diff options
Diffstat (limited to 'net/ipv4/gre_demux.c')
-rw-r--r-- | net/ipv4/gre_demux.c | 235 |
1 files changed, 1 insertions, 234 deletions
diff --git a/net/ipv4/gre_demux.c b/net/ipv4/gre_demux.c index 4a7b5b2..d9c552a 100644 --- a/net/ipv4/gre_demux.c +++ b/net/ipv4/gre_demux.c @@ -31,7 +31,6 @@ #include <net/xfrm.h> static const struct gre_protocol __rcu *gre_proto[GREPROTO_MAX] __read_mostly; -static struct gre_cisco_protocol __rcu *gre_cisco_proto_list[GRE_IP_PROTO_MAX]; int gre_add_protocol(const struct gre_protocol *proto, u8 version) { @@ -61,197 +60,6 @@ int gre_del_protocol(const struct gre_protocol *proto, u8 version) } EXPORT_SYMBOL_GPL(gre_del_protocol); -void gre_build_header(struct sk_buff *skb, const struct tnl_ptk_info *tpi, - int hdr_len) -{ - struct gre_base_hdr *greh; - - skb_push(skb, hdr_len); - - skb_reset_transport_header(skb); - greh = (struct gre_base_hdr *)skb->data; - greh->flags = tnl_flags_to_gre_flags(tpi->flags); - greh->protocol = tpi->proto; - - if (tpi->flags&(TUNNEL_KEY|TUNNEL_CSUM|TUNNEL_SEQ)) { - __be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4); - - if (tpi->flags&TUNNEL_SEQ) { - *ptr = tpi->seq; - ptr--; - } - if (tpi->flags&TUNNEL_KEY) { - *ptr = tpi->key; - ptr--; - } - if (tpi->flags&TUNNEL_CSUM && - !(skb_shinfo(skb)->gso_type & - (SKB_GSO_GRE|SKB_GSO_GRE_CSUM))) { - *ptr = 0; - *(__sum16 *)ptr = csum_fold(skb_checksum(skb, 0, - skb->len, 0)); - } - } -} -EXPORT_SYMBOL_GPL(gre_build_header); - -static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, - bool *csum_err) -{ - const struct gre_base_hdr *greh; - __be32 *options; - int hdr_len; - - if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr)))) - return -EINVAL; - - greh = (struct gre_base_hdr *)skb_transport_header(skb); - if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING))) - return -EINVAL; - - tpi->flags = gre_flags_to_tnl_flags(greh->flags); - hdr_len = ip_gre_calc_hlen(tpi->flags); - - if (!pskb_may_pull(skb, hdr_len)) - return -EINVAL; - - greh = (struct gre_base_hdr *)skb_transport_header(skb); - tpi->proto = greh->protocol; - - options = (__be32 *)(greh + 1); - if (greh->flags & GRE_CSUM) { - if (skb_checksum_simple_validate(skb)) { - *csum_err = true; - return -EINVAL; - } - - skb_checksum_try_convert(skb, IPPROTO_GRE, 0, - null_compute_pseudo); - - options++; - } - - if (greh->flags & GRE_KEY) { - tpi->key = *options; - options++; - } else - tpi->key = 0; - - if (unlikely(greh->flags & GRE_SEQ)) { - tpi->seq = *options; - options++; - } else - tpi->seq = 0; - - /* WCCP version 1 and 2 protocol decoding. - * - Change protocol to IP - * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header - */ - if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) { - tpi->proto = htons(ETH_P_IP); - if ((*(u8 *)options & 0xF0) != 0x40) { - hdr_len += 4; - if (!pskb_may_pull(skb, hdr_len)) - return -EINVAL; - } - } - - return iptunnel_pull_header(skb, hdr_len, tpi->proto); -} - -static int gre_cisco_rcv(struct sk_buff *skb) -{ - struct tnl_ptk_info tpi; - int i; - bool csum_err = false; - -#ifdef CONFIG_NET_IPGRE_BROADCAST - if (ipv4_is_multicast(ip_hdr(skb)->daddr)) { - /* Looped back packet, drop it! */ - if (rt_is_output_route(skb_rtable(skb))) - goto drop; - } -#endif - - if (parse_gre_header(skb, &tpi, &csum_err) < 0) - goto drop; - - rcu_read_lock(); - for (i = 0; i < GRE_IP_PROTO_MAX; i++) { - struct gre_cisco_protocol *proto; - int ret; - - proto = rcu_dereference(gre_cisco_proto_list[i]); - if (!proto) - continue; - ret = proto->handler(skb, &tpi); - if (ret == PACKET_RCVD) { - rcu_read_unlock(); - return 0; - } - } - rcu_read_unlock(); - - icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); -drop: - kfree_skb(skb); - return 0; -} - -static void gre_cisco_err(struct sk_buff *skb, u32 info) -{ - /* All the routers (except for Linux) return only - * 8 bytes of packet payload. It means, that precise relaying of - * ICMP in the real Internet is absolutely infeasible. - * - * Moreover, Cisco "wise men" put GRE key to the third word - * in GRE header. It makes impossible maintaining even soft - * state for keyed - * GRE tunnels with enabled checksum. Tell them "thank you". - * - * Well, I wonder, rfc1812 was written by Cisco employee, - * what the hell these idiots break standards established - * by themselves??? - */ - - const int type = icmp_hdr(skb)->type; - const int code = icmp_hdr(skb)->code; - struct tnl_ptk_info tpi; - bool csum_err = false; - int i; - - if (parse_gre_header(skb, &tpi, &csum_err)) { - if (!csum_err) /* ignore csum errors. */ - return; - } - - if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { - ipv4_update_pmtu(skb, dev_net(skb->dev), info, - skb->dev->ifindex, 0, IPPROTO_GRE, 0); - return; - } - if (type == ICMP_REDIRECT) { - ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, 0, - IPPROTO_GRE, 0); - return; - } - - rcu_read_lock(); - for (i = 0; i < GRE_IP_PROTO_MAX; i++) { - struct gre_cisco_protocol *proto; - - proto = rcu_dereference(gre_cisco_proto_list[i]); - if (!proto) - continue; - - if (proto->err_handler(skb, info, &tpi) == PACKET_RCVD) - goto out; - - } -out: - rcu_read_unlock(); -} - static int gre_rcv(struct sk_buff *skb) { const struct gre_protocol *proto; @@ -302,60 +110,19 @@ static const struct net_protocol net_gre_protocol = { .netns_ok = 1, }; -static const struct gre_protocol ipgre_protocol = { - .handler = gre_cisco_rcv, - .err_handler = gre_cisco_err, -}; - -int gre_cisco_register(struct gre_cisco_protocol *newp) -{ - struct gre_cisco_protocol **proto = (struct gre_cisco_protocol **) - &gre_cisco_proto_list[newp->priority]; - - return (cmpxchg(proto, NULL, newp) == NULL) ? 0 : -EBUSY; -} -EXPORT_SYMBOL_GPL(gre_cisco_register); - -int gre_cisco_unregister(struct gre_cisco_protocol *del_proto) -{ - struct gre_cisco_protocol **proto = (struct gre_cisco_protocol **) - &gre_cisco_proto_list[del_proto->priority]; - int ret; - - ret = (cmpxchg(proto, del_proto, NULL) == del_proto) ? 0 : -EINVAL; - - if (ret) - return ret; - - synchronize_net(); - return 0; -} -EXPORT_SYMBOL_GPL(gre_cisco_unregister); - static int __init gre_init(void) { pr_info("GRE over IPv4 demultiplexor driver\n"); if (inet_add_protocol(&net_gre_protocol, IPPROTO_GRE) < 0) { pr_err("can't add protocol\n"); - goto err; - } - - if (gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0) { - pr_info("%s: can't add ipgre handler\n", __func__); - goto err_gre; + return -EAGAIN; } - return 0; -err_gre: - inet_del_protocol(&net_gre_protocol, IPPROTO_GRE); -err: - return -EAGAIN; } static void __exit gre_exit(void) { - gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); inet_del_protocol(&net_gre_protocol, IPPROTO_GRE); } |