From 5ec0b86e5c1ff060720b5a6cd1af9d93ec993650 Mon Sep 17 00:00:00 2001

From: Martin Sehnoutka <msehnout@redhat.com>

Date: Thu, 29 Sep 2016 11:14:03 +0200

Subject: [PATCH 17/59] Fix an issue with timestamps during DST.

vsftpd now checks whether a file was uploaded during DST and

adjust the timestamp accordingly.

---

 sysutil.c | 104 ++++++++++++++++++++++++++++++++++++++++++++++----------------

 1 file changed, 77 insertions(+), 27 deletions(-)

diff --git a/sysutil.c b/sysutil.c

index c848356..2abdd13 100644

--- a/sysutil.c

+++ b/sysutil.c

@@ -26,8 +26,10 @@

 /* For Linux, this adds nothing :-) */

 #include "port/porting_junk.h"

+#define F_LOCALTIME "/etc/localtime"

+#define BUFTZSIZ 64

+

 #include <signal.h>

-#include <string.h>

 #include <stdlib.h>

 #include <unistd.h>

 #include <sys/types.h>

@@ -56,6 +58,11 @@

 #include <netdb.h>

 #include <sys/resource.h>

+#ifndef __USE_GNU

+  #define __USE_GNU

+#endif

+#include <string.h>

+

 /* Private variables to this file */

 /* Current umask() */

 static unsigned int s_current_umask;

@@ -2574,49 +2581,92 @@ error:

   die("reopening standard file descriptors to /dev/null failed");

 }

+char* vsf_sysutil_get_tz()

+{

+  char *ret_tz = NULL;

+  char buff[BUFTZSIZ];

+  off_t s_pos, e_pos;

+  size_t rcnt, rest;

+  int fd;

+

+  if ((fd = open(F_LOCALTIME, O_RDONLY)) > -1)

+  {

+    if ((e_pos = lseek(fd, 0, SEEK_END)) <= 0)

+    {

+      close(fd);

+      return NULL;

+    }

+    s_pos = e_pos > BUFTZSIZ ? e_pos - BUFTZSIZ : 0;

+    lseek(fd, s_pos, SEEK_SET);

+    rcnt = read(fd, buff, BUFTZSIZ);

+

+    if (rcnt && buff[rcnt-1] == '\n')

+    {

+      buff[rcnt-1] = 0;

+      e_pos--;

+    }

+

+    do {

+       char *nl = memrchr(buff, '\n', rcnt);

+       if (rcnt && nl)

+       {

+         int offset = (++nl) - buff;

+         int len = e_pos - s_pos - offset;

+         if (len)

+         {

+           lseek(fd, s_pos + offset, SEEK_SET);

+           ret_tz = calloc(1, len+4);

+           memcpy(ret_tz, "TZ=", 3);

+           rcnt = read(fd, ret_tz+3, len);

+         }

+         break;

+       }

+       if (!s_pos)

+       {

+         break;

+       }

+       rest = s_pos > BUFTZSIZ ? s_pos - BUFTZSIZ : 0;

+       s_pos -= rest;

+       lseek(fd, s_pos, SEEK_SET);

+       rcnt = read(fd, buff, rest);

+    } while (rcnt > 0);

+

+    close (fd);

+  }

+

+  return ret_tz;

+}

+

 void

 vsf_sysutil_tzset(void)

 {

   int retval;

-  char tzbuf[sizeof("+HHMM!")];

+  char *tz=NULL, tzbuf[sizeof("+HHMM!")];

   time_t the_time = time(NULL);

   struct tm* p_tm;

+

+  /* Set our timezone in the TZ environment variable to cater for the fact

+   * that modern glibc does not cache /etc/localtime (which becomes inaccessible

+   * when we chroot().

+   */

+  tz = vsf_sysutil_get_tz();;

+  if (tz)

+  {

+    putenv(tz);

+  }

   tzset();

   p_tm = localtime(&the_time);

   if (p_tm == NULL)

   {

     die("localtime");

   }

-  /* Set our timezone in the TZ environment variable to cater for the fact

-   * that modern glibc does not cache /etc/localtime (which becomes inaccessible

-   * when we chroot().

-   */

   retval = strftime(tzbuf, sizeof(tzbuf), "%z", p_tm);

   tzbuf[sizeof(tzbuf) - 1] = '\0';

   if (retval == 5)

   {

-    /* Static because putenv() does not copy the string. */

-    static char envtz[sizeof("TZ=UTC-hh:mm")];

-    /* Insert a colon so we have e.g. -05:00 instead of -0500 */

-    tzbuf[5] = tzbuf[4];

-    tzbuf[4] = tzbuf[3];

-    tzbuf[3] = ':';

-    /* Invert the sign - we just got the offset _from_ UTC but for TZ, we need

-     * the offset _to_ UTC.

-     */

-    if (tzbuf[0] == '+')

-    {

-      tzbuf[0] = '-';

-    }

-    else

-    {

-      tzbuf[0] = '+';

-    }

-    snprintf(envtz, sizeof(envtz), "TZ=UTC%s", tzbuf);

-    putenv(envtz);

     s_timezone = ((tzbuf[1] - '0') * 10 + (tzbuf[2] - '0')) * 60 * 60;

-    s_timezone += ((tzbuf[4] - '0') * 10 + (tzbuf[5] - '0')) * 60;

-    if (tzbuf[0] == '-')

+    s_timezone += ((tzbuf[3] - '0') * 10 + (tzbuf[4] - '0')) * 60;

+    if (tzbuf[0] == '+')

     {

       s_timezone *= -1;

     }

-- 

2.14.4