/* * 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 <net/sock.h> #include <net/checksum.h> #include <net/ip.h> #include <net/tcp_states.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 *); 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); /* * 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; 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_rqst *rqstp; 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; 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_DEAD, &svsk->sk_flags)) { /* Don't enqueue dead sockets */ dprintk("svc: socket %p is dead, not enqueued\n", svsk->sk_sk); goto out_unlock; } 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; } set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags); if (((svsk->sk_reserved + serv->sv_bufsz)*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, svsk->sk_reserved+serv->sv_bufsz, svc_sock_wspace(svsk)); goto out_unlock; } clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags); /* 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); } 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_init(&svsk->sk_ready); dprintk("svc: socket %p dequeued, inuse=%d\n", svsk->sk_sk, 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) { 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; 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); svc_free_allpages(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 */ 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 xdr_buf *xdr) { struct svc_sock *svsk = rqstp->rq_sock; struct socket *sock = svsk->sk_sock; int slen; 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 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; slen = xdr->len; if (rqstp->rq_prot == IPPROTO_UDP) { /* set the source and destination */ struct msghdr msg; msg.msg_name = &rqstp->rq_addr; msg.msg_namelen = sizeof(rqstp->rq_addr); msg.msg_iov = NULL; msg.msg_iovlen = 0; msg.msg_flags = MSG_MORE; 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; if (sock_sendmsg(sock, &msg, 0) < 0) goto out; } /* send head */ if (slen == xdr->head[0].iov_len) flags = 0; len = sock->ops->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 = sock->ops->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 = sock->ops->sendpage(sock, rqstp->rq_respages[rqstp->rq_restailpage], ((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 %x)\n", rqstp->rq_sock, xdr->head[0].iov_base, xdr->head[0].iov_len, xdr->len, len, rqstp->rq_addr.sin_addr.s_addr); 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 kvec *iov, int nr, int buflen) { 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_control = NULL; msg.msg_controllen = 0; msg.msg_flags = MSG_DONTWAIT; len = kernel_recvmsg(sock, &msg, iov, nr, buflen, MSG_DONTWAIT); /* 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->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) 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->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)) { printk(KERN_WARNING "RPC svc_write_space: some sleeping on %p\n", svsk); wake_up_interruptible(sk->sk_sleep); } } /* * Receive a datagram from a UDP socket. */ extern int csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb); 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; 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); if ((rqstp->rq_deferred = svc_deferred_dequeue(svsk))) { svc_sock_received(svsk); return svc_deferred_recv(rqstp); } clear_bit(SK_DATA, &svsk->sk_flags); while ((skb = skb_recv_datagram(svsk->sk_sk, 0, 1, &err)) == NULL) { if (err == -EAGAIN) { svc_sock_received(svsk); return err; } /* possibly an icmp error */ dprintk("svc: recvfrom returned error %d\n", -err); } if (skb->stamp.tv_sec == 0) { skb->stamp.tv_sec = xtime.tv_sec; skb->stamp.tv_usec = xtime.tv_nsec / NSEC_PER_USEC; /* Don't enable netstamp, sunrpc doesn't need that much accuracy */ } svsk->sk_sk->sk_stamp = skb->stamp; 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; /* 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 (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->ip_summed != CHECKSUM_UNNECESSARY) { if ((unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum))) { skb_free_datagram(svsk->sk_sk, skb); return 0; } skb->ip_summed = CHECKSUM_UNNECESSARY; } 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; } else { rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len; rqstp->rq_argused += (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) { 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_bufsz, 3 * svsk->sk_server->sv_bufsz); set_bit(SK_DATA, &svsk->sk_flags); /* might have come in before data_ready set up */ set_bit(SK_CHNGBUF, &svsk->sk_flags); } /* * 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->sk_state); if (sk->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->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->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; dprintk("svc: socket %p TCP (connected) state change %d (svsk %p)\n", sk, sk->sk_state, sk->sk_user_data); if (!(svsk = (struct svc_sock *) sk->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->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; dprintk("svc: socket %p TCP data ready (svsk %p)\n", sk, sk->sk_user_data); if (!