Typo fix.
[open-adventure.git] / saveresume.c
index 6cb48ae058c557bdb5b22e86faa540beefeb9242..100c925d400ab77c0dc2c5a354a5bfb24bac2f48 100644 (file)
-#include <stdlib.h>
-#include <string.h>
-
-#include "advent.h"
-#include "database.h"
-#include "newdb.h"
-#include "linenoise/linenoise.h"
-
 /*
+ * Saving and resuming.
+ *
  * (ESR) This replaces  a bunch of particularly nasty FORTRAN-derived code;
  * see the history.adoc file in the source distribution for discussion.
+ *
+ * SPDX-FileCopyrightText: (C) 1977, 2005 by Will Crowther and Don Woods
+ * SPDX-License-Identifier: BSD-2-Clause
  */
 
-#define VRSION 26      /* bump on save format change */
+#include <ctype.h>
+#include <inttypes.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#include "advent.h"
 
 /*
- * If you change the first three members, the resume function may not properly
- * reject saves from older versions.  Yes, this glues us to a hardware-
- * dependent length of long.  Later members can change, but bump the version
- * when you do that.
+ * Use this to detect endianness mismatch.  Can't be unchanged by byte-swapping.
  */
-struct save_t {
-    long savetime;
-    long mode;         /* not used, must be present for version detection */
-    long version;
-    struct game_t game;
-    long bird;
-    long bivalve;
-};
+#define ENDIAN_MAGIC 2317
+
 struct save_t save;
 
-int saveresume(FILE *input, bool resume)
+#define IGNORE(r)                                                              \
+       do {                                                                   \
+               if (r) {                                                       \
+               }                                                              \
+       } while (0)
+
+int savefile(FILE *fp) {
+       /* Save game to file. No input or output from user. */
+       memcpy(&save.magic, ADVENT_MAGIC, sizeof(ADVENT_MAGIC));
+       if (save.version == 0) {
+               save.version = SAVE_VERSION;
+       }
+       if (save.canary == 0) {
+               save.canary = ENDIAN_MAGIC;
+       }
+       save.game = game;
+       IGNORE(fwrite(&save, sizeof(struct save_t), 1, fp));
+       return (0);
+}
+
 /* Suspend and resume */
-{
-    long i, k;
-    FILE *fp = NULL;
-     
-    if (!resume) {
+
+static char *strip(char *name) {
+       // Trim leading whitespace
+       while (isspace((unsigned char)*name)) {
+               name++; // LCOV_EXCL_LINE
+       }
+       if (*name != '\0') {
+               // Trim trailing whitespace;
+               // might be left there by autocomplete
+               char *end = name + strlen(name) - 1;
+               while (end > name && isspace((unsigned char)*end)) {
+                       end--;
+               }
+               // Write new null terminator character
+               end[1] = '\0';
+       }
+
+       return name;
+}
+
+int suspend(void) {
        /*  Suspend.  Offer to save things in a file, but charging
         *  some points (so can't win by using saved games to retry
-        *  battles or to start over after learning zzword). */
-       RSPEAK(ARB_260);
-       if (!YES(input,ARB_200,ARB_54,ARB_54)) return GO_CLEAROBJ;
-       game.saved=game.saved+5;
-    }
-    else
-    {
-       /*  Resume.  Read a suspended game back from a file. */
-       if (game.loc != 1 || game.abbrev[1] != 1) {
-           RSPEAK(ARB_268);
-           if (!YES(input,ARB_200,ARB_54,ARB_54)) return GO_CLEAROBJ;
-       }
-    }
-
-    while (fp == NULL) {
-       char* name = linenoise("\nFile name: ");
-       if (name == NULL)
-           return GO_TOP;
-       fp = fopen(name,(resume ? READ_MODE : WRITE_MODE));
-       if (fp == NULL)
-           printf("Can't open file %s, try again.\n", name); 
-       linenoiseFree(name);
-    }
-    
-    DATIME(&i,&k);
-    k=i+650*k;
-    if (!resume)
-    {
-       save.savetime = k;
-       save.mode = -1;
-       save.version = VRSION;
-       memcpy(&save.game, &game, sizeof(struct game_t));
-       save.bird = OBJSND[BIRD];
-       save.bivalve = OBJTXT[OYSTER];
-       IGNORE(fwrite(&save, sizeof(struct save_t), 1, fp));
+        *  battles or to start over after learning zzword).
