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    Subject[PATCH 2.6.17-rc6-mm1 ] net: RFC 3828-compliant UDP-Lite support
    Date
    Attached is an extension which adds RFC3828 - compliant UDP-Lite functionality 
    to the IPv4 networking stack.

    The code has been adapted from our stable kernel patch, which we have been
    maintaining and testing extensively over the last 9 months. The attached
    has been tested to run ok so far on i386, dual-processor, and AMD architectures.

    Due to the similarities to UDP, a lot of code from net/ipv4/udp.c has been
    reused; whereas checksumming code has been rewritten entirely - in particular
    with regard to ensuring correct behaviour in various and unusual cases, such
    as fragmentation and split. Use CONFIG_IP_UDPLITE=y to enable, find docs attached.

    Please CC: any feedback/discussion to gerrit.renker@ukuug.org

    Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
    Signed-off-by: William Stanislaus <william@erg.abdn.ac.uk>
    ---


    Documentation/networking/udp_lite.txt | 246 ++++
    include/asm-mips/socket.h | 2
    include/linux/in.h | 1
    include/linux/net.h | 16
    include/linux/skbuff.h | 15
    include/linux/snmp.h | 18
    include/linux/socket.h | 1
    include/linux/udplite.h | 89 +
    include/net/snmp.h | 7
    include/net/udplite.h | 65 +
    include/net/xfrm.h | 2
    net/Kconfig | 1
    net/Makefile | 1
    net/core/sock.c | 7
    net/ipv4/af_inet.c | 64 +
    net/ipv4/proc.c | 32
    net/udp_lite/Kbuild | 1
    net/udp_lite/Kconfig | 20
    net/udp_lite/udplitev4.c | 1730 ++++++++++++++++++++++++++++++++++
    19 files changed, 2296 insertions(+), 22 deletions(-)



    diff -Nurp a/Documentation/networking/udp_lite.txt b/Documentation/networking/udp_lite.txt
    --- a/Documentation/networking/udp_lite.txt 1970-01-01 01:00:00.000000000 +0100
    +++ b/Documentation/networking/udp_lite.txt 2006-06-07 22:07:26.000000000 +0100
    @@ -0,0 +1,246 @@
    + ===========================================================================
    + The UDP-Lite protocol (RFC 3828)
    + ===========================================================================
    +
    + last modified: Wed 7 Jun 2006
    +
    +
    + UDP-Lite is a Standards-Track IETF transport protocol which features a
    + variable-length checksum. This has advantages for transport of multimedia
    + (video, VoIP) over wireless networks, as partly damaged packets can still be
    + fed into the codec instead of being discarded due to a failed checksum test.
    +
    + This file briefly describes the existing kernel support and the socket API.
    + For in-depth information, you can consult:-
    +
    + o The UDP-Lite Homepage: http://www.erg.abdn.ac.uk/users/gerrit/udp-lite/
    + Fom here you can always also pull the latest patch for the stable
    + kernel tree and example application source code.
    +
    + o The UDP-Lite HOWTO on
    + http://www.erg.abdn.ac.uk/users/gerrit/udp-lite/files/UDP-Lite-HOWTO.txt
    +
    + o The Ethereal UDP-Lite WiKi (with capture files):
    + http://wiki.ethereal.com/Lightweight_User_Datagram_Protocol
    +
    + o The Protocol Spec: RFC 3828, http://www.ietf.org/rfc/rfc3828.txt
    +
    +
    +
    + I) APPLICATIONS
    +
    + Several applications have ported successfully to UDP-Lite. Ethereal
    + now comes with UDP-Lite support by default. The tarball on
    +
    + http://www.erg.abdn.ac.uk/users/gerrit/udp-lite/files/udplite_linux.tar.gz
    +
    + has source code for several client-server and network testing examples.
    +
    + Porting applications to UDP-Lite is straightforward: only socket level and
    + IPPROTO need to be changed, senders additionally set the checksum coverage
    + length (default = header length = 8). Details are in the next section.
    +
    +
    +
    + II) PROGRAMMING API
    +
    + UDP-Lite introduces a new socket type, the SOCK_LDGRAM (note the L) for
    + lightweight, connection-less services. These are the socket options:
    +
    + * Sender checksum coverage: UDPLITE_SOCKOPT_SEND_CSCOV
    +
    + For instance,
    +
    + int val = 20;
    + setsockopt(s, SOL_UDPLITE, UDPLITE_SOCKOPT_SEND_CSCOV, &val, sizeof(int));
    +
    + sets the checksum coverage length to 20 (12b data + 8b header).
    +
    +
    + * Receiver checksum coverage: UDPLITE_SOCKOPT_RECV_CSCOV
    +
    + This option is analogously used at the receiver to set its
    + checksum coverage.
    + While the checksum coverage at the sender means the /actual/
    + length that will be used for the checksum, the receiver
    + checksum coverage stands for the /minimum/ coverage value a
    + receiver is willing to accept; and may drop packets which do
    + not meet this threshold.
    +
    + A detailed description of the socket options is in section IV.
    +
    +
    +
    + III) HEADER FILES
    +
    + The socket API requires support in header files in /usr/include:
    + * /usr/include/netinet/udplite.h
    + * /usr/include/netinet/in.h
    + * /usr/include/bits/socket.h
    + Changes are minor and replicate the information contained in the patched
    + kernel include files; details and example files for various distros can
    + be found on the UDP-Lite homepage
    +
    +
    +
    + IV) KERNEL BEHAVIOUR WITH REGARD TO THE VARIOUS SOCKET OPTIONS
    +
    + To enable debugging messages, the log level must be set to 8, as most
    + messages use the KERN_DEBUG level (7).
    +
    +
    + 1) Sender Socket Options
    +
    + If the sender specifies a value of 0 as coverage length, the module
    + assumes full coverage, transmits a packet with coverage length of 0
    + and according checksum. If the sender specifies a coverage < 8 and
    + different from 0, the kernel assumes 8 as default value. Finally,
    + if the specified coverage length exceeds the packet length, the packet
    + length is used instead as coverage length.
    +
    +
    + 2) Receiver Socket Options
    +
    + The receiver specifies the minimum value of the coverage length it
    + is willing to accept. A value of 0 here indicates that the receiver
    + always wants the whole of the packet covered. In this case, all
    + partially covered packets are dropped and an error is logged.
    +
    + It is not possible to specify illegal values (<0 and <8); in these
    + cases the default of 8 is assumed.
    +
    + All packets arriving with a coverage value less than the specified
    + threshold are discarded, these events are also logged.
    +
    +
    + 3) Disabling the Checksum Computation
    +
    + On both sender and receiver, trying to disable the UDP Lite checksum
    + (option SO_NO_CHECK) in setsockopt(2) results in an error. Thus
    +
    + setsockopt(sockfd,SOL_SOCKET, SO_NO_CHECK, ... );
    +
    + will always result in an error, while
    +
    + getsockopt(sockfd, SOL_SOCKET, SO_NO_CHECK, &value,...);
    +
    + will always return a value of 0 (meaning checksum enabled). Packets
    + with a zero checksum field are silently discarded by the receiver.
    +
    +
    + 4) Fragmentation
    +
    + The checksum computation respects both buffersize and MTU. The size
    + of UDP Lite packets is determined by the size of the send buffer. The
    + minimum size of the send buffer is 2048 (defined as SOCK_MIN_SNDBUF
    + in include/net/sock.h), the default value is configurable as
    + net.core.wmem_default or via setting the SO_SNDBUF socket(7)
    + option. The maximum upper bound for the send buffer is determined
    + by net.core.wmem_max.
    +
    + Given a payload size larger than the send buffer size, UDP Lite will
    + split the payload into several individual packets, filling up the
    + send buffer size in each case.
    +
    + The precise value also depends on the interface MTU. The interface MTU,
    + in turn, may trigger IP fragmentation. In this case, the generated
    + UDP Lite packet is split into several IP packets, of which only the
    + first one contains the header.
    +
    + The send buffer size has implications on the checksum coverage length.
    + Consider the following example:
    +
    + Payload: 1536 bytes Send Buffer: 1024 bytes
    + MTU : 1500 bytes Coverage Length: 856 bytes
    +
    + UDP Lite will ship the 1536 bytes in two separate packets:
    +
    + Packet 1: 1024 payload + 8 byte header + 20 byte IP header = 1052 bytes
    + Packet 2: 520 payload + 8 byte header + 20 byte IP header = 528 bytes
    +
    + The coverage packet covers the UDP Lite header and 848 bytes of the
    + payload in the first packet, the second packet is fully covered. Note
    + that for the second packet, the coverage length exceeds the packet
    + length. The kernel always re-adjusts the coverage length to the packet
    + length in such cases.
    +
    + As an example of what happens when one UDP Lite packet is split into
    + several tiny fragments, consider the following example.
    +
    + Payload: 1024 bytes Send buffer size: 1024 bytes
    + MTU: 300 bytes Coverage length: 575 bytes
    +
    + +-+-----------+--------------+--------------+--------------+
    + |8| 272 | 280 | 280 | 280 |
    + +-+-----------+--------------+--------------+--------------+
    + 280 560 840 1032
    + ^
    + *****checksum coverage*************
    +
    + The UDP Lite module generates one 1032 byte packet (1024 + 8 byte
    + header). According to the interface MTU, these are split into 4 IP
    + packets (280 byte IP payload + 20 byte IP header). The kernel module
    + sums the contents of the entire first two packets, plus 15 bytes of
    + the last packet before releasing the fragments to the IP module.
    +
    +
    +
    + V) UDP-LITE RUNTIME STATISTICS AND THEIR MEANING
    +
    + Exceptional and error conditions are logged to syslog at the KERN_DEBUG
    + level. Live statistics about UDP-Lite are available in /proc/net/snmp
    + and can--with newer versions of netstat--be queried using
    +
    + netstat -svu
    +
    + This displays UDP-Lite statistics variables, whose meaning is as follows.
    +
    + InDatagrams: Total number of received datagrams (as in UDP).
    +
    + InPartialCov: Number of received datagrams with csum coverage < length.
    +
    + NoPorts: Number of packets received to an unknown port (as in UDP).
    + These cases are counted separately (not as InErrors).
    +
    + InErrors: Number of erroneous UDP-Lite packets. Errors include:
    + * internal socket queue receive errors
    + * packet too short (less than 8 bytes or stated
    + coverage length exceeds received length)
    + * no socket available for ICMP error condition
    + * xfrm4_policy_check returned error
    + * application has specified larger min. coverage
    + length than that of incoming packet (cf. below)
    + * checksum coverage violated (InBadCoverage)
    + * bad checksum (InBadChecksum)
    +
    + InBadCoverage: Datagrams with invalid checksum coverage (also InErrors):
    + * coverage length is less than the minimum 8
    + * coverage length exceeds actual datagram length
    +
    + InBadChecksum: Datagrams with wrong checksum (also InErrors).
    +
    + OutDatagrams: Total number of sent datagrams.
    +
    + OutPartialCov: Number of sent datagrams with csum coverage < length.
    +
    + If a receiving application has specified a minimum coverage length and
    + received a packet with a smaller coverage value than this, or if it has
    + specified full coverage (UDP mode) and received a partially covered packet,
    + this counts as error (under InErrors), and an error message is logged.
    +
    +
    +
    + VI) OPEN ISSUES
    +
    + At the University of Aberdeen (where this patch was developed), much work
    + has gone into making sure that the UDP-Lite v4 variant behaves according
    + to spec. We have been maintaining and updating a patch for the stable
    + kernel tree since 2.6.12.4 and have run extensive experiments to verify
    + the protocol behaviour. As a result, there was no time left to develop an
    + IPv6 extension with the same degree of testing.
    + Secondly, the statistics variables detailed in the previous section are
    + not standardized. A MIB for UDP-Lite does not (yet) exist. For a person
    + familiar with SNMP/ASN.1 it would be a trivial task to turn the above
    + variable definitions into a MIB, in the same manner as per e.g. RFC 2013.
    + Anyone interested in helping with these two issues should contact us at
    + <gerrit@erg.abdn.ac.uk>.
    diff -Nurp a/include/asm-mips/socket.h b/include/asm-mips/socket.h
    --- a/include/asm-mips/socket.h 2006-06-05 21:52:55.000000000 +0100
    +++ b/include/asm-mips/socket.h 2006-06-07 21:28:09.000000000 +0100
    @@ -80,6 +80,7 @@ To add: #define SO_REUSEPORT 0x0200 /* A
    *
    * @SOCK_DGRAM - datagram (conn.less) socket
    * @SOCK_STREAM - stream (connection) socket
    + * @SOCK_LDGRAM - UDP Lite (conn.less) datagram socket (see RFC 3828)
    * @SOCK_RAW - raw socket
    * @SOCK_RDM - reliably-delivered message
    * @SOCK_SEQPACKET - sequential packet socket
    @@ -93,6 +94,7 @@ enum sock_type {
    SOCK_RDM = 4,
    SOCK_SEQPACKET = 5,
    SOCK_DCCP = 6,
    + SOCK_LDGRAM = 7,
    SOCK_PACKET = 10,
    };

    diff -Nurp a/include/linux/in.h b/include/linux/in.h
    --- a/include/linux/in.h 2006-06-07 20:44:01.000000000 +0100
    +++ b/include/linux/in.h 2006-06-07 21:28:09.000000000 +0100
    @@ -44,6 +44,7 @@ enum {

