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xprtsock.c
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xprtsock.c
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/*
* linux/net/sunrpc/xprtsock.c
*
* Client-side transport implementation for sockets.
*
* TCP callback races fixes (C) 1998 Red Hat Software <[email protected]>
* TCP send fixes (C) 1998 Red Hat Software <[email protected]>
* TCP NFS related read + write fixes
* (C) 1999 Dave Airlie, University of Limerick, Ireland <[email protected]>
*
* Rewrite of larges part of the code in order to stabilize TCP stuff.
* Fix behaviour when socket buffer is full.
* (C) 1999 Trond Myklebust <[email protected]>
*
* IP socket transport implementation, (C) 2005 Chuck Lever <[email protected]>
*
* IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
*/
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/capability.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/sunrpc/xprtsock.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;
/*
* We can register our own files under /proc/sys/sunrpc by
* calling register_sysctl_table() again. The files in that
* directory become the union of all files registered there.
*
* We simply need to make sure that we don't collide with
* someone else's file names!
*/
#ifdef RPC_DEBUG
static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
static struct ctl_table_header *sunrpc_table_header;
/*
* FIXME: changing the UDP slot table size should also resize the UDP
* socket buffers for existing UDP transports
*/
static ctl_table xs_tunables_table[] = {
{
.ctl_name = CTL_SLOTTABLE_UDP,
.procname = "udp_slot_table_entries",
.data = &xprt_udp_slot_table_entries,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec_minmax,
.strategy = &sysctl_intvec,
.extra1 = &min_slot_table_size,
.extra2 = &max_slot_table_size
},
{
.ctl_name = CTL_SLOTTABLE_TCP,
.procname = "tcp_slot_table_entries",
.data = &xprt_tcp_slot_table_entries,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec_minmax,
.strategy = &sysctl_intvec,
.extra1 = &min_slot_table_size,
.extra2 = &max_slot_table_size
},
{
.ctl_name = CTL_MIN_RESVPORT,
.procname = "min_resvport",
.data = &xprt_min_resvport,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec_minmax,
.strategy = &sysctl_intvec,
.extra1 = &xprt_min_resvport_limit,
.extra2 = &xprt_max_resvport_limit
},
{
.ctl_name = CTL_MAX_RESVPORT,
.procname = "max_resvport",
.data = &xprt_max_resvport,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec_minmax,
.strategy = &sysctl_intvec,
.extra1 = &xprt_min_resvport_limit,
.extra2 = &xprt_max_resvport_limit
},
{
.ctl_name = 0,
},
};
static ctl_table sunrpc_table[] = {
{
.ctl_name = CTL_SUNRPC,
.procname = "sunrpc",
.mode = 0555,
.child = xs_tunables_table
},
{
.ctl_name = 0,
},
};
#endif
/*
* 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
struct sock_xprt {
struct rpc_xprt xprt;
/*
* Network layer
*/
struct socket * sock;
struct sock * inet;
/*
* State of TCP reply receive
*/
__be32 tcp_fraghdr,
tcp_xid;
u32 tcp_offset,
tcp_reclen;
unsigned long tcp_copied,
tcp_flags;
/*
* Connection of transports
*/
struct delayed_work connect_worker;
struct sockaddr_storage addr;
unsigned short port;
/*
* UDP socket buffer size parameters
*/
size_t rcvsize,
sndsize;
/*
* Saved socket callback addresses
*/
void (*old_data_ready)(struct sock *, int);
void (*old_state_change)(struct sock *);
void (*old_write_space)(struct sock *);
};
/*
* TCP receive state flags
*/
#define TCP_RCV_LAST_FRAG (1UL << 0)
#define TCP_RCV_COPY_FRAGHDR (1UL << 1)
#define TCP_RCV_COPY_XID (1UL << 2)
#define TCP_RCV_COPY_DATA (1UL << 3)
static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
{
return (struct sockaddr *) &xprt->addr;
}
static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
{
return (struct sockaddr_in *) &xprt->addr;
}
static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
{
return (struct sockaddr_in6 *) &xprt->addr;
}
static void xs_format_ipv4_peer_addresses(struct rpc_xprt *xprt,
const char *protocol,