(svsk = (struct svc_sock *)(sk->sk_user_data))) goto out; set_bit(SK_DATA, &svsk->sk_flags); svc_sock_enqueue(svsk); out: if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) wake_up_interruptible(sk->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; err = sock_create_lite(PF_INET, SOCK_STREAM, IPPROTO_TCP, &newsock); if (err) { if (err == -ENOMEM) printk(KERN_WARNING "%s: no more sockets!\n", serv->sv_name); return; } dprintk("svc: tcp_accept %p allocated\n", newsock); 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)); /* 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, 0))) goto failed; /* 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 " "%u.%u.%u.%u:%d\n", serv->sv_name, NIPQUAD(sin.sin_addr.s_addr), ntohs(sin.sin_port)); } /* * 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); 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[RPCSVC_MAXPAGES]; 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 (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 a 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 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. */ 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_bufsz) { 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[0] = rqstp->rq_arg.head[0]; vlen = PAGE_SIZE; pnum = 1; while (vlen < len) { vec[pnum].iov_base = page_address(rqstp->rq_argpages[rqstp->rq_argused++]); vec[pnum].iov_len = PAGE_SIZE; pnum++; vlen += PAGE_SIZE; } /* 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); svc_sock_received(svsk); } 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; u32 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); svc_delete_socket(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_bufsz, 3 * svsk->sk_server->sv_bufsz); 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. */ int svc_recv(struct svc_serv *serv, struct svc_rqst *rqstp, long timeout) { struct svc_sock *svsk =NULL; int len; 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); /* Initialize the buffers */ /* first reclaim pages that were moved to response list */ svc_pushback_allpages(rqstp); /* now allocate needed pages. If we get a failure, sleep briefly */ pages = 2 + (serv->sv_bufsz + PAGE_SIZE -1) / PAGE_SIZE; while (rqstp->rq_arghi < pages) { struct page *p = alloc_page(GFP_KERNEL); if (!p) { set_current_state(TASK_UNINTERRUPTIBLE); schedule_timeout(HZ/2); continue; } rqstp->rq_argpages[rqstp->rq_arghi++] = p; } /* 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_argpages[0]); arg->head[0].iov_len = PAGE_SIZE; rqstp->rq_argused = 1; arg->pages = rqstp->rq_argpages + 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(); 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 (get_seconds() - 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); try_to_freeze(); 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) { rqstp->rq_res.len = 0; svc_sock_release(rqstp); return -EAGAIN; } svsk->sk_lastrecv = get_seconds(); if (test_bit(SK_TEMP, &svsk->sk_flags)) { /* push active sockets to end of list */ spin_lock_bh(&serv->sv_lock); if (!list_empty(&svsk->sk_list)) list_move_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_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_sem to serialize outgoing data. */ down(&svsk->sk_sem); if (test_bit(SK_DEAD, &svsk->sk_flags)) len = -ENOTCONN; else len = svsk->sk_sendto(rqstp); up(&svsk->sk_sem); 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; /* 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; svsk->sk_lastrecv = get_seconds(); INIT_LIST_HEAD(&svsk->sk_deferred); INIT_LIST_HEAD(&svsk->sk_ready); sema_init(&svsk->sk_sem, 1); /* Initialize the socket */ if (sock->type == SOCK_DGRAM) svc_udp_init(svsk); else svc_tcp_init(svsk); 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); clear_bit(SK_BUSY, &svsk->sk_flags); svc_sock_enqueue(svsk); 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_kern(PF_INET, type, protocol, &sock)) < 0) return error; if (sin != NULL) { if (type == SOCK_STREAM) sock->sk->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); 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); list_del_init(&svsk->sk_list); list_del_init(&svsk->sk_ready); if (!test_and_set_bit(SK_DEAD, &svsk->sk_flags)) if (test_bit(SK_TEMP, &svsk->sk_flags)) serv->sv_tmpcnt--; 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); } /* * 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_serv *serv = dreq->owner; 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_bh(&serv->sv_lock); list_add(&dr->handle.recent, &svsk->sk_deferred); spin_unlock_bh(&serv->sv_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; dr->addr = rqstp->rq_addr; dr->argslen = rqstp->rq_arg.len >> 2; memcpy(dr->args, rqstp->rq_arg.head[0].iov_base-skip, dr->argslen<<2); } spin_lock_bh(&rqstp->rq_server->sv_lock); rqstp->rq_sock->sk_inuse++; dr->svsk = rqstp->rq_sock; spin_unlock_bh(&rqstp->rq_server->sv_lock); 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; rqstp->rq_addr = dr->addr; return dr->argslen<<2; } static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk) { struct svc_deferred_req *dr = NULL; struct svc_serv *serv = svsk->sk_server; if (!test_bit(SK_DEFERRED, &svsk->sk_flags)) return NULL; spin_lock_bh(&serv->sv_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_bh(&serv->sv_lock); return dr; }