Re: Question about ldap_search_ext_s and memory leak

Jean-Marc Choulet wrote:

Hello,

I have a little with this very simple program :

#include <iostream> #include <stdlib.h> #define LDAP_DEPRECATED 1 #include <ldap.h>

using namespace std;

const char* server = "ldap://ldap.xxxx.fr"; const char* cacert_file = "cacert.pem"; const char* root_dn = "cn=replicator,ou=DSA,dc=xxxx,dc=fr"; const char* root_pw = "xxxx"; const char* aliased_people_dn ="ou=AliasedPeople,dc=xxxx,dc=fr";

int main(int argc, char *argv[]) { if (argc != 3) { cerr << "Usage: " << argv[0] << " username password" << endl; return 1; }

 LDAP *ld;
 int version = LDAP_VERSION3;
 int rc;

 if ((rc = ldap_initialize(&ld, server)) != LDAP_SUCCESS) {
     cerr << "ldap_initialize: " << server << endl;
     return EXIT_FAILURE;
 }

 if ((rc = ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, &version))

!= LDAP_OPT_SUCCESS) { cerr << "ldap_set_option error: " << ldap_err2string(rc) << endl; return EXIT_FAILURE; }

 if ((rc = ldap_set_option(NULL, LDAP_OPT_X_TLS_CACERTFILE,

cacert_file)) != LDAP_OPT_SUCCESS ) { cerr << "ldap_set_option error: " << ldap_err2string(rc) << endl; return EXIT_FAILURE; }

 if ((rc = ldap_start_tls_s(ld, NULL, NULL)) != LDAP_SUCCESS)
 {
     cerr << "ldap_start_tls_s error: " << ldap_err2string(rc) << endl;
     return EXIT_FAILURE;
 }

 if ((rc = ldap_bind_s(ld, root_dn, root_pw, LDAP_AUTH_SIMPLE)) !=

LDAP_SUCCESS) { cerr << "ldap_bind_s: " << ldap_err2string(rc) << endl; return EXIT_FAILURE; }

 cout << "user replicator authenticated :)." << endl;

 LDAPMessage *pResult;
 struct berval cred;
 char *pDN;

 std::string filter("uid=" + string(argv[1]));

 rc = ldap_search_ext_s(ld, aliased_people_dn, LDAP_SCOPE_SUBTREE,
                        filter.c_str(), NULL, 0, NULL, NULL,
                        NULL, LDAP_NO_LIMIT, &pResult);

 if (rc != LDAP_SUCCESS)
 {
     cerr << "ldap_search_ext_s error: " << ldap_err2string(rc) <<

endl; ldap_unbind_s(ld); return EXIT_FAILURE; }

 struct berval **vals;
 LDAPMessage    *pEntry;
 string          user_dn;

 if (ldap_count_entries(ld, pResult) == 1) {
     pEntry = ldap_first_entry(ld, pResult);
     pDN = ldap_get_dn(ld, pEntry);
     vals = ldap_get_values_len(ld, pEntry, "aliasedObjectName");

     if (vals) {
         user_dn = vals[0]->bv_val;
         ldap_value_free_len(vals);
     }
     ldap_memfree(pDN);
 }
 else {
     cout << "aliasedObjectName attribute not found" << endl;
     ldap_unbind_s(ld);
     return EXIT_FAILURE;
 }

 ldap_memfree(pResult);

 if ((rc = ldap_bind_s(ld, user_dn.c_str(), argv[2],

LDAP_AUTH_SIMPLE)) != LDAP_SUCCESS) { cerr << "user " << argv[1] << " not authenticated" << endl; ldap_unbind_s(ld); return EXIT_FAILURE; }

 cout << "user " << argv[1] << " (" << user_dn << ") authenticated"

<< endl;

 ldap_unbind_s(ld);

 return EXIT_SUCCESS;

}

My program works fine but, if I use valgrind, I have memory leaks :

Read the ldap_result(3) manpage again. You're supposed to use ldap_msgfree() on the result, not ldap_memfree().

==13616== LEAK SUMMARY: ==13616== definitely lost: 136 bytes in 2 blocks ==13616== indirectly lost: 284 bytes in 3 blocks ==13616== possibly lost: 0 bytes in 0 blocks ==13616== still reachable: 260,033 bytes in 1,152 blocks ==13616== suppressed: 0 bytes in 0 blocks ==13616== Reachable blocks (those to which a pointer was found) are not shown. ==13616== To see them, rerun with: --leak-check=full --show-leak-kinds=all ==13616== ==13616== For counts of detected and suppressed errors, rerun with: -v ==13616== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 0 from 0)

I don't understand why. Do you have a idea ?

I work on Ubuntu 14.04. The OpenLDAP version is 2.4.31.

Thanks,

Jean-Marc.