simplify fetch_from_buf; cull idle dnsworkers.

svn:r354

src/or/buffers.c

@@ -135,20 +135,14 @@ int write_to_buf(char *string, int string_len,
 int fetch_from_buf(char *string, int string_len,
                    char **buf, int *buflen, int *buf_datalen) {
 
-  /* if there are string_len bytes in buf, write them onto string,
+  /* There must be string_len bytes in buf; write them onto string,
    * then memmove buf back (that is, remove them from buf).
    *
-   * If there are not enough bytes on the buffer to fill string, return -1.
-   *
    * Return the number of bytes still on the buffer. */
 
   assert(string && buf && *buf && buflen && buf_datalen);
+  assert(string_len <= *buf_datalen); /* make sure we don't ask for too much */
 
-  /* this is the point where you would grow the buffer, if you want to */
-
-  if(string_len > *buf_datalen) /* we want too much. sorry. */
-    return -1;
- 
   memcpy(string,*buf,string_len);
   *buf_datalen -= string_len;
   memmove(*buf, *buf+string_len, *buf_datalen);

src/or/connection.c

@@ -568,9 +568,7 @@ repeat_connection_package_raw_inbuf:
     cell.length = amount_to_process;
   }
 
-  if(connection_fetch_from_buf(cell.payload+RELAY_HEADER_SIZE, 
-                               cell.length, conn) < 0)
-    return -1;
+  connection_fetch_from_buf(cell.payload+RELAY_HEADER_SIZE, cell.length, conn);
 
   circ = circuit_get_by_conn(conn);
   if(!circ) {
@@ -695,9 +693,7 @@ int connection_process_cell_from_inbuf(connection_t *conn) {
   if(conn->inbuf_datalen < CELL_NETWORK_SIZE) /* entire response available? */
     return 0; /* not yet */
 
-  if(connection_fetch_from_buf(crypted,CELL_NETWORK_SIZE,conn) < 0) {
-    return -1;
-  }
+  connection_fetch_from_buf(crypted,CELL_NETWORK_SIZE,conn);
 
 #if 0
   printf("Cell header crypttext: ");

src/or/connection_ap.c

@@ -19,8 +19,7 @@ int ap_handshake_process_socks(connection_t *conn) {
     if(conn->inbuf_datalen < sizeof(socks4_t)) /* basic info available? */
       return 0; /* not yet */
 
-    if(connection_fetch_from_buf((char *)&socks4_info,sizeof(socks4_t),conn) < 0)
-      return -1;
+    connection_fetch_from_buf((char *)&socks4_info,sizeof(socks4_t),conn);
 
     log_fn(LOG_DEBUG,"Successfully read socks info.");
 
@@ -67,8 +66,7 @@ int ap_handshake_process_socks(connection_t *conn) {
       ap_handshake_socks_reply(conn, SOCKS4_REQUEST_REJECT);
       return -1;
     }
-    if(connection_fetch_from_buf(tmpbuf,amt,conn) < 0)
-      return -1;
+    connection_fetch_from_buf(tmpbuf,amt,conn);
     conn->read_username = 1;
     log_fn(LOG_DEBUG,"Successfully read username.");
   }
@@ -82,8 +80,7 @@ int ap_handshake_process_socks(connection_t *conn) {
       ap_handshake_socks_reply(conn, SOCKS4_REQUEST_REJECT);
       return -1;
     }
-    if(connection_fetch_from_buf(tmpbuf,amt,conn) < 0)
-      return -1;
+    connection_fetch_from_buf(tmpbuf,amt,conn);
 
     conn->dest_addr = strdup(tmpbuf);
     log_fn(LOG_NOTICE,"successfully read dest addr '%s'",

src/or/connection_or.c

@@ -372,9 +372,7 @@ or_handshake_client_process_auth(connection_t *conn) {
   if(conn->inbuf_datalen < 128) /* entire response available? */
     return 0; /* not yet */
 
-  if(connection_fetch_from_buf(cipher,128,conn) < 0) {
-    return -1;    
-  }
+  connection_fetch_from_buf(cipher,128,conn);
   log(LOG_DEBUG,"or_handshake_client_process_auth() : Received auth.");
 
   /* decrypt response */
@@ -483,9 +481,7 @@ or_handshake_server_process_auth(connection_t *conn) {
   if(conn->inbuf_datalen < 128) /* entire response available? */
     return 0; /* not yet */  
 
-  if(connection_fetch_from_buf(cipher,128,conn) < 0) {
-    return -1;
-  }
+  connection_fetch_from_buf(cipher,128,conn);
   log(LOG_DEBUG,"or_handshake_server_process_auth() : Received auth.");
 
   /* decrypt response */
@@ -632,9 +628,7 @@ or_handshake_server_process_nonce(connection_t *conn) {
   if(conn->inbuf_datalen < 128) /* entire response available? */
     return 0; /* not yet */
 
-  if(connection_fetch_from_buf(cipher,128,conn) < 0) {
-    return -1;    
-  }
+  connection_fetch_from_buf(cipher,128,conn);
   log(LOG_DEBUG,"or_handshake_server_process_nonce() : Received auth.");
 
   /* decrypt response */

src/or/directory.c

@@ -186,9 +186,7 @@ int directory_handle_command(connection_t *conn) {
     return 0; /* not yet */
   }
 
