/*	$OpenBSD: parse.y,v 1.42 2018/07/13 08:42:49 reyk Exp $	*/

/*
 * Copyright (c) 2007-2016 Reyk Floeter <reyk@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/queue.h>
#include <sys/socket.h>
#include <sys/uio.h>

#include <machine/vmmvar.h>

#include <net/if.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <stdarg.h>
#include <string.h>
#include <ctype.h>
#include <netdb.h>
#include <util.h>
#include <errno.h>
#include <err.h>
#include <pwd.h>
#include <grp.h>

#include "proc.h"
#include "vmd.h"

TAILQ_HEAD(files, file)		 files = TAILQ_HEAD_INITIALIZER(files);
static 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;
} *file, *topfile;
struct file	*pushfile(const char *, int);
int		 popfile(void);
int		 yyparse(void);
int		 yylex(void);
int		 yyerror(const char *, ...)
    __attribute__((__format__ (printf, 1, 2)))
    __attribute__((__nonnull__ (1)));
int		 kw_cmp(const void *, const void *);
int		 lookup(char *);
int		 igetc(void);
int		 lgetc(int);
void		 lungetc(int);
int		 findeol(void);

TAILQ_HEAD(symhead, sym)	 symhead = TAILQ_HEAD_INITIALIZER(symhead);
struct sym {
	TAILQ_ENTRY(sym)	 entry;
	int			 used;
	int			 persist;
	char			*nam;
	char			*val;
};
int		 symset(const char *, const char *, int);
char		*symget(const char *);

ssize_t		 parse_size(char *, int64_t);
int		 parse_disk(char *);

static struct vmop_create_params vmc;
static struct vm_create_params	*vcp;
static struct vmd_switch	*vsw;
static char			 vsw_type[IF_NAMESIZE];
static int			 vcp_disable;
static size_t			 vcp_nnics;
static int			 errors;
extern struct vmd		*env;
extern const char		*vmd_descsw[];

typedef struct {
	union {
		uint8_t		 lladdr[ETHER_ADDR_LEN];
		int64_t		 number;
		char		*string;
		struct {
			uid_t	 uid;
			int64_t	 gid;
		}		 owner;
	} v;
	int lineno;
} YYSTYPE;

%}


%token	INCLUDE ERROR
%token	ADD ALLOW BOOT CDROM DISABLE DISK DOWN ENABLE GROUP INSTANCE INTERFACE
%token	LLADDR LOCAL LOCKED MEMORY NIFS OWNER PATH PREFIX RDOMAIN SIZE SOCKET
%token	SWITCH UP VM VMID
%token	<v.number>	NUMBER
%token	<v.string>	STRING
%type	<v.lladdr>	lladdr
%type	<v.number>	disable
%type	<v.number>	local
%type	<v.number>	locked
%type	<v.number>	updown
%type	<v.owner>	owner_id
%type	<v.string>	optstring
%type	<v.string>	string
%type	<v.string>	vm_instance

%%

grammar		: /* empty */
		| grammar include '\n'
		| grammar '\n'
		| grammar varset '\n'
		| grammar main '\n'
		| grammar switch '\n'
		| grammar vm '\n'
		| grammar error '\n'		{ file->errors++; }
		;

include		: INCLUDE string		{
			struct file	*nfile;

			if ((nfile = pushfile($2, 0)) == NULL) {
				yyerror("failed to include file %s", $2);
				free($2);
				YYERROR;
			}
			free($2);

			file = nfile;
			lungetc('\n');
		}
		;

varset		: STRING '=' STRING		{
			char *s = $1;
			while (*s++) {
				if (isspace((unsigned char)*s)) {
					yyerror("macro name cannot contain "
					    "whitespace");
					free($1);
					free($3);
					YYERROR;
				}
			}
			if (symset($1, $3, 0) == -1)
				fatalx("cannot store variable");
			free($1);
			free($3);
		}
		;

main		: LOCAL PREFIX STRING {
			struct address	 h;

