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IABSD.fr/src/usr.sbin/eigrpd/parse.y

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  • Author : naddy
    Date : 2021-10-15 15:01:27
    Hash : 08f6ba19
    Message : Don't declare variables as "unsigned char *" that are passed to functions that take "char *" arguments. Where such chars are assigned to int or passed to ctype functions, explicitly cast them to unsigned char. For OpenBSD's clang, -Wpointer-sign has been disabled by default, but when the parse.y code was built elsewhere, the compiler would complain. With help from millert@ ok benno@ deraadt@

  • usr.sbin/eigrpd/parse.y
  • /*	$OpenBSD: parse.y,v 1.32 2021/10/15 15:01:28 naddy Exp $ */
    
    /*
     * Copyright (c) 2015 Renato Westphal <renato@openbsd.org>
     * Copyright (c) 2004, 2005 Esben Norby <norby@openbsd.org>
     * Copyright (c) 2004 Ryan McBride <mcbride@openbsd.org>
     * Copyright (c) 2002, 2003, 2004 Henning Brauer <henning@openbsd.org>
     * Copyright (c) 2001 Markus Friedl.  All rights reserved.
     * Copyright (c) 2001 Daniel Hartmeier.  All rights reserved.
     * Copyright (c) 2001 Theo de Raadt.  All rights reserved.
     *
     * Permission to use, copy, modify, and distribute this software for any
     * purpose with or without fee is hereby granted, provided that the above
     * copyright notice and this permission notice appear in all copies.
     *
     * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
     * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
     * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
     * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
     * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     */
    
    %{
    #include <sys/types.h>
    #include <sys/socket.h>
    #include <sys/stat.h>
    #include <net/route.h>
    
    #include <arpa/inet.h>
    #include <ctype.h>
    #include <err.h>
    #include <ifaddrs.h>
    #include <limits.h>
    #include <stdio.h>
    #include <syslog.h>
    #include <unistd.h>
    
    #include "eigrpd.h"
    #include "eigrpe.h"
    #include "log.h"
    
    struct file {
    	TAILQ_ENTRY(file)	 entry;
    	FILE			*stream;
    	char			*name;
    	size_t			 ungetpos;
    	size_t			 ungetsize;
    	u_char			*ungetbuf;
    	int			 eof_reached;
    	int			 lineno;
    	int			 errors;
    };
    TAILQ_HEAD(files, file);
    
    struct sym {
    	TAILQ_ENTRY(sym)	 entry;
    	int			 used;
    	int			 persist;
    	char			*nam;
    	char			*val;
    };
    TAILQ_HEAD(symhead, sym);
    
    struct config_defaults {
    	uint8_t		kvalues[6];
    	uint16_t	active_timeout;
    	uint8_t		maximum_hops;
    	uint8_t		maximum_paths;
    	uint8_t		variance;
    	struct redist_metric *dflt_metric;
    	uint16_t	hello_interval;
    	uint16_t	hello_holdtime;
    	uint32_t	delay;
    	uint32_t	bandwidth;
    	uint8_t		splithorizon;
    };
    
    typedef struct {
    	union {
    		int64_t			 number;
    		char			*string;
    		struct redistribute	*redist;
    		struct redist_metric	*redist_metric;
    	} v;
    	int lineno;
    } YYSTYPE;
    
    static int		 yyerror(const char *, ...)
        __attribute__((__format__ (printf, 1, 2)))
        __attribute__((__nonnull__ (1)));
    static int		 kw_cmp(const void *, const void *);
    static int		 lookup(char *);
    static int		 igetc(void);
    static int		 lgetc(int);
    void			 lungetc(int);
    static int		 findeol(void);
    static int		 yylex(void);
    static int		 check_file_secrecy(int, const char *);
    static struct file	*pushfile(const char *, int);
    static int		 popfile(void);
    static int		 yyparse(void);
    static int		 symset(const char *, const char *, int);
    static char		*symget(const char *);
    static struct eigrp	*conf_get_instance(uint16_t);
    static struct eigrp_iface *conf_get_if(struct kif *);
    int			 conf_check_rdomain(unsigned int);
    static void		 clear_config(struct eigrpd_conf *xconf);
    static uint32_t	 get_rtr_id(void);
    static int		 get_prefix(const char *, union eigrpd_addr *, uint8_t *);
    
    static struct file		*file, *topfile;
    static struct files		 files = TAILQ_HEAD_INITIALIZER(files);
    static struct symhead		 symhead = TAILQ_HEAD_INITIALIZER(symhead);
    static struct eigrpd_conf	*conf;
    static int			 errors;
    
    static int			 af;
    static struct eigrp		*eigrp;
    static struct eigrp_iface	*ei;
    
    static struct config_defaults	 globaldefs;
    static struct config_defaults	 afdefs;
    static struct config_defaults	 asdefs;
    static struct config_defaults	 ifacedefs;
    static struct config_defaults	*defs;
    