const char *netid)
{
struct sockaddr_in *addr = xs_addr_in(xprt);
char *buf;
buf = kzalloc(20, GFP_KERNEL);
if (buf) {
snprintf(buf, 20, NIPQUAD_FMT,
NIPQUAD(addr->sin_addr.s_addr));
}
xprt->address_strings[RPC_DISPLAY_ADDR] = buf;
buf = kzalloc(8, GFP_KERNEL);
if (buf) {
snprintf(buf, 8, "%u",
ntohs(addr->sin_port));
}
xprt->address_strings[RPC_DISPLAY_PORT] = buf;
xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
buf = kzalloc(48, GFP_KERNEL);
if (buf) {
snprintf(buf, 48, "addr="NIPQUAD_FMT" port=%u proto=%s",
NIPQUAD(addr->sin_addr.s_addr),
ntohs(addr->sin_port),
protocol);
}
xprt->address_strings[RPC_DISPLAY_ALL] = buf;
buf = kzalloc(10, GFP_KERNEL);
if (buf) {
snprintf(buf, 10, "%02x%02x%02x%02x",
NIPQUAD(addr->sin_addr.s_addr));
}
xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = buf;
buf = kzalloc(8, GFP_KERNEL);
if (buf) {
snprintf(buf, 8, "%4hx",
ntohs(addr->sin_port));
}
xprt->address_strings[RPC_DISPLAY_HEX_PORT] = buf;
buf = kzalloc(30, GFP_KERNEL);
if (buf) {
snprintf(buf, 30, NIPQUAD_FMT".%u.%u",
NIPQUAD(addr->sin_addr.s_addr),
ntohs(addr->sin_port) >> 8,
ntohs(addr->sin_port) & 0xff);
}
xprt->address_strings[RPC_DISPLAY_UNIVERSAL_ADDR] = buf;
xprt->address_strings[RPC_DISPLAY_NETID] = netid;
}
static void xs_format_ipv6_peer_addresses(struct rpc_xprt *xprt,
const char *protocol,
const char *netid)
{
struct sockaddr_in6 *addr = xs_addr_in6(xprt);
char *buf;
buf = kzalloc(40, GFP_KERNEL);
if (buf) {
snprintf(buf, 40, NIP6_FMT,
NIP6(addr->sin6_addr));
}
xprt->address_strings[RPC_DISPLAY_ADDR] = buf;
buf = kzalloc(8, GFP_KERNEL);
if (buf) {
snprintf(buf, 8, "%u",
ntohs(addr->sin6_port));
}
xprt->address_strings[RPC_DISPLAY_PORT] = buf;
xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
buf = kzalloc(64, GFP_KERNEL);
if (buf) {
snprintf(buf, 64, "addr="NIP6_FMT" port=%u proto=%s",
NIP6(addr->sin6_addr),
ntohs(addr->sin6_port),
protocol);
}
xprt->address_strings[RPC_DISPLAY_ALL] = buf;
buf = kzalloc(36, GFP_KERNEL);
if (buf) {
snprintf(buf, 36, NIP6_SEQFMT,
NIP6(addr->sin6_addr));
}
xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = buf;
buf = kzalloc(8, GFP_KERNEL);
if (buf) {
snprintf(buf, 8, "%4hx",
ntohs(addr->sin6_port));
}
xprt->address_strings[RPC_DISPLAY_HEX_PORT] = buf;
buf = kzalloc(50, GFP_KERNEL);
if (buf) {
snprintf(buf, 50, NIP6_FMT".%u.%u",
NIP6(addr->sin6_addr),
ntohs(addr->sin6_port) >> 8,
ntohs(addr->sin6_port) & 0xff);
}
xprt->address_strings[RPC_DISPLAY_UNIVERSAL_ADDR] = buf;
xprt->address_strings[RPC_DISPLAY_NETID] = netid;
}
static void xs_free_peer_addresses(struct rpc_xprt *xprt)
{
unsigned int i;
for (i = 0; i < RPC_DISPLAY_MAX; i++)
switch (i) {
case RPC_DISPLAY_PROTO:
case RPC_DISPLAY_NETID:
continue;
default:
kfree(xprt->address_strings[i]);
}
}
#define XS_SENDMSG_FLAGS (MSG_DONTWAIT | MSG_NOSIGNAL)
static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
{
struct msghdr msg = {
.msg_name = addr,
.msg_namelen = addrlen,
.msg_flags = XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
};
struct kvec iov = {
.iov_base = vec->iov_base + base,
.iov_len = vec->iov_len - base,
};
if (iov.iov_len != 0)
return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
return kernel_sendmsg(sock, &msg, NULL, 0, 0);
}
static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more)
{
struct page **ppage;
unsigned int remainder;
int err, sent = 0;
remainder = xdr->page_len - base;
base += xdr->page_base;
ppage = xdr->pages + (base >> PAGE_SHIFT);
base &= ~PAGE_MASK;
for(;;) {
unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
int flags = XS_SENDMSG_FLAGS;
remainder -= len;
if (remainder != 0 || more)
flags |= MSG_MORE;
err = sock->ops->sendpage(sock, *ppage, base, len, flags);
if (remainder == 0 || err != len)
break;
sent += err;
ppage++;
base = 0;
}
if (sent == 0)
return err;
if (err > 0)
sent += err;
return sent;
}
/**
* 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 int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base)
{
unsigned int remainder = xdr->len - base;
int err, sent = 0;
if (unlikely(!sock))
