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

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  • Author : anton
    Date : 2019-05-14 06:05:45
    Hash : c5ee7fb3
    Message : Add support for `boot device' to vm.conf grammar which is the `-B device' counterpart from vmctl. ok mlarkin@

  • usr.sbin/vmd/parse.y
  • /*	$OpenBSD: parse.y,v 1.52 2019/05/14 06:05:45 anton 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 <unistd.h>
    #include <ctype.h>
    #include <netdb.h>
    #include <util.h>
    #include <errno.h>
    #include <err.h>
    #include <fcntl.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 *, int);
    unsigned int	 parse_format(const 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 DEVICE DISABLE DISK DOWN ENABLE FORMAT GROUP
    %token	INET6 INSTANCE INTERFACE LLADDR LOCAL LOCKED MEMORY NET NIFS OWNER
    %token	PATH PREFIX RDOMAIN SIZE SOCKET SWITCH UP VM VMID
    %token	<v.number>	NUMBER
    %token	<v.string>	STRING
    %type	<v.lladdr>	lladdr
    %type	<v.number>	bootdevice
    %type	<v.number>	disable
    %type	<v.number>	image_format
    %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 INET6 {
    			env->vmd_cfg.cfg_flags |= VMD_CFG_INET6;
    		}
    		| LOCAL INET6 PREFIX STRING {
    			struct address	 h;
    
    			if (host($4, &h) == -1 ||
    			    h.ss.ss_family != AF_INET6 ||
    			    h.prefixlen > 64 || h.prefixlen < 0) {
    				yyerror("invalid local inet6 prefix: %s", $4);
    				free($4);
    				YYERROR;
    			}
    
    			env->vmd_cfg.cfg_flags |= VMD_CFG_INET6;
    			env->vmd_cfg.cfg_flags &= ~VMD_CFG_AUTOINET6;
    			memcpy(&env->vmd_cfg.cfg_localprefix6, &h, sizeof(h));
    		}
    		| LOCAL PREFIX STRING {
    			struct address	 h;
    
    			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_state & VM_STATE_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_state |= VM_STATE_DISABLED;
    					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 image_format	{
    			if (parse_disk($2, $3) != 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			{
    			char	 path[PATH_MAX];
    
    			if (vcp->vcp_kernel[0] != '\0') {
    				yyerror("kernel specified more than once");
    				free($2);
    				YYERROR;
    
    			}
    			if (realpath($2, path) == NULL) {
    				yyerror("kernel path not found: %s",
    				    strerror(errno));
    				free($2);
    				YYERROR;
    			}
    			free($2);
    			if (strlcpy(vcp->vcp_kernel, path,
    			    sizeof(vcp->vcp_kernel)) >=
    			    sizeof(vcp->vcp_kernel)) {
    				yyerror("kernel name too long");
    				YYERROR;
    			}
    			vmc.vmc_flags |= VMOP_CREATE_KERNEL;
    		}
    		| BOOT DEVICE bootdevice	{
    			vmc.vmc_bootdevice = $3;
    		}
    		| 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);
    		}
    		;
    
    image_format	: /* none 	*/	{
    			$$ = 0;
    		}
    	     	| FORMAT string		{
    			if (($$ = parse_format($2)) == 0) {
    				yyerror("unrecognized disk format %s", $2);
    				free($2);
    				YYERROR;
    			}
    		}
    		;
    
    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; }
    		;
    
    bootdevice	: CDROM				{ $$ = VMBOOTDEV_CDROM; }
    		| DISK				{ $$ = VMBOOTDEV_DISK; }
    		| NET				{ $$ = VMBOOTDEV_NET; }
    		;
    
    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 },
    		{ "device",		DEVICE },
    		{ "disable",		DISABLE },
    		{ "disk",		DISK },
    		{ "down",		DOWN },
    		{ "enable",		ENABLE },
    		{ "format",		FORMAT },
    		{ "group",		GROUP },
    		{ "id",			VMID },
    		{ "include",		INCLUDE },
    		{ "inet6",		INET6 },
    		{ "instance",		INSTANCE },
    		{ "interface",		INTERFACE },
    		{ "interfaces",		NIFS },
    		{ "lladdr",		LLADDR },
    		{ "local",		LOCAL },
    		{ "locked",		LOCKED },
    		{ "memory",		MEMORY },
    		{ "net",		NET },
    		{ "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 || 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)
    			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 ((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(*--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 ((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)
    				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;
    
    	if ((val = strrchr(s, '=')) == NULL)
    		return (-1);
    	sym = strndup(s, val - s);
    	if (sym == NULL)
    		fatal("%s: strndup", __func__);
    	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, int type)
    {
    	char	 buf[BUFSIZ], path[PATH_MAX];
    	int	 fd;
    	ssize_t	 len;
    
    	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 (!type) {
    		/* Use raw as the default format */
    		type = VMDF_RAW;
    
    		/* Try to derive the format from the file signature */
    		if ((fd = open(path, O_RDONLY)) != -1) {
    			len = read(fd, buf, sizeof(buf));
    			close(fd);
    			if (len >= (ssize_t)strlen(VM_MAGIC_QCOW) &&
    			    strncmp(buf, VM_MAGIC_QCOW,
    			    strlen(VM_MAGIC_QCOW)) == 0) {
    				/* The qcow version will be checked later */
    				type = VMDF_QCOW2;
    			}
    		}
    	}
    
    	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);
    	}
    	vmc.vmc_disktypes[vcp->vcp_ndisks] = type;
    
    	vcp->vcp_ndisks++;
    
    	return (0);
    }
    
    unsigned int
    parse_format(const char *word)
    {
    	if (strcasecmp(word, "raw") == 0)
    		return (VMDF_RAW);
    	else if (strcasecmp(word, "qcow2") == 0)
    		return (VMDF_QCOW2);
    	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);
    }