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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [net/] [sunrpc/] [svcsock.c] - Blame information for rev 1765

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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/version.h>
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/checksum.h>
#include <net/ip.h>
#include <asm/uaccess.h>
#include <asm/ioctls.h>
 
#include <linux/sunrpc/types.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/stats.h>
 
/* SMP locking strategy:
 *
 *      svc_serv->sv_lock protects most stuff for that service.
 *
 *      Some flags can be set to certain values at any time
 *      providing that certain rules are followed:
 *
 *      SK_BUSY  can be set to 0 at any time.
 *              svc_sock_enqueue must be called afterwards
 *      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.
 *
 */
 
#define RPCDBG_FACILITY RPCDBG_SVCSOCK
 
 
static struct svc_sock *svc_setup_socket(struct svc_serv *, struct socket *,
                                         int *errp, int pmap_reg);
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 *);
 
 
/*
 * Queue up an idle server thread.  Must have serv->sv_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 polute
 * the cache.
 */
static inline void
svc_serv_enqueue(struct svc_serv *serv, struct svc_rqst *rqstp)
{
        list_add(&rqstp->rq_list, &serv->sv_threads);
}
 
/*
 * Dequeue an nfsd thread.  Must have serv->sv_lock held.
 */
static inline void
svc_serv_dequeue(struct svc_serv *serv, 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;
 
        if (!skb)
                return;
        rqstp->rq_skbuff = NULL;
 
        dprintk("svc: service %p, releasing skb %p\n", rqstp, skb);
        skb_free_datagram(rqstp->rq_sock->sk_sk, skb);
}
 
/*
 * 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_rqst *rqstp;
 
        if (!(svsk->sk_flags &
              ( (1<<SK_CONN)|(1<<SK_DATA)|(1<<SK_CLOSE)) ))
                return;
        if (test_bit(SK_DEAD, &svsk->sk_flags))
                return;
 
        spin_lock_bh(&serv->sv_lock);
 
        if (!list_empty(&serv->sv_threads) &&
            !list_empty(&serv->sv_sockets))
                printk(KERN_ERR
                        "svc_sock_enqueue: threads and sockets both waiting??\n");
 
        if (test_bit(SK_BUSY, &svsk->sk_flags)) {
                /* Don't enqueue socket while daemon is receiving */
                dprintk("svc: socket %p busy, not enqueued\n", svsk->sk_sk);
                goto out_unlock;
        }
 
        if (((svsk->sk_reserved + serv->sv_bufsz)*2
             > sock_wspace(svsk->sk_sk))
            && !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, svsk->sk_reserved+serv->sv_bufsz,
                        sock_wspace(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.
         */
        set_bit(SK_BUSY, &svsk->sk_flags);
 
        if (!list_empty(&serv->sv_threads)) {
                rqstp = list_entry(serv->sv_threads.next,
                                   struct svc_rqst,
                                   rq_list);
                dprintk("svc: socket %p served by daemon %p\n",
                        svsk->sk_sk, rqstp);
                svc_serv_dequeue(serv, 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;
                svsk->sk_inuse++;
                rqstp->rq_reserved = serv->sv_bufsz;
                svsk->sk_reserved += rqstp->rq_reserved;
                wake_up(&rqstp->rq_wait);
        } else {
                dprintk("svc: socket %p put into queue\n", svsk->sk_sk);
                list_add_tail(&svsk->sk_ready, &serv->sv_sockets);
                set_bit(SK_QUED, &svsk->sk_flags);
        }
 
out_unlock:
        spin_unlock_bh(&serv->sv_lock);
}
 
/*
 * Dequeue the first socket.  Must be called with the serv->sv_lock held.
 */
static inline struct svc_sock *
svc_sock_dequeue(struct svc_serv *serv)
{
        struct svc_sock *svsk;
 
        if (list_empty(&serv->sv_sockets))
                return NULL;
 
        svsk = list_entry(serv->sv_sockets.next,
                          struct svc_sock, sk_ready);
        list_del(&svsk->sk_ready);
 
        dprintk("svc: socket %p dequeued, inuse=%d\n",
                svsk->sk_sk, svsk->sk_inuse);
        clear_bit(SK_QUED, &svsk->sk_flags);
 
