Annotation of src/usr.bin/rsh/kcmd.c, Revision 1.1
1.1 ! deraadt 1: /* $OpenBSD: kcmd.c,v 1.15 2002/02/17 19:42:31 millert Exp $ */
! 2: /* $NetBSD: kcmd.c,v 1.2 1995/03/21 07:58:32 cgd Exp $ */
! 3:
! 4: /*
! 5: * Copyright (c) 1983, 1993
! 6: * The Regents of the University of California. All rights reserved.
! 7: *
! 8: * Redistribution and use in source and binary forms, with or without
! 9: * modification, are permitted provided that the following conditions
! 10: * are met:
! 11: * 1. Redistributions of source code must retain the above copyright
! 12: * notice, this list of conditions and the following disclaimer.
! 13: * 2. Redistributions in binary form must reproduce the above copyright
! 14: * notice, this list of conditions and the following disclaimer in the
! 15: * documentation and/or other materials provided with the distribution.
! 16: * 3. All advertising materials mentioning features or use of this software
! 17: * must display the following acknowledgement:
! 18: * This product includes software developed by the University of
! 19: * California, Berkeley and its contributors.
! 20: * 4. Neither the name of the University nor the names of its contributors
! 21: * may be used to endorse or promote products derived from this software
! 22: * without specific prior written permission.
! 23: *
! 24: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 25: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 26: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 27: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 28: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 29: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 30: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 31: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 32: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 33: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 34: * SUCH DAMAGE.
! 35: */
! 36:
! 37: #ifndef lint
! 38: #if 0
! 39: static char Xsccsid[] = "derived from @(#)rcmd.c 5.17 (Berkeley) 6/27/88";
! 40: static char sccsid[] = "@(#)kcmd.c 8.2 (Berkeley) 8/19/93";
! 41: #else
! 42: static char rcsid[] = "$OpenBSD: kcmd.c,v 1.15 2002/02/17 19:42:31 millert Exp $";
! 43: #endif
! 44: #endif /* not lint */
! 45:
! 46: #include <sys/param.h>
! 47: #include <sys/file.h>
! 48: #include <sys/socket.h>
! 49: #include <sys/stat.h>
! 50:
! 51: #include <netinet/in.h>
! 52: #include <arpa/inet.h>
! 53:
! 54: #include <des.h>
! 55: #include <kerberosIV/krb.h>
! 56:
! 57: #include <ctype.h>
! 58: #include <errno.h>
! 59: #include <netdb.h>
! 60: #include <pwd.h>
! 61: #include <signal.h>
! 62: #include <stdio.h>
! 63: #include <stdlib.h>
! 64: #include <string.h>
! 65: #include <unistd.h>
! 66:
! 67: #include <err.h>
! 68:
! 69: #ifndef MAXHOSTNAMELEN
! 70: #define MAXHOSTNAMELEN 64
! 71: #endif
! 72:
! 73: #define START_PORT 5120 /* arbitrary */
! 74:
! 75: int getport(int *);
! 76: int kcmd(int *, char **, u_short, char *, char *, char *,
! 77: int *, KTEXT, char *, char *, CREDENTIALS *,
! 78: Key_schedule, MSG_DAT *, struct sockaddr_in *,
! 79: struct sockaddr_in *, long);
! 80:
! 81: int
! 82: kcmd(sock, ahost, rport, locuser, remuser, cmd, fd2p, ticket, service, realm,
! 83: cred, schedule, msg_data, laddr, faddr, authopts)
