Optimize sip_is_known_sip_header()

Profling SIP shows that gperf generated hashing code, is
3 times faster than using GHashTable & g_str_hash/_equal()

This result in about 1% improve of whole dissection (sip traffic with filter).

Change-Id: Id6bf64bacd872e2d1c30a1b6356db444b25ba326
Reviewed-on: https://code.wireshark.org/review/2116
Reviewed-by: Anders Broman <a.broman58@gmail.com>

6 files changed, 788 insertions, 294 deletions

diff --git a/epan/CMakeLists.txt b/epan/CMakeLists.txt
index 48b08b4246..b0468a0e59 100644
--- a/epan/CMakeLists.txt
+++ b/epan/CMakeLists.txt
@@ -1204,6 +1204,7 @@ set(DISSECTOR_SRC
 	dissectors/packet-sigcomp.c
 	dissectors/packet-simulcrypt.c
 	dissectors/packet-sip.c
+	dissectors/packet-sip-hdrs.c
 	dissectors/packet-sipfrag.c
 	dissectors/packet-sita.c
 	dissectors/packet-skinny.c
diff --git a/epan/dissectors/Makefile.common b/epan/dissectors/Makefile.common
index 02a747840f..5d58a92eb5 100644
--- a/epan/dissectors/Makefile.common
+++ b/epan/dissectors/Makefile.common
@@ -1130,6 +1130,7 @@ DISSECTOR_SRC = \
 	packet-sigcomp.c	\
 	packet-simulcrypt.c	\
 	packet-sip.c		\
+	packet-sip-hdrs.c	\
 	packet-sipfrag.c	\
 	packet-sita.c		\
 	packet-skinny.c		\
@@ -1631,6 +1632,7 @@ DISSECTOR_INCLUDES =	\
 	packet-sdp.h	\
 	packet-ses.h	\
 	packet-sip.h	\
+	packet-sip-hdrs.h	\
 	packet-skinny.h		\
 	packet-sll.h	\
 	packet-smb.h	\
diff --git a/epan/dissectors/packet-sip-hdrs.c b/epan/dissectors/packet-sip-hdrs.c
new file mode 100644
index 0000000000..ae79dc467e
--- /dev/null
+++ b/epan/dissectors/packet-sip-hdrs.c
@@ -0,0 +1,459 @@
+/* ANSI-C code produced by gperf version 3.0.4 */
+/* Command-line: gperf -m 500 -D packet-sip-hdrs.gperf  */
+/* Computed positions: -k'1,3,7,$' */
+
+#if !((' ' == 32) && ('!' == 33) && ('"' == 34) && ('#' == 35) \
+      && ('%' == 37) && ('&' == 38) && ('\'' == 39) && ('(' == 40) \
+      && (')' == 41) && ('*' == 42) && ('+' == 43) && (',' == 44) \
+      && ('-' == 45) && ('.' == 46) && ('/' == 47) && ('0' == 48) \
+      && ('1' == 49) && ('2' == 50) && ('3' == 51) && ('4' == 52) \
+      && ('5' == 53) && ('6' == 54) && ('7' == 55) && ('8' == 56) \
+      && ('9' == 57) && (':' == 58) && (';' == 59) && ('<' == 60) \
+      && ('=' == 61) && ('>' == 62) && ('?' == 63) && ('A' == 65) \
+      && ('B' == 66) && ('C' == 67) && ('D' == 68) && ('E' == 69) \
+      && ('F' == 70) && ('G' == 71) && ('H' == 72) && ('I' == 73) \
+      && ('J' == 74) && ('K' == 75) && ('L' == 76) && ('M' == 77) \
+      && ('N' == 78) && ('O' == 79) && ('P' == 80) && ('Q' == 81) \
+      && ('R' == 82) && ('S' == 83) && ('T' == 84) && ('U' == 85) \
+      && ('V' == 86) && ('W' == 87) && ('X' == 88) && ('Y' == 89) \
+      && ('Z' == 90) && ('[' == 91) && ('\\' == 92) && (']' == 93) \
+      && ('^' == 94) && ('_' == 95) && ('a' == 97) && ('b' == 98) \
+      && ('c' == 99) && ('d' == 100) && ('e' == 101) && ('f' == 102) \
+      && ('g' == 103) && ('h' == 104) && ('i' == 105) && ('j' == 106) \
+      && ('k' == 107) && ('l' == 108) && ('m' == 109) && ('n' == 110) \
+      && ('o' == 111) && ('p' == 112) && ('q' == 113) && ('r' == 114) \
+      && ('s' == 115) && ('t' == 116) && ('u' == 117) && ('v' == 118) \
+      && ('w' == 119) && ('x' == 120) && ('y' == 121) && ('z' == 122) \
+      && ('{' == 123) && ('|' == 124) && ('}' == 125) && ('~' == 126))
+/* The character set is not based on ISO-646.  */
+#error "gperf generated tables don't work with this execution character set. Please report a bug to <bug-gnu-gperf@gnu.org>."
+#endif
+
+#line 1 "packet-sip-hdrs.gperf"
+
+#include <string.h>
+
+#include "packet-sip-hdrs.h"
+#line 16 "packet-sip-hdrs.gperf"
+struct name_pos { const char *name; int pos; };
+
+#define TOTAL_KEYWORDS 134
+#define MIN_WORD_LENGTH 1
+#define MAX_WORD_LENGTH 29
+#define MIN_HASH_VALUE 3
+#define MAX_HASH_VALUE 220
+/* maximum key range = 218, duplicates = 0 */
+
+#ifdef __GNUC__
+__inline
+#else
+#ifdef __cplusplus
+inline
+#endif
+#endif
+static unsigned int
+_sip_header_hash (register const char *str, register unsigned int len)
+{
+  static const unsigned char asso_values[] =
+    {
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221,  55, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221,  27,  11,   4,
+       54,   2,  75,  32, 103,  21,   6,  35,  12,  86,
+        3,  39,   6,  34,   9,   7,   1,  82,  58,  86,
+        8,  59,   4, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221, 221, 221, 221, 221,
+      221, 221, 221, 221, 221, 221
+    };
+  register int hval = len;
+
+  switch (hval)
+    {
+      default:
+        hval += asso_values[(unsigned char)str[6]];
+      /*FALLTHROUGH*/
+      case 6:
+      case 5:
+      case 4:
+      case 3:
+        hval += asso_values[(unsigned char)str[2]];
+      /*FALLTHROUGH*/
+      case 2:
+      case 1:
+        hval += asso_values[(unsigned char)str[0]];
+        break;
+    }
+  return hval + asso_values[(unsigned char)str[len - 1]];
+}
+
+#ifdef __GNUC__
+__inline
+#if defined __GNUC_STDC_INLINE__ || defined __GNUC_GNU_INLINE__
+__attribute__ ((__gnu_inline__))
+#endif
+#endif
+const struct name_pos *
+_sip_header_find (register const char *str, register unsigned int len)
+{
+  static const unsigned char lengthtable[] =
+    {
+       1,  1,  1,  1,  5,  1,  1,  7,  1,  1, 12,  1,  1, 16,
+       7, 15,  7, 19,  6,  8, 13,  4, 19, 15, 13,  6, 15, 18,
+       2,  1,  4,  6, 15, 16,  4, 14,  4,  7,  1, 16, 11, 18,
+      12,  4, 18,  8,  9, 13, 19,  9, 17, 13,  1, 18, 16, 13,
+       9, 29,  1,  8, 10, 12, 17, 14, 14, 15, 19, 14, 10, 12,
+       8, 18, 20, 19,  8, 17,  6,  5, 10, 21, 14, 11, 15, 13,
+      13, 13,  1, 13,  9, 11, 11,  4,  3, 10,  1,  1, 19, 12,
+      12, 17, 14, 10, 18,  9,  5,  7,  8, 15, 20,  9, 12, 11,
+      20, 17, 21, 12,  9, 19,  1,  7, 10, 11, 15,  1,  7, 24,
+       1, 12, 12, 16, 11,  4, 11, 12
+    };
+  static const struct name_pos wordlist[] =
+    {
+#line 151 "packet-sip-hdrs.gperf"
+      {"t", POS_TO},
+#line 137 "packet-sip-hdrs.gperf"
+      {"e", POS_CONTENT_ENCODING},
