#include <linux/skbuff.h>
#include <net/ip_tunnels.h>
+struct gre_base_hdr {
+ __be16 flags;
+ __be16 protocol;
+};
+#define GRE_HEADER_SECTION 4
+
#define GREPROTO_CISCO 0
#define GREPROTO_PPTP 1
#define GREPROTO_MAX 2
void (*err_handler)(struct sk_buff *skb, u32 info);
};
-struct gre_base_hdr {
- __be16 flags;
- __be16 protocol;
-};
-#define GRE_HEADER_SECTION 4
-
int gre_add_protocol(const struct gre_protocol *proto, u8 version);
int gre_del_protocol(const struct gre_protocol *proto, u8 version);
-struct gre_cisco_protocol {
- int (*handler)(struct sk_buff *skb, const struct tnl_ptk_info *tpi);
- int (*err_handler)(struct sk_buff *skb, u32 info,
- const struct tnl_ptk_info *tpi);
- u8 priority;
-};
-
-int gre_cisco_register(struct gre_cisco_protocol *proto);
-int gre_cisco_unregister(struct gre_cisco_protocol *proto);
-
struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
u8 name_assign_type);
-
-static inline int ip_gre_calc_hlen(__be16 o_flags)
-{
- int addend = 4;
-
- if (o_flags&TUNNEL_CSUM)
- addend += 4;
- if (o_flags&TUNNEL_KEY)
- addend += 4;
- if (o_flags&TUNNEL_SEQ)
- addend += 4;
- return addend;
-}
-
-static inline __be16 gre_flags_to_tnl_flags(__be16 flags)
-{
- __be16 tflags = 0;
-
- if (flags & GRE_CSUM)
- tflags |= TUNNEL_CSUM;
- if (flags & GRE_ROUTING)
- tflags |= TUNNEL_ROUTING;
- if (flags & GRE_KEY)
- tflags |= TUNNEL_KEY;
- if (flags & GRE_SEQ)
- tflags |= TUNNEL_SEQ;
- if (flags & GRE_STRICT)
- tflags |= TUNNEL_STRICT;
- if (flags & GRE_REC)
- tflags |= TUNNEL_REC;
- if (flags & GRE_VERSION)
- tflags |= TUNNEL_VERSION;
-
- return tflags;
-}
-
-static inline __be16 tnl_flags_to_gre_flags(__be16 tflags)
-{
- __be16 flags = 0;
-
- if (tflags & TUNNEL_CSUM)
- flags |= GRE_CSUM;
- if (tflags & TUNNEL_ROUTING)
- flags |= GRE_ROUTING;
- if (tflags & TUNNEL_KEY)
- flags |= GRE_KEY;
- if (tflags & TUNNEL_SEQ)
- flags |= GRE_SEQ;
- if (tflags & TUNNEL_STRICT)
- flags |= GRE_STRICT;
- if (tflags & TUNNEL_REC)
- flags |= GRE_REC;
- if (tflags & TUNNEL_VERSION)
- flags |= GRE_VERSION;
-
- return flags;
-}
-
#endif
#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)
{
}
EXPORT_SYMBOL_GPL(gre_del_protocol);
-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;
.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;
+ return -EAGAIN;
}
-
- if (gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0) {
- pr_info("%s: can't add ipgre handler\n", __func__);
- goto err_gre;
- }
-
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);
}
static int ipgre_net_id __read_mostly;
static int gre_tap_net_id __read_mostly;
-static int ipgre_err(struct sk_buff *skb, u32 info,
- const struct tnl_ptk_info *tpi)
+static int ip_gre_calc_hlen(__be16 o_flags)
+{
+ int addend = 4;
+
+ if (o_flags & TUNNEL_CSUM)
+ addend += 4;
+ if (o_flags & TUNNEL_KEY)
+ addend += 4;
+ if (o_flags & TUNNEL_SEQ)
+ addend += 4;
+ return addend;
+}
+
+static __be16 gre_flags_to_tnl_flags(__be16 flags)
+{
+ __be16 tflags = 0;
+
+ if (flags & GRE_CSUM)
+ tflags |= TUNNEL_CSUM;
+ if (flags & GRE_ROUTING)
+ tflags |= TUNNEL_ROUTING;
+ if (flags & GRE_KEY)
+ tflags |= TUNNEL_KEY;
+ if (flags & GRE_SEQ)
+ tflags |= TUNNEL_SEQ;
+ if (flags & GRE_STRICT)
+ tflags |= TUNNEL_STRICT;
+ if (flags & GRE_REC)
+ tflags |= TUNNEL_REC;
+ if (flags & GRE_VERSION)
