/* update-game-score.c --- Update a score file
- Copyright (C) 2002 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
This file is part of GNU Emacs.
You should have received a copy of the GNU General Public License
along with GNU Emacs; see the file COPYING. If not, write to
-the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
+the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA. */
/* This program is allows a game to securely and atomically update a
- score file. It should be installed setgid, owned by an appropriate
- group like `games'.
+ score file. It should be installed setuid, owned by an appropriate
+ user like `games'.
+
+ Alternatively, it can be compiled without HAVE_SHARED_GAME_DIR
+ defined, and in that case it will store scores in the user's home
+ directory (it should NOT be setuid).
Created 2002/03/22, by Colin Walters <walters@debian.org>
*/
-#define _GNU_SOURCE
+#include <config.h>
+#ifdef HAVE_UNISTD_H
#include <unistd.h>
+#endif
#include <errno.h>
+#ifdef HAVE_STRING_H
#include <string.h>
+#endif
+#ifdef HAVE_STDLIB_H
#include <stdlib.h>
+#endif
#include <stdio.h>
#include <time.h>
#include <pwd.h>
#include <ctype.h>
+#ifdef HAVE_FCNTL_H
#include <fcntl.h>
+#endif
+#ifdef STDC_HEADERS
+#include <stdarg.h>
+#endif
#include <sys/stat.h>
-#include <config.h>
+
+/* Needed for SunOS4, for instance. */
+extern char *optarg;
+extern int optind, opterr;
#define MAX_ATTEMPTS 5
+#define MAX_SCORES 200
+#define MAX_DATA_LEN 1024
-#ifdef HAVE_SHARED_GAME_DIR
-#define SCORE_FILE_PREFIX HAVE_SHARED_GAME_DIR
+/* Declare the prototype for a general external function. */
+#if defined (PROTOTYPES) || defined (WINDOWSNT)
+#define P_(proto) proto
#else
-#define SCORE_FILE_PREFIX "$HOME"
+#define P_(proto) ()
+#endif
+
+#ifndef HAVE_DIFFTIME
+/* OK on POSIX (time_t is arithmetic type) modulo overflow in subtraction. */
+#define difftime(t1, t0) (double)((t1) - (t0))
#endif
int
-usage(int err)
+usage (err)
+ int err;
{
- fprintf(stdout, "Usage: update-game-score [-m MAX ] [ -r ] game/scorefile SCORE DATA\n");
- fprintf(stdout, " update-game-score -h\n");
- fprintf(stdout, " -h\t\tDisplay this help.\n");
- fprintf(stdout, " -m MAX\t\tLimit the maximum number of scores to MAX.\n");
- fprintf(stdout, " -r\t\tSort the scores in increasing order.\n");
- exit(err);
+ fprintf (stdout, "Usage: update-game-score [-m MAX ] [ -r ] game/scorefile SCORE DATA\n");
+ fprintf (stdout, " update-game-score -h\n");
+ fprintf (stdout, " -h\t\tDisplay this help.\n");
+ fprintf (stdout, " -m MAX\t\tLimit the maximum number of scores to MAX.\n");
+ fprintf (stdout, " -r\t\tSort the scores in increasing order.\n");
+ fprintf (stdout, " -d DIR\t\tStore scores in DIR (only if not setuid).\n");
+ exit (err);
}
-int
-lock_file(const char *filename, void **state);
-int
-unlock_file(const char *filename, void *state);
+int lock_file P_ ((const char *filename, void **state));
+int unlock_file P_ ((const char *filename, void *state));
struct score_entry
{
char *data;
};
-int
-read_scores(const char *filename, struct score_entry **scores,
- int *count);
-int
-push_score(struct score_entry **scores, int *count,
- int newscore, char *username, char *newdata);
+int read_scores P_ ((const char *filename, struct score_entry **scores,
+ int *count));
+int push_score P_ ((struct score_entry **scores, int *count,
+ int newscore, char *username, char *newdata));
