add NOFLOODING on utmpserver

git-svn-id: http://opensvn.csie.org/pttbbs/trunk/pttbbs@2701 63ad8ddf-47c3-0310-b6dd-a9e9d9715204

1 files changed, 110 insertions, 40 deletions

diff --git a/cacheserver/utmpserver.c b/cacheserver/utmpserver.c
index 2fb3f7ab..05a5ccfd 100644
--- a/cacheserver/utmpserver.c
+++ b/cacheserver/utmpserver.c
@@ -9,6 +9,23 @@ struct {
     int     reject[MAX_REJECT];
 } utmp[USHM_SIZE];
 
+#ifdef NOFLOODING
+#define MAXWAIT 1024
+#define FLUSHTIME (3600*6)
+
+struct {
+    time_t  lasttime;
+    int     count;
+} flooding[MAX_USERS];
+
+int nWaits, lastflushtime;
+struct {
+    int     uid;
+    int     fd;
+    int     index;
+} waitqueue[MAXWAIT];
+#endif /* NOFLOODING */
+
 inline int countarray(int *s, int max)
 {
     int     i;
@@ -68,11 +85,70 @@ void initdata(int index)
 	      sizeof(int), qsort_intcompar);
 }
 
+inline void syncutmp(int cfd)
+{
+    int     nSynced = 0, i;
+    for( i = 0 ; i < USHM_SIZE ; ++i, ++nSynced )
+	if( toread(cfd, &utmp[i].uid, sizeof(utmp[i].uid)) > 0      &&
+	    toread(cfd, utmp[i].friend, sizeof(utmp[i].friend)) > 0 &&
+	    toread(cfd, utmp[i].reject, sizeof(utmp[i].reject)) > 0 ){
+	    if( utmp[i].uid )
+		initdata(i);
+	}
+	else
+	    for( ; i < USHM_SIZE ; ++i )
+		utmp[i].uid = 0;
+    close(cfd);
+    fprintf(stderr, "%d users synced\n", nSynced);
+}
+
+void processlogin(int cfd, int uid, int index)
+{
+    if( toread(cfd, utmp[index].friend, sizeof(utmp[index].friend)) > 0 &&
+	toread(cfd, utmp[index].reject, sizeof(utmp[index].reject)) > 0 ){
+	/* 因為 logout 的時候並不會通知 utmpserver , 可能會查到一些
+	   已經 logout 的帳號。所以不能只取 MAX_FRIEND 而要多取一些 */
+#define MAX_FS   (2 * MAX_FRIEND)
+	int     iu, nFrs, stat, rstat;
+	ocfs_t  fs[MAX_FS];
+
+	utmp[index].uid = uid;
+	initdata(index);
+
+	for( nFrs = iu = 0 ; iu < USHM_SIZE && nFrs < MAX_FS ; ++iu )
+	    if( iu != index && utmp[iu].uid ){
+		if( (stat = set_friend_bit(index, iu)) ){
+		    rstat = reverse_friend_stat(stat);
+		    fs[nFrs].index = iu;
+		    fs[nFrs].uid = utmp[iu].uid;
+		    fs[nFrs].friendstat = (stat << 24) + iu;
+		    fs[nFrs].rfriendstat = (rstat << 24) + index;
+		    ++nFrs;
+		}
+	    }
+	
+	towrite(cfd, &fs, sizeof(ocfs_t) * nFrs);
+    }
+    close(cfd);
+}
+
+#ifdef NOFLOODING
+void flushwaitqueue(void)
+{
+    int     i;
+    for( i = 0 ; i < nWaits ; ++i )
+	processlogin(waitqueue[i].fd, waitqueue[i].uid, waitqueue[i].index);
+    lastflushtime = time(NULL);
+    nWaits = 0;
+    memset(flooding, 0, sizeof(flooding));
+}
+#endif
+
 /* XXX 具有被 DoS 的可能, 請用 firewall 之類擋起來 */
 int main(int argc, char **argv)
 {
     struct  sockaddr_in     clientaddr;
-    int     ch, port = 5120, sfd, cfd, len, index, i, uid;
+    int     ch, port = 5120, sfd, cfd, len, index, uid;
     char   *iface_ip = NULL;
 
     while( (ch = getopt(argc, argv, "p:i:h")) != -1 )
@@ -92,7 +168,15 @@ int main(int argc, char **argv)
     if( (sfd = tobind(iface_ip, port)) < 0 )
 	return 1;
 
