啤酒

一个空白者

 

用C写的“读取系统日志”,花了我不少时间的,虽然不难

     #include <stdio.h>
//#include <unistd.h>
#include <string.h>
#include <time.h>

#include <windows.h>

#define BUFFER_SIZE 1024*64

//#define DEFAULT_FILE  "C:\\ossec-extracted-evt.log"

FILE *fp;
int event_record=0;


/* Event logging local structure */
typedef struct _os_el
{
    int time_of_last; 
    char *event_name;

    EVENTLOGRECORD *er;
    HANDLE h;

    DWORD record;
}os_el;
os_el el[3];
int el_last = 0;


/** int startEL(char *app, os_el *el)
 * Starts the event logging for each el
 */
int startEL(char *app, os_el *el)
{
    /* Opening the event log */
    el->h = OpenEventLog(NULL, app);
    if(!el->h)
    {
        return(0);    
    }

    el->event_name = app;
    GetOldestEventLogRecord(el->h, &el->record);

    return(1);
}

 

/** char *el_GetCategory(int category_id)
 * Returns a string related to the category id of the log.
 */
//得到一个事件的类型,,输入是一个事件类型id输出是汉字串
char *el_GetCategory(int category_id)
{
    char *cat;
    switch(category_id)
    {
        case EVENTLOG_ERROR_TYPE:
            cat = "错误";
            break;
        case EVENTLOG_WARNING_TYPE:
            cat = "警告";
            break;
        case EVENTLOG_INFORMATION_TYPE:
            cat = "信息";
            break;
        case EVENTLOG_AUDIT_SUCCESS:
            cat = "审核成功";
            break;
        case EVENTLOG_AUDIT_FAILURE:
            cat = "审核失败";
            break;
        default:
            cat = "Unknown";
            break;
    }
    return(cat);
}


/** int el_getEventDLL(char *evt_name, char *event_sourcename, char *event)
 * Returns the event.
 */
int el_getEventDLL(char *evt_name, char *event_sourcename, char *event)
{
    HKEY key;
    DWORD ret;
    char keyname[256];


    keyname[255] = '\0';

    _snprintf(keyname, 254,
            "System\\CurrentControlSet\\Services\\EventLog\\%s\\%s",
            evt_name,
            event_sourcename);

    /* Opening registry */    
    if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, keyname, 0, KEY_ALL_ACCESS, &key)
            != ERROR_SUCCESS)
    {
        return(0);   
    }


    ret = MAX_PATH -1; 
    if (RegQueryValueEx(key, "EventMessageFile", NULL,
                NULL, (LPBYTE)event, &ret) != ERROR_SUCCESS)
    {
        event[0] = '\0'; 
        return(0);
    }

    RegCloseKey(key);
    return(1);
}

 

/** char *el_Getmessage()
 * Returns a descriptive message of the event.
 */
//输出是时间描述信息
char *el_GetMessage(EVENTLOGRECORD *er,  char *event_name,
      char * event_sourcename, LPTSTR *el_sstring)
{
    DWORD fm_flags = 0;
    char tmp_str[257];
    char event[MAX_PATH +1];
    char *curr_str;
    char *next_str;
    LPSTR message = NULL;

    HMODULE hevt;

    /* Initializing variables */
    event[MAX_PATH] = '\0';
    tmp_str[256] = '\0';

    /* Flags for format event */
    fm_flags |= FORMAT_MESSAGE_FROM_HMODULE;
    fm_flags |= FORMAT_MESSAGE_ALLOCATE_BUFFER;
    fm_flags |= FORMAT_MESSAGE_ARGUMENT_ARRAY;

    /* Get the file name from the registry (stored on event) */
    if(!el_getEventDLL(event_name, event_sourcename, event))
    {
        return(NULL);    
    }    

    curr_str = event;

    /* If our event has multiple libraries, try each one of them */
    while((next_str = strchr(curr_str, ';')))
    {
        *next_str = '\0';
        next_str++;

        ExpandEnvironmentStrings(curr_str, tmp_str, 255);
        hevt = LoadLibraryEx(tmp_str, NULL, DONT_RESOLVE_DLL_REFERENCES);
        if(hevt)
        {
            if(!FormatMessage(fm_flags, hevt, er->EventID,
                        0,
                        (LPTSTR) &message, 0, el_sstring))
            {
                message = NULL;   
            }
            FreeLibrary(hevt);

