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| author | James Chapman <jchapman@katalix.com> | 2007-06-28 00:37:46 +0200 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-07-11 07:15:57 +0200 |
| commit | 342f0234c71b40da785dd6a7ce1dd481ecbfdb81 (patch) | |
| tree | b6d7295cd484449f3f6478fe3e796fc8988534a3 /net | |
| parent | [NET]: dev: secondary unicast address support (diff) | |
| download | linux-342f0234c71b40da785dd6a7ce1dd481ecbfdb81.tar.xz linux-342f0234c71b40da785dd6a7ce1dd481ecbfdb81.zip | |
[UDP]: Introduce UDP encapsulation type for L2TP
This patch adds a new UDP_ENCAP_L2TPINUDP encapsulation type for UDP
sockets. When a UDP socket's encap_type is UDP_ENCAP_L2TPINUDP, the
skb is delivered to a function pointed to by the udp_sock's
encap_rcv funcptr. If the skb isn't wanted by L2TP, it returns >0, which
causes it to be passed through to UDP.
Include padding to put the new encap_rcv field on a 4-byte boundary.
Previously, the only user of UDP encap sockets was ESP, so when
CONFIG_XFRM was not defined, some of the encap code was compiled
out. This patch changes that. As a result, udp_encap_rcv() will
now do a little more work when CONFIG_XFRM is not defined.
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/udp.c | 27 |
1 files changed, 23 insertions, 4 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index facb7e29304e..b9276f8bdac5 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -70,6 +70,7 @@ * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind * a single port at the same time. * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support + * James Chapman : Add L2TP encapsulation type. * * * This program is free software; you can redistribute it and/or @@ -923,12 +924,10 @@ int udp_disconnect(struct sock *sk, int flags) * 1 if the UDP system should process it * 0 if we should drop this packet * -1 if it should get processed by xfrm4_rcv_encap + * -2 if it should get processed by l2tp */ static int udp_encap_rcv(struct sock * sk, struct sk_buff *skb) { -#ifndef CONFIG_XFRM - return 1; -#else struct udp_sock *up = udp_sk(sk); struct udphdr *uh; struct iphdr *iph; @@ -983,8 +982,14 @@ static int udp_encap_rcv(struct sock * sk, struct sk_buff *skb) /* Must be an IKE packet.. pass it through */ return 1; break; + case UDP_ENCAP_L2TPINUDP: + /* Let caller know to send this to l2tp */ + return -2; } +#ifndef CONFIG_XFRM + return 1; +#else /* At this point we are sure that this is an ESPinUDP packet, * so we need to remove 'len' bytes from the packet (the UDP * header and optional ESP marker bytes) and then modify the @@ -1055,12 +1060,25 @@ int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb) kfree_skb(skb); return 0; } - if (ret < 0) { + if (ret == -1) { /* process the ESP packet */ ret = xfrm4_rcv_encap(skb, up->encap_type); UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag); return -ret; } + if (ret == -2) { + /* process the L2TP packet */ + if (up->encap_rcv != NULL) { + ret = (*up->encap_rcv)(sk, skb); + if (ret <= 0) { + UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag); + return ret; + } + + /* FALLTHROUGH -- pass up as UDP packet */ + } + } + /* FALLTHROUGH -- it's a UDP Packet */ } @@ -1349,6 +1367,7 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname, case 0: case UDP_ENCAP_ESPINUDP: case UDP_ENCAP_ESPINUDP_NON_IKE: + case UDP_ENCAP_L2TPINUDP: up->encap_type = val; break; default: |