    IPPROTO_COMP = 108, /* Compression Header protocol */
    IPPROTO_SCTP = 132, /* Stream Control Transport Protocol */
    + IPPROTO_UDPLITE = 136, /* UDP-Lite Protocol (RFC 3828) */

    IPPROTO_RAW = 255, /* Raw IP packets */
    IPPROTO_MAX
    diff -Nurp a/include/linux/net.h b/include/linux/net.h
    --- a/include/linux/net.h 2006-06-07 20:49:51.000000000 +0100
    +++ b/include/linux/net.h 2006-06-07 21:28:09.000000000 +0100
    @@ -67,6 +67,7 @@ typedef enum {
    * enum sock_type - Socket types
    * @SOCK_STREAM: stream (connection) socket
    * @SOCK_DGRAM: datagram (conn.less) socket
    + * @SOCK_LDGRAM: UDP Lite datagram socket (see RFC 3828)
    * @SOCK_RAW: raw socket
    * @SOCK_RDM: reliably-delivered message
    * @SOCK_SEQPACKET: sequential packet socket
    @@ -79,13 +80,14 @@ typedef enum {
    * overrides this enum for binary compat reasons.
    */
    enum sock_type {
    - SOCK_STREAM = 1,
    - SOCK_DGRAM = 2,
    - SOCK_RAW = 3,
    - SOCK_RDM = 4,
    - SOCK_SEQPACKET = 5,
    - SOCK_DCCP = 6,
    - SOCK_PACKET = 10,
    + SOCK_STREAM = 1,
    + SOCK_DGRAM = 2,
    + SOCK_RAW = 3,
    + SOCK_RDM = 4,
    + SOCK_SEQPACKET = 5,
    + SOCK_DCCP = 6,
    + SOCK_LDGRAM = 7,
    + SOCK_PACKET = 10,
    };

    #define SOCK_MAX (SOCK_PACKET + 1)
    diff -Nurp a/include/linux/skbuff.h b/include/linux/skbuff.h
    --- a/include/linux/skbuff.h 2006-06-07 20:49:51.000000000 +0100
    +++ b/include/linux/skbuff.h 2006-06-07 21:28:09.000000000 +0100
    @@ -223,13 +223,14 @@ struct sk_buff {
    struct net_device *input_dev;

    union {
    - struct tcphdr *th;
    - struct udphdr *uh;
    - struct icmphdr *icmph;
    - struct igmphdr *igmph;
    - struct iphdr *ipiph;
    - struct ipv6hdr *ipv6h;
    - unsigned char *raw;
    + struct tcphdr *th;
    + struct udphdr *uh;
    + struct udplitehdr *ulh; /* UDP-Lite (RFC 3828) */
    + struct icmphdr *icmph;
    + struct igmphdr *igmph;
    + struct iphdr *ipiph;
    + struct ipv6hdr *ipv6h;
    + unsigned char *raw;
    } h;

    union {
    diff -Nurp a/include/linux/snmp.h b/include/linux/snmp.h
    --- a/include/linux/snmp.h 2006-06-05 21:52:55.000000000 +0100
    +++ b/include/linux/snmp.h 2006-06-07 21:28:09.000000000 +0100
    @@ -158,6 +158,24 @@ enum
    __UDP_MIB_MAX
    };

    +/*
    + * UDP Lite (RFC 3828) runtime statistics.
    + * A MIB does not exist yet, but these statistics are useful nevertheless.
    + */
    +enum
    +{
    + UDPLITE_MIB_NUM = 0,
    + UDPLITE_MIB_INDATAGRAMS, /* total received datagramns */
    + UDPLITE_MIB_INDATAGRAMS_PARTIAL_CHECK, /* rcvd datagrams with partial coverage */
    + UDPLITE_MIB_NOPORTS, /* rcvd datagrams with port errors */
    + UDPLITE_MIB_INERRORS, /* total erroneous rcvd datagrams */
    + UDPLITE_MIB_INERRORS_CHECKSUM_COVERAGE, /* checksum coverage errors */
    + UDPLITE_MIB_INERRORS_CHECKSUMMING, /* checksum itself did not qualify */
    + UDPLITE_MIB_OUTDATAGRAMS, /* total sent datagrams */
    + UDPLITE_MIB_OUTDATAGRAMS_PARTIAL_CHECK, /* sent datagrams with partial coverage */
    + __UDPLITE_MIB_MAX
    +};
    +
    /* sctp mib definitions */
    /*
    * draft-ietf-sigtran-sctp-mib-07.txt
    diff -Nurp a/include/linux/socket.h b/include/linux/socket.h
    --- a/include/linux/socket.h 2006-06-07 20:49:51.000000000 +0100
    +++ b/include/linux/socket.h 2006-06-07 21:28:09.000000000 +0100
    @@ -264,6 +264,7 @@ struct ucred {
    #define SOL_IPV6 41
    #define SOL_ICMPV6 58
    #define SOL_SCTP 132
    +#define SOL_UDPLITE 136 /* UDP-Lite (RFC 3828) */
    #define SOL_RAW 255
    #define SOL_IPX 256
    #define SOL_AX25 257
    diff -Nurp a/include/linux/udplite.h b/include/linux/udplite.h
    --- a/include/linux/udplite.h 1970-01-01 01:00:00.000000000 +0100
    +++ b/include/linux/udplite.h 2006-06-07 21:27:36.000000000 +0100
    @@ -0,0 +1,89 @@
    +/*
    + * Header file for UDP Lite (RFC 3828),
    + * see net/udp_lite for further details.
    + */
    +#ifndef _LINUX_UDPLITE_H
    +#define _LINUX_UDPLITE_H
    +#include <linux/types.h>
    +
    +/**
    + * struct udplitehdr - UDP-Lite header re-interpreting UDP (RFC 768) fields
    + *
    + * @source: source port number (as in UDP)
    + * @dest: destination port number (as in UDP)
    + * @checklen: checksum coverage length
    + * @check: checksum field (as in UDP)
    + *
    + * For the detailed header semantics see RFC 3828.
    + */
    +struct udplitehdr {
    + __u16 source;
    + __u16 dest;
    + __u16 checklen;
    + __u16 check;
    +};
    +
    +
    +/* UDP Lite socket options:
    + * Sender specifies actual coverage length.
    + * Receiver specifies _minimal_ coverage length. */
    +#define UDPLITE_SOCKOPT_SEND_CSCOV 10 /* sender */
    +#define UDPLITE_SOCKOPT_RECV_CSCOV 11 /* receiver */
    +
    +#define UDPLITE_CORK 1 /* Never send part. complete segm. */
    +
    +
    +
    +/* checksum coverage set flags */
    +#define UDPLITE_SEND_CHCKFLAG 0x1
    +#define UDPLITE_RECV_CHCKFLAG 0x2
    +
    +
    +/* FIXME: UDP-Lite encapsulation types ??? */
    +#define UDPLITE_ENCAP 100 /* accept encapsulated pkts */
    +#define UDPLITE_ENCAP_ESPINUDPLITE_NON_IKE 1
    +#define UDPLITE_ENCAP_ESPINUDPLITE 2
    +
    +
    +#ifdef __KERNEL__
    +
    +#include <linux/config.h>
    +#include <net/sock.h>
    +#include <linux/ip.h>
    +/**
    + * struct udplite_sock - unreliable UDP-Lite datagram service
    + *
    + * @inet: has to be the first member
    + * @pending: any pending frames?
    + * @corkflag: when cork is required
    + * @encap_type: is this an encapsulation socket?
    + * @len: total length of pending frames
    + * @pcslen: partial checksum coverage length for sending socket
    + * @pcrlen: partial checksum coverage length for receiving socket
    + * @pcflag: partial checksum coverage flag
    + *
    + * NOTE: Checksum coverage length has different semantics for sending and
    + * receiving sockets.
    + *
    + */
    +struct udplite_sock {
    + struct inet_sock inet;
    + int pending;
    + unsigned int corkflag;
    + __u16 encap_type;
    + /* The following members retain the information to create a
    + * UDP-Lite header when the socket is uncorked. */
    + __u16 len;
    + __u16 pcslen;
    + __u16 pcrlen;
    + __u8 pcflag;
    +};
    +
    +static inline struct udplite_sock *udplite_sk(const struct sock *sk)
    +{
    + return (struct udplite_sock *)sk;
    +}
    +
    +#endif /* __KERNEL__ */
    +
    +#endif /* _LINUX_UDPLITE_H */
    diff -Nurp a/include/net/snmp.h b/include/net/snmp.h
    --- a/include/net/snmp.h 2006-06-05 21:52:55.000000000 +0100
    +++ b/include/net/snmp.h 2006-06-07 21:28:09.000000000 +0100
    @@ -100,6 +100,13 @@ struct udp_mib {
    unsigned long mibs[UDP_MIB_MAX];
    } __SNMP_MIB_ALIGN__;

