Discussion :

[zodd]

Bonjour,

Je suis en train d'essayer de reprendre le code source d'une commande Lunix pour le mettre dans un slot appelé par un bouton dans Qt.
Du coup je part d'un code en C où il y a le parsing des données entrées en ligne de commande et j'essaie de remplacé ce qui est entré au clavier par les contenu des QLineEdit de ma fenêtre (pour l'instant j'utilise de simples Array à la place):

voilà la fonction de départ:

Code :

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int
main(int argc, char *argv[])
{
    netsnmp_session session, *ss;
    netsnmp_pdu    *pdu, *response = NULL;
    netsnmp_variable_list *vars;
    int             arg;
    int             count;
    int             current_name = 0;
    int             current_type = 0;
    int             current_value = 0;
    char           *names[SNMP_MAX_CMDLINE_OIDS];
    char            types[SNMP_MAX_CMDLINE_OIDS];
    char           *values[SNMP_MAX_CMDLINE_OIDS];
    oid             name[MAX_OID_LEN];
    size_t          name_length;
    int             status;
    int             failures = 0;
    int             exitval = 0;
 
    putenv(strdup("POSIXLY_CORRECT=1"));
 
    /*
     * get the common command line arguments 
     */
    switch (arg = snmp_parse_args(argc, argv, &session, "C:", optProc)) {
    case NETSNMP_PARSE_ARGS_ERROR:
        exit(1);
    case NETSNMP_PARSE_ARGS_SUCCESS_EXIT:
        exit(0);
    case NETSNMP_PARSE_ARGS_ERROR_USAGE:
        usage();
        exit(1);
    default:
        break;
    }
 
    if (arg >= argc) {
        fprintf(stderr, "Missing object name\n");
        usage();
        exit(1);
    }
    if ((argc - arg) > 3*SNMP_MAX_CMDLINE_OIDS) {
        fprintf(stderr, "Too many assignments specified. ");
        fprintf(stderr, "Only %d allowed in one request.\n", SNMP_MAX_CMDLINE_OIDS);
        usage();
        exit(1);
    }
 
    /*
     * get object names, types, and values 
     */
    for (; arg < argc; arg++) {
        DEBUGMSGTL(("snmp_parse_args", "handling (#%d): %s %s %s\n",
                    arg,argv[arg], arg+1 < argc ? argv[arg+1] : NULL,
                    arg+2 < argc ? argv[arg+2] : NULL));
        names[current_name++] = argv[arg++];
        if (arg < argc) {
            switch (*argv[arg]) {
            case '=':
            case 'i':
            case 'u':
            case '3':
            case 't':
            case 'a':
            case 'o':
            case 's':
            case 'x':
            case 'd':
            case 'b':
#ifdef NETSNMP_WITH_OPAQUE_SPECIAL_TYPES
            case 'I':
            case 'U':
            case 'F':
            case 'D':
#endif                          /* NETSNMP_WITH_OPAQUE_SPECIAL_TYPES */
                types[current_type++] = *argv[arg++];
                break;
            default:
                fprintf(stderr, "%s: Bad object type: %c\n", argv[arg - 1],
                        *argv[arg]);
                exit(1);
            }
        } else {
            fprintf(stderr, "%s: Needs type and value\n", argv[arg - 1]);
            exit(1);
        }
        if (arg < argc)
            values[current_value++] = argv[arg];
        else {
            fprintf(stderr, "%s: Needs value\n", argv[arg - 2]);
            exit(1);
        }
    }
 
    SOCK_STARTUP;
 
    /*
     * open an SNMP session 
     */
    ss = snmp_open(&session);
    if (ss == NULL) {
        /*
         * diagnose snmp_open errors with the input netsnmp_session pointer 
         */
        snmp_sess_perror("snmpset", &session);
        SOCK_CLEANUP;
        exit(1);
    }
 
    /*
     * create PDU for SET request and add object names and values to request 
     */
    pdu = snmp_pdu_create(SNMP_MSG_SET);
    for (count = 0; count < current_name; count++) {
        name_length = MAX_OID_LEN;
        if (snmp_parse_oid(names[count], name, &name_length) == NULL) {
            snmp_perror(names[count]);
            failures++;
        } else
            if (snmp_add_var
                (pdu, name, name_length, types[count], values[count])) {
            snmp_perror(names[count]);
            failures++;
        }
    }
 
    if (failures) {
        snmp_close(ss);
        SOCK_CLEANUP;
        exit(1);
    }
 
