[Nagiosplug-devel] check_tcp cores on Solaris when connection refused - have a fix

[Lynne Lawrence]

Folks,

Nice project - thanks for all your work!  

I write because I have found a problem with netutils.c which causes 
check_tcp to core on my Solaris 8 system.  I am "tcp-pinging" the jabber 
port on some servers and found that running the following against a host 
where the jabber service is down causes check_tcp to core:

myuser: LD_LIBRARY_PATH=/usr/local/ssl/lib old/check_tcp -p 5222 -H 
10.149.71.141
Segmentation Fault(coredump)
myuser: pstack core
core 'core' of 28148:   old/check_tcp -p 5222 -H 10.149.71.141
 ff374b44 freeaddrinfo (0, 0, 10, 1, 21b84, 144f4) + 8
 00014510 my_connect (0, 2e000, 2e2e0, 6, 2151c, ffbefc30) + 100
 00012d38 main     (5, 2e000, ffbefcc4, 2e000, 2e000, 1c000) + 160
 00012a64 _start   (0, 0, 0, 0, 0, 0) + 5c

I have modified netutils.c so that it now returns correctly:

user: LD_LIBRARY_PATH=/usr/local/ssl/lib new/check_tcp -p 5222 -H 
10.149.71.141
Connection refused

Here is the change I made to netutils.c (This change made to the 
netutils.c I checked out of cvs today)  I don't know that this is the 
best solution, but it certainly works :-):

*** netutils.c.new      Thu Sep 30 11:53:26 2004
--- netutils.c  Thu Sep 30 14:05:02 2004
***************
*** 214,219 ****
--- 214,220 ----
  {
        struct addrinfo hints;
        struct addrinfo *res;
+       struct addrinfo *orig_res;
        char port_str[6];
        int result;

***************
*** 230,235 ****
--- 231,237 ----
                return STATE_UNKNOWN;
        }
        else {
+         orig_res = res;
                while (res) {
                        /* attempt to create a socket */
                        *sd = socket (res->ai_family, (proto == 
IPPROTO_UDP) ?
***************
*** 237,243 ****

                        if (*sd < 0) {
                                printf ("Socket creation failed\n");
!                               freeaddrinfo (res);
                                return STATE_UNKNOWN;
                        }

--- 239,245 ----

                        if (*sd < 0) {
                                printf ("Socket creation failed\n");
!                               freeaddrinfo (orig_res);
                                return STATE_UNKNOWN;
                        }

***************
*** 260,266 ****
                        close (*sd);
                        res = res->ai_next;
                }
!               freeaddrinfo (res);
        }

        if (result == 0)
--- 262,268 ----
                        close (*sd);
                        res = res->ai_next;
                }
!               freeaddrinfo (orig_res);
        }

        if (result == 0)

I am not a member of this list, though I am on the users list, so please 
respond directly if there is a need. - thanks again - Lynne