+#line 143 "packet-sip-hdrs.gperf"
+      {"n", POS_IDENTITY_INFO},
+#line 139 "packet-sip-hdrs.gperf"
+      {"c", POS_CONTENT_TYPE},
+#line 41 "packet-sip-hdrs.gperf"
+      {"event", POS_EVENT},
+#line 146 "packet-sip-hdrs.gperf"
+      {"j", POS_REJECT_CONTACT},
+#line 149 "packet-sip-hdrs.gperf"
+      {"s", POS_SUBJECT},
+#line 32 "packet-sip-hdrs.gperf"
+      {"contact", POS_CONTACT},
+#line 148 "packet-sip-hdrs.gperf"
+      {"x", POS_SESSION_EXPIRES},
+#line 144 "packet-sip-hdrs.gperf"
+      {"r", POS_REFER_TO},
+#line 37 "packet-sip-hdrs.gperf"
+      {"content-type", POS_CONTENT_TYPE},
+#line 145 "packet-sip-hdrs.gperf"
+      {"b", POS_REFERED_BY},
+#line 138 "packet-sip-hdrs.gperf"
+      {"l", POS_CONTENT_LENGTH},
+#line 35 "packet-sip-hdrs.gperf"
+      {"content-language", POS_CONTENT_LANGUAGE},
+#line 118 "packet-sip-hdrs.gperf"
+      {"subject", POS_SUBJECT},
+#line 110 "packet-sip-hdrs.gperf"
+      {"security-client", POS_SECURITY_CLIENT},
+#line 42 "packet-sip-hdrs.gperf"
+      {"expires", POS_EXPIRES},
+#line 33 "packet-sip-hdrs.gperf"
+      {"content-disposition", POS_CONTENT_DISPOSITION},
+#line 113 "packet-sip-hdrs.gperf"
+      {"server", POS_SERVER},
+#line 102 "packet-sip-hdrs.gperf"
+      {"replaces", POS_REPLACES},
+#line 114 "packet-sip-hdrs.gperf"
+      {"service-route", POS_SERVICE_ROUTE},
+#line 54 "packet-sip-hdrs.gperf"
+      {"join", POS_JOIN},
+#line 77 "packet-sip-hdrs.gperf"
+      {"p-preferred-service", POS_P_PREFERRED_SERV},
+#line 111 "packet-sip-hdrs.gperf"
+      {"security-server", POS_SECURITY_SERVER},
+#line 80 "packet-sip-hdrs.gperf"
+      {"p-served-user", POS_P_SERVED_USER},
+#line 19 "packet-sip-hdrs.gperf"
+      {"accept",	POS_ACCEPT},
+#line 115 "packet-sip-hdrs.gperf"
+      {"session-expires", POS_SESSION_EXPIRES},
+#line 79 "packet-sip-hdrs.gperf"
+      {"p-refused-uri-list", POS_P_REFUSED_URI_LST},
+#line 124 "packet-sip-hdrs.gperf"
+      {"to", POS_TO},
+#line 135 "packet-sip-hdrs.gperf"
+      {"i", POS_CALL_ID},
+#line 38 "packet-sip-hdrs.gperf"
+      {"cseq", POS_CSEQ},
+#line 94 "packet-sip-hdrs.gperf"
+      {"reason", POS_REASON},
+#line 125 "packet-sip-hdrs.gperf"
+      {"trigger-consent", POS_TRIGGER_CONSENT},
+#line 88 "packet-sip-hdrs.gperf"
+      {"priv-answer-mode", POS_PRIV_ANSWER_MODE},
+#line 109 "packet-sip-hdrs.gperf"
+      {"rseq", POS_RSEQ},
+#line 62 "packet-sip-hdrs.gperf"
+      {"p-answer-state", POS_P_ANSWER_STATE},
+#line 93 "packet-sip-hdrs.gperf"
+      {"rack", POS_RACK},
+#line 105 "packet-sip-hdrs.gperf"
+      {"require", POS_REQUIRE},
+#line 133 "packet-sip-hdrs.gperf"
+      {"a", POS_ACCEPT_CONTACT},
+#line 34 "packet-sip-hdrs.gperf"
+      {"content-encoding", POS_CONTENT_ENCODING},
+#line 107 "packet-sip-hdrs.gperf"
+      {"retry-after", POS_RETRY_AFTER},
+#line 119 "packet-sip-hdrs.gperf"
+      {"subscription-state", POS_SUBSCRIPTION_STATE},
+#line 26 "packet-sip-hdrs.gperf"
+      {"allow-events", POS_ALLOW_EVENTS},
+#line 39 "packet-sip-hdrs.gperf"
+      {"date", POS_DATE},
+#line 64 "packet-sip-hdrs.gperf"
+      {"p-asserted-service", POS_P_ASSERTED_SERV},
+#line 103 "packet-sip-hdrs.gperf"
+      {"reply-to", POS_REPLY_TO},
+#line 97 "packet-sip-hdrs.gperf"
+      {"recv-info", POS_RECV_INFO},
+#line 29 "packet-sip-hdrs.gperf"
+      {"authorization", POS_AUTHORIZATION},
+#line 104 "packet-sip-hdrs.gperf"
+      {"request-disposition", POS_REQUEST_DISPOSITION},
+#line 31 "packet-sip-hdrs.gperf"
+      {"call-info", POS_CALL_INFO},
+#line 68 "packet-sip-hdrs.gperf"
+      {"p-charging-vector", POS_P_CHARGING_VECTOR},
+#line 92 "packet-sip-hdrs.gperf"
+      {"proxy-require", POS_PROXY_REQUIRE},
+#line 150 "packet-sip-hdrs.gperf"
+      {"k", POS_SUPPORTED},
+#line 84 "packet-sip-hdrs.gperf"
+      {"permission-missing", POS_PERMISSION_MISSING},
+#line 65 "packet-sip-hdrs.gperf"
+      {"p-associated-uri", POS_P_ASSOCIATED_URI},
+#line 51 "packet-sip-hdrs.gperf"
+      {"identity-info", POS_IDENTITY_INFO},
+#line 120 "packet-sip-hdrs.gperf"
+      {"supported", POS_SUPPORTED},
+#line 67 "packet-sip-hdrs.gperf"
+      {"p-charging-function-addresses", POS_P_CHARGING_FUNC_ADDRESSES},
+#line 140 "packet-sip-hdrs.gperf"
+      {"o", POS_EVENT},
+#line 116 "packet-sip-hdrs.gperf"
+      {"sip-etag", POS_SIP_ETAG},
+#line 40 "packet-sip-hdrs.gperf"
+      {"error-info", POS_ERROR_INFO},
+#line 96 "packet-sip-hdrs.gperf"
+      {"record-route", POS_RECORD_ROUTE},
+#line 66 "packet-sip-hdrs.gperf"
+      {"p-called-party-id", POS_P_CALLED_PARTY_ID},
+#line 73 "packet-sip-hdrs.gperf"
+      {"p-dcs-redirect", POS_P_DCS_REDIRECT},
+#line 101 "packet-sip-hdrs.gperf"
+      {"reject-contact", POS_REJECT_CONTACT},
+#line 112 "packet-sip-hdrs.gperf"
+      {"security-verify", POS_SECURITY_VERIFY},
+#line 28 "packet-sip-hdrs.gperf"
+      {"authentication-info", POS_AUTHENTICATION_INFO},
+#line 85 "packet-sip-hdrs.gperf"
+      {"policy-contact", POS_POLICY_CONTACT},
+#line 72 "packet-sip-hdrs.gperf"
+      {"p-dcs-laes", POS_P_DCS_LAES},
+#line 60 "packet-sip-hdrs.gperf"
+      {"organization", POS_ORGANIZATION},
+#line 50 "packet-sip-hdrs.gperf"
+      {"identity", POS_IDENTITY},
+#line 90 "packet-sip-hdrs.gperf"
+      {"proxy-authenticate", POS_PROXY_AUTHENTICATE},
+#line 76 "packet-sip-hdrs.gperf"
+      {"p-preferred-identity", POS_P_PREFERRED_IDENTITY},
+#line 91 "packet-sip-hdrs.gperf"
+      {"proxy-authorization", POS_PROXY_AUTHORIZATION},
+#line 87 "packet-sip-hdrs.gperf"
+      {"priority", POS_PRIORITY},
+#line 106 "packet-sip-hdrs.gperf"
+      {"resource-priority", POS_RESOURCE_PRIORITY},
+#line 59 "packet-sip-hdrs.gperf"
+      {"min-se", POS_MIN_SE},
+#line 108 "packet-sip-hdrs.gperf"
+      {"route", POS_ROUTE},
+#line 24 "packet-sip-hdrs.gperf"
+      {"alert-info", POS_ALERT_INFO},
+#line 61 "packet-sip-hdrs.gperf"
+      {"p-access-network-info", POS_P_ACCESS_NETWORK_INFO},
+#line 20 "packet-sip-hdrs.gperf"
+      {"accept-contact", POS_ACCEPT_CONTACT},
+#line 27 "packet-sip-hdrs.gperf"
+      {"answer-mode", POS_ANSWER_MODE},
