android_kernel_xiaomi_sm8350/include/linux/sunrpc/svc.h
J. Bruce Fields 6f54e2d0d3 [PATCH] knfsd: svcrpc: WARN() instead of returning an error from svc_take_page
Every caller of svc_take_page ignores its return value and assumes it
succeeded.  So just WARN() instead of returning an ignored error.  This would
have saved some time debugging a recent nfsd4 problem.

If there are still failure cases here, then the result is probably that we
overwrite an earlier part of the reply while xdr-encoding.

While the corrupted reply is a nasty bug, it would be worse to panic here and
create the possibility of a remote DOS; hence WARN() instead of BUG().

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Ingo Oeser <ioe-lkml@rameria.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11 06:18:52 -07:00

322 lines
9.5 KiB
C

/*
* linux/include/linux/sunrpc/svc.h
*
* RPC server declarations.
*
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
*/
#ifndef SUNRPC_SVC_H
#define SUNRPC_SVC_H
#include <linux/in.h>
#include <linux/sunrpc/types.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/svcauth.h>
#include <linux/wait.h>
#include <linux/mm.h>
/*
* RPC service.
*
* An RPC service is a ``daemon,'' possibly multithreaded, which
* receives and processes incoming RPC messages.
* It has one or more transport sockets associated with it, and maintains
* a list of idle threads waiting for input.
*
* We currently do not support more than one RPC program per daemon.
*/
struct svc_serv {
struct list_head sv_threads; /* idle server threads */
struct list_head sv_sockets; /* pending sockets */
struct svc_program * sv_program; /* RPC program */
struct svc_stat * sv_stats; /* RPC statistics */
spinlock_t sv_lock;
unsigned int sv_nrthreads; /* # of server threads */
unsigned int sv_bufsz; /* datagram buffer size */
unsigned int sv_xdrsize; /* XDR buffer size */
struct list_head sv_permsocks; /* all permanent sockets */
struct list_head sv_tempsocks; /* all temporary sockets */
int sv_tmpcnt; /* count of temporary sockets */
char * sv_name; /* service name */
};
/*
* Maximum payload size supported by a kernel RPC server.
* This is use to determine the max number of pages nfsd is
* willing to return in a single READ operation.
*/
#define RPCSVC_MAXPAYLOAD (64*1024u)
/*
* RPC Requsts and replies are stored in one or more pages.
* We maintain an array of pages for each server thread.
* Requests are copied into these pages as they arrive. Remaining
* pages are available to write the reply into.
*
* Pages are sent using ->sendpage so each server thread needs to
* allocate more to replace those used in sending. To help keep track
* of these pages we have a receive list where all pages initialy live,
* and a send list where pages are moved to when there are to be part
* of a reply.
*
* We use xdr_buf for holding responses as it fits well with NFS
* read responses (that have a header, and some data pages, and possibly
* a tail) and means we can share some client side routines.
*
* The xdr_buf.head kvec always points to the first page in the rq_*pages
* list. The xdr_buf.pages pointer points to the second page on that
* list. xdr_buf.tail points to the end of the first page.
* This assumes that the non-page part of an rpc reply will fit
* in a page - NFSd ensures this. lockd also has no trouble.
*
* Each request/reply pair can have at most one "payload", plus two pages,
* one for the request, and one for the reply.
*/
#define RPCSVC_MAXPAGES ((RPCSVC_MAXPAYLOAD+PAGE_SIZE-1)/PAGE_SIZE + 2)
static inline u32 svc_getu32(struct kvec *iov)
{
u32 val, *vp;
vp = iov->iov_base;
val = *vp++;
iov->iov_base = (void*)vp;
iov->iov_len -= sizeof(u32);
return val;
}
static inline void svc_ungetu32(struct kvec *iov)
{
u32 *vp = (u32 *)iov->iov_base;
iov->iov_base = (void *)(vp - 1);
iov->iov_len += sizeof(*vp);
}
static inline void svc_putu32(struct kvec *iov, u32 val)
{
u32 *vp = iov->iov_base + iov->iov_len;
*vp = val;
iov->iov_len += sizeof(u32);
}
/*
* The context of a single thread, including the request currently being
* processed.
* NOTE: First two items must be prev/next.
*/
struct svc_rqst {
struct list_head rq_list; /* idle list */
struct svc_sock * rq_sock; /* socket */
struct sockaddr_in rq_addr; /* peer address */
int rq_addrlen;
struct svc_serv * rq_server; /* RPC service definition */
struct svc_procedure * rq_procinfo; /* procedure info */
struct auth_ops * rq_authop; /* authentication flavour */
struct svc_cred rq_cred; /* auth info */
struct sk_buff * rq_skbuff; /* fast recv inet buffer */
struct svc_deferred_req*rq_deferred; /* deferred request we are replaying */
struct xdr_buf rq_arg;
struct xdr_buf rq_res;
struct page * rq_argpages[RPCSVC_MAXPAGES];
struct page * rq_respages[RPCSVC_MAXPAGES];
int rq_restailpage;
short rq_argused; /* pages used for argument */
short rq_arghi; /* pages available in argument page list */
short rq_resused; /* pages used for result */
u32 rq_xid; /* transmission id */
u32 rq_prog; /* program number */
u32 rq_vers; /* program version */
