freebsd-dev/sys/rpc/svc_vc.c
Bjoern A. Zeeb 1fb51a12f2 Mfp4 CH=177274,177280,177284-177285,177297,177324-177325
VNET socket push back:
  try to minimize the number of places where we have to switch vnets
  and narrow down the time we stay switched.  Add assertions to the
  socket code to catch possibly unset vnets as seen in r204147.

  While this reduces the number of vnet recursion in some places like
  NFS, POSIX local sockets and some netgraph, .. recursions are
  impossible to fix.

  The current expectations are documented at the beginning of
  uipc_socket.c along with the other information there.

  Sponsored by: The FreeBSD Foundation
  Sponsored by: CK Software GmbH
  Reviewed by:  jhb
  Tested by:    zec

Tested by:	Mikolaj Golub (to.my.trociny gmail.com)
MFC after:	2 weeks
2011-02-16 21:29:13 +00:00

774 lines
18 KiB
C

/* $NetBSD: svc_vc.c,v 1.7 2000/08/03 00:01:53 fvdl Exp $ */
/*
* Sun RPC is a product of Sun Microsystems, Inc. and is provided for
* unrestricted use provided that this legend is included on all tape
* media and as a part of the software program in whole or part. Users
* may copy or modify Sun RPC without charge, but are not authorized
* to license or distribute it to anyone else except as part of a product or
* program developed by the user.
*
* SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
* WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
* PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
*
* Sun RPC is provided with no support and without any obligation on the
* part of Sun Microsystems, Inc. to assist in its use, correction,
* modification or enhancement.
*
* SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
* INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
* OR ANY PART THEREOF.
*
* In no event will Sun Microsystems, Inc. be liable for any lost revenue
* or profits or other special, indirect and consequential damages, even if
* Sun has been advised of the possibility of such damages.
*
* Sun Microsystems, Inc.
* 2550 Garcia Avenue
* Mountain View, California 94043
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char *sccsid2 = "@(#)svc_tcp.c 1.21 87/08/11 Copyr 1984 Sun Micro";
static char *sccsid = "@(#)svc_tcp.c 2.2 88/08/01 4.0 RPCSRC";
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* svc_vc.c, Server side for Connection Oriented based RPC.
*
* Actually implements two flavors of transporter -
* a tcp rendezvouser (a listner and connection establisher)
* and a record/tcp stream.
*/
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sx.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <net/vnet.h>
#include <netinet/tcp.h>
#include <rpc/rpc.h>
#include <rpc/rpc_com.h>
#include <security/mac/mac_framework.h>
static bool_t svc_vc_rendezvous_recv(SVCXPRT *, struct rpc_msg *,
struct sockaddr **, struct mbuf **);
static enum xprt_stat svc_vc_rendezvous_stat(SVCXPRT *);
static void svc_vc_rendezvous_destroy(SVCXPRT *);
static bool_t svc_vc_null(void);
static void svc_vc_destroy(SVCXPRT *);
static enum xprt_stat svc_vc_stat(SVCXPRT *);
static bool_t svc_vc_recv(SVCXPRT *, struct rpc_msg *,
struct sockaddr **, struct mbuf **);
static bool_t svc_vc_reply(SVCXPRT *, struct rpc_msg *,
struct sockaddr *, struct mbuf *);
static bool_t svc_vc_control(SVCXPRT *xprt, const u_int rq, void *in);
static bool_t svc_vc_rendezvous_control (SVCXPRT *xprt, const u_int rq,
void *in);
static SVCXPRT *svc_vc_create_conn(SVCPOOL *pool, struct socket *so,
struct sockaddr *raddr);
static int svc_vc_accept(struct socket *head, struct socket **sop);
static int svc_vc_soupcall(struct socket *so, void *arg, int waitflag);
static struct xp_ops svc_vc_rendezvous_ops = {
.xp_recv = svc_vc_rendezvous_recv,
.xp_stat = svc_vc_rendezvous_stat,
.xp_reply = (bool_t (*)(SVCXPRT *, struct rpc_msg *,
struct sockaddr *, struct mbuf *))svc_vc_null,
.xp_destroy = svc_vc_rendezvous_destroy,
.xp_control = svc_vc_rendezvous_control
};
static struct xp_ops svc_vc_ops = {
.xp_recv = svc_vc_recv,
.xp_stat = svc_vc_stat,
.xp_reply = svc_vc_reply,
.xp_destroy = svc_vc_destroy,
.xp_control = svc_vc_control
};
struct cf_conn { /* kept in xprt->xp_p1 for actual connection */
enum xprt_stat strm_stat;
struct mbuf *mpending; /* unparsed data read from the socket */
struct mbuf *mreq; /* current record being built from mpending */
uint32_t resid; /* number of bytes needed for fragment */
bool_t eor; /* reading last fragment of current record */
};
/*
* Usage:
* xprt = svc_vc_create(sock, send_buf_size, recv_buf_size);
*
* Creates, registers, and returns a (rpc) tcp based transporter.