! 84: int *sock;
! 85: char **ahost;
! 86: u_short rport;
! 87: char *locuser, *remuser, *cmd;
! 88: int *fd2p;
! 89: KTEXT ticket;
! 90: char *service;
! 91: char *realm;
! 92: CREDENTIALS *cred;
! 93: Key_schedule schedule;
! 94: MSG_DAT *msg_data;
! 95: struct sockaddr_in *laddr, *faddr;
! 96: long authopts;
! 97: {
! 98: int s, timo = 1, pid;
! 99: sigset_t mask, oldmask;
! 100: struct sockaddr_in sin, from;
! 101: char c;
! 102: int lport = IPPORT_RESERVED - 1;
! 103: struct hostent *hp;
! 104: int rc;
! 105: char *host_save;
! 106: int status;
! 107:
! 108: pid = getpid();
! 109: hp = gethostbyname(*ahost);
! 110: if (hp == NULL) {
! 111: herror(*ahost);
! 112: return (-1);
! 113: }
! 114: if ((host_save = strdup(hp->h_name)) == NULL) {
! 115: warn("can't allocate memory");
! 116: return (-1);
! 117: }
! 118: *ahost = host_save;
! 119:
! 120: /* If realm is null, look up from table */
! 121: if (realm == NULL || realm[0] == '\0')
! 122: realm = krb_realmofhost(host_save);
! 123:
! 124: sigemptyset(&mask);
! 125: sigaddset(&mask, SIGURG);
! 126: sigprocmask(SIG_BLOCK, &mask, &oldmask);
! 127: for (;;) {
! 128: s = getport(&lport);
! 129: if (s < 0) {
! 130: if (errno == EAGAIN)
! 131: fprintf(stderr,
! 132: "kcmd(socket): All ports in use\n");
! 133: else
! 134: perror("kcmd: socket");
! 135: sigprocmask(SIG_SETMASK, &oldmask, NULL);
! 136: return (-1);
! 137: }
! 138: fcntl(s, F_SETOWN, pid);
! 139: bzero(&sin, sizeof sin);
! 140: sin.sin_len = sizeof(struct sockaddr_in);
! 141: sin.sin_family = hp->h_addrtype;
! 142: sin.sin_port = rport;
! 143: bcopy(hp->h_addr_list[0], &sin.sin_addr, hp->h_length);
! 144: if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
! 145: break;
! 146: (void) close(s);
! 147: if (errno == EADDRINUSE) {
! 148: lport--;
! 149: continue;
! 150: }
! 151: /*
! 152: * don't wait very long for Kerberos rcmd.
! 153: */
! 154: if (errno == ECONNREFUSED && timo <= 4) {
! 155: /* sleep(timo); don't wait at all here */
! 156: timo *= 2;
! 157: continue;
! 158: }
! 159: if (hp->h_addr_list[1] != NULL) {
! 160: int oerrno = errno;
! 161:
! 162: fprintf(stderr,
! 163: "kcmd: connect to address %s: ",
! 164: inet_ntoa(sin.sin_addr));
! 165: errno = oerrno;
! 166: perror(NULL);
! 167: hp->h_addr_list++;
! 168: bcopy(hp->h_addr_list[0], &sin.sin_addr, hp->h_length);
! 169: fprintf(stderr, "Trying %s...\n",
! 170: inet_ntoa(sin.sin_addr));
! 171: continue;
! 172: }
! 173: if (errno != ECONNREFUSED)
! 174: perror(hp->h_name);
! 175: sigprocmask(SIG_SETMASK, &oldmask, NULL);
! 176: return (-1);
! 177: }
! 178: if (fd2p == 0) {
! 179: write(s, "", 1);
! 180: lport = 0;
! 181: } else {
! 182: char num[8];
! 183: int s2 = getport(&lport), s3;
! 184: int len = sizeof(from);
! 185:
! 186: if (s2 < 0) {
! 187: status = -1;
! 188: goto bad;
! 189: }
! 190: listen(s2, 1);
! 191: (void) snprintf(num, sizeof(num), "%d", lport);
! 192: if (write(s, num, strlen(num) + 1) != strlen(num) + 1) {
! 193: perror("kcmd(write): setting up stderr");
! 194: (void) close(s2);
! 195: status = -1;
! 196: goto bad;
! 197: }
! 198: again:
! 199: s3 = accept(s2, (struct sockaddr *)&from, &len);
! 200: /*
! 201: * XXX careful for ftp bounce attacks. If discovered, shut them
! 202: * down and check for the real auxiliary channel to connect.
