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-rw-r--r--include/linux/icmpv6.h5
-rw-r--r--include/net/ip_tunnels.h1
-rw-r--r--include/uapi/linux/icmp.h1
-rw-r--r--net/ipv4/gre_demux.c1
-rw-r--r--net/ipv4/ip_gre.c9
-rw-r--r--net/ipv6/icmp.c72
-rw-r--r--net/ipv6/ip6_icmp.c2
-rw-r--r--net/ipv6/sit.c44
8 files changed, 92 insertions, 43 deletions
diff --git a/include/linux/icmpv6.h b/include/linux/icmpv6.h
index 630f45335c73..57086e9fc64c 100644
--- a/include/linux/icmpv6.h
+++ b/include/linux/icmpv6.h
@@ -14,9 +14,12 @@ static inline struct icmp6hdr *icmp6_hdr(const struct sk_buff *skb)
#if IS_ENABLED(CONFIG_IPV6)
extern void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info);
-typedef void ip6_icmp_send_t(struct sk_buff *skb, u8 type, u8 code, __u32 info);
+typedef void ip6_icmp_send_t(struct sk_buff *skb, u8 type, u8 code, __u32 info,
+ const struct in6_addr *force_saddr);
extern int inet6_register_icmp_sender(ip6_icmp_send_t *fn);
extern int inet6_unregister_icmp_sender(ip6_icmp_send_t *fn);
+int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
+ unsigned int data_len);
#else
diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h
index 9222678426a1..a5e7035fb93f 100644
--- a/include/net/ip_tunnels.h
+++ b/include/net/ip_tunnels.h
@@ -157,6 +157,7 @@ struct tnl_ptk_info {
__be16 proto;
__be32 key;
__be32 seq;
+ int hdr_len;
};
#define PACKET_RCVD 0
diff --git a/include/uapi/linux/icmp.h b/include/uapi/linux/icmp.h
index 16fff055f734..fddd9d736284 100644
--- a/include/uapi/linux/icmp.h
+++ b/include/uapi/linux/icmp.h
@@ -79,6 +79,7 @@ struct icmphdr {
__be16 __unused;
__be16 mtu;
} frag;
+ __u8 reserved[4];
} un;
};
diff --git a/net/ipv4/gre_demux.c b/net/ipv4/gre_demux.c
index 4c39f4fd332a..c4c3e439f424 100644
--- a/net/ipv4/gre_demux.c
+++ b/net/ipv4/gre_demux.c
@@ -117,6 +117,7 @@ int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
if ((*(u8 *)options & 0xF0) != 0x40)
hdr_len += 4;
}
+ tpi->hdr_len = hdr_len;
return hdr_len;
}
EXPORT_SYMBOL(gre_parse_header);
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 0f8ca3fca00a..8eec78f53f9e 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -144,6 +144,7 @@ static void ipgre_err(struct sk_buff *skb, u32 info,
const struct iphdr *iph;
const int type = icmp_hdr(skb)->type;
const int code = icmp_hdr(skb)->code;
+ unsigned int data_len = 0;
struct ip_tunnel *t;
switch (type) {
@@ -169,6 +170,7 @@ static void ipgre_err(struct sk_buff *skb, u32 info,
case ICMP_TIME_EXCEEDED:
if (code != ICMP_EXC_TTL)
return;
+ data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
break;
case ICMP_REDIRECT:
@@ -187,6 +189,13 @@ static void ipgre_err(struct sk_buff *skb, u32 info,
if (!t)
return;
+#if IS_ENABLED(CONFIG_IPV6)
+ if (tpi->proto == htons(ETH_P_IPV6) &&
+ !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len,
+ type, data_len))
+ return;
+#endif
+
if (t->parms.iph.daddr == 0 ||
ipv4_is_multicast(t->parms.iph.daddr))
return;
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index e32a72fb9982..fd11f5856ce8 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -388,7 +388,8 @@ relookup_failed:
/*
* Send an ICMP message in response to a packet in error
*/
-static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
+static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
+ const struct in6_addr *force_saddr)
{
struct net *net = dev_net(skb->dev);
struct inet6_dev *idev = NULL;
@@ -475,6 +476,8 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
memset(&fl6, 0, sizeof(fl6));
fl6.flowi6_proto = IPPROTO_ICMPV6;
fl6.daddr = hdr->saddr;
+ if (force_saddr)
+ saddr = force_saddr;
if (saddr)
fl6.saddr = *saddr;
fl6.flowi6_mark = mark;
@@ -551,10 +554,75 @@ out:
*/
void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
{
- icmp6_send(skb, ICMPV6_PARAMPROB, code, pos);
+ icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL);
kfree_skb(skb);
}
