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