proc.c

LINUX1.0内核源代码,学习LINUX编程的一定要看。

	if (!(p = nfs_rpc_verify(p0)))
		status = NFSERR_IO;
	else if ((status = ntohl(*p++)) == NFS_OK) {
		p = xdr_decode_fhandle(p, fhandle);
		p = xdr_decode_fattr(p, fattr);
		PRINTK("NFS reply create\n");
	}
	else {
		if (!ruid && current->euid == 0 && current->uid != 0) {
			ruid = 1;
			goto retry;
		}
		PRINTK("NFS reply create failed = %d\n", status);
	}
	nfs_rpc_free(p0);
	return -nfs_stat_to_errno(status);
}

int nfs_proc_remove(struct nfs_server *server, struct nfs_fh *dir, const char *name)
{
	int *p, *p0;
	int status;
	int ruid = 0;

	PRINTK("NFS call  remove %s\n", name);
	if (!(p0 = nfs_rpc_alloc()))
		return -EIO;
retry:
	p = nfs_rpc_header(p0, NFSPROC_REMOVE, ruid);
	p = xdr_encode_fhandle(p, dir);
	p = xdr_encode_string(p, name);
	if ((status = nfs_rpc_call(server, p0, p)) < 0) {
		nfs_rpc_free(p0);
		return status;
	}
	if (!(p = nfs_rpc_verify(p0)))
		status = NFSERR_IO;
	else if ((status = ntohl(*p++)) == NFS_OK) {
		PRINTK("NFS reply remove\n");
	}
	else {
		if (!ruid && current->euid == 0 && current->uid != 0) {
			ruid = 1;
			goto retry;
		}
		PRINTK("NFS reply remove failed = %d\n", status);
	}
	nfs_rpc_free(p0);
	return -nfs_stat_to_errno(status);
}

int nfs_proc_rename(struct nfs_server *server,
		    struct nfs_fh *old_dir, const char *old_name,
		    struct nfs_fh *new_dir, const char *new_name)
{
	int *p, *p0;
	int status;
	int ruid = 0;

	PRINTK("NFS call  rename %s -> %s\n", old_name, new_name);
	if (!(p0 = nfs_rpc_alloc()))
		return -EIO;
retry:
	p = nfs_rpc_header(p0, NFSPROC_RENAME, ruid);
	p = xdr_encode_fhandle(p, old_dir);
	p = xdr_encode_string(p, old_name);
	p = xdr_encode_fhandle(p, new_dir);
	p = xdr_encode_string(p, new_name);
	if ((status = nfs_rpc_call(server, p0, p)) < 0) {
		nfs_rpc_free(p0);
		return status;
	}
	if (!(p = nfs_rpc_verify(p0)))
		status = NFSERR_IO;
	else if ((status = ntohl(*p++)) == NFS_OK) {
		PRINTK("NFS reply rename\n");
	}
	else {
		if (!ruid && current->euid == 0 && current->uid != 0) {
			ruid = 1;
			goto retry;
		}
		PRINTK("NFS reply rename failed = %d\n", status);
	}
	nfs_rpc_free(p0);
	return -nfs_stat_to_errno(status);
}

int nfs_proc_link(struct nfs_server *server, struct nfs_fh *fhandle,
		  struct nfs_fh *dir, const char *name)
{
	int *p, *p0;
	int status;
	int ruid = 0;

