rfc compliant sip option parsing + new unit test

RFC 3261 section 8.2.2.3 states that if any unsupported options
are found in the Require header field, a "420 (Bad Extension)"
response should be sent with an Unsupported header field containing
only the unsupported options.

This is not currently being done correctly.  Right now, if Asterisk
detects any unsupported sip options in a Require header the entire
list of options are returned in the Unsupported header even if some
of those options are in fact supported.  This patch fixes that by
building an unsupported options character buffer when parsing the
options that can be sent with the 420 response.  A unit test verifying
this functionality has been created.  Some code refactoring was required.

Review: https://reviewboard.asterisk.org/r/680/



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@272880 65c4cc65-6c06-0410-ace0-fbb531ad65f3

2 files changed, 66 insertions, 0 deletions

diff --git a/channels/sip/include/reqresp_parser.h b/channels/sip/include/reqresp_parser.h
index 60fc64698..58784a621 100644
--- a/channels/sip/include/reqresp_parser.h
+++ b/channels/sip/include/reqresp_parser.h
@@ -122,4 +122,18 @@ void sip_request_parser_register_tests(void);
  */
 void sip_request_parser_unregister_tests(void);
 
+/*!
+ * \brief Parse supported header in incoming packet
+ *
+ * \details This function parses through the options parameters and
+ * builds a bit field representing all the SIP options in that field. When an
+ * item is found that is not supported, it is copied to the unsupported
+ * out buffer.
+ *
+ * \param option list
+ * \param unsupported out buffer (optional)
+ * \param unsupported out buffer length (optional)
+ */
+unsigned int parse_sip_options(const char *options, char *unsupported, size_t unsupported_len);
+
 #endif
diff --git a/channels/sip/include/sip.h b/channels/sip/include/sip.h
index ca8a897f4..01cbb2c73 100644
--- a/channels/sip/include/sip.h
+++ b/channels/sip/include/sip.h
@@ -1698,5 +1698,57 @@ struct contact {
 
 AST_LIST_HEAD_NOLOCK(contactliststruct, contact);
 
+/*! \brief List of well-known SIP options. If we get this in a require,
+   we should check the list and answer accordingly. */
+static const struct cfsip_options {
+	int id;             /*!< Bitmap ID */
+	int supported;      /*!< Supported by Asterisk ? */
+	char * const text;  /*!< Text id, as in standard */
+} sip_options[] = {	/* XXX used in 3 places */
+	/* RFC3262: PRACK 100% reliability */
+	{ SIP_OPT_100REL,	NOT_SUPPORTED,	"100rel" },
+	/* RFC3959: SIP Early session support */
+	{ SIP_OPT_EARLY_SESSION, NOT_SUPPORTED,	"early-session" },
+	/* SIMPLE events:  RFC4662 */
+	{ SIP_OPT_EVENTLIST,	NOT_SUPPORTED,	"eventlist" },
+	/* RFC 4916- Connected line ID updates */
+	{ SIP_OPT_FROMCHANGE,	NOT_SUPPORTED,	"from-change" },
+	/* GRUU: Globally Routable User Agent URI's */
+	{ SIP_OPT_GRUU,		NOT_SUPPORTED,	"gruu" },
+	/* RFC4244 History info */
+	{ SIP_OPT_HISTINFO,	NOT_SUPPORTED,	"histinfo" },
+	/* RFC3911: SIP Join header support */
+	{ SIP_OPT_JOIN,		NOT_SUPPORTED,	"join" },
+	/* Disable the REFER subscription, RFC 4488 */
+	{ SIP_OPT_NOREFERSUB,	NOT_SUPPORTED,	"norefersub" },
+	/* SIP outbound - the final NAT battle - draft-sip-outbound */
+	{ SIP_OPT_OUTBOUND,	NOT_SUPPORTED,	"outbound" },
+	/* RFC3327: Path support */
+	{ SIP_OPT_PATH,		NOT_SUPPORTED,	"path" },
+	/* RFC3840: Callee preferences */
+	{ SIP_OPT_PREF,		NOT_SUPPORTED,	"pref" },
+	/* RFC3312: Precondition support */
+	{ SIP_OPT_PRECONDITION,	NOT_SUPPORTED,	"precondition" },
+	/* RFC3323: Privacy with proxies*/
+	{ SIP_OPT_PRIVACY,	NOT_SUPPORTED,	"privacy" },
+	/* RFC-ietf-sip-uri-list-conferencing-02.txt conference invite lists */
+	{ SIP_OPT_RECLISTINV,	NOT_SUPPORTED,	"recipient-list-invite" },
+	/* RFC-ietf-sip-uri-list-subscribe-02.txt - subscription lists */
+	{ SIP_OPT_RECLISTSUB,	NOT_SUPPORTED,	"recipient-list-subscribe" },
+	/* RFC3891: Replaces: header for transfer */
+	{ SIP_OPT_REPLACES,	SUPPORTED,	"replaces" },
+	/* One version of Polycom firmware has the wrong label */
+	{ SIP_OPT_REPLACES,	SUPPORTED,	"replace" },
+	/* RFC4412 Resource priorities */
+	{ SIP_OPT_RESPRIORITY,	NOT_SUPPORTED,	"resource-priority" },
+	/* RFC3329: Security agreement mechanism */
+	{ SIP_OPT_SEC_AGREE,	NOT_SUPPORTED,	"sec_agree" },
+	/* RFC4092: Usage of the SDP ANAT Semantics in the SIP */
+	{ SIP_OPT_SDP_ANAT,	NOT_SUPPORTED,	"sdp-anat" },
+	/* RFC4028: SIP Session-Timers */
+	{ SIP_OPT_TIMER,	SUPPORTED,	"timer" },
+	/* RFC4538: Target-dialog */
+	{ SIP_OPT_TARGET_DIALOG,NOT_SUPPORTED,	"tdialog" },
+};
 
 #endif