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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/net/sunrpc/svcsock.c

1966 строки
50 KiB
C
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/*
* linux/net/sunrpc/svcsock.c
*
* These are the RPC server socket internals.
*
* The server scheduling algorithm does not always distribute the load
* evenly when servicing a single client. May need to modify the
* svc_sock_enqueue procedure...
*
* TCP support is largely untested and may be a little slow. The problem
* is that we currently do two separate recvfrom's, one for the 4-byte
* record length, and the second for the actual record. This could possibly
* be improved by always reading a minimum size of around 100 bytes and
* tucking any superfluous bytes away in a temporary store. Still, that
* leaves write requests out in the rain. An alternative may be to peek at
* the first skb in the queue, and if it matches the next TCP sequence
* number, to extract the record marker. Yuck.
*
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/net.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/udp.h>
#include <linux/tcp.h>
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/file.h>
#include <linux/freezer.h>
#include <net/sock.h>
#include <net/checksum.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/tcp_states.h>
#include <asm/uaccess.h>
#include <asm/ioctls.h>
#include <linux/sunrpc/types.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/stats.h>
/* SMP locking strategy:
*
* svc_pool->sp_lock protects most of the fields of that pool.
* svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt.
* when both need to be taken (rare), svc_serv->sv_lock is first.
* BKL protects svc_serv->sv_nrthread.
* svc_sock->sk_lock protects the svc_sock->sk_deferred list
* and the ->sk_info_authunix cache.
* svc_sock->sk_flags.SK_BUSY prevents a svc_sock being enqueued multiply.
*
* Some flags can be set to certain values at any time
* providing that certain rules are followed:
*
* SK_CONN, SK_DATA, can be set or cleared at any time.
* after a set, svc_sock_enqueue must be called.
* after a clear, the socket must be read/accepted
* if this succeeds, it must be set again.
* SK_CLOSE can set at any time. It is never cleared.
* sk_inuse contains a bias of '1' until SK_DEAD is set.
* so when sk_inuse hits zero, we know the socket is dead
* and no-one is using it.
* SK_DEAD can only be set while SK_BUSY is held which ensures
* no other thread will be using the socket or will try to
* set SK_DEAD.
*
*/
#define RPCDBG_FACILITY RPCDBG_SVCSOCK
static struct svc_sock *svc_setup_socket(struct svc_serv *, struct socket *,
int *errp, int flags);
static void svc_delete_socket(struct svc_sock *svsk);
static void svc_udp_data_ready(struct sock *, int);
static int svc_udp_recvfrom(struct svc_rqst *);
static int svc_udp_sendto(struct svc_rqst *);
static void svc_close_socket(struct svc_sock *svsk);
static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk);
static int svc_deferred_recv(struct svc_rqst *rqstp);
static struct cache_deferred_req *svc_defer(struct cache_req *req);
/* apparently the "standard" is that clients close
* idle connections after 5 minutes, servers after
* 6 minutes
* http://www.connectathon.org/talks96/nfstcp.pdf
*/
static int svc_conn_age_period = 6*60;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
static struct lock_class_key svc_key[2];
static struct lock_class_key svc_slock_key[2];
static inline void svc_reclassify_socket(struct socket *sock)
{
struct sock *sk = sock->sk;
BUG_ON(sk->sk_lock.owner != NULL);
switch (sk->sk_family) {
case AF_INET:
sock_lock_init_class_and_name(sk, "slock-AF_INET-NFSD",
&svc_slock_key[0], "sk_lock-AF_INET-NFSD", &svc_key[0]);
break;
case AF_INET6:
sock_lock_init_class_and_name(sk, "slock-AF_INET6-NFSD",
&svc_slock_key[1], "sk_lock-AF_INET6-NFSD", &svc_key[1]);
break;
default:
BUG();
}
}
#else
static inline void svc_reclassify_socket(struct socket *sock)
{
}
#endif
static char *__svc_print_addr(struct sockaddr *addr, char *buf, size_t len)
{
switch (addr->sa_family) {
case AF_INET:
snprintf(buf, len, "%u.%u.%u.%u, port=%u",
NIPQUAD(((struct sockaddr_in *) addr)->sin_addr),
ntohs(((struct sockaddr_in *) addr)->sin_port));
break;
case AF_INET6:
snprintf(buf, len, "%x:%x:%x:%x:%x:%x:%x:%x, port=%u",
NIP6(((struct sockaddr_in6 *) addr)->sin6_addr),
ntohs(((struct sockaddr_in6 *) addr)->sin6_port));
break;
default:
snprintf(buf, len, "unknown address type: %d", addr->sa_family);
break;
}
return buf;
}
/**
* svc_print_addr - Format rq_addr field for printing
* @rqstp: svc_rqst struct containing address to print
* @buf: target buffer for formatted address
* @len: length of target buffer
*
*/
char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len)
{
return __svc_print_addr(svc_addr(rqstp), buf, len);
}
EXPORT_SYMBOL_GPL(svc_print_addr);
/*
* Queue up an idle server thread. Must have pool->sp_lock held.
* Note: this is really a stack rather than a queue, so that we only
* use as many different threads as we need, and the rest don't pollute
* the cache.
*/
static inline void
svc_thread_enqueue(struct svc_pool *pool, struct svc_rqst *rqstp)
{
list_add(&rqstp->rq_list, &pool->sp_threads);
}
/*
* Dequeue an nfsd thread. Must have pool->sp_lock held.
*/
static inline void
svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp)
{
list_del(&rqstp->rq_list);
}
/*
* Release an skbuff after use
*/
static inline void
svc_release_skb(struct svc_rqst *rqstp)
{
struct sk_buff *skb = rqstp->rq_skbuff;
struct svc_deferred_req *dr = rqstp->rq_deferred;
if (skb) {
rqstp->rq_skbuff = NULL;
dprintk("svc: service %p, releasing skb %p\n", rqstp, skb);
skb_free_datagram(rqstp->rq_sock->sk_sk, skb);
}
if (dr) {
rqstp->rq_deferred = NULL;
kfree(dr);
}
}
/*
* Any space to write?
*/
static inline unsigned long
svc_sock_wspace(struct svc_sock *svsk)
{
int wspace;
if (svsk->sk_sock->type == SOCK_STREAM)
wspace = sk_stream_wspace(svsk->sk_sk);
else
wspace = sock_wspace(svsk->sk_sk);
return wspace;
}
/*
* Queue up a socket with data pending. If there are idle nfsd
* processes, wake 'em up.
*
*/
static void
svc_sock_enqueue(struct svc_sock *svsk)
{
struct svc_serv *serv = svsk->sk_server;
struct svc_pool *pool;
struct svc_rqst *rqstp;
int cpu;
if (!(svsk->sk_flags &
( (1<<SK_CONN)|(1<<SK_DATA)|(1<<SK_CLOSE)|(1<<SK_DEFERRED)) ))
return;
if (test_bit(SK_DEAD, &svsk->sk_flags))
return;
cpu = get_cpu();
pool = svc_pool_for_cpu(svsk->sk_server, cpu);
put_cpu();
spin_lock_bh(&pool->sp_lock);
if (!list_empty(&pool->sp_threads) &&
!list_empty(&pool->sp_sockets))
printk(KERN_ERR
"svc_sock_enqueue: threads and sockets both waiting??\n");
if (test_bit(SK_DEAD, &svsk->sk_flags)) {
/* Don't enqueue dead sockets */
dprintk("svc: socket %p is dead, not enqueued\n", svsk->sk_sk);
goto out_unlock;
}
/* Mark socket as busy. It will remain in this state until the
* server has processed all pending data and put the socket back
* on the idle list. We update SK_BUSY atomically because
* it also guards against trying to enqueue the svc_sock twice.
