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-rw-r--r--include/linux/icmp.h4
-rw-r--r--include/net/inet_sock.h1
-rw-r--r--include/uapi/linux/errqueue.h14
-rw-r--r--include/uapi/linux/icmp.h22
-rw-r--r--include/uapi/linux/in.h1
-rw-r--r--net/ipv4/icmp.c71
-rw-r--r--net/ipv4/ip_sockglue.c12
7 files changed, 124 insertions, 1 deletions
diff --git a/include/linux/icmp.h b/include/linux/icmp.h
index 81ca84ce3119..8fc38a34cb20 100644
--- a/include/linux/icmp.h
+++ b/include/linux/icmp.h
@@ -15,6 +15,7 @@
#include <linux/skbuff.h>
#include <uapi/linux/icmp.h>
+#include <uapi/linux/errqueue.h>
static inline struct icmphdr *icmp_hdr(const struct sk_buff *skb)
{
@@ -35,4 +36,7 @@ static inline bool icmp_is_err(int type)
return false;
}
+void ip_icmp_error_rfc4884(const struct sk_buff *skb,
+ struct sock_ee_data_rfc4884 *out);
+
#endif /* _LINUX_ICMP_H */
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index a7ce00af6c44..a3702d1d4875 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -225,6 +225,7 @@ struct inet_sock {
mc_all:1,
nodefrag:1;
__u8 bind_address_no_port:1,
+ recverr_rfc4884:1,
defer_connect:1; /* Indicates that fastopen_connect is set
* and cookie exists so we defer connect
* until first data frame is written
diff --git a/include/uapi/linux/errqueue.h b/include/uapi/linux/errqueue.h
index ca5cb3e3c6df..3c70e8ac14b8 100644
--- a/include/uapi/linux/errqueue.h
+++ b/include/uapi/linux/errqueue.h
@@ -5,6 +5,13 @@
#include <linux/types.h>
#include <linux/time_types.h>
+/* RFC 4884: return offset to extension struct + validation */
+struct sock_ee_data_rfc4884 {
+ __u16 len;
+ __u8 flags;
+ __u8 reserved;
+};
+
struct sock_extended_err {
__u32 ee_errno;
__u8 ee_origin;
@@ -12,7 +19,10 @@ struct sock_extended_err {
__u8 ee_code;
__u8 ee_pad;
__u32 ee_info;
- __u32 ee_data;
+ union {
+ __u32 ee_data;
+ struct sock_ee_data_rfc4884 ee_rfc4884;
+ };
};
#define SO_EE_ORIGIN_NONE 0
@@ -31,6 +41,8 @@ struct sock_extended_err {
#define SO_EE_CODE_TXTIME_INVALID_PARAM 1
#define SO_EE_CODE_TXTIME_MISSED 2
+#define SO_EE_RFC4884_FLAG_INVALID 1
+
/**
* struct scm_timestamping - timestamps exposed through cmsg
*
diff --git a/include/uapi/linux/icmp.h b/include/uapi/linux/icmp.h
index 5589eeb791ca..fb169a50895e 100644
--- a/include/uapi/linux/icmp.h
+++ b/include/uapi/linux/icmp.h
@@ -19,6 +19,7 @@
#define _UAPI_LINUX_ICMP_H
#include <linux/types.h>
+#include <asm/byteorder.h>
#define ICMP_ECHOREPLY 0 /* Echo Reply */
#define ICMP_DEST_UNREACH 3 /* Destination Unreachable */
@@ -95,5 +96,26 @@ struct icmp_filter {
__u32 data;
};
+/* RFC 4884 extension struct: one per message */
+struct icmp_ext_hdr {
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+ __u8 reserved1:4,
+ version:4;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+ __u8 version:4,
+ reserved1:4;
+#else
+#error "Please fix <asm/byteorder.h>"
+#endif
+ __u8 reserved2;
+ __sum16 checksum;
+};
+
+/* RFC 4884 extension object header: one for each object */
+struct icmp_extobj_hdr {
+ __be16 length;
+ __u8 class_num;
+ __u8 class_type;
+};
#endif /* _UAPI_LINUX_ICMP_H */
diff --git a/include/uapi/linux/in.h b/include/uapi/linux/in.h
index 8533bf07450f..3d0d8231dc19 100644
--- a/include/uapi/linux/in.h
+++ b/include/uapi/linux/in.h
@@ -123,6 +123,7 @@ struct in_addr {
#define IP_CHECKSUM 23
