Adding upstream version 4.2.2.upstream/4.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 431 insertions, 0 deletions

diff --git a/epan/dissectors/packet-gsm_sms_ud.c b/epan/dissectors/packet-gsm_sms_ud.c
new file mode 100644
index 00000000..f1b25630
--- /dev/null
+++ b/epan/dissectors/packet-gsm_sms_ud.c
@@ -0,0 +1,431 @@
+/* packet-gsm_sms_ud.c
+ * Routines for GSM SMS TP-UD (GSM 03.40) dissection
+ *
+ * Refer to the AUTHORS file or the AUTHORS section in the man page
+ * for contacting the author(s) of this file.
+ *
+ * Separated from the SMPP dissector by Chris Wilson.
+ *
+ * UDH and WSP dissection of SMS message, Short Message reassembly,
+ * "Decode Short Message with Port Number UDH as CL-WSP" preference,
+ * "Always try subdissection of 1st fragment" preference,
+ * provided by Olivier Biot.
+ *
+ * Note on SMS Message reassembly
+ * ------------------------------
+ *   The current Short Message reassembly is possible thanks to the
+ *   message identifier (8 or 16 bit identifier). It is able to reassemble
+ *   short messages that are sent over either the same SMPP connection or
+ *   distinct SMPP connections. Normally the reassembly code is able to deal
+ *   with duplicate message identifiers since the fragment_add_seq_check()
+ *   call is used.
+ *
+ *   The SMS TP-UD preference "always try subdissection of 1st fragment" allows
+ *   a subdissector to be called for the first Short Message fragment,
+ *   even if reassembly is not possible. This way partial dissection
+ *   is still possible. This preference is switched off by default.
+ *
+ * Note on Short Message decoding as CL-WSP
+ * ----------------------------------------
+ *    The SMS TP-UD preference "port_number_udh_means_wsp" is switched off
+ *    by default. If it is enabled, then any Short Message with a Port Number
+ *    UDH will be decoded as CL-WSP if:
+ *    -  The Short Message is not segmented
+ *    -  The entire segmented Short Message is reassembled
+ *    -  It is the 1st segment of an unreassembled Short Message (if the
+ *       "always try subdissection of 1st fragment" preference is enabled)
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "config.h"
+
+#include <epan/packet.h>
+
+#include <epan/prefs.h>
+#include <epan/reassemble.h>
+#include "packet-gsm_sms.h"
+#include "packet-smpp.h"
+
+void proto_register_gsm_sms_ud(void);
+void proto_reg_handoff_gsm_sms_ud(void);
+
+static int proto_gsm_sms_ud = -1;
+
+/*
+ * Short Message fragment handling
+ */
+static int hf_gsm_sms_ud_fragments = -1;
+static int hf_gsm_sms_ud_fragment = -1;
+static int hf_gsm_sms_ud_fragment_overlap = -1;
+static int hf_gsm_sms_ud_fragment_overlap_conflicts = -1;
+static int hf_gsm_sms_ud_fragment_multiple_tails = -1;
+static int hf_gsm_sms_ud_fragment_too_long_fragment = -1;
+static int hf_gsm_sms_ud_fragment_error = -1;
+static int hf_gsm_sms_ud_fragment_count = -1;
+static int hf_gsm_sms_ud_reassembled_in = -1;
+static int hf_gsm_sms_ud_reassembled_length = -1;
+static int hf_gsm_sms_ud_short_msg = -1;
+
+static gint ett_gsm_sms = -1;
+static gint ett_gsm_sms_ud_fragment = -1;
+static gint ett_gsm_sms_ud_fragments = -1;
+
+/* Subdissector declarations */
+static dissector_table_t gsm_sms_dissector_table;
+
+/* Short Message reassembly */
+static reassembly_table sm_reassembly_table;
+
+static const fragment_items sm_frag_items = {
+    /* Fragment subtrees */
+    &ett_gsm_sms_ud_fragment,
+    &ett_gsm_sms_ud_fragments,
+    /* Fragment fields */
+    &hf_gsm_sms_ud_fragments,
+    &hf_gsm_sms_ud_fragment,
+    &hf_gsm_sms_ud_fragment_overlap,
+    &hf_gsm_sms_ud_fragment_overlap_conflicts,
+    &hf_gsm_sms_ud_fragment_multiple_tails,
+    &hf_gsm_sms_ud_fragment_too_long_fragment,
+    &hf_gsm_sms_ud_fragment_error,
+    &hf_gsm_sms_ud_fragment_count,
+    /* Reassembled in field */
+    &hf_gsm_sms_ud_reassembled_in,
+    /* Reassembled length field */
+    &hf_gsm_sms_ud_reassembled_length,
+    /* Reassembled data field */
+    NULL,
+    /* Tag */
+    "Short Message fragments"
+};
+
+/* Dissect all SM data as WSP if the UDH contains a Port Number IE */
+static gboolean port_number_udh_means_wsp = FALSE;
+
+/* Always try dissecting the 1st fragment of a SM,
+ * even if it is not reassembled */
+static gboolean try_dissect_1st_frag = FALSE;
+
+/* Prevent subdissectors changing column data */
+static gboolean prevent_subdissectors_changing_columns = FALSE;
+
+static dissector_handle_t wsp_handle;
+
+/* Parse Short Message. This function is only called from the SMPP
+ * dissector if the UDH present, or if the UDH fields were obtained
+ * elsewhere in SMPP TLVs.
