diff options
Diffstat (limited to 'ui/decode_as_utils.c')
| -rw-r--r-- | ui/decode_as_utils.c | 410 |
1 files changed, 410 insertions, 0 deletions
diff --git a/ui/decode_as_utils.c b/ui/decode_as_utils.c index ce66fd2ecf..aec14d5f8d 100644 --- a/ui/decode_as_utils.c +++ b/ui/decode_as_utils.c @@ -37,6 +37,7 @@ #include "wsutil/file_util.h" #include "wsutil/filesystem.h" +#include "wsutil/cmdarg_err.h" #include "ws_version_info.h" /* XXX - We might want to switch this to a UAT */ @@ -345,6 +346,415 @@ save_decode_as_entries(gchar** err) return 0; } +static const char* prev_display_dissector_name = NULL; + +/* +* For a dissector table, print on the stream described by output, +* its short name (which is what's used in the "-d" option) and its +* descriptive name. +*/ +static void +display_dissector_table_names(const char *table_name, const char *ui_name, +gpointer output) +{ + if ((prev_display_dissector_name == NULL) || + (strcmp(prev_display_dissector_name, table_name) != 0)) { + fprintf((FILE *)output, "\t%s (%s)\n", table_name, ui_name); + prev_display_dissector_name = table_name; + } +} + +/* +* For a dissector handle, print on the stream described by output, +* the filter name (which is what's used in the "-d" option) and the full +* name for the protocol that corresponds to this handle. +*/ +static void +display_dissector_names(const gchar *table _U_, gpointer handle, gpointer output) +{ + int proto_id; + const gchar *proto_filter_name; + const gchar *proto_ui_name; + + proto_id = dissector_handle_get_protocol_index((dissector_handle_t)handle); + + if (proto_id != -1) { + proto_filter_name = proto_get_protocol_filter_name(proto_id); + proto_ui_name = proto_get_protocol_name(proto_id); + g_assert(proto_filter_name != NULL); + g_assert(proto_ui_name != NULL); + + if ((prev_display_dissector_name == NULL) || + (strcmp(prev_display_dissector_name, proto_filter_name) != 0)) { + fprintf((FILE *)output, "\t%s (%s)\n", + proto_filter_name, + proto_ui_name); + prev_display_dissector_name = proto_filter_name; + } + } +} + +/* +* Allow dissector key names to be sorted alphabetically +*/ + +static gint +compare_dissector_key_name(gconstpointer dissector_a, gconstpointer dissector_b) +{ + return strcmp((const char*)dissector_a, (const char*)dissector_b); +} + +/* +* Print all layer type names supported. +* We send the output to the stream described by the handle output. +*/ +static void +fprint_all_layer_types(FILE *output) + +{ + prev_display_dissector_name = NULL; + dissector_all_tables_foreach_table(display_dissector_table_names, (gpointer)output, (GCompareFunc)compare_dissector_key_name); +} + +/* +* Print all protocol names supported for a specific layer type. +* table_name contains the layer type name in which the search is performed. +* We send the output to the stream described by the handle output. +*/ +static void +fprint_all_protocols_for_layer_types(FILE *output, gchar *table_name) + +{ + prev_display_dissector_name = NULL; + dissector_table_foreach_handle(table_name, + display_dissector_names, + (gpointer)output); +} + +/* +* The protocol_name_search structure is used by find_protocol_name_func() +* to pass parameters and store results +*/ +struct protocol_name_search{ + gchar *searched_name; /* Protocol filter name we are looking for */ + dissector_handle_t matched_handle; /* Handle for a dissector whose protocol has the specified filter name */ + guint nb_match; /* How many dissectors matched searched_name */ +}; +typedef struct protocol_name_search *protocol_name_search_t; + +/* +* This function parses all dissectors associated with a table to find the +* one whose protocol has the specified filter name. It is called +* as a reference function in a call to dissector_table_foreach_handle. +* The name we are looking for, as well as the results, are stored in the +* protocol_name_search struct pointed to by user_data. +* If called using dissector_table_foreach_handle, we actually parse the +* whole list of dissectors. +*/ +static void +find_protocol_name_func(const gchar *table _U_, gpointer handle, gpointer user_data) + +{ + int proto_id; + const gchar *protocol_filter_name; + protocol_name_search_t search_info; + + g_assert(handle); + + search_info = (protocol_name_search_t)user_data; + + proto_id = dissector_handle_get_protocol_index((dissector_handle_t)handle); + if (proto_id != -1) { + protocol_filter_name = proto_get_protocol_filter_name(proto_id); + g_assert(protocol_filter_name != NULL); + if (strcmp(protocol_filter_name, search_info->searched_name) == 0) { + /* Found a match */ + if (search_info->nb_match == 0) { + /* Record this handle only if this is the first match */ + search_info->matched_handle = (dissector_handle_t)handle; /* Record the handle for this matching dissector */ + } + search_info->nb_match++; + } + } +} + +/* +* The function below parses the command-line parameters for the decode as +* feature (a string pointer by cl_param). +* It checks the format of