0.4.4/src/emul_parse.c

/*
 *  Copyright (C) 2005-2007  Anders Gavare.  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright  
 *     notice, this list of conditions and the following disclaimer in the 
 *     documentation and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 *  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE   
 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 *  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 *  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 *  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 *  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 *  SUCH DAMAGE.
 *
 *
 *  $Id: emul_parse.c,v 1.45 2006/12/30 13:30:52 debug Exp $
 *
 *  Set up an emulation by parsing a config file.
 *
 *  TODO: REWRITE THIS FROM SCRATCH! :-)
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "diskimage.h"
#include "emul.h"
#include "machine.h"
#include "misc.h"
#include "net.h"


#define is_word_char(ch)        ( \
        (ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z') || \
        ch == '_' || ch == '$' || (ch >= '0' && ch <= '9') )

#define MAX_WORD_LEN            200

#define EXPECT_WORD                     1
#define EXPECT_LEFT_PARENTHESIS         2
#define EXPECT_RIGHT_PARENTHESIS        4

static int parenthesis_level = 0;


/*
 *  read_one_word():
 *
 *  Reads the file f until it has read a complete word. Whitespace is ignored,
 *  and also any exclamation mark ('!') and anything following an exclamation
 *  mark on a line.
 *
 *  Used internally by emul_parse_config().
 */
static void read_one_word(FILE *f, char *buf, int buflen, int *line,
        int expect)
{
        int ch;
        int done = 0;
        int curlen = 0;
        int in_word = 0;

        while (!done) {
                if (curlen >= buflen - 1)
                        break;

                ch = fgetc(f);
                if (ch == EOF)
                        break;

                if (in_word) {
                        if (is_word_char(ch)) {
                                buf[curlen++] = ch;
                                if (curlen == buflen - 1)
                                        done = 1;
                                continue;
                        } else {
                                if (ungetc(ch, f) == EOF) {
                                        fatal("ungetc() failed?\n");
                                        exit(1);
                                }
                                break;
                        }
                }

                if (ch == '\n') {
                        (*line) ++;
                        continue;
                }

                if (ch == '\r')
                        continue;

                if (ch == '!') {
                        /*  Skip until newline:  */
                        while (ch != '\n' && ch != EOF)
                                ch = fgetc(f);
                        if (ch == '\n')
                                (*line) ++;
                        continue;
                }

                if (ch == '{') {
                        int depth = 1;

                        /*  Skip until '}':  */
                        while (depth > 0) {
                                ch = fgetc(f);
                                if (ch == '\n')
                                        (*line) ++;
                                if (ch == '{')
                                        depth ++;
                                if (ch == '}')
                                        depth --;
                                if (ch == EOF) {
                                        fatal("line %i: unexpected EOF inside"
                                            " a nested comment\n", *line);
                                        exit(1);
                                }
                        }
                        continue;
                }

                /*  Whitespace?  */
                if (ch <= ' ')
                        continue;

                if (ch == '"' || ch == '\'') {
                        /*  This is a quoted word.  */
                        int start_ch = ch;

                        if (expect & EXPECT_LEFT_PARENTHESIS) {
                                fatal("unexpected character '%c', line %i\n",
                                    ch, *line);
                                exit(1);
                        }

                        while (curlen < buflen - 1) {
                                ch = fgetc(f);
                                if (ch == '\n') {
                                        fatal("line %i: newline inside"
                                            " quotes?\n", *line);
                                        exit(1);
                                }
                                if (ch == EOF) {
                                        fatal("line %i: EOF inside a quoted"
                                            " string?\n", *line);
                                        exit(1);
                                }
                                if (ch == start_ch)
                                        break;
                                buf[curlen++] = ch;
                        }
                        break;
                }

                if ((expect & EXPECT_WORD) && is_word_char(ch)) {
                        buf[curlen++] = ch;
                        in_word = 1;
                        if (curlen == buflen - 1)
                                done = 1;
                } else {
                        if ((expect & EXPECT_LEFT_PARENTHESIS) && ch == '(') {
                                parenthesis_level ++;
                                buf[curlen++] = ch;
                                break;
                        }
                        if ((expect & EXPECT_RIGHT_PARENTHESIS) && ch == ')') {
                                parenthesis_level --;
                                buf[curlen++] = ch;
                                break;
                        }