        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)
{
        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_resbuf.len<<2;
 
        if (space < rqstp->rq_reserved) {
                struct svc_sock *svsk = rqstp->rq_sock;
                spin_lock_bh(&svsk->sk_server->sv_lock);
                svsk->sk_reserved -= (rqstp->rq_reserved - space);
                rqstp->rq_reserved = space;
                spin_unlock_bh(&svsk->sk_server->sv_lock);
 
                svc_sock_enqueue(svsk);
        }
}
 
/*
 * Release a socket after use.
 */
static inline void
svc_sock_put(struct svc_sock *svsk)
{
        struct svc_serv *serv = svsk->sk_server;
 
        spin_lock_bh(&serv->sv_lock);
        if (!--(svsk->sk_inuse) && test_bit(SK_DEAD, &svsk->sk_flags)) {
                spin_unlock_bh(&serv->sv_lock);
                dprintk("svc: releasing dead socket\n");
                sock_release(svsk->sk_sock);
                kfree(svsk);
        }
        else
                spin_unlock_bh(&serv->sv_lock);
}
 
static void
svc_sock_release(struct svc_rqst *rqstp)
{
        struct svc_sock *svsk = rqstp->rq_sock;
 
        svc_release_skb(rqstp);
 
        /* 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_resbuf.len<<2) >  rqstp->rq_reserved)
                printk(KERN_ERR "RPC request reserved %d but used %d\n",
                       rqstp->rq_reserved,
                       rqstp->rq_resbuf.len<<2);
 
        rqstp->rq_resbuf.buf = rqstp->rq_resbuf.base;
        rqstp->rq_resbuf.len = 0;
        svc_reserve(rqstp, 0);
        rqstp->rq_sock = NULL;
 
        svc_sock_put(svsk);
}
 
/*
 * External function to wake up a server waiting for data
 */
void
svc_wake_up(struct svc_serv *serv)
{
        struct svc_rqst *rqstp;
 
        spin_lock_bh(&serv->sv_lock);
        if (!list_empty(&serv->sv_threads)) {
                rqstp = list_entry(serv->sv_threads.next,
                                   struct svc_rqst,
                                   rq_list);
                dprintk("svc: daemon %p woken up.\n", rqstp);
                /*
                svc_serv_dequeue(serv, rqstp);
                rqstp->rq_sock = NULL;
                 */
                wake_up(&rqstp->rq_wait);
        }
        spin_unlock_bh(&serv->sv_lock);
}
 
/*
 * Generic sendto routine
 */
static int
svc_sendto(struct svc_rqst *rqstp, struct iovec *iov, int nr)
{
        mm_segment_t    oldfs;
        struct svc_sock *svsk = rqstp->rq_sock;
        struct socket   *sock = svsk->sk_sock;
        struct msghdr   msg;
        char            buffer[CMSG_SPACE(sizeof(struct in_pktinfo))];
        struct cmsghdr *cmh = (struct cmsghdr *)buffer;
        struct in_pktinfo *pki = (struct in_pktinfo *)CMSG_DATA(cmh);
        int             i, buflen, len;
 
        for (i = buflen = 0; i < nr; i++)
                buflen += iov[i].iov_len;
 
        msg.msg_name    = &rqstp->rq_addr;
        msg.msg_namelen = sizeof(rqstp->rq_addr);
        msg.msg_iov     = iov;
        msg.msg_iovlen  = nr;
        if (rqstp->rq_prot == IPPROTO_UDP) {
                msg.msg_control = cmh;
                msg.msg_controllen = sizeof(buffer);
                cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
                cmh->cmsg_level = SOL_IP;
                cmh->cmsg_type = IP_PKTINFO;
                pki->ipi_ifindex = 0;
                pki->ipi_spec_dst.s_addr = rqstp->rq_daddr;
        } else {
                msg.msg_control = NULL;
                msg.msg_controllen = 0;
        }
 
