--- /dev/null
+/*
+ * linux/net/sunrpc/xprtsock.c
+ *
+ * Client-side transport implementation for sockets.
+ *
+ * TCP callback races fixes (C) 1998 Red Hat Software <alan@redhat.com>
+ * TCP send fixes (C) 1998 Red Hat Software <alan@redhat.com>
+ * TCP NFS related read + write fixes
+ * (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
+ *
+ * Rewrite of larges part of the code in order to stabilize TCP stuff.
+ * Fix behaviour when socket buffer is full.
+ * (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
+ *
+ * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/capability.h>
+#include <linux/sched.h>
+#include <linux/pagemap.h>
+#include <linux/errno.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/net.h>
+#include <linux/mm.h>
+#include <linux/udp.h>
+#include <linux/tcp.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/sched.h>
+#include <linux/file.h>
+
+#include <net/sock.h>
+#include <net/checksum.h>
+#include <net/udp.h>
+#include <net/tcp.h>
+
+/*
+ * xprtsock tunables
+ */
+unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
+unsigned int xprt_tcp_slot_table_entries = RPC_DEF_SLOT_TABLE;
+
+unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
+unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
+
+/*
+ * How many times to try sending a request on a socket before waiting
+ * for the socket buffer to clear.
+ */
+#define XS_SENDMSG_RETRY (10U)
+
+/*
+ * Time out for an RPC UDP socket connect. UDP socket connects are
+ * synchronous, but we set a timeout anyway in case of resource
+ * exhaustion on the local host.
+ */
+#define XS_UDP_CONN_TO (5U * HZ)
+
+/*
+ * Wait duration for an RPC TCP connection to be established. Solaris
+ * NFS over TCP uses 60 seconds, for example, which is in line with how
+ * long a server takes to reboot.
+ */
+#define XS_TCP_CONN_TO (60U * HZ)
+
+/*
+ * Wait duration for a reply from the RPC portmapper.
+ */
+#define XS_BIND_TO (60U * HZ)
+
+/*
+ * Delay if a UDP socket connect error occurs. This is most likely some
+ * kind of resource problem on the local host.
+ */
+#define XS_UDP_REEST_TO (2U * HZ)
+
+/*
+ * The reestablish timeout allows clients to delay for a bit before attempting
+ * to reconnect to a server that just dropped our connection.
+ *
+ * We implement an exponential backoff when trying to reestablish a TCP
+ * transport connection with the server. Some servers like to drop a TCP
+ * connection when they are overworked, so we start with a short timeout and
+ * increase over time if the server is down or not responding.
+ */
+#define XS_TCP_INIT_REEST_TO (3U * HZ)
+#define XS_TCP_MAX_REEST_TO (5U * 60 * HZ)
+
+/*
+ * TCP idle timeout; client drops the transport socket if it is idle
+ * for this long. Note that we also timeout UDP sockets to prevent
+ * holding port numbers when there is no RPC traffic.
+ */
+#define XS_IDLE_DISC_TO (5U * 60 * HZ)
+
+#ifdef RPC_DEBUG
+# undef RPC_DEBUG_DATA
+# define RPCDBG_FACILITY RPCDBG_TRANS
+#endif
+
+#ifdef RPC_DEBUG_DATA
+static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
+{
+ u8 *buf = (u8 *) packet;
+ int j;
+
+ dprintk("RPC: %s\n", msg);
+ for (j = 0; j < count && j < 128; j += 4) {
+ if (!(j & 31)) {
+ if (j)
+ dprintk("\n");
+ dprintk("0x%04x ", j);
+ }
+ dprintk("%02x%02x%02x%02x ",
+ buf[j], buf[j+1], buf[j+2], buf[j+3]);
+ }
+ dprintk("\n");
+}
+#else
+static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
+{
+ /* NOP */
+}
+#endif
+
+#define XS_SENDMSG_FLAGS (MSG_DONTWAIT | MSG_NOSIGNAL)
+
+static inline int xs_send_head(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, unsigned int len)
+{
+ struct kvec iov = {
+ .iov_base = xdr->head[0].iov_base + base,
+ .iov_len = len - base,
+ };
+ struct msghdr msg = {
+ .msg_name = addr,
+ .msg_namelen = addrlen,
+ .msg_flags = XS_SENDMSG_FLAGS,
+ };
+
+ if (xdr->len > len)
+ msg.msg_flags |= MSG_MORE;
+
+ if (likely(iov.iov_len))
+ return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
+ return kernel_sendmsg(sock, &msg, NULL, 0, 0);
+}
+
+static int xs_send_tail(struct socket *sock, struct xdr_buf *xdr, unsigned int base, unsigned int len)
+{
+ struct kvec iov = {
+ .iov_base = xdr->tail[0].iov_base + base,
+ .iov_len = len - base,
+ };
+ struct msghdr msg = {
+ .msg_flags = XS_SENDMSG_FLAGS,
+ };
+
+ return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
+}
+
+/**
+ * xs_sendpages - write pages directly to a socket
+ * @sock: socket to send on
+ * @addr: UDP only -- address of destination
+ * @addrlen: UDP only -- length of destination address
+ * @xdr: buffer containing this request
+ * @base: starting position in the buffer
+ *
+ */
