net: implement IP_RECVTOS for IP_PKTOPTIONS

Currently, it is not easily possible to get TOS/DSCP value of packets from
an incoming TCP stream. The mechanism is there, IP_PKTOPTIONS getsockopt
with IP_RECVTOS set, the same way as incoming TTL can be queried. This is
not actually implemented for TOS, though.

This patch adds this functionality, both for IPv4 (IP_PKTOPTIONS) and IPv6
(IPV6_2292PKTOPTIONS). For IPv4, like in the IP_RECVTTL case, the value of
the TOS field is stored from the other party's ACK.

This is needed for proxies which require DSCP transparency. One such example
is at http://zph.bratcheda.org/.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jiri Benc 2012-02-09 09:35:49 +00:00 committed by David S. Miller
parent 7a3198a897
commit 4c507d2897
8 changed files with 17 additions and 1 deletions

View File

@ -366,7 +366,7 @@ struct ipv6_pinfo {
dontfrag:1;
__u8 min_hopcount;
__u8 tclass;
__u8 padding;
__u8 rcv_tclass;
__u32 dst_cookie;

View File

@ -168,6 +168,7 @@ struct inet_sock {
transparent:1,
mc_all:1,
nodefrag:1;
__u8 rcv_tos;
int uc_index;
int mc_index;
__be32 mc_addr;

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@ -381,6 +381,7 @@ lookup_protocol:
inet->mc_all = 1;
inet->mc_index = 0;
inet->mc_list = NULL;
inet->rcv_tos = 0;
sk_refcnt_debug_inc(sk);

View File

@ -1289,6 +1289,10 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
int hlim = inet->mc_ttl;
put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
}
if (inet->cmsg_flags & IP_CMSG_TOS) {
int tos = inet->rcv_tos;
put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
}
len -= msg.msg_controllen;
return put_user(len, optlen);
}

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@ -1463,6 +1463,7 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
ireq->opt = NULL;
newinet->mc_index = inet_iif(skb);
newinet->mc_ttl = ip_hdr(skb)->ttl;
newinet->rcv_tos = ip_hdr(skb)->tos;
inet_csk(newsk)->icsk_ext_hdr_len = 0;
if (inet_opt)
inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen;

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@ -214,6 +214,7 @@ lookup_protocol:
inet->mc_ttl = 1;
inet->mc_index = 0;
inet->mc_list = NULL;
inet->rcv_tos = 0;
if (ipv4_config.no_pmtu_disc)
inet->pmtudisc = IP_PMTUDISC_DONT;

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@ -1017,6 +1017,10 @@ static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
int hlim = np->mcast_hops;
put_cmsg(&msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
}
if (np->rxopt.bits.rxtclass) {
int tclass = np->rcv_tclass;
put_cmsg(&msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
}
if (np->rxopt.bits.rxoinfo) {
struct in6_pktinfo src_info;
src_info.ipi6_ifindex = np->mcast_oif ? np->mcast_oif :

View File

@ -1282,6 +1282,7 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
newnp->opt = NULL;
newnp->mcast_oif = inet6_iif(skb);
newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
/*
* No need to charge this sock to the relevant IPv6 refcnt debug socks count
@ -1360,6 +1361,7 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
newnp->opt = NULL;
newnp->mcast_oif = inet6_iif(skb);
newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
/* Clone native IPv6 options from listening socket (if any)
@ -1562,6 +1564,8 @@ ipv6_pktoptions:
np->mcast_oif = inet6_iif(opt_skb);
if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
if (np->rxopt.bits.rxtclass)
np->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
if (ipv6_opt_accepted(sk, opt_skb)) {
skb_set_owner_r(opt_skb, sk);
opt_skb = xchg(&np->pktoptions, opt_skb);