check in for Bug 6959

Add the ability to run a user defined script to determine wan load-balancing interface health

includes sample http test (scripts/http_test.pl). Configuration will look as follows:

 wan {
     interface-health eth0 {
         nexthop 10.3.0.1
         test 1 {
             test-script /tmp/http_test.pl
             type user-defined
         }
     }
     interface-health eth1 {
         nexthop 10.3.0.1
         test 1 {
             test-script /tmp/http_test.pl
             type user-defined
         }
     }

With corresponding output:

vyatta@vyatta# run show wan-load-balance
Interface:  eth0
  Status:  active
  Last Status Change:  Wed Mar 30 19:03:59 2011
  +Test:  user  Script: /tmp/http_test.pl
    Last Interface Success:  0s
    Last Interface Failure:  n/a
    # Interface Failure(s):  0

Interface:  eth1
  Status:  failed
  Last Status Change:  Wed Mar 30 19:03:59 2011
  -Test:  user  Script: /tmp/http_test.pl
    Last Interface Success:  n/a
    Last Interface Failure:  0s
    # Interface Failure(s):  52

Scripts returns 0 for success, non-zero for failure.

1 files changed, 146 insertions, 0 deletions

diff --git a/src/lbtest_user.cc b/src/lbtest_user.cc
new file mode 100644
index 0000000..4dbed74
--- /dev/null
+++ b/src/lbtest_user.cc
@@ -0,0 +1,146 @@
+/*
+ * Module: lbtest_user.cc
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+#include <syslog.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <iostream>
+#include <string>
+#include <algorithm>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include "lbdata.hh"
+#include "lbtest_user.hh"
+
+using namespace std;
+
+/**
+ *
+ *
+ **/
+void
+LBTestUser::send(LBHealth &health)
+{
+  if (_debug) {
+    cout << "LBTestUser::process()" << endl;
+  }
+
+  _status_line = name() + "\t" + string("Script: ") + _script;
+  
+
+  //need to set environment variable for interface
+
+  //execute script
+  string environment = "export WLB_SCRIPT_IFACE=" + health._interface;
+  string cmd = "/bin/bash -p -c '" + environment + ";umask 000; " + _script + ";'";
+  string out;
+  if (system_out(cmd,out) == 0) {
+    _state = LBTest::K_SUCCESS;
+  }
+  else {
+    _state = LBTest::K_FAILURE;
+  }
+  return;
+}
+
+int
+LBTestUser::system_out(const string &cmd, string &out) 
+{
+  //  fprintf(out_stream,"system out\n");
+  if (cmd.empty()) {
+    return -1;               
+  }
+
+  int cp[2]; // Child to parent pipe
+  if( pipe(cp) < 0) {                                                                                                       
+    return -1;
+  }
+
+  pid_t pid = fork();                                                                                 
+  if (pid == 0) {                                                                                          
+    //child
+    close(cp[0]);
+    close(0); // Close current stdin.
+    dup2(cp[1],STDOUT_FILENO); // Make stdout go to write end of pipe.
+    dup2(cp[1],STDERR_FILENO); // Make stderr go to write end of pipe.
+    //    fcntl(cp[1],F_SETFD,fcntl(cp[1],F_GETFD) & (~FD_CLOEXEC));
+    close(cp[1]);
+    int ret = 0;  
+
+
+    //set user and group here
+    setregid(getegid(),getegid());
+    setreuid(geteuid(),geteuid());
+
+    //    fprintf(out_stream,"executing: %s\n",cmd);
+    if (execl("/bin/sh","sh","-c",cmd.c_str(),NULL) == -1) {                                   
+      ret = errno;
+    }
+    close(cp[1]);
+    exit(ret);
+  }
+  else {
+    //parent         
+    char buf[8192];
+    memset(buf,'\0',8192);
+    close(cp[1]);
+    fd_set rfds;
+    struct timeval tv;
+
+    int flags = fcntl(cp[0], F_GETFL, 0);
+    fcntl(cp[0], F_SETFL, flags | O_NONBLOCK);
+
+    FD_ZERO(&rfds);
+    FD_SET(cp[0], &rfds);
+    tv.tv_sec = 1;
+    tv.tv_usec = 0;
+    while (select(FD_SETSIZE, &rfds, NULL, NULL, &tv) != -1) {
+      int err = 0;
+      if ((err = read(cp[0], &buf, 8191)) > 0) {
+	out += string(buf);
+      }
+      else if (err == -1 && errno == EAGAIN) {
+	//try again
+      }
+      else {
+	break;
+      }
+      FD_ZERO(&rfds);
+      FD_SET(cp[0], &rfds);
+      tv.tv_sec = 1;
+      tv.tv_usec = 0;
+
+      fflush(NULL);
+    }
+
+    //now wait on child to kick the bucket                  
+    int status;
+    wait(&status);
+    close(cp[0]);
+    return WEXITSTATUS(status);
+  }
+}
+
+
+/**
+ *
+ *
+ **/
+string
+LBTestUser::dump()
+{
+  char buf[20];
+  sprintf(buf,"%u",_resp_time);
+  string foo = string("script: ") + _script + ", resp_time: " + buf;
+  return foo;
+}