servconf.c - platform/external/openssh - Gitiles

 /*
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
  *                    All rights reserved
  *
  * As far as I am concerned, the code I have written for this software
  * can be used freely for any purpose.  Any derived versions of this
  * software must be clearly marked as such, and if the derived work is
  * incompatible with the protocol description in the RFC file, it must be
  * called by a name other than "ssh" or "Secure Shell".
  */

 #include "includes.h"
 RCSID("$OpenBSD: servconf.c,v 1.65 2001/02/04 15:32:24 stevesk Exp $");

 #ifdef KRB4
 #include <krb.h>
 #endif
 #ifdef AFS
 #include <kafs.h>
 #endif

 #include "ssh.h"
 #include "log.h"
 #include "servconf.h"
 #include "xmalloc.h"
 #include "compat.h"
 #include "pathnames.h"
 #include "tildexpand.h"
 #include "misc.h"
 #include "cipher.h"

 /* add listen address */
 void add_listen_addr(ServerOptions *options, char *addr);

 /* AF_UNSPEC or AF_INET or AF_INET6 */
 extern int IPv4or6;

 /* Initializes the server options to their default values. */

 void
 initialize_server_options(ServerOptions *options)
 {
 	memset(options, 0, sizeof(*options));
 	options->num_ports = 0;
 	options->ports_from_cmdline = 0;
 	options->listen_addrs = NULL;
 	options->num_host_key_files = 0;
 	options->pid_file = NULL;
 	options->server_key_bits = -1;
 	options->login_grace_time = -1;
 	options->key_regeneration_time = -1;
 	options->permit_root_login = -1;
 	options->ignore_rhosts = -1;
 	options->ignore_user_known_hosts = -1;
 	options->print_motd = -1;
 	options->check_mail = -1;
 	options->x11_forwarding = -1;
 	options->x11_display_offset = -1;
 	options->xauth_location = NULL;
 	options->strict_modes = -1;
 	options->keepalives = -1;
 	options->log_facility = (SyslogFacility) - 1;
 	options->log_level = (LogLevel) - 1;
 	options->rhosts_authentication = -1;
 	options->rhosts_rsa_authentication = -1;
 	options->rsa_authentication = -1;
 	options->pubkey_authentication = -1;
 #ifdef KRB4
 	options->kerberos_authentication = -1;
 	options->kerberos_or_local_passwd = -1;
 	options->kerberos_ticket_cleanup = -1;
 #endif
 #ifdef AFS
 	options->kerberos_tgt_passing = -1;
 	options->afs_token_passing = -1;
 #endif
 	options->password_authentication = -1;
 	options->kbd_interactive_authentication = -1;
 	options->challenge_reponse_authentication = -1;
 	options->permit_empty_passwd = -1;
 	options->use_login = -1;
 	options->allow_tcp_forwarding = -1;
 	options->num_allow_users = 0;
 	options->num_deny_users = 0;
 	options->num_allow_groups = 0;
 	options->num_deny_groups = 0;
 	options->ciphers = NULL;
 	options->protocol = SSH_PROTO_UNKNOWN;
 	options->gateway_ports = -1;
 	options->num_subsystems = 0;
 	options->max_startups_begin = -1;
 	options->max_startups_rate = -1;
 	options->max_startups = -1;
 	options->banner = NULL;
 	options->reverse_mapping_check = -1;
 }

 void
 fill_default_server_options(ServerOptions *options)
 {
 	if (options->protocol == SSH_PROTO_UNKNOWN)
 		options->protocol = SSH_PROTO_1|SSH_PROTO_2;
 	if (options->num_host_key_files == 0) {
 		/* fill default hostkeys for protocols */
 		if (options->protocol & SSH_PROTO_1)
 			options->host_key_files[options->num_host_key_files++] = _PATH_HOST_KEY_FILE;
 		if (options->protocol & SSH_PROTO_2)
 			options->host_key_files[options->num_host_key_files++] = _PATH_HOST_DSA_KEY_FILE;
 	}
 	if (options->num_ports == 0)
 		options->ports[options->num_ports++] = SSH_DEFAULT_PORT;
 	if (options->listen_addrs == NULL)
 		add_listen_addr(options, NULL);
 	if (options->pid_file == NULL)
 		options->pid_file = _PATH_SSH_DAEMON_PID_FILE;
 	if (options->server_key_bits == -1)
 		options->server_key_bits = 768;
 	if (options->login_grace_time == -1)
 		options->login_grace_time = 600;
 	if (options->key_regeneration_time == -1)
 		options->key_regeneration_time = 3600;
 	if (options->permit_root_login == -1)
 		options->permit_root_login = 1;			/* yes */
 	if (options->ignore_rhosts == -1)
 		options->ignore_rhosts = 1;
 	if (options->ignore_user_known_hosts == -1)
 		options->ignore_user_known_hosts = 0;
 	if (options->check_mail == -1)
 		options->check_mail = 0;
 	if (options->print_motd == -1)
 		options->print_motd = 1;
 	if (options->x11_forwarding == -1)
 		options->x11_forwarding = 0;
 	if (options->x11_display_offset == -1)
 		options->x11_display_offset = 10;
 #ifdef XAUTH_PATH
 	if (options->xauth_location == NULL)
 		options->xauth_location = XAUTH_PATH;
 #endif /* XAUTH_PATH */
 	if (options->strict_modes == -1)
 		options->strict_modes = 1;
 	if (options->keepalives == -1)
 		options->keepalives = 1;
 	if (options->log_facility == (SyslogFacility) (-1))
 		options->log_facility = SYSLOG_FACILITY_AUTH;
 	if (options->log_level == (LogLevel) (-1))
 		options->log_level = SYSLOG_LEVEL_INFO;
 	if (options->rhosts_authentication == -1)
 		options->rhosts_authentication = 0;
 	if (options->rhosts_rsa_authentication == -1)
 		options->rhosts_rsa_authentication = 0;
 	if (options->rsa_authentication == -1)
 		options->rsa_authentication = 1;
 	if (options->pubkey_authentication == -1)
 		options->pubkey_authentication = 1;
 #ifdef KRB4
 	if (options->kerberos_authentication == -1)
 		options->kerberos_authentication = (access(KEYFILE, R_OK) == 0);
 	if (options->kerberos_or_local_passwd == -1)
 		options->kerberos_or_local_passwd = 1;
 	if (options->kerberos_ticket_cleanup == -1)
 		options->kerberos_ticket_cleanup = 1;
 #endif /* KRB4 */
 #ifdef AFS
 	if (options->kerberos_tgt_passing == -1)
 		options->kerberos_tgt_passing = 0;
 	if (options->afs_token_passing == -1)
 		options->afs_token_passing = k_hasafs();
 #endif /* AFS */
 	if (options->password_authentication == -1)
 		options->password_authentication = 1;
 	if (options->kbd_interactive_authentication == -1)
 		options->kbd_interactive_authentication = 0;
 	if (options->challenge_reponse_authentication == -1)
 		options->challenge_reponse_authentication = 1;
 	if (options->permit_empty_passwd == -1)
 		options->permit_empty_passwd = 0;
 	if (options->use_login == -1)
 		options->use_login = 0;
 	if (options->allow_tcp_forwarding == -1)
 		options->allow_tcp_forwarding = 1;
 	if (options->gateway_ports == -1)
 		options->gateway_ports = 0;
 	if (options->max_startups == -1)
 		options->max_startups = 10;
 	if (options->max_startups_rate == -1)
 		options->max_startups_rate = 100;		/* 100% */
 	if (options->max_startups_begin == -1)
 		options->max_startups_begin = options->max_startups;
 	if (options->reverse_mapping_check == -1)
 		options->reverse_mapping_check = 0;
 }

