libnl: /data/src/libnl3/lib/mpls.c Source File

libnl 3.10.0

mpls.c
1/* SPDX-License-Identifier: LGPL-2.1-only */
2/*
3 * Adapted from mpls_ntop and mpls_pton copied from iproute2,
4 * lib/mpls_ntop.c and lib/mpls_pton.c
5 */
6
7#include "nl-default.h"
8
9#include <stdio.h>
10
11#include <linux/mpls.h>
12
13#include <netlink/netlink-compat.h>
14
15#include "mpls.h"
16
17static const char *mpls_ntop1(const struct mpls_label *addr,
18 char *buf, size_t buflen)
19{
20 size_t destlen = buflen;
21 char *dest = buf;
22 int count = 0;
23
24 while (1) {
25 uint32_t entry = ntohl(addr[count++].entry);
26 uint32_t label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
27 int len = snprintf(dest, destlen, "%u", label);
28
29 if (len < 0 || (unsigned)len >= destlen)
30 break;
31
32 /* Is this the end? */
33 if (entry & MPLS_LS_S_MASK)
34 return buf;
35
36 dest += len;
37 destlen -= len;
38 if (destlen) {
39 *dest = '/';
40 dest++;
41 destlen--;
42 }
43 }
44 errno = E2BIG;
45
46 return NULL;
47}
48
49const char *mpls_ntop(int af, const void *addr, char *buf, size_t buflen)
50{
51 switch(af) {
52 case AF_MPLS:
53 errno = 0;
54 return mpls_ntop1((struct mpls_label *)addr, buf, buflen);
55 }
56
57 errno = EINVAL;
58 return NULL;
59}
60
61static int mpls_pton1(const char *name, struct mpls_label *addr,
62 unsigned int maxlabels)
63{
64 char *endp;
65 unsigned count;
66
67 for (count = 0; count < maxlabels; count++) {
68 unsigned long label;
69
70 label = strtoul(name, &endp, 0);
71 /* Fail when the label value is out or range */
72 if (label >= (1 << 20))
73 return 0;
74
75 if (endp == name) /* no digits */
76 return 0;
77
78 addr->entry = htonl(label << MPLS_LS_LABEL_SHIFT);
79 if (*endp == '\0') {
80 addr->entry |= htonl(1 << MPLS_LS_S_SHIFT);
81 return (count + 1) * sizeof(struct mpls_label);
82 }
83
84 /* Bad character in the address */
85 if (*endp != '/')
86 return 0;
87
88 name = endp + 1;
89 addr += 1;
90 }
91
92 /* The address was too long */
93 return 0;
94}
95
96int mpls_pton(int af, const char *src, void *addr, size_t alen)
97{
98 unsigned int maxlabels = alen / sizeof(struct mpls_label);
99 int err;
100
101 switch(af) {
102 case AF_MPLS:
103 errno = 0;
104 err = mpls_pton1(src, (struct mpls_label *)addr, maxlabels);
105 break;
106 default:
107 errno = EAFNOSUPPORT;
108 err = -1;
109 }
110
111 return err;
112}