')
+                               value = (value << 4) + *p - '0';
+                       else if (*p >= 'A' && *p <= 'F')
+                               value = (value << 4) + *p - 'A' + 10;
+                       else if (*p >= 'a' && *p <= 'f')
+                               value = (value << 4) + *p - 'a' + 10;
+                       else
+                               return default_value;
+                       p++;
+               } while (*p != 0);
+       } else {
+               if (*p == '-' || *p == '+')
+                       negative = (*p++ == '-');
+
+               do {
+                       if (*p >= '0' && *p <= '9')
+                               value = (value * 10) + *p - '0';
+                       else
+                               return default_value;
+                       p++;
+               } while (*p != 0);
+       }
+
+       return negative ? -value : value;
+}
+
+bool cmdline_parse_bool(const char *param)
+{
+       return get_param(param, NULL, 0);
+}