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[NET]: Supporting UDP-Lite (RFC 3828) in Linux

Browse Source 
This is a revision of the previously submitted patch, which alters
the way files are organized and compiled in the following manner:

	* UDP and UDP-Lite now use separate object files
	* source file dependencies resolved via header files
	  net/ipv{4,6}/udp_impl.h
	* order of inclusion files in udp.c/udplite.c adapted
	  accordingly

[NET/IPv4]: Support for the UDP-Lite protocol (RFC 3828)

This patch adds support for UDP-Lite to the IPv4 stack, provided as an
extension to the existing UDPv4 code:
        * generic routines are all located in net/ipv4/udp.c
        * UDP-Lite specific routines are in net/ipv4/udplite.c
        * MIB/statistics support in /proc/net/snmp and /proc/net/udplite
        * shared API with extensions for partial checksum coverage

[NET/IPv6]: Extension for UDP-Lite over IPv6

It extends the existing UDPv6 code base with support for UDP-Lite
in the same manner as per UDPv4. In particular,
        * UDPv6 generic and shared code is in net/ipv6/udp.c
        * UDP-Litev6 specific extensions are in net/ipv6/udplite.c
        * MIB/statistics support in /proc/net/snmp6 and /proc/net/udplite6
        * support for IPV6_ADDRFORM
        * aligned the coding style of protocol initialisation with af_inet6.c
        * made the error handling in udpv6_queue_rcv_skb consistent;
          to return `-1' on error on all error cases
        * consolidation of shared code

[NET]: UDP-Lite Documentation and basic XFRM/Netfilter support

The UDP-Lite patch further provides
        * API documentation for UDP-Lite
        * basic xfrm support
        * basic netfilter support for IPv4 and IPv6 (LOG target)

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Gerrit Renker
2006-11-27 11:10:57 -08:00
committed by David S. Miller
parent 6051e2f4fb
commit ba4e58eca8
28 changed files with 1443 additions and 404 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
include/linux/in.h
View File

@@ -45,6 +45,7 @@ enum {
IPPROTO_COMP = 108, /* Compression Header protocol */
IPPROTO_SCTP = 132, /* Stream Control Transport Protocol */
IPPROTO_UDPLITE = 136, /* UDP-Lite (RFC 3828) */
IPPROTO_RAW = 255, /* Raw IP packets */
IPPROTO_MAX

1
include/linux/socket.h
View File

@@ -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

12
include/linux/udp.h
View File

@@ -38,6 +38,7 @@ struct udphdr {
#include <linux/types.h>
#include <net/inet_sock.h>
#define UDP_HTABLE_SIZE 128
struct udp_sock {
/* inet_sock has to be the first member */
@@ -50,12 +51,23 @@ struct udp_sock {
* when the socket is uncorked.
*/
__u16 len; /* total length of pending frames */
/*
* Fields specific to UDP-Lite.
*/
__u16 pcslen;
__u16 pcrlen;
/* indicator bits used by pcflag: */
#define UDPLITE_BIT 0x1 /* set by udplite proto init function */
#define UDPLITE_SEND_CC 0x2 /* set via udplite setsockopt */
#define UDPLITE_RECV_CC 0x4 /* set via udplite setsocktopt */
__u8 pcflag; /* marks socket as UDP-Lite if > 0 */
};
static inline struct udp_sock *udp_sk(const struct sock *sk)
{
return (struct udp_sock *)sk;
}
#define IS_UDPLITE(__sk) (udp_sk(__sk)->pcflag)
#endif

12
include/net/ipv6.h
View File

@@ -158,9 +158,13 @@ DECLARE_SNMP_STAT(struct icmpv6_mib, icmpv6_statistics);
SNMP_INC_STATS_OFFSET_BH(icmpv6_statistics, field, _offset); \
})
DECLARE_SNMP_STAT(struct udp_mib, udp_stats_in6);
#define UDP6_INC_STATS(field) SNMP_INC_STATS(udp_stats_in6, field)
#define UDP6_INC_STATS_BH(field) SNMP_INC_STATS_BH(udp_stats_in6, field)
#define UDP6_INC_STATS_USER(field) SNMP_INC_STATS_USER(udp_stats_in6, field)
DECLARE_SNMP_STAT(struct udp_mib, udplite_stats_in6);
#define UDP6_INC_STATS_BH(field, is_udplite) do { \
if (is_udplite) SNMP_INC_STATS_BH(udplite_stats_in6, field); \
else SNMP_INC_STATS_BH(udp_stats_in6, field); } while(0)
#define UDP6_INC_STATS_USER(field, is_udplite) do { \
if (is_udplite) SNMP_INC_STATS_USER(udplite_stats_in6, field); \
else SNMP_INC_STATS_USER(udp_stats_in6, field); } while(0)
int snmp6_register_dev(struct inet6_dev *idev);
int snmp6_unregister_dev(struct inet6_dev *idev);
@@ -604,6 +608,8 @@ extern int tcp6_proc_init(void);
extern void tcp6_proc_exit(void);
extern int udp6_proc_init(void);
extern void udp6_proc_exit(void);
extern int udplite6_proc_init(void);
extern void udplite6_proc_exit(void);
extern int ipv6_misc_proc_init(void);
extern void ipv6_misc_proc_exit(void);