                        fatal("unexpected character '%c', line %i\n",
                            ch, *line);
                        exit(1);
                }
        }

        buf[curlen] = '\0';
}


#define PARSESTATE_NONE                 0
#define PARSESTATE_EMUL                 1
#define PARSESTATE_NET                  2
#define PARSESTATE_MACHINE              3

static char cur_net_ipv4net[50];
static char cur_net_ipv4len[50];
static char cur_net_local_port[10];
#define MAX_N_REMOTE            20
#define MAX_REMOTE_LEN          100
static char *cur_net_remote[MAX_N_REMOTE];
static int cur_net_n_remote;

static char cur_machine_name[50];
static char cur_machine_cpu[50];
static char cur_machine_type[50];
static char cur_machine_subtype[50];
static char cur_machine_bootname[150];
static char cur_machine_bootarg[250];
static char cur_machine_slowsi[10];
static char cur_machine_prom_emulation[10];
static char cur_machine_use_x11[10];
static char cur_machine_x11_scaledown[10];
static char cur_machine_byte_order[20];
static char cur_machine_random_mem[10];
static char cur_machine_random_cpu[10];
static char cur_machine_force_netboot[10];
static char cur_machine_start_paused[10];
static char cur_machine_ncpus[10];
static char cur_machine_n_gfx_cards[10];
static char cur_machine_serial_nr[10];
static char cur_machine_emulated_hz[10];
static char cur_machine_memory[10];
#define MAX_N_LOAD              15
#define MAX_LOAD_LEN            2000
static char *cur_machine_load[MAX_N_LOAD];
static int cur_machine_n_load;
#define MAX_N_DISK              10
#define MAX_DISK_LEN            2000
static char *cur_machine_disk[MAX_N_DISK];
static int cur_machine_n_disk;
#define MAX_N_DEVICE            20
#define MAX_DEVICE_LEN          400
static char *cur_machine_device[MAX_N_DISK];
static int cur_machine_n_device;
#define MAX_N_X11_DISP          5
#define MAX_X11_DISP_LEN        1000
static char *cur_machine_x11_disp[MAX_N_X11_DISP];
static int cur_machine_n_x11_disp;

#define WORD(w,var) {                                           \
                if (strcmp(word, w) == 0) {                     \
                        read_one_word(f, word, maxbuflen,       \
                            line, EXPECT_LEFT_PARENTHESIS);     \
                        read_one_word(f, var, sizeof(var),      \
                            line, EXPECT_WORD);                 \
                        read_one_word(f, word, maxbuflen,       \
                            line, EXPECT_RIGHT_PARENTHESIS);    \
                        return;                                 \
                }                                               \
        }

static void parse__machine(struct emul *e, FILE *f, int *in_emul, int *line,
        int *parsestate, char *word, size_t maxbuflen);


/*
 *  parse_on_off():
 *
 *  Returns 1 for "on", "yes", "enable", or "1".
 *  Returns 0 for "off", "no", "disable", or "0".
 *  Prints a fatal warning and exit()s for other values.
 */
int parse_on_off(char *s)
{
        if (strcasecmp(s, "on") == 0 || strcasecmp(s, "yes") == 0 ||
            strcasecmp(s, "enable") == 0 || strcasecmp(s, "1") == 0)
                return 1;
        if (strcasecmp(s, "off") == 0 || strcasecmp(s, "no") == 0 ||
            strcasecmp(s, "disable") == 0 || strcasecmp(s, "0") == 0)
                return 0;

        fprintf(stderr, "parse_on_off(): WARNING: unknown value '%s'\n", s);

        return 0;
}


/*
 *  parse__emul():
 *
 *  name, net, machine
 */
static void parse__emul(struct emul *e, FILE *f, int *in_emul, int *line,
        int *parsestate, char *word, size_t maxbuflen)
{
        if (word[0] == ')') {
                *parsestate = PARSESTATE_NONE;
                return;
        }

        if (strcmp(word, "name") == 0) {
                char tmp[200];
                read_one_word(f, word, maxbuflen,
                    line, EXPECT_LEFT_PARENTHESIS);
                read_one_word(f, tmp, sizeof(tmp), line, EXPECT_WORD);
                read_one_word(f, word, maxbuflen,
                    line, EXPECT_RIGHT_PARENTHESIS);
                if (e->name != NULL) {
                        free(e->name);
                        e->name = NULL;
                }
                e->name = strdup(tmp);
                if (e->name == NULL) {
                        fprintf(stderr, "out of memory in parse__emul()\n");
                        exit(1);
                }
                debug("name: \"%s\"\n", e->name);
                return;
        }

        if (strcmp(word, "net") == 0) {
                *parsestate = PARSESTATE_NET;
                read_one_word(f, word, maxbuflen,
                    line, EXPECT_LEFT_PARENTHESIS);

