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-rw-r--r--include/net/inet_sock.h1
-rw-r--r--include/uapi/linux/in.h1
-rw-r--r--net/ipv4/ip_sockglue.c26
3 files changed, 28 insertions, 0 deletions
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index 236a81034fef..c9cff977a7fb 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -228,6 +228,7 @@ struct inet_sock {
#define IP_CMSG_PASSSEC BIT(5)
#define IP_CMSG_ORIGDSTADDR BIT(6)
#define IP_CMSG_CHECKSUM BIT(7)
+#define IP_CMSG_RECVFRAGSIZE BIT(8)
/**
* sk_to_full_sk - Access to a full socket
diff --git a/include/uapi/linux/in.h b/include/uapi/linux/in.h
index eaf94919291a..4e557f4e9553 100644
--- a/include/uapi/linux/in.h
+++ b/include/uapi/linux/in.h
@@ -117,6 +117,7 @@ struct in_addr {
#define IP_NODEFRAG 22
#define IP_CHECKSUM 23
#define IP_BIND_ADDRESS_NO_PORT 24
+#define IP_RECVFRAGSIZE 25
/* IP_MTU_DISCOVER values */
#define IP_PMTUDISC_DONT 0 /* Never send DF frames */
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index b8a2d63d1fb8..ecbaae200131 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -97,6 +97,17 @@ static void ip_cmsg_recv_retopts(struct msghdr *msg, struct sk_buff *skb)
put_cmsg(msg, SOL_IP, IP_RETOPTS, opt->optlen, opt->__data);
}
+static void ip_cmsg_recv_fragsize(struct msghdr *msg, struct sk_buff *skb)
+{
+ int val;
+
+ if (IPCB(skb)->frag_max_size == 0)
+ return;
+
+ val = IPCB(skb)->frag_max_size;
+ put_cmsg(msg, SOL_IP, IP_RECVFRAGSIZE, sizeof(val), &val);
+}
+
static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
int tlen, int offset)
{
@@ -218,6 +229,9 @@ void ip_cmsg_recv_offset(struct msghdr *msg, struct sk_buff *skb,
if (flags & IP_CMSG_CHECKSUM)
ip_cmsg_recv_checksum(msg, skb, tlen, offset);
+
+ if (flags & IP_CMSG_RECVFRAGSIZE)
+ ip_cmsg_recv_fragsize(msg, skb);
}
EXPORT_SYMBOL(ip_cmsg_recv_offset);
@@ -614,6 +628,7 @@ static int do_ip_setsockopt(struct sock *sk, int level,
case IP_MULTICAST_LOOP:
case IP_RECVORIGDSTADDR:
case IP_CHECKSUM:
+ case IP_RECVFRAGSIZE:
if (optlen >= sizeof(int)) {
if (get_user(val, (int __user *) optval))
return -EFAULT;
@@ -726,6 +741,14 @@ static int do_ip_setsockopt(struct sock *sk, int level,
}
}
break;
+ case IP_RECVFRAGSIZE:
+ if (sk->sk_type != SOCK_RAW && sk->sk_type != SOCK_DGRAM)
+ goto e_inval;
+ if (val)
+ inet->cmsg_flags |= IP_CMSG_RECVFRAGSIZE;
+ else
+ inet->cmsg_flags &= ~IP_CMSG_RECVFRAGSIZE;
+ break;
case IP_TOS: /* This sets both TOS and Precedence */
if (sk->sk_type == SOCK_STREAM) {
val &= ~INET_ECN_MASK;
@@ -1357,6 +1380,9 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
case IP_CHECKSUM:
val = (inet->cmsg_flags & IP_CMSG_CHECKSUM) != 0;
break;
+ case IP_RECVFRAGSIZE:
+ val = (inet->cmsg_flags & IP_CMSG_RECVFRAGSIZE) != 0;
+ break;
case IP_TOS:
val = inet->tos;
break;