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Message-Id: <200608281910.26115@strip-the-willow>
Date: Mon, 28 Aug 2006 19:10:25 +0100
From: gerrit@....abdn.ac.uk
To: davem@...emloft.net
Cc: jmorris@...ei.org, alan@...rguk.ukuu.org.uk, kuznet@....inr.ac.ru,
pekkas@...core.fi, kaber@...eworks.de, yoshfuji@...ux-ipv6.org,
netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [RFC][PATCHv2 2.6.18-rc4-mm3 2/3] net/ipv4: UDP and generic UDP(-Lite) processing
[Net/IPv4]: REVISED Modifications to the UDP module and generic UDP/-Lite processing.
Signed-off-by: Gerrit Renker <gerrit@....abdn.ac.uk>
---
include/net/udp.h | 68 ++++++-
net/ipv4/udp.c | 489 ++++++++++++++++++++++++++++++++++++------------------
2 files changed, 395 insertions(+), 162 deletions(-)
diff --git a/include/net/udp.h b/include/net/udp.h
index 766fba1..77c5fb9 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -26,9 +26,48 @@ #include <linux/list.h>
#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
+#include <net/udplite.h>
+
+/**
+ * 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))
+
+/*
+ * Generic checksumming routines for UDP(-Lite) v4 and v6
+ */
+static inline u16 __udp_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_checksum_complete(struct sk_buff *skb)
+{
+ return skb->ip_summed != CHECKSUM_UNNECESSARY &&
+ __udp_checksum_complete(skb);
+}
/* udp.c: This needs to be shared by v4 and v6 because the lookup
* and hashing code needs to work with different AF's yet
@@ -39,16 +78,24 @@ extern rwlock_t udp_hash_lock;
extern int udp_port_rover;
-static inline int udp_lport_inuse(u16 num)
+/*
+ * XXX: since udp_v{4,6}_get_port use common code, these two functions
+ * will soon go
+ */
+static inline int __udp_lport_inuse(u16 num, struct hlist_head udptable[])
{
struct sock *sk;
struct hlist_node *node;
- sk_for_each(sk, node, &udp_hash[num & (UDP_HTABLE_SIZE - 1)])
+ sk_for_each(sk, node, &udptable[num & (UDP_HTABLE_SIZE - 1)])
if (inet_sk(sk)->num == num)
return 1;
return 0;
}
+static __inline__ int udp_lport_inuse(u16 num)
+{
+ return __udp_lport_inuse(num, udp_hash);
+}
/* Note: this must match 'valbool' in sock_setsockopt */
#define UDP_CSUM_NOXMIT 1
@@ -75,21 +122,32 @@ extern unsigned int udp_poll(struct file
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)
+#define UDP_DEC_STATS_BH(field, is_udplite) do { \
+ if (is_udplite) SNMP_DEC_STATS_BH(udplite_statistics, field); \
+ else SNMP_DEC_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;
};
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 514c1e9..5ca0db3 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -92,10 +92,8 @@ #include <linux/errno.h>
#include <linux/timer.h>
#include <linux/mm.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>
@@ -108,6 +106,8 @@ #include <net/route.h>
#include <net/inet_common.h>
#include <net/checksum.h>
#include <net/xfrm.h>
+/* the extensions for UDP-Lite (RFC 3828) */
+#include "udplite.c"
/*
* Snmp MIB for the UDP layer
@@ -121,7 +121,13 @@ DEFINE_RWLOCK(udp_hash_lock);
/* Shared by v4/v6 udp. */
int udp_port_rover;
-static int udp_v4_get_port(struct sock *sk, unsigned short snum)
+static __inline__ int udp_v4_get_port(struct sock *sk, unsigned short snum)
+{
+ return __udp_get_port(sk, snum, udp_hash, &udp_port_rover);