    +
    +/* UDP Lite (RFC 3828) */
    +#define UDPLITE_MIB_MAX __UDPLITE_MIB_MAX
    +struct udplite_mib {
    + unsigned long mibs[UDPLITE_MIB_MAX];
    +} __SNMP_MIB_ALIGN__;
    +
    /* SCTP */
    #define SCTP_MIB_MAX __SCTP_MIB_MAX
    struct sctp_mib {
    diff -Nurp a/include/net/udplite.h b/include/net/udplite.h
    --- a/include/net/udplite.h 1970-01-01 01:00:00.000000000 +0100
    +++ b/include/net/udplite.h 2006-06-07 21:16:56.000000000 +0100
    @@ -0,0 +1,65 @@
    +/*
    + * Header file for UDP Lite (RFC 3828)
    + */
    +#ifndef _UDPLITE_H
    +#define _UDPLITE_H
    +
    +#include <linux/udplite.h>
    +#include <linux/seq_file.h>
    +#include <linux/list.h>
    +#include <linux/ip.h>
    +#include <net/sock.h>
    +#include <net/snmp.h>
    +
    +/* In_UDP Lite the checksum MUST always be computed, hence in contrast to UDP,
    + * there is no UDPLITE_CSUM_DEFAULT and no UDPLITE_CSUM_NOXMIT */
    +#define UDPLITE_HTABLE_SIZE 128
    +
    +
    +/* net/udp_lite/udplitev4.c */
    +extern struct proto udplite_prot;
    +
    +extern void udplite_err(struct sk_buff *, u32);
    +extern int udplite_sendmsg(struct kiocb *iocb, struct sock *sk,
    + struct msghdr *msg, size_t len);
    +extern int udplite_rcv(struct sk_buff *skb);
    +extern int udplite_ioctl(struct sock *sk, int cmd, unsigned long arg);
    +extern int udplite_disconnect(struct sock *sk, int flags);
    +extern unsigned int udplite_poll(struct file *file, struct socket *sock,
    + poll_table * wait);
    +
    +/*
    + * SNMP MIB for the UDP-Lite layer
    + */
    +DECLARE_SNMP_STAT(struct udplite_mib, udplite_statistics);
    +#define UDPLITE_INC_STATS(f) SNMP_INC_STATS(udplite_statistics, f)
    +#define UDPLITE_INC_STATS_BH(f) SNMP_INC_STATS_BH(udplite_statistics, f)
    +#define UDPLITE_INC_STATS_USER(f) SNMP_INC_STATS_USER(udplite_statistics, f)
    +
    +
    +#ifdef CONFIG_PROC_FS
    +/*
    + * /proc
    + */
    +struct udplite_seq_afinfo {
    + struct module *owner;
    + char *name;
    + sa_family_t family;
    + int (*seq_show) (struct seq_file *m, void *v);
    + struct file_operations *seq_fops;
    +};
    +
    +struct udplite_iter_state {
    + sa_family_t family;
    + int bucket;
    + struct seq_operations seq_ops;
    +};
    +
    +extern int udplite_proc_register(struct udplite_seq_afinfo *afinfo);
    +extern void udplite_proc_unregister(struct udplite_seq_afinfo *afinfo);
    +
    +extern int udplite4_proc_init(void);
    +extern void udplite4_proc_exit(void);
    +#endif /* CONFIG_PROC_FS */
    +
    +#endif /* _UDPLITE_H */
    diff -Nurp a/include/net/xfrm.h b/include/net/xfrm.h
    --- a/include/net/xfrm.h 2006-06-07 20:49:52.000000000 +0100
    +++ b/include/net/xfrm.h 2006-06-07 21:28:09.000000000 +0100
    @@ -501,6 +501,7 @@ u16 xfrm_flowi_sport(struct flowi *fl)
    switch(fl->proto) {
    case IPPROTO_TCP:
    case IPPROTO_UDP:
    + case IPPROTO_UDPLITE:
    case IPPROTO_SCTP:
    port = fl->fl_ip_sport;
    break;
    @@ -521,6 +522,7 @@ u16 xfrm_flowi_dport(struct flowi *fl)
    switch(fl->proto) {
    case IPPROTO_TCP:
    case IPPROTO_UDP:
    + case IPPROTO_UDPLITE:
    case IPPROTO_SCTP:
    port = fl->fl_ip_dport;
    break;
    diff -Nurp a/net/Kconfig b/net/Kconfig
    --- a/net/Kconfig 2006-06-07 20:49:53.000000000 +0100
    +++ b/net/Kconfig 2006-06-07 21:28:09.000000000 +0100
    @@ -164,6 +164,7 @@ endif

    source "net/dccp/Kconfig"
    source "net/sctp/Kconfig"
    +source "net/udp_lite/Kconfig"
    source "net/tipc/Kconfig"
    source "net/atm/Kconfig"
    source "net/bridge/Kconfig"
    diff -Nurp a/net/Makefile b/net/Makefile
    --- a/net/Makefile 2006-06-05 21:52:55.000000000 +0100
    +++ b/net/Makefile 2006-06-07 21:28:09.000000000 +0100
    @@ -44,6 +44,7 @@ obj-$(CONFIG_ECONET) += econet/
    obj-$(CONFIG_VLAN_8021Q) += 8021q/
    obj-$(CONFIG_IP_DCCP) += dccp/
    obj-$(CONFIG_IP_SCTP) += sctp/
    +obj-$(CONFIG_IP_UDPLITE) += udp_lite/
    obj-$(CONFIG_IEEE80211) += ieee80211/
    obj-$(CONFIG_TIPC) += tipc/

    diff -Nurp a/net/core/sock.c b/net/core/sock.c
    --- a/net/core/sock.c 2006-06-07 20:49:52.000000000 +0100
    +++ b/net/core/sock.c 2006-06-07 21:28:09.000000000 +0100
    @@ -426,7 +426,12 @@ set_rcvbuf:
    break;

    case SO_NO_CHECK:
    - sk->sk_no_check = valbool;
    + /* UDP-Lite (RFC 3828) mandates checksumming,
    + * hence user must not enable this option. */
    + if (sk->sk_protocol == IPPROTO_UDPLITE)
    + ret = -EOPNOTSUPP;
    + else
    + sk->sk_no_check = valbool;
    break;

    case SO_PRIORITY:
    diff -Nurp a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
    --- a/net/ipv4/af_inet.c 2006-06-07 20:44:09.000000000 +0100
    +++ b/net/ipv4/af_inet.c 2006-06-07 21:28:09.000000000 +0100
    @@ -15,6 +15,8 @@
    * Changes (see also sock.c)
    *
    * piggy,
    + * W. Stanislaus : Added the UDP-Lite protocol (RFC 3828),
    + * (maintainer: <gerrit@erg.abdn.ac.uk>)
    * Karl Knutson : Socket protocol table
    * A.N.Kuznetsov : Socket death error in accept().
    * John Richardson : Fix non blocking error in connect()
    @@ -104,6 +106,7 @@
    #include <net/inet_connection_sock.h>
    #include <net/tcp.h>
    #include <net/udp.h>
    +#include <net/udplite.h> /* UDP Lite (RFC 3828) */
    #include <linux/skbuff.h>
    #include <net/sock.h>
    #include <net/raw.h>
    @@ -838,6 +841,30 @@ const struct proto_ops inet_dgram_ops =
    };

    /*
    + * For SOCK_LDGRAM sockets, these support the UDP Lite protocol (RFC 3828).
    + */
    +struct proto_ops inet_ldgram_ops = {
    + .family = PF_INET,
    + .owner = THIS_MODULE,
    + .release = inet_release,
    + .bind = inet_bind,
    + .connect = inet_dgram_connect,
    + .socketpair = sock_no_socketpair,
    + .accept = sock_no_accept,
    + .getname = inet_getname,
    + .poll = udplite_poll,
    + .ioctl = inet_ioctl,
    + .listen = sock_no_listen,
    + .shutdown = inet_shutdown,
    + .setsockopt = sock_common_setsockopt,
    + .getsockopt = sock_common_getsockopt,
    + .sendmsg = inet_sendmsg,
    + .recvmsg = sock_common_recvmsg,
    + .mmap = sock_no_mmap,
    + .sendpage = inet_sendpage,
    +};
    +
    +/*
    * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
    * udp_poll
    */
    @@ -898,6 +925,15 @@ static struct inet_protosw inetsw_array[
    .flags = INET_PROTOSW_PERMANENT,
    },

    + {
    + .type = SOCK_LDGRAM, /* UDP-Lite (RFC 3828) */
    + .protocol = IPPROTO_UDPLITE,
    + .prot = &udplite_prot,
    + .ops = &inet_ldgram_ops,
    + .capability = -1,
    + .no_check = 0, /* checksum mandatory */
    + .flags = INET_PROTOSW_PERMANENT,
    + },

    {
    .type = SOCK_RAW,
    @@ -1114,6 +1150,12 @@ static struct net_protocol udp_protocol
    .no_policy = 1,
    };

    +static struct net_protocol udplite_protocol = { /* UDP-Lite (RFC 3828) */
    + .handler = udplite_rcv,
    + .err_handler = udplite_err,
    + .no_policy = 1,
    +};
    +
    static struct net_protocol icmp_protocol = {
    .handler = icmp_rcv,
    };
    @@ -1130,11 +1172,13 @@ static int __init init_ipv4_mibs(void)
    tcp_statistics[1] = alloc_percpu(struct tcp_mib);
    udp_statistics[0] = alloc_percpu(struct udp_mib);
    udp_statistics[1] = alloc_percpu(struct udp_mib);
    - if (!
    - (net_statistics[0] && net_statistics[1] && ip_statistics[0]
    - && ip_statistics[1] && tcp_statistics[0] && tcp_statistics[1]
    - && udp_statistics[0] && udp_statistics[1]))
    - return -ENOMEM;
    + udplite_statistics[0] = alloc_percpu(struct udplite_mib);
    + udplite_statistics[1] = alloc_percpu(struct udplite_mib);
    + if (!(net_statistics[0] && net_statistics[1] && ip_statistics[0]
    + && ip_statistics[1] && tcp_statistics[0] && tcp_statistics[1]
    + && udp_statistics[0] && udp_statistics[1]
    + && udplite_statistics[0] && udplite_statistics[1]) )
    + return -ENOMEM;

    (void) tcp_mib_init();

    @@ -1172,6 +1216,10 @@ static int __init inet_init(void)
    if (rc)
    goto out_unregister_tcp_proto;

    + rc = proto_register(&udplite_prot, 1); /* UDP Lite (RFC 3828) */
    + if (rc)
    + goto out_unregister_udp_proto; /* XXX: not entirely sure --gr */
    +
    rc = proto_register(&raw_prot, 1);
    if (rc)
    goto out_unregister_udp_proto;
    @@ -1190,6 +1238,8 @@ static int __init inet_init(void)
    printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n");
    if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
    printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n");
    + if (inet_add_protocol(&udplite_protocol, IPPROTO_UDPLITE) < 0)
    + printk(KERN_CRIT "inet_init: Cannot add UDP-Lite protocol\n");
    if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
    printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n");
    #ifdef CONFIG_IP_MULTICAST
    @@ -1272,6 +1322,8 @@ static int __init ipv4_proc_init(void)
    goto out_tcp;
    if (udp4_proc_init())
    goto out_udp;
    + if (udplite4_proc_init())
    + goto out_udplite;
    if (fib_proc_init())
    goto out_fib;
    if (ip_misc_proc_init())
    @@ -1281,6 +1333,8 @@ out:
    out_misc:
    fib_proc_exit();
    out_fib:
    + udplite4_proc_exit();
    +out_udplite:
    udp4_proc_exit();
    out_udp:
    tcp4_proc_exit();
    diff -Nurp a/net/ipv4/proc.c b/net/ipv4/proc.c
    --- a/net/ipv4/proc.c 2006-06-07 20:44:12.000000000 +0100
    +++ b/net/ipv4/proc.c 2006-06-07 21:28:09.000000000 +0100
    @@ -14,6 +14,10 @@
    * Fred Baumgarten, <dc6iq@insu1.etec.uni-karlsruhe.de>
    * Erik Schoenfelder, <schoenfr@ibr.cs.tu-bs.de>
    *
    + * Changes:
    + * William Stanislaus: added support for UDP-Lite protocol (RFC 3828),
    + * code maintained by Gerrit Renker <gerrit@erg.abdn.ac.uk>
    + *
    * Fixes:
    * Alan Cox : UDP sockets show the rxqueue/txqueue
    * using hint flag for the netinfo.
    @@ -38,6 +42,7 @@
    #include <net/protocol.h>
    #include <net/tcp.h>
    #include <net/udp.h>
    +#include <net/udplite.h> /* UDP Lite (RFC 3828) */
    #include <linux/inetdevice.h>
    #include <linux/proc_fs.h>
    #include <linux/seq_file.h>
    @@ -66,9 +71,10 @@ static int sockstat_seq_show(struct seq_
    tcp_death_row.tw_count, atomic_read(&tcp_sockets_allocated),
    atomic_read(&tcp_memory_allocated));
    seq_printf(seq, "UDP: inuse %d\n", fold_prot_inuse(&udp_prot));
    + seq_printf(seq, "UDPLITE: inuse %d\n", fold_prot_inuse(&udplite_prot));
    seq_printf(seq, "RAW: inuse %d\n", fold_prot_inuse(&raw_prot));
    - seq_printf(seq, "FRAG: inuse %d memory %d\n", ip_frag_nqueues,
    - atomic_read(&ip_frag_mem));
    + seq_printf(seq, "FRAG: inuse %d memory %d\n", ip_frag_nqueues,
    + atomic_read(&ip_frag_mem));
    return 0;
    }

    @@ -176,6 +182,18 @@ static const struct snmp_mib snmp4_udp_l
    SNMP_MIB_SENTINEL
    };