* Once *xprt is initialized, it is registered as a transporter
* see (svc.h, xprt_register). This routine returns
* a NULL if a problem occurred.
*
* The filedescriptor passed in is expected to refer to a bound, but
* not yet connected socket.
*
* Since streams do buffered io similar to stdio, the caller can specify
* how big the send and receive buffers are via the second and third parms;
* 0 => use the system default.
*/
SVCXPRT *
svc_vc_create(SVCPOOL *pool, struct socket *so, size_t sendsize,
size_t recvsize)
{
SVCXPRT *xprt;
struct sockaddr* sa;
int error;
if (so->so_state & SS_ISCONNECTED) {
error = so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa);
if (error)
return (NULL);
xprt = svc_vc_create_conn(pool, so, sa);
free(sa, M_SONAME);
return (xprt);
}
xprt = svc_xprt_alloc();
sx_init(&xprt->xp_lock, "xprt->xp_lock");
xprt->xp_pool = pool;
xprt->xp_socket = so;
xprt->xp_p1 = NULL;
xprt->xp_p2 = NULL;
xprt->xp_ops = &svc_vc_rendezvous_ops;
error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa);
if (error) {
goto cleanup_svc_vc_create;
}
memcpy(&xprt->xp_ltaddr, sa, sa->sa_len);
free(sa, M_SONAME);
xprt_register(xprt);
solisten(so, SOMAXCONN, curthread);
SOCKBUF_LOCK(&so->so_rcv);
xprt->xp_upcallset = 1;
soupcall_set(so, SO_RCV, svc_vc_soupcall, xprt);
SOCKBUF_UNLOCK(&so->so_rcv);
return (xprt);
cleanup_svc_vc_create:
if (xprt)
svc_xprt_free(xprt);
return (NULL);
}
/*
* Create a new transport for a socket optained via soaccept().
*/
SVCXPRT *
svc_vc_create_conn(SVCPOOL *pool, struct socket *so, struct sockaddr *raddr)
{
SVCXPRT *xprt = NULL;
struct cf_conn *cd = NULL;
struct sockaddr* sa = NULL;
struct sockopt opt;
int one = 1;
int error;
bzero(&opt, sizeof(struct sockopt));
opt.sopt_dir = SOPT_SET;
opt.sopt_level = SOL_SOCKET;
opt.sopt_name = SO_KEEPALIVE;
opt.sopt_val = &one;
opt.sopt_valsize = sizeof(one);
error = sosetopt(so, &opt);
if (error) {
return (NULL);
}
if (so->so_proto->pr_protocol == IPPROTO_TCP) {
bzero(&opt, sizeof(struct sockopt));
opt.sopt_dir = SOPT_SET;
opt.sopt_level = IPPROTO_TCP;
opt.sopt_name = TCP_NODELAY;
opt.sopt_val = &one;
opt.sopt_valsize = sizeof(one);
error = sosetopt(so, &opt);
if (error) {
return (NULL);
}
}
cd = mem_alloc(sizeof(*cd));
cd->strm_stat = XPRT_IDLE;
xprt = svc_xprt_alloc();
sx_init(&xprt->xp_lock, "xprt->xp_lock");
xprt->xp_pool = pool;
xprt->xp_socket = so;
xprt->xp_p1 = cd;
xprt->xp_p2 = NULL;
xprt->xp_ops = &svc_vc_ops;
/*
* See http://www.connectathon.org/talks96/nfstcp.pdf - client
* has a 5 minute timer, server has a 6 minute timer.
*/
xprt->xp_idletimeout = 6 * 60;
memcpy(&xprt->xp_rtaddr, raddr, raddr->sa_len);
error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa);
if (error)
goto cleanup_svc_vc_create;
memcpy(&xprt->xp_ltaddr, sa, sa->sa_len);
free(sa, M_SONAME);
xprt_register(xprt);
SOCKBUF_LOCK(&so->so_rcv);
xprt->xp_upcallset = 1;
soupcall_set(so, SO_RCV, svc_vc_soupcall, xprt);
SOCKBUF_UNLOCK(&so->so_rcv);
/*
* Throw the transport into the active list in case it already
* has some data buffered.
