The self-contained UDP-Litev4 module for v4; logically completely separate from
ipv4/udp.c.
--
include/net/udplite.h | 86 +++++++++++++++++++++++
net/ipv4/udplite.c | 186 ++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 272 insertions(+)
diff --git a/include/net/udplite.h b/include/net/udplite.h
new file mode 100644
index 0000000..90d7aec
--- /dev/null
+++ b/include/net/udplite.h
@@ -0,0 +1,86 @@
+/*
+ * Definitions for the UDP-Lite (RFC 3828) code.
+ */
+#ifndef _UDPLITE_H
+#define _UDPLITE_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);
+}
+
+/*
+ * Functions used by UDP-Litev4 and UDP-Litev6
+ */
+/* calculate checksum coverage set for outgoing packets */
+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 u32 udplite_csum_outgoing(struct sock *sk, int cscov)
+{
+ struct sk_buff *skb;
+ int off, len;
+ u32 csum = 0;
+
+ 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;
+}
+
+/*
+ * net/ipv4/udplite.c
+ */
+extern void udplite4_register(void);
+extern int udplite_get_port(struct sock *sk, unsigned short snum,
+ int (*scmp)(const struct sock *, const struct sock *));
+extern int udplite_checksum_init(struct sk_buff *skb, struct udphdr *uh,
+ u16 len, u32 saddr, u32 daddr );
+#endif /* _UDPLITE_H */
diff --git a/net/ipv4/udplite.c b/net/ipv4/udplite.c
new file mode 100644
index 0000000..7f6498d
--- /dev/null
+++ b/net/ipv4/udplite.c
@@ -0,0 +1,186 @@
+/*
+ * UDPLITE An implementation of the UDP-Lite protocol (RFC 3828).
+ *
+ * Version: $Id: udplite.c,v 1.24 2006/09/18 21:50:59 gerrit Exp gerrit $
+ *
+ * Authors: Gerrit Renker <[EMAIL PROTECTED]>
+ *
+ * Changes:
+ * Fixes:
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+struct hlist_head udplite_hash[UDP_HTABLE_SIZE];
+static int udplite_port_rover;
+DEFINE_SNMP_STAT(struct udp_mib, udplite_statistics) __read_mostly;
+
+/* Designate sk as UDP-Lite socket */
+static inline int udplite_sk_init(struct sock *sk)
+{
+ udp_sk(sk)->pcflag = UDPLITE_BIT;
+ return 0;
+}
+
+__inline__ int udplite_get_port(struct sock *sk, unsigned short p,
+ int (*c)(const struct sock *, const struct sock *))
+{
+ return __udp_lib_get_port(sk, p, udplite_hash, &udplite_port_rover, c);
+}
+
+static __inline__ int udplite_v4_get_port(struct sock *sk, unsigned short snum)
+{
+ return udplite_get_port(sk, snum, ipv4_rcv_saddr_equal);
+}
+
+static __inline__ struct sock *udplite_v4_lookup(u32 saddr, u16 sport,
+ u32 daddr, u16 dport, int dif)
+{
+ return __udp4_lib_lookup(saddr, sport, daddr, dport, dif, udplite_hash);
+}
+
+static __inline__ int udplite_v4_mcast_deliver(struct sk_buff *skb,
+ struct udphdr *uh, u32 saddr, u32 daddr)
+{
+ return __udp4_lib_mcast_deliver(skb, uh, saddr, daddr, udplite_hash);
+}
+
+__inline__ void udplite_err(struct sk_buff *skb, u32 info)
+{
+ return __udp4_lib_err(skb, info, udplite_hash);
+}
+
+int udplite_checksum_init(struct sk_buff *skb, struct udphdr *uh,
+ u16 len, u32 saddr, u32 daddr )
+{
+ 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 csum field"
+ "(%d.%d.%d.%d:%d -> %d.%d.%d.%d:%d)\n", NIPQUAD(saddr),
+ ntohs(uh->source), NIPQUAD(daddr), ntohs(uh->dest) );
+ return 0;
+ }
+
+ UDP_SKB_CB(skb)->partial_cov = 0;
+ cscov = ntohs(uh->len);
+
+ if (cscov == 0) /* Indicates that full coverage is required. */
+ cscov = len;
+ else if (cscov < 8 || cscov > len) {
+ /*
+ * Coverage length violates RFC 3828: log and discard silently.