+ * Call WSP dissector if port matches WSP traffic.
+ */
+static void
+parse_gsm_sms_ud_message(proto_tree *sm_tree, tvbuff_t *tvb, packet_info *pinfo, smpp_data_t *smpp_data)
+{
+    tvbuff_t      *sm_tvb                    = NULL;
+    proto_tree    *top_tree;
+    guint          sm_len                    = tvb_reported_length(tvb);
+    guint32        i                         = 0;
+    /* Multiple Messages UDH */
+    gboolean       is_fragmented             = FALSE;
+    fragment_head *fd_sm                     = NULL;
+    gboolean       save_fragmented           = FALSE;
+    gboolean       try_gsm_sms_ud_reassemble = FALSE;
+    /* SMS Message reassembly */
+    gboolean       reassembled               = FALSE;
+    guint32        reassembled_in            = 0;
+
+    gsm_sms_udh_fields_t *udh_fields = NULL;
+    if (smpp_data) {
+        udh_fields = smpp_data->udh_fields;
+    }
+
+    top_tree = proto_tree_get_parent_tree(sm_tree);
+
+    if (!udh_fields) {
+        udh_fields = wmem_new0(pinfo->pool, gsm_sms_udh_fields_t);
+    }
+
+    if (smpp_data && smpp_data->udhi) {
+        /* XXX: We don't handle different encodings in this dissector yet,
+         * so just treat everything as 8-bit binary encoding. */
+        guint8 fill_bits = 0;
+        guint8 udl = sm_len;
+        dis_field_udh(tvb, pinfo, sm_tree, &i, &sm_len, &udl, OTHER, &fill_bits, udh_fields);
+    }
+
+    if (tvb_reported_length_remaining(tvb, i) <= 0)
+        return; /* No more data */
+
+    if (udh_fields->frags > 1) {
+        is_fragmented = TRUE;
+    }
+
+    /*
+     * Try reassembling the packets.
+     * XXX - fragment numbers are 1-origin, but the fragment number
+     * field could be 0.
+     * Should we flag a fragmented message with a fragment number field
+     * of 0?
+     * What if the fragment count is 0?  Should we flag that as well?
+     */
+    if (is_fragmented && udh_fields->frag != 0 && udh_fields->frags != 0 &&
+        tvb_bytes_exist(tvb, i, sm_len)) {
+        try_gsm_sms_ud_reassemble = TRUE;
+        save_fragmented = pinfo->fragmented;
+        pinfo->fragmented = TRUE;
+        fd_sm = fragment_add_seq_check(&sm_reassembly_table,
+                tvb, i,
+                pinfo,
+                udh_fields->sm_id,    /* guint32 ID for fragments belonging together */
+                NULL,
+                udh_fields->frag-1,   /* guint32 fragment sequence number */
+                sm_len,               /* guint32 fragment length */
+                (udh_fields->frag != udh_fields->frags));     /* More fragments? */
+        if (fd_sm) {
+            reassembled    = TRUE;
+            reassembled_in = fd_sm->reassembled_in;
+        }
+        sm_tvb = process_reassembled_data(tvb, i, pinfo,
+            "Reassembled Short Message", fd_sm, &sm_frag_items,
+            NULL, sm_tree);
+        if (reassembled) { /* Reassembled */
+            col_append_str(pinfo->cinfo, COL_INFO,
+                        " (Short Message Reassembled)");
+        } else {
+            /* Not last packet of reassembled Short Message */
+            col_append_fstr(pinfo->cinfo, COL_INFO,
+                    " (Short Message fragment %u of %u)", udh_fields->frag, udh_fields->frags);
+        }
+    } /* Else: not fragmented */
+
+    if (! sm_tvb) /* One single Short Message, or not reassembled */
+        sm_tvb = tvb_new_subset_remaining(tvb, i);
+    /* Try calling a subdissector */
+    if (sm_tvb) {
+        if ((reassembled && pinfo->num == reassembled_in)
+            || udh_fields->frag==0 || (udh_fields->frag==1 && try_dissect_1st_frag)) {
+            /* Try calling a subdissector only if:
+             *  - the Short Message is reassembled in this very packet,
+             *  - the Short Message consists of only one "fragment",
+             *  - the preference "Always Try Dissection for 1st SM fragment"
+             *    is switched on, and this is the SM's 1st fragment. */
+            if (udh_fields->port_src || udh_fields->port_dst) {
+                gboolean disallow_write = FALSE; /* TRUE if we changed writability
+                                    of the columns of the summary */