+}
+
+int __udp_get_port(struct sock *sk, unsigned short snum,
+ struct hlist_head udptable[], int *port_rover)
{
struct hlist_node *node;
struct sock *sk2;
@@ -131,16 +137,16 @@ static int udp_v4_get_port(struct sock *
if (snum == 0) {
int best_size_so_far, best, result, i;
- if (udp_port_rover > sysctl_local_port_range[1] ||
- udp_port_rover < sysctl_local_port_range[0])
- udp_port_rover = sysctl_local_port_range[0];
+ if (*port_rover > sysctl_local_port_range[1] ||
+ *port_rover < sysctl_local_port_range[0])
+ *port_rover = sysctl_local_port_range[0];
best_size_so_far = 32767;
- best = result = udp_port_rover;
+ best = result = *port_rover;
for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) {
struct hlist_head *list;
int size;
- list = &udp_hash[result & (UDP_HTABLE_SIZE - 1)];
+ list = &udptable[result & (UDP_HTABLE_SIZE - 1)];
if (hlist_empty(list)) {
if (result > sysctl_local_port_range[1])
result = sysctl_local_port_range[0] +
@@ -162,16 +168,16 @@ static int udp_v4_get_port(struct sock *
result = sysctl_local_port_range[0]
+ ((result - sysctl_local_port_range[0]) &
(UDP_HTABLE_SIZE - 1));
- if (!udp_lport_inuse(result))
+ if (! __udp_lport_inuse(result, udptable))
break;
}
if (i >= (1 << 16) / UDP_HTABLE_SIZE)
goto fail;
gotit:
- udp_port_rover = snum = result;
+ *port_rover = snum = result;
} else {
sk_for_each(sk2, node,
- &udp_hash[snum & (UDP_HTABLE_SIZE - 1)]) {
+ &udptable[snum & (UDP_HTABLE_SIZE - 1)]) {
struct inet_sock *inet2 = inet_sk(sk2);
if (inet2->num == snum &&
@@ -189,7 +195,7 @@ gotit:
}
inet->num = snum;
if (sk_unhashed(sk)) {
- struct hlist_head *h = &udp_hash[snum & (UDP_HTABLE_SIZE - 1)];
+ struct hlist_head *h = &udptable[snum & (UDP_HTABLE_SIZE - 1)];
sk_add_node(sk, h);
sock_prot_inc_use(sk->sk_prot);
@@ -220,15 +226,22 @@ static void udp_v4_unhash(struct sock *s
/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
* harder than this. -DaveM
*/
-static struct sock *udp_v4_lookup_longway(u32 saddr, u16 sport,
- u32 daddr, u16 dport, int dif)
+static __inline__ struct sock *udp_v4_lookup(u32 saddr, u16 sport,
+ u32 daddr, u16 dport, int dif)
+{
+ return __udp_lookup(saddr, sport, daddr, dport, dif, udp_hash);
+}
+
+struct sock *__udp_lookup(u32 saddr, u16 sport, u32 daddr, u16 dport, int dif,
+ struct hlist_head udptable[] )
{
struct sock *sk, *result = NULL;
struct hlist_node *node;
unsigned short hnum = ntohs(dport);
int badness = -1;
- sk_for_each(sk, node, &udp_hash[hnum & (UDP_HTABLE_SIZE - 1)]) {
+ read_lock(&udp_hash_lock);
+ sk_for_each(sk, node, &udptable[hnum & (UDP_HTABLE_SIZE - 1)]) {
struct inet_sock *inet = inet_sk(sk);
if (inet->num == hnum && !ipv6_only_sock(sk)) {
@@ -262,20 +275,11 @@ static struct sock *udp_v4_lookup_longwa
}
}
}
- return result;
-}
-
-static __inline__ struct sock *udp_v4_lookup(u32 saddr, u16 sport,
- u32 daddr, u16 dport, int dif)
-{
- struct sock *sk;
-
- read_lock(&udp_hash_lock);
- sk = udp_v4_lookup_longway(saddr, sport, daddr, dport, dif);
- if (sk)
- sock_hold(sk);
+ if (result)
+ sock_hold(result);
read_unlock(&udp_hash_lock);
- return sk;
+
+ return result;
}
static inline struct sock *udp_v4_mcast_next(struct sock *sk,
@@ -317,7 +321,12 @@ found:
* to find the appropriate port.
