/* expert.c * Collecting Expert information. * * Implemented as a tap named "expert". * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later */ #include "config.h" #define WS_LOG_DOMAIN LOG_DOMAIN_EPAN #include #include #include "packet.h" #include "expert.h" #include "uat.h" #include "prefs.h" #include #include #include "tap.h" #include #include /* proto_expert cannot be static because it's referenced in the * print routines */ int proto_expert; static int proto_malformed; static int expert_tap; static int highest_severity; static int ett_expert; static int ett_subexpert; static int hf_expert_msg; static int hf_expert_group; static int hf_expert_severity; struct expert_module { const char *proto_name; int proto_id; /* Cache this for registering hfs */ }; /* List which stores protocols and expert_info that have been registered */ typedef struct _gpa_expertinfo_t { uint32_t len; uint32_t allocated_len; expert_field_info **ei; } gpa_expertinfo_t; static gpa_expertinfo_t gpa_expertinfo; /* Hash table of abbreviations and IDs */ static GHashTable *gpa_name_map; /* Deregistered expert infos */ static GPtrArray *deregistered_expertinfos; const value_string expert_group_vals[] = { { PI_CHECKSUM, "Checksum" }, { PI_SEQUENCE, "Sequence" }, { PI_RESPONSE_CODE, "Response" }, { PI_REQUEST_CODE, "Request" }, { PI_UNDECODED, "Undecoded" }, { PI_REASSEMBLE, "Reassemble" }, { PI_MALFORMED, "Malformed" }, { PI_DEBUG, "Debug" }, { PI_PROTOCOL, "Protocol" }, { PI_SECURITY, "Security" }, { PI_COMMENTS_GROUP, "Comment" }, { PI_DECRYPTION, "Decryption" }, { PI_ASSUMPTION, "Assumption" }, { PI_DEPRECATED, "Deprecated" }, { PI_RECEIVE, "Receive" }, { PI_INTERFACE, "Interface" }, { PI_DISSECTOR_BUG, "Dissector bug" }, { 0, NULL } }; const value_string expert_severity_vals[] = { { PI_ERROR, "Error" }, { PI_WARN, "Warning" }, { PI_NOTE, "Note" }, { PI_CHAT, "Chat" }, { PI_COMMENT, "Comment" }, { 0, NULL } }; /* Possible values for a checksum evaluation */ const value_string expert_checksum_vals[] = { { EXPERT_CHECKSUM_DISABLED, "Disabled" }, { EXPERT_CHECKSUM_UNKNOWN, "Unknown" }, { EXPERT_CHECKSUM_GOOD, "Good" }, { EXPERT_CHECKSUM_BAD, "Bad" }, { 0, NULL } }; static expert_field_info *expert_registrar_get_byname(const char *field_name); /*----------------------------------------------------------------------------*/ /* UAT for customizing severity levels. */ /*----------------------------------------------------------------------------*/ typedef struct { char *field; uint32_t severity; } expert_level_entry_t; static expert_level_entry_t *uat_expert_entries; static unsigned expert_level_entry_count; /* Array of field names currently in UAT */ static GArray *uat_saved_fields; UAT_CSTRING_CB_DEF(uat_expert_entries, field, expert_level_entry_t) UAT_VS_DEF(uat_expert_entries, severity, expert_level_entry_t, uint32_t, PI_ERROR, "Error") static bool uat_expert_update_cb(void *r, char **err) { expert_level_entry_t *rec = (expert_level_entry_t *)r; if (expert_registrar_get_byname(rec->field) == NULL) { *err = ws_strdup_printf("Expert Info field doesn't exist: %s", rec->field); return false; } return true; } static void *uat_expert_copy_cb(void *n, const void *o, size_t siz _U_) { expert_level_entry_t *new_record = (expert_level_entry_t*)n; const expert_level_entry_t *old_record = (const expert_level_entry_t *)o; new_record->field = g_strdup(old_record->field); new_record->severity = old_record->severity; return new_record; } static