+static inline int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base)
+{
+ struct page **ppage = xdr->pages;
+ unsigned int len, pglen = xdr->page_len;
+ int err, ret = 0;
+ ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int);
+
+ if (unlikely(!sock))
+ return -ENOTCONN;
+
+ clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
+
+ len = xdr->head[0].iov_len;
+ if (base < len || (addr != NULL && base == 0)) {
+ err = xs_send_head(sock, addr, addrlen, xdr, base, len);
+ if (ret == 0)
+ ret = err;
+ else if (err > 0)
+ ret += err;
+ if (err != (len - base))
+ goto out;
+ base = 0;
+ } else
+ base -= len;
+
+ if (unlikely(pglen == 0))
+ goto copy_tail;
+ if (unlikely(base >= pglen)) {
+ base -= pglen;
+ goto copy_tail;
+ }
+ if (base || xdr->page_base) {
+ pglen -= base;
+ base += xdr->page_base;
+ ppage += base >> PAGE_CACHE_SHIFT;
+ base &= ~PAGE_CACHE_MASK;
+ }
+
+ sendpage = sock->ops->sendpage ? : sock_no_sendpage;
+ do {
+ int flags = XS_SENDMSG_FLAGS;
+
+ len = PAGE_CACHE_SIZE;
+ if (base)
+ len -= base;
+ if (pglen < len)
+ len = pglen;
+
+ if (pglen != len || xdr->tail[0].iov_len != 0)
+ flags |= MSG_MORE;
+
+ /* Hmm... We might be dealing with highmem pages */
+ if (PageHighMem(*ppage))
+ sendpage = sock_no_sendpage;
+ err = sendpage(sock, *ppage, base, len, flags);
+ if (ret == 0)
+ ret = err;
+ else if (err > 0)
+ ret += err;
+ if (err != len)
+ goto out;
+ base = 0;
+ ppage++;
+ } while ((pglen -= len) != 0);
+copy_tail:
+ len = xdr->tail[0].iov_len;
+ if (base < len) {
+ err = xs_send_tail(sock, xdr, base, len);
+ if (ret == 0)
+ ret = err;
+ else if (err > 0)
+ ret += err;
+ }
+out:
+ return ret;
+}
+
+/**
+ * xs_nospace - place task on wait queue if transmit was incomplete
+ * @task: task to put to sleep
+ *
+ */
+static void xs_nospace(struct rpc_task *task)
+{
+ struct rpc_rqst *req = task->tk_rqstp;
+ struct rpc_xprt *xprt = req->rq_xprt;
+
+ dprintk("RPC: %4d xmit incomplete (%u left of %u)\n",
+ task->tk_pid, req->rq_slen - req->rq_bytes_sent,
+ req->rq_slen);
+
+ if (test_bit(SOCK_ASYNC_NOSPACE, &xprt->sock->flags)) {
+ /* Protect against races with write_space */
+ spin_lock_bh(&xprt->transport_lock);
+
+ /* Don't race with disconnect */
+ if (!xprt_connected(xprt))
+ task->tk_status = -ENOTCONN;
+ else if (test_bit(SOCK_NOSPACE, &xprt->sock->flags))
+ xprt_wait_for_buffer_space(task);
+
+ spin_unlock_bh(&xprt->transport_lock);
+ } else
+ /* Keep holding the socket if it is blocked */
+ rpc_delay(task, HZ>>4);
+}
+
+/**
+ * xs_udp_send_request - write an RPC request to a UDP socket
+ * @task: address of RPC task that manages the state of an RPC request
+ *
+ * Return values:
+ * 0: The request has been sent
+ * EAGAIN: The socket was blocked, please call again later to
+ * complete the request
+ * ENOTCONN: Caller needs to invoke connect logic then call again
+ * other: Some other error occured, the request was not sent
+ */
+static int xs_udp_send_request(struct rpc_task *task)
+{
+ struct rpc_rqst *req = task->tk_rqstp;
+ struct rpc_xprt *xprt = req->rq_xprt;
+ struct xdr_buf *xdr = &req->rq_snd_buf;
+ int status;
+
+ xs_pktdump("packet data:",
+ req->rq_svec->iov_base,
+ req->rq_svec->iov_len);
+
+ req->rq_xtime = jiffies;
+ status = xs_sendpages(xprt->sock, (struct sockaddr *) &xprt->addr,
+ sizeof(xprt->addr), xdr, req->rq_bytes_sent);
+
+ dprintk("RPC: xs_udp_send_request(%u) = %d\n",
+ xdr->len - req->rq_bytes_sent, status);
+
+ if (likely(status >= (int) req->rq_slen))
+ return 0;
+
+ /* Still some bytes left; set up for a retry later. */
+ if (status > 0)
+ status = -EAGAIN;
+
+ switch (status) {
+ case -ENETUNREACH:
+ case -EPIPE:
+ case -ECONNREFUSED:
+ /* When the server has died, an ICMP port unreachable message
+ * prompts ECONNREFUSED. */
+ break;
+ case -EAGAIN:
+ xs_nospace(task);
+ break;
+ default:
+ dprintk("RPC: sendmsg returned unrecognized error %d\n",
+ -status);
+ break;
+ }
+
+ return status;
+}
+
+static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf)
+{
+ u32 reclen = buf->len - sizeof(rpc_fraghdr);
+ rpc_fraghdr *base = buf->head[0].iov_base;
+ *base = htonl(RPC_LAST_STREAM_FRAGMENT | reclen);
+}
+
+/**
+ * xs_tcp_send_request - write an RPC request to a TCP socket
+ * @task: address of RPC task that manages the state of an RPC request
+ *
+ * Return values:
+ * 0: The request has been sent
+ * EAGAIN: The socket was blocked, please call again later to
+ * complete the request
+ * ENOTCONN: Caller needs to invoke connect logic then call again
+ * other: Some other error occured, the request was not sent
+ *
+ * XXX: In the case of soft timeouts, should we eventually give up
+ * if sendmsg is not able to make progress?