*/
-void udp_err(struct sk_buff *skb, u32 info)
+__inline__ void udp_err(struct sk_buff *skb, u32 info)
+{
+ return __udp_err(skb, info, udp_hash);
+}
+
+void __udp_err(struct sk_buff *skb, u32 info, struct hlist_head udptable[])
{
struct inet_sock *inet;
struct iphdr *iph = (struct iphdr*)skb->data;
@@ -328,7 +337,8 @@ void udp_err(struct sk_buff *skb, u32 in
int harderr;
int err;
- sk = udp_v4_lookup(iph->daddr, uh->dest, iph->saddr, uh->source, skb->dev->ifindex);
+ sk = __udp_lookup(iph->daddr, uh->dest, iph->saddr, uh->source,
+ skb->dev->ifindex, udptable );
if (sk == NULL) {
ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
return; /* No socket for error */
@@ -396,33 +406,17 @@ static void udp_flush_pending_frames(str
}
}
-/*
- * Push out all pending data as one UDP datagram. Socket is locked.
- */
-static int udp_push_pending_frames(struct sock *sk, struct udp_sock *up)
+static void udp_csum_outgoing(struct sock *sk, struct sk_buff *skb,
+ int totlen, u32 src, u32 dst )
{
- struct inet_sock *inet = inet_sk(sk);
- struct flowi *fl = &inet->cork.fl;
- struct sk_buff *skb;
- struct udphdr *uh;
- int err = 0;
-
- /* Grab the skbuff where UDP header space exists. */
- if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
- goto out;
+ unsigned int csum = 0;
+ struct udphdr *uh = skb->h.uh;
- /*
- * Create a UDP header
- */
- uh = skb->h.uh;
- uh->source = fl->fl_ip_sport;
- uh->dest = fl->fl_ip_dport;
- uh->len = htons(up->len);
uh->check = 0;
if (sk->sk_no_check == UDP_CSUM_NOXMIT) {
skb->ip_summed = CHECKSUM_NONE;
- goto send;
+ return;
}
if (skb_queue_len(&sk->sk_write_queue) == 1) {
@@ -431,42 +425,95 @@ static int udp_push_pending_frames(struc
*/
if (skb->ip_summed == CHECKSUM_PARTIAL) {
skb->csum = offsetof(struct udphdr, check);
- uh->check = ~csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst,
- up->len, IPPROTO_UDP, 0);
- } else {
- skb->csum = csum_partial((char *)uh,
- sizeof(struct udphdr), skb->csum);
- uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst,
- up->len, IPPROTO_UDP, skb->csum);
- if (uh->check == 0)
- uh->check = -1;
- }
+ uh->check = ~csum_tcpudp_magic(src, dst,
+ totlen, IPPROTO_UDP, 0);
+ return;
+ } else {
+ csum = csum_partial(skb->h.raw,
+ sizeof(struct udphdr), skb->csum);
+ }
} else {
- unsigned int csum = 0;
/*
* HW-checksum won't work as there are two or more
* fragments on the socket so that all csums of sk_buffs
* should be together.
*/
if (skb->ip_summed == CHECKSUM_PARTIAL) {
- int offset = (unsigned char *)uh - skb->data;
+ int offset = skb->h.raw - skb->data;
skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
skb->ip_summed = CHECKSUM_NONE;
- } else {
- skb->csum = csum_partial((char *)uh,
- sizeof(struct udphdr), skb->csum);
- }
+ } else
+ skb->csum = csum_partial(skb->h.raw,
+ sizeof(struct udphdr), skb->csum);
skb_queue_walk(&sk->sk_write_queue, skb) {
csum = csum_add(csum, skb->csum);
}
- uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst,
- up->len, IPPROTO_UDP, csum);
- if (uh->check == 0)
- uh->check = -1;
}
-send:
+
+ uh->check = csum_tcpudp_magic(src, dst, totlen, IPPROTO_UDP, csum);
+ if (uh->check == 0)
+ uh->check = -1;
+}
+
+/*
+ * Push out all pending data as one UDP datagram. Socket is locked.
+ */
+static int udp_push_pending_frames(struct sock *sk, struct udp_sock *up)
+{
+ struct inet_sock *inet = inet_sk(sk);
+ struct flowi *fl = &inet->cork.fl;
+ struct sk_buff *skb;
+ struct udphdr *uh;
+ int err = 0;
+ u16 cscov = up->len;
+
+ /* Grab the skbuff where UDP header space exists. */
+ if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
+ goto out;
+
+ /*
+ * Create a UDP header
+ */
+ uh = skb->h.uh;
+ uh->source = fl->fl_ip_sport;
+ uh->dest = fl->fl_ip_dport;
+ uh->len = htons(up->len);
+
+ /*
+ * If sender has set `partial coverage' socket option on a
+ * UDP-Lite socket, adjust coverage length accordingly.