*/
sx_xlock(&xprt->xp_lock);
xprt_active(xprt);
sx_xunlock(&xprt->xp_lock);
return (xprt);
cleanup_svc_vc_create:
if (xprt) {
mem_free(xprt, sizeof(*xprt));
}
if (cd)
mem_free(cd, sizeof(*cd));
return (NULL);
}
/*
* This does all of the accept except the final call to soaccept. The
* caller will call soaccept after dropping its locks (soaccept may
* call malloc).
*/
int
svc_vc_accept(struct socket *head, struct socket **sop)
{
int error = 0;
struct socket *so;
if ((head->so_options & SO_ACCEPTCONN) == 0) {
error = EINVAL;
goto done;
}
#ifdef MAC
error = mac_socket_check_accept(curthread->td_ucred, head);
if (error != 0)
goto done;
#endif
ACCEPT_LOCK();
if (TAILQ_EMPTY(&head->so_comp)) {
ACCEPT_UNLOCK();
error = EWOULDBLOCK;
goto done;
}
so = TAILQ_FIRST(&head->so_comp);
KASSERT(!(so->so_qstate & SQ_INCOMP), ("svc_vc_accept: so SQ_INCOMP"));
KASSERT(so->so_qstate & SQ_COMP, ("svc_vc_accept: so not SQ_COMP"));
/*
* Before changing the flags on the socket, we have to bump the
* reference count. Otherwise, if the protocol calls sofree(),
* the socket will be released due to a zero refcount.
* XXX might not need soref() since this is simpler than kern_accept.
*/
SOCK_LOCK(so); /* soref() and so_state update */
soref(so); /* file descriptor reference */
TAILQ_REMOVE(&head->so_comp, so, so_list);
head->so_qlen--;
so->so_state |= (head->so_state & SS_NBIO);
so->so_qstate &= ~SQ_COMP;
so->so_head = NULL;
SOCK_UNLOCK(so);
ACCEPT_UNLOCK();
*sop = so;
/* connection has been removed from the listen queue */
KNOTE_UNLOCKED(&head->so_rcv.sb_sel.si_note, 0);
done:
return (error);
}
/*ARGSUSED*/
static bool_t
svc_vc_rendezvous_recv(SVCXPRT *xprt, struct rpc_msg *msg,
struct sockaddr **addrp, struct mbuf **mp)
{
struct socket *so = NULL;
struct sockaddr *sa = NULL;
int error;
SVCXPRT *new_xprt;
/*
* The socket upcall calls xprt_active() which will eventually
* cause the server to call us here. We attempt to accept a
* connection from the socket and turn it into a new
* transport. If the accept fails, we have drained all pending
* connections so we call xprt_inactive().
*/
sx_xlock(&xprt->xp_lock);
error = svc_vc_accept(xprt->xp_socket, &so);
if (error == EWOULDBLOCK) {
/*
* We must re-test for new connections after taking
* the lock to protect us in the case where a new
* connection arrives after our call to accept fails
* with EWOULDBLOCK. The pool lock protects us from
* racing the upcall after our TAILQ_EMPTY() call
* returns false.
*/
ACCEPT_LOCK();
mtx_lock(&xprt->xp_pool->sp_lock);
if (TAILQ_EMPTY(&xprt->xp_socket->so_comp))
xprt_inactive_locked(xprt);
mtx_unlock(&xprt->xp_pool->sp_lock);
ACCEPT_UNLOCK();
sx_xunlock(&xprt->xp_lock);
return (FALSE);
}
if (error) {
SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
if (xprt->xp_upcallset) {
xprt->xp_upcallset = 0;
soupcall_clear(xprt->xp_socket, SO_RCV);
}
SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
xprt_inactive(xprt);
sx_xunlock(&xprt->xp_lock);
return (FALSE);
}
sx_xunlock(&xprt->xp_lock);
sa = 0;
error = soaccept(so, &sa);
if (error) {
/*
* XXX not sure if I need to call sofree or soclose here.
*/
if (sa)
free(sa, M_SONAME);
return (FALSE);
}
/*
* svc_vc_create_conn will call xprt_register - we don't need
* to do anything with the new connection except derefence it.