    +static struct snmp_mib snmp4_udplite_list[] = { /* UDP Lite (gerrit@erg.abdn.ac.uk) */
    + SNMP_MIB_ITEM("InDatagrams", UDPLITE_MIB_INDATAGRAMS),
    + SNMP_MIB_ITEM("InPartialCov", UDPLITE_MIB_INDATAGRAMS_PARTIAL_CHECK),
    + SNMP_MIB_ITEM("NoPorts", UDPLITE_MIB_NOPORTS),
    + SNMP_MIB_ITEM("InErrors", UDPLITE_MIB_INERRORS),
    + SNMP_MIB_ITEM("InBadChecksum", UDPLITE_MIB_INERRORS_CHECKSUMMING),
    + SNMP_MIB_ITEM("InBadCoverage", UDPLITE_MIB_INERRORS_CHECKSUM_COVERAGE),
    + SNMP_MIB_ITEM("OutDatagrams", UDPLITE_MIB_OUTDATAGRAMS),
    + SNMP_MIB_ITEM("OutPartialCov", UDPLITE_MIB_OUTDATAGRAMS_PARTIAL_CHECK),
    + SNMP_MIB_SENTINEL
    +};
    +
    static const struct snmp_mib snmp4_net_list[] = {
    SNMP_MIB_ITEM("SyncookiesSent", LINUX_MIB_SYNCOOKIESSENT),
    SNMP_MIB_ITEM("SyncookiesRecv", LINUX_MIB_SYNCOOKIESRECV),
    @@ -302,6 +320,16 @@ static int snmp_seq_show(struct seq_file
    fold_field((void **) udp_statistics,
    snmp4_udp_list[i].entry));