+ * All other cases default to traditional UDP checksum mode.
+ */
+ 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.
+ */
+ }
+
+ if(up->pcflag)
+ udplite_csum_outgoing(sk, skb, up->len, cscov,
+ fl->fl4_src, fl->fl4_dst);
+ else
+ udp_csum_outgoing(sk, skb, up->len, fl->fl4_src, fl->fl4_dst);
+
+
err = ip_push_pending_frames(sk);
out:
up->len = 0;
@@ -475,11 +522,6 @@ out:
}
-static unsigned short udp_check(struct udphdr *uh, int len, unsigned long saddr, unsigned long daddr, unsigned long base)
-{
- return(csum_tcpudp_magic(saddr, daddr, len, IPPROTO_UDP, base));
-}
-
int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
size_t len)
{
@@ -493,8 +535,9 @@ int udp_sendmsg(struct kiocb *iocb, stru
u32 daddr, faddr, saddr;
u16 dport;
u8 tos;
- int err;
+ int err, is_udplite = up->pcflag;
int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
+ int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
if (len > 0xFFFF)
return -EMSGSIZE;
@@ -599,7 +642,7 @@ int udp_sendmsg(struct kiocb *iocb, stru
{ .daddr = faddr,
.saddr = saddr,
.tos = tos } },
- .proto = IPPROTO_UDP,
+ .proto = sk->sk_protocol,
.uli_u = { .ports =
{ .sport = inet->sport,
.dport = dport } } };
@@ -645,7 +688,8 @@ back_from_confirm:
do_append_data:
up->len += ulen;
- err = ip_append_data(sk, ip_generic_getfrag, msg->msg_iov, ulen,
+ getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
+ err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
sizeof(struct udphdr), &ipc, rt,
corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
if (err)
@@ -659,7 +703,7 @@ out:
if (free)
kfree(ipc.opt);
if (!err) {
- UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS);
+ UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS, is_udplite);
return len;
}
/*
@@ -670,7 +714,7 @@ out:
* seems like overkill.
*/
if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
- UDP_INC_STATS_USER(UDP_MIB_SNDBUFERRORS);
+ UDP_INC_STATS_USER(UDP_MIB_SNDBUFERRORS, is_udplite);
}
return err;
@@ -770,17 +814,6 @@ int udp_ioctl(struct sock *sk, int cmd,
return(0);
}
-static __inline__ int __udp_checksum_complete(struct sk_buff *skb)
-{
- return __skb_checksum_complete(skb);
-}
-
-static __inline__ int udp_checksum_complete(struct sk_buff *skb)
-{
- return skb->ip_summed != CHECKSUM_UNNECESSARY &&
- __udp_checksum_complete(skb);
-}
-
/*
* This should be easy, if there is something there we
* return it, otherwise we block.
@@ -792,7 +825,7 @@ static int udp_recvmsg(struct kiocb *ioc
struct inet_sock *inet = inet_sk(sk);
struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
struct sk_buff *skb;
- int copied, err;
+ int copied, err, copy_only, is_udplite = IS_UDPLITE(sk);
/*
* Check any passed addresses
@@ -814,17 +847,26 @@ try_again:
msg->msg_flags |= MSG_TRUNC;
}
- if (skb->ip_summed==CHECKSUM_UNNECESSARY) {
- err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
- copied);
- } else if (msg->msg_flags&MSG_TRUNC) {
+ /*
+ * Decide whether to checksum and/or copy data.
+ *
+ * UDP: checksum may have been computed in HW,
+ * (re-)compute it if message is truncated.
+ * UDP-Lite: always needs to checksum, no HW support.