 /* Keyword tokens. */
 typedef enum {
 	sBadOption,		/* == unknown option */
 	sPort, sHostKeyFile, sServerKeyBits, sLoginGraceTime, sKeyRegenerationTime,
 	sPermitRootLogin, sLogFacility, sLogLevel,
 	sRhostsAuthentication, sRhostsRSAAuthentication, sRSAAuthentication,
 #ifdef KRB4
 	sKerberosAuthentication, sKerberosOrLocalPasswd, sKerberosTicketCleanup,
 #endif
 #ifdef AFS
 	sKerberosTgtPassing, sAFSTokenPassing,
 #endif
 	sChallengeResponseAuthentication,
 	sPasswordAuthentication, sKbdInteractiveAuthentication, sListenAddress,
 	sPrintMotd, sIgnoreRhosts, sX11Forwarding, sX11DisplayOffset,
 	sStrictModes, sEmptyPasswd, sRandomSeedFile, sKeepAlives, sCheckMail,
 	sUseLogin, sAllowTcpForwarding,
 	sAllowUsers, sDenyUsers, sAllowGroups, sDenyGroups,
 	sIgnoreUserKnownHosts, sCiphers, sProtocol, sPidFile,
 	sGatewayPorts, sPubkeyAuthentication, sXAuthLocation, sSubsystem, sMaxStartups,
 	sBanner, sReverseMappingCheck
 } ServerOpCodes;

 /* Textual representation of the tokens. */
 static struct {
 	const char *name;
 	ServerOpCodes opcode;
 } keywords[] = {
 	{ "port", sPort },
 	{ "hostkey", sHostKeyFile },
 	{ "hostdsakey", sHostKeyFile },					/* alias */
 	{ "pidfile", sPidFile },
 	{ "serverkeybits", sServerKeyBits },
 	{ "logingracetime", sLoginGraceTime },
 	{ "keyregenerationinterval", sKeyRegenerationTime },
 	{ "permitrootlogin", sPermitRootLogin },
 	{ "syslogfacility", sLogFacility },
 	{ "loglevel", sLogLevel },
 	{ "rhostsauthentication", sRhostsAuthentication },
 	{ "rhostsrsaauthentication", sRhostsRSAAuthentication },
 	{ "rsaauthentication", sRSAAuthentication },
 	{ "pubkeyauthentication", sPubkeyAuthentication },
 	{ "dsaauthentication", sPubkeyAuthentication },			/* alias */
 #ifdef KRB4
 	{ "kerberosauthentication", sKerberosAuthentication },
 	{ "kerberosorlocalpasswd", sKerberosOrLocalPasswd },
 	{ "kerberosticketcleanup", sKerberosTicketCleanup },
 #endif
 #ifdef AFS
 	{ "kerberostgtpassing", sKerberosTgtPassing },
 	{ "afstokenpassing", sAFSTokenPassing },
 #endif
 	{ "passwordauthentication", sPasswordAuthentication },
 	{ "kbdinteractiveauthentication", sKbdInteractiveAuthentication },
 	{ "challengeresponseauthentication", sChallengeResponseAuthentication },
 	{ "skeyauthentication", sChallengeResponseAuthentication }, /* alias */
 	{ "checkmail", sCheckMail },
 	{ "listenaddress", sListenAddress },
 	{ "printmotd", sPrintMotd },
 	{ "ignorerhosts", sIgnoreRhosts },
 	{ "ignoreuserknownhosts", sIgnoreUserKnownHosts },
 	{ "x11forwarding", sX11Forwarding },
 	{ "x11displayoffset", sX11DisplayOffset },
 	{ "xauthlocation", sXAuthLocation },
 	{ "strictmodes", sStrictModes },
 	{ "permitemptypasswords", sEmptyPasswd },
 	{ "uselogin", sUseLogin },
 	{ "randomseed", sRandomSeedFile },
 	{ "keepalive", sKeepAlives },
 	{ "allowtcpforwarding", sAllowTcpForwarding },
 	{ "allowusers", sAllowUsers },
 	{ "denyusers", sDenyUsers },
 	{ "allowgroups", sAllowGroups },
 	{ "denygroups", sDenyGroups },
 	{ "ciphers", sCiphers },
 	{ "protocol", sProtocol },
 	{ "gatewayports", sGatewayPorts },
 	{ "subsystem", sSubsystem },
 	{ "maxstartups", sMaxStartups },
 	{ "banner", sBanner },
 	{ "reversemappingcheck", sReverseMappingCheck },
 	{ NULL, 0 }
 };

 /*
  * Returns the number of the token pointed to by cp of length len. Never
  * returns if the token is not known.
  */

 static ServerOpCodes
 parse_token(const char *cp, const char *filename,
 	    int linenum)
 {
 	u_int i;

 	for (i = 0; keywords[i].name; i++)
 		if (strcasecmp(cp, keywords[i].name) == 0)
 			return keywords[i].opcode;

 	fprintf(stderr, "%s: line %d: Bad configuration option: %s\n",
 		filename, linenum, cp);
 	return sBadOption;
 }

 /*
  * add listen address
  */
 void
 add_listen_addr(ServerOptions *options, char *addr)
 {
 	struct addrinfo hints, *ai, *aitop;
 	char strport[NI_MAXSERV];
 	int gaierr;
 	int i;

 	if (options->num_ports == 0)
 		options->ports[options->num_ports++] = SSH_DEFAULT_PORT;
 	for (i = 0; i < options->num_ports; i++) {
 		memset(&hints, 0, sizeof(hints));
 		hints.ai_family = IPv4or6;
 		hints.ai_socktype = SOCK_STREAM;
 		hints.ai_flags = (addr == NULL) ? AI_PASSIVE : 0;
 		snprintf(strport, sizeof strport, "%d", options->ports[i]);
 		if ((gaierr = getaddrinfo(addr, strport, &hints, &aitop)) != 0)
 			fatal("bad addr or host: %s (%s)\n",
 			    addr ? addr : "<NULL>",
 			    gai_strerror(gaierr));
 		for (ai = aitop; ai->ai_next; ai = ai->ai_next)
 			;
 		ai->ai_next = options->listen_addrs;
 		options->listen_addrs = aitop;
 	}
 }