                /*  Default net:  */
                strlcpy(cur_net_ipv4net, NET_DEFAULT_IPV4_MASK,
                    sizeof(cur_net_ipv4net));
                snprintf(cur_net_ipv4len, sizeof(cur_net_ipv4len), "%i",
                    NET_DEFAULT_IPV4_LEN);
                strlcpy(cur_net_local_port, "", sizeof(cur_net_local_port));
                cur_net_n_remote = 0;
                return;
        }

        if (strcmp(word, "machine") == 0) {
                *parsestate = PARSESTATE_MACHINE;
                read_one_word(f, word, maxbuflen,
                    line, EXPECT_LEFT_PARENTHESIS);

                /*  A "zero state":  */
                cur_machine_name[0] = '\0';
                cur_machine_cpu[0] = '\0';
                cur_machine_type[0] = '\0';
                cur_machine_subtype[0] = '\0';
                cur_machine_bootname[0] = '\0';
                cur_machine_bootarg[0] = '\0';
                cur_machine_n_load = 0;
                cur_machine_n_disk = 0;
                cur_machine_n_device = 0;
                cur_machine_n_x11_disp = 0;
                cur_machine_slowsi[0] = '\0';
                cur_machine_prom_emulation[0] = '\0';
                cur_machine_use_x11[0] = '\0';
                cur_machine_x11_scaledown[0] = '\0';
                cur_machine_byte_order[0] = '\0';
                cur_machine_random_mem[0] = '\0';
                cur_machine_random_cpu[0] = '\0';
                cur_machine_force_netboot[0] = '\0';
                cur_machine_start_paused[0] = '\0';
                cur_machine_ncpus[0] = '\0';
                cur_machine_n_gfx_cards[0] = '\0';
                cur_machine_serial_nr[0] = '\0';
                cur_machine_emulated_hz[0] = '\0';
                cur_machine_memory[0] = '\0';
                return;
        }

        fatal("line %i: not expecting '%s' in an 'emul' section\n",
            *line, word);
        exit(1);
}


/*
 *  parse__net():
 *
 *  Simple words: ipv4net, ipv4len, local_port
 *
 *  Complex: add_remote
 *
 *  TODO: more words? for example an option to disable the gateway? that would
 *  have to be implemented correctly in src/net.c first.
 */
static void parse__net(struct emul *e, FILE *f, int *in_emul, int *line,
        int *parsestate, char *word, size_t maxbuflen)
{
        int i;

        if (word[0] == ')') {
                /*  Finished with the 'net' section. Let's create the net:  */
                if (e->net != NULL) {
                        fatal("line %i: more than one net isn't really "
                            "supported yet\n", *line);
                        exit(1);
                }

                if (!cur_net_local_port[0])
                        strlcpy(cur_net_local_port, "0",
                            sizeof(cur_net_local_port));

                e->net = net_init(e, NET_INIT_FLAG_GATEWAY,
                    cur_net_ipv4net, atoi(cur_net_ipv4len),
                    cur_net_remote, cur_net_n_remote,
                    atoi(cur_net_local_port), NULL);

                if (e->net == NULL) {
                        fatal("line %i: fatal error: could not create"
                            " the net (?)\n", *line);
                        exit(1);
                }

                for (i=0; i<cur_net_n_remote; i++) {
                        free(cur_net_remote[i]);
                        cur_net_remote[i] = NULL;
                }

                *parsestate = PARSESTATE_EMUL;
                return;
        }

        WORD("ipv4net", cur_net_ipv4net);
        WORD("ipv4len", cur_net_ipv4len);
        WORD("local_port", cur_net_local_port);

        if (strcmp(word, "add_remote") == 0) {
                read_one_word(f, word, maxbuflen,
                    line, EXPECT_LEFT_PARENTHESIS);
                if (cur_net_n_remote >= MAX_N_REMOTE) {
                        fprintf(stderr, "too many remote networks\n");
                        exit(1);
                }
                cur_net_remote[cur_net_n_remote] = malloc(MAX_REMOTE_LEN);
                if (cur_net_remote[cur_net_n_remote] == NULL) {
                        fprintf(stderr, "out of memory\n");
                        exit(1);
                }
                read_one_word(f, cur_net_remote[cur_net_n_remote],
                    MAX_REMOTE_LEN, line, EXPECT_WORD);
                cur_net_n_remote ++;
                read_one_word(f, word, maxbuflen, line,
                    EXPECT_RIGHT_PARENTHESIS);
                return;
        }

        fatal("line %i: not expecting '%s' in a 'net' section\n", *line, word);
        exit(1);
}