+void sort_scores P_ ((struct score_entry *scores, int count, int reverse));
+int write_scores P_ ((const char *filename, const struct score_entry *scores,
+ int count));
+
+void lose P_ ((const char *msg)) NO_RETURN;
+
void
-sort_scores(struct score_entry *scores, int count, int reverse);
-int
-write_scores(const char *filename, const struct score_entry *scores,
- int count);
+lose (msg)
+ const char *msg;
+{
+ fprintf (stderr, "%s\n", msg);
+ exit (EXIT_FAILURE);
+}
+
+void lose_syserr P_ ((const char *msg)) NO_RETURN;
+/* Taken from sysdep.c. */
+#ifndef HAVE_STRERROR
+#ifndef WINDOWSNT
char *
-get_user_id(struct passwd *buf)
+strerror (errnum)
+ int errnum;
+{
+ extern char *sys_errlist[];
+ extern int sys_nerr;
+
+ if (errnum >= 0 && errnum < sys_nerr)
+ return sys_errlist[errnum];
+ return (char *) "Unknown error";
+}
+#endif /* not WINDOWSNT */
+#endif /* ! HAVE_STRERROR */
+
+void
+lose_syserr (msg)
+ const char *msg;
+{
+ fprintf (stderr, "%s: %s\n", msg, strerror (errno));
+ exit (EXIT_FAILURE);
+}
+
+char *
+get_user_id P_ ((void))
{
char *name;
+ struct passwd *buf = getpwuid (getuid ());
if (!buf)
{
int count = 1;
- int uid = (int) getuid();
- while (uid /= 10)
+ int uid = (int) getuid ();
+ int tuid = uid;
+ while (tuid /= 10)
count++;
- name = malloc(count+1);
- sprintf(name, "%d", uid);
+ name = malloc (count+1);
+ if (!name)
+ return NULL;
+ sprintf (name, "%d", uid);
return name;
}
return buf->pw_name;
}
char *
-get_home_dir(struct passwd *buf)
+get_prefix (running_suid, user_prefix)
+ int running_suid;
+ char *user_prefix;
{
- if (!buf)
- return NULL;
- return buf->pw_dir;
+ if (!running_suid && user_prefix == NULL)
+ lose ("Not using a shared game directory, and no prefix given.");
+ if (running_suid)
+ {
+#ifdef HAVE_SHARED_GAME_DIR
+ return HAVE_SHARED_GAME_DIR;
+#else
+ lose ("This program was compiled without HAVE_SHARED_GAME_DIR,\n and should not be suid.");
+#endif
+ }
+ return user_prefix;
}
int
-main(int argc, char **argv)
+main (argc, argv)
+ int argc;
+ char **argv;
{
- int c;
+ int c, running_suid;
void *lockstate;
- char *scorefile, *prefix;
+ char *user_id, *scorefile, *prefix, *user_prefix = NULL;
struct stat buf;
struct score_entry *scores;
- int newscore, scorecount, reverse = 0, max = -1;
+ int newscore, scorecount, reverse = 0, max = MAX_SCORES;
char *newdata;
- struct passwd *passwdbuf;
- srand(time(0));
+ srand (time (0));
- while ((c = getopt(argc, argv, "hrm:")) != -1)
+ while ((c = getopt (argc, argv, "hrm:d:")) != -1)
switch (c)
{
case 'h':
- usage(0);
+ usage (EXIT_SUCCESS);
+ break;
+ case 'd':
+ user_prefix = optarg;
break;
case 'r':
reverse = 1;
break;
case 'm':
- max = atoi(optarg);
+ max = atoi (optarg);
+ if (max > MAX_SCORES)
+ max = MAX_SCORES;
break;
default:
- usage(1);
+ usage (EXIT_FAILURE);
}
if (optind+3 != argc)
- usage(1);
+ usage (EXIT_FAILURE);
- passwdbuf = getpwuid(getuid());
+ running_suid = (getuid () != geteuid ());
- if (!strcmp(SCORE_FILE_PREFIX, "$HOME"))
- {
- prefix = get_home_dir(passwdbuf);
- if (!prefix)
- {
- fprintf(stderr, "Unable to determine home directory\n");
- exit(1);
- }
- }
- else
- prefix = SCORE_FILE_PREFIX;
-
- scorefile = malloc(strlen(prefix) + strlen(argv[optind]) + 1);
+ prefix = get_prefix (running_suid, user_prefix);
+
+ scorefile = malloc (strlen (prefix) + strlen (argv[optind]) + 2);
if (!scorefile)
- {
- fprintf(stderr, "Couldn't create score file name: %s\n",
