Send NOOPs to the server during slow connections to prevent timeouts. Bug #134

3 files changed, 32 insertions, 1 deletions

diff --git a/common/smtppass.c b/common/smtppass.c
index dc1cf77..8b71f4d 100644
--- a/common/smtppass.c
+++ b/common/smtppass.c
@@ -78,7 +78,7 @@ typedef struct spthread
 spthread_t;
 
 /* -----------------------------------------------------------------------
- *  STRINGS
+ *  DATA
  */
 
 #define CRLF                "\r\n"
@@ -93,6 +93,7 @@ spthread_t;
 #define SMTP_REJPREFIX      "550 Content Rejected; "
 
 #define SMTP_DATA           "DATA" CRLF
+#define SMTP_NOOP           "NOOP" CRLF
 #define SMTP_BANNER         "220 smtp.passthru" CRLF
 #define SMTP_HELO_RSP       "250 smtp.passthru" CRLF
 #define SMTP_EHLO_RSP       "250-smtp.passthru" CRLF
@@ -126,6 +127,9 @@ spthread_t;
 
 #define LINE_TOO_LONG(l)      ((l) >= (SP_LINE_LENGTH - 2))
 
+/* The amount interval at which to send NOOPS to server */
+#define INTERACTION_DELTA   10
+
 /* -----------------------------------------------------------------------
  *  CONFIGURATION OPTIONS
  *
@@ -179,6 +183,7 @@ static int read_server_response(spctx_t* ctx);
 static int parse_config_file(const char* configfile);
 static char* parse_address(char* line);
 static const char* get_successful_rsp(const char* line, int* cont);
+static void do_server_noop(spctx_t* ctx);
 
 /* Used externally in some cases */
 int sp_parse_option(const char* name, const char* option);
@@ -1123,6 +1128,14 @@ int sp_read_data(spctx_t* ctx, const char** data)
         return -1;
     };
 
+    /*
+     * During this time we're just reading from the client. If we haven't
+     * had any interaction with the server recently then send something
+     * to let it know we're still around.
+     */
+    if((ctx->server.last_action + INTERACTION_DELTA) < time(NULL))
+        do_server_noop(ctx);
+
     if(ctx->_crlf && strcmp(ctx->client.line, DATA_END_SIG) == 0)
         return 0;
 
@@ -1373,6 +1386,12 @@ static int read_server_response(spctx_t* ctx)
     return 0;
 }
 
+static void do_server_noop(spctx_t* ctx)
+{
+    if(spio_write_data(ctx, &(ctx->server), SMTP_NOOP) != -1)
+        spio_read_line(ctx, &(ctx->server), SPIO_DISCARD);
+}
+
 void sp_setup_forked(spctx_t* ctx, int file)
 {
     /* Signals we've messed with */
diff --git a/common/smtppass.h b/common/smtppass.h
index aebace1..e7fc780 100644
--- a/common/smtppass.h
+++ b/common/smtppass.h
@@ -66,6 +66,7 @@ typedef struct spio
 {
     int fd;                             /* The file descriptor wrapped */
     const char* name;                   /* The name for logging */
+    time_t last_action;                 /* Time of last action on descriptor */
 
     /* Internal use only */
     char line[SP_LINE_LENGTH];
@@ -124,6 +125,7 @@ typedef struct spctx
     int _crlf;                      /* Private data */
     char _l1[SP_LINE_LENGTH];
     char _l2[SP_LINE_LENGTH];
+    time_t _tm;
 }
 spctx_t;
 
diff --git a/common/spio.c b/common/spio.c
index 67d32b1..4075e9a 100644
--- a/common/spio.c
+++ b/common/spio.c
@@ -245,6 +245,9 @@ unsigned int spio_select(spctx_t* ctx, ...)
         if(i > (sizeof(int) * 8) - 2)
             break;
 
+        /* We have data on the descriptor, which is an action */
+        io->last_action = time(NULL);
+
         /* Check if the buffer has something in it */
         if(FD_ISSET(io->fd, &mask))
             ret |= (1 << i);
@@ -363,6 +366,9 @@ int read_raw(spctx_t* ctx, spio_t* io, int opts)
             return count;
         }
 
+        /* Read data which is a descriptor action */
+        io->last_action = time(NULL);
+
         /* Check for a new line */
         p = (char*)memchr(at, '\n', x);
         if(p != NULL)
@@ -489,6 +495,8 @@ int spio_write_data_raw(spctx_t* ctx, spio_t* io, unsigned char* buf, int len)
     if(io->fd == -1)
         return 0;
 
+    io->last_action = time(NULL);
+
     while(len > 0)
     {
         r = write(io->fd, buf, len);
@@ -556,6 +564,8 @@ void spio_read_junk(spctx_t* ctx, spio_t* io)
         if(l <= 0)
             break;
 
+        io->last_action = time(NULL);
+
         buf[l] = 0;
         t = trim_start(buf);