144743Smarkm /* 244743Smarkm * General skeleton for adding options to the access control language. The 344743Smarkm * features offered by this module are documented in the hosts_options(5) 444743Smarkm * manual page (source file: hosts_options.5, "nroff -man" format). 544743Smarkm * 644743Smarkm * Notes and warnings for those who want to add features: 744743Smarkm * 844743Smarkm * In case of errors, abort options processing and deny access. There are too 944743Smarkm * many irreversible side effects to make error recovery feasible. For 1044743Smarkm * example, it makes no sense to continue after we have already changed the 1144743Smarkm * userid. 1244743Smarkm * 1344743Smarkm * In case of errors, do not terminate the process: the routines might be 1444743Smarkm * called from a long-running daemon that should run forever. Instead, call 1544743Smarkm * tcpd_jump() which does a non-local goto back into the hosts_access() 1644743Smarkm * routine. 1744743Smarkm * 1844743Smarkm * In case of severe errors, use clean_exit() instead of directly calling 1944743Smarkm * exit(), or the inetd may loop on an UDP request. 2044743Smarkm * 2144743Smarkm * In verification mode (for example, with the "tcpdmatch" command) the 2244743Smarkm * "dry_run" flag is set. In this mode, an option function should just "say" 2344743Smarkm * what it is going to do instead of really doing it. 2444743Smarkm * 2544743Smarkm * Some option functions do not return (for example, the twist option passes 2644743Smarkm * control to another program). In verification mode (dry_run flag is set) 2744743Smarkm * such options should clear the "dry_run" flag to inform the caller of this 2844743Smarkm * course of action. 2971045Sdwmalone * 3071045Sdwmalone * $FreeBSD$ 3144743Smarkm */ 3244743Smarkm 3344743Smarkm#ifndef lint 3444743Smarkmstatic char sccsid[] = "@(#) options.c 1.17 96/02/11 17:01:31"; 3544743Smarkm#endif 3644743Smarkm 3744743Smarkm/* System libraries. */ 3844743Smarkm 3944743Smarkm#include <sys/types.h> 4044743Smarkm#include <sys/param.h> 4144743Smarkm#include <sys/socket.h> 4244743Smarkm#include <sys/stat.h> 4344743Smarkm#include <netinet/in.h> 4444743Smarkm#include <netdb.h> 4544743Smarkm#include <stdio.h> 4671045Sdwmalone#define SYSLOG_NAMES 4744743Smarkm#include <syslog.h> 4844743Smarkm#include <pwd.h> 4944743Smarkm#include <grp.h> 5044743Smarkm#include <ctype.h> 5144743Smarkm#include <setjmp.h> 5244743Smarkm#include <string.h> 5344743Smarkm 5444743Smarkm#ifndef MAXPATHNAMELEN 5544743Smarkm#define MAXPATHNAMELEN BUFSIZ 5644743Smarkm#endif 5744743Smarkm 5844743Smarkm/* Local stuff. */ 5944743Smarkm 6044743Smarkm#include "tcpd.h" 6144743Smarkm 6244743Smarkm/* Options runtime support. */ 6344743Smarkm 6444743Smarkmint dry_run = 0; /* flag set in verification mode */ 6544743Smarkmextern jmp_buf tcpd_buf; /* tcpd_jump() support */ 6644743Smarkm 6744743Smarkm/* Options parser support. */ 6844743Smarkm 6944743Smarkmstatic char whitespace_eq[] = "= \t\r\n"; 7044743Smarkm#define whitespace (whitespace_eq + 1) 7144743Smarkm 7244743Smarkmstatic char *get_field(); /* chew :-delimited field off string */ 7344743Smarkmstatic char *chop_string(); /* strip leading and trailing blanks */ 7444743Smarkm 7544743Smarkm/* List of functions that implement the options. Add yours here. */ 7644743Smarkm 7744743Smarkmstatic void user_option(); /* execute "user name.group" option */ 7844743Smarkmstatic void group_option(); /* execute "group