lib/mpls_pton.c

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2
   3 #include <errno.h>
   4 #include <string.h>
   5 #include <sys/types.h>
   6 #include <netinet/in.h>
   7 #include <linux/mpls.h>
   8
   9 #include "utils.h"
  10
  11
  12 static int mpls_pton1(const char *name, struct mpls_label *addr,
  13                       unsigned int maxlabels)
  14 {
  15         char *endp;
  16         unsigned count;
  17
  18         for (count = 0; count < maxlabels; count++) {
  19                 unsigned long label;
  20
  21                 label = strtoul(name, &endp, 0);
  22                 /* Fail when the label value is out or range */
  23                 if (label >= (1 << 20))
  24                         return 0;
  25
  26                 if (endp == name) /* no digits */
  27                         return 0;
  28
  29                 addr->entry = htonl(label << MPLS_LS_LABEL_SHIFT);
  30                 if (*endp == '\0') {
  31                         addr->entry |= htonl(1 << MPLS_LS_S_SHIFT);
  32                         return 1;
  33                 }
  34
  35                 /* Bad character in the address */
  36                 if (*endp != '/')
  37                         return 0;
  38
  39                 name = endp + 1;
  40                 addr += 1;
  41         }
  42         /* The address was too long */
  43         fprintf(stderr, "Error: too many labels.\n");
  44         return 0;
  45 }
  46
  47 int mpls_pton(int af, const char *src, void *addr, size_t alen)
  48 {
  49         unsigned int maxlabels = alen / sizeof(struct mpls_label);
  50         int err;
  51
  52         switch(af) {
  53         case AF_MPLS:
  54                 errno = 0;
  55                 err = mpls_pton1(src, (struct mpls_label *)addr, maxlabels);
  56                 break;
  57         default:
  58                 errno = EAFNOSUPPORT;
  59                 err = -1;
  60         }
  61
  62         return err;
  63 }