SIP dissector, from Heikki Vatiainen.

svn path=/trunk/; revision=2562

1 files changed, 224 insertions, 0 deletions

diff --git a/packet-sip.c b/packet-sip.c
new file mode 100644
index 0000000000..b307407486
--- /dev/null
+++ b/packet-sip.c
@@ -0,0 +1,224 @@
+/* packet-sip.c
+ * Routines for the Session Initiation Protocol (SIP) dissection.
+ * RFC 2543
+ * 
+ * TODO: Make sure that any of CRLF, CR or LF is treated as valid line terminator.
+ *       Pay attention to Content-Type: It might not always be SDP.
+ *       Add hf_* fields for filtering support.
+ *
+ * Copyright 2000, Heikki Vatiainen <hessu@cs.tut.fi>
+ *
+ * $Id: packet-sip.c,v 1.1 2000/11/04 07:50:47 guy Exp $
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@zing.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * Copied from packet-cops.c
+ * 
+ * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <glib.h>
+#include "packet.h"
+#include "packet-sdp.h"
+
+#define TCP_PORT_SIP 5060
+#define UDP_PORT_SIP 5060
+
+/* Initialize the protocol and registered fields */
+static gint proto_sip = -1;
+static gint hf_msg_hdr = -1;
+
+/* Initialize the subtree pointers */
+static gint ett_sip = -1;
+static gint ett_sip_hdr = -1;
+
+static const char *sip_methods[] = {
+        "<Invalid method>",      /* Pad so that the real methods start at index 1 */
+        "INVITE",
+        "ACK",
+        "OPTIONS",
+        "BYE",
+        "CANCEL",
+        "REGISTER"
+};
+
+static int sip_is_request(const char *line);
+static guint8 *sip_kill_version(guint8 *orig, guint8 *killed);
+static gint sip_get_msg_offset(tvbuff_t *tvb, guint32 offset);
+ 
+/* Code to actually dissect the packets */
+static void dissect_sip(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+        guint8 buf[1500], tmp[1500];
+        guint32 offset;
+        gint eol, msg_offset;
+        tvbuff_t *next_tvb;
+        const guint8 *next_pd;
+        int next_offset;
+
+	CHECK_DISPLAY_AS_DATA(proto_sip, tvb, pinfo, tree);
+
+        pinfo->current_proto = "SIP";
+        if (check_col(pinfo->fd, COL_PROTOCOL)) 
+                col_add_str(pinfo->fd, COL_PROTOCOL, "SIP");
+    
+        offset = 0;
+        eol = tvb_find_guint8(tvb, 0, tvb_length(tvb), '\r');
+        if (eol < 0) goto bad;
+        eol = tvb_get_nstringz0(tvb, 0, eol, buf);
+        if (eol < 0) goto bad;
+        eol += 2;
+        if (tvb_get_guint8(tvb, eol) == '\n') {
+                eol++;
+        }
+
+        if (check_col(pinfo->fd, COL_INFO))
+                col_add_fstr(pinfo->fd, COL_INFO, "%s: %s",
+                             sip_is_request(buf) ? "Request" : "Status",
+                             sip_kill_version(buf, tmp));
+
+        col_set_writable(pinfo->fd, FALSE);
+
+        if (tree) {
+                proto_item *ti, *th;
+                proto_tree *sip_tree, *hdr_tree;
+
+                ti = proto_tree_add_item(tree, proto_sip, tvb, 0, tvb_length(tvb), FALSE);
+                sip_tree = proto_item_add_subtree(ti, ett_sip);
+
+                proto_tree_add_text(sip_tree, tvb, offset, eol, "%s-Line: %s",
+                                    sip_is_request(buf) ? "Request" : "Status", buf);
+
+                offset = eol;
+                msg_offset = sip_get_msg_offset(tvb, offset);
+                if (msg_offset < 0) goto bad;
+                th = proto_tree_add_item(sip_tree, hf_msg_hdr, tvb, offset, msg_offset - offset, FALSE);
+                hdr_tree = proto_item_add_subtree(th, ett_sip_hdr);
+                
