Finalize fixing of netconfig loosing incident

 * need to set & check errno that tells us whether our tempfile was fresh created or already there
 * remove tmpfile on error
 * don't use fopen() because we can't specify the flags we need for that
 * ftruncate() the tempfile at the right place

diff --git a/citadel/modules/network/serv_network.c b/citadel/modules/network/serv_network.c
index 9c36f848ff269bb2f12277c279090d0e40e626e1..7186ebdd9a11b93c339f39feb67cdfdbe7400489 100644 (file)
--- a/citadel/modules/network/serv_network.c
+++ b/citadel/modules/network/serv_network.c
@@ -429,26 +429,27 @@ void cmd_snet(char *argbuf) {
        memcpy(tempfilename, filename, len + 1);
 
        memset(&StatBuf, 0, sizeof(struct stat));
-       if (stat(filename, &StatBuf)  == -1)
-               StatBuf.st_size = 80; /* Not there? guess 80 chars line. */
+       if ((stat(filename, &StatBuf)  == -1) || (StatBuf.st_size == 0))
+               StatBuf.st_size = 80; /* Not there or empty? guess 80 chars line. */
 
        sprintf(tempfilename + len, ".%d", CC->cs_pid);
+       errno = 0;
+       TmpFD = open(tempfilename, O_CREAT|O_EXCL|O_RDWR, S_IRUSR|S_IWUSR);
 
-       TmpFD = open(tempfilename, O_CREAT|O_EXCL);
-
-       if (TmpFD > 0)
+       if ((TmpFD > 0) && (errno == 0))
        {
                char *tmp = malloc(StatBuf.st_size * 2);
-               memset(tmp, 0, StatBuf.st_size * 2);
+               memset(tmp, ' ', StatBuf.st_size * 2);
                rc = write(TmpFD, tmp, StatBuf.st_size * 2);
                free(tmp);
-               if (rc <= 0)
+               if ((rc <= 0) || (rc != StatBuf.st_size * 2))
                {
                        close(TmpFD);
                        cprintf("%d Unable to allocate the space required for %s: %s\n",
                                ERROR + INTERNAL_ERROR,
                                tempfilename,
                                strerror(errno));
+                       unlink(tempfilename);
                        return;
                }       
                lseek(TmpFD, SEEK_SET, 0);
@@ -458,8 +459,7 @@ void cmd_snet(char *argbuf) {
                        ERROR + INTERNAL_ERROR,
                        tempfilename,
                        strerror(errno));
-
-
+               unlink(tempfilename);
        }
        Line = NewStrBuf();
 
@@ -476,14 +476,14 @@ void cmd_snet(char *argbuf) {
                len += StrLength(Line);
        }
        FreeStrBuf(&Line);
-       ftruncate(TmpFD, len + 1);
+       ftruncate(TmpFD, len);
        close(TmpFD);
 
        /* Now copy the temp file to its permanent location.
         * (We copy instead of link because they may be on different filesystems)
         */
        begin_critical_section(S_NETCONFIGS);
-       rename(filename, tempfilename);
+       rename(tempfilename, filename);
        end_critical_section(S_NETCONFIGS);
 }
 
@@ -1088,7 +1088,7 @@ void free_spoolcontrol_struct(SpoolControl **scc)
 int writenfree_spoolcontrol_file(SpoolControl **scc, char *filename)
 {
        char tempfilename[PATH_MAX];
-       FILE *fp;
+       int TmpFD;
        SpoolControl *sc;
        namelist *nptr = NULL;
        maplist *mptr = NULL;
@@ -1112,15 +1112,17 @@ int writenfree_spoolcontrol_file(SpoolControl **scc, char *filename)
 
        sprintf(tempfilename + len, ".%ld-%ld", reltid, unixtime);
        sc = *scc;
-       fp = fopen(tempfilename, "w");
+       errno = 0;
+       TmpFD = open(tempfilename, O_CREAT|O_EXCL|O_RDWR, S_IRUSR|S_IWUSR);
        Cfg = NewStrBuf();
-       if (fp == NULL) {
+       if ((TmpFD < 0) || (errno != 0)) {
                CtdlLogPrintf(CTDL_CRIT, "ERROR: cannot open %s: %s\n",
                        filename, strerror(errno));
                free_spoolcontrol_struct(scc);
+               unlink(tempfilename);
        }
        else {
-               fprintf(fp, "lastsent|%ld\n", sc->lastsent);
+               StrBufAppendPrintf(Cfg, "lastsent|%ld\n", sc->lastsent);
 
                /* Write out the listrecps while freeing from memory at the
                 * same time.  Am I clever or what?  :)
@@ -1160,17 +1162,19 @@ int writenfree_spoolcontrol_file(SpoolControl **scc, char *filename)
                }
                free(sc->misc);
 
-               rc = fwrite(ChrPtr(Cfg), StrLength(Cfg), 1, fp);
-               if (rc >=0)
+               rc = write(TmpFD, ChrPtr(Cfg), StrLength(Cfg));
+               if ((rc >=0 ) && (rc == StrLength(Cfg))) 
                {
-                       fclose(fp);
-                       rename(filename, tempfilename);
+                       close(TmpFD);
+                       rename(tempfilename, filename);
                }
                else {
                        CtdlLogPrintf(CTDL_EMERG, 
-                                     "unable to write %s; not enough space on the disk?\n", 
-                                     tempfilename);
-                       fclose(fp);
+                                     "unable to write %s; [%s]; not enough space on the disk?\n", 
+                                     tempfilename, 
+                                     strerror(errno));
+                       close(TmpFD);
+                       unlink(tempfilename);
                }
                FreeStrBuf(&Cfg);
                free(sc);