- strerror(errno));
- goto fail;
- }
- strcpy(scorefile, prefix);
- strcat(scorefile, argv[optind]);
- newscore = atoi(argv[optind+1]);
+ lose_syserr ("Couldn't allocate score file");
+
+ strcpy (scorefile, prefix);
+ strcat (scorefile, "/");
+ strcat (scorefile, argv[optind]);
+ newscore = atoi (argv[optind+1]);
newdata = argv[optind+2];
-
- if (stat(scorefile, &buf) < 0)
- {
- fprintf(stderr, "Failed to access scores file \"%s\": %s\n",
- scorefile, strerror(errno));
- goto fail;
- }
- if (lock_file(scorefile, &lockstate) < 0)
- {
- fprintf(stderr, "Failed to lock scores file \"%s\": %s\n",
- scorefile, strerror(errno));
- goto fail;
- }
- if (read_scores(scorefile, &scores, &scorecount) < 0)
+ if (strlen (newdata) > MAX_DATA_LEN)
+ newdata[MAX_DATA_LEN] = '\0';
+
+ user_id = get_user_id ();
+ if (user_id == NULL)
+ lose_syserr ("Couldn't determine user id");
+
+ if (stat (scorefile, &buf) < 0)
+ lose_syserr ("Failed to access scores file");
+
+ if (lock_file (scorefile, &lockstate) < 0)
+ lose_syserr ("Failed to lock scores file");
+
+ if (read_scores (scorefile, &scores, &scorecount) < 0)
{
- fprintf(stderr, "Failed to read scores file \"%s\": %s\n",
- scorefile, strerror(errno));
- goto fail_unlock;
+ unlock_file (scorefile, lockstate);
+ lose_syserr ("Failed to read scores file");
}
- push_score(&scores, &scorecount, newscore, get_user_id(passwdbuf), newdata);
- sort_scores(scores, scorecount, reverse);
- if (write_scores(scorefile, scores, scorecount) < 0)
+ push_score (&scores, &scorecount, newscore, user_id, newdata);
+ /* Limit the number of scores. If we're using reverse sorting, then
+ we should increment the beginning of the array, to skip over the
+ *smallest* scores. Otherwise, we just decrement the number of
+ scores, since the smallest will be at the end. */
+ if (scorecount > MAX_SCORES)
+ scorecount -= (scorecount - MAX_SCORES);
+ if (reverse)
+ scores += (scorecount - MAX_SCORES);
+ sort_scores (scores, scorecount, reverse);
+ if (write_scores (scorefile, scores, scorecount) < 0)
{
- fprintf(stderr, "Failed to write scores file \"%s\": %s\n",
- scorefile, strerror(errno));
- goto fail_unlock;
+ unlock_file (scorefile, lockstate);
+ lose_syserr ("Failed to write scores file");
}
- unlock_file(scorefile, lockstate);
- exit(0);
- fail_unlock:
- unlock_file(scorefile, lockstate);
- fail:
- exit(1);
+ unlock_file (scorefile, lockstate);
+ exit (EXIT_SUCCESS);
}
int
-read_score(FILE *f, struct score_entry *score)
+read_score (f, score)
+ FILE *f;
+ struct score_entry *score;
{
int c;
- if (feof(f))
+ if (feof (f))
return 1;
- while ((c = getc(f)) != EOF
- && isdigit(c))
+ while ((c = getc (f)) != EOF
+ && isdigit (c))
{
score->score *= 10;
score->score += (c-48);
}
- while ((c = getc(f)) != EOF
- && isspace(c))
+ while ((c = getc (f)) != EOF
+ && isspace (c))
;
if (c == EOF)
return -1;
- ungetc(c, f);
+ ungetc (c, f);
#ifdef HAVE_GETDELIM
{
- int count = 0;
- if (getdelim(&score->username, &count, ' ', f) < 1
+ size_t count = 0;
+ if (getdelim (&score->username, &count, ' ', f) < 1
|| score->username == NULL)
return -1;
+ /* Trim the space */
+ score->username[strlen (score->username)-1] = '\0';
}
#else
{
int unameread = 0;
int unamelen = 30;
- char *username = malloc(unamelen);
+ char *username = malloc (unamelen);
if (!username)
return -1;
-
- while ((c = getc(f)) != EOF
- && !isspace(c))
+
