Apache模块:每个请求的输出都在不断增长

我有一个基于Apache模块API的项目的想法。因此,我编写了第一个Apache模块来学习API——只是简单的主机名查找:

URL:  http://localhost/hostname/stackoverflow.com
Response data:
Host: stackoverflow.com
Address: 69.59.196.211
Address type: AF_INET

当请求在处理程序路径后不包含主机名时,我只希望响应数据说:

“在请求中找不到主机名。”

除了一件事外,所有这些都可以工作:错误响应会不断附加到产生错误结果的后续请求上。主机名查找结果(提供主机名时)不会出现这种情况。问题示例:

Request 1:  http://192.168.1.3/hostname
Response data:
Hostname not found in request.

Request 2:  http://192.168.1.3/hostname
Response data:
Hostname not found in request.
Hostname not found in request.

Request 3:  http://192.168.1.3/hostname
Response data:
Hostname not found in request.
Hostname not found in request.
Hostname not found in request.

我确信我在错误情况下对输出缓冲区做了一些错误——有人能指出问题所在吗?代码如下:

#include <sys/types.h>
#include <netdb.h>
#include <stdio.h>
#include <stdarg.h>

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include "httpd.h"
#include "http_log.h"
#include "http_config.h"


static void log_info(request_rec *r, const char *fmt, ...){
    char log_msg[100];
    memset(log_msg,100,0x00);
    va_list args;
    va_start(args,fmt);
    vsprintf(log_msg,fmt,args);
    va_end(args);
    ap_log_error(APLOG_MARK,APLOG_INFO,APR_SUCCESS,r->server,log_msg,NULL);
}
static void log_err(request_rec *r, const char *fmt, ...){
    char log_msg[100];
    memset(log_msg,100,0x00);
    va_list args;
    va_start(args,fmt);
    vsprintf(log_msg,fmt,args);
    va_end(args);
    ap_log_error(APLOG_MARK,APLOG_ERR,APR_SUCCESS,r->server,log_msg,NULL);
}

int count_chrinstr(const char *haystack, const char needle){
    int n=0;
    char *next;
    while( (next=strchr(haystack,needle)) != NULL ){
        haystack=next+1;
        n++;
    }

    return n;
}
void parse_uri(char *uri, char *pieces[]){
    int i=0;
    char *next_tok=strtok(uri,"/");
    while( next_tok != NULL ){
        pieces[i]=next_tok;
        i++;
        next_tok=strtok(NULL,"/");
    }
}

void lookup_hostname(request_rec *r, char *output){
    int num_parts=count_chrinstr(r->uri,'/');
    log_info(r,"Number of parts: %d",num_parts);
    if(num_parts<2){
        log_err(r,"Hostname not found in request, exiting.",NULL);
        strcat(output,"Hostname not found in request.<br>\n");
        return;
    }

    char *pieces[num_parts];
    parse_uri(r->uri,pieces);
    char *host_entered=pieces[1];

    struct hostent *h=gethostbyname(host_entered);

    //host
    output += sprintf(output,"Host: %s<br>\n", h->h_name);

    //aliases
    int i=0;
    while(h->h_aliases[i] != NULL){
        output += sprintf(output,"Alias: %s<br>\n",h->h_aliases[i]);
        i++;
    }

    //addresses
    i=0;
    while(h->h_addr_list[i] != NULL){
        char *net_addr=inet_ntoa( *(struct in_addr*)(h->h_addr_list[i]));
        output += sprintf(output,"Address: %s<br>\n",net_addr);
        i++;
    }
    log_info(r,"Added addresses to output.",NULL);

    //address type
    if(h->h_addrtype != NULL){
        switch(h->h_addrtype){
            case 2:
                strcat(output,"Address type: AF_INET<br>\n");
                break;
            case 10:
                strcat(output,"Address type: AF_INET6<br>\n");
                break;
            default:
                strcat(output,"Address type: Unknown<br>\n");
                break;
        }
    }

}

static int hostname_handler(request_rec *r) {
  if (!r->handler || strcasecmp(r->handler, "hostname") != 0) {
    return DECLINED;
  }

  if (r->method_number != M_GET) {
    return HTTP_METHOD_NOT_ALLOWED;
  }

  char result[10000];
  memset(result,10000,0x00);

  log_info(r,"Starting hostname lookup.",NULL);
  lookup_hostname(r,result);
  ap_set_content_type(r, "text/html");
  ap_rputs(result, r);
  ap_finalize_request_protocol(r);

  return OK;
}


static void hostname_hooks(apr_pool_t *pool) {
  ap_hook_handler(hostname_handler, NULL, NULL, APR_HOOK_MIDDLE);
}

module AP_MODULE_DECLARE_DATA hostname_module = {
  STANDARD20_MODULE_STUFF,
  NULL,
  NULL,
  NULL,
  NULL,
  NULL,
  hostname_hooks
};

事先谢谢,

AJ