! 203: */
! 204: if (from.sin_family == AF_INET && from.sin_port == htons(20)) {
! 205: (void) close(s3);
! 206: goto again;
! 207: }
! 208: (void) close(s2);
! 209: if (s3 < 0) {
! 210: perror("kcmd:accept");
! 211: lport = 0;
! 212: status = -1;
! 213: goto bad;
! 214: }
! 215: *fd2p = s3;
! 216: from.sin_port = ntohs(from.sin_port);
! 217: if (from.sin_family != AF_INET ||
! 218: from.sin_port >= IPPORT_RESERVED ||
! 219: from.sin_port < IPPORT_RESERVED / 2) {
! 220: fprintf(stderr,
! 221: "kcmd(socket): protocol failure in circuit setup.\n");
! 222: status = -1;
! 223: goto bad2;
! 224: }
! 225: }
! 226: /*
! 227: * Kerberos-authenticated service. Don't have to send locuser,
! 228: * since its already in the ticket, and we'll extract it on
! 229: * the other side.
! 230: */
! 231: /* (void) write(s, locuser, strlen(locuser)+1); */
! 232:
! 233: /* set up the needed stuff for mutual auth, but only if necessary */
! 234: if (authopts & KOPT_DO_MUTUAL) {
! 235: int sin_len;
! 236: *faddr = sin;
! 237:
! 238: sin_len = sizeof(struct sockaddr_in);
! 239: if (getsockname(s, (struct sockaddr *)laddr, &sin_len) < 0) {
! 240: perror("kcmd(getsockname)");
! 241: status = -1;
! 242: goto bad2;
! 243: }
! 244: }
! 245: if ((status = krb_sendauth(authopts, s, ticket, service, *ahost,
! 246: realm, (unsigned long) getpid(), msg_data,
! 247: cred, schedule,
! 248: laddr,
! 249: faddr,
! 250: "KCMDV0.1")) != KSUCCESS)
! 251: goto bad2;
! 252:
! 253: (void) write(s, remuser, strlen(remuser)+1);
! 254: (void) write(s, cmd, strlen(cmd)+1);
! 255:
! 256: if ((rc = read(s, &c, 1)) != 1) {
! 257: if (rc == -1)
! 258: perror(*ahost);
! 259: else
! 260: fprintf(stderr,"kcmd: bad connection with remote host\n");
! 261: status = -1;
! 262: goto bad2;
! 263: }
! 264: if (c != '\0') {
! 265: while (read(s, &c, 1) == 1) {
! 266: (void) write(2, &c, 1);
! 267: if (c == '\n')
! 268: break;
! 269: }
! 270: status = -1;
! 271: goto bad2;
! 272: }
! 273: sigprocmask(SIG_SETMASK, &oldmask, NULL);
! 274: *sock = s;
! 275: return (KSUCCESS);
! 276: bad2:
! 277: if (lport)
! 278: (void) close(*fd2p);
! 279: bad:
! 280: (void) close(s);
! 281: sigprocmask(SIG_SETMASK, &oldmask, NULL);
! 282: return (status);
! 283: }
! 284:
! 285: int
! 286: getport(alport)
! 287: int *alport;
! 288: {
! 289: struct sockaddr_in sin;
! 290: int s;
! 291:
! 292: /* First try to get a "reserved" [sic] port, for interoperability with
! 293: broken klogind (aix, e.g.) */
! 294:
! 295: s = rresvport(alport);
! 296: if (s >= 0)
! 297: return s;
! 298:
! 299: /* Failed; if EACCES, we're not root, so just get an unreserved port
! 300: and hope that's good enough */
! 301:
! 302: if (errno != EACCES)
! 303: return -1;
! 304:
! 305: if (*alport < IPPORT_RESERVED)
! 306: *alport = START_PORT;
! 307: sin.sin_family = AF_INET;
! 308: sin.sin_addr.s_addr = INADDR_ANY;
! 309: s = socket(AF_INET, SOCK_STREAM, 0);
! 310: if (s < 0)
! 311: return (-1);
! 312: for (;;) {
! 313: sin.sin_port = htons((u_short)*alport);
! 314: if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
! 315: return (s);
! 316: if (errno != EADDRINUSE) {
! 317: (void) close(s);
! 318: return (-1);
! 319: }
! 320: (*alport)--;
! 321: if (*alport == IPPORT_RESERVED) {
! 322: (void) close(s);
! 323: errno = EAGAIN; /* close */
! 324: return (-1);
! 325: }
! 326: }
! 327: }
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