void uat_expert_free_cb(void*r) { expert_level_entry_t *rec = (expert_level_entry_t *)r; g_free(rec->field); } static void uat_expert_post_update_cb(void) { unsigned i; expert_field_info *field; /* Reset any of the previous list of expert info fields to their original severity */ for ( i = 0 ; i < uat_saved_fields->len; i++ ) { field = g_array_index(uat_saved_fields, expert_field_info*, i); if (field != NULL) { field->severity = field->orig_severity; } } g_array_set_size(uat_saved_fields, 0); for (i = 0; i < expert_level_entry_count; i++) { field = expert_registrar_get_byname(uat_expert_entries[i].field); if (field != NULL) { field->severity = uat_expert_entries[i].severity; g_array_append_val(uat_saved_fields, field); } } } #define EXPERT_REGISTRAR_GET_NTH(eiindex, expinfo) \ if((unsigned)eiindex >= gpa_expertinfo.len && wireshark_abort_on_dissector_bug) \ ws_error("Unregistered expert info! index=%d", eiindex); \ DISSECTOR_ASSERT_HINT((unsigned)eiindex < gpa_expertinfo.len, "Unregistered expert info!"); \ DISSECTOR_ASSERT_HINT(gpa_expertinfo.ei[eiindex] != NULL, "Unregistered expert info!"); \ expinfo = gpa_expertinfo.ei[eiindex]; void expert_packet_init(void) { module_t *module_expert; uat_t *expert_uat; static hf_register_info hf[] = { { &hf_expert_msg, { "Message", "_ws.expert.message", FT_STRING, BASE_NONE, NULL, 0, "Wireshark expert information", HFILL } }, { &hf_expert_group, { "Group", "_ws.expert.group", FT_UINT32, BASE_NONE, VALS(expert_group_vals), 0, "Wireshark expert group", HFILL } }, { &hf_expert_severity, { "Severity level", "_ws.expert.severity", FT_UINT32, BASE_NONE, VALS(expert_severity_vals), 0, "Wireshark expert severity level", HFILL } } }; static int *ett[] = { &ett_expert, &ett_subexpert }; /* UAT for overriding severity levels */ static uat_field_t custom_expert_fields[] = { UAT_FLD_CSTRING(uat_expert_entries, field, "Field name", "Expert Info filter name"), UAT_FLD_VS(uat_expert_entries, severity, "Severity", expert_severity_vals, "Custom severity level"), UAT_END_FIELDS }; if (expert_tap == 0) { expert_tap = register_tap("expert"); } if (proto_expert <= 0) { proto_expert = proto_register_protocol("Expert Info", "Expert", "_ws.expert"); proto_register_field_array(proto_expert, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); proto_set_cant_toggle(proto_expert); module_expert = prefs_register_protocol(proto_expert, NULL); //Since "expert" is really a pseudo protocol, it shouldn't be //categorized with other "real" protocols when it comes to //preferences. Since it's just a UAT, don't bury it in //with the other protocols module_expert->use_gui = false; expert_uat = uat_new("Expert Info Severity Level Configuration", sizeof(expert_level_entry_t), "expert_severity", true, (void **)&uat_expert_entries, &expert_level_entry_count, UAT_AFFECTS_DISSECTION, NULL, uat_expert_copy_cb, uat_expert_update_cb, uat_expert_free_cb, uat_expert_post_update_cb, NULL, custom_expert_fields); prefs_register_uat_preference(module_expert, "expert_severity_levels", "Severity Level Configuration", "A table that overrides Expert Info field severity levels to user configured levels", expert_uat); } highest_severity = 0; proto_malformed = proto_get_id_by_filter_name("_ws.malformed"); } void expert_init(void) { gpa_expertinfo.len = 0; gpa_expertinfo.allocated_len = 0; gpa_expertinfo.ei = NULL; gpa_name_map = g_hash_table_new_full(g_str_hash, g_str_equal, NULL, NULL); uat_saved_fields = g_array_new(false, false, sizeof(expert_field_info*)); deregistered_expertinfos = g_ptr_array_new(); } void expert_packet_cleanup(void) { } void expert_cleanup(void) { if (gpa_expertinfo.allocated_len) { gpa_expertinfo.len = 0; gpa_expertinfo.allocated_len = 0; g_free(gpa_expertinfo.ei); gpa_expertinfo.ei = NULL; } /* Free the abbrev/ID GTree */ if (gpa_name_map) { g_hash_table_destroy(gpa_name_map); gpa_name_map = NULL; } /* Free the UAT saved fields */ if (uat_saved_fields) { g_array_free(uat_saved_fields, true); uat_saved_fields = NULL; } if (deregistered_expertinfos) { g_ptr_array_free(deregistered_expertinfos, true); deregistered_expertinfos = NULL; } } int expert_get_highest_severity(void) { return highest_severity; } void expert_update_comment_count(uint64_t count) { if (count==0 && highest_severity==PI_COMMENT) highest_severity = 0; } expert_module_t *expert_register_protocol(int id) { expert_module_t *module; protocol_t *protocol; protocol = find_protocol_by_id(id); module = wmem_new(wmem_epan_scope(), expert_module_t); module->proto_id = id; module->proto_name = proto_get_protocol_short_name(protocol); return module; } void expert_deregister_expertinfo (const char *abbrev) { expert_field_info *expinfo = (expert_field_info*)g_hash_table_lookup(gpa_name_map, abbrev); if (expinfo) { g_ptr_array_add(deregistered_expertinfos, gpa_expertinfo.ei[expinfo->id]); g_hash_table_steal(gpa_name_map, abbrev); } } void expert_deregister_protocol (expert_module_t *module) { wmem_free(wmem_epan_scope(), module); } static void free_deregistered_expertinfo (void *data, void *user_data _U_) { expert_field_info *expinfo = (expert_field_info *) data; gpa_expertinfo.ei[expinfo->id] = NULL; /* Invalidate this id */ } void expert_free_deregistered_expertinfos (void) { g_ptr_array_foreach(deregistered_expertinfos, free_deregistered_expertinfo, NULL); g_ptr_array_free(deregistered_expertinfos, true); deregistered_expertinfos = g_ptr_array_new(); } static int expert_register_field_init(expert_field_info *expinfo, expert_module_t *module) { /* Check for valid group and severity vals */ switch (expinfo->group) { case PI_CHECKSUM: case PI_SEQUENCE: case PI_RESPONSE_CODE: case PI_REQUEST_CODE: case PI_UNDECODED: case PI_REASSEMBLE: case PI_MALFORMED: case PI_DEBUG: case PI_PROTOCOL: case PI_SECURITY: case PI_COMMENTS_GROUP: case PI_DECRYPTION: case PI_ASSUMPTION: case PI_DEPRECATED: case PI_RECEIVE: case PI_INTERFACE: case PI_DISSECTOR_BUG: break; default: REPORT_DISSECTOR_BUG("Expert info for %s has invalid group=0x%08x\n", expinfo->name, expinfo->group); } switch (expinfo->severity) { case PI_COMMENT: case PI_CHAT: case PI_NOTE: case PI_WARN: case PI_ERROR: break; default: REPORT_DISSECTOR_BUG("Expert info for %s has invalid severity=0x%08x\n", expinfo->name, expinfo->severity); } expinfo->protocol = module->proto_name; /* if we always add and never delete, then id == len - 1 is correct */ if (gpa_expertinfo.len >= gpa_expertinfo.allocated_len) { if (!gpa_expertinfo.ei) { gpa_expertinfo.allocated_len = PRE_ALLOC_EXPERT_FIELDS_MEM; gpa_expertinfo.ei = (expert_field_info **)g_malloc(sizeof(expert_field_info *)*PRE_ALLOC_EXPERT_FIELDS_MEM); } else { gpa_expertinfo.allocated_len += 1000; gpa_expertinfo.ei = (expert_field_info **)g_realloc(gpa_expertinfo.ei, sizeof(expert_field_info *)*gpa_expertinfo.allocated_len); } } gpa_expertinfo.ei[gpa_expertinfo.len] = expinfo; gpa_expertinfo.len++; expinfo->id = gpa_expertinfo.len - 