 /* Reads the server configuration file. */

 void
 read_server_config(ServerOptions *options, const char *filename)
 {
 	FILE *f;
 	char line[1024];
 	char *cp, **charptr, *arg;
 	int linenum, *intptr, value;
 	int bad_options = 0;
 	ServerOpCodes opcode;
 	int i;

 	f = fopen(filename, "r");
 	if (!f) {
 		perror(filename);
 		exit(1);
 	}
 	linenum = 0;
 	while (fgets(line, sizeof(line), f)) {
 		linenum++;
 		cp = line;
 		arg = strdelim(&cp);
 		/* Ignore leading whitespace */
 		if (*arg == '\0')
 			arg = strdelim(&cp);
 		if (!arg || !*arg || *arg == '#')
 			continue;
 		intptr = NULL;
 		charptr = NULL;
 		opcode = parse_token(arg, filename, linenum);
 		switch (opcode) {
 		case sBadOption:
 			bad_options++;
 			continue;
 		case sPort:
 			/* ignore ports from configfile if cmdline specifies ports */
 			if (options->ports_from_cmdline)
 				continue;
 			if (options->listen_addrs != NULL)
 				fatal("%s line %d: ports must be specified before "
 				    "ListenAdress.\n", filename, linenum);
 			if (options->num_ports >= MAX_PORTS)
 				fatal("%s line %d: too many ports.\n",
 				    filename, linenum);
 			arg = strdelim(&cp);
 			if (!arg || *arg == '\0')
 				fatal("%s line %d: missing port number.\n",
 				    filename, linenum);
 			options->ports[options->num_ports++] = atoi(arg);
 			break;

 		case sServerKeyBits:
 			intptr = &options->server_key_bits;
 parse_int:
 			arg = strdelim(&cp);
 			if (!arg || *arg == '\0') {
 				fprintf(stderr, "%s line %d: missing integer value.\n",
 					filename, linenum);
 				exit(1);
 			}
 			value = atoi(arg);
 			if (*intptr == -1)
 				*intptr = value;
 			break;

 		case sLoginGraceTime:
 			intptr = &options->login_grace_time;
 			goto parse_int;

 		case sKeyRegenerationTime:
 			intptr = &options->key_regeneration_time;
 			goto parse_int;

 		case sListenAddress:
 			arg = strdelim(&cp);
 			if (!arg || *arg == '\0')
 				fatal("%s line %d: missing inet addr.\n",
 				    filename, linenum);
 			add_listen_addr(options, arg);
 			break;

 		case sHostKeyFile:
 			intptr = &options->num_host_key_files;
 			if (*intptr >= MAX_HOSTKEYS) {
 				fprintf(stderr, "%s line %d: to many host keys specified (max %d).\n",
 				    filename, linenum, MAX_HOSTKEYS);
 				exit(1);
 			}
 			charptr = &options->host_key_files[*intptr];
 parse_filename:
 			arg = strdelim(&cp);
 			if (!arg || *arg == '\0') {
 				fprintf(stderr, "%s line %d: missing file name.\n",
 				    filename, linenum);
 				exit(1);
 			}
 			if (*charptr == NULL) {
 				*charptr = tilde_expand_filename(arg, getuid());
 				/* increase optional counter */
 				if (intptr != NULL)
 					*intptr = *intptr + 1;
 			}
 			break;

 		case sPidFile:
 			charptr = &options->pid_file;
 			goto parse_filename;

 		case sRandomSeedFile:
 			fprintf(stderr, "%s line %d: \"randomseed\" option is obsolete.\n",
 				filename, linenum);
 			arg = strdelim(&cp);
 			break;

 		case sPermitRootLogin:
 			intptr = &options->permit_root_login;
 			arg = strdelim(&cp);
 			if (!arg || *arg == '\0') {
 				fprintf(stderr, "%s line %d: missing yes/without-password/no argument.\n",
 					filename, linenum);
 				exit(1);
 			}
 			if (strcmp(arg, "without-password") == 0)
 				value = 2;
 			else if (strcmp(arg, "yes") == 0)
 				value = 1;
 			else if (strcmp(arg, "no") == 0)
 				value = 0;
 			else {
 				fprintf(stderr, "%s line %d: Bad yes/without-password/no argument: %s\n",
 					filename, linenum, arg);
 				exit(1);
 			}
 			if (*intptr == -1)
 				*intptr = value;
 			break;

 		case sIgnoreRhosts:
 			intptr = &options->ignore_rhosts;
 parse_flag:
 			arg = strdelim(&cp);
 			if (!arg || *arg == '\0') {
 				fprintf(stderr, "%s line %d: missing yes/no argument.\n",
 					filename, linenum);
 				exit(1);
 			}
 			if (strcmp(arg, "yes") == 0)
 				value = 1;
 			else if (strcmp(arg, "no") == 0)
 				value = 0;
 			else {
 				fprintf(stderr, "%s line %d: Bad yes/no argument: %s\n",
 					filename, linenum, arg);
 				exit(1);
 			}
 			if (*intptr == -1)
 				*intptr = value;
 			break;

 		case sIgnoreUserKnownHosts:
 			intptr = &options->ignore_user_known_hosts;
 			goto parse_flag;

 		case sRhostsAuthentication:
 			intptr = &options->rhosts_authentication;
 			goto parse_flag;

 		case sRhostsRSAAuthentication:
 			intptr = &options->rhosts_rsa_authentication;
 			goto parse_flag;

 		case sRSAAuthentication:
 			intptr = &options->rsa_authentication;
 			goto parse_flag;

 		case sPubkeyAuthentication:
 			intptr = &options->pubkey_authentication;
 			goto parse_flag;

 #ifdef KRB4
 		case sKerberosAuthentication:
 			intptr = &options->kerberos_authentication;
 			goto parse_flag;

 		case sKerberosOrLocalPasswd:
 			intptr = &options->kerberos_or_local_passwd;
 			goto parse_flag;

 		case sKerberosTicketCleanup:
 			intptr = &options->kerberos_ticket_cleanup;
 			goto parse_flag;
 #endif