u32 rq_proc; /* procedure number */
u32 rq_prot; /* IP protocol */
unsigned short
rq_secure : 1; /* secure port */
__u32 rq_daddr; /* dest addr of request - reply from here */
void * rq_argp; /* decoded arguments */
void * rq_resp; /* xdr'd results */
void * rq_auth_data; /* flavor-specific data */
int rq_reserved; /* space on socket outq
* reserved for this request
*/
struct cache_req rq_chandle; /* handle passed to caches for
* request delaying
*/
/* Catering to nfsd */
struct auth_domain * rq_client; /* RPC peer info */
struct svc_cacherep * rq_cacherep; /* cache info */
struct knfsd_fh * rq_reffh; /* Referrence filehandle, used to
* determine what device number
* to report (real or virtual)
*/
wait_queue_head_t rq_wait; /* synchronization */
};
/*
* Check buffer bounds after decoding arguments
*/
static inline int
xdr_argsize_check(struct svc_rqst *rqstp, u32 *p)
{
char *cp = (char *)p;
struct kvec *vec = &rqstp->rq_arg.head[0];
return cp >= (char*)vec->iov_base
&& cp <= (char*)vec->iov_base + vec->iov_len;
}
static inline int
xdr_ressize_check(struct svc_rqst *rqstp, u32 *p)
{
struct kvec *vec = &rqstp->rq_res.head[0];
char *cp = (char*)p;
vec->iov_len = cp - (char*)vec->iov_base;
return vec->iov_len <= PAGE_SIZE;
}
static inline struct page *
svc_take_res_page(struct svc_rqst *rqstp)
{
if (rqstp->rq_arghi <= rqstp->rq_argused)
return NULL;
rqstp->rq_arghi--;
rqstp->rq_respages[rqstp->rq_resused] =
rqstp->rq_argpages[rqstp->rq_arghi];
return rqstp->rq_respages[rqstp->rq_resused++];
}
static inline void svc_take_page(struct svc_rqst *rqstp)
{
if (rqstp->rq_arghi <= rqstp->rq_argused) {
WARN_ON(1);
return;
}
rqstp->rq_arghi--;
rqstp->rq_respages[rqstp->rq_resused] =
rqstp->rq_argpages[rqstp->rq_arghi];
rqstp->rq_resused++;
}
static inline void svc_pushback_allpages(struct svc_rqst *rqstp)
{
while (rqstp->rq_resused) {
if (rqstp->rq_respages[--rqstp->rq_resused] == NULL)
continue;
rqstp->rq_argpages[rqstp->rq_arghi++] =
rqstp->rq_respages[rqstp->rq_resused];
rqstp->rq_respages[rqstp->rq_resused] = NULL;
}
}
static inline void svc_pushback_unused_pages(struct svc_rqst *rqstp)
{
while (rqstp->rq_resused &&
rqstp->rq_res.pages != &rqstp->rq_respages[rqstp->rq_resused]) {
if (rqstp->rq_respages[--rqstp->rq_resused] != NULL) {
rqstp->rq_argpages[rqstp->rq_arghi++] =
rqstp->rq_respages[rqstp->rq_resused];
rqstp->rq_respages[rqstp->rq_resused] = NULL;
}
}
}
static inline void svc_free_allpages(struct svc_rqst *rqstp)
{
while (rqstp->rq_resused) {
if (rqstp->rq_respages[--rqstp->rq_resused] == NULL)
continue;
put_page(rqstp->rq_respages[rqstp->rq_resused]);
rqstp->rq_respages[rqstp->rq_resused] = NULL;
}
}
struct svc_deferred_req {
u32 prot; /* protocol (UDP or TCP) */
struct sockaddr_in addr;
struct svc_sock *svsk; /* where reply must go */
u32 daddr; /* where reply must come from */
struct cache_deferred_req handle;
int argslen;
u32 args[0];
};
/*
* List of RPC programs on the same transport endpoint
*/
struct svc_program {
struct svc_program * pg_next; /* other programs (same xprt) */
u32 pg_prog; /* program number */
unsigned int pg_lovers; /* lowest version */
unsigned int pg_hivers; /* lowest version */
unsigned int pg_nvers; /* number of versions */
struct svc_version ** pg_vers; /* version array */
char * pg_name; /* service name */
char * pg_class; /* class name: services sharing authentication */
struct svc_stat * pg_stats; /* rpc statistics */
int (*pg_authenticate)(struct svc_rqst *);
};
/*
* RPC program version
*/
struct svc_version {
u32 vs_vers; /* version number */
u32 vs_nproc; /* number of procedures */
struct svc_procedure * vs_proc; /* per-procedure info */
u32 vs_xdrsize; /* xdrsize needed for this version */
/* Override dispatch function (e.g. when caching replies).
* A return value of 0 means drop the request.
* vs_dispatch == NULL means use default dispatcher.
*/
int (*vs_dispatch)(struct svc_rqst *, u32 *);
};
/*
* RPC procedure info
*/
typedef int (*svc_procfunc)(struct svc_rqst *, void *argp, void *resp);
struct svc_procedure {
svc_procfunc pc_func; /* process the request */
kxdrproc_t pc_decode; /* XDR decode args */
kxdrproc_t pc_encode; /* XDR encode result */
kxdrproc_t pc_release; /* XDR free result */
unsigned int pc_argsize; /* argument struct size */
unsigned int pc_ressize; /* result struct size */
unsigned int pc_count; /* call count */
unsigned int pc_cachetype; /* cache info (NFS) */
unsigned int pc_xdrressize; /* maximum size of XDR reply */
};
/*
* This is the RPC server thread function prototype
*/
typedef void (*svc_thread_fn)(struct svc_rqst *);
/*
* Function prototypes.
*/
struct svc_serv * svc_create(struct svc_program *, unsigned int);
int svc_create_thread(svc_thread_fn, struct svc_serv *);
void svc_exit_thread(struct svc_rqst *);
void svc_destroy(struct svc_serv *);
int svc_process(struct svc_serv *, struct svc_rqst *);
int svc_register(struct svc_serv *, int, unsigned short);
void svc_wake_up(struct svc_serv *);
void svc_reserve(struct svc_rqst *rqstp, int space);
#endif /* SUNRPC_SVC_H */