            /* If we have a message, we can return it */
            if(message)
                return(message);
        }

        curr_str = next_str;  
    }

    ExpandEnvironmentStrings(curr_str, tmp_str, 255);
    hevt = LoadLibraryEx(tmp_str, NULL, DONT_RESOLVE_DLL_REFERENCES);
    if(hevt)
    {
        int hr;   
        if(!(hr = FormatMessage(fm_flags, hevt, er->EventID,
                        0,
                        (LPTSTR) &message, 0, el_sstring)))
        {
            message = NULL;   
        }
        FreeLibrary(hevt);

        /* If we have a message, we can return it */
        if(message)
            return(message);
    }

    return(NULL);
}

 

/** void Read_event(os_el *el)
 * Reads the event log.
 */
void Read_event(os_el *el, int printit)
{
    DWORD nstr;
    DWORD user_size;
    DWORD domain_size;
    DWORD read, needed;
    int size_left;
    int str_size;

    char *mbuffer[BUFFER_SIZE];
    LPSTR sstr = NULL;

    char *tmp_str = NULL;
    char *event_category;   //事件类型
    char *event_sourcename;   //事件来源
    char *event_computername;  //事件计算机名
    char *event_descriptive_msg; //事件描述

    char event_el_user[257];  //事件用户
    char event_el_domain[257];  //事件域
    char el_string[1025];
    char final_out_msg[1024];  //最后输出的信息
    LPSTR el_sstring[57];

    /* Er must point to the mbuffer */
    el->er = (EVENTLOGRECORD *) &mbuffer;

    /* Zeroing the last values */
    el_string[1024] = '\0';
    event_el_user[256] = '\0';
    event_el_domain[256] = '\0';
    final_out_msg[1023] = '\0';
    el_sstring[56] = NULL;

    /* Reading the event log */    
    while(ReadEventLog(el->h,
                EVENTLOG_FORWARDS_READ | EVENTLOG_SEQUENTIAL_READ,
                0,
                el->er, BUFFER_SIZE -1, &read, &needed))
    {
        while(read > 0)
        {

            /* We need to initialize every variable before the loop */
   //得到事件的类型
            event_category = el_GetCategory(el->er->EventType);
   //得到事件来源
            event_sourcename = (LPSTR) ((LPBYTE) el->er + sizeof(EVENTLOGRECORD));
   //得到计算机名
            event_computername = event_sourcename + strlen(event_sourcename) + 1;
   //给描述信息初始化
            event_descriptive_msg = NULL;


            /* 初始化domain/user尺寸 */
            user_size = 255; domain_size = 255;
            event_el_domain[0] = '\0';
            event_el_user[0] = '\0';


            /* 设置时间的一些描述 some description */
            if(el->er->NumStrings)
            { 
                size_left = 1020; 

                sstr = (LPSTR)((LPBYTE)el->er + el->er->StringOffset);
                el_string[0] = '\0';

                for (nstr = 0;nstr < el->er->NumStrings;nstr++)
                {
                    str_size = strlen(sstr); 
                    strncat(el_string, sstr, size_left);

                    tmp_str= strchr(el_string, '\0');
                    if(tmp_str)
                    {
                        *tmp_str = ' ';  
                        tmp_str++; *tmp_str = '\0';
                    }
                    size_left-=str_size + 1;

                    if(nstr <= 54)
                        el_sstring[nstr] = (LPSTR)sstr;

                    sstr = strchr( (LPSTR)sstr, '\0');
                    sstr++;
     
                }

                /* Get a more descriptive message (if available) */
                event_descriptive_msg = el_GetMessage(el->er, el->event_name, event_sourcename, el_sstring);
                if(event_descriptive_msg != NULL)
                {
                    /* Remove any \n or \r */
                    tmp_str = event_descriptive_msg;   
                    while((tmp_str = strchr(tmp_str, '\n')))
                    {
                        *tmp_str = ' ';
                        tmp_str++;
      

     
                    }   

                    tmp_str = event_descriptive_msg;   
                    while((tmp_str = strchr(tmp_str, '\r')))
                    {
                        *tmp_str = ' ';
                        tmp_str++;
      //strchr(tmp_str, '\n');

                    }   
                }
            }
            else
            {
                strncpy(el_string, "(no message)", 1020); 
            }


            /* 得到username */
            if (el->er->UserSidLength)
            {
                SID_NAME_USE account_type;
                if(!LookupAccountSid(NULL, (SID *)((LPSTR)el->er + el->er->UserSidOffset),
                            event_el_user, &user_size, event_el_domain, &domain_size, &account_type))  
                {
                    strncpy(event_el_user, "(no user)", 255);
                    strncpy(event_el_domain, "no domain", 255);
                }