			/* The local prefix is IPv4-only */
			if (host($3, &h) == -1 ||
			    h.ss.ss_family != AF_INET ||
			    h.prefixlen > 32 || h.prefixlen < 0) {
				yyerror("invalid local prefix: %s", $3);
				free($3);
				YYERROR;
			}

			memcpy(&env->vmd_cfg.cfg_localprefix, &h, sizeof(h));
		}
		| SOCKET OWNER owner_id {
			env->vmd_ps.ps_csock.cs_uid = $3.uid;
			env->vmd_ps.ps_csock.cs_gid = $3.gid == -1 ? 0 : $3.gid;
		}
		;

switch		: SWITCH string			{
			if ((vsw = calloc(1, sizeof(*vsw))) == NULL)
				fatal("could not allocate switch");

			vsw->sw_id = env->vmd_nswitches + 1;
			vsw->sw_name = $2;
			vsw->sw_flags = VMIFF_UP;

			vcp_disable = 0;
		} '{' optnl switch_opts_l '}'	{
			if (strnlen(vsw->sw_ifname,
			    sizeof(vsw->sw_ifname)) == 0) {
				yyerror("switch \"%s\" "
				    "is missing interface name",
				    vsw->sw_name);
				YYERROR;
			}

			if (vcp_disable) {
				log_debug("%s:%d: switch \"%s\""
				    " skipped (disabled)",
				    file->name, yylval.lineno, vsw->sw_name);
			} else if (!env->vmd_noaction) {
				TAILQ_INSERT_TAIL(env->vmd_switches,
				    vsw, sw_entry);
				env->vmd_nswitches++;
				log_debug("%s:%d: switch \"%s\" registered",
				    file->name, yylval.lineno, vsw->sw_name);
			}
		}
		;

switch_opts_l	: switch_opts_l switch_opts nl
		| switch_opts optnl
		;

switch_opts	: disable			{
			vcp_disable = $1;
		}
		| GROUP string			{
			if (priv_validgroup($2) == -1) {
				yyerror("invalid group name: %s", $2);
				free($2);
				YYERROR;
			}
			vsw->sw_group = $2;
		}
		| INTERFACE string		{
			if (priv_getiftype($2, vsw_type, NULL) == -1 ||
			    priv_findname(vsw_type, vmd_descsw) == -1) {
				yyerror("invalid switch interface: %s", $2);
				free($2);
				YYERROR;
			}

			if (strlcpy(vsw->sw_ifname, $2,
			    sizeof(vsw->sw_ifname)) >= sizeof(vsw->sw_ifname)) {
				yyerror("switch interface too long: %s", $2);
				free($2);
				YYERROR;
			}
			free($2);
		}
		| LOCKED LLADDR			{
			vsw->sw_flags |= VMIFF_LOCKED;
		}
		| RDOMAIN NUMBER		{
			if ($2 < 0 || $2 > RT_TABLEID_MAX) {
				yyerror("invalid rdomain: %lld", $2);
				YYERROR;
			}
			vsw->sw_flags |= VMIFF_RDOMAIN;
			vsw->sw_rdomain = $2;
		}
		| updown			{
			if ($1)
				vsw->sw_flags |= VMIFF_UP;
			else
				vsw->sw_flags &= ~VMIFF_UP;
		}
		;

vm		: VM string vm_instance		{
			unsigned int	 i;
			char		*name;

			memset(&vmc, 0, sizeof(vmc));
			vcp = &vmc.vmc_params;
			vcp_disable = 0;
			vcp_nnics = 0;

			if ($3 != NULL) {
				/* This is an instance of a pre-configured VM */
				if (strlcpy(vmc.vmc_instance, $2,
				    sizeof(vmc.vmc_instance)) >=
				    sizeof(vmc.vmc_instance)) {
					yyerror("vm %s name too long", $2);
					free($2);
					free($3);
					YYERROR;
				}
				
				free($2);
				name = $3;
				vmc.vmc_flags |= VMOP_CREATE_INSTANCE;
			} else
				name = $2;

			for (i = 0; i < VMM_MAX_NICS_PER_VM; i++) {
				/* Set the interface to UP by default */
				vmc.vmc_ifflags[i] |= IFF_UP;
			}

			if (strlcpy(vcp->vcp_name, name,
			    sizeof(vcp->vcp_name)) >= sizeof(vcp->vcp_name)) {
				yyerror("vm name too long");
				free($2);
				free($3);
				YYERROR;
			}