+ while ((c = getc (f)) != EOF
+ && !isspace (c))
{
- if (unameread == unamelen)
- {
- if (!(username = realloc(username, unamelen *= 2)))
- return -1;
- }
+ if (unameread >= unamelen-1)
+ if (!(username = realloc (username, unamelen *= 2)))
+ return -1;
username[unameread] = c;
unameread++;
}
- if (c == EOF)
+ if (c == EOF)
return -1;
username[unameread] = '\0';
score->username = username;
#endif
#ifdef HAVE_GETLINE
score->data = NULL;
- errno = ESUCCES;
+ errno = 0;
{
- int len;
- if (getline(&score->data, &len, f) < 0)
+ size_t len;
+ if (getline (&score->data, &len, f) < 0)
return -1;
- score->data[strlen(score->data)-1] = '\0';
+ score->data[strlen (score->data)-1] = '\0';
}
#else
{
int cur = 0;
int len = 16;
- char *buf = malloc(len);
+ char *buf = malloc (len);
if (!buf)
return -1;
- while ((c = getc(f)) != EOF
+ while ((c = getc (f)) != EOF
&& c != '\n')
{
if (cur >= len-1)
{
- if (!(buf = realloc(buf, len *= 2)))
+ if (!(buf = realloc (buf, len *= 2)))
return -1;
}
buf[cur] = c;
}
int
-read_scores(const char *filename, struct score_entry **scores,
- int *count)
+read_scores (filename, scores, count)
+ const char *filename;
+ struct score_entry **scores;
+ int *count;
{
int readval, scorecount, cursize;
struct score_entry *ret;
- FILE *f = fopen(filename, "r");
- if (!f)
+ FILE *f = fopen (filename, "r");
+ if (!f)
return -1;
scorecount = 0;
cursize = 16;
- ret = malloc(sizeof(struct score_entry) * cursize);
- if (!ret)
+ ret = (struct score_entry *) malloc (sizeof (struct score_entry) * cursize);
+ if (!ret)
return -1;
- while ((readval = read_score(f, &ret[scorecount])) == 0)
+ while ((readval = read_score (f, &ret[scorecount])) == 0)
{
/* We encoutered an error */
if (readval < 0)
scorecount++;
if (scorecount >= cursize)
{
- ret = realloc(ret, cursize *= 2);
+ cursize *= 2;
+ ret = (struct score_entry *)
+ realloc (ret, (sizeof (struct score_entry) * cursize));
if (!ret)
return -1;
}
}
int
-score_compare(const void *a, const void *b)
+score_compare (a, b)
+ const void *a;
+ const void *b;
{
const struct score_entry *sa = (const struct score_entry *) a;
const struct score_entry *sb = (const struct score_entry *) b;
}
int
-score_compare_reverse(const void *a, const void *b)
+score_compare_reverse (a, b)
+ const void *a;
+ const void *b;
{
const struct score_entry *sa = (const struct score_entry *) a;
const struct score_entry *sb = (const struct score_entry *) b;
}
int
-push_score(struct score_entry **scores, int *count,
- int newscore, char *username, char *newdata)
+push_score (scores, count, newscore, username, newdata)
+ struct score_entry **scores;
+ int *count; int newscore;
+ char *username;
+ char *newdata;
{
- struct score_entry *newscores = realloc(*scores,
- sizeof(struct score_entry) * ((*count) + 1));
+ struct score_entry *newscores
+ = (struct score_entry *) realloc (*scores,
+ sizeof (struct score_entry) * ((*count) + 1));
if (!newscores)
return -1;
newscores[*count].score = newscore;
*scores = newscores;
return 0;
}
-
+
void
-sort_scores(struct score_entry *scores, int count, int reverse)
+sort_scores (scores, count, reverse)
+ struct score_entry *scores;
+ int count;
+ int reverse;
{
- qsort(scores, count, sizeof(struct score_entry),
+ qsort (scores, count, sizeof (struct score_entry),
reverse ? score_compare_reverse : score_compare);
}
int
-write_scores(const char *filename, const struct score_entry *scores,
- int count)