    + seq_puts(seq, "\nUdpLite:"); /* UDP Lite (RFC 3828) */
    + for (i = 0; snmp4_udplite_list[i].name != NULL; i++)
    + seq_printf(seq, " %s", snmp4_udplite_list[i].name);
    +
    + seq_puts(seq, "\nUdpLite:");
    + for (i = 0; snmp4_udplite_list[i].name != NULL; i++)
    + seq_printf(seq, " %lu",
    + fold_field((void **) udplite_statistics,
    + snmp4_udplite_list[i].entry));
    +
    seq_putc(seq, '\n');
    return 0;
    }
    diff -Nurp a/net/udp_lite/Kbuild b/net/udp_lite/Kbuild
    --- a/net/udp_lite/Kbuild 1970-01-01 01:00:00.000000000 +0100
    +++ b/net/udp_lite/Kbuild 2006-06-07 21:16:56.000000000 +0100
    @@ -0,0 +1 @@
    +obj-$(CONFIG_IP_UDPLITE) += udplitev4.o
    diff -Nurp a/net/udp_lite/Kconfig b/net/udp_lite/Kconfig
    --- a/net/udp_lite/Kconfig 1970-01-01 01:00:00.000000000 +0100
    +++ b/net/udp_lite/Kconfig 2006-06-07 21:38:56.000000000 +0100
    @@ -0,0 +1,20 @@
    +config IP_UDPLITE
    + bool "The UDP-Lite Protocol (EXPERIMENTAL)"
    + depends on INET && EXPERIMENTAL
    + default n
    + ---help---
    + The UDP Lite Protocol (RFC 3828, <http://tools.ietf.org/html/rfc3828>)
    +
    + UDP-Lite is a Standards-Track IETF transport protocol. It features a
    + variable-length checksum, which allows partially damaged packets to be
    + forwarded to media codecs, rather than being discarded due to invalid
    + (UDP) checksum values. This can have advantages for the transport of
    + multimedia (e.g. video/audio) over wireless networks.
    +
    + The socket API resembles that of UDP. Applications must indicate their
    + wish to utilise the partial checksum coverage feature offered by UDP-
    + Lite by setting a socket option.
    +
    + More information can be found in Documentation/networking/udp_lite.txt
    +
    + If in doubt, say N.
    diff -Nurp a/net/udp_lite/udplitev4.c b/net/udp_lite/udplitev4.c
    --- a/net/udp_lite/udplitev4.c 1970-01-01 01:00:00.000000000 +0100
    +++ b/net/udp_lite/udplitev4.c 2006-06-07 21:32:28.000000000 +0100
    @@ -0,0 +1,1730 @@
    +/*
    + * UDPLITE An implementation of the UDP-Lite protocol as standardised in
    + * RFC 3828. UDP-Lite is based on UDP: this code is a revision of
    + * the original udp.c code with regard to all those aspects in
    + * which UDP-Lite differs from UDP.
    + *
    + * Version: $Id: udplitev4.c,v 1.3 2006/05/25 13:57:06 root Exp root $
    + *
    + * Authors: Gerrit Renker <gerrit@erg.abdn.ac.uk>
    + * William Stanislaus <william@erg.abdn.ac.uk>
    + *
    + * based on original code from udp.c, by Ross Biro, Fred N. van
    + * Kempen, Arnt Gulbrandsen, Alan Cox, and Hirokazu Takahashi
    + *
    + * Changes:
    + *
    + */
    +#include <asm/system.h>
    +#include <asm/uaccess.h>
    +#include <asm/ioctls.h>
    +#include <linux/types.h>
    +#include <linux/fcntl.h>
    +#include <linux/module.h>
    +#include <linux/socket.h>
    +#include <linux/sockios.h>
    +#include <linux/igmp.h>
    +#include <linux/in.h>
    +#include <linux/errno.h>
    +#include <linux/timer.h>
    +#include <linux/mm.h>
    +#include <linux/config.h>
    +#include <linux/inet.h>
    +#include <linux/ipv6.h>
    +#include <linux/netdevice.h>
    +#include <net/snmp.h>
    +#include <net/ip.h>
    +#include <net/tcp_states.h>
    +#include <net/protocol.h>
    +#include <linux/skbuff.h>
    +#include <linux/proc_fs.h>
    +#include <linux/seq_file.h>
    +#include <net/sock.h>
    +#include <net/udplite.h>
    +#include <net/icmp.h>
    +#include <net/route.h>
    +#include <net/inet_common.h>
    +#include <net/checksum.h>
    +#include <net/xfrm.h>
    +
    +/*
    + * SNMP MIB for the UDP-Lite layer
    + */
    +DEFINE_SNMP_STAT(struct udplite_mib, udplite_statistics);
    +
    +/*
    + * Global variables
    + */
    +int udplite_port_rover;
    +struct hlist_head udplite_hash[UDPLITE_HTABLE_SIZE];
    +DEFINE_RWLOCK(udplite_hash_lock);
    +
    +
    +
    +static inline int udplite_lport_inuse(u16 num)
    +{
    + struct sock *sk;
    + struct hlist_node *node;
    +
    + sk_for_each(sk, node, &udplite_hash[num & (UDPLITE_HTABLE_SIZE - 1)])
    + if (inet_sk(sk)->num == num)
    + return 1;
    + return 0;
    +}
    +
    +/* The following function is identical to the one used in udp.c: */
    +
    +static int udplite_v4_get_port(struct sock *sk, unsigned short snum)
    +{
    + struct hlist_node *node;
    + struct sock *sk2;
    + struct inet_sock *inet = inet_sk(sk);
    +
    + write_lock_bh(&udplite_hash_lock);
    + if (snum == 0) {
    + int best_size_so_far, best, result, i;
    +
    + if (udplite_port_rover > sysctl_local_port_range[1] ||
    + udplite_port_rover < sysctl_local_port_range[0])
    + udplite_port_rover = sysctl_local_port_range[0];
    + best_size_so_far = 32767;
    + best = result = udplite_port_rover;
    + for (i = 0; i < UDPLITE_HTABLE_SIZE; i++, result++) {
    + struct hlist_head *list;
    + int size;
    +
    + list =
    + &udplite_hash[result & (UDPLITE_HTABLE_SIZE - 1)];
    + if (hlist_empty(list)) {
    + if (result > sysctl_local_port_range[1])
    + result = sysctl_local_port_range[0] +
    + ((result -
    + sysctl_local_port_range[0]) &
    + (UDPLITE_HTABLE_SIZE - 1));
    + goto gotit;
    + }
    + size = 0;
    + sk_for_each(sk2, node, list)
    + if (++size >= best_size_so_far)
    + goto next;
    + best_size_so_far = size;
    + best = result;
    + next:;
    + }
    + result = best;
    + for (i = 0; i < (1 << 16) / UDPLITE_HTABLE_SIZE;
    + i++, result += UDPLITE_HTABLE_SIZE) {
    + if (result > sysctl_local_port_range[1])
    + result = sysctl_local_port_range[0]
    + + ((result - sysctl_local_port_range[0]) &
    + (UDPLITE_HTABLE_SIZE - 1));
    + if (!udplite_lport_inuse(result))
    + break;
    + }
    + if (i >= (1 << 16) / UDPLITE_HTABLE_SIZE)
    + goto fail;
    + gotit:
    + udplite_port_rover = snum = result;
    + } else {
    + sk_for_each(sk2, node,
    + &udplite_hash[snum & (UDPLITE_HTABLE_SIZE - 1)]) {
    + struct inet_sock *inet2 = inet_sk(sk2);
    +
    + if (inet2->num == snum &&
    + sk2 != sk &&
    + !ipv6_only_sock(sk2) &&
    + (!sk2->sk_bound_dev_if ||
    + !sk->sk_bound_dev_if ||
    + sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
    + (!inet2->rcv_saddr ||
    + !inet->rcv_saddr ||
    + inet2->rcv_saddr == inet->rcv_saddr) &&
    + (!sk2->sk_reuse || !sk->sk_reuse))
    + goto fail;
    + }
    + }
    + inet->num = snum;
    + if (sk_unhashed(sk)) {
    + struct hlist_head *h =
    + &udplite_hash[snum & (UDPLITE_HTABLE_SIZE - 1)];
    +
    + sk_add_node(sk, h);
    + sock_prot_inc_use(sk->sk_prot);
    + }
    + write_unlock_bh(&udplite_hash_lock);
    + return 0;
    +
    + fail:
    + write_unlock_bh(&udplite_hash_lock);
    + return 1;
    +}
    +
    +static void udplite_v4_hash(struct sock *sk) /* Identical to udp.c */
    +{
    + BUG();
    +}
    +
    +static void udplite_v4_unhash(struct sock *sk) /* Identical to udp.c */
    +{
    + write_lock_bh(&udplite_hash_lock);
    + if (sk_del_node_init(sk)) {
    + inet_sk(sk)->num = 0;
    + sock_prot_dec_use(sk->sk_prot);
    + }
    + write_unlock_bh(&udplite_hash_lock);
    +}
    +
    +
    +/* The following function is identical to the one used in udp.c: */
    +
    +static struct sock *udplite_v4_lookup_longway(u32 saddr, u16 sport,
    + u32 daddr, u16 dport, int dif)
    +{
    + struct sock *sk,
    + *result = NULL;
    + struct hlist_node *node;
    + unsigned short hnum = ntohs(dport);
    + int badness = -1;
    +
    + sk_for_each(sk, node, &udplite_hash[hnum & (UDPLITE_HTABLE_SIZE - 1)]) {
    + struct inet_sock *inet = inet_sk(sk);
    +
    + if (inet->num == hnum && !ipv6_only_sock(sk)) {
    + int score = (sk->sk_family == PF_INET ? 1 : 0);
    + if (inet->rcv_saddr) {
    + if (inet->rcv_saddr != daddr)
    + continue;
    + score += 2;
    + }
    + if (inet->daddr) {
    + if (inet->daddr != saddr)
    + continue;
    + score += 2;
    + }
    + if (inet->dport) {
    + if (inet->dport != sport)
    + continue;
    + score += 2;
    + }
    + if (sk->sk_bound_dev_if) {
    + if (sk->sk_bound_dev_if != dif)
    + continue;
    + score += 2;
    + }
    + if (score == 9) {
    + result = sk;
    + break;
    + } else if (score > badness) {
    + result = sk;
    + badness = score;
    + }
    + }
    + }
    + return result;
    +}
    +
    +/* The following function is identical to the one used in udp.c: */
    +
    +static __inline__ struct sock *udplite_v4_lookup(u32 saddr, u16 sport,
    + u32 daddr, u16 dport, int dif)
    +{
    + struct sock *sk;
    +
    + read_lock(&udplite_hash_lock);
    + sk = udplite_v4_lookup_longway(saddr, sport, daddr, dport, dif);
    + if (sk)
    + sock_hold(sk);
    + read_unlock(&udplite_hash_lock);
    + return sk;
    +}
    +
    +/* The following function is identical to the one used in udp.c: */
    +
    +static inline struct sock *udplite_v4_mcast_next(struct sock *sk,
    + u16 loc_port, u32 loc_addr,
    + u16 rmt_port, u32 rmt_addr,
    + int dif)
    +{
    + struct hlist_node *node;
    + struct sock *s = sk;
    + unsigned short hnum = ntohs(loc_port);
    +
    + sk_for_each_from(s, node) {
    + struct inet_sock *inet = inet_sk(s);
    +
    + if (inet->num != hnum ||
    + (inet->daddr && inet->daddr != rmt_addr) ||
    + (inet->dport != rmt_port && inet->dport) ||
    + (inet->rcv_saddr && inet->rcv_saddr != loc_addr) ||
    + ipv6_only_sock(s) ||
    + (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
    + continue;
    + if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
    + continue;
    + goto found;
    + }
    + s = NULL;
    + found:
    + return s;
    +}
    +
    +/**
    + * udplite_err - handle error conditions (taken from udp.c)
    + * @skb:
    + * @info:
    + *
    + * This routine is called by the ICMP module when it gets some
    + * sort of error condition. If err < 0 then the socket should
    + * be closed and the error returned to the user. If err > 0
    + * it's just the icmp type << 8 | icmp code.
    + * Header points to the ip header of the error packet. We move
    + * on past this. Then (as it used to claim before adjustment)
    + * header points to the first 8 bytes of the UDP-Lite header.
    + * We need to find the appropriate port.
    + */
    +
    +void udplite_err(struct sk_buff *skb, u32 info)
    +{
    + struct inet_sock *inet;
    + struct iphdr *iph = (struct iphdr *)skb->data;
    + struct udplitehdr *uh = (struct udplitehdr *)
    + (skb->data + (iph->ihl << 2));
    + int type = skb->h.icmph->type,
    + code = skb->h.icmph->code;
    + struct sock *sk;
    + int harderr, err;
    +
    + sk = udplite_v4_lookup(iph->daddr, uh->dest, iph->saddr, uh->source,
    + skb->dev->ifindex);
    + if (sk == NULL) {
    + ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
    + return; /* No socket for error */
    + }
    +
    + err = 0;
    + harderr = 0;
    + inet = inet_sk(sk);
    +
    + switch (type) {
    + default:
    + case ICMP_TIME_EXCEEDED:
    + err = EHOSTUNREACH;
    + break;
    + case ICMP_SOURCE_QUENCH:
    + goto out;
    + case ICMP_PARAMETERPROB:
    + err = EPROTO;
    + harderr = 1;
    + break;
    + case ICMP_DEST_UNREACH:
    + if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
    + if (inet->pmtudisc != IP_PMTUDISC_DONT) {
    + err = EMSGSIZE;
    + harderr = 1;
    + break;
    + }
    + goto out;
    + }
    + err = EHOSTUNREACH;
    + if (code <= NR_ICMP_UNREACH) {
    + harderr = icmp_err_convert[code].fatal;
    + err = icmp_err_convert[code].errno;
    + }
    + break;
    + }
    +
    + /*
    + * This is handled as in UDP (cf. RFC 1122, sec. 4.1.3.3),
    + * ICMP errors are passed back to the application.
    + */
    + if (!inet->recverr) {
    + if (!harderr || sk->sk_state != TCP_ESTABLISHED)
    + goto out;
    + } else {
    + ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *) (uh + 1));
    + }
    + sk->sk_err = err;
    + sk->sk_error_report(sk);
    + out:
    + sock_put(sk);
    +}
    +
    +/**
    + * udplite_flush_pending_frames - taken from udp.c
    + *
    + * Throw away all pending data and cancel the corking. Socket is locked.
    + */
    +static void udplite_flush_pending_frames(struct sock *sk)
    +{
    + struct udplite_sock *up = udplite_sk(sk);
    +
    + if (up->pending) {
    + up->len = 0;
    + up->pending = 0;
    + ip_flush_pending_frames(sk);
    + }
    +}
    +
    +/**
    + * udplite_push_pending_frames - send pending data
    + *
    + * Push out all pending data as one UDP-Lite datagram. Socket is locked.
    + * This code is modelled after the original in udp.c, but has been heavily
    + * modified in all parts that relate to (partial) checksum computation.
    + */
    +static int udplite_push_pending_frames(struct sock *sk, struct udplite_sock *up)