 #ifdef AFS
 		case sKerberosTgtPassing:
 			intptr = &options->kerberos_tgt_passing;
 			goto parse_flag;

 		case sAFSTokenPassing:
 			intptr = &options->afs_token_passing;
 			goto parse_flag;
 #endif

 		case sPasswordAuthentication:
 			intptr = &options->password_authentication;
 			goto parse_flag;

 		case sKbdInteractiveAuthentication:
 			intptr = &options->kbd_interactive_authentication;
 			goto parse_flag;

 		case sCheckMail:
 			intptr = &options->check_mail;
 			goto parse_flag;

 		case sChallengeResponseAuthentication:
 			intptr = &options->challenge_reponse_authentication;
 			goto parse_flag;

 		case sPrintMotd:
 			intptr = &options->print_motd;
 			goto parse_flag;

 		case sX11Forwarding:
 			intptr = &options->x11_forwarding;
 			goto parse_flag;

 		case sX11DisplayOffset:
 			intptr = &options->x11_display_offset;
 			goto parse_int;

 		case sXAuthLocation:
 			charptr = &options->xauth_location;
 			goto parse_filename;

 		case sStrictModes:
 			intptr = &options->strict_modes;
 			goto parse_flag;

 		case sKeepAlives:
 			intptr = &options->keepalives;
 			goto parse_flag;

 		case sEmptyPasswd:
 			intptr = &options->permit_empty_passwd;
 			goto parse_flag;

 		case sUseLogin:
 			intptr = &options->use_login;
 			goto parse_flag;

 		case sGatewayPorts:
 			intptr = &options->gateway_ports;
 			goto parse_flag;

 		case sReverseMappingCheck:
 			intptr = &options->reverse_mapping_check;
 			goto parse_flag;

 		case sLogFacility:
 			intptr = (int *) &options->log_facility;
 			arg = strdelim(&cp);
 			value = log_facility_number(arg);
 			if (value == (SyslogFacility) - 1)
 				fatal("%.200s line %d: unsupported log facility '%s'\n",
 				    filename, linenum, arg ? arg : "<NONE>");
 			if (*intptr == -1)
 				*intptr = (SyslogFacility) value;
 			break;

 		case sLogLevel:
 			intptr = (int *) &options->log_level;
 			arg = strdelim(&cp);
 			value = log_level_number(arg);
 			if (value == (LogLevel) - 1)
 				fatal("%.200s line %d: unsupported log level '%s'\n",
 				    filename, linenum, arg ? arg : "<NONE>");
 			if (*intptr == -1)
 				*intptr = (LogLevel) value;
 			break;

 		case sAllowTcpForwarding:
 			intptr = &options->allow_tcp_forwarding;
 			goto parse_flag;

 		case sAllowUsers:
 			while ((arg = strdelim(&cp)) && *arg != '\0') {
 				if (options->num_allow_users >= MAX_ALLOW_USERS)
 					fatal("%s line %d: too many allow users.\n",
 					    filename, linenum);
 				options->allow_users[options->num_allow_users++] = xstrdup(arg);
 			}
 			break;

 		case sDenyUsers:
 			while ((arg = strdelim(&cp)) && *arg != '\0') {
 				if (options->num_deny_users >= MAX_DENY_USERS)
 					fatal( "%s line %d: too many deny users.\n",
 					    filename, linenum);
 				options->deny_users[options->num_deny_users++] = xstrdup(arg);
 			}
 			break;

 		case sAllowGroups:
 			while ((arg = strdelim(&cp)) && *arg != '\0') {
 				if (options->num_allow_groups >= MAX_ALLOW_GROUPS)
 					fatal("%s line %d: too many allow groups.\n",
 					    filename, linenum);
 				options->allow_groups[options->num_allow_groups++] = xstrdup(arg);
 			}
 			break;

 		case sDenyGroups:
 			while ((arg = strdelim(&cp)) && *arg != '\0') {
 				if (options->num_deny_groups >= MAX_DENY_GROUPS)
 					fatal("%s line %d: too many deny groups.\n",
 					    filename, linenum);
 				options->deny_groups[options->num_deny_groups++] = xstrdup(arg);
 			}
 			break;

 		case sCiphers:
 			arg = strdelim(&cp);
 			if (!arg || *arg == '\0')
 				fatal("%s line %d: Missing argument.", filename, linenum);
 			if (!ciphers_valid(arg))
 				fatal("%s line %d: Bad SSH2 cipher spec '%s'.",
 				    filename, linenum, arg ? arg : "<NONE>");
 			if (options->ciphers == NULL)
 				options->ciphers = xstrdup(arg);
 			break;

 		case sProtocol:
 			intptr = &options->protocol;
 			arg = strdelim(&cp);
 			if (!arg || *arg == '\0')
 				fatal("%s line %d: Missing argument.", filename, linenum);
 			value = proto_spec(arg);
 			if (value == SSH_PROTO_UNKNOWN)
 				fatal("%s line %d: Bad protocol spec '%s'.",
 				      filename, linenum, arg ? arg : "<NONE>");
 			if (*intptr == SSH_PROTO_UNKNOWN)
 				*intptr = value;
 			break;

 		case sSubsystem:
 			if(options->num_subsystems >= MAX_SUBSYSTEMS) {
 				fatal("%s line %d: too many subsystems defined.",
 				      filename, linenum);
 			}
 			arg = strdelim(&cp);
 			if (!arg || *arg == '\0')
 				fatal("%s line %d: Missing subsystem name.",
 				      filename, linenum);
 			for (i = 0; i < options->num_subsystems; i++)
 				if(strcmp(arg, options->subsystem_name[i]) == 0)
 					fatal("%s line %d: Subsystem '%s' already defined.",
 					      filename, linenum, arg);
 			options->subsystem_name[options->num_subsystems] = xstrdup(arg);
 			arg = strdelim(&cp);
 			if (!arg || *arg == '\0')
 				fatal("%s line %d: Missing subsystem command.",
 				      filename, linenum);
 			options->subsystem_command[options->num_subsystems] = xstrdup(arg);
 			options->num_subsystems++;
 			break;

 		case sMaxStartups:
 			arg = strdelim(&cp);
 			if (!arg || *arg == '\0')
 				fatal("%s line %d: Missing MaxStartups spec.",
 				      filename, linenum);
 			if (sscanf(arg, "%d:%d:%d",
 			    &options->max_startups_begin,
 			    &options->max_startups_rate,
 			    &options->max_startups) == 3) {
 				if (options->max_startups_begin >
 				    options->max_startups ||
 				    options->max_startups_rate > 100 ||
 				    options->max_startups_rate < 1)
 				fatal("%s line %d: Illegal MaxStartups spec.",
 				      filename, linenum);
 				break;
 			}
 			intptr = &options->max_startups;
 			goto parse_int;

