path: root/net/sunrpc/svc.c

/*
 * linux/net/sunrpc/svc.c
 *
 * High-level RPC service routines
 *
 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/linkage.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/net.h>
#include <linux/in.h>
#include <linux/mm.h>

#include <linux/sunrpc/types.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/stats.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/clnt.h>

#define RPCDBG_FACILITY	RPCDBG_SVCDSP
#define RPC_PARANOIA 1

/*
 * Create an RPC service
 */
struct svc_serv *
svc_create(struct svc_program *prog, unsigned int bufsize)
{
	struct svc_serv	*serv;
	int vers;
	unsigned int xdrsize;

	if (!(serv = kzalloc(sizeof(*serv), GFP_KERNEL)))
		return NULL;
	serv->sv_name      = prog->pg_name;
	serv->sv_program   = prog;
	serv->sv_nrthreads = 1;
	serv->sv_stats     = prog->pg_stats;
	serv->sv_bufsz	   = bufsize? bufsize : 4096;
	xdrsize = 0;
	while (prog) {
		prog->pg_lovers = prog->pg_nvers-1;
		for (vers=0; vers<prog->pg_nvers ; vers++)
			if (prog->pg_vers[vers]) {
				prog->pg_hivers = vers;
				if (prog->pg_lovers > vers)
					prog->pg_lovers = vers;
				if (prog->pg_vers[vers]->vs_xdrsize > xdrsize)
					xdrsize = prog->pg_vers[vers]->vs_xdrsize;
			}
		prog = prog->pg_next;
	}
	serv->sv_xdrsize   = xdrsize;
	INIT_LIST_HEAD(&serv->sv_threads);
	INIT_LIST_HEAD(&serv->sv_sockets);
	INIT_LIST_HEAD(&serv->sv_tempsocks);
	INIT_LIST_HEAD(&serv->sv_permsocks);
	spin_lock_init(&serv->sv_lock);

	/* Remove any stale portmap registrations */
	svc_register(serv, 0, 0);

	return serv;
}

/*
 * Destroy an RPC service
 */
void
svc_destroy(struct svc_serv *serv)
{
	struct svc_sock	*svsk;

	dprintk("RPC: svc_destroy(%s, %d)\n",
				serv->sv_program->pg_name,
				serv->sv_nrthreads);

	if (serv->sv_nrthreads) {
		if (--(serv->sv_nrthreads) != 0) {
			svc_sock_update_bufs(serv);
			return;
		}
	} else
		printk("svc_destroy: no threads for serv=%p!\n", serv);

	while (!list_empty(&serv->sv_tempsocks)) {
		svsk = list_entry(serv->sv_tempsocks.next,
				  struct svc_sock,
				  sk_list);
		svc_delete_socket(svsk);
	}
	while (!list_empty(&serv->sv_permsocks)) {
		svsk = list_entry(serv->sv_permsocks.next,
				  struct svc_sock,
				  sk_list);
		svc_delete_socket(svsk);
	}
	
	cache_clean_deferred(serv);

	/* Unregister service with the portmapper */
	svc_register(serv, 0, 0);
	kfree(serv);
}

/*
 * Allocate an RPC server's buffer space.
 * We allocate pages and place them in rq_argpages.
 */
static int
svc_init_buffer(struct svc_rqst *rqstp, unsigned int size)
{
	int pages;
	int arghi;
	
	if (size > RPCSVC_MAXPAYLOAD)
		size = RPCSVC_MAXPAYLOAD;
	pages = 2 + (size+ PAGE_SIZE -1) / PAGE_SIZE;
	rqstp->rq_argused = 0;
	rqstp->rq_resused = 0;
	arghi = 0;
	BUG_ON(pages > RPCSVC_MAXPAGES);
	while (pages) {
		struct page *p = alloc_page(GFP_KERNEL);
		if (!p)
			break;
		rqstp->rq_argpages[arghi++] = p;
		pages--;
	}
	rqstp->rq_arghi = arghi;
	return ! pages;
}

/*
 * Release an RPC server buffer
 */
static void
svc_release_buffer(struct svc_rqst *rqstp)
{
	while (rqstp->rq_arghi)
		put_page(rqstp->rq_argpages[--rqstp->rq_arghi]);
	while (rqstp->rq_resused) {
		if (rqstp->rq_respages[--rqstp->rq_resused] == NULL)
			continue;
		put_page(rqstp->rq_respages[rqstp->rq_resused]);
	}
	rqstp->rq_argused = 0;
}

/*
 * Create a server thread
 */
int
svc_create_thread(svc_thread_fn func, struct svc_serv *serv)
{
	struct svc_rqst	*rqstp;
	int		error = -ENOMEM;

	rqstp = kzalloc(sizeof(*rqstp), GFP_KERNEL);
	if (!rqstp)
		goto out;

	init_waitqueue_head(&rqstp->rq_wait);

	if (!(rqstp->rq_argp = kmalloc(serv->sv_xdrsize, GFP_KERNEL))
	 || !(rqstp->rq_resp = kmalloc(serv->sv_xdrsize, GFP_KERNEL))
	 || !svc_init_buffer(rqstp, serv->sv_bufsz))
		goto out_thread;

	serv->sv_nrthreads++;
	rqstp->rq_server = serv;
	error = kernel_thread((int (*)(void *)) func, rqstp, 0);
	if (error < 0)
		goto out_thread;
	svc_sock_update_bufs(serv);
	error = 0;
out:
	return error;

out_thread:
	svc_exit_thread(rqstp);
	goto out;
}

/*
 * Destroy an RPC server thread
 */
void
svc_exit_thread(struct svc_rqst *rqstp)
{
	struct svc_serv	*serv = rqstp->rq_server;

	svc_release_buffer(rqstp);
	kfree(rqstp->rq_resp);
	kfree(rqstp->rq_argp);
	kfree(rqstp->rq_auth_data);
	kfree(rqstp);

	/* Release the server */
	if (serv)
		svc_destroy(serv);
}

/*
 * Register an RPC service with the local portmapper.
 * To unregister a service, call this routine with 
 * proto and port == 0.
 */
int
svc_register(struct svc_serv *serv, int proto, unsigned short port)
{
	struct svc_program	*progp;
	unsigned long		flags;
	int			i, error = 0, dummy;

	progp = serv->sv_program;

	dprintk("RPC: svc_register(%s, %s, %d)\n",
		progp->pg_name, proto == IPPROTO_UDP? "udp" : "tcp", port);

	if (!port)
		clear_thread_flag(TIF_SIGPENDING);

	for (i = 0; i < progp->pg_nvers; i++) {
		if (progp->pg_vers[i] == NULL)
			continue;
		error = rpc_register(progp->pg_prog, i, proto, port, &dummy);
		if (error < 0)
			break;
		if (port && !dummy) {
			error = -EACCES;
			break;
		}
	}

	if (!port) {
		spin_lock_irqsave(&current->sighand->siglock, flags);
		recalc_sigpending();
		spin_unlock_irqrestore(&current->sighand->siglock, flags);
	}

	return error;
}

/*
 * Process the RPC request.
 */
int
svc_process(struct svc_serv *serv, struct svc_rqst *rqstp)
{
	struct svc_program	*progp;
	struct svc_version	*versp = NULL;	/* compiler food */
	struct svc_procedure	*procp = NULL;
	struct kvec *		argv = &rqstp->rq_arg.head[0];
	struct kvec *		resv = &rqstp->rq_res.head[0];
	kxdrproc_t		xdr;
	u32