*/
if (test_and_set_bit(SK_BUSY, &svsk->sk_flags)) {
/* Don't enqueue socket while already enqueued */
dprintk("svc: socket %p busy, not enqueued\n", svsk->sk_sk);
goto out_unlock;
}
BUG_ON(svsk->sk_pool != NULL);
svsk->sk_pool = pool;
set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
if (((atomic_read(&svsk->sk_reserved) + serv->sv_max_mesg)*2
> svc_sock_wspace(svsk))
&& !test_bit(SK_CLOSE, &svsk->sk_flags)
&& !test_bit(SK_CONN, &svsk->sk_flags)) {
/* Don't enqueue while not enough space for reply */
dprintk("svc: socket %p no space, %d*2 > %ld, not enqueued\n",
svsk->sk_sk, atomic_read(&svsk->sk_reserved)+serv->sv_max_mesg,
svc_sock_wspace(svsk));
svsk->sk_pool = NULL;
clear_bit(SK_BUSY, &svsk->sk_flags);
goto out_unlock;
}
clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
if (!list_empty(&pool->sp_threads)) {
rqstp = list_entry(pool->sp_threads.next,
struct svc_rqst,
rq_list);
dprintk("svc: socket %p served by daemon %p\n",
svsk->sk_sk, rqstp);
svc_thread_dequeue(pool, rqstp);
if (rqstp->rq_sock)
printk(KERN_ERR
"svc_sock_enqueue: server %p, rq_sock=%p!\n",
rqstp, rqstp->rq_sock);
rqstp->rq_sock = svsk;
atomic_inc(&svsk->sk_inuse);
rqstp->rq_reserved = serv->sv_max_mesg;
atomic_add(rqstp->rq_reserved, &svsk->sk_reserved);
BUG_ON(svsk->sk_pool != pool);
wake_up(&rqstp->rq_wait);
} else {
dprintk("svc: socket %p put into queue\n", svsk->sk_sk);
list_add_tail(&svsk->sk_ready, &pool->sp_sockets);
BUG_ON(svsk->sk_pool != pool);
}
out_unlock:
spin_unlock_bh(&pool->sp_lock);
}
/*
* Dequeue the first socket. Must be called with the pool->sp_lock held.
*/
static inline struct svc_sock *
svc_sock_dequeue(struct svc_pool *pool)
{
struct svc_sock *svsk;
if (list_empty(&pool->sp_sockets))
return NULL;
svsk = list_entry(pool->sp_sockets.next,
struct svc_sock, sk_ready);
list_del_init(&svsk->sk_ready);
dprintk("svc: socket %p dequeued, inuse=%d\n",
svsk->sk_sk, atomic_read(&svsk->sk_inuse));
return svsk;
}
/*
* Having read something from a socket, check whether it
* needs to be re-enqueued.
* Note: SK_DATA only gets cleared when a read-attempt finds
* no (or insufficient) data.
*/
static inline void
svc_sock_received(struct svc_sock *svsk)
{
svsk->sk_pool = NULL;
clear_bit(SK_BUSY, &svsk->sk_flags);
svc_sock_enqueue(svsk);
}
/**
* svc_reserve - change the space reserved for the reply to a request.
* @rqstp: The request in question
* @space: new max space to reserve
*
* Each request reserves some space on the output queue of the socket
* to make sure the reply fits. This function reduces that reserved
* space to be the amount of space used already, plus @space.
*
*/
void svc_reserve(struct svc_rqst *rqstp, int space)
{
space += rqstp->rq_res.head[0].iov_len;
if (space < rqstp->rq_reserved) {
struct svc_sock *svsk = rqstp->rq_sock;
atomic_sub((rqstp->rq_reserved - space), &svsk->sk_reserved);
rqstp->rq_reserved = space;
svc_sock_enqueue(svsk);
}
}
/*
* Release a socket after use.
*/
static inline void
svc_sock_put(struct svc_sock *svsk)
{
if (atomic_dec_and_test(&svsk->sk_inuse)) {
BUG_ON(! test_bit(SK_DEAD, &svsk->sk_flags));
dprintk("svc: releasing dead socket\n");
if (svsk->sk_sock->file)
sockfd_put(svsk->sk_sock);
else
sock_release(svsk->sk_sock);
if (svsk->sk_info_authunix != NULL)
svcauth_unix_info_release(svsk->sk_info_authunix);
kfree(svsk);
}
}
static void
svc_sock_release(struct svc_rqst *rqstp)
{
struct svc_sock *svsk = rqstp->rq_sock;
svc_release_skb(rqstp);
svc_free_res_pages(rqstp);
rqstp->rq_res.page_len = 0;
rqstp->rq_res.page_base = 0;
/* Reset response buffer and release
* the reservation.
* But first, check that enough space was reserved
* for the reply, otherwise we have a bug!
*/
if ((rqstp->rq_res.len) > rqstp->rq_reserved)
printk(KERN_ERR "RPC request reserved %d but used %d\n",
rqstp->rq_reserved,
rqstp->rq_res.len);
rqstp->rq_res.head[0].iov_len = 0;
svc_reserve(rqstp, 0);
rqstp->rq_sock = NULL;
svc_sock_put(svsk);
}
/*
* External function to wake up a server waiting for data
* This really only makes sense for services like lockd
* which have exactly one thread anyway.
*/
void
svc_wake_up(struct svc_serv *serv)
{
struct svc_rqst *rqstp;
unsigned int i;
struct svc_pool *pool;
for (i = 0; i < serv->sv_nrpools; i++) {
pool = &serv->sv_pools[i];
spin_lock_bh(&pool->sp_lock);
if (!list_empty(&pool->sp_threads)) {
rqstp = list_entry(pool->sp_threads.next,
struct svc_rqst,
rq_list);
dprintk("svc: daemon %p woken up.\n", rqstp);
/*
svc_thread_dequeue(pool, rqstp);
rqstp->rq_sock = NULL;
*/
wake_up(&rqstp->rq_wait);
}
spin_unlock_bh(&pool->sp_lock);
}
}
union svc_pktinfo_u {
struct in_pktinfo pkti;
struct in6_pktinfo pkti6;
};
#define SVC_PKTINFO_SPACE \
CMSG_SPACE(sizeof(union svc_pktinfo_u))
static void svc_set_cmsg_data(struct svc_rqst *rqstp, struct cmsghdr *cmh)
{
switch (rqstp->rq_sock->sk_sk->sk_family) {
case AF_INET: {
struct in_pktinfo *pki = CMSG_DATA(cmh);
cmh->cmsg_level = SOL_IP;
cmh->cmsg_type = IP_PKTINFO;
pki->ipi_ifindex = 0;
pki->ipi_spec_dst.s_addr = rqstp->rq_daddr.addr.s_addr;
cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
}
break;
case AF_INET6: {
struct in6_pktinfo *pki = CMSG_DATA(cmh);
cmh->cmsg_level = SOL_IPV6;
cmh->cmsg_type = IPV6_PKTINFO;
pki->ipi6_ifindex = 0;
ipv6_addr_copy(&pki->ipi6_addr,
&rqstp->rq_daddr.addr6);
cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
}
break;
}
return;
}
/*
* Generic sendto routine
*/
static int
svc_sendto(struct svc_rqst *rqstp, struct xdr_buf *xdr)
{
struct svc_sock *svsk = rqstp->rq_sock;
struct socket *sock = svsk->sk_sock;
int slen;
union {
struct cmsghdr hdr;
long all[SVC_PKTINFO_SPACE / sizeof(long)];
} buffer;
struct cmsghdr *cmh = &buffer.hdr;
int len = 0;
int result;
int size;
struct page **ppage = xdr->pages;
size_t base = xdr->page_base;