        /* This was MSG_DONTWAIT, but I now want it to wait.
         * The only thing that it would wait for is memory and
         * if we are fairly low on memory, then we aren't likely
         * to make much progress anyway.
         * sk->sndtimeo is set to 30seconds just in case.
         */
        msg.msg_flags   = 0;
 
        oldfs = get_fs(); set_fs(KERNEL_DS);
        len = sock_sendmsg(sock, &msg, buflen);
        set_fs(oldfs);
 
        dprintk("svc: socket %p sendto([%p %Zu... ], %d, %d) = %d\n",
                        rqstp->rq_sock, iov[0].iov_base, iov[0].iov_len, nr, buflen, len);
 
        return len;
}
 
/*
 * Check input queue length
 */
static int
svc_recv_available(struct svc_sock *svsk)
{
        mm_segment_t    oldfs;
        struct socket   *sock = svsk->sk_sock;
        int             avail, err;
 
        oldfs = get_fs(); set_fs(KERNEL_DS);
        err = sock->ops->ioctl(sock, TIOCINQ, (unsigned long) &avail);
        set_fs(oldfs);
 
        return (err >= 0)? avail : err;
}
 
/*
 * Generic recvfrom routine.
 */
static int
svc_recvfrom(struct svc_rqst *rqstp, struct iovec *iov, int nr, int buflen)
{
        mm_segment_t    oldfs;
        struct msghdr   msg;
        struct socket   *sock;
        int             len, alen;
 
        rqstp->rq_addrlen = sizeof(rqstp->rq_addr);
        sock = rqstp->rq_sock->sk_sock;
 
        msg.msg_name    = &rqstp->rq_addr;
        msg.msg_namelen = sizeof(rqstp->rq_addr);
        msg.msg_iov     = iov;
        msg.msg_iovlen  = nr;
        msg.msg_control = NULL;
        msg.msg_controllen = 0;
 
        msg.msg_flags   = MSG_DONTWAIT;
 
        oldfs = get_fs(); set_fs(KERNEL_DS);
        len = sock_recvmsg(sock, &msg, buflen, MSG_DONTWAIT);
        set_fs(oldfs);
 
        /* sock_recvmsg doesn't fill in the name/namelen, so we must..
         * possibly we should cache this in the svc_sock structure
         * at accept time. FIXME
         */
        alen = sizeof(rqstp->rq_addr);
        sock->ops->getname(sock, (struct sockaddr *)&rqstp->rq_addr, &alen, 1);
 
        dprintk("svc: socket %p recvfrom(%p, %Zu) = %d\n",
                rqstp->rq_sock, 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->sndbuf = snd * 2;
        sock->sk->rcvbuf = rcv * 2;
        sock->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->user_data);
 
        if (!svsk)
                goto out;
        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);
 out:
        if (sk->sleep && waitqueue_active(sk->sleep))
                wake_up_interruptible(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->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->sleep && waitqueue_active(sk->sleep))
                wake_up_interruptible(sk->sleep);
}
 
/*
 * 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;
        u32             *data;
        int             err, len;
 
        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.
                 */
                svc_sock_setbufsize(svsk->sk_sock,
                                    (serv->sv_nrthreads+3)* serv->sv_bufsz,
                                    (serv->sv_nrthreads+3)* serv->sv_bufsz);
 
        clear_bit(SK_DATA, &svsk->sk_flags);
        while ((skb = skb_recv_datagram(svsk->sk_sk, 0, 1, &err)) == NULL) {
                svc_sock_received(svsk);
                if (err == -EAGAIN)
                        return err;
                /* possibly an icmp error */
                dprintk("svc: recvfrom returned error %d\n", -err);
        }
        set_bit(SK_DATA, &svsk->sk_flags); /* there may be more data... */
 
        /* Sorry. */
        if (skb_is_nonlinear(skb)) {
                if (skb_linearize(skb, GFP_KERNEL) != 0) {
                        kfree_skb(skb);
                        svc_sock_received(svsk);
                        return 0;
                }
        }
 
        if (skb->ip_summed != CHECKSUM_UNNECESSARY) {
                if ((unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum))) {
                        skb_free_datagram(svsk->sk_sk, skb);
                        svc_sock_received(svsk);
                        return 0;
                }
        }
 
 
        len  = skb->len - sizeof(struct udphdr);
        data = (u32 *) (skb->data + sizeof(struct udphdr));
 
        rqstp->rq_skbuff      = skb;
        rqstp->rq_argbuf.base = data;
        rqstp->rq_argbuf.buf  = data;
        rqstp->rq_argbuf.len  = (len >> 2);
        /* rqstp->rq_resbuf      = rqstp->rq_defbuf; */
        rqstp->rq_prot        = IPPROTO_UDP;
 