			/* set default user/group permissions */
			vmc.vmc_owner.uid = 0;
			vmc.vmc_owner.gid = -1;
		} '{' optnl vm_opts_l '}'	{
			struct vmd_vm	*vm;
			int		 ret;

			/* configured interfaces vs. number of interfaces */
			if (vcp_nnics > vcp->vcp_nnics)
				vcp->vcp_nnics = vcp_nnics;

			if (!env->vmd_noaction) {
				ret = vm_register(&env->vmd_ps, &vmc,
				    &vm, 0, 0);
				if (ret == -1 && errno == EALREADY) {
					log_debug("%s:%d: vm \"%s\""
					    " skipped (%s)",
					    file->name, yylval.lineno,
					    vcp->vcp_name, vm->vm_running ?
					    "running" : "already exists");
				} else if (ret == -1) {
					yyerror("vm \"%s\" failed: %s",
					    vcp->vcp_name, strerror(errno));
					YYERROR;
				} else {
					if (vcp_disable)
						vm->vm_disabled = 1;
					log_debug("%s:%d: vm \"%s\" "
					    "registered (%s)",
					    file->name, yylval.lineno,
					    vcp->vcp_name,
					    vcp_disable ?
					    "disabled" : "enabled");
				}
				vm->vm_from_config = 1;
			}
		}
		;

vm_instance	: /* empty */			{ $$ = NULL; }
		| INSTANCE string		{ $$ = $2; }
		;

vm_opts_l	: vm_opts_l vm_opts nl
		| vm_opts optnl
		;

vm_opts		: disable			{
			vcp_disable = $1;
		}
		| DISK string			{
			if (parse_disk($2) != 0) {
				yyerror("failed to parse disks: %s", $2);
				free($2);
				YYERROR;
			}
			free($2);
			vmc.vmc_flags |= VMOP_CREATE_DISK;
		}
		| local INTERFACE optstring iface_opts_o {
			unsigned int	i;
			char		type[IF_NAMESIZE];

			i = vcp_nnics;
			if (++vcp_nnics > VMM_MAX_NICS_PER_VM) {
				yyerror("too many interfaces: %zu", vcp_nnics);
				free($3);
				YYERROR;
			}

			if ($1)
				vmc.vmc_ifflags[i] |= VMIFF_LOCAL;
			if ($3 != NULL) {
				if (strcmp($3, "tap") != 0 &&
				    (priv_getiftype($3, type, NULL) == -1 ||
				    strcmp(type, "tap") != 0)) {
					yyerror("invalid interface: %s", $3);
					free($3);
					YYERROR;
				}

				if (strlcpy(vmc.vmc_ifnames[i], $3,
				    sizeof(vmc.vmc_ifnames[i])) >=
				    sizeof(vmc.vmc_ifnames[i])) {
					yyerror("interface name too long: %s",
					    $3);
					free($3);
					YYERROR;
				}
			}
			free($3);
			vmc.vmc_flags |= VMOP_CREATE_NETWORK;
		}
		| BOOT string			{
			if (vcp->vcp_kernel[0] != '\0') {
				yyerror("kernel specified more than once");
				free($2);
				YYERROR;

			}
			if (strlcpy(vcp->vcp_kernel, $2,
			    sizeof(vcp->vcp_kernel)) >=
			    sizeof(vcp->vcp_kernel)) {
				yyerror("kernel name too long");
				free($2);
				YYERROR;
			}
			free($2);
			vmc.vmc_flags |= VMOP_CREATE_KERNEL;
		}
		| CDROM string			{
			if (vcp->vcp_cdrom[0] != '\0') {
				yyerror("cdrom specified more than once");
				free($2);
				YYERROR;