            }

            else
            {
                strncpy(event_el_user, "A", 255); 
                strncpy(event_el_domain, "N", 255); 
            }

            if(printit)
            {
                tm   *event_time   =   localtime((const   long   *)&el->er->TimeWritten);

                _snprintf(final_out_msg, 1022,
                        "事件记录序号:%d\n事件:%s\n日期:%.4hd-%.2hd-%.2hd\n时间: %.2hd:%.2hd:%.2hd\n事件类型:%s\n事件来源:%s\n事件ID:(%u)\n用户:%s/%s\n计算机:%s\n描述:\n%s\n\n\n",
      event_record,
      el->event_name,
      event_time->tm_year   +   1900,
      event_time->tm_mon   +   1,
      event_time->tm_mday,
      event_time->tm_hour,
      event_time->tm_min,
      event_time->tm_sec, 
                        event_category,
      event_sourcename,
                       
                        (WORD)el->er->EventID,
                        event_el_domain,
                        event_el_user,
                       
      event_computername,
                        event_descriptive_msg != NULL?event_descriptive_msg:el_string); 
              
         fprintf(fp, "%s\n", final_out_msg); 
            }

            if(event_descriptive_msg != NULL)
                LocalFree(event_descriptive_msg);

            /* Changing the point to the er */
            read -= el->er->Length;
            el->er = (EVENTLOGRECORD *)((LPBYTE) el->er + el->er->Length);
   event_record++;
        }  

        /* Setting er to the beginning of the buffer */ 
        el->er = (EVENTLOGRECORD *)&mbuffer;
  
    }
}


/** void win_startel()
 * Starts the event logging for windows
 */
void win_startel(char *eventlog)
{
    event_record=1;
 startEL(eventlog, &el[el_last]);
    Read_event(&el[el_last],1);
    el_last++;
}
////////////////////////////////////////////////////////
////main////////////////////////////////////////////////
////////////////////////////////////////////////////////
int main()
{
   fp = fopen("C:\\Documents and Settings\\Administrator\\桌面\\Read_log.txt","w");
   if(!fp)
 {
  printf("Unable to open file\n");
  exit(1);
 }
   else
   {
  printf("open file\n"); 
   }


 fprintf(fp, "\n\n***********安全日志***********\n\n\n"); 
 win_startel("Security");
 printf("安全日志打开\n");

 fprintf(fp, "\n\n***********应用日志***********\n\n\n"); 
 win_startel("Application");
 printf("应用日志打开\n");


 fprintf(fp, "\n\n***********系统日志***********\n\n\n"); 
 win_startel("System");
 printf("系统日志打开\n");

 

 

 fclose(fp);
 if(fclose(fp))
 {
  printf("关闭了\n");
 }
 else
 {
  printf("还开着呢了,,抓紧关它吧\n");
 }
 return(0);
}

posted on 2006-08-28 14:18 啤酒 阅读(2517) 评论(7)  编辑 收藏 引用

评论

# re: 用C写的“读取系统日志”,花了我不少时间的,虽然不难 2006-08-28 14:39 万连文

写的好,但是还是转化为C++类用起来才方便  回复  更多评论   

# re: 用C写的“读取系统日志”,花了我不少时间的,虽然不难 2006-08-28 17:49 啤酒


我本相做个分析,所以就直接读了
但是分析起来比较困难
实在不止到用什么算法合适,策略也不好定  回复  更多评论   

# re: 用C写的“读取系统日志”,花了我不少时间的,虽然不难 2006-08-29 09:53 游客

@啤酒
不错,还是写的可以的,以后我也写一个试试  回复  更多评论   

# re: 用C写的“读取系统日志”,花了我不少时间的,虽然不难 2006-08-31 09:24 Khan's Notebook

呵呵,我c写了一个读取日志的, c虽然麻烦,但是直接..  回复  更多评论   

# re: 用C写的“读取系统日志”,花了我不少时间的,虽然不难 2009-03-27 15:42

你只是修改了OSSEC的源码而已,只有1%是你自己写的。
不过你能看懂OSSEC的代码也不错。  回复  更多评论   

# re: 用C写的“读取系统日志”,花了我不少时间的,虽然不难 2011-04-11 15:05 韩长坤

代码功能是有的 不过 有内存泄露哦 你忘记了CloseEventLog  回复  更多评论   

# re: 用C写的“读取系统日志”,花了我不少时间的,虽然不难 2012-05-18 17:08 huang

非常感谢!  回复  更多评论   


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