nfs.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

/* Copyright © 2003 Russ Cox, MIT; see /sys/src/libsunrpc/COPYING */
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <fcall.h>
#include <thread.h>
#include <9p.h>
#include <sunrpc.h>
#include <nfs3.h>

SunClient *nfscli;
SunClient *mntcli;
char *defaultpath = "/";
Channel *fschan;
char *sys;
int verbose;
int readplus = 0;


typedef struct Auth Auth;
struct Auth
{
	int ref;
	uchar *data;
	int ndata;
};

typedef struct FidAux FidAux;
struct FidAux
{
	Nfs3Handle handle;

	u64int cookie;	/* for continuing directory reads */
	char *name;	/* botch: for remove and rename */
	Nfs3Handle parent;	/* botch: for remove and rename */
	char err[ERRMAX];	/* for walk1 */
	Auth *auth;
};

/*
 * various RPCs.  here is where we'd insert support for NFS v2
 */

void
portCall(SunCall *c, PortCallType type)
{
	c->rpc.prog = PortProgram;
	c->rpc.vers = PortVersion;
	c->rpc.proc = type>>1;
	c->rpc.iscall = !(type&1);
	c->type = type;
}

int
getport(SunClient *client, uint prog, uint vers, uint prot, uint *port)
{
	PortTGetport tx;
	PortRGetport rx;

	memset(&tx, 0, sizeof tx);
	portCall(&tx.call, PortCallTGetport);
	tx.map.prog = prog;
	tx.map.vers = vers;
	tx.map.prot = prot;

	memset(&rx, 0, sizeof rx);
	portCall(&rx.call, PortCallRGetport);

	if(sunClientRpc(client, 0, &tx.call, &rx.call, nil) < 0)
		return -1;
	*port = rx.port;
	return 0;
}

void
mountCall(Auth *a, SunCall *c, NfsMount3CallType type)
{
	c->rpc.iscall = !(type&1);
	c->rpc.proc = type>>1;
	c->rpc.prog = NfsMount3Program;
	c->rpc.vers = NfsMount3Version;
	if(c->rpc.iscall && a){
		c->rpc.cred.flavor = SunAuthSys;
		c->rpc.cred.data = a->data;
		c->rpc.cred.ndata = a->ndata;
	}
	c->type = type;
}

int
mountNull(ulong tag)
{
	NfsMount3TNull tx;
	NfsMount3RNull rx;

	memset(&tx, 0, sizeof tx);
	mountCall(nil, &tx.call, NfsMount3CallTNull);

	memset(&rx, 0, sizeof rx);
	mountCall(nil, &rx.call, NfsMount3CallTNull);

	return sunClientRpc(mntcli, tag, &tx.call, &rx.call, nil);
}

int
mountMnt(Auth *a, ulong tag, char *path, Nfs3Handle *h)
{
	uchar *freeme;
	NfsMount3TMnt tx;
	NfsMount3RMnt rx;

	memset(&tx, 0, sizeof tx);
	mountCall(a, &tx.call, NfsMount3CallTMnt);
	tx.path = path;

	memset(&rx, 0, sizeof rx);
	mountCall(a, &rx.call, NfsMount3CallRMnt);
	if(sunClientRpc(mntcli, tag, &tx.call, &rx.call, &freeme) < 0)
		return -1;
	if(rx.status != Nfs3Ok){
		nfs3Errstr(rx.status);
		return -1;
	}
if(verbose)print("handle %.*H\n", rx.len, rx.handle);
	if(rx.len >= Nfs3MaxHandleSize){
		free(freeme);
		werrstr("server-returned handle too long");
		return -1;
	}
	memmove(h->h, rx.handle, rx.len);
	h->len = rx.len;
	free(freeme);
	return 0;
}

void
nfs3Call(Auth *a, SunCall *c, Nfs3CallType type)
{
	c->rpc.iscall = !(type&1);
	c->rpc.proc = type>>1;
	c->rpc.prog = Nfs3Program;
	c->rpc.vers = Nfs3Version;
	if(c->rpc.iscall && a){
		c->rpc.cred.flavor = SunAuthSys;
		c->rpc.cred.data = a->data;
		c->rpc.cred.ndata = a->ndata;
	}
	c->type = type;
}