name" option */ 7944743Smarkmstatic void umask_option(); /* execute "umask mask" option */ 8044743Smarkmstatic void linger_option(); /* execute "linger time" option */ 8144743Smarkmstatic void keepalive_option(); /* execute "keepalive" option */ 8244743Smarkmstatic void spawn_option(); /* execute "spawn command" option */ 8344743Smarkmstatic void twist_option(); /* execute "twist command" option */ 8444743Smarkmstatic void rfc931_option(); /* execute "rfc931" option */ 8544743Smarkmstatic void setenv_option(); /* execute "setenv name value" */ 8644743Smarkmstatic void nice_option(); /* execute "nice" option */ 8744743Smarkmstatic void severity_option(); /* execute "severity value" */ 8844743Smarkmstatic void allow_option(); /* execute "allow" option */ 8944743Smarkmstatic void deny_option(); /* execute "deny" option */ 9044743Smarkmstatic void banners_option(); /* execute "banners path" option */ 9144743Smarkm 9244743Smarkm/* Structure of the options table. */ 9344743Smarkm 9444743Smarkmstruct option { 9544743Smarkm char *name; /* keyword name, case is ignored */ 9644743Smarkm void (*func) (); /* function that does the real work */ 9744743Smarkm int flags; /* see below... */ 9844743Smarkm}; 9944743Smarkm 10044743Smarkm#define NEED_ARG (1<<1) /* option requires argument */ 10144743Smarkm#define USE_LAST (1<<2) /* option must be last */ 10244743Smarkm#define OPT_ARG (1<<3) /* option has optional argument */ 10344743Smarkm#define EXPAND_ARG (1<<4) /* do %x expansion on argument */ 10444743Smarkm 10544743Smarkm#define need_arg(o) ((o)->flags & NEED_ARG) 10644743Smarkm#define opt_arg(o) ((o)->flags & OPT_ARG) 10744743Smarkm#define permit_arg(o) ((o)->flags & (NEED_ARG | OPT_ARG)) 10844743Smarkm#define use_last(o) ((o)->flags & USE_LAST) 10944743Smarkm#define expand_arg(o) ((o)->flags & EXPAND_ARG) 11044743Smarkm 11144743Smarkm/* List of known keywords. Add yours here. */ 11244743Smarkm 11344743Smarkmstatic struct option option_table[] = { 11444743Smarkm "user", user_option, NEED_ARG, 11544743Smarkm "group", group_option, NEED_ARG, 11644743Smarkm "umask", umask_option, NEED_ARG, 11744743Smarkm "linger", linger_option, NEED_ARG, 11844743Smarkm "keepalive", keepalive_option, 0, 11944743Smarkm "spawn", spawn_option, NEED_ARG | EXPAND_ARG, 12044743Smarkm "twist", twist_option, NEED_ARG | EXPAND_ARG | USE_LAST, 12144743Smarkm "rfc931", rfc931_option, OPT_ARG, 12244743Smarkm "setenv", setenv_option, NEED_ARG | EXPAND_ARG, 12344743Smarkm "nice", nice_option, OPT_ARG, 12444743Smarkm "severity", severity_option, NEED_ARG, 12544743Smarkm "allow", allow_option, USE_LAST, 12644743Smarkm "deny", deny_option, USE_LAST, 12744743Smarkm "banners", banners_option, NEED_ARG, 12844743Smarkm 0, 12944743Smarkm}; 13044743Smarkm 13144743Smarkm/* process_options - process access control options */ 13244743Smarkm 13344743Smarkmvoid process_options(options, request) 13444743Smarkmchar *options; 13544743Smarkmstruct request_info *request; 13644743Smarkm{ 13744743Smarkm char *key; 13844743Smarkm char *value; 13944743Smarkm char *curr_opt; 14044743Smarkm char *next_opt; 14144743Smarkm struct option *op; 14244743Smarkm char bf[BUFSIZ]; 14344743Smarkm 14444743Smarkm for (curr_opt = get_field(options); curr_opt; curr_opt = next_opt) { 14544743Smarkm next_opt = get_field((char *) 0); 14644743Smarkm 14744743Smarkm /* 14844743Smarkm * Separate the option into name and value parts. For backwards 14944743Smarkm * compatibility we ignore exactly one '=' between name and value. 