From 1a72d7c5377a1395e623b68558a59ece9c277c98 Mon Sep 17 00:00:00 2001
From: joonicks <god@joonicks.eu>
Date: Wed, 12 Dec 2018 14:30:01 +0100
Subject: [PATCH] safer sessionsaving

---
 VERSIONS      |  3 +++
 src/core.c    |  5 ++++-
 src/defines.h | 10 ++++++++++
 src/io.c      |  2 +-
 src/main.c    |  8 +++++---
 5 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/VERSIONS b/VERSIONS
index 02173b3..9602ccf 100644
--- a/VERSIONS
+++ b/VERSIONS
@@ -1,5 +1,8 @@
 3.1 -- WORK IN PROGRESS (~May, 2018)
 
+ * Changed: Session config is saved to "filename.sessiontemp" and once the save is complete
+   its moved to "filename.session", just in case something happens that might create a corrupt
+   session file (eg, SIGSEGV).
  * Added: SERVERSILENCETIMEOUT, maximum idle timer for server connection. in case of lost FIN packets
  * Fixed: Compiles clean with -std=c89
  * Added: $guid to esay variables
diff --git a/src/core.c b/src/core.c
index ae3002a..0366b09 100644
--- a/src/core.c
+++ b/src/core.c
@@ -148,7 +148,8 @@ int write_session(void)
 	UniVar	*varval;
 	int	j,sf;
 
-	if ((sf = open(SESSIONFILE,O_WRONLY|O_CREAT|O_TRUNC,NEWFILEMODE)) < 0)
+	/* save to filename.sessiontemp at first, in case SIGSEGV happens */
+	if ((sf = open(SESSIONTEMPFILE,O_WRONLY|O_CREAT|O_TRUNC,NEWFILEMODE)) < 0)
 		return(FALSE);
 
 #ifdef RAWDNS
@@ -311,6 +312,8 @@ int write_session(void)
 	}
 
 	close(sf);
+	unlink(SESSIONFILE);
+	rename(SESSIONTEMPFILE,SESSIONFILE);
 	return(TRUE);
 }
 
diff --git a/src/defines.h b/src/defines.h
index 633f47d..e253e13 100644
--- a/src/defines.h
+++ b/src/defines.h
@@ -30,6 +30,16 @@
 #define LS	/* nothing */
 #endif /* LIBRARY */
 
+/*
+ *  startup ==
+ */
+#define STARTUP_RUNNING		0
+#define STARTUP_ECHOTOCONSOLE	(startup > 1 && startup < 1000)
+#define STARTUP_COMMANDANDEXIT	3
+#define STARTUP_TESTRUN		6
+#define STARTUP_NORMALSTART	1000
+#define STARTUP_SIGSEGV		31337
+
 /*
  *  Channel Crap
  */
diff --git a/src/io.c b/src/io.c
index 55983f9..71d81c9 100644
--- a/src/io.c
+++ b/src/io.c
@@ -355,7 +355,7 @@ void to_user_q(const char *target, const char *format, ...)
 
 	stringcat(message,"\n");
 
-	if (startup > 0)
+	if (STARTUP_ECHOTOCONSOLE)
 	{
 		write(1,message,strlen(message));
 		return;
diff --git a/src/main.c b/src/main.c
index f46ed5f..2ea05bf 100644
--- a/src/main.c
+++ b/src/main.c
@@ -448,6 +448,7 @@ void sig_segv(int crap, siginfo_t *si, void *uap)
 	greg_t	*rsp,*rip; /* general registers */
 
 	time(&now);
+	startup = STARTUP_SIGSEGV;
 
 	debug("(sigsegv) trying to access "mx_pfmt"\n",(mx_ptr)si->si_addr);
 	mctx = &((ucontext_t *)uap)->uc_mcontext;
@@ -919,6 +920,7 @@ int main(int argc, char **argv, char **envp)
 #endif
 
 	uptime = time(&now);
+	startup = STARTUP_NORMALSTART;
 
 	if ((getuid() == 0) || (geteuid() == 0))
 	{
@@ -1060,7 +1062,7 @@ int main(int argc, char **argv, char **envp)
 				to_file(1,"error: Missing argument for -e <command string>\n");
 			_exit(0);
 		case 't':
-			startup = 666;
+			startup = STARTUP_TESTRUN;
 			break;
 		case 'f':
 			if (opt[2] != 0)
@@ -1276,12 +1278,12 @@ int main(int argc, char **argv, char **envp)
 	monitor_fs(executable);
 #endif
 
-	if (startup == 666)
+	if (startup == STARTUP_TESTRUN)
 	{
 		to_file(1,"init: test run completed, exiting...\n");
 		_exit(0);
 	}
-	startup = FALSE;
+	startup = STARTUP_RUNNING;
 #ifdef DEBUG
 	debug("(main) entering doit()...\n");
 #endif