1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/netlink.h>
3 #include <linux/rtnetlink.h>
4 #include <linux/types.h>
5 #include <net/ip.h>
6 #include <net/net_namespace.h>
7 #include <net/tcp.h>
8
ip_metrics_convert(struct net * net,struct nlattr * fc_mx,int fc_mx_len,u32 * metrics,struct netlink_ext_ack * extack)9 static int ip_metrics_convert(struct net *net, struct nlattr *fc_mx,
10 int fc_mx_len, u32 *metrics,
11 struct netlink_ext_ack *extack)
12 {
13 bool ecn_ca = false;
14 struct nlattr *nla;
15 int remaining;
16
17 if (!fc_mx)
18 return 0;
19
20 nla_for_each_attr(nla, fc_mx, fc_mx_len, remaining) {
21 int type = nla_type(nla);
22 u32 val;
23
24 if (!type)
25 continue;
26 if (type > RTAX_MAX) {
27 NL_SET_ERR_MSG(extack, "Invalid metric type");
28 return -EINVAL;
29 }
30
31 if (type == RTAX_CC_ALGO) {
32 char tmp[TCP_CA_NAME_MAX];
33
34 nla_strscpy(tmp, nla, sizeof(tmp));
35 val = tcp_ca_get_key_by_name(net, tmp, &ecn_ca);
36 if (val == TCP_CA_UNSPEC) {
37 NL_SET_ERR_MSG(extack, "Unknown tcp congestion algorithm");
38 return -EINVAL;
39 }
40 } else {
41 if (nla_len(nla) != sizeof(u32)) {
42 NL_SET_ERR_MSG_ATTR(extack, nla,
43 "Invalid attribute in metrics");
44 return -EINVAL;
45 }
46 val = nla_get_u32(nla);
47 }
48 if (type == RTAX_ADVMSS && val > 65535 - 40)
49 val = 65535 - 40;
50 if (type == RTAX_MTU && val > 65535 - 15)
51 val = 65535 - 15;
52 if (type == RTAX_HOPLIMIT && val > 255)
53 val = 255;
54 if (type == RTAX_FEATURES && (val & ~RTAX_FEATURE_MASK)) {
55 NL_SET_ERR_MSG(extack, "Unknown flag set in feature mask in metrics attribute");
56 return -EINVAL;
57 }
58 metrics[type - 1] = val;
59 }
60
61 if (ecn_ca)
62 metrics[RTAX_FEATURES - 1] |= DST_FEATURE_ECN_CA;
63
64 return 0;
65 }
66
ip_fib_metrics_init(struct net * net,struct nlattr * fc_mx,int fc_mx_len,struct netlink_ext_ack * extack)67 struct dst_metrics *ip_fib_metrics_init(struct net *net, struct nlattr *fc_mx,
68 int fc_mx_len,
69 struct netlink_ext_ack *extack)
70 {
71 struct dst_metrics *fib_metrics;
72 int err;
73
74 if (!fc_mx)
75 return (struct dst_metrics *)&dst_default_metrics;
76
77 fib_metrics = kzalloc(sizeof(*fib_metrics), GFP_KERNEL);
78 if (unlikely(!fib_metrics))
79 return ERR_PTR(-ENOMEM);
80
81 err = ip_metrics_convert(net, fc_mx, fc_mx_len, fib_metrics->metrics,
82 extack);
83 if (!err) {
84 refcount_set(&fib_metrics->refcnt, 1);
85 } else {
86 kfree(fib_metrics);
87 fib_metrics = ERR_PTR(err);
88 }
89
90 return fib_metrics;
91 }
92 EXPORT_SYMBOL_GPL(ip_fib_metrics_init);
93