+#line 22 "packet-sip-hdrs.gperf"
+      {"accept-language", POS_ACCEPT_LANGUAGE},
+#line 78 "packet-sip-hdrs.gperf"
+      {"p-profile-key", POS_P_PROFILE_KEY},
+#line 95 "packet-sip-hdrs.gperf"
+      {"reason-phrase", POS_REASON_PHRASE},
+#line 74 "packet-sip-hdrs.gperf"
+      {"p-early-media", POS_P_EARLY_MEDIA},
+#line 147 "packet-sip-hdrs.gperf"
+      {"d", POS_REQUEST_DISPOSITION},
+#line 122 "packet-sip-hdrs.gperf"
+      {"target-dialog", POS_TARGET_DIALOG},
+#line 98 "packet-sip-hdrs.gperf"
+      {"refer-sub", POS_REFER_SUB},
+#line 46 "packet-sip-hdrs.gperf"
+      {"geolocation", POS_GEOLOCATION},
+#line 58 "packet-sip-hdrs.gperf"
+      {"min-expires", POS_MIN_EXPIRES},
+#line 83 "packet-sip-hdrs.gperf"
+      {"path", POS_PATH},
+#line 128 "packet-sip-hdrs.gperf"
+      {"via", POS_VIA},
+#line 70 "packet-sip-hdrs.gperf"
+      {"p-dcs-osps", POS_P_DCS_OSPS},
+#line 152 "packet-sip-hdrs.gperf"
+      {"v", POS_VIA},
+#line 142 "packet-sip-hdrs.gperf"
+      {"y", POS_IDENTITY},
+#line 63 "packet-sip-hdrs.gperf"
+      {"p-asserted-identity", POS_P_ASSERTED_IDENTITY},
+#line 56 "packet-sip-hdrs.gperf"
+      {"max-forwards", POS_MAX_FORWARDS},
+#line 43 "packet-sip-hdrs.gperf"
+      {"feature-caps", POS_FEATURE_CAPS},
+#line 47 "packet-sip-hdrs.gperf"
+      {"geolocation-error", POS_GEOLOCATION_ERROR},
+#line 36 "packet-sip-hdrs.gperf"
+      {"content-length", POS_CONTENT_LENGTH},
+#line 127 "packet-sip-hdrs.gperf"
+      {"user-agent", POS_USER_AGENT},
+#line 71 "packet-sip-hdrs.gperf"
+      {"p-dcs-billing-info", POS_P_DCS_BILLING_INFO},
+#line 123 "packet-sip-hdrs.gperf"
+      {"timestamp", POS_TIMESTAMP},
+#line 25 "packet-sip-hdrs.gperf"
+      {"allow", POS_ALLOW},
+#line 30 "packet-sip-hdrs.gperf"
+      {"call-id", POS_CALL_ID},
+#line 99 "packet-sip-hdrs.gperf"
+      {"refer-to", POS_REFER_TO},
+#line 21 "packet-sip-hdrs.gperf"
+      {"accept-encoding", POS_ACCEPT_ENCODING},
+#line 69 "packet-sip-hdrs.gperf"
+      {"p-dcs-trace-party-id", POS_P_DCS_TRACE_PARTY_ID},
+#line 86 "packet-sip-hdrs.gperf"
+      {"policy-id", POS_POLICY_ID},
+#line 52 "packet-sip-hdrs.gperf"
+      {"info-package", POS_INFO_PKG},
+#line 53 "packet-sip-hdrs.gperf"
+      {"in-reply-to", POS_IN_REPLY_TO},
+#line 82 "packet-sip-hdrs.gperf"
+      {"p-visited-network-id", POS_P_VISITED_NETWORK_ID},
+#line 121 "packet-sip-hdrs.gperf"
+      {"suppress-if-match", POS_SUPPRESS_IF_MATCH},
+#line 75 "packet-sip-hdrs.gperf"
+      {"p-media-authorization", POS_P_MEDIA_AUTHORIZATION},
+#line 132 "packet-sip-hdrs.gperf"
+      {"user-to-user", POS_USER_TO_USER},
+#line 131 "packet-sip-hdrs.gperf"
+      {"diversion", POS_DIVERSION},
+#line 48 "packet-sip-hdrs.gperf"
+      {"geolocation-routing", POS_GEOLOCATION_ROUTING},
+#line 141 "packet-sip-hdrs.gperf"
+      {"f", POS_FROM},
+#line 89 "packet-sip-hdrs.gperf"
+      {"privacy", POS_PRIVACY},
+#line 44 "packet-sip-hdrs.gperf"
+      {"flow-timer", POS_FLOW_TIMER},
+#line 100 "packet-sip-hdrs.gperf"
+      {"referred-by", POS_REFERED_BY},
+#line 81 "packet-sip-hdrs.gperf"
+      {"p-user-database", POS_P_USER_DATABASE},
+#line 134 "packet-sip-hdrs.gperf"
+      {"u", POS_ALLOW_EVENTS},
+#line 129 "packet-sip-hdrs.gperf"
+      {"warning", POS_WARNING},
+#line 23 "packet-sip-hdrs.gperf"
+      {"accept-resource-priority", POS_ACCEPT_RESOURCE_PRIORITY},
+#line 136 "packet-sip-hdrs.gperf"
+      {"m", POS_CONTACT},
+#line 117 "packet-sip-hdrs.gperf"
+      {"sip-if-match", POS_SIP_IF_MATCH},
+#line 57 "packet-sip-hdrs.gperf"
+      {"mime-version", POS_MIME_VERSION},
+#line 130 "packet-sip-hdrs.gperf"
+      {"www-authenticate", POS_WWW_AUTHENTICATE},
+#line 126 "packet-sip-hdrs.gperf"
+      {"unsupported", POS_UNSUPPORTED},
+#line 45 "packet-sip-hdrs.gperf"
+      {"from", POS_FROM},
+#line 55 "packet-sip-hdrs.gperf"
+      {"max-breadth", POS_MAX_BREADTH},
+#line 49 "packet-sip-hdrs.gperf"
+      {"history-info", POS_HISTORY_INFO}
+    };
+
+  static const short lookup[] =
+    {
+       -1,  -1,  -1,   0,  -1,   1,  -1,   2,  -1,   3,
+        4,  -1,  -1,   5,  -1,   6,   7,   8,  -1,   9,
+       -1,  -1,  10,  11,  -1,  12,  13,  14,  15,  16,
+       17,  18,  19,  20,  21,  22,  23,  24,  25,  26,
+       -1,  27,  28,  29,  30,  31,  -1,  32,  33,  34,
+       -1,  35,  36,  -1,  37,  38,  39,  40,  -1,  41,
+       42,  43,  44,  45,  46,  47,  48,  49,  50,  51,
+       -1,  52,  53,  -1,  54,  -1,  55,  56,  57,  58,
+       59,  60,  61,  62,  63,  64,  65,  66,  67,  68,
+       69,  70,  71,  72,  73,  74,  75,  76,  77,  78,
+       79,  80,  81,  82,  -1,  83,  84,  85,  -1,  86,
+       87,  88,  89,  90,  91,  92,  93,  94,  -1,  95,
+       96,  -1,  97,  98,  99, 100,  -1, 101, 102, 103,
+      104, 105, 106, 107,  -1, 108, 109, 110, 111, 112,
+      113,  -1,  -1, 114, 115, 116,  -1,  -1,  -1, 117,
+       -1, 118, 119,  -1, 120,  -1, 121,  -1,  -1,  -1,
+      122,  -1,  -1,  -1,  -1, 123, 124,  -1,  -1, 125,
+       -1,  -1,  -1, 126,  -1,  -1,  -1,  -1,  -1,  -1,
+       -1,  -1,  -1, 127,  -1,  -1,  -1,  -1,  -1, 128,
+       -1, 129,  -1, 130,  -1,  -1,  -1,  -1,  -1,  -1,
+       -1,  -1,  -1,  -1, 131,  -1,  -1,  -1,  -1,  -1,
+      132,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,  -1,
+      133
+    };
+
+  if (len <= MAX_WORD_LENGTH && len >= MIN_WORD_LENGTH)
+    {
+      register int key = _sip_header_hash (str, len);
+
+      if (key <= MAX_HASH_VALUE && key >= 0)
+        {
+          register int index = lookup[key];
+
+          if (index >= 0)
+            {
+              if (len == lengthtable[index])
+                {
+                  register const char *s = wordlist[index].name;
+
+                  if (*str == *s && !memcmp (str + 1, s + 1, len - 1))
+                    return &wordlist[index];
+                }
+            }
+        }
+    }
+  return 0;
+}
+#line 153 "packet-sip-hdrs.gperf"
+
+int sip_is_known_sip_header(const char *header_name, unsigned int header_len)
+{
+	const struct name_pos *npos = _sip_header_find(header_name, header_len);