        /* Get sender address */
        rqstp->rq_addr.sin_family = AF_INET;
        rqstp->rq_addr.sin_port = skb->h.uh->source;
        rqstp->rq_addr.sin_addr.s_addr = skb->nh.iph->saddr;
        rqstp->rq_daddr = skb->nh.iph->daddr;
 
        if (serv->sv_stats)
                serv->sv_stats->netudpcnt++;
 
        /* One down, maybe more to go... */
        svsk->sk_sk->stamp = skb->stamp;
        svc_sock_received(svsk);
 
        return len;
}
 
static int
svc_udp_sendto(struct svc_rqst *rqstp)
{
        struct svc_buf  *bufp = &rqstp->rq_resbuf;
        int             error;
 
        /* Set up the first element of the reply iovec.
         * Any other iovecs that may be in use have been taken
         * care of by the server implementation itself.
         */
        /* bufp->base = bufp->area; */
        bufp->iov[0].iov_base = bufp->base;
        bufp->iov[0].iov_len  = bufp->len << 2;
 
        error = svc_sendto(rqstp, bufp->iov, bufp->nriov);
        if (error == -ECONNREFUSED)
                /* ICMP error on earlier request. */
                error = svc_sendto(rqstp, bufp->iov, bufp->nriov);
 
        return error;
}
 
static int
svc_udp_init(struct svc_sock *svsk)
{
        svsk->sk_sk->data_ready = svc_udp_data_ready;
        svsk->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_bufsz,
                            3 * svsk->sk_server->sv_bufsz);
 
        set_bit(SK_CHNGBUF, &svsk->sk_flags);
 
        return 0;
}
 
/*
 * 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;
 
        dprintk("svc: socket %p TCP (listen) state change %d\n",
                        sk, sk->state);
 
        if  (sk->state != TCP_LISTEN) {
                /*
                 * 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.
                 */
                goto out;
        }
        if (!(svsk = (struct svc_sock *) sk->user_data)) {
                printk("svc: socket %p: no user data\n", sk);
                goto out;
        }
        set_bit(SK_CONN, &svsk->sk_flags);
        svc_sock_enqueue(svsk);
 out:
        if (sk->sleep && waitqueue_active(sk->sleep))
                wake_up_interruptible_all(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;
 
        dprintk("svc: socket %p TCP (connected) state change %d (svsk %p)\n",
                        sk, sk->state, sk->user_data);
 
        if (!(svsk = (struct svc_sock *) sk->user_data)) {
                printk("svc: socket %p: no user data\n", sk);
                goto out;
        }
        set_bit(SK_CLOSE, &svsk->sk_flags);
        svc_sock_enqueue(svsk);
 out:
        if (sk->sleep && waitqueue_active(sk->sleep))
                wake_up_interruptible_all(sk->sleep);
}
 
static void
svc_tcp_data_ready(struct sock *sk, int count)
{
        struct svc_sock *       svsk;
 
        dprintk("svc: socket %p TCP data ready (svsk %p)\n",
                        sk, sk->user_data);
        if (!(svsk = (struct svc_sock *)(sk->user_data)))
                goto out;
        set_bit(SK_DATA, &svsk->sk_flags);
        svc_sock_enqueue(svsk);
 out:
        if (sk->sleep && waitqueue_active(sk->sleep))
                wake_up_interruptible(sk->sleep);
}
 