+#ifdef NOFLOODING
+    lastflushtime = time(NULL);
+#endif
     while( 1 ){
+#ifdef NOFLOODING
+	if( lastflushtime < (time(NULL) - 1800) )
+	    flushwaitqueue();
+#endif
+
 	len = sizeof(clientaddr);
 	if( (cfd = accept(sfd, (struct sockaddr *)&clientaddr, &len)) < 0 ){
 	    if( errno != EINTR )
@@ -101,49 +185,35 @@ int main(int argc, char **argv)
 	}
 	toread(cfd, &index, sizeof(index));
 	if( index == -1 ){
-	    int     nSynced = 0;
-	    for( i = 0 ; i < USHM_SIZE ; ++i, ++nSynced )
-		if( toread(cfd, &utmp[i].uid, sizeof(utmp[i].uid)) > 0      &&
-		    toread(cfd, utmp[i].friend, sizeof(utmp[i].friend)) > 0 &&
-		    toread(cfd, utmp[i].reject, sizeof(utmp[i].reject)) > 0 ){
-		    if( utmp[i].uid )
-			initdata(i);
-		}
-		else
-		    for( ; i < USHM_SIZE ; ++i )
-			utmp[i].uid = 0;
-	    close(cfd);
-	    fprintf(stderr, "%d users synced\n", nSynced);
+	    syncutmp(cfd);
 	    continue;
 	}
 
-	if( toread(cfd, &uid, sizeof(uid)) > 0                              &&
-	    toread(cfd, utmp[index].friend, sizeof(utmp[index].friend)) > 0 &&
-	    toread(cfd, utmp[index].reject, sizeof(utmp[index].reject)) > 0 ){
-	    /* 因為 logout 的時候並不會通知 utmpserver , 可能會查到一些
-	       已經 logout 的帳號。所以不能只取 MAX_FRIEND 而要多取一些 */
-#define MAX_FS   (2 * MAX_FRIEND)
-	    int     iu, nFrs, stat, rstat;
-	    ocfs_t  fs[MAX_FS];
-
-	    utmp[index].uid = uid;
-	    initdata(index);
-
-	    for( nFrs = iu = 0 ; iu < USHM_SIZE && nFrs < MAX_FS ; ++iu )
-		if( iu != index && utmp[iu].uid ){
-		    if( (stat = set_friend_bit(index, iu)) ){
-			rstat = reverse_friend_stat(stat);
-			fs[nFrs].index = iu;
-			fs[nFrs].uid = utmp[iu].uid;
-			fs[nFrs].friendstat = (stat << 24) + iu;
-			fs[nFrs].rfriendstat = (rstat << 24) + index;
-			++nFrs;
-		    }
-		}
-
-	    towrite(cfd, &fs, sizeof(ocfs_t) * nFrs);
+	if( toread(cfd, &uid, sizeof(uid)) > 0 ){
+	    if( !(0 < uid || uid > MAX_USERS) ){ /* for safety */
+		close(cfd);
+		continue;
+	    }
+
+#ifdef NOFLOODING
+	    if( (time(NULL) - flooding[uid].lasttime) < 20 )
+		++flooding[uid].count;
+	    if( flooding[uid].count > 10 ){
+		if( nWaits == MAXWAIT )
+		    flushwaitqueue();
+		waitqueue[nWaits].uid = uid;
+		waitqueue[nWaits].index = index;
+		waitqueue[nWaits].fd = cfd;
+		++nWaits;
+
+		continue;
+	    }
+	    flooding[uid].lasttime = time(NULL);
+#endif
+
+	    /* cfd will be closed in processlogin() */
+	    processlogin(cfd, uid, index);
 	}
-	close(cfd);
     }
     return 0;
 }