Log die() calls to syslog

Pass messages given to die(), die2() and bug() to syslog. Currently this
functionality requires waiting for a short amount of time (1 second is
used) after logging the message and before exiting. This is a workaround
for the following systemd bug:
https://github.com/systemd/systemd/issues/2913

The need for this workaround is the main reason why I decided not to
enable this functionality by default.

Resolves: rhbz#1318198
Resolves: rhbz#1582672

logging.c

@@ -30,10 +30,6 @@ static void vsf_log_do_log_to_file(int fd, struct mystr* p_str);
 void
 vsf_log_init(struct vsf_session* p_sess)
 {
-  if (tunable_syslog_enable || tunable_tcp_wrappers)
-  {
-    vsf_sysutil_openlog(0);
-  }
   if (!tunable_xferlog_enable && !tunable_dual_log_enable)
   {
     return;
@@ -389,3 +385,12 @@ vsf_log_do_log_vsftpd_format(struct vsf_session* p_sess, struct mystr* p_str,
   }
 }
 
+void
+vsf_log_die(const char* p_text)
+{
+  struct mystr log_str = INIT_MYSTR;
+
+  str_append_text(&log_str, "ERROR: ");
+  str_append_text(&log_str, p_text);
+  str_syslog(&log_str, 1);
+}

logging.h

@@ -91,5 +91,7 @@ void vsf_log_line(struct vsf_session* p_sess, enum EVSFLogEntryType what,
 void vsf_log_failed_line(struct vsf_session* p_sess, enum EVSFLogEntryType what,
                   struct mystr* p_str);
 
+void vsf_log_die(const char* p_text);
+
 #endif /* VSF_LOGGING_H */
 

main.c

@@ -120,6 +120,10 @@ main(int argc, const char* argv[])
     }
     vsf_sysutil_free(p_statbuf);
   }
+  if (tunable_log_die || tunable_syslog_enable || tunable_tcp_wrappers)
+  {
+    vsf_sysutil_openlog(0);
+  }
   /* Resolve pasv_address if required */
   if (tunable_pasv_address && tunable_pasv_addr_resolve)
   {

parseconf.c

@@ -112,6 +112,7 @@ parseconf_bool_array[] =
   { "seccomp_sandbox", &tunable_seccomp_sandbox },
   { "allow_writeable_chroot", &tunable_allow_writeable_chroot },
   { "better_stou", &tunable_better_stou },
+  { "log_die", &tunable_log_die },
   { 0, 0 }
 };
 

tcpwrap.c

@@ -27,15 +27,12 @@ int
 vsf_tcp_wrapper_ok(int remote_fd)
 {
   struct request_info req;
-  vsf_sysutil_openlog(0);
   request_init(&req, RQ_DAEMON, "vsftpd", RQ_FILE, remote_fd, 0);
   fromhost(&req);
   if (!hosts_access(&req))
   {
-    vsf_sysutil_closelog();
     return 0;
   }
-  vsf_sysutil_closelog();
   return 1;
 }
 

tunables.c

@@ -93,6 +93,7 @@ int tunable_http_enable;
 int tunable_seccomp_sandbox;
 int tunable_allow_writeable_chroot;
 int tunable_better_stou;
+int tunable_log_die;
 
 unsigned int tunable_accept_timeout;
 unsigned int tunable_connect_timeout;
@@ -241,6 +242,7 @@ tunables_load_defaults()
   tunable_seccomp_sandbox = 0;
   tunable_allow_writeable_chroot = 0;
   tunable_better_stou = 0;
+  tunable_log_die = 0;
 
   tunable_accept_timeout = 60;
   tunable_connect_timeout = 60;

tunables.h

@@ -96,6 +96,8 @@ extern int tunable_allow_writeable_chroot;    /* Allow misconfiguration */
 extern int tunable_better_stou;               /* Use better file name generation
                                                * algorithm for the STOU command
 					       */
+extern int tunable_log_die;                   /* Log calls to die(), die2()
+                                               * and bug() */
 
 /* Integer/numeric defines */
 extern unsigned int tunable_accept_timeout;

utility.c

@@ -9,6 +9,8 @@
 #include "sysutil.h"
 #include "str.h"
 #include "defs.h"
+#include "logging.h"
+#include "tunables.h"
 
 #define DIE_DEBUG
 
@@ -41,11 +43,20 @@ void
 bug(const char* p_text)
 {
   /* Rats. Try and write the reason to the network for diagnostics */
+  if (tunable_log_die)
+  {
+    vsf_log_die(p_text);
+  }
   vsf_sysutil_activate_noblock(VSFTP_COMMAND_FD);
   (void) vsf_sysutil_write_loop(VSFTP_COMMAND_FD, "500 OOPS: ", 10);
   (void) vsf_sysutil_write_loop(VSFTP_COMMAND_FD, p_text,
                                 vsf_sysutil_strlen(p_text));
   (void) vsf_sysutil_write_loop(VSFTP_COMMAND_FD, "\r\n", 2);
+  if (tunable_log_die)
+  {
+    /* Workaround for https://github.com/systemd/systemd/issues/2913 */
+    vsf_sysutil_sleep(1.0);
+  }
   vsf_sysutil_exit(2);
 }
 

vsftpd.conf.5

@@ -358,6 +358,16 @@ wanting to e.g. append a file.
 
 Default: YES
 .TP
+.B log_die
+Log an error to syslog when some error condition occurs and vsftpd decides
+to quit. Internally, the error messages given to the functions die(), die2()
+and bug() are passed to syslog. Currently this functionality requires waiting
+for a short amount of time (1 second is used) after logging the message and
+before exiting. This is a workaround for the following systemd bug:
+https://github.com/systemd/systemd/issues/2913
+
+Default: NO
+.TP
 .B log_ftp_protocol
 When enabled, all FTP requests and responses are logged, providing the option
 xferlog_std_format is not enabled. Useful for debugging.