+
+	if (!npos)
+		return -1;
+	return npos->pos;
+}
diff --git a/epan/dissectors/packet-sip-hdrs.gperf b/epan/dissectors/packet-sip-hdrs.gperf
new file mode 100644
index 0000000000..5ca2fca734
--- /dev/null
+++ b/epan/dissectors/packet-sip-hdrs.gperf
@@ -0,0 +1,161 @@
+%{
+#include <string.h>
+
+#include "packet-sip-hdrs.h"
+%}
+
+%compare-lengths
+%readonly-tables
+%struct-type
+%null-strings
+%language=ANSI-C
+
+%define lookup-function-name _sip_header_find
+%define hash-function-name   _sip_header_hash
+
+struct name_pos { const char *name; int pos; };
+
+%%
+accept,	POS_ACCEPT
+accept-contact, POS_ACCEPT_CONTACT
+accept-encoding, POS_ACCEPT_ENCODING
+accept-language, POS_ACCEPT_LANGUAGE
+accept-resource-priority, POS_ACCEPT_RESOURCE_PRIORITY
+alert-info, POS_ALERT_INFO
+allow, POS_ALLOW
+allow-events, POS_ALLOW_EVENTS
+answer-mode, POS_ANSWER_MODE
+authentication-info, POS_AUTHENTICATION_INFO
+authorization, POS_AUTHORIZATION
+call-id, POS_CALL_ID
+call-info, POS_CALL_INFO
+contact, POS_CONTACT
+content-disposition, POS_CONTENT_DISPOSITION
+content-encoding, POS_CONTENT_ENCODING
+content-language, POS_CONTENT_LANGUAGE
+content-length, POS_CONTENT_LENGTH
+content-type, POS_CONTENT_TYPE
+cseq, POS_CSEQ
+date, POS_DATE
+error-info, POS_ERROR_INFO
+event, POS_EVENT
+expires, POS_EXPIRES
+feature-caps, POS_FEATURE_CAPS
+flow-timer, POS_FLOW_TIMER
+from, POS_FROM
+geolocation, POS_GEOLOCATION
+geolocation-error, POS_GEOLOCATION_ERROR
+geolocation-routing, POS_GEOLOCATION_ROUTING
+history-info, POS_HISTORY_INFO
+identity, POS_IDENTITY
+identity-info, POS_IDENTITY_INFO
+info-package, POS_INFO_PKG
+in-reply-to, POS_IN_REPLY_TO
+join, POS_JOIN
+max-breadth, POS_MAX_BREADTH
+max-forwards, POS_MAX_FORWARDS
+mime-version, POS_MIME_VERSION
+min-expires, POS_MIN_EXPIRES
+min-se, POS_MIN_SE
+organization, POS_ORGANIZATION
+p-access-network-info, POS_P_ACCESS_NETWORK_INFO
+p-answer-state, POS_P_ANSWER_STATE
+p-asserted-identity, POS_P_ASSERTED_IDENTITY
+p-asserted-service, POS_P_ASSERTED_SERV
+p-associated-uri, POS_P_ASSOCIATED_URI
+p-called-party-id, POS_P_CALLED_PARTY_ID
+p-charging-function-addresses, POS_P_CHARGING_FUNC_ADDRESSES
+p-charging-vector, POS_P_CHARGING_VECTOR
+p-dcs-trace-party-id, POS_P_DCS_TRACE_PARTY_ID
+p-dcs-osps, POS_P_DCS_OSPS
+p-dcs-billing-info, POS_P_DCS_BILLING_INFO
+p-dcs-laes, POS_P_DCS_LAES
+p-dcs-redirect, POS_P_DCS_REDIRECT
+p-early-media, POS_P_EARLY_MEDIA
+p-media-authorization, POS_P_MEDIA_AUTHORIZATION
+p-preferred-identity, POS_P_PREFERRED_IDENTITY
+p-preferred-service, POS_P_PREFERRED_SERV
+p-profile-key, POS_P_PROFILE_KEY
+p-refused-uri-list, POS_P_REFUSED_URI_LST
+p-served-user, POS_P_SERVED_USER
+p-user-database, POS_P_USER_DATABASE
+p-visited-network-id, POS_P_VISITED_NETWORK_ID
+path, POS_PATH
+permission-missing, POS_PERMISSION_MISSING
+policy-contact, POS_POLICY_CONTACT
+policy-id, POS_POLICY_ID
+priority, POS_PRIORITY
+priv-answer-mode, POS_PRIV_ANSWER_MODE
+privacy, POS_PRIVACY
+proxy-authenticate, POS_PROXY_AUTHENTICATE
+proxy-authorization, POS_PROXY_AUTHORIZATION
+proxy-require, POS_PROXY_REQUIRE
+rack, POS_RACK
+reason, POS_REASON
+reason-phrase, POS_REASON_PHRASE
+record-route, POS_RECORD_ROUTE
+recv-info, POS_RECV_INFO
+refer-sub, POS_REFER_SUB
+refer-to, POS_REFER_TO
+referred-by, POS_REFERED_BY
+reject-contact, POS_REJECT_CONTACT
+replaces, POS_REPLACES
+reply-to, POS_REPLY_TO
+request-disposition, POS_REQUEST_DISPOSITION
+require, POS_REQUIRE
+resource-priority, POS_RESOURCE_PRIORITY
+retry-after, POS_RETRY_AFTER
+route, POS_ROUTE
+rseq, POS_RSEQ
+security-client, POS_SECURITY_CLIENT
+security-server, POS_SECURITY_SERVER
+security-verify, POS_SECURITY_VERIFY
+server, POS_SERVER
+service-route, POS_SERVICE_ROUTE
+session-expires, POS_SESSION_EXPIRES
+sip-etag, POS_SIP_ETAG
+sip-if-match, POS_SIP_IF_MATCH
+subject, POS_SUBJECT
+subscription-state, POS_SUBSCRIPTION_STATE
+supported, POS_SUPPORTED
+suppress-if-match, POS_SUPPRESS_IF_MATCH
+target-dialog, POS_TARGET_DIALOG
+timestamp, POS_TIMESTAMP
+to, POS_TO
+trigger-consent, POS_TRIGGER_CONSENT
+unsupported, POS_UNSUPPORTED
+user-agent, POS_USER_AGENT
+via, POS_VIA
+warning, POS_WARNING
+www-authenticate, POS_WWW_AUTHENTICATE
+diversion, POS_DIVERSION
+user-to-user, POS_USER_TO_USER
+a, POS_ACCEPT_CONTACT
+u, POS_ALLOW_EVENTS
+i, POS_CALL_ID
+m, POS_CONTACT
+e, POS_CONTENT_ENCODING
+l, POS_CONTENT_LENGTH
+c, POS_CONTENT_TYPE
+o, POS_EVENT
+f, POS_FROM
+y, POS_IDENTITY
+n, POS_IDENTITY_INFO
+r, POS_REFER_TO
+b, POS_REFERED_BY
+j, POS_REJECT_CONTACT
+d, POS_REQUEST_DISPOSITION
+x, POS_SESSION_EXPIRES
+s, POS_SUBJECT
+k, POS_SUPPORTED
+t, POS_TO
+v, POS_VIA
+%%
+int sip_is_known_sip_header(const char *header_name, unsigned int header_len)
+{
+	const struct name_pos *npos = _sip_header_find(header_name, header_len);
+
+	if (!npos)
+		return -1;
+	return npos->pos;
+}
diff --git a/epan/dissectors/packet-sip-hdrs.h b/epan/dissectors/packet-sip-hdrs.h
new file mode 100644
index 0000000000..279f0d48fb
--- /dev/null
+++ b/epan/dissectors/packet-sip-hdrs.h
@@ -0,0 +1,163 @@
+/* packet-sip-hdrs.h
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef __PACKET_SIP_HDRS_H__
+#define __PACKET_SIP_HDRS_H__
+
+/*
+ * ########################### HOWTO ###########################
+ * In order to add new header for sip do:
+ *
+ * 1/ add your-header, POS_FOO_BAR to packet-sip-hdrs.gperf
+ * 2/ add below #define POS_FOO_BAR next_value
+ * 3/ update hf_header_array[] in packet-sip.c
+ * 4/ run gperf -m 500 -D packet-sip-hdrs.gperf > packet-sip-hdrs.c
+ * #############################################################
+ */
+
+/* from RFC 3261
+ * Updated with info from http://www.iana.org/assignments/sip-parameters
+ * (last updated 2009-11-11)
+ * Updated with: http://www.ietf.org/internet-drafts/draft-ietf-sip-resource-priority-05.txt
+ */
+
+#define POS_ACCEPT                       1
+#define POS_ACCEPT_CONTACT               2 /* RFC3841  */
+#define POS_ACCEPT_ENCODING              3
+#define POS_ACCEPT_LANGUAGE              4
