Tidy up pipe-to-parent code in DNS TCP path.

src/cache.c

@@ -799,10 +799,12 @@ void cache_end_insert(void)
 	      char *name = cache_get_name(new_chain);
 	      ssize_t m = strlen(name);
 	      unsigned int flags = new_chain->flags;
+	      unsigned char op = PIPE_OP_RR;
 #ifdef HAVE_DNSSEC
 	      u16 class = new_chain->uid;
 #endif
 	      
+	      read_write(daemon->pipe_to_parent, &op, sizeof(op), RW_WRITE);
 	      read_write(daemon->pipe_to_parent, (unsigned char *)&m, sizeof(m), RW_WRITE);
 	      read_write(daemon->pipe_to_parent, (unsigned char *)name, m, RW_WRITE);
 	      read_write(daemon->pipe_to_parent, (unsigned char *)&new_chain->ttd, sizeof(new_chain->ttd), RW_WRITE);
@@ -838,12 +840,18 @@ void cache_end_insert(void)
   /* signal end of cache insert in master process */
   if (daemon->pipe_to_parent != -1)
     {
-      ssize_t m = -1;
+      unsigned char op = PIPE_OP_END;
-
+      read_write(daemon->pipe_to_parent, &op, sizeof(op), RW_WRITE);
-      read_write(daemon->pipe_to_parent, (unsigned char *)&m, sizeof(m), RW_WRITE);
+    }
+}
 
 #ifdef HAVE_DNSSEC
+void cache_update_hwm(void)
+{
   /* Sneak out possibly updated crypto HWM values. */
+  unsigned char op = PIPE_OP_STATS;
+
+  read_write(daemon->pipe_to_parent, &op, sizeof(op), RW_WRITE);
   read_write(daemon->pipe_to_parent,
 	     (unsigned char *)&daemon->metrics[METRIC_CRYPTO_HWM],
 	     sizeof(daemon->metrics[METRIC_CRYPTO_HWM]), RW_WRITE);
@@ -853,12 +861,8 @@ void cache_end_insert(void)
   read_write(daemon->pipe_to_parent,
 	     (unsigned char *)&daemon->metrics[METRIC_WORK_HWM],
 	     sizeof(daemon->metrics[METRIC_WORK_HWM]), RW_WRITE);
-#endif
-    }
-      
-  new_chain = NULL;
 }
-
+#endif
 
 /* A marshalled cache entry arrives on fd, read, unmarshall and insert into cache of master process. */
 int cache_recv_insert(time_t now, int fd)
@@ -869,18 +873,24 @@ int cache_recv_insert(time_t now, int fd)
   time_t ttd;
   unsigned int flags;
   struct crec *crecp = NULL;
+  unsigned char op;
   
   cache_start_insert();
   
   while (1)
     {
- 
+      if (!read_write(fd, &op, sizeof(op), RW_READ))
-      if (!read_write(fd, (unsigned char *)&m, sizeof(m), RW_READ))
 	return 0;
       
-      if (m == -1)
+      switch (op)
 	{
+	case PIPE_OP_END:
+	  cache_end_insert();
+	  return 1;
+	  
 #ifdef HAVE_DNSSEC
+	case PIPE_OP_STATS:
+	  {
 	    /* Sneak in possibly updated crypto HWM. */
 	    unsigned int val;
 
@@ -896,16 +906,13 @@ int cache_recv_insert(time_t now, int fd)
 	      return 0;
 	    if (val > daemon->metrics[METRIC_WORK_HWM])
 	      daemon->metrics[METRIC_WORK_HWM] = val;
-#endif
-	  cache_end_insert();
 	    return 1;
 	  }
 	  
-#ifdef HAVE_DNSSEC
+	case PIPE_OP_RESULT:
+	  {
 	    /* UDP validation moved to TCP to avoid truncation. 
 	       Restart UDP validation process with the returned result. */
-      if (m == -2)
-	{
 	    int status, uid, keycount, validatecount;
 	    int *keycountp, *validatecountp;
 	    size_t ret_len;
@@ -950,7 +957,9 @@ int cache_recv_insert(time_t now, int fd)
 	  }
 #endif
 	  