    %}
    
    %token	ROUTERID AS FIBUPDATE RDOMAIN REDISTRIBUTE METRIC DFLTMETRIC
    %token	MAXHOPS MAXPATHS VARIANCE FIBPRIORITY_INT FIBPRIORITY_EXT
    %token	FIBPRIORITY_SUMM SUMMARY_ADDR
    %token	AF IPV4 IPV6 HELLOINTERVAL HOLDTIME KVALUES ACTIVETIMEOUT
    %token	INTERFACE PASSIVE DELAY BANDWIDTH SPLITHORIZON
    %token	YES NO
    %token	INCLUDE
    %token	ERROR
    %token	<v.string>	STRING
    %token	<v.number>	NUMBER
    %type	<v.number>	yesno no eigrp_af
    %type	<v.string>	string
    %type	<v.redist>	redistribute
    %type	<v.redist_metric> redist_metric opt_red_metric
    
    %%
    
    grammar		: /* empty */
    		| grammar include '\n'
    		| grammar '\n'
    		| grammar conf_main '\n'
    		| grammar varset '\n'
    		| grammar af '\n'
    		| grammar error '\n'		{ file->errors++; }
    		;
    
    include		: INCLUDE STRING {
    			struct file	*nfile;
    
    			if ((nfile = pushfile($2,
    			    !(global.cmd_opts & EIGRPD_OPT_NOACTION))) == NULL) {
    				yyerror("failed to include file %s", $2);
    				free($2);
    				YYERROR;
    			}
    			free($2);
    
    			file = nfile;
    			lungetc('\n');
    		}
    		;
    
    string		: string STRING	{
    			if (asprintf(&$$, "%s %s", $1, $2) == -1) {
    				free($1);
    				free($2);
    				yyerror("string: asprintf");
    				YYERROR;
    			}
    			free($1);
    			free($2);
    		}
    		| STRING
    		;
    
    optnl		: '\n' optnl
    		|
    		;
    
    nl		: '\n' optnl		/* one newline or more */
    		;
    
    yesno		: YES	{ $$ = 1; }
    		| NO	{ $$ = 0; }
    		;
    
    no		: /* empty */	{ $$ = 0; }
    		| NO		{ $$ = 1; }
    		;
    
    eigrp_af	: IPV4	{ $$ = AF_INET; }
    		| IPV6	{ $$ = AF_INET6; }
    		;
    
    varset		: STRING '=' string {
    			char *s = $1;
    			if (global.cmd_opts & EIGRPD_OPT_VERBOSE)
    				printf("%s = \"%s\"\n", $1, $3);
    			while (*s++) {
    				if (isspace((unsigned char)*s)) {
    					yyerror("macro name cannot contain "
    					    "whitespace");
    					free($1);
    					free($3);
    					YYERROR;
    				}
    			}
    			if (symset($1, $3, 0) == -1)
    				fatal("cannot store variable");
    			free($1);
    			free($3);
    		}
    		;
    
    conf_main	: ROUTERID STRING {
    			if (!inet_aton($2, &conf->rtr_id)) {
    				yyerror("error parsing router-id");
    				free($2);
    				YYERROR;
    			}
    			free($2);
    			if (bad_addr_v4(conf->rtr_id)) {
    				yyerror("invalid router-id");
    				YYERROR;
    			}
    		}
    		| FIBUPDATE yesno {
    			if ($2 == 0)
    				conf->flags |= EIGRPD_FLAG_NO_FIB_UPDATE;
    			else
    				conf->flags &= ~EIGRPD_FLAG_NO_FIB_UPDATE;
    		}
    		| RDOMAIN NUMBER {
    			if ($2 < 0 || $2 > RT_TABLEID_MAX) {
    				yyerror("invalid rdomain");
    				YYERROR;
    			}
    			conf->rdomain = $2;
    		}
    		| FIBPRIORITY_INT NUMBER {
    			if ($2 <= RTP_NONE || $2 > RTP_MAX) {
    				yyerror("invalid fib-priority");
    				YYERROR;
    			}
    			conf->fib_priority_internal = $2;
    		}
    		| FIBPRIORITY_EXT NUMBER {
    			if ($2 <= RTP_NONE || $2 > RTP_MAX) {
    				yyerror("invalid fib-priority");
    				YYERROR;
    			}
    			conf->fib_priority_external = $2;
    		}
    		| FIBPRIORITY_SUMM NUMBER {
    			if ($2 <= RTP_NONE || $2 > RTP_MAX) {
    				yyerror("invalid fib-priority");
    				YYERROR;
    			}
    			conf->fib_priority_summary = $2;
    		}
    		| defaults
    		;
    
    af		: AF eigrp_af {
    			af = $2;
    			afdefs = *defs;
    			defs = &afdefs;
    		} af_block {
    			af = AF_UNSPEC;
    			defs = &globaldefs;
    		}
    		;
    
    af_block	: '{' optnl afopts_l '}'
    		| '{' optnl '}'
    		|
    		;
    
    afopts_l	: afopts_l afoptsl nl
    		| afoptsl optnl
    		;
    
    afoptsl		: as
    		| defaults
    		;
    
    as		: AS NUMBER {
    			if ($2 < EIGRP_MIN_AS || $2 > EIGRP_MAX_AS) {
    				yyerror("invalid autonomous-system");
    				YYERROR;
    			}
    			eigrp = conf_get_instance($2);
    			if (eigrp == NULL)
    				YYERROR;
    
    			asdefs = *defs;
    			defs = &asdefs;
    		} as_block {
    			memcpy(eigrp->kvalues, defs->kvalues,
    			    sizeof(eigrp->kvalues));
    			eigrp->active_timeout = defs->active_timeout;
    			eigrp->maximum_hops = defs->maximum_hops;
    			eigrp->maximum_paths = defs->maximum_paths;
    			eigrp->variance = defs->variance;
    			eigrp->dflt_metric = defs->dflt_metric;
    			eigrp = NULL;
    			defs = &afdefs;
    		}
    		;
    