unsigned int pglen = xdr->page_len;
unsigned int flags = MSG_MORE;
char buf[RPC_MAX_ADDRBUFLEN];
slen = xdr->len;
if (rqstp->rq_prot == IPPROTO_UDP) {
struct msghdr msg = {
.msg_name = &rqstp->rq_addr,
.msg_namelen = rqstp->rq_addrlen,
.msg_control = cmh,
.msg_controllen = sizeof(buffer),
.msg_flags = MSG_MORE,
};
svc_set_cmsg_data(rqstp, cmh);
if (sock_sendmsg(sock, &msg, 0) < 0)
goto out;
}
/* send head */
if (slen == xdr->head[0].iov_len)
flags = 0;
len = kernel_sendpage(sock, rqstp->rq_respages[0], 0,
xdr->head[0].iov_len, flags);
if (len != xdr->head[0].iov_len)
goto out;
slen -= xdr->head[0].iov_len;
if (slen == 0)
goto out;
/* send page data */
size = PAGE_SIZE - base < pglen ? PAGE_SIZE - base : pglen;
while (pglen > 0) {
if (slen == size)
flags = 0;
result = kernel_sendpage(sock, *ppage, base, size, flags);
if (result > 0)
len += result;
if (result != size)
goto out;
slen -= size;
pglen -= size;
size = PAGE_SIZE < pglen ? PAGE_SIZE : pglen;
base = 0;
ppage++;
}
/* send tail */
if (xdr->tail[0].iov_len) {
result = kernel_sendpage(sock, rqstp->rq_respages[0],
((unsigned long)xdr->tail[0].iov_base)
& (PAGE_SIZE-1),
xdr->tail[0].iov_len, 0);
if (result > 0)
len += result;
}
out:
dprintk("svc: socket %p sendto([%p %Zu... ], %d) = %d (addr %s)\n",
rqstp->rq_sock, xdr->head[0].iov_base, xdr->head[0].iov_len,
xdr->len, len, svc_print_addr(rqstp, buf, sizeof(buf)));
return len;
}
/*
* Report socket names for nfsdfs
*/
static int one_sock_name(char *buf, struct svc_sock *svsk)
{
int len;
switch(svsk->sk_sk->sk_family) {
case AF_INET:
len = sprintf(buf, "ipv4 %s %u.%u.%u.%u %d\n",
svsk->sk_sk->sk_protocol==IPPROTO_UDP?
"udp" : "tcp",
NIPQUAD(inet_sk(svsk->sk_sk)->rcv_saddr),
inet_sk(svsk->sk_sk)->num);
break;
default:
len = sprintf(buf, "*unknown-%d*\n",
svsk->sk_sk->sk_family);
}
return len;
}
int
svc_sock_names(char *buf, struct svc_serv *serv, char *toclose)
{
struct svc_sock *svsk, *closesk = NULL;
int len = 0;
if (!serv)
return 0;
spin_lock_bh(&serv->sv_lock);
list_for_each_entry(svsk, &serv->sv_permsocks, sk_list) {
int onelen = one_sock_name(buf+len, svsk);
if (toclose && strcmp(toclose, buf+len) == 0)
closesk = svsk;
else
len += onelen;
}
spin_unlock_bh(&serv->sv_lock);
if (closesk)
/* Should unregister with portmap, but you cannot
* unregister just one protocol...
*/
svc_close_socket(closesk);
else if (toclose)
return -ENOENT;
return len;
}
EXPORT_SYMBOL(svc_sock_names);
/*
* Check input queue length
*/
static int
svc_recv_available(struct svc_sock *svsk)
{
struct socket *sock = svsk->sk_sock;
int avail, err;
err = kernel_sock_ioctl(sock, TIOCINQ, (unsigned long) &avail);
return (err >= 0)? avail : err;
}
/*
* Generic recvfrom routine.
*/
static int
svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov, int nr, int buflen)
{
struct svc_sock *svsk = rqstp->rq_sock;
struct msghdr msg = {
.msg_flags = MSG_DONTWAIT,
};
struct sockaddr *sin;
int len;
len = kernel_recvmsg(svsk->sk_sock, &msg, iov, nr, buflen,
msg.msg_flags);
/* sock_recvmsg doesn't fill in the name/namelen, so we must..
*/
memcpy(&rqstp->rq_addr, &svsk->sk_remote, svsk->sk_remotelen);
rqstp->rq_addrlen = svsk->sk_remotelen;
/* Destination address in request is needed for binding the
* source address in RPC callbacks later.
*/
sin = (struct sockaddr *)&svsk->sk_local;
switch (sin->sa_family) {
case AF_INET:
rqstp->rq_daddr.addr = ((struct sockaddr_in *)sin)->sin_addr;
break;
case AF_INET6:
rqstp->rq_daddr.addr6 = ((struct sockaddr_in6 *)sin)->sin6_addr;
break;
}
dprintk("svc: socket %p recvfrom(%p, %Zu) = %d\n",
svsk, iov[0].iov_base, iov[0].iov_len, len);
return len;
}
/*
* Set socket snd and rcv buffer lengths
*/
static inline void
svc_sock_setbufsize(struct socket *sock, unsigned int snd, unsigned int rcv)
{
#if 0
mm_segment_t oldfs;
oldfs = get_fs(); set_fs(KERNEL_DS);
sock_setsockopt(sock, SOL_SOCKET, SO_SNDBUF,
(char*)&snd, sizeof(snd));
sock_setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
(char*)&rcv, sizeof(rcv));
#else
/* sock_setsockopt limits use to sysctl_?mem_max,
* which isn't acceptable. Until that is made conditional
* on not having CAP_SYS_RESOURCE or similar, we go direct...
* DaveM said I could!
*/
lock_sock(sock->sk);
sock->sk->sk_sndbuf = snd * 2;
sock->sk->sk_rcvbuf = rcv * 2;
sock->sk->sk_userlocks |= SOCK_SNDBUF_LOCK|SOCK_RCVBUF_LOCK;
release_sock(sock->sk);
#endif
}
/*
* INET callback when data has been received on the socket.
*/
static void
svc_udp_data_ready(struct sock *sk, int count)
{
struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
if (svsk) {
dprintk("svc: socket %p(inet %p), count=%d, busy=%d\n",
svsk, sk, count, test_bit(SK_BUSY, &svsk->sk_flags));
set_bit(SK_DATA, &svsk->sk_flags);
svc_sock_enqueue(svsk);
}
if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
wake_up_interruptible(sk->sk_sleep);
}
/*
* INET callback when space is newly available on the socket.
*/
static void
svc_write_space(struct sock *sk)
{
struct svc_sock *svsk = (struct svc_sock *)(sk->sk_user_data);
if (svsk) {
dprintk("svc: socket %p(inet %p), write_space busy=%d\n",
svsk, sk, test_bit(SK_BUSY, &svsk->sk_flags));
svc_sock_enqueue(svsk);
}
if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) {
dprintk("RPC svc_write_space: someone sleeping on %p\n",
svsk);
wake_up_interruptible(sk->sk_sleep);
}
}
static inline void svc_udp_get_dest_address(struct svc_rqst *rqstp,
struct cmsghdr *cmh)
{
switch (rqstp->rq_sock->sk_sk->sk_family) {
case AF_INET: {
struct in_pktinfo *pki = CMSG_DATA(cmh);
rqstp->rq_daddr.addr.s_addr = pki->ipi_spec_dst.s_addr;
break;
}
case AF_INET6: {
struct in6_pktinfo *pki = CMSG_DATA(cmh);
ipv6_addr_copy(&rqstp->rq_daddr.addr6, &pki->ipi6_addr);
break;
}
}
}
/*
* Receive a datagram from a UDP socket.
