add some initial simplistic TLV parser
diff --git a/include/openbsc/tlv.h b/include/openbsc/tlv.h
index 70d0319..668644b 100644
--- a/include/openbsc/tlv.h
+++ b/include/openbsc/tlv.h
@@ -4,10 +4,14 @@
#include <sys/types.h>
#include <string.h>
+#include <openbsc/msgb.h>
+
#define TLV_GROSS_LEN(x) (x+2)
#define TLV16_GROSS_LEN(x) ((2*x)+2)
#define TL16V_GROSS_LEN(x) (x+3)
+/* TLV generation */
+
static inline u_int8_t *tlv_put(u_int8_t *buf, u_int8_t tag, u_int8_t len,
const u_int8_t *val)
{
@@ -102,5 +106,19 @@
return tv16_put(buf, tag, val);
}
+/* TLV parsing */
+
+struct tlv_p_entry {
+ u_int8_t len;
+ u_int8_t *val;
+};
+
+struct tlv_parser {
+ struct tlv_p_entry lv[0xff];
+};
+
+#define TLVP_PRESENT(x, y) (x->lv[y].val)
+#define TLVP_LEN(x, y) x->lv[y].len
+#define TLVP_VAL(x, y) x->lv[y].val
#endif /* _TLV_H */
diff --git a/src/tlv_parser.c b/src/tlv_parser.c
new file mode 100644
index 0000000..182c54d
--- /dev/null
+++ b/src/tlv_parser.c
@@ -0,0 +1,25 @@
+#include <openbsc/tlv.h>
+
+int tlv_parse(struct tlv_parser *parser, u_int8_t *data, int data_len)
+{
+ u_int8_t *cur = data;
+ memset(parser, 0, sizeof(*parser));
+
+ while (cur +2 <= data + data_len) {
+ u_int8_t tag, len;
+ u_int8_t *val;
+
+ tag = *cur++;
+ len = *cur++;
+ val = cur;
+
+ parser->lv[tag].len = len;
+ parser->lv[tag].val = val;
+
+ if (cur + len > data + data_len)
+ break;
+
+ cur += len;
+ }
+ return 0;
+}