    as_block	: '{' optnl asopts_l '}'
    		| '{' optnl '}'
    		|
    		;
    
    asopts_l	: asopts_l asoptsl nl
    		| asoptsl optnl
    		;
    
    asoptsl		: interface
    		| redistribute {
    			SIMPLEQ_INSERT_TAIL(&eigrp->redist_list, $1, entry);
    		}
    		| defaults
    		;
    
    interface	: INTERFACE STRING {
    			struct kif	*kif;
    
    			if ((kif = kif_findname($2)) == NULL) {
    				yyerror("unknown interface %s", $2);
    				free($2);
    				YYERROR;
    			}
    			free($2);
    			ei = conf_get_if(kif);
    			if (ei == NULL)
    				YYERROR;
    
    			ifacedefs = *defs;
    			defs = &ifacedefs;
    		} interface_block {
    			ei->hello_holdtime = defs->hello_holdtime;
    			ei->hello_interval = defs->hello_interval;
    			ei->delay = defs->delay;
    			ei->bandwidth = defs->bandwidth;
    			ei->splithorizon = defs->splithorizon;
    			ei = NULL;
    			defs = &asdefs;
    		}
    		;
    
    interface_block	: '{' optnl interfaceopts_l '}'
    		| '{' optnl '}'
    		|
    		;
    
    interfaceopts_l	: interfaceopts_l interfaceoptsl nl
    		| interfaceoptsl optnl
    		;
    
    interfaceoptsl	: PASSIVE { ei->passive = 1; }
    		| SUMMARY_ADDR STRING {
    			struct summary_addr	*s, *tmp;
    
    			if ((s = calloc(1, sizeof(*s))) == NULL)
    				fatal(NULL);
    			if (get_prefix($2, &s->prefix, &s->prefixlen) < 0) {
    				yyerror("invalid summary-address");
    				free($2);
    				free(s);
    				YYERROR;
    			}
    			free($2);
    
    			TAILQ_FOREACH(tmp, &ei->summary_list, entry) {
    				if (eigrp_prefixcmp(af, &s->prefix,
    				    &tmp->prefix, min(s->prefixlen,
    				    tmp->prefixlen)) == 0) {
    					yyerror("summary-address conflicts "
    					    "with another summary-address "
    					    "already configured");
    					YYERROR;
    				}
    			}
    
    			TAILQ_INSERT_TAIL(&ei->summary_list, s, entry);
    		}
    		| iface_defaults
    		;
    
    redistribute	: no REDISTRIBUTE STRING opt_red_metric {
    			struct redistribute	*r;
    
    			if ((r = calloc(1, sizeof(*r))) == NULL)
    				fatal(NULL);
    			if (!strcmp($3, "default"))
    				r->type = REDIST_DEFAULT;
    			else if (!strcmp($3, "static"))
    				r->type = REDIST_STATIC;
    			else if (!strcmp($3, "rip"))
    				r->type = REDIST_RIP;
    			else if (!strcmp($3, "ospf"))
    				r->type = REDIST_OSPF;
    			else if (!strcmp($3, "connected"))
    				r->type = REDIST_CONNECTED;
    			else if (get_prefix($3, &r->addr, &r->prefixlen) >= 0)
    				r->type = REDIST_ADDR;
    			else {
    				yyerror("invalid redistribute");
    				free($3);
    				free(r);
    				YYERROR;
    			}
    
    			r->af = af;
    			if ($1)
    				r->type |= REDIST_NO;
    			r->metric = $4;
    			free($3);
    			$$ = r;
    		}
    		;
    
    redist_metric	: NUMBER NUMBER NUMBER NUMBER NUMBER {
    			struct redist_metric	*m;
    
    			if ($1 < MIN_BANDWIDTH || $1 > MAX_BANDWIDTH) {
    				yyerror("bandwidth out of range (%d-%d)",
    				    MIN_BANDWIDTH, MAX_BANDWIDTH);
    				YYERROR;
    			}
    			if ($2 < MIN_DELAY || $2 > MAX_DELAY) {
    				yyerror("delay out of range (%d-%d)",
    				    MIN_DELAY, MAX_DELAY);
    				YYERROR;
    			}
    			if ($3 < MIN_RELIABILITY || $3 > MAX_RELIABILITY) {
    				yyerror("reliability out of range (%d-%d)",
    				    MIN_RELIABILITY, MAX_RELIABILITY);
    				YYERROR;
    			}
    			if ($4 < MIN_LOAD || $4 > MAX_LOAD) {
    				yyerror("load out of range (%d-%d)",
    				    MIN_LOAD, MAX_LOAD);
    				YYERROR;
    			}
    			if ($5 < MIN_MTU || $5 > MAX_MTU) {
    				yyerror("mtu out of range (%d-%d)",
    				    MIN_MTU, MAX_MTU);
    				YYERROR;
    			}
    
    			if ((m = calloc(1, sizeof(*m))) == NULL)
    				fatal(NULL);
    			m->bandwidth = $1;
    			m->delay = $2;
    			m->reliability = $3;
    			m->load = $4;
    			m->mtu = $5;
    