+ */
+ copy_only = (skb->ip_summed == CHECKSUM_UNNECESSARY);
+
+ if (is_udplite || (!copy_only && msg->msg_flags&MSG_TRUNC)) {
if (__udp_checksum_complete(skb))
goto csum_copy_err;
- err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
- copied);
- } else {
- err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
+ copy_only = 1;
+ }
+ if (copy_only)
+ err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
+ msg->msg_iov, copied );
+ else {
+ err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
if (err == -EINVAL)
goto csum_copy_err;
}
@@ -855,7 +897,8 @@ out:
return err;
csum_copy_err:
- UDP_INC_STATS_BH(UDP_MIB_INERRORS);
+ UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite);
+ UDP_DEC_STATS_BH(UDP_MIB_INDATAGRAMS, is_udplite);
skb_kill_datagram(sk, skb, flags);
@@ -996,10 +1039,8 @@ static int udp_queue_rcv_skb(struct sock
/*
* 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 (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
+ goto drop;
nf_reset(skb);
if (up->encap_type) {
@@ -1023,31 +1064,77 @@ static int udp_queue_rcv_skb(struct sock
if (ret < 0) {
/* process the ESP packet */
ret = xfrm4_rcv_encap(skb, up->encap_type);
- UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS);
+ UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
return -ret;
}
/* FALLTHROUGH -- it's a UDP Packet */
}
if (sk->sk_filter && skb->ip_summed != CHECKSUM_UNNECESSARY) {
- if (__udp_checksum_complete(skb)) {
- UDP_INC_STATS_BH(UDP_MIB_INERRORS);
- kfree_skb(skb);
- return -1;
- }
+ if (__udp_checksum_complete(skb))
+ goto drop;
skb->ip_summed = CHECKSUM_UNNECESSARY;
}
+ /*
+ * UDP-Lite specific tests, ignored on UDP sockets
+ * XXX: may be better to do them before sk->sk_filter
+ */
+ if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
+
+ /*
+ * 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 (up->pcrlen == 0) { /* full coverage was set */
+ LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage "
+ "%d while full coverage %d requested\n",
+ UDP_SKB_CB(skb)->cscov, skb->len);
+ goto drop;
+ }
+ /* The next case involves violating the min. coverage requested
+ * by the receiver. This is subtle: if receiver wants x and x is
+ * greater than the buffersize/MTU then receiver will complain
+ * that it wants x while sender emits packets of smaller size y.
+ * Therefore the above ...()->partial_cov statement is essential.
+ */
+ if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
+ LIMIT_NETDEBUG(KERN_WARNING
+ "UDPLITE: coverage %d too small, need min %d\n",
+ UDP_SKB_CB(skb)->cscov, up->pcrlen);
+ goto drop;
+ }
+ }
+
if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) {
/* Note that an ENOMEM error is charged twice */
if (rc == -ENOMEM)
- UDP_INC_STATS_BH(UDP_MIB_RCVBUFERRORS);
- UDP_INC_STATS_BH(UDP_MIB_INERRORS);
- kfree_skb(skb);
- return -1;
+ UDP_INC_STATS_BH(UDP_MIB_RCVBUFERRORS, up->pcflag);
+ goto drop;
}
- UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS);
+ /*
+ * XXX Incrementing this counter when the datagram is later taken off
+ * the queue due to receive failure is problematic, cf.
+ * http://bugzilla.kernel.org/show_bug.cgi?id=6660
+ * This module counts correctly by decrementing InDatagrams whenever
+ * the datagram is popped off a queue without being actually delivered,
+ * see udp_recvmsg() and udp_poll().
+ */
+ UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
return 0;
+
+drop:
+ UDP_INC_STATS_BH(UDP_MIB_INERRORS, up->pcflag);
+ kfree_skb(skb);
+ return -1;
}
/*
@@ -1056,14 +1143,20 @@ static int udp_queue_rcv_skb(struct sock
* Note: called only from the BH handler context,
* so we don't need to lock the hashes.