/*
 * Accept a TCP connection
 */
static void
svc_tcp_accept(struct svc_sock *svsk)
{
        struct sockaddr_in sin;
        struct svc_serv *serv = svsk->sk_server;
        struct socket   *sock = svsk->sk_sock;
        struct socket   *newsock;
        struct proto_ops *ops;
        struct svc_sock *newsvsk;
        int             err, slen;
 
        dprintk("svc: tcp_accept %p sock %p\n", svsk, sock);
        if (!sock)
                return;
 
        if (!(newsock = sock_alloc())) {
                printk(KERN_WARNING "%s: no more sockets!\n", serv->sv_name);
                return;
        }
        dprintk("svc: tcp_accept %p allocated\n", newsock);
 
        newsock->type = sock->type;
        newsock->ops = ops = sock->ops;
 
        clear_bit(SK_CONN, &svsk->sk_flags);
        if ((err = ops->accept(sock, newsock, O_NONBLOCK)) < 0) {
                if (err != -EAGAIN && net_ratelimit())
                        printk(KERN_WARNING "%s: accept failed (err %d)!\n",
                                   serv->sv_name, -err);
                goto failed;            /* aborted connection or whatever */
        }
        set_bit(SK_CONN, &svsk->sk_flags);
        svc_sock_enqueue(svsk);
 
        slen = sizeof(sin);
        err = ops->getname(newsock, (struct sockaddr *) &sin, &slen, 1);
        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 encription, the IP of the host won't
         * tell us anything. For now just warn about unpriv connections.
         */
        if (ntohs(sin.sin_port) >= 1024) {
                dprintk(KERN_WARNING
                        "%s: connect from unprivileged port: %u.%u.%u.%u:%d\n",
                        serv->sv_name,
                        NIPQUAD(sin.sin_addr.s_addr), ntohs(sin.sin_port));
        }
 
        dprintk("%s: connect from %u.%u.%u.%u:%04x\n", serv->sv_name,
                        NIPQUAD(sin.sin_addr.s_addr), ntohs(sin.sin_port));
 
        if (!(newsvsk = svc_setup_socket(serv, newsock, &err, 0)))
                goto failed;
 
        /* make sure that a write doesn't block forever when
         * low on memory
         */
        newsock->sk->sndtimeo = HZ*30;
 
        /* Precharge. Data may have arrived on the socket before we
         * installed the data_ready callback.
         */
        set_bit(SK_DATA, &newsvsk->sk_flags);
        svc_sock_enqueue(newsvsk);
 
        /* make sure that we don't have too many active connections.
         * If we have, something must be dropped.
         * We randomly choose between newest and oldest (in terms
         * of recent activity) and drop it.
         */
        if (serv->sv_tmpcnt > (serv->sv_nrthreads+3)*10) {
                struct svc_sock *svsk = NULL;
                spin_lock_bh(&serv->sv_lock);
                if (!list_empty(&serv->sv_tempsocks)) {
                        if (net_random()&1)
                                svsk = list_entry(serv->sv_tempsocks.prev,
                                                  struct svc_sock,
                                                  sk_list);
                        else
                                svsk = list_entry(serv->sv_tempsocks.next,
                                                  struct svc_sock,
                                                  sk_list);
                        set_bit(SK_CLOSE, &svsk->sk_flags);
                        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;
        struct svc_buf  *bufp = &rqstp->rq_argbuf;
        int             len;
 
        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 (test_bit(SK_CLOSE, &svsk->sk_flags)) {
                svc_delete_socket(svsk);
                return 0;
        }
 
        if (test_bit(SK_CONN, &svsk->sk_flags)) {
                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.
                 * rcvbuf just needs to be able to hold a few requests.
                 * Normally they will be removed from the queue
                 * as soon as a complete request arrives.
                 */
                svc_sock_setbufsize(svsk->sk_sock,
                                    (serv->sv_nrthreads+3) *
                                    serv->sv_bufsz,
                                    3 * serv->sv_bufsz);
 
        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 iovec    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 %ld)\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. */
                        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 > (bufp->buflen<<2)) {
                        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 */
        }
        set_bit(SK_DATA, &svsk->sk_flags);
 
        /* Frob argbuf */
        bufp->iov[0].iov_base += 4;
        bufp->iov[0].iov_len  -= 4;
 
        /* Now receive data */
        len = svc_recvfrom(rqstp, bufp->iov, bufp->nriov, svsk->sk_reclen);
        if (len < 0)
                goto error;
 
        dprintk("svc: TCP complete record (%d bytes)\n", len);
 
