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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:0.381 / U:0.396 seconds]
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