2
include/net/transp_v6.h
View File

@@ -11,6 +11,7 @@
extern struct proto rawv6_prot;
extern struct proto udpv6_prot;
extern struct proto udplitev6_prot;
extern struct proto tcpv6_prot;
struct flowi;
@@ -24,6 +25,7 @@ extern void ipv6_destopt_init(void);
/* transport protocols */
extern void rawv6_init(void);
extern void udpv6_init(void);
extern void udplitev6_init(void);
extern void tcpv6_init(void);
extern int udpv6_connect(struct sock *sk,

91
include/net/udp.h
View File

@@ -26,9 +26,28 @@
#include <net/inet_sock.h>
#include <net/sock.h>
#include <net/snmp.h>
#include <net/ip.h>
#include <linux/ipv6.h>
#include <linux/seq_file.h>
#define UDP_HTABLE_SIZE 128
/**
* struct udp_skb_cb - UDP(-Lite) private variables
*
* @header: private variables used by IPv4/IPv6
* @cscov: checksum coverage length (UDP-Lite only)
* @partial_cov: if set indicates partial csum coverage
*/
struct udp_skb_cb {
union {
struct inet_skb_parm h4;
#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
struct inet6_skb_parm h6;
#endif
} header;
__u16 cscov;
__u8 partial_cov;
};
#define UDP_SKB_CB(__skb) ((struct udp_skb_cb *)((__skb)->cb))
extern struct hlist_head udp_hash[UDP_HTABLE_SIZE];
extern rwlock_t udp_hash_lock;
@@ -47,6 +66,62 @@ extern struct proto udp_prot;
struct sk_buff;
/*
* Generic checksumming routines for UDP(-Lite) v4 and v6
*/
static inline u16 __udp_lib_checksum_complete(struct sk_buff *skb)
{
if (! UDP_SKB_CB(skb)->partial_cov)
return __skb_checksum_complete(skb);
return csum_fold(skb_checksum(skb, 0, UDP_SKB_CB(skb)->cscov,
skb->csum));
}
static __inline__ int udp_lib_checksum_complete(struct sk_buff *skb)
{
return skb->ip_summed != CHECKSUM_UNNECESSARY &&
__udp_lib_checksum_complete(skb);
}
/**
* udp_csum_outgoing - compute UDPv4/v6 checksum over fragments
* @sk: socket we are writing to
* @skb: sk_buff containing the filled-in UDP header
* (checksum field must be zeroed out)
*/
static inline u32 udp_csum_outgoing(struct sock *sk, struct sk_buff *skb)
{
u32 csum = csum_partial(skb->h.raw, sizeof(struct udphdr), 0);
skb_queue_walk(&sk->sk_write_queue, skb) {
csum = csum_add(csum, skb->csum);
}
return csum;
}
/* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
static inline void udp_lib_hash(struct sock *sk)
{
BUG();
}
static inline void udp_lib_unhash(struct sock *sk)
{
write_lock_bh(&udp_hash_lock);
if (sk_del_node_init(sk)) {
inet_sk(sk)->num = 0;
sock_prot_dec_use(sk->sk_prot);
}
write_unlock_bh(&udp_hash_lock);
}
static inline void udp_lib_close(struct sock *sk, long timeout)
{
sk_common_release(sk);
}
/* net/ipv4/udp.c */
extern int udp_get_port(struct sock *sk, unsigned short snum,
int (*saddr_cmp)(const struct sock *, const struct sock *));
extern void udp_err(struct sk_buff *, u32);
@@ -61,21 +136,29 @@ extern unsigned int udp_poll(struct file *file, struct socket *sock,
poll_table *wait);
DECLARE_SNMP_STAT(struct udp_mib, udp_statistics);
#define UDP_INC_STATS(field) SNMP_INC_STATS(udp_statistics, field)
#define UDP_INC_STATS_BH(field) SNMP_INC_STATS_BH(udp_statistics, field)
#define UDP_INC_STATS_USER(field) SNMP_INC_STATS_USER(udp_statistics, field)
/*
* SNMP statistics for UDP and UDP-Lite
*/
#define UDP_INC_STATS_USER(field, is_udplite) do { \
if (is_udplite) SNMP_INC_STATS_USER(udplite_statistics, field); \
else SNMP_INC_STATS_USER(udp_statistics, field); } while(0)
#define UDP_INC_STATS_BH(field, is_udplite) do { \
if (is_udplite) SNMP_INC_STATS_BH(udplite_statistics, field); \
else SNMP_INC_STATS_BH(udp_statistics, field); } while(0)
/* /proc */
struct udp_seq_afinfo {
struct module *owner;
char *name;
sa_family_t family;
struct hlist_head *hashtable;
int (*seq_show) (struct seq_file *m, void *v);
struct file_operations *seq_fops;
};
struct udp_iter_state {
sa_family_t family;
struct hlist_head *hashtable;
int bucket;
struct seq_operations seq_ops;
};