+ */
+static int xs_tcp_send_request(struct rpc_task *task)
+{
+ struct rpc_rqst *req = task->tk_rqstp;
+ struct rpc_xprt *xprt = req->rq_xprt;
+ struct xdr_buf *xdr = &req->rq_snd_buf;
+ int status, retry = 0;
+
+ xs_encode_tcp_record_marker(&req->rq_snd_buf);
+
+ xs_pktdump("packet data:",
+ req->rq_svec->iov_base,
+ req->rq_svec->iov_len);
+
+ /* Continue transmitting the packet/record. We must be careful
+ * to cope with writespace callbacks arriving _after_ we have
+ * called sendmsg(). */
+ while (1) {
+ req->rq_xtime = jiffies;
+ status = xs_sendpages(xprt->sock, NULL, 0, xdr,
+ req->rq_bytes_sent);
+
+ dprintk("RPC: xs_tcp_send_request(%u) = %d\n",
+ xdr->len - req->rq_bytes_sent, status);
+
+ if (unlikely(status < 0))
+ break;
+
+ /* If we've sent the entire packet, immediately
+ * reset the count of bytes sent. */
+ req->rq_bytes_sent += status;
+ task->tk_bytes_sent += status;
+ if (likely(req->rq_bytes_sent >= req->rq_slen)) {
+ req->rq_bytes_sent = 0;
+ return 0;
+ }
+
+ status = -EAGAIN;
+ if (retry++ > XS_SENDMSG_RETRY)
+ break;
+ }
+
+ switch (status) {
+ case -EAGAIN:
+ xs_nospace(task);
+ break;
+ case -ECONNREFUSED:
+ case -ECONNRESET:
+ case -ENOTCONN:
+ case -EPIPE:
+ status = -ENOTCONN;
+ break;
+ default:
+ dprintk("RPC: sendmsg returned unrecognized error %d\n",
+ -status);
+ xprt_disconnect(xprt);
+ break;
+ }
+
+ return status;
+}
+
+/**
+ * xs_close - close a socket
+ * @xprt: transport
+ *
+ * This is used when all requests are complete; ie, no DRC state remains
+ * on the server we want to save.
+ */
+static void xs_close(struct rpc_xprt *xprt)
+{
+ struct socket *sock = xprt->sock;
+ struct sock *sk = xprt->inet;
+
+ if (!sk)
+ goto clear_close_wait;
+
+ dprintk("RPC: xs_close xprt %p\n", xprt);
+
+ write_lock_bh(&sk->sk_callback_lock);
+ xprt->inet = NULL;
+ xprt->sock = NULL;
+
+ sk->sk_user_data = NULL;
+ sk->sk_data_ready = xprt->old_data_ready;
+ sk->sk_state_change = xprt->old_state_change;
+ sk->sk_write_space = xprt->old_write_space;
+ write_unlock_bh(&sk->sk_callback_lock);
+
+ sk->sk_no_check = 0;
+
+ sock_release(sock);
+clear_close_wait:
+ smp_mb__before_clear_bit();
+ clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
+ smp_mb__after_clear_bit();
+}
+
+/**
+ * xs_destroy - prepare to shutdown a transport
+ * @xprt: doomed transport
+ *
+ */
+static void xs_destroy(struct rpc_xprt *xprt)
+{
+ dprintk("RPC: xs_destroy xprt %p\n", xprt);
+
+ cancel_delayed_work(&xprt->connect_worker);
+ flush_scheduled_work();
+
+ xprt_disconnect(xprt);
+ xs_close(xprt);
+ kfree(xprt->slot);
+}
+
+static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
+{
+ return (struct rpc_xprt *) sk->sk_user_data;
+}
+
+/**
+ * xs_udp_data_ready - "data ready" callback for UDP sockets
+ * @sk: socket with data to read
+ * @len: how much data to read
+ *
+ */
+static void xs_udp_data_ready(struct sock *sk, int len)
+{
+ struct rpc_task *task;
+ struct rpc_xprt *xprt;
+ struct rpc_rqst *rovr;
+ struct sk_buff *skb;
+ int err, repsize, copied;
+ u32 _xid, *xp;
+
+ read_lock(&sk->sk_callback_lock);
+ dprintk("RPC: xs_udp_data_ready...\n");
+ if (!(xprt = xprt_from_sock(sk)))
+ goto out;
+
+ if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
+ goto out;
+
+ if (xprt->shutdown)
+ goto dropit;
+
+ repsize = skb->len - sizeof(struct udphdr);
+ if (repsize < 4) {
+ dprintk("RPC: impossible RPC reply size %d!\n", repsize);
+ goto dropit;
+ }
+
+ /* Copy the XID from the skb... */
+ xp = skb_header_pointer(skb, sizeof(struct udphdr),
+ sizeof(_xid), &_xid);
+ if (xp == NULL)
+ goto dropit;
+
+ /* Look up and lock the request corresponding to the given XID */
+ spin_lock(&xprt->transport_lock);
+ rovr = xprt_lookup_rqst(xprt, *xp);
+ if (!rovr)
+ goto out_unlock;
+ task = rovr->rq_task;
+
+ if ((copied = rovr->rq_private_buf.buflen) > repsize)
+ copied = repsize;
+
+ /* Suck it into the iovec, verify checksum if not done by hw. */
+ if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb))
+ goto out_unlock;
+
+ /* Something worked... */