*/
-static int udp_v4_mcast_deliver(struct sk_buff *skb, struct udphdr *uh,
- u32 saddr, u32 daddr)
+static __inline__ int udp_v4_mcast_deliver(struct sk_buff *skb,
+ struct udphdr *uh, u32 saddr, u32 daddr)
+{
+ return __udp_mcast_deliver(skb, uh, saddr, daddr, udp_hash);
+}
+
+int __udp_mcast_deliver(struct sk_buff *skb, struct udphdr *uh,
+ u32 saddr, u32 daddr, struct hlist_head udptable[])
{
struct sock *sk;
int dif;
read_lock(&udp_hash_lock);
- sk = sk_head(&udp_hash[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]);
+ sk = sk_head(&udptable[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]);
dif = skb->dev->ifindex;
sk = udp_v4_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif);
if (sk) {
@@ -1103,7 +1196,7 @@ static void udp_checksum_init(struct sk_
if (uh->check == 0) {
skb->ip_summed = CHECKSUM_UNNECESSARY;
} else if (skb->ip_summed == CHECKSUM_COMPLETE) {
- if (!udp_check(uh, ulen, saddr, daddr, skb->csum))
+ if (!csum_tcpudp_magic(saddr,daddr,ulen, IPPROTO_UDP, skb->csum))
skb->ip_summed = CHECKSUM_UNNECESSARY;
}
if (skb->ip_summed != CHECKSUM_UNNECESSARY)
@@ -1111,13 +1204,20 @@ static void udp_checksum_init(struct sk_
/* Probably, we should checksum udp header (it should be in cache
* in any case) and data in tiny packets (< rx copybreak).
*/
+
+ /* UDP = UDP-Lite with a non-partial checksum coverage */
+ UDP_SKB_CB(skb)->partial_cov = 0;
}
/*
* All we need to do is get the socket, and then do a checksum.
*/
-
-int udp_rcv(struct sk_buff *skb)
+__inline__ int udp_rcv(struct sk_buff *skb)
+{
+ return __udp_common_rcv(skb, 0);
+}
+
+int __udp_common_rcv(struct sk_buff *skb, int is_udplite)
{
struct sock *sk;
struct udphdr *uh;
@@ -1126,29 +1226,39 @@ int udp_rcv(struct sk_buff *skb)
u32 saddr = skb->nh.iph->saddr;
u32 daddr = skb->nh.iph->daddr;
int len = skb->len;
+ struct hlist_head *ht = is_udplite? udplite_hash : udp_hash;
/*
- * Validate the packet and the UDP length.
+ * Validate the packet.
*/
if (!pskb_may_pull(skb, sizeof(struct udphdr)))
- goto no_header;
+ goto drop; /* No space for header. */
uh = skb->h.uh;
ulen = ntohs(uh->len);
- if (ulen > len || ulen < sizeof(*uh))
- goto short_packet;
+ if (! is_udplite) {
+ if (ulen > len || ulen < sizeof(*uh))
+ goto short_packet;
+
+ if (pskb_trim_rcsum(skb, ulen))
+ goto short_packet;
- if (pskb_trim_rcsum(skb, ulen))
- goto short_packet;
+ udp_checksum_init(skb, uh, ulen, saddr, daddr);
- udp_checksum_init(skb, uh, ulen, saddr, daddr);
+ } else { /* UDP-Lite: we must not trim here */
+ if (len < sizeof(*uh))
+ goto short_packet;
+
+ if (! udplite_checksum_init(skb, uh, len, saddr, daddr))
+ goto csum_error;
+ }
if(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
- return udp_v4_mcast_deliver(skb, uh, saddr, daddr);
+ return __udp_mcast_deliver(skb, uh, saddr, daddr, ht);
- sk = udp_v4_lookup(saddr, uh->source, daddr, uh->dest, skb->dev->ifindex);
+ sk = __udp_lookup(saddr, uh->source, daddr, uh->dest, skb->dev->ifindex, ht);
if (sk != NULL) {
int ret = udp_queue_rcv_skb(sk, skb);
@@ -1170,7 +1280,7 @@ int udp_rcv(struct sk_buff *skb)
if (udp_checksum_complete(skb))
goto csum_error;
- UDP_INC_STATS_BH(UDP_MIB_NOPORTS);
+ UDP_INC_STATS_BH(UDP_MIB_NOPORTS, is_udplite);
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
/*
@@ -1181,31 +1291,30 @@ int udp_rcv(struct sk_buff *skb)
return(0);
short_packet:
- LIMIT_NETDEBUG(KERN_DEBUG "UDP: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n",
+ LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n",
+ is_udplite? "-Lite" : "",
NIPQUAD(saddr),
ntohs(uh->source),
ulen,
len,
NIPQUAD(daddr),
ntohs(uh->dest));
-no_header:
- UDP_INC_STATS_BH(UDP_MIB_INERRORS);
- kfree_skb(skb);
- return(0);
+ goto drop;
csum_error:
/*
* RFC1122: OK. Discards the bad packet silently (as far as
* the network is concerned, anyway) as per 4.1.3.4 (MUST).