#define IP_BIND_ADDRESS_NO_PORT 24
#define IP_RECVFRAGSIZE 25
+#define IP_RECVERR_RFC4884 26
/* IP_MTU_DISCOVER values */
#define IP_PMTUDISC_DONT 0 /* Never send DF frames */
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index e30515f89802..793aebf07c2a 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -1116,6 +1116,77 @@ error:
goto drop;
}
+static bool ip_icmp_error_rfc4884_validate(const struct sk_buff *skb, int off)
+{
+ struct icmp_extobj_hdr *objh, _objh;
+ struct icmp_ext_hdr *exth, _exth;
+ u16 olen;
+
+ exth = skb_header_pointer(skb, off, sizeof(_exth), &_exth);
+ if (!exth)
+ return false;
+ if (exth->version != 2)
+ return true;
+
+ if (exth->checksum &&
+ csum_fold(skb_checksum(skb, off, skb->len - off, 0)))
+ return false;
+
+ off += sizeof(_exth);
+ while (off < skb->len) {
+ objh = skb_header_pointer(skb, off, sizeof(_objh), &_objh);
+ if (!objh)
+ return false;
+
+ olen = ntohs(objh->length);
+ if (olen < sizeof(_objh))
+ return false;
+
+ off += olen;
+ if (off > skb->len)
+ return false;
+ }
+
+ return true;
+}
+
+void ip_icmp_error_rfc4884(const struct sk_buff *skb,
+ struct sock_ee_data_rfc4884 *out)
+{
+ int hlen, off;
+
+ switch (icmp_hdr(skb)->type) {
+ case ICMP_DEST_UNREACH:
+ case ICMP_TIME_EXCEEDED:
+ case ICMP_PARAMETERPROB:
+ break;
+ default:
+ return;
+ }
+
+ /* outer headers up to inner iph. skb->data is at inner payload */
+ hlen = -skb_transport_offset(skb) - sizeof(struct icmphdr);
+
+ /* per rfc 791: maximum packet length of 576 bytes */
+ if (hlen + skb->len > 576)
+ return;
+
+ /* per rfc 4884: minimal datagram length of 128 bytes */
+ off = icmp_hdr(skb)->un.reserved[1] * sizeof(u32);
+ if (off < 128)
+ return;
+
+ /* kernel has stripped headers: return payload offset in bytes */
+ off -= hlen;
+ if (off + sizeof(struct icmp_ext_hdr) > skb->len)
+ return;
+
+ out->len = off;
+
+ if (!ip_icmp_error_rfc4884_validate(skb, off))
+ out->flags |= SO_EE_RFC4884_FLAG_INVALID;
+}
+
int icmp_err(struct sk_buff *skb, u32 info)
{
struct iphdr *iph = (struct iphdr *)skb->data;
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 86b3b9a7cea3..a5ea02d7a183 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -411,6 +411,9 @@ void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
serr->port = port;
if (skb_pull(skb, payload - skb->data)) {
+ if (inet_sk(sk)->recverr_rfc4884)
+ ip_icmp_error_rfc4884(skb, &serr->ee.ee_rfc4884);
+
skb_reset_transport_header(skb);
if (sock_queue_err_skb(sk, skb) == 0)
return;
@@ -904,6 +907,7 @@ static int do_ip_setsockopt(struct sock *sk, int level,
case IP_RECVORIGDSTADDR:
case IP_CHECKSUM:
case IP_RECVFRAGSIZE:
+ case IP_RECVERR_RFC4884:
if (optlen >= sizeof(int)) {
if (get_user(val, (int __user *) optval))
return -EFAULT;
@@ -1063,6 +1067,11 @@ static int do_ip_setsockopt(struct sock *sk, int level,
if (!val)
skb_queue_purge(&sk->sk_error_queue);
break;
+ case IP_RECVERR_RFC4884:
+ if (val < 0 || val > 1)
+ goto e_inval;
+ inet->recverr_rfc4884 = !!val;
+ break;
case IP_MULTICAST_TTL:
if (sk->sk_type == SOCK_STREAM)
goto e_inval;
@@ -1611,6 +1620,9 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
case IP_RECVERR:
val = inet->recverr;
break;
+ case IP_RECVERR_RFC4884:
+ val = inet->recverr_rfc4884;
+ break;
case IP_MULTICAST_TTL:
val = inet->mc_ttl;
break;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.