    /*
     * do the request 
     */
    status = snmp_synch_response(ss, pdu, &response);
    if (status == STAT_SUCCESS) {
        if (response->errstat == SNMP_ERR_NOERROR) {
            if (!quiet) {
                for (vars = response->variables; vars;
                     vars = vars->next_variable)
                    print_variable(vars->name, vars->name_length, vars);
            }
        } else {
            fprintf(stderr, "Error in packet.\nReason: %s\n",
                    snmp_errstring(response->errstat));
            if (response->errindex != 0) {
                fprintf(stderr, "Failed object: ");
                for (count = 1, vars = response->variables;
                     vars && (count != response->errindex);
                     vars = vars->next_variable, count++);
                if (vars)
                    fprint_objid(stderr, vars->name, vars->name_length);
                fprintf(stderr, "\n");
            }
            exitval = 2;
        }
    } else if (status == STAT_TIMEOUT) {
        fprintf(stderr, "Timeout: No Response from %s\n",
                session.peername);
        exitval = 1;
    } else {                    /* status == STAT_ERROR */
        snmp_sess_perror("snmpset", ss);
        exitval = 1;
    }
 
    if (response)
        snmp_free_pdu(response);
    snmp_close(ss);
    SOCK_CLEANUP;
    return exitval;
}

et voilà ce que j'en ai fait pour l'instant:

Code :

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void MainWindow::SnmpSet() {
  init_snmp("snmp set");
  struct snmp_session sessionToPeer;
  snmp_sess_init(&sessionToPeer);
 
  sessionToPeer.peername = strdup(agentDeviceAddressLineEdit->text().toStdString().c_str());
  /*memory allocated by strdup() will be freed by calling snmp_close() */
  if(snmpVersion1RadioButton->isChecked()) {/* snmp version 1 is obsolete, do nothing about it. */
  }
  if(snmpVersion2RadioButton->isChecked()) {/* only version 2 community is implemented here */
    sessionToPeer.version = SNMP_VERSION_2c;
    sessionToPeer.community = (u_char*) (strdup(communityLineEdit->text().toStdString().c_str()));
    sessionToPeer.community_len = strlen((const char*) sessionToPeer.community);
  }
  if(snmpVersion3RadioButton->isChecked()) { //TODO: implement SNMP version 3 options. more item may be needed to add to combo box.
 