*/
- LIMIT_NETDEBUG(KERN_DEBUG "UDP: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n",
+ LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n",
+ is_udplite? "-Lite" : "",
NIPQUAD(saddr),
ntohs(uh->source),
NIPQUAD(daddr),
ntohs(uh->dest),
ulen);
drop:
- UDP_INC_STATS_BH(UDP_MIB_INERRORS);
+ UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite);
kfree_skb(skb);
return(0);
}
@@ -1259,6 +1368,32 @@ static int do_udp_setsockopt(struct sock
}
break;
+ /*
+ * UDP-Lite's partial checksum coverage (RFC 3828).
+ */
+ /* The sender sets actual checksum coverage length via this option.
+ * The case coverage > packet length is handled by send module. */
+ case UDPLITE_SEND_CSCOV:
+ if (!up->pcflag) /* Disable the option on UDP sockets */
+ return -ENOPROTOOPT;
+ if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
+ val = 8;
+ up->pcslen = val;
+ up->pcflag |= UDPLITE_SEND_CC;
+ break;
+
+ /* The receiver specifies a minimum checksum coverage value. To make
+ * sense, this should be set to at least 8 (as done below). If zero is
+ * used, this again means full checksum coverage. */
+ case UDPLITE_RECV_CSCOV:
+ if (!up->pcflag) /* Disable the option on UDP sockets */
+ return -ENOPROTOOPT;
+ if (val != 0 && val < 8) /* Avoid silly minimal values. */
+ val = 8;
+ up->pcrlen = val;
+ up->pcflag |= UDPLITE_RECV_CC;
+ break;
+
default:
err = -ENOPROTOOPT;
break;
@@ -1270,18 +1405,18 @@ static int do_udp_setsockopt(struct sock
static int udp_setsockopt(struct sock *sk, int level, int optname,
char __user *optval, int optlen)
{
- if (level != SOL_UDP)
- return ip_setsockopt(sk, level, optname, optval, optlen);
- return do_udp_setsockopt(sk, level, optname, optval, optlen);
+ if (level == SOL_UDP || level == SOL_UDPLITE)
+ return do_udp_setsockopt(sk, level, optname, optval, optlen);
+ return ip_setsockopt(sk, level, optname, optval, optlen);
}
#ifdef CONFIG_COMPAT
static int compat_udp_setsockopt(struct sock *sk, int level, int optname,
char __user *optval, int optlen)
{
- if (level != SOL_UDP)
- return compat_ip_setsockopt(sk, level, optname, optval, optlen);
- return do_udp_setsockopt(sk, level, optname, optval, optlen);
+ if (level == SOL_UDP || level == SOL_UDPLITE)
+ return do_udp_setsockopt(sk, level, optname, optval, optlen);
+ return compat_ip_setsockopt(sk, level, optname, optval, optlen);
}
#endif
@@ -1308,6 +1443,15 @@ static int do_udp_getsockopt(struct sock
val = up->encap_type;
break;
+ /* the following two always return 0 on UDP sockets */
+ case UDPLITE_SEND_CSCOV:
+ val = up->pcslen;
+ break;
+
+ case UDPLITE_RECV_CSCOV:
+ val = up->pcrlen;
+ break;
+
default:
return -ENOPROTOOPT;
};
@@ -1322,18 +1466,18 @@ static int do_udp_getsockopt(struct sock
static int udp_getsockopt(struct sock *sk, int level, int optname,
char __user *optval, int __user *optlen)
{
- if (level != SOL_UDP)
- return ip_getsockopt(sk, level, optname, optval, optlen);
- return do_udp_getsockopt(sk, level, optname, optval, optlen);
+ if (level == SOL_UDP || level == SOL_UDPLITE)
+ return do_udp_getsockopt(sk, level, optname, optval, optlen);
+ return ip_getsockopt(sk, level, optname, optval, optlen);
}
#ifdef CONFIG_COMPAT
static int compat_udp_getsockopt(struct sock *sk, int level, int optname,
char __user *optval, int __user *optlen)
{
- if (level != SOL_UDP)
- return compat_ip_getsockopt(sk, level, optname, optval, optlen);
- return do_udp_getsockopt(sk, level, optname, optval, optlen);
+ if (level == SOL_UDP || level == SOL_UDPLITE)
+ return do_udp_getsockopt(sk, level, optname, optval, optlen);
+ return compat_ip_getsockopt(sk, level, optname, optval, optlen);
}
#endif
/**
@@ -1353,6 +1497,7 @@ unsigned int udp_poll(struct file *file,
{
unsigned int mask = datagram_poll(file, sock, wait);
struct sock *sk = sock->sk;
+ int is_lite = IS_UDPLITE(sk);
/* Check for false positives due to checksum errors */
if ( (mask & POLLRDNORM) &&
@@ -1364,7 +1509,11 @@ unsigned int udp_poll(struct file *file,
spin_lock_bh(&rcvq->lock);
while ((skb = skb_peek(rcvq)) != NULL) {
if (udp_checksum_complete(skb)) {
- UDP_INC_STATS_BH(UDP_MIB_INERRORS);
+ /* The datagram has already been counted as
+ * InDatagram when earlier it was enqueued.
