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

1 files changed, 231 insertions, 0 deletions

diff --git a/channels/sip/reqresp_parser.c b/channels/sip/reqresp_parser.c
index 446e9637f..bf35bc226 100644
--- a/channels/sip/reqresp_parser.c
+++ b/channels/sip/reqresp_parser.c
@@ -1575,6 +1575,235 @@ AST_TEST_DEFINE(parse_contact_header_test)
 	return res;
 }
 
+/*!
+ * \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)
+{
+	char *next, *sep;
+	char *temp;
+	int i, found, supported;
+	unsigned int profile = 0;
+
+	char *out = unsupported;
+	size_t outlen = unsupported_len;
+	char *cur_out = out;
+
+	if (out && (outlen > 0)) {
+		memset(out, 0, outlen);
+	}
+
+	if (ast_strlen_zero(options) )
+		return 0;
+
+	temp = ast_strdupa(options);
+
+	ast_debug(3, "Begin: parsing SIP \"Supported: %s\"\n", options);
+
+	for (next = temp; next; next = sep) {
+		found = FALSE;
+		supported = FALSE;
+		if ((sep = strchr(next, ',')) != NULL) {
+			*sep++ = '\0';
+		}
+
+		/* trim leading and trailing whitespace */
+		next = ast_strip(next);
+
+		if (ast_strlen_zero(next)) {
+			continue; /* if there is a blank argument in there just skip it */
+		}
+
+		ast_debug(3, "Found SIP option: -%s-\n", next);
+		for (i = 0; i < ARRAY_LEN(sip_options); i++) {
+			if (!strcasecmp(next, sip_options[i].text)) {
+				profile |= sip_options[i].id;
+				if (sip_options[i].supported == SUPPORTED) {
+					supported = TRUE;
+				}
+				found = TRUE;
+				ast_debug(3, "Matched SIP option: %s\n", next);
+				break;
+			}
+		}
+
+		/* If option is not supported, add to unsupported out buffer */
+		if (!supported && out && outlen) {
+			size_t copylen = strlen(next);
+			size_t cur_outlen = strlen(out);
+			/* Check to see if there is enough room to store this option.
+			 * Copy length is string length plus 2 for the ',' and '\0' */
+			if ((cur_outlen + copylen + 2) < outlen) {
+				/* if this isn't the first item, add the ',' */
+				if (cur_outlen) {
+					*cur_out = ',';
+					cur_out++;
+					cur_outlen++;
+				}
+				ast_copy_string(cur_out, next, (outlen - cur_outlen));
+				cur_out += copylen;
+			}
+		}
+
+		if (!found) {
+			profile |= SIP_OPT_UNKNOWN;
+			if (!strncasecmp(next, "x-", 2))
+				ast_debug(3, "Found private SIP option, not supported: %s\n", next);
+			else
+				ast_debug(3, "Found no match for SIP option: %s (Please file bug report!)\n", next);
+		}
+	}
+
+	return profile;
+}
+
+AST_TEST_DEFINE(sip_parse_options_test)
+{
+	int res = AST_TEST_PASS;
+	char unsupported[64];
+	unsigned int option_profile = 0;
+	struct testdata {
+		char *name;
+		char *input_options;
+		char *expected_unsupported;
+		unsigned int expected_profile;
+		AST_LIST_ENTRY(testdata) list;
+	};
+
+	struct testdata *testdataptr;
+	static AST_LIST_HEAD_NOLOCK(testdataliststruct, testdata) testdatalist;
+
+	struct testdata test1 = {
+		.name = "test_all_unsupported",
+		.input_options = "unsupported1,,, ,unsupported2,unsupported3,unsupported4",
+		.expected_unsupported = "unsupported1,unsupported2,unsupported3,unsupported4",
+		.expected_profile = SIP_OPT_UNKNOWN,
+	};
+	struct testdata test2 = {
+		.name = "test_all_unsupported_one_supported",
+		.input_options = "  unsupported1, replaces,   unsupported3  , , , ,unsupported4",
+		.expected_unsupported = "unsupported1,unsupported3,unsupported4",
+		.expected_profile = SIP_OPT_UNKNOWN | SIP_OPT_REPLACES
+	};
+	struct testdata test3 = {
+		.name = "test_two_supported_two_unsupported",
+		.input_options = ",,  timer  ,replaces     ,unsupported3,unsupported4",
+		.expected_unsupported = "unsupported3,unsupported4",
+		.expected_profile = SIP_OPT_UNKNOWN | SIP_OPT_REPLACES | SIP_OPT_TIMER,
+	};
+
+	struct testdata test4 = {
+		.name = "test_all_supported",
+		.input_options = "timer,replaces",
+		.expected_unsupported = "",
+		.expected_profile = SIP_OPT_REPLACES | SIP_OPT_TIMER,
+	};
+
+	struct testdata test5 = {
+		.name = "test_all_supported_redundant",
+		.input_options = "timer,replaces,timer,replace,timer,replaces",
+		.expected_unsupported = "",