    			$$ = m;
    		}
    		;
    
    opt_red_metric	: /* empty */		{ $$ = NULL; }
    		| METRIC redist_metric 	{ $$ = $2; }
    		;
    
    defaults	: KVALUES NUMBER NUMBER NUMBER NUMBER NUMBER NUMBER {
    			if ($2 < MIN_KVALUE || $2 > MAX_KVALUE ||
    			    $3 < MIN_KVALUE || $3 > MAX_KVALUE ||
    			    $4 < MIN_KVALUE || $4 > MAX_KVALUE ||
    			    $5 < MIN_KVALUE || $5 > MAX_KVALUE ||
    			    $6 < MIN_KVALUE || $6 > MAX_KVALUE ||
    			    $7 < MIN_KVALUE || $7 > MAX_KVALUE) {
    				yyerror("k-value out of range (%d-%d)",
    				    MIN_KVALUE, MAX_KVALUE);
    				YYERROR;
    			}
    			defs->kvalues[0] = $2;
    			defs->kvalues[1] = $3;
    			defs->kvalues[2] = $4;
    			defs->kvalues[3] = $5;
    			defs->kvalues[4] = $6;
    			defs->kvalues[5] = $7;
    		}
    		| ACTIVETIMEOUT NUMBER {
    			if ($2 < MIN_ACTIVE_TIMEOUT ||
    			    $2 > MAX_ACTIVE_TIMEOUT) {
    				yyerror("active-timeout out of range (%d-%d)",
    				    MIN_ACTIVE_TIMEOUT, MAX_ACTIVE_TIMEOUT);
    				YYERROR;
    			}
    			defs->active_timeout = $2;
    		}
    		| MAXHOPS NUMBER {
    			if ($2 < MIN_MAXIMUM_HOPS ||
    			    $2 > MAX_MAXIMUM_HOPS) {
    				yyerror("maximum-hops out of range (%d-%d)",
    				    MIN_MAXIMUM_HOPS, MAX_MAXIMUM_HOPS);
    				YYERROR;
    			}
    			defs->maximum_hops = $2;
    		}
    		| MAXPATHS NUMBER {
    			if ($2 < MIN_MAXIMUM_PATHS ||
    			    $2 > MAX_MAXIMUM_PATHS) {
    				yyerror("maximum-paths out of range (%d-%d)",
    				    MIN_MAXIMUM_PATHS, MAX_MAXIMUM_PATHS);
    				YYERROR;
    			}
    			defs->maximum_paths = $2;
    		}
    		| VARIANCE NUMBER {
    			if ($2 < MIN_VARIANCE ||
    			    $2 > MAX_VARIANCE) {
    				yyerror("variance out of range (%d-%d)",
    				    MIN_VARIANCE, MAX_VARIANCE);
    				YYERROR;
    			}
    			defs->variance = $2;
    		}
    		| DFLTMETRIC redist_metric {
    			defs->dflt_metric = $2;
    		}
    		| iface_defaults
    		;
    
    iface_defaults	: HELLOINTERVAL NUMBER {
    			if ($2 < MIN_HELLO_INTERVAL ||
    			    $2 > MAX_HELLO_INTERVAL) {
    				yyerror("hello-interval out of range (%d-%d)",
    				    MIN_HELLO_INTERVAL, MAX_HELLO_INTERVAL);
    				YYERROR;
    			}
    			defs->hello_interval = $2;
    		}
    		| HOLDTIME NUMBER {
    			if ($2 < MIN_HELLO_HOLDTIME ||
    			    $2 > MAX_HELLO_HOLDTIME) {
    				yyerror("hold-timel out of range (%d-%d)",
    				    MIN_HELLO_HOLDTIME,
    				    MAX_HELLO_HOLDTIME);
    				YYERROR;
    			}
    			defs->hello_holdtime = $2;
    		}
    		| DELAY NUMBER {
    			if ($2 < MIN_DELAY || $2 > MAX_DELAY) {
    				yyerror("delay out of range (%d-%d)",
    				    MIN_DELAY, MAX_DELAY);
    				YYERROR;
    			}
    			defs->delay = $2;
    		}
    		| BANDWIDTH NUMBER {
    			if ($2 < MIN_BANDWIDTH || $2 > MAX_BANDWIDTH) {
    				yyerror("bandwidth out of range (%d-%d)",
    				    MIN_BANDWIDTH, MAX_BANDWIDTH);
    				YYERROR;
    			}
    			defs->bandwidth = $2;
    		}
    		| SPLITHORIZON yesno {
    			defs->splithorizon = $2;
    		}
    		;
    