+ * Update count of really received datagrams. */
+ UDP_DEC_STATS_BH(UDP_MIB_INDATAGRAMS, is_lite);
+ UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_lite);
__skb_unlink(skb, rcvq);
kfree_skb(skb);
} else {
@@ -1407,6 +1556,30 @@ #ifdef CONFIG_COMPAT
#endif
};
+struct proto udplite_prot = {
+ .name = "UDP-Lite",
+ .owner = THIS_MODULE,
+ .close = udp_close,
+ .connect = ip4_datagram_connect,
+ .disconnect = udp_disconnect,
+ .ioctl = udp_ioctl,
+ .init = udplite_sk_init,
+ .destroy = udp_destroy_sock,
+ .setsockopt = udp_setsockopt,
+ .getsockopt = udp_getsockopt,
+ .sendmsg = udp_sendmsg,
+ .recvmsg = udp_recvmsg,
+ .sendpage = udp_sendpage,
+ .backlog_rcv = udp_queue_rcv_skb,
+ .hash = udp_v4_hash,
+ .unhash = udp_v4_unhash,
+ .get_port = udplite_v4_get_port,
+ .obj_size = sizeof(struct udp_sock),
+#ifdef CONFIG_COMPAT
+ .compat_setsockopt = compat_udp_setsockopt,
+ .compat_getsockopt = compat_udp_getsockopt,
+#endif
+};
/* ------------------------------------------------------------------------ */
#ifdef CONFIG_PROC_FS
@@ -1417,7 +1590,7 @@ static struct sock *udp_get_first(struct
for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
struct hlist_node *node;
- sk_for_each(sk, node, &udp_hash[state->bucket]) {
+ sk_for_each(sk, node, state->hashtable + state->bucket) {
if (sk->sk_family == state->family)
goto found;
}
@@ -1438,7 +1611,7 @@ try_again:
} while (sk && sk->sk_family != state->family);
if (!sk && ++state->bucket < UDP_HTABLE_SIZE) {
- sk = sk_head(&udp_hash[state->bucket]);
+ sk = sk_head(state->hashtable + state->bucket);
goto try_again;
}
return sk;
@@ -1488,6 +1661,7 @@ static int udp_seq_open(struct inode *in
if (!s)
goto out;
s->family = afinfo->family;
+ s->hashtable = afinfo->hashtable;
s->seq_ops.start = udp_seq_start;
s->seq_ops.next = udp_seq_next;
s->seq_ops.show = afinfo->seq_show;
@@ -1554,7 +1728,7 @@ static void udp4_format_sock(struct sock
atomic_read(&sp->sk_refcnt), sp);
}
-static int udp4_seq_show(struct seq_file *seq, void *v)
+int udp4_seq_show(struct seq_file *seq, void *v)
{
if (v == SEQ_START_TOKEN)
seq_printf(seq, "%-127s\n",
@@ -1577,6 +1751,7 @@ static struct udp_seq_afinfo udp4_seq_af
.owner = THIS_MODULE,
.name = "udp",
.family = AF_INET,
+ .hashtable = udp_hash,
.seq_show = udp4_seq_show,
.seq_fops = &udp4_seq_fops,
};
-
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