diff options
Diffstat (limited to 'usr.sbin/rpc.yppasswdd/yppasswd_comm.c')
-rw-r--r-- | usr.sbin/rpc.yppasswdd/yppasswd_comm.c | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/usr.sbin/rpc.yppasswdd/yppasswd_comm.c b/usr.sbin/rpc.yppasswdd/yppasswd_comm.c new file mode 100644 index 0000000..d43d961 --- /dev/null +++ b/usr.sbin/rpc.yppasswdd/yppasswd_comm.c @@ -0,0 +1,300 @@ +/* + * Copyright (c) 1995, 1996 + * Bill Paul <wpaul@ctr.columbia.edu>. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by Bill Paul. + * 4. Neither the name of the author nor the names of any co-contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL Bill Paul OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $Id: yppasswd_comm.c,v 1.10 1996/02/03 04:41:59 wpaul Exp $ + */ + +/* + * This file contains a UNIX domain socket communications package + * that lets a client process send pseudo-RPCs to rpc.yppasswdd + * without using IP. This 'local-only' communications channel is + * only used when the superuser runs passwd(1) or chpass(1) on + * the NIS master server. The idea is that we want to grant the + * superuser permission to perfom certain special operations, but + * we need an iron-clad way to tell when we're receiving a request + * from the superuser and when we aren't. To connect to a UNIX + * domain socket, one needs to be able to access a file in the + * filesystem. The socket created by rpc.yppasswdd is owned by + * root and has all its permission bits cleared, so the only + * user who can sucessfully connect() to it is root. + * + * It is the server's responsibility to initialize the listening + * socket with the makeservsock() function and to add the socket to + * the set of file descriptors monitored by the svc_run() loop. + * Once this is done, calls made through the UNIX domain socket + * can be handled almost exactly like a normal RPC. We even use + * the XDR functions for serializing data between the client and + * server to simplify the passing of complex data structures. + */ + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <unistd.h> +#include <err.h> +#include <errno.h> +#include <sys/time.h> +#include <sys/types.h> +#include <sys/socket.h> +#include <sys/un.h> +#include <sys/fcntl.h> +#include <rpc/rpc.h> +#include <rpcsvc/yp.h> +#include "yppasswd_comm.h" +#include "yppasswd_private.h" +#include "ypxfr_extern.h" + +#ifndef lint +static const char rcsid[] = "$Id: yppasswd_comm.c,v 1.10 1996/02/03 04:41:59 wpaul Exp $"; +#endif + +char *sockname = "/var/run/ypsock"; +FILE *serv_fp; +FILE *clnt_fp; +int serv_sock; +int clnt_sock; + +/* + * serialize_data() and serialize_resp() are what really do most of + * the work. These functions (ab)use xdrstdio_create() as the interface + * to the XDR library. The RPC library uses xdrrec_create() and friends + * for TCP based connections. I suppose we could use that here, but + * the interface is a bit too complicated to justify using in an + * applicatuion such as this. With xdrstdio_create(), the only catch + * is that we need to provide a buffered file stream rather than + * a simple socket descriptor, but we can easily turn the latter into + * the former using fdopen(2). + * + * Doing things this way buys us the ability to change the form of + * the data being exchanged without having to modify any of the + * routines in this package. + */ +static int serialize_data(data, fp, op) + struct master_yppasswd *data; + FILE *fp; + int op; +{ + XDR xdrs; + + xdrstdio_create(&xdrs, fp, op); + + if (!xdr_master_yppasswd(&xdrs, data)) { + xdr_destroy(&xdrs); + return(1); + } + return(0); +} + +static int serialize_resp(resp, fp, op) + int *resp; + FILE *fp; + int