libnl  3.7.0
nh_encap_mpls.c
1 /* SPDX-License-Identifier: LGPL-2.1-only */
2 
3 #include <netlink-private/netlink.h>
4 #include <netlink-private/types.h>
5 #include <netlink-private/route/nexthop-encap.h>
6 #include <netlink/route/nexthop.h>
7 #include <linux/mpls_iptunnel.h>
8 #include <linux/lwtunnel.h>
9 
11  struct nl_addr *dst;
12  uint8_t ttl;
13 };
14 
15 static void mpls_encap_dump(void *priv, struct nl_dump_params *dp)
16 {
17  struct mpls_iptunnel_encap *encap_info = priv;
18  char buf[256];
19 
20  nl_dump(dp, "%s ", nl_addr2str(encap_info->dst, buf, sizeof(buf)));
21 
22  if (encap_info->ttl)
23  nl_dump(dp, "ttl %u ", encap_info->ttl);
24 }
25 
26 static int mpls_encap_build_msg(struct nl_msg *msg, void *priv)
27 {
28  struct mpls_iptunnel_encap *encap_info = priv;
29 
30  NLA_PUT_ADDR(msg, MPLS_IPTUNNEL_DST, encap_info->dst);
31  if (encap_info->ttl)
32  NLA_PUT_U8(msg, MPLS_IPTUNNEL_TTL, encap_info->ttl);
33 
34  return 0;
35 
36 nla_put_failure:
37  return -NLE_MSGSIZE;
38 }
39 
40 static void mpls_encap_destructor(void *priv)
41 {
42  struct mpls_iptunnel_encap *encap_info = priv;
43 
44  nl_addr_put(encap_info->dst);
45 }
46 
47 static struct nla_policy mpls_encap_policy[MPLS_IPTUNNEL_MAX + 1] = {
48  [MPLS_IPTUNNEL_DST] = { .type = NLA_U32 },
49  [MPLS_IPTUNNEL_TTL] = { .type = NLA_U8 },
50 };
51 
52 static int mpls_encap_parse_msg(struct nlattr *nla, struct rtnl_nexthop *nh)
53 {
54  struct nlattr *tb[MPLS_IPTUNNEL_MAX + 1];
55  struct nl_addr *labels;
56  uint8_t ttl = 0;
57  int err;
58 
59  err = nla_parse_nested(tb, MPLS_IPTUNNEL_MAX, nla, mpls_encap_policy);
60  if (err < 0)
61  return err;
62 
63  if (!tb[MPLS_IPTUNNEL_DST])
64  return -NLE_INVAL;
65 
66  labels = nl_addr_alloc_attr(tb[MPLS_IPTUNNEL_DST], AF_MPLS);
67  if (!labels)
68  return -NLE_NOMEM;
69 
70  if (tb[MPLS_IPTUNNEL_TTL])
71  ttl = nla_get_u8(tb[MPLS_IPTUNNEL_TTL]);
72 
73  err = rtnl_route_nh_encap_mpls(nh, labels, ttl);
74 
75  nl_addr_put(labels);
76 
77  return err;
78 }
79 
80 static int mpls_encap_compare(void *_a, void *_b)
81 {
82  struct mpls_iptunnel_encap *a = _a;
83  struct mpls_iptunnel_encap *b = _b;
84  int diff = 0;
85 
86  diff |= (a->ttl != b->ttl);
87  diff |= nl_addr_cmp(a->dst, b->dst);
88 
89  return diff;
90 }
91 
92 struct nh_encap_ops mpls_encap_ops = {
93  .encap_type = LWTUNNEL_ENCAP_MPLS,
94  .build_msg = mpls_encap_build_msg,
95  .parse_msg = mpls_encap_parse_msg,
96  .compare = mpls_encap_compare,
97  .dump = mpls_encap_dump,
98  .destructor = mpls_encap_destructor,
99 };
100 
101 int rtnl_route_nh_encap_mpls(struct rtnl_nexthop *nh,
102  struct nl_addr *addr,
103  uint8_t ttl)
104 {
105  struct mpls_iptunnel_encap *mpls_encap;
106  struct rtnl_nh_encap *rtnh_encap;
107 
108  if (!addr)
109  return -NLE_INVAL;