*/
static int
svc_udp_recvfrom(struct svc_rqst *rqstp)
{
struct svc_sock *svsk = rqstp->rq_sock;
struct svc_serv *serv = svsk->sk_server;
struct sk_buff *skb;
union {
struct cmsghdr hdr;
long all[SVC_PKTINFO_SPACE / sizeof(long)];
} buffer;
struct cmsghdr *cmh = &buffer.hdr;
int err, len;
struct msghdr msg = {
.msg_name = svc_addr(rqstp),
.msg_control = cmh,
.msg_controllen = sizeof(buffer),
.msg_flags = MSG_DONTWAIT,
};
if (test_and_clear_bit(SK_CHNGBUF, &svsk->sk_flags))
/* udp sockets need large rcvbuf as all pending
* requests are still in that buffer. sndbuf must
* also be large enough that there is enough space
* for one reply per thread. We count all threads
* rather than threads in a particular pool, which
* provides an upper bound on the number of threads
* which will access the socket.
*/
svc_sock_setbufsize(svsk->sk_sock,
(serv->sv_nrthreads+3) * serv->sv_max_mesg,
(serv->sv_nrthreads+3) * serv->sv_max_mesg);
if ((rqstp->rq_deferred = svc_deferred_dequeue(svsk))) {
svc_sock_received(svsk);
return svc_deferred_recv(rqstp);
}
if (test_bit(SK_CLOSE, &svsk->sk_flags)) {
svc_delete_socket(svsk);
return 0;
}
clear_bit(SK_DATA, &svsk->sk_flags);
skb = NULL;
err = kernel_recvmsg(svsk->sk_sock, &msg, NULL,
0, 0, MSG_PEEK | MSG_DONTWAIT);
if (err >= 0)
skb = skb_recv_datagram(svsk->sk_sk, 0, 1, &err);
if (skb == NULL) {
if (err != -EAGAIN) {
/* possibly an icmp error */
dprintk("svc: recvfrom returned error %d\n", -err);
set_bit(SK_DATA, &svsk->sk_flags);
}
svc_sock_received(svsk);
return -EAGAIN;
}
rqstp->rq_addrlen = sizeof(rqstp->rq_addr);
if (skb->tstamp.tv64 == 0) {
skb->tstamp = ktime_get_real();
/* Don't enable netstamp, sunrpc doesn't
need that much accuracy */
}
svsk->sk_sk->sk_stamp = skb->tstamp;
set_bit(SK_DATA, &svsk->sk_flags); /* there may be more data... */
/*
* Maybe more packets - kick another thread ASAP.
*/
svc_sock_received(svsk);
len = skb->len - sizeof(struct udphdr);
rqstp->rq_arg.len = len;
rqstp->rq_prot = IPPROTO_UDP;
if (cmh->cmsg_level != IPPROTO_IP ||
cmh->cmsg_type != IP_PKTINFO) {
if (net_ratelimit())
printk("rpcsvc: received unknown control message:"
"%d/%d\n",
cmh->cmsg_level, cmh->cmsg_type);
skb_free_datagram(svsk->sk_sk, skb);
return 0;
}
svc_udp_get_dest_address(rqstp, cmh);
if (skb_is_nonlinear(skb)) {
/* we have to copy */
local_bh_disable();
if (csum_partial_copy_to_xdr(&rqstp->rq_arg, skb)) {
local_bh_enable();
/* checksum error */
skb_free_datagram(svsk->sk_sk, skb);
return 0;
}
local_bh_enable();
skb_free_datagram(svsk->sk_sk, skb);
} else {
/* we can use it in-place */
rqstp->rq_arg.head[0].iov_base = skb->data + sizeof(struct udphdr);
rqstp->rq_arg.head[0].iov_len = len;
if (skb_checksum_complete(skb)) {
skb_free_datagram(svsk->sk_sk, skb);
return 0;
}
rqstp->rq_skbuff = skb;
}
rqstp->rq_arg.page_base = 0;
if (len <= rqstp->rq_arg.head[0].iov_len) {
rqstp->rq_arg.head[0].iov_len = len;
rqstp->rq_arg.page_len = 0;
rqstp->rq_respages = rqstp->rq_pages+1;
} else {
rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
rqstp->rq_respages = rqstp->rq_pages + 1 +
(rqstp->rq_arg.page_len + PAGE_SIZE - 1)/ PAGE_SIZE;
}
if (serv->sv_stats)
serv->sv_stats->netudpcnt++;
return len;
}
static int
svc_udp_sendto(struct svc_rqst *rqstp)
{
int error;
error = svc_sendto(rqstp, &rqstp->rq_res);
if (error == -ECONNREFUSED)
/* ICMP error on earlier request. */
error = svc_sendto(rqstp, &rqstp->rq_res);
return error;
}
static void
svc_udp_init(struct svc_sock *svsk)
{
int one = 1;
mm_segment_t oldfs;
svsk->sk_sk->sk_data_ready = svc_udp_data_ready;
svsk->sk_sk->sk_write_space = svc_write_space;
svsk->sk_recvfrom = svc_udp_recvfrom;
svsk->sk_sendto = svc_udp_sendto;
/* initialise setting must have enough space to
* receive and respond to one request.
* svc_udp_recvfrom will re-adjust if necessary
*/
svc_sock_setbufsize(svsk->sk_sock,
3 * svsk->sk_server->sv_max_mesg,
3 * svsk->sk_server->sv_max_mesg);
set_bit(SK_DATA, &svsk->sk_flags); /* might have come in before data_ready set up */
set_bit(SK_CHNGBUF, &svsk->sk_flags);
oldfs = get_fs();
set_fs(KERNEL_DS);
/* make sure we get destination address info */
svsk->sk_sock->ops->setsockopt(svsk->sk_sock, IPPROTO_IP, IP_PKTINFO,
(char __user *)&one, sizeof(one));
set_fs(oldfs);
}
/*
* A data_ready event on a listening socket means there's a connection
* pending. Do not use state_change as a substitute for it.
*/
static void
svc_tcp_listen_data_ready(struct sock *sk, int count_unused)
{
struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
dprintk("svc: socket %p TCP (listen) state change %d\n",
sk, sk->sk_state);
/*
* This callback may called twice when a new connection
* is established as a child socket inherits everything
* from a parent LISTEN socket.
* 1) data_ready method of the parent socket will be called
* when one of child sockets become ESTABLISHED.
* 2) data_ready method of the child socket may be called
* when it receives data before the socket is accepted.
* In case of 2, we should ignore it silently.
*/
if (sk->sk_state == TCP_LISTEN) {
if (svsk) {
set_bit(SK_CONN, &svsk->sk_flags);
svc_sock_enqueue(svsk);
} else
printk("svc: socket %p: no user data\n", sk);
}
if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
wake_up_interruptible_all(sk->sk_sleep);
}
/*
* A state change on a connected socket means it's dying or dead.