			}
			if (strlcpy(vcp->vcp_cdrom, $2,
			    sizeof(vcp->vcp_cdrom)) >=
			    sizeof(vcp->vcp_cdrom)) {
				yyerror("cdrom name too long");
				free($2);
				YYERROR;
			}
			free($2);
			vmc.vmc_flags |= VMOP_CREATE_CDROM;
		}
		| NIFS NUMBER			{
			if (vcp->vcp_nnics != 0) {
				yyerror("interfaces specified more than once");
				YYERROR;
			}
			if ($2 < 0 || $2 > VMM_MAX_NICS_PER_VM) {
				yyerror("too many interfaces: %lld", $2);
				YYERROR;
			}
			vcp->vcp_nnics = (size_t)$2;
			vmc.vmc_flags |= VMOP_CREATE_NETWORK;
		}
		| MEMORY NUMBER			{
			ssize_t	 res;
			if (vcp->vcp_memranges[0].vmr_size != 0) {
				yyerror("memory specified more than once");
				YYERROR;
			}
			if ((res = parse_size(NULL, $2)) == -1) {
				yyerror("failed to parse size: %lld", $2);
				YYERROR;
			}
			vcp->vcp_memranges[0].vmr_size = (size_t)res;
			vmc.vmc_flags |= VMOP_CREATE_MEMORY;
		}
		| MEMORY STRING			{
			ssize_t	 res;
			if (vcp->vcp_memranges[0].vmr_size != 0) {
				yyerror("argument specified more than once");
				free($2);
				YYERROR;
			}
			if ((res = parse_size($2, 0)) == -1) {
				yyerror("failed to parse size: %s", $2);
				free($2);
				YYERROR;
			}
			vcp->vcp_memranges[0].vmr_size = (size_t)res;
			vmc.vmc_flags |= VMOP_CREATE_MEMORY;
		}
		| OWNER owner_id		{
			vmc.vmc_owner.uid = $2.uid;
			vmc.vmc_owner.gid = $2.gid;
		}
		| instance
		;

instance	: ALLOW INSTANCE '{' optnl instance_l '}'
		| ALLOW INSTANCE instance_flags
		;

instance_l	: instance_flags optcommanl instance_l
		| instance_flags optnl
		;

instance_flags	: BOOT		{ vmc.vmc_insflags |= VMOP_CREATE_KERNEL; }
		| MEMORY	{ vmc.vmc_insflags |= VMOP_CREATE_MEMORY; }
		| INTERFACE	{ vmc.vmc_insflags |= VMOP_CREATE_NETWORK; }
		| DISK		{ vmc.vmc_insflags |= VMOP_CREATE_DISK; }
		| CDROM		{ vmc.vmc_insflags |= VMOP_CREATE_CDROM; }
		| INSTANCE	{ vmc.vmc_insflags |= VMOP_CREATE_INSTANCE; }
		| OWNER owner_id {
			vmc.vmc_insowner.uid = $2.uid;
			vmc.vmc_insowner.gid = $2.gid;
		}
		;

owner_id	: /* none */		{
			$$.uid = 0;
			$$.gid = -1;
		}
		| NUMBER		{
			$$.uid = $1;
			$$.gid = -1;
		}
		| STRING		{
			char		*user, *group;
			struct passwd	*pw;
			struct group	*gr;

			$$.uid = 0;
			$$.gid = -1;

			user = $1;
			if ((group = strchr(user, ':')) != NULL) {
				if (group == user)
					user = NULL;
				*group++ = '\0';
			}

			if (user != NULL && *user) {
				if ((pw = getpwnam(user)) == NULL) {
					yyerror("failed to get user: %s",
					    user);
					free($1);
					YYERROR;
				}
				$$.uid = pw->pw_uid;
			}

			if (group != NULL && *group) {
				if ((gr = getgrnam(group)) == NULL) {
					yyerror("failed to get group: %s",
					    group);
					free($1);
					YYERROR;
				}
				$$.gid = gr->gr_gid;
			}

			free($1);
		}
		;

iface_opts_o	: '{' optnl iface_opts_l '}'
		| iface_opts_c
		| /* empty */
		;

iface_opts_l	: iface_opts_l iface_opts optnl
		| iface_opts optnl
		;

iface_opts_c	: iface_opts_c iface_opts optcomma
		| iface_opts
		;

iface_opts	: SWITCH string			{
			unsigned int	i = vcp_nnics;

			/* No need to check if the switch exists */
			if (strlcpy(vmc.vmc_ifswitch[i], $2,
			    sizeof(vmc.vmc_ifswitch[i])) >=
			    sizeof(vmc.vmc_ifswitch[i])) {
				yyerror("switch name too long: %s", $2);
				free($2);
				YYERROR;
			}
			free($2);
		}
		| GROUP string			{
			unsigned int	i = vcp_nnics;

			if (priv_validgroup($2) == -1) {
				yyerror("invalid group name: %s", $2);
				free($2);
				YYERROR;
			}