 		case sBanner:
 			charptr = &options->banner;
 			goto parse_filename;

 		default:
 			fprintf(stderr, "%s line %d: Missing handler for opcode %s (%d)\n",
 				filename, linenum, arg, opcode);
 			exit(1);
 		}
 		if ((arg = strdelim(&cp)) != NULL && *arg != '\0') {
 			fprintf(stderr,
 				"%s line %d: garbage at end of line; \"%.200s\".\n",
 				filename, linenum, arg);
 			exit(1);
 		}
 	}
 	fclose(f);
 	if (bad_options > 0) {
 		fprintf(stderr, "%s: terminating, %d bad configuration options\n",
 			filename, bad_options);
 		exit(1);
 	}
 }
	/*
	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
	* All rights reserved
	*
	* As far as I am concerned, the code I have written for this software
	* can be used freely for any purpose. Any derived versions of this
	* software must be clearly marked as such, and if the derived work is
	* incompatible with the protocol description in the RFC file, it must be
	* called by a name other than "ssh" or "Secure Shell".
	*/

	#include "includes.h"
	RCSID("$OpenBSD: servconf.c,v 1.65 2001/02/04 15:32:24 stevesk Exp $");

	#ifdef KRB4
	#include <krb.h>
	#endif
	#ifdef AFS
	#include <kafs.h>
	#endif

	#include "ssh.h"
	#include "log.h"
	#include "servconf.h"
	#include "xmalloc.h"
	#include "compat.h"
	#include "pathnames.h"
	#include "tildexpand.h"
	#include "misc.h"
	#include "cipher.h"

	/* add listen address */
	void add_listen_addr(ServerOptions options, char addr);

	/* AF_UNSPEC or AF_INET or AF_INET6 */
	extern int IPv4or6;

	/* Initializes the server options to their default values. */

	void
	initialize_server_options(ServerOptions *options)
	{
	memset(options, 0, sizeof(*options));
	options->num_ports = 0;
	options->ports_from_cmdline = 0;
	options->listen_addrs = NULL;
	options->num_host_key_files = 0;
	options->pid_file = NULL;
	options->server_key_bits = -1;
	options->login_grace_time = -1;
	options->key_regeneration_time = -1;
	options->permit_root_login = -1;
	options->ignore_rhosts = -1;
	options->ignore_user_known_hosts = -1;
	options->print_motd = -1;
	options->check_mail = -1;
	options->x11_forwarding = -1;
	options->x11_display_offset = -1;
	options->xauth_location = NULL;
	options->strict_modes = -1;
	options->keepalives = -1;
	options->log_facility = (SyslogFacility) - 1;
	options->log_level = (LogLevel) - 1;
	options->rhosts_authentication = -1;
	options->rhosts_rsa_authentication = -1;
	options->rsa_authentication = -1;
	options->pubkey_authentication = -1;
	#ifdef KRB4
	options->kerberos_authentication = -1;
	options->kerberos_or_local_passwd = -1;
	options->kerberos_ticket_cleanup = -1;
	#endif
	#ifdef AFS
	options->kerberos_tgt_passing = -1;
	options->afs_token_passing = -1;
	#endif
	options->password_authentication = -1;
	options->kbd_interactive_authentication = -1;
	options->challenge_reponse_authentication = -1;
	options->permit_empty_passwd = -1;
	options->use_login = -1;
	options->allow_tcp_forwarding = -1;
	options->num_allow_users = 0;
	options->num_deny_users = 0;
	options->num_allow_groups = 0;
	options->num_deny_groups = 0;
	options->ciphers = NULL;
	options->protocol = SSH_PROTO_UNKNOWN;
	options->gateway_ports = -1;
	options->num_subsystems = 0;
	options->max_startups_begin = -1;
	options->max_startups_rate = -1;
	options->max_startups = -1;
	options->banner = NULL;
	options->reverse_mapping_check = -1;
	}

	void
	fill_default_server_options(ServerOptions *options)
	{
	if (options->protocol == SSH_PROTO_UNKNOWN)
	options->protocol = SSH_PROTO_1\|SSH_PROTO_2;
	if (options->num_host_key_files == 0) {
	/* fill default hostkeys for protocols */
	if (options->protocol & SSH_PROTO_1)
	options->host_key_files[options->num_host_key_files++] = _PATH_HOST_KEY_FILE;
	if (options->protocol & SSH_PROTO_2)
	options->host_key_files[options->num_host_key_files++] = _PATH_HOST_DSA_KEY_FILE;
	}
	if (options->num_ports == 0)
	options->ports[options->num_ports++] = SSH_DEFAULT_PORT;
	if (options->listen_addrs == NULL)
	add_listen_addr(options, NULL);
	if (options->pid_file == NULL)
	options->pid_file = _PATH_SSH_DAEMON_PID_FILE;
	if (options->server_key_bits == -1)
	options->server_key_bits = 768;
	if (options->login_grace_time == -1)
	options->login_grace_time = 600;
	if (options->key_regeneration_time == -1)
	options->key_regeneration_time = 3600;
	if (options->permit_root_login == -1)
	options->permit_root_login = 1; /* yes */
	if (options->ignore_rhosts == -1)
	options->ignore_rhosts = 1;
	if (options->ignore_user_known_hosts == -1)
	options->ignore_user_known_hosts = 0;
	if (options->check_mail == -1)
	options->check_mail = 0;
	if (options->print_motd == -1)
	options->print_motd = 1;
	if (options->x11_forwarding == -1)
	options->x11_forwarding = 0;
	if (options->x11_display_offset == -1)
	options->x11_display_offset = 10;
	#ifdef XAUTH_PATH
	if (options->xauth_location == NULL)
	options->xauth_location = XAUTH_PATH;
	#endif /* XAUTH_PATH */
	if (options->strict_modes == -1)
	options->strict_modes = 1;
	if (options->keepalives == -1)
	options->keepalives = 1;
	if (options->log_facility == (SyslogFacility) (-1))
	options->log_facility = SYSLOG_FACILITY_AUTH;
	if (options->log_level == (LogLevel) (-1))
	options->log_level = SYSLOG_LEVEL_INFO;
	if (options->rhosts_authentication == -1)
	options->rhosts_authentication = 0;
	if (options->rhosts_rsa_authentication == -1)
	options->rhosts_rsa_authentication = 0;
	if (options->rsa_authentication == -1)
	options->rsa_authentication = 1;
	if (options->pubkey_authentication == -1)
	options->pubkey_authentication = 1;
	#ifdef KRB4
	if (options->kerberos_authentication == -1)
	options->kerberos_authentication = (access(KEYFILE, R_OK) == 0);
	if (options->kerberos_or_local_passwd == -1)
	options->kerberos_or_local_passwd = 1;
	if (options->kerberos_ticket_cleanup == -1)
	options->kerberos_ticket_cleanup = 1;
	#endif /* KRB4 */
	#ifdef AFS
	if (options->kerberos_tgt_passing == -1)
	options->kerberos_tgt_passing = 0;
	if (options->afs_token_passing == -1)
	options->afs_token_passing = k_hasafs();
	#endif /* AFS */
	if (options->password_authentication == -1)
	options->password_authentication = 1;
	if (options->kbd_interactive_authentication == -1)
	options->kbd_interactive_authentication = 0;
	if (options->challenge_reponse_authentication == -1)
	options->challenge_reponse_authentication = 1;
	if (options->permit_empty_passwd == -1)
	options->permit_empty_passwd = 0;
	if (options->use_login == -1)
	options->use_login = 0;
	if (options->allow_tcp_forwarding == -1)
	options->allow_tcp_forwarding = 1;
	if (options->gateway_ports == -1)
	options->gateway_ports = 0;
	if (options->max_startups == -1)
	options->max_startups = 10;
	if (options->max_startups_rate == -1)
	options->max_startups_rate = 100; /* 100% */
	if (options->max_startups_begin == -1)
	options->max_startups_begin = options->max_startups;
	if (options->reverse_mapping_check == -1)
	options->reverse_mapping_check = 0;
	}