    %%
    
    struct keywords {
    	const char	*k_name;
    	int		 k_val;
    };
    
    static int
    yyerror(const char *fmt, ...)
    {
    	va_list		 ap;
    	char		*msg;
    
    	file->errors++;
    	va_start(ap, fmt);
    	if (vasprintf(&msg, fmt, ap) == -1)
    		fatalx("yyerror vasprintf");
    	va_end(ap);
    	logit(LOG_CRIT, "%s:%d: %s", file->name, yylval.lineno, msg);
    	free(msg);
    	return (0);
    }
    
    static int
    kw_cmp(const void *k, const void *e)
    {
    	return (strcmp(k, ((const struct keywords *)e)->k_name));
    }
    
    static int
    lookup(char *s)
    {
    	/* this has to be sorted always */
    	static const struct keywords keywords[] = {
    		{"active-timeout",		ACTIVETIMEOUT},
    		{"address-family",		AF},
    		{"autonomous-system",		AS},
    		{"bandwidth",			BANDWIDTH},
    		{"default-metric",		DFLTMETRIC},
    		{"delay",			DELAY},
    		{"fib-priority-external",	FIBPRIORITY_EXT},
    		{"fib-priority-internal",	FIBPRIORITY_INT},
    		{"fib-priority-summary",	FIBPRIORITY_SUMM},
    		{"fib-update",			FIBUPDATE},
    		{"hello-interval",		HELLOINTERVAL},
    		{"holdtime",			HOLDTIME},
    		{"include",			INCLUDE},
    		{"interface",			INTERFACE},
    		{"ipv4",			IPV4},
    		{"ipv6",			IPV6},
    		{"k-values",			KVALUES},
    		{"maximum-hops",		MAXHOPS},
    		{"maximum-paths",		MAXPATHS},
    		{"metric",			METRIC},
    		{"no",				NO},
    		{"passive",			PASSIVE},
    		{"rdomain",			RDOMAIN},
    		{"redistribute",		REDISTRIBUTE},
    		{"router-id",			ROUTERID},
    		{"split-horizon",		SPLITHORIZON},
    		{"summary-address",		SUMMARY_ADDR},
    		{"variance",			VARIANCE},
    		{"yes",				YES}
    	};
    	const struct keywords	*p;
    
    	p = bsearch(s, keywords, sizeof(keywords)/sizeof(keywords[0]),
    	    sizeof(keywords[0]), kw_cmp);
    
    	if (p)
    		return (p->k_val);
    	else
    		return (STRING);
    }
    
    #define START_EXPAND	1
    #define DONE_EXPAND	2
    
    static int	expanding;
    
    int
    igetc(void)
    {
    	int	c;
    
    	while (1) {
    		if (file->ungetpos > 0)
    			c = file->ungetbuf[--file->ungetpos];
    		else
    			c = getc(file->stream);
    
    		if (c == START_EXPAND)
    			expanding = 1;
    		else if (c == DONE_EXPAND)
    			expanding = 0;
    		else
    			break;
    	}
    	return (c);
    }
    
    static int
    lgetc(int quotec)
    {
    	int		c, next;
    
    	if (quotec) {
    		if ((c = igetc()) == EOF) {
    			yyerror("reached end of file while parsing "
    			    "quoted string");
    			if (file == topfile || popfile() == EOF)
    				return (EOF);
    			return (quotec);
    		}
    		return (c);
    	}
    
    	while ((c = igetc()) == '\\') {
    		next = igetc();
    		if (next != '\n') {
    			c = next;
    			break;
    		}
    		yylval.lineno = file->lineno;
    		file->lineno++;
    	}
    
    	if (c == EOF) {
    		/*
    		 * Fake EOL when hit EOF for the first time. This gets line
    		 * count right if last line in included file is syntactically
    		 * invalid and has no newline.
    		 */
    		if (file->eof_reached == 0) {
    			file->eof_reached = 1;
    			return ('\n');
    		}
    		while (c == EOF) {
    			if (file == topfile || popfile() == EOF)
    				return (EOF);
    			c = igetc();
    		}
    	}
    	return (c);
    }
    
    void
    lungetc(int c)
    {
    	if (c == EOF)
    		return;
    
    	if (file->ungetpos >= file->ungetsize) {
    		void *p = reallocarray(file->ungetbuf, file->ungetsize, 2);
    		if (p == NULL)
    			err(1, "%s", __func__);
    		file->ungetbuf = p;
    		file->ungetsize *= 2;
    	}
    	file->ungetbuf[file->ungetpos++] = c;
    }
    
    static int
    findeol(void)
    {
    	int	c;
    
    	/* skip to either EOF or the first real EOL */
    	while (1) {
    		c = lgetc(0);
    		if (c == '\n') {
    			file->lineno++;
    			break;
    		}
    		if (c == EOF)
    			break;
    	}
    	return (ERROR);
    }
    
    static int
    yylex(void)
    {
    	char	 buf[8096];
    	char	*p, *val;
    	int	 quotec, next, c;
    	int	 token;
    
    top:
    	p = buf;
    	while ((c = lgetc(0)) == ' ' || c == '\t')
    		; /* nothing */
    
    	yylval.lineno = file->lineno;
    	if (c == '#')
    		while ((c = lgetc(0)) != '\n' && c != EOF)
    			; /* nothing */
    	if (c == '$' && !expanding) {
    		while (1) {
    			if ((c = lgetc(0)) == EOF)
    				return (0);
    
    			if (p + 1 >= buf + sizeof(buf) - 1) {
    				yyerror("string too long");
    				return (findeol());
    			}
    			if (isalnum(c) || c == '_') {
    				*p++ = c;
    				continue;
    			}
    			*p = '\0';
    			lungetc(c);
    			break;
    		}
    		val = symget(buf);
    		if (val == NULL) {
    			yyerror("macro '%s' not defined", buf);
    			return (findeol());
    		}
    		p = val + strlen(val) - 1;
    		lungetc(DONE_EXPAND);
    		while (p >= val) {
    			lungetc((unsigned char)*p);
    			p--;
    		}
    		lungetc(START_EXPAND);
    		goto top;
    	}
    
