From 52e7e6293c12f7d223091a8840ce4c8a8c96cb52 Mon Sep 17 00:00:00 2001
From: Janos SUTO <sj@acts.hu>
Date: Wed, 27 Nov 2019 21:08:00 +0100
Subject: [PATCH] Protect fsync() and close() from SIGALRM

Signed-off-by: Janos SUTO <sj@acts.hu>
---
 etc/example.conf | 4 ++--
 src/cfg.c        | 2 +-
 src/misc.c       | 2 +-
 src/smtp.c       | 9 +++++++++
 4 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/etc/example.conf b/etc/example.conf
index 739a236c..c002a15d 100644
--- a/etc/example.conf
+++ b/etc/example.conf
@@ -66,8 +66,8 @@ listen_port=25
 
 clamd_socket=/tmp/clamd
 
-; check for client timeout interval. Default: 30 sec
-check_for_client_timeout_interval=30
+; check for client timeout interval. Default: 20 sec
+check_for_client_timeout_interval=20
 
 ; smtp timeout. Default: 60 sec
 smtp_timeout=60
diff --git a/src/cfg.c b/src/cfg.c
index a49cf16a..7734d985 100644
--- a/src/cfg.c
+++ b/src/cfg.c
@@ -62,7 +62,7 @@ struct _parse_rule config_parse_rules[] =
    { "archive_emails_not_having_message_id", "integer", (void*) int_parser, offsetof(struct config, archive_emails_not_having_message_id), "0", sizeof(int)},
    { "archive_only_mydomains", "integer", (void*) int_parser, offsetof(struct config, archive_only_mydomains), "0", sizeof(int)},
    { "backlog", "integer", (void*) int_parser, offsetof(struct config, backlog), "20", sizeof(int)},
-   { "check_for_client_timeout_interval", "integer", (void*) int_parser, offsetof(struct config, check_for_client_timeout_interval), "30", sizeof(int)},
+   { "check_for_client_timeout_interval", "integer", (void*) int_parser, offsetof(struct config, check_for_client_timeout_interval), "20", sizeof(int)},
    { "cipher_list", "string", (void*) string_parser, offsetof(struct config, cipher_list), "ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:ECDH+3DES:DH+3DES:RSA+AESGCM:RSA+AES:RSA+3DES:!aNULL:!MD5:!DSS", MAXVAL-1},
    { "clamd_addr", "string", (void*) string_parser, offsetof(struct config, clamd_addr), "", MAXVAL-1},
    { "clamd_port", "integer", (void*) int_parser, offsetof(struct config, clamd_port), "0", sizeof(int)},
diff --git a/src/misc.c b/src/misc.c
index 89a72a17..2e107227 100644
--- a/src/misc.c
+++ b/src/misc.c
@@ -77,7 +77,7 @@ void __fatal(char *s){
 }
 
 /*
- * calculate the difference betwwen two timevals in [usec]
+ * calculate the difference between two timevals in [usec]
  */
 
 long tvdiff(struct timeval a, struct timeval b){
diff --git a/src/smtp.c b/src/smtp.c
index 6f77cdae..484c4172 100644
--- a/src/smtp.c
+++ b/src/smtp.c
@@ -8,6 +8,7 @@
 #include <arpa/inet.h>
 #include <fcntl.h>
 #include <syslog.h>
+#include <signal.h>
 #include <unistd.h>
 #include <openssl/ssl.h>
 #include <openssl/err.h>
@@ -266,13 +267,21 @@ void process_command_data(struct smtp_session *session, struct config *cfg){
 
 void process_command_period(struct smtp_session *session){
    char buf[SMALLBUFSIZE];
+   struct timezone tz;
+   struct timeval tv1, tv2;
 
    session->protocol_state = SMTP_STATE_PERIOD;
 
    // TODO: add some error handling
 
+   sig_block(SIGALRM);
+   gettimeofday(&tv1, &tz);
    fsync(session->fd);
    close(session->fd);
+   gettimeofday(&tv2, &tz);
+   sig_unblock(SIGALRM);
+
+   syslog(LOG_PRIORITY, "fsync()+close() took %ld [us]", tvdiff(tv2, tv1));
 
    session->fd = -1;