	PRINTK("NFS call  link %s\n", name);
	if (!(p0 = nfs_rpc_alloc()))
		return -EIO;
retry:
	p = nfs_rpc_header(p0, NFSPROC_LINK, ruid);
	p = xdr_encode_fhandle(p, fhandle);
	p = xdr_encode_fhandle(p, dir);
	p = xdr_encode_string(p, name);
	if ((status = nfs_rpc_call(server, p0, p)) < 0) {
		nfs_rpc_free(p0);
		return status;
	}
	if (!(p = nfs_rpc_verify(p0)))
		status = NFSERR_IO;
	else if ((status = ntohl(*p++)) == NFS_OK) {
		PRINTK("NFS reply link\n");
	}
	else {
		if (!ruid && current->euid == 0 && current->uid != 0) {
			ruid = 1;
			goto retry;
		}
		PRINTK("NFS reply link failed = %d\n", status);
	}
	nfs_rpc_free(p0);
	return -nfs_stat_to_errno(status);
}

int nfs_proc_symlink(struct nfs_server *server, struct nfs_fh *dir,
		     const char *name, const char *path, struct nfs_sattr *sattr)
{
	int *p, *p0;
	int status;
	int ruid = 0;

	PRINTK("NFS call  symlink %s -> %s\n", name, path);
	if (!(p0 = nfs_rpc_alloc()))
		return -EIO;
retry:
	p = nfs_rpc_header(p0, NFSPROC_SYMLINK, ruid);
	p = xdr_encode_fhandle(p, dir);
	p = xdr_encode_string(p, name);
	p = xdr_encode_string(p, path);
	p = xdr_encode_sattr(p, sattr);
	if ((status = nfs_rpc_call(server, p0, p)) < 0) {
		nfs_rpc_free(p0);
		return status;
	}
	if (!(p = nfs_rpc_verify(p0)))
		status = NFSERR_IO;
	else if ((status = ntohl(*p++)) == NFS_OK) {
		PRINTK("NFS reply symlink\n");
	}
	else {
		if (!ruid && current->euid == 0 && current->uid != 0) {
			ruid = 1;
			goto retry;
		}
		PRINTK("NFS reply symlink failed = %d\n", status);
	}
	nfs_rpc_free(p0);
	return -nfs_stat_to_errno(status);
}

int nfs_proc_mkdir(struct nfs_server *server, struct nfs_fh *dir,
		   const char *name, struct nfs_sattr *sattr,
		   struct nfs_fh *fhandle, struct nfs_fattr *fattr)
{
	int *p, *p0;
	int status;
	int ruid = 0;

	PRINTK("NFS call  mkdir %s\n", name);
	if (!(p0 = nfs_rpc_alloc()))
		return -EIO;
retry:
	p = nfs_rpc_header(p0, NFSPROC_MKDIR, ruid);
	p = xdr_encode_fhandle(p, dir);
	p = xdr_encode_string(p, name);
	p = xdr_encode_sattr(p, sattr);
	if ((status = nfs_rpc_call(server, p0, p)) < 0) {
		nfs_rpc_free(p0);
		return status;
	}
	if (!(p = nfs_rpc_verify(p0)))
		status = NFSERR_IO;
	else if ((status = ntohl(*p++)) == NFS_OK) {
		p = xdr_decode_fhandle(p, fhandle);
		p = xdr_decode_fattr(p, fattr);
		PRINTK("NFS reply mkdir\n");
	}
	else {
		if (!ruid && current->euid == 0 && current->uid != 0) {
			ruid = 1;
			goto retry;
		}
		PRINTK("NFS reply mkdir failed = %d\n", status);
	}
	nfs_rpc_free(p0);
	return -nfs_stat_to_errno(status);
}

int nfs_proc_rmdir(struct nfs_server *server, struct nfs_fh *dir, const char *name)
{
	int *p, *p0;
	int status;
	int ruid = 0;

