Adding upstream version 4.2.2.upstream/4.2.2

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

1 files changed, 550 insertions, 0 deletions

diff --git a/epan/decode_as.c b/epan/decode_as.c
new file mode 100644
index 0000000..72afd0c
--- /dev/null
+++ b/epan/decode_as.c
@@ -0,0 +1,550 @@
+/* decode_as.c
+ * Routines for dissector Decode As handlers
+ *
+ * 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 <glib.h>
+
+#include "decode_as.h"
+#include "packet.h"
+#include "prefs.h"
+#include "prefs-int.h"
+#include "wsutil/file_util.h"
+#include "wsutil/filesystem.h"
+#include "epan/dissectors/packet-dcerpc.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <wsutil/ws_assert.h>
+
+GList *decode_as_list = NULL;
+
+void register_decode_as(decode_as_t* reg)
+{
+    dissector_table_t decode_table;
+
+    /* Ensure valid functions */
+    ws_assert(reg->populate_list);
+    ws_assert(reg->reset_value);
+    ws_assert(reg->change_value);
+
+    decode_table = find_dissector_table(reg->table_name);
+    if (decode_table != NULL)
+    {
+        dissector_table_allow_decode_as(decode_table);
+    }
+
+    decode_as_list = g_list_prepend(decode_as_list, reg);
+}
+
+static void next_proto_prompt(packet_info *pinfo _U_, gchar *result)
+{
+    snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "Next level protocol as");
+}
+
+static gpointer next_proto_value(packet_info *pinfo _U_)
+{
+    return 0;
+}
+
+static build_valid_func next_proto_values[] = { next_proto_value };
+static decode_as_value_t next_proto_da_values =
+                        { next_proto_prompt, 1, next_proto_values };
+
+dissector_table_t register_decode_as_next_proto(int proto, const gchar *table_name, const gchar *ui_name, build_label_func label_func)
+{
+    decode_as_t *da;
+
+    dissector_table_t dt = register_dissector_table(table_name, ui_name, proto, FT_NONE, BASE_NONE);
+
+    da = wmem_new0(wmem_epan_scope(), decode_as_t);
+    da->name = wmem_strdup(wmem_epan_scope(), proto_get_protocol_filter_name(proto));
+    da->table_name = wmem_strdup(wmem_epan_scope(), table_name);
+    da->num_items = 1;
+    if (label_func == NULL)
+    {
+        da->values = &next_proto_da_values;
+    }
+    else
+    {
+        da->values = wmem_new(wmem_epan_scope(), decode_as_value_t);
+        da->values->label_func = label_func;
+        da->values->num_values = 1;
+        da->values->build_values = next_proto_values;
+    }
+    da->populate_list = decode_as_default_populate_list;
+    da->reset_value = decode_as_default_reset;
+    da->change_value = decode_as_default_change;
+
+    register_decode_as(da);
+    return dt;
+}
+
+struct decode_as_default_populate
+{
+    decode_as_add_to_list_func add_to_list;
+    gpointer ui_element;
+};
+
+static void
+decode_proto_add_to_list (const gchar *table_name, gpointer value, gpointer user_data)
+{
+    struct decode_as_default_populate* populate = (struct decode_as_default_populate*)user_data;
+    const gchar     *dissector_description;
+    gint       i;
+    dissector_handle_t handle;
+
+
+    handle = (dissector_handle_t)value;
+    dissector_description = dissector_handle_get_description(handle);
+
+    i = dissector_handle_get_protocol_index(handle);
+    if (i >= 0 && !proto_is_protocol_enabled(find_protocol_by_id(i)))
+        return;
+
+    populate->add_to_list(table_name, dissector_description, value, populate->ui_element);
+}
+
+void decode_as_default_populate_list(const gchar *table_name, decode_as_add_to_list_func add_to_list, gpointer ui_element)
+{
+    struct decode_as_default_populate populate;
+
+    populate.add_to_list = add_to_list;
+    populate.ui_element = ui_element;
+
+    dissector_table_foreach_handle(table_name, decode_proto_add_to_list, &populate);
+}
+
+gboolean decode_as_default_reset(const gchar *name, gconstpointer pattern)
+{
+    switch (get_dissector_table_selector_type(name)) {
+    case FT_UINT8:
+    case FT_UINT16:
+    case FT_UINT24:
+    case FT_UINT32:
+        dissector_reset_uint(name, GPOINTER_TO_UINT(pattern));
+        return TRUE;
+    case FT_NONE:
+        dissector_reset_payload(name);
+        return TRUE;
+    case FT_STRING:
+    case FT_STRINGZ:
+    case FT_UINT_STRING:
+    case FT_STRINGZPAD:
+    case FT_STRINGZTRUNC:
+        dissector_reset_string(name, (!pattern)?"":(const gchar *) pattern);
+        return TRUE;
+    default:
+        return FALSE;
+    };
+
+    return TRUE;
+}
+
+gboolean decode_as_default_change(const gchar *name, gconstpointer pattern, gconstpointer handle, const gchar *list_name _U_)
+{
+    const dissector_handle_t dissector = (const dissector_handle_t)handle;
+    switch (get_dissector_table_selector_type(name)) {
+    case FT_UINT8:
+    case FT_UINT16:
+    case FT_UINT24:
+    case FT_UINT32:
+        dissector_change_uint(name, GPOINTER_TO_UINT(pattern), dissector);
+        return TRUE;
+    case FT_NONE:
+        dissector_change_payload(name, dissector);
+        return TRUE;
+    case FT_STRING:
+    case FT_STRINGZ:
+    case FT_UINT_STRING:
+    case FT_STRINGZPAD:
+    case FT_STRINGZTRUNC:
+        dissector_change_string(name, (!pattern)?"":(const gchar *) pattern, dissector);
+        return TRUE;
+    default:
+        return FALSE;
+    };
+
+    return TRUE;
+}
+
+/* Some useful utilities for Decode As */
+
+/*
+ * A list of dissectors that need to be reset.