+ dst_confirm(skb->dst);
+
+ xprt_adjust_cwnd(task, copied);
+ xprt_update_rtt(task);
+ xprt_complete_rqst(task, copied);
+
+ out_unlock:
+ spin_unlock(&xprt->transport_lock);
+ dropit:
+ skb_free_datagram(sk, skb);
+ out:
+ read_unlock(&sk->sk_callback_lock);
+}
+
+static inline size_t xs_tcp_copy_data(skb_reader_t *desc, void *p, size_t len)
+{
+ if (len > desc->count)
+ len = desc->count;
+ if (skb_copy_bits(desc->skb, desc->offset, p, len)) {
+ dprintk("RPC: failed to copy %zu bytes from skb. %zu bytes remain\n",
+ len, desc->count);
+ return 0;
+ }
+ desc->offset += len;
+ desc->count -= len;
+ dprintk("RPC: copied %zu bytes from skb. %zu bytes remain\n",
+ len, desc->count);
+ return len;
+}
+
+static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, skb_reader_t *desc)
+{
+ size_t len, used;
+ char *p;
+
+ p = ((char *) &xprt->tcp_recm) + xprt->tcp_offset;
+ len = sizeof(xprt->tcp_recm) - xprt->tcp_offset;
+ used = xs_tcp_copy_data(desc, p, len);
+ xprt->tcp_offset += used;
+ if (used != len)
+ return;
+
+ xprt->tcp_reclen = ntohl(xprt->tcp_recm);
+ if (xprt->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
+ xprt->tcp_flags |= XPRT_LAST_FRAG;
+ else
+ xprt->tcp_flags &= ~XPRT_LAST_FRAG;
+ xprt->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
+
+ xprt->tcp_flags &= ~XPRT_COPY_RECM;
+ xprt->tcp_offset = 0;
+
+ /* Sanity check of the record length */
+ if (unlikely(xprt->tcp_reclen < 4)) {
+ dprintk("RPC: invalid TCP record fragment length\n");
+ xprt_disconnect(xprt);
+ return;
+ }
+ dprintk("RPC: reading TCP record fragment of length %d\n",
+ xprt->tcp_reclen);
+}
+
+static void xs_tcp_check_recm(struct rpc_xprt *xprt)
+{
+ dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u, tcp_flags = %lx\n",
+ xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen, xprt->tcp_flags);
+ if (xprt->tcp_offset == xprt->tcp_reclen) {
+ xprt->tcp_flags |= XPRT_COPY_RECM;
+ xprt->tcp_offset = 0;
+ if (xprt->tcp_flags & XPRT_LAST_FRAG) {
+ xprt->tcp_flags &= ~XPRT_COPY_DATA;
+ xprt->tcp_flags |= XPRT_COPY_XID;
+ xprt->tcp_copied = 0;
+ }
+ }
+}
+
+static inline void xs_tcp_read_xid(struct rpc_xprt *xprt, skb_reader_t *desc)
+{
+ size_t len, used;
+ char *p;
+
+ len = sizeof(xprt->tcp_xid) - xprt->tcp_offset;
+ dprintk("RPC: reading XID (%Zu bytes)\n", len);
+ p = ((char *) &xprt->tcp_xid) + xprt->tcp_offset;
+ used = xs_tcp_copy_data(desc, p, len);
+ xprt->tcp_offset += used;
+ if (used != len)
+ return;
+ xprt->tcp_flags &= ~XPRT_COPY_XID;
+ xprt->tcp_flags |= XPRT_COPY_DATA;
+ xprt->tcp_copied = 4;
+ dprintk("RPC: reading reply for XID %08x\n",
+ ntohl(xprt->tcp_xid));
+ xs_tcp_check_recm(xprt);
+}
+
+static inline void xs_tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc)
+{
+ struct rpc_rqst *req;
+ struct xdr_buf *rcvbuf;
+ size_t len;
+ ssize_t r;
+
+ /* Find and lock the request corresponding to this xid */
+ spin_lock(&xprt->transport_lock);
+ req = xprt_lookup_rqst(xprt, xprt->tcp_xid);
+ if (!req) {
+ xprt->tcp_flags &= ~XPRT_COPY_DATA;
+ dprintk("RPC: XID %08x request not found!\n",
+ ntohl(xprt->tcp_xid));
+ spin_unlock(&xprt->transport_lock);
+ return;
+ }
+
+ rcvbuf = &req->rq_private_buf;
+ len = desc->count;
+ if (len > xprt->tcp_reclen - xprt->tcp_offset) {
+ skb_reader_t my_desc;
+
+ len = xprt->tcp_reclen - xprt->tcp_offset;
+ memcpy(&my_desc, desc, sizeof(my_desc));
+ my_desc.count = len;
+ r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
+ &my_desc, xs_tcp_copy_data);
+ desc->count -= r;
+ desc->offset += r;
+ } else
+ r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
+ desc, xs_tcp_copy_data);
+
+ if (r > 0) {
+ xprt->tcp_copied += r;
+ xprt->tcp_offset += r;
+ }
+ if (r != len) {
+ /* Error when copying to the receive buffer,
+ * usually because we weren't able to allocate
+ * additional buffer pages. All we can do now
+ * is turn off XPRT_COPY_DATA, so the request
+ * will not receive any additional updates,
+ * and time out.
+ * Any remaining data from this record will
+ * be discarded.