-  if(connection_fetch_from_buf(buf,strlen(getstring),conn) < 0) {
-    return -1;    
-  }
+  connection_fetch_from_buf(buf,strlen(getstring),conn);
 
   if(strncasecmp(buf,getstring,strlen("GET / HTTP/"))) {
     log_fn(LOG_DEBUG,"Command doesn't seem to be a get. Closing,");
@@ -224,10 +222,7 @@ int directory_handle_reading(connection_t *conn) {
     if(amt < 0) /* not there yet */
       return 0;
     headers = tor_malloc(amt+1);
-    if(connection_fetch_from_buf(headers,amt,conn) < 0) {
-      log_fn(LOG_DEBUG,"fetch_from_buf failed (reading headers).");
-      return -1;
-    }
+    connection_fetch_from_buf(headers,amt,conn);
     headers[amt] = 0; /* null terminate it, */
     free(headers); /* and then throw it away */
     reading_headers = 0;
@@ -243,10 +238,7 @@ int directory_handle_reading(connection_t *conn) {
   log_fn(LOG_DEBUG,"Pulling %d bytes in at offset %d.",
     amt, directorylen);
 
-  if(connection_fetch_from_buf(the_directory+directorylen,amt,conn) < 0) {
-    log_fn(LOG_DEBUG,"fetch_from_buf failed (reading dir).");
-    return -1;    
-  }
+  connection_fetch_from_buf(the_directory+directorylen,amt,conn);
 
   directorylen += amt;
 

src/or/dns.c

@@ -14,6 +14,7 @@
 
 #define MAX_DNSWORKERS 50
 #define MIN_DNSWORKERS 3
+#define MAX_IDLE_DNSWORKERS 10
 
 int num_workers=0;
 int num_workers_busy=0;
@@ -118,21 +119,14 @@ int dns_resolve(connection_t *exitconn) {
 static int dns_assign_to_worker(connection_t *exitconn) {
   connection_t *dnsconn;
   unsigned char len;
-  struct hostent *rent;
 
   spawn_enough_workers(); /* respawn here, to be sure there are enough */
 
   dnsconn = connection_get_by_type_state(CONN_TYPE_DNSWORKER, DNSWORKER_STATE_IDLE);
 
   if(!dnsconn) {
-    log(LOG_INFO,"dns_assign_to_worker(): no idle dns workers. Doing it myself.");
-
-    /* short version which does it all right here */
-    rent = gethostbyname(exitconn->address);
-    if (!rent) {
-      return dns_found_answer(exitconn->address, 0);
-    }
-    return dns_found_answer(exitconn->address, *(uint32_t *)rent->h_addr);
+    log(LOG_INFO,"dns_assign_to_worker(): no idle dns workers. Failing.");
+    return -1;
   }
 
   dnsconn->address = strdup(exitconn->address);
@@ -217,11 +211,7 @@ int connection_dns_process_inbuf(connection_t *conn) {
     return 0; /* not yet */
   assert(conn->inbuf_datalen == 4);
 
-  if(connection_fetch_from_buf((char*)&answer,sizeof(answer),conn) < 0) {
-    log(LOG_ERR,"connection_dnsworker_process_inbuf(): Broken inbuf. Worker dying.");
-    /* XXX exitconn's never going to get his answer :( */
-    return -1;
-  }
+  connection_fetch_from_buf((char*)&answer,sizeof(answer),conn);
 
   dns_found_answer(conn->address, answer);
 
@@ -324,6 +314,14 @@ static int dns_spawn_worker(void) {
 static void spawn_enough_workers(void) {
   int num_workers_needed; /* aim to have 1 more than needed,
                            * but no less than min and no more than max */
+  connection_t *dnsconn;
+
+  if(num_workers_busy == MAX_DNSWORKERS) {
+    /* We always want at least one worker idle.
+     * So find the oldest busy worker and kill it.
+     */
+
+  }
 
   if(num_workers_busy >= MIN_DNSWORKERS)
     num_workers_needed = num_workers_busy+1;
@@ -341,7 +339,13 @@ static void spawn_enough_workers(void) {
     num_workers++;
   }
 
-  /* FFFF this is where we will cull extra workers */
+  while(num_workers > num_workers_needed+MAX_IDLE_DNSWORKERS) { /* too many idle? */
+    /* cull excess workers */
+    dnsconn = connection_get_by_type_state(CONN_TYPE_DNSWORKER, DNSWORKER_STATE_IDLE);
+    assert(dnsconn);
+    dnsconn->marked_for_close = 1;
+    num_workers--;
+  }
 }
 
 /*

src/or/test.c

@@ -120,10 +120,6 @@ test_buffers() {
   test_memeq(str+10,buf,246);
   test_eq(buf_datalen,246);
 
-  test_eq(-1, fetch_from_buf(str2, 247, &buf, &buflen, &buf_datalen));
-  test_memeq(str+10,buf,246);
-  test_eq(buf_datalen, 246);
-  
   test_eq(0, fetch_from_buf(str2, 246, &buf, &buflen, &buf_datalen));
   test_memeq(str2, str+10, 246);
   test_eq(buflen,MAX_BUF_SIZE);