*/
static void
svc_tcp_state_change(struct sock *sk)
{
struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
dprintk("svc: socket %p TCP (connected) state change %d (svsk %p)\n",
sk, sk->sk_state, sk->sk_user_data);
if (!svsk)
printk("svc: socket %p: no user data\n", sk);
else {
set_bit(SK_CLOSE, &svsk->sk_flags);
svc_sock_enqueue(svsk);
}
if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
wake_up_interruptible_all(sk->sk_sleep);
}
static void
svc_tcp_data_ready(struct sock *sk, int count)
{
struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
dprintk("svc: socket %p TCP data ready (svsk %p)\n",
sk, sk->sk_user_data);
if (svsk) {
set_bit(SK_DATA, &svsk->sk_flags);
svc_sock_enqueue(svsk);
}
if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
wake_up_interruptible(sk->sk_sleep);
}
static inline int svc_port_is_privileged(struct sockaddr *sin)
{
switch (sin->sa_family) {
case AF_INET:
return ntohs(((struct sockaddr_in *)sin)->sin_port)
< PROT_SOCK;
case AF_INET6:
return ntohs(((struct sockaddr_in6 *)sin)->sin6_port)
< PROT_SOCK;
default:
return 0;
}
}
/*
* Accept a TCP connection
*/
static void
svc_tcp_accept(struct svc_sock *svsk)
{
struct sockaddr_storage addr;
struct sockaddr *sin = (struct sockaddr *) &addr;
struct svc_serv *serv = svsk->sk_server;
struct socket *sock = svsk->sk_sock;
struct socket *newsock;
struct svc_sock *newsvsk;
int err, slen;
char buf[RPC_MAX_ADDRBUFLEN];
dprintk("svc: tcp_accept %p sock %p\n", svsk, sock);
if (!sock)
return;
clear_bit(SK_CONN, &svsk->sk_flags);
err = kernel_accept(sock, &newsock, O_NONBLOCK);
if (err < 0) {
if (err == -ENOMEM)
printk(KERN_WARNING "%s: no more sockets!\n",
serv->sv_name);
else if (err != -EAGAIN && net_ratelimit())
printk(KERN_WARNING "%s: accept failed (err %d)!\n",
serv->sv_name, -err);
return;
}
set_bit(SK_CONN, &svsk->sk_flags);
svc_sock_enqueue(svsk);
err = kernel_getpeername(newsock, sin, &slen);
if (err < 0) {
if (net_ratelimit())
printk(KERN_WARNING "%s: peername failed (err %d)!\n",
serv->sv_name, -err);
goto failed; /* aborted connection or whatever */
}
/* Ideally, we would want to reject connections from unauthorized
* hosts here, but when we get encryption, the IP of the host won't
* tell us anything. For now just warn about unpriv connections.
*/
if (!svc_port_is_privileged(sin)) {
dprintk(KERN_WARNING
"%s: connect from unprivileged port: %s\n",
serv->sv_name,
__svc_print_addr(sin, buf, sizeof(buf)));
}
dprintk("%s: connect from %s\n", serv->sv_name,
__svc_print_addr(sin, buf, sizeof(buf)));
/* make sure that a write doesn't block forever when
* low on memory
*/
newsock->sk->sk_sndtimeo = HZ*30;
if (!(newsvsk = svc_setup_socket(serv, newsock, &err,
(SVC_SOCK_ANONYMOUS | SVC_SOCK_TEMPORARY))))
goto failed;
memcpy(&newsvsk->sk_remote, sin, slen);
newsvsk->sk_remotelen = slen;
err = kernel_getsockname(newsock, sin, &slen);
if (unlikely(err < 0)) {
dprintk("svc_tcp_accept: kernel_getsockname error %d\n", -err);
slen = offsetof(struct sockaddr, sa_data);
}
memcpy(&newsvsk->sk_local, sin, slen);
svc_sock_received(newsvsk);
/* make sure that we don't have too many active connections.
* If we have, something must be dropped.
*
* There's no point in trying to do random drop here for
* DoS prevention. The NFS clients does 1 reconnect in 15
* seconds. An attacker can easily beat that.
*
* The only somewhat efficient mechanism would be if drop
* old connections from the same IP first. But right now
* we don't even record the client IP in svc_sock.
*/
if (serv->sv_tmpcnt > (serv->sv_nrthreads+3)*20) {
struct svc_sock *svsk = NULL;
spin_lock_bh(&serv->sv_lock);
if (!list_empty(&serv->sv_tempsocks)) {
if (net_ratelimit()) {
/* Try to help the admin */
printk(KERN_NOTICE "%s: too many open TCP "
"sockets, consider increasing the "
"number of nfsd threads\n",
serv->sv_name);
printk(KERN_NOTICE
"%s: last TCP connect from %s\n",
serv->sv_name, buf);
}
/*
* Always select the oldest socket. It's not fair,
* but so is life
*/
svsk = list_entry(serv->sv_tempsocks.prev,
struct svc_sock,
sk_list);
set_bit(SK_CLOSE, &svsk->sk_flags);
atomic_inc(&svsk->sk_inuse);
}
spin_unlock_bh(&serv->sv_lock);
if (svsk) {
svc_sock_enqueue(svsk);
svc_sock_put(svsk);
}
}
if (serv->sv_stats)
serv->sv_stats->nettcpconn++;
return;
failed:
sock_release(newsock);
return;
}
/*
* Receive data from a TCP socket.
*/
static int
svc_tcp_recvfrom(struct svc_rqst *rqstp)
{
struct svc_sock *svsk = rqstp->rq_sock;
struct svc_serv *serv = svsk->sk_server;
int len;
struct kvec *vec;
int pnum, vlen;
dprintk("svc: tcp_recv %p data %d conn %d close %d\n",
svsk, test_bit(SK_DATA, &svsk->sk_flags),
test_bit(SK_CONN, &svsk->sk_flags),
test_bit(SK_CLOSE, &svsk->sk_flags));
if ((rqstp->rq_deferred = svc_deferred_dequeue(svsk))) {
svc_sock_received(svsk);
return svc_deferred_recv(rqstp);
}
if (test_bit(SK_CLOSE, &svsk->sk_flags)) {
svc_delete_socket(svsk);
return 0;
}
if (svsk->sk_sk->sk_state == TCP_LISTEN) {
svc_tcp_accept(svsk);
svc_sock_received(svsk);
return 0;
}
if (test_and_clear_bit(SK_CHNGBUF, &svsk->sk_flags))
/* sndbuf needs to have room for one request
* per thread, otherwise we can stall even when the
* network isn't a bottleneck.
*
* We count all threads rather than threads in a
* particular pool, which provides an upper bound
* on the number of threads which will access the socket.
*
* rcvbuf just needs to be able to hold a few requests.
* Normally they will be removed from the queue
* as soon a a complete request arrives.
*/
svc_sock_setbufsize(svsk->sk_sock,
(serv->sv_nrthreads+3) * serv->sv_max_mesg,
3 * serv->sv_max_mesg);
clear_bit(SK_DATA, &svsk->sk_flags);
/* Receive data. If we haven't got the record length yet, get
* the next four bytes. Otherwise try to gobble up as much as
* possible up to the complete record length.
*/
if (svsk->sk_tcplen < 4) {
unsigned long want = 4 - svsk->sk_tcplen;
struct kvec iov;
iov.iov_base = ((char *) &svsk->sk_reclen) + svsk->sk_tcplen;
iov.iov_len = want;
if ((len = svc_recvfrom(rqstp, &iov, 1, want)) < 0)
goto error;
svsk->sk_tcplen += len;
if (len < want) {
dprintk("svc: short recvfrom while reading record length (%d of %lu)\n",
len, want);
svc_sock_received(svsk);
return -EAGAIN; /* record header not complete */
}
svsk->sk_reclen = ntohl(svsk->sk_reclen);
if (!(svsk->sk_reclen & 0x80000000)) {
/* FIXME: technically, a record can be fragmented,
* and non-terminal fragments will not have the top
* bit set in the fragment length header.