+ */
+static GSList *dissector_reset_list = NULL;
+
+/*
+ * A callback function to parse each "decode as" entry in the file and apply the change
+ */
+static prefs_set_pref_e
+read_set_decode_as_entries(gchar *key, const gchar *value,
+                           void *user_data,
+                           gboolean return_range_errors _U_)
+{
+    gchar *values[4] = {NULL, NULL, NULL, NULL};
+    gchar delimiter[4] = {',', ',', ',','\0'};
+    gchar *pch;
+    guint i, j;
+    GHashTable* processed_entries = (GHashTable*)user_data;
+    dissector_table_t sub_dissectors;
+    prefs_set_pref_e retval = PREFS_SET_OK;
+    gboolean is_valid = FALSE;
+
+    if (strcmp(key, DECODE_AS_ENTRY) == 0) {
+        /* Parse csv into table, selector, initial, current */
+        for (i = 0; i < 4; i++) {
+            pch = strchr(value, delimiter[i]);
+            if (pch == NULL) {
+                for (j = 0; j < i; j++) {
+                    g_free(values[j]);
+                }
+                return PREFS_SET_SYNTAX_ERR;
+            }
+            values[i] = g_strndup(value, pch - value);
+            value = pch + 1;
+        }
+        sub_dissectors = find_dissector_table(values[0]);
+        if (sub_dissectors != NULL) {
+            dissector_handle_t handle;
+            ftenum_t selector_type;
+            pref_t* pref_value;
+            module_t *module;
+            const char* proto_name;
+
+            selector_type = dissector_table_get_type(sub_dissectors);
+
+            handle = dissector_table_get_dissector_handle(sub_dissectors, values[3]);
+            if (handle != NULL || g_ascii_strcasecmp(values[3], DECODE_AS_NONE) == 0) {
+                is_valid = TRUE;
+            }
+
+            if (is_valid) {
+                if (FT_IS_STRING(selector_type)) {
+                    dissector_change_string(values[0], values[1], handle);
+                } else {
+                    char *p;
+                    long long_value;
+
+                    long_value = strtol(values[1], &p, 0);
+                    if (p == values[0] || *p != '\0' || long_value < 0 ||
+                          (unsigned long)long_value > UINT_MAX) {
+                        retval = PREFS_SET_SYNTAX_ERR;
+                        is_valid = FALSE;
+                    } else {
+                        dissector_change_uint(values[0], (guint)long_value, handle);
+                    }
+
+                    /* Now apply the value data back to dissector table preference */
+                    if (handle != NULL) {
+                        proto_name = proto_get_protocol_filter_name(dissector_handle_get_protocol_index(handle));
+                        module = prefs_find_module(proto_name);
+                        pref_value = prefs_find_preference(module, values[0]);
+                        if (pref_value != NULL) {
+                            gboolean replace = FALSE;
+                            if (g_hash_table_lookup(processed_entries, proto_name) == NULL) {
+                                /* First decode as entry for this protocol, ranges may be replaced */
+                                replace = TRUE;
+
+                                /* Remember we've processed this protocol */
+                                g_hash_table_insert(processed_entries, (gpointer)proto_name, (gpointer)proto_name);
+                            }
+
+                            prefs_add_decode_as_value(pref_value, (guint)long_value, replace);
+                            module->prefs_changed_flags |= prefs_get_effect_flags(pref_value);
+                        }
+                    }
+                }
+            }
+            if (is_valid) {
+                decode_build_reset_list(values[0], selector_type, values[1], NULL, NULL);
+            }
+        } else {
+            retval = PREFS_SET_SYNTAX_ERR;
+        }
+
+    } else {
+        retval = PREFS_SET_NO_SUCH_PREF;
+    }
+
+    for (i = 0; i < 4; i++) {
+        g_free(values[i]);
+    }
+    return retval;
+}
+
+void
+load_decode_as_entries(void)
+{
+    char   *daf_path;
+    FILE   *daf;
+
+    decode_clear_all();
+
+    daf_path = get_persconffile_path(DECODE_AS_ENTRIES_FILE_NAME, TRUE);
+    if ((daf = ws_fopen(daf_path, "r")) != NULL) {
+        /* Store saved entries for better range processing */
+        GHashTable* processed_entries = g_hash_table_new(g_str_hash, g_str_equal);
+        read_prefs_file(daf_path, daf, read_set_decode_as_entries, processed_entries);
+        g_hash_table_destroy(processed_entries);
+        fclose(daf);