int
nfsNull(ulong tag)
{
	Nfs3TNull tx;
	Nfs3RNull rx;

	memset(&tx, 0, sizeof tx);
	nfs3Call(nil, &tx.call, Nfs3CallTNull);

	memset(&rx, 0, sizeof rx);
	nfs3Call(nil, &rx.call, Nfs3CallTNull);

	return sunClientRpc(nfscli, tag, &tx.call, &rx.call, nil);
}

int
nfsGetattr(Auth *a, ulong tag, Nfs3Handle *h, Nfs3Attr *attr)
{
	Nfs3TGetattr tx;
	Nfs3RGetattr rx;

	memset(&tx, 0, sizeof tx);
	nfs3Call(a, &tx.call, Nfs3CallTGetattr);
	tx.handle = *h;	

	memset(&rx, 0, sizeof rx);
	nfs3Call(a, &rx.call, Nfs3CallRGetattr);

	if(sunClientRpc(nfscli, tag, &tx.call, &rx.call, nil) < 0)
		return -1;
	if(rx.status != Nfs3Ok){
		nfs3Errstr(rx.status);
		return -1;
	}

	*attr = rx.attr;
	return 0;
}

int
nfsAccess(Auth *a, ulong tag, Nfs3Handle *h, ulong want, ulong *got, u1int *have, Nfs3Attr *attr)
{
	Nfs3TAccess tx;
	Nfs3RAccess rx;

	memset(&tx, 0, sizeof tx);
	nfs3Call(a, &tx.call, Nfs3CallTAccess);
	tx.handle = *h;
	tx.access = want;

	memset(&rx, 0, sizeof rx);
	nfs3Call(a, &rx.call, Nfs3CallRAccess);

	if(sunClientRpc(nfscli, tag, &tx.call, &rx.call, nil) < 0)
		return -1;
	if(rx.status != Nfs3Ok){
		nfs3Errstr(rx.status);
		return -1;
	}

	*got = rx.access;

	*have = rx.haveAttr;
	if(rx.haveAttr)
		*attr = rx.attr;
	return 0;
}

int
nfsMkdir(Auth *a, ulong tag, Nfs3Handle *h, char *name, Nfs3Handle *nh, ulong mode, uint gid,
	u1int *have, Nfs3Attr *attr)
{
	Nfs3TMkdir tx;
	Nfs3RMkdir rx;

	memset(&tx, 0, sizeof tx);
	nfs3Call(a, &tx.call, Nfs3CallTMkdir);
	tx.handle = *h;
	tx.name = name;
	tx.attr.setMode = 1;
	tx.attr.mode = mode;
	tx.attr.setGid = 1;
	tx.attr.gid = gid;

	memset(&rx, 0, sizeof rx);
	nfs3Call(a, &rx.call, Nfs3CallRMkdir);

	if(sunClientRpc(nfscli, tag, &tx.call, &rx.call, nil) < 0)
		return -1;
	if(rx.status != Nfs3Ok){
		nfs3Errstr(rx.status);
		return -1;
	}

	if(!rx.haveHandle){
		werrstr("nfs mkdir did not return handle");
		return -1;
	}
	*nh = rx.handle;

	*have = rx.haveAttr;
	if(rx.haveAttr)
		*attr = rx.attr;
	return 0;
}

int
nfsCreate(Auth *a, ulong tag, Nfs3Handle *h, char *name, Nfs3Handle *nh, ulong mode, uint gid,
	u1int *have, Nfs3Attr *attr)
{
	Nfs3TCreate tx;
	Nfs3RCreate rx;

	memset(&tx, 0, sizeof tx);
	nfs3Call(a, &tx.call, Nfs3CallTCreate);
	tx.handle = *h;
	tx.name = name;
	tx.attr.setMode = 1;
	tx.attr.mode = mode;
	tx.attr.setGid = 1;
	tx.attr.gid = gid;

	memset(&rx, 0, sizeof rx);
	nfs3Call(a, &rx.call, Nfs3CallRCreate);

	if(sunClientRpc(nfscli, tag, &tx.call, &rx.call, nil) < 0)
		return -1;
	if(rx.status != Nfs3Ok){
		nfs3Errstr(rx.status);
		return -1;
	}

	if(!rx.haveHandle){
		werrstr("nfs create did not return handle");
		return -1;
	}
	*nh = rx.handle;