+		.expected_profile = SIP_OPT_REPLACES | SIP_OPT_TIMER,
+	};
+	struct testdata test6 = {
+		.name = "test_buffer_overflow",
+		.input_options = "unsupported1,replaces,timer,unsupported4,unsupported_huge____"
+		"____________________________________,__________________________________________"
+		"________________________________________________",
+		.expected_unsupported = "unsupported1,unsupported4",
+		.expected_profile = SIP_OPT_UNKNOWN | SIP_OPT_REPLACES | SIP_OPT_TIMER,
+	};
+	struct testdata test7 = {
+		.name = "test_null_input",
+		.input_options = NULL,
+		.expected_unsupported = "",
+		.expected_profile = 0,
+	};
+	struct testdata test8 = {
+		.name = "test_whitespace_input",
+		.input_options = "         ",
+		.expected_unsupported = "",
+		.expected_profile = 0,
+	};
+	struct testdata test9 = {
+		.name = "test_whitespace_plus_option_input",
+		.input_options = " , , ,timer , ,  , ,        ,    ",
+		.expected_unsupported = "",
+		.expected_profile = SIP_OPT_TIMER,
+	};
+
+	switch (cmd) {
+	case TEST_INIT:
+		info->name = "sip_parse_options_test";
+		info->category = "channels/chan_sip/";
+		info->summary = "Tests parsing of sip options";
+		info->description =
+							"Tests parsing of SIP options from supported and required "
+							"header fields.  Verifies when unsupported options are encountered "
+							"that they are appended to the unsupported out buffer and that the "
+							"correct bit field representnig the option profile is returned.";
+		return AST_TEST_NOT_RUN;
+	case TEST_EXECUTE:
+		break;
+	}
+
+	AST_LIST_HEAD_SET_NOLOCK(&testdatalist, &test1);
+	AST_LIST_INSERT_TAIL(&testdatalist, &test2, list);
+	AST_LIST_INSERT_TAIL(&testdatalist, &test3, list);
+	AST_LIST_INSERT_TAIL(&testdatalist, &test4, list);
+	AST_LIST_INSERT_TAIL(&testdatalist, &test5, list);
+	AST_LIST_INSERT_TAIL(&testdatalist, &test6, list);
+	AST_LIST_INSERT_TAIL(&testdatalist, &test7, list);
+	AST_LIST_INSERT_TAIL(&testdatalist, &test8, list);
+	AST_LIST_INSERT_TAIL(&testdatalist, &test9, list);
+
+	/* Test with unsupported char buffer */
+	AST_LIST_TRAVERSE(&testdatalist, testdataptr, list) {
+		option_profile = parse_sip_options(testdataptr->input_options, unsupported, ARRAY_LEN(unsupported));
+		if (option_profile != testdataptr->expected_profile ||
+			strcmp(unsupported, testdataptr->expected_unsupported)) {
+			ast_test_status_update(test, "Test with output buffer \"%s\", expected unsupported: %s actual unsupported:"
+				"%s expected bit profile: %x actual bit profile: %x\n",
+				testdataptr->name,
+				testdataptr->expected_unsupported,
+				unsupported,
+				testdataptr->expected_profile,
+				option_profile);
+			res = AST_TEST_FAIL;
+		} else {
+			ast_test_status_update(test, "\"%s\" passed got expected unsupported: %s and bit profile: %x\n",
+				testdataptr->name,
+				unsupported,
+				option_profile);
+		}
+
+		option_profile = parse_sip_options(testdataptr->input_options, NULL, 0);
+		if (option_profile != testdataptr->expected_profile) {
+			ast_test_status_update(test, "NULL output test \"%s\", expected bit profile: %x actual bit profile: %x\n",
+				testdataptr->name,
+				testdataptr->expected_profile,
+				option_profile);
+			res = AST_TEST_FAIL;
+		} else {
+			ast_test_status_update(test, "\"%s\" with NULL output buf passed, bit profile: %x\n",
+				testdataptr->name,
+				option_profile);
+		}
+	}
+
+	return res;
+}
+
+
 void sip_request_parser_register_tests(void)
 {
 	AST_TEST_REGISTER(get_calleridname_test);
@@ -1584,6 +1813,7 @@ void sip_request_parser_register_tests(void)
 	AST_TEST_REGISTER(sip_parse_uri_fully_test);
 	AST_TEST_REGISTER(parse_name_andor_addr_test);
 	AST_TEST_REGISTER(parse_contact_header_test);
+	AST_TEST_REGISTER(sip_parse_options_test);
 }
 void sip_request_parser_unregister_tests(void)
 {
@@ -1594,4 +1824,5 @@ void sip_request_parser_unregister_tests(void)
 	AST_TEST_UNREGISTER(sip_parse_uri_fully_test);
 	AST_TEST_UNREGISTER(parse_name_andor_addr_test);
 	AST_TEST_UNREGISTER(parse_contact_header_test);
+	AST_TEST_UNREGISTER(sip_parse_options_test);
 }