*/
new_xprt = svc_vc_create_conn(xprt->xp_pool, so, sa);
if (!new_xprt) {
soclose(so);
} else {
SVC_RELEASE(new_xprt);
}
free(sa, M_SONAME);
return (FALSE); /* there is never an rpc msg to be processed */
}
/*ARGSUSED*/
static enum xprt_stat
svc_vc_rendezvous_stat(SVCXPRT *xprt)
{
return (XPRT_IDLE);
}
static void
svc_vc_destroy_common(SVCXPRT *xprt)
{
SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
if (xprt->xp_upcallset) {
xprt->xp_upcallset = 0;
soupcall_clear(xprt->xp_socket, SO_RCV);
}
SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
sx_destroy(&xprt->xp_lock);
if (xprt->xp_socket)
(void)soclose(xprt->xp_socket);
if (xprt->xp_netid)
(void) mem_free(xprt->xp_netid, strlen(xprt->xp_netid) + 1);
svc_xprt_free(xprt);
}
static void
svc_vc_rendezvous_destroy(SVCXPRT *xprt)
{
svc_vc_destroy_common(xprt);
}
static void
svc_vc_destroy(SVCXPRT *xprt)
{
struct cf_conn *cd = (struct cf_conn *)xprt->xp_p1;
svc_vc_destroy_common(xprt);
if (cd->mreq)
m_freem(cd->mreq);
if (cd->mpending)
m_freem(cd->mpending);
mem_free(cd, sizeof(*cd));
}
/*ARGSUSED*/
static bool_t
svc_vc_control(SVCXPRT *xprt, const u_int rq, void *in)
{
return (FALSE);
}
static bool_t
svc_vc_rendezvous_control(SVCXPRT *xprt, const u_int rq, void *in)
{
return (FALSE);
}
static enum xprt_stat
svc_vc_stat(SVCXPRT *xprt)
{
struct cf_conn *cd;
struct mbuf *m;
size_t n;
cd = (struct cf_conn *)(xprt->xp_p1);
if (cd->strm_stat == XPRT_DIED)
return (XPRT_DIED);
/*
* Return XPRT_MOREREQS if we have buffered data and we are
* mid-record or if we have enough data for a record
* marker. Since this is only a hint, we read mpending and
* resid outside the lock. We do need to take the lock if we
* have to traverse the mbuf chain.
*/
if (cd->mpending) {
if (cd->resid)
return (XPRT_MOREREQS);
n = 0;
sx_xlock(&xprt->xp_lock);
m = cd->mpending;
while (m && n < sizeof(uint32_t)) {
n += m->m_len;
m = m->m_next;
}
sx_xunlock(&xprt->xp_lock);
if (n >= sizeof(uint32_t))
return (XPRT_MOREREQS);
}
if (soreadable(xprt->xp_socket))
return (XPRT_MOREREQS);
return (XPRT_IDLE);
}
static bool_t
svc_vc_recv(SVCXPRT *xprt, struct rpc_msg *msg,
struct sockaddr **addrp, struct mbuf **mp)
{
struct cf_conn *cd = (struct cf_conn *) xprt->xp_p1;
struct uio uio;
struct mbuf *m;
XDR xdrs;
int error, rcvflag;
/*
* Serialise access to the socket and our own record parsing
* state.
*/
sx_xlock(&xprt->xp_lock);
for (;;) {
/*
* If we have an mbuf chain in cd->mpending, try to parse a
* record from it, leaving the result in cd->mreq. If we don't
* have a complete record, leave the partial result in
* cd->mreq and try to read more from the socket.
*/
if (cd->mpending) {
/*
* If cd->resid is non-zero, we have part of the
* record already, otherwise we are expecting a record
* marker.
*/
if (!cd->resid) {
/*
* See if there is enough data buffered to
* make up a record marker. Make sure we can
* handle the case where the record marker is
* split across more than one mbuf.
*/
size_t n = 0;
uint32_t header;
m = cd->mpending;
while (n < sizeof(uint32_t) && m) {
n += m->m_len;
m = m->m_next;
}
if (n < sizeof(uint32_t))
goto readmore;
m_copydata(cd->mpending, 0, sizeof(header),
(char *)&header);
header = ntohl(header);
cd->eor = (header & 0x80000000) != 0;
cd->resid = header & 0x7fffffff;
m_adj(cd->mpending, sizeof(uint32_t));
}
/*
* Start pulling off mbufs from cd->mpending
* until we either have a complete record or
* we run out of data. We use m_split to pull
* data - it will pull as much as possible and
* split the last mbuf if necessary.
*/
while (cd->mpending && cd->resid) {
m = cd->mpending;
if (cd->mpending->m_next
|| cd->mpending->m_len > cd->resid)
cd->mpending = m_split(cd->mpending,
cd->resid, M_WAIT);
else
cd->mpending = NULL;
if (cd->mreq)
m_last(cd->mreq)->m_next = m;
else
cd->mreq = m;
while (m) {
cd->resid -= m->m_len;
m = m->m_next;
}
}
/*
* If cd->resid is zero now, we have managed to
* receive a record fragment from the stream. Check
* for the end-of-record mark to see if we need more.