+                if (prevent_subdissectors_changing_columns && col_get_writable(pinfo->cinfo, -1)) {
+                    disallow_write = TRUE;
+                    col_set_writable(pinfo->cinfo, -1, FALSE);
+                }
+
+                if (port_number_udh_means_wsp) {
+                    call_dissector(wsp_handle, sm_tvb, pinfo, top_tree);
+                } else {
+                    if (! dissector_try_uint(gsm_sms_dissector_table, udh_fields->port_src,
+                                sm_tvb, pinfo, top_tree)) {
+                        if (! dissector_try_uint(gsm_sms_dissector_table, udh_fields->port_dst,
+                                    sm_tvb, pinfo, top_tree)) {
+                            if (sm_tree) { /* Only display if needed */
+                                proto_tree_add_item(sm_tree, hf_gsm_sms_ud_short_msg, sm_tvb, 0, -1, ENC_NA);
+                            }
+                        }
+                    }
+                }
+
+                if (disallow_write)
+                    col_set_writable(pinfo->cinfo, -1, TRUE);
+            } else { /* No ports IE */
+                proto_tree_add_item(sm_tree, hf_gsm_sms_ud_short_msg, sm_tvb, 0, -1, ENC_NA);
+            }
+        } else {
+            /* The packet is not reassembled,
+             * or it is reassembled in another packet */
+            proto_tree_add_bytes_format(sm_tree, hf_gsm_sms_ud_short_msg, sm_tvb, 0, -1,
+                    NULL, "Unreassembled Short Message fragment %u of %u",
+                    udh_fields->frag, udh_fields->frags);
+        }
+    }
+
+    if (try_gsm_sms_ud_reassemble) /* Clean up defragmentation */
+        pinfo->fragmented = save_fragmented;
+    return;
+}
+
+static int
+dissect_gsm_sms_ud(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data)
+{
+    proto_item *ti;
+    proto_tree *subtree;
+    smpp_data_t *smpp_data = NULL;
+
+    if (data) {
+        smpp_data = (smpp_data_t*)data;
+    }
+
+    ti      = proto_tree_add_item(tree, proto_gsm_sms_ud, tvb, 0, -1, ENC_NA);
+    subtree = proto_item_add_subtree(ti, ett_gsm_sms);
+    parse_gsm_sms_ud_message(subtree, tvb, pinfo, smpp_data);
+    return tvb_captured_length(tvb);
+}
+
+/* Register the protocol with Wireshark */
+void
+proto_register_gsm_sms_ud(void)
+{
+    module_t *gsm_sms_ud_module; /* Preferences for GSM SMS UD */
+
+    /* Setup list of header fields  */
+    static hf_register_info hf[] = {
+        /*
+         * Short Message fragment reassembly
+         */
+        {   &hf_gsm_sms_ud_fragments,
+            {   "Short Message fragments", "gsm_sms_ud.fragments",
+                FT_NONE, BASE_NONE, NULL, 0x00,
+                "GSM Short Message fragments",
+                HFILL
+            }
+        },
+        {   &hf_gsm_sms_ud_fragment,
+            {   "Short Message fragment", "gsm_sms_ud.fragment",
+                FT_FRAMENUM, BASE_NONE, NULL, 0x00,
+                "GSM Short Message fragment",
+                HFILL
+            }
+        },
+        {   &hf_gsm_sms_ud_fragment_overlap,
+            {   "Short Message fragment overlap", "gsm_sms_ud.fragment.overlap",
+                FT_BOOLEAN, BASE_NONE, NULL, 0x0,
+                "GSM Short Message fragment overlaps with other fragment(s)",
+                HFILL
+            }
+        },
+        {   &hf_gsm_sms_ud_fragment_overlap_conflicts,
+            {   "Short Message fragment overlapping with conflicting data",
+                "gsm_sms_ud.fragment.overlap.conflicts",
+                FT_BOOLEAN, BASE_NONE, NULL, 0x0,
+                "GSM Short Message fragment overlaps with conflicting data",
+                HFILL
+            }
+        },
+        {   &hf_gsm_sms_ud_fragment_multiple_tails,
+            {   "Short Message has multiple tail fragments",
+                "gsm_sms_ud.fragment.multiple_tails",
+                FT_BOOLEAN, BASE_NONE, NULL, 0x0,
+                "GSM Short Message fragment has multiple tail fragments",
+                HFILL
+            }
+        },
+        {   &hf_gsm_sms_ud_fragment_too_long_fragment,
+            {   "Short Message fragment too long",
+                "gsm_sms_ud.fragment.too_long_fragment",
+                FT_BOOLEAN, BASE_NONE, NULL, 0x0,