	PRINTK("NFS call  rmdir %s\n", name);
	if (!(p0 = nfs_rpc_alloc()))
		return -EIO;
retry:
	p = nfs_rpc_header(p0, NFSPROC_RMDIR, ruid);
	p = xdr_encode_fhandle(p, dir);
	p = xdr_encode_string(p, name);
	if ((status = nfs_rpc_call(server, p0, p)) < 0) {
		nfs_rpc_free(p0);
		return status;
	}
	if (!(p = nfs_rpc_verify(p0)))
		status = NFSERR_IO;
	else if ((status = ntohl(*p++)) == NFS_OK) {
		PRINTK("NFS reply rmdir\n");
	}
	else {
		if (!ruid && current->euid == 0 && current->uid != 0) {
			ruid = 1;
			goto retry;
		}
		PRINTK("NFS reply rmdir failed = %d\n", status);
	}
	nfs_rpc_free(p0);
	return -nfs_stat_to_errno(status);
}

int nfs_proc_readdir(struct nfs_server *server, struct nfs_fh *fhandle,
		     int cookie, int count, struct nfs_entry *entry)
{
	int *p, *p0;
	int status;
	int ruid = 0;
	int i = 0; /* = 0 is for gcc */
	int size;
	int eof;

	PRINTK("NFS call  readdir %d @ %d\n", count, cookie);
	size = server->rsize;
	if (!(p0 = nfs_rpc_alloc()))
		return -EIO;
retry:
	p = nfs_rpc_header(p0, NFSPROC_READDIR, ruid);
	p = xdr_encode_fhandle(p, fhandle);
	*p++ = htonl(cookie);
	*p++ = htonl(size);
	if ((status = nfs_rpc_call(server, p0, p)) < 0) {
		nfs_rpc_free(p0);
		return status;
	}
	if (!(p = nfs_rpc_verify(p0)))
		status = NFSERR_IO;
	else if ((status = ntohl(*p++)) == NFS_OK) {
		for (i = 0; i < count && *p++; i++) {
			if (!(p = xdr_decode_entry(p, entry++)))
				break;
		}
		if (!p) {
			printk("nfs_proc_readdir: giant filename\n");
			status = NFSERR_IO;
		}
		else {
			eof = (i == count && !*p++ && *p++)
			      || (i < count && *p++);
			if (eof && i)
				entry[-1].eof = 1;
			PRINTK("NFS reply readdir %d %s\n", i,
			       eof ? "eof" : "");
		}
	}
	else {
		if (!ruid && current->euid == 0 && current->uid != 0) {
			ruid = 1;
			goto retry;
		}
		PRINTK("NFS reply readdir failed = %d\n", status);
	}
	nfs_rpc_free(p0);
	return (status == NFS_OK) ? i : -nfs_stat_to_errno(status);
}

int nfs_proc_statfs(struct nfs_server *server, struct nfs_fh *fhandle,
		    struct nfs_fsinfo *res)
{
	int *p, *p0;
	int status;
	int ruid = 0;

	PRINTK("NFS call  statfs\n");
	if (!(p0 = nfs_rpc_alloc()))
		return -EIO;
retry:
	p = nfs_rpc_header(p0, NFSPROC_STATFS, ruid);
	p = xdr_encode_fhandle(p, fhandle);
	if ((status = nfs_rpc_call(server, p0, p)) < 0) {
		nfs_rpc_free(p0);
		return status;
	}
	if (!(p = nfs_rpc_verify(p0)))
		status = NFSERR_IO;
	else if ((status = ntohl(*p++)) == NFS_OK) {
		p = xdr_decode_fsinfo(p, res);
		PRINTK("NFS reply statfs\n");
	}
	else {
		if (!ruid && current->euid == 0 && current->uid != 0) {
			ruid = 1;
			goto retry;
		}
		PRINTK("NFS reply statfs failed = %d\n", status);
	}
	nfs_rpc_free(p0);
	return -nfs_stat_to_errno(status);
}