15044743Smarkm */ 15144743Smarkm curr_opt = chop_string(curr_opt); 15244743Smarkm if (*(value = curr_opt + strcspn(curr_opt, whitespace_eq))) { 15344743Smarkm if (*value != '=') { 15444743Smarkm *value++ = 0; 15544743Smarkm value += strspn(value, whitespace); 15644743Smarkm } 15744743Smarkm if (*value == '=') { 15844743Smarkm *value++ = 0; 15944743Smarkm value += strspn(value, whitespace); 16044743Smarkm } 16144743Smarkm } 16244743Smarkm if (*value == 0) 16344743Smarkm value = 0; 16444743Smarkm key = curr_opt; 16544743Smarkm 16644743Smarkm /* 16744743Smarkm * Disallow missing option names (and empty option fields). 16844743Smarkm */ 16944743Smarkm if (*key == 0) 17044743Smarkm tcpd_jump("missing option name"); 17144743Smarkm 17244743Smarkm /* 17344743Smarkm * Lookup the option-specific info and do some common error checks. 17444743Smarkm * Delegate option-specific processing to the specific functions. 17544743Smarkm */ 17644743Smarkm 17744743Smarkm for (op = option_table; op->name && STR_NE(op->name, key); op++) 17844743Smarkm /* VOID */ ; 17944743Smarkm if (op->name == 0) 18044743Smarkm tcpd_jump("bad option name: \"%s\"", key); 18144743Smarkm if (!value && need_arg(op)) 18244743Smarkm tcpd_jump("option \"%s\" requires value", key); 18344743Smarkm if (value && !permit_arg(op)) 18444743Smarkm tcpd_jump("option \"%s\" requires no value", key); 18544743Smarkm if (next_opt && use_last(op)) 18644743Smarkm tcpd_jump("option \"%s\" must be at end", key); 18744743Smarkm if (value && expand_arg(op)) 18844743Smarkm value = chop_string(percent_x(bf, sizeof(bf), value, request)); 18944743Smarkm if (hosts_access_verbose) 19044743Smarkm syslog(LOG_DEBUG, "option: %s %s", key, value ? value : ""); 19144743Smarkm (*(op->func)) (value, request); 19244743Smarkm } 19344743Smarkm} 19444743Smarkm 19544743Smarkm/* allow_option - grant access */ 19644743Smarkm 19744743Smarkm/* ARGSUSED */ 19844743Smarkm 19944743Smarkmstatic void allow_option(value, request) 20044743Smarkmchar *value; 20144743Smarkmstruct request_info *request; 20244743Smarkm{ 20344743Smarkm longjmp(tcpd_buf, AC_PERMIT); 20444743Smarkm} 20544743Smarkm 20644743Smarkm/* deny_option - deny access */ 20744743Smarkm 20844743Smarkm/* ARGSUSED */ 20944743Smarkm 21044743Smarkmstatic void deny_option(value, request) 21144743Smarkmchar *value; 21244743Smarkmstruct request_info *request; 21344743Smarkm{ 21444743Smarkm longjmp(tcpd_buf, AC_DENY); 21544743Smarkm} 21644743Smarkm 21744743Smarkm/* banners_option - expand %<char>, terminate each line with CRLF */ 21844743Smarkm 21944743Smarkmstatic void banners_option(value, request) 22044743Smarkmchar *value; 22144743Smarkmstruct request_info *request; 22244743Smarkm{ 22344743Smarkm char path[MAXPATHNAMELEN]; 22444743Smarkm char ibuf[BUFSIZ]; 22544743Smarkm char obuf[2 * BUFSIZ]; 22644743Smarkm struct stat st; 22744743Smarkm int ch; 22844743Smarkm FILE *fp; 22944743Smarkm 23044743Smarkm sprintf(path, "%s/%s", value, eval_daemon(request)); 23144743Smarkm if ((fp = fopen(path, "r")) != 0) { 23244743Smarkm while ((ch = fgetc(fp)) == 0) 23344743Smarkm write(request->fd, "", 1); 23444743Smarkm ungetc(ch, fp); 23544743Smarkm while (fgets(ibuf, sizeof(ibuf) - 1, fp)) { 23644743Smarkm if (split_at(ibuf, '\n')) 23744743Smarkm strcat(ibuf, "\r\n"); 23844743Smarkm percent_x(obuf, sizeof(obuf), ibuf, request); 23944743Smarkm write(request->fd, obuf, strlen(obuf)); 24044743Smarkm } 