/* * slave/kpropd.c * * Copyright 1990,1991 by the Massachusetts Institute of Technology. * All Rights Reserved. * * Export of this software from the United States of America may * require a specific license from the United States Government. * It is the responsibility of any person or organization contemplating * export to obtain such a license before exporting. * * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and * distribute this software and its documentation for any purpose and * without fee is hereby granted, provided that the above copyright * notice appear in all copies and that both that copyright notice and * this permission notice appear in supporting documentation, and that * the name of M.I.T. not be used in advertising or publicity pertaining * to distribution of the software without specific, written prior * permission. M.I.T. makes no representations about the suitability of * this software for any purpose. It is provided "as is" without express * or implied warranty. * * * XXX We need to modify the protocol so that an acknowledge is set * after each block, instead after the entire series is sent over. * The reason for this is so that error packets can get interpreted * right away. If you don't do this, the sender may never get the * error packet, because it will die an EPIPE trying to complete the * write... */ #include #include #include #include #include #ifndef POSIX_TERMIOS #include #endif #include #include #include #include #include #include #include #include #include #include #include #include "k5-int.h" #include "com_err.h" #include #include "kprop.h" #define SYSLOG_CLASS LOG_DAEMON static char *kprop_version = KPROP_PROT_VERSION; char *progname; int debug = 0; char *srvtab = 0; int standalone = 0; krb5_principal server; /* This is our server principal name */ krb5_principal client; /* This is who we're talking to */ krb5_context kpropd_context; krb5_auth_context auth_context; char *realm = NULL; /* Our realm */ char *file = KPROPD_DEFAULT_FILE; char *temp_file_name; char *kdb5_util = KPROPD_DEFAULT_KDB5_UTIL; char *kerb_database = NULL; char *acl_file_name = KPROPD_ACL_FILE; int database_fd; krb5_address sender_addr; krb5_address receiver_addr; short port = 0; void PRS PROTOTYPE((char**)); void do_standalone PROTOTYPE((void)); void doit PROTOTYPE((int)); void kerberos_authenticate PROTOTYPE((krb5_context, int, krb5_principal *, struct sockaddr_in)); krb5_boolean authorized_principal PROTOTYPE((krb5_context, krb5_principal)); void recv_database PROTOTYPE((krb5_context, int, int, krb5_data *)); void load_database PROTOTYPE((krb5_context, char *, char *)); void send_error PROTOTYPE((krb5_context, int, krb5_error_code, char *)); void recv_error PROTOTYPE((krb5_context, krb5_data *)); static void usage() { fprintf(stderr, "\nUsage: %s [-r realm] [-s srvtab] [-dS] [-f slave_file]\n", progname); fprintf(stderr, "\t[-F kerberos_db_file ] [-p kdb5_util_pathname]\n"); fprintf(stderr, "\t[-P port] [-a acl_file]\n"); exit(1); } void main(argc, argv) int argc; char **argv; { PRS(argv); if (standalone) do_standalone(); else doit(0); exit(0); } void do_standalone() { struct sockaddr_in sin, frominet; struct servent *sp; int finet, fromlen, s; int ret; finet = socket(AF_INET, SOCK_STREAM, 0); if (finet < 0) { com_err(progname, errno, "while obtaining socket"); exit(1); } memset((char *) &sin,0, sizeof(sin)); if(!port) { sp = getservbyname(KPROP_SERVICE, "tcp"); if (sp == NULL) { com_err(progname, 0, "%s/tcp: unknown service", KPROP_SERVICE); exit(1); } sin.sin_port = sp->s_port; } else { sin.sin_port = port; } sin.sin_family = AF_INET; if ((ret = bind(finet, (struct sockaddr *) &sin, sizeof(sin))) < 0) { if (debug) { int on = 1; fprintf(stderr, "%s: attempting to rebind socket with SO_REUSEADDR\n", progname); if (setsockopt(finet, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(on)) < 