/*
 * Here are a few RPC-assist functions.
 */

static int *nfs_rpc_header(int *p, int procedure, int ruid)
{
	int *p1, *p2;
	int i;
	static int xid = 0;
	unsigned char *sys = (unsigned char *) system_utsname.nodename;

	if (xid == 0) {
		xid = CURRENT_TIME;
		xid ^= (sys[3]<<24) | (sys[2]<<16) | (sys[1]<<8) | sys[0];
	}
	*p++ = htonl(++xid);
	*p++ = htonl(RPC_CALL);
	*p++ = htonl(RPC_VERSION);
	*p++ = htonl(NFS_PROGRAM);
	*p++ = htonl(NFS_VERSION);
	*p++ = htonl(procedure);
	*p++ = htonl(RPC_AUTH_UNIX);
	p1 = p++;
	*p++ = htonl(CURRENT_TIME); /* traditional, could be anything */
	p = xdr_encode_string(p, (char *) sys);
	*p++ = htonl(ruid ? current->uid : current->euid);
	*p++ = htonl(current->egid);
	p2 = p++;
	for (i = 0; i < 16 && i < NGROUPS && current->groups[i] != NOGROUP; i++)
		*p++ = htonl(current->groups[i]);
	*p2 = htonl(i);
	*p1 = htonl((p - (p1 + 1)) << 2);
	*p++ = htonl(RPC_AUTH_NULL);
	*p++ = htonl(0);
	return p;
}

static int *nfs_rpc_verify(int *p)
{
	unsigned int n;

	p++;
	if ((n = ntohl(*p++)) != RPC_REPLY) {
		printk("nfs_rpc_verify: not an RPC reply: %d\n", n);
		return NULL;
	}
	if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
		printk("nfs_rpc_verify: RPC call rejected: %d\n", n);
		return NULL;
	}
	switch (n = ntohl(*p++)) {
	case RPC_AUTH_NULL: case RPC_AUTH_UNIX: case RPC_AUTH_SHORT:
		break;
	default:
		printk("nfs_rpc_verify: bad RPC authentication type: %d\n", n);
		return NULL;
	}
	if ((n = ntohl(*p++)) > 400) {
		printk("nfs_rpc_verify: giant auth size\n");
		return NULL;
	}
	p += (n + 3) >> 2;
	if ((n = ntohl(*p++)) != RPC_SUCCESS) {
		printk("nfs_rpc_verify: RPC call failed: %d\n", n);
		return NULL;
	}
	return p;
}
	
/*
 * We need to translate between nfs status return values and
 * the local errno values which may not be the same.
 */

#ifndef EDQUOT
#define EDQUOT	ENOSPC
#endif

static struct {
	int stat;
	int errno;
} nfs_errtbl[] = {
	{ NFS_OK,		0		},
	{ NFSERR_PERM,		EPERM		},
	{ NFSERR_NOENT,		ENOENT		},
	{ NFSERR_IO,		EIO		},
	{ NFSERR_NXIO,		ENXIO		},
	{ NFSERR_ACCES,		EACCES		},
	{ NFSERR_EXIST,		EEXIST		},
	{ NFSERR_NODEV,		ENODEV		},
	{ NFSERR_NOTDIR,	ENOTDIR		},
	{ NFSERR_ISDIR,		EISDIR		},
	{ NFSERR_INVAL,		EINVAL		},
	{ NFSERR_FBIG,		EFBIG		},
	{ NFSERR_NOSPC,		ENOSPC		},
	{ NFSERR_ROFS,		EROFS		},
	{ NFSERR_NAMETOOLONG,	ENAMETOOLONG	},
	{ NFSERR_NOTEMPTY,	ENOTEMPTY	},
	{ NFSERR_DQUOT,		EDQUOT		},
	{ NFSERR_STALE,		ESTALE		},
#ifdef EWFLUSH
	{ NFSERR_WFLUSH,	EWFLUSH		},
#endif
	{ -1,			EIO		}
};

static int nfs_stat_to_errno(int stat)
{
	int i;

	for (i = 0; nfs_errtbl[i].stat != -1; i++) {
		if (nfs_errtbl[i].stat == stat)
			return nfs_errtbl[i].errno;
	}
	printk("nfs_stat_to_errno: bad nfs status return value: %d\n", stat);
	return nfs_errtbl[i].errno;
}