the command-line, searches for a matching table +* and dissector. If a table/dissector match is not found, we display a +* summary of the available tables/dissectors (on stderr) and return FALSE. +* If everything is fine, we get the "Decode as" preference activated, +* then we return TRUE. +*/ +gboolean decode_as_command_option(const gchar *cl_param) +{ + gchar *table_name; + guint32 selector, selector2; + gchar *decoded_param; + gchar *remaining_param; + gchar *selector_str; + gchar *dissector_str; + dissector_handle_t dissector_matching; + dissector_table_t table_matching; + ftenum_t dissector_table_selector_type; + struct protocol_name_search user_protocol_name; + guint64 i; + char op; + + /* The following code will allocate and copy the command-line options in a string pointed by decoded_param */ + + g_assert(cl_param); + decoded_param = g_strdup(cl_param); + g_assert(decoded_param); + + + /* The lines below will parse this string (modifying it) to extract all + necessary information. Note that decoded_param is still needed since + strings are not copied - we just save pointers. */ + + /* This section extracts a layer type (table_name) from decoded_param */ + table_name = decoded_param; /* Layer type string starts from beginning */ + + remaining_param = strchr(table_name, '='); + if (remaining_param == NULL) { + cmdarg_err("Parameter \"%s\" doesn't follow the template \"%s\"", cl_param, DECODE_AS_ARG_TEMPLATE); + /* If the argument does not follow the template, carry on anyway to check + if the table name is at least correct. If remaining_param is NULL, + we'll exit anyway further down */ + } + else { + *remaining_param = '\0'; /* Terminate the layer type string (table_name) where '=' was detected */ + } + + /* Remove leading and trailing spaces from the table name */ + while (table_name[0] == ' ') + table_name++; + while (table_name[strlen(table_name) - 1] == ' ') + table_name[strlen(table_name) - 1] = '\0'; /* Note: if empty string, while loop will eventually exit */ + + /* The following part searches a table matching with the layer type specified */ + table_matching = NULL; + + /* Look for the requested table */ + if (!(*(table_name))) { /* Is the table name empty, if so, don't even search for anything, display a message */ + cmdarg_err("No layer type specified"); /* Note, we don't exit here, but table_matching will remain NULL, so we exit below */ + } + else { + table_matching = find_dissector_table(table_name); + if (!table_matching) { + cmdarg_err("Unknown layer type -- %s", table_name); /* Note, we don't exit here, but table_matching will remain NULL, so we exit below */ + } + } + + if (!table_matching) { + /* Display a list of supported layer types to help the user, if the + specified layer type was not found */ + cmdarg_err("Valid layer types are:"); + fprint_all_layer_types(stderr); + } + if (remaining_param == NULL || !table_matching) { + /* Exit if the layer type was not found, or if no '=' separator was found + (see above) */ + g_free(decoded_param); + return FALSE; + } + + if (*(remaining_param + 1) != '=') { /* Check for "==" and not only '=' */ + cmdarg_err("WARNING: -d requires \"==\" instead of \"=\". Option will be treated as \"%s==%s\"", table_name, remaining_param + 1); + } + else { + remaining_param++; /* Move to the second '=' */ + *remaining_param = '\0'; /* Remove the second '=' */ + } + remaining_param++; /* Position after the layer type string */ + + /* This section extracts a selector value (selector_str) from decoded_param */ + + selector_str = remaining_param; /* Next part starts with the selector number */ + + remaining_param = strchr(selector_str, ','); + if (remaining_param == NULL) { + cmdarg_err("Parameter \"%s\" doesn't follow the template \"%s\"", cl_param, DECODE_AS_ARG_TEMPLATE); + /* If the argument does not follow the template, carry on anyway to check + if the selector value is at least correct. If remaining_param is NULL, + we'll exit anyway further down */ + } + else { + *remaining_param = '\0'; /* Terminate the selector number string (selector_str) where ',' was detected */ + } + + dissector_table_selector_type = get_dissector_table_selector_type(table_name); + + switch (dissector_table_selector_type) { + + case FT_UINT8: + case FT_UINT16: + case FT_UINT24: + case FT_UINT32: + /* The selector for this table is an unsigned number. Parse it as such. + There's no need to remove leading and trailing spaces from the + selector number string, because sscanf will do that for us. */ + switch (sscanf(selector_str, "%u%c%u", &selector, &op, &selector2)) { + case 1: + op = '\0'; + break; + case 3: + if (op != ':' && op != '-') { + cmdarg_err("Invalid selector numeric range \"%s\"", selector_str); + g_free(decoded_param); + return FALSE; + } + if (op == ':') { + if ((selector2 == 0) || ((guint64)selector + selector2 - 1) > G_MAXUINT32) { + cmdarg_err("Invalid selector numeric range \"%s\"", selector_str); + g_free(decoded_param); + return