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Message-Id: <200608281159.21583@strip-the-willow>
Date: Mon, 28 Aug 2006 11:59:21 +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: Re: [RFC][PATCH 0/3] net: a lighter UDP-Lite (RFC 3828)
[NET/IPv4]: update for udp.c only, to match 2.6.18-rc4-mm3
This is an update only, as the previous patch can not cope
with recent changes to udp.c (all other files remain the same).
Up-to-date, complete patches can always be taken from
http://www.erg.abdn.ac.uk/users/gerrit/udp-lite/files/udplite_linux.tar.gz
Signed-off-by: Gerrit Renker <gerrit@....abdn.ac.uk>
---
udp.c | 606 ++++++++++++++++++++++++++++++++++++++++++++----------------------
1 file changed, 410 insertions(+), 196 deletions(-)
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 514c1e9..4ddd8e6 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>
@@ -121,7 +119,19 @@ 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)
+/* the extensions for UDP-Lite (RFC 3828) */
+#include "udplite.c"
+
+/**
+ * __udp_get_port - find an unbound UDP(-Lite) port
+ *
+ * @sk: udp_sock
+ * @snum: port number to look up
+ * @udptable: hash list table, must be of UDP_HTABLE_SIZE
+ * @port_rover: pointer to record of last unallocated port
+ */
+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 +141,16 @@ 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 +172,16 @@ 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 +199,7 @@ 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);
@@ -202,6 +212,11 @@ fail:
return 1;
}
+static __inline__ int udp_v4_get_port(struct sock *sk, unsigned short snum)
+{
+ return __udp_get_port(sk, snum, udp_hash, &udp_port_rover);
+}
+
static void udp_v4_hash(struct sock *sk)
{
BUG();
@@ -217,18 +232,24 @@ static void udp_v4_unhash(struct sock *s
write_unlock_bh(&udp_hash_lock);
}
-/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
- * harder than this. -DaveM
+/**
+ * __udp_lookup - find UDP(-Lite) socket
+ *
+ * @udptable: hash list table, must be of UDP_HTABLE_SIZE
+ *
+ * UDP 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)
+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 +283,17 @@ static struct sock *udp_v4_lookup_longwa
}
}
}
+ if (result)
+ sock_hold(result);
+ read_unlock(&udp_hash_lock);
+
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);
- read_unlock(&udp_hash_lock);
- return sk;
+ return __udp_lookup(saddr, sport, daddr, dport, dif, udp_hash);
}
static inline struct sock *udp_v4_mcast_next(struct sock *sk,
@@ -306,7 +324,11 @@ found:
return s;
}
-/*
+/**
+ * __udp_err - generic UDP/-Lite error routine
+ *
+ * @udptable: hash list table, must be of UDP_HTABLE_SIZE
+ *
* 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
@@ -316,8 +338,7 @@ found:
* header points to the first 8 bytes of the udp header. We need
* to find the appropriate port.
*/
-
-void udp_err(struct sk_buff *skb, u32 info)
+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 +349,8 @@ 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 */
@@ -382,6 +404,11 @@ out:
sock_put(sk);
}
+__inline__ void udp_err(struct sk_buff *skb, u32 info)
+{
+ return __udp_err(skb, info, udp_hash);
+}
+
/*
* Throw away all pending data and cancel the corking. Socket is locked.
*/
@@ -396,33 +423,17 @@ 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;
+ unsigned int csum = 0;
+ struct udphdr *uh = skb->h.uh;
- /* 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);
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 +442,95 @@ 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);
+ uh->check = ~csum_tcpudp_magic(src, dst, totlen,
+ IPPROTO_UDP, 0 );
+ return;
} 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;
+ 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
+ * 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.
+ * 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,
+ 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/-Lite 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;
@@ -474,12 +538,11 @@ out:
return err;
}
-
-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));
-}
-
+/**
+ * udp_sendmsg - generic UDP/-Lite send routine
+ *
+ * This function is udplite-aware and works for both protocols.
