[AGENT++] Hi, all, why these code lead to memry leak?

[cheng wan]

The code below is main for:
1)Get tcp info from /proc/net/tcp.
2)tcp_conn_table_index() is to compute the index of tcpConnEntry.
   Indexes:	1: tcpConnLocalAddress
	2: tcpConnLocalPort
	3: tcpConnRemAddress
	4: tcpConnRemPort
3)Before add one row to   tcpConnEntry::instance, I use
tcpConnEntry::instance->clear() to clear all the rows
4)get_proc_net_tcp() is excuted by one 2 seconds timer
The memory keeps growning.
Thank you all.


uin32_t tcp_conn_local_address, tcp_conn_local_port, tcp_conn_rem_address,
tcp_conn_rem_port, tcp_conn_state;

void tcp_conn_table_index(struct in_addr local_address,
        uint32_t local_port,
        struct in_addr rem_address,
        uint32_t rem_port,
        char *buf) {
    char *local_address_ptr = inet_ntoa(local_address); // in_addr to char *
    IpAddress ip_address_one(local_address_ptr);
    char *rem_address_ptr = inet_ntoa(rem_address); // in_addr to char *
    IpAddress ip_address_two(rem_address_ptr);
    snprintf(buf, MAXLINE, "%d.%d.%d.%d.%d.%d.%d.%d.%d.%d",
            (unsigned char)ip_address_one[0],
            (unsigned char)ip_address_one[1],
            (unsigned char)ip_address_one[2],
            (unsigned char)ip_address_one[3],
            local_port,
            (unsigned char)ip_address_two[0],
            (unsigned char)ip_address_two[1],
            (unsigned char)ip_address_two[2],
            (unsigned char)ip_address_two[3],
            rem_port
            );
}

void get_proc_net_tcp()
{
    FILE *in = NULL;
    in = fopen ("/proc/net/tcp", "r");
    char line [MAXLINE];
    int32_t num;
    static int map_states[] = { 1, 5, 3, 4, 7, 10, 11, 1, 6, 9, 2, 8 };

    if(!in) {
        XLOG_WARNING("unable to open /proc/net/tcp, %s\n", strerror(errno));
        return false;
    }

    tcpConnEntry::instance->clear();

    while (line == fgets(line, sizeof(line), in)) {
        sscanf(line, "%d: %x:%x %x:%x %x", &num,
                 &tcp_conn_local_address,
                 &tcp_conn_local_port,
                 &tcp_conn_rem_address,
                 &tcp_conn_rem_port,
                 &tcp_conn_state);
        struct in_addr local_address, rem_address;
        memcpy(&local_address, &tcp_conn_local_address, sizeof(struct in_addr));
        memcpy(&rem_address, &tcp_conn_rem_address, sizeof(struct in_addr));

        string local_address_str = inet_ntoa(local_address);
        string rem_address_str = inet_ntoa(rem_address);

        char buf[MAXLINE];
        memset(buf, 0, sizeof(buf));
        tcp_conn_table_index(local_address, tcp_conn_local_port,
                rem_address, tcp_conn_rem_port, buf);

        MibTableRow* row = tcpConnEntry::instance->add_row(buf);

        if((tcp_conn_state >= 0) && (tcp_conn_state < 12)) {
            tcp_conn_state = map_states[tcp_conn_state];
        } else {
            tcp_conn_state = 1;
        }

        tcpConnEntry::instance->set_row(row,
                tcp_conn_state,
                local_address_str.c_str(),
                tcp_conn_local_port,
                rem_address_str.c_str(),
                tcp_conn_rem_port
                );

    }
    fclose(in);
    return true;
}