/* * 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; 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... */ 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, .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, }; 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, }; /** * 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; }