/*
 *  parse__machine():
 */
static void parse__machine(struct emul *e, FILE *f, int *in_emul, int *line,
        int *parsestate, char *word, size_t maxbuflen)
{
        int r, i;

        if (word[0] == ')') {
                /*  Finished with the 'machine' section.  */
                struct machine *m;

                if (!cur_machine_name[0])
                        strlcpy(cur_machine_name, "no_name",
                            sizeof(cur_machine_name));

                m = emul_add_machine(e, cur_machine_name);

                r = machine_name_to_type(cur_machine_type, cur_machine_subtype,
                    &m->machine_type, &m->machine_subtype, &m->arch);
                if (!r)
                        exit(1);

                if (cur_machine_cpu[0])
                        m->cpu_name = strdup(cur_machine_cpu);

                if (!cur_machine_use_x11[0])
                        strlcpy(cur_machine_use_x11, "no",
                            sizeof(cur_machine_use_x11));
                m->use_x11 = parse_on_off(cur_machine_use_x11);

                if (!cur_machine_slowsi[0])
                        strlcpy(cur_machine_slowsi, "no",
                            sizeof(cur_machine_slowsi));
                m->slow_serial_interrupts_hack_for_linux =
                    parse_on_off(cur_machine_slowsi);

                if (!cur_machine_prom_emulation[0])
                        strlcpy(cur_machine_prom_emulation, "yes",
                            sizeof(cur_machine_prom_emulation));
                m->prom_emulation = parse_on_off(cur_machine_prom_emulation);

                if (!cur_machine_random_mem[0])
                        strlcpy(cur_machine_random_mem, "no",
                            sizeof(cur_machine_random_mem));
                m->random_mem_contents =
                    parse_on_off(cur_machine_random_mem);

                if (!cur_machine_random_cpu[0])
                        strlcpy(cur_machine_random_cpu, "no",
                            sizeof(cur_machine_random_cpu));
                m->use_random_bootstrap_cpu =
                    parse_on_off(cur_machine_random_cpu);

                m->byte_order_override = NO_BYTE_ORDER_OVERRIDE;
                if (cur_machine_byte_order[0]) {
                        if (strncasecmp(cur_machine_byte_order, "big", 3) == 0)
                                m->byte_order_override = EMUL_BIG_ENDIAN;
                        else if (strncasecmp(cur_machine_byte_order, "little",
                            6) == 0)
                                m->byte_order_override = EMUL_LITTLE_ENDIAN;
                        else {
                                fatal("Byte order must be big-endian or"
                                    " little-endian\n");
                                exit(1);
                        }
                }

                if (!cur_machine_force_netboot[0])
                        strlcpy(cur_machine_force_netboot, "no",
                            sizeof(cur_machine_force_netboot));
                m->force_netboot = parse_on_off(cur_machine_force_netboot);

                if (!cur_machine_start_paused[0])
                        strlcpy(cur_machine_start_paused, "no",
                            sizeof(cur_machine_start_paused));
                m->start_paused = parse_on_off(cur_machine_start_paused);

                /*  NOTE: Default nr of CPUs is 0:  */
                if (!cur_machine_ncpus[0])
                        strlcpy(cur_machine_ncpus, "0",
                            sizeof(cur_machine_ncpus));
                m->ncpus = atoi(cur_machine_ncpus);

                if (cur_machine_n_gfx_cards[0])
                        m->n_gfx_cards = atoi(cur_machine_n_gfx_cards);

                if (cur_machine_serial_nr[0]) {
                        m->serial_nr = atoi(cur_machine_serial_nr);
                        e->next_serial_nr = m->serial_nr+1;
                }

                if (cur_machine_emulated_hz[0]) {
                        m->emulated_hz = mystrtoull(cur_machine_emulated_hz,
                            NULL, 0);
                }

