add stampfilefd() to avoid race condition

git-svn-id: http://opensvn.csie.org/pttbbs/trunk/pttbbs@1998 63ad8ddf-47c3-0310-b6dd-a9e9d9715204

3 files changed, 35 insertions, 8 deletions

diff --git a/include/proto.h b/include/proto.h
index c6731ad1..206593cb 100644
--- a/include/proto.h
+++ b/include/proto.h
@@ -425,6 +425,7 @@ int get_record_keep(char *fpath, void *rptr, int size, int id, int *fd);
 void prints(char *fmt, ...) GCC_CHECK_FORMAT(1,2);
 int append_record(char *fpath, fileheader_t *record, int size);
 int stampfile(char *fpath, fileheader_t *fh);
+int stampfilefd(char *fpath, fileheader_t *fh);
 void stampdir(char *fpath, fileheader_t *fh);
 int get_num_records(char *fpath, int size);
 int get_records(char *fpath, void *rptr, int size, int id, int number);
diff --git a/mbbsd/record.c b/mbbsd/record.c
index c8393f6f..d50fb611 100644
--- a/mbbsd/record.c
+++ b/mbbsd/record.c
@@ -474,6 +474,37 @@ stampfile(char *fpath, fileheader_t * fh)
     return 0;
 }
 
+int
+stampfilefd(char *fpath, fileheader_t * fh)
+{
+    char           *ip = fpath;
+    time_t          dtime = COMMON_TIME;
+    struct tm      *ptime;
+    int             fd;
+
+    if (access(fpath, X_OK | R_OK | W_OK))
+	mkdir(fpath, 0755);
+
+    while (*(++ip))
+	;
+    *ip++ = '/';
+
+    while( 1 ) {
+	sprintf(ip, "M.%d.A.%3.3X", (int)++dtime, rand() & 0xFFF);
+	if( (fd = open(fpath, O_CREAT | O_EXCL | O_WRONLY, 0644)) != -1 )
+	    break;
+	if( errno != EEXIST )
+	    return -1;
+    }
+
+    memset(fh, 0, sizeof(fileheader_t));
+    strlcpy(fh->filename, ip, sizeof(fh->filename));
+    ptime = localtime(&dtime);
+    snprintf(fh->date, sizeof(fh->date),
+	     "%2d/%02d", ptime->tm_mon + 1, ptime->tm_mday);
+    return fd;
+}
+
 void
 stampdir(char *fpath, fileheader_t * fh)
 {
diff --git a/util/bbsmail.c b/util/bbsmail.c
index a58d5763..2ca997b8 100644
--- a/util/bbsmail.c
+++ b/util/bbsmail.c
@@ -78,7 +78,7 @@ void str_decode_M3(unsigned char *str);
 
 int mail2bbs(char *userid)
 {
-    int     uid;
+    int     uid, fd;
     fileheader_t mymail;
     char genbuf[512], title[512], sender[512], filename[512], *ip, *ptr;
     time_t tmp_time;
@@ -156,9 +156,6 @@ int mail2bbs(char *userid)
     if( strchr(sender, '@') == NULL )	/* ¥Ñ local host ±H«H */
 	strcat(sender, "@" MYHOSTNAME);
 
-/* allocate a file for the new mail */
-    stampfile(filename, &mymail);
-
 #ifdef HMM_USE_ANTI_SPAM
     for (n = 0; notitle[n]; n++)
 	if (strstr(title, notitle[n]))
@@ -178,11 +175,9 @@ int mail2bbs(char *userid)
 	}	
 #endif
 
-    if ((fout = fopen(filename, "w")) == NULL)
-    {
-	printf("Cannot open %s\n", filename);
+    if( (fd = stampfilefd(filename, &mymail)) == -1 ||
+	(fout = fdopen(fd, "wt")) == NULL )
 	return -1;
-    }
 
     if (!title[0])
 	sprintf(title, "¨Ó¦Û %.64s", sender);