    	switch (c) {
    	case '\'':
    	case '"':
    		quotec = c;
    		while (1) {
    			if ((c = lgetc(quotec)) == EOF)
    				return (0);
    			if (c == '\n') {
    				file->lineno++;
    				continue;
    			} else if (c == '\\') {
    				if ((next = lgetc(quotec)) == EOF)
    					return (0);
    				if (next == quotec || next == ' ' ||
    				    next == '\t')
    					c = next;
    				else if (next == '\n') {
    					file->lineno++;
    					continue;
    				} else
    					lungetc(next);
    			} else if (c == quotec) {
    				*p = '\0';
    				break;
    			} else if (c == '\0') {
    				yyerror("syntax error");
    				return (findeol());
    			}
    			if (p + 1 >= buf + sizeof(buf) - 1) {
    				yyerror("string too long");
    				return (findeol());
    			}
    			*p++ = c;
    		}
    		yylval.v.string = strdup(buf);
    		if (yylval.v.string == NULL)
    			err(1, "%s", __func__);
    		return (STRING);
    	}
    
    #define allowed_to_end_number(x) \
    	(isspace(x) || x == ')' || x ==',' || x == '/' || x == '}' || x == '=')
    
    	if (c == '-' || isdigit(c)) {
    		do {
    			*p++ = c;
    			if ((size_t)(p-buf) >= sizeof(buf)) {
    				yyerror("string too long");
    				return (findeol());
    			}
    		} while ((c = lgetc(0)) != EOF && isdigit(c));
    		lungetc(c);
    		if (p == buf + 1 && buf[0] == '-')
    			goto nodigits;
    		if (c == EOF || allowed_to_end_number(c)) {
    			const char *errstr = NULL;
    
    			*p = '\0';
    			yylval.v.number = strtonum(buf, LLONG_MIN,
    			    LLONG_MAX, &errstr);
    			if (errstr) {
    				yyerror("\"%s\" invalid number: %s",
    				    buf, errstr);
    				return (findeol());
    			}
    			return (NUMBER);
    		} else {
    nodigits:
    			while (p > buf + 1)
    				lungetc((unsigned char)*--p);
    			c = (unsigned char)*--p;
    			if (c == '-')
    				return (c);
    		}
    	}
    
    #define allowed_in_string(x) \
    	(isalnum(x) || (ispunct(x) && x != '(' && x != ')' && \
    	x != '{' && x != '}' && \
    	x != '!' && x != '=' && x != '#' && \
    	x != ','))
    
    	if (isalnum(c) || c == ':' || c == '_') {
    		do {
    			*p++ = c;
    			if ((size_t)(p-buf) >= sizeof(buf)) {
    				yyerror("string too long");
    				return (findeol());
    			}
    		} while ((c = lgetc(0)) != EOF && (allowed_in_string(c)));
    		lungetc(c);
    		*p = '\0';
    		if ((token = lookup(buf)) == STRING)
    			if ((yylval.v.string = strdup(buf)) == NULL)
    				err(1, "%s", __func__);
    		return (token);
    	}
    	if (c == '\n') {
    		yylval.lineno = file->lineno;
    		file->lineno++;
    	}
    	if (c == EOF)
    		return (0);
    	return (c);
    }
    
    static int
    check_file_secrecy(int fd, const char *fname)
    {
    	struct stat	st;
    
    	if (fstat(fd, &st)) {
    		log_warn("cannot stat %s", fname);
    		return (-1);
    	}
    	if (st.st_uid != 0 && st.st_uid != getuid()) {
    		log_warnx("%s: owner not root or current user", fname);
    		return (-1);
    	}
    	if (st.st_mode & (S_IWGRP | S_IXGRP | S_IRWXO)) {
    		log_warnx("%s: group writable or world read/writable", fname);
    		return (-1);
    	}
    	return (0);
    }
    
    static struct file *
    pushfile(const char *name, int secret)
    {
    	struct file	*nfile;
    
    	if ((nfile = calloc(1, sizeof(struct file))) == NULL) {
    		log_warn("%s", __func__);
    		return (NULL);
    	}
    	if ((nfile->name = strdup(name)) == NULL) {
    		log_warn("%s", __func__);
    		free(nfile);
    		return (NULL);
    	}
    	if ((nfile->stream = fopen(nfile->name, "r")) == NULL) {
    		log_warn("%s: %s", __func__, nfile->name);
    		free(nfile->name);
    		free(nfile);
    		return (NULL);
    	} else if (secret &&
    	    check_file_secrecy(fileno(nfile->stream), nfile->name)) {
    		fclose(nfile->stream);
    		free(nfile->name);
    		free(nfile);
    		return (NULL);
    	}
    	nfile->lineno = TAILQ_EMPTY(&files) ? 1 : 0;
    	nfile->ungetsize = 16;
    	nfile->ungetbuf = malloc(nfile->ungetsize);
    	if (nfile->ungetbuf == NULL) {
    		log_warn("%s", __func__);
    		fclose(nfile->stream);
    		free(nfile->name);
    		free(nfile);
    		return (NULL);
    	}
    	TAILQ_INSERT_TAIL(&files, nfile, entry);
    	return (nfile);
    }
    
    static int
    popfile(void)
    {
    	struct file	*prev;
    
    	if ((prev = TAILQ_PREV(file, files, entry)) != NULL)
    		prev->errors += file->errors;
    