			/* No need to check if the group exists */
			(void)strlcpy(vmc.vmc_ifgroup[i], $2,
			    sizeof(vmc.vmc_ifgroup[i]));
			free($2);
		}
		| locked LLADDR lladdr		{
			if ($1)
				vmc.vmc_ifflags[vcp_nnics] |= VMIFF_LOCKED;
			memcpy(vcp->vcp_macs[vcp_nnics], $3, ETHER_ADDR_LEN);
		}
		| RDOMAIN NUMBER		{
			if ($2 < 0 || $2 > RT_TABLEID_MAX) {
				yyerror("invalid rdomain: %lld", $2);
				YYERROR;
			}
			vmc.vmc_ifflags[vcp_nnics] |= VMIFF_RDOMAIN;
			vmc.vmc_ifrdomain[vcp_nnics] = $2;
		}
		| updown			{
			if ($1)
				vmc.vmc_ifflags[vcp_nnics] |= VMIFF_UP;
			else
				vmc.vmc_ifflags[vcp_nnics] &= ~VMIFF_UP;
		}
		;

optstring	: STRING			{ $$ = $1; }
		| /* empty */			{ $$ = NULL; }
		;

string		: STRING string			{
			if (asprintf(&$$, "%s%s", $1, $2) == -1)
				fatal("asprintf string");
			free($1);
			free($2);
		}
		| STRING
		;

lladdr		: STRING			{
			struct ether_addr *ea;

			if ((ea = ether_aton($1)) == NULL) {
				yyerror("invalid address: %s\n", $1);
				free($1);
				YYERROR;
			}
			free($1);

			memcpy($$, ea, ETHER_ADDR_LEN);
		}
		;

local		: /* empty */			{ $$ = 0; }
		| LOCAL				{ $$ = 1; }
		;

locked		: /* empty */			{ $$ = 0; }
		| LOCKED			{ $$ = 1; }
		;

updown		: UP				{ $$ = 1; }
		| DOWN				{ $$ = 0; }
		;

disable		: ENABLE			{ $$ = 0; }
		| DISABLE			{ $$ = 1; }
		;

optcomma	: ','
		|
		;

optnl		: '\n' optnl
		|
		;

optcommanl	: ',' optnl
		| nl
		;

nl		: '\n' optnl
		;

%%

struct keywords {
	const char	*k_name;
	int		 k_val;
};

int
yyerror(const char *fmt, ...)
{
	va_list		 ap;
	char		*msg;

	file->errors++;
	va_start(ap, fmt);
	if (vasprintf(&msg, fmt, ap) == -1)
		fatal("yyerror vasprintf");
	va_end(ap);
	log_warnx("%s:%d: %s", file->name, yylval.lineno, msg);
	free(msg);
	return (0);
}

int
kw_cmp(const void *k, const void *e)
{
	return (strcmp(k, ((const struct keywords *)e)->k_name));
}

int
lookup(char *s)
{
	/* this has to be sorted always */
	static const struct keywords keywords[] = {
		{ "add",		ADD },
		{ "allow",		ALLOW },
		{ "boot",		BOOT },
		{ "cdrom",		CDROM },
		{ "disable",		DISABLE },
		{ "disk",		DISK },
		{ "down",		DOWN },
		{ "enable",		ENABLE },
		{ "group",		GROUP },
		{ "id",			VMID },
		{ "include",		INCLUDE },
		{ "instance",		INSTANCE },
		{ "interface",		INTERFACE },
		{ "interfaces",		NIFS },
		{ "lladdr",		LLADDR },
		{ "local",		LOCAL },
		{ "locked",		LOCKED },
		{ "memory",		MEMORY },
		{ "owner",		OWNER },
		{ "prefix",		PREFIX },
		{ "rdomain",		RDOMAIN },
		{ "size",		SIZE },
		{ "socket",		SOCKET },
		{ "switch",		SWITCH },
		{ "up",			UP },
		{ "vm",			VM }
	};
	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);
}

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 == '\t' || c == ' ') {
		/* Compress blanks to a single space. */
		do {
			c = getc(file->stream);
		} while (c == '\t' || c == ' ');
		ungetc(c, file->stream);
		c = ' ';
	}