149
include/net/udplite.h Normal file
View File

@@ -0,0 +1,149 @@
/*
* Definitions for the UDP-Lite (RFC 3828) code.
*/
#ifndef _UDPLITE_H
#define _UDPLITE_H
/* UDP-Lite socket options */
#define UDPLITE_SEND_CSCOV 10 /* sender partial coverage (as sent) */
#define UDPLITE_RECV_CSCOV 11 /* receiver partial coverage (threshold ) */
extern struct proto udplite_prot;
extern struct hlist_head udplite_hash[UDP_HTABLE_SIZE];
/* UDP-Lite does not have a standardized MIB yet, so we inherit from UDP */
DECLARE_SNMP_STAT(struct udp_mib, udplite_statistics);
/*
* Checksum computation is all in software, hence simpler getfrag.
*/
static __inline__ int udplite_getfrag(void *from, char *to, int offset,
int len, int odd, struct sk_buff *skb)
{
return memcpy_fromiovecend(to, (struct iovec *) from, offset, len);
}
/* Designate sk as UDP-Lite socket */
static inline int udplite_sk_init(struct sock *sk)
{
udp_sk(sk)->pcflag = UDPLITE_BIT;
return 0;
}
/*
* Checksumming routines
*/
static inline int udplite_checksum_init(struct sk_buff *skb, struct udphdr *uh)
{
u16 cscov;
/* In UDPv4 a zero checksum means that the transmitter generated no
* checksum. UDP-Lite (like IPv6) mandates checksums, hence packets
* with a zero checksum field are illegal. */
if (uh->check == 0) {
LIMIT_NETDEBUG(KERN_DEBUG "UDPLITE: zeroed checksum field\n");
return 1;
}
UDP_SKB_CB(skb)->partial_cov = 0;
cscov = ntohs(uh->len);
if (cscov == 0) /* Indicates that full coverage is required. */
cscov = skb->len;
else if (cscov < 8 || cscov > skb->len) {
/*
* Coverage length violates RFC 3828: log and discard silently.
*/
LIMIT_NETDEBUG(KERN_DEBUG "UDPLITE: bad csum coverage %d/%d\n",
cscov, skb->len);
return 1;
} else if (cscov < skb->len)
UDP_SKB_CB(skb)->partial_cov = 1;
UDP_SKB_CB(skb)->cscov = cscov;
/*
* There is no known NIC manufacturer supporting UDP-Lite yet,
* hence ip_summed is always (re-)set to CHECKSUM_NONE.
*/
skb->ip_summed = CHECKSUM_NONE;
return 0;
}
static __inline__ int udplite4_csum_init(struct sk_buff *skb, struct udphdr *uh)
{
int rc = udplite_checksum_init(skb, uh);
if (!rc)
skb->csum = csum_tcpudp_nofold(skb->nh.iph->saddr,
skb->nh.iph->daddr,
skb->len, IPPROTO_UDPLITE, 0);
return rc;
}
static __inline__ int udplite6_csum_init(struct sk_buff *skb, struct udphdr *uh)
{
int rc = udplite_checksum_init(skb, uh);
if (!rc)
skb->csum = ~csum_ipv6_magic(&skb->nh.ipv6h->saddr,
&skb->nh.ipv6h->daddr,
skb->len, IPPROTO_UDPLITE, 0);
return rc;
}
static inline int udplite_sender_cscov(struct udp_sock *up, struct udphdr *uh)
{
int cscov = up->len;
/*
* Sender has set `partial coverage' option on UDP-Lite socket
*/
if (up->pcflag & UDPLITE_SEND_CC) {
if (up->pcslen < up->len) {
/* up->pcslen == 0 means that full coverage is required,
* partial coverage only if 0 < up->pcslen < up->len */
if (0 < up->pcslen) {
cscov = up->pcslen;
}
uh->len = htons(up->pcslen);
}
/*
* NOTE: Causes for the error case `up->pcslen > up->len':
* (i) Application error (will not be penalized).
* (ii) Payload too big for send buffer: data is split
* into several packets, each with its own header.
* In this case (e.g. last segment), coverage may
* exceed packet length.
* Since packets with coverage length > packet length are
* illegal, we fall back to the defaults here.
*/
}
return cscov;
}
static inline u32 udplite_csum_outgoing(struct sock *sk, struct sk_buff *skb)
{
u32 csum = 0;
int off, len, cscov = udplite_sender_cscov(udp_sk(sk), skb->h.uh);
skb->ip_summed = CHECKSUM_NONE; /* no HW support for checksumming */
skb_queue_walk(&sk->sk_write_queue, skb) {
off = skb->h.raw - skb->data;
len = skb->len - off;
csum = skb_checksum(skb, off, (cscov > len)? len : cscov, csum);
if ((cscov -= len) <= 0)
break;
}
return csum;
}
extern void udplite4_register(void);
extern int udplite_get_port(struct sock *sk, unsigned short snum,
int (*scmp)(const struct sock *, const struct sock *));
#endif /* _UDPLITE_H */

2
include/net/xfrm.h
View File

@@ -468,6 +468,7 @@ __be16 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;
@@ -493,6 +494,7 @@ __be16 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;