diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h index 605ca421d5ab..eb16c7beed1e 100644 --- a/include/net/inet_sock.h +++ b/include/net/inet_sock.h @@ -203,6 +203,7 @@ struct inet_sock { #define IP_CMSG_RETOPTS BIT(4) #define IP_CMSG_PASSSEC BIT(5) #define IP_CMSG_ORIGDSTADDR BIT(6) +#define IP_CMSG_CHECKSUM BIT(7) static inline struct inet_sock *inet_sk(const struct sock *sk) { diff --git a/include/uapi/linux/in.h b/include/uapi/linux/in.h index c33a65e3d62c..589ced069e8a 100644 --- a/include/uapi/linux/in.h +++ b/include/uapi/linux/in.h @@ -109,6 +109,7 @@ struct in_addr { #define IP_MINTTL 21 #define IP_NODEFRAG 22 +#define IP_CHECKSUM 23 /* 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 513d506ffebb..a317797b3cd0 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -37,6 +37,7 @@ #include #include #include +#include #if IS_ENABLED(CONFIG_IPV6) #include #endif @@ -96,6 +97,20 @@ 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_checksum(struct msghdr *msg, struct sk_buff *skb, + int offset) +{ + __wsum csum = skb->csum; + + if (skb->ip_summed != CHECKSUM_COMPLETE) + return; + + if (offset != 0) + csum = csum_sub(csum, csum_partial(skb->data, offset, 0)); + + put_cmsg(msg, SOL_IP, IP_CHECKSUM, sizeof(__wsum), &csum); +} + static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb) { char *secdata; @@ -191,9 +206,16 @@ void ip_cmsg_recv_offset(struct msghdr *msg, struct sk_buff *skb, return; } - if (flags & IP_CMSG_ORIGDSTADDR) + if (flags & IP_CMSG_ORIGDSTADDR) { ip_cmsg_recv_dstaddr(msg, skb); + flags &= ~IP_CMSG_ORIGDSTADDR; + if (!flags) + return; + } + + if (flags & IP_CMSG_CHECKSUM) + ip_cmsg_recv_checksum(msg, skb, offset); } EXPORT_SYMBOL(ip_cmsg_recv_offset); @@ -533,6 +555,7 @@ static int do_ip_setsockopt(struct sock *sk, int level, case IP_MULTICAST_ALL: case IP_MULTICAST_LOOP: case IP_RECVORIGDSTADDR: + case IP_CHECKSUM: if (optlen >= sizeof(int)) { if (get_user(val, (int __user *) optval)) return -EFAULT; @@ -630,6 +653,19 @@ static int do_ip_setsockopt(struct sock *sk, int level, else inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR; break; + case IP_CHECKSUM: + if (val) { + if (!(inet->cmsg_flags & IP_CMSG_CHECKSUM)) { + inet_inc_convert_csum(sk); + inet->cmsg_flags |= IP_CMSG_CHECKSUM; + } + } else { + if (inet->cmsg_flags & IP_CMSG_CHECKSUM) { + inet_dec_convert_csum(sk); + inet->cmsg_flags &= ~IP_CMSG_CHECKSUM; + } + } + break; case IP_TOS: /* This sets both TOS and Precedence */ if (sk->sk_type == SOCK_STREAM) { val &= ~INET_ECN_MASK; @@ -1233,6 +1269,9 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname, case IP_RECVORIGDSTADDR: val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0; break; + case IP_CHECKSUM: + val = (inet->cmsg_flags & IP_CMSG_CHECKSUM) != 0; + break; case IP_TOS: val = inet->tos; break; diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 53358d88f110..97ef1f8b7be8 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1329,7 +1329,7 @@ try_again: *addr_len = sizeof(*sin); } if (inet->cmsg_flags) - ip_cmsg_recv(msg, skb); + ip_cmsg_recv_offset(msg, skb, sizeof(struct udphdr)); err = copied; if (flags & MSG_TRUNC)