+ */
int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
size_t len)
{
@@ -493,8 +556,9 @@ 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 +663,7 @@ 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 } } };
@@ -645,8 +709,9 @@ back_from_confirm:
do_append_data:
up->len += ulen;
- err = ip_append_data(sk, ip_generic_getfrag, msg->msg_iov, ulen,
- sizeof(struct udphdr), &ipc, rt,
+ 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)
udp_flush_pending_frames(sk);
@@ -659,7 +724,7 @@ 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 +735,7 @@ 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;
@@ -682,8 +747,13 @@ do_confirm:
goto out;
}
-static int udp_sendpage(struct sock *sk, struct page *page, int offset,
- size_t size, int flags)
+/**
+ * udp_sendpage - generic UDP/-Lite sendpage routine
+ *
+ * This function is udplite-aware and can be used on both sockets.
+ */
+int udp_sendpage(struct sock *sk, struct page *page, int offset,
+ size_t size, int flags)
{
struct udp_sock *up = udp_sk(sk);
int ret;
@@ -731,12 +801,12 @@ out:
}
/*
- * IOCTL requests applicable to the UDP protocol
+ * IOCTL requests applicable to the UDP(-Lite) protocol
*/
-
+
int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
- switch(cmd)
+ switch(cmd)
{
case SIOCOUTQ:
{
@@ -770,29 +840,21 @@ 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.
+/**
+ * udp_recvmsg - generic UDP/-Lite receive processing
+ *
+ * This routine is udplite-aware and works for both protocols.
+ * Principle: if there is something there we return it, otherwise we block.
*/
-static int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
- size_t len, int noblock, int flags, int *addr_len)
+int udp_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;
+ int copied, err, copy_only, is_udplite = IS_UDPLITE(sk);
/*
* Check any passed addresses
@@ -814,21 +876,30 @@ 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;
}
-
if (err)
goto out_free;
@@ -855,7 +926,8 @@ out:
return err;
csum_copy_err:
- UDP_INC_STATS_BH(UDP_MIB_INERRORS);
+ UDP_DEC_STATS_BH(UDP_MIB_INDATAGRAMS, is_udplite);
+ UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite);
skb_kill_datagram(sk, skb, flags);
@@ -864,7 +936,6 @@ csum_copy_err:
goto try_again;
}
-
int udp_disconnect(struct sock *sk, int flags)
{
struct inet_sock *inet = inet_sk(sk);
@@ -892,8 +963,12 @@ static void udp_close(struct sock *sk, l
sk_common_release(sk);
}
-/* return:
- * 1 if the the UDP system should process it
+/**
+ * udp_encap_rcv - handle encapsulated packets
+ *
+ * This routine is udplite-aware and works on both sockets.
+ * 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
*/
@@ -980,7 +1055,11 @@ #else
#endif
}
-/* returns:
+/**
+ * udp_queue_rcv_skb - receive queue processing
+ *
+ * This routine is udplite-aware and works on both sockets.
+ * returns:
* -1: error
* 0: success
* >0: "udp encap" protocol resubmission
@@ -988,7 +1067,7 @@ #endif
* Note that in the success and error cases, the skb is assumed to
* have either been requeued or freed.
*/
-static int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
+int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
{
struct udp_sock *up = udp_sk(sk);
int rc;
@@ -996,10 +1075,8 @@ 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) {
@@ -1010,7 +1087,7 @@ static int udp_queue_rcv_skb(struct sock
* 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 socket.
+ * pass this up the UDP/-Lite socket.
*/
int ret;
@@ -1023,47 +1100,94 @@ 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 */
+ /* FALLTHROUGH -- it's a UDP/-Lite 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;
+ /*
+ * UDP-Lite specific tests, ignored on UDP sockets
+ */
+ 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 (sk->sk_filter && skb->ip_summed != CHECKSUM_UNNECESSARY) {
+ if (__udp_checksum_complete(skb))
+ goto drop;
skb->ip_summed = CHECKSUM_UNNECESSARY;
}
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;
}
-/*
- * Multicasts and broadcasts go to each listener.
