From 584ca31f469dece9a83cdce33953ba23b115945c Mon Sep 17 00:00:00 2001 From: Tom Parkin Date: Thu, 23 Jul 2020 12:29:53 +0100 Subject: [PATCH] l2tp: cleanup netlink send of tunnel address information l2tp_nl_tunnel_send has conditionally compiled code to support AF_INET6, which makes the code difficult to follow and triggers checkpatch warnings. Split the code out into functions to handle the AF_INET v.s. AF_INET6 cases, which both improves readability and resolves the checkpatch warnings. Signed-off-by: Tom Parkin Signed-off-by: David S. Miller --- net/l2tp/l2tp_netlink.c | 126 ++++++++++++++++++++++------------------ 1 file changed, 70 insertions(+), 56 deletions(-) diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c index fc26ebad2f4f..0021cc03417e 100644 --- a/net/l2tp/l2tp_netlink.c +++ b/net/l2tp/l2tp_netlink.c @@ -310,16 +310,79 @@ out: return ret; } +#if IS_ENABLED(CONFIG_IPV6) +static int l2tp_nl_tunnel_send_addr6(struct sk_buff *skb, struct sock *sk, + enum l2tp_encap_type encap) +{ + struct inet_sock *inet = inet_sk(sk); + struct ipv6_pinfo *np = inet6_sk(sk); + + switch (encap) { + case L2TP_ENCAPTYPE_UDP: + if (udp_get_no_check6_tx(sk) && + nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX)) + return -1; + if (udp_get_no_check6_rx(sk) && + nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX)) + return -1; + if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) || + nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport))) + return -1; + fallthrough; + case L2TP_ENCAPTYPE_IP: + if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR, &np->saddr) || + nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR, &sk->sk_v6_daddr)) + return -1; + break; + } + return 0; +} +#endif + +static int l2tp_nl_tunnel_send_addr4(struct sk_buff *skb, struct sock *sk, + enum l2tp_encap_type encap) +{ + struct inet_sock *inet = inet_sk(sk); + + switch (encap) { + case L2TP_ENCAPTYPE_UDP: + if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx) || + nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) || + nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport))) + return -1; + fallthrough; + case L2TP_ENCAPTYPE_IP: + if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR, inet->inet_saddr) || + nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR, inet->inet_daddr)) + return -1; + break; + } + + return 0; +} + +/* Append attributes for the tunnel address, handling the different attribute types + * used for different tunnel encapsulation and AF_INET v.s. AF_INET6. + */ +static int l2tp_nl_tunnel_send_addr(struct sk_buff *skb, struct l2tp_tunnel *tunnel) +{ + struct sock *sk = tunnel->sock; + + if (!sk) + return 0; + +#if IS_ENABLED(CONFIG_IPV6) + if (sk->sk_family == AF_INET6) + return l2tp_nl_tunnel_send_addr6(skb, sk, tunnel->encap); +#endif + return l2tp_nl_tunnel_send_addr4(skb, sk, tunnel->encap); +} + static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags, struct l2tp_tunnel *tunnel, u8 cmd) { void *hdr; struct nlattr *nest; - struct sock *sk = NULL; - struct inet_sock *inet; -#if IS_ENABLED(CONFIG_IPV6) - struct ipv6_pinfo *np = NULL; -#endif hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd); if (!hdr) @@ -363,58 +426,9 @@ static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int fla goto nla_put_failure; nla_nest_end(skb, nest); - sk = tunnel->sock; - if (!sk) - goto out; + if (l2tp_nl_tunnel_send_addr(skb, tunnel)) + goto nla_put_failure; -#if IS_ENABLED(CONFIG_IPV6) - if (sk->sk_family == AF_INET6) - np = inet6_sk(sk); -#endif - - inet = inet_sk(sk); - - switch (tunnel->encap) { - case L2TP_ENCAPTYPE_UDP: - switch (sk->sk_family) { - case AF_INET: - if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx)) - goto nla_put_failure; - break; -#if IS_ENABLED(CONFIG_IPV6) - case AF_INET6: - if (udp_get_no_check6_tx(sk) && - nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX)) - goto nla_put_failure; - if (udp_get_no_check6_rx(sk) && - nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX)) - goto nla_put_failure; - break; -#endif - } - if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) || - nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport))) - goto nla_put_failure; - /* fall through */ - case L2TP_ENCAPTYPE_IP: -#if IS_ENABLED(CONFIG_IPV6) - if (np) { - if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR, - &np->saddr) || - nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR, - &sk->sk_v6_daddr)) - goto nla_put_failure; - } else -#endif - if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR, - inet->inet_saddr) || - nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR, - inet->inet_daddr)) - goto nla_put_failure; - break; - } - -out: genlmsg_end(skb, hdr); return 0;