+                "GSM Short Message fragment data goes beyond the packet end",
+                HFILL
+            }
+        },
+        {   &hf_gsm_sms_ud_fragment_error,
+            {   "Short Message defragmentation error", "gsm_sms_ud.fragment.error",
+                FT_FRAMENUM, BASE_NONE, NULL, 0x00,
+                "GSM Short Message defragmentation error due to illegal fragments",
+                HFILL
+            }
+        },
+        {   &hf_gsm_sms_ud_fragment_count,
+            {   "Short Message fragment count", "gsm_sms_ud.fragment.count",
+                FT_UINT32, BASE_DEC, NULL, 0x00,
+                NULL,
+                HFILL
+            }
+        },
+        {   &hf_gsm_sms_ud_reassembled_in,
+            {   "Reassembled in",
+                "gsm_sms_ud.reassembled.in",
+                FT_FRAMENUM, BASE_NONE, NULL, 0x00,
+                "GSM Short Message has been reassembled in this packet.",
+                HFILL
+            }
+        },
+        {   &hf_gsm_sms_ud_reassembled_length,
+            {   "Reassembled Short Message length",
+                "gsm_sms_ud.reassembled.length",
+                FT_UINT32, BASE_DEC, NULL, 0x00,
+                "The total length of the reassembled payload",
+                HFILL
+            }
+        },
+        {   &hf_gsm_sms_ud_short_msg,
+            {   "Short Message body",
+                "gsm_sms_ud.short_msg",
+                FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL
+            }
+        },
+    };
+
+    static gint *ett[] = {
+    &ett_gsm_sms,
+    &ett_gsm_sms_ud_fragment,
+    &ett_gsm_sms_ud_fragments,
+    };
+    /* Register the protocol name and description */
+    proto_gsm_sms_ud = proto_register_protocol("GSM Short Message Service User Data", "GSM SMS UD", "gsm_sms_ud");
+
+    /* Required function calls to register header fields and subtrees used */
+    proto_register_field_array(proto_gsm_sms_ud, hf, array_length(hf));
+    proto_register_subtree_array(ett, array_length(ett));
+
+    /* Subdissector code */
+    gsm_sms_dissector_table = register_dissector_table("gsm_sms_ud.udh.port",
+        "GSM SMS port IE in UDH", proto_gsm_sms_ud, FT_UINT16, BASE_DEC);
+
+    /* Preferences for GSM SMS UD */
+    gsm_sms_ud_module = prefs_register_protocol(proto_gsm_sms_ud, NULL);
+    /* For reading older preference files with "smpp-gsm-sms." preferences */
+    prefs_register_module_alias("smpp-gsm-sms", gsm_sms_ud_module);
+    prefs_register_bool_preference(gsm_sms_ud_module,
+        "port_number_udh_means_wsp",
+        "Port Number IE in UDH always triggers CL-WSP dissection",
+        "Always decode a GSM Short Message as Connectionless WSP "
+        "if a Port Number Information Element is present "
+        "in the SMS User Data Header.",
+        &port_number_udh_means_wsp);
+    prefs_register_bool_preference(gsm_sms_ud_module, "try_dissect_1st_fragment",
+        "Always try subdissection of 1st Short Message fragment",
+        "Always try subdissection of the 1st fragment of a fragmented "
+        "GSM Short Message. If reassembly is possible, the Short Message "
+        "may be dissected twice (once as a short frame, once in its "
+        "entirety).",
+        &try_dissect_1st_frag);
+    prefs_register_bool_preference(gsm_sms_ud_module, "prevent_dissectors_chg_cols",
+            "Prevent sub-dissectors from changing column data",
+        "Prevent sub-dissectors from replacing column data with their "
+        "own. Eg. Prevent WSP dissector overwriting SMPP information.",
+        &prevent_subdissectors_changing_columns);
+
+    register_dissector("gsm_sms_ud", dissect_gsm_sms_ud, proto_gsm_sms_ud);
+
+    reassembly_table_register(&sm_reassembly_table,
+                          &addresses_reassembly_table_functions);
+}
+
+void
+proto_reg_handoff_gsm_sms_ud(void)
+{
+    wsp_handle = find_dissector_add_dependency("wsp-cl", proto_gsm_sms_ud);
+    DISSECTOR_ASSERT(wsp_handle);
+}
+
+/*
+ * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 4
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * vi: set shiftwidth=4 tabstop=8 expandtab:
+ * :indentSize=4:tabSize=8:noTabs=true:
+ */