+/**
+ * __udp_mcast_deliver - generic multicast delivery
*
+ * UDP(-Lite) 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 udp_v4_mcast_deliver(struct sk_buff *skb, struct udphdr *uh,
- u32 saddr, u32 daddr)
+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) {
@@ -1092,10 +1216,16 @@ static int udp_v4_mcast_deliver(struct s
return 0;
}
-/* Initialize UDP checksum. If exited with zero value (success),
- * CHECKSUM_UNNECESSARY means, that no more checks are required.
- * Otherwise, csum completion requires chacksumming packet body,
- * including udp header and folding it to skb->csum.
+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);
+}
+
+/* Initialize UDP checksum.
+ * CHECKSUM_UNNECESSARY means that no more checks are required.
+ * Otherwise, csum completion requires checksumming packet body,
+ * including udp header, and folding it to skb->csum.
*/
static void udp_checksum_init(struct sk_buff *skb, struct udphdr *uh,
unsigned short ulen, u32 saddr, u32 daddr)
@@ -1103,7 +1233,7 @@ 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)
@@ -1111,51 +1241,61 @@ 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.
+ * All we need to do is get the socket, and then do a checksum.
*/
-
-int udp_rcv(struct sk_buff *skb)
+int __udp_common_rcv(struct sk_buff *skb, int is_udplite)
{
struct sock *sk;
- struct udphdr *uh;
+ struct udphdr *uh = skb->h.uh;
unsigned short ulen;
struct rtable *rt = (struct rtable*)skb->dst;
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;
-
- uh = skb->h.uh;
+ goto drop; /* No space for header. */
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);
sock_put(sk);
/* a return value > 0 means to resubmit the input, but
- * it it wants the return to be -protocol, or 0
+ * it wants the return to be -protocol, or 0
*/
if (ret > 0)
return -ret;
@@ -1170,7 +1310,7 @@ 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);
/*
@@ -1181,35 +1321,39 @@ 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).
+ /*
+ * 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);
}
+__inline__ int udp_rcv(struct sk_buff *skb)
+{
+ return __udp_common_rcv(skb, 0);
+}
+
static int udp_destroy_sock(struct sock *sk)
{
lock_sock(sk);
@@ -1219,7 +1363,7 @@ static int udp_destroy_sock(struct sock
}
/*
- * Socket option code for UDP
+ * Socket option code for UDP and UDP-Lite (shared).
*/
static int do_udp_setsockopt(struct sock *sk, int level, int optname,
char __user *optval, int optlen)
@@ -1259,6 +1403,32 @@ 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;
@@ -1267,21 +1437,21 @@ static int do_udp_setsockopt(struct sock
return err;
}
-static int udp_setsockopt(struct sock *sk, int level, int optname,
- char __user *optval, int optlen)
+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)
+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 +1478,15 @@ 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;
};
@@ -1319,25 +1498,26 @@ static int do_udp_getsockopt(struct sock
return 0;
}
-static int udp_getsockopt(struct sock *sk, int level, int optname,
- char __user *optval, int __user *optlen)
+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)
+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
+
/**
- * udp_poll - wait for a UDP event.
+ * udp_poll - wait for a UDP(-Lite) event.
* @file - file struct
* @sock - socket
* @wait - poll table
@@ -1348,11 +1528,14 @@ #endif
* 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.
+ *
+ * The routine is udplite-aware and works for both protocols.
*/
unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
{
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 +1547,11 @@ 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 +1594,31 @@ #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 +1629,7 @@ 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 +1650,7 @@ 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 +1700,7 @@ 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 +1767,7 @@ 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 +1790,7 @@ 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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