+    }
+    g_free(daf_path);
+}
+
+
+/* Make a sorted list of the enties as we are fetching them from a hash table. Then write it out from the sorted list */
+static void
+decode_as_write_entry (const gchar *table_name, ftenum_t selector_type,
+                       gpointer key, gpointer value, gpointer user_data)
+{
+    GList **decode_as_rows_list = (GList **)user_data;
+    dissector_handle_t current, initial;
+    const gchar *current_dissector_name, *initial_dissector_name, *decode_as_row;
+
+    current = dtbl_entry_get_handle((dtbl_entry_t *)value);
+    if (current == NULL)
+        current_dissector_name = DECODE_AS_NONE;
+    else
+        current_dissector_name = dissector_handle_get_description(current);
+    initial = dtbl_entry_get_initial_handle((dtbl_entry_t *)value);
+    if (initial == NULL)
+        initial_dissector_name = DECODE_AS_NONE;
+    else
+        initial_dissector_name = dissector_handle_get_description(initial);
+
+    switch (selector_type) {
+
+    case FT_UINT8:
+    case FT_UINT16:
+    case FT_UINT24:
+    case FT_UINT32:
+        /*
+         * XXX - write these in decimal, regardless of the base of
+         * the dissector table's selector, as older versions of
+         * Wireshark used atoi() when reading this file, and
+         * failed to handle hex or octal numbers.
+         *
+         * That will be fixed in future 1.10 and 1.12 releases,
+         * but pre-1.10 releases are at end-of-life and won't
+         * be fixed.
+         */
+        decode_as_row = ws_strdup_printf(
+            DECODE_AS_ENTRY ": %s,%u,%s,%s\n",
+            table_name, GPOINTER_TO_UINT(key), initial_dissector_name,
+            current_dissector_name);
+        break;
+    case FT_NONE:
+        /*
+         * XXX - Just put a placeholder for the key value.  Currently
+         * FT_NONE dissector table uses a single uint value for
+         * a placeholder
+         */
+        decode_as_row = ws_strdup_printf(
+            DECODE_AS_ENTRY ": %s,0,%s,%s\n",
+            table_name, initial_dissector_name,
+            current_dissector_name);
+        break;
+
+    case FT_STRING:
+    case FT_STRINGZ:
+    case FT_UINT_STRING:
+    case FT_STRINGZPAD:
+    case FT_STRINGZTRUNC:
+        decode_as_row = ws_strdup_printf(
+            DECODE_AS_ENTRY ": %s,%s,%s,%s\n",
+            table_name, (gchar *)key, initial_dissector_name,
+            current_dissector_name);
+        break;
+
+    default:
+        ws_assert_not_reached();
+        break;
+    }
+
+    /* Do we need a better sort function ???*/
+    *decode_as_rows_list = g_list_insert_sorted (*decode_as_rows_list, (gpointer)decode_as_row,
+        (GCompareFunc)g_ascii_strcasecmp);
+
+}
+
+/* Print the sorted rows to File */
+static void
+decode_as_print_rows(gpointer data, gpointer user_data)
+{
+    FILE *da_file = (FILE *)user_data;
+    const gchar *decode_as_row = (const gchar *)data;
+
+    fprintf(da_file, "%s",decode_as_row);
+
+}
+int
+save_decode_as_entries(gchar** err)
+{
+    char *pf_dir_path;
+    char *daf_path;
+    FILE *da_file;
+    GList *decode_as_rows_list = NULL;
+
+    if (create_persconffile_dir(&pf_dir_path) == -1) {
+        *err = ws_strdup_printf("Can't create directory\n\"%s\"\nfor recent file: %s.",
+                                pf_dir_path, g_strerror(errno));
+        g_free(pf_dir_path);
+        return -1;
+    }
+
+    daf_path = get_persconffile_path(DECODE_AS_ENTRIES_FILE_NAME, TRUE);
+    if ((da_file = ws_fopen(daf_path, "w")) == NULL) {
+        *err = ws_strdup_printf("Can't open decode_as_entries file\n\"%s\": %s.",
+                                daf_path, g_strerror(errno));
+        g_free(daf_path);
+        return -1;
+    }
+
+    fprintf(da_file, "# \"Decode As\" entries file for %s " VERSION ".\n"
+        "#\n"
+        "# This file is regenerated each time \"Decode As\" preferences\n"
+        "# are saved within %s. Making manual changes should be safe,\n"
+        "# however.\n",
+        get_configuration_namespace(), get_configuration_namespace());
+
+    dissector_all_tables_foreach_changed(decode_as_write_entry, &decode_as_rows_list);
+
+    g_list_foreach(decode_as_rows_list, decode_as_print_rows, da_file);
+
+    fclose(da_file);
+    g_free(daf_path);
+    g_list_free_full(decode_as_rows_list, g_free);
+
+    return 0;
+}
+
+/*
+ * Data structure for tracking which dissector need to be reset.  This
+ * structure is necessary as a hash table entry cannot be removed
+ * while a g_hash_table_foreach walk is in progress.