+ */
+ xprt->tcp_flags &= ~XPRT_COPY_DATA;
+ dprintk("RPC: XID %08x truncated request\n",
+ ntohl(xprt->tcp_xid));
+ dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n",
+ xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen);
+ goto out;
+ }
+
+ dprintk("RPC: XID %08x read %Zd bytes\n",
+ ntohl(xprt->tcp_xid), r);
+ dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n",
+ xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen);
+
+ if (xprt->tcp_copied == req->rq_private_buf.buflen)
+ xprt->tcp_flags &= ~XPRT_COPY_DATA;
+ else if (xprt->tcp_offset == xprt->tcp_reclen) {
+ if (xprt->tcp_flags & XPRT_LAST_FRAG)
+ xprt->tcp_flags &= ~XPRT_COPY_DATA;
+ }
+
+out:
+ if (!(xprt->tcp_flags & XPRT_COPY_DATA))
+ xprt_complete_rqst(req->rq_task, xprt->tcp_copied);
+ spin_unlock(&xprt->transport_lock);
+ xs_tcp_check_recm(xprt);
+}
+
+static inline void xs_tcp_read_discard(struct rpc_xprt *xprt, skb_reader_t *desc)
+{
+ size_t len;
+
+ len = xprt->tcp_reclen - xprt->tcp_offset;
+ if (len > desc->count)
+ len = desc->count;
+ desc->count -= len;
+ desc->offset += len;
+ xprt->tcp_offset += len;
+ dprintk("RPC: discarded %Zu bytes\n", len);
+ xs_tcp_check_recm(xprt);
+}
+
+static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
+{
+ struct rpc_xprt *xprt = rd_desc->arg.data;
+ skb_reader_t desc = {
+ .skb = skb,
+ .offset = offset,
+ .count = len,
+ .csum = 0
+ };
+
+ dprintk("RPC: xs_tcp_data_recv started\n");
+ do {
+ /* Read in a new fragment marker if necessary */
+ /* Can we ever really expect to get completely empty fragments? */
+ if (xprt->tcp_flags & XPRT_COPY_RECM) {
+ xs_tcp_read_fraghdr(xprt, &desc);
+ continue;
+ }
+ /* Read in the xid if necessary */
+ if (xprt->tcp_flags & XPRT_COPY_XID) {
+ xs_tcp_read_xid(xprt, &desc);
+ continue;
+ }
+ /* Read in the request data */
+ if (xprt->tcp_flags & XPRT_COPY_DATA) {
+ xs_tcp_read_request(xprt, &desc);
+ continue;
+ }
+ /* Skip over any trailing bytes on short reads */
+ xs_tcp_read_discard(xprt, &desc);
+ } while (desc.count);
+ dprintk("RPC: xs_tcp_data_recv done\n");
+ return len - desc.count;
+}
+
+/**
+ * xs_tcp_data_ready - "data ready" callback for TCP sockets
+ * @sk: socket with data to read
+ * @bytes: how much data to read
+ *
+ */
+static void xs_tcp_data_ready(struct sock *sk, int bytes)
+{
+ struct rpc_xprt *xprt;
+ read_descriptor_t rd_desc;
+
+ read_lock(&sk->sk_callback_lock);
+ dprintk("RPC: xs_tcp_data_ready...\n");
+ if (!(xprt = xprt_from_sock(sk)))
+ goto out;
+ if (xprt->shutdown)
+ goto out;
+
+ /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
+ rd_desc.arg.data = xprt;
+ rd_desc.count = 65536;
+ tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
+out:
+ read_unlock(&sk->sk_callback_lock);
+}
+
+/**
+ * xs_tcp_state_change - callback to handle TCP socket state changes
+ * @sk: socket whose state has changed
+ *
+ */
+static void xs_tcp_state_change(struct sock *sk)
+{
+ struct rpc_xprt *xprt;
+
+ read_lock(&sk->sk_callback_lock);
+ if (!(xprt = xprt_from_sock(sk)))
+ goto out;
+ dprintk("RPC: xs_tcp_state_change client %p...\n", xprt);
+ dprintk("RPC: state %x conn %d dead %d zapped %d\n",
+ sk->sk_state, xprt_connected(xprt),
+ sock_flag(sk, SOCK_DEAD),
+ sock_flag(sk, SOCK_ZAPPED));
+
+ switch (sk->sk_state) {
+ case TCP_ESTABLISHED:
+ spin_lock_bh(&xprt->transport_lock);
+ if (!xprt_test_and_set_connected(xprt)) {
+ /* Reset TCP record info */
+ xprt->tcp_offset = 0;
+ xprt->tcp_reclen = 0;
+ xprt->tcp_copied = 0;
+ xprt->tcp_flags = XPRT_COPY_RECM | XPRT_COPY_XID;
+ xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
+ xprt_wake_pending_tasks(xprt, 0);
+ }
+ spin_unlock_bh(&xprt->transport_lock);
+ break;
+ case TCP_SYN_SENT:
+ case TCP_SYN_RECV:
+ break;
+ case TCP_CLOSE_WAIT:
+ /* Try to schedule an autoclose RPC calls */
+ set_bit(XPRT_CLOSE_WAIT, &xprt->state);
+ if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
+ schedule_work(&xprt->task_cleanup);
+ default:
+ xprt_disconnect(xprt);
+ }
+ out:
+ read_unlock(&sk->sk_callback_lock);
+}
+
+/**
+ * xs_udp_write_space - callback invoked when socket buffer space
+ * becomes available
+ * @sk: socket whose state has changed
+ *
+ * Called when more output buffer space is available for this socket.
+ * We try not to wake our writers until they can make "significant"
+ * progress, otherwise we'll waste resources thrashing kernel_sendmsg
+ * with a bunch of small requests.