+#define POS_ACCEPT_RESOURCE_PRIORITY     5 /* RFC4412 */
+#define POS_ALERT_INFO                   6
+#define POS_ALLOW                        7
+#define POS_ALLOW_EVENTS                 8 /* RFC3265  */
+#define POS_ANSWER_MODE                  9 /* RFC5373 */
+#define POS_AUTHENTICATION_INFO         10
+#define POS_AUTHORIZATION               11
+#define POS_CALL_ID                     12
+#define POS_CALL_INFO                   13
+#define POS_CONTACT                     14
+#define POS_CONTENT_DISPOSITION         15
+#define POS_CONTENT_ENCODING            16
+#define POS_CONTENT_LANGUAGE            17
+#define POS_CONTENT_LENGTH              18
+#define POS_CONTENT_TYPE                19
+#define POS_CSEQ                        20
+#define POS_DATE                        21
+#define POS_ERROR_INFO                  22
+#define POS_EVENT                       23
+#define POS_EXPIRES                     24
+#define POS_FEATURE_CAPS                25  /* [RFC6809 */
+#define POS_FLOW_TIMER                  26  /* RFC5626  */
+#define POS_FROM                        27
+#define POS_GEOLOCATION                 28
+#define POS_GEOLOCATION_ERROR           29
+#define POS_GEOLOCATION_ROUTING         30
+#define POS_HISTORY_INFO                31  /* RFC4244  */
+#define POS_IDENTITY                    32  /* RFC4474  */
+#define POS_IDENTITY_INFO               33  /* RFC4474  */
+#define POS_INFO_PKG                    34  /* RFC-ietf-sipcore-info-events-10.txt  */
+#define POS_IN_REPLY_TO                 35  /* RFC3261  */
+#define POS_JOIN                        36  /* RFC3911  */
+#define POS_MAX_BREADTH                 37  /* RFC5393*/
+#define POS_MAX_FORWARDS                38
+#define POS_MIME_VERSION                39
+#define POS_MIN_EXPIRES                 40
+#define POS_MIN_SE                      41  /* RFC4028  */
+#define POS_ORGANIZATION                42  /* RFC3261  */
+#define POS_P_ACCESS_NETWORK_INFO       43  /* RFC3455  */
+#define POS_P_ANSWER_STATE              44  /* RFC4964  */
+#define POS_P_ASSERTED_IDENTITY         45  /* RFC3325  */
+#define POS_P_ASSERTED_SERV             46  /* RFC6050  */
+#define POS_P_ASSOCIATED_URI            47  /* RFC3455  */
+#define POS_P_CALLED_PARTY_ID           48  /* RFC3455  */
+#define POS_P_CHARGING_FUNC_ADDRESSES   49  /* RFC3455  */
+#define POS_P_CHARGING_VECTOR           50  /* RFC3455  */
+#define POS_P_DCS_TRACE_PARTY_ID        51  /* RFC5503  */
+#define POS_P_DCS_OSPS                  52  /* RFC5503  */
+#define POS_P_DCS_BILLING_INFO          53  /* RFC5503  */
+#define POS_P_DCS_LAES                  54  /* RFC5503  */
+#define POS_P_DCS_REDIRECT              55  /* RFC5503  */
+#define POS_P_EARLY_MEDIA               56  /* RFC5009  */
+#define POS_P_MEDIA_AUTHORIZATION       57  /* RFC3313  */
+#define POS_P_PREFERRED_IDENTITY        58  /* RFC3325  */
+#define POS_P_PREFERRED_SERV            59  /* RFC6050  */
+#define POS_P_PROFILE_KEY               60  /* RFC5002  */
+#define POS_P_REFUSED_URI_LST           61  /* RFC5318  */
+#define POS_P_SERVED_USER               62  /* RFC5502  */
+#define POS_P_USER_DATABASE             63  /* RFC4457  */
+#define POS_P_VISITED_NETWORK_ID        64  /* RFC3455  */
+#define POS_PATH                        65  /* RFC3327  */
+#define POS_PERMISSION_MISSING          66  /* RFC5360  */
+#define POS_POLICY_CONTACT              67  /* RFC3261  */
+#define POS_POLICY_ID                   68  /* RFC3261  */
+#define POS_PRIORITY                    69  /* RFC3261  */
+#define POS_PRIV_ANSWER_MODE            70  /* RFC5373  */
+#define POS_PRIVACY                     71  /* RFC3323  */
+#define POS_PROXY_AUTHENTICATE          72
+#define POS_PROXY_AUTHORIZATION         73
+#define POS_PROXY_REQUIRE               74
+#define POS_RACK                        75  /* RFC3262  */
+#define POS_REASON                      76  /* RFC3326  */
+#define POS_REASON_PHRASE               77  /* RFC3326  */
+#define POS_RECORD_ROUTE                78
+#define POS_RECV_INFO                   79  /* RFC-ietf-sipcore-info-events-10.txt*/
+#define POS_REFER_SUB                   80  /* RFC4488  */
+#define POS_REFER_TO                    81  /* RFC3515  */
+#define POS_REFERED_BY                  82  /* RFC3892  */
+#define POS_REJECT_CONTACT              83  /* RFC3841  */
+#define POS_REPLACES                    84  /* RFC3891  */
+#define POS_REPLY_TO                    85  /* RFC3261  */
+#define POS_REQUEST_DISPOSITION         86  /* RFC3841  */
+#define POS_REQUIRE                     87  /* RFC3261  */
+#define POS_RESOURCE_PRIORITY           88  /* RFC4412  */
+#define POS_RETRY_AFTER                 89  /* RFC3261  */
+#define POS_ROUTE                       90  /* RFC3261  */
+#define POS_RSEQ                        91  /* RFC3262  */
+#define POS_SECURITY_CLIENT             92  /* RFC3329  */
+#define POS_SECURITY_SERVER             93  /* RFC3329  */
+#define POS_SECURITY_VERIFY             94  /* RFC3329  */
+#define POS_SERVER                      95  /* RFC3261  */
+#define POS_SERVICE_ROUTE               96  /* RFC3608  */
+#define POS_SESSION_EXPIRES             97  /* RFC4028  */
+#define POS_SIP_ETAG                    98  /* RFC3903  */
+#define POS_SIP_IF_MATCH                99  /* RFC3903  */
+#define POS_SUBJECT                     100  /* RFC3261  */
+#define POS_SUBSCRIPTION_STATE          101  /* RFC3265  */
+#define POS_SUPPORTED                   102  /* RFC3261  */
+#define POS_SUPPRESS_IF_MATCH           103  /* RFC5839  */
+#define POS_TARGET_DIALOG               104  /* RFC4538  */
+#define POS_TIMESTAMP                   105  /* RFC3261  */
+#define POS_TO                          106  /* RFC3261  */
+#define POS_TRIGGER_CONSENT             107  /* RFC5360  */
+#define POS_UNSUPPORTED                 108  /* RFC3261  */
+#define POS_USER_AGENT                  109  /* RFC3261  */
+#define POS_VIA                         110  /* RFC3261  */
+#define POS_WARNING                     111  /* RFC3261  */