* But apparently no known nfs clients send fragmented
* records. */
if (net_ratelimit())
printk(KERN_NOTICE "RPC: bad TCP reclen 0x%08lx"
" (non-terminal)\n",
(unsigned long) svsk->sk_reclen);
goto err_delete;
}
svsk->sk_reclen &= 0x7fffffff;
dprintk("svc: TCP record, %d bytes\n", svsk->sk_reclen);
if (svsk->sk_reclen > serv->sv_max_mesg) {
if (net_ratelimit())
printk(KERN_NOTICE "RPC: bad TCP reclen 0x%08lx"
" (large)\n",
(unsigned long) svsk->sk_reclen);
goto err_delete;
}
}
/* Check whether enough data is available */
len = svc_recv_available(svsk);
if (len < 0)
goto error;
if (len < svsk->sk_reclen) {
dprintk("svc: incomplete TCP record (%d of %d)\n",
len, svsk->sk_reclen);
svc_sock_received(svsk);
return -EAGAIN; /* record not complete */
}
len = svsk->sk_reclen;
set_bit(SK_DATA, &svsk->sk_flags);
vec = rqstp->rq_vec;
vec[0] = rqstp->rq_arg.head[0];
vlen = PAGE_SIZE;
pnum = 1;
while (vlen < len) {
vec[pnum].iov_base = page_address(rqstp->rq_pages[pnum]);
vec[pnum].iov_len = PAGE_SIZE;
pnum++;
vlen += PAGE_SIZE;
}
rqstp->rq_respages = &rqstp->rq_pages[pnum];
/* Now receive data */
len = svc_recvfrom(rqstp, vec, pnum, len);
if (len < 0)
goto error;
dprintk("svc: TCP complete record (%d bytes)\n", len);
rqstp->rq_arg.len = len;
rqstp->rq_arg.page_base = 0;
if (len <= rqstp->rq_arg.head[0].iov_len) {
rqstp->rq_arg.head[0].iov_len = len;
rqstp->rq_arg.page_len = 0;
} else {
rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
}
rqstp->rq_skbuff = NULL;
rqstp->rq_prot = IPPROTO_TCP;
/* Reset TCP read info */
svsk->sk_reclen = 0;
svsk->sk_tcplen = 0;
svc_sock_received(svsk);
if (serv->sv_stats)
serv->sv_stats->nettcpcnt++;
return len;
err_delete:
svc_delete_socket(svsk);
return -EAGAIN;
error:
if (len == -EAGAIN) {
dprintk("RPC: TCP recvfrom got EAGAIN\n");
svc_sock_received(svsk);
} else {
printk(KERN_NOTICE "%s: recvfrom returned errno %d\n",
svsk->sk_server->sv_name, -len);
goto err_delete;
}
return len;
}
/*
* Send out data on TCP socket.
*/
static int
svc_tcp_sendto(struct svc_rqst *rqstp)
{
struct xdr_buf *xbufp = &rqstp->rq_res;
int sent;
__be32 reclen;
/* Set up the first element of the reply kvec.
* Any other kvecs that may be in use have been taken
* care of by the server implementation itself.
*/
reclen = htonl(0x80000000|((xbufp->len ) - 4));
memcpy(xbufp->head[0].iov_base, &reclen, 4);
if (test_bit(SK_DEAD, &rqstp->rq_sock->sk_flags))
return -ENOTCONN;
sent = svc_sendto(rqstp, &rqstp->rq_res);
if (sent != xbufp->len) {
printk(KERN_NOTICE "rpc-srv/tcp: %s: %s %d when sending %d bytes - shutting down socket\n",
rqstp->rq_sock->sk_server->sv_name,
(sent<0)?"got error":"sent only",
sent, xbufp->len);
set_bit(SK_CLOSE, &rqstp->rq_sock->sk_flags);
svc_sock_enqueue(rqstp->rq_sock);
sent = -EAGAIN;
}
return sent;
}
static void
svc_tcp_init(struct svc_sock *svsk)
{
struct sock *sk = svsk->sk_sk;
struct tcp_sock *tp = tcp_sk(sk);
svsk->sk_recvfrom = svc_tcp_recvfrom;
svsk->sk_sendto = svc_tcp_sendto;
if (sk->sk_state == TCP_LISTEN) {
dprintk("setting up TCP socket for listening\n");
sk->sk_data_ready = svc_tcp_listen_data_ready;
set_bit(SK_CONN, &svsk->sk_flags);
} else {
dprintk("setting up TCP socket for reading\n");
sk->sk_state_change = svc_tcp_state_change;
sk->sk_data_ready = svc_tcp_data_ready;
sk->sk_write_space = svc_write_space;
svsk->sk_reclen = 0;
svsk->sk_tcplen = 0;
tp->nonagle = 1; /* disable Nagle's algorithm */
/* initialise setting must have enough space to
* receive and respond to one request.
* svc_tcp_recvfrom will re-adjust if necessary
*/
svc_sock_setbufsize(svsk->sk_sock,
3 * svsk->sk_server->sv_max_mesg,
3 * svsk->sk_server->sv_max_mesg);
set_bit(SK_CHNGBUF, &svsk->sk_flags);
set_bit(SK_DATA, &svsk->sk_flags);
if (sk->sk_state != TCP_ESTABLISHED)
set_bit(SK_CLOSE, &svsk->sk_flags);
}
}
void
svc_sock_update_bufs(struct svc_serv *serv)
{
/*
* The number of server threads has changed. Update
* rcvbuf and sndbuf accordingly on all sockets
*/
struct list_head *le;
spin_lock_bh(&serv->sv_lock);
list_for_each(le, &serv->sv_permsocks) {
struct svc_sock *svsk =
list_entry(le, struct svc_sock, sk_list);
set_bit(SK_CHNGBUF, &svsk->sk_flags);
}
list_for_each(le, &serv->sv_tempsocks) {
struct svc_sock *svsk =
list_entry(le, struct svc_sock, sk_list);
set_bit(SK_CHNGBUF, &svsk->sk_flags);
}
spin_unlock_bh(&serv->sv_lock);
}
/*
* Receive the next request on any socket. This code is carefully
* organised not to touch any cachelines in the shared svc_serv
* structure, only cachelines in the local svc_pool.
*/
int
svc_recv(struct svc_rqst *rqstp, long timeout)
{
struct svc_sock *svsk = NULL;
struct svc_serv *serv = rqstp->rq_server;
struct svc_pool *pool = rqstp->rq_pool;
int len, i;
int pages;
struct xdr_buf *arg;
DECLARE_WAITQUEUE(wait, current);
dprintk("svc: server %p waiting for data (to = %ld)\n",
rqstp, timeout);
if (rqstp->rq_sock)
printk(KERN_ERR
"svc_recv: service %p, socket not NULL!\n",
rqstp);
if (waitqueue_active(&rqstp->rq_wait))
printk(KERN_ERR
"svc_recv: service %p, wait queue active!\n",
rqstp);
/* now allocate needed pages. If we get a failure, sleep briefly */
pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE;
for (i=0; i < pages ; i++)
while (rqstp->rq_pages[i] == NULL) {
struct page *p = alloc_page(GFP_KERNEL);
if (!p)
schedule_timeout_uninterruptible(msecs_to_jiffies(500));
rqstp->rq_pages[i] = p;
}
rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */
BUG_ON(pages >= RPCSVC_MAXPAGES);
/* Make arg->head point to first page and arg->pages point to rest */
arg = &rqstp->rq_arg;
arg->head[0].iov_base = page_address(rqstp->rq_pages[0]);
arg->head[0].iov_len = PAGE_SIZE;
arg->pages = rqstp->rq_pages + 1;
arg->page_base = 0;
/* save at least one page for response */
arg->page_len = (pages-2)*PAGE_SIZE;
arg->len = (pages-1)*PAGE_SIZE;
arg->tail[0].iov_len = 0;
try_to_freeze();
cond_resched();
if (signalled())
return -EINTR;
spin_lock_bh(&pool->sp_lock);
if ((svsk = svc_sock_dequeue(pool)) != NULL) {
rqstp->rq_sock = svsk;
atomic_inc(&svsk->sk_inuse);
rqstp->rq_reserved = serv->sv_max_mesg;
atomic_add(rqstp->rq_reserved, &svsk->sk_reserved);
} else {
/* No data pending. Go to sleep */
svc_thread_enqueue(pool, rqstp);
/*
* We have to be able to interrupt this wait
* to bring down the daemons ...