+ */
+static void xs_udp_write_space(struct sock *sk)
+{
+ read_lock(&sk->sk_callback_lock);
+
+ /* from net/core/sock.c:sock_def_write_space */
+ if (sock_writeable(sk)) {
+ struct socket *sock;
+ struct rpc_xprt *xprt;
+
+ if (unlikely(!(sock = sk->sk_socket)))
+ goto out;
+ if (unlikely(!(xprt = xprt_from_sock(sk))))
+ goto out;
+ if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags)))
+ goto out;
+
+ xprt_write_space(xprt);
+ }
+
+ out:
+ read_unlock(&sk->sk_callback_lock);
+}
+
+/**
+ * xs_tcp_write_space - callback invoked when socket buffer space
+ * becomes available
+ * @sk: socket whose state has changed
+ *
+ * Called when more output buffer space is available for this socket.
+ * We try not to wake our writers until they can make "significant"
+ * progress, otherwise we'll waste resources thrashing kernel_sendmsg
+ * with a bunch of small requests.
+ */
+static void xs_tcp_write_space(struct sock *sk)
+{
+ read_lock(&sk->sk_callback_lock);
+
+ /* from net/core/stream.c:sk_stream_write_space */
+ if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
+ struct socket *sock;
+ struct rpc_xprt *xprt;
+
+ if (unlikely(!(sock = sk->sk_socket)))
+ goto out;
+ if (unlikely(!(xprt = xprt_from_sock(sk))))
+ goto out;
+ if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags)))
+ goto out;
+
+ xprt_write_space(xprt);
+ }
+
+ out:
+ read_unlock(&sk->sk_callback_lock);
+}
+
+static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
+{
+ struct sock *sk = xprt->inet;
+
+ if (xprt->rcvsize) {
+ sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
+ sk->sk_rcvbuf = xprt->rcvsize * xprt->max_reqs * 2;
+ }
+ if (xprt->sndsize) {
+ sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
+ sk->sk_sndbuf = xprt->sndsize * xprt->max_reqs * 2;
+ sk->sk_write_space(sk);
+ }
+}
+
+/**
+ * xs_udp_set_buffer_size - set send and receive limits
+ * @xprt: generic transport
+ * @sndsize: requested size of send buffer, in bytes
+ * @rcvsize: requested size of receive buffer, in bytes
+ *
+ * Set socket send and receive buffer size limits.
+ */
+static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
+{
+ xprt->sndsize = 0;
+ if (sndsize)
+ xprt->sndsize = sndsize + 1024;
+ xprt->rcvsize = 0;
+ if (rcvsize)
+ xprt->rcvsize = rcvsize + 1024;
+
+ xs_udp_do_set_buffer_size(xprt);
+}
+
+/**
+ * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
+ * @task: task that timed out
+ *
+ * Adjust the congestion window after a retransmit timeout has occurred.
+ */
+static void xs_udp_timer(struct rpc_task *task)
+{
+ xprt_adjust_cwnd(task, -ETIMEDOUT);
+}
+
+/**
+ * xs_set_port - reset the port number in the remote endpoint address
+ * @xprt: generic transport
+ * @port: new port number
+ *
+ */
+static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
+{
+ dprintk("RPC: setting port for xprt %p to %u\n", xprt, port);
+ xprt->addr.sin_port = htons(port);
+}
+
+static int xs_bindresvport(struct rpc_xprt *xprt, struct socket *sock)
+{
+ struct sockaddr_in myaddr = {
+ .sin_family = AF_INET,
+ };
+ int err;
+ unsigned short port = xprt->port;
+
+ do {
+ myaddr.sin_port = htons(port);
+ err = sock->ops->bind(sock, (struct sockaddr *) &myaddr,
+ sizeof(myaddr));
+ if (err == 0) {
+ xprt->port = port;
+ dprintk("RPC: xs_bindresvport bound to port %u\n",
+ port);
+ return 0;
+ }
+ if (port <= xprt_min_resvport)
+ port = xprt_max_resvport;
+ else
+ port--;
+ } while (err == -EADDRINUSE && port != xprt->port);
+
+ dprintk("RPC: can't bind to reserved port (%d).\n", -err);
+ return err;
+}
+
+/**
+ * xs_udp_connect_worker - set up a UDP socket
+ * @args: RPC transport to connect
+ *
+ * Invoked by a work queue tasklet.
+ */
+static void xs_udp_connect_worker(void *args)
+{
+ struct rpc_xprt *xprt = (struct rpc_xprt *) args;
+ struct socket *sock = xprt->sock;
+ int err, status = -EIO;
+
+ if (xprt->shutdown || xprt->addr.sin_port == 0)
+ goto out;
+
+ dprintk("RPC: xs_udp_connect_worker for xprt %p\n", xprt);
+
+ /* Start by resetting any existing state */
+ xs_close(xprt);
+
+ if ((err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) {
+ dprintk("RPC: can't create UDP transport socket (%d).\n", -err);
+ goto out;
+ }
+
+ if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) {
+ sock_release(sock);
+ goto out;
+ }
+
+ if (!xprt->inet) {
+ struct sock *sk = sock->sk;
+
+ write_lock_bh(&sk->sk_callback_lock);
+
+ sk->sk_user_data = xprt;
+ xprt->old_data_ready = sk->sk_data_ready;
+ xprt->old_state_change = sk->sk_state_change;
+ xprt->old_write_space = sk->sk_write_space;
+ sk->sk_data_ready = xs_udp_data_ready;
+ sk->sk_write_space = xs_udp_write_space;
+ sk->sk_no_check = UDP_CSUM_NORCV;
+ sk->sk_allocation = GFP_ATOMIC;
+
+ xprt_set_connected(xprt);
+
+ /* Reset to new socket */
+ xprt->sock = sock;
+ xprt->inet = sk;
+
+ write_unlock_bh(&sk->sk_callback_lock);
+ }
+ xs_udp_do_set_buffer_size(xprt);
+ status = 0;
+out:
+ xprt_wake_pending_tasks(xprt, status);
+ xprt_clear_connecting(xprt);
+}
+
+/*
+ * We need to preserve the port number so the reply cache on the server can
+ * find our cached RPC replies when we get around to reconnecting.
