diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h index 236a81034fefec203e27bb73b5a1e5d7d512f8d5..c9cff977a7fb2cc9d8446715cc09a51e5090aff9 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 eaf94919291aaf78419a5f43b17d66eb07f12600..4e557f4e95538a26d19375415437733a9b084c6c 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 b8a2d63d1fb82f5084a0d98911b8110816dee963..ecbaae200131a880111fc221b581dc00958826b7 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;