	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;
}

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);
}

int
yylex(void)
{
	u_char	 buf[8096];
	u_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(*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 || c == ' ' || c == '\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)
			fatal("yylex: strdup");
		return (STRING);
	}

#define allowed_to_end_number(x) \
	(isspace(x) || x == ')' || x ==',' || x == '/' || x == '}' || x == '=')

	if (c == '-' || isdigit(c)) {
		do {
			*p++ = c;
			if ((unsigned)(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(*--p);
			c = *--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 == '_' || c == '/') {
		do {
			*p++ = c;
			if ((unsigned)(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)
				fatal("yylex: strdup");
		return (token);
	}
	if (c == '\n') {
		yylval.lineno = file->lineno;
		file->lineno++;
	}
	if (c == EOF)
		return (0);
	return (c);
}

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) {
		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);
}

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);
}

int
parse_config(const char *filename)
{
	struct sym	*sym, *next;

	if ((file = pushfile(filename, 0)) == NULL) {
		log_warn("failed to open %s", filename);
		if (errno == ENOENT)
			return (0);
		return (-1);
	}
	topfile = file;
	setservent(1);

	/* Set the default switch type */
	(void)strlcpy(vsw_type, VMD_SWITCH_TYPE, sizeof(vsw_type));

	yyparse();
	errors = file->errors;
	popfile();

	endservent();

	/* Free macros and check which have not been used. */
	TAILQ_FOREACH_SAFE(sym, &symhead, entry, next) {
		if (!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);
		}
	}

	if (errors)
		return (-1);

	return (0);
}

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;
	size_t	len;

	if ((val = strrchr(s, '=')) == NULL)
		return (-1);

	len = (val - s) + 1;
	if ((sym = malloc(len)) == NULL)
		fatal("cmdline_symset: malloc");

	(void)strlcpy(sym, s, len);

	ret = symset(sym, val + 1, 1);
	free(sym);

	return (ret);
}

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);
}

ssize_t
parse_size(char *word, int64_t val)
{
	ssize_t		 size;
	long long	 res;

	if (word != NULL) {
		if (scan_scaled(word, &res) != 0) {
			log_warn("invalid size: %s", word);
			return (-1);
		}
		val = (int64_t)res;
	}

	if (val < (1024 * 1024)) {
		log_warnx("size must be at least one megabyte");
		return (-1);
	} else
		size = val / 1024 / 1024;

	if ((size * 1024 * 1024) != val)
		log_warnx("size rounded to %zd megabytes", size);

	return ((ssize_t)size);
}

int
parse_disk(char *word)
{
	char	path[PATH_MAX];

	if (vcp->vcp_ndisks >= VMM_MAX_DISKS_PER_VM) {
		log_warnx("too many disks");
		return (-1);
	}

	if (realpath(word, path) == NULL) {
		log_warn("disk %s", word);
		return (-1);
	}

	if (strlcpy(vcp->vcp_disks[vcp->vcp_ndisks], path,
	    VMM_MAX_PATH_DISK) >= VMM_MAX_PATH_DISK) {
		log_warnx("disk path too long");
		return (-1);
	}

	vcp->vcp_ndisks++;

	return (0);
}

int
host(const char *str, struct address *h)
{
	struct addrinfo		 hints, *res;
	int			 prefixlen;
	char			*s, *p;
	const char		*errstr;

	if ((s = strdup(str)) == NULL) {
		log_warn("%s", __func__);
		goto fail;
	}

	if ((p = strrchr(s, '/')) != NULL) {
		*p++ = '\0';
		prefixlen = strtonum(p, 0, 128, &errstr);
		if (errstr) {
			log_warnx("prefixlen is %s: %s", errstr, p);
			goto fail;
		}
	} else
		prefixlen = 128;

	memset(&hints, 0, sizeof(hints));
	hints.ai_family = AF_UNSPEC;
	hints.ai_flags = AI_NUMERICHOST;
	if (getaddrinfo(s, NULL, &hints, &res) == 0) {
		memset(h, 0, sizeof(*h));
		memcpy(&h->ss, res->ai_addr, res->ai_addrlen);
		h->prefixlen = prefixlen;
		freeaddrinfo(res);
		free(s);
		return (0);
	}

 fail:
	free(s);
	return (-1);
}