110 
111  rtnh_encap = calloc(1, sizeof(*rtnh_encap));
112  if (!rtnh_encap)
113  return -NLE_NOMEM;
114 
115  mpls_encap = calloc(1, sizeof(*mpls_encap));
116  if (!mpls_encap) {
117  free(rtnh_encap);
118  return -NLE_NOMEM;
119  }
120 
121  mpls_encap->dst = nl_addr_get(addr);
122  mpls_encap->ttl = ttl;
123 
124  rtnh_encap->priv = mpls_encap;
125  rtnh_encap->ops = &mpls_encap_ops;
126 
127  nh_set_encap(nh, rtnh_encap);
128 
129  return 0;
130 }
131 
132 struct nl_addr *rtnl_route_nh_get_encap_mpls_dst(struct rtnl_nexthop *nh)
133 {
134  struct mpls_iptunnel_encap *mpls_encap;
135 
136  if (!nh->rtnh_encap || nh->rtnh_encap->ops->encap_type != LWTUNNEL_ENCAP_MPLS)
137  return NULL;
138 
139  mpls_encap = (struct mpls_iptunnel_encap *)nh->rtnh_encap->priv;
140  if (!mpls_encap)
141  return NULL;
142 
143  return mpls_encap->dst;
144 }
145 
146 uint8_t rtnl_route_nh_get_encap_mpls_ttl(struct rtnl_nexthop *nh)
147 {
148  struct mpls_iptunnel_encap *mpls_encap;
149 
150  if (!nh->rtnh_encap || nh->rtnh_encap->ops->encap_type != LWTUNNEL_ENCAP_MPLS)
151  return 0;
152 
153  mpls_encap = (struct mpls_iptunnel_encap *)nh->rtnh_encap->priv;
154  if (!mpls_encap)
155  return 0;
156 
157  return mpls_encap->ttl;
158 }
char * nl_addr2str(const struct nl_addr *addr, char *buf, size_t size)
Convert abstract address object to character string.
Definition: addr.c:993
struct nl_addr * nl_addr_alloc_attr(const struct nlattr *nla, int family)
Allocate abstract address based on Netlink attribute.
Definition: addr.c:256
int nl_addr_cmp(const struct nl_addr *a, const struct nl_addr *b)
Compare abstract addresses.
Definition: addr.c:579
struct nl_addr * nl_addr_get(struct nl_addr *addr)
Increase the reference counter of an abstract address.
Definition: addr.c:517
void nl_addr_put(struct nl_addr *addr)
Decrease the reference counter of an abstract address.
Definition: addr.c:533
#define NLA_PUT_U8(msg, attrtype, value)
Add 8 bit integer attribute to netlink message.
Definition: attr.h:194
#define NLA_PUT_ADDR(msg, attrtype, addr)
Add address attribute to netlink message.
Definition: attr.h:283
uint8_t nla_get_u8(const struct nlattr *nla)
Return value of 8 bit integer attribute.
Definition: attr.c:599
int nla_parse_nested(struct nlattr *tb[], int maxtype, struct nlattr *nla, const struct nla_policy *policy)
Create attribute index based on nested attribute.
Definition: attr.c:1013
@ NLA_U8
8 bit integer
Definition: attr.h:35
@ NLA_U32
32 bit integer
Definition: attr.h:37
void nl_dump(struct nl_dump_params *params, const char *fmt,...)
Dump a formatted character string.
Definition: utils.c:955
Dumping parameters.
Definition: types.h:28
Attribute validation policy.
Definition: attr.h:63
uint16_t type
Type of attribute or NLA_UNSPEC.
Definition: attr.h:65