0) com_err(progname, errno, "in setsockopt(SO_REUSEADDR)"); ret = bind(finet, (struct sockaddr *) &sin, sizeof(sin)); } if (ret < 0) { perror("bind"); com_err(progname, errno, "while binding listener socket"); exit(1); } } if (!debug) daemon(1, 0); #ifdef PID_FILE if ((pidfile = fopen(PID_FILE, "w")) != NULL) { fprintf(pidfile, "%d\n", getpid()); fclose(pidfile); } else com_err(progname, errno, "while opening pid file %s for writing", PID_FILE); #endif if (listen(finet, 5) < 0) { com_err(progname, errno, "in listen call"); exit(1); } while (1) { int child_pid; memset((char *)&frominet, 0, sizeof(frominet)); fromlen = sizeof(frominet); s = accept(finet, (struct sockaddr *) &frominet, &fromlen); if (s < 0) { if (errno != EINTR) com_err(progname, errno, "from accept system call"); continue; } if (debug) child_pid = 0; else child_pid = fork(); switch (child_pid) { case -1: com_err(progname, errno, "while forking"); exit(1); case 0: (void) close(finet); doit(s); close(s); _exit(0); default: wait(0); close(s); } } } void doit(fd) int fd; { struct sockaddr_in from; int on = 1, fromlen; struct hostent *hp; krb5_error_code retval; krb5_data confmsg; int lock_fd; int omask; fromlen = sizeof (from); if (getpeername(fd, (struct sockaddr *) &from, &fromlen) < 0) { fprintf(stderr, "%s: ", progname); perror("getpeername"); exit(1); } if (setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (caddr_t) &on, sizeof (on)) < 0) { com_err(progname, errno, "while attempting setsockopt (SO_KEEPALIVE)"); } if (!(hp = gethostbyaddr((char *) &(from.sin_addr.s_addr), fromlen, AF_INET))) { syslog(LOG_INFO, "Connection from %s", inet_ntoa(from.sin_addr)); if (debug) printf("Connection from %s\n", inet_ntoa(from.sin_addr)); } else { syslog(LOG_INFO, "Connection from %s", hp->h_name); if (debug) printf("Connection from %s\n", hp->h_name); } /* * Now do the authentication */ kerberos_authenticate(kpropd_context, fd, &client, from); if (!authorized_principal(kpropd_context, client)) { char *name; if (retval = krb5_unparse_name(kpropd_context, client, &name)) { com_err(progname, retval, "While unparsing client name"); exit(1); } syslog(LOG_WARNING, "Rejected connection from unauthorized principal %s", name); free(name); exit(1); } omask = umask(077); lock_fd = open(temp_file_name, O_RDWR|O_CREAT, 0600); (void) umask(omask); retval = krb5_lock_file(kpropd_context, lock_fd, KRB5_LOCKMODE_EXCLUSIVE|KRB5_LOCKMODE_DONTBLOCK); if (retval) { com_err(progname, retval, "while trying to lock '%s'", temp_file_name); exit(1); } if ((database_fd = open(temp_file_name, O_WRONLY|O_CREAT|O_TRUNC, 0600)) < 0) { com_err(progname, errno, "while opening database file, '%s'", temp_file_name); exit(1); } recv_database(kpropd_context, fd, database_fd, &confmsg); if (rename(temp_file_name, file)) { com_err(progname, errno, "While renaming %s to %s", temp_file_name, file); exit(1); } retval = krb5_lock_file(kpropd_context, lock_fd, KRB5_LOCKMODE_SHARED); if (retval) { com_err(progname, retval, "while downgrading lock on '%s'", temp_file_name); exit(1); } load_database(kpropd_context, kdb5_util, file); retval = krb5_lock_file(kpropd_context, lock_fd, KRB5_LOCKMODE_UNLOCK); if (retval) { com_err(progname, retval, "while unlocking '%s'", temp_file_name); exit(1); } (void)close(lock_fd); /* * Send the acknowledgement message generated in * recv_database, then close the socket. */ if (retval = krb5_write_message(kpropd_context, (void *) &fd, &confmsg)) { krb5_xfree(confmsg.data); com_err(progname, retval, "while sending # of received bytes"); exit(1); } krb5_xfree(confmsg.data); if (close(fd) < 0) { com_err(progname, errno, "while trying to close database file"); exit(1); } exit(0); } static void kpropd_com_err_proc(whoami, code, fmt, args) const char *whoami; long code; const char *fmt; va_list args; { char