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 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_strlcpy(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 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