*/
if (cd->resid == 0) {
if (!cd->eor)
continue;
/*
* Success - we have a complete record in
* cd->mreq.
*/
xdrmbuf_create(&xdrs, cd->mreq, XDR_DECODE);
cd->mreq = NULL;
sx_xunlock(&xprt->xp_lock);
if (! xdr_callmsg(&xdrs, msg)) {
XDR_DESTROY(&xdrs);
return (FALSE);
}
*addrp = NULL;
*mp = xdrmbuf_getall(&xdrs);
XDR_DESTROY(&xdrs);
return (TRUE);
}
}
readmore:
/*
* The socket upcall calls xprt_active() which will eventually
* cause the server to call us here. We attempt to
* read as much as possible from the socket and put
* the result in cd->mpending. If the read fails,
* we have drained both cd->mpending and the socket so
* we can call xprt_inactive().
*/
uio.uio_resid = 1000000000;
uio.uio_td = curthread;
m = NULL;
rcvflag = MSG_DONTWAIT;
error = soreceive(xprt->xp_socket, NULL, &uio, &m, NULL,
&rcvflag);
if (error == EWOULDBLOCK) {
/*
* We must re-test for readability after
* taking the lock to protect us in the case
* where a new packet arrives on the socket
* after our call to soreceive fails with
* EWOULDBLOCK. The pool lock protects us from
* racing the upcall after our soreadable()
* call returns false.
*/
mtx_lock(&xprt->xp_pool->sp_lock);
if (!soreadable(xprt->xp_socket))
xprt_inactive_locked(xprt);
mtx_unlock(&xprt->xp_pool->sp_lock);
sx_xunlock(&xprt->xp_lock);
return (FALSE);
}
if (error) {
SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
if (xprt->xp_upcallset) {
xprt->xp_upcallset = 0;
soupcall_clear(xprt->xp_socket, SO_RCV);
}
SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
xprt_inactive(xprt);
cd->strm_stat = XPRT_DIED;
sx_xunlock(&xprt->xp_lock);
return (FALSE);
}
if (!m) {
/*
* EOF - the other end has closed the socket.
*/
xprt_inactive(xprt);
cd->strm_stat = XPRT_DIED;
sx_xunlock(&xprt->xp_lock);
return (FALSE);
}
if (cd->mpending)
m_last(cd->mpending)->m_next = m;
else
cd->mpending = m;
}
}
static bool_t
svc_vc_reply(SVCXPRT *xprt, struct rpc_msg *msg,
struct sockaddr *addr, struct mbuf *m)
{
XDR xdrs;
struct mbuf *mrep;
bool_t stat = TRUE;
int error;
/*
* Leave space for record mark.
*/
MGETHDR(mrep, M_WAIT, MT_DATA);
mrep->m_len = 0;
mrep->m_data += sizeof(uint32_t);
xdrmbuf_create(&xdrs, mrep, XDR_ENCODE);
if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
if (!xdr_replymsg(&xdrs, msg))
stat = FALSE;
else
xdrmbuf_append(&xdrs, m);
} else {
stat = xdr_replymsg(&xdrs, msg);
}
if (stat) {
m_fixhdr(mrep);
/*
* Prepend a record marker containing the reply length.
*/
M_PREPEND(mrep, sizeof(uint32_t), M_WAIT);
*mtod(mrep, uint32_t *) =
htonl(0x80000000 | (mrep->m_pkthdr.len
- sizeof(uint32_t)));
error = sosend(xprt->xp_socket, NULL, NULL, mrep, NULL,
0, curthread);
if (!error) {
stat = TRUE;
}
} else {
m_freem(mrep);
}
XDR_DESTROY(&xdrs);
xprt->xp_p2 = NULL;
return (stat);
}
static bool_t
svc_vc_null()
{
return (FALSE);
}
static int
svc_vc_soupcall(struct socket *so, void *arg, int waitflag)
{
SVCXPRT *xprt = (SVCXPRT *) arg;
xprt_active(xprt);
return (SU_OK);
}
#if 0
/*
* Get the effective UID of the sending process. Used by rpcbind, keyserv
* and rpc.yppasswdd on AF_LOCAL.
*/
int
__rpc_get_local_uid(SVCXPRT *transp, uid_t *uid) {
int sock, ret;
gid_t egid;
uid_t euid;
struct sockaddr *sa;
sock = transp->xp_fd;
sa = (struct sockaddr *)transp->xp_rtaddr;
if (sa->sa_family == AF_LOCAL) {
ret = getpeereid(sock, &euid, &egid);
if (ret == 0)
*uid = euid;
return (ret);
} else
return (-1);
}
#endif