error_buf[8096]; error_buf[0] = '\0'; if (fmt) vsprintf(error_buf, fmt, args); syslog(LOG_ERR, "%s%s%s%s%s", whoami ? whoami : "", whoami ? ": " : "", code ? error_message(code) : "", code ? " " : "", error_buf); } void PRS(argv) char **argv; { register char *word, ch; char *cp; struct hostent *hp; char my_host_name[MAXHOSTNAMELEN], buf[BUFSIZ]; krb5_error_code retval; static const char tmp[] = ".temp"; retval = krb5_init_context(&kpropd_context); if (retval) { com_err(argv[0], retval, "while initializing krb5"); exit(1); } progname = *argv++; while (word = *argv++) { if (*word == '-') { word++; while (word && (ch = *word++)) { switch(ch){ case 'f': if (*word) file = word; else file = *argv++; if (!file) usage(); word = 0; break; case 'F': if (*word) kerb_database = word; else kerb_database = *argv++; if (!kerb_database) usage(); word = 0; break; case 'p': if (*word) kdb5_util = word; else kdb5_util = *argv++; if (!kdb5_util) usage(); word = 0; break; case 'P': if (*word) port = htons(atoi(word)); else port = htons(atoi(*argv++)); if (!port) usage(); word = 0; break; case 'r': if (*word) realm = word; else realm = *argv++; if (!realm) usage(); word = 0; break; case 's': if (*word) srvtab = word; else srvtab = *argv++; if (!srvtab) usage(); word = 0; break; case 'd': debug++; break; case 'S': standalone++; break; case 'a': if (*word) acl_file_name = word; else acl_file_name = *argv++; if (!acl_file_name) usage(); word = 0; break; default: usage(); } } } else /* We don't take any arguments, only options */ usage(); } /* * If not in debug mode, switch com_err reporting to syslog */ if (! debug) { openlog("kpropd", LOG_PID | LOG_ODELAY, SYSLOG_CLASS); set_com_err_hook(kpropd_com_err_proc); } /* * Get my hostname, so we can construct my service name */ retval = krb5_sname_to_principal(kpropd_context, NULL, KPROP_SERVICE_NAME, KRB5_NT_SRV_HST, &server); if (retval) { com_err(progname, retval, "While trying to construct my service name"); exit(1); } if (realm) { (void) krb5_xfree(krb5_princ_realm(context, server)->data); krb5_princ_set_realm_length(context, server, strlen(realm)); krb5_princ_set_realm_data(context, server, strdup(realm)); } /* * Construct the name of the temporary file. */ if ((temp_file_name = (char *) malloc(strlen(file) + strlen(tmp) + 1)) == NULL) { com_err(progname, ENOMEM, "while allocating filename for temp file"); exit(1); } strcpy(temp_file_name, file); strcat(temp_file_name, tmp); } /* * Figure out who's calling on the other end of the connection.... */ void kerberos_authenticate(context, fd, clientp, sin) krb5_context context; int fd; krb5_principal * clientp; struct sockaddr_in sin; { krb5_error_code retval; krb5_ticket * ticket; struct sockaddr_in r_sin; int sin_length; krb5_keytab keytab = NULL; /* * Set recv_addr and send_addr */ sender_addr.addrtype = ADDRTYPE_INET; sender_addr.length = sizeof(sin.sin_addr); sender_addr.contents = (krb5_octet *) malloc(sizeof(sin.sin_addr)); memcpy((char *) sender_addr.contents, (char *) &sin.sin_addr, sizeof(sin.sin_addr)); sin_length = sizeof(r_sin); if (getsockname(fd, (struct sockaddr *) &r_sin, &sin_length)) { com_err(progname, errno, "while getting local socket address"); exit(1); } receiver_addr.addrtype = ADDRTYPE_INET; receiver_addr.length = sizeof(r_sin.sin_addr); receiver_addr.contents = (krb5_octet *) malloc(sizeof(r_sin.sin_addr)); memcpy((char *) receiver_addr.contents, (char *) &r_sin.sin_addr, sizeof(r_sin.sin_addr)); if (debug) { char *name; if (retval = krb5_unparse_name(context, server, &name)) { com_err(progname, retval, "While unparsing client name"); exit(1); } printf("krb5_recvauth(%d, %s, %s, ...)