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 | |
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 | nla_for_each_attr(nla, fc_mx, fc_mx_len, remaining) { |
19 | int type = nla_type(nla); |
20 | u32 val; |
21 | |
22 | if (!type) |
23 | continue; |
24 | if (type > RTAX_MAX) { |
25 | NL_SET_ERR_MSG(extack, "Invalid metric type" ); |
26 | return -EINVAL; |
27 | } |
28 | |
29 | type = array_index_nospec(type, RTAX_MAX + 1); |
30 | if (type == RTAX_CC_ALGO) { |
31 | char tmp[TCP_CA_NAME_MAX]; |
32 | |
33 | nla_strscpy(dst: tmp, nla, dstsize: sizeof(tmp)); |
34 | val = tcp_ca_get_key_by_name(net, name: tmp, ecn_ca: &ecn_ca); |
35 | if (val == TCP_CA_UNSPEC) { |
36 | NL_SET_ERR_MSG(extack, "Unknown tcp congestion algorithm" ); |
37 | return -EINVAL; |
38 | } |
39 | } else { |
40 | if (nla_len(nla) != sizeof(u32)) { |
41 | NL_SET_ERR_MSG_ATTR(extack, nla, |
42 | "Invalid attribute in metrics" ); |
43 | return -EINVAL; |
44 | } |
45 | val = nla_get_u32(nla); |
46 | } |
47 | if (type == RTAX_ADVMSS && val > 65535 - 40) |
48 | val = 65535 - 40; |
49 | if (type == RTAX_MTU && val > 65535 - 15) |
50 | val = 65535 - 15; |
51 | if (type == RTAX_HOPLIMIT && val > 255) |
52 | val = 255; |
53 | if (type == RTAX_FEATURES && (val & ~RTAX_FEATURE_MASK)) { |
54 | NL_SET_ERR_MSG(extack, "Unknown flag set in feature mask in metrics attribute" ); |
55 | return -EINVAL; |
56 | } |
57 | metrics[type - 1] = val; |
58 | } |
59 | |
60 | if (ecn_ca) |
61 | metrics[RTAX_FEATURES - 1] |= DST_FEATURE_ECN_CA; |
62 | |
63 | return 0; |
64 | } |
65 | |
66 | struct dst_metrics *ip_fib_metrics_init(struct net *net, struct nlattr *fc_mx, |
67 | int fc_mx_len, |
68 | struct netlink_ext_ack *extack) |
69 | { |
70 | struct dst_metrics *fib_metrics; |
71 | int err; |
72 | |
73 | if (!fc_mx) |
74 | return (struct dst_metrics *)&dst_default_metrics; |
75 | |
76 | fib_metrics = kzalloc(size: sizeof(*fib_metrics), GFP_KERNEL); |
77 | if (unlikely(!fib_metrics)) |
78 | return ERR_PTR(error: -ENOMEM); |
79 | |
80 | err = ip_metrics_convert(net, fc_mx, fc_mx_len, metrics: fib_metrics->metrics, |
81 | extack); |
82 | if (!err) { |
83 | refcount_set(r: &fib_metrics->refcnt, n: 1); |
84 | } else { |
85 | kfree(objp: fib_metrics); |
86 | fib_metrics = ERR_PTR(error: err); |
87 | } |
88 | |
89 | return fib_metrics; |
90 | } |
91 | EXPORT_SYMBOL_GPL(ip_fib_metrics_init); |
92 | |