        /* Position reply write pointer immediately after
         * record length */
        rqstp->rq_resbuf.buf += 1;
        rqstp->rq_resbuf.len  = 1;
 
        rqstp->rq_skbuff      = 0;
        rqstp->rq_argbuf.buf += 1;
        rqstp->rq_argbuf.len  = (len >> 2);
        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);
                svc_sock_received(svsk);
        }
 
        return len;
}
 
/*
 * Send out data on TCP socket.
 */
static int
svc_tcp_sendto(struct svc_rqst *rqstp)
{
        struct svc_buf  *bufp = &rqstp->rq_resbuf;
        int sent;
 
        /* Set up the first element of the reply iovec.
         * Any other iovecs that may be in use have been taken
         * care of by the server implementation itself.
         */
        bufp->iov[0].iov_base = bufp->base;
        bufp->iov[0].iov_len  = bufp->len << 2;
        bufp->base[0] = htonl(0x80000000|((bufp->len << 2) - 4));
 
        if (test_bit(SK_DEAD, &rqstp->rq_sock->sk_flags))
                return -ENOTCONN;
 
        sent = svc_sendto(rqstp, bufp->iov, bufp->nriov);
        if (sent != bufp->len<<2) {
                printk(KERN_NOTICE "rpc-srv/tcp: %s: sent only %d bytes of %d - shutting down socket\n",
                       rqstp->rq_sock->sk_server->sv_name,
                       sent, bufp->len << 2);
                svc_delete_socket(rqstp->rq_sock);
                sent = -EAGAIN;
        }
        return sent;
}
 
static int
svc_tcp_init(struct svc_sock *svsk)
{
        struct sock     *sk = svsk->sk_sk;
        struct tcp_opt  *tp = &(sk->tp_pinfo.af_tcp);
 
        svsk->sk_recvfrom = svc_tcp_recvfrom;
        svsk->sk_sendto = svc_tcp_sendto;
 
        if (sk->state == TCP_LISTEN) {
                dprintk("setting up TCP socket for listening\n");
                sk->data_ready = svc_tcp_listen_data_ready;
        } else {
                dprintk("setting up TCP socket for reading\n");
                sk->state_change = svc_tcp_state_change;
                sk->data_ready = svc_tcp_data_ready;
                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_bufsz,
                                    3 * svsk->sk_server->sv_bufsz);
 
                set_bit(SK_CHNGBUF, &svsk->sk_flags);
                if (sk->state != TCP_ESTABLISHED)
                        set_bit(SK_CLOSE, &svsk->sk_flags);
        }
 
        return 0;
}
 
void
svc_sock_update_bufs(struct svc_serv *serv)
{
        /*
         * The number of server threads has changed.
         * flag all socket to the snd/rcv buffer sizes
         * updated.
         * We don't just do it, as the locking is rather
         * awkward at this point
         */
        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.
 */
int
svc_recv(struct svc_serv *serv, struct svc_rqst *rqstp, long timeout)
{
        struct svc_sock         *svsk =NULL;
        int                     len;
        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);
 
        /* Initialize the buffers */
        rqstp->rq_argbuf = rqstp->rq_defbuf;
        rqstp->rq_resbuf = rqstp->rq_defbuf;
 
        if (signalled())
                return -EINTR;
 
        spin_lock_bh(&serv->sv_lock);
        if (!list_empty(&serv->sv_tempsocks)) {
                svsk = list_entry(serv->sv_tempsocks.next,
                                  struct svc_sock, sk_list);
                /* apparently the "standard" is that clients close
                 * idle connections after 5 minutes, servers after
                 * 6 minutes
                 *   http://www.connectathon.org/talks96/nfstcp.pdf
                 */
                if (CURRENT_TIME - svsk->sk_lastrecv < 6*60
                    || test_bit(SK_BUSY, &svsk->sk_flags))
                        svsk = NULL;
        }
        if (svsk) {
                set_bit(SK_BUSY, &svsk->sk_flags);
                set_bit(SK_CLOSE, &svsk->sk_flags);
                rqstp->rq_sock = svsk;
                svsk->sk_inuse++;
        } else if ((svsk = svc_sock_dequeue(serv)) != NULL) {
                rqstp->rq_sock = svsk;
                svsk->sk_inuse++;
                rqstp->rq_reserved = serv->sv_bufsz;
                svsk->sk_reserved += rqstp->rq_reserved;
        } else {
                /* No data pending. Go to sleep */
                svc_serv_enqueue(serv, 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(&serv->sv_lock);
 