+                /* - 2 since we have a CRLF separating the message-body */
+                while (msg_offset - 2 > offset) {
+                        int err;
+                        eol = tvb_find_guint8(tvb, offset, tvb_length_remaining(tvb, offset), '\r');
+                        err = tvb_get_nstringz0(tvb, offset, eol - offset, buf);
+                        if (err < 0) goto bad;
+                        proto_tree_add_text(hdr_tree, tvb, offset, strlen(buf) + 2, "%s", buf);
+                        offset = eol + 2;
+                }
+                offset += 2;  /* Skip the CRLF mentioned above */
+       }
+
+        if (tvb_length_remaining(tvb, offset) > 0) {
+                next_tvb = tvb_new_subset(tvb, offset, -1, -1);
+                tvb_compat(next_tvb, &next_pd, &next_offset);
+                dissect_sdp(next_pd, next_offset, pinfo->fd, tree);
+        }
+
+        return;
+
+  bad:
+        next_tvb = tvb_new_subset(tvb, offset, -1, -1);
+        dissect_data(tvb, pinfo, tree);
+
+        return;
+}
+
+/* Returns the offset to the start of the optional message-body, or
+ * -1 for an error.
+ */
+static gint sip_get_msg_offset(tvbuff_t *tvb, guint32 offset)
+{
+        gint eol;
+
+        while ((eol = tvb_find_guint8(tvb, offset, tvb_length_remaining(tvb, offset), '\r')) > 0) {
+                        if (tvb_get_guint8(tvb, eol + 1) == '\n' && 
+                            tvb_get_guint8(tvb, eol + 2) == '\r' && 
+                            tvb_get_guint8(tvb, eol + 3) == '\n')
+                                return eol + 4;
+                        offset = eol + 2;
+        }
+
+        return -1;
+}
+                
+/* Remove the SIP-Version, 7 characters, from Request- or Status-Line.
+ * Returns the modifed Line
+ */
+static guint8 *sip_kill_version(guint8 *orig, guint8 *killed)
+{
+        if (sip_is_request(orig)) {
+                strncpy(killed, orig, strlen(orig) - strlen("SIP/2.0"));
+                killed[strlen(orig) - strlen("SIP/2.0")] = '\0';
+        } else
+                strcpy(killed, orig + strlen("SIP/2.0") + 1); /* + 1 to skip the space */
+        
+        return killed;
+}
+
+static int sip_is_request(const char *line)
+{
+        int i;
+
+        for (i = 1; i < array_length(sip_methods); i++) {
+                if (strncmp(line, sip_methods[i], strlen(sip_methods[i])) == 0)
+                        return i;
+        }
+
+        return 0;
+}
+
+/* Register the protocol with Ethereal */
+void proto_register_sip(void)
+{                 
+
+        /* Setup list of header fields */
+        static hf_register_info hf[] = {
+
+                { &hf_msg_hdr,
+                        { "Message Header",           "sip.msg_hdr",
+                        FT_NONE, 0, NULL, 0,
+                        "Message Header in SIP message" }
+                },
+        };
+
+        /* Setup protocol subtree array */
+        static gint *ett[] = {
+                &ett_sip,
+                &ett_sip_hdr,
+        };
+
+        /* Register the protocol name and description */
+        proto_sip = proto_register_protocol("Session Initiation Protocol", "sip");
+
+        /* Required function calls to register the header fields and subtrees used */
+        proto_register_field_array(proto_sip, hf, array_length(hf));
+        proto_register_subtree_array(ett, array_length(ett));
+};
+
+void
+proto_reg_handoff_sip(void)
+{
+        dissector_add("tcp.port", TCP_PORT_SIP, dissect_sip);
+        dissector_add("udp.port", UDP_PORT_SIP, dissect_sip);
+}