diff options
Diffstat (limited to 'net/ipv4/udp.c')
| -rw-r--r-- | net/ipv4/udp.c | 140 |
1 files changed, 23 insertions, 117 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index facb7e29304..28355350fb6 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 @@ -919,104 +920,6 @@ int udp_disconnect(struct sock *sk, int flags) return 0; } -/* return: - * 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 - */ -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; - int iphlen, len; - - __u8 *udpdata; - __be32 *udpdata32; - __u16 encap_type = up->encap_type; - - /* if we're overly short, let UDP handle it */ - len = skb->len - sizeof(struct udphdr); - if (len <= 0) - return 1; - - /* if this is not encapsulated socket, then just return now */ - if (!encap_type) - return 1; - - /* If this is a paged skb, make sure we pull up - * whatever data we need to look at. */ - if (!pskb_may_pull(skb, sizeof(struct udphdr) + min(len, 8))) - return 1; - - /* Now we can get the pointers */ - uh = udp_hdr(skb); - udpdata = (__u8 *)uh + sizeof(struct udphdr); - udpdata32 = (__be32 *)udpdata; - - switch (encap_type) { - default: - case UDP_ENCAP_ESPINUDP: - /* Check if this is a keepalive packet. If so, eat it. */ - if (len == 1 && udpdata[0] == 0xff) { - return 0; - } else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0) { - /* ESP Packet without Non-ESP header */ - len = sizeof(struct udphdr); - } else - /* Must be an IKE packet.. pass it through */ - return 1; - break; - case UDP_ENCAP_ESPINUDP_NON_IKE: - /* Check if this is a keepalive packet. If so, eat it. */ - if (len == 1 && udpdata[0] == 0xff) { - return 0; - } else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) && - udpdata32[0] == 0 && udpdata32[1] == 0) { - - /* ESP Packet with Non-IKE marker */ - len = sizeof(struct udphdr) + 2 * sizeof(u32); - } else - /* Must be an IKE packet.. pass it through */ - return 1; - break; - } - - /* 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 - * protocol to ESP, and then call into the transform receiver. - */ - if (skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) - return 0; - - /* Now we can update and verify the packet length... */ - iph = ip_hdr(skb); - iphlen = iph->ihl << 2; - iph->tot_len = htons(ntohs(iph->tot_len) - len); - if (skb->len < iphlen + len) { - /* packet is too small!?! */ - return 0; - } - - /* pull the data buffer up to the ESP header and set the - * transport header to point to ESP. Keep UDP on the stack - * for later. - */ - __skb_pull(skb, len); - skb_reset_transport_header(skb); - - /* modify the protocol (it's ESP!) */ - iph->protocol = IPPROTO_ESP; - - /* and let the caller know to send this into the ESP processor... */ - return -1; -#endif -} - /* returns: * -1: error * 0: success @@ -1039,28 +942,28 @@ int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb) if (up->encap_type) { /* - * This is an encapsulation socket, so let's see if this is - * an encapsulated packet. - * If it's a keepalive packet, then just eat it. - * If it's an encapsulateed packet, then pass it to the - * IPsec xfrm input and return the response - * appropriately. Otherwise, just fall through and - * pass this up the UDP socket. + * This is an encapsulation socket so pass the skb to + * the socket's udp_encap_rcv() hook. Otherwise, just + * fall through and pass this up the UDP socket. + * up->encap_rcv() returns the following value: + * =0 if skb was successfully passed to the encap + * handler or was discarded by it. + * >0 if skb should be passed on to UDP. + * <0 if skb should be resubmitted as proto -N */ - int ret; - ret = udp_encap_rcv(sk, skb); - if (ret == 0) { - /* Eat the packet .. */ - kfree_skb(skb); - return 0; - } - if (ret < 0) { - /* process the ESP packet */ - ret = xfrm4_rcv_encap(skb, up->encap_type); - UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag); - return -ret; + /* if we're overly short, let UDP handle it */ + if (skb->len > sizeof(struct udphdr) && + up->encap_rcv != NULL) { + int ret; + + ret = (*up->encap_rcv)(sk, skb); + if (ret <= 0) { + UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag); + return -ret; + } } + /* FALLTHROUGH -- it's a UDP Packet */ } @@ -1349,6 +1252,9 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname, case 0: case UDP_ENCAP_ESPINUDP: case UDP_ENCAP_ESPINUDP_NON_IKE: + up->encap_rcv = xfrm4_udp_encap_rcv; + /* FALLTHROUGH */ + case UDP_ENCAP_L2TPINUDP: up->encap_type = val; break; default: |