1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/netlink.h>
3 #include <linux/nospec.h>
4 #include <linux/rtnetlink.h>
5 #include <linux/types.h>
6 #include <net/ip.h>
7 #include <net/net_namespace.h>
8 #include <net/tcp.h>
9
ip_metrics_convert(struct net * net,struct nlattr * fc_mx,int fc_mx_len,u32 * metrics,struct netlink_ext_ack * extack)10 static int ip_metrics_convert(struct net *net, struct nlattr *fc_mx,
11 int fc_mx_len, u32 *metrics,
12 struct netlink_ext_ack *extack)
13 {
14 bool ecn_ca = false;
15 struct nlattr *nla;
16 int remaining;
17
18 if (!fc_mx)
19 return 0;
20
21 nla_for_each_attr(nla, fc_mx, fc_mx_len, remaining) {
22 int type = nla_type(nla);
23 u32 val;
24
25 if (!type)
26 continue;
27 if (type > RTAX_MAX) {
28 NL_SET_ERR_MSG(extack, "Invalid metric type");
29 return -EINVAL;
30 }
31
32 type = array_index_nospec(type, RTAX_MAX + 1);
33 if (type == RTAX_CC_ALGO) {
34 char tmp[TCP_CA_NAME_MAX];
35
36 nla_strlcpy(tmp, nla, sizeof(tmp));
37 val = tcp_ca_get_key_by_name(net, tmp, &ecn_ca);
38 if (val == TCP_CA_UNSPEC) {
39 NL_SET_ERR_MSG(extack, "Unknown tcp congestion algorithm");
40 return -EINVAL;
41 }
42 } else {
43 if (nla_len(nla) != sizeof(u32)) {
44 NL_SET_ERR_MSG_ATTR(extack, nla,
45 "Invalid attribute in metrics");
46 return -EINVAL;
47 }
48 val = nla_get_u32(nla);
49 }
50 if (type == RTAX_ADVMSS && val > 65535 - 40)
51 val = 65535 - 40;
52 if (type == RTAX_MTU && val > 65535 - 15)
53 val = 65535 - 15;
54 if (type == RTAX_HOPLIMIT && val > 255)
55 val = 255;
56 if (type == RTAX_FEATURES && (val & ~RTAX_FEATURE_MASK)) {
57 NL_SET_ERR_MSG(extack, "Unknown flag set in feature mask in metrics attribute");
58 return -EINVAL;
59 }
60 metrics[type - 1] = val;
61 }
62
63 if (ecn_ca)
64 metrics[RTAX_FEATURES - 1] |= DST_FEATURE_ECN_CA;
65
66 return 0;
67 }
68
ip_fib_metrics_init(struct net * net,struct nlattr * fc_mx,int fc_mx_len,struct netlink_ext_ack * extack)69 struct dst_metrics *ip_fib_metrics_init(struct net *net, struct nlattr *fc_mx,
70 int fc_mx_len,
71 struct netlink_ext_ack *extack)
72 {
73 struct dst_metrics *fib_metrics;
74 int err;
75
76 if (!fc_mx)
77 return (struct dst_metrics *)&dst_default_metrics;
78
79 fib_metrics = kzalloc(sizeof(*fib_metrics), GFP_KERNEL);
80 if (unlikely(!fib_metrics))
81 return ERR_PTR(-ENOMEM);
82
83 err = ip_metrics_convert(net, fc_mx, fc_mx_len, fib_metrics->metrics,
84 extack);
85 if (!err) {
86 refcount_set(&fib_metrics->refcnt, 1);
87 } else {
88 kfree(fib_metrics);
89 fib_metrics = ERR_PTR(err);
90 }
91
92 return fib_metrics;
93 }
94 EXPORT_SYMBOL_GPL(ip_fib_metrics_init);
95