+/************/
+/* AVPs. */
+/************/
+#define rs_avp_is_string(vp) (rs_avp_typeof(vp) == RS_TYPE_STRING)
+#define rs_avp_is_integer(vp) (rs_avp_typeof(vp) == RS_TYPE_INTEGER)
+#define rs_avp_is_ipaddr(vp) (rs_avp_typeof(vp) == RS_TYPE_IPADDR)
+#define rs_avp_is_date(vp) (rs_avp_typeof(vp) == RS_TYPE_DATE)
+#define rs_avp_is_octets(vp) (rs_avp_typeof(vp) == RS_TYPE_OCTETS)
+#define rs_avp_is_ifid(vp) (rs_avp_typeof(vp) == RS_TYPE_IFID)
+#define rs_avp_is_ipv6addr(vp) (rs_avp_typeof(vp) == RS_TYPE_IPV6ADDR)
+#define rs_avp_is_ipv6prefix(vp) (rs_avp_typeof(vp) == RS_TYPE_IPV6PREFIX)
+#define rs_avp_is_byte(vp) (rs_avp_typeof(vp) == RS_TYPE_BYTE)
+#define rs_avp_is_short(vp) (rs_avp_typeof(vp) == RS_TYPE_SHORT)
+#define rs_avp_is_tlv(vp) (rs_avp_typeof(vp) == RS_TYPE_TLV)
+
+/** The maximum length of a RADIUS attribute.
+ *
+ * The RFCs require that a RADIUS attribute transport no more than
+ * 253 octets of data. We add an extra byte for a trailing NUL, so
+ * that the VALUE_PAIR::vp_strvalue field can be handled as a C
+ * string.
+ */
+#define RS_MAX_STRING_LEN 254
+
+/** Free the AVP list \a vps */
+void
+rs_avp_free(rs_avp **vps);
+
+/** Return the length of AVP \a vp in bytes */
+size_t
+rs_avp_length(rs_const_avp *vp);
+
+/** Return the type of \a vp */
+rs_attr_type_t
+rs_avp_typeof(rs_const_avp *vp);
+
+/** Retrieve the attribute and vendor ID of \a vp */
+void
+rs_avp_attrid(rs_const_avp *vp, unsigned int *attr, unsigned int *vendor);
+
+/** Add \a vp to the list pointed to by \a head */
+void
+rs_avp_append(rs_avp **head, rs_avp *vp);
+
+/** Find an AVP in \a vp that matches \a attr and \a vendor */
+rs_avp *
+rs_avp_find(rs_avp *vp, unsigned int attr, unsigned int vendor);
+
+/** Find an AVP in \a vp that matches \a attr and \a vendor */
+rs_const_avp *
+rs_avp_find_const(rs_const_avp *vp, unsigned int attr, unsigned int vendor);
+
+/** Alloc a new AVP for \a attr and \a vendor */
+rs_avp *
+rs_avp_alloc(unsigned int attr, unsigned int vendor);
+
+/** Duplicate existing AVP \a vp */
+rs_avp *
+rs_avp_dup(rs_const_avp *vp);
+
+/** Remove matching AVP from list \a vps */
+int
+rs_avp_delete(rs_avp **vps, unsigned int attr, unsigned int vendor);
+
+/** Return next AVP in list */
+rs_avp *
+rs_avp_next(rs_avp *vp);
+
+/** Return next AVP in list */
+rs_const_avp *
+rs_avp_next_const(rs_const_avp *avp);
+
+/** Return string value of \a vp */
+const char *
+rs_avp_string_value(rs_const_avp *vp);
+
+/** Set AVP \a vp to string \a str */
+int
+rs_avp_string_set(rs_avp *vp, const char *str);
+
+/** Return integer value of \a vp */
+uint32_t
+rs_avp_integer_value(rs_const_avp *vp);
+
+/** Set AVP \a vp to integer \a val */
+int
+rs_avp_integer_set(rs_avp *vp, uint32_t val);
+
+/** Return IPv4 value of \a vp */
+uint32_t
+rs_avp_ipaddr_value(rs_const_avp *vp);
+
+/** Set AVP \a vp to IPv4 address \a in */
+int
+rs_avp_ipaddr_set(rs_avp *vp, struct in_addr in);
+
+/** Return POSIX time value of \a vp */
+time_t
+rs_avp_date_value(rs_const_avp *vp);
+
+/** Set AVP \a vp to POSIX time \a date */
+int
+rs_avp_date_set(rs_avp *vp, time_t date);
+
+/** Return constant pointer to octets in \a vp */
+const unsigned char *
+rs_avp_octets_value_const_ptr(rs_const_avp *vp);
+
+/** Return pointer to octets in \a vp */
+unsigned char *
+rs_avp_octets_value_ptr(rs_avp *vp);
+
+/** Retrieve octet pointer \a p and length \a len from \a vp */
+int
+rs_avp_octets_value_byref(rs_avp *vp,
+ unsigned char **p,
+ size_t *len);
+
+/** Copy octets from \a vp into \a buf and \a len */
+int
+rs_avp_octets_value(rs_const_avp *vp,
+ unsigned char *buf,
+ size_t *len);
+
+/**
+ * Copy octets possibly fragmented across multiple VPs
+ * into \a buf and \a len
+ */
+int
+rs_avp_fragmented_value(rs_const_avp *vps,
+ unsigned char *buf,
+ size_t *len);
+
+/** Copy \a len octets in \a buf to AVP \a vp */
+int
+rs_avp_octets_set(rs_avp *vp,
+ const unsigned char *buf,
+ size_t len);
+
+/** Return IFID value of \a vp */
+int
+rs_avp_ifid_value(rs_const_avp *vp, uint8_t val[8]);
+
+int
+rs_avp_ifid_set(rs_avp *vp, const uint8_t val[8]);
+
+/** Return byte value of \a vp */
+uint8_t
+rs_avp_byte_value(rs_const_avp *vp);
+
+/** Set AVP \a vp to byte \a val */
+int
+rs_avp_byte_set(rs_avp *vp, uint8_t val);
+
+/** Return short value of \a vp */
+uint16_t
+rs_avp_short_value(rs_const_avp *vp);
+
+/** Set AVP \a vp to short integer \a val */
+int
+rs_avp_short_set(rs_avp *vp, uint16_t val);
+
+/** Display possibly \a canonical attribute name into \a buffer */
+int
+rs_attr_display_name (unsigned int attr,
+ unsigned int vendor,
+ char *buffer,
+ size_t bufsize,
+ int canonical);
+
+/** Display AVP \a vp into \a buffer */
+size_t
+rs_avp_display_value(rs_const_avp *vp,
+ char *buffer,
+ size_t buflen);
+
+int
+rs_attr_parse_name (const char *name,
+ unsigned int *attr,
+ unsigned int *vendor);
+
+/** Lookup attribute \a name */
+int
+rs_attr_find(const char *name,
+ unsigned int *attr,
+ unsigned int *vendor);
+
+/** Return dictionary name for AVP \a vp */
+const char *
+rs_avp_name(rs_const_avp *vp);
+