+ */
+ LIMIT_NETDEBUG(KERN_DEBUG "UDPLITE: bad csum coverage %d/%d "
+ "(%d.%d.%d.%d:%d -> %d.%d.%d.%d:%d)\n", cscov, len,
+ NIPQUAD(saddr), ntohs(uh->source),
+ NIPQUAD(daddr), ntohs(uh->dest) );
+ return 0;
+
+ } else if (cscov < len)
+ UDP_SKB_CB(skb)->partial_cov = 1;
+
+ UDP_SKB_CB(skb)->cscov = cscov;
+
+ /*
+ * Initialise pseudo-header for checksum computation.
+ *
+ * There is no known NIC manufacturer supporting UDP-Lite yet,
+ * hence ip_summed is always (re-)set to CHECKSUM_NONE.
+ */
+ skb->csum = csum_tcpudp_nofold(saddr, daddr, len, IPPROTO_UDPLITE, 0);
+ skb->ip_summed = CHECKSUM_NONE;
+
+ return 1;
+}
+
+__inline__ int udplite_rcv(struct sk_buff *skb)
+{
+ return __udp4_lib_rcv(skb, udplite_hash, 1);
+}
+
+struct proto udplite_prot = {
+ .name = "UDP-Lite",
+ .owner = THIS_MODULE,
+ .close = udp_close,
+ .connect = ip4_datagram_connect,
+ .disconnect = udp_disconnect,
+ .ioctl = udp_ioctl,
+ .init = udplite_sk_init,
+ .destroy = udp_destroy_sock,
+ .setsockopt = udp_setsockopt,
+ .getsockopt = udp_getsockopt,
+ .sendmsg = udp_sendmsg,
+ .recvmsg = udp_recvmsg,
+ .sendpage = udp_sendpage,
+ .backlog_rcv = udp_queue_rcv_skb,
+ .hash = udp_lib_hash,
+ .unhash = udp_lib_unhash,
+ .get_port = udplite_v4_get_port,
+ .obj_size = sizeof(struct udp_sock),
+#ifdef CONFIG_COMPAT
+ .compat_setsockopt = compat_udp_setsockopt,
+ .compat_getsockopt = compat_udp_getsockopt,
+#endif
+};
+
+static struct net_protocol udplite_protocol = {
+ .handler = udplite_rcv,
+ .err_handler = udplite_err,
+ .no_policy = 1,
+};
+
+static struct inet_protosw udplite4_protosw = {
+ .type = SOCK_DGRAM,
+ .protocol = IPPROTO_UDPLITE,
+ .prot = &udplite_prot,
+ .ops = &inet_dgram_ops,
+ .capability = -1,
+ .no_check = 0, /* must checksum (RFC 3828) */
+ .flags = INET_PROTOSW_PERMANENT,
+};
+
+#ifdef CONFIG_PROC_FS
+static struct file_operations udplite4_seq_fops;
+static struct udp_seq_afinfo udplite4_seq_afinfo = {
+ .owner = THIS_MODULE,
+ .name = "udplite",
+ .family = AF_INET,
+ .hashtable = udplite_hash,
+ .seq_show = udp4_seq_show,
+ .seq_fops = &udplite4_seq_fops,
+};
+#endif /* CONFIG_PROC_FS */
+
+
+void __init udplite4_register(void)
+{
+ if (proto_register(&udplite_prot, 1))
+ goto out_register_err;
+
+ if (inet_add_protocol(&udplite_protocol, IPPROTO_UDPLITE) < 0)
+ goto out_unregister_proto;
+
+ inet_register_protosw(&udplite4_protosw);
+
+#ifdef CONFIG_PROC_FS
+ if (udp_proc_register(&udplite4_seq_afinfo)) /* udplite4_proc_init() */
+ printk(KERN_ERR "udplite4: Cannot register /proc!\n");
+#endif /* CONFIG_PROC_FS */
+ return;
+
+out_unregister_proto:
+ proto_unregister(&udplite_prot);
+out_register_err:
+ printk(KERN_CRIT "udplite4_register: Cannot add UDP-Lite protocol.\n");
+}
+
+EXPORT_SYMBOL(udplite_hash);
+EXPORT_SYMBOL(udplite_prot);
+EXPORT_SYMBOL(udplite_get_port); /* for v6 */
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