*/
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&rqstp->rq_wait, &wait);
spin_unlock_bh(&pool->sp_lock);
schedule_timeout(timeout);
try_to_freeze();
spin_lock_bh(&pool->sp_lock);
remove_wait_queue(&rqstp->rq_wait, &wait);
if (!(svsk = rqstp->rq_sock)) {
svc_thread_dequeue(pool, rqstp);
spin_unlock_bh(&pool->sp_lock);
dprintk("svc: server %p, no data yet\n", rqstp);
return signalled()? -EINTR : -EAGAIN;
}
}
spin_unlock_bh(&pool->sp_lock);
dprintk("svc: server %p, pool %u, socket %p, inuse=%d\n",
rqstp, pool->sp_id, svsk, atomic_read(&svsk->sk_inuse));
len = svsk->sk_recvfrom(rqstp);
dprintk("svc: got len=%d\n", len);
/* No data, incomplete (TCP) read, or accept() */
if (len == 0 || len == -EAGAIN) {
rqstp->rq_res.len = 0;
svc_sock_release(rqstp);
return -EAGAIN;
}
svsk->sk_lastrecv = get_seconds();
clear_bit(SK_OLD, &svsk->sk_flags);
rqstp->rq_secure = svc_port_is_privileged(svc_addr(rqstp));
rqstp->rq_chandle.defer = svc_defer;
if (serv->sv_stats)
serv->sv_stats->netcnt++;
return len;
}
/*
* Drop request
*/
void
svc_drop(struct svc_rqst *rqstp)
{
dprintk("svc: socket %p dropped request\n", rqstp->rq_sock);
svc_sock_release(rqstp);
}
/*
* Return reply to client.
*/
int
svc_send(struct svc_rqst *rqstp)
{
struct svc_sock *svsk;
int len;
struct xdr_buf *xb;
if ((svsk = rqstp->rq_sock) == NULL) {
printk(KERN_WARNING "NULL socket pointer in %s:%d\n",
__FILE__, __LINE__);
return -EFAULT;
}
/* release the receive skb before sending the reply */
svc_release_skb(rqstp);
/* calculate over-all length */
xb = & rqstp->rq_res;
xb->len = xb->head[0].iov_len +
xb->page_len +
xb->tail[0].iov_len;
/* Grab svsk->sk_mutex to serialize outgoing data. */
mutex_lock(&svsk->sk_mutex);
if (test_bit(SK_DEAD, &svsk->sk_flags))
len = -ENOTCONN;
else
len = svsk->sk_sendto(rqstp);
mutex_unlock(&svsk->sk_mutex);
svc_sock_release(rqstp);
if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
return 0;
return len;
}
/*
* Timer function to close old temporary sockets, using
* a mark-and-sweep algorithm.
*/
static void
svc_age_temp_sockets(unsigned long closure)
{
struct svc_serv *serv = (struct svc_serv *)closure;
struct svc_sock *svsk;
struct list_head *le, *next;
LIST_HEAD(to_be_aged);
dprintk("svc_age_temp_sockets\n");
if (!spin_trylock_bh(&serv->sv_lock)) {
/* busy, try again 1 sec later */
dprintk("svc_age_temp_sockets: busy\n");
mod_timer(&serv->sv_temptimer, jiffies + HZ);
return;
}
list_for_each_safe(le, next, &serv->sv_tempsocks) {
svsk = list_entry(le, struct svc_sock, sk_list);
if (!test_and_set_bit(SK_OLD, &svsk->sk_flags))
continue;
if (atomic_read(&svsk->sk_inuse) || test_bit(SK_BUSY, &svsk->sk_flags))
continue;
atomic_inc(&svsk->sk_inuse);
list_move(le, &to_be_aged);
set_bit(SK_CLOSE, &svsk->sk_flags);
set_bit(SK_DETACHED, &svsk->sk_flags);
}
spin_unlock_bh(&serv->sv_lock);
while (!list_empty(&to_be_aged)) {
le = to_be_aged.next;
/* fiddling the sk_list node is safe 'cos we're SK_DETACHED */
list_del_init(le);
svsk = list_entry(le, struct svc_sock, sk_list);
dprintk("queuing svsk %p for closing, %lu seconds old\n",
svsk, get_seconds() - svsk->sk_lastrecv);
/* a thread will dequeue and close it soon */
svc_sock_enqueue(svsk);
svc_sock_put(svsk);
}
mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ);
}
/*
* Initialize socket for RPC use and create svc_sock struct
* XXX: May want to setsockopt SO_SNDBUF and SO_RCVBUF.
*/
static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
struct socket *sock,
int *errp, int flags)
{
struct svc_sock *svsk;
struct sock *inet;
int pmap_register = !(flags & SVC_SOCK_ANONYMOUS);
int is_temporary = flags & SVC_SOCK_TEMPORARY;
dprintk("svc: svc_setup_socket %p\n", sock);
if (!(svsk = kzalloc(sizeof(*svsk), GFP_KERNEL))) {
*errp = -ENOMEM;
return NULL;
}
inet = sock->sk;
/* Register socket with portmapper */
if (*errp >= 0 && pmap_register)
*errp = svc_register(serv, inet->sk_protocol,
ntohs(inet_sk(inet)->sport));
if (*errp < 0) {
kfree(svsk);
return NULL;
}
set_bit(SK_BUSY, &svsk->sk_flags);
inet->sk_user_data = svsk;
svsk->sk_sock = sock;
svsk->sk_sk = inet;
svsk->sk_ostate = inet->sk_state_change;
svsk->sk_odata = inet->sk_data_ready;
svsk->sk_owspace = inet->sk_write_space;
svsk->sk_server = serv;
atomic_set(&svsk->sk_inuse, 1);
svsk->sk_lastrecv = get_seconds();
spin_lock_init(&svsk->sk_lock);
INIT_LIST_HEAD(&svsk->sk_deferred);
INIT_LIST_HEAD(&svsk->sk_ready);
mutex_init(&svsk->sk_mutex);
/* Initialize the socket */
if (sock->type == SOCK_DGRAM)
svc_udp_init(svsk);
else
svc_tcp_init(svsk);
spin_lock_bh(&serv->sv_lock);
if (is_temporary) {
set_bit(SK_TEMP, &svsk->sk_flags);
list_add(&svsk->sk_list, &serv->sv_tempsocks);
serv->sv_tmpcnt++;
if (serv->sv_temptimer.function == NULL) {
/* setup timer to age temp sockets */
setup_timer(&serv->sv_temptimer, svc_age_temp_sockets,
(unsigned long)serv);
mod_timer(&serv->sv_temptimer,
jiffies + svc_conn_age_period * HZ);
}
} else {
clear_bit(SK_TEMP, &svsk->sk_flags);
list_add(&svsk->sk_list, &serv->sv_permsocks);
}
spin_unlock_bh(&serv->sv_lock);
dprintk("svc: svc_setup_socket created %p (inet %p)\n",
svsk, svsk->sk_sk);
return svsk;
}
int svc_addsock(struct svc_serv *serv,
int fd,
char *name_return,
int *proto)
{
int err = 0;
struct socket *so = sockfd_lookup(fd, &err);
struct svc_sock *svsk = NULL;
if (!so)
return err;
if (so->sk->sk_family != AF_INET)
err = -EAFNOSUPPORT;
else if (so->sk->sk_protocol != IPPROTO_TCP &&
so->sk->sk_protocol != IPPROTO_UDP)
err = -EPROTONOSUPPORT;
else if (so->state > SS_UNCONNECTED)
err = -EISCONN;
else {
svsk = svc_setup_socket(serv, so, &err, SVC_SOCK_DEFAULTS);
if (svsk) {
svc_sock_received(svsk);
err = 0;
}
}
if (err) {
sockfd_put(so);
return err;
}
if (proto) *proto = so->sk->sk_protocol;
return one_sock_name(name_return, svsk);
}
EXPORT_SYMBOL_GPL(svc_addsock);
/*
* Create socket for RPC service.