\n", fd, kprop_version, name); free(name); } if (retval = krb5_auth_con_init(context, &auth_context)) { syslog(LOG_ERR, "Error in krb5_auth_con_ini: %s",error_message(retval)); exit(1); } if (retval = krb5_auth_con_setflags(context, auth_context, KRB5_AUTH_CONTEXT_DO_SEQUENCE)) { syslog(LOG_ERR, "Error in krb5_auth_con_setflags: %s", error_message(retval)); exit(1); } if (retval = krb5_auth_con_setaddrs(context, auth_context, &receiver_addr, &sender_addr)) { syslog(LOG_ERR, "Error in krb5_auth_con_setaddrs: %s", error_message(retval)); exit(1); } if (srvtab) { if (retval = krb5_kt_resolve(context, srvtab, &keytab)) { syslog(LOG_ERR, "Error in krb5_kt_resolve: %s", error_message(retval)); exit(1); } } if (retval = krb5_recvauth(context, &auth_context, (void *) &fd, kprop_version, server, 0, keytab, &ticket)){ syslog(LOG_ERR, "Error in krb5_recvauth: %s", error_message(retval)); exit(1); } if (retval = krb5_copy_principal(context, ticket->enc_part2->client, clientp)) { syslog(LOG_ERR, "Error in krb5_copy_prinicpal: %s", error_message(retval)); exit(1); } if (debug) { char * name; if (retval = krb5_unparse_name(context, *clientp, &name)) { com_err(progname, retval, "While unparsing client name"); exit(1); } printf("authenticated client: %s\n", name); free(name); } krb5_free_ticket(context, ticket); } krb5_boolean authorized_principal(context, p) krb5_context context; krb5_principal p; { char *name; char buf[1024]; krb5_error_code retval; FILE *acl_file; int end; retval = krb5_unparse_name(context, p, &name); if (retval) return FALSE; acl_file = fopen(acl_file_name, "r"); if (!acl_file) return FALSE; while (!feof(acl_file)) { if (!fgets(buf, sizeof(buf), acl_file)) break; end = strlen(buf) - 1; if (buf[end] == '\n') buf[end] = '\0'; if (!strcmp(name, buf)) { free(name); fclose(acl_file); return TRUE; } } free(name); fclose(acl_file); return FALSE; } void recv_database(context, fd, database_fd, confmsg) krb5_context context; int fd; int database_fd; krb5_data *confmsg; { int database_size; int received_size, n; char buf[1024]; krb5_data inbuf, outbuf; krb5_error_code retval; /* * Receive and decode size from client */ if (retval = krb5_read_message(context, (void *) &fd, &inbuf)) { send_error(context, fd, retval, "while reading database size"); com_err(progname, retval, "while reading size of database from client"); exit(1); } if (krb5_is_krb_error(&inbuf)) recv_error(context, &inbuf); if (retval = krb5_rd_safe(context,auth_context,&inbuf,&outbuf,NULL)) { send_error(context, fd, retval, "while decoding database size"); krb5_xfree(inbuf.data); com_err(progname, retval, "while decoding database size from client"); exit(1); } memcpy((char *) &database_size, outbuf.data, sizeof(database_size)); krb5_xfree(inbuf.data); krb5_xfree(outbuf.data); database_size = ntohl(database_size); /* * Initialize the initial vector. */ if (retval = krb5_auth_con_initivector(context, auth_context)) { send_error(context, fd, retval, "failed while initializing i_vector"); com_err(progname, retval, "while initializing i_vector"); exit(1); } /* * Now start receiving the database from the net */ received_size = 0; while (received_size < database_size) { if (retval = krb5_read_message(context, (void *) &fd, &inbuf)) { sprintf(buf, "while reading database block starting at offset %d", received_size); com_err(progname, retval, buf); send_error(context, fd, retval, buf); exit(1); } if (krb5_is_krb_error(&inbuf)) recv_error(context, &inbuf); if (retval = krb5_rd_priv(context, auth_context, &inbuf, &outbuf, NULL)) { sprintf(buf, "while decoding database block starting at offset %d", received_size); com_err(progname, retval, buf); send_error(context, fd, retval, buf); krb5_xfree(inbuf.data); exit(1); } n = write(database_fd, outbuf.data, outbuf.length); krb5_xfree(inbuf.data); krb5_xfree(outbuf.data); if (n < 0) { sprintf(buf, "while writing database block starting at offset %d", received_size); send_error(context, fd, errno, buf); } else if (n != outbuf.length) { sprintf(buf, "incomplete write while writing database