                schedule_timeout(timeout);
 
                spin_lock_bh(&serv->sv_lock);
                remove_wait_queue(&rqstp->rq_wait, &wait);
 
                if (!(svsk = rqstp->rq_sock)) {
                        svc_serv_dequeue(serv, rqstp);
                        spin_unlock_bh(&serv->sv_lock);
                        dprintk("svc: server %p, no data yet\n", rqstp);
                        return signalled()? -EINTR : -EAGAIN;
                }
        }
        spin_unlock_bh(&serv->sv_lock);
 
        dprintk("svc: server %p, socket %p, inuse=%d\n",
                 rqstp, svsk, 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) {
                svc_sock_release(rqstp);
                return -EAGAIN;
        }
        svsk->sk_lastrecv = CURRENT_TIME;
        if (test_bit(SK_TEMP, &svsk->sk_flags)) {
                /* push active sockets to end of list */
                spin_lock_bh(&serv->sv_lock);
                list_del(&svsk->sk_list);
                list_add_tail(&svsk->sk_list, &serv->sv_tempsocks);
                spin_unlock_bh(&serv->sv_lock);
        }
 
        rqstp->rq_secure  = ntohs(rqstp->rq_addr.sin_port) < 1024;
        rqstp->rq_userset = 0;
        rqstp->rq_verfed  = 0;
 
        svc_getlong(&rqstp->rq_argbuf, rqstp->rq_xid);
        svc_putlong(&rqstp->rq_resbuf, rqstp->rq_xid);
 
        /* Assume that the reply consists of a single buffer. */
        rqstp->rq_resbuf.nriov = 1;
 
        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;
 
        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);
 
        len = svsk->sk_sendto(rqstp);
        svc_sock_release(rqstp);
 
        if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
                return 0;
        return len;
}
 
/*
 * 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 pmap_register)
{
        struct svc_sock *svsk;
        struct sock     *inet;
 
        dprintk("svc: svc_setup_socket %p\n", sock);
        if (!(svsk = kmalloc(sizeof(*svsk), GFP_KERNEL))) {
                *errp = -ENOMEM;
                return NULL;
        }
        memset(svsk, 0, sizeof(*svsk));
 
        inet = sock->sk;
        inet->user_data = svsk;
        svsk->sk_sock = sock;
        svsk->sk_sk = inet;
        svsk->sk_ostate = inet->state_change;
        svsk->sk_odata = inet->data_ready;
        svsk->sk_owspace = inet->write_space;
        svsk->sk_server = serv;
        svsk->sk_lastrecv = CURRENT_TIME;
 
        /* Initialize the socket */
        if (sock->type == SOCK_DGRAM)
                *errp = svc_udp_init(svsk);
        else
                *errp = svc_tcp_init(svsk);
if (svsk->sk_sk == NULL)
        printk(KERN_WARNING "svsk->sk_sk == NULL after svc_prot_init!\n");
 
        /* Register socket with portmapper */
        if (*errp >= 0 && pmap_register)
                *errp = svc_register(serv, inet->protocol, ntohs(inet->sport));
 
        if (*errp < 0) {
                inet->user_data = NULL;
                kfree(svsk);
                return NULL;
        }
 
 
        spin_lock_bh(&serv->sv_lock);
        if (!pmap_register) {
                set_bit(SK_TEMP, &svsk->sk_flags);
                list_add(&svsk->sk_list, &serv->sv_tempsocks);
                serv->sv_tmpcnt++;
        } 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;
}
 
/*
 * Create socket for RPC service.
 */
static int
svc_create_socket(struct svc_serv *serv, int protocol, struct sockaddr_in *sin)
{
        struct svc_sock *svsk;
        struct socket   *sock;
        int             error;
        int             type;
 
        dprintk("svc: svc_create_socket(%s, %d, %u.%u.%u.%u:%d)\n",
                                serv->sv_program->pg_name, protocol,
                                NIPQUAD(sin->sin_addr.s_addr),
                                ntohs(sin->sin_port));
 