-      if (!read_write(fd, (unsigned char *)daemon->namebuff, m, RW_READ) ||
+	case PIPE_OP_RR:
+	  if (!read_write(fd, (unsigned char *)&m, sizeof(m), RW_READ) ||
+	      !read_write(fd, (unsigned char *)daemon->namebuff, m, RW_READ) ||
 	      !read_write(fd, (unsigned char *)&ttd, sizeof(ttd), RW_READ) ||
 	      !read_write(fd, (unsigned char *)&flags, sizeof(flags), RW_READ) ||
 	      !read_write(fd, (unsigned char *)&addr, sizeof(addr), RW_READ))
@@ -1003,6 +1012,12 @@ int cache_recv_insert(time_t now, int fd)
 #endif
 	      crecp = really_insert(daemon->namebuff, &addr, class, now, ttl, flags);
 	    }
+
+	  /* loop reading RRs, since we don't want to go back to the poll() loop
+	     and start processing other queries which might pollute the insertion
+	     chain. The child will never block between the first OP_RR and the OP_END */
+	  continue;
+	}
     }
 }
 	

src/dnsmasq.c

@@ -2124,6 +2124,10 @@ static void do_tcp_connection(struct listener *listener, time_t now, int slot)
   
   if (!option_bool(OPT_DEBUG))
     {
+#ifdef HAVE_DNSSEC
+       cache_update_hwm(); /* Sneak out possibly updated crypto HWM values. */
+#endif
+
       close(daemon->pipe_to_parent);
       flush_log();
       _exit(0);
@@ -2229,10 +2233,10 @@ int swap_to_tcp(struct frec *forward, time_t now, int status, struct dns_header
   
    if (!option_bool(OPT_DEBUG))
      {
-       ssize_t m = -2;
+       unsigned char op = PIPE_OP_RESULT;
 
        /* tell our parent we're done, and what the result was then exit. */
-       read_write(daemon->pipe_to_parent, (unsigned char *)&m, sizeof(m), RW_WRITE);
+       read_write(daemon->pipe_to_parent, &op, sizeof(op), RW_WRITE);
        read_write(daemon->pipe_to_parent, (unsigned char *)&status, sizeof(status), RW_WRITE);
        read_write(daemon->pipe_to_parent, (unsigned char *)plen, sizeof(*plen), RW_WRITE);
        read_write(daemon->pipe_to_parent, (unsigned char *)header, *plen, RW_WRITE);
@@ -2242,6 +2246,9 @@ int swap_to_tcp(struct frec *forward, time_t now, int status, struct dns_header
        read_write(daemon->pipe_to_parent, (unsigned char *)&keycount, sizeof(keycount), RW_WRITE);
        read_write(daemon->pipe_to_parent, (unsigned char *)validatecount, sizeof(*validatecount), RW_WRITE);
        read_write(daemon->pipe_to_parent, (unsigned char *)&validatecount, sizeof(validatecount), RW_WRITE);
+      
+       cache_update_hwm(); /* Sneak out possibly updated crypto HWM values. */
+              
        close(daemon->pipe_to_parent);
        
        flush_log();

src/dnsmasq.h

@@ -537,6 +537,10 @@ struct crec {
 #define SRC_HOSTS     2
 #define SRC_AH        3
 
+#define PIPE_OP_RR      1  /* Resource record */
+#define PIPE_OP_END     2  /* Cache entry complete: commit */
+#define PIPE_OP_RESULT  3  /* validation result. */
+#define PIPE_OP_STATS   4  /* Update parent's stats */
 
 /* struct sockaddr is not large enough to hold any address,
    and specifically not big enough to hold an IPv6 address.
@@ -1354,6 +1358,9 @@ void cache_end_insert(void);
 void cache_start_insert(void);
 unsigned int cache_remove_uid(const unsigned int uid);
 int cache_recv_insert(time_t now, int fd);
+#ifdef HAVE_DNSSEC
+void cache_update_hwm(void);
+#endif
 struct crec *cache_insert(char *name, union all_addr *addr, unsigned short class, 
 			  time_t now, unsigned long ttl, unsigned int flags);
 void cache_reload(void);