block starting at \noffset %d (%d written, %d expected)", received_size, n, outbuf.length); send_error(context, fd, KRB5KRB_ERR_GENERIC, buf); } received_size += outbuf.length; } /* * OK, we've seen the entire file. Did we get too many bytes? */ if (received_size > database_size) { sprintf(buf, "Received %d bytes, expected %d bytes for database file", received_size, database_size); send_error(context, fd, KRB5KRB_ERR_GENERIC, buf); } /* * Create message acknowledging number of bytes received, but * don't send it until kdb5_util returns successfully. */ database_size = htonl(database_size); inbuf.data = (char *) &database_size; inbuf.length = sizeof(database_size); if (retval = krb5_mk_safe(context,auth_context,&inbuf,confmsg,NULL)) { com_err(progname, retval, "while encoding # of receieved bytes"); send_error(context, fd, retval, "while encoding # of received bytes"); exit(1); } } void send_error(context, fd, err_code, err_text) krb5_context context; int fd; krb5_error_code err_code; char *err_text; { krb5_error error; const char *text; krb5_data outbuf; char buf[1024]; memset((char *)&error, 0, sizeof(error)); krb5_us_timeofday(context, &error.stime, &error.susec); error.server = server; error.client = client; if (err_text) text = err_text; else text = error_message(err_code); error.error = err_code - ERROR_TABLE_BASE_krb5; if (error.error > 127) { error.error = KRB_ERR_GENERIC; if (err_text) { sprintf(buf, "%s %s", error_message(err_code), err_text); text = buf; } } error.text.length = strlen(text) + 1; if (error.text.data = malloc(error.text.length)) { strcpy(error.text.data, text); if (!krb5_mk_error(context, &error, &outbuf)) { (void) krb5_write_message(context, (void *)&fd,&outbuf); krb5_xfree(outbuf.data); } free(error.text.data); } } void recv_error(context, inbuf) krb5_context context; krb5_data *inbuf; { krb5_error *error; krb5_error_code retval; if (retval = krb5_rd_error(context, inbuf, &error)) { com_err(progname, retval, "while decoding error packet from client"); exit(1); } if (error->error == KRB_ERR_GENERIC) { if (error->text.data) fprintf(stderr, "Generic remote error: %s\n", error->text.data); } else if (error->error) { com_err(progname, error->error + ERROR_TABLE_BASE_krb5, "signalled from server"); if (error->text.data) fprintf(stderr, "Error text from client: %s\n", error->text.data); } krb5_free_error(context, error); exit(1); } void load_database(context, kdb5_util, database_file_name) krb5_context context; char *kdb5_util; char *database_file_name; { static char *edit_av[10]; int error_ret, save_stderr; int child_pid; int count; /* has been included, so BSD will be defined on BSD systems */ #if BSD > 0 && BSD <= 43 #ifndef WEXITSTATUS #define WEXITSTATUS(w) (w).w_retcode #endif union wait waitb; #else int waitb; #endif krb5_error_code retval; if (debug) printf("calling kdb5_util to load database\n"); edit_av[0] = kdb5_util; count = 1; if (realm) { edit_av[count++] = "-r"; edit_av[count++] = realm; } edit_av[count++] = "load"; if (kerb_database) { edit_av[count++] = "-d"; edit_av[count++] = kerb_database; } edit_av[count++] = database_file_name; edit_av[count++] = NULL; switch(child_pid = fork()) { case -1: com_err(progname, errno, "while trying to fork %s", kdb5_util); exit(1); case 0: if (!debug) { save_stderr = dup(2); close(0); close(1); close(2); open("/dev/null", O_RDWR); dup(0); dup(0); } execv(kdb5_util, edit_av); retval = errno; if (!debug) dup2(save_stderr, 2); com_err(progname, retval, "while trying to exec %s", kdb5_util); _exit(1); /*NOTREACHED*/ default: if (debug) printf("Child PID is %d\n", child_pid); if (wait(&waitb) < 0) { com_err(progname, errno, "while waiting for %s", kdb5_util); exit(1); } } if (error_ret = WEXITSTATUS(waitb)) { com_err(progname, 0, "%s returned a bad exit status (%d)", kdb5_util, error_ret); exit(1); } return; }