+#define POS_WWW_AUTHENTICATE            112  /* RFC3261  */
+#define POS_DIVERSION                   113  /* RFC5806  */
+#define POS_USER_TO_USER                114  /* draft-johnston-sipping-cc-uui-09  */
+
+/* Encryption (Deprecated)       [RFC3261] */
+/* Hide                          [RFC3261] (deprecated)*/
+/* Response-Key (Deprecated)     [RFC3261] */
+
+extern int sip_is_known_sip_header(const char *header_name, unsigned int header_len);
+
+#endif /* __PACKET_SIP_HDRS_H__ */
diff --git a/epan/dissectors/packet-sip.c b/epan/dissectors/packet-sip.c
index 0797f5cc7e..22d96efeb7 100644
--- a/epan/dissectors/packet-sip.c
+++ b/epan/dissectors/packet-sip.c
@@ -54,6 +54,7 @@
 
 #include "packet-isup.h"
 #include "packet-sip.h"
+#include "packet-sip-hdrs.h"
 
 #include "packet-sdp.h"  /* SDP needs a transport layer to determine request/response */
 
@@ -271,255 +272,6 @@ static const char *sip_methods[] = {
         "PUBLISH"
 };
 
-/* from RFC 3261
- * Updated with info from http://www.iana.org/assignments/sip-parameters
- * (last updated 2009-11-11)
- * Updated with: http://www.ietf.org/internet-drafts/draft-ietf-sip-resource-priority-05.txt
- */
-typedef struct {
-        const char *name;
-        const char *compact_name;
-} sip_header_t;
-static const sip_header_t sip_headers[] = {
-    { "Unknown-header",                 NULL }, /* 0 Pad so that the real headers start at index 1 */
-    { "Accept",                         NULL }, /* 1 */
-#define POS_ACCEPT                       1
-    { "Accept-Contact",                 "a"  }, /* 2 RFC3841  */
-#define POS_ACCEPT_CONTACT               2
-    { "Accept-Encoding",                NULL }, /* 3 */
-#define POS_ACCEPT_ENCODING              3
-    { "Accept-Language",                NULL }, /* 4 */
-#define POS_ACCEPT_LANGUAGE              4
-    { "Accept-Resource-Priority",       NULL }, /* 5 RFC4412 */
-#define POS_ACCEPT_RESOURCE_PRIORITY     5
-    { "Alert-Info",                     NULL },
-#define POS_ALERT_INFO                   6
-    { "Allow",                          NULL },
-#define POS_ALLOW                        7
-    { "Allow-Events",                   "u"  }, /* 8 RFC3265  */
-#define POS_ALLOW_EVENTS                 8
-    { "Answer-Mode",                    NULL }, /* 9 RFC5373 */
-#define POS_ANSWER_MODE                  9
-    { "Authentication-Info",            NULL },
-#define POS_AUTHENTICATION_INFO         10
-    { "Authorization",                  NULL }, /* 11 */
-#define POS_AUTHORIZATION               11
-    { "Call-ID",                        "i"  },
-#define POS_CALL_ID                     12
-    { "Call-Info",                      NULL },
-#define POS_CALL_INFO                   13
-    { "Contact",                        "m"  },
-#define POS_CONTACT                     14
-    { "Content-Disposition",            NULL },
-#define POS_CONTENT_DISPOSITION         15
-    { "Content-Encoding",               "e"  },  /*  16 */
-#define POS_CONTENT_ENCODING            16
-    { "Content-Language",               NULL },
-#define POS_CONTENT_LANGUAGE            17
-    { "Content-Length",                 "l"  },
-#define POS_CONTENT_LENGTH              18
-    { "Content-Type",                   "c"  },
-#define POS_CONTENT_TYPE                19
-    { "CSeq",                           NULL },
-#define POS_CSEQ                        20
-    { "Date",                           NULL },  /*  21 */
-#define POS_DATE                        21
-/*              Encryption (Deprecated)       [RFC3261] */
-    { "Error-Info",                     NULL },  /*  22 */
-#define POS_ERROR_INFO                  22
-    { "Event",                          "o"  },  /*  23 */
-#define POS_EVENT                       23
-    { "Expires",                        NULL },  /*  24 */
-#define POS_EXPIRES                     24
-    { "Feature-Caps",                   NULL },  /*  25 [RFC6809 */
-#define POS_FEATURE_CAPS                25
-    { "Flow-Timer",                     NULL },  /*  26 RFC5626  */
-#define POS_FLOW_TIMER                  26
-    { "From",                           "f"  },  /*  27 */
-#define POS_FROM                        27
-
-    { "Geolocation",                   NULL  },  /*  28 */
-#define POS_GEOLOCATION                 28
-    { "Geolocation-Error",             NULL  },  /*  29 */
-#define POS_GEOLOCATION_ERROR           29
-    { "Geolocation-Routing",           NULL  },  /*  30 */
-#define POS_GEOLOCATION_ROUTING         30
-
-/*              Hide                          [RFC3261] (deprecated)*/
-    { "History-Info",                   NULL },  /*  31 RFC4244  */
-#define POS_HISTORY_INFO                31
-    { "Identity",                       "y"  },  /*  32 RFC4474  */
-#define POS_IDENTITY                    32
-    { "Identity-Info",                  "n"  },  /*  33 RFC4474  */
-#define POS_IDENTITY_INFO               33
-    { "Info-Package",                   NULL },  /*  34 RFC-ietf-sipcore-info-events-10.txt  */
-#define POS_INFO_PKG                    34
-    { "In-Reply-To",                    NULL },  /*  35 RFC3261  */
-#define POS_IN_REPLY_TO                 35
-    { "Join",                           NULL },  /*  36 RFC3911  */
-#define POS_JOIN                        36
-    { "Max-Breadth",                    NULL },  /*  37 RFC5393*/
-#define POS_MAX_BREADTH                 37
-    { "Max-Forwards",                   NULL },  /*  38 */
-#define POS_MAX_FORWARDS                38
-    { "MIME-Version",                   NULL },  /*  39 */
-#define POS_MIME_VERSION                39
-    { "Min-Expires",                    NULL },  /*  40 */
-#define POS_MIN_EXPIRES                 40
-    { "Min-SE",                         NULL },  /*  41 RFC4028  */
-#define POS_MIN_SE                      41
-    { "Organization",                   NULL },  /*  42 RFC3261  */
-#define POS_ORGANIZATION                42
-    { "P-Access-Network-Info",          NULL },  /*  43 RFC3455  */
-#define POS_P_ACCESS_NETWORK_INFO       43