    +{
    + struct inet_sock *inet = inet_sk(sk);
    + struct flowi *fl = &inet->cork.fl;
    + struct sk_buff *skb;
    + struct udplitehdr *uh;
    + int offset, /* within skb structure */
    + err = 0;
    + unsigned short clen = 0, /* checksum coverage length */
    + len;
    + unsigned int csum = 0; /* Intermediate checksum value. */
    +
    + /* Grab the skbuff where UDP-Lite header space exists. */
    + if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
    + goto out;
    +
    + /*
    + * Create a UDP-Lite header
    + */
    + uh = skb->h.ulh;
    + uh->source = fl->fl_ip_sport;
    + uh->dest = fl->fl_ip_dport;
    + uh->check = 0;
    +
    + offset = (unsigned char *)uh - skb->data;
    +
    +
    + if (up->pcflag & UDPLITE_SEND_CHCKFLAG) {
    + /* Sender has requested partial coverage via sockopts. */
    + if (up->pcslen < up->len) {
    + if (up->pcslen == 0) /* Full coverage (RFC 3828) */
    + clen = up->len;
    + else { /* Genuine partial coverage */
    + clen = up->pcslen;
    + UDPLITE_INC_STATS_BH
    + (UDPLITE_MIB_OUTDATAGRAMS_PARTIAL_CHECK);
    + }
    + uh->checklen = htons(up->pcslen);
    +
    + } else { /* up->pcslen >= up->len */
    + /*
    + * Causes for up->pcslen > up->len (error):
    + * (i) Sender 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 fragment), coverage length may
    + * exceed packet length.
    + * Since packets with coverage length > packet length
    + * are illegal, we adjust in both cases to the maximum
    + * upper bound.
    + */
    + clen = up->len;
    + uh->checklen = htons(clen);
    + }
    + } else { /* No flag: emulate UDP. */
    + clen = up->len;
    + uh->checklen = htons(clen);
    + }
    +
    + /*
    + * Checksum computation: is mandatory in UDP-Lite (RFC 3828).
    + * There are no known drivers which would allow HW offloading of csum.
    + */
    + skb->ip_summed = CHECKSUM_NONE;
    +
    + if (skb_queue_len(&sk->sk_write_queue) == 1) {
    + /* Only one fragment on the socket. */
    + csum = csum_partial(skb->data + offset, clen, 0);
    +
    + } else { /* Packet is fragmented. */
    +
    + if (clen <= (skb->len - offset)) {
    + /* Coverage lies within the first frame. */
    + csum = csum_partial(skb->data + offset, clen, 0);
    +
    + } else { /* Collect the checksum over the fragments */
    + skb_queue_walk(&sk->sk_write_queue, skb) {
    + offset = (unsigned char*)skb->h.raw - skb->data;
    + len = skb->len - offset;
    +
    + skb->csum =
    + csum_partial(skb->data + offset,
    + (clen > len) ? len : clen, 0);
    + csum = csum_add(csum, skb->csum);
    +
    + if (clen < len) /* Enough seen. */
    + break;
    + clen -= len;
    + }
    + }
    + }
    + /* Finalise the checksum by adding the pseudo-header. */
    + uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len,
    + IPPROTO_UDPLITE, csum);
    +
    + /* RFC 3828: if computed checksum is 0, transmit it as all ones.
    + * The transmitted checksum MUST NOT be all zeroes (sec. 3.1). */
    + if (uh->check == 0)
    + uh->check = -1;
    +
    + err = ip_push_pending_frames(sk); /* Send the datagram (fragments). */
    +out:
    + up->len = 0;
    + up->pending = 0;
    + return err;
    +}
    +
    +/**
    + * udplite_sendmsg - send function
    + *
    + * Code taken from udp.c but modified with regard to UDP-Lite specifics.
    + */
    +int udplite_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
    + size_t len)
    +{
    + struct inet_sock *inet = inet_sk(sk);
    + struct udplite_sock *up = udplite_sk(sk);
    + struct ipcm_cookie ipc;
    + struct rtable *rt = NULL;
    + int free = 0, err,
    + connected = 0,
    + ulen = len; /* UDP-Lite length */
    + u32 daddr, faddr, saddr;
    + u16 dport;
    + u8 tos;
    + int corkreq = up->corkflag || msg->msg_flags & MSG_MORE;
    +
    + if (len > 0xFFFF)
    + return -EMSGSIZE;
    +
    + /*
    + * Check the flags.
    + */
    + if (msg->msg_flags & MSG_OOB) /* BSD error message compatibility */
    + return -EOPNOTSUPP;
    +
    + ipc.opt = NULL;
    +
    + if (up->pending) {
    + /*
    + * There are pending frames.
    + * The socket lock must be held while it's corked.
    + */
    + lock_sock(sk);
    + if (likely(up->pending)) {
    + if (unlikely(up->pending != AF_INET)) {
    + release_sock(sk);
    + return -EINVAL;
    + }
    + goto do_append_data;
    + }
    + release_sock(sk);
    + }
    + ulen += sizeof(struct udplitehdr);
    +
    + /*
    + * Get and verify the address.
    + */
    + if (msg->msg_name) {
    + struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
    + if (msg->msg_namelen < sizeof(*usin))
    + return -EINVAL;
    + if (usin->sin_family != AF_INET) {
    + if (usin->sin_family != AF_UNSPEC)
    + return -EAFNOSUPPORT;
    + }
    +
    + daddr = usin->sin_addr.s_addr;
    + dport = usin->sin_port;
    + if (dport == 0)
    + return -EINVAL;
    + } else {
    + if (sk->sk_state != TCP_ESTABLISHED)
    + return -EDESTADDRREQ;
    + daddr = inet->daddr;
    + dport = inet->dport;
    + /* Open fast path for connected socket.
    + * Route will not be used, if at least one option is set.
    + */
    + connected = 1;
    + }
    + ipc.addr = inet->saddr;
    +
    + ipc.oif = sk->sk_bound_dev_if;
    + if (msg->msg_controllen) {
    + err = ip_cmsg_send(msg, &ipc);
    + if (err)
    + return err;
    + if (ipc.opt)
    + free = 1;
    + connected = 0;
    + }
    + if (!ipc.opt)
    + ipc.opt = inet->opt;
    +
    + saddr = ipc.addr;
    + ipc.addr = faddr = daddr;
    +
    + if (ipc.opt && ipc.opt->srr) {
    + if (!daddr)
    + return -EINVAL;
    + faddr = ipc.opt->faddr;
    + connected = 0;
    + }
    + tos = RT_TOS(inet->tos);
    + if (sock_flag(sk, SOCK_LOCALROUTE) ||
    + (msg->msg_flags & MSG_DONTROUTE) ||
    + (ipc.opt && ipc.opt->is_strictroute)) {
    + tos |= RTO_ONLINK;
    + connected = 0;
    + }
    +
    + if (MULTICAST(daddr)) {
    + if (!ipc.oif)
    + ipc.oif = inet->mc_index;
    + if (!saddr)
    + saddr = inet->mc_addr;
    + connected = 0;
    + }
    +
    + if (connected)
    + rt = (struct rtable *)sk_dst_check(sk, 0);
    +
    + if (rt == NULL) {
    + struct flowi fl = {
    + .oif = ipc.oif,
    + .nl_u = {.ip4_u =
    + {.daddr = faddr,.saddr = saddr,.tos = tos}},
    + .proto = IPPROTO_UDPLITE,
    + .uli_u = {.ports =
    + {.sport = inet->sport,.dport = dport}}
    + };
    +
    + err =
    + ip_route_output_flow(&rt, &fl, sk,
    + !(msg->msg_flags & MSG_DONTWAIT));
    + if (err)
    + goto out;
    +
    + err = -EACCES;
    + if ((rt->rt_flags & RTCF_BROADCAST) &&
    + !sock_flag(sk, SOCK_BROADCAST))
    + goto out;
    + if (connected)
    + sk_dst_set(sk, dst_clone(&rt->u.dst));
    + }
    +
    + if (msg->msg_flags & MSG_CONFIRM)
    + goto do_confirm;
    +
    +back_from_confirm:
    +
    + saddr = rt->rt_src;
    + if (!ipc.addr)
    + daddr = ipc.addr = rt->rt_dst;
    +
    + lock_sock(sk);
    + if (unlikely(up->pending)) {
    + /* The socket is already corked while preparing it. */
    + /* ... which is an evident application bug. --ANK */
    + release_sock(sk);
    +
    + LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: cork app bug 2\n");
    + err = -EINVAL;
    + goto out;
    + }
    + /*
    + * Now cork the socket to pend data.
    + */
    + inet->cork.fl.fl4_dst = daddr;
    + inet->cork.fl.fl_ip_dport = dport;
    + inet->cork.fl.fl4_src = saddr;
    + inet->cork.fl.fl_ip_sport = inet->sport;
    + up->pending = AF_INET;
    +
    +do_append_data:
    + up->len += ulen;
    + err = ip_append_data(sk, ip_generic_getfrag, msg->msg_iov, ulen,
    + sizeof(struct udplitehdr), &ipc, rt,
    + corkreq ? msg->msg_flags | MSG_MORE
    + : msg->msg_flags);
    + if (err)
    + udplite_flush_pending_frames(sk);
    + else if (!corkreq)
    + err = udplite_push_pending_frames(sk, up);
    + release_sock(sk);
    +
    +out:
    + ip_rt_put(rt);
    + if (free)
    + kfree(ipc.opt);
    + if (!err) {
    + UDPLITE_INC_STATS_USER(UDPLITE_MIB_OUTDATAGRAMS);
    + return len;
    + }
    + return err;
    +
    +do_confirm:
    + dst_confirm(&rt->u.dst);
    + if (!(msg->msg_flags & MSG_PROBE) || len)
    + goto back_from_confirm;
    + err = 0;
    + goto out;
    +}
    +
    +/* as in udp.c */
    +static int udplite_sendpage(struct sock *sk, struct page *page, int offset,
    + size_t size, int flags)
    +{
    + struct udplite_sock *up = udplite_sk(sk);
    + int ret;
    +
    + if (!up->pending) {
    + struct msghdr msg = {.msg_flags = flags | MSG_MORE };
    +
    + /* Call udplite_sendmsg to specify destination address which
    + * sendpage interface can't pass.
    + * This will succeed only when the socket is connected.
    + */
    + ret = udplite_sendmsg(NULL, sk, &msg, 0);
    + if (ret < 0)
    + return ret;
    + }
    +
    + lock_sock(sk);
    +
    + if (unlikely(!up->pending)) {
    + release_sock(sk);
    +
    + LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: cork app bug 3\n");
    + return -EINVAL;
    + }
    +
    + ret = ip_append_page(sk, page, offset, size, flags);
    + if (ret == -EOPNOTSUPP) {
    + release_sock(sk);
    + return sock_no_sendpage(sk->sk_socket, page, offset,
    + size, flags);
    + }
    + if (ret < 0) {
    + udplite_flush_pending_frames(sk);
    + goto out;
    + }
    +
    + up->len += size;
    + if (!(up->corkflag || (flags & MSG_MORE)))
    + ret = udplite_push_pending_frames(sk, up);
    + if (!ret)
    + ret = size;
    +out:
    + release_sock(sk);
    + return ret;
    +}
    +
    +/**
    + * udplite_ioctl - taken from udp.c
    + *
    + * IOCTL requests applicable to the UDP-Lite protocol
    + */
    +int udplite_ioctl(struct sock *sk, int cmd, unsigned long arg)
    +{
    + switch (cmd) {
    + case SIOCOUTQ:
    + {
    + int amount = atomic_read(&sk->sk_wmem_alloc);
    + return put_user(amount, (int __user *)arg);
    + }
    +
    + case SIOCINQ:
    + {
    + struct sk_buff *skb;
    + unsigned long amount;
    +
    + amount = 0;
    + spin_lock_bh(&sk->sk_receive_queue.lock);
    + skb = skb_peek(&sk->sk_receive_queue);
    + if (skb != NULL) {
    + /*
    + * We will only return the amount
    + * of this packet since that is all
    + * that will be read.
    + */
    + amount = skb->len - sizeof(struct udplitehdr);
    + }
    + spin_unlock_bh(&sk->sk_receive_queue.lock);
    + return put_user(amount, (int __user *)arg);
    + }
    +
    + default:
    + return -ENOIOCTLCMD;
    + }
    + return (0);
    +}
    +
    +/*---------------------------------------------------------------------------
    + * Checksumming functions used for receiving and polling events.
    + *---------------------------------------------------------------------------*/
    +/**
    + * __udplite_checksum_complete - UDP-Lite csum workhorse
    + *
    + * Returns 1 on error, 0 if checksum is fine.
    + */
    +static __inline__ int __udplite_checksum_complete(struct sk_buff *skb)
    +{
    + struct udplitehdr *uh;
    + unsigned short len, /* Total length of the UDP-Lite packet. */
    + clen; /* Coverage length as stated in header. */
    + int offset; /* Offset of UDP-Lite header within buff. */
    +
    + uh = skb->h.ulh;
    + clen = ntohs(uh->checklen);
    + offset = (unsigned char *)uh - skb->data;
    + len = skb->len - offset;
    +
    + if (clen == 0) /* Honour full packet coverage. */
    + clen = len;
    +
    + /* Don't checksum if we have illegal coverage lengths (RFC 3828).
    + * FIXME: The syslog messages are really there to flag bug conditions,
    + * illegal checksum coverage length problems should have been resolved
    + * before this routine is called. */
    + if (clen < 8 || clen > len) { /* Using clen > len leads to crash! */
    + LIMIT_NETDEBUG(KERN_WARNING
    + "UDPLITE: Illegal coverage length %d (length %d).\n",
    + clen, len);
    + return 1;
    + } else if (uh->check == 0) {
    + LIMIT_NETDEBUG(KERN_WARNING
    + "UDPLITE: Illegal packet - zero checksum.\n");
    + return 1;
    + } else /* packet is law-abiding, so checksum it */
    + return (unsigned short)
    + csum_fold(skb_checksum(skb, offset, clen, skb->csum));
    +}
    +
    +
    +/**
    + * udplite_checksum_complete - finalise UDP-Lite csum computation
    + *
    + * Return 0 if no checksum required or checksum computes ok.
    + */
    +static __inline__ int udplite_checksum_complete(struct sk_buff *skb)
    +{
    + return skb->ip_summed != CHECKSUM_UNNECESSARY
    + && __udplite_checksum_complete(skb);
    +}
    +
    +/**
    + * udplite_recvmsg - receive a message (taken from udp.c)
    + */
    +static int udplite_recvmsg(struct kiocb *iocb,
    + struct sock *sk,
    + struct msghdr *msg,
    + size_t len, int noblock, int flags, int *addr_len)
    +{