        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;
 
        if ((error = sock_create(PF_INET, type, protocol, &sock)) < 0)
                return error;
 
        if (sin != NULL) {
                if (type == SOCK_STREAM)
                        sock->sk->reuse = 1; /* allow address reuse */
                error = sock->ops->bind(sock, (struct sockaddr *) sin,
                                                sizeof(*sin));
                if (error < 0)
                        goto bummer;
        }
 
        if (protocol == IPPROTO_TCP) {
                if ((error = sock->ops->listen(sock, 64)) < 0)
                        goto bummer;
        }
 
        if ((svsk = svc_setup_socket(serv, sock, &error, 1)) != NULL)
                return 0;
 
bummer:
        dprintk("svc: svc_create_socket error = %d\n", -error);
        sock_release(sock);
        return error;
}
 
/*
 * Remove a dead socket
 */
void
svc_delete_socket(struct svc_sock *svsk)
{
        struct svc_serv *serv;
        struct sock     *sk;
 
        dprintk("svc: svc_delete_socket(%p)\n", svsk);
 
        if (test_and_set_bit(SK_DEAD, &svsk->sk_flags))
                return ;
 
        serv = svsk->sk_server;
        sk = svsk->sk_sk;
 
        sk->state_change = svsk->sk_ostate;
        sk->data_ready = svsk->sk_odata;
        sk->write_space = svsk->sk_owspace;
 
        spin_lock_bh(&serv->sv_lock);
 
        list_del(&svsk->sk_list);
        if (test_bit(SK_TEMP, &svsk->sk_flags))
                serv->sv_tmpcnt--;
        if (test_bit(SK_QUED, &svsk->sk_flags))
                list_del(&svsk->sk_ready);
 
 
        if (!svsk->sk_inuse) {
                spin_unlock_bh(&serv->sv_lock);
                sock_release(svsk->sk_sock);
                kfree(svsk);
        } else {
                spin_unlock_bh(&serv->sv_lock);
                dprintk(KERN_NOTICE "svc: server socket destroy delayed\n");
                /* svsk->sk_server = NULL; */
        }
}
 
/*
 * Make a socket for nfsd and lockd
 */
int
svc_makesock(struct svc_serv *serv, int protocol, unsigned short port)
{
        struct sockaddr_in      sin;
 
        dprintk("svc: creating socket proto = %d\n", protocol);
        sin.sin_family      = AF_INET;
        sin.sin_addr.s_addr = INADDR_ANY;
        sin.sin_port        = htons(port);
        return svc_create_socket(serv, protocol, &sin);
}
 
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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [net/] [sunrpc/] [svcsock.c] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	1275	phoenix	`/*`
2			`* linux/net/sunrpc/svcsock.c`
3			`*`
4			`* These are the RPC server socket internals.`
5			`*`
6			`* The server scheduling algorithm does not always distribute the load`
7			`* evenly when servicing a single client. May need to modify the`
8			`* svc_sock_enqueue procedure...`
9			`*`
10			`* TCP support is largely untested and may be a little slow. The problem`
11			`* is that we currently do two separate recvfrom's, one for the 4-byte`
12			`* record length, and the second for the actual record. This could possibly`
13			`* be improved by always reading a minimum size of around 100 bytes and`
14			`* tucking any superfluous bytes away in a temporary store. Still, that`
15			`* leaves write requests out in the rain. An alternative may be to peek at`
16			`* the first skb in the queue, and if it matches the next TCP sequence`
17			`* number, to extract the record marker. Yuck.`
18			`*`
19			`* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>`
20			`*/`
21
22			`#include <linux/sched.h>`
23			`#include <linux/errno.h>`
24			`#include <linux/fcntl.h>`
25			`#include <linux/net.h>`
26			`#include <linux/in.h>`
27			`#include <linux/inet.h>`
28			`#include <linux/udp.h>`
29			`#include <linux/version.h>`
30			`#include <linux/unistd.h>`
31			`#include <linux/slab.h>`
32			`#include <linux/netdevice.h>`
33			`#include <linux/skbuff.h>`
34			`#include <net/sock.h>`
35			`#include <net/checksum.h>`
36			`#include <net/ip.h>`
37			`#include <asm/uaccess.h>`
38			`#include <asm/ioctls.h>`
39
40			`#include <linux/sunrpc/types.h>`