	*have = rx.haveAttr;
	if(rx.haveAttr)
		*attr = rx.attr;
	return 0;
}

int
nfsRead(Auth *a, ulong tag, Nfs3Handle *h, u32int count, u64int offset,
	uchar **pp, u32int *pcount, uchar **pfreeme)
{
	uchar *freeme;
	Nfs3TRead tx;
	Nfs3RRead rx;

	memset(&tx, 0, sizeof tx);
	nfs3Call(a, &tx.call, Nfs3CallTRead);
	tx.handle = *h;
	tx.count = count;
	tx.offset = offset;

	memset(&rx, 0, sizeof rx);
	nfs3Call(a, &rx.call, Nfs3CallRRead);

	if(sunClientRpc(nfscli, tag, &tx.call, &rx.call, &freeme) < 0)
		return -1;
	if(rx.status != Nfs3Ok){
		nfs3Errstr(rx.status);
		return -1;
	}
	if(rx.count != rx.ndata){
		werrstr("nfs read returned count=%ud ndata=%ud", (uint)rx.count, (uint)rx.ndata);
		free(freeme);
		return -1;
	}
	*pfreeme = freeme;
	*pcount = rx.count;
	*pp = rx.data;
	return 0;
}

int
nfsWrite(Auth *a, ulong tag, Nfs3Handle *h, uchar *data, u32int count, u64int offset, u32int *pcount)
{
	Nfs3TWrite tx;
	Nfs3RWrite rx;

	memset(&tx, 0, sizeof tx);
	nfs3Call(a, &tx.call, Nfs3CallTWrite);
	tx.handle = *h;
	tx.count = count;
	tx.offset = offset;
	tx.data = data;
	tx.ndata = count;

	memset(&rx, 0, sizeof rx);
	nfs3Call(a, &rx.call, Nfs3CallRWrite);

	if(sunClientRpc(nfscli, tag, &tx.call, &rx.call, nil) < 0)
		return -1;
	if(rx.status != Nfs3Ok){
		nfs3Errstr(rx.status);
		return -1;
	}

	*pcount = rx.count;
	return 0;
}

int
nfsRmdir(Auth *a, ulong tag, Nfs3Handle *h, char *name)
{
	Nfs3TRmdir tx;
	Nfs3RRmdir rx;

	memset(&tx, 0, sizeof tx);
	nfs3Call(a, &tx.call, Nfs3CallTRmdir);
	tx.handle = *h;
	tx.name = name;

	memset(&rx, 0, sizeof rx);
	nfs3Call(a, &rx.call, Nfs3CallRRmdir);

	if(sunClientRpc(nfscli, tag, &tx.call, &rx.call, nil) < 0)
		return -1;
	if(rx.status != Nfs3Ok){
		nfs3Errstr(rx.status);
		return -1;
	}
	return 0;
}

int
nfsRemove(Auth *a, ulong tag, Nfs3Handle *h, char *name)
{
	Nfs3TRemove tx;
	Nfs3RRemove rx;

	memset(&tx, 0, sizeof tx);
	nfs3Call(a, &tx.call, Nfs3CallTRemove);
	tx.handle = *h;
	tx.name = name;

	memset(&rx, 0, sizeof rx);
	nfs3Call(a, &rx.call, Nfs3CallRRemove);

	if(sunClientRpc(nfscli, tag, &tx.call, &rx.call, nil) < 0)
		return -1;
	if(rx.status != Nfs3Ok){
		nfs3Errstr(rx.status);
		return -1;
	}
	return 0;
}

int
nfsRename(Auth *a, ulong tag, Nfs3Handle *h, char *name, Nfs3Handle *th, char *tname)
{
	Nfs3TRename tx;
	Nfs3RRename rx;

	memset(&tx, 0, sizeof tx);
	nfs3Call(a, &tx.call, Nfs3CallTRename);
	tx.from.handle = *h;
	tx.from.name = name;
	tx.to.handle = *th;
	tx.to.name = tname;

	memset(&rx, 0, sizeof rx);
	nfs3Call(a, &rx.call, Nfs3CallRRename);

