add support for holding a tcp connection open

[unix-history] / usr / src / lib / libc / net / res_send.c

diff --git a/usr/src/lib/libc/net/res_send.c b/usr/src/lib/libc/net/res_send.c
index e189878..e7f2d89 100644 (file)
--- a/usr/src/lib/libc/net/res_send.c
+++ b/usr/src/lib/libc/net/res_send.c
@@ -6,7 +6,7 @@
  */
 
 #ifndef lint
  */
 
 #ifndef lint

-static char sccsid[] = "@(#)res_send.c 6.1 (Berkeley) %G%";
+static char sccsid[] = "@(#)res_send.c 6.2 (Berkeley) %G%";

 #endif not lint
 
 /*
 #endif not lint
 
 /*


@@ -24,6 +24,8 @@ static char sccsid[] = "@(#)res_send.c        6.1 (Berkeley) %G%";
 
 extern int errno;
 
 
 extern int errno;
 

+#define KEEPOPEN (RES_USEVC|RES_STAYOPEN)
+

 res_send(buf, buflen, answer, anslen)
        char *buf;
        int buflen;
 res_send(buf, buflen, answer, anslen)
        char *buf;
        int buflen;


@@ -31,7 +33,8 @@ res_send(buf, buflen, answer, anslen)
        int anslen;
 {
        register int n;
        int anslen;
 {
        register int n;

-       int s, retry, v_circuit, resplen, ns;
+       int retry, v_circuit, resplen, ns;
+       static int s = -1;

        u_short id, len;
        char *cp;
        int dsmask;
        u_short id, len;
        char *cp;
        int dsmask;


@@ -49,7 +52,6 @@ res_send(buf, buflen, answer, anslen)
                if (res_init() == -1) {
                        return(-1);
                }
                if (res_init() == -1) {
                        return(-1);
                }

-       s = -1;

        v_circuit = (_res.options & RES_USEVC) || buflen > PACKETSZ;
        id = hp->id;
        /*
        v_circuit = (_res.options & RES_USEVC) || buflen > PACKETSZ;
        id = hp->id;
        /*


@@ -66,17 +68,18 @@ res_send(buf, buflen, answer, anslen)
                        /*
                         * Use virtual circuit.
                         */
                        /*
                         * Use virtual circuit.
                         */

-                       if (s < 0)
+                       if (s < 0) {

                                s = socket(AF_INET, SOCK_STREAM, 0);
                                s = socket(AF_INET, SOCK_STREAM, 0);

-                       if (connect(s, &(_res.nsaddr_list[ns]), 
-                          sizeof(struct sockaddr)) < 0) {
+                               if (connect(s, &(_res.nsaddr_list[ns]), 
+                                  sizeof(struct sockaddr)) < 0) {

 #ifdef DEBUG
 #ifdef DEBUG

-                               if (_res.options & RES_DEBUG)
-                                       printf("connect failed %d\n", errno);
+                                       if (_res.options & RES_DEBUG)
+                                           printf("connect failed %d\n",errno);

 #endif DEBUG
 #endif DEBUG

-                               (void) close(s);
-                               s = -1;
-                               continue;
+                                       (void) close(s);
+                                       s = -1;
+                                       continue;
+                               }

                        }
                        /*
                         * Send length & message
                        }
                        /*
                         * Send length & message


@@ -203,8 +206,18 @@ res_send(buf, buflen, answer, anslen)
                        p_query(answer);
                }
 #endif DEBUG
                        p_query(answer);
                }
 #endif DEBUG

-               (void) close(s);
-               return (resplen);
+               /*
+                * We are going to assume that the first server is preferred
+                * over the rest (i.e. it is on the local machine) and only
+                * keep that one open.
+                */
+               if ((_res.options & KEEPOPEN) == KEEPOPEN && ns == 0) {
+                       return (resplen);
+               } else {
+                       (void) close(s);
+                       s = -1;
+                       return (resplen);
+               }

           }
        }
        (void) close(s);
           }
        }
        (void) close(s);