return -ENOTCONN;
clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
if (base != 0) {
addr = NULL;
addrlen = 0;
}
if (base < xdr->head[0].iov_len || addr != NULL) {
unsigned int len = xdr->head[0].iov_len - base;
remainder -= len;
err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
if (remainder == 0 || err != len)
goto out;
sent += err;
base = 0;
} else
base -= xdr->head[0].iov_len;
if (base < xdr->page_len) {
unsigned int len = xdr->page_len - base;
remainder -= len;
err = xs_send_pagedata(sock, xdr, base, remainder != 0);
if (remainder == 0 || err != len)
goto out;
sent += err;
base = 0;
} else
base -= xdr->page_len;
if (base >= xdr->tail[0].iov_len)
return sent;
err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
out:
if (sent == 0)
return err;
if (err > 0)
sent += err;
return sent;
}
static void xs_nospace_callback(struct rpc_task *task)
{
struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
transport->inet->sk_write_pending--;
clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
}
/**
* 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;
struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
task->tk_pid, req->rq_slen - req->rq_bytes_sent,
req->rq_slen);
/* Protect against races with write_space */
spin_lock_bh(&xprt->transport_lock);
/* Don't race with disconnect */
if (xprt_connected(xprt)) {
if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
/*
* Notify TCP that we're limited by the application
* window size
*/
set_bit(SOCK_NOSPACE, &transport->sock->flags);
transport->inet->sk_write_pending++;
/* ...and wait for more buffer space */
xprt_wait_for_buffer_space(task, xs_nospace_callback);
}
} else {
clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
task->tk_status = -ENOTCONN;
}
spin_unlock_bh(&xprt->transport_lock);
}
/**
* 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 sock_xprt *transport = container_of(xprt, struct sock_xprt, 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);
status = xs_sendpages(transport->sock,
xs_addr(xprt),
xprt->addrlen, xdr,
req->rq_bytes_sent);
dprintk("RPC: xs_udp_send_request(%u) = %d\n",
xdr->len - req->rq_bytes_sent, status);
if (status >= 0) {
task->tk_bytes_sent += status;
if (status >= req->rq_slen)
return 0;
/* Still some bytes left; set up for a retry later. */
status = -EAGAIN;
}
switch (status) {
case -EAGAIN:
xs_nospace(task);
break;
case -ENETUNREACH:
case -EPIPE:
case -ECONNREFUSED:
/* When the server has died, an ICMP port unreachable message
* prompts ECONNREFUSED. */
clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
break;
default:
clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
dprintk("RPC: sendmsg returned unrecognized error %d\n",
-status);
}
return status;
}
/**
* xs_tcp_shutdown - gracefully shut down a TCP socket
* @xprt: transport
*
* Initiates a graceful shutdown of the TCP socket by calling the
* equivalent of shutdown(SHUT_WR);
*/
static void xs_tcp_shutdown(struct rpc_xprt *xprt)
{
struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
struct socket *sock = transport->sock;
if (sock != NULL)
kernel_sock_shutdown(sock, SHUT_WR);
}
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 sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
struct xdr_buf *xdr = &req->rq_snd_buf;
int status;
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) {
status = xs_sendpages(transport->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;
}
if (status != 0)
continue;
status = -EAGAIN;
break;
}
switch (status) {
case -EAGAIN:
xs_nospace(task);
break;
case -ECONNREFUSED:
case -ECONNRESET:
case -ENOTCONN:
case -EPIPE:
status = -ENOTCONN;
clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
break;
default:
dprintk("RPC: sendmsg returned unrecognized error %d\n",
-status);
clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
xs_tcp_shutdown(xprt);
}
return status;
}
/**
* xs_tcp_release_xprt - clean up after a tcp transmission
* @xprt: transport
* @task: rpc task
*
* This cleans up if an error causes us to abort the transmission of a request.