-    { "P-Answer-State",                 NULL },  /*  44 RFC4964  */
-#define POS_P_ANSWER_STATE              44
-    { "P-Asserted-Identity",            NULL },  /*  45 RFC3325  */
-#define POS_P_ASSERTED_IDENTITY         45
-    { "P-Asserted-Service",             NULL },  /*  46 RFC6050  */
-#define POS_P_ASSERTED_SERV             46
-    { "P-Associated-URI",               NULL },  /*  47 RFC3455  */
-#define POS_P_ASSOCIATED_URI            47
-    { "P-Called-Party-ID",              NULL },  /*  48 RFC3455  */
-#define POS_P_CALLED_PARTY_ID           48
-    { "P-Charging-Function-Addresses",  NULL },  /*  49 RFC3455  */
-#define POS_P_CHARGING_FUNC_ADDRESSES   49
-    { "P-Charging-Vector",              NULL },  /*  50 RFC3455  */
-#define POS_P_CHARGING_VECTOR           50
-    { "P-DCS-Trace-Party-ID",           NULL },  /*  51 RFC5503  */
-#define POS_P_DCS_TRACE_PARTY_ID        51
-    { "P-DCS-OSPS",                     NULL },  /*  52 RFC5503  */
-#define POS_P_DCS_OSPS                  52
-    { "P-DCS-Billing-Info",             NULL },  /*  53 RFC5503  */
-#define POS_P_DCS_BILLING_INFO          53
-    { "P-DCS-LAES",                     NULL },  /*  54 RFC5503  */
-#define POS_P_DCS_LAES                  54
-    { "P-DCS-Redirect",                 NULL },  /*  55 RFC5503  */
-#define POS_P_DCS_REDIRECT              55
-    { "P-Early-Media",                  NULL },  /*  56 RFC5009  */
-#define POS_P_EARLY_MEDIA               56
-    { "P-Media-Authorization",          NULL },  /*  57 RFC3313  */
-#define POS_P_MEDIA_AUTHORIZATION       57
-    { "P-Preferred-Identity",           NULL },  /*  58 RFC3325  */
-#define POS_P_PREFERRED_IDENTITY        58
-    { "P-Preferred-Service",            NULL },  /*  58 RFC6050  */
-#define POS_P_PREFERRED_SERV            59
-    { "P-Profile-Key",                  NULL },  /*  60 RFC5002  */
-#define POS_P_PROFILE_KEY               60
-    { "P-Refused-URI-List",             NULL },  /*  61 RFC5318  */
-#define POS_P_REFUSED_URI_LST           61
-    { "P-Served-User",                  NULL },  /*  62 RFC5502  */
-#define POS_P_SERVED_USER               62
-    { "P-User-Database",                NULL },  /*  63 RFC4457  */
-#define POS_P_USER_DATABASE             63
-    { "P-Visited-Network-ID",           NULL },  /*  64 RFC3455  */
-#define POS_P_VISITED_NETWORK_ID        64
-    { "Path",                           NULL },  /*  65 RFC3327  */
-#define POS_PATH                        65
-    { "Permission-Missing",             NULL },  /*  66 RFC5360  */
-#define POS_PERMISSION_MISSING          66
-    { "Policy-Contact",                 NULL },  /*  67 RFC3261  */
-#define POS_POLICY_CONTACT              67
-    { "Policy-ID",                      NULL },  /*  68 RFC3261  */
-#define POS_POLICY_ID                   68
-    { "Priority",                       NULL },  /*  69 RFC3261  */
-#define POS_PRIORITY                    69
-    { "Priv-Answer-Mode",               NULL },  /*  70 RFC5373  */
-#define POS_PRIV_ANSWER_MODE            70
-    { "Privacy",                        NULL },  /*  71 RFC3323  */
-#define POS_PRIVACY                     71
-    { "Proxy-Authenticate",             NULL },  /*  72 */
-#define POS_PROXY_AUTHENTICATE          72
-    { "Proxy-Authorization",            NULL },  /*  73 */
-#define POS_PROXY_AUTHORIZATION         73
-    { "Proxy-Require",                  NULL },  /*  74 */
-#define POS_PROXY_REQUIRE               74
-    { "RAck",                           NULL },  /*  75 RFC3262  */
-#define POS_RACK                        75
-    { "Reason",                         NULL },  /*  76 RFC3326  */
-#define POS_REASON                      76
-    { "Reason-Phrase",                  NULL },  /*  77 RFC3326  */
-#define POS_REASON_PHRASE               77
-    { "Record-Route",                   NULL },  /*  78 */
-#define POS_RECORD_ROUTE                78
-    { "Recv-Info",                      NULL },  /*  79 RFC-ietf-sipcore-info-events-10.txt*/
-#define POS_RECV_INFO                   79
-    { "Refer-Sub",                      NULL },  /*  80 RFC4488  */
-#define POS_REFER_SUB                   80
-    { "Refer-To",                       "r"  },  /*  81 RFC3515  */
-#define POS_REFER_TO                    81
-    { "Referred-By",                    "b"  },  /*  82 RFC3892  */
-#define POS_REFERED_BY                  82
-    { "Reject-Contact",                 "j"  },  /*  83 RFC3841  */
-#define POS_REJECT_CONTACT              83
-    { "Replaces",                       NULL },  /*  84 RFC3891  */
-#define POS_REPLACES                    84
-    { "Reply-To",                       NULL },  /*  85 RFC3261  */
-#define POS_REPLY_TO                    85
-    { "Request-Disposition",            "d"  },  /*  86 RFC3841  */
-#define POS_REQUEST_DISPOSITION         86
-    { "Require",                        NULL },  /*  87 RFC3261  */
-#define POS_REQUIRE                     87
-    { "Resource-Priority",              NULL },  /*  88 RFC4412  */
-#define POS_RESOURCE_PRIORITY           88
-    /*{ "Response-Key (Deprecated)     [RFC3261]*/
-    { "Retry-After",                    NULL },  /*  89 RFC3261  */
-#define POS_RETRY_AFTER                 89
-    { "Route",                          NULL },  /*  90 RFC3261  */
-#define POS_ROUTE                       90
-    { "RSeq",                           NULL },  /*  91 RFC3262  */
-#define POS_RSEQ                        91
-    { "Security-Client",                NULL },  /*  92 RFC3329  */
-#define POS_SECURITY_CLIENT             92
-    { "Security-Server",                NULL },  /*  93 RFC3329  */
-#define POS_SECURITY_SERVER             93
-    { "Security-Verify",                NULL },  /*  94 RFC3329  */
-#define POS_SECURITY_VERIFY             94
-    { "Server",                         NULL },  /*  95 RFC3261  */
-#define POS_SERVER                      95
-    { "Service-Route",                  NULL },  /*  96 RFC3608  */
-#define POS_SERVICE_ROUTE               96
-    { "Session-Expires",                "x"  },  /*  97 RFC4028  */