*/
static int svc_create_socket(struct svc_serv *serv, int protocol,
struct sockaddr *sin, int len, int flags)
{
struct svc_sock *svsk;
struct socket *sock;
int error;
int type;
char buf[RPC_MAX_ADDRBUFLEN];
dprintk("svc: svc_create_socket(%s, %d, %s)\n",
serv->sv_program->pg_name, protocol,
__svc_print_addr(sin, buf, sizeof(buf)));
if (protocol != IPPROTO_UDP && protocol != IPPROTO_TCP) {
printk(KERN_WARNING "svc: only UDP and TCP "
"sockets supported\n");
return -EINVAL;
}
type = (protocol == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM;
error = sock_create_kern(sin->sa_family, type, protocol, &sock);
if (error < 0)
return error;
svc_reclassify_socket(sock);
if (type == SOCK_STREAM)
sock->sk->sk_reuse = 1; /* allow address reuse */
error = kernel_bind(sock, sin, len);
if (error < 0)
goto bummer;
if (protocol == IPPROTO_TCP) {
if ((error = kernel_listen(sock, 64)) < 0)
goto bummer;
}
if ((svsk = svc_setup_socket(serv, sock, &error, flags)) != NULL) {
svc_sock_received(svsk);
return ntohs(inet_sk(svsk->sk_sk)->sport);
}
bummer:
dprintk("svc: svc_create_socket error = %d\n", -error);
sock_release(sock);
return error;
}
/*
* Remove a dead socket
*/
static void
svc_delete_socket(struct svc_sock *svsk)
{
struct svc_serv *serv;
struct sock *sk;
dprintk("svc: svc_delete_socket(%p)\n", svsk);
serv = svsk->sk_server;
sk = svsk->sk_sk;
sk->sk_state_change = svsk->sk_ostate;
sk->sk_data_ready = svsk->sk_odata;
sk->sk_write_space = svsk->sk_owspace;
spin_lock_bh(&serv->sv_lock);
if (!test_and_set_bit(SK_DETACHED, &svsk->sk_flags))
list_del_init(&svsk->sk_list);
/*
* We used to delete the svc_sock from whichever list
* it's sk_ready node was on, but we don't actually
* need to. This is because the only time we're called
* while still attached to a queue, the queue itself
* is about to be destroyed (in svc_destroy).
*/
if (!test_and_set_bit(SK_DEAD, &svsk->sk_flags)) {
BUG_ON(atomic_read(&svsk->sk_inuse)<2);
atomic_dec(&svsk->sk_inuse);
if (test_bit(SK_TEMP, &svsk->sk_flags))
serv->sv_tmpcnt--;
}
spin_unlock_bh(&serv->sv_lock);
}
static void svc_close_socket(struct svc_sock *svsk)
{
set_bit(SK_CLOSE, &svsk->sk_flags);
if (test_and_set_bit(SK_BUSY, &svsk->sk_flags))
/* someone else will have to effect the close */
return;
atomic_inc(&svsk->sk_inuse);
svc_delete_socket(svsk);
clear_bit(SK_BUSY, &svsk->sk_flags);
svc_sock_put(svsk);
}
void svc_force_close_socket(struct svc_sock *svsk)
{
set_bit(SK_CLOSE, &svsk->sk_flags);
if (test_bit(SK_BUSY, &svsk->sk_flags)) {
/* Waiting to be processed, but no threads left,
* So just remove it from the waiting list
*/
list_del_init(&svsk->sk_ready);
clear_bit(SK_BUSY, &svsk->sk_flags);
}
svc_close_socket(svsk);
}
/**
* svc_makesock - Make a socket for nfsd and lockd
* @serv: RPC server structure
* @protocol: transport protocol to use
* @port: port to use
* @flags: requested socket characteristics
*
*/
int svc_makesock(struct svc_serv *serv, int protocol, unsigned short port,
int flags)
{
struct sockaddr_in sin = {
.sin_family = AF_INET,
.sin_addr.s_addr = INADDR_ANY,
.sin_port = htons(port),
};
dprintk("svc: creating socket proto = %d\n", protocol);
return svc_create_socket(serv, protocol, (struct sockaddr *) &sin,
sizeof(sin), flags);
}
/*
* Handle defer and revisit of requests
*/
static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
{
struct svc_deferred_req *dr = container_of(dreq, struct svc_deferred_req, handle);
struct svc_sock *svsk;
if (too_many) {
svc_sock_put(dr->svsk);
kfree(dr);
return;
}
dprintk("revisit queued\n");
svsk = dr->svsk;
dr->svsk = NULL;
spin_lock(&svsk->sk_lock);
list_add(&dr->handle.recent, &svsk->sk_deferred);
spin_unlock(&svsk->sk_lock);
set_bit(SK_DEFERRED, &svsk->sk_flags);
svc_sock_enqueue(svsk);
svc_sock_put(svsk);
}
static struct cache_deferred_req *
svc_defer(struct cache_req *req)
{
struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
int size = sizeof(struct svc_deferred_req) + (rqstp->rq_arg.len);
struct svc_deferred_req *dr;
if (rqstp->rq_arg.page_len)
return NULL; /* if more than a page, give up FIXME */
if (rqstp->rq_deferred) {
dr = rqstp->rq_deferred;
rqstp->rq_deferred = NULL;
} else {
int skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
/* FIXME maybe discard if size too large */
dr = kmalloc(size, GFP_KERNEL);
if (dr == NULL)
return NULL;
dr->handle.owner = rqstp->rq_server;
dr->prot = rqstp->rq_prot;
memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen);
dr->addrlen = rqstp->rq_addrlen;
dr->daddr = rqstp->rq_daddr;
dr->argslen = rqstp->rq_arg.len >> 2;
memcpy(dr->args, rqstp->rq_arg.head[0].iov_base-skip, dr->argslen<<2);
}
atomic_inc(&rqstp->rq_sock->sk_inuse);
dr->svsk = rqstp->rq_sock;
dr->handle.revisit = svc_revisit;
return &dr->handle;
}
/*
* recv data from a deferred request into an active one
*/
static int svc_deferred_recv(struct svc_rqst *rqstp)
{
struct svc_deferred_req *dr = rqstp->rq_deferred;
rqstp->rq_arg.head[0].iov_base = dr->args;
rqstp->rq_arg.head[0].iov_len = dr->argslen<<2;
rqstp->rq_arg.page_len = 0;
rqstp->rq_arg.len = dr->argslen<<2;
rqstp->rq_prot = dr->prot;
memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen);
rqstp->rq_addrlen = dr->addrlen;
rqstp->rq_daddr = dr->daddr;
rqstp->rq_respages = rqstp->rq_pages;
return dr->argslen<<2;
}
static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk)
{
struct svc_deferred_req *dr = NULL;
if (!test_bit(SK_DEFERRED, &svsk->sk_flags))
return NULL;
spin_lock(&svsk->sk_lock);
clear_bit(SK_DEFERRED, &svsk->sk_flags);
if (!list_empty(&svsk->sk_deferred)) {
dr = list_entry(svsk->sk_deferred.next,
struct svc_deferred_req,
handle.recent);
list_del_init(&dr->handle.recent);
set_bit(SK_DEFERRED, &svsk->sk_flags);
}
spin_unlock(&svsk->sk_lock);
return dr;
}
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