+        *  If ADVENT_NOSAVE is defined, gripe instead. */
+
+#if defined ADVENT_NOSAVE || defined ADVENT_AUTOSAVE
+       rspeak(SAVERESUME_DISABLED);
+       return GO_TOP;
+#endif
+       FILE *fp = NULL;
+
+       rspeak(SUSPEND_WARNING);
+       if (!yes_or_no(arbitrary_messages[THIS_ACCEPTABLE],
+                      arbitrary_messages[OK_MAN],
+                      arbitrary_messages[OK_MAN])) {
+               return GO_CLEAROBJ;
+       }
+       game.saved = game.saved + 5;
+
+       while (fp == NULL) {
+               char *name = myreadline("\nFile name: ");
+               if (name == NULL) {
+                       return GO_TOP;
+               }
+               name = strip(name);
+               if (strlen(name) == 0) {
+                       return GO_TOP; // LCOV_EXCL_LINE
+               }
+               fp = fopen(strip(name), WRITE_MODE);
+               if (fp == NULL) {
+                       printf("Can't open file %s, try again.\n", name);
+               }
+               free(name);
+       }
+
+       savefile(fp);
        fclose(fp);
-       RSPEAK(ARB_266);
-       exit(0);
-    } else {
+       rspeak(RESUME_HELP);
+       exit(EXIT_SUCCESS);
+}
+
+int resume(void) {
+       /*  Resume.  Read a suspended game back from a file.
+        *  If ADVENT_NOSAVE is defined, gripe instead. */
+
+#if defined ADVENT_NOSAVE || defined ADVENT_AUTOSAVE
+       rspeak(SAVERESUME_DISABLED);
+       return GO_TOP;
+#endif
+       FILE *fp = NULL;
+
+       if (game.loc != LOC_START || game.locs[LOC_START].abbrev != 1) {
+               rspeak(RESUME_ABANDON);
+               if (!yes_or_no(arbitrary_messages[THIS_ACCEPTABLE],
+                              arbitrary_messages[OK_MAN],
+                              arbitrary_messages[OK_MAN])) {
+                       return GO_CLEAROBJ;
+               }
+       }
+
+       while (fp == NULL) {
+               char *name = myreadline("\nFile name: ");
+               if (name == NULL) {
+                       return GO_TOP;
+               }
+               name = strip(name);
+               if (strlen(name) == 0) {
+                       return GO_TOP; // LCOV_EXCL_LINE
+               }
+               fp = fopen(name, READ_MODE);
+               if (fp == NULL) {
+                       printf("Can't open file %s, try again.\n", name);
+               }
+               free(name);
+       }
+
+       return restore(fp);
+}
+
+int restore(FILE *fp) {
+       /*  Read and restore game state from file, assuming
+        *  sane initial state.