op; +{ + XDR xdrs; + + xdrstdio_create(&xdrs, fp, op); + + if (!xdr_int(&xdrs, resp)) { + xdr_destroy(&xdrs); + return(1); + } + return(0); +} + +/* + * Build the server's listening socket. The descriptor generated + * here will be monitored for new connections by the svc_run() loop. + */ +int makeservsock() +{ + static int ypsock; + struct sockaddr_un us; + int len; + + unlink(sockname); + + if ((ypsock = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) + err(1, "failed to create UNIX domain socket"); + + bzero((char *)&us, sizeof(us)); + us.sun_family = AF_UNIX; + strcpy((char *)&us.sun_path, sockname); + len = strlen(us.sun_path) + sizeof(us.sun_family) + 1; + + if (bind(ypsock, (struct sockaddr *)&us, len) == -1) + err(1,"failed to bind UNIX domain socket"); + + listen (ypsock, 1); + + return(ypsock); +} + +/* + * Create a socket for a client and try to connect() it to the + * server. + */ +static int makeclntsock() +{ + static int ypsock; + struct sockaddr_un us; + int len; + + if ((ypsock = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) { + warn("failed to create UNIX domain socket"); + return(-1); + } + + bzero((char *)&us, sizeof(us)); + us.sun_family = AF_UNIX; + strcpy((char *)&us.sun_path, sockname); + len = strlen(us.sun_path) + sizeof(us.sun_family) + 1; + + if (connect(ypsock, (struct sockaddr *)&us, len) == -1) { + warn("failed to connect to server"); + return(-1); + } + + return(ypsock); +} + +/* + * This function is used by the server to accept a new connection + * from a client and read its request data into a master_yppasswd + * stucture. + */ +struct master_yppasswd *getdat(sock) + int sock; +{ + int len; + struct sockaddr_un us; + static struct master_yppasswd pw; + struct timeval tv; + fd_set fds; + + FD_ZERO(&fds); + FD_SET(sock, &fds); + + tv.tv_sec = CONNECTION_TIMEOUT; + tv.tv_usec = 0; + + switch(select(FD_SETSIZE, &fds, NULL, NULL, &tv)) { + case 0: + yp_error("select timed out"); + return(NULL); + break; + case -1: + yp_error("select() failed: %s", strerror(errno)); + return(NULL); + break; + default: + break; + } + + if ((serv_sock = accept(sock, (struct sockaddr *)&us, &len)) == -1) { + yp_error("accept failed: %s", strerror(errno)); + return(NULL); + } + + if ((serv_fp = fdopen(serv_sock, "r+")) == NULL) { + yp_error("fdopen failed: %s",strerror(errno)); + return(NULL); + } + + if (serialize_data(&pw, serv_fp, XDR_DECODE)) { + yp_error("failed to receive data"); + return(NULL); + } + + return(&pw); +} + +/* + * Client uses this to read back a response code (a single + * integer) from the server. Note that we don't need to implement + * any special XDR function for this since an int is a base data + * type which the XDR library can handle directly. + */ +int *getresp() +{ + static int resp; + + if (serialize_resp(&resp, clnt_fp, XDR_DECODE)) { + warn("failed to receive response"); + return(NULL); + } + + fclose(clnt_fp); + close(clnt_sock); + return(&resp); +} + +/* + * Create a connection to the server and send a reqest + * to be processed. + */ +int senddat(pw) + struct master_yppasswd *pw; +{ + + if ((clnt_sock = makeclntsock()) == -1) { + warn("failed to create socket"); + return(1); + } + + if ((clnt_fp = fdopen(clnt_sock, "r+")) == NULL) { + warn("fdopen failed"); + return(1); + } + + if (serialize_data(pw, clnt_fp, XDR_ENCODE)) { + warn("failed to send data"); + return(1); + } + + return(0); +} + +/* + * This sends a response code back to the client. + */ +int sendresp(resp) + int resp; +{ + + if (serialize_resp(&resp, serv_fp, XDR_ENCODE)) { + yp_error("failed to send response"); + return(-1); + } + + fclose(serv_fp); + close(serv_sock); + return(0); +} |