Xar

不解释

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <string.h>
#include <iconv.h>
#include <inttypes.h>
#include <sys/stat.h>
#include <sys/mman.h>

#define MYIPFILE "MyIP.dat"
//#define DEBUG
#define prints(string) {printf("##DEBUG##\t");int i=0; while(string[i] != 0x20 ){printf("%c", string[i++]);} endl();}
#define endl() printf("\n")
#define init(id, fp) {																			\
					char *pt; 																	\
					/*FIRST = *(uint16_t *)(fp + 0x8); 		*/									\
					/*RDLEN = *(uint16_t *)(fp + 0xa);*/											\
					pt = (char *)(fp + FIRST);													\
					/*while(*pt == 0x20) {++pt;++FIRST;} */											\
					/*while(*(pt-1) != 0x20) {--pt;--FIRST;}	/*in case that FIRST was not exac*/	\
					id = (pseudo_t *)pt;														\
					}

#define update(idx, pseudo) {\
					idx.pse = pseudo;\
					int a, b, c, d;\
					sscanf(pseudo->startip, "%d.%d.%d.%d", &a, &b, &c, &d);\
					idx.startip = a<<24|b<<16|c<<8|d;\
					sscanf(pseudo->endip, "%d.%d.%d.%d", &a, &b, &c, &d);\
					idx.endip = a<<24|b<<16|c<<8|d;\
					}

#define printip(intt) {\
					printf("%d.%d.%d.%d ", (intt&0xFF000000)>>24, (intt&0xFF0000)>>16, (intt&0xFF00)>>8, intt&0xFF);\
}

#define demo(index) 	{																	\
						rd_gbk_t rd_gbk;													\
						rd_uni_t rd_uni;													\
						memset(&rd_gbk, 0, sizeof(rd_gbk_t));								\
						memset(&rd_uni, 0, sizeof(rd_uni_t));								\
						memcpy(rd_gbk.country, index.pse->country, 13);						\
						memcpy(rd_gbk.area, index.pse->area, 60);							\
						int i;																\
						for(i=0; i<13; ++i){												\
							if(rd_gbk.country[i] == 0x20) rd_gbk.country[i] = 0x00;			\
						}																	\
						for(i=0; i<60; ++i){												\
							if(rd_gbk.area[i] == 0x20) rd_gbk.area[i] = 0x00;				\
						}																	\
						enconv(rd_gbk.country, rd_uni.country);								\
						enconv(rd_gbk.area, rd_uni.area);									\
						printip(index.startip); printip(index.endip);printf("\t");			\
						printf("%s %s\n", rd_uni.country, rd_uni.area);						\
					}

typedef struct record_gbk_t {
	char country[16];
	char area[64];
	}rd_gbk_t;

typedef struct record_uni_t {
	char country[32];
	char area[128];
	}rd_uni_t;

typedef struct pseudo_t {
	char startip[16];
	char endip[16];
	char country[10];
	char area[92];
	}pseudo_t;//each size should be adjusted
	//used to point to each record in FILE

typedef struct index_t {
	uint32_t startip;
	uint32_t endip;
	pseudo_t *pse;
	}index_t;

uint16_t FIRST = 0xc2;//initialize location/p of the first record
uint16_t RDLEN = 0x86;//initialize length of record

int enconv(char *pin, char *pout){
	size_t inleft, outleft;
	iconv_t cd;
	if((cd = iconv_open("UTF-8", "GBK")) == (iconv_t) -1) return -1;
	if(iconv(cd, &pin, &inleft, &pout, &outleft) == (size_t) -1) return -1;
	iconv_close(cd);
	return 0;
}

int main(int argc, char **argv){
	if(argc != 2){
		//print version info;
		return 1;
	}
	int fd;
	if((fd=open(MYIPFILE, O_RDONLY))<0){
		fprintf(stderr, "file not exists.\n");
		exit(1);
	}
	struct stat filestat;
	if(fstat(fd, &filestat)<0){
		fprintf(stderr, "fstat error.\n");
		exit(1);
	}
	//void *mmap(void *addr, size_t len, int prot, int flags, int fd, off_t offset);

	void *fp;
	if((fp = mmap(NULL,filestat.st_size, PROT_READ, MAP_PRIVATE, fd, 0))==MAP_FAILED){
		fprintf(stderr, "mmap error.\n");
		exit(1);
	}

	pseudo_t *pseudo;
	init(pseudo, fp);//locate the *pseudo to point the first record

#ifdef DEBUG
	printf("##DEBUG##\tsizeof(pseudo_t): 0x%x\n", sizeof(pseudo_t));
	printf("##DEBUG##\tFIRST = 0x%x\n##DEBUG##\trecord starts from %p\n", FIRST, pseudo);
	prints(pseudo->startip);
	prints(pseudo->endip);
	index_t idx;
	update(idx, pseudo);
	printf("##DEBUG##\tfirst record: start_ip==%08x\tend_ip==%08x\n", idx.startip, idx.endip);
	endl();
#endif

	index_t index;
	update(index, pseudo);//initialized
	uint32_t span = index.endip - index.startip;
	int j=0, count = (filestat.st_size - FIRST)/RDLEN;
	//printf("%d, %d, %d\n", count, RDLEN, (int)filestat.st_size);
	int a, b, c, d;
	uint32_t startip, endip, target;
	sscanf(argv[1], "%d.%d.%d.%d", &a, &b, &c, &d);
	target = a<<24|b<<16|c<<8|d;
	//printf("%x\n", target);
	while(j<count){
		++j;
		sscanf(pseudo->startip, "%d.%d.%d.%d", &a, &b, &c, &d);
		startip = a<<24|b<<16|c<<8|d;
		sscanf(pseudo->endip, "%d.%d.%d.%d", &a, &b, &c, &d);
		endip = a<<24|b<<16|c<<8|d;
		if(startip <= target && target <= endip && span > endip - startip) {
			update(index, pseudo);
			span = endip - startip;
		}
		pseudo++;
	}

	demo(index);

	close(fd);
	munmap(fp, filestat.st_size);
	return 0;
}