24144743Smarkm fclose(fp); 24244743Smarkm } else if (stat(value, &st) < 0) { 24344743Smarkm tcpd_warn("%s: %m", value); 24444743Smarkm } 24544743Smarkm} 24644743Smarkm 24744743Smarkm/* group_option - switch group id */ 24844743Smarkm 24944743Smarkm/* ARGSUSED */ 25044743Smarkm 25144743Smarkmstatic void group_option(value, request) 25244743Smarkmchar *value; 25344743Smarkmstruct request_info *request; 25444743Smarkm{ 25544743Smarkm struct group *grp; 25644743Smarkm struct group *getgrnam(); 25744743Smarkm 25844743Smarkm if ((grp = getgrnam(value)) == 0) 25944743Smarkm tcpd_jump("unknown group: \"%s\"", value); 26044743Smarkm endgrent(); 26144743Smarkm 26244743Smarkm if (dry_run == 0 && setgid(grp->gr_gid)) 26344743Smarkm tcpd_jump("setgid(%s): %m", value); 26444743Smarkm} 26544743Smarkm 26644743Smarkm/* user_option - switch user id */ 26744743Smarkm 26844743Smarkm/* ARGSUSED */ 26944743Smarkm 27044743Smarkmstatic void user_option(value, request) 27144743Smarkmchar *value; 27244743Smarkmstruct request_info *request; 27344743Smarkm{ 27444743Smarkm struct passwd *pwd; 27544743Smarkm struct passwd *getpwnam(); 27644743Smarkm char *group; 27744743Smarkm 27844743Smarkm if ((group = split_at(value, '.')) != 0) 27944743Smarkm group_option(group, request); 28044743Smarkm if ((pwd = getpwnam(value)) == 0) 28144743Smarkm tcpd_jump("unknown user: \"%s\"", value); 28244743Smarkm endpwent(); 28344743Smarkm 28444743Smarkm if (dry_run == 0 && setuid(pwd->pw_uid)) 28544743Smarkm tcpd_jump("setuid(%s): %m", value); 28644743Smarkm} 28744743Smarkm 28844743Smarkm/* umask_option - set file creation mask */ 28944743Smarkm 29044743Smarkm/* ARGSUSED */ 29144743Smarkm 29244743Smarkmstatic void umask_option(value, request) 29344743Smarkmchar *value; 29444743Smarkmstruct request_info *request; 29544743Smarkm{ 29644743Smarkm unsigned mask; 29744743Smarkm char junk; 29844743Smarkm 29944743Smarkm if (sscanf(value, "%o%c", &mask, &junk) != 1 || (mask & 0777) != mask) 30044743Smarkm tcpd_jump("bad umask value: \"%s\"", value); 30144743Smarkm (void) umask(mask); 30244743Smarkm} 30344743Smarkm 30444743Smarkm/* spawn_option - spawn a shell command and wait */ 30544743Smarkm 30644743Smarkm/* ARGSUSED */ 30744743Smarkm 30844743Smarkmstatic void spawn_option(value, request) 30944743Smarkmchar *value; 31044743Smarkmstruct request_info *request; 31144743Smarkm{ 31244743Smarkm if (dry_run == 0) 31344743Smarkm shell_cmd(value); 31444743Smarkm} 31544743Smarkm 31644743Smarkm/* linger_option - set the socket linger time (Marc Boucher <marc@cam.org>) */ 31744743Smarkm 31844743Smarkm/* ARGSUSED */ 31944743Smarkm 32044743Smarkmstatic void linger_option(value, request) 32144743Smarkmchar *value; 32244743Smarkmstruct request_info *request; 32344743Smarkm{ 32444743Smarkm struct linger linger; 32544743Smarkm char junk; 32644743Smarkm 32744743Smarkm if (sscanf(value, "%d%c", &linger.l_linger, &junk) != 1 32844743Smarkm || linger.l_linger < 0) 32944743Smarkm tcpd_jump("bad linger value: \"%s\"", value); 33044743Smarkm if (dry_run == 0) { 33144743Smarkm linger.l_onoff = (linger.l_linger != 0); 33244743Smarkm if (setsockopt(request->fd, SOL_SOCKET, SO_LINGER, (char *) &linger, 33344743Smarkm sizeof(linger)) < 0) 33444743Smarkm tcpd_warn("setsockopt SO_LINGER %d: %m", linger.l_linger); 33544743Smarkm } 33644743Smarkm} 33744743Smarkm 33844743Smarkm/* keepalive_option - set the socket keepalive option */ 33944743Smarkm 34044743Smarkm/* ARGSUSED */ 