This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / include / net / udplite.h

diff --git a/include/net/udplite.h b/include/net/udplite.h
new file mode 100644 (file)
index 0000000..67ac514
--- /dev/null
+++ b/include/net/udplite.h
@@ -0,0 +1,151 @@
+/*
+ *     Definitions for the UDP-Lite (RFC 3828) code.
+ */
+#ifndef _UDPLITE_H
+#define _UDPLITE_H
+
+#include <net/ip6_checksum.h>
+
+/* UDP-Lite socket options */
+#define UDPLITE_SEND_CSCOV   10 /* sender partial coverage (as sent)      */
+#define UDPLITE_RECV_CSCOV   11 /* receiver partial coverage (threshold ) */
+
+extern struct proto            udplite_prot;
+extern struct hlist_head       udplite_hash[UDP_HTABLE_SIZE];
+
+/* UDP-Lite does not have a standardized MIB yet, so we inherit from UDP */
+DECLARE_SNMP_STAT(struct udp_mib, udplite_statistics);
+
+/*
+ *     Checksum computation is all in software, hence simpler getfrag.
+ */
+static __inline__ int udplite_getfrag(void *from, char *to, int  offset,
+                                     int len, int odd, struct sk_buff *skb)
+{
+       return memcpy_fromiovecend(to, (struct iovec *) from, offset, len);
+}
+
+/* Designate sk as UDP-Lite socket */
+static inline int udplite_sk_init(struct sock *sk)
+{
+       udp_sk(sk)->pcflag = UDPLITE_BIT;
+       return 0;
+}
+
+/*
+ *     Checksumming routines
+ */
+static inline int udplite_checksum_init(struct sk_buff *skb, struct udphdr *uh)
+{
+       u16 cscov;
+
+        /* In UDPv4 a zero checksum means that the transmitter generated no
+         * checksum. UDP-Lite (like IPv6) mandates checksums, hence packets
+         * with a zero checksum field are illegal.                            */
+       if (uh->check == 0) {
+               LIMIT_NETDEBUG(KERN_DEBUG "UDPLITE: zeroed checksum field\n");
+               return 1;
+       }
+
+        UDP_SKB_CB(skb)->partial_cov = 0;
+       cscov = ntohs(uh->len);
+
+       if (cscov == 0)          /* Indicates that full coverage is required. */
+               cscov = skb->len;
+       else if (cscov < 8  || cscov > skb->len) {
+               /*
+                * Coverage length violates RFC 3828: log and discard silently.
+                */
+               LIMIT_NETDEBUG(KERN_DEBUG "UDPLITE: bad csum coverage %d/%d\n",
+                              cscov, skb->len);
+               return 1;
+
+       } else if (cscov < skb->len)
+               UDP_SKB_CB(skb)->partial_cov = 1;
+
+        UDP_SKB_CB(skb)->cscov = cscov;
+
+       /*
+        * There is no known NIC manufacturer supporting UDP-Lite yet,
+        * hence ip_summed is always (re-)set to CHECKSUM_NONE.
+        */
+       skb->ip_summed = CHECKSUM_NONE;
+
+       return 0;
+}
+
+static __inline__ int udplite4_csum_init(struct sk_buff *skb, struct udphdr *uh)
+{
+       int rc = udplite_checksum_init(skb, uh);
+
+       if (!rc)
+               skb->csum = csum_tcpudp_nofold(skb->nh.iph->saddr,
+                                              skb->nh.iph->daddr,
+                                              skb->len, IPPROTO_UDPLITE, 0);
+       return rc;
+}
+
+static __inline__ int udplite6_csum_init(struct sk_buff *skb, struct udphdr *uh)
+{
+       int rc = udplite_checksum_init(skb, uh);
+
+       if (!rc)
+               skb->csum = ~csum_unfold(csum_ipv6_magic(&skb->nh.ipv6h->saddr,
+                                            &skb->nh.ipv6h->daddr,
+                                            skb->len, IPPROTO_UDPLITE, 0));
+       return rc;
+}
+
+static inline int udplite_sender_cscov(struct udp_sock *up, struct udphdr *uh)
+{
+       int cscov = up->len;
+
+       /*
+        * Sender has set `partial coverage' option on UDP-Lite socket
+        */
+       if (up->pcflag & UDPLITE_SEND_CC)    {
+               if (up->pcslen < up->len) {
+               /* up->pcslen == 0 means that full coverage is required,
+                * partial coverage only if  0 < up->pcslen < up->len */
+                       if (0 < up->pcslen) {
+                              cscov = up->pcslen;
+                       }
+                       uh->len = htons(up->pcslen);
+               }
+       /*
+        * NOTE: Causes for the error case  `up->pcslen > up->len':
+        *        (i)  Application error (will not be penalized).
+        *       (ii)  Payload too big for send buffer: data is split
+        *             into several packets, each with its own header.
+        *             In this case (e.g. last segment), coverage may
+        *             exceed packet length.
+        *       Since packets with coverage length > packet length are
+        *       illegal, we fall back to the defaults here.
+        */
+       }
+       return cscov;
+}
+
+static inline __wsum udplite_csum_outgoing(struct sock *sk, struct sk_buff *skb)
+{
+       int off, len, cscov = udplite_sender_cscov(udp_sk(sk), skb->h.uh);
+       __wsum csum = 0;
+
+       skb->ip_summed = CHECKSUM_NONE;     /* no HW support for checksumming */
+
+       skb_queue_walk(&sk->sk_write_queue, skb) {
+               off = skb->h.raw - skb->data;
+               len = skb->len - off;
+
+               csum = skb_checksum(skb, off, (cscov > len)? len : cscov, csum);
+
+               if ((cscov -= len) <= 0)
+                       break;
+       }
+       return csum;
+}
+
+extern void    udplite4_register(void);
+extern int     udplite_get_port(struct sock *sk, unsigned short snum,
+                       int (*scmp)(const struct sock *, const struct sock *));
+#endif /* _UDPLITE_H */