    	TAILQ_REMOVE(&files, file, entry);
    	fclose(file->stream);
    	free(file->name);
    	free(file->ungetbuf);
    	free(file);
    	file = prev;
    	return (file ? 0 : EOF);
    }
    
    struct eigrpd_conf *
    parse_config(char *filename)
    {
    	struct sym	*sym, *next;
    
    	conf = config_new_empty();
    	conf->rdomain = 0;
    	conf->fib_priority_internal = RTP_EIGRP;
    	conf->fib_priority_external = RTP_EIGRP;
    	conf->fib_priority_summary = RTP_EIGRP;
    
    	defs = &globaldefs;
    	defs->kvalues[0] = defs->kvalues[2] = 1;
    	defs->active_timeout = DEFAULT_ACTIVE_TIMEOUT;
    	defs->maximum_hops = DEFAULT_MAXIMUM_HOPS;
    	defs->maximum_paths = DEFAULT_MAXIMUM_PATHS;
    	defs->variance = DEFAULT_VARIANCE;
    	defs->hello_holdtime = DEFAULT_HELLO_HOLDTIME;
    	defs->hello_interval = DEFAULT_HELLO_INTERVAL;
    	defs->delay = DEFAULT_DELAY;
    	defs->bandwidth = DEFAULT_BANDWIDTH;
    	defs->splithorizon = 1;
    
    	if ((file = pushfile(filename,
    	    !(global.cmd_opts & EIGRPD_OPT_NOACTION))) == NULL) {
    		free(conf);
    		return (NULL);
    	}
    	topfile = file;
    
    	yyparse();
    	errors = file->errors;
    	popfile();
    
    	/* Free macros and check which have not been used. */
    	TAILQ_FOREACH_SAFE(sym, &symhead, entry, next) {
    		if ((global.cmd_opts & EIGRPD_OPT_VERBOSE2) && !sym->used)
    			fprintf(stderr, "warning: macro '%s' not "
    			    "used\n", sym->nam);
    		if (!sym->persist) {
    			free(sym->nam);
    			free(sym->val);
    			TAILQ_REMOVE(&symhead, sym, entry);
    			free(sym);
    		}
    	}
    
    	/* check that all interfaces belong to the configured rdomain */
    	errors += conf_check_rdomain(conf->rdomain);
    
    	if (errors) {
    		clear_config(conf);
    		return (NULL);
    	}
    
    	if (conf->rtr_id.s_addr == 0)
    		conf->rtr_id.s_addr = get_rtr_id();
    
    	return (conf);
    }
    
    static int
    symset(const char *nam, const char *val, int persist)
    {
    	struct sym	*sym;
    
    	TAILQ_FOREACH(sym, &symhead, entry) {
    		if (strcmp(nam, sym->nam) == 0)
    			break;
    	}
    
    	if (sym != NULL) {
    		if (sym->persist == 1)
    			return (0);
    		else {
    			free(sym->nam);
    			free(sym->val);
    			TAILQ_REMOVE(&symhead, sym, entry);
    			free(sym);
    		}
    	}
    	if ((sym = calloc(1, sizeof(*sym))) == NULL)
    		return (-1);
    
    	sym->nam = strdup(nam);
    	if (sym->nam == NULL) {
    		free(sym);
    		return (-1);
    	}
    	sym->val = strdup(val);
    	if (sym->val == NULL) {
    		free(sym->nam);
    		free(sym);
    		return (-1);
    	}
    	sym->used = 0;
    	sym->persist = persist;
    	TAILQ_INSERT_TAIL(&symhead, sym, entry);
    	return (0);
    }
    
    int
    cmdline_symset(char *s)
    {
    	char	*sym, *val;
    	int	ret;
    
    	if ((val = strrchr(s, '=')) == NULL)
    		return (-1);
    	sym = strndup(s, val - s);
    	if (sym == NULL)
    		errx(1, "%s: strndup", __func__);
    	ret = symset(sym, val + 1, 1);
    	free(sym);
    
    	return (ret);
    }
    
    static char *
    symget(const char *nam)
    {
    	struct sym	*sym;
    
    	TAILQ_FOREACH(sym, &symhead, entry) {
    		if (strcmp(nam, sym->nam) == 0) {
    			sym->used = 1;
    			return (sym->val);
    		}
    	}
    	return (NULL);
    }
    
    static struct eigrp *
    conf_get_instance(uint16_t as)
    {
    	struct eigrp	*e, *tmp;
    
    	if (eigrp_find(conf, af, as)) {
    		yyerror("autonomous-system %u already configured"
    		    "for address-family %s", as, af_name(af));
    		return (NULL);
    	}
    
    	e = calloc(1, sizeof(struct eigrp));
    	if (e == NULL)
    		fatal(NULL);
    
    	e->af = af;
    	e->as = as;
    	SIMPLEQ_INIT(&e->redist_list);
    	TAILQ_INIT(&e->ei_list);
    	RB_INIT(&e->nbrs);
    	RB_INIT(&e->topology);
    
    	/* start local sequence number used by RTP */
    	e->seq_num = 1;
    