	/* Keyword tokens. */
	typedef enum {
	sBadOption, /* == unknown option */
	sPort, sHostKeyFile, sServerKeyBits, sLoginGraceTime, sKeyRegenerationTime,
	sPermitRootLogin, sLogFacility, sLogLevel,
	sRhostsAuthentication, sRhostsRSAAuthentication, sRSAAuthentication,
	#ifdef KRB4
	sKerberosAuthentication, sKerberosOrLocalPasswd, sKerberosTicketCleanup,
	#endif
	#ifdef AFS
	sKerberosTgtPassing, sAFSTokenPassing,
	#endif
	sChallengeResponseAuthentication,
	sPasswordAuthentication, sKbdInteractiveAuthentication, sListenAddress,
	sPrintMotd, sIgnoreRhosts, sX11Forwarding, sX11DisplayOffset,
	sStrictModes, sEmptyPasswd, sRandomSeedFile, sKeepAlives, sCheckMail,
	sUseLogin, sAllowTcpForwarding,
	sAllowUsers, sDenyUsers, sAllowGroups, sDenyGroups,
	sIgnoreUserKnownHosts, sCiphers, sProtocol, sPidFile,
	sGatewayPorts, sPubkeyAuthentication, sXAuthLocation, sSubsystem, sMaxStartups,
	sBanner, sReverseMappingCheck
	} ServerOpCodes;

	/* Textual representation of the tokens. */
	static struct {
	const char *name;
	ServerOpCodes opcode;
	} keywords[] = {
	{ "port", sPort },
	{ "hostkey", sHostKeyFile },
	{ "hostdsakey", sHostKeyFile }, /* alias */
	{ "pidfile", sPidFile },
	{ "serverkeybits", sServerKeyBits },
	{ "logingracetime", sLoginGraceTime },
	{ "keyregenerationinterval", sKeyRegenerationTime },
	{ "permitrootlogin", sPermitRootLogin },
	{ "syslogfacility", sLogFacility },
	{ "loglevel", sLogLevel },
	{ "rhostsauthentication", sRhostsAuthentication },
	{ "rhostsrsaauthentication", sRhostsRSAAuthentication },
	{ "rsaauthentication", sRSAAuthentication },
	{ "pubkeyauthentication", sPubkeyAuthentication },
	{ "dsaauthentication", sPubkeyAuthentication }, /* alias */
	#ifdef KRB4
	{ "kerberosauthentication", sKerberosAuthentication },
	{ "kerberosorlocalpasswd", sKerberosOrLocalPasswd },
	{ "kerberosticketcleanup", sKerberosTicketCleanup },
	#endif
	#ifdef AFS
	{ "kerberostgtpassing", sKerberosTgtPassing },
	{ "afstokenpassing", sAFSTokenPassing },
	#endif
	{ "passwordauthentication", sPasswordAuthentication },
	{ "kbdinteractiveauthentication", sKbdInteractiveAuthentication },
	{ "challengeresponseauthentication", sChallengeResponseAuthentication },
	{ "skeyauthentication", sChallengeResponseAuthentication }, /* alias */
	{ "checkmail", sCheckMail },
	{ "listenaddress", sListenAddress },
	{ "printmotd", sPrintMotd },
	{ "ignorerhosts", sIgnoreRhosts },
	{ "ignoreuserknownhosts", sIgnoreUserKnownHosts },
	{ "x11forwarding", sX11Forwarding },
	{ "x11displayoffset", sX11DisplayOffset },
	{ "xauthlocation", sXAuthLocation },
	{ "strictmodes", sStrictModes },
	{ "permitemptypasswords", sEmptyPasswd },
	{ "uselogin", sUseLogin },
	{ "randomseed", sRandomSeedFile },
	{ "keepalive", sKeepAlives },
	{ "allowtcpforwarding", sAllowTcpForwarding },
	{ "allowusers", sAllowUsers },
	{ "denyusers", sDenyUsers },
	{ "allowgroups", sAllowGroups },
	{ "denygroups", sDenyGroups },
	{ "ciphers", sCiphers },
	{ "protocol", sProtocol },
	{ "gatewayports", sGatewayPorts },
	{ "subsystem", sSubsystem },
	{ "maxstartups", sMaxStartups },
	{ "banner", sBanner },
	{ "reversemappingcheck", sReverseMappingCheck },
	{ NULL, 0 }
	};

	/*
	* Returns the number of the token pointed to by cp of length len. Never
	* returns if the token is not known.
	*/

	static ServerOpCodes
	parse_token(const char cp, const char filename,
	int linenum)
	{
	u_int i;

	for (i = 0; keywords[i].name; i++)
	if (strcasecmp(cp, keywords[i].name) == 0)
	return keywords[i].opcode;

	fprintf(stderr, "%s: line %d: Bad configuration option: %s\n",
	filename, linenum, cp);
	return sBadOption;
	}