                /*  NOTE: Default nr of CPUs is 0:  */
                if (!cur_machine_memory[0])
                        strlcpy(cur_machine_memory, "0",
                            sizeof(cur_machine_memory));
                m->physical_ram_in_mb = atoi(cur_machine_memory);

                if (!cur_machine_x11_scaledown[0])
                        m->x11_scaledown = 1;
                else {
                        m->x11_scaledown = atoi(cur_machine_x11_scaledown);
                        if (m->x11_scaledown < 0) {
                                m->x11_scaleup = 0 - m->x11_scaledown;
                                m->x11_scaledown = 1;
                        }
                        if (m->x11_scaledown < 1) {
                                fprintf(stderr, "Invalid scaledown value"
                                    " (%i)\n", m->x11_scaledown);
                                exit(1);
                        }
                }

                for (i=0; i<cur_machine_n_disk; i++) {
                        diskimage_add(m, cur_machine_disk[i]);
                        free(cur_machine_disk[i]);
                        cur_machine_disk[i] = NULL;
                }

                m->boot_kernel_filename = strdup(cur_machine_bootname);

                if (cur_machine_bootarg[0])
                        m->boot_string_argument = strdup(cur_machine_bootarg);

                for (i=0; i<cur_machine_n_x11_disp; i++) {
                        m->x11_n_display_names ++;
                        m->x11_display_names = realloc(
                            m->x11_display_names, m->x11_n_display_names
                            * sizeof(char *));
                        if (m->x11_display_names == NULL) {
                                printf("out of memory\n");
                                exit(1);
                        }
                        m->x11_display_names[m->x11_n_display_names-1] =
                            strdup(cur_machine_x11_disp[i]);
                        if (m->x11_display_names
                           [m->x11_n_display_names-1] == NULL) {
                                printf("out of memory\n");
                                exit(1);
                        }
                        free(cur_machine_x11_disp[i]);
                        cur_machine_x11_disp[i] = NULL;
                }

                emul_machine_setup(m,
                    cur_machine_n_load, cur_machine_load,
                    cur_machine_n_device, cur_machine_device);

                for (i=0; i<cur_machine_n_device; i++) {
                        free(cur_machine_device[i]);
                        cur_machine_device[i] = NULL;
                }

                for (i=0; i<cur_machine_n_load; i++) {
                        free(cur_machine_load[i]);
                        cur_machine_load[i] = NULL;
                }

                *parsestate = PARSESTATE_EMUL;
                return;
        }

        WORD("name", cur_machine_name);
        WORD("cpu", cur_machine_cpu);
        WORD("type", cur_machine_type);
        WORD("subtype", cur_machine_subtype);
        WORD("bootname", cur_machine_bootname);
        WORD("bootarg", cur_machine_bootarg);
        WORD("slow_serial_interrupts_hack_for_linux", cur_machine_slowsi);
        WORD("prom_emulation", cur_machine_prom_emulation);
        WORD("use_x11", cur_machine_use_x11);
        WORD("x11_scaledown", cur_machine_x11_scaledown);
        WORD("byte_order", cur_machine_byte_order);
        WORD("random_mem_contents", cur_machine_random_mem);
        WORD("use_random_bootstrap_cpu", cur_machine_random_cpu);
        WORD("force_netboot", cur_machine_force_netboot);
        WORD("ncpus", cur_machine_ncpus);
        WORD("serial_nr", cur_machine_serial_nr);
        WORD("n_gfx_cards", cur_machine_n_gfx_cards);
        WORD("emulated_hz", cur_machine_emulated_hz);
        WORD("memory", cur_machine_memory);
        WORD("start_paused", cur_machine_start_paused);

        if (strcmp(word, "load") == 0) {
                read_one_word(f, word, maxbuflen,
                    line, EXPECT_LEFT_PARENTHESIS);
                if (cur_machine_n_load >= MAX_N_LOAD) {
                        fprintf(stderr, "too many loads\n");
                        exit(1);
                }
                cur_machine_load[cur_machine_n_load] = malloc(MAX_LOAD_LEN);
                if (cur_machine_load[cur_machine_n_load] == NULL) {
                        fprintf(stderr, "out of memory\n");
                        exit(1);
                }
                read_one_word(f, cur_machine_load[cur_machine_n_load],
                    MAX_LOAD_LEN, line, EXPECT_WORD);
                cur_machine_n_load ++;
                read_one_word(f, word, maxbuflen,
                    line, EXPECT_RIGHT_PARENTHESIS);
                return;
        }