+ */
+static void xs_tcp_reuse_connection(struct rpc_xprt *xprt)
+{
+ int result;
+ struct socket *sock = xprt->sock;
+ struct sockaddr any;
+
+ dprintk("RPC: disconnecting xprt %p to reuse port\n", xprt);
+
+ /*
+ * Disconnect the transport socket by doing a connect operation
+ * with AF_UNSPEC. This should return immediately...
+ */
+ memset(&any, 0, sizeof(any));
+ any.sa_family = AF_UNSPEC;
+ result = sock->ops->connect(sock, &any, sizeof(any), 0);
+ if (result)
+ dprintk("RPC: AF_UNSPEC connect return code %d\n",
+ result);
+}
+
+/**
+ * xs_tcp_connect_worker - connect a TCP socket to a remote endpoint
+ * @args: RPC transport to connect
+ *
+ * Invoked by a work queue tasklet.
+ */
+static void xs_tcp_connect_worker(void *args)
+{
+ struct rpc_xprt *xprt = (struct rpc_xprt *)args;
+ struct socket *sock = xprt->sock;
+ int err, status = -EIO;
+
+ if (xprt->shutdown || xprt->addr.sin_port == 0)
+ goto out;
+
+ dprintk("RPC: xs_tcp_connect_worker for xprt %p\n", xprt);
+
+ if (!xprt->sock) {
+ /* start from scratch */
+ if ((err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
+ dprintk("RPC: can't create TCP transport socket (%d).\n", -err);
+ goto out;
+ }
+
+ if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) {
+ sock_release(sock);
+ goto out;
+ }
+ } else
+ /* "close" the socket, preserving the local port */
+ xs_tcp_reuse_connection(xprt);
+
+ if (!xprt->inet) {
+ struct sock *sk = sock->sk;
+
+ write_lock_bh(&sk->sk_callback_lock);
+
+ sk->sk_user_data = xprt;
+ xprt->old_data_ready = sk->sk_data_ready;
+ xprt->old_state_change = sk->sk_state_change;
+ xprt->old_write_space = sk->sk_write_space;
+ sk->sk_data_ready = xs_tcp_data_ready;
+ sk->sk_state_change = xs_tcp_state_change;
+ sk->sk_write_space = xs_tcp_write_space;
+ sk->sk_allocation = GFP_ATOMIC;
+
+ /* socket options */
+ sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
+ sock_reset_flag(sk, SOCK_LINGER);
+ tcp_sk(sk)->linger2 = 0;
+ tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
+
+ xprt_clear_connected(xprt);
+
+ /* Reset to new socket */
+ xprt->sock = sock;
+ xprt->inet = sk;
+
+ write_unlock_bh(&sk->sk_callback_lock);
+ }
+
+ /* Tell the socket layer to start connecting... */
+ xprt->stat.connect_count++;
+ xprt->stat.connect_start = jiffies;
+ status = sock->ops->connect(sock, (struct sockaddr *) &xprt->addr,
+ sizeof(xprt->addr), O_NONBLOCK);
+ dprintk("RPC: %p connect status %d connected %d sock state %d\n",
+ xprt, -status, xprt_connected(xprt), sock->sk->sk_state);
+ if (status < 0) {
+ switch (status) {
+ case -EINPROGRESS:
+ case -EALREADY:
+ goto out_clear;
+ case -ECONNREFUSED:
+ case -ECONNRESET:
+ /* retry with existing socket, after a delay */
+ break;
+ default:
+ /* get rid of existing socket, and retry */
+ xs_close(xprt);
+ break;
+ }
+ }
+out:
+ xprt_wake_pending_tasks(xprt, status);
+out_clear:
+ xprt_clear_connecting(xprt);
+}
+
+/**
+ * xs_connect - connect a socket to a remote endpoint
+ * @task: address of RPC task that manages state of connect request
+ *
+ * TCP: If the remote end dropped the connection, delay reconnecting.
+ *
+ * UDP socket connects are synchronous, but we use a work queue anyway
+ * to guarantee that even unprivileged user processes can set up a
+ * socket on a privileged port.
+ *
+ * If a UDP socket connect fails, the delay behavior here prevents
+ * retry floods (hard mounts).