+ tflags |= TUNNEL_VERSION;
+
+ return tflags;
+}
+
+static __be16 tnl_flags_to_gre_flags(__be16 tflags)
+{
+ __be16 flags = 0;
+
+ if (tflags & TUNNEL_CSUM)
+ flags |= GRE_CSUM;
+ if (tflags & TUNNEL_ROUTING)
+ flags |= GRE_ROUTING;
+ if (tflags & TUNNEL_KEY)
+ flags |= GRE_KEY;
+ if (tflags & TUNNEL_SEQ)
+ flags |= GRE_SEQ;
+ if (tflags & TUNNEL_STRICT)
+ flags |= GRE_STRICT;
+ if (tflags & TUNNEL_REC)
+ flags |= GRE_REC;
+ if (tflags & TUNNEL_VERSION)
+ flags |= GRE_VERSION;
+
+ return flags;
+}
+
+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 void ipgre_err(struct sk_buff *skb, u32 info,
+ const struct tnl_ptk_info *tpi)
{
/* All the routers (except for Linux) return only
switch (type) {
default:
case ICMP_PARAMETERPROB:
- return PACKET_RCVD;
+ return;
case ICMP_DEST_UNREACH:
switch (code) {
case ICMP_SR_FAILED:
case ICMP_PORT_UNREACH:
/* Impossible event. */
- return PACKET_RCVD;
+ return;
default:
/* All others are translated to HOST_UNREACH.
rfc2003 contains "deep thoughts" about NET_UNREACH,
break;
}
break;
+
case ICMP_TIME_EXCEEDED:
if (code != ICMP_EXC_TTL)
- return PACKET_RCVD;
+ return;
break;
case ICMP_REDIRECT:
iph->daddr, iph->saddr, tpi->key);
if (!t)
- return PACKET_REJECT;
+ return;
if (t->parms.iph.daddr == 0 ||
ipv4_is_multicast(t->parms.iph.daddr))
- return PACKET_RCVD;
+ return;
if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
- return PACKET_RCVD;
+ return;
if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
t->err_count++;
else
t->err_count = 1;
t->err_time = jiffies;
- return PACKET_RCVD;
+}
+
+static void gre_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;
+
+ 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;
+ }
+
+ ipgre_err(skb, info, &tpi);
}
static __be64 key_to_tunnel_id(__be32 key)
return PACKET_REJECT;
}
+static int gre_rcv(struct sk_buff *skb)
+{
+ struct tnl_ptk_info tpi;
+ 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;
+
+ if (ipgre_rcv(skb, &tpi) == PACKET_RCVD)
+ return 0;
+
+ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
+drop:
+ kfree_skb(skb);
+ return 0;
+}
+
static void build_header(struct sk_buff *skb, int hdr_len, __be16 flags,
__be16 proto, __be32 key, __be32 seq)
{
return ip_tunnel_init(dev);
}
-static struct gre_cisco_protocol ipgre_protocol = {
- .handler = ipgre_rcv,
- .err_handler = ipgre_err,
- .priority = 0,
+static const struct gre_protocol ipgre_protocol = {
+ .handler = gre_rcv,
+ .err_handler = gre_err,
};
static int __net_init ipgre_init_net(struct net *net)
if (err < 0)
goto pnet_tap_faied;
- err = gre_cisco_register(&ipgre_protocol);
+ err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
if (err < 0) {
pr_info("%s: can't add protocol\n", __func__);
goto add_proto_failed;
tap_ops_failed:
rtnl_link_unregister(&ipgre_link_ops);
rtnl_link_failed:
- gre_cisco_unregister(&ipgre_protocol);
+ gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
add_proto_failed:
unregister_pernet_device(&ipgre_tap_net_ops);
pnet_tap_faied:
{
rtnl_link_unregister(&ipgre_tap_ops);
rtnl_link_unregister(&ipgre_link_ops);
- gre_cisco_unregister(&ipgre_protocol);
+ gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
unregister_pernet_device(&ipgre_tap_net_ops);
unregister_pernet_device(&ipgre_net_ops);
}
projects / cascardo / linux.git / commitdiff