* In this case, the socket may need to be reset in order to avoid confusing
* the server.
*/
static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
{
struct rpc_rqst *req;
if (task != xprt->snd_task)
return;
if (task == NULL)
goto out_release;
req = task->tk_rqstp;
if (req->rq_bytes_sent == 0)
goto out_release;
if (req->rq_bytes_sent == req->rq_snd_buf.len)
goto out_release;
set_bit(XPRT_CLOSE_WAIT, &task->tk_xprt->state);
out_release:
xprt_release_xprt(xprt, task);
}
/**
* 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 sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
struct socket *sock = transport->sock;
struct sock *sk = transport->inet;
if (!sk)
goto clear_close_wait;
dprintk("RPC: xs_close xprt %p\n", xprt);
write_lock_bh(&sk->sk_callback_lock);
transport->inet = NULL;
transport->sock = NULL;
sk->sk_user_data = NULL;
sk->sk_data_ready = transport->old_data_ready;
sk->sk_state_change = transport->old_state_change;
sk->sk_write_space = transport->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);
clear_bit(XPRT_CLOSING, &xprt->state);
smp_mb__after_clear_bit();
xprt_disconnect_done(xprt);
}
/**
* xs_destroy - prepare to shutdown a transport
* @xprt: doomed transport
*
*/
static void xs_destroy(struct rpc_xprt *xprt)
{
struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
dprintk("RPC: xs_destroy xprt %p\n", xprt);
cancel_rearming_delayed_work(&transport->connect_worker);
xs_close(xprt);
xs_free_peer_addresses(xprt);
kfree(xprt->slot);
kfree(xprt);
module_put(THIS_MODULE);
}
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;
__be32 *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)) {
UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
goto out_unlock;
}
UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
/* 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 void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
{
struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
size_t len, used;
char *p;
p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
used = xdr_skb_read_bits(desc, p, len);
transport->tcp_offset += used;
if (used != len)
return;
transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
transport->tcp_flags |= TCP_RCV_LAST_FRAG;
else
transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
transport->tcp_offset = 0;
/* Sanity check of the record length */
if (unlikely(transport->tcp_reclen < 4)) {
dprintk("RPC: invalid TCP record fragment length\n");
xprt_force_disconnect(xprt);
return;
}
dprintk("RPC: reading TCP record fragment of length %d\n",
transport->tcp_reclen);
}
static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
{
if (transport->tcp_offset == transport->tcp_reclen) {
transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
transport->tcp_offset = 0;
if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
transport->tcp_flags |= TCP_RCV_COPY_XID;
transport->tcp_copied = 0;
}
}
}
static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
{
size_t len, used;
char *p;
len = sizeof(transport->tcp_xid) - transport->tcp_offset;
dprintk("RPC: reading XID (%Zu bytes)\n", len);
p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
used = xdr_skb_read_bits(desc, p, len);
transport->tcp_offset += used;
if (used != len)
return;
transport->tcp_flags &= ~TCP_RCV_COPY_XID;
transport->tcp_flags |= TCP_RCV_COPY_DATA;
transport->tcp_copied = 4;
dprintk("RPC: reading reply for XID %08x\n",
ntohl(transport->tcp_xid));
xs_tcp_check_fraghdr(transport);
}
static inline void xs_tcp_read_request(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
{
struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
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, transport->tcp_xid);
if (!req) {
transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
dprintk("RPC: XID %08x request not found!\n",
ntohl(transport->tcp_xid));
spin_unlock(&xprt->transport_lock);
return;
}
rcvbuf = &req->rq_private_buf;
len = desc->count;
if (len > transport->tcp_reclen - transport->tcp_offset) {
struct xdr_skb_reader my_desc;
len = transport->tcp_reclen - transport->tcp_offset;
memcpy(&my_desc, desc, sizeof(my_desc));
my_desc.count = len;
r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
&my_desc, xdr_skb_read_bits);
desc->count -= r;
desc->offset += r;
} else
r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
desc, xdr_skb_read_bits);
if (r > 0) {
transport->tcp_copied += r;
transport->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 TCP_RCV_COPY_DATA, so the request
* will not receive any additional updates,
* and time out.
* Any remaining data from this record will
* be discarded.
*/
transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
dprintk("RPC: XID %08x truncated request\n",
ntohl(transport->tcp_xid));
dprintk("RPC: xprt = %p, tcp_copied = %lu, "
"tcp_offset = %u, tcp_reclen = %u\n",