R/find-short.R

In hrbrmstr/rrecog: Pattern Recognition for Hosts, Services and Content

.recog_pick <- function(recog_db, source, protocols = ".*", matches = NULL) {

  if (
    identical(
      attr(recog_db[[1]]$fingerpints[[1]]$compiled_pattern, ".compiled"),
      new("externalptr")
    )) {
    stop(
      "The external pointers for the compiled patterns are not valid. ",
      "Please re-load the data you are supplying to the `recog_db` parameter."
    )
  }

  protocol_matchers <- if (is.null(protocols)) {
    numeric()
  } else {
    which(grepl(protocols, map_chr(recog_db, "protocol")))
  }

  matches_matchers <- if (is.null(matches)) {
    numeric()
  } else {
    which(grepl(matches, map_chr(recog_db, "matches")))
  }

  matchers <- unique(c(protocol_matchers, matches_matchers))

  if (length(matchers) == 0) return(list())

  out <- data.frame(stringsAsFactors=FALSE)

  for(fps in recog_db[matchers]) {

    preference <- fps$preference_value

    for(fp in fps$fingerpints) {
      res <- ore::ore_search(fp$compiled_pattern, source, simplify=TRUE)
      if (!is.null(res)) {
        grps <- as.vector(ore::groups(res))
        lapply(fp$params, function(.x) {
          value <- if (.x$position == 0) .x$value else grps[.x$position]
          as.list(set_names(value, .x$name))
        }) %>% unlist(recursive = FALSE) %>%
          as.data.frame(stringsAsFactors=FALSE) -> mat_out
        mat_out$preference <- preference
        mat_out$description <- fp$description
        mat_out$pattern <- fp$pattern
        mat_out$orig <- source
        out <- mat_out
        break
      }
    }

    if (nrow(out) > 0) break

  }

  class(out) <- c("tbl_df", "tbl", "data.frame")

  out

}

#' Find first fingerprint match for a given source
#'
#' Unlike the full search sibling, this function will only return
#' the first match found. It does this in `preference_value` order
#' but is not guaranteed to find the best match, only the first one
#' (for speed).
#'
#' @md
#' @param recog_db a structure created with [load_fingerprints()] or
#'        [use_builtin_fingerprints()]
#' @param source the 1-element character vector to compare against
#' @param protocol,matches regexs to limit what you're comparing against. These
#'        are boolean **OR'd** together
#' @export
#' @examples
#' recog_db <- use_builtin_fingerprints()
#' recog_pick(recog_db, "VShell_Special_Edition_2_5_0_204 VShell", "ssh")
recog_pick <- memoise::memoise(.recog_pick)