#ifndef lint static char sccsid[] = "@(#)rcmd.c 4.4 12/17/82"; #endif #include #include #include #include #include #include extern errno; char *index(), *sprintf(); int rcmdoptions; rcmd(ahost, rport, locuser, remuser, cmd, fd2p) char **ahost; int rport; char *locuser, *remuser, *cmd; int *fd2p; { int s, timo = 1; struct sockaddr_in sin, sin2, from; char c; short port; int lport = IPPORT_RESERVED - 1; struct hostent *hp; hp = gethostbyname(*ahost); if (hp == 0) { fprintf(stderr, "%s: unknown host\n", *ahost); return (-1); } *ahost = hp->h_name; retry: s = rresvport(rcmdoptions|SO_KEEPALIVE, &lport); if (s < 0) return (-1); sin.sin_family = hp->h_addrtype; bcopy(hp->h_addr, (caddr_t)&sin.sin_addr, hp->h_length); sin.sin_port = rport; if (connect(s, (caddr_t)&sin, sizeof (sin), 0) < 0) { if (errno == EADDRINUSE) { close(s); lport--; goto retry; } if (errno == ECONNREFUSED && timo <= 16) { (void) close(s); sleep(timo); timo *= 2; goto retry; } perror(hp->h_name); return (-1); } lport--; if (fd2p == 0) { write(s, "", 1); port = 0; } else { char num[8]; int s2 = rresvport(rcmdoptions|SO_ACCEPTCONN, &lport), s3; if (s2 < 0) { (void) close(s); return (-1); } listen(s2, 1); socketaddr(s2, &sin2); port = htons((u_short)sin2.sin_port); (void) sprintf(num, "%d", port); (void) write(s, num, strlen(num)+1); { int len = sizeof (from); s3 = accept(s2, &from, &len, 0); close(s2); if (s3 < 0) { perror("accept"); port = 0; goto bad; } } *fd2p = s3; from.sin_port = ntohs((u_short)from.sin_port); if (from.sin_family != AF_INET || from.sin_port >= IPPORT_RESERVED) { fprintf(stderr, "socket: protocol failure in circuit setup.\n"); goto bad2; } } (void) write(s, locuser, strlen(locuser)+1); (void) write(s, remuser, strlen(remuser)+1); (void) write(s, cmd, strlen(cmd)+1); if (read(s, &c, 1) != 1) { perror(*ahost); goto bad2; } if (c != 0) { while (read(s, &c, 1) == 1) { (void) write(2, &c, 1); if (c == '\n') break; } goto bad2; } return (s); bad2: if (port) (void) close(*fd2p); bad: (void) close(s); return (-1); } rresvport(options, alport) int options, *alport; { struct sockaddr_in sin; int s; sin.sin_family = AF_INET; sin.sin_addr.s_addr = 0; s = socket(AF_INET, SOCK_STREAM, 0, 0); if (s < 0) return (-1); for (;;) { sin.sin_port = htons((u_short)*alport); if (bind(s, (caddr_t)&sin, sizeof (sin), 0) >= 0) return (s); if (errno != EADDRINUSE && errno != EADDRNOTAVAIL) { perror("socket"); return (-1); } (*alport)--; if (*alport == IPPORT_RESERVED/2) { fprintf(stderr, "socket: All ports in use\n"); return (-1); } } } ruserok(rhost, ruser, luser) char *rhost, *ruser, *luser; { FILE *hostf; char ahost[32]; int first = 1; hostf = fopen("/etc/hosts.equiv", "r"); again: if (hostf) { while (fgets(ahost, sizeof (ahost), hostf)) { char *user; if (index(ahost, '\n')) *index(ahost, '\n') = 0; user = index(ahost, ' '); if (user) *user++ = 0; if (!strcmp(rhost, ahost) && !strcmp(ruser, user ? user : luser)) goto ok; } (void) fclose(hostf); } if (first == 1) { first = 0; hostf = fopen(".rhosts", "r"); goto again; } return (-1); ok: (void) fclose(hostf); return (0); } socketaddr(x, y) { syscall(103,x,y); }