metrics.c 2.2 KB

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192
  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. static int ip_metrics_convert(struct net *net, struct nlattr *fc_mx,
  9. int fc_mx_len, u32 *metrics,
  10. struct netlink_ext_ack *extack)
  11. {
  12. bool ecn_ca = false;
  13. struct nlattr *nla;
  14. int remaining;
  15. if (!fc_mx)
  16. return 0;
  17. nla_for_each_attr(nla, fc_mx, fc_mx_len, remaining) {
  18. int type = nla_type(nla);
  19. u32 val;
  20. if (!type)
  21. continue;
  22. if (type > RTAX_MAX) {
  23. NL_SET_ERR_MSG(extack, "Invalid metric type");
  24. return -EINVAL;
  25. }
  26. if (type == RTAX_CC_ALGO) {
  27. char tmp[TCP_CA_NAME_MAX];
  28. nla_strlcpy(tmp, nla, sizeof(tmp));
  29. val = tcp_ca_get_key_by_name(net, tmp, &ecn_ca);
  30. if (val == TCP_CA_UNSPEC) {
  31. NL_SET_ERR_MSG(extack, "Unknown tcp congestion algorithm");
  32. return -EINVAL;
  33. }
  34. } else {
  35. if (nla_len(nla) != sizeof(u32)) {
  36. NL_SET_ERR_MSG_ATTR(extack, nla,
  37. "Invalid attribute in metrics");
  38. return -EINVAL;
  39. }
  40. val = nla_get_u32(nla);
  41. }
  42. if (type == RTAX_ADVMSS && val > 65535 - 40)
  43. val = 65535 - 40;
  44. if (type == RTAX_MTU && val > 65535 - 15)
  45. val = 65535 - 15;
  46. if (type == RTAX_HOPLIMIT && val > 255)
  47. val = 255;
  48. if (type == RTAX_FEATURES && (val & ~RTAX_FEATURE_MASK)) {
  49. NL_SET_ERR_MSG(extack, "Unknown flag set in feature mask in metrics attribute");
  50. return -EINVAL;
  51. }
  52. metrics[type - 1] = val;
  53. }
  54. if (ecn_ca)
  55. metrics[RTAX_FEATURES - 1] |= DST_FEATURE_ECN_CA;
  56. return 0;
  57. }
  58. struct dst_metrics *ip_fib_metrics_init(struct net *net, struct nlattr *fc_mx,
  59. int fc_mx_len,
  60. struct netlink_ext_ack *extack)
  61. {
  62. struct dst_metrics *fib_metrics;
  63. int err;
  64. if (!fc_mx)
  65. return (struct dst_metrics *)&dst_default_metrics;
  66. fib_metrics = kzalloc(sizeof(*fib_metrics), GFP_KERNEL);
  67. if (unlikely(!fib_metrics))
  68. return ERR_PTR(-ENOMEM);
  69. err = ip_metrics_convert(net, fc_mx, fc_mx_len, fib_metrics->metrics,
  70. extack);
  71. if (!err) {
  72. refcount_set(&fib_metrics->refcnt, 1);
  73. } else {
  74. kfree(fib_metrics);
  75. fib_metrics = ERR_PTR(err);
  76. }
  77. return fib_metrics;
  78. }
  79. EXPORT_SYMBOL_GPL(ip_fib_metrics_init);