diff options
Diffstat (limited to 'net/sunrpc/xprtsock.c')
| -rw-r--r-- | net/sunrpc/xprtsock.c | 1261 |
1 files changed, 1261 insertions, 0 deletions
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c new file mode 100644 index 000000000000..0a51fd46a848 --- /dev/null +++ b/net/sunrpc/xprtsock.c @@ -0,0 +1,1261 @@ +/* + * 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/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; + 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) + return; + + 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); +} + +/** + * 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; + default: + xprt_disconnect(xprt); + break; + } + 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); +} + +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; + + 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; + + /* 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... */ + 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(); + } +} + +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, + .connect = xs_connect, + .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, +}; + +static struct rpc_xprt_ops xs_tcp_ops = { + .reserve_xprt = xprt_reserve_xprt, + .release_xprt = xprt_release_xprt, + .connect = xs_connect, + .send_request = xs_tcp_send_request, + .set_retrans_timeout = xprt_set_retrans_timeout_def, + .close = xs_close, + .destroy = xs_destroy, +}; + +/** + * 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; +} |