    + struct inet_sock *inet = inet_sk(sk);
    + struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
    + struct sk_buff *skb;
    + int copied, err;
    +
    + /*
    + * Check any passed addresses
    + */
    + if (addr_len)
    + *addr_len = sizeof(*sin);
    +
    + if (flags & MSG_ERRQUEUE)
    + return ip_recv_error(sk, msg, len);
    +
    + try_again:
    + skb = skb_recv_datagram(sk, flags, noblock, &err);
    + if (!skb)
    + goto out;
    +
    + copied = skb->len - sizeof(struct udplitehdr);
    + if (copied > len) {
    + copied = len;
    + msg->msg_flags |= MSG_TRUNC;
    + }
    +
    + if (udplite_checksum_complete(skb)) /* Checksum validation */
    + goto csum_copy_err;
    +
    + err =
    + skb_copy_datagram_iovec(skb, sizeof(struct udplitehdr),
    + msg->msg_iov, copied);
    + if (err)
    + goto out_free;
    +
    + sock_recv_timestamp(msg, sk, skb);
    +
    + if (sin) { /* Copy the address. */
    + sin->sin_family = AF_INET;
    + sin->sin_port = skb->h.uh->source;
    + sin->sin_addr.s_addr = skb->nh.iph->saddr;
    + memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
    + }
    + if (inet->cmsg_flags)
    + ip_cmsg_recv(msg, skb);
    +
    + err = copied;
    + if (flags & MSG_TRUNC)
    + err = skb->len - sizeof(struct udplitehdr);
    +
    + out_free:
    + skb_free_datagram(sk, skb);
    + out:
    + return err;
    +
    + csum_copy_err:
    + LIMIT_NETDEBUG(KERN_DEBUG "UDPLITE: csum error in recvmsg.\n");
    + UDPLITE_INC_STATS_BH(UDPLITE_MIB_INERRORS_CHECKSUMMING);
    + UDPLITE_INC_STATS_BH(UDPLITE_MIB_INERRORS);
    + if (flags & MSG_PEEK) { /* Clear queue. */
    + int clear = 0;
    + spin_lock_bh(&sk->sk_receive_queue.lock);
    + if (skb == skb_peek(&sk->sk_receive_queue)) {
    + __skb_unlink(skb, &sk->sk_receive_queue);
    + clear = 1;
    + }
    + spin_unlock_bh(&sk->sk_receive_queue.lock);
    + if (clear)
    + kfree_skb(skb);
    + }
    +
    + skb_free_datagram(sk, skb);
    +
    + if (noblock)
    + return -EAGAIN;
    + goto try_again;
    +}
    +
    +/* The following function is identical to the one used in udp.c: */
    +
    +int udplite_disconnect(struct sock *sk, int flags)
    +{
    + struct inet_sock *inet = inet_sk(sk);
    +
    + /*
    + * 1003.1g - break association.
    + */
    + sk->sk_state = TCP_CLOSE;
    + sk->sk_bound_dev_if = 0;
    + inet->daddr = 0;
    + inet->dport = 0;
    + if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
    + inet_reset_saddr(sk);
    +
    + if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
    + sk->sk_prot->unhash(sk);
    + inet->sport = 0;
    + }
    + sk_dst_reset(sk);
    + return 0;
    +}
    +
    +
    +static void udplite_close(struct sock *sk, long timeout)
    +{
    + sk_common_release(sk);
    +}
    +
    +/**
    + * udplite_encap_rcv - taken from udp.c
    + *
    + * Return:
    + * 1 if the the UDP-Lite system should process it
    + * 0 if we should drop this packet
    + * -1 if it should get processed by xfrm4_rcv_encap
    + */
    +
    +static int udplite_encap_rcv(struct sock *sk, struct sk_buff *skb)
    +{
    +#ifndef CONFIG_XFRM
    + return 1;
    +#else
    + struct udplite_sock *up = udplite_sk(sk);
    + struct udplitehdr *uh = skb->h.ulh;
    + struct iphdr *iph;
    + int iphlen, len;
    +
    + __u8 *udplitedata = (__u8 *) uh + sizeof(struct udplitehdr);
    + __u32 *udplitedata32 = (__u32 *) udplitedata;
    + __u16 encap_type = up->encap_type;
    +
    + /* if we're overly short, let UDP-Lite handle it */
    + if (udplitedata > skb->tail)
    + return 1;
    +
    + /* if this is not encapsulated socket, then just return now */
    + if (!encap_type)
    + return 1;
    +
    + len = skb->tail - udplitedata;
    +
    + switch (encap_type) {
    + default:
    + case UDPLITE_ENCAP_ESPINUDPLITE:
    + /* Check if this is a keepalive packet. If so, eat it. */
    + if (len == 1 && udplitedata[0] == 0xff) {
    + return 0;
    + } else if (len > sizeof(struct ip_esp_hdr)
    + && udplitedata32[0] != 0) {
    + /* ESP Packet without Non-ESP header */
    + len = sizeof(struct udplitehdr);
    + } else
    + /* Must be an IKE packet.. pass it through */
    + return 1;
    + break;
    + case UDPLITE_ENCAP_ESPINUDPLITE_NON_IKE:
    + /* Check if this is a keepalive packet. If so, eat it. */
    + if (len == 1 && udplitedata[0] == 0xff) {
    + return 0;
    + } else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) &&
    + udplitedata32[0] == 0 && udplitedata32[1] == 0) {
    +
    + /* ESP Packet with Non-IKE marker */
    + len = sizeof(struct udplitehdr) + 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 ESP-in-UDP-Lite packet,
    + * so we need to remove 'len' bytes from the packet (the UDP-Lite
    + * 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 = skb->nh.iph;
    + 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-Lite on the stack
    + * for later.
    + */
    + skb->h.raw = skb_pull(skb, len);
    +
    + /* 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
    +}
    +
    +/**
    + * udplite_queue_rcv - same code as in udp.c
    + *
    + * Returns:
    + * -1: error
    + * 0: success
    + * >0: "UDP-Lite encap" protocol resubmission
    + *
    + * Note that in the success and error cases, the skb is assumed to
    + * have either been requeued or freed.
    + */
    +
    +static int udplite_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
    +{
    + struct udplite_sock *up = udplite_sk(sk);
    +
    + /*
    + * Charge it to the socket, dropping if the queue is full.
    + */
    + if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) {
    + kfree_skb(skb);
    + return -1;
    + }
    +
    + 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-Lite socket.
    + */
    + int ret;
    +
    + ret = udplite_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);
    + UDPLITE_INC_STATS_BH(UDPLITE_MIB_INDATAGRAMS);
    + return -ret;
    + }
    + /* FALLTHROUGH -- it's a UDP-Lite Packet */
    + }
    + /*
    + * FIXME: The use of encapsulated packets has not yet been tested. The
    + * code below reflects the common-sense options, but may have to check
    + * whether it works in all possible cases. -- gr
    + */
    + if (sk->sk_filter && skb->ip_summed != CHECKSUM_UNNECESSARY) {
    + if (__udplite_checksum_complete(skb)) {
    + UDPLITE_INC_STATS_BH(UDPLITE_MIB_INERRORS_CHECKSUMMING);
    + UDPLITE_INC_STATS_BH(UDPLITE_MIB_INERRORS);
    + kfree_skb(skb);
    + return -1;
    + }
    + skb->ip_summed = CHECKSUM_UNNECESSARY;
    + }
    +
    + if (sock_queue_rcv_skb(sk, skb) < 0) {
    + UDPLITE_INC_STATS_BH(UDPLITE_MIB_INERRORS);
    + kfree_skb(skb);
    + return -1;
    + }
    + UDPLITE_INC_STATS_BH(UDPLITE_MIB_INDATAGRAMS);
    + return 0;
    +}
    +
    +/*
    + * udplite_v4_mcast_deliver - code taken from udp.c
    + *
    + * Multicasts and broadcasts go to each listener.
    + * Note: called only from the BH handler context,
    + * so we don't need to lock the hashes.
    + */
    +static int udplite_v4_mcast_deliver(struct sk_buff *skb, struct udplitehdr *uh,
    + u32 saddr, u32 daddr)
    +{
    + struct sock *sk;
    + int dif;
    +
    + read_lock(&udplite_hash_lock);
    + sk = sk_head(&udplite_hash
    + [ntohs(uh->dest) & (UDPLITE_HTABLE_SIZE - 1)]);
    + dif = skb->dev->ifindex;
    + sk = udplite_v4_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif);
    + if (sk) {
    + struct sock *sknext = NULL;
    +
    + do {
    + struct sk_buff *skb1 = skb;
    +
    + sknext =
    + udplite_v4_mcast_next(sk_next(sk), uh->dest, daddr,
    + uh->source, saddr, dif);
    + if (sknext)
    + skb1 = skb_clone(skb, GFP_ATOMIC);
    +
    + if (skb1) {
    + int ret = udplite_queue_rcv_skb(sk, skb1);
    + if (ret > 0)
    + /* we should probably re-process instead
    + * of dropping packets here. */
    + kfree_skb(skb1);
    + }
    + sk = sknext;
    + } while (sknext);
    + } else
    + kfree_skb(skb);
    + read_unlock(&udplite_hash_lock);
    + return 0;
    +}
    +
    +/**
    + * udplite_checksum_init - Initialize UDP-Lite checksum.
    + *
    + * If exited with zero value (success), CHECKSUM_UNNECESSARY means that
    + * no more checks are required. Otherwise, csum completion requires to
    + * checksum packet body plus UDP-Lite header, and folding it to skb->csum.
    + */
    +static int udplite_checksum_init(struct sk_buff *skb,
    + struct udplitehdr *uh,
    + unsigned short clen, u32 saddr, u32 daddr)
    +{
    + /* 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) {
    + return 1;
    + } else if (skb->ip_summed == CHECKSUM_HW) {
    + skb->ip_summed = CHECKSUM_UNNECESSARY;
    + if (csum_tcpudp_magic
    + (saddr, daddr, clen, IPPROTO_UDPLITE, skb->csum) == 0)
    + return 0;
    + LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: hw csum failure.\n");
    + skb->ip_summed = CHECKSUM_NONE;
    + }
    + if (skb->ip_summed != CHECKSUM_UNNECESSARY)
    + skb->csum =
    + csum_tcpudp_nofold(saddr, daddr, clen, IPPROTO_UDPLITE, 0);
    + return 0;
    +}
    +
    +/**
    + * udplite_rcv - receive packets
    + *
    + * This code is modelled after the one in udp.c, but heavily modified
    + * with regard to the differences in computing the checksum.
    + */
    +int udplite_rcv(struct sk_buff *skb)
    +{
    + struct sock *sk;
    + struct udplitehdr *uh;
    + u32 saddr = skb->nh.iph->saddr,
    + daddr = skb->nh.iph->daddr;
    + int len = skb->len; /* total packet length */
    + unsigned short clen; /* csum coverage length */
    + struct udplite_sock *up;
    + struct rtable *rt = (struct rtable *)skb->dst;
    +
    + /*
    + * Validate the packet and the UDP-Lite length.
    + */
    + if (!pskb_may_pull(skb, sizeof(struct udplitehdr)))
    + goto drop; /* No header. */
    +
    + uh = skb->h.ulh;
    + sk = udplite_v4_lookup(saddr, uh->source, daddr, uh->dest,
    + skb->dev->ifindex);
    + up = udplite_sk(sk);
    + clen = ntohs(uh->checklen);
    +
    + if (sk == NULL)
    + goto no_port;
    +
    + if (len < sizeof(*uh)) /* Unlike udp.c, pskb_trim makes */
    + goto short_packet; /* no sense, since len = skb->len */
    +
    + if (clen == 0) /* Indicates that full coverage is required. */
    + clen = len;
    + else if (clen < 8 || /* Illegal coverage length, 8 is minimum. */
    + clen > len) /* Coverage length exceeds datagram length. */
    + goto csumlen_error;
    + else if (clen < len) /* Normal: partial coverage required. */
    + UDPLITE_INC_STATS_BH(UDPLITE_MIB_INDATAGRAMS_PARTIAL_CHECK);
    +
    + if (up->pcflag & UDPLITE_RECV_CHCKFLAG) { /* min. coverage was set */
    + /*
    + * MIB statistics other than incrementing the error count are
    + * disabled for the following two types of errors: these depend
    + * on the application settings, not on the functioning of the
    + * protocol stack as such.
    + *
    + * RFC 3828 here recommends (sec 3.3): "There should also be a
    + * way ... to ... at least let the receiving application block
    + * delivery of packets with coverage values less than a value
    + * provided by the application."
    + */
    + if (clen < len) {
    + if (up->pcrlen == 0) {
    + LIMIT_NETDEBUG(KERN_WARNING
    + "UDPLITE: partial coverage %d, but "
    + "full coverage %d requ. "
    + "(IP %d.%d.%d.%d:%d -> %d.%d.%d.%d:%d)\n",
    + clen, len, NIPQUAD(saddr),
    + ntohs(uh->source), NIPQUAD(daddr),
    + ntohs(uh->dest));
    + goto drop;
    + }
    + } else if (clen < up->pcrlen) { /* here: clen=len */
    + LIMIT_NETDEBUG(KERN_WARNING
    + "UDPLITE: coverage %d too small, need min. %d "
    + "(IP %d.%d.%d.%d:%d -> %d.%d.%d.%d:%d)\n", clen,
    + up->pcrlen, NIPQUAD(saddr), ntohs(uh->source),
    + NIPQUAD(daddr), ntohs(uh->dest));
    + goto drop;
    + }
    + }
    + /* Compute initial checksum, including pseudo-header. */
    + if (udplite_checksum_init(skb, uh, len, saddr, daddr) < 0)
    + goto csum_error;
    +
    + if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
    + return udplite_v4_mcast_deliver(skb, uh, saddr, daddr);
    +
    + if (sk != NULL) {
    + int ret = udplite_queue_rcv_skb(sk, skb);
    + sock_put(sk);
    +
    + /*
    + * A return value > 0 means to resubmit the input, but
    + * it wants the return to be -protocol, or 0.
    + *
    + */
    + if (ret > 0)
    + return -ret;
    + return 0;
    + }
    + if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
    + goto drop;
    +
    + /* No socket. Drop packet silently, if checksum is wrong */
    + if (udplite_checksum_complete(skb))
    + goto csum_error;
    +
    +no_port:
    + /*
    + * Got a UDP-Lite packet to a port to which we don't wanna listen.
    + * Ignore it and increment the count of `NoPort' messages.
    + */
    + UDPLITE_INC_STATS_BH(UDPLITE_MIB_NOPORTS);
    + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
    + kfree_skb(skb);
    + return (0);
    +
    +short_packet:
    + LIMIT_NETDEBUG(KERN_NOTICE "UDPLITE: short packet, %d/%d bytes "
    + "(%u.%u.%u.%u:%u -> %u.%u.%u.%u:%u\n)\n",
    + len, clen, NIPQUAD(saddr), ntohs(uh->source),
    + NIPQUAD(daddr), ntohs(uh->dest) );
    + goto drop;
    +
    +csumlen_error:
    + /*
    + * 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, len %d)\n",
    + clen, NIPQUAD(saddr), ntohs(uh->source),
    + NIPQUAD(daddr), ntohs(uh->dest), len);
    + UDPLITE_INC_STATS_BH(UDPLITE_MIB_INERRORS_CHECKSUM_COVERAGE);
    + goto drop;
    +
    +csum_error:
    + /*
    + * Checksum violated: proceed as per RFC 1122/3828.
    + */
    + LIMIT_NETDEBUG(KERN_DEBUG "UDPLITE: bad checksum "
    + "(%d.%d.%d.%d:%d -> %d.%d.%d.%d:%d)\n", NIPQUAD(saddr),
    + ntohs(uh->source), NIPQUAD(daddr), ntohs(uh->dest));
    + UDPLITE_INC_STATS_BH(UDPLITE_MIB_INERRORS_CHECKSUMMING);
    +
    +drop:
    + UDPLITE_INC_STATS_BH(UDPLITE_MIB_INERRORS);
    + kfree_skb(skb);
    + return (0);
    +}
    +
    +static int udplite_destroy_sock(struct sock *sk)
    +{
    + lock_sock(sk);
    + udplite_flush_pending_frames(sk);
    + release_sock(sk);
    + return 0;
    +}
    +
    +/**
    + * udplite_setsocktopt - set UDP-Lite socket options
    + *
    + * This function is very similar to udp.c, the only difference being
    + * the two new socket options for setting receiver/sender csum coverage.
    + */
    +static int udplite_setsockopt(struct sock *sk,
    + int level,
    + int optname, char __user * optval, int optlen)
    +{
    + struct udplite_sock *up = udplite_sk(sk);
    + int val;
    + int err = 0;
    +
    + if (level != SOL_UDPLITE)
    + return ip_setsockopt(sk, level, optname, optval, optlen);
    +
    + if (optlen < sizeof(int))
    + return -EINVAL;
    +
    + if (get_user(val, (int __user *)optval))
    + return -EFAULT;
    +
    + switch (optname) {
    + case UDPLITE_CORK:
    + if (val != 0) {
    + up->corkflag = 1;
    + } else {
    + up->corkflag = 0;
    + lock_sock(sk);
    + udplite_push_pending_frames(sk, up);
    + release_sock(sk);
    + }
    + break;
    +
    + case UDPLITE_ENCAP:
    + switch (val) {
    + case 0:
    + case UDP_ENCAP_ESPINUDP:
    + case UDP_ENCAP_ESPINUDP_NON_IKE:
    + up->encap_type = val;
    + break;
    + default:
    + err = -ENOPROTOOPT;
    + break;
    + }
    + break;
    + /* Sender sets actual checksum coverage length via this option.
    + The case coverage > packet length is handled by send module. */
    + case UDPLITE_SOCKOPT_SEND_CSCOV:
    + if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
    + val = 8;
    + up->pcslen = val;
    + up->pcflag |= UDPLITE_SEND_CHCKFLAG;
    + break;
    +
    + /* The receiver specifies a minimum checksum coverage value. To make
    + * sense, this should be set to 8 (as done below). */
    + case UDPLITE_SOCKOPT_RECV_CSCOV:
    + if (val != 0 && val < 8) /* Disallow silly minimal values. */
    + val = 8;
    + up->pcrlen = val;
    + up->pcflag |= UDPLITE_RECV_CHCKFLAG;
    + break;
    +
    + default:
    + err = -ENOPROTOOPT;
    + break;
    + };
    +
    + return err;
    +}
    +
    +/**
    + * udplite_getsockopt - as per udp.c
    + */
    +static int udplite_getsockopt(struct sock *sk, int level, int optname,
    + char __user * optval, int __user * optlen)
    +{
    + struct udplite_sock *up = udplite_sk(sk);
    + int val, len;
    +
    + if (level != SOL_UDPLITE)
    + return ip_getsockopt(sk, level, optname, optval, optlen);
    +
    + if (get_user(len, optlen))
    + return -EFAULT;
    +
    + len = min_t(unsigned int, len, sizeof(int));
    +
    + if (len < 0)
    + return -EINVAL;
    +
    + switch (optname) {
    + case UDPLITE_CORK:
    + val = up->corkflag;
    + break;
    +
    + case UDPLITE_ENCAP:
    + val = up->encap_type;
    + break;
    +
    + case UDPLITE_SOCKOPT_SEND_CSCOV:
    + val = up->pcslen;
    + break;
    +
    + case UDPLITE_SOCKOPT_RECV_CSCOV:
    + val = up->pcrlen;
    + break;
    +
    + default:
    + return -ENOPROTOOPT;
    + };
    +
    + if (put_user(len, optlen))
    + return -EFAULT;
    + if (copy_to_user(optval, &val, len))
    + return -EFAULT;
    + return 0;
    +}
    +
    +/**
    + * udplite_poll - wait for a UDP-Lite event (agrees mostly with udp.c)
    + *
    + * @file: file struct
    + * @sock: socket
    + * @wait: poll table
    + *
    + * This is same as datagram poll, except for the special case of
    + * blocking sockets. If application is using a blocking fd
    + * and a packet with checksum error is in the queue;
    + * then it could get return from select indicating data available
    + * but then block when reading it. Add special case code
    + * to work around these arguably broken applications.
    + */
    +
    +unsigned int udplite_poll(struct file *file, struct socket *sock,
    + poll_table *wait)
    +{
    + unsigned int mask = datagram_poll(file, sock, wait);
    + struct sock *sk = sock->sk;
    +
    + /* Check for false positives due to checksum errors */
    + if ((mask & POLLRDNORM) &&
    + !(file->f_flags & O_NONBLOCK) &&
    + !(sk->sk_shutdown & RCV_SHUTDOWN)) {
    + struct sk_buff_head *rcvq = &sk->sk_receive_queue;
    + struct sk_buff *skb;
    +
    + spin_lock_bh(&rcvq->lock);
    + while ((skb = skb_peek(rcvq)) != NULL) {
    + if (udplite_checksum_complete(skb)) {
    + /* checksum invalidated */
    + UDPLITE_INC_STATS_BH
    + (UDPLITE_MIB_INERRORS_CHECKSUMMING);
    + UDPLITE_INC_STATS_BH(UDPLITE_MIB_INERRORS);
    + __skb_unlink(skb, rcvq);
    + kfree_skb(skb);
    + } else {
    + skb->ip_summed = CHECKSUM_UNNECESSARY;
    + break;
    + }
    + }
    + spin_unlock_bh(&rcvq->lock);
    +
    + if (skb == NULL) /* Nothing to see, move along. */
    + mask &= ~(POLLIN | POLLRDNORM);
    + }
    +
    + return mask;
    +
    +}
    +
    +
    +struct proto udplite_prot = {
    + .name = "UDPLITE",
    + .owner = THIS_MODULE,
    + .close = udplite_close,
    + .connect = ip4_datagram_connect,
    + .disconnect = udplite_disconnect,
    + .ioctl = udplite_ioctl,
    + .destroy = udplite_destroy_sock,
    + .setsockopt = udplite_setsockopt,
    + .getsockopt = udplite_getsockopt,
    + .sendmsg = udplite_sendmsg,
    + .recvmsg = udplite_recvmsg,
    + .sendpage = udplite_sendpage,
    + .backlog_rcv = udplite_queue_rcv_skb,
    + .hash = udplite_v4_hash,
    + .unhash = udplite_v4_unhash,
    + .get_port = udplite_v4_get_port,
    + .obj_size = sizeof(struct udplite_sock),
    +};
    +
    +/*-------------------------------------------------------------------------
    + * Operations related to the proc filesystem. These are are all taken
    + * (modulo name change) from udp.c
    + *-------------------------------------------------------------------------*/
    +#ifdef CONFIG_PROC_FS
    +static struct sock *udplite_get_first(struct seq_file *seq)
    +{
    + struct sock *sk;
    + struct udplite_iter_state *state = seq->private;
    +
    + for (state->bucket = 0; state->bucket < UDPLITE_HTABLE_SIZE;
    + ++state->bucket) {
    + struct hlist_node *node;
    + sk_for_each(sk, node, &udplite_hash[state->bucket]) {
    + if (sk->sk_family == state->family)
    + goto found;
    + }
    + }
    + sk = NULL;
    +found:
    + return sk;
    +}
    +
    +static struct sock *udplite_get_next(struct seq_file *seq, struct sock *sk)
    +{
    + struct udplite_iter_state *state = seq->private;
    +
    + do {
    + sk = sk_next(sk);
    +try_again:
    + ;
    + } while (sk && sk->sk_family != state->family);
    +
    + if (!sk && ++state->bucket < UDPLITE_HTABLE_SIZE) {
    + sk = sk_head(&udplite_hash[state->bucket]);
    + goto try_again;
    + }
    + return sk;
    +}
    +
    +static struct sock *udplite_get_idx(struct seq_file *seq, loff_t pos)
    +{
    + struct sock *sk = udplite_get_first(seq);
    +
    + if (sk)
    + while (pos && (sk = udplite_get_next(seq, sk)) != NULL)
    + --pos;
    + return pos? NULL : sk;
    +}
    +
    +static void *udplite_seq_start(struct seq_file *seq, loff_t * pos)
    +{
    + read_lock(&udplite_hash_lock);
    + return *pos ? udplite_get_idx(seq, *pos - 1) : (void *)1;
    +}
    +
    +static void *udplite_seq_next(struct seq_file *seq, void *v, loff_t * pos)
    +{
    + struct sock *sk;
    +
    + if (v == (void *)1)
    + sk = udplite_get_idx(seq, 0);
    + else
    + sk = udplite_get_next(seq, v);
    +
    + ++*pos;
    + return sk;
    +}
    +
    +static void udplite_seq_stop(struct seq_file *seq, void *v)
    +{
    + read_unlock(&udplite_hash_lock);
    +}
    +
    +static int udplite_seq_open(struct inode *inode, struct file *file)
    +{
    + struct udplite_seq_afinfo *afinfo = PDE(inode)->data;
    + struct seq_file *seq;
    + int rc = -ENOMEM;
    + struct udplite_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
    +
    + if (!s)
    + goto out;
    + memset(s, 0, sizeof(*s));
    + s->family = afinfo->family;
    + s->seq_ops.start = udplite_seq_start;
    + s->seq_ops.next = udplite_seq_next;
    + s->seq_ops.show = afinfo->seq_show;
    + s->seq_ops.stop = udplite_seq_stop;
    +
    + rc = seq_open(file, &s->seq_ops);
    + if (rc)
    + goto out_kfree;
    +
    + seq = file->private_data;
    + seq->private = s;
    +out:
    + return rc;
    +out_kfree:
    + kfree(s);
    + goto out;
    +}
    +
    +/* ------------------------------------------------------------------------ */
    +int udplite_proc_register(struct udplite_seq_afinfo *afinfo)
    +{
    + struct proc_dir_entry *p;
    + int rc = 0;
    +
    + if (!afinfo)
    + return -EINVAL;
    + afinfo->seq_fops->owner = afinfo->owner;
    + afinfo->seq_fops->open = udplite_seq_open;
    + afinfo->seq_fops->read = seq_read;
    + afinfo->seq_fops->llseek = seq_lseek;
    + afinfo->seq_fops->release = seq_release_private;
    +
    + p = proc_net_fops_create(afinfo->name, S_IRUGO, afinfo->seq_fops);
    + if (p)
    + p->data = afinfo;
    + else
    + rc = -ENOMEM;
    + return rc;
    +}
    +
    +void udplite_proc_unregister(struct udplite_seq_afinfo *afinfo)
    +{
    + if (!afinfo)
    + return;
    + proc_net_remove(afinfo->name);
    + memset(afinfo->seq_fops, 0, sizeof(*afinfo->seq_fops));
    +}
    +
    +
    +static void udplite4_format_sock(struct sock *sp, char *tmpbuf, int bucket)
    +{
    + struct inet_sock *inet = inet_sk(sp);
    + unsigned int dest = inet->daddr;
    + unsigned int src = inet->rcv_saddr;
    + __u16 destp = ntohs(inet->dport);
    + __u16 srcp = ntohs(inet->sport);
    +
    + sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"
    + " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p",
    + bucket, src, srcp, dest, destp, sp->sk_state,
    + atomic_read(&sp->sk_wmem_alloc),
    + atomic_read(&sp->sk_rmem_alloc),
    + 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
    + atomic_read(&sp->sk_refcnt), sp);
    +}
    +
    +static int udplite4_seq_show(struct seq_file *seq, void *v)
    +{
    + if (v == SEQ_START_TOKEN)
    + seq_printf(seq, "%-127s\n",
    + " sl local_address rem_address st tx_queue "
    + "rx_queue tr tm->when retrnsmt uid timeout "
    + "inode");
    + else {
    + char tmpbuf[129];
    + struct udplite_iter_state *state = seq->private;
    +
    + udplite4_format_sock(v, tmpbuf, state->bucket);
    + seq_printf(seq, "%-127s\n", tmpbuf);
    + }
    + return 0;
    +}
    +
    +/* ------------------------------------------------------------------------ */
    +static struct file_operations udplite4_seq_fops;
    +
    +static struct udplite_seq_afinfo udplite4_seq_afinfo = {
    + .owner = THIS_MODULE,
    + .name = "udplite",
    + .family = AF_INET,
    + .seq_show = udplite4_seq_show,
    + .seq_fops = &udplite4_seq_fops,
    +};
    +
    +
    +int __init udplite4_proc_init(void)
    +{
    + return udplite_proc_register(&udplite4_seq_afinfo);
    +}
    +
    +void udplite4_proc_exit(void)
    +{
    + udplite_proc_unregister(&udplite4_seq_afinfo);
    +}
    +#endif /* CONFIG_PROC_FS */
    +/* ------------------------------------------------------------------------ */
    +
    +EXPORT_SYMBOL(udplite_disconnect);
    +EXPORT_SYMBOL(udplite_hash);
    +EXPORT_SYMBOL(udplite_hash_lock);
    +EXPORT_SYMBOL(udplite_ioctl);
    +EXPORT_SYMBOL(udplite_port_rover);
    +EXPORT_SYMBOL(udplite_prot);
    +EXPORT_SYMBOL(udplite_sendmsg);
    +EXPORT_SYMBOL(udplite_poll);
    +
    +#ifdef CONFIG_PROC_FS
    +EXPORT_SYMBOL(udplite_proc_register);
    +EXPORT_SYMBOL(udplite_proc_unregister);
    +#endif
    -
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      Last update: 2006-06-08 12:54    [W:0.171 / U:60.080 seconds]
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