lib/mpls.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * mpls functions
   4  *
   5  * Copyright (C) 2018 Cumulus Networks, Inc.
   6  *                    Donald Sharp
   7  */
   8 #include <zebra.h>
   9 #include <mpls.h>
  10 #include <memory.h>
  11
  12 /*
  13  * String to label conversion, labels separated by '/'.
  14  *
  15  * @param label_str labels separated by /
  16  * @param num_labels number of labels; zero if conversion was unsuccessful
  17  * @param labels preallocated mpls_label_t array of size MPLS_MAX_LABELS; only
  18  *               modified if the conversion succeeded
  19  * @return  0 on success
  20  *         -1 if the string could not be parsed as integers
  21  *         -2 if a label was inside the reserved range (0-15)
  22  *         -3 if the number of labels given exceeds MPLS_MAX_LABELS
  23  */
  24 int mpls_str2label(const char *label_str, uint8_t *num_labels,
  25                    mpls_label_t *labels)
  26 {
  27         char *ostr;                       // copy of label string (start)
  28         char *lstr;                       // copy of label string
  29         char *nump;                       // pointer to next segment
  30         char *endp;                       // end pointer
  31         int i;                            // for iterating label_str
  32         int rc;                           // return code
  33         mpls_label_t pl[MPLS_MAX_LABELS]; // parsed labels
  34
  35         /* labels to zero until we have a successful parse */
  36         ostr = lstr = XSTRDUP(MTYPE_TMP, label_str);
  37         *num_labels = 0;
  38         rc = 0;
  39
  40         for (i = 0; i < MPLS_MAX_LABELS && lstr && !rc; i++) {
  41                 nump = strsep(&lstr, "/");
  42                 pl[i] = strtoul(nump, &endp, 10);
  43
  44                 /* format check */
  45                 if (*endp != '\0')
  46                         rc = -1;
  47                 /* validity check */
  48                 else if (!IS_MPLS_UNRESERVED_LABEL(pl[i]))
  49                         rc = -2;
  50         }
  51
  52         /* excess labels */
  53         if (!rc && i == MPLS_MAX_LABELS && lstr)
  54                 rc = -3;
  55
  56         if (!rc) {
  57                 *num_labels = i;
  58                 memcpy(labels, pl, *num_labels * sizeof(mpls_label_t));
  59         }
  60
  61         XFREE(MTYPE_TMP, ostr);
  62
  63         return rc;
  64 }
  65
  66 /*
  67  * Label to string conversion, labels in string separated by '/'.
  68  */
  69 char *mpls_label2str(uint8_t num_labels, const mpls_label_t *labels, char *buf,
  70                      int len, enum lsp_types_t type, int pretty)
  71 {
  72         char label_buf[BUFSIZ];
  73         int i;
  74
  75         buf[0] = '\0';
  76         for (i = 0; i < num_labels; i++) {
  77                 if (i != 0)
  78                         strlcat(buf, "/", len);
  79                 if (pretty)
  80                         label2str(labels[i], type, label_buf,
  81                                   sizeof(label_buf));
  82                 else
  83                         snprintf(label_buf, sizeof(label_buf), "%u",
  84                                  ((type == ZEBRA_LSP_EVPN)
  85                                           ? label2vni(&labels[i])
  86                                           : labels[i]));
  87
  88                 strlcat(buf, label_buf, len);
  89         }
  90
  91         return buf;
  92 }