34144743Smarkm 34244743Smarkmstatic void keepalive_option(value, request) 34344743Smarkmchar *value; 34444743Smarkmstruct request_info *request; 34544743Smarkm{ 34644743Smarkm static int on = 1; 34744743Smarkm 34844743Smarkm if (dry_run == 0 && setsockopt(request->fd, SOL_SOCKET, SO_KEEPALIVE, 34944743Smarkm (char *) &on, sizeof(on)) < 0) 35044743Smarkm tcpd_warn("setsockopt SO_KEEPALIVE: %m"); 35144743Smarkm} 35244743Smarkm 35344743Smarkm/* nice_option - set nice value */ 35444743Smarkm 35544743Smarkm/* ARGSUSED */ 35644743Smarkm 35744743Smarkmstatic void nice_option(value, request) 35844743Smarkmchar *value; 35944743Smarkmstruct request_info *request; 36044743Smarkm{ 36144743Smarkm int niceval = 10; 36244743Smarkm char junk; 36344743Smarkm 36444743Smarkm if (value != 0 && sscanf(value, "%d%c", &niceval, &junk) != 1) 36544743Smarkm tcpd_jump("bad nice value: \"%s\"", value); 36644743Smarkm if (dry_run == 0 && nice(niceval) < 0) 36744743Smarkm tcpd_warn("nice(%d): %m", niceval); 36844743Smarkm} 36944743Smarkm 37044743Smarkm/* twist_option - replace process by shell command */ 37144743Smarkm 37244743Smarkmstatic void twist_option(value, request) 37344743Smarkmchar *value; 37444743Smarkmstruct request_info *request; 37544743Smarkm{ 37644743Smarkm char *error; 37744743Smarkm 37844743Smarkm if (dry_run != 0) { 37944743Smarkm dry_run = 0; 38044743Smarkm } else { 38144743Smarkm if (resident > 0) 38244743Smarkm tcpd_jump("twist option in resident process"); 38344743Smarkm 38444743Smarkm syslog(deny_severity, "twist %s to %s", eval_client(request), value); 38544743Smarkm 38644743Smarkm /* Before switching to the shell, set up stdin, stdout and stderr. */ 38744743Smarkm 38844743Smarkm#define maybe_dup2(from, to) ((from == to) ? to : (close(to), dup(from))) 38944743Smarkm 39044743Smarkm if (maybe_dup2(request->fd, 0) != 0 || 39144743Smarkm maybe_dup2(request->fd, 1) != 1 || 39244743Smarkm maybe_dup2(request->fd, 2) != 2) { 39344743Smarkm error = "twist_option: dup: %m"; 39444743Smarkm } else { 39544743Smarkm if (request->fd > 2) 39644743Smarkm close(request->fd); 39744743Smarkm (void) execl("/bin/sh", "sh", "-c", value, (char *) 0); 39844743Smarkm error = "twist_option: /bin/sh: %m"; 39944743Smarkm } 40044743Smarkm 40144743Smarkm /* Something went wrong: we MUST terminate the process. */ 40244743Smarkm 40344743Smarkm tcpd_warn(error); 40444743Smarkm clean_exit(request); 40544743Smarkm } 40644743Smarkm} 40744743Smarkm 40844743Smarkm/* rfc931_option - look up remote user name */ 40944743Smarkm 41044743Smarkmstatic void rfc931_option(value, request) 41144743Smarkmchar *value; 41244743Smarkmstruct request_info *request; 41344743Smarkm{ 41444743Smarkm int timeout; 41544743Smarkm char junk; 41644743Smarkm 41744743Smarkm if (value != 0) { 41844743Smarkm if (sscanf(value, "%d%c", &timeout, &junk) != 1 || timeout <= 0) 41944743Smarkm tcpd_jump("bad rfc931 timeout: \"%s\"", value); 42044743Smarkm rfc931_timeout = timeout; 42144743Smarkm } 42244743Smarkm (void) eval_user(request); 42344743Smarkm} 42444743Smarkm 42544743Smarkm/* setenv_option - set environment variable */ 42644743Smarkm 42744743Smarkm/* ARGSUSED */ 42844743Smarkm 42944743Smarkmstatic void setenv_option(value, request) 43044743Smarkmchar *value; 43144743Smarkmstruct request_info *request; 43244743Smarkm{ 43344743Smarkm char *var_value; 43444743Smarkm 43544743Smarkm if (*(var_value = value + strcspn(value, whitespace))) 43644743Smarkm *var_value++ = 