  }
  sessionToPeer.retries = retriesSpinBox->value();
  sessionToPeer.timeout = timeoutSpinBox->value();
  SOCK_STARTUP;
  struct snmp_session* sessionReturnedByLibrary = snmp_open(&sessionToPeer);
  if(sessionReturnedByLibrary == NULL) {
#ifdef QT_DEBUG
    snmp_sess_perror((const char*) "No Ack!", sessionReturnedByLibrary);
#endif //QT_DEBUG
    SOCK_CLEANUP;
    return;
  }
  struct snmp_pdu* requestPdu = snmp_pdu_create(SNMP_MSG_SET);
  oid requestOid[MAX_OID_LEN];
  size_t requestOidLength = MAX_OID_LEN;
  snmp_parse_oid(mibFileLocationLineEdit->text().toAscii(), requestOid, &requestOidLength);
  char typeArray[6]={'s','t','r','i','n','g'};
  char *valuesArray[6];
  *valuesArray[0]='c';
  *valuesArray[1]='h';
  *valuesArray[2]='t';
  *valuesArray[3]='e';
  *valuesArray[4]='s';
  *valuesArray[5]='t';
  snmp_add_var(requestPdu, requestOid, requestOidLength, typeArray[6], valuesArray[6]);//snmp_add_null_var(requestPdu, requestOid, requestOidLength);
  struct snmp_pdu* responsePdu = NULL;
  int snmpStatus = snmp_synch_response(sessionReturnedByLibrary, requestPdu, &responsePdu);
  if(snmpStatus == STAT_SUCCESS and responsePdu->errstat == SNMP_ERR_NOERROR) {
    /* SUCCESS: Print the result variables */
    struct variable_list *snmpVariables;
#ifdef QT_DEBUG
    for(snmpVariables = responsePdu->variables; snmpVariables; snmpVariables = snmpVariables->next_variable) {
      print_variable(snmpVariables->name, snmpVariables->name_length, snmpVariables);
    }
#endif //QT_DEBUG
    /* retrieve response that we're interested. */
#ifdef QT_DEBUG
    int count = 1;
#endif //QT_DEBUG
    for(snmpVariables = responsePdu->variables; snmpVariables != NULL; snmpVariables = snmpVariables->next_variable) {
      if(snmpVariables->type == ASN_OCTET_STR) {
        char* response = (char *) malloc(1 + snmpVariables->val_len);
        memcpy(response, snmpVariables->val.string, snmpVariables->val_len);
        response[snmpVariables->val_len] = '\0';
#ifdef QT_DEBUG
        printf("value #%d is a string: %s\n", count++, response);
#endif //QT_DEBUG
        resultTextEdit->setText(QString(response));
        free(response);
      } else {
#ifdef QT_DEBUG
        printf("value #%d is NOT a string! Ack!\n", count++);
#endif //QT_DEBUG
      }
    }
  } else {
    /* FAILURE: print what goes wrong! */
#ifdef QT_DEBUG
    if(snmpStatus == STAT_SUCCESS) {
      fprintf(stderr, "Error in packet\nReason: %s\n", snmp_errstring(responsePdu->errstat));
    } else if(snmpStatus == STAT_TIMEOUT) {
      fprintf(stderr, "Timeout: No response from %s.\n", sessionToPeer.peername);
    } else {
      snmp_sess_perror("snmp get", sessionReturnedByLibrary);
    }
#endif //QT_DEBUG
  }
 
  /*
   * Clean up:
   *  1) free the response.
   *  2) close the session.
   */
  if(responsePdu) {
    snmp_free_pdu(responsePdu);
  }
  snmp_close(sessionReturnedByLibrary);
 
  SOCK_CLEANUP;
}

Le problème c'est que lorsque je clique sur le bouton qui envoie le signal au slot, tout se ferme. et je n'ai pas de "mode debug" car j'utilise cmake et pas qmake car je n'arrive pas à m'en servir sur ce projet..

[LittleWhite]

Bonjour,

Pour un mode debug avec GCC (ou MinGW) on peut juste dire à CMake de rajouter l'option "-g". Après, je ne sais pas trop d'où peut venir le bogue, mais j'imagine un pointeur NULL.

[zodd]

Merci pour ta réponse. c'est bon j'ai trouvé comment faire en ajoutant ça dans mon cmakelists.txt:

list( APPEND CMAKE_CXX_FLAGS "-g")

[LittleWhite]

Et cela vous a donné des indications sur le problème ?

[zodd]

Carrément, du coup c'est bon j'ai pu trouver d'où venait le problème et me concentrer dessus.. après avoir un peu fouiller dans le code des fonction appelé j'en ai tiré un résultat fonctionnel
Voilà donc ma fonction SET qui marche ("figée" pour des objets chaînes de caractères mais ce détail est facile à régler):

Code :

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void MainWindow::SnmpSet() {
  init_snmp("snmp set");
  struct snmp_session sessionToPeer;
  snmp_sess_init(&sessionToPeer);
 
  sessionToPeer.peername = strdup(agentDeviceAddressLineEdit->text().toStdString().c_str());
  /*memory allocated by strdup() will be freed by calling snmp_close() */
  if(snmpVersion1RadioButton->isChecked()) {/* snmp version 1 is obsolete, do nothing about it. */
  }
  if(snmpVersion2RadioButton->isChecked()) {/* only version 2 community is implemented here */
    sessionToPeer.version = SNMP_VERSION_2c;
    sessionToPeer.community = (u_char*) (strdup(communityLineEdit->text().toStdString().c_str()));
    sessionToPeer.community_len = strlen((const char*) sessionToPeer.community);
  }
  if(snmpVersion3RadioButton->isChecked()) { //TODO: implement SNMP version 3 options. more item may be needed to add to combo box.
 
