/** * Handle request_header events for remote IP extraction. * * Extract the "request_headers" field (a list) from the transactions's * data provider instance, then loop through the list, looking for the * "X-Forwarded-For" field. If found, the first value in the (comma * separated) list replaces the local ip address string in the connection * object. * * @param[in] ib IronBee object * @param[in,out] tx Transaction object * @param[in] event Event type * @param[in] cbdata Callback data (not used) * * @returns Status code */ static ib_status_t modua_remoteip(ib_engine_t *ib, ib_tx_t *tx, ib_state_event_type_t event, void *cbdata) { assert(ib != NULL); assert(tx != NULL); assert(tx->data != NULL); assert(event == request_header_finished_event); ib_field_t *field = NULL; ib_status_t rc = IB_OK; const ib_bytestr_t *bs; const uint8_t *data; size_t len; char *buf; uint8_t *comma; const ib_list_t *list; const ib_list_node_t *node; const ib_field_t *forwarded; uint8_t *stripped; size_t num; ib_flags_t flags; ib_log_debug3_tx(tx, "Checking for alternate remote address"); /* Extract the X-Forwarded-For from the provider instance */ rc = ib_data_get(tx->data, "request_headers:X-Forwarded-For", &field); if ( (field == NULL) || (rc != IB_OK) ) { ib_log_debug_tx(tx, "No X-Forwarded-For field"); return IB_OK; } /* Because we asked for a filtered item, what we get back is a list */ rc = ib_field_value(field, ib_ftype_list_out(&list)); if (rc != IB_OK) { ib_log_debug_tx(tx, "No request header collection"); return rc; } num = ib_list_elements(list); if (num == 0) { ib_log_debug_tx(tx, "No X-Forwarded-For header found"); return rc; } else if (num != 1) { ib_log_debug_tx(tx, "%zd X-Forwarded-For headers found: ignoring", num); return rc; } node = ib_list_last_const(list); if ( (node == NULL) || (node->data == NULL) ) { ib_log_notice_tx(tx, "Invalid X-Forwarded-For header found"); return rc; } forwarded = (const ib_field_t *)node->data; /* Found it: copy the data into a newly allocated string buffer */ rc = ib_field_value_type(forwarded, ib_ftype_bytestr_out(&bs), IB_FTYPE_BYTESTR); if (rc != IB_OK) { ib_log_notice_tx(tx, "Invalid X-Forwarded-For header value"); return rc; } if (bs == NULL) { ib_log_notice_tx(tx, "X-Forwarded-For header not a bytestr"); return IB_EINVAL; } len = ib_bytestr_length(bs); data = ib_bytestr_const_ptr(bs); /* Search for a comma in the buffer */ comma = memchr(data, ',', len); if (comma != NULL) { len = comma - data; } /* Trim whitespace */ stripped = (uint8_t *)data; rc = ib_strtrim_lr_ex(IB_STROP_INPLACE, tx->mp, stripped, len, &stripped, &len, &flags); if (rc != IB_OK) { return rc; } /* Verify that it looks like a valid IP v4/6 address */ rc = ib_ip_validate_ex((const char *)stripped, len); if (rc != IB_OK) { ib_log_error_tx(tx, "X-Forwarded-For \"%.*s\" is not a valid IP address", (int)len, stripped ); return IB_OK; } /* Allocate memory for copy of stripped string */ buf = (char *)ib_mpool_alloc(tx->mp, len+1); if (buf == NULL) { ib_log_error_tx(tx, "Failed to allocate %zd bytes for remote address", len+1); return IB_EALLOC; } /* Copy the string out */ memcpy(buf, stripped, len); buf[len] = '\0'; ib_log_debug_tx(tx, "Remote address changed to \"%s\"", buf); /* This will lose the pointer to the original address * buffer, but it should be cleaned up with the rest * of the memory pool. */ tx->er_ipstr = buf; /* Update the remote address field in the tx collection */ rc = ib_data_add_bytestr(tx->data, "remote_addr", (uint8_t*)buf, len, NULL); if (rc != IB_OK) { ib_log_error_tx(tx, "Failed to create remote address TX field: %s", ib_status_to_string(rc)); return rc; } return IB_OK; }