    	/* order by address-family and then by autonomous-system */
    	TAILQ_FOREACH(tmp, &conf->instances, entry)
    		if (tmp->af > e->af ||
    		    (tmp->af == e->af && tmp->as > e->as))
    			break;
    	if (tmp)
    		TAILQ_INSERT_BEFORE(tmp, e, entry);
    	else
    		TAILQ_INSERT_TAIL(&conf->instances, e, entry);
    
    	return (e);
    }
    
    static struct eigrp_iface *
    conf_get_if(struct kif *kif)
    {
    	struct eigrp_iface	*e;
    
    	TAILQ_FOREACH(e, &eigrp->ei_list, e_entry)
    		if (e->iface->ifindex == kif->ifindex) {
    			yyerror("interface %s already configured "
    			    "for address-family %s and "
    			    "autonomous-system %u", kif->ifname,
    			    af_name(af), eigrp->as);
    			return (NULL);
    		}
    
    	e = eigrp_if_new(conf, eigrp, kif);
    
    	return (e);
    }
    
    int
    conf_check_rdomain(unsigned int rdomain)
    {
    	struct iface	*iface;
    	int		 errs = 0;
    
    	TAILQ_FOREACH(iface, &conf->iface_list, entry) {
    		if (iface->rdomain != rdomain) {
    			logit(LOG_CRIT, "interface %s not in rdomain %u",
    			    iface->name, rdomain);
    			errs++;
    		}
    	}
    
    	return (errs);
    }
    
    static void
    clear_config(struct eigrpd_conf *xconf)
    {
    	struct eigrp		*e;
    	struct redistribute	*r;
    	struct eigrp_iface	*i;
    	struct summary_addr	*s;
    
    	while ((e = TAILQ_FIRST(&xconf->instances)) != NULL) {
    		while (!SIMPLEQ_EMPTY(&e->redist_list)) {
    			r = SIMPLEQ_FIRST(&e->redist_list);
    			SIMPLEQ_REMOVE_HEAD(&e->redist_list, entry);
    			free(r);
    		}
    
    		while ((i = TAILQ_FIRST(&e->ei_list)) != NULL) {
    			RB_REMOVE(iface_id_head, &ifaces_by_id, i);
    			TAILQ_REMOVE(&e->ei_list, i, e_entry);
    			TAILQ_REMOVE(&e->ei_list, i, i_entry);
    			while ((s = TAILQ_FIRST(&i->summary_list)) != NULL) {
    				TAILQ_REMOVE(&i->summary_list, s, entry);
    				free(s);
    			}
    			if (TAILQ_EMPTY(&i->iface->ei_list)) {
    				TAILQ_REMOVE(&xconf->iface_list, i->iface, entry);
    				free(i->iface);
    			}
    			free(i);
    		}
    
    		TAILQ_REMOVE(&xconf->instances, e, entry);
    		free(e);
    	}
    
    	free(xconf);
    }
    
    static uint32_t
    get_rtr_id(void)
    {
    	struct ifaddrs		*ifap, *ifa;
    	uint32_t		 ip = 0, cur, localnet;
    
    	localnet = htonl(INADDR_LOOPBACK & IN_CLASSA_NET);
    
    	if (getifaddrs(&ifap) == -1)
    		fatal("getifaddrs");
    
    	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
    		if (strncmp(ifa->ifa_name, "carp", 4) == 0)
    			continue;
    		if (ifa->ifa_addr == NULL ||
    		    ifa->ifa_addr->sa_family != AF_INET)
    			continue;
    		cur = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr;
    		if ((cur & localnet) == localnet)	/* skip 127/8 */
    			continue;
    		if (ntohl(cur) < ntohl(ip) || ip == 0)
    			ip = cur;
    	}
    	freeifaddrs(ifap);
    
    	if (ip == 0)
    		fatal("router-id is 0.0.0.0");
    
    	return (ip);
    }
    
    static int
    get_prefix(const char *s, union eigrpd_addr *addr, uint8_t *plen)
    {
    	char			*p, *ps;
    	const char		*errstr;
    	int			 maxplen;
    
    	switch (af) {
    	case AF_INET:
    		maxplen = 32;
    		break;
    	case AF_INET6:
    		maxplen = 128;
    		break;
    	default:
    		return (-1);
    	}
    
    	if ((p = strrchr(s, '/')) != NULL) {
    		*plen = strtonum(p + 1, 0, maxplen, &errstr);
    		if (errstr) {
    			log_warnx("prefixlen is %s: %s", errstr, p + 1);
    			return (-1);
    		}
    		if ((ps = malloc(strlen(s) - strlen(p) + 1)) == NULL)
    			fatal("get_prefix: malloc");
    		strlcpy(ps, s, strlen(s) - strlen(p) + 1);
    	} else {
    		if ((ps = strdup(s)) == NULL)
    			fatal("get_prefix: strdup");
    		*plen = maxplen;
    	}
    
    	memset(addr, 0, sizeof(union eigrpd_addr));
    	switch (af) {
    	case AF_INET:
    		if (inet_pton(AF_INET, ps, &addr->v4) != 1) {
    			free(ps);
    			return (-1);
    		}
    		break;
    	case AF_INET6:
    		if (inet_pton(AF_INET6, ps, &addr->v6) != 1) {
    			free(ps);
    			return (-1);
    		}
    		break;
    	default:
    		free(ps);
    		return (-1);
    	}
    	eigrp_applymask(af, addr, addr, *plen);
    	free(ps);
    
    	return (0);
    }