FALSE; + } + } + else if (selector2 < selector) { + /* We could swap them for the user, but maybe it's better to call + * this out as an error in case it's not what was intended? */ + cmdarg_err("Invalid selector numeric range \"%s\"", selector_str); + g_free(decoded_param); + return FALSE; + } + break; + default: + cmdarg_err("Invalid selector number \"%s\"", selector_str); + g_free(decoded_param); + return FALSE; + } + break; + + case FT_STRING: + case FT_STRINGZ: + case FT_UINT_STRING: + case FT_STRINGZPAD: + /* The selector for this table is a string. */ + break; + + default: + /* There are currently no dissector tables with any types other + than the ones listed above. */ + g_assert_not_reached(); + } + + if (remaining_param == NULL) { + /* Exit if no ',' separator was found (see above) */ + cmdarg_err("Valid protocols for layer type \"%s\" are:", table_name); + fprint_all_protocols_for_layer_types(stderr, table_name); + g_free(decoded_param); + return FALSE; + } + + remaining_param++; /* Position after the selector number string */ + + /* This section extracts a protocol filter name (dissector_str) from decoded_param */ + + dissector_str = remaining_param; /* All the rest of the string is the dissector (decode as protocol) name */ + + /* Remove leading and trailing spaces from the dissector name */ + while (dissector_str[0] == ' ') + dissector_str++; + while (dissector_str[strlen(dissector_str) - 1] == ' ') + dissector_str[strlen(dissector_str) - 1] = '\0'; /* Note: if empty string, while loop will eventually exit */ + + dissector_matching = NULL; + + /* We now have a pointer to the handle for the requested table inside the variable table_matching */ + if (!(*dissector_str)) { /* Is the dissector name empty, if so, don't even search for a matching dissector and display all dissectors found for the selected table */ + cmdarg_err("No protocol name specified"); /* Note, we don't exit here, but dissector_matching will remain NULL, so we exit below */ + } + else { + user_protocol_name.nb_match = 0; + user_protocol_name.searched_name = dissector_str; + user_protocol_name.matched_handle = NULL; + + dissector_table_foreach_handle(table_name, find_protocol_name_func, &user_protocol_name); /* Go and perform the search for this dissector in the this table's dissectors' names and shortnames */ + + if (user_protocol_name.nb_match != 0) { + dissector_matching = user_protocol_name.matched_handle; + if (user_protocol_name.nb_match > 1) { + cmdarg_err("WARNING: Protocol \"%s\" matched %u dissectors, first one will be used", dissector_str, user_protocol_name.nb_match); + } + } + else { + /* OK, check whether the problem is that there isn't any such + protocol, or that there is but it's not specified as a protocol + that's valid for that dissector table. + Note, we don't exit here, but dissector_matching will remain NULL, + so we exit below */ + if (proto_get_id_by_filter_name(dissector_str) == -1) { + /* No such protocol */ + cmdarg_err("Unknown protocol -- \"%s\"", dissector_str); + } + else { + cmdarg_err("Protocol \"%s\" isn't valid for layer type \"%s\"", + dissector_str, table_name); + } + } + } + + if (!dissector_matching) { + cmdarg_err("Valid protocols for layer type \"%s\" are:", table_name); + fprint_all_protocols_for_layer_types(stderr, table_name); + g_free(decoded_param); + return FALSE; + } + + /* This is the end of the code that parses the command-line options. + All information is now stored in the variables: + table_name + selector + dissector_matching + The above variables that are strings are still pointing to areas within + decoded_parm. decoded_parm thus still needs to be kept allocated in + until we stop needing these variables + decoded_param will be deallocated at each exit point of this function */ + + + /* We now have a pointer to the handle for the requested dissector + (requested protocol) inside the variable dissector_matching */ + switch (dissector_table_selector_type) { + + case FT_UINT8: + case FT_UINT16: + case FT_UINT24: + case FT_UINT32: + /* The selector for this table is an unsigned number. */ + if (op == '\0') { + dissector_change_uint(table_name, selector, dissector_matching); + } + else if (op == ':') { + for (i = selector; i < (guint64)selector + selector2; i++) { + dissector_change_uint(table_name, (guint32)i, dissector_matching); + } + } + else { /* op == '-' */ + for (i = selector; i <= selector2; i++) { + dissector_change_uint(table_name, (guint32)i, dissector_matching); + } + } + break; + + case FT_STRING: + case FT_STRINGZ: + case FT_UINT_STRING: + case FT_STRINGZPAD: + /* The selector for this table is a string. */ + dissector_change_string(table_name, selector_str, dissector_matching); + break; + + default: + /* There are currently no dissector tables with any types other + than the ones listed above. */ + g_assert_not_reached(); + } + g_free(decoded_param); /* "Decode As" rule has been successfully added */ + return TRUE; +} + /* * Editor modelines * |