+/* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
+ * if sufficient data bytes are available
+ * @nhs is the size of the tunnel header(s) :
+ * Either an IPv4 header for SIT encap
+ * an IPv4 header + GRE header for GRE encap
+ */
+int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
+ unsigned int data_len)
+{
+ struct in6_addr temp_saddr;
+ struct rt6_info *rt;
+ struct sk_buff *skb2;
+ u32 info = 0;
+
+ if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8))
+ return 1;
+
+ /* RFC 4884 (partial) support for ICMP extensions */
+ if (data_len < 128 || (data_len & 7) || skb->len < data_len)
+ data_len = 0;
+
+ skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC);
+
+ if (!skb2)
+ return 1;
+
+ skb_dst_drop(skb2);
+ skb_pull(skb2, nhs);
+ skb_reset_network_header(skb2);
+
+ rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0, 0);
+
+ if (rt && rt->dst.dev)
+ skb2->dev = rt->dst.dev;
+
+ ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
+
+ if (data_len) {
+ /* RFC 4884 (partial) support :
+ * insert 0 padding at the end, before the extensions
+ */
+ __skb_push(skb2, nhs);
+ skb_reset_network_header(skb2);
+ memmove(skb2->data, skb2->data + nhs, data_len - nhs);
+ memset(skb2->data + data_len - nhs, 0, nhs);
+ /* RFC 4884 4.5 : Length is measured in 64-bit words,
+ * and stored in reserved[0]
+ */
+ info = (data_len/8) << 24;
+ }
+ if (type == ICMP_TIME_EXCEEDED)
+ icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
+ info, &temp_saddr);
+ else
+ icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
+ info, &temp_saddr);
+ if (rt)
+ ip6_rt_put(rt);
+
+ kfree_skb(skb2);
+
+ return 0;
+}
+EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
+
static void icmpv6_echo_reply(struct sk_buff *skb)
{
struct net *net = dev_net(skb->dev);
diff --git a/net/ipv6/ip6_icmp.c b/net/ipv6/ip6_icmp.c
index 14dacc544c3e..713676f14a0e 100644
--- a/net/ipv6/ip6_icmp.c
+++ b/net/ipv6/ip6_icmp.c
@@ -39,7 +39,7 @@ void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
if (!send)
goto out;
- send(skb, type, code, info);
+ send(skb, type, code, info, NULL);
out:
rcu_read_unlock();
}
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index d9f2bd6ef72d..cdd714690f95 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -479,47 +479,12 @@ static void ipip6_tunnel_uninit(struct net_device *dev)
dev_put(dev);
}
-/* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
- * if sufficient data bytes are available
- */
-static int ipip6_err_gen_icmpv6_unreach(struct sk_buff *skb)
-{
- int ihl = ((const struct iphdr *)skb->data)->ihl*4;
- struct rt6_info *rt;
- struct sk_buff *skb2;
-
- if (!pskb_may_pull(skb, ihl + sizeof(struct ipv6hdr) + 8))
- return 1;
-
- skb2 = skb_clone(skb, GFP_ATOMIC);
-
- if (!skb2)
- return 1;
-
- skb_dst_drop(skb2);
- skb_pull(skb2, ihl);
- skb_reset_network_header(skb2);
-
- rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0, 0);
-
- if (rt && rt->dst.dev)
- skb2->dev = rt->dst.dev;
-
- icmpv6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
-
- if (rt)
- ip6_rt_put(rt);
-
- kfree_skb(skb2);
-
- return 0;
-}
-
static int ipip6_err(struct sk_buff *skb, u32 info)
{
const struct iphdr *iph = (const struct iphdr *)skb->data;
const int type = icmp_hdr(skb)->type;
const int code = icmp_hdr(skb)->code;
+ unsigned int data_len = 0;
struct ip_tunnel *t;
int err;
@@ -544,6 +509,7 @@ static int ipip6_err(struct sk_buff *skb, u32 info)
case ICMP_TIME_EXCEEDED:
if (code != ICMP_EXC_TTL)
return 0;
+ data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
break;
case ICMP_REDIRECT:
break;
@@ -571,11 +537,11 @@ static int ipip6_err(struct sk_buff *skb, u32 info)
goto out;
}
- if (t->parms.iph.daddr == 0)
+ err = 0;
+ if (!ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
goto out;
- err = 0;
- if (!ipip6_err_gen_icmpv6_unreach(skb))
+ if (t->parms.iph.daddr == 0)
goto out;
if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.