        if (strcmp(word, "disk") == 0) {
                read_one_word(f, word, maxbuflen,
                    line, EXPECT_LEFT_PARENTHESIS);
                if (cur_machine_n_disk >= MAX_N_DISK) {
                        fprintf(stderr, "too many disks\n");
                        exit(1);
                }
                cur_machine_disk[cur_machine_n_disk] = malloc(MAX_DISK_LEN);
                if (cur_machine_disk[cur_machine_n_disk] == NULL) {
                        fprintf(stderr, "out of memory\n");
                        exit(1);
                }
                read_one_word(f, cur_machine_disk[cur_machine_n_disk],
                    MAX_DISK_LEN, line, EXPECT_WORD);
                cur_machine_n_disk ++;
                read_one_word(f, word, maxbuflen,
                    line, EXPECT_RIGHT_PARENTHESIS);
                return;
        }

        if (strcmp(word, "device") == 0) {
                read_one_word(f, word, maxbuflen,
                    line, EXPECT_LEFT_PARENTHESIS);
                if (cur_machine_n_device >= MAX_N_DEVICE) {
                        fprintf(stderr, "too many devices\n");
                        exit(1);
                }
                cur_machine_device[cur_machine_n_device] =
                    malloc(MAX_DEVICE_LEN);
                if (cur_machine_device[cur_machine_n_device] == NULL) {
                        fprintf(stderr, "out of memory\n");
                        exit(1);
                }
                read_one_word(f, cur_machine_device[cur_machine_n_device],
                    MAX_DEVICE_LEN, line, EXPECT_WORD);
                cur_machine_n_device ++;
                read_one_word(f, word, maxbuflen,
                    line, EXPECT_RIGHT_PARENTHESIS);
                return;
        }

        if (strcmp(word, "add_x11_display") == 0) {
                read_one_word(f, word, maxbuflen,
                    line, EXPECT_LEFT_PARENTHESIS);
                if (cur_machine_n_x11_disp >= MAX_N_X11_DISP) {
                        fprintf(stderr, "too many x11 displays\n");
                        exit(1);
                }
                cur_machine_x11_disp[cur_machine_n_x11_disp] =
                    malloc(MAX_X11_DISP_LEN);
                if (cur_machine_x11_disp[cur_machine_n_x11_disp] == NULL) {
                        fprintf(stderr, "out of memory\n");
                        exit(1);
                }
                read_one_word(f, cur_machine_x11_disp[cur_machine_n_x11_disp],
                    MAX_X11_DISP_LEN, line, EXPECT_WORD);
                cur_machine_n_x11_disp ++;
                read_one_word(f, word, maxbuflen,
                    line, EXPECT_RIGHT_PARENTHESIS);
                return;
        }

        fatal("line %i: not expecting '%s' in a 'machine' section\n",
            *line, word);
        exit(1);
}


/*
 *  emul_parse_config():
 *
 *  Set up an emulation by parsing a config file.
 */
void emul_parse_config(struct emul *e, char *fname)
{
        FILE *f = fopen(fname, "r");
        char word[MAX_WORD_LEN];
        int in_emul = 0;
        int line = 1;
        int parsestate = PARSESTATE_EMUL;

        /*  debug("emul_parse_config()\n");  */
        if (f == NULL) {
                perror(fname);
                exit(1);
        }

        while (!feof(f)) {
                read_one_word(f, word, sizeof(word), &line,
                    EXPECT_WORD | EXPECT_RIGHT_PARENTHESIS);
                if (!word[0])
                        break;

                /*  debug("word = '%s'\n", word);  */

                switch (parsestate) {
                case PARSESTATE_EMUL:
                        parse__emul(e, f, &in_emul, &line, &parsestate,
                            word, sizeof(word));
                        break;
                case PARSESTATE_NET:
                        parse__net(e, f, &in_emul, &line, &parsestate,
                            word, sizeof(word));
                        break;
                case PARSESTATE_MACHINE:
                        parse__machine(e, f, &in_emul, &line, &parsestate,
                            word, sizeof(word));
                        break;
                case PARSESTATE_NONE:
                        break;
                default:
                        fatal("INTERNAL ERROR in emul_parse.c ("
                            "parsestate %i is not imlemented yet?)\n",
                            parsestate);
                        exit(1);
                }
        }

        if (parenthesis_level != 0) {
                fatal("EOF but not enough right parentheses?\n");
                exit(1);
        }

        fclose(f);
}