/** * Handle request_header events for remote IP extraction. * * Extract the "request_headers" field (a list) from the transactions's * data provider instance, then loop through the list, looking for the * "X-Forwarded-For" field. If found, the first value in the (comma * separated) list replaces the local ip address string in the connection * object. * * @param[in] ib IronBee object * @param[in,out] tx Transaction object * @param[in] event Event type * @param[in] cbdata Callback data (module) * * @returns Status code */ static ib_status_t modua_remoteip(ib_engine_t *ib, ib_tx_t *tx, ib_state_event_type_t event, void *cbdata) { assert(ib != NULL); assert(tx != NULL); assert(tx->var_store != NULL); assert(event == request_header_finished_event); const ib_module_t *m = (const ib_module_t *)cbdata; ib_field_t *field = NULL; ib_status_t rc = IB_OK; const ib_bytestr_t *bs; const uint8_t *data; size_t len; char *buf; uint8_t *comma; const ib_list_t *list; const ib_list_node_t *node; const ib_field_t *forwarded; uint8_t *stripped; size_t num; ib_flags_t flags; const modua_config_t *cfg; rc = ib_context_module_config(ib_context_main(ib), m, &cfg); if (rc != IB_OK) { ib_log_error_tx(tx, "Can't fetch configuration: %s", ib_status_to_string(rc)); return rc; } ib_log_debug3_tx(tx, "Checking for alternate remote address"); /* Extract the X-Forwarded-For header field */ rc = ib_var_target_get_const( cfg->forwarded_for, &list, tx->mp, tx->var_store ); if (rc == IB_ENOENT || ib_list_elements(list) == 0) { ib_log_debug_tx(tx, "No X-Forwarded-For"); return IB_OK; } if (rc != IB_OK) { ib_log_error_tx(tx, "Cannot retrieve request_headers:User-Agent: %d", rc); return rc; } num = ib_list_elements(list); if (num == 0) { ib_log_debug_tx(tx, "No X-Forwarded-For header found"); return rc; } else if (num != 1) { ib_log_debug_tx(tx, "%zd X-Forwarded-For headers found: ignoring", num); return rc; } node = ib_list_last_const(list); if ( (node == NULL) || (node->data == NULL) ) { ib_log_notice_tx(tx, "Invalid X-Forwarded-For header found"); return rc; } forwarded = (const ib_field_t *)node->data; /* Found it: copy the data into a newly allocated string buffer */ rc = ib_field_value_type(forwarded, ib_ftype_bytestr_out(&bs), IB_FTYPE_BYTESTR); if (rc != IB_OK) { ib_log_notice_tx(tx, "Invalid X-Forwarded-For header value"); return rc; } if (bs == NULL) { ib_log_notice_tx(tx, "X-Forwarded-For header not a bytestr"); return IB_EINVAL; } len = ib_bytestr_length(bs); data = ib_bytestr_const_ptr(bs); /* Search for a comma in the buffer */ comma = memchr(data, ',', len); if (comma != NULL) { len = comma - data; } /* Trim whitespace */ stripped = (uint8_t *)data; rc = ib_strtrim_lr_ex(IB_STROP_INPLACE, tx->mp, stripped, len, &stripped, &len, &flags); if (rc != IB_OK) { return rc; } /* Verify that it looks like a valid IP v4/6 address */ rc = ib_ip_validate_ex((const char *)stripped, len); if (rc != IB_OK) { ib_log_error_tx(tx, "X-Forwarded-For \"%.*s\" is not a valid IP address", (int)len, stripped ); return IB_OK; } /* Allocate memory for copy of stripped string */ buf = (char *)ib_mpool_alloc(tx->mp, len+1); if (buf == NULL) { ib_log_error_tx(tx, "Failed to allocate %zd bytes for remote address", len+1); return IB_EALLOC; } /* Copy the string out */ memcpy(buf, stripped, len); buf[len] = '\0'; ib_log_debug_tx(tx, "Remote address changed to \"%s\"", buf); /* This will lose the pointer to the original address * buffer, but it should be cleaned up with the rest * of the memory pool. */ tx->er_ipstr = buf; /* Update the remote address field in the tx collection */ rc = ib_field_create_bytestr_alias( &field, tx->mp, "", 0, (uint8_t *)buf, len ); if (rc != IB_OK) { ib_log_error_tx(tx, "Failed to create field for remote_addr: %s", ib_status_to_string(rc)); return rc; } rc = ib_var_source_set(cfg->remote_addr, tx->var_store, field); if (rc != IB_OK) { ib_log_error_tx(tx, "Failed to set remote address var: %s", ib_status_to_string(rc)); return rc; } return IB_OK; }