	/*
	* add listen address
	*/
	void
	add_listen_addr(ServerOptions options, char addr)
	{
	struct addrinfo hints, ai, aitop;
	char strport[NI_MAXSERV];
	int gaierr;
	int i;

	if (options->num_ports == 0)
	options->ports[options->num_ports++] = SSH_DEFAULT_PORT;
	for (i = 0; i < options->num_ports; i++) {
	memset(&hints, 0, sizeof(hints));
	hints.ai_family = IPv4or6;
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_flags = (addr == NULL) ? AI_PASSIVE : 0;
	snprintf(strport, sizeof strport, "%d", options->ports[i]);
	if ((gaierr = getaddrinfo(addr, strport, &hints, &aitop)) != 0)
	fatal("bad addr or host: %s (%s)\n",
	addr ? addr : "<NULL>",
	gai_strerror(gaierr));
	for (ai = aitop; ai->ai_next; ai = ai->ai_next)
	;
	ai->ai_next = options->listen_addrs;
	options->listen_addrs = aitop;
	}
	}

	/* Reads the server configuration file. */

	void
	read_server_config(ServerOptions options, const char filename)
	{
	FILE *f;
	char line[1024];
	char cp, charptr, arg;
	int linenum, *intptr, value;
	int bad_options = 0;
	ServerOpCodes opcode;
	int i;

	f = fopen(filename, "r");
	if (!f) {
	perror(filename);
	exit(1);
	}
	linenum = 0;
	while (fgets(line, sizeof(line), f)) {
	linenum++;
	cp = line;
	arg = strdelim(&cp);
	/* Ignore leading whitespace */
	if (*arg == '\0')
	arg = strdelim(&cp);
	if (!arg \|\| !arg \|\| arg == '#')
	continue;
	intptr = NULL;
	charptr = NULL;
	opcode = parse_token(arg, filename, linenum);
	switch (opcode) {
	case sBadOption:
	bad_options++;
	continue;
	case sPort:
	/* ignore ports from configfile if cmdline specifies ports */
	if (options->ports_from_cmdline)
	continue;
	if (options->listen_addrs != NULL)
	fatal("%s line %d: ports must be specified before "
	"ListenAdress.\n", filename, linenum);
	if (options->num_ports >= MAX_PORTS)
	fatal("%s line %d: too many ports.\n",
	filename, linenum);
	arg = strdelim(&cp);
	if (!arg \|\| *arg == '\0')
	fatal("%s line %d: missing port number.\n",
	filename, linenum);
	options->ports[options->num_ports++] = atoi(arg);
	break;

	case sServerKeyBits:
	intptr = &options->server_key_bits;
	parse_int:
	arg = strdelim(&cp);
	if (!arg \|\| *arg == '\0') {
	fprintf(stderr, "%s line %d: missing integer value.\n",
	filename, linenum);
	exit(1);
	}
	value = atoi(arg);
	if (*intptr == -1)
	*intptr = value;
	break;

	case sLoginGraceTime:
	intptr = &options->login_grace_time;
	goto parse_int;

	case sKeyRegenerationTime:
	intptr = &options->key_regeneration_time;
	goto parse_int;

	case sListenAddress:
	arg = strdelim(&cp);
	if (!arg \|\| *arg == '\0')
	fatal("%s line %d: missing inet addr.\n",
	filename, linenum);
	add_listen_addr(options, arg);
	break;

	case sHostKeyFile:
	intptr = &options->num_host_key_files;
	if (*intptr >= MAX_HOSTKEYS) {
	fprintf(stderr, "%s line %d: to many host keys specified (max %d).\n",
	filename, linenum, MAX_HOSTKEYS);
	exit(1);
	}
	charptr = &options->host_key_files[*intptr];
	parse_filename:
	arg = strdelim(&cp);
	if (!arg \|\| *arg == '\0') {
	fprintf(stderr, "%s line %d: missing file name.\n",
	filename, linenum);
	exit(1);
	}
	if (*charptr == NULL) {
	*charptr = tilde_expand_filename(arg, getuid());
	/* increase optional counter */
	if (intptr != NULL)
	intptr = intptr + 1;
	}
	break;

	case sPidFile:
	charptr = &options->pid_file;
	goto parse_filename;

	case sRandomSeedFile:
	fprintf(stderr, "%s line %d: \"randomseed\" option is obsolete.\n",
	filename, linenum);
	arg = strdelim(&cp);
	break;

	case sPermitRootLogin:
	intptr = &options->permit_root_login;
	arg = strdelim(&cp);
	if (!arg \|\| *arg == '\0') {
	fprintf(stderr, "%s line %d: missing yes/without-password/no argument.\n",
	filename, linenum);
	exit(1);
	}
	if (strcmp(arg, "without-password") == 0)
	value = 2;
	else if (strcmp(arg, "yes") == 0)
	value = 1;
	else if (strcmp(arg, "no") == 0)
	value = 0;
	else {
	fprintf(stderr, "%s line %d: Bad yes/without-password/no argument: %s\n",
	filename, linenum, arg);
	exit(1);
	}
	if (*intptr == -1)
	*intptr = value;
	break;

	case sIgnoreRhosts:
	intptr = &options->ignore_rhosts;
	parse_flag:
	arg = strdelim(&cp);
	if (!arg \|\| *arg == '\0') {
	fprintf(stderr, "%s line %d: missing yes/no argument.\n",
	filename, linenum);
	exit(1);
	}
	if (strcmp(arg, "yes") == 0)
	value = 1;
	else if (strcmp(arg, "no") == 0)
	value = 0;
	else {
	fprintf(stderr, "%s line %d: Bad yes/no argument: %s\n",
	filename, linenum, arg);
	exit(1);
	}
	if (*intptr == -1)
	*intptr = value;
	break;

	case sIgnoreUserKnownHosts:
	intptr = &options->ignore_user_known_hosts;
	goto parse_flag;

	case sRhostsAuthentication:
	intptr = &options->rhosts_authentication;
	goto parse_flag;

	case sRhostsRSAAuthentication:
	intptr = &options->rhosts_rsa_authentication;
	goto parse_flag;

	case sRSAAuthentication:
	intptr = &options->rsa_authentication;
	goto parse_flag;

	case sPubkeyAuthentication:
	intptr = &options->pubkey_authentication;
	goto parse_flag;

	#ifdef KRB4
	case sKerberosAuthentication:
	intptr = &options->kerberos_authentication;
	goto parse_flag;

	case sKerberosOrLocalPasswd:
	intptr = &options->kerberos_or_local_passwd;
	goto parse_flag;

	case sKerberosTicketCleanup:
	intptr = &options->kerberos_ticket_cleanup;
	goto parse_flag;
	#endif