1; /* Save the original severity so it can be restored by the UAT */ expinfo->orig_severity = expinfo->severity; /* save field name for lookup */ g_hash_table_insert(gpa_name_map, (void *) (expinfo->name), expinfo); return expinfo->id; } /* for use with static arrays only, since we don't allocate our own copies of the expert_field_info struct contained within the exp_register_info struct */ void expert_register_field_array(expert_module_t *module, ei_register_info *exp, const int num_records) { int i; ei_register_info *ptr = exp; for (i = 0; i < num_records; i++, ptr++) { /* * Make sure we haven't registered this yet. * Most fields have variables associated with them * that are initialized to -1; some have array elements, * or possibly uninitialized variables, so we also allow * 0 (which is unlikely to be the field ID we get back * from "expert_register_field_init()"). */ if (ptr->ids->ei != -1 && ptr->ids->ei != 0) { fprintf(stderr, "Duplicate field detected in call to expert_register_field_array: '%s' is already registered, name=%s\n", ptr->eiinfo.summary, ptr->eiinfo.name); return; } /* Register the field with the experts */ ptr->ids->ei = expert_register_field_init(&ptr->eiinfo, module); /* Register with the header field info, so it's display filterable */ ptr->eiinfo.hf_info.p_id = &ptr->ids->hf; ptr->eiinfo.hf_info.hfinfo.name = ptr->eiinfo.summary; ptr->eiinfo.hf_info.hfinfo.abbrev = ptr->eiinfo.name; proto_register_field_array(module->proto_id, &ptr->eiinfo.hf_info, 1); } } /* Finds a record in the expert array by name. * For the moment, this function is only used "internally" * but may find a reason to be exported */ static expert_field_info * expert_registrar_get_byname(const char *field_name) { expert_field_info *hfinfo; if (!field_name) return NULL; hfinfo = (expert_field_info*)g_hash_table_lookup(gpa_name_map, field_name); return hfinfo; } /** * Get summary text of an expert_info field. * This is intended for use in expert_add_info_format or proto_tree_add_expert_format * to get the "base" string to then append additional information */ const char* expert_get_summary(expert_field *eiindex) { expert_field_info *eiinfo; /* Look up the item */ EXPERT_REGISTRAR_GET_NTH(eiindex->ei, eiinfo); return eiinfo->summary; } /** clear flags according to the mask and set new flag values */ #define FI_REPLACE_FLAGS(fi, mask, flags_in) { \ (fi->flags = (fi)->flags & ~(mask)); \ (fi->flags = (fi)->flags | (flags_in)); \ } /* set's the PI_ flags to a protocol item * (and its parent items till the toplevel) */ static void // NOLINTNEXTLINE(misc-no-recursion) expert_set_item_flags(proto_item *pi, const int group, const unsigned severity) { if (pi != NULL && PITEM_FINFO(pi) != NULL && (severity >= FI_GET_FLAG(PITEM_FINFO(pi), PI_SEVERITY_MASK))) { FI_REPLACE_FLAGS(PITEM_FINFO(pi), PI_GROUP_MASK, group); FI_REPLACE_FLAGS(PITEM_FINFO(pi), PI_SEVERITY_MASK, severity); /* propagate till toplevel item */ pi = proto_item_get_parent(pi); // We recurse here, but we're limited by our tree depth checks in proto.c expert_set_item_flags(pi, group, severity); } } static proto_tree* expert_create_tree(proto_item *pi, int group, int severity, const char *msg) { proto_tree *tree; proto_item *ti; tree = proto_item_add_subtree(pi, ett_expert); ti = proto_tree_add_protocol_format(tree, proto_expert, NULL, 0, 0, "Expert Info (%s/%s): %s", val_to_str(severity, expert_severity_vals, "Unknown (%u)"), val_to_str(group, expert_group_vals, "Unknown (%u)"), msg); proto_item_set_generated(ti); if (group == PI_MALFORMED) { /* Add hidden malformed protocol filter */ proto_item *malformed_ti = proto_tree_add_item(tree, proto_malformed, NULL, 0, 0, ENC_NA); proto_item_set_hidden(malformed_ti); } return proto_item_add_subtree(ti, ett_subexpert); } static proto_tree* expert_set_info_vformat(packet_info *pinfo, proto_item *pi, int group, int severity, int hf_index, bool use_vaformat, const char *format, va_list ap) { char formatted[ITEM_LABEL_LENGTH]; int pos; int tap; expert_info_t *ei; proto_tree *tree; proto_item *ti; if (pinfo == NULL && pi && pi->tree_data) { pinfo = PTREE_DATA(pi)->pinfo; } /* if this packet isn't loaded because of a read filter, don't output anything */ if (pinfo == NULL || pinfo->num == 0) { return NULL; } if (severity > highest_severity) { highest_severity = severity; } /* XXX: can we get rid of these checks and make them programming errors instead now? */ if (pi != NULL && PITEM_FINFO(pi) != NULL) { expert_set_item_flags(pi, group, severity); } if ((pi == NULL) || (PITEM_FINFO(pi) == NULL) || ((unsigned)severity >= FI_GET_FLAG(PITEM_FINFO(pi), PI_SEVERITY_MASK))) { col_add_str(pinfo->cinfo, COL_EXPERT, val_to_str(severity, expert_severity_vals, "Unknown (%u)")); } if (use_vaformat) { pos = vsnprintf(formatted, ITEM_LABEL_LENGTH, format, ap); } else { pos = (int)g_strlcpy(formatted, format, ITEM_LABEL_LENGTH); } /* Both vsnprintf and g_strlcpy return the number of bytes attempted * to write. */ if (pos >= ITEM_LABEL_LENGTH) { /* Truncation occurred. It might have split a UTF-8 character. */ ws_utf8_truncate(formatted, ITEM_LABEL_LENGTH - 1); } tree = expert_create_tree(pi, group, severity, formatted); if (hf_index <= 0) { /* If no filterable expert info, just add the message */ ti = proto_tree_add_string(tree, hf_expert_msg, NULL, 0, 0, formatted); proto_item_set_generated(ti); } else { /* If filterable expert info, hide the "generic" form of the message, and generate the formatted filterable expert info */ ti = proto_tree_add_none_format(tree, hf_index, NULL, 0, 0, "%s", formatted); proto_item_set_generated(ti); ti = proto_tree_add_string(tree, hf_expert_msg, NULL, 0, 0, formatted); proto_item_set_hidden(ti); } ti = proto_tree_add_uint_format_value(tree, hf_expert_severity, NULL, 0, 0, severity, "%s", val_to_str_const(severity, expert_severity_vals, "Unknown")); proto_item_set_generated(ti); ti = proto_tree_add_uint_format_value(tree, hf_expert_group, NULL, 0, 0, group, "%s", val_to_str_const(group, expert_group_vals, "Unknown")); proto_item_set_generated(ti); tap = have_tap_listener(expert_tap); if (!tap) return tree; ei = wmem_new(pinfo->pool, expert_info_t); ei->packet_num = pinfo->num; ei->group = group; ei->severity = severity; ei->hf_index = hf_index; ei->protocol = pinfo->current_proto; ei->summary = wmem_strdup(pinfo->pool, formatted); /* if we have a proto_item (not a faked item), set expert attributes to it */ if (pi != NULL && PITEM_FINFO(pi) != NULL) { ei->pitem = pi; } /* XXX: remove this because we don't have an internal-only function now? */ else { ei->pitem = NULL; } tap_queue_packet(expert_tap, pinfo, ei); return tree; } /* Helper function for expert_add_info() to work around compiler's special needs on ARM */ static inline proto_tree* expert_add_info_internal(packet_info *pinfo, proto_item *pi, expert_field *expindex, ...) { /* the va_list is ignored */ va_list unused; expert_field_info *eiinfo; proto_tree *tree; /* Look up the item */ EXPERT_REGISTRAR_GET_NTH(expindex->ei, eiinfo); va_start(unused, expindex); tree = expert_set_info_vformat(pinfo, pi, eiinfo->group, eiinfo->severity, *eiinfo->hf_info.p_id, false, eiinfo->summary, unused); va_end(unused); return tree; } proto_item * expert_add_info(packet_info *pinfo, proto_item *pi, expert_field *expindex) { proto_tree *tree; tree = expert_add_info_internal(pinfo, pi, expindex); return (proto_item *)tree; } proto_item * expert_add_info_format(packet_info *pinfo, proto_item *pi, expert_field *expindex, const char *format, ...) { va_list ap; expert_field_info *eiinfo; proto_tree *tree; /* Look up the item */ EXPERT_REGISTRAR_GET_NTH(expindex->ei, eiinfo); va_start(ap, format); tree = expert_set_info_vformat(pinfo, pi, eiinfo->group, eiinfo->severity, *eiinfo->hf_info.p_id, true, format, ap); va_end(ap); return (proto_item *)tree; } /* Helper function for expert_add_expert() to work around compiler's special needs on ARM */ static inline proto_item * proto_tree_add_expert_internal(proto_tree *tree, packet_info *pinfo, expert_field *expindex, tvbuff_t *tvb, int start, int length, ...) { expert_field_info *eiinfo; proto_item *ti; int item_length, captured_length; va_list unused; /* Look up the item */ EXPERT_REGISTRAR_GET_NTH(expindex->ei, eiinfo); /* Make sure this doesn't throw an exception when adding the item */ item_length = length; captured_length = tvb_captured_length_remaining(tvb, start); if (captured_length < 0) item_length = 0; else if (captured_length < item_length) item_length = captured_length; ti = proto_tree_add_text_internal(tree, tvb, start, item_length, "%s", eiinfo->summary); va_start(unused, length); expert_set_info_vformat(pinfo, ti, eiinfo->group, eiinfo->severity, *eiinfo->hf_info.p_id, false, eiinfo->summary, unused); va_end(unused); /* But make sure it throws an exception *after* adding the item */ if (length != -1) { tvb_ensure_bytes_exist(tvb, start, length); } return ti; } proto_item * proto_tree_add_expert(proto_tree *tree, packet_info *pinfo, expert_field *expindex, tvbuff_t *tvb, int start, int length) { return proto_tree_add_expert_internal(tree, pinfo, expindex, tvb, start, length); } proto_item * proto_tree_add_expert_format(proto_tree *tree, packet_info *pinfo, expert_field *expindex, tvbuff_t *tvb, int start, int length, const char *format, ...) { va_list ap; expert_field_info *eiinfo; int item_length, captured_length; proto_item *ti; /* Look up the item */ EXPERT_REGISTRAR_GET_NTH(expindex->ei, eiinfo); /* Make sure this doesn't throw an exception when adding the item */ item_length = length; captured_length = tvb_captured_length_remaining(tvb, start); if (captured_length < 0) item_length = 0; else if (captured_length < item_length) item_length = captured_length; va_start(ap, format); ti = proto_tree_add_text_valist_internal(tree, tvb, start, item_length, format, ap); va_end(ap); va_start(ap, format); expert_set_info_vformat(pinfo, ti, eiinfo->group, eiinfo->severity, *eiinfo->hf_info.p_id, true, format, ap); va_end(ap); /* But make sure it throws an exception *after* adding the item */ if (length != -1) { tvb_ensure_bytes_exist(tvb, start, length); } return ti; } /* * Editor modelines - https://www.wireshark.org/tools/modelines.html * * Local variables: * c-basic-offset: 8 * tab-width: 8 * indent-tabs-mode: t * End: * * vi: set shiftwidth=8 tabstop=8 noexpandtab: * :indentSize=8:tabSize=8:noTabs=false: */