+ */
+typedef struct dissector_delete_item {
+    /* The name of the dissector table */
+    gchar *ddi_table_name;
+    /* The type of the selector in that dissector table */
+    ftenum_t ddi_selector_type;
+    /* The selector in the dissector table */
+    union {
+        guint   sel_uint;
+        char    *sel_string;
+    } ddi_selector;
+} dissector_delete_item_t;
+
+void
+decode_build_reset_list (const gchar *table_name, ftenum_t selector_type,
+                         gpointer key, gpointer value _U_,
+                         gpointer user_data _U_)
+{
+    dissector_delete_item_t *item;
+
+    item = g_new(dissector_delete_item_t,1);
+    item->ddi_table_name = g_strdup(table_name);
+    item->ddi_selector_type = selector_type;
+    switch (selector_type) {
+
+    case FT_UINT8:
+    case FT_UINT16:
+    case FT_UINT24:
+    case FT_UINT32:
+        item->ddi_selector.sel_uint = GPOINTER_TO_UINT(key);
+        break;
+
+    case FT_NONE:
+        /* Not really needed, but prevents the assert */
+        item->ddi_selector.sel_uint = 0;
+        break;
+
+    case FT_STRING:
+    case FT_STRINGZ:
+    case FT_UINT_STRING:
+    case FT_STRINGZPAD:
+    case FT_STRINGZTRUNC:
+        item->ddi_selector.sel_string = g_strdup((char *)key);
+        break;
+
+    default:
+        ws_assert_not_reached();
+    }
+    dissector_reset_list = g_slist_prepend(dissector_reset_list, item);
+}
+
+/* clear all settings */
+void
+decode_clear_all(void)
+{
+    dissector_delete_item_t *item;
+    GSList *tmp;
+
+    dissector_all_tables_foreach_changed(decode_build_reset_list, NULL);
+
+    for (tmp = dissector_reset_list; tmp; tmp = g_slist_next(tmp)) {
+        item = (dissector_delete_item_t *)tmp->data;
+        switch (item->ddi_selector_type) {
+
+        case FT_UINT8:
+        case FT_UINT16:
+        case FT_UINT24:
+        case FT_UINT32:
+            dissector_reset_uint(item->ddi_table_name,
+                                 item->ddi_selector.sel_uint);
+            break;
+
+        case FT_NONE:
+            dissector_reset_payload(item->ddi_table_name);
+            break;
+
+        case FT_STRING:
+        case FT_STRINGZ:
+        case FT_UINT_STRING:
+        case FT_STRINGZPAD:
+        case FT_STRINGZTRUNC:
+            dissector_reset_string(item->ddi_table_name,
+                                   item->ddi_selector.sel_string);
+            g_free(item->ddi_selector.sel_string);
+            break;
+
+        default:
+            ws_assert_not_reached();
+        }
+        g_free(item->ddi_table_name);
+        g_free(item);
+    }
+    g_slist_free(dissector_reset_list);
+    dissector_reset_list = NULL;
+
+    decode_dcerpc_reset_all();
+}
+
+void
+decode_cleanup(void)
+{
+    g_list_free(decode_as_list);
+    decode_as_list = NULL;
+}
+
+/*
+ * Editor modelines
+ *
+ * Local Variables:
+ * c-basic-offset: 4
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * ex: set shiftwidth=4 tabstop=8 expandtab:
+ * :indentSize=4:tabSize=8:noTabs=true:
+ */