	if(sunClientRpc(nfscli, tag, &tx.call, &rx.call, nil) < 0)
		return -1;
	if(rx.status != Nfs3Ok){
		nfs3Errstr(rx.status);
		return -1;
	}
	return 0;
}

int
nfsSetattr(Auth *a, ulong tag, Nfs3Handle *h, Nfs3SetAttr *attr)
{
	Nfs3TSetattr tx;
	Nfs3RSetattr rx;

	memset(&tx, 0, sizeof tx);
	nfs3Call(a, &tx.call, Nfs3CallTSetattr);
	tx.handle = *h;
	tx.attr = *attr;

	memset(&rx, 0, sizeof rx);
	nfs3Call(a, &rx.call, Nfs3CallRSetattr);

	if(sunClientRpc(nfscli, tag, &tx.call, &rx.call, nil) < 0)
		return -1;
	if(rx.status != Nfs3Ok){
		nfs3Errstr(rx.status);
		return -1;
	}
	return 0;
}

int
nfsCommit(Auth *a, ulong tag, Nfs3Handle *h)
{
	Nfs3TCommit tx;
	Nfs3RCommit rx;

	memset(&tx, 0, sizeof tx);
	nfs3Call(a, &tx.call, Nfs3CallTCommit);
	tx.handle = *h;

	memset(&rx, 0, sizeof rx);
	nfs3Call(a, &rx.call, Nfs3CallRCommit);

	if(sunClientRpc(nfscli, tag, &tx.call, &rx.call, nil) < 0)
		return -1;

	if(rx.status != Nfs3Ok){
		nfs3Errstr(rx.status);
		return -1;
	}
	return 0;
}

int
nfsLookup(Auth *a, ulong tag, Nfs3Handle *h, char *name, Nfs3Handle *nh, u1int *have, Nfs3Attr *attr)
{
	Nfs3TLookup tx;
	Nfs3RLookup rx;

	memset(&tx, 0, sizeof tx);
	nfs3Call(a, &tx.call, Nfs3CallTLookup);
	tx.handle = *h;
	tx.name = name;

	memset(&rx, 0, sizeof rx);
	nfs3Call(a, &rx.call, Nfs3CallRLookup);

	if(sunClientRpc(nfscli, tag, &tx.call, &rx.call, nil) < 0)
		return -1;

	if(rx.status != Nfs3Ok){
		nfs3Errstr(rx.status);
		return -1;
	}
	*nh = rx.handle;
	*have = rx.haveAttr;
	if(rx.haveAttr)
		*attr = rx.attr;
	return 0;
}

int
nfsReadDirPlus(Auth *a, ulong tag, Nfs3Handle *h, u32int count, u64int cookie, uchar **pp,
	u32int *pcount, int (**unpack)(uchar*, uchar*, uchar**, Nfs3Entry*), uchar **pfreeme)
{
	Nfs3TReadDirPlus tx;
	Nfs3RReadDirPlus rx;

	memset(&tx, 0, sizeof tx);
	nfs3Call(a, &tx.call, Nfs3CallTReadDirPlus);
	tx.handle = *h;
	tx.maxCount = count;
	tx.dirCount = 1000;
	tx.cookie = cookie;

	memset(&rx, 0, sizeof rx);
	nfs3Call(a, &rx.call, Nfs3CallRReadDirPlus);

	if(sunClientRpc(nfscli, tag, &tx.call, &rx.call, pfreeme) < 0)
		return -1;
	if(rx.status != Nfs3Ok){
		free(*pfreeme);
		*pfreeme = 0;
		nfs3Errstr(rx.status);
		return -1;
	}

	*unpack = nfs3EntryPlusUnpack;
	*pcount = rx.count;
	*pp = rx.data;
	return 0;
}

int
nfsReadDir(Auth *a, ulong tag, Nfs3Handle *h, u32int count, u64int cookie, uchar **pp,
	u32int *pcount, int (**unpack)(uchar*, uchar*, uchar**, Nfs3Entry*), uchar **pfreeme)
{
	/* BUG: try readdirplus */
	char e[ERRMAX];
	Nfs3TReadDir tx;
	Nfs3RReadDir rx;

	if(readplus!=-1){
		if(nfsReadDirPlus(a, tag, h, count, cookie, pp, pcount, unpack, pfreeme) == 0){
			readplus = 1;