-#define POS_SESSION_EXPIRES             97
-    { "SIP-ETag",                       NULL },  /*  98 RFC3903  */
-#define POS_SIP_ETAG                    98
-    { "SIP-If-Match",                   NULL },  /*  99 RFC3903  */
-#define POS_SIP_IF_MATCH                99
-    { "Subject",                        "s"  },  /* 100 RFC3261  */
-#define POS_SUBJECT                     100
-    { "Subscription-State",             NULL },  /* 101 RFC3265  */
-#define POS_SUBSCRIPTION_STATE          101
-    { "Supported",                      "k"  },  /* 102 RFC3261  */
-#define POS_SUPPORTED                   102
-    { "Suppress-If-Match",              NULL },  /* 103 RFC5839  */
-#define POS_SUPPRESS_IF_MATCH           103
-    { "Target-Dialog",                  NULL },  /* 104 RFC4538  */
-#define POS_TARGET_DIALOG               104
-    { "Timestamp",                      NULL },  /* 105 RFC3261  */
-#define POS_TIMESTAMP                   105
-    { "To",                             "t"  },  /* 106 RFC3261  */
-#define POS_TO                          106
-    { "Trigger-Consent",                NULL },  /* 107 RFC5360  */
-#define POS_TRIGGER_CONSENT             107
-    { "Unsupported",                    NULL },  /* 108 RFC3261  */
-#define POS_UNSUPPORTED                 108
-    { "User-Agent",                     NULL },  /* 109 RFC3261  */
-#define POS_USER_AGENT                  109
-    { "Via",                            "v"  },  /* 110 RFC3261  */
-#define POS_VIA                         110
-    { "Warning",                        NULL },  /* 111 RFC3261  */
-#define POS_WARNING                     111
-    { "WWW-Authenticate",               NULL },  /* 112 RFC3261  */
-#define POS_WWW_AUTHENTICATE            112
-    { "Diversion",                      NULL },  /* 113 RFC5806  */
-#define POS_DIVERSION                   113
-    { "User-to-User",                   NULL },  /* 106 draft-johnston-sipping-cc-uui-09  */
-#define POS_USER_TO_USER                114
-};
-
-
-
-
 static gint hf_header_array[] = {
     -1, /* 0"Unknown-header" - Pad so that the real headers start at index 1 */
     -1, /* 1"Accept"                                    */
@@ -833,7 +585,6 @@ static line_type_t sip_parse_line(tvbuff_t *tvb, int offset, gint linelen,
     guint *token_1_len);
 static gboolean sip_is_known_request(tvbuff_t *tvb, int meth_offset,
     guint meth_len, guint *meth_idx);
-static gint sip_is_known_sip_header(gchar *header_name, guint header_len);
 static void dfilter_sip_request_line(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo, gint offset,
     guint meth_len, gint linelen);
 static void dfilter_sip_status_line(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo, gint line_end, gint offset);
@@ -894,7 +645,6 @@ static sip_info_value_t *stat_info;
  ****************************************************************************/
 
 static GHashTable *sip_hash = NULL;           /* Hash table */
-static GHashTable *sip_headers_hash = NULL;     /* Hash table */
 
 /* Types for hash table keys and values */
 #define MAX_CALL_ID_SIZE 128
@@ -967,28 +717,12 @@ static gint sip_equal(gconstpointer v, gconstpointer v2)
 static void
 sip_init_protocol(void)
 {
-     guint i;
-     gchar *value_copy;
-
     /* Destroy any existing hashes. */
     if (sip_hash)
         g_hash_table_destroy(sip_hash);
 
     /* Now create them again */
     sip_hash = g_hash_table_new(g_str_hash , sip_equal);
-    /* Create a hashtable with the SIP headers; it will be used to find the related hf entry (POS_x).
-     * This is faster than the previously used for loop.
-     * There is no g_hash_table_destroy as the lifetime is the same as the lifetime of Wireshark.
-     */
-    if(!sip_headers_hash){
-        sip_headers_hash = g_hash_table_new(g_str_hash , g_str_equal);
-        for (i = 1; i < array_length(sip_headers); i++){
-            value_copy = g_strdup (sip_headers[i].name);
-            /* Store (and compare) the string in lower case) */
-            ascii_strdown_inplace(value_copy);
-            g_hash_table_insert(sip_headers_hash, (gpointer)value_copy, GINT_TO_POINTER(i));
-        }
-    }
 }
 /* Call the export PDU tap with relevant data */
 static void
@@ -2990,8 +2724,7 @@ dissect_sip_common(tvbuff_t *tvb, int offset, int remaining_length, packet_info
                                 proto_tree_add_string_format(hdr_tree,
                                                              hf_header_array[hf_index], tvb,
                                                              offset, next_offset - offset,
-                                                             value+sub_value_offset, "%s String too big: %d bytes",
-                                                             sip_headers[POS_CSEQ].name,
+                                                             value+sub_value_offset, "CSeq String too big: %d bytes",
                                                              strlen_to_copy);
                             }
                             THROW(ReportedBoundsError);
@@ -3969,31 +3702,6 @@ static gboolean sip_is_known_request(tvbuff_t *tvb, int meth_offset,
     return FALSE;
 }
 
-/*
- * Returns index of method in sip_headers
- * Header namne should be in lower case
- */
-static gint sip_is_known_sip_header(gchar *header_name, guint header_len)
-{
-    guint pos;
-
-    /* Compact name is one character long */
-    if(header_len>1){
-        pos = GPOINTER_TO_UINT(g_hash_table_lookup(sip_headers_hash, header_name));
-        if (pos!=0)
-            return pos;
-    }
-
-    /* Look for compact name match */
-    for (pos = 1; pos < array_length(sip_headers); pos++) {
-        if (sip_headers[pos].compact_name != NULL &&
-                header_len == strlen(sip_headers[pos].compact_name) &&
-                g_ascii_strncasecmp(header_name, sip_headers[pos].compact_name, header_len) == 0)
-            return pos;
-    }
-
-    return -1;
-}
 
 /*
  * Display the entire message as raw text.