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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 | // SPDX-License-Identifier: GPL-2.0-or-later /* * IP Payload Compression Protocol (IPComp) - RFC3173. * * Copyright (c) 2003 James Morris <jmorris@intercode.com.au> * * Todo: * - Tunable compression parameters. * - Compression stats. * - Adaptive compression. */ #include <linux/module.h> #include <linux/err.h> #include <linux/rtnetlink.h> #include <net/ip.h> #include <net/xfrm.h> #include <net/icmp.h> #include <net/ipcomp.h> #include <net/protocol.h> #include <net/sock.h> static int ipcomp4_err(struct sk_buff *skb, u32 info) { struct net *net = dev_net(skb->dev); __be32 spi; const struct iphdr *iph = (const struct iphdr *)skb->data; struct ip_comp_hdr *ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2)); struct xfrm_state *x; switch (icmp_hdr(skb)->type) { case ICMP_DEST_UNREACH: if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) return 0; break; case ICMP_REDIRECT: break; default: return 0; } spi = htonl(ntohs(ipch->cpi)); x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET); if (!x) return 0; if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) ipv4_update_pmtu(skb, net, info, 0, IPPROTO_COMP); else ipv4_redirect(skb, net, 0, IPPROTO_COMP); xfrm_state_put(x); return 0; } /* We always hold one tunnel user reference to indicate a tunnel */ static struct xfrm_state *ipcomp_tunnel_create(struct xfrm_state *x) { struct net *net = xs_net(x); struct xfrm_state *t; t = xfrm_state_alloc(net); if (!t) goto out; t->id.proto = IPPROTO_IPIP; t->id.spi = x->props.saddr.a4; t->id.daddr.a4 = x->id.daddr.a4; memcpy(&t->sel, &x->sel, sizeof(t->sel)); t->props.family = AF_INET; t->props.mode = x->props.mode; t->props.saddr.a4 = x->props.saddr.a4; t->props.flags = x->props.flags; t->props.extra_flags = x->props.extra_flags; memcpy(&t->mark, &x->mark, sizeof(t->mark)); t->if_id = x->if_id; if (xfrm_init_state(t)) goto error; atomic_set(&t->tunnel_users, 1); out: return t; error: t->km.state = XFRM_STATE_DEAD; xfrm_state_put(t); t = NULL; goto out; } /* * Must be protected by xfrm_cfg_mutex. State and tunnel user references are * always incremented on success. */ static int ipcomp_tunnel_attach(struct xfrm_state *x) { struct net *net = xs_net(x); int err = 0; struct xfrm_state *t; u32 mark = x->mark.v & x->mark.m; t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr.a4, x->props.saddr.a4, IPPROTO_IPIP, AF_INET); if (!t) { t = ipcomp_tunnel_create(x); if (!t) { err = -EINVAL; goto out; } xfrm_state_insert(t); xfrm_state_hold(t); } x->tunnel = t; atomic_inc(&t->tunnel_users); out: return err; } static int ipcomp4_init_state(struct xfrm_state *x, struct netlink_ext_ack *extack) { int err = -EINVAL; x->props.header_len = 0; switch (x->props.mode) { case XFRM_MODE_TRANSPORT: break; case XFRM_MODE_TUNNEL: x->props.header_len += sizeof(struct iphdr); break; default: NL_SET_ERR_MSG(extack, "Unsupported XFRM mode for IPcomp"); goto out; } err = ipcomp_init_state(x, extack); if (err) goto out; if (x->props.mode == XFRM_MODE_TUNNEL) { err = ipcomp_tunnel_attach(x); if (err) { NL_SET_ERR_MSG(extack, "Kernel error: failed to initialize the associated state"); goto out; } } err = 0; out: return err; } static int ipcomp4_rcv_cb(struct sk_buff *skb, int err) { return 0; } static const struct xfrm_type ipcomp_type = { .owner = THIS_MODULE, .proto = IPPROTO_COMP, .init_state = ipcomp4_init_state, .destructor = ipcomp_destroy, .input = ipcomp_input, .output = ipcomp_output }; static struct xfrm4_protocol ipcomp4_protocol = { .handler = xfrm4_rcv, .input_handler = xfrm_input, .cb_handler = ipcomp4_rcv_cb, .err_handler = ipcomp4_err, .priority = 0, }; static int __init ipcomp4_init(void) { if (xfrm_register_type(&ipcomp_type, AF_INET) < 0) { pr_info("%s: can't add xfrm type\n", __func__); return -EAGAIN; } if (xfrm4_protocol_register(&ipcomp4_protocol, IPPROTO_COMP) < 0) { pr_info("%s: can't add protocol\n", __func__); xfrm_unregister_type(&ipcomp_type, AF_INET); return -EAGAIN; } return 0; } static void __exit ipcomp4_fini(void) { if (xfrm4_protocol_deregister(&ipcomp4_protocol, IPPROTO_COMP) < 0) pr_info("%s: can't remove protocol\n", __func__); xfrm_unregister_type(&ipcomp_type, AF_INET); } module_init(ipcomp4_init); module_exit(ipcomp4_fini); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp/IPv4) - RFC3173"); MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>"); MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_COMP); |