+ */
+static void xs_connect(struct rpc_task *task)
+{
+ struct rpc_xprt *xprt = task->tk_xprt;
+
+ if (xprt_test_and_set_connecting(xprt))
+ return;
+
+ if (xprt->sock != NULL) {
+ dprintk("RPC: xs_connect delayed xprt %p for %lu seconds\n",
+ xprt, xprt->reestablish_timeout / HZ);
+ schedule_delayed_work(&xprt->connect_worker,
+ xprt->reestablish_timeout);
+ xprt->reestablish_timeout <<= 1;
+ if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
+ xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
+ } else {
+ dprintk("RPC: xs_connect scheduled xprt %p\n", xprt);
+ schedule_work(&xprt->connect_worker);
+
+ /* flush_scheduled_work can sleep... */
+ if (!RPC_IS_ASYNC(task))
+ flush_scheduled_work();
+ }
+}
+
+/**
+ * xs_udp_print_stats - display UDP socket-specifc stats
+ * @xprt: rpc_xprt struct containing statistics
+ * @seq: output file
+ *
+ */
+static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
+{
+ seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %Lu %Lu\n",
+ xprt->port,
+ xprt->stat.bind_count,
+ xprt->stat.sends,
+ xprt->stat.recvs,
+ xprt->stat.bad_xids,
+ xprt->stat.req_u,
+ xprt->stat.bklog_u);
+}
+
+/**
+ * xs_tcp_print_stats - display TCP socket-specifc stats
+ * @xprt: rpc_xprt struct containing statistics
+ * @seq: output file
+ *
+ */
+static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
+{
+ long idle_time = 0;
+
+ if (xprt_connected(xprt))
+ idle_time = (long)(jiffies - xprt->last_used) / HZ;
+
+ seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu\n",
+ xprt->port,
+ xprt->stat.bind_count,
+ xprt->stat.connect_count,
+ xprt->stat.connect_time,
+ idle_time,
+ xprt->stat.sends,
+ xprt->stat.recvs,
+ xprt->stat.bad_xids,
+ xprt->stat.req_u,
+ xprt->stat.bklog_u);
+}
+
+static struct rpc_xprt_ops xs_udp_ops = {
+ .set_buffer_size = xs_udp_set_buffer_size,
+ .reserve_xprt = xprt_reserve_xprt_cong,
+ .release_xprt = xprt_release_xprt_cong,
+ .set_port = xs_set_port,
+ .connect = xs_connect,
+ .buf_alloc = rpc_malloc,
+ .buf_free = rpc_free,
+ .send_request = xs_udp_send_request,
+ .set_retrans_timeout = xprt_set_retrans_timeout_rtt,
+ .timer = xs_udp_timer,
+ .release_request = xprt_release_rqst_cong,
+ .close = xs_close,
+ .destroy = xs_destroy,
+ .print_stats = xs_udp_print_stats,
+};
+
+static struct rpc_xprt_ops xs_tcp_ops = {
+ .reserve_xprt = xprt_reserve_xprt,
+ .release_xprt = xprt_release_xprt,
+ .set_port = xs_set_port,
+ .connect = xs_connect,
+ .buf_alloc = rpc_malloc,
+ .buf_free = rpc_free,
+ .send_request = xs_tcp_send_request,
+ .set_retrans_timeout = xprt_set_retrans_timeout_def,
+ .close = xs_close,
+ .destroy = xs_destroy,
+ .print_stats = xs_tcp_print_stats,
+};
+
+/**
+ * xs_setup_udp - Set up transport to use a UDP socket
+ * @xprt: transport to set up
+ * @to: timeout parameters
+ *
+ */
+int xs_setup_udp(struct rpc_xprt *xprt, struct rpc_timeout *to)
+{
+ size_t slot_table_size;
+
+ dprintk("RPC: setting up udp-ipv4 transport...\n");
+
+ xprt->max_reqs = xprt_udp_slot_table_entries;
+ slot_table_size = xprt->max_reqs * sizeof(xprt->slot[0]);
+ xprt->slot = kmalloc(slot_table_size, GFP_KERNEL);
+ if (xprt->slot == NULL)
+ return -ENOMEM;
+ memset(xprt->slot, 0, slot_table_size);
+
+ xprt->prot = IPPROTO_UDP;
+ xprt->port = xprt_max_resvport;
+ xprt->tsh_size = 0;
+ xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
+ /* XXX: header size can vary due to auth type, IPv6, etc. */
+ xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
+
+ INIT_WORK(&xprt->connect_worker, xs_udp_connect_worker, xprt);
+ xprt->bind_timeout = XS_BIND_TO;
+ xprt->connect_timeout = XS_UDP_CONN_TO;
+ xprt->reestablish_timeout = XS_UDP_REEST_TO;
+ xprt->idle_timeout = XS_IDLE_DISC_TO;
+
+ xprt->ops = &xs_udp_ops;
+
+ if (to)
+ xprt->timeout = *to;
+ else
+ xprt_set_timeout(&xprt->timeout, 5, 5 * HZ);
+
+ return 0;
+}
+
+/**
+ * xs_setup_tcp - Set up transport to use a TCP socket
+ * @xprt: transport to set up
+ * @to: timeout parameters
+ *
+ */
+int xs_setup_tcp(struct rpc_xprt *xprt, struct rpc_timeout *to)
+{
+ size_t slot_table_size;
+
+ dprintk("RPC: setting up tcp-ipv4 transport...\n");
+
+ xprt->max_reqs = xprt_tcp_slot_table_entries;
+ slot_table_size = xprt->max_reqs * sizeof(xprt->slot[0]);
+ xprt->slot = kmalloc(slot_table_size, GFP_KERNEL);
+ if (xprt->slot == NULL)
+ return -ENOMEM;
+ memset(xprt->slot, 0, slot_table_size);
+
+ xprt->prot = IPPROTO_TCP;
+ xprt->port = xprt_max_resvport;
+ xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
+ xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
+ xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
+
+ INIT_WORK(&xprt->connect_worker, xs_tcp_connect_worker, xprt);
+ xprt->bind_timeout = XS_BIND_TO;
+ xprt->connect_timeout = XS_TCP_CONN_TO;
+ xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
+ xprt->idle_timeout = XS_IDLE_DISC_TO;
+
+ xprt->ops = &xs_tcp_ops;
+
+ if (to)
+ xprt->timeout = *to;
+ else
+ xprt_set_timeout(&xprt->timeout, 2, 60 * HZ);
+
+ return 0;
+}
git://git.onelab.eu / linux-2.6.git / blobdiff