+write_scores (filename, scores, count)
+ const char *filename;
+ const struct score_entry * scores;
+ int count;
{
- FILE *f;
+ FILE *f;
int i;
- char *tempfile = malloc(strlen(filename) + strlen(".tempXXXXXX") + 1);
+ char *tempfile = malloc (strlen (filename) + strlen (".tempXXXXXX") + 1);
if (!tempfile)
return -1;
- strcpy(tempfile, filename);
- strcat(tempfile, ".tempXXXXXX");
- if (mkstemp(tempfile) < 0
- || !(f = fopen(tempfile, "w")))
+ strcpy (tempfile, filename);
+ strcat (tempfile, ".tempXXXXXX");
+#ifdef HAVE_MKSTEMP
+ if (mkstemp (tempfile) < 0
+#else
+ if (mktemp (tempfile) != tempfile
+#endif
+ || !(f = fopen (tempfile, "w")))
return -1;
for (i = 0; i < count; i++)
- if (fprintf(f, "%ld %s %s\n", scores[i].score, scores[i].username,
+ if (fprintf (f, "%ld %s %s\n", scores[i].score, scores[i].username,
scores[i].data) < 0)
return -1;
- fclose(f);
- rename(tempfile, filename);
- return 0;
-}
-
-#if 0
-int
-lock_file(const char *filename, void **state)
-{
- struct flock lock;
- int *istate;
- int fd, attempts = 0, ret = 0;
- lock.l_type = F_WRLCK;
- lock.l_whence = SEEK_SET;
- lock.l_start = 0;
- lock.l_len = 0;
- istate = malloc(sizeof(int));
- if (!istate)
+ fclose (f);
+ if (rename (tempfile, filename) < 0)
return -1;
- if ((fd = open(filename, O_RDWR, 0600)) < 0)
+ if (chmod (filename, 0644) < 0)
return -1;
- *istate = fd;
- trylock:
- attempts++;
- if ((ret = fcntl(fd, F_GETLK, &lock)) == -1)
- {
- if (ret == EACCES || ret == EAGAIN)
- if (attempts > MAX_ATTEMPTS)
- exit(1);
- else
- {
- sleep((rand() % 3)+1);
- goto trylock;
- }
- else
- ret = 0 ;
- }
- else
- ret = 0;
- *state = istate;
- return ret;
-}
-
-int
-unlock_file(const char *filename, void *state)
-{
- int fd, ret;
- fd = *((int *) state);
- free(state);
- ret = close(fd);
- return ret;
+ return 0;
}
-#else
-
int
-lock_file(const char *filename, void **state)
+lock_file (filename, state)
+ const char *filename;
+ void **state;
{
int fd;
+ struct stat buf;
int attempts = 0;
char *lockext = ".lockfile";
- char *lockpath = malloc(strlen(filename) + strlen(lockext) + 60);
+ char *lockpath = malloc (strlen (filename) + strlen (lockext) + 60);
if (!lockpath)
return -1;
- strcpy(lockpath, filename);
- strcat(lockpath, lockext);
+ strcpy (lockpath, filename);
+ strcat (lockpath, lockext);
*state = lockpath;
trylock:
attempts++;
- if ((fd = open(lockpath, O_CREAT | O_EXCL, 0600)) < 0)
+ /* If the lock is over an hour old, delete it. */
+ if (stat (lockpath, &buf) == 0
+ && (difftime (buf.st_ctime, time (NULL) > 60*60)))
+ unlink (lockpath);
+ fd = open (lockpath, O_CREAT | O_EXCL, 0600);
+ if (fd < 0)
{
if (errno == EEXIST)
{
/* Break the lock; we won't corrupt the file, but we might
lose some scores. */
if (attempts > MAX_ATTEMPTS)
- unlink(lockpath);
- else
- sleep((rand() % 2)+1);
+ {
+ unlink (lockpath);
+ attempts = 0;
+ }
+ sleep ((rand () % 2)+1);
goto trylock;
}
else
return -1;
}
- close(fd);
+ close (fd);
return 0;
}
int
-unlock_file(const char *filename, void *state)
+unlock_file (filename, state)
+ const char *filename;
+ void *state;
{
char *lockpath = (char *) state;
- int ret = unlink(lockpath);
+ int ret = unlink (lockpath);
int saved_errno = errno;
- free(lockpath);
+ free (lockpath);
errno = saved_errno;
return ret;
}
-#endif
+/* arch-tag: 2bf5c52e-4beb-463a-954e-c58b9c64736b
+ (do not change this comment) */
+
+/* update-game-score.c ends here */