0; 43744743Smarkm if (setenv(chop_string(value), chop_string(var_value), 1)) 43844743Smarkm tcpd_jump("memory allocation failure"); 43944743Smarkm} 44044743Smarkm 44144743Smarkm/* severity_map - lookup facility or severity value */ 44244743Smarkm 44344743Smarkmstatic int severity_map(table, name) 44471045SdwmaloneCODE *table; 44544743Smarkmchar *name; 44644743Smarkm{ 44771045Sdwmalone CODE *t; 44844743Smarkm 44971045Sdwmalone for (t = table; t->c_name; t++) 45071045Sdwmalone if (STR_EQ(t->c_name, name)) 45171045Sdwmalone return (t->c_val); 45244743Smarkm tcpd_jump("bad syslog facility or severity: \"%s\"", name); 45344743Smarkm /* NOTREACHED */ 45444743Smarkm} 45544743Smarkm 45644743Smarkm/* severity_option - change logging severity for this event (Dave Mitchell) */ 45744743Smarkm 45844743Smarkm/* ARGSUSED */ 45944743Smarkm 46044743Smarkmstatic void severity_option(value, request) 46144743Smarkmchar *value; 46244743Smarkmstruct request_info *request; 46344743Smarkm{ 46444743Smarkm char *level = split_at(value, '.'); 46544743Smarkm 46644743Smarkm allow_severity = deny_severity = level ? 46771045Sdwmalone severity_map(facilitynames, value) | severity_map(prioritynames, level) 46871045Sdwmalone : severity_map(prioritynames, value); 46944743Smarkm} 47044743Smarkm 47144743Smarkm/* get_field - return pointer to next field in string */ 47244743Smarkm 47344743Smarkmstatic char *get_field(string) 47444743Smarkmchar *string; 47544743Smarkm{ 47644743Smarkm static char *last = ""; 47744743Smarkm char *src; 47844743Smarkm char *dst; 47944743Smarkm char *ret; 48044743Smarkm int ch; 48144743Smarkm 48244743Smarkm /* 48344743Smarkm * This function returns pointers to successive fields within a given 48444743Smarkm * string. ":" is the field separator; warn if the rule ends in one. It 48544743Smarkm * replaces a "\:" sequence by ":", without treating the result of 48644743Smarkm * substitution as field terminator. A null argument means resume search 48744743Smarkm * where the previous call terminated. This function destroys its 48844743Smarkm * argument. 48944743Smarkm * 49044743Smarkm * Work from explicit source or from memory. While processing \: we 49144743Smarkm * overwrite the input. This way we do not have to maintain buffers for 49244743Smarkm * copies of input fields. 49344743Smarkm */ 49444743Smarkm 49544743Smarkm src = dst = ret = (string ? string : last); 49644743Smarkm if (src[0] == 0) 49744743Smarkm return (0); 49844743Smarkm 49944743Smarkm while (ch = *src) { 50044743Smarkm if (ch == ':') { 50144743Smarkm if (*++src == 0) 50244743Smarkm tcpd_warn("rule ends in \":\""); 50344743Smarkm break; 50444743Smarkm } 50544743Smarkm if (ch == '\\' && src[1] == ':') 50644743Smarkm src++; 50744743Smarkm *dst++ = *src++; 50844743Smarkm } 50944743Smarkm last = src; 51044743Smarkm *dst = 0; 51144743Smarkm return (ret); 51244743Smarkm} 51344743Smarkm 51444743Smarkm/* chop_string - strip leading and trailing blanks from string */ 51544743Smarkm 51644743Smarkmstatic char *chop_string(string) 51744743Smarkmregister char *string; 51844743Smarkm{ 51944743Smarkm char *start = 0; 52044743Smarkm char *end; 52144743Smarkm char *cp; 52244743Smarkm 52344743Smarkm for (cp = string; *cp; cp++) { 52444743Smarkm if (!isspace(*cp)) { 52544743Smarkm if (start == 0) 52644743Smarkm start = cp; 52744743Smarkm end = cp; 52844743Smarkm } 52944743Smarkm } 53044743Smarkm return (start ? (end[1] = 0, start) : cp); 53144743Smarkm} 532