+        *  If ADVENT_NOSAVE is defined, gripe instead. */
+#ifdef ADVENT_NOSAVE
+       rspeak(SAVERESUME_DISABLED);
+       return GO_TOP;
+#endif
+
        IGNORE(fread(&save, sizeof(struct save_t), 1, fp));
        fclose(fp);
-       if (save.version != VRSION) {
-           SETPRM(1,k/10,MOD(k,10));
-           SETPRM(3,VRSION/10,MOD(VRSION,10));
-           RSPEAK(ARB_269);
+       if (memcmp(save.magic, ADVENT_MAGIC, sizeof(ADVENT_MAGIC)) != 0 ||
+           save.canary != ENDIAN_MAGIC) {
+               rspeak(BAD_SAVE);
+       } else if (save.version != SAVE_VERSION) {
+               rspeak(VERSION_SKEW, save.version / 10, MOD(save.version, 10),
+                      SAVE_VERSION / 10, MOD(SAVE_VERSION, 10));
+       } else if (!is_valid(save.game)) {
+               rspeak(SAVE_TAMPERING);
+               exit(EXIT_SUCCESS);
        } else {
-           memcpy(&game, &save.game, sizeof(struct game_t));
-           OBJSND[BIRD] = save.bird;
-           OBJTXT[OYSTER] = save.bivalve;
-           game.zzword=RNDVOC(3,game.zzword);
+               game = save.game;
        }
        return GO_TOP;
-    }
+}
+
+bool is_valid(struct game_t valgame) {
+       /*  Save files can be roughly grouped into three groups:
+        *  With valid, reachable state, with valid, but unreachable
+        *  state and with invalid state. We check that state is
+        *  valid: no states are outside minimal or maximal value
+        */
+
+       /* Prevent division by zero */
+       if (valgame.abbnum == 0) {
+               return false; // LCOV_EXCL_LINE
+       }
+
+       /* Check for RNG overflow. Truncate */
+       if (valgame.lcg_x >= LCG_M) {
+               return false;
+       }
+
+       /*  Bounds check for locations */
+       if (valgame.chloc < -1 || valgame.chloc > NLOCATIONS ||
+           valgame.chloc2 < -1 || valgame.chloc2 > NLOCATIONS ||
+           valgame.loc < 0 || valgame.loc > NLOCATIONS || valgame.newloc < 0 ||
+           valgame.newloc > NLOCATIONS || valgame.oldloc < 0 ||
+           valgame.oldloc > NLOCATIONS || valgame.oldlc2 < 0 ||
+           valgame.oldlc2 > NLOCATIONS) {
+               return false; // LCOV_EXCL_LINE
+       }
+       /*  Bounds check for location arrays */
+       for (int i = 0; i <= NDWARVES; i++) {
+               if (valgame.dwarves[i].loc < -1 ||
+                   valgame.dwarves[i].loc > NLOCATIONS ||
+                   valgame.dwarves[i].oldloc < -1 ||
+                   valgame.dwarves[i].oldloc > NLOCATIONS) {
+                       return false; // LCOV_EXCL_LINE
+               }
+       }
+
+       for (int i = 0; i <= NOBJECTS; i++) {
+               if (valgame.objects[i].place < -1 ||
+                   valgame.objects[i].place > NLOCATIONS ||
+                   valgame.objects[i].fixed < -1 ||
+                   valgame.objects[i].fixed > NLOCATIONS) {
+                       return false; // LCOV_EXCL_LINE
+               }
+       }
+
+       /*  Bounds check for dwarves */
+       if (valgame.dtotal < 0 || valgame.dtotal > NDWARVES ||
+           valgame.dkill < 0 || valgame.dkill > NDWARVES) {
+               return false; // LCOV_EXCL_LINE
+       }
+
+       /*  Validate that we didn't die too many times in save */
+       if (valgame.numdie >= NDEATHS) {
+               return false; // LCOV_EXCL_LINE
+       }
+
+       /* Recalculate tally, throw the towel if in disagreement */
+       int temp_tally = 0;
+       for (int treasure = 1; treasure <= NOBJECTS; treasure++) {
+               if (objects[treasure].is_treasure) {
+                       if (PROP_IS_NOTFOUND2(valgame, treasure)) {
+                               ++temp_tally;
+                       }
+               }
+       }
+       if (temp_tally != valgame.tally) {
+               return false; // LCOV_EXCL_LINE
+       }
+
+       /* Check that properties of objects aren't beyond expected */
+       for (obj_t obj = 0; obj <= NOBJECTS; obj++) {
+               if (PROP_IS_INVALID(valgame.objects[obj].prop)) {
+                       return false; // LCOV_EXCL_LINE
+               }
+       }
+
+       /* Check that values in linked lists for objects in locations are inside
+        * bounds */
+       for (loc_t loc = LOC_NOWHERE; loc <= NLOCATIONS; loc++) {
+               if (valgame.locs[loc].atloc < NO_OBJECT ||
+                   valgame.locs[loc].atloc > NOBJECTS * 2) {
+                       return false; // LCOV_EXCL_LINE
+               }
+       }
+       for (obj_t obj = 0; obj <= NOBJECTS * 2; obj++) {
+               if (valgame.link[obj] < NO_OBJECT ||
+                   valgame.link[obj] > NOBJECTS * 2) {
+                       return false; // LCOV_EXCL_LINE
+               }
+       }
+
+       return true;
 }
 
 /* end */