  }
  sessionToPeer.retries = retriesSpinBox->value();
  sessionToPeer.timeout = timeoutSpinBox->value();
  SOCK_STARTUP;
  struct snmp_session* sessionReturnedByLibrary = snmp_open(&sessionToPeer);
  if(sessionReturnedByLibrary == NULL) {
#ifdef QT_DEBUG
    snmp_sess_perror((const char*) "No Ack!", sessionReturnedByLibrary);
#endif //QT_DEBUG
    SOCK_CLEANUP;
    return;
  }
  struct snmp_pdu* requestPdu = snmp_pdu_create(SNMP_MSG_SET);
  oid requestOid[MAX_OID_LEN];
  size_t requestOidLength = MAX_OID_LEN;
  snmp_parse_oid(mibFileLocationLineEdit->text().toAscii(), requestOid, &requestOidLength);
  /*
  if (tp && type == '=') {
         switch (tp->type) {
        case TYPE_INTEGER:
        case TYPE_INTEGER32:
            type = 'i';
            break;
        case TYPE_GAUGE:
        case TYPE_UNSIGNED32:
            type = 'u';
            break;
        case TYPE_UINTEGER:
            type = '3';
            break;
        case TYPE_COUNTER:
            type = 'c';
            break;
        case TYPE_COUNTER64:
            type = 'C';
            break;
        case TYPE_TIMETICKS:
            type = 't';
            break;
        case TYPE_OCTETSTR:
            type = 's';
            break;
        case TYPE_BITSTRING:
            type = 'b';
            break;
        case TYPE_IPADDR:
            type = 'a';
            break;
        case TYPE_OBJID:
            type = 'o';
            break;
        }
*/
  snmp_add_var(requestPdu, requestOid, requestOidLength, 's', valueLineEdit->text().toAscii());//valuesArray[6]);//snmp_add_null_var(requestPdu, requestOid, requestOidLength);
  struct snmp_pdu* responsePdu = NULL;
  int snmpStatus = snmp_synch_response(sessionReturnedByLibrary, requestPdu, &responsePdu);
  if(snmpStatus == STAT_SUCCESS and responsePdu->errstat == SNMP_ERR_NOERROR) {
    /* SUCCESS: Print the result variables */
    struct variable_list *snmpVariables;
#ifdef QT_DEBUG
    for(snmpVariables = responsePdu->variables; snmpVariables; snmpVariables = snmpVariables->next_variable) {
      print_variable(snmpVariables->name, snmpVariables->name_length, snmpVariables);
    }
#endif //QT_DEBUG
    /* retrieve response that we're interested. */
#ifdef QT_DEBUG
    int count = 1;
#endif //QT_DEBUG
    for(snmpVariables = responsePdu->variables; snmpVariables != NULL; snmpVariables = snmpVariables->next_variable) {
      if(snmpVariables->type == ASN_OCTET_STR) {
        char* response = (char *) malloc(1 + snmpVariables->val_len);
        memcpy(response, snmpVariables->val.string, snmpVariables->val_len);
        response[snmpVariables->val_len] = '\0';
#ifdef QT_DEBUG
        printf("value #%d is a string: %s\n", count++, response);
#endif //QT_DEBUG
        resultTextEdit->append(QString(response));
        free(response);
      } else {
#ifdef QT_DEBUG
        printf("value #%d is NOT a string! Ack!\n", count++);
#endif //QT_DEBUG
      }
    }
  } else {
    /* FAILURE: print what goes wrong! */
#ifdef QT_DEBUG
    if(snmpStatus == STAT_SUCCESS) {
      fprintf(stderr, "Error in packet\nReason: %s\n", snmp_errstring(responsePdu->errstat));
    } else if(snmpStatus == STAT_TIMEOUT) {
      fprintf(stderr, "Timeout: No response from %s.\n", sessionToPeer.peername);
    } else {
      snmp_sess_perror("snmp get", sessionReturnedByLibrary);
    }
#endif //QT_DEBUG
  }
 
  /*
   * Clean up:
   *  1) free the response.
   *  2) close the session.
   */
  if(responsePdu) {
    snmp_free_pdu(responsePdu);
  }
  snmp_close(sessionReturnedByLibrary);
 
  SOCK_CLEANUP;
}