	#ifdef AFS
	case sKerberosTgtPassing:
	intptr = &options->kerberos_tgt_passing;
	goto parse_flag;

	case sAFSTokenPassing:
	intptr = &options->afs_token_passing;
	goto parse_flag;
	#endif

	case sPasswordAuthentication:
	intptr = &options->password_authentication;
	goto parse_flag;

	case sKbdInteractiveAuthentication:
	intptr = &options->kbd_interactive_authentication;
	goto parse_flag;

	case sCheckMail:
	intptr = &options->check_mail;
	goto parse_flag;

	case sChallengeResponseAuthentication:
	intptr = &options->challenge_reponse_authentication;
	goto parse_flag;

	case sPrintMotd:
	intptr = &options->print_motd;
	goto parse_flag;

	case sX11Forwarding:
	intptr = &options->x11_forwarding;
	goto parse_flag;

	case sX11DisplayOffset:
	intptr = &options->x11_display_offset;
	goto parse_int;

	case sXAuthLocation:
	charptr = &options->xauth_location;
	goto parse_filename;

	case sStrictModes:
	intptr = &options->strict_modes;
	goto parse_flag;

	case sKeepAlives:
	intptr = &options->keepalives;
	goto parse_flag;

	case sEmptyPasswd:
	intptr = &options->permit_empty_passwd;
	goto parse_flag;

	case sUseLogin:
	intptr = &options->use_login;
	goto parse_flag;

	case sGatewayPorts:
	intptr = &options->gateway_ports;
	goto parse_flag;

	case sReverseMappingCheck:
	intptr = &options->reverse_mapping_check;
	goto parse_flag;

	case sLogFacility:
	intptr = (int *) &options->log_facility;
	arg = strdelim(&cp);
	value = log_facility_number(arg);
	if (value == (SyslogFacility) - 1)
	fatal("%.200s line %d: unsupported log facility '%s'\n",
	filename, linenum, arg ? arg : "<NONE>");
	if (*intptr == -1)
	*intptr = (SyslogFacility) value;
	break;

	case sLogLevel:
	intptr = (int *) &options->log_level;
	arg = strdelim(&cp);
	value = log_level_number(arg);
	if (value == (LogLevel) - 1)
	fatal("%.200s line %d: unsupported log level '%s'\n",
	filename, linenum, arg ? arg : "<NONE>");
	if (*intptr == -1)
	*intptr = (LogLevel) value;
	break;

	case sAllowTcpForwarding:
	intptr = &options->allow_tcp_forwarding;
	goto parse_flag;

	case sAllowUsers:
	while ((arg = strdelim(&cp)) && *arg != '\0') {
	if (options->num_allow_users >= MAX_ALLOW_USERS)
	fatal("%s line %d: too many allow users.\n",
	filename, linenum);
	options->allow_users[options->num_allow_users++] = xstrdup(arg);
	}
	break;

	case sDenyUsers:
	while ((arg = strdelim(&cp)) && *arg != '\0') {
	if (options->num_deny_users >= MAX_DENY_USERS)
	fatal( "%s line %d: too many deny users.\n",
	filename, linenum);
	options->deny_users[options->num_deny_users++] = xstrdup(arg);
	}
	break;

	case sAllowGroups:
	while ((arg = strdelim(&cp)) && *arg != '\0') {
	if (options->num_allow_groups >= MAX_ALLOW_GROUPS)
	fatal("%s line %d: too many allow groups.\n",
	filename, linenum);
	options->allow_groups[options->num_allow_groups++] = xstrdup(arg);
	}
	break;

	case sDenyGroups:
	while ((arg = strdelim(&cp)) && *arg != '\0') {
	if (options->num_deny_groups >= MAX_DENY_GROUPS)
	fatal("%s line %d: too many deny groups.\n",
	filename, linenum);
	options->deny_groups[options->num_deny_groups++] = xstrdup(arg);
	}
	break;

	case sCiphers:
	arg = strdelim(&cp);
	if (!arg \|\| *arg == '\0')
	fatal("%s line %d: Missing argument.", filename, linenum);
	if (!ciphers_valid(arg))
	fatal("%s line %d: Bad SSH2 cipher spec '%s'.",
	filename, linenum, arg ? arg : "<NONE>");
	if (options->ciphers == NULL)
	options->ciphers = xstrdup(arg);
	break;

	case sProtocol:
	intptr = &options->protocol;
	arg = strdelim(&cp);
	if (!arg \|\| *arg == '\0')
	fatal("%s line %d: Missing argument.", filename, linenum);
	value = proto_spec(arg);
	if (value == SSH_PROTO_UNKNOWN)
	fatal("%s line %d: Bad protocol spec '%s'.",
	filename, linenum, arg ? arg : "<NONE>");
	if (*intptr == SSH_PROTO_UNKNOWN)
	*intptr = value;
	break;

	case sSubsystem:
	if(options->num_subsystems >= MAX_SUBSYSTEMS) {
	fatal("%s line %d: too many subsystems defined.",
	filename, linenum);
	}
	arg = strdelim(&cp);
	if (!arg \|\| *arg == '\0')
	fatal("%s line %d: Missing subsystem name.",
	filename, linenum);
	for (i = 0; i < options->num_subsystems; i++)
	if(strcmp(arg, options->subsystem_name[i]) == 0)
	fatal("%s line %d: Subsystem '%s' already defined.",
	filename, linenum, arg);
	options->subsystem_name[options->num_subsystems] = xstrdup(arg);
	arg = strdelim(&cp);
	if (!arg \|\| *arg == '\0')
	fatal("%s line %d: Missing subsystem command.",
	filename, linenum);
	options->subsystem_command[options->num_subsystems] = xstrdup(arg);
	options->num_subsystems++;
	break;

	case sMaxStartups:
	arg = strdelim(&cp);
	if (!arg \|\| *arg == '\0')
	fatal("%s line %d: Missing MaxStartups spec.",
	filename, linenum);
	if (sscanf(arg, "%d:%d:%d",
	&options->max_startups_begin,
	&options->max_startups_rate,
	&options->max_startups) == 3) {
	if (options->max_startups_begin >
	options->max_startups \|\|
	options->max_startups_rate > 100 \|\|
	options->max_startups_rate < 1)
	fatal("%s line %d: Illegal MaxStartups spec.",
	filename, linenum);
	break;
	}
	intptr = &options->max_startups;
	goto parse_int;

	case sBanner:
	charptr = &options->banner;
	goto parse_filename;

	default:
	fprintf(stderr, "%s line %d: Missing handler for opcode %s (%d)\n",
	filename, linenum, arg, opcode);
	exit(1);
	}
	if ((arg = strdelim(&cp)) != NULL && *arg != '\0') {
	fprintf(stderr,
	"%s line %d: garbage at end of line; \"%.200s\".\n",
	filename, linenum, arg);
	exit(1);
	}
	}
	fclose(f);
	if (bad_options